August 2004
NASA/CR—2004–208941
Advanced Life Support
Baseline Values and Assumptions Document
Anthony J. Hanford, Ph.D., Editor
Lockheed Martin Space Operations
Houston, Texas 77058
August 2004
NASA/CR—2004–208941
Advanced Life Support
Baseline Values and Assumptions Document
Anthony J. Hanford, Ph.D., Editor
Lockheed Martin Space Operations
Houston, Texas 77058
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NASA/CR—2004–208941
Advanced Life Support
Baseline Values and Assumptions Document
Anthony J. Hanford, Ph.D., Editor
Lockheed Martin Space Operations
Houston, Texas 77058
National Aeronautics and
Space Administration
Johnson Space Center
Houston, Texas 77058-3696
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Contents
Section
Page
i
1
I
NTRODUCTION
.................................................................................................................................2
1.1
P
URPOSE AND
P
ROCESS
..................................................................................................................2
1.2
A
DVANTAGES
.................................................................................................................................3
1.3
S
YSTEMS
I
NTEGRATION
,
M
ODELING
,
AND
A
NALYSIS
E
LEMENT
....................................................3
1.4
A
CKNOWLEDGEMENT
.....................................................................................................................3
2
A
PPROACH
........................................................................................................................................4
2.1
D
EVELOPMENT
...............................................................................................................................4
2.2
C
ONTEXT
........................................................................................................................................4
2.3
B
ACKGROUND
................................................................................................................................4
2.3.1
Equivalent System Mass Description.........................................................................................4
2.3.2
Definition of Infrastructure ........................................................................................................4
2.3.3
Definition of Modeling ..............................................................................................................5
2.3.4
Units and Values ........................................................................................................................5
2.4
L
IFE
S
UPPORT
S
UBSYSTEMS
W
ITHIN THE
A
DVANCED
L
IFE
S
UPPORT
P
ROJECT
..............................5
2.5
A
PPLICABLE
D
OCUMENTS
..............................................................................................................7
3
O
VERALL
A
SSUMPTIONS
..................................................................................................................9
3.1
M
ISSIONS
.......................................................................................................................................9
3.1.1
Typical Values for Exploration Missions...................................................................................9
3.1.2
Long-Term Extraterrestrial Bases ............................................................................................10
3.2
I
NFRASTRUCTURE
C
OSTS AND
E
QUIVALENCIES
...........................................................................11
3.2.1
Pressurized Volume or Primary Structure Costs......................................................................18
3.2.2
Secondary Structure Costs .......................................................................................................24
3.2.3
Power Costs .............................................................................................................................24
3.2.4
Thermal Energy Management Costs........................................................................................29
3.2.5
Crewtime Costs........................................................................................................................32
3.2.6
Location Factors.......................................................................................................................32
3.3
C
REW
C
HARACTERISTICS
.............................................................................................................33
3.3.1
Crew Metabolic Rate ...............................................................................................................33
3.3.2
Crewtime Estimates .................................................................................................................34
3.3.3
Nominal Human Interfaces ......................................................................................................37
4
L
IFE
S
UPPORT
S
UBSYSTEM
A
SSUMPTIONS AND
V
ALUES
..............................................................39
4.1
A
IR
S
UBSYSTEM
...........................................................................................................................39
4.1.1
Design Values for Atmospheric Systems.................................................................................39
4.1.2
Gas Storage ..............................................................................................................................42
4.2
B
IOMASS
S
UBSYSTEM
..................................................................................................................42
4.2.1
Plant Growth Chambers ...........................................................................................................42
4.2.1.1
Lighting Assumptions ..........................................................................................................................42
4.2.1.2
Lighting Equipment Data .....................................................................................................................43
4.2.1.3
Plant Growth Chamber Cost Factors ....................................................................................................44
4.2.1.4
Biomass Production Chamber Specifications for an Integrated Test Facility.......................................44
4.2.2
Plant Values .............................................................................................................................46
4.2.2.1
Static Values Describing Plant Growth ................................................................................................46
4.2.2.2
Static Values to Support Plant Growth.................................................................................................51
4.2.3
Modified Energy Cascade Models for Crop Growth ...............................................................53
4.2.3.1
Modified Energy Cascade Models for Crop Biomass Production ........................................................53
4.2.3.2
Modified Energy Cascade Models for Crop Transpiration...................................................................59
4.2.3.3
Modified Energy Cascade Model Constants for Nominal Temperature Regimes and Photoperiods ...61
4.3
F
OOD
S
UBSYSTEM
........................................................................................................................66
4.3.1
Physical Parameters for Historical Food Flight Systems .........................................................66
4.3.2
Physical Parameters of Refrigeration Equipment ....................................................................67
4.3.3
Crewtime for the Food Subsystem...........................................................................................69
4.3.4
Food Subsystem Waste Generation .........................................................................................69
4.3.5
Overall Food Subsystem Parameters........................................................................................69
Contents
Section
Page
ii
4.3.6
Food Subsystems Based on Biomass Production Systems.......................................................70
4.3.7
Food Processing .......................................................................................................................77
4.4
T
HERMAL
M
ANAGEMENT
.............................................................................................................77
4.4.1
Heat Transfer Mechanisms ......................................................................................................78
4.4.1.1
Conduction ...........................................................................................................................................78
4.4.1.2
Convection ...........................................................................................................................................78
4.4.1.3
Radiation ..............................................................................................................................................78
4.4.1.4
Heat Transfer with Phase Change ........................................................................................................79
4.4.2
Thermal Management Organization.........................................................................................79
4.4.2.1
Passive and Active Thermal Management ...........................................................................................79
4.4.2.2
Thermal Subsystem and Cooling External Interface ............................................................................80
4.4.2.3
General Thermal Management Architecture ........................................................................................80
4.4.3
Thermal Management Technology ..........................................................................................83
4.4.3.1
Historical Thermal Management Approaches ......................................................................................83
4.4.3.2
Advanced Thermal Management Approaches......................................................................................85
4.4.4
Radiant Energy Balance...........................................................................................................86
4.4.5
Thermal Management Values ..................................................................................................87
4.5
W
ASTE
S
UBSYSTEM
.....................................................................................................................90
4.5.1
Historical Data on Skylab ........................................................................................................91
4.5.2
Historical Waste Loads from Shuttle Missions........................................................................91
4.5.3
Solid Waste Management for the International Space Station Mission ...................................93
4.5.4
Solid Waste Management for Future Long-Duration Missions .............................................100
4.5.4.1
Feces ..................................................................................................................................................102
4.5.4.2
Urine ..................................................................................................................................................102
4.5.4.3
Menstruation ......................................................................................................................................103
4.5.4.4
Toilet Paper ........................................................................................................................................103
4.5.4.5
Miscellaneous Body Wastes...............................................................................................................104
4.5.4.6
Consumable Hygiene Products...........................................................................................................105
4.5.4.7
Food Packaging, Inedible Biomass, and Wasted Food.......................................................................105
4.5.4.8
Paper, Tape, Miscellaneous Hygiene Products, and Clothing ............................................................106
4.5.4.9
Greywater and Brine ..........................................................................................................................107
4.5.4.10
Other Waste Streams..........................................................................................................................107
4.6
W
ATER
S
UBSYSTEM
...................................................................................................................109
4.6.1
Design Values for Water Subsystems ....................................................................................109
4.6.2
Wastewater Component Contaminant Loading .....................................................................112
4.6.3
Wastewater and Intermediate Water System Solution Formulations for Testing ..................117
4.6.3.1
Transit Mission Wastewater Ersatz ....................................................................................................118
4.6.3.2
Early Planetary Base Wastewater Ersatz............................................................................................120
4.6.3.3
Biological Water Processor Effluent Ersatz .......................................................................................123
4.6.3.4
Reverse Osmosis Subsystem Permeate Ersatz....................................................................................125
4.6.3.5
Air Evaporation Subsystem Condensate Ersatz..................................................................................130
5
L
IFE
S
UPPORT
E
XTERNAL
I
NTERFACE
A
SSUMPTIONS AND
V
ALUES
..........................................135
5.1
C
OOLING
E
XTERNAL
I
NTERFACE
................................................................................................135
5.2
E
XTRAVEHICULAR
A
CTIVITY
S
UPPORT
E
XTERNAL
I
NTERFACE
.................................................135
5.2.1
Operations During Transit to Mars ........................................................................................136
5.2.2
Martian Surface Operations ...................................................................................................137
5.2.3
Lunar Surface Operations ......................................................................................................138
5.3
H
UMAN
A
CCOMMODATIONS
E
XTERNAL
I
NTERFACE
..................................................................139
5.3.1
Clothing .................................................................................................................................139
5.4
I
N
-S
ITU
R
ESOURCE
U
TILIZATION
E
XTERNAL
I
NTERFACE
...........................................................140
5.5
I
NTEGRATED
C
ONTROL
E
XTERNAL
I
NTERFACE
..........................................................................142
5.5.1
Sensors ...................................................................................................................................142
5.6
P
OWER
E
XTERNAL
I
NTERFACE
...................................................................................................143
5.7
R
ADIATION
P
ROTECTION
E
XTERNAL
I
NTERFACE
.......................................................................143
6
R
EFERENCES
.................................................................................................................................144
Contents
Section
Page
iii
7
A
PPENDICES
..................................................................................................................................154
7.1
A
PPENDIX
A:
A
CRONYMS AND
A
BBREVIATIONS
.......................................................................154
7.2
A
PPENDIX
B:
A
BBREVIATIONS FOR
U
NITS
.................................................................................156
7.3
A
PPENDIX
C:
L
IFE
S
UPPORT
E
QUIPMENT
P
ARAMETERS FROM THE
A
DVANCED
L
IFE
S
UPPORT
D
ATABASE
..................................................................................................................157
7.3.1
International Space Station ....................................................................................................157
7.3.2
Spacelab .................................................................................................................................163
7.3.3
Space Shuttle Program ...........................................................................................................165
Tables
iv
Table 2.4.1
Advanced Life Support Subsystem Descriptions and Interfaces ............................................6
Table 2.4.2
Advanced Life Support External Interfaces Descriptions and Interfaces ...............................7
Table 3.2.1
Luna Mission Infrastructure Costs........................................................................................14
Table 3.2.2
Mars Mission Infrastructure Costs........................................................................................16
Table 3.2.3
Cost of Pressurized Volume .................................................................................................19
Table 3.2.4
Masses of Inflatable Shell Components................................................................................21
Table 3.2.5
Estimated Masses and Volume-Mass Penalties for Inflatable Module Configurations........22
Table 3.2.6
Estimated Masses for Inflatable Modules.............................................................................23
Table 3.2.7
Secondary Structure Masses .................................................................................................24
Table 3.2.8
Advanced Mission Power Costs and Equivalencies .............................................................28
Table 3.2.9
Advanced Mission Thermal Energy Management Costs and Equivalencies........................31
Table 3.2.10
Location Factors for Near-Term Missions............................................................................32
Table 3.3.1
Crewmember Mass Limits....................................................................................................34
Table 3.3.2
Human Metabolic Rates .......................................................................................................34
Table 3.3.3
Time Allocation for a Nominal Crew Schedule in a Weightless Environment ...................35
Table 3.3.4
Crewtime per Crewmember per Week .................................................................................35
Table 3.3.5
Crewtime-Mass Penalty Values Based Upon Fiscal Year 2001 Advanced Life Support
Research and Technology Development Metric...................................................................36
Table 3.3.6
Summary of Nominal Human Metabolic Interface Values ..................................................38
Table 4.1.1
Typical Steady-State Values for Vehicle Atmospheres........................................................39
Table 4.1.2
Model for Trace Contaminant Generation from Human Metabolism ..................................40
Table 4.1.3
Model for Trace Contaminant Generation from Cabin Equipment .....................................41
Table 4.1.4
Gas Storage...........................................................................................................................42
Table 4.2.1
Lighting Data........................................................................................................................42
Table 4.2.2
High Pressure Sodium Lighting Data ...................................................................................43
Table 4.2.3
Plant Growth Chamber Equivalent System Mass per Growing Area ...................................44
Table 4.2.4
Physical Parameters for the First Biomass Production Chamber in BIO-Plex .....................45
Table 4.2.5
Growing Area Dimensions for the First BIO-Plex Biomass Production Chamber...............46
Table 4.2.6
Advanced Life Support Cultivars, Intended Usage, and Environmental Growth Conditions47
Table 4.2.7
Overall Physical Properties at Maturity for Nominal Crops.................................................48
Table 4.2.8
Nominal and Highest Biomass Production, Composition, and Metabolic Products.............49
Table 4.2.9
Inedible Biomass Generation for Advanced Life Support Diets ..........................................50
Table 4.2.10
Plant Growth and Support Requirements per Dry Biomass .................................................51
Table 4.2.11
Composition of Initial Nutrient Solution ..............................................................................52
Table 4.2.12
Composition of Replenishment Nutrient Solution................................................................52
Table 4.2.13
Values for the Exponent n in MEC Models..........................................................................53
Table 4.2.14
Summary of Modified Energy Cascade Model Variables for Biomass Production..............55
Table 4.2.15
Biomass Production Model Constants .................................................................................56
Table 4.2.16
Format for Tables of Coefficients for Equations Employing MPR Fits ...............................57
Table 4.2.17
Maximum Canopy Quantum Yield, CQY
MAX
, Coefficients for Dry Bean ..........................57
Table 4.2.18
Maximum Canopy Quantum Yield, CQY
MAX
, Coefficients for Lettuce..............................57
Table 4.2.19
Maximum Canopy Quantum Yield, CQY
MAX
, Coefficients for Peanut...............................57
Table 4.2.20
Maximum Canopy Quantum Yield, CQY
MAX
, Coefficients for Rice ..................................58
Table 4.2.21
Maximum Canopy Quantum Yield, CQY
MAX
, Coefficients for Soybean............................58
Table 4.2.22
Maximum Canopy Quantum Yield, CQY
MAX
, Coefficients for Sweet Potato.....................58
Table 4.2.23
Maximum Canopy Quantum Yield, CQY
MAX
, Coefficients for Tomato .............................58
Table 4.2.24
Maximum Canopy Quantum Yield, CQY
MAX
, Coefficients for Wheat ...............................58
Table 4.2.25
Maximum Canopy Quantum Yield, CQY
MAX
, Coefficients for White Potato.....................59
Table 4.2.26
Summary of Modified Energy Cascade Model Variables for Canopy Transpiration...........60
Table 4.2.27
Nominal Temperature Regimes, Planting Densities, and Photoperiods
for the Plant Growth and Transpiration Models ...................................................................61
Table 4.2.28
Biomass Production Model Time Constants for Nominal Temperature Regime
and Photoperiod....................................................................................................................62
Table 4.2.29
Biomass Carbon and Oxygen Production Fractions for Nominal Temperature Regime
and Photoperiod....................................................................................................................62
Table 4.2.30
Canopy Closure Time, t
A
, Coefficients for Dry Bean with Nominal Conditions .................63
Tables
v
Table 4.2.31
Canopy Closure Time, t
A
, Coefficients for Lettuce with Nominal Conditions.....................63
Table 4.2.32
Canopy Closure Time, t
A
, Coefficients for Peanut with Nominal Conditions......................63
Table 4.2.33
Canopy Closure Time, t
A
, Coefficients for Rice with Nominal Conditions .........................63
Table 4.2.34
Canopy Closure Time, t
A
, Coefficients for Soybean with Nominal Conditions...................64
Table 4.2.35
Canopy Closure Time, t
A
, Coefficients for Sweet Potato with Nominal Conditions............64
Table 4.2.36
Canopy Closure Time, t
A
, Coefficients for Tomato with Nominal Conditions ....................64
Table 4.2.37
Canopy Closure Time, t
A
, Coefficients for Wheat with Nominal Conditions ......................64
Table 4.2.38
Canopy Closure Time, t
A
, Coefficients for White Potato with Nominal Conditions............64
Table 4.2.39
MEC Model Parameters for Low-Light Conditions, Nominal Temperature Regimes .........65
Table 4.3.1
Historical and Near-Term Food Subsystem Masses.............................................................67
Table 4.3.2
International Space Station Refrigerator/Freezer Properties ................................................68
Table 4.3.3
Frozen Food Storage on a Property per Frozen-Food-Mass Basis .......................................68
Table 4.3.4
Food Quantity and Packaging...............................................................................................70
Table 4.3.5
Menu Masses for Diets Using Advanced Life Support Crops and Resupplied Foods..........71
Table 4.3.6
Nutritional Content of Diets Using Advanced Life Support Crops and Resupplied Foods..72
Table 4.3.7
Properties of Early Mars Diets for Intravehicular Activities Using Resupplied Foods ........73
Table 4.3.8
Nutritional Content of Early Mars Diets for Intravehicular Activities Using Resupplied Foods
..............................................................................................................................................74
Table 4.3.9
Menu Masses for Diets Using Advanced Life Support Crops and Resupplied Foods..........75
Table 4.3.10
Nutritional Content of Diets Using Advanced Life Support Crops and Resupplied Foods..76
Table 4.3.11
Updated ALS Salad Crop Only Dietary Contributions.........................................................77
Table 4.3.12
Overall Crops Masses for Updated Salad Crop Only Diet ...................................................77
Table 4.4.1
Surface Optical Properties for Common Exterior Space Material........................................88
Table 4.4.2
Crew Cabin Thermal Ranges................................................................................................88
Table 4.4.3
Transport Properties for Common Thermal Management Loop Working Fluids.................89
Table 4.4.4
Thermodynamic Properties of Common Thermal Management Phase-Change Materials for
Liquid-Vapor Transitions .....................................................................................................90
Table 4.4.5
Thermodynamic Properties of Common Thermal Management Phase-Change Materials for
Solid-Liquid Transitions.......................................................................................................90
Table 4.5.1
Waste Analysis for STS-51D Trash......................................................................................92
Table 4.5.2
Shuttle Crew Provision Wastes from Past Missions.............................................................93
Table 4.5.3
International Space Station Reference Mission Vehicle Wastes ..........................................94
Table 4.5.4
Advanced Mars Exploration Reference Mission Vehicle Wastes ........................................97
Table 4.5.5
Summary Information on Wastes for Developing Waste Models for Future Long-Duration
Missions .............................................................................................................................101
Table 4.5.6
Information on Feces ..........................................................................................................102
Table 4.5.7
Information on Urine ..........................................................................................................103
Table 4.5.8
Information on Menstruation..............................................................................................103
Table 4.5.9
Information on Toilet Paper................................................................................................104
Table 4.5.10
Information on Miscellaneous Body Wastes ......................................................................104
Table 4.5.11
Information on Consumable Hygiene Products..................................................................105
Table 4.5.12
Information on Food Packaging, Inedible Biomass, and Wasted Food..............................106
Table 4.5.13
Information on Paper, Tape, Miscellaneous Hygiene Products, and Clothing ...................107
Table 4.5.14
Information on Other Waste Streams .................................................................................108
Table 4.6.1
Steady-State Values for Vehicle Water Usage for Short-Duration Missions ....................109
Table 4.6.2
Typical Steady-State Water Usage Rates for Various Missions ........................................110
Table 4.6.3
Typical Steady-State Wastewater Generation Rates for Various Missions ........................111
Table 4.6.4
Wastewater Contaminants in Extravehicular Mobility Unit Stream...................................112
Table 4.6.5
Wastewater Contaminants in Crew Latent Condensate......................................................113
Table 4.6.6
Wastewater Contaminants in Crew Shower Stream ...........................................................114
Table 4.6.7
Wastewater Contaminants in Crew Hygiene Stream..........................................................115
Table 4.6.8
Wastewater Contaminants in Crew Urine Stream ..............................................................116
Table 4.6.9
Wastewater Contaminants in Animal Latent Condensate...................................................117
Table 4.6.10
Concentrate 1: Urine 1 – Organic Compounds for TM Wastewater Ersatz (C1) ..............118
Table 4.6.11
Concentrate 2: Urine 2 – Inorganic Compounds for TM Wastewater Ersatz (C2) ............118
Table 4.6.12
Concentrate 3: Humidity Condensate for TM Wastewater Ersatz (C3) .............................119
Tables
vi
Table 4.6.13
Concentrate 4: Sabatier Product Water for TM Wastewater Ersatz (C4) ...........................119
Table 4.6.14
US Urine Pretreatment (per liter of wastewater) for TM Wastewater Ersatz .....................119
Table 4.6.15
Average Solution Properties for Transit Mission Wastewater Ersatz.................................120
Table 4.6.16
Concentrate 1: Inorganic Compounds 1 for EPB Wastewater Ersatz (C1) ........................121
Table 4.6.17
Concentrate 2: Inorganic Compounds 2 for EPB Wastewater Ersatz (C2) .......................121
Table 4.6.18
Concentrate 3: Humidity Condensate for EPB Wastewater Ersatz (C3) ...........................121
Table 4.6.19
Concentrate 4: Sabatier Product Water for EPB Wastewater Ersatz (C4) .........................121
Table 4.6.20
Concentrate 5: Hygiene Water for EPB Wastewater Ersatz (C5) ......................................122
Table 4.6.21
Concentrate 6: Urine Organics for EPB Wastewater Ersatz (C6) ......................................122
Table 4.6.22
Average Solution Properties for Early Planetary Base Wastewater Ersatz ........................123
Table 4.6.23
Concentrate 1: Inorganic Compounds 1 for BWP Effluent Ersatz (C1) ............................123
Table 4.6.24
Concentrate 2: Inorganic Compounds 2 for BWP Effluent Ersatz (C2) ............................124
Table 4.6.25
Concentrate 3: Soluble Organic Compounds for BWP Effluent Ersatz (C3) ....................124
Table 4.6.26
Concentrate 4: Insoluble Organic Compounds for BWP Effluent Ersatz (C4) ..................124
Table 4.6.27
Concentrate 5: Volatile Organic Carbon Compounds for BWP Effluent Ersatz (C5) .......124
Table 4.6.28
Average Solution Properties for Biological Water Processor Effluent Ersatz....................125
Table 4.6.29
Concentrate 1: Inorganic Compounds 1 for RO Permeate (Nominal) Ersatz (C1) ............126
Table 4.6.30
Concentrate 2: Inorganic Compounds 2 for RO Permeate (Nominal) Ersatz (C2) ............126
Table 4.6.31
Concentrate 3: Soluble Organic Compounds for RO Permeate (Nominal) Ersatz (C3) ....126
Table 4.6.32
Concentrate 4: Insoluble Organic Compounds for RO Permeate (Nominal) Ersatz (C4) .126
Table 4.6.33
Concentrate 5: Volatile Organic Compounds for RO Permeate (Nominal) Ersatz (C5) ...126
Table 4.6.34
Average Solution Properties for Reverse Osmosis Permeate (Nominal) Ersatz.................127
Table 4.6.35
Concentrate 1: Inorganic Compounds 1 for RO Permeate (Worst-case) Ersatz (C1) ........128
Table 4.6.36
Concentrate 2: Inorganic Compounds 2 for RO Permeate (Worst-case) Ersatz (C2) ........128
Table 4.6.37
Concentrate 3: Soluble Organic Compounds for RO Permeate (Worst-case) Ersatz (C3) 128
Table 4.6.38
Concentrate 4: Insoluble Organic Compounds for RO Permeate (Worst-case) Ersatz (C4) 128
Table 4.6.39
Concentrate 5: Volatile Organic Compounds for RO Permeate (Worst-case) Ersatz (C5) 129
Table 4.6.40
Average Solution Properties for Reverse Osmosis Permeate (Worst-case) Ersatz.............130
Table 4.6.41
Concentrate 1: Inorganic Compounds for AES Condensate (Nominal) Ersatz (C1) .........130
Table 4.6.42
Concentrate 3: Soluble Organic Compounds for AES Condensate (Nominal) Ersatz (C3) 130
Table 4.6.43
Concentrate 4: Insoluble Organic Compounds for AES Condensate (Nominal) Ersatz C4) 131
Table 4.6.44
Concentrate 5: Volatile Organic Compounds for AES Condensate (Nominal) Ersatz (C5) 131
Table 4.6.45
Average Solution Properties for Air Evaporation Condensate (Nominal) Ersatz...............132
Table 4.6.46
Concentrate 1: Inorganic Compounds for AES Condensate (Worst-case) Ersatz (C1) .....132
Table 4.6.47
Concentrate 3: Effluent Soluble Organic Compounds
for AES Condensate (Worst-case) Ersatz (C3) ..................................................................132
Table 4.6.48
Concentrate 4: Insoluble Organic Compounds for AES Condensate (Worst-case) Ersatz (C4)
............................................................................................................................................133
Table 4.6.49
Concentrate 5: Volatile Organic Compounds for AES Condensate (Worst-case) Ersatz (C5)
............................................................................................................................................133
Table 4.6.50
Average Solution Properties for Air Evaporation Condensate (Worst-case) Ersatz...........134
Table 5.2.1
Local Accelerations Due to Gravity ...................................................................................135
Table 5.2.2
Historical Extravehicular Activity Masses .........................................................................136
Table 5.2.3
Weights of Historical Spacesuits Under Gravitational Loadings .......................................136
Table 5.2.4
Summary of Extravehicular Activity Values for Mars Surface Operations........................138
Table 5.2.5
Extravehicular Activity Metabolic Loads...........................................................................138
Table 5.3.1
Clothing and Laundry Options ...........................................................................................139
Table 5.3.2
Early ISS Laundry Equipment Specifications ....................................................................140
Table 5.3.3
Advanced Washer/Dryer Specifications.............................................................................140
Table 5.4.1
Nitrogen Gas Losses Associated with International Space Station Technology.................141
Table 5.4.2
Nitrogen Gas Losses for the Mars Design Reference Mission (One Cycle)
Using ISS Technologies .....................................................................................................141
Table 5.4.3
Estimation of Cost Leverages from In-Situ Resource Utilization .....................................142
Table 5.5.1
Sensor Mass Estimates .......................................................................................................142
Table 7.3.1
International Space Station Atmosphere Control and Supply.............................................157
Table 7.3.2
International Space Station Atmosphere Revitalization Subsystem ...................................159
Tables
vii
Table 7.3.3
International Space Station Temperature and Humidity Control........................................160
Table 7.3.4
International Space Station Fire Detection and Suppression ..............................................161
Table 7.3.5
International Space Station Vacuum Services ....................................................................161
Table 7.3.6
International Space Station Water Recovery and Management..........................................162
Table 7.3.7
Spacelab Atmosphere Revitalization Subsystem................................................................163
Table 7.3.8
Spacelab Active Thermal Control Subsystem ....................................................................163
Table 7.3.9
Spacelab Temperature and Humidity Control ....................................................................164
Table 7.3.10
Spacelab Water Recovery and Management ......................................................................164
Table 7.3.11
Space Shuttle Atmosphere Revitalization Subsystem ........................................................165
Table 7.3.12
Space Shuttle Airlock Support Subsystem .........................................................................167
Table 7.3.13
Space Shuttle Active Thermal Control Subsystem.............................................................168
Table 7.3.14
Space Shuttle Water Recovery and Management...............................................................169
1
Introduction
The Advanced Life Support (ALS) Baseline Values and Assumptions Document (BVAD) provides
analysts and modelers as well as other ALS researchers with a common set of initial values and assumptions called a
baseline. This baseline, in turn, provides a common point of origin from which all Systems Integration, Modeling,
and Analysis (SIMA) Element studies will depart.
1.1
Purpose and Process
The BVAD identifies specific physical quantities that define life support systems from an analysis and
modeling perspective. For each physical quantity so identified, the BVAD provides a nominal or baseline value plus
a range of possible or observed values. Finally, the BVAD documents each entry with a description of the quantity’s
use, value selection rationale, and appropriate references.
The baseline values listed in the BVAD are designed to provide defaults for those quantities within each
study that are not of particular interest for that study and may be adequately described by default values.
For example, the direct solar irradiation for vehicles orbiting around Luna varies between
1,323 W/m² and 1,414 W/m² with a mean value of 1,367 W/m² (K&K, 1998). Accordingly, the solar
constant at Luna naturally varies by 91 W/m² (6.7 %). Williams (1997) lists a mean value of
1,380 W/m² for the solar constant at Luna. While any value from 1,323 W/m² to 1,414 W/m² may be
selected for the solar constant in a study sited in Luna orbit, a mean value of 1,370 W/m² may be
defined as the baseline solar flux at Luna. Consequently, all studies would use a consistent value of
1,370 W/m² unless they were specifically exploring the effect of varying the solar constant.
This example is well bounded. Some life support assumptions are similarly well bounded. Others, such as
the growth rate for plants, are not well bounded. For these, reasonable upper and lower values are given, although
other values showing a greater range could be used.
Without an agreement, each researcher will generally select his/her baseline values using whatever sources
are available and/or deemed most accurate. While values from one researcher to the next may be similar, variations
in input values lead to further variations in results when one compares studies from multiple sources. As such, it is
more difficult to assess the significance of variations in results between studies from different sources without
conducting additional analyses to bring the multiple studies to a similar baseline.
Values for this document were taken from a variety of sources. Several SIMA researchers, in addition to
the authors, helped to prepare the manuscript. As part of the process of assigning values to each of the life support
quantities, the writers evaluated and debated each entry to produce a set of mutually agreeable values with
corresponding limits. Ultimately, comments from all readers are welcomed and encouraged. To allow the BVAD to
maintain its utility as a store of modeling and analysis information, the BVAD is a living document that will be
updated as necessary to reflect new technology and/or scientific discoveries.
The ALS Project controls the BVAD, while SIMA maintains and updates the BVAD. Subsequent releases
will be made as required. Please send comments to:
Mr. M. K. Ewert
Lead, Systems Integration, Modeling, and Analysis Element
National Aeronautics and Space Administration
Lyndon B. Johnson Space Center
2101 NASA Road One, Mail Code EC2
Houston, Texas 77058
E-mail: Michael.k.ewert1@jsc.nasa.gov
2
1.2
Advantages
Aside from the advantages implied above, the BVAD provides several additional benefits:
•
The BVAD allows the life support analysis community to carefully review and evaluate input study
assumptions. Such review will lead to greater confidence in and understanding of the studies.
•
Each study can now benefit from the “best†available input values and assumptions by drawing upon
information collected by a group of researchers instead of a single researcher. Further, such values reflect
the combined expertise of the group as a whole rather than one individual.
•
The BVAD process identifies those quantities that are not well-defined by current information. Such
quantities are primary candidates for parametric studies to determine their importance on modeling and
analysis results. Further, this approach identifies values that may require additional experimental input to
adequately quantify.
•
The BVAD allows researchers from multiple sites to efficiently and quickly compare results from multiple
studies. Because each study uses the same baseline, the variations between studies arise from differences in
models or the parameters varied rather than a complex combined effect that includes variations in the
assumed baseline.
•
The BVAD will allow any researcher to conduct a follow-on study to any previous work because
assumptions from each study will be clearly available and carefully recorded. Further, researchers can
reference the BVAD for their baseline parameter values except those that are unique to their specific study.
1.3
Systems Integration, Modeling, and Analysis Element
SIMA is the element within the ALS Project responsible for maintaining this document. One objective of
the SIMA Element is to encourage and improve communication between the various modelers within the ALS
Project.
1.4
Acknowledgments
1
Many researchers contributed information or insights to make this current draft possible. The BVAD editor
would like to specifically acknowledge the following individuals for their contributions: James E. Alleman, Ph.D.
(Purdue University), Molly S. Anderson (NASA/JSC), Scott Bell (TRACLabs), David Bergeron, Charles Bourland,
Ph.D., Cheryl B. Brown (Lockheed Martin), Juan M. Castillo (Lockheed Martin), James Cavazzoni, Ph.D. (Rutgers,
The State University of New Jersey), Nicholas Coppa, Ph.D. (Nanomaterials Company), Katherine R. Daues
(NASA/JSC), Alan E. Drysdale, Ph.D. (The Boeing Company), Bruce E. Duffield (Lockheed Martin), Michael K.
Ewert (NASA/JSC), John W. Fisher (NASA/ARC), David R. Fletcher (NASA/JSC), James R. Geffre (NASA/JSC),
John A. Hogan, Ph.D. (Rutgers, The State University of New Jersey), Jean B. Hunter, Ph.D. (Cornell University),
Frank F. Jeng (Lockheed Martin), Kevin E. Lange, Ph.D. (Lockheed Martin), Wen-Ching Lee (Hernandez
Engineering), Julie A. Levri (NASA/ARC), Sabrina Maxwell, Seza Orcun, Ph.D. (Purdue University), Michele
Perchonok, Ph.D. (National Space Biomedical Research Institute), Jay L. Perry (NASA/MSFC), Karen D. Pickering
(NASA/JSC), Susan D. Ramsey, Luis F. Rodriguez, Ph.D. (National Research Council), Michael Rouen
(NASA/JSC), Kathy Ruminsky, Laura A. Shaw (NASA/JSC), David A. Vaccari, Ph.D. (Stevens Institute of
Technology), Yael Vodovotz, Ph.D., Kanapathipi Wignarajah, Ph.D. (Enterprise Advisory Services Inc.), Raymond
Wheeler, Ph.D. (NASA/KSC), and Kristina R. Wines (NASA/JSC).
1
The National Aeronautics and Space Administration (NASA) Centers abbreviated here are Ames Research Center (ARC),
Lyndon B. Johnson Space Center (JSC), John F. Kennedy Space Center (KSC), and George C. Marshall Space Flight
Center (MSFC).
3
2
Approach
The assumptions here are derived from various sources and are organized into sets of similar data. These
assumptions relate to the scenarios, the mission infrastructure, and the various life support subsystems. References
are documented—where possible—to provide traceability.
2.1
Development
The baseline values and assumptions are based on experience in developing static and dynamic models of
life support systems. Where numerical values are given, and an attempt has been made to focus on quantitative data,
an attempt has been made to include upper and lower limits as well as a recommended value. In some cases, the
upper and lower limits are definite values set by the physics or biology of the situation. For other cases, they are
representative values that will not often be exceeded in a real system.
2.2
Context
This document assumes no particular mission, but does focus on long-duration space missions. In some
cases, the data may be applicable to only certain missions. The reader is directed to Stafford, et al
.
(2001) for more
details on potential mission scenarios.
2.3
Background
2.3.1
Equivalent System Mass Description
Equivalent system mass (ESM) is a technique by which several physical quantities describing a system or
subsystem may be reduced to a single physical parameter, mass.
2
The primary advantage is to allow comparison of
two life support systems with different parameters using a single scale. This is accomplished by determining
appropriate mass penalties or conversion factors to convert the non-mass physical inputs to an equivalent mass. For
systems that require power, for example, the Power External Interface can yield an appropriate power-mass penalty
by dividing the average power plant output by the total mass of the generating power plant. Thus, for a nuclear
power plant on an independent lander that, on average, delivers 100 kW of electrical power and has an overall mass
of 8,708 kg (Mason, et al
.
, 1992)
3
the power-mass penalty is 11.48 W/kg. This power-mass penalty effectively
assigns a fraction of the Power External Interface mass to a power-using subsystem in place of the power
requirement of the subsystem. In like manner, mass penalties to account for heat rejection and volume within a
pressurized shell are defined. A crewtime mass penalty is also defined below. The definition of equivalent mass for
a system is the sum of the equipment and consumable commodity mass plus the power, volume, thermal energy
management, and crewtime requirements as masses. Please see Levri, et al
.
(2003) for additional information on
ESM.
2.3.2
Definition of Infrastructure
Infrastructure is everything necessary to operate the life support equipment that is not otherwise
specifically defined elsewhere as a component of the life support system. For an overall life support system analysis,
the system includes the life support equipment. Necessary infrastructure, then, may include all necessary supplies
and equipment for electrical power generation or a pressurized cabin in which the equipment operates. Some
infrastructure, though vital to overall system success, may have a small or negligible impact on a study’s primary
focus. For example, data and communications infrastructure generally have little impact on the equivalent system
mass of a life support system and can therefore be safely neglected in this case. Table 2.4.1 and Table 2.4.2 identify
the most common and significant interactions between life support subsystems and other spacecraft systems outside
of the life support system. Section 3.2 discusses and lists infrastructure cost factors for overall life support system
2
An ESM evaluation is very similar in form to computing the net present value of a project and is a method used for ranking
a system or subsystem concept relative to other concepts.
3
The actual mass quoted here has been adjusted slightly to account for some differences between the work listed in the
reference and the desired system.
4
analyses while Section 4.6.3 provides additional information about commodity demands to and from the ALS
External Interfaces.
2.3.3
Definition of Modeling
A model is an analogous system that mimics the behavior of a real system. Within ALS, mathematical
models are used to predict or simulate, control, design, optimize, or facilitate an understanding of an ALS system, a
component, or a subsystem. Models might be quite simple, calculating overall masses, for example, or quite
complex, involving gas exchange at the molecular or plant growth levels. This document includes and supports both
types of models.
2.3.4
Units and Values
All numerical assumptions are given using the Système Internationale d’Unités (SI) units. This approach is
consistent with the current philosophy within the Crew and Thermal Systems Division (CTSD): all analysis tasks for
advanced systems shall use SI units. A list of SI units for physical quantities of interest is provided in the
Appendices.
Generally, lower, nominal, and upper values are provided. Unless stated otherwise, the numbers are
intended to represent average values under nominal conditions for different design cases. Short-term fluctuations are
not considered, nor are emergency or contingency situations except as explicitly noted. Values not listed per capita
are based on a crew of six, unless otherwise stated.
2.4
Life Support Subsystems Within the Advanced Life Support Project
Hanford (2000) provides a generic description of life support subsystems and subsystem and external
interface relationships for the ALS Project. This classification originally arose from a Systems Modeling and
Analysis Project
4
workshop in the fall of 1999 and now, after review and revision, is the current standard definition
for the ALS Project.
5
Information within the BVAD and future analysis tasks will be organized according to this
structure.
As noted above, other formats to describe life support systems exist. This one specifically classifies those
disciplines housed within and funded by the ALS Project as subsystems [Table 2.4.1] while those disciplines that
interact with life support subsystems but are not the sole responsibility of the ALS Project are external life support
interfaces [Table 2.4.2]. Because of this distinction, Air, Biomass, Food, Thermal, Waste, and Water are classified
as subsystems. Crew
6
, Cooling, Extravehicular Activity (EVA) Support, Human Accommodations, In-Situ
Resource Utilization, Integrated Control, Power, and Radiation Protection are classified as external life support
interfaces. The interfaces listed in the last column for each subsystem or external interface are generally inclusive in
an attempt to account for all possible interactions, even if some of those interactions are highly unlikely.
Please note: within this document, ALS subsystem names such as “Air Subsystem†and “Biomass
Subsystem†are proper nouns. However, the generic terms “system†and “subsystem†are often used interchangeably
in the text within this document to refer to similar suites of equipment. This laxness with respect to nomenclature
reflects the constantly changing perspective of ALS researchers and analysts while considering many different
technologies or groups of technologies. In reality, most life support equipment is constructed from several lower-
level components and also fits within a higher-level assembly. Consequently, the terms “system†and “subsystemâ€
vary according to the current problem definition and often differ for other problems or studies.
4
The Systems Integration, Modeling, and Analysis element was previously named Systems Modeling and Analysis Project.
5
Work on the Bioregenerative Planetary Life Support Systems Test Complex (BIO-Plex) predates this organizational
structure. Deviations from Table 2.4.1 and Table 2.4.2 exist for historical documentation.
6
Though the presence of the crew alone justifies the inclusion of the life support subsystems, the crewmembers are external
to the life support equipment and are listed as an external interface.
5
Table 2.4.1
Advanced Life Support Subsystem Descriptions and Interfaces
Subsystem Description
Life
Support System Interfaces
Air
The Air Subsystem stores and maintains the vehicle
cabin atmospheric gases, including pressure control,
overall composition, and trace constituents. The Air
Subsystem is also responsible for fire detection and
suppression and vacuum services.
Biomass, Food, Thermal, Waste,
Water, Crew, EVA Support,
Human Accommodations,
In-Situ Resource Utilization,
Integrated Control, Power
Biomass
The Biomass Subsystem produces, stores, and provides
raw agricultural products to the Food Subsystem while
regenerating air and water. This subsystem is not
present in a solely physicochemical life support system.
Air, Food, Thermal, Waste,
Water, Crew,
In-Situ Resource Utilization,
Integrated Control, Power
Food
The Food Subsystem receives harvested agricultural
products from the Biomass Subsystem, stabilizes them
as necessary, storing raw and stabilized agricultural
products, food ingredients, and prepackaged food and
beverage items. The Food Subsystem transforms the
raw agricultural products into a ready-to-eat form via
food processing and meal preparation operations. In the
absence of the Biomass Subsystem, this subsystem
operates only on prepackaged, stored products.
Air, Biomass, Thermal, Waste,
Water, Crew, EVA Support,
Human Accommodations,
Integrated Control, Power,
Radiation Protection
Thermal
The Thermal Subsystem is responsible for maintaining
cabin temperature and humidity within appropriate
bounds and for rejecting the collected waste heat to the
Cooling Interface. Note: Equipment to remove thermal
loads from the cabin atmosphere normally provides
sufficient air circulation.
Air, Biomass, Food,
Waste, Water, Crew, Cooling,
EVA Support,
Human Accommodations,
Integrated Control, Power
Waste
The Waste Subsystem collects and conditions waste
material from anywhere in the habitat, including:
packaging, human wastes, inedible biomass, and brines
from other subsystems such as the Water Subsystem.
The Waste Subsystem may sterilize and store the waste
or reclaim life support commodities, depending on the
life support system closure and/or mission duration.
Air, Biomass, Food, Thermal,
Water, Crew, EVA Support,
Integrated Control,
Human Accommodations, Power,
Radiation Protection
Water
The Water Subsystem collects wastewater from all
possible sources, recovers and transports potable water,
and stores and provides the water at the appropriate
purity for crew consumption and hygiene as well as
external users.
Air, Biomass, Food, Thermal,
Waste, Crew, Cooling,
EVA Support,
Human Accommodations,
In-Situ Resource Utilization,
Integrated Control, Power,
Radiation Protection
6
Table 2.4.2
Advanced Life Support External Interfaces Descriptions and Interfaces
External Life
Support Interfaces
Description Life
Support System Interfaces
Crew
The Crew Interface interacts with most life
support subsystems and external interfaces.
Crewmembers have been, and should continue
to be, the foremost consumers of life support
commodities as well as the primary producers of
waste products. Finally, life support
technologies are specifically designed to provide
for the health, safety, and maximum efficiency
of crewmembers.
Air, Biomass, Food, Thermal,
Waste, Water, EVA Support,
Human Accommodations,
In-Situ Resource Utilization,
Integrated Control, Power,
Radiation Protection.
Cooling
The Cooling Interface rejects vehicle thermal
loads, delivered by the Thermal Subsystem, to
the external environment.
Thermal, Water,
Integrated Control, Power
Extravehicular
Activity Support
The Extravehicular Activity Support Interface
provides life support consumables for
extravehicular activities, including oxygen,
water, and food. It also provides for the removal
of carbon dioxide and waste.
Air, Food, Thermal, Waste,
Water, Crew,
Human Accommodations,
Integrated Control, Power
Human
Accommodations
The Human Accommodations Interface is
responsible for the crew cabin layout, crew
clothing (including laundering), and the crew’s
interaction with the life support system.
Air, Biomass, Food, Thermal,
Waste, Water, Crew,
EVA Support, Integrated Control,
Power
In-Situ Resource
Utilization
The In-Situ Resource Utilization Interface
provides life support commodities, such as
gases, water, and regolith from local planetary
materials for use throughout the life support
system.
Air, Biomass, Water, Crew,
Integrated Control, Power,
Radiation Protection
Integrated Control
The Integrated Control Interface provides
appropriate control for the life support system.
ALL
Power The
Power
Interface
provides the necessary
energy to support all equipment and functions
within the life support system.
ALL
Radiation
Protection
The Radiation Protection Interface provides
protection from environmental radiation.
Food, Waste, Water, Crew,
In-Situ Resource Utilization,
Power
2.5
Applicable Documents
The BVAD is intended to provide values for analysis and modeling tasks. Analysis and modeling is
charged with examining both off-nominal and diverse technology options. As a result, many studies may consider
situations that differ from the accepted bounds listed in the various documents containing requirements. However,
when applicable, the BVAD is intended to capture the individual extremes for inputs that are appropriate for human
spaceflight. Further, while the nominal values throughout this document should be consistent with one another, off-
nominal values may not be consistent with other values within this document. The user should independently verify
the validity of using off-nominal values.
As noted, the BVAD attempts to provide inputs for all quantities of importance for studies associated with
life support systems. However, as research within the ALS Project constantly changes, many studies will require
inputs for quantities not listed here. In such situations, analysts should use whatever values are appropriate and
7
available and so note and reference those values in their reports or documentation. Further, analysts are asked to
report such omissions to SIMA and provide any and all information that could be used to determine values for such
omitted quantities.
The following documents are other important references for life support. The latest revision is noted below
and will be available electronically at
http://advlifesupport.jsc.nasa.gov
. Subsequent releases will be considered in
updating this document.
Duffield, B. E. (2003) “Advanced Life Support Requirements Document,†JSC-38571 (CTSD-ADV-245),
Revision C, National Aeronautics and Space Administration, Johnson Space Center, Houston, Texas,
February, 2003.
Stafford, K. W., Jerng, L. T., Drysdale, A. E., Maxwell, S., Levri, J. A. (2001) “Advanced Life Support
Systems Integration, Modeling, and Analysis Reference Missions Document,†edited by Ewert, M. K., and
Hanford, A. J., JSC-39502, Revision A, National Aeronautics and Space Administration, Lyndon B.
Johnson Space Center, Houston, Texas, November, 2001.
Parameters that are non-negotiable for any reason are considered ALS requirements and are documented
within Duffield (2003). Some of the assumptions documented here may in time become requirements while others
will be uncertain until NASA embarks on a specific mission. Some possible future missions are documented in
Stafford, et al
.
(2001), a companion document to the BVAD.
8
3
Overall Assumptions
3.1
Missions
The mission affects analyses and models by changing the weighting of the various pieces of the system in
terms of time dependent items, equipment design, and infrastructure cost. It can also require different contingency
planning for a mission with a short-term abort option (e.g., low-Earth orbit or lunar missions) versus one without
such an option (e.g., Mars missions).
3.1.1
Typical Values for Exploration Missions
Primarily, the missions supported here are outlined in the Advanced Life Support Systems Integration,
Modeling, and Analysis Reference Missions Document (Stafford, et al., 2001) and focus on near-Earth sites
including low-Earth orbit, Luna, near-Earth asteroids, and Mars. Assumptions are given in Table 3.1.1 for mission
parameters associated with missions described within Stafford, et al. (2001) and some other possible near-term
missions.
Generically, recent NASA exploration mission architectures stipulate separate vehicles for each of three
distinct mission phases. The crew travels to and from the vicinity of an extraterrestrial destination in a dedicated
transit vehicle. The crew transfers to a waiting descent/ascent lander to travel from orbit to a surface site, landing
near a larger prepositioned surface habitat. The crew spends the majority of its surface phase operating from the
surface habitat. At the end of the surface phase, the crew transfers back to the waiting transit vehicle using the
descent/ascent lander. Table 3.1.1 assumes this generic architecture.
7
The given volume assumptions in Table 3.1.1 describing unobstructed or free volume per crewmember
8
are specified in terms of tolerable, performance, and optimal for the listed mission segment. For purposes here,
performance should be viewed as nominal. Two possible surface missions are mentioned with respect to lunar
missions. Required by NASA (2001a), nominal possible mission configurations would provide either a 3-day or a
30-day surface phase. Drake (1999) proposes a nominal mission for its descent/ascent vehicle of roughly 7 days, but
contingency might stretch this occupancy to 30 days. As a final note, a mission architecture in which multiple crews
visit the same surface site and a new crew module is sent with each crew, the actual crew volume will probably
increase for later missions because earlier crew modules could be linked together to form a much larger habitable
volume.
7
Though not presented in Stafford, et al. (2001) or mentioned here explicitly, missions to asteroids or comets are possible,
and such ventures would not likely need a surface habitat, for example. Rather, the exploration missions here assume a site
on a relatively large celestial body with appreciable inherent gravity.
8
These values are also called net habitable volume, which is the remaining pressurized cabin volume after accounting for
losses due to equipment, stowage, trash, and other items that decrease volume (Ramsey, 2002).
9
Table 3.1.1
Mission Assumptions
Assumptions
Parameter Units
Lower Nominal Upper
References
Crew Size
people
4
(1)
6
(2)
9
(1)
Visits to One Site
–
1
(2)
3
(2)
7
(4)
Destination: Luna
Volume:
9
Tolerable Performance
Optimal
Transit Phase
m³/person
1.13
(5)
3.54
(5)
4.25
(5)
Descent / Ascent m³/person
1.27
(5)
3.54
(5)
4.39
(5)
Surface, 3 days
m³/person
1.27
(5)
3.54
(5)
4.39
(5)
Surface, 30 days m³/person
2.26
(5)
4.25
(5)
10.62
(5)
Duration:
10
Minimum
Nominal
Maximum
Transit Phase
d
3
(6)
5
(6)
7
(6)
Descent / Ascent d
5
(6)
8
(5)
8
(5)
Surface Phase
d
3
(7)
3 or 30
(7)
11
30
(7)
Destination: Mars
Volume:
9
Tolerable Performance
Optimal
Transit Phase
m³/person
5.10
(5)
9.91
(5)
18.41
(5)
Descent / Ascent,
7 days
m³/person 1.13
(5)
3.54
(5)
4.25
(5)
Descent / Ascent,
30 days
m³/person 2.27
(5)
4.25
(5)
10.62
(5)
Surface Phase
m³/person
5.10
(5)
9.91
(5)
18.41
(5)
Duration:
10
Minimum
Nominal
Maximum
Transit Phase
d
110
(2)
180
(2)
180
(2)
Descent / Ascent d
7
(5)
7
(5)
30
(5)
Surface Phase
d
540
(2)
600
(2)
619
(2)
(1)
SMAP (1999)
(2)
Hoffman & Kaplan (1997)
(3)
NASA (1995)
(4)
Stafford, et al. (2001)
(5)
Ramsey (2002)
(6)
Geffre (2002)
(7)
Fletcher (2001)
3.1.2
Long-Term Extraterrestrial Bases
While a goal of ALS is a long-duration facility in an extraterrestrial site, NASA currently has few
specifications for such a mission. For now, a long-duration integrated test bed may provide a terrestrial analog for an
eventual base. Such an integrated life support test stand is typically a closed-chamber facility comprised of five
chambers and an airlock connected by a tunnel.
12
This facility will provide integrated test facilities for technologies
that will likely be used for an early human base on Luna or Mars. Each facility module is 185.15 m
3
in volume. The
9
The volume here specifically is unobstructed or free volume within the crew cabin.
10
This mission would have an immediate abort-to-orbit option, although not necessarily an immediate return option.
11
The intended nominal surface stay depends on the vehicles provided.
12
Editor’s Note:
At this time, the scope and purpose of the integrated test stand to support hardware development within the
ALS Project is under review. Because of prior programs such as BIO-Plex, very precise values are available for some
earlier facilities. Consequently, the configuration and specifications for the actual ALS integrated testing facility may differ
from those listed here. The values listed are likely representative of an integrated bioregenerative research facility and, by
analog, to a long-duration extraterrestrial surface facility.
10
tunnel is 263.43
m
3
. The airlock volume is 48 m
3
. The total volume is estimated to be 1,237 m
3
, or 309 m
3
per
crewmember, assuming the nominal crew of four people. Internal air pressure will be approximately ambient.
This test facility optimally supports four people, but during overlaps for crew rotation, up to eight people
may be supported for up to 72 hours (Tri, 2000). While the planned duration for tests is under review, past testing
concepts have mentioned 120- through 400+- day missions most often. An initial test involving human beings may
be 120 days in duration (Tri, 2000). Plant scientists favor tests of 240 days because this would allow two complete
cropping cycles based on harvest dates for crops with the longest life cycle.
A facility similar to this test facility could be built on Luna or Mars with similar configuration and
constraints. Some likely differences for an actual extraterrestrial base would be mission duration, with a probable
minimum duration of 540 days for any mission to Mars (see Table 3.1.1), and an operational lifetime of up to fifteen
years.
3.2
Infrastructure Costs and Equivalencies
Infrastructure costs (ex: mass, volume, power, thermal energy management, crewtime) are key factors in
overall system analysis. They effectively apportion a fraction of the infrastructure mass to each component of the
life support system. It is far easier to decide on reasonable figures for these parameters early in a study than to try to
objectively determine them at the end of the study. Appropriate infrastructure costs and equivalencies for two
possible near-term exploration objectives, Luna and Mars, are provided in Table 3.2.1 and Table 3.2.2. The listed
penalties for volume account for primary structure only, including micrometeoroid and orbital debris protection and
radiation protection for the crew, if necessary. Table 3.2.7 provides information on secondary structure, including
the racks and conditioned volumes such as refrigerated spaces.
The nominal values listed in Table 3.2.1 and Table 3.2.2 correspond to current technology with few
improvements or synergistic advantages. Less conservative values, with comments on applicability, are presented in
Table 3.2.3, Table 3.2.8 and Table 3.2.9.
Infrastructure costs vary according to certain variables, including but not limited to: external mission
environment, technologies used, and mission duration. For example, a power system using solar photovoltaic
generation to provide electrical power for a transit vehicle has different energy storage requirements than a
comparable system with similar architecture for an equatorial lunar base. Likewise, the thermal environment of
interplanetary space differs from the thermal environment of the lunar or Martian surface. The tables here include
values for surface locales indicative of equatorial sites. Studies at polar sites should use very different values,
especially for thermal energy management.
Table 3.2.1 and Table 3.2.2 provide two volume cost factors. The first entry, for shielded volume, reflects
pressurized primary structure with sufficient radiation protection to provide a safe environment for the crew. The
second entry, for unshielded volume, models pressurized primary structure without any radiation protection other
than what the pressure shell may provide. The crew will spend limited time within pressurized volume without
radiation protection. Thus, the former value applies to technologies and equipment that are susceptible to
environmental radiation or require significant crew interaction while the latter may be used for technologies and
equipment that are insensitive to interplanetary radiation and require little crew interaction. The fourth entry, for
thermal energy management, is a combined assessment considering hardware from the Thermal Subsystem and the
Cooling External Interface. These values are combined here for convenience.
11
Table 3.2.1
Luna Mission Infrastructure Costs
Assumptions
Parameter Units
Lower
Nominal Upper
References
Transit
Shielded Volume
kg/m³
80.8
(1)
Unshielded Volume
kg/m³
45.2
(1)
Power kg/kW
237
(2)
Thermal Energy Management:
Thermal and Cooling
kg/kW 55
(3)
65
(3)
65
(3)
Crewtime
kg/CM-h
TBD
Surface
Shielded Volume
kg/m³
102.0
(1)
133.1
(1)
137.3
(1)
Unshielded Volume
kg/m³
9.16
(1)
13.40
(1)
Power kg/kW
54
(2)
749
(2)
749
(2)
Thermal Energy Management:
Thermal and Cooling
kg/kW 97
(3)
102
(3)
246
(3)
Crewtime
kg/CM-h
TBD
(1)
See Table 3.2.3
(2)
See Table 3.2.8
(3)
See Table 3.2.9
Table 3.2.2
Mars Mission Infrastructure Costs
Assumptions
Parameter Units
Lower
Nominal Upper
References
Transit
Shielded Volume
kg/m³
215.5
(1)
219.7
(1)
Unshielded Volume
kg/m³
9.16
(1)
13.40
(1)
Power kg/kW
237
(2)
Thermal Energy Management:
Thermal and Cooling
kg/kW 60
(3)
70
(3)
Crewtime kg/CM-h
1.14
(4)
1.14
(4)
1.54
(4)
Surface
Shielded Volume
kg/m³
215.5
(1)
219.7
(1)
Unshielded Volume
kg/m³
9.16
(1)
13.40
(1)
Power kg/kW
54
(2)
228
(2)
338
(2)
Thermal Energy Management:
Thermal and Cooling
kg/kW 146
(3)
170
(3)
Crewtime kg/CM-h
1.25
(4)
1.25
(4)
1.50
(4)
(1)
See Table 3.2.3
(1)
See Table 3.2.8
(3)
See Table 3.2.9
(4)
See Table 3.3.5
3.2.1
Pressurized Volume or Primary Structure Costs
Pressurized volume houses the crew and crew-accessible systems. Characteristic volume costs are
presented in Table 3.2.3. The International Space Station (ISS) common module currently provides pressurized
volume in low-Earth orbit. Alternately, an inflatable module can be used. In both cases, the lower value reflects
primary structure with protection for micrometeoroids and orbital debris while the upper value, if known, also
includes some dedicated radiation protection.
12
The aerodynamic crew capsule in Table 3.2.3 is based on an ellipse sled and is designed to aero-capture in
the upper atmosphere upon returning to Earth (NASA, 2001a). The second entry reflects the crew cabin structure
without radiation shielding while the first entry reflects the crew cabin with sufficient radiation shielding for a lunar
transit mission. Nominally, according to concepts within NASA (2001a), crew vehicles for near-term lunar missions
will aero-capture upon returning to Earth, therefore, referenced nominal values include thermal protection for
aerodynamic heating.
Table 3.2.3
Cost of Pressurized Volume
Assumptions [kg/m³]
Technology/Approach Lower
Nominal
Upper
References
Low-Earth Orbit
ISS Module (shell only)
66.7
(1)
Inflatable Module
19.61
(2)
28.1
(2)
32.4
(2)
Lunar Mission – Transit
Shielded Aerodynamic Crew
Capsule (Ellipse Sled)
80.8
(3)
Unshielded Aerodynamic Crew
Capsule (Ellipse Sled)
45.2
(3)
Lunar Mission – Surface
Shielded Inflatable Module
102.0
(4)
13
133.1
(4)
13
137.3
(4)
14
Unshielded Inflatable Module
9.16
(2)
15
13.40
(2)
15
Martian Mission – Surface
16
Shielded Inflatable Module
17
215.5
(4)
13
219.7
(4)
14
Unshielded Inflatable Module
9.16
(2)
15
13.40
(2)
15
(1)
Hanford (1997)
(2)
See Table 3.2.5
(3)
NASA (2001a)
(4)
See Table 3.2.6.
The cost factors listed for inflatable modules, both for lunar and Martian missions, assume surface sites.
The unshielded value reflects the primary structure without any radiation protection, presuming that some “to be
determined†in-situ resources, such as regolith, a natural cavern, or local atmosphere, will provide the necessary
radiation protection. The nominal shielded value assumes sufficient radiation protection for the location, assuming
the surface locale provides no beneficial protection against radiation. The upper value for shielded volume also
includes avionics and power management and distribution masses. Often, however, this last cost is associated with
the Power External Interface and, therefore, should not also be assessed against the structure mass.
In recent studies, transit vehicles for Martian missions are generally larger than corresponding vehicles for
lunar missions, so the volume-mass penalties for surface applications are suitable for transit applications. In fact, the
radiation protection values for the Martian missions are sized with the assumption that a crew is present during
transfer to Mars. Because Mars itself will provide some shielding, the transfer segment is the most severe
environment and provides the criteria for sizing radiation protection.
The appropriate volume cost factor generally depends on the sensitivity of specific equipment to the
external environment or whether the crew must regularly interact with the equipment. As noted above, in radiation
intensive environments anywhere beyond the Van Allen Belts, cost factors for shielded volume should be used
13
Estimate based on primary structure plus shielding mass.
14
Estimate based on all listed module masses, including avionics and power management and distribution.
15
Estimate based on primary structure mass only. Habitats sited on a planetary surface might use in-situ resources for
radiation shielding and micrometeoroid protection. Additional equipment may be required to construct such shielding, but
the associated mass should be considerably less than the corresponding masses from Earth.
16
Transit vehicles for Martian missions are generally larger, based on current concepts, so volume-mass penalties for surface
applications would also be suitable for transit applications.
17
These values are derived from hazards associated with interplanetary space transit. Vehicles on the surface of Mars would
receive some beneficial shielding from the local Martian environment, but the extent of that shielding is unclear.
13
whenever equipment is sensitive to radiation or must be frequently accessed by the crew. This value reflects the cost
of placing equipment within the primary crew cabin. The cost for unshielded volume applies whenever the
technology is not sensitive to radiation but must remain within a pressurized environment. The crew might service
such equipment infrequently. Finally, some technologies might be located outside the pressurized cabin. While this
is unlikely for most life support equipment, the associated volume cost factor would be much less than the lower
value, approaching zero.
Leakage is technology dependent. The specification for ISS modules is 83 kg leakage per module per year
(0.18% per day), but tests have shown the actual leakage rate is significantly lower than this specification.
Currently the United States uses the ISS common module to provide pressurized volume. However, this
design is massive and more costly than some alternatives. Inflatable modules have been suggested since the Apollo
Program. TransHab (Kilbourn, 1998, and NASA, 1999), presented in Table 3.2.4, is a robust inflatable module
designed for low-Earth orbit trials while attached to ISS. TransHab encloses 329.4 m³ within a primary shell with an
inner surface area of 250.9 m². A connecting tunnel provides access to ISS with an additional 12.6 m³. The values in
Table 3.2.4 include micrometeoroid protection and a storm shelter for radiation protection in low-Earth orbit against
solar particle events. Less substantial inflatable modules could be used on a planetary surface if in-situ resources,
such as regolith or caverns, provide meteoroid and radiation protection. Finally, since the ISS common module and
TransHab are designed using different design philosophies, a rigorous comparison between the two approaches is
not intended. Rather, the values here document both approaches.
Table 3.2.4
Masses of Inflatable Shell Components
Item
Mass
[kg]
References
Inflatable Shell Assembly, including Liner, Bladder, and Restraint
1,265
Multi-Layer Insulation
235
Micrometeoroid and Orbital Debris Protection
3,208
Other (Windows, Deployment and Attachment Systems)
204
Central Core Structure, including End Cones
1,405
Water Containment
18
(Enclosing 18.8 m³ and covering 40.1 m²)
142
Radiation Protection Media (A 0.0574 m thick water shield)
2,304
Initial Inflation System
502
Avionics and Power Management and Distribution
1,398
Total Mass
10,663
Based on TransHab
technology. See
Kilbourn (1998),
NASA (1999), and Atwell
and Badhwar (2000)
Based on Table 3.2.4, several cost factors for various configurations of the components presented are
possible. See Table 3.2.6 presents estimates for masses and volume-mass penalties for several configurations of
inflatable modules. The first estimate, based on findings reviewed by Duffield (2001), uses 0.0622 m of hydrogen-
impregnated carbon nanofibers to protect the crew quarters from solar particle events. Such a configuration is
designed for a lunar mission. The assumed containment mass is 5% of the total shielding material mass. The second
estimate assumes 0.0622 m of hydrogen-impregnated carbon nanofibers surround the entire crew cabin. The third
estimate assumes 0.100 m of water surround the entire crew cabin for a lunar mission, which is a common “rule of
thumb†in some recent design scenarios. Again, this shielding only protects against solar particle events. The
containment mass, based on Kilbourn (1998), is 6.2% of the shielding material mass. Finally, the last estimate
employs 2.43 m of liquid hydrogen to shield against both solar particle events and galactic cosmic radiation (see
Duffield [2001]). The assumed containment mass is 50% of the shielding material mass, and this is likely a lower
limit.
While each configuration is not independently viable, they provide background for other estimates. The applicable
volume is 329.4 m³.
18
The water tank surrounding the crew quarters is actually integrated with the central core structure.
14
Table 3.2.6 presents estimates for masses and volume-mass penalties for several configurations of
inflatable modules. The first estimate, based on findings reviewed by Duffield (2001), uses 0.0622 m of hydrogen-
impregnated carbon nanofibers to protect the crew quarters from solar particle events. Such a configuration is
designed for a lunar mission. The assumed containment mass is 5% of the total shielding material mass. The second
estimate assumes 0.0622 m of hydrogen-impregnated carbon nanofibers surround the entire crew cabin. The third
estimate assumes 0.100 m of water surround the entire crew cabin for a lunar mission, which is a common “rule of
thumb†in some recent design scenarios. Again, this shielding only protects against solar particle events. The
containment mass, based on Kilbourn (1998), is 6.2% of the shielding material mass. Finally, the last estimate
employs 2.43 m of liquid hydrogen to shield against both solar particle events and galactic cosmic radiation (see
Duffield [2001]). The assumed containment mass is 50% of the shielding material mass, and this is likely a lower
limit.
Table 3.2.5
Estimated Masses and Volume-Mass Penalties for Inflatable Module Configurations
Configuration
Mass
[kg]
Volume-Mass
Penalty
[kg/m³]
Volume-Mass
Penalty
[m³/kg]
All Inflatable Module components listed in Table 3.2.4
10,663
32.37
0.0309
Previous Option without Avionics
and Power Management and Distribution
9,265 28.13 0.0355
Primary Shell and Central Core Only
3,016
9.16
0.1092
Previous Option plus Multi-Layer Insulation
and Micrometeoroid and Orbital Debris Protection
6,459 19.61 0.0510
Previous Option plus Initial Inflation System
6,961
21.13
0.0473
Previous Option plus Avionics and
Power Management and Distribution
8,359 25.38 0.0394
Avionics and Power Management and Distribution alone
1,398
4.24
15
Table 3.2.6
Estimated Masses for Inflatable Modules
Item (Based on TransHab
Architecture)
Mass for
Lunar
Mission
[kg]
Mass for
Lunar
Mission
[kg]
Mass for
Lunar
Mission
[kg]
Mass for
Martian
Mission
[kg] References
Primary Structure Mass
(Core, Shell)
(1)
19
6,961 6,961 6,961 6,961
Shielding Mass is 0.0622 m of
Hydrogen-Impregnated
Carbon Nanofibers
Around Crew Quarters
(2)
5,618
Tankage (5 %)
(3)
281
Shielding Mass is 0.0622 m of
Hydrogen-Impregnated
Carbon Nanofibers
Around Full Shell
(2)
35,119
Tankage (5 %)
(3)
1,756
Shielding Mass is 0.100 m of
Water Around Full Shell
25,094
Tankage (6.2 %)
(4)
1,556
Shielding Mass is 2.43 m of
Liquid Hydrogen
Around Full Shell
(2)
42,685
Tankage (50 %)
(5)
21,342
Total
Mass
12,860 43,836 33,611 70,988
Volume-Mass Penalty [kg/m³]
133.1
102.0
215.5
[m³/kg]
0.007514 0.009799 0.004640
(1)
Kilbourn (1998) and
NASA (1999)
(2)
Duffield (2001)
(3)
Estimated
(4)
Computed from
Kilbourn (1998)
(5)
Assumed (This value
is probably a lower
limit on the actual
tank mass.)
The options in Table 3.2.6 differ from each other and reflect different commonly proposed design
alternatives. The third option, using 0.100 m of water for a lunar mission, is a reference value because the protection
is inferior compared to the other lunar options and it is insufficient to shield the crew cabin versus the expected
radiation environment.
If avionics and power management and distribution masses are included, as shown in Table 3.2.6 presents
estimates for masses and volume-mass penalties for several configurations of inflatable modules. The first estimate,
based on findings reviewed by Duffield (2001), uses 0.0622 m of hydrogen-impregnated carbon nanofibers to
protect the crew quarters from solar particle events. Such a configuration is designed for a lunar mission. The
assumed containment mass is 5% of the total shielding material mass. The second estimate assumes 0.0622 m of
19
See the fifth configuration in Table 3.2.6 presents estimates for masses and volume-mass penalties for
several configurations of inflatable modules. The first estimate, based on findings reviewed by Duffield (2001), uses
0.0622 m of hydrogen-impregnated carbon nanofibers to protect the crew quarters from solar particle events. Such a
configuration is designed for a lunar mission. The assumed containment mass is 5% of the total shielding material
mass. The second estimate assumes 0.0622 m of hydrogen-impregnated carbon nanofibers surround the entire crew
cabin. The third estimate assumes 0.100 m of water surround the entire crew cabin for a lunar mission, which is a
common “rule of thumb†in some recent design scenarios. Again, this shielding only protects against solar particle
events. The containment mass, based on Kilbourn (1998), is 6.2% of the shielding material mass. Finally, the last
estimate employs 2.43 m of liquid hydrogen to shield against both solar particle events and galactic cosmic radiation
(see Duffield [2001]). The assumed containment mass is 50% of the shielding material mass, and this is likely a
lower limit.
16
hydrogen-impregnated carbon nanofibers surround the entire crew cabin. The third estimate assumes 0.100 m of
water surround the entire crew cabin for a lunar mission, which is a common “rule of thumb†in some recent design
scenarios. Again, this shielding only protects against solar particle events. The containment mass, based on Kilbourn
(1998), is 6.2% of the shielding material mass. Finally, the last estimate employs 2.43 m of liquid hydrogen to shield
against both solar particle events and galactic cosmic radiation (see Duffield [2001]). The assumed containment
mass is 50% of the shielding material mass, and this is likely a lower limit.
Table 3.2.5, this will add an additional 4.24 kg/m³ to the volume-mass penalties listed above. However,
these masses are often accounted for in other factors, such as the power-mass penalty. Without radiation shielding or
micrometeoroid protection, the primary shell and structure of the inflatable module has a volume-mass penalty of
9.157 kg/m³ or 0.1092 m³/kg. This would be an appropriate estimate for a habitat shielded by local resources,
whether regolith or in a natural feature such as a lava tube or cavern.
3.2.2
Secondary Structure Costs
The values in the previous tables quantify the vehicle’s primary structural mass, including the pressure
vessel and radiation shielding. However, many systems also require additional secondary structure, such as a
payload rack, drawers, or refrigeration. Based on data from the ISS Program (Green, et al., 2000), Table 3.2.7
provides estimates for secondary structure masses. Though somewhat simplistic, the volume, power, and thermal
energy management for equipment housed within or mounted to secondary structure is assumed to be identical to the
values for the uninstalled piece of equipment. Assuming a piece of equipment is not to be mounted directly to the
vehicle primary structure, most are mounted to an International Standard Payload Rack. Small items are placed
within trays and drawers of a stowage rack while some foodstuffs and experiments require the chilled climate
provided by a refrigerator or freezer. For example: 100 kg of food stored within a refrigerator would incur a
secondary mass penalty of 136 kg in addition to any power, thermal energy management, or volume penalties, but a
100-kg pump mounted to the vehicle floor would have no associated secondary mass even though power, thermal
energy management, and volume – to account for primary structure – might still apply.
Table 3.2.7
Secondary Structure Masses
Mounting Configuration
Secondary
Structure Mass
per Mass of
Equipment
[kg
Secondary Structure
/kg
Equipment
]
Internal
Cargo
Volume
[m³]
Reference
Directly to Primary Structure
(No Secondary Structure)
0.00
n/a
Directly to International Standard Payload
Rack
0.21
1.57
Within Trays of a Stowage Rack
0.80
0.9
Within Refrigerator/Freezer Rack
1.36
0.614
(1)
Information from
Green, et al. (2000)
except as noted.
(1)
Toups, et al. (2001)
The external volume for an International Standard Payload Rack is 2.00 m³ (Rodriguez and England, 1998).
The Stowage Rack and the Refrigerator/Freezer Rack are derived from the International Standard Payload Rack and
have the same external dimensions.
3.2.3
Power Costs
Selection of power systems for a near-term mission to Mars is an important issue. From an engineering
perspective, nuclear propulsion and nuclear power for the surface may be essential to provide the required power at
an acceptable cost. Table 3.2.8 provides a number of power-generation options for various possibilities. Historically,
in low-Earth orbit, power is either stored in batteries or, alternatively, generated by non-regenerative fuel cells or
solar photovoltaic (PV) panels with some form of energy storage for periods when the vehicle is in shadow. The first
two entries in Table 3.2.8 reflect power generation using ISS technology both with and without energy storage,
provided by batteries. The first value, with energy storage, should be the default power generation option for low-
17
Earth orbit on vehicles of comparable size. The second value applies only for technologies operating while ISS is in
sunlight, not operating while in shadow. For nominal calculations, ISS is in shadow for roughly 36 minutes of each
92 minute orbit at its median altitude. The third table entry assumes Shuttle nonregenerative fuel cells. These fuel
cells use hydrogen and oxygen as reactants , gaining power and water as products. The cost assumes a six-day
mission, and the cost for longer missions rised sharply as mission duration increases.
The power system for transit is a hybrid of deployable PV arrays with batteries and fuel cells. The latter
provides power during mission phases in which the PV arrays are stowed (such as during an aerocapture maneuver).
This system is prototypic of a power system for a small Eearth-Luna transit vehicle.
Providing continuous power on Luna using solar PV power generation requires considerable energy storage
capacity for any non-polar surface site. The first surface generation entry for Luna in Table 3.2.8 assumes solar PV
power generation using tracking arrays with regenerable fuel cells for energy storage. Because most life support
equipment requires almost continuous power when compared to the lunar diurnal cycle, this first case is the most
common. Users with power profiles that closely approximate the diurnal cycle on Luna can avoid costly energy
storage devices as noted in the second and third entries in Table 3.2.8
.
, but such users will likely be exceptions.
Table 3.2.8 lists two solar-driven power generation technologies for Martian surface operations. Solar
dynamic systems concentrate incident solar radiation using a spectral parabolic mirror and achieving high
temperatures at a focal point to drive a generator. Local dust is an obstacle to this approach. As above, regenerative
fuel cells provide energy storage for periods of local darkness.
As on Luna, solar PV power generation on Mars requires very large arrays to provide adequate power
during low-light conditions, such as dust storms (Drake, 1998), and these arrays may be costly and difficult to
maintain in a dusty environment. Even more problematic than solar power generation on Mars would be solar power
generation on sites located away from the equator. The two options provided in Table 3.2.8
.
for power generation
using PV arrays on the Martian surface assume some advances in PV cell efficiency over current technology, as
noted in their entries. They also employ regenerable fuel cells for energy storage during periods of local darkness.
Nuclear generators would provide continuous power regardless of the external environment. The nuclear
power options presented in Table 3.2.8
.
are based on technology developed for the SP100 program and they should
be typical of this approach. However, nuclear reactors of this capacity have not yet been developed for use in space.
The first nuclear generation option deploys the reactor, using thermoelectric power conversion, on a robotic cart,
while the second nuclear generation option deploys the same reactor on an independent lander that has no mobility
once it is on the planetary surface. Both options provide complete shielding for the reactor core when placed 1 km
from the crew habitat. Further, both of the first two options are ready for operation with little crew interaction. The
third nuclear generation option emplaces a reactor, with a more efficient Brayton engine for power conversion,
within a hole in the planetary surface, providing shielding in place of shielding from Earth. The estimate includes
equipment for emplacement, and this may even be autonomous. The fourth nuclear generation option employs a
much larger reactor core than the previous three options, and so benefits from an economy of scale. It also employs
a Stirling engine for power conversion. Because power systems based on nuclear reactors offer the most economical
performance, compared to other currently available technologies, especially for systems designed to generate a
megawatt or more, under certain mission variables, nuclear power options may be selected.
18
Table 3.2.8
Advanced Mission Power Costs and Equivalencies
Power Cost Options
Earth Orbit
kg/kW
e
kW/kg Comments
References
Solar PV Power Generation with
Batteries for Power Storage
20
476
(1)
0.0021
Continuous Power with
Deployable PV Cells
21
Solar PV Power Generation
without Power Storage
22
239
(1)
0.0045
In Sun Power Only with
Deployable PV Cells
23
Non-Regenerative,
Hydrogen-Oxygen Fuel Cells
100
(1)
0.010
Shuttle Technology for
a Six-day Mission
Transit
kg/kW
e
kW/kg Comments
Earth-Luna Transit:
Hybrid Solar Array System
237
(2)
0.0042
PV Arrays + Batteries
and Fuel Cells.
(1)
Hanford and Ewert
(1996)
(2)
NASA (2001a)
(3)
Hughes (1995) and
Ewert, et al. (1996)
(4)
NASA (1989)
(5)
Cataldo (1998)
Surface – Luna
kg/kW
e
kW/kg Comments
Solar Photovoltaic (PV) Power Generation at Equatorial Site on Luna
With Regenerative Fuel Cell
Power Storage
749
(3)
0.0013
Tracking
PV
Arrays
62
(3)
0.016 Tracking
PV
Arrays
Without Power Storage
20
(3)
0.050 Horizontal Arrays
22
Surface – Mars
kg/kW
e
kW/kg Comments
Solar Dynamic Power Generation at Equatorial Site on Mars
With Regenerative Fuel Cell
Power Storage
338
(4)
0.0030
Without Power Storage
149
(4)
0.0067
Solar Photovoltaic Power Generation at Equatorial Site on Mars
178
(5)
0.0056 30% PV Cell Efficiency
With Regenerative Fuel Cell
Power Storage
228
(5)
0.0044 20% PV Cell Efficiency
Surface – Site Independent
kg/kW
e
kW/kg Comments
Nuclear Power Generation Based on SP100 Program
23
On a Mobile Cart
226
(5)
0.0044
On an Independent Lander
87
(5)
0.011
100 kW
e
capacity;
Shielding Included
54
(5)
0.019 100
kW
e
capacity
Emplaced in an Excavated
Hole (Excavation
Equipment is Included)
29
(5)
0.035 1
MW
e
capacity.
20
The value includes significant structures to attach or rotate the solar photovoltaic panel clusters.
21
The value here assumes International Space Station equipment with associated masses and performance.
22
While tracking solar photovoltaic arrays have a fairly constant electrical output when the Sun is above the horizon, the
electrical output from a horizontal array varies as the Sun moves across the sky, peaking at noon.
A horizontal array is appropriate for systems whose power consumption is proportional to the Sun’s position above the
local horizon, such as a vapor compression heat pump whose peak thermal energy management load is at local noon.
23
The systems used to develop these infrastructure estimates assume generation of 100 kW
electric
of user power continuously
that are sited 1 km from the base. For scenarios using one or more 100 kW
e
systems, these values are appropriate. Systems
delivering considerably less power will have higher power-mass-penalty values while very large systems, such as a 1 MW
e
nuclear power system, will have a lower power-mass-penalty.
19
3.2.4
Thermal Energy Management Costs
The values in Table 3.2.9. come from a variety of sources. The internal thermal control system values are
derived from studies of a lunar base, but they are considered typical of other enclosed cabins. The transit vehicle
external thermal control system estimates are based on Shuttle technology. The primary heat rejection technology is
radiators while an evaporative device, a flash evaporator, provides supplemental cooling. Transit vehicle external
thermal control system estimates are provided both with and without supplemental evaporative cooling devices.
Because a vehicle cannot reject heat using radiant transfer while aero-capturing or entering a planetary atmosphere,
some other technology, like evaporative cooling, supplements the radiators. Vehicles that do not experience
aerodynamic heating may use an external thermal control system without any evaporative cooling. The external
thermal control system value for ISS includes significant penalties for thermal-control-system-specific structure that
is not necessary for transit vehicles with their lesser heat loads. See Hanford and Ewert (1996) for a detailed
disposition of ISS external thermal control system masses.
Options for cooling habitats at a lunar surface site rely on horizontal radiators. Some options also use a
vapor compression heat pump powered by a dedicated solar PV array. While the heat pump is only available as the
Sun is above the local horizon, the radiators alone for this option are sized to reject the design load in the absence of
sunlight. All options assume an equatorial site, which is the most severe for the lunar surface.
Finally, the external thermal control system options for the Martian surface use only radiators sized for the
worst environmental conditions expected at an equatorial site—a moderate dust storm—and assume the environment
does not impact the radiator surface properties. Sites in the Martian southern hemisphere can be more severe
thermally than equatorial sites.
For each external thermal control system option above, less massive approaches are available with
additional mission restrictions. In particular, the options listed with lightweight radiators are conservative
approximations and research will reduce equipment masses further than these estimates may indicate (see Weaver
and Westheimer [2002]). The technologies here are generally available but are far from optimal for specific
applications.
•
Note: The cost of a complete thermal energy management system is the sum of the internal thermal control
system cost plus the appropriate external thermal control system cost. The external thermal control system
costs include the Cooling External Interface costs.
•
Note: The inverse thermal-energy-management-mass penalties, given in kW/kg, may not be summed
directly. Rather, only the reciprocal values, given in terms of kg/kW, may be summed directly.
20
Table 3.2.9
Advanced Mission Thermal Energy Management Costs and Equivalencies
Internal Thermal Control System Cost
Vehicle/Site
Independent kg/kW kW/kg Comments
References
Flow Loop
with Heat Acquisition Devices
~25
(1)
~0.040
Half of Heat Load is
acquired by Coldplates.
External Thermal Control System Cost Options
Transit or Low-Earth Orbit
kg/kW
kW/kg
Comments
Current Technology, Vehicles:
Flow-Through Radiators Only
30.4
(2)
0.0329
Shuttle Technology:
Aluminum, Body-
Mounted Radiators with
Silver Teflon Surface
Coating.
Lightweight, Flow-Through
Radiators Only
~20
(4)
~0.05
As above with
Composite, Flow-
Through Radiators.
Flow-Through Radiators with a
Supplemental Expendable
Cooling Subsystem
40.0
(2)
0.0250
“Current Technology,
Vehicles,†with an
additional Flash
Evaporator Subsystem.
(1)
Estimated from
Hanford and Ewert
(1996) and
Ewert, et al. (1999)
(2)
Hanford and Ewert
(1996)
(3)
Estimated from
Hanford and Ewert
(1996) and
Hanford (1998)
(4)
Estimated.
Lightweight, Flow-Through
Radiators with a Supplemental
Expendable Cooling Subsystem
~30
(4)
~0.033
As above with
Composite, Flow-
Through Radiators
Current Technology,
Space Stations:
ISS
24
323.9
(2)
0.00309
ISS Technology:
Aluminum, Anti-Sun
Tracking Radiators with
Z-93 Surface Coating.
Surface
–
Luna
kg/kW kW/kg Comments
Notes
For an Equatorial Site using Horizontal Radiators with Silver Teflon Coating
Current Technology:
Flow-Through Radiators Only
221
(1)
0.0045
Aluminum, Surface-
Mounted Radiators
Lightweight, Flow-Through
Radiators Only
~190
(4)
~0.0053
As above with
Composite Radiators.
Flow-Through Radiators + Solar
Vapor Compression Heat Pump
(SVCHp)
77
(1)
0.013
Aluminum, Surface-
Mounted Radiators
with SVCHp
Lightweight, Flow-Through
Radiators with Solar Vapor
Compression Heat Pump
~72
(4)
~0.014
As above with
Composite Radiators.
Surface – Mars
kg/kW
kW/kg
Comments
For an Equatorial Site using Vertical Radiators with Silver Teflon Coating
Current Technology:
Flow-Through Radiators Only
~145
(3)
~0.0069
Aluminum, Surface-
Mounted Radiators
Lightweight, Flow-Through
Radiators Only
~121
(3)
~0.0083
As above with
Composite Radiators.
•
The cost of a
complete thermal
energy
management
system is the sum
of the internal
thermal control
system cost plus
the appropriate
external thermal
control system cost.
•
Inverse values,
given here in
kW/kg, may not be
summed directly.
24
The value includes significant structures to attach or rotate the thermal radiator clusters.
21
3.2.5
Crewtime Costs
Life support equipment requires crewtime for operations and maintenance. This crewtime can be small for
some systems and large for others. Notably for functions related to food—food production, food product
preparation, meal preparation, and waste disposal—the crewtime may be very large. The cost of crewtime is derived
from the life support system ESM and the crewtime available. Typical equivalencies vary from about 0.1 to 10
crewmember-hours per kg of ESM. Section 3.3.2 provides additional details.
3.2.6
Location Factors
Location factors
25
describe the additional resources necessary to move a kilogram of payload from low-
Earth orbit to some location elsewhere in space. The additional resources here refer to propulsion assets such as
engines, fuel, tankage, and associated propulsion-related structure.
26
Specifically, a location factor represents the
additional mass necessary in low-Earth orbit [kg] to push a mass of payload [kg] to a particular destination. Location
factors allow comparisons between cases where all payloads do not share the same transportation history. In other
words, one payload option may stay entirely aboard one vehicle during the entire mission, while another payload
option may jettison mass midway through the mission, reducing its associated propulsion costs for the remainder of
the mission. Levri, et al. (2003) details use of location factors within equivalent system mass assessments.
Location factors for two destinations, Luna and Mars, are presented in Table 3.2.10. Estimates for Mars
assume the Mars Dual Lander architecture, while estimates for Luna are based on a similar architecture using Luna
as the destination. Both sets of estimates assume chemical propulsion and aero-braking when possible, which is
current technology for human spaceflight within NASA.
27
Table 3.2.10
Location Factors for Near-Term Missions
Location Factor [kg/kg]
Mission Element (Segment)
Lower Nominal
Upper Reference
Luna
Lunar Transfer Vehicle (Full Trip)
7.36
(1)
Lunar Transfer Vehicle
(To Lunar Orbit Only)
5.09
(2)
(1)
Geffre (2003)
(2)
Geffre (2004)
Lunar Lander (To Lunar Surface
and back to Lunar Orbit)
12.78
(1)
Lunar Lander
(To Lunar Surface Only)
6.98
(1)
Mars
28
Mars Transfer Vehicle (Full Trip)
6.77
(1)
6.77
(1)
11.14
(1)
Mars Transfer Vehicle
(To Mars Orbit Only)
3.16
(2)
3.16
(2)
4.37
(2)
Mars Lander (To Martian Surface
and back to Martian Orbit)
10.50
(1)
10.50
(1)
15.83
(1)
Mars Lander
(To Martian Surface Only)
3.77
(1)
3.77
(1)
5.33
(1)
Transfer Vehicles travel from low-Earth orbit to either Luna orbit or Mars orbit, then return. The first
estimate is for a complete trip to and from the celestial body listed, while the second estimate is for payloads that
travel only to the celestial body listed, then remain behind when the Transfer Vehicle returns.
Landers travel from low-Earth orbit to either the Lunar or Martian surface and, in some cases, back to orbit.
For example, within the Mars Dual Lander architecture are two landers. The first, the Mars Descent / Ascent Lander,
travels to Martian orbit robotically. In orbit, the Mars Transit Vehicle will
rendezvous
with the Mars Descent/Ascent
25
Some researchers use the term “gear ratio†for “location factor.†However, these terms refer to the same concept.
26
Recall that cabin structure, power, cooling, and crewtime costs or penalties are already assessed with other factors.
27
Advanced propulsion concepts may yield much lower location factors in the future, but development of advanced
propulsion systems for human spaceflight currently has high programmatic risks.
28
Mars Dual Lander architecture.
22
Lander and the crew transfers to the latter vehicle for the trip to the Martian surface. At the end of the surface stay,
the Mars Descent / Ascent Lander returns the crew to Martian orbit and the Mars Transit Vehicle for the trip back to
Earth. The second lander, the Surface Habitat Lander, travels and lands robotically on Mars. The crew transfers to
the Surface Habitat Lander once they are on the surface. Thus, the Mars Descent/Ascent Lander represents a case in
which any mass that stays on the vehicle throughout its mission travels all the way to the Martian surface and then
back to Martian orbit. The Surface Habitat Lander, however, only travels to the Martian surface.
29
Per Levri, et al. (2003), location factors multiply the equivalent system masses to which they apply. The
location factors given in Table 3.2.10 have units of “kilograms of total vehicle in low-Earth orbit divided by
kilograms of life support hardware in low-Earth orbit.†Thus, an equivalent system mass corrected for location is
the product of the equivalent system mass contributions due to the physical attributes of the hardware and the
location factor.
Example: A piece of equipment with an equivalent system mass of 2.0 kg as payload on a Mars Transfer
Vehicle would have an equivalent system mass corrected for location of 13.54 kg if it remains on board during the
entire mission from Earth, to Mars, and back to Earth. Or, this value may be expressed as an equivalent system mass
is 2.0 kg for the payload hardware and other payload equivalencies and an additional 11.54 kg in equivalent system
mass for propulsion in low-Earth orbit to move the payload to Mars and back.
Alternatively, location factors in Table 3.2.10 may be expressed as ratios. Thus, the location factor for a
full trip to and from Mars aboard a Mars Transfer Vehicle may be expressed as 5.77 kg of additional mass for
propulsion in low-Earth orbit for every 1 kg of payload that travels to Mars and back, or, in shorthand notation,
5.77:1. Using this approach yields the same result as the second form in the example above.
3.3
Crew Characteristics
The primary purpose of the life support system is to maintain the crew, and particular crew characteristics
will drive equipment requirements. From an analysis perspective, the human metabolic rate and available time are
necessary input values.
3.3.1
Crew Metabolic Rate
The metabolic load affects air revitalization, food use, and heat production directly and, to a lesser extent,
also affects water use, waste production, and other functions. Lane, et al. (1996) lists metabolic energy requirements
as shown in Table 3.3.2. The average metabolic rate assumed for a 70 kg crewmember is 11.82 MJ/CM-d
(136.8 W/CM), per NASA (1991)
30
. Here, crewtime is expressed in “crewmember-hours†(CM-h) or
“crewmember-days†(CM-d) where the prefix “crewmember†(CM) identifies a single individual conducting a task
for the appended duration. Actual metabolic rate varies with lean body mass, environment, and level of physical
activity. However, because lean body mass data are difficult to collect, a combination of total body mass and gender
are often substituted for this parameter. Embedded in this substitution is the generalization that males have a greater
percentage of lean tissue than females for the same total body mass. Thus, NASA (1995) defines the crewmember
mass range from a 95
th
percentile American male, with a total body mass of 98.5 kg, to a 5
th
percentile Japanese
female, with a total mass of 41.0 kg. (See Table 3.3.1) Metabolism increases due to physical exertion, and a heavy
workload can generate more than 800 W/CM of thermal loading. Few people can continue this level of exertion for
extended periods, though the total energy expenditure for an exceptionally active 70 kg male could be as high as
18 MJ/CM-d (208.3 W/CM) of thermal loading on the crew cabin or extravehicular mobility unit (EMU) (Metabolic
data from Muller and Tobin, 1980.). Thus, EVA, as noted in Section 5.2, and exercise protocols can elevate
metabolic rate. These data do not account for any metabolic effects due to low gravity. Data given in following
sections are scaled for low and high levels of activity and for small and large people. The values derived using
Table 3.3.2 account for a moderate level of exercise.
29
“Mars Transit Vehicle,†“Mars Descent / Ascent Lander,†and “Surface Habitat Lander†are specific names for vehicles
from the Mars Dual Lander architecture. “Transfer Vehicle†and “Lander†are more generic names used here to
differentiate between two types of vehicles that commonly appear in NASA advanced studies.
30
NASA has used these design values since, or before, the Space Station Freedom program.
23
Table 3.3.1
Crewmember Mass Limits
Limits
Units
Lower
Nominal
Upper
Reference
Crewmember
Mass
kg
41.0 70.0 98.5
From NASA (1995).
Table 3.3.2
Human Metabolic Rates
Gender
Age [y]
Metabolic Rate
31
[kJ/CM-d] Reference
18 – 30
1.7 (64.02•m + 2,841)
Male
30 – 60
1.7 (48.53•m + 3,678)
18 – 30
1.6 (61.50•m + 2,075)
Female
30 – 60
1.6 (36.40•m + 3,469)
Converted from
Lane, et al.
(1996).
3.3.2
Crewtime Estimates
Crewtime is an important commodity on any human mission. In fact, wise usage of crewtime is the core of
all exploration in which human beings take part. Historically, crewtime for life support functions has been limited to
monitoring equipment and infrequently replacing expendables. Support for the Biomass Subsystem and the
associated Food Subsystem, however, could easily consume a substantial fraction of the crew’s time if designed
with inadequate automation.
The information here is meant to outline the time available to a crewmember during a standard workweek.
Gall (1999) proposes a generic schedule for crewtime on ISS. This is assumed with slight modifications here as
shown below in Table 3.3.3.
Several of the categories in Table 3.3.3 deserve additional explanation. The category “scheduled crew
activities†includes, among other things, system and vehicle maintenance, according to Gall (1999). Thus, life
support system maintenance deducts crewtime from other mission objectives. The category “meals†includes pre-
meal preparation and post-meal clean up in addition to actual meal consumption. It is assumed here that the time for
meals would not diminish on a vacation day. “Weekly cleaning†is assumed here to include laundry operations, if
applicable, in addition to general vehicle cleaning operations. For ISS this is scheduled as four hours per
crewmember per week during the weekend, or two hours per crewmember per weekend-day. “Exercise†is assumed
to include pre- and post-exercise operations, such as post-exercise hygiene operations. In short, exercise includes
some overhead in addition to the actual time spent exercising. “Sleep†denotes time for rest. The ISS schedule
devotes 80 minutes total of “daily payload operations†per non-weekday to support experiments that demand daily
attention (Gall, 1999). Here, the daily payload operations were extended to 90 minutes, or 15 minutes per
crewmember per day for a six-member crew, and it is assumed that daily payload operations would be necessary
even on a vacation day.
Here, the last five categories in Table 3.3.3, ground coordination and planning, exercise, sleep, daily
payload operations, and free time, are not available for life support operations under nominal scheduling scenarios.
For purposes here, they are classified as Invariantly-Scheduled Time (IST).
Time other than IST, theoretically, may be available for either maintaining the life support system or for
other activities if the life support system uses less time. This time block is designated here as Variably-Scheduled
Time (VST). VST includes not only time for mission objectives, but also time scheduled for life support operations,
such as equipment maintenance, meal preparation, consumption and clean-up, and laundry operations. Realistically,
using the entire block of VST for life support functions is unacceptable, though the total VST places an upper limit
on available time. Further, any time not used for life support operations may be employed to accomplish mission
objectives while not impacting the IST.
As outlined in Gall (1999), ISS will operate on a standard week of seven 24-hour days. The standard
workweek, for planning purposes, is five days followed by a two-day weekend. Vacation is allotted as eight days per
crewmember per year regardless of nationality.
31
The metabolic rate is the product of a basal rate and an activity factor. The basal rate, in parentheses, depends on
crewmember mass [kg],
m
, and a second, mass-independent coefficient. The activity factor here is correlated as a function
of gender while the other coefficients are correlated as functions of both gender and age.
24
Table 3.3.3
Time Allocation for a Nominal Crew Schedule in a Weightless Environment
32
Activity
Weekday
[CM-
h /CM-d]
Weekend Day
[CM-h/CM-d]
Vacation Day
[CM-h/CM-d]
Scheduled
Crew
Activities 7.75 0.00 0.00
Meals
3.50 3.50 3.50
Weekly
Cleaning
0.00 2.00 0.00
Variably
Scheduled
Time
Ground Coordination and Planning
0.50 0.50 0.00
Exercise
2.00 2.00 0.00
Sleep
8.50 8.50 8.50
Daily
Payload
Operations 0.25 0.25 0.25
Free Time
1.50
7.25
11.75
Invariantly
Scheduled
Time
Total
24.00 24.00 24.00
Assuming the standard ISS workweek and vacation schedule, a crewmember will have, on average,
66.3 CM-h/wk of VST and 101.7 CM-h/wk of IST in a weightless environment.
33
Assuming the exercise time is
0.5 CM-h/d shorter due to working against gravity, a crewmember will have 68.8 CM-h/wk of VST and
99.2 CM-h/wk of IST on a planetary surface. Minimally, a crewmember might be expected to work at least
50 CM-h/wk, recalling that this VST includes maintaining the life support equipment and meal operations. The
maximum available VST might be 10% greater than the average values but, based on Skylab experience, this rate
can only be maintained for periods of 28 days or less.
Table 3.3.4
Crewtime per Crewmember per Week
Assumptions [CM-h/wk]
Mission Phase
Lower Nominal
Upper
34
References
Transit/Weightlessness 50
(1)
66.3
(2)
72.9
(1)
Surface/Hypogravity 50
(1)
68.8
(1)
75.7
(1)
(1)
Estimated (see above)
(2)
Gall (1999)
To assess the cost associated with adding an operation that requires crew intervention, a crewtime mass
penalty is computed by dividing the total per capita life support system mass by the VST crewtime. This penalty
may be applied to determine the ESM associated with crew operations. Typical values might vary between
0.1 kg/CM-h and 10 kg/CM-h.
Two philosophies are commonly employed by researchers to determine a crewtime-mass-penalty (CTMP).
The first assumes that each hour of crewtime required by the life support systems is equally valuable. The second, as
32
From Gall (1999) for International Space Station crews. Note: Time estimates are given for a nominal week inside of ISS
excluding variations for critical mission functions such as docking/undocking operations and/or EVAs.
33
The term "microgravity" is often used to designate the condition experienced in Earth orbit. However, until one is
relatively far away from the Earth, gravity is still present, and an older term, "weightlessness," is more accurate. In low-
Earth orbit, the force of gravity is still about 95% of what it is on the surface of the Earth, but objects falling freely –
whether in orbit or falling towards the atmosphere or in any other trajectory not involving non-gravitational external forces,
such as propulsion or atmospheric drag – do not feel any force. "Weight" is the term used for the force felt when a human’s
feet press against the Earth, holding the individual against the force of gravity. In free fall, there is no such force, hence, the
term "weightless" is more accurate. To get true microgravity – a millionth of that on the surface of the Earth – the Sun's
gravity must be considered also. At the distance of the Moon, this is about twice that of the Earth. To encounter true
microgravity, one would have to travel out to near the edge of the Solar System, about as far as the orbit of Uranus. In
many situations, the difference between microgravity and weightlessness does not matter. However, it can have effects
with fluids, rotational movement, and large structures, and has been investigated for use with tethers.
34
The listed upper limit for crewtime per week is 10% above the average values discussed in the text. Firm upper limits are
not currently known, but they are likely to be no greater than these values, especially for operations lasting more than a
week or two.
25
forwarded by Levri, et al. (2000), assumes that each additional hour of time required by the life support system is
more valuable than the previous hour. The first approach is consistent with the philosophy adopted to compute the
other mass-equivalencies (see Section 3.2), while the second tends to more severely penalize a life support system
architecture that makes large demands on crewtime. The first approach is recommended for general use.
The first approach used to determine CTMP assumes each hour of crewtime is equally valuable. Once a
value for crewtime is established, changes in crewtime have a linear effect on the overall equivalent mass of a life
support system. Table 3.3.5 provides CTMP values for several mission possibilities computed using Equation 3.3-3.
Inputs for these values come from or are based on the Advanced Life Support Research and Technology
Development Metric for Fiscal Year 2001 (Drysdale and Hanford, 2002). The mission elements referenced in
Table 3.3.5 are detailed in Stafford, et al. (2001). Please note the Advanced Life Support Research and Technology
Development Metric for Fiscal Year 2001 used a previous set of infrastructure values than those presented above in
Section 3.2. The lower and nominal values in Table 3.3.5 are derived from life support systems using ALS
technologies, while the upper values reflect ISS technologies.
Table 3.3.5
Crewtime-Mass Penalty Values Based Upon Fiscal Year 2001 Advanced Life Support
Research and Technology Development Metric
Assumptions [kg/CM-h]
Mission Lower
Nominal
Upper
Reference
Low Earth Orbit
ISS, Assembly Complete for
United States On-orbit Segment
0.49 0.49 0.65
Mars
Mars
Transit
Vehicle
1.14 1.14 1.54
Mars Descent / Ascent Lander
6.01
6.01
8.39
Surface
Habitat
Lander
1.25 1.25 1.50
Drysdale and Hanford
(2002)
The second approach to determine CTMP values assumes each hour of crewtime required by the life
support system is more valuable than the previous hour. Thus, the CTMP is computed by dividing the life support
system mass, excluding crewtime, by the total available crewtime that is not devoted to personal activities or to
maintaining the life support system. Equivalently, this latter denominator is VST minus time devoted to the life
support system. This value is effectively fixed once the total crewtime, crewtime devoted to the life support system
and the life support system mass are determined. However, this value is a function of crewtime required to service
and maintain the life support system, so it will vary if its component values change.
Assuming each hour of crewtime is more valuable than the previous hours of crewtime, Levri, et al. (2000)
present a formulation for the second crewtime-value formulation. They define the following terms:
Symbol Units
Physical
Meaning
ESM
w/o ch
[kg]
Equivalent system mass (ESM) for the life support system
without accounting for crewtime spent for life support. Or, the
“non-crewtime†portion of ESM.
ESM
LSS
[kg]
Component of life support ESM to support crewtime involved
in life support. Or, the “crewtime†portion of ESM.
ESM
Total
[kg]
Total life support system ESM; ESM
w/o ch
+ ESM
LSS
.
t
LSS
[CM-h/wk]
Crewtime spent on the life support system. This is identical to
the portion of VST spent of life support.
t
MP
[CM-h/wk]
The total crewtime per week available for life support system
maintenance or mission-related objectives. This is equivalent to
VST.
t
MP-LSS
[CM-h/wk]
Crewtime per week not devoted to the life support system or to
personal activities; t
MP
- t
LSS
. This is crewtime available for
mission-related objectives such as science or exploration.
26
Levri, et al. (2000) then assume that the overall ESM of the life support system, including the crewtime, is
proportional to the total mission production time as the ESM of the life support system without crewtime is
proportional to mission production time less the time for life support, or:
MP
Total
t
ESM
=
LSS
MP
ch
o
/
w
t
ESM
−
Equation 3.3-1
Alternatively, the overall ESM of the life support system is:
ESM
Total
= ESM
w/o ch
⎟⎟
âŽ
⎞
⎜⎜
âŽ
⎛
−
LSS
MP
MP
t
t
Equation 3.3-2
Using this approach, as crewtime for life support increases, the crewtime per week not devoted to life
support or to personal activities, t
MP-LSS
, decreases, and the overall ESM for the life support system increases in a
non-linear manner. In fact, as t
MP-LSS
approaches zero, the overall ESM for the life support system approaches
infinity.
Thus, here CTMP is derived by dividing the life support equivalent system mass excluding crewtime by the
total available crewtime not devoted to personal activities or life support maintenance.
CTMP =
MP
ch
o
/
w
t
ESM
Equation 3.3-3
3.3.3
Nominal Human Interfaces
Nominal balances of major life support commodities are summarized in Table 3.3.6 for a standard 70 kg
crewmember with a respiratory quotient
35
of 0.869 during IVAs. The water loads include 0.345 kg/CM-d of
metabolically generated water. Actual values depend on many factors, including physical workload, diet, and
individual metabolism.
For a food system based on the Shuttle Training Menu, as detailed above, Levri (2002) lists the properties
of the rehydration apparatus and conduction oven collectively as 36.3 kg occupying 0.094 m³ based on the Shuttle
galley. During use, the rehydration apparatus consumes up to 0.540 kW to heat water. The conduction oven, when
operational, consumes up to 0.360 kW for heaters and 0.060 kW for fans. Thus, the maximum total power load for
the galley is 0.960 kW during operation.
Perchonok, et al. (2002) reports a loaded ISS food container for Phase II averages 5.5 kg each and contains
nine meals plus snacks. This is equivalent to a single day’s food for three ISS crewmembers. This is equivalent, on
average, to 0.611 kg/meal, assuming snacks are extensions of the standard meals, or 1.83 kg/CM-d. Individual food
container masses vary according to individual crew entrée preferences and nutritional requirements, and the
containers themselves are placed in racks, incurring a secondary structure penalty not included in the masses above.
35
Respiratory quotient is defined as moles of carbon dioxide produced divided by moles of oxygen consumed.
27
Table 3.3.6
Summary of Nominal Human Metabolic Interface Values
Balance
36
Interface Units
Nominal
Value References
Basis
Overall
Body
Mass
kg
70.0
Respiratory
Quotient
0.869
Air
−
m
Carbon Dioxide Load
kg/CM-d
0.998
+ m
Oxygen Consumed
kg/CM-d
0.835
Food
+ m
Food Consumed; Mass
37
kg/CM-d
0.617
38
+ E
Food Consumed; Energy Content
MJ/CM-d
11.82
+ m
Potable Water Consumed
39
kg/CM-d
3.909
(1)
Thermal
−
E
Total Metabolic Heat Load
40
MJ/CM-d
11.82
Sensible Metabolic Heat Load
MJ/CM-d
6.31
Latent Metabolic Heat Load
41
MJ/CM-d
5.51
Waste
−
m
Fecal Solid Waste (dry basis)
kg/CM-d
0.032
−
m
Perspiration Solid Waste (dry basis)
kg/CM-d
0.018
−
m
Urine Solid Waste (dry basis)
kg/CM-d
0.059
Water
42
−
m
Fecal Water
kg/CM-d
0.091
−
m
Respiration and Perspiration Water
43
kg/CM-d
2.277
−
m
Urine Water
kg/CM-d
1.886
(1)
Converted from
NASA (1991) unless noted
otherwise.
(1)
From NASA (1991)
and Perchonok (2001)
36
Masses consumed by the crewmember are denoted by “+
m
,†while masses rejected by the crewmember are denoted by
“-
m
.†Likewise, energy entering the crewmember is denoted by “+
E
,†while energy rejected by the crewmember is
denoted by “-
E
.â€
37
This assumes a completely dehydrated or dry basis.
38
Dry mass with no water content. Bourland (1998) gives a value of 0.674 kg/CM-d. (See Table 3.2.9).
39
This value includes drink water and moisture contained within consumed food. Food is not generally dehydrated.
40
The total metabolic heat load is the summation of the sensible and latent metabolic heat loads.
41
Assuming a latent heat for water of 2,420 kJ/kg.
42
The difference between the water load sum of fecal water, respiration and perspiration water, and urine water, and the
potable water consumed, as given above, is metabolic water. Here, metabolic water is 0.345 kg/CM-d. Also, the water
values below are consistent with the dry basis waste values above.
43
The respiration and perspiration water corresponds to the latent metabolic heat load above.
28
4
Life Support Subsystem Assumptions and Values
4.1
Air Subsystem
4.1.1
Design Values for Atmospheric Systems
Air regeneration is one of the more time-critical life support functions. Typical control (steady state) values
are given in Table 4.1.1. Total pressure is an issue. Some generally prefer to use normal sea-level pressure because
that is the condition under which most known data were collected and because people can live satisfactorily for
extended periods under these conditions. Others, however, prefer lower pressures, to reduce the mass of required
gas, the mass of the vehicle, and the requirement to pre-breathe with current EMUs or “spacesuits.†Reduced
pressure normally entails increasing the percentage of oxygen, relative to other gases in the cabin atmosphere, which
increases the risk of fire. Here, a nominal cabin pressure of 70.3 kPa is assumed based on Lin (1997).
The tolerable partial pressure of carbon dioxide, p(CO
2
), for humans, is higher than what is accepted as
desirable for most plants. The generally accepted optimum for plants is 0.120 kPa (1,200 ppm), but the practical
upper limit on carbon dioxide for plant chambers is currently unknown. Separate atmospheric concentrations could
be used for crew compartments and plant chambers by regulating inter-chamber gas transfer rates. Earth normal
p(CO
2
) is 0.035 kPa to 0.040 kPa (350 to 400 ppm).
Table 4.1.1
Typical Steady-State Values for Vehicle Atmospheres
Assumptions
44
Parameter Units
Lower
Nominal Upper References
Carbon Dioxide Generated
kg/CM-d
0.466
(1)
0.998
(2)
2.241
(1)
Oxygen Consumed
kg/CM-d
0.385
(1)
0.835
(2)
1.852
(1)
p(CO
2
) for Crew
45
kPa 0.031
(6)
0.4
(3)
0.71
(6)
p(CO
2
) for Plants
47
kPa 0.04
(4)
0.12
(5)
TBD
p(O
2
) for Crew
kPa
18.0
(6)
18.0 - 23.1
(6)
23.1
(6)
Total Cabin Pressure
kPa
48.0
(6)
46
70.3
(3)
102.7
(6)
Temperature K
291.5
(6)
295.2
(6)
299.8
(6)
Relative Humidity
%
25
(6)
60
(6)
70
(6)
Perspired Water Vapor
kg/CM-d
0.036
(7)
0.699
(7)
1.973
(7)
Respired Water Vapor
kg/CM-d
0.803
(7)
0.885
(7)
0.975
(7)
Leakage Rate (spaceflight) %/d
0
0.05
(8)
0.14
(8)
Leakage Rate (test bed)
%/d
1
(9)
5
(9)
10
(9)
(1)
calculated based upon
lower and upper
metabolic rates.
(2)
NASA (1991)
(3)
Lin (1997)
(4)
Earth normal
(5)
accepted optimum for
plant growth
(6)
Duffield (2003)
(7)
Boeing (2002)
(8)
computed from
NASA (1998) and
Boeing (1994)
(9)
Eckart (1996)
In addition to the carbon dioxide load noted above in Table 4.1.1, human beings also emit volatile
compounds, products of metabolic processes, on a per crewmember per diem basis, as noted in Table 4.1.2, while
Table 4.1.3 details emissions from cabin equipment on a per mass of equipment per diem basis (Perry, 1998). This
44
The values here are averages for nominal operation of the life support system. Degraded or emergency life support system
values may differ.
45
While any contaminant removal technology must, by requirement, maintain that contaminant’s concentration below a set
value, the nominal concentration likely corresponds to that provided when the technology is operating most efficiently
rather than to some specific value (Lange, 1999). Barring other constraints, technology efficiency dictates the nominal
carbon dioxide concentration derived from any carbon dioxide removal equipment. However, the values here provide
carbon dioxide concentrations for studies that do not explicitly determine such values independently.
46
An almost pure oxygen atmosphere, such as was utilized for early spacecraft (Mercury, Gemini, and Apollo), has a total
pressure of 34.5 kPa. Skylab used an atmosphere at 34.4 kPa (258 millimeters of mercury), but the crews reported
numerous discomforting effects.
29
model (Perry, 1998) lists trace contaminant emissions accounting for greater than 97% of the observed loading
during past Shuttle and Spacelab missions, while Perry (1995) gives a complete listing of observed emissions for
Shuttle and Spacelab. In addition to the emission rates, Table 4.1.2 and Table 4.1.3 list the International Union of
Pure and Applied Chemistry (IUPAC) name
47
of the compound in brackets, when it differs from the common name,
along with the molecular weight (MW). Current spacecraft maximum allowable concentration (SMAC)
requirements for these compounds may be found in Duffield (2003). These compounds are historically removed by
the trace contaminant control technologies.
To estimate a loading rate for contaminant removal design, Perry (1998) recommends using the mean rate
plus one standard deviation. For more conservative designs, the maximum design loading case should be no more
than the mean rate plus 1.6 standard deviations.
Table 4.1.2
Model for Trace Contaminant Generation from Human Metabolism
48
Component
MW
Mean Rate [mg/d-kg]
Standard Deviation [mg/d-kg]
ammonia 17.00
350.0
1.36
methane 16.04
234.0
94.7
hydrogen 2.02
31.3
19.0
carbon monoxide
28.01
13.8
3.74
acetone [2-propanone] 58.08
9.63
9.12
methyl ethyl ketone [2-butanone] 72.11
8.74 2.86
ethane 30.07
4.29
2.41
propane 44.09
3.29
2.10
ethyl alcohol [ethanol]
46.07
2.18
2.08
benzene 78.11
1.18
0.972
isopropyl alcohol [2-propanol]
60.09
1.02
0.671
isoprene [2-methyl-1,3-butadiene]
68.12
0.913
0.643
pentane 72.15
0.765
0.457
toluene [methylbenzene]
92.15
0.462
0.179
n-propyl alcohol [1-propanol]
60.09
0.408
0.168
methyl alcohol [methanol]
32.04
0.396
0.478
n-butyl alcohol [1-butanol] 74.12
0.395
0.122
ethyl acetate [ethanoic acid ethyl ester]
88.11
0.391
0.384
ethylbenzene 106.16
0.373
0.156
hexahydrophenol [cyclohexanol] 100.16
0.370 0.130
acetaldehyde [ethanal] 44.05
0.338
0.258
p-dioxane [1,4-dioxane]
88.11
0.317
0.142
carbolic acid [phenol]
94.11
0.258
0.060
formaldehyde [methanal]
30.03
0.167
0.264
methyl chloroform [1,1,1-trichloroethane]
133.41
0.161
0.249
propionaldehyde [propanal]
58.08
0.154
0.266
butyl acetate [ethanoic acid butyl ester]
116.16
0.132
0.0512
hexamethylene [cyclohexane]
84.16
0.121
0.0512
isobutyl acetate [ethanoic acid isobutyl ester]
116.16
0.0761
0.0301
methyl isobutyl ketone [4-methyl-2-pentanone] 100.16
0.0747
0.0251
methylene chloride [dichloromethane]
84.93
0.0647
0.0245
chlorophene [chlorobenzene]
112.56
0.0497
0.0208
isobutyl alcohol [2-methyl-1-propanol] 74.12
0.0477
0.0827
tetrachloroethylene [tetrachloroethane]
165.83
0.0472
0.0195
o-xylene [1,2-dimethylbenzene]
106.16
0.0323
0.0242
m-xylene [1,3-dimethylbenzene]
106.16
0.0323
0.0242
p-xylene [1,4-dimethylbenzene]
106.16
0.0323
0.0242
propylbenzene 120.20
0.0276
0.0107
propyl acetate [ethanoic acid propyl ester]
102.13
0.00146
0.00252
n-amyl alcohol [1-pentanol]
88.15
0.000866
0.00150
47
The Commission on Nomenclature by The Council of the International Union of Pure and Applied Chemistry (IUPAC) at
Paris, 1957, defined IUPAC nomenclature.
48
From Perry (1998).
30
Table 4.1.3
Model for Trace Contaminant Generation from Cabin Equipment
49
Component
MW
Mean Rate [mg/d-kg]
Standard Deviation [mg/d-kg]
Freon 113 [1,1,2-trichloro-1,2,2-trifluoroethane]
187.40
0.00864
0.0103
ethyl alcohol [ethanol]
46.07
0.00353
0.00432
methyl ethyl ketone [2-butanone]
72.11
0.00281
0.00320
isopropyl alcohol [2-propanol]
60.09
0.00251
0.00148
n-butyl alcohol [1-butanol]
74.12
0.00227
0.00244
acetone [2-propanone]
58.08
0.00223
0.00139
toluene [methylbenzene]
92.15
0.00153
0.000455
carbon monoxide
28.01
0.00137
0.000658
methylene chloride [dichloromethane]
84.93
0.00112
0.00103
methyl isobutyl ketone [4-methyl-2-pentanone]
100.16
0.000864
0.000546
methyl alcohol [methanol]
32.04
0.000855
0.000418
chlorophene [chlorobenzene]
112.56
0.000784
0.000760
Freon 11 [trichlorofluoromethane]
137.40
0.000771
0.000637
m-xylene [1,3-dimethylbenzene]
106.16
0.000703
0.00132
p-xylene [1,4-dimethylbenzene]
106.16
0.000668
0.000412
methane 16.04
0.000543
0.000096
cellosolve acetate [ethanoic acid 2-ethoxyethyl ester]
132.16
0.000461
0.000285
pimelic ketone [cyclohexanone]
98.14
0.000434
0.000228
isobutyl alcohol [2-methyl-1-propanol]
74.12
0.000414
0.000433
methyl chloroform [1,1,1-trichloromethane]
133.41
0.000414
0.000258
butyl acetate [ethanoic acid butyl ester]
116.16
0.000398
0.000348
tetrachloroethylene [tetrachloroethane]
165.83
0.000380
0.000348
n-butylaldehyde [butanal]
72.10
0.000311
0.000548
o-xylene [1,2-dimethylbenzene]
106.16
0.000307
0.000249
ethyl cellosolve [2-ethoxyethanol]
90.12
0.000281
0.000383
hexahydrophenol [cyclohexanol]
100.16
0.000267
0.000489
octamethylcyclotetraoxosilane 296.62
0.000184
0.000086
propionaldehyde [propanal]
58.08
0.000162
0.000157
carbolic acid [phenol]
94.11
0.000159
0.000324
ethyl acetate [ethanoic acid ethyl ester]
88.11
0.000158
0.000138
hexamethylene [cyclohexane]
84.16
0.000148
0.000231
adipic ketone [cyclopentanone]
84.11
0.000148
0.000322
propyl acetate [ethanoic acid propyl ester]
102.13
0.000118
0.000220
mesityl oxide [4-methyl-3-penten-2-one]
98.14
0.000116
0.000075
hexamethylcyclotrioxosilane 222.40
0.000115
4.65
×
10
-5
n-propyl alcohol [1-propanol]
60.09
0.000111
0.000130
propylbenzene 120.20
9.61
×
10
-5
0.000119
ethylbenzene 106.16
8.38
×
10
-5
6.60
×
10
-5
Halon 1301 [bromotrifluoromethane]
148.90
8.06
×
10
-5
0.000180
trimethylsilanol 90.21
7.89
×
10
-5
8.98
×
10
-5
n-amyl alcohol [1-pentanol]
88.15
7.20
×
10
-5
9.00
×
10
-5
acetaldehyde [ethanal]
44.05
6.86
×
10
-5
3.99
×
10
-5
methyl methacrylate [2-methyl propenoic acid methyl ester]
100.12
6.78
×
10
-5
6.19
×
10
-5
methyl acetate [ethanoic acid methyl ester]
74.08
6.18
×
10
-5
7.91
×
10
-5
isobutyl acetate [ethanoic acid isobutyl ester]
116.16
5.85
×
10
-5
9.32
×
10
-5
p-dioxane [1,4-dioxane]
88.11
5.76
×
10
-5
5.60
×
10
-5
pentane 72.15
4.46
×
10
-5
5.08
×
10
-5
tert-butyl alcohol [2-methyl-2-propanol]
74.12
4.36
×
10
-5
3.02
×
10
-5
ethylene dichloride [1,2-dichloroethane]
98.97
4.24
×
10
-5
3.50
×
10
-5
ammonia 17.00
4.11
×
10
-5
4.35
×
10
-5
decamethylcyclopentaoxosilane 370.64
2.30
×
10
-5
2.66
×
10
-5
benzene 78.11
1.51
×
10
-5
1.00
×
10
-5
Freon 12 [dichlorodifluoromethane]
120.91
6.25
×
10
-6
7.21
×
10
-6
hydrogen 2.02
2.41
×
10
-6
3.50
×
10
-6
propane 44.09
4.27
×
10
-7
4.94
×
10
-7
ethane 30.07
4.07
×
10
-7
7.60
×
10
-7
formaldehyde [methanal]
30.03
1.74
×
10
-8
2.67
×
10
-8
49
From Perry (1998).
31
4.1.2
Gas Storage
Gas storage is necessary for any life support system. Gas can be stored in pressure vessels, as a cryogenic
fluid, adsorbed, or chemically combined. The cost of storage depends on the gas, with the “permanent†gases, such
as nitrogen and oxygen, requiring higher pressure and remain in the gaseous state at normal temperatures, while the
“non-permanent†gases, such as carbon dioxide, can be stored as liquids under pressure. Cryogenic storage requires
either continuous thermal energy management or use of a small quantity of the gas to provide cooling by
evaporation. Adsorption and chemical combination are very gas-specific and vary in performance. See Table 4.1.4
for known gas storage tankage masses.
Table 4.1.4
Gas Storage
Performance [kg of tankage/kg of gas
]
Type of Storage
Nitrogen
Oxygen
References
Pressure Vessel
0.556 – 1.70
(1)
0.364
(2)
Cryogenic Storage
0.524
(2)
0.429
(2)
(1)
Lafuse (2001)
(2)
From Ham. Stand. (1970)
4.2
Biomass Subsystem
4.2.1
Plant Growth Chambers
4.2.1.1
Lighting Assumptions
Plants offer the greatest opportunity for self-sufficiency and, possibly, cost reduction for long-duration
missions, but at the same time have some of the greatest unknowns. An attempt has been made to estimate the mass
of a plant growth system on the surface of an extraterrestrial body such as Mars. Two uncertainties are the cost of
power, and the availability of water locally. The initial assumption, as shown in Table 4.2.1, is that natural lighting
cannot be used since Mars is farther from the Sun than the Earth. Significant quantities of dust are always present in
the Martian atmosphere and global dust storms occur during Martian spring that often last for as long as a month
during which the light levels are reduced significantly.
In addition, fresh food is crucial to crew welfare, and nutritionists generally recommend deriving food from
original sources such as grown plants and/or livestock. Because livestock production is more expensive even
terrestrially, early in-situ food production will likely concentrate on growing crops. Since shipped fresh foodstuffs
from crops are heavier than dehydrated or low-moisture foods due to the significant mass associated with natural
moisture, plants will probably be grown on an extraterrestrial body. The proportion of food that will be grown
locally versus what proportion will be shipped remains variable.
Table 4.2.1
Lighting Data
Parameter [Units]
Low
Nominal High References
Light Conversion Efficiency
[W
photosynthetically active radiation
/W
electrical
]
50
0.18
(1)
0.3
(2)
0.5
(1)
Light Delivery Efficiency [PPF
delivered
/PPF
emitted
]
51
0.3
(1)
0.37
(2)
0.7
(1)
Overall Lighting Efficiency
0.05
(1)
0.11
(2)
0.35
(1)
(1)
Sager (1999)
(2)
Ewert (1998)
A key parameter for plant growth is lighting, and electrical lighting might provide the necessary lighting.
The efficiency of electrical lighting depends on the efficiency of the conversion of electricity into radiant energy,
and the direction of this energy onto the plant canopy. The conversion efficiency depends on the type of lamp.
Accordingly, many factors impact photosynthetically active radiation (PAR). Photosynthetic photon flux (PPF) is
the light absorbed by the plants and used for photosynthesis, and is similar in extent to visible light, but has a
different graph of absorption versus wavelength, peaking in the red and blue rather than in the yellow. Incandescent
50
Light Conversion Efficiency describes the proportion of lighting system power that eventually becomes PPF.
51
Light Delivery Efficiency describes the proportion of PPF at the lamp surface that is delivered to the canopy.
32
lamps work well because they are red-rich, but the conversion efficiency is low. High-pressure discharge lamps
produce more light, but the spectrum is not as photosynthetically efficient. New lamp types, such as microwave
lamps, have good efficiency and spectrum (Sager, 1999). Direction of the energy to the canopy depends on the
geometry of the lamp, the distance from the lamp to the canopy, and the quality of the reflectors. The Biomass
Production Chamber (BPC) at Kennedy Space Center used relatively unsophisticated reflectors and achieved a
rating of approximately only 30%. Much higher ratings can be achieved, but it is difficult to maintain these high
ratings over long time periods.
4.2.1.2
Lighting Equipment Data
Additional assumptions can be made about specific lighting systems. Data for 400 W high-pressure sodium
lights (HPS) are shown below.
Table 4.2.2
High Pressure Sodium Lighting Data
Units
Low
Nominal
High
References
Lamp Power
(not including ballast)
kW --
0.4
(2)
--
Lamp Mass
kg
0.21
(2)
Lamp Life
10³ h
20
(1)
24
(1)
Number of 400 W Lamps per
Area to Give 1,000
µ
mol/(m²•s)
lamps/m²
1.43
(3)
4.504
(4)
9.259
(3)
Time to Change Out Lamps
CM-h
0.03
(5)
Photoperiod per Day
52
h/d 10
(1)
10-24
53
24
(1)
Lamp Volume for Resupply
m³
×
10
-
³
0.625
(1)
Ballast Power
kW/lamp
0.03
(1)
0.06
(2)
0.08
(1)
Ballast Mass
kg/lamp
2.85
(6)
4.76
(1)
9.52
(2)
Ballast Life
10³ h
88
(7)
Mass of Coldplate, Water
Barrier, Condensing Heat
Exchangers per Growing Area
kg/m²
4.43
(8)
54
7.02
(8)
55
25.83
(8)
56
Height of Lighting Assembly
m
0.15
(9)
0.3
(1)
Lamp Resupply Mass Factor
kg/kg
0.8
(10)
Lamp Resupply Volume Factor m³/m³
0.5
(1)
(1)
Drysdale (1999a)
(2)
Hanford (1997)
(3)
Hunter and Drysdale
(2002) based on
Sager (1999)
(4)
Hunter and Drysdale
(2002) based on
Ewert (1998)
(5)
A rough value from
Hunter, J.
(6)
Ewert (2001)
(7)
Barta and Ewert
(2002)
(8)
Ewert (1998)
(9)
BIO-Plex drawings
(10)
See Table 3.2.7. This
value corresponds
to storing lamps
within trays.
Resupply mass and volume factor account for the extra mass and volume required to package replacement
lamps. This is in addition to any mass and volume associated with the lamp itself.
52
This is generally crop dependent, although the values here provide the range for all ALS crops.
53
See Table 4.2.6 for nominal photoperiods of candidate ALS crops.
54
This system uses only a bulb in a water jacket. Transmissivity, relative to the baseline case using a coldplate and no barrier,
is 0.92. The ratio of total radiation to PAR is 1.6 compared to 2.0 for the baseline.
Note: This configuration provided the best overall performance in testing.
55
This system uses a bulb in a water jacket with a Teflon barrier. Transmissivity, relative to the baseline case using a
coldplate and no barrier, is 0.846. The estimated ratio of total radiation to PAR is 1.6 compared to 2.0 for the baseline.
56
This system uses a coldplate with a glass barrier. Transmissivity, relative to the baseline case using a coldplate and no
barrier, is 0.89. The ratio of total radiation to PAR is 1.7 compared to 2.0 for the baseline.
33
4.2.1.3
Plant Growth Chamber Cost Factors
The cost factors for a plant growth chamber have been estimated on a square-meter basis. This addresses
the plant growth chamber itself. If crew access is needed, and it generally will be, provision must be made for that
access. A reasonable number might be 25-50% of the plant canopy area. Lower numbers may be adequate if
extensive physical automation is planned. A higher number may be appropriate if most tasks are performed
manually. Crew access space would not, however, require the equipment and other costs shown here. Crew height
will be greater than the height of most plants that have been considered for ALS crops. Layout of the crops and crew
space will depend on issues such as the type of plant lighting. Therefore, if natural lighting is to be used, only a
single layer of crops might be possible due to the diffuseness of light on Mars. In this case, the limiting height would
be the taller of the crew and the plants. Table 4.2.3 (Drysdale, 1999b) presents preliminary values for an optimized
biomass production chamber based on projecting current NASA growth chambers to flight configurations.
Table 4.2.3
Plant Growth Chamber Equivalent System Mass per Growing Area
Component
Mass
[kg/m
2
]
Volume
[m
3
/m
2
]
Power
[kW/m
2
]
Thermal
Energy
Management
[kW/m
2
]
Crew-
time
[CM-h
/m
2
•
y]
Logistics
[kg
/m
2
•
y] Reference
Crops
20.0
– – –
13.0
Shoot Zone
3.6
0.67
0.3
57
0.3
59
– –
Root Zone and
Nutrients
36.8 0.11 0.14
0.14 TBD TBD
From Drysdale
(1999b)
Lamps 22.9
0.25
2.1
2.1
0.027
0.57
Ballasts 8.4
TBD
0.075
0.075
0.032
3.24
Mechanization
Systems
4.1 TBD TBD TBD TBD
TBD
Secondary
Structure
5.7
– – –
– –
Total 101.5
1.03
2.6
2.6
13.1
3.81
4.2.1.4
Biomass Production Chamber Specifications for an Integrated Test Facility
Barta, et al. (1999) presents preliminary physical values for the first biomass production chamber of the
now-suspended Bioregenerative Planetary Life Support Systems Test Complex (see Table 4.2.4).
58
Because many
conditions will vary as a function of test goals and each cultivar’s needs, nominal values are not generally
appropriate. Further, some values, as noted, are controlled for the chamber overall while others may be set for each
shelf of crops. Nominally, the total atmospheric pressure is maintained at 101±3 kPa. For the plants alone, the plant
chamber atmosphere must be at least 5.0 % oxygen. However, to support human respiration without personal
protective equipment, the chamber atmosphere must be 18.5 % oxygen. Interested readers should also consult
Wheeler, et al. (2003) for crop-specific guidance using NASA’s envisioned biomass production technologies.
57
Power consumption and thermal energy management within the shoot zone reflect fans for gas movement.
58
Editor’s Note:
At this time, the scope and purpose of the integrated test stand to support hardware development within the
ALS Project is under review. Because of prior programs such as the Bioregenerative Planetary Life Support Systems Test
Complex (BIO-Plex), very precise values are available for some earlier facilities. The configuration and specifications in
the actual ALS integrated testing facility, however, may differ from those listed here. The values here are likely
representative of a bioregenerative research facility.
34
Table 4.2.4
Physical Parameters for the First Biomass Production Chamber in BIO-Plex
Parameter Units
Low
High
Overall Chamber Values:
Reference
Oxygen Concentration
%
18.5
(5.0)
59
23.5
Partial Pressure of Carbon Dioxide
kPa
0.03
1.0
From Barta, et al. (1999).
Values Controlled per Shelf:
Air Temperature, Dark Cycle
°C
15
25
Air Temperature, Light Cycle
°C
16
35
Relative Humidity
%
65
85
Air Velocity
m/s
0.2
0.7
Photosynthetic Photon Flux
µmol/m²•s
0
1,500
Photoperiod h
0
24
Nutrient Solution pH
60
– 3.0
8.0
Nutrient Solution Conductivity
S/m
< 0
0.30
Nutrient Solution Flow Rate
/Growth Area
L/s•m² <
0 0.1
Nutrient Solution Depth
m
0.10
0.15
Shoot Zone Height
m
0.35
0.70
Root Zone Depth
m
0.10
0.15
The total growth area within the first BIO-Plex biomass production chamber is 79.6 m² (Castillo, 2000).
This growing area is arranged in ten shelves stacked in three columns. The center stack contains four shelves while
each side stack provides three shelves that conform to the chamber wall profile. Specific shelf dimensions are listed
in Table 4.2.5. Aisles between growing area shelves are 0.508 m wide.
59
Nominally, to allow human entry into the biomass production chamber, oxygen concentration will be maintained at or
above 18.5%. The lower listed limit will support plant respiration and thus applies if unprotected human beings will not
enter the biomass production chamber.
60
Potential of hydrogen (pH)
35
Table 4.2.5
Growing Area Dimensions for the First BIO-Plex Biomass Production Chamber
Shelf Location
61
Shelf Width [m]
Shoot Zone Height [m]
Growth Area [m²]
Left Shelving Stack:
Shelf 1 (top)
0.360
0.440
2.87
Shelf 2 (middle)
0.720
0.700
5.73
Shelf 3 (bottom)
0.360
0.400
2.87
Center Shelving Stack:
Shelf 1 (top)
1.500
0.500
14.17
Shelf 2
1.500
0.500
14.17
Shelf 3
1.500
0.500
14.17
Shelf 4 (bottom)
1.500
0.500
14.17
Right Shelving Stack:
Shelf 1 (top)
0.360
0.440
2.87
Shelf 2 (middle)
0.720
0.700
5.73
Shelf 3 (bottom)
0.360
0.400
2.87
Total
79.6
4.2.2
Plant Values
4.2.2.1
Static Values Describing Plant Growth
Plant growth rates depend on the type of plant (species and cultivar) and the growth conditions. Table 4.2.6
through Table 4.2.8 provide design values for candidate ALS Project crops (Behrend and Henninger, 1998).
Table 4.2.6 lists nominal environmental conditions for each crop. Table 4.2.7 presents overall life-cycle growth rates
in terms of grams of biomass per square meter per day. The dry mass (dw), fresh mass (fw)
62
, and water content for
both edible and inedible biomass are given. The harvest index is the ratio of edible biomass to total biomass.
Table 4.2.8 provides nominal and upper biomass generation rates. The lower rate is zero. The given upper limit is
the highest rate recorded in the literature. These may not be the absolute maximum, however. For example, wheat
may well produce higher growth rates with higher light intensities (Bugbee, 1998). These maximal rates are
generally for small chambers under ideal conditions, and they might be difficult to achieve in larger chambers that
have been optimized for spaceflight. The nominal rates are derived from testing within the ALS Biomass Production
Chamber at Kennedy Space Center (Wheeler, 2001b), and the values presented may be composite or average values
from several different tests. These rates are lower partly because of the lower light levels, but a less homogeneous
environment, due to the larger scale, may also impact the growth rates. Table 4.2.8 also presents the biomass
chemical composition in terms of carbon and the metabolic reactants and products averaged over the crop life cycle.
61
Locations are defined with respect to viewing the biomass production chamber from either end. Shelf numbers are defined
such that “1†is the top shelf, and shelves below in the same stack are numbered sequentially. From Castillo (2000). Barta,
et al. (1999) details earlier work for the BIO-Plex biomass production chamber configuration and quotes slightly longer
shelves for both the left and right shelving stacks. In both the earlier work and the current configuration, the center growing
areas are identical.
62
Historically, “dw†and “fw†denote “dry weight†and “fresh weight,†respectively. Scientifically, these quantities are
masses and not weights. Weight is a force derived from the gravitational attraction between a body and, practically, a much
larger body such as a planet. Accordingly, a body always has mass, but it has weight only within a planet’s gravitational
field.
36
Table 4.2.6
Advanced Life Support Cultivars, Intended Usage, and Environmental Growth Conditions
Temperatures [
°
C]
(3)
Crop
ALS
Transit
Crop
(1)
ALS
Surface
Crop
(1)
Photosynthetic
Photon Flux
[mol/(m²•d)]
Diurnal
Photo-
Period
[h/d]
(3)
Growth
Period
63
[d
AP
]
Air
during
Day
Air
during
Night
Nutrient
Solution
References
Cabbage
×
×
17
(2)
85
(4)
>25
Carrot
×
×
17
(2)
75
(4)
16-18
Chard
×
×
17
(2)
16
45
(3)
23 23 23
Celery
17
(2)
75
(4)
Dry Bean
×
24
(3)
18
85
(5)
28 24 26
Green Onion
17
(2)
50
(5)
Lettuce
×
×
17
(3)
16
28
(3)
23 23 23
Mushroom
0
0
Onion
×
×
17
50
Pea
24
(2)
75
(4)
Peanut
×
27
(3)
12
104
(3)
26 22 24
Pepper
27
(2)
85
(5)
Radish
×
×
17
(3)
16
25
(4)
23 23 23
Red Beet
17
(3)
16
38
(3)
23 23 23
Rice
×
33
(3)
12
85
(3)
28 24 24
Snap Bean
24
(2)
85
(5)
28 24 26
Soybean
×
28
(3)
12
97
(3)
26 22 24
Spinach
×
×
17
(3)
16
30
(4)
23 23 23
Strawberry
22
(3)
12
85
(4)
20 16 18
Sweet Potato
×
28
(3)
12
85
(5)
26 22 24
Tomato
×
×
27
(3)
12
85
(3)
24 24 24
Wheat
×
115
(4)
20-24 79
(3)
20 20 18
White Potato
×
28
(3)
12 132
20 16 18
Information from
Drysdale (2001)
except as noted.
(1)
Behrend and
Henninger (1998)
(2)
Estimated by
similarity to other
crops.
(3)
Wheeler, et al.
(2003)
(4)
Wheeler (2001b)
(5)
Ball, et al. (2001)
and EDIS (2001)
63
Growth period is measured here in terms of “days after planting,†[d
AP
].
37
Table 4.2.7
Overall Physical Properties at Maturity for Nominal Crops
Edible Biomass Productivity
Inedible Biomass Productivity
Crop
Mature
Plant
Height
[m]
Harvest
Index
[%]
Dry Basis
[g
dw
/m²
•
d]
Fresh
Basis
[g
fw
/m²
•
d]
Fresh
Basis
Water
Content
[%]
Dry Basis
[g
dw
/m²
•
d]
Fresh
Basis
[g
fw
/m²
•
d]
Fresh
Basis
Water
Content
[%] References
Cabbage 0.35
90
6.06
(2)
75.78 92
0.67 6.74 90
Carrot 0.25
60
8.98
(2)
74.83 88
5.99 59.87 90
Chard 0.45
(1)
65
(1)
7.00
(1)
87.50 92
3.77 37.69 90
Celery 0.25
90
10.33
(2)
103.27
90
1.15 11.47 90
Dry Bean
0.50
(1)
40
(1)
10.00
(3)
11.11 10
15.00 150.00 90
Green Onion
0.25
90
9.00
(3)
81.82 89
1.00 10.00 90
Lettuce 0.25
(1)
90
(1)
6.57
(1)
131.35
95
0.73 7.30 90
Mushroom 90
90
90
Onion 0.25
80
9.00 81.82 89
2.25 22.50 90
Pea 0.50
40
10.73
(2)
12.20 12
16.10 161.00 90
Peanut 0.65
(1)
25
(1)
5.63
(1)
5.96 5.6
16.88 168.75 90
Pepper 0.40
45
10.43
(3)
148.94
93
12.74 127.43 90
Radish 0.20
(1)
50
(1)
5.50
(3)
91.67 94
(3)
5.50 55.00 90
Red Beet
0.45
(1)
65
(1)
6.50 32.50 80
3.50 35.00 90
Rice 0.80
(1)
30
(1)
9.07
(1)
10.30 12
21.16 211.58 90
Snap Bean
0.50
40
11.88
(2)
148.50
92
(3)
17.82 178.20 90
Soybean 0.55
(1)
40
(1)
4.54
(1)
5.04 10
6.80 68.04 90
Spinach 0.25
(1)
90
(1)
6.57
(3)
72.97 91
0.73 7.30 90
Strawberry 0.25
(1)
35
(1)
7.79
(2)
77.88 90
14.46 144.46 90
Sweet Potato
0.65
(1)
40
(1)
15.00
(3)
51.72 71
22.50 225.00 90
Tomato 0.40
(1)
45
(1)
10.43
(1)
173.76
94
12.74 127.43 90
Wheat 0.50
(1)
40
(1)
20.00
(3)
22.73 12
30.00 300.00 90
White Potato
0.65
(1)
70
(1)
21.06
(1)
105.30
80
9.03 90.25 90
Information from
Drysdale (2001)
except as noted.
(1)
Wheeler, et al.
(2003)
(2)
Ball, et al. (2001)
and EDIS (2001)
(3)
Wheeler (2001b)
38
Table 4.2.8
Nominal and Highest Biomass Production, Composition, and Metabolic Products
Metabolic Reactants and Products
Total Biomass
(Edible + Inedible),
Dry Basis
[g
dw
/m²
•
d]
Crop
Nominal High
Carbon
Content
[%]
Oxygen (O
2
)
Production
[g/m²
•
d]
Carbon
Dioxide (CO
2
)
Uptake
[g/m²
•
d]
Water (H
2
O)
Uptake /
Transpiration
[kg/m²
•
d]
References
Cabbage 6.74
10.0
40
7.19 9.88 1.77
Carrot 14.97
16.7
41
16.36 22.50 1.77
Chard 10.77
40
11.49 15.79 1.77
Celery 11.47
40
12.24 16.83 1.24
Dry Bean
25.00
46
30.67 42.17 2.53
Green Onion
10.00
40
10.67 14.67 1.74
Lettuce 7.30
7.9
40
(1)
7.78 10.70 1.77
Mushroom
Onion 11.25
40
12.00 16.50 1.74
Pea 26.83
40
(3)
32.92 45.26 2.46
Peanut 22.50
36.0
60
(2)
35.84 49.28 2.77
Pepper 23.17
40
24.71 33.98 2.77
Radish 11.00
40
(2)
11.86 16.31 1.77
Red Beet
10.00
41
7.11 9.77 1.77
Rice 30.23
39.0
45
(2)
36.55 50.26 3.43
Snap Bean
29.70
46
36.43 50.09 2.46
Soybean 11.34
20.0
46
(1)
13.91 19.13 2.88
Spinach 7.30
40
7.78 10.70 1.77
Strawberry 22.25
43
(2)
25.32 34.82 2.22
Sweet Potato
37.50
51.3
41
(2)
41.12 56.54 2.88
Tomato 23.17
37.8
43
(2)
26.36 36.24 2.77
Wheat 50.00
150.0
42
(1)
56.00 77.00 11.79
White Potato
30.08
50.0
41
(1)
32.23 45.23 2.88
Information from
Drysdale (2001)
except as noted.
(1)
Wheeler, et al.
(1995)
(2)
Calculated
(3)
Orcun and Wheeler
(2003)
39
Table 4.2.9
Inedible Biomass Generation for Advanced Life Support Diets
Diet
Using
Only
ALS Salad Crops
Diet Using Salad and
Carbohydrate Crops
Diet
Using
All ALS Crops
Crop
ALS
Crop
Edible
Biomass
[g/m²•d]
Inedible
Biomass
[g/m²•d]
Diet
Growing
Area
[m²/CM]
Total
Inedible
Biomass
[kg/CM-d]
Diet
Growing
Area
[m²/CM]
Total
Inedible
Biomass
[kg/CM-d]
Diet
Growing
Area
[m²/CM]
Total
Inedible
Biomass
[kg/CM-d]
Cabbage
×
75.78 6.74
0.256 0.002
0.033 0.000
n/a n/a
Carrot
×
74.83 59.87
0.488 0.029
0.535 0.032
0.536 0.032
Chard
×
87.50
37.69
n/a n/a
n/a n/a
n/a n/a
Celery
103.27
11.47
n/a n/a
0.073
0.001
n/a n/a
Dry Bean
×
11.11
150.00
n/a n/a
1.170
0.176
1.926
0.289
Green
Onion
81.82 10.00
0.055 0.001
0.416 0.004
0.276 0.003
Lettuce
×
131.35 7.30
0.119 0.001
0.160 0.001
0.057 0.000
Mushroom
n/a n/a
TBD
0.0013
n/a n/a
Onion
×
81.82
22.50
n/a n/a
n/a n/a
n/a n/a
Pea
12.20
161.00
n/a n/a
0.311
0.050
n/a n/a
Peanut
×
5.96
168.75
n/a n/a
n/a n/a
4.832
0.815
Pepper
148.94
127.43
n/a n/a
0.208
0.027
n/a n/a
Radish
×
91.67 55.00
0.098 0.005
n/a n/a 0.164 0.008
Red
Beet
32.50
35.00
n/a n/a
n/a n/a
n/a n/a
Rice
×
10.30
211.58
n/a n/a
n/a n/a
2.078
0.440
Snap
Bean
148.50
178.20
n/a n/a
0.067
0.012
n/a n/a
Soybean
×
5.04
68.04
n/a n/a
n/a n/a
46.429
3.159
Spinach
×
72.97 7.30
0.066 0.000
0.548 0.004
0.635 0.005
Strawberry
77.88
144.46
n/a n/a
n/a n/a
n/a n/a
Sweet Potato
×
51.72
225.00
n/a n/a
3.480
0.783
1.485
0.334
Tomato
×
173.76 127.43
0.265 0.034
1.209 0.154
1.642 0.209
Wheat
×
22.73
300.00
n/a n/a
9.679
2.904
4.237
1.271
White Potato
×
105.30
90.25
n/a n/a
1.614
0.146
0.994
0.090
Total
1.35 0.07
19.50 4.29
65.29 6.66
40
Plant environmental demands differ compared to the crew’s requirements. For example, the optimum
p(CO
2
) for plant growth is roughly 0.120 kPa (Wheeler, et al., 1993). Sensitivity may vary from species to species,
but plants do appear to have reduced productivity at p(CO
2
) considered within the normal range for crew (up to
about 1.0 kPa). Similarly, plants require higher relative humidity – about 75% – to avoid water stress and minimize
nutrient solution usage. Such humidity levels are at the high end for crew comfort. Further, some key plants, such as
wheat and potatoes, are most productive at temperatures below the standard crew comfort zone. Finally, some
evidence indicates that plants might grow better under atmospheres with partial pressures of oxygen below the
values associated with nominal conditions on Earth. However, because human beings live with plants on Earth,
plants and crew can live in a common atmosphere.
Table 4.2.9 enumerates growing areas and inedible biomass production associated with the ALS Project
diets presented in Section 4.3.6. The edible biomass values are the nominal values listed above in Table 4.2.7. The
total inedible biomass production is based on the edible biomass production and the harvest index, and does not
include any waste associated with uneaten portions or the material removed during food preparation.
4.2.2.2
Static Values to Support Plant Growth
Table 4.2.10 presents some details about plant growth with current hydroponic technology, providing water
and nutrient use necessary to keep the plants healthy. Luxuriant nutrient levels were provided, so lower levels of
nutrients might also suffice. The nutrient solution shown was formulated to require only acid addition for pH
control. However, alternative formulations might require less active pH control (and thus fewer consumables to
maintain the pH). Finally, plant productivity varies from one cropping cycle to the next even under controlled
conditions, so the values here should be viewed as typical. Actual productivity from any real cropping cycle might
vary.
Table 4.2.10
Plant Growth and Support Requirements per Dry Biomass
Units
Soybean
Wheat
Potato
Lettuce
Reference
Water Usage per
Dry Biomass
L/g
dw
0.32 0.13 0.15 0.34
Stock Usage per
Dry Biomass
L/g
dw
0.026 0.021 0.022 0.034
Acid Usage per
Dry Biomass
64
g
acid
/g
dw
0.0548 0.0744 0.0428 0.0618
From Wheeler, et al.
(1999).
Table 4.2.11 and Table 4.2.12 describe the major ionic components of the nutrient solutions used for
studies within the ALS Biomass Production Chamber at Kennedy Space Center as determined from Wheeler, et al.
(1996) and Wheeler, et al. (1997). As indicated, the initial stock solution, which is at the desired concentration to
support plant growth, is more dilute than the mixture of two replenishment solutions that are added incrementally, as
necessary, to replace nutrient used by plants or otherwise lost. For this facility, replenishment solution is added in a
fixed concentration as a function of electrical conductivity regardless of which ions are depleted. Each salt primarily
contributes one important element, as noted. The elemental concentrations, then, are with respect to the listed
important element. Note that because pH is controlled by adding nitric acid (HNO
3
), the nitrogen content must also
be considered in calculating the nitrogen provided to the plants. In addition, minerals might be lost to the plants
through uptake by microorganisms and by precipitation from solution. Nitrogen may leave nutrient solution via
volatilization as nitrogen gas or as nitrogen oxides. Finally, to inhibit ionic build-up within the nutrient solution due
to the procedures outlined here, especially sodium or boron, the nutrient solution is often replaced at regular
intervals.
64
One mole of nitric acid (HNO
3
) contains 63.013 grams of solute.
41
Table 4.2.11
Composition of Initial Nutrient Solution
Content
Initial Ionic
Component
Important
Element
Elemental
Atomic
Weight
Concentration
[meq/L]
65
Ion
Molecular
Weight
Valence
g/L
(element)
g/L
(ion)
Reference
Nitrate, NO
3
–
Nitrogen,
N
14.01
7.5
62.00
–1
0.1051 0.465
Phosphate, PO
4
3–
Phosphorous, P
30.97
0.5
94.97
–3
0.0465 0.142
Potassium, K
+
Potassium, K
39.10
3
39.10
+1
0.1173 0.117
Calcium, Ca
2+
Calcium,
Ca
40.08
2.5
40.08
+2
0.2004 0.200
Magnesium, Mg
2+
Magnesium, Mg
24.31
1
24.31
+2
0.0486 0.049
Sulfate, SO
4
2–
Sulfur,
S
32.06
1
96.06
–2
0.0641 0.192
Total
1.166
Wheeler, et al. (1996)
Table 4.2.12
Composition of Replenishment Nutrient Solution
Content
Replenishment Ionic
Component
Important
Element
Elemental
Atomic
Weight
Concentration
[meq/L]
67
Ion
Molecular
Weight
Valence
g/L
(element)
g/L
(ion)
Reference
Nitrate, NO
3
–
Nitrogen,
N
14.01
75
62.00
–1
1.051
4.650
Phosphate, PO
4
3–
Phosphorous, P
30.97
7.5
94.97
–3
0.697
2.137
Potassium, K
+
Potassium, K
39.10
68
39.10
+1
2.659
2.659
Calcium, Ca
2+
Calcium,
Ca
40.08
7.5
40.08
+2
0.601
0.601
Magnesium, Mg
2+
Magnesium, Mg
24.31
9.8
24.31
+2
0.476
0.476
Sulfate, SO
4
2–
Sulfur,
S
32.06
9.8
96.06
–2
0.628
1.883
Total
12.406
Wheeler, et al. (1997)
65
Here the units, [meq/L], denote milli-equivalent weights of the ionic component per liter of solution. An equivalent weight is the ion’s molecular weight divided by the
absolute value of the ion’s valence.
42
4.2.3
Modified Energy Cascade Models for Crop Growth
Cavazzoni (2001) presents a package of models appropriate for use in system-level modeling. These Modified
Energy Cascade (MEC) models build upon the earlier work of Volk, et al. (1995) and benefit from studies by Monje
(1998), Monje and Bugbee (1998), and Jones and Cavazzoni (2000)
66
.
The MEC models calculate biomass production, on a dry-mass basis, as a function of photosynthetic photo flux,
PPF, and the atmospheric carbon dioxide concentration, [CO
2
].
67
The atmospheric temperatures, one for light periods
and a second for dark periods, and the photoperiod are constant and the plant growth is not limited by water or nutrients.
These models accommodate daily variations in PPF and [CO
2
], but weighted values of PPF and [CO
2
] should be used to
estimate time for canopy closure, t
A
. The models generally apply over a range of PPF from 200 to 1,000 µmol/m²
•
s
68
and a range of [CO
2
] from 330 to 1,300 µmol/mol. For rice and wheat, these models apply up to 2,000 µmol/m²
•
s. The
PPF range for lettuce is limited to 200 to 500 µmol/m²
•
s, because a light integral of only 17 mol/m²
•
d is recommended
to prevent leaf tip burn. See, for example, Hopper, et al. (1997), for recommended PPF requirements for crop growth.
4.2.3.1
Modified Energy Cascade Models for Crop Biomass Production
The following material outlines the top-level MEC models developed by Cavazzoni (2001) in detail. The
various parameters depend upon the crop cultivar and growing conditions. Parameters for nominal conditions of lighting,
temperature, and atmospheric composition are presented in Section 4.2.3.3.
The fraction of PPF absorbed by the plant canopy, A, is a function of time, t, in terms of days after emergence
[d
AE
], and the time for canopy closure, t
A
[d
AE
] by the following relationship:
A = A
MAX
n
A
t
t
⎟⎟
âŽ
⎞
⎜⎜
âŽ
⎛
for t < t
A
A = A
MAX
for t > t
A
Equation
4.2-1
where A
MAX
is 0.93 and n is enumerated for various crops in Table 4.2.13 below. t
A
is computed as a function of PPF and
[CO
2
] for each crop. This function is presented below with appropriate coefficients.
Table 4.2.13
Values for the Exponent n in MEC Models
Crop n
Wheat 1.0
Rice, Soybean, Sweet Potato
1.5
Dry Bean, Peanut, White Potato
2.0
Lettuce, Tomato
2.5
66
Jones and Cavazzoni present the Top-Level Energy Cascade models. Though the Modified Energy Cascade equations and the
Top-Level Energy Cascade equations share some ideas, the Top-Level Energy Cascade equations provide models for quantities
that are input parameters for the Modified Energy Cascade equations. Further, the Modified Energy Cascade equations include
models to compute biomass oxygen generation.
67
Other environmental and physiological factors may also vary. See Cavazzoni (2001) for complete details on this model.
68
Photosynthetic
photon flux (PPF) is commonly expressed in units of either µmol/(m²
•
s), as listed here, or mol/(m²
•
d), as
denoted in Table 4.2.6. The units for PPF are related by the expression:
PPF [µmol/(m²
•
s)] = PPF [mol/(m²
•
d)]
×
1/H
×
(1 h/3600 s)
×
(10
6
µmol/1 mol)
where H is photoperiod [h/d]. See Table 4.2.27 for nominal values of H, which are designated H
O
. Because units for PPF depend
upon the duration during which crops receive photosynthetic irradiation, the conversion to a “per day†basis depends on the
diurnal photoperiod per day.
43
The canopy quantum yield, CQY, [µmol
Carbon Fixed
/µmol
Absorbed PPF
] is defined by:
CQY = CQY
MAX
for t < t
Q
CQY = CQY
MAX
– (CQY
MAX
– CQY
MIN
)
(
)
(
)
Q
M
Q
t
t
t
t
−
−
for
t
Q
< t < t
M
Equation 4.2-2
where t
M
is time at crop harvest or maturity [d
AE
], and t
Q
is the time at onset of canopy senescence [d
AE
]. t
M
and t
Q
are
model constants. CQY
MAX
is a crop-specific function of PPF and [CO
2
], as noted below, while CQY
MIN
is a crop-specific
constant.
The 24-hour carbon use efficiency, CUE
24
, a fraction, is constant for most crops. In such cases, a single value is
listed under CUE
MAX
in the tables below. For legumes, CUE
24
is described by:
CUE
24
= CUE
MAX
for t < t
Q
CUE
24
= CUE
MAX
– (CUE
MAX
– CUE
MIN
)
(
)
(
)
Q
M
Q
t
t
t
t
−
−
for
t
Q
< t < t
M
Equation 4.2-3
where CUE
MAX
and CUE
MIN
are model inputs unique to each crop.
The daily carbon gain, DCG, [mol
Carbon
/m²
•
d] is computed from:
DCG = 0.0036
mol
mol
h
s
µ
×
H
×
CUE
24
×
A
×
CQY
×
PPF
Equation 4.2-4
where H is the photoperiod [h/d], a crop-specific model input. Photoperiod may vary daily, but see Cavazzoni (2001) for
the assumptions involved.
The daily oxygen production, DOP, [
2
O
mol
/m²
•
d] may be computed using:
DOP = OPF
×
DCG
Equation 4.2-5
where OPF is the oxygen production fraction [
2
O
mol
/mol
Carbon
], which is a crop specific parameter.
The crop growth rate, CGR [g/m²
•
d], is related to DCG by:
CGR = MW
C
BCF
DCG
Equation 4.2-6
where MW
C
is the molecular weight of carbon, 12.011 g/mol, and BCF is the biomass carbon fraction, another crop-
specific constant.
The total crop biomass, on a dry basis, TCB [g/m²], is determined by integrating CGR, from t = 0 to the time of
interest, such as harvest, t
M
. Or:
TCB =
∫
M
t
0
dt
CGR
Equation 4.2-7
Total edible biomass, on a dry basis, TEB [g/m²], may be estimated by integrating the product of CGR and the
fraction of daily carbon gain allocated to edible biomass, XFRT, from time storage organs begin to form, t
E
[d
AE
]. Both
XFRT and t
E
are tabulated below:
TEB =
∫
M
E
t
t
dt
CGR
XFRT
Equation 4.2-8
Inedible biomass is the difference between TCB and TEB.
44
Table 4.2.14
Summary of Modified Energy Cascade Model Variables for Biomass Production
Variable Units
Description
Reference/Value
A
--
fraction of PPF absorbed by the plant canopy
Equation 4.2-1
A
MAX
--
maximum value for A
0.93
BCF
--
biomass carbon fraction
Table 4.2.29
CGR
g/m²
•
d
crop growth rate
Equation 4.2-6
C
i
varies
coefficients in functions describing t
A
and
CQY
MAX
Table 4.2.16
[CO
2
]
Air
CO
mol
mol
2
µ
atmospheric concentration of carbon dioxide;
model variable
none
CQY
PPF
.
Ab
Fixed
.
C
mol
mol
µ
µ
canopy quantum yield
Equation 4.2-2
CQY
MAX
PPF
.
Ab
Fixed
.
C
mol
mol
µ
µ
maximum value for CQY that applies until t
Q
Equation
4.2-9
CQY
MIN
PPF
.
Ab
Fixed
.
C
mol
mol
µ
µ
minimum value for CQY at t
M
Table
4.2.15
CUE
24
--
24-hour carbon use efficiency; a fraction
Equation 4.2-3
CUE
MAX
--
maximum value for CUE
24
that applies until t
Q
Table
4.2.15
CUE
MIN
--
minimum value for CUE
24
at t
M
Table
4.2.15
DCG
mol
Carbon
/m²
•
d
daily carbon gain
Equation 4.2-4
DOP
2
O
mol
/m²
•
d
daily oxygen production
Equation 4.2-5
H h/d
Photoperiod
Table
4.2.27
MW
C
g/mol
molecular weight of carbon
12.011
n --
an
exponent
Table
4.2.13
OPF
Carbon
O
mol
mol
2
oxygen production fraction
Table 4.2.29
PPF
s
m
mol
2
Photon
•
µ
photosynthetic photon flux; model variable
none
TCB
g/m²
total crop biomass, on a dry basis
Equation 4.2-7
TEB
g/m²
total edible biomass, on a dry basis
Equation 4.2-8
t d
AE
time;
model
variable
none
t
A
d
AE
time until canopy closure
Equation
4.2-17
t
E
d
AE
time at onset of organ formation
Table 4.2.28
t
M
d
AE
time at harvest or crop maturity
Table 4.2.28
t
Q
d
AE
time until onset of canopy senescence
Table 4.2.28
XFRT --
fraction of daily carbon gain allocated to edible
biomass after t
E
Table 4.2.28
45
The environmentally dependent parameters for these models are provided in the sections below. The MEC
variables for biomass production models are summarized in Table 4.2.14. General model constants, which depend only
on the crop cultivar and not on environmental conditions, are listed in Table 4.2.15.
Table 4.2.15
Biomass Production Model Constants
69
Crop Specific
Cultivar
CQY
MIN
[µmol
C Fixed
/µmol
Ab. PPF
]
CUE
MAX
CUE
MIN
Dry Bean
Meso Amer. Hab. 1 – Determinate
0.02 0.65 0.50
70
Lettuce
Waldmann’s Green
n/a 0.625
n/a
Peanut
Pronto
0.02 0.65 0.30
Rice
Early maturing types
0.01 0.64
n/a
Soybean
Hoyt
0.02 0.65 0.30
Sweet Potato
TU-82-155 (Tuskegee University)
n/a 0.625
n/a
Tomato
Reinmann Philippe 75/59
0.01 0.65
n/a
Wheat
Veery 10
0.01 0.64
n/a
White Potato
Norland or Denali
0.02 0.625
n/a
Based on multivariable polynomial regression (MPR), the functions for maximum canopy quantum yield,
CQY
MAX
[µmol
Carbon Fixed
/µmol
Absorbed PPF
], have the general form:
CQY
MAX
( PPF, [CO
2
] ) = C
1
PPF
1
]
CO
[
1
2
+ C
2
PPF
1
+ C
3
PPF
]
CO
[
2
+ C
4
PPF
]
CO
[
2
2
+
C
5
PPF
]
CO
[
3
2
+ C
6
]
CO
[
1
2
+ Constant + C
8
[CO
2
] + C
9
[CO
2
]
2
+ C
10
[CO
2
]
3
+
C
11
]
CO
[
PPF
2
+ C
12
PPF + C
13
PPF [CO
2
] + C
14
PPF [CO
2
]
2
+ C
15
PPF [CO
2
]
3
+
C
16
]
CO
[
PPF
2
2
+ C
17
PPF
2
+ C
18
PPF
2
[CO
2
] + C
19
PPF
2
[CO
2
]
2
+ C
20
PPF
2
[CO
2
]
3
+
C
21
]
CO
[
PPF
2
3
+ C
22
PPF
3
+ C
23
PPF
3
[CO
2
] + C
24
PPF
3
[CO
2
]
2
+ C
25
PPF
3
[CO
2
]
3
Equation 4.2-9
where C
1
through C
25
again denote coefficients. PPF is designated in [µmol/m²
•
s], while [CO
2
] is measured in
⎥
⎦
⎤
⎢
⎣
⎡µ
Air
CO
mol
mol
2
. To simplify the presentation of these functions, Table 4.2.17 through Table 4.2.25 present the coefficient
values for each crop in a matrix of the form presented in Table 4.2.16.
69
The parameters in this table apply independent of temperature regime, photoperiod, or planting density.
70
This suggested value is based on Wheeler (2001a) whereby growth costs are less for dry bean than for soybean and peanut.
46
Table 4.2.16
Format for Tables of Coefficients for Equations Employing MPR Fits
1/PPF 1 PPF PPF
2
PPF
3
1/[CO
2
]
1/PPF
×
1/[CO
2
]
or C
1
1/[CO
2
]
or C
6
PPF/[CO
2
]
or C
11
PPF
2
/[CO
2
]
or C
16
PPF
3
/[CO
2
]
or C
21
1
1/PPF
or C
2
Constant Term
PPF
or C
12
PPF
2
or C
17
PPF
3
or C
22
[CO
2
]
[CO
2
]/PPF
or C
3
[CO
2
]
or C
8
PPF [CO
2
]
or C
13
PPF
2
[CO
2
]
or C
18
PPF
3
[CO
2
]
or C
23
[CO
2
]
2
[CO
2
]
2
/PPF
or C
4
[CO
2
]
2
or C
9
PPF [CO
2
]
2
or C
14
PPF
2
[CO
2
]
2
or C
19
PPF
3
[CO
2
]
2
or C
24
[CO
2
]
3
[CO
2
]
3
/PPF
or C
5
[CO
2
]
3
or C
10
PPF [CO
2
]
3
or C
15
PPF
2
[CO
2
]
3
or C
20
PPF
3
[CO
2
]
3
or C
25
The coefficients for CQY
MAX
are independent of photoperiod and planting density and are only a weak function
of temperature regime. Consequently, for life-support crop-growth scenarios, the CQY
MAX
coefficients are essentially
functions of the crop cultivar alone. See Cavazzoni (2001) for applicability under extreme temperature ranges.
Table 4.2.17
Maximum Canopy Quantum Yield, CQY
MAX
, Coefficients for Dry Bean
1/PPF 1 PPF PPF
2
PPF
3
1/[CO
2
]
0 0 0 0 0
1
0
4.191
×
10
-2
-1.238
×
10
-5
0 0
[CO
2
]
0
5.3852
×
10
-5
0
-1.544
×
10
-11
0
[CO
2
]
2
0
-2.1275
×
10
-8
0
6.469
×
10
-15
0
[CO
2
]
3
0 0 0 0 0
Table 4.2.18
Maximum Canopy Quantum Yield, CQY
MAX
, Coefficients for Lettuce
1/PPF 1 PPF PPF
2
PPF
3
1/[CO
2
]
0 0 0 0 0
1
0
4.4763
×
10
-2
-1.1701
×
10
-5
0 0
[CO
2
]
0
5.163
×
10
-5
0
-1.9731
×
10
-11
0
[CO
2
]
2
0
-2.075
×
10
-8
0
8.9265
×
10
-15
0
[CO
2
]
3
0 0 0 0 0
Table 4.2.19
Maximum Canopy Quantum Yield, CQY
MAX
, Coefficients for Peanut
1/PPF 1 PPF PPF
2
PPF
3
1/[CO
2
]
0 0 0 0 0
1
0
4.1513
×
10
-2
0
-2.1582
×
10
-8
0
[CO
2
]
0
5.1157
×
10
-5
4.0864
×
10
-8
-1.0468
×
10
-10
4.8541
×
10
-14
[CO
2
]
2
0
-2.0992
×
10
-8
0 0 0
[CO
2
]
3
0 0 0 0
3.9259
×
10
-21
47
Table 4.2.20
Maximum Canopy Quantum Yield, CQY
MAX
, Coefficients for Rice
1/PPF 1 PPF PPF
2
PPF
3
1/[CO
2
]
0 0 0 0 0
1
0
3.6186
×
10
-2
0
-2.6712
×
10
-9
0
[CO
2
]
0
6.1457
×
10
-5
-9.1477
×
10
-9
0 0
[CO
2
]
2
0
-2.4322
×
10
-8
3.889
×
10
-12
0 0
[CO
2
]
3
0 0 0 0 0
Table 4.2.21
Maximum Canopy Quantum Yield, CQY
MAX
, Coefficients for Soybean
1/PPF 1 PPF PPF
2
PPF
3
1/[CO
2
]
0 0 0 0 0
1
0
4.1513
×
10
-2
0
-2.1582
×
10
-8
0
[CO
2
]
0
5.1157
×
10
-5
4.0864
×
10
-8
-1.0468
×
10
-10
4.8541
×
10
-14
[CO
2
]
2
0
-2.0992
×
10
-8
0 0 0
[CO
2
]
3
0 0 0 0
3.9259
×
10
-21
Note: The function for soybean here is identical to the function for peanut.
Table 4.2.22
Maximum Canopy Quantum Yield, CQY
MAX
, Coefficients for Sweet Potato
1/PPF 1 PPF PPF
2
PPF
3
1/[CO
2
]
0 0 0 0 0
1
0
3.9317
×
10
-2
-1.3836
×
10
-5
0 0
[CO
2
]
0
5.6741
×
10
-5
-6.3397
×
10
-9
-1.3464
×
10
-11
0
[CO
2
]
2
0
-2.1797
×
10
-8
0
7.7362
×
10
-15
0
[CO
2
]
3
0 0 0 0 0
Table 4.2.23
Maximum Canopy Quantum Yield, CQY
MAX
, Coefficients for Tomato
1/PPF 1 PPF PPF
2
PPF
3
1/[CO
2
]
0 0 0 0 0
1
0
4.0061
×
10
-2
0
-7.1241
×
10
-9
0
[CO
2
]
0
5.688
×
10
-5
-1.182
×
10
-8
0 0
[CO
2
]
2
0
-2.2598
×
10
-8
5.0264
×
10
-12
0 0
[CO
2
]
3
0 0 0 0 0
Table 4.2.24
Maximum Canopy Quantum Yield, CQY
MAX
, Coefficients for Wheat
1/PPF 1 PPF PPF
2
PPF
3
1/[CO
2
]
0 0 0 0 0
1
0
4.4793
×
10
-2
-5.1946
×
10
-6
0 0
[CO
2
]
0
5.1583
×
10
-5
0
-4.9303
×
10
-12
0
[CO
2
]
2
0
-2.0724
×
10
-8
0
2.2255
×
10
-15
0
[CO
2
]
3
0 0 0 0 0
48
Table 4.2.25
Maximum Canopy Quantum Yield, CQY
MAX
, Coefficients for White Potato
1/PPF 1 PPF PPF
2
PPF
3
1/[CO
2
]
0 0 0 0 0
1
0
4.6929
×
10
-2
0 0
-1.9602
×
10
-11
[CO
2
]
0
5.0910
×
10
-5
0
-1.5272
×
10
-11
0
[CO
2
]
2
0
-2.1878
×
10
-8
0 0 0
[CO
2
]
3
0 0
4.3976
×
10
-15
0 0
4.2.3.2
Modified Energy Cascade Models for Crop Transpiration
Following the approach in Section 4.2.3.1 for biomass production, this section focuses on a similar model to
predict crop canopy transpiration. In fact, the crop transpiration model employs many of the parameters computed by the
algorithm above. The model in this section was adapted from Monje (1998).
The vapor pressure deficit, VPD [kPa], is the difference between the saturated vapor pressure for air at the mean
atmospheric temperature, VP
SAT
[kPa], and the actual vapor pressure for the atmosphere, VP
AIR
[kPa]. Or:
VP
SAT
= 0.611
⎥
⎦
⎤
⎢
⎣
⎡
+
239
T
T
4
.
17
LIGHT
LIGHT
e
VP
AIR
= VP
SAT
×
RH
VPD = VP
SAT
- VP
AIR
Equation 4.2-10
where T
LIGHT
[
°
C] is the mean atmospheric temperature during the crop’s light cycle and RH is the mean atmospheric
relative humidity as a fraction bounded between 0 and 1, inclusive. Calculation of VP
SAT
assumes that the temperature of
the canopy leaves, from which transpiration originates, is equal to the mean light-cycle air temperature, T
LIGHT
.
The gross canopy photosynthesis, P
GROSS
[µmol
Carbon
/m²
•
s], may be expressed in terms of previously defined
values as:
P
GROSS
= A
×
CQY
×
PPF
Equation 4.2-11
The net canopy photosynthesis, P
NET
[µmol
Carbon
/m²
•
s], may be expressed as:
P
NET
=
⎥
⎦
⎤
⎢
⎣
⎡
×
+
−
PG
24
PG
PG
D
CUE
H
D
H
D
P
GROSS
Equation 4.2-12
where D
PG
[h/d] is the length of the plant growth chamber’s diurnal cycle. During development of these models,
Cavazzoni (2001) assumed a value of 24.0 h/d for D
PG
, which is consistent with ground-based data gathered to date.
The canopy surface conductance, g
C
[mol
Water
/m²
•
s], is based on the canopy stomatal conductance, g
S
[mol
Water
/m²
•
s], and the atmospheric aerodynamic conductance, g
A
[mol
Water
/m²
•
s].
g
C
=
S
A
S
A
g
g
g
g
+
×
Equation 4.2-13
49
The following models for g
S
and values for g
A
were derived from the experimental conditions studied by Monje
(1998).
Table 4.2.26
Summary of Modified Energy Cascade Model Variables for Canopy Transpiration
Variable Units
Description
Reference/Value
A
--
fraction of PPF absorbed by the plant canopy
Equation 4.2-1
[CO
2
]
Air
CO
mol
mol
2
µ
atmospheric concentration of carbon dioxide;
model variable
none
CQY
Photon
Carbon
mol
mol
µ
µ
canopy quantum yield
Equation 4.2-2
CUE
24
--
24-hour carbon use efficiency; a fraction
Equation 4.2-3
D
PG
h/d
plant growth diurnal cycle
24
71
DTR
L
Water
/m²
•
d
daily canopy transpiration rate
Equation 4.2-16
g
A
mol
Water
/m²
•
s
atmospheric aerodynamic conductance
Equation 4.2-14
and
Equation 4.2-15
g
C
mol
Water
/m²
•
s
canopy surface conductance
Equation 4.2-13
g
S
mol
Water
/m²
•
s
canopy stomatal conductance
Equation 4.2-14
and
Equation 4.2-15
H h/d
photoperiod;
model
variable
none
72
H
O
h/d
nominal
photoperiod
Table
4.2.27
MW
W
g/mol
molecular weight of water
18.015
P
ATM
kPa
total atmospheric pressure; model variable
none
P
GROSS
s
m
mol
2
Carbon
•
µ
gross canopy photosynthesis
Equation 4.2-11
P
NET
s
m
mol
2
Carbon
•
µ
net canopy photosynthesis
Equation 4.2-12
PPF
s
m
mol
2
Photon
•
µ
photosynthetic photon flux; model variable
none
PPF
E
s
m
mol
2
Photon
•
µ
effective photosynthetic photon flux
Equation 4.2-18
RH
--
atmospheric relative humidity; model variable
none
T
LIGHT
°
C
atmospheric temperature during crop’s light cycle
Table 4.2.27
VP
AIR
kPa
actual moisture vapor pressure
Equation 4.2-10
VP
SAT
kPa
saturated moisture vapor pressure
Equation 4.2-10
VPD
kPa
vapor pressure deficit
Equation 4.2-10
Ï
W
g/L density
of
water
998.23
71
This value applies to data used to date from terrestrial test facilities. More generally, it’s the length of a local sol.
72
For the nominal case, assume the photoperiod, H, equals the nominal photoperiod, H
O
, which is listed in Table 4.2.27.
50
With planophile-type canopies, such as for dry bean, lettuce, peanut, soybean, sweet potato, tomato, and white
potato, g
S
and g
A
are computed as:
g
S
=
(
)
[
]
⎟⎟
âŽ
⎞
⎜⎜
âŽ
⎛
−
−
2
NET
LIGHT
CO
P
VPD
54
.
10
96
.
19
T
717
.
1
g
A
= 2.5
Equation 4.2-14
With erectophile canopies, such as for rice and wheat, g
S
and g
A
have the form:
g
S
=
[
]
⎟⎟
âŽ
⎞
⎜⎜
âŽ
⎛
+
2
NET
CO
P
RH
32
.
15
1389
.
0
g
A
= 5.5
Equation 4.2-15
The daily canopy transpiration rate, DTR [L
Water
/m²
•
d], is:
DTR = 3600
h
s
H
⎟⎟
âŽ
⎞
⎜⎜
âŽ
⎛
Ï
W
W
MW
g
C
⎟⎟
âŽ
⎞
⎜⎜
âŽ
⎛
ATM
P
VPD
Equation 4.2-16
where P
ATM
[kPa] is the total atmospheric pressure, MW
W
is the molecular weight of water, 18.015 g/mol, and
Ï
W
is the
density of water, 998.23 g/L at 20
°
C.
The parameters for the transpiration model are provided in the sections below and the variables are summarized
in Table 4.2.26
4.2.3.3
Modified Energy Cascade Model Constants for Nominal Temperature Regimes and Photoperiods
For nominal temperature regimes and photoperiods, MEC model constants are provided here for the parameters
in Section 4.2.3.1 and Section 4.2.3.2.
Note: Some values in Table 4.2.27 differ from the corresponding values listed in Table 4.2.6.
Table 4.2.27
Nominal Temperature Regimes, Planting Densities, and Photoperiods
for the Plant Growth and Transpiration Models
Crop
Nominal
Photoperiod
H
O
[h/d]
Planting
Density
73
[plants/m²]
Light Cycle
Temperature,
T
LIGHT
[
°
C]
Dark Cycle
Temperature,
T
DARK
74
[
°
C]
Dry
Bean 12 7 26 22
Lettuce 16
19.2
23
23
Peanut 12 7 26 22
Rice
12 200 29 21
Soybean 12 35 26 22
Sweet
Potato
18 16 28 22
Tomato 12 6.3
26 22
Wheat 20 720 23 23
White Potato
12
6.4
20
16
73
Planting density affects the time to canopy closure, t
A
, even though an explicit functionality is not apparent.
74
The MEC models do not explicitly use the dark cycle temperature, but because the dark cycle temperature affects a crop’s
development, these values are assumed implicitly for this set of parameters.
51
Table 4.2.28
Biomass Production Model Time Constants for Nominal Temperature Regime and Photoperiod
Crop
Fraction of
Edible Biomass
After t
E
XFRT
Time at Onset of
Edible Biomass
Formation, t
E
[d
AE
]
Time at Onset
of Canopy
Senescence, t
Q
[d
AE
]
Time at
Harvest,
t
M
[d
AE
]
Dry Bean
0.97
40
42
63
Lettuce 0.95
1
n/a
75
30
Peanut 0.49 49
65 110
Rice 0.98 57 61 88
Soybean 0.95
46
48
86
Sweet Potato
1.00
33
n/a
77
120
Tomato 0.70 41
56 80
Wheat 1.00 34 33 62
White Potato
1.00
45
75
138
76
Table 4.2.29
Biomass Carbon and Oxygen Production Fractions for Nominal Temperature Regime
and Photoperiod
Crop
Biomass Carbon
Fraction,
BCF
Oxygen Production
Fraction
[mol O
2
/mol C]
Crop
Biomass Carbon
Fraction,
BCF
Oxygen Production
Fraction
[mol O
2
/mol C]
Dry Bean
0.45
1.10
Sweet Potato
0.44
1.02
Lettuce 0.40
1.08
Tomato 0.42
1.09
Peanut 0.50
1.19
Wheat 0.44
1.07
Rice 0.44
1.08
White
Potato
0.41
1.02
Soybean 0.46
1.16
The functions for the canopy closure time, t
A
[d
AE
], have the general form:
t
A
( PPF
E
, [CO
2
] ) = C
1
E
PPF
1
]
CO
[
1
2
+ C
2
E
PPF
1
+ C
3
E
2
PPF
]
CO
[
+ C
4
E
2
2
PPF
]
CO
[
+ C
5
E
3
2
PPF
]
CO
[
+ C
6
]
CO
[
1
2
+ Constant + C
8
[CO
2
] + C
9
[CO
2
]
2
+ C
10
[CO
2
]
3
+ C
11
]
CO
[
PPF
2
E
+ C
12
PPF
E
+ C
13
PPF
E
[CO
2
] + C
14
PPF
E
[CO
2
]
2
+ C
15
PPF
E
[CO
2
]
3
+ C
16
]
CO
[
PPF
2
2
E
+ C
17
PPF
E
2
+ C
18
PPF
E
2
[CO
2
] + C
19
PPF
E
2
[CO
2
]
2
+ C
20
PPF
E
2
[CO
2
]
3
+ C
21
]
CO
[
PPF
2
3
E
+ C
22
PPF
E
3
+ C
23
PPF
E
3
[CO
2
] + C
24
PPF
E
3
[CO
2
]
2
+ C
25
PPF
E
3
[CO
2
]
3
Equation 4.2-17
where C
1
through C
25
denote coefficients. PPF
E
is expressed in [µmol/m²
•
s], while [CO
2
] is measured in
⎥
⎦
⎤
⎢
⎣
⎡µ
Air
CO
mol
mol
2
.
To simplify the presentation of these functions, Table 4.2.30 through Table 4.2.38 present the coefficient values for each
crop in a matrix using the form of Table 4.2.16 above.
75
This crop is harvested before the canopy reaches senescence.
76
White potato plants are harvested at t = 105 d
AE
, but t
M
= 138 d
AE
is used for the models.
52
The effective photosynthetic photon flux, PPF
E
[µmol/m²
•
s], (Rodriguez and Bell, 2004) is:
PPF
E
= PPF
⎟⎟
âŽ
⎞
⎜⎜
âŽ
⎛
O
H
H
Equation 4.2-18
where values for nominal photoperiod, H
O
[h/d], are tabulated in Table 4.2.27.
Table 4.2.30
Canopy Closure Time, t
A
, Coefficients for Dry Bean with Nominal Conditions
1/PPF
E
1 PPF
E
PPF
E
2
PPF
E
3
1/[CO
2
]
2.9041
×
10
5
0 0 0 0
1
1.5594
×
10
3
15.840
6.1120
×
10
–3
0 0
[CO
2
]
0 0 0
- 3.7409
×
10
-9
0
[CO
2
]
2
0 0 0 0 0
[CO
2
]
3
0 0 0 0
9.6484
×
10
–19
Table 4.2.31
Canopy Closure Time, t
A
, Coefficients for Lettuce with Nominal Conditions
1/PPF
E
1 PPF
E
PPF
E
2
PPF
E
3
1/[CO
2
]
0 0
1.8760
0 0
1
1.0289
×
10
4
1.7571
0 0 0
[CO
2
]
-
3.7018
0 0 0 0
[CO
2
]
2
0
2.3127
×
10
-6
0 0 0
[CO
2
]
3
3.6648
×
10
-7
0 0 0 0
Table 4.2.32
Canopy Closure Time, t
A
, Coefficients for Peanut with Nominal Conditions
1/PPF
E
1 PPF
E
PPF
E
2
PPF
E
3
1/[CO
2
]
3.7487
×
10
6
-
1.8840
×
10
4
51.256 -
0.05963
2.5969
×
10
-5
1
2.9200
×
10
3
23.912 0
5.5180
×
10
–6
0
[CO
2
]
0 0 0 0 0
[CO
2
]
2
0 0 0 0 0
[CO
2
]
3
9.4008
×
10
–8
0 0 0 0
Table 4.2.33
Canopy Closure Time, t
A
, Coefficients for Rice with Nominal Conditions
1/PPF
E
1 PPF
E
PPF
E
2
PPF
E
3
1/[CO
2
]
6.5914
×
10
6
-
3.748
×
10
3
0 0 0
1
2.5776
×
10
4
0 0
4.5207
×
10
–6
0
[CO
2
]
0 -
0.043378
4.562
×
10
–5
-
1.4936
×
10
–8
0
[CO
2
]
2
6.4532
×
10
–3
0 0 0 0
[CO
2
]
3
0 0 0 0 0
53
Table 4.2.34
Canopy Closure Time, t
A
, Coefficients for Soybean with Nominal Conditions
1/PPF
E
1 PPF
E
PPF
E
2
PPF
E
3
1/[CO
2
]
6.7978
×
10
6
-
4.326
×
10
4
112.63 -
0.13637
6.6918
×
10
–5
1
- 4.3658
×
10
3
33.959 0
0
- 2.1367
×
10
–8
[CO
2
]
1.5573
0 0 0
1.5467
×
10
–11
[CO
2
]
2
0 0
- 4.911
×
10
–9
0 0
[CO
2
]
3
0 0 0 0 0
Table 4.2.35
Canopy Closure Time, t
A
, Coefficients for Sweet Potato with Nominal Conditions
1/PPF
E
1 PPF
E
PPF
E
2
PPF
E
3
1/[CO
2
]
1.2070
×
10
6
0 0 0
4.0109
×
10
–7
1
4.9484
×
10
3
4.2978
0 0 0
[CO
2
]
0 0 0 0
2.0193
×
10
–12
[CO
2
]
2
0 0 0 0 0
[CO
2
]
3
0 0 0 0 0
Table 4.2.36
Canopy Closure Time, t
A
, Coefficients for Tomato with Nominal Conditions
1/PPF
E
1 PPF
E
PPF
E
2
PPF
E
3
1/[CO
2
]
6.2774
×
10
5
0 0.44686
0 0
1
3.1724
×
10
3
24.281
5.6276
×
10
-3
-
3.0690
×
10
–6
0
[CO
2
]
0 0 0 0 0
[CO
2
]
2
0 0 0 0 0
[CO
2
]
3
0 0 0 0 0
Table 4.2.37
Canopy Closure Time, t
A
, Coefficients for Wheat with Nominal Conditions
1/PPF
E
1 PPF
E
PPF
E
2
PPF
E
3
1/[CO
2
]
9.5488
×
10
4
0 0.3419
- 1.9076
×
10
–4
0
1
1.0686
×
10
3
15.977
1.9733
×
10
–4
0 0
[CO
2
]
0 0 0 0 0
[CO
2
]
2
0 0 0 0 0
[CO
2
]
3
0 0 0 0 0
Table 4.2.38
Canopy Closure Time, t
A
, Coefficients for White Potato with Nominal Conditions
1/PPF
E
1 PPF
E
PPF
E
2
PPF
E
3
1/[CO
2
]
6.5773
×
10
5
0 0 0 0
1
8.5626
×
10
3
0 0.042749
- 1.7905
×
10
–5
0
[CO
2
]
0 0
8.8437
×
10
–7
0 0
[CO
2
]
2
0 0 0 0 0
[CO
2
]
3
0 0 0 0 0
54
For certain crops under low-lighting conditions, the relationships above for t
A
and A
MAX
require modification.
Physically, the canopy does not close under low light, so A
MAX
does not reach 0.93, for the nominal photoperiod and
planting densities listed in Table 4.2.27. Consequently, to use the models above under such conditions and obtain
reasonably accurate results, modified values for the time at canopy closure, t
A
, and the maximum fraction of PPF
absorbed by the plant canopy, A
MAX
, are required. Table 4.2.39 provides modified values for the conditions listed, where
t
A
is the time until the listed A
MAX
is attained. The nominal photoperiods and planting densities associated with these
values are also given for reference, and they are consistent with values provided in Table 4.2.27 above.
Table 4.2.39
MEC Model Parameters for Low-Light Conditions, Nominal Temperature Regimes
Crop
Photo-
period
[h/d]
Planting
Density
[plants/m²]
PPF
[µmol/m²
•
s]
[CO
2
]
[µmol/mol]
t
A
[d
AE
] A
MAX
330 32
0.18
660 32
0.35
990 32
0.46
200
1,320 32
0.49
Lettuce
16 19.2
300 330
32
0.75
330 45
0.13
660 45
0.21
990 45
0.26
200
1,320 45
0.28
330 50
0.33
660 50
0.50
990 50
0.59
300
1,320 50
0.62
330 50
0.57
660 50
0.75
990 50
0.82
Rice
12 200
400
1,320 50
0.83
330 30
0.58
660 30
0.76
990 30
0.84
200
1,320 30
0.86
Sweet
Potato
18 16
300 330
31
0.90
330 36
0.34
660 38
0.49
990 38
0.58
200
1,320 39
0.60
330 40
0.80
White
Potato
12 6.4
300
660 42
0.90
MEC model constants for additional temperature regimes are reported in Cavazzoni (2001).
55
4.3
Food Subsystem
Food, though historically omitted from life support analysis, has significant impacts on closure and the cost of
crew support. In particular, food, if grown on-site, can regenerate some or all of the crew’s air and water. If more than
about 25% of the food, by dry mass, is produced locally, all the required water can be regenerated by the same process. If
approximately 50% or more of the food, by dry mass, is produced on site, all the required air can be regenerated by the
same process (Drysdale, et al., 1997).
The former value depends on the crop and growth conditions. The latter number, however, depends on the
cropping scenario and the overall harvest index.
4.3.1
Physical Parameters for Historical Food Flight Systems
The crew food energy requirement will depend on the crew itself, its lean body mass in particular, and the
amount of physical work it performs. Extravehicular activity (EVA), for example, requires additional food energy
compared with crews conducting only intravehicular activities (IVA) because more physical work is typically associated
with an EVA. Unless specified otherwise, this document assumes an average body mass of 70 kg, and an intravehicular
metabolic requirement of 11.82 MJ/CM-d, which are consistent with Duffield (2003) and derived from NASA (1991).
The mass of food required depends heavily on the lipid content and the degree of hydration. A 30 % lipid
content, by metabolic energy, is generally recommended though much lower levels of lipids have been suggested by
some sources. Degree of hydration is largely a function of the type of food, and the method of processing and storage.
Fresh foods can have as much as 99 % water content, by mass, while dehydrated foods have as little as 3 % moisture.
Food quality is not specifically discussed here, because this topic is addressed when the Food Subsystem is
designed. However, food quality can have a tremendous impact on crew morale and the success of a long-duration
mission. The mass of food also depends on food quality. For example, a greater mass of protein is required if it is of
inferior quality. Digestibility will also vary, being lowest for vegetarian diets. As noted above, these factors are currently
beyond the scope of this discussion.
Besides the mass of food itself, food requires packaging and/or appropriate containment to protect it from
degradation and contamination. Packaging includes wrapping and/or boxes around the food itself, such as for individual
servings. Appropriate containment describes stowage, such as food lockers, provision of a suitable atmosphere,
temperature, and other environmental conditions, such as freezers for some foods, and secondary structure to house the
stowage and environmentally conditioned chambers. Section 3.2.2 provides estimates for supporting secondary structure
with the Food Subsystem. Analysis of Table 4.3.1, which presents estimates of associated food packaging masses from
historical systems, indicates that an additional ~15 % mass penalty, based on fresh food mass, is appropriate for
individually packaged meals. Note the values presented in Table 4.3.1 are historical or predicted averages for indicated
programs and, therefore, may or may not provide 11.82 MJ/CM-d of metabolic energy.
For a food system based on the Shuttle Training Menu, as detailed above, Levri (2002) lists the properties of the
rehydration apparatus and conduction oven collectively as 36.3 kg occupying 0.094 m³ based on the Shuttle galley.
During use, the rehydration apparatus consumes up to 0.540 kW to heat water. The conduction oven, when operational,
consumes up to 0.360 kW for heaters and 0.060 kW for fans. Thus, the maximum total power load for the galley is
0.960 kW during operation.
Perchonok, et al. (2002) reports a loaded ISS food container for Phase II averages 5.5 kg each and contains nine
meals plus snacks. This is equivalent to a single day’s food for three ISS crewmembers. This is equivalent, on average, to
0.611 kg/meal, assuming snacks are extensions of the standard meals, or 1.83 kg/CM-d. Individual food container
masses vary according to individual crew entrée preferences and nutritional requirements, and the containers themselves
are placed in racks, incurring a secondary structure penalty not included in the masses above.
56
Table 4.3.1
Historical and Near-Term Food Subsystem Masses
Parameter
Mass
[kg/CM-d]
Volume
[m³/CM-d] Comments
Water
Content
[%]
References
IVA Food, dw
0.67
(1)
A
Reference
Value
0
(1)
Space Transportation Food System
STS Food
77
0.66
(2)
Food Dehydrated,
11.82 MJ/CM-d
0
(2)
1.147
(2)
Food As-Shipped,
No Packaging,
11.82 MJ/CM-d
42
(2)
0.26
(2)
Packaging Alone (clean)
0.35
(2)
Container Mass
(ISS “Pantry-style storageâ€)
without secondary
structure
78
1.76
(2)
0.0048
(2)
Food As-Shipped, Packaged
(ISS “Pantry-style storageâ€),
and within a Container
42
(2)
International Space Station Food Systems
Phase II
79
1.83
(3)
TBD
Food As-Shipped, Packaged
with Food Container
TBD
Phase III
80
1.955
Food As-Shipped,
No Packaging
66
0.345
Packaging
Alone
2.3
0.006570
Food As-Consumed,
Packaged
Information from
Bourland (1998) or
Vodovotz (1999), except
as noted.
(1)
NASA (1995),
Section 7.2.2.2.3
(2)
Levri (2002)
(3)
Perchonok, et al.
(2002)
4.3.2
Physical Parameters of Refrigeration Equipment
Table 4.3.2 presents characteristics for the ISS refrigerator / freezer technology. These units were designed, but
ISS Program deferred launching them along with the planned frozen food system. The internal volume and internal load
apply to the internal refrigerator or freezer cargo capacity within a single unit assigned to a single rack, while the other
parameters generally describe the exterior properties of the overall unit.
Each ISS refrigerator/freezer fits within one ISS rack and has four cold volume compartments, each with a
dedicated thermoelectric thermal energy management system. An ISS refrigerator/freezer may operate in one of three
modes, depending on the thermostat settings for the internal compartments. In freezer mode, all four compartments operate
as freezers; in refrigerator mode, all four compartments operate as refrigerators; and in refrigerator/freezer mode, two
compartments operate as refrigerators while the other two operate as freezers. The overall thermodynamic coefficient of
performance (COP
S
) for the ISS refrigerator/freezer in freezer mode is 0.36 (Ewert, 2002a). Waste heat is rejected to the
internal thermal control loops. The ISS unit has an operational lifetime of 10 y, with ground servicing provided once a year.
77
Shuttle food systems are provided for reference only. They do not meet nutritional requirements for long-duration space flight.
(For example, while this diet meets all minimum nutritional requirements, it exceeds the limit for sodium and iron for a
weightless diet.) These food systems do not use any refrigeration.
78
Historically, Bourland (1999) reports an empty food locker has 6.4-kg mass. Filled, this locker holds up to 42 meals (Perchonok, et
al., 2002) (overall filled locker mass: 24.5 kg [Bourland, 1999], equivalent to 0.583 kg/meal, or 1.75 kg/CM-d). The Shuttle food
system is shelf-stable without frozen components. Assessments (Levri, 2002) assume ISS pantry-style storage and not Shuttle lockers.
79
ISS Assembly Phase food system. This system is shelf stable.
80
ISS Assembly Complete food system. This food is provided as 50% frozen products. For a 540 CM-d (six crew for 90 d) food
supply, 1.84 m³ of refrigerated storage is required.
57
Table 4.3.2
International Space Station Refrigerator/Freezer Properties
Units
Freezer Mode
Refrig./Freezer Mode
References
Unit Mass
kg
321.0
(1)
321.0
(1)
Secondary Structure Mass
kg
91
(2)
91
(2)
Volume, Including Rack
m³
2.00
(3)
2.00
(3)
Volume, Without Rack
m³
1.16
(3)
1.16
(3)
Power kW
0.268
(4)
0.205
(4)
Thermal Energy Management
kW
0.297
(4)
0.228
(4)
Crewtime CM-h/y
0
(1)
0
(1)
Logistics kg/y
321.0
(1)
321.0
(1)
Internal Load
kg
295
(1)
295
(1)
Internal Volume
m³
0.614
(1)
0.614
(1)
81
(1)
Toups, et al. (2001)
(2)
Shepherd (2001)
(3)
Vonau (2002)
(4)
Winter, et al.
(2001)
More generally, Table 4.3.3 lists properties for frozen food storage per frozen-food-mass (ffm) basis. The nominal
and low values reflect advanced or anticipated technologies while the high values are based on ISS technology. Vapor
compression and Stirling refrigeration technologies are more efficient, generally exhibiting higher COP
S
values than
thermoelectric approaches. However, these advanced technologies are at low technology readiness and require further
development to meet spaceflight requirements, especially with respect to weightlessness and acoustics (Ewert, 2002a).
Table 4.3.3
Frozen Food Storage on a Property per Frozen-Food-Mass Basis
Assumptions
Characteristic Units
Low
Nominal High
References
1/COP
S
thermal
electrical
kW
kW
0.5
(1)
1.0
(1)
9.2
(1)
1/R
S
kW/m²
•
K
×
10
−
3
0.28
(1)
0.32
(1)
0.32
(1)
kg
220
(4)
321
(2)
Mass
82
kg/kg
ffm
0.75
1.09
m³
TBD
2.00
(3)
External Volume, Including Rack
m³/kg
ffm
×
10
−
3
6.78
m³
1.16
(4)
External Volume, Excluding Rack
m³/kg
ffm
×
10
−
3
3.93
kW 0.048
(1)
0.096
(1)
0.268
(1)
Power
kW/kg
ffm
×
10
−
3
0.16 0.33 0.91
kW 0.053
(1)
0.106
(1)
0.297
(1)
Thermal Energy Management
kW/kg
ffm
×
10
−
3
0.18 0.36 1.01
CM-h/y
0.0 0.0 0.0
Crewtime
CM-h/(y•kg
ffm
)
0.0 0.0 0.0
kg/y 0.0
0.0
321
(2)
Logistics
kg/(y•kg
ffm
) 0.0 0.0 1.09
(1)
Ewert (2002a)
(2)
Toups, et al. (2001)
(3)
Rodriguez and
England (1998)
(4)
Vonau (2002)
81
In refrigerator/freezer mode, half of the internal cold volume is a refrigerator while the other half is a freezer.
82
Including the freezer mass and rack but excluding the secondary structure.
58
As described in Ewert (2002b) and presented in Equation 4.3-1, the specific power consumption for a cooled
volume within a cabinet,
RF
W
ˆ
[kW/kg
ffm
], may be expressed as an empirical function of two system-level values, the
composite thermal resistance, R
S
[m²
•
K/kW], and COP
S
[kW
electrical
/kW
thermal
]. R
S
characterizes the overall resistance to
heat transfer to or from a cooled volume, such as a refrigerator or freezer, through the cabinet wall accounting for
insulation, door seals, and any other pathways for heat transfer. COP
S
is the system-level coefficient of performance
defined as the net heat removed from the cooled volume divided by the total electrical power consumed by the
refrigerator or freezer unit including the heat pump cycle and all supporting equipment. The assumed frozen food density
within the cooled volume, including packaging and gaps, is 480 kg/m³. The assumed air temperature within the cooled
volume is
−
22
°
C, while the ambient external cabin temperature is 23
°
C.
⎟⎟
âŽ
⎞
⎜⎜
âŽ
⎛
⎟⎟
âŽ
⎞
⎜⎜
âŽ
⎛
=
S
S
RF
COP
1
R
1
028
.
1
W
ˆ
Equation 4.3-1
4.3.3
Crewtime for the Food Subsystem
Overall crewtime requirements in the galley depend on the form in which food is shipped and food preparation
requirements. Crewtime required for food preparation during Space Transportation System (STS, or Shuttle) missions is
45-90 minutes per day for a crew of up to six (NASA, 1996). This approach uses individually packaged servings. If food
preparation requires more than heating and/or re-hydration, then the additional preparation complexity increases
crewtime for preparation compared with current systems. However, more involved preparation may allow for higher
quality food.
Hunter (1999) provides another estimate of crewtime for food preparation. Hunter’s model assumes each
crewmember eats ten different food dishes per day. For a crew of six, each dish prepared using ingredients provided by
bioregenerative methods requires 15 to 45 minutes each while each dish taken from resupplied stocks requires an
average of 6 minutes to prepare based on NASA (1996). Assuming meals prepared using bioregenerative methods each
require an average of 30 minutes to prepare, a diet based on crops grown on-site would require 5.0 CM-h/d, or
0.83 CM-h/CM-d, assuming a crew of six. Daily meals prepared completely from resupplied foods would require
1.0 CM-h/d, or 0.17 CM-h/CM-d. Assuming five dishes are prepared from crops grown on site and five dishes are
prepared from resupplied stocks, daily meal preparation time would be 3.0 CM-h/d or 0.50 CM-h/CM-d.
Kloeris, et al. (1998) report meal preparation time during the Lunar Mars Life Support Test Program (LMLSTP)
Phase III test while using the 10-day BIO-Plex menu averaged 4.6 CM-h/d.
There will also be crewtime requirements to process the crops into edible food ingredients. These times, though
expected to be significant, have not been calculated to date.
4.3.4
Food Subsystem Waste Generation
Wastage will depend on the type of food and the type of preparation, but can be quite large. For example,
during the 10-day BIO-Plex menu test conducted during the LMLSTP Phase III, total waste, including preparation, plate
waste, and unused, leftover food, was 42% (Kloeris, et al., 1998). Typically, much lower values are assumed for
prepackaged food systems. Wastage occurs both due to food adhering to its packaging and due to plate wastage. Waste
model values are noted below and in Section 4.5.4.7 for both historical pre-packaged food systems and projected food
systems based on crops from bioregenerative life support systems.
4.3.5
Overall Food Subsystem Parameters
Typical values from the literature for food-related masses are shown in Table 4.3.4. However, the food mass
values here do not reflect as great a range as is associated with the metabolic gas exchange values in Table 4.1.1. The
listed food masses in Table 4.3.4 are “as shipped†and before addition of any hydration fluid and reflect historical pre-
packaged food systems, although the upper value for crewtime is associated with a Food Subsystem using crop products
derived from a biomass production chamber.
59
Table 4.3.4
Food Quantity and Packaging
Assumptions
Parameter Units
Lower
Nominal Upper
References
IVA Food, dry mass
83
kg/CM-d
0.54
(8)
0.617
(1)
0.66
(2)
IVA Human Metabolic
Water Production
kg/CM-d
0.345
(1)
IVA Energy
MJ/CM-d
11.82
(1)
IVA Potable Water
Consumption
kg/CM-d
3.909
(3)
EVA Food, dry mass,
added
84
kg/CM-h
+
0.029
(4)
EVA Metabolic Water
Production added
86
kg/CM-h
+
0.016
(4)
EVA Energy added
86
MJ/CM-h
+
0.570
(5)
EVA Potable Water
Consumption
kg/CM-h
0.24
(1)
Packaging
85
kg/kg
+ 15 %
Crewtime
CM-h/d 1 – 1.5
(6)
1.5
(6)
4.6+
(7)
86
(1)
NASA (1991)
(2)
Levri (2002)
(3)
Perchonok (2001)
and NASA (1991)
(4)
Derived from
McBarron, et al.
(1993); metabolic
rate of 293 W/CM
and a respiratory
quotient of 0.9.
(5)
Rouen (2001)
(6)
NASA (1996)
(7)
Kloeris, et al. (1998)
(8)
Lange and Lin (1998)
4.3.6
Food Subsystems Based on Biomass Production Systems
The ALS Project assumes that crops within a biomass production chamber will be grown and harvested on a
bulk basis rather than quasi-continuously. This assumption is designed to minimize crewtime requirements by making
crew activities more efficient, and may be revisited when more data are available. The three diets presented here assume
differing availabilities for crops grown on-site. In all cases, the menus given in Table 4.3.5 and Table 4.3.6 are designed
for use as a unit in order to maintain nutritional integrity. However, minor changes may include moving small amounts
of crops from the list to be grown and into the resupplied mass, especially for those items (such as rice) that are prepared
for consumption without post-growth processing operations that will reduce the total edible biomass from the original
crop. All diets are comparable in nutritional content to the ISS Assembly Complete food system.
Table 4.3.5 provides wet or fresh masses for the dietary components, as received from the Biomass Subsystem
while Table 4.3.6 provides the corresponding nutritional information.
In all cases, the menus given in Table 4.3.5 and Table 4.3.6 are designed for use as a unit in order to maintain
nutritional integrity. However, minor changes may include moving small amounts of crops from the list to be grown and
into the resupplied mass, especially for those items (such as rice) that are prepared for consumption without post-growth
processing operations that will reduce the total edible biomass from the original crop. All diets are comparable in
nutritional content to the ISS Assembly Complete food system.
83
On a dry mass (dw) basis.
84
EVA requirements are in addition to any IVA requirements.
85
Packaging accounts for individual food packages only. Secondary structure, lockers, and trays are additional.
86
This value is derived using “ready to use†ingredients and includes no crop processing to develop ingredients. An estimate
including crop processing to develop ingredients might be double this value, or ~9 CM-h/d, or more.
60
Table 4.3.5
Menu Masses for Diets Using Advanced Life Support Crops and Resupplied Foods
Average Production Based on Consumption,
Fresh Mass [kg/CM-d]
Crop
Diet Using
Only ALS
Salad Crops
87
Diet Using
Salad and
Carbohydrate
Crops
88
Diet Using All
ALS Crops
89
Cabbage
0.0194 0.0025 n/a
Carrot 0.0365
0.040
0.0401
Celery n/a
0.0075
n/a
Dry Bean, incl. lentil and
pinto
n/a 0.013
0.0214
Green Onion
0.0045
0.034
0.0226
Lettuce 0.0156
0.021
0.0075
Mushroom n/a
0.0013
n/a
Pea n/a
0.0038
n/a
Peanut
n/a n/a 0.0288
Peppers n/a
0.031
n/a
Radish 0.009
n/a
0.0150
Rice
n/a n/a 0.0214
Snap Bean
n/a
0.010
n/a
Soybean
n/a n/a 0.2340
Spinach 0.0048
0.040
0.0463
Sweet Potato
n/a
0.18
0.0768
Tomato 0.0460
0.21
0.2854
Wheat n/a
0.22
0.0963
White Potato
n/a
0.17
0.1047
Crop Sub Total
0.1358
1.0
1.00
Water
90
1.1581 2.1
0.6053
Resupplied Foodstuffs
1.168
91
0.5
93,
92
0.0944
Total 2.462
3.6
1.70
Potable Water
93
2.0 2.0 2.0
Food
Processing
Waste
TBD TBD 0.094
87
From Hall, et al. (2000). This diet assumes a 10-day cycle.
88
From Hall and Vodovotz (1999). This diet assumes a 20-day cycle.
89
From Ruminsky and Hentges (2000). This diet assumes a 10-day cycle.
90
Water for hydration, cooking, and food preparation only. Water for clean-up is not included. Water tankage is not included.
91
Resupplied food is a combination of STS and ISS foodstuffs.
92
Oil is included as resupply. No frozen or refrigerated foods are assumed for this calculation. Packaging is not included.
Resupplied food is about 40 % moisture by mass. Resupplied food includes meat.
93
The crew also requires 2.0 L/CM-d for drinks, again excluding packaging/tankage. (Perchonok, 2001)
61
Table 4.3.6
Nutritional Content of Diets Using Advanced Life Support Crops and Resupplied Foods
Dietary
Component Units Goal
Diet Using
Only ALS
Salad
Crops
89
Diet Using
Salad and
Carbohydrate
Crops
90
Diet Using All
ALS Crops
91
Energy MJ/CM-d
11.82
94
9.31 9.74
7.74
Carbohydrate g/CM-d
–
312.179
357.1
314.12
Fat g/CM-d
–
71.9141
71.6
46.84
Protein g/CM-d
–
91.2913 73.1 54.91
Calcium, Ca
mg/CM-d 1,000 – 1,200
95
925.557 812 545
Iron, Fe
mg/CM-d < 10
97
19.2385
21.5
17.23
Magnesium, Mg mg/CM-d 350
97
294.687
386
376.48
Phosphorous, P
mg/CM-d < 1.5 Ca intake
97
1,440.68
1,356
1,079.52
Potassium, K
mg/CM-d ~ 3,500
97
3,316.57
3,723 3,179.86
Sodium, Na
mg/CM-d 1,500 – 3,500
97
3,909.56 3,600
3,205.96
Zinc, Zn
mg/CM-d 15
97
12.8077
10
7.5
Dietary Fiber
g/CM-d
10 – 25
97
25.1129 33.3 28.5
Percentage of Energy Contributed to Diet
Carbohydrate
%
50 – 55
97
55.5
61 68.1
Fat
%
30 – 35
97
28.7
27 22.4
Protein
%
12 – 15
97
16.2
12 12
The Diet Using Only ALS Salad Crops (Hall, et al., 2000) is aimed at near-term missions and supplements the
more traditional packaged food systems with fresh food in the form of salad crops. The bulk of the nutritional content is
supplied by the packaged food and the degree of closure is low.
The Diet Using Salad and Carbohydrate Crops (Hall and Vodovotz, 1999) is also aimed at near-term missions,
but this diet provides somewhere around half of the necessary mass through crops grown on-site. Resupply includes
products high in protein, such as meat, in addition to seasonings and other supporting foodstuffs. Oil is also provided via
resupply, as typical oil crops are not grown for this diet. Overall, this approach provides greater on-site food closure,
adds only moderate additional food processing, and provides variety equivalent to that of a vegetable garden.
The Diet Using All ALS Crops (Ruminsky and Hentges, 2000) uses a wide variety of species, and provides a
high degree of closure. Oil is provided from peanut, but the specific processing has not been identified. With respect to
closure, the resupply mass includes herbs and condiments. As the ALS crop variety is limited, resupply items provide
necessary nutrients that are not available in sufficient quantities within the grown biomass.
Levri, et al. (2001) examined prepackaged food systems for exploration missions to Mars using the standard
Shuttle Training Menu with a 7-day menu cycle as a basis. To support the nominal NASA crewmember, the standard
Shuttle Training Menu was adjusted slightly to raise the energy content to 11.82 MJ/CM-d. Data collected by Levri, et
al. (2001) showed the practical minimum wastage rate of resupplied food for situations in which the crew attempts to eat
all of the food with which they are supplied is 3 % by mass. This remaining 3 % of the food mass adheres to the inside of
the food packaging.
94
From NASA (1991).
95
From Lane, et al. (1996).
62
Table 4.3.7 presents mass and volume properties for three study food systems, as formulated by Levri, et al.
(2001), which are modified from the standard Shuttle Training Menu. Each system assumes crew metabolic loads
consistent with intravehicular activities. “As-shipped†food contains any moisture present when the food is packaged for
launch. Food “as-consumed†also includes any additional water that is added to rehydrate food items and powdered
beverages before consumption. The additional drinking water is computed based on the assumption that a crewmember
consumes at least 239.0 milliliters of water, either within food or in addition to food, for every Mega-Joule of metabolic
energy within the consumed food to provide proper hydration for metabolic assimilation of the food.
96
Some sources,
such as the National Research Council (1989), recommend as much as 358.5 milliliters of water per Mega-Joule of
energy in the consumed food. Generally, these food systems are stored under ambient conditions in an ISS food locker.
Frozen storage, when noted, assumes an ISS thermoelectric freezer (Section 4.3.2). Locker and freezer volumes are
computed with respect to external dimensions.
Table 4.3.7
Properties of Early Mars Diets for Intravehicular Activities Using Resupplied Foods
Units
Modified
Shuttle
Training
Menu
97
Low
Moisture
Content
Menu
99
Menu
Containing
Some
Frozen
Food
99
IVA Food Properties, No Packaging
Food,
Dry
Mass
kg/CM-d
0.66 0.66 0.66
Food
“As-Shippedâ€
kg/CM-d
1.15 0.92 1.37
Moisture Content of Food “As-Shipped†%
42
28
52
Food “As-Consumed,†with Rehydration
kg/CM-d
2.40 2.20 2.38
Additional Drinking Water
kg/CM-d
1.132 1.322 1.153
IVA Food Packaging Properties
Packaging
Mass
kg/CM-d
0.26 0.27 0.24
IVA Food Locker Properties
98
Locker
Mass
kg/CM-d
0.35 0.32 0.25
Locker
Volume
m³/CM-d
0.00482 0.00452 0.00354
IVA Food Freezer Properties
Freezer Mass
kg/CM-d
n/a n/a 0.808
Freezer
Volume
m³/CM-d
n/a n/a 0.00231
IVA Food and Packaging Waste
Trash
Mass
kg/CM-d
0.33 0.32 0.29
96
Alternately, this guideline may be formulated as 1.0 milliliters of water per kilocalorie of food energy consumed.
97
From Levri (2002). The values here include material that normally clings to food packaging and is discarded.
98
Food maintained at ambient conditions is stored in lockers aboard ISS. These values assume ISS “Pantry-style storage.
63
Table 4.3.8 provides the nutritional analysis for the food systems presented in Table 4.3.7. However, unlike
Table 4.3.7, which is based on all food “as shipped,†including food that adheres to the food packaging and is not
consumed by the crewmember, values in Table 4.3.8 consider only the edible material a nominal crewmember consumes,
and assume the crewmember attempts to eat all of the food within a package and only wastes material that adheres to the
package walls.
Table 4.3.8
Nutritional Content of Early Mars Diets for Intravehicular Activities Using Resupplied Foods
Dietary Component
Units
Modified
Shuttle
Training
Menu
99
Low Moisture
Content
Menu
101
Menu
Containing
Some Frozen
Food
101
Energy MJ/CM-d
11.82
11.82
11.82
Carbohydrate g/CM-d
376
382
371
Fat g/CM-d
97
93
97
Protein g/CM-d
113
115
116
Dietary Fiber
g/CM-d
33
33
37
Ash g/CM-d
27
25
30
Water in Food
100
g/CM-d 466
248
690
Rehydration Water
g/CM-d
1,227
1,255
982
Additional Drinking Water
101
g/CM-d 1,132
1,322
1,153
Percentage of Energy Contributed to Diet
Carbohydrate %
53
54
53
Fat %
31
30
31
Protein %
16
16
16
Based on the dietary contributions of salad crops suggested by Perchonok, et al. (2002) and data compiled by
Levri, et al. (2001), four diets using ALS salad crops and resupplied food systems are presented in Table 4.3.9. The crop
values listed here are based on fresh salad crops, as received from the Biomass Subsystem, less any biomass removed
during preparation. Resupplied foodstuffs are listed “as-shipped,†without rehydration water, and do not include
packaging materials. Values here do not include material that adheres to packaging and that is ultimately wasted.
Drinking water is listed near the bottom of the table. As above, the drink water assumes that a crewmember consumes at
least 239.0 milliliters of water, either within food or in addition to food, for every Mega-Joule of metabolic energy within
the consumed food to provide proper hydration for metabolic assimilation of the food. The listings for food processing
waste consider wasted edible biomass from preparation of the salad crops plus resupplied food that adheres to packaging
materials. Here it is assumed that 3 % of the food mass within a prepackaged food item will adhere to the packaging.
99
From Levri (2002). The values here are based on food “as consumed†by a crewmember, excluding material that normally
clings to the food packaging.
100
Moisture, or water, held in the food as shipped before rehydration.
101
The additional drinking water is computed based on the assumption that a crewmember consumes at least 239.0 milliliters of
water, either within food or in addition to food, for every Mega-Joule of metabolic energy within the consumed food to provide
proper hydration for metabolic assimilation of the food. These values are identical to those in Table 4.3.7 because losses were
neither measured nor assumed.
64
Table 4.3.9
Menu Masses for Diets Using Advanced Life Support Crops and Resupplied Foods
Average Production Based on Consumption, Fresh Mass [kg/CM-d]
Crop
Diet Using
Shuttle
Training
Menu and
ALS Salad
Crops
102
Diet Using
Low Moisture
Content Menu
and ALS Salad
Crops
104
Diet Using ISS
Assembly
Complete
Menu with
Some Frozen
Food and ALS
Salad Crops
104
Diet Using
Shuttle
Training
Menu and
ALS Salad
Crops plus
Potato
104
Cabbage
0.0107 0.0107 0.0107 0.0107
Carrot
0.0357 0.0357 0.0357 0.0357
Celery
n/a n/a n/a n/a
Dry Bean, inc. lentil and pinto
n/a n/a n/a n/a
Green
Onion n/a n/a n/a n/a
Lettuce
0.0097 0.0097 0.0097 0.0097
Mushroom
n/a n/a n/a n/a
Pea
n/a n/a n/a n/a
Peanut
n/a n/a n/a n/a
Peppers
n/a n/a n/a n/a
Radish
0.0114 0.0114 0.0114 0.0114
Rice
n/a n/a n/a n/a
Snap
Bean
n/a n/a n/a n/a
Soybean
n/a n/a n/a n/a
Spinach
0.0134 0.0134 0.0134 0.0134
Sweet
Potato n/a n/a n/a n/a
Tomato
0.0143 0.0143 0.0143 0.0143
Wheat
n/a n/a n/a n/a
White
Potato n/a n/a n/a 0.0840
Crop
Sub
Total 0.0953 0.0953 0.0953 0.1793
Rehydration Water
103
1.2173 1.2455 0.9744 1.1822
Resupplied Foodstuffs
104
1.1030 0.8831 1.3200 1.0703
Total
2.4154 2.2239 2.3897 2.4319
Drinking Water
105
1.058 1.246 1.079 1.050
Food Processing Waste
106
0.0371 0.0303 0.0438 0.0386
102
From Levri (2002). The values here are reflect food “as-shipped,†for prepackaged food, and “as-received†from the Biomass
Subsystem, less preparation waste, for food grown locally. Wasted food mass is listed separately at the bottom of the table.
Crewmembers consume all other masses in this table except for wasted mass.
103
Water for rehydration only. Water for clean-up is not included. Water tankage is not included.
104
Masses are for food “as shipped,†without packaging, storage lockers, or water for hydration.
105
Again, this listing excludes packaging/tankage.
106
These values include the wasted portion of fresh, edible biomass, as well as the wasted portion of resupplied, “as-consumedâ€
food. These values do not include packaging.
65
Table 4.3.10 provides the nutritional analysis for the food systems presented in Table 4.3.9. As above, values in
Table 4.3.10 consider only the edible material a nominal crewmember consumes, and the crewmember only wastes food
material that adheres to the package walls or serving dishes and some edible biomass from crop preparation.
Table 4.3.10
Nutritional Content of Diets Using Advanced Life Support Crops and Resupplied Foods
Dietary
Component
Units
Diet Using
Shuttle
Training
Menu and
ALS Salad
Crops
107
Diet Using
Low Moisture
Content
Menu and
ALS Salad
Crops
109
Diet Using
ISS Assembly
Complete
Menu with
Some Frozen
Food and
ALS Salad
Crops
109
Diet Using
Shuttle
Training
Menu and
ALS Salad
Crops plus
Potato
109
Energy MJ/CM-d
11.82 11.82 11.82 11.82
Carbohydrate
g/CM-d
376 383 372 385
Fat g/CM-d
96 93 97 93
Protein
g/CM-d
114 115 116 111
Dietary
Fiber
g/CM-d
35 35 39 36
Ash g/CM-d
28 26 31 28
Water in
Food
108
g/CM-d
550 333 772 595
Percentage of Energy Contributed to Diet
Carbohydrate
%
53 54 53 54
Fat %
31 30 31 30
Protein
%
16 16 16 16
The four diets, presented in Table 4.3.9 and Table 4.3.10, are derived from the standard Shuttle Training Menu
and work by Levri, et al. (2001). The first and fourth diets included prepackaged items from the Modified Shuttle
Training Menu (see Table 4.3.7 and Table 4.3.8). The second diet considers prepackaged items from the Low Moisture
Content Menu while the third diet employs the Modified Shuttle Training Menu with some frozen items to simulate a
food system similar to what is planned for ISS when that facility is completely assembled.
Perchonok, et al. (2002) provide estimates for salad servings based on preliminary menus for early mission
scenario testing. This overall approach assumes a prepackaged food system augmented with grown salad crop, and the
diet is analogous to the Diet Using Only ALS Salad Crops from Hall, et al. (2000). Note Table 4.3.11 provides inputs
only for the dietary contributions derived directly from the vegetables. The supporting prepackaged food items are not
included.
Perchonok, et al. (2002) assumes:
•
Salad is served four times per week.
•
Raw carrots are served as a snack once per week.
•
Steamed carrots are served once per week.
•
Steamed or raw spinach is served once per week.
•
Bok choy can be served as cole slaw once per week.
107
From Levri (2002). The values here are based on food “as consumed†by a crewmember, excluding edible material that
normally clings to food packaging or serving dishes.
108
Moisture, or water, held in the food as shipped before rehydration.
66
Table 4.3.12 provides overall values for locally grown crops for this diet.
Table 4.3.11
Updated ALS Salad Crop Only Dietary Contributions
Menu Item
Vegetable
Serving
Size
109
[g]
Number
per Week
Serving Rate
110
[kg/CM-d]
Salad 1
Lettuce
34
2
0.00971
Carrot
40
2
0.01114
Radish
40
2
0.01143
Salad 2
Spinach
20
2
0.01086
Tomato
(Cherry)
50
2
0.01429
Snack Carrot
85
1 0.01214
Steamed Side Dish
Spinach
55
1
0.00786
Cole Slaw
Cabbage
63
1
0.009
Table 4.3.12
Overall Crops Masses for Updated Salad Crop Only Diet
Vegetable
Serving Rate
112
[kg/CM-d]
Cabbage 0.009
Carrot 0.03542
Lettuce 0.00971
Radish 0.01143
Spinach 0.01872
Tomato (Cherry)
0.01429
Total 0.09857
4.3.7
Food Processing
Food processing takes the edible biomass produced by plant crops, either fresh or as prepared for storage, and
produces food products and ingredients such as pasta and flour. These food products may be stored or used immediately,
together with ingredients supplied from the Earth (or, for analog testing, from outside the facility), and prepared to
provide food.
For long-duration missions beyond low Earth orbit, current planning envisions that crops will be grown and
processed on a bulk basis. Hunter and Drysdale (1996) estimated the equipment mass to perform food processing for a
crew of four to be about 655 kg. However, this is a very preliminary estimate, and the actual processing equipment will
likely differ. Thus, the value here is a suitable “placeholder†until more definitive values are available.
4.4
Thermal Management
Thermal management, in terms of its most direct impact on a spacecraft, maintains temperatures throughout the
vehicle. Or, from another perspective, thermal energy, or heat, transfers from regions of high temperature to regions of
low temperature. The thermal management hardware regulates when and how thermal energy transfers from regions of
high temperature within the spacecraft to regions of low temperature outside of the spacecraft so that all components
within the spacecraft are maintained between their prescribed temperature limits. Specifically, thermal management does
not directly address heating associated with aerodynamic drag, although aerodynamic heating may impose greater
109
Mass “as prepared.â€
110
Mass per crewmember per day “as grown.†This is listed as fresh edible biomass. The associated inedible biomass is also
produced as given in Table 4.2.7.
67
thermal loads for the thermal management hardware, such as when heat conducts through the vehicle structure and into
the crew cabin. Heating generated by aerodynamic drag is managed by the thermal protection system.
4.4.1
Heat Transfer Mechanisms
An outline of underlying mechanisms of heat transfer can be beneficial in understanding heat management
technology, so a brief explanation of heat transfer mechanisms is detailed below. However, please see Incropera and
DeWitt (1985), the primary reference for this section, for a more thorough discussion.
Physically, heat transfers from high to low temperature via one of three distinct mechanisms. These
mechanisms are conduction, convection, and radiation. Heat transfer with a phase change is sometimes discussed
separately and may be viewed as a fourth heat transfer mechanism
111
.
4.4.1.1
Conduction
Conduction describes the transfer of heat within matter by diffusion, or heat transfer through matter in the
absence of macroscopic bulk motion of the matter. An example is heat moving up the shaft of a metal spoon sitting in a
heated pot on a stove. The thermal energy, which is expressed as vibrational, rotational, and translational energy on
atomic scales, is transferred from more-quickly vibrating atoms closer to the heated surface to less-quickly vibrating
atoms further from the heated surface by interactions between adjacent atoms.
4.4.1.2
Convection
Convection describes the transfer of heat in which matter acquires heat, by close molecular interaction, such as
is described above for conduction, then bulk motion of that matter carries both the matter and thermal energy away from
its location of origin. For example, heat may diffuse from hotter metal to an adjacent cooler moving fluid, then the bulk
motion of the moving fluid carries the heat away from its origin. Likewise, the reverse process, that of transferring heat
from a hot moving fluid to a cooler solid, is also convection.
4.4.1.3
Radiation
Radiant heat transfer is an exchange of heat between two surfaces without any intervening matter. Specifically,
heat transfers from one surface to another surface that it can “see†simply by virtue of a temperature difference between
the two surfaces. In a perfect vacuum, which is approximated in free space, no intervening matter is present to convey
heat from one surface to another by either conduction or convection, yet heat does transfer from a hotter surface to a
cooler surface via electromagnetic waves in the mechanism called radiation. Warm spacecraft reject their thermal loads
from relatively hot surfaces to relatively cold space by radiant heat transfer. Please note that while radiation also
describes the mechanism by which other forms of energy, such as solar particles and x-rays, pass through a vacuum,
thermal radiation merely transfers heat and has no additional mutagenic effect on biological creatures exposed to it.
Please note also that while radiant transfer is generally of the greatest importance in a vacuum, radiant transfer occurs in
all situations where two surfaces that can “see†each other are at different temperatures, even if, for example, a fluid fills
the gap between those two surfaces and heat is transferred to or from the surfaces also by conduction and/or
convection.
112
111
As noted below, phase change represents a special case of one of the three heat transfer mechanisms with the additional
stipulation that one of the participating materials changes its physical state as a result of gaining or losing heat. However, even
though phase change is not a unique mechanism, it is sometimes useful to distinguish heat transfer operations with phase change
from other heat transfer operations.
112
Within a pressurized crew cabin, though all three heat-transfer mechanisms are active, conduction and/or convection usually
dominate compared to radiant exchange. Physically, the driving potentials for conduction and convection heat transfer are
proportional to the simple difference in temperature while the driving potential for radiant heat transfer is proportional to the
difference in temperature to the fourth power. Within the crew cabin, coupled with appropriate transport properties, conduction
and convection are greater in magnitude than corresponding radiant exchanges. Thus, within a crew cabin, analysts often neglect
radiant exchange with only a minor loss in accuracy. As a cautionary note, there are situations, especially within terrestrial
industry, in which radiant exchange is significant or dominates as the preferred heat transfer mechanism even when conduction
and/or convection are also viable modes. Please see Incropera and DeWitt (1985) for a more expansive discussion.
68
4.4.1.4
Heat Transfer with Phase Change
Phase change describes heat transfer when matter accepts or discharges heat and changes its physical state.
Though it is mentioned here separately, phase change is really a specialized case of one of the three heat transfer
mechanisms in which matter changes state. As an example, when water boils in a stovetop pan, liquid water approaches
the bottom of the heated pan and leaves in the form of steam bubbles after accepting heat. This change is really heat
transfer by convection with the matter undergoing bulk motion and changing its state from liquid to vapor upon
accepting heat from the solid. Likewise, phase change may occur in situations without bulk motion, such as when butter
melts between two slices of hot bread, which is an example of conduction with phase change of a participating
conducting material.
4.4.2
Thermal Management Organization
Thermal management may be subdivided in several ways. One organization classifies thermal management as
either passive or active. Passive thermal management hardware encourages or inhibits heat transfer as the heat passes
directly through the hardware and eventually to the external environment, radiating from the vehicle’s entire external
surface. Active thermal management hardware acquires thermal loads near where the loads are generated and then
transports those loads to some other portion of the vehicle before the loads are discharged to the environment by
specifically designed radiating surfaces.
4.4.2.1
Passive and Active Thermal Management
Thermal management hardware may be classified as either passive or active. As outlined below, passive
thermal management hardware is generally integrated into the vehicle structure and retards the flow of thermal energy
either in to or out of the vehicle. Active thermal management hardware acquires thermal loads at or near their point of
generation and transports those loads to the exterior of the vehicle for rejection.
4.4.2.1.1
P
ASSIVE
T
HERMAL
M
ANAGEMENT
Passive thermal management hardware controls heat leakage from the vehicle and maintains cabin walls within
prescribed temperature bounds. Passive thermal management hardware is deployed within the vehicle structure and
generally takes the form of insulation and resistive heaters. Insulation impedes the transfer of heat either in to and out of
the vehicle while resistive heaters allow active control of the wall temperatures when completely passive approaches are
inadequate. Because passive thermal management hardware is generally incorporated into the vehicle structure, it is
included within mass penalties for the vehicle structure.
4.4.2.1.2
A
CTIVE
T
HERMAL
M
ANAGEMENT
Active thermal management hardware removes excess thermal loads from within the vehicle to the environment
by physically transporting those loads from their site of generation to an appropriate rejection site. Active thermal
management is comprised of three basic processes. These are: acquisition of thermal energy, transport of thermal energy,
and rejection of thermal energy. Acquisition hardware is comprised of fans, coldplates, and condensing heat exchangers
for primary functionality. Transport hardware can use, theoretically, any mechanism. Historically, for human spacecraft,
transport relies on a liquid working fluid constrained within an enclosed flow channel, using the convection heat transfer
mechanism to take loads from acquisition devices and to release loads to rejection devices.
113
Using this architecture,
transport hardware consists of fluid tubes or pipes, pumps, accumulators, and valves. The working fluid may be two-
phase, but NASA has typically employed single-phase working fluids. Finally, rejection hardware may be radiators,
devices that reject expendable materials carrying thermal loads, such as a flash evaporator or a sublimator, or phase
change devices such as packages containing phase change materials. Thermal management infrastructure penalties
generally represent active thermal management hardware.
113
It is possible to foresee thermal transport using either conduction or radiant heat transfer. For short distances, relatively small
thermal loads, or even highly temperature-tolerant equipment, conduction via solid material pathways to the exterior of the
vehicle is possible. In fact, passive thermal management uses conduction as its transport mechanism through the vehicle
structure. Radiant transport mechanisms are also possible, but less likely, within a vehicle because convective heat transfer
within a working fluid is generally more efficient for relatively small temperature differences associated with temperature
variations within a vehicle than is radiant heat transfer.
69
4.4.2.2
Thermal Subsystem and Cooling External Interface
Active thermal management may be further subdivided into the Thermal Subsystem, an ALS subsystem, and
Cooling, which is an external interface to the ALS concept of the life support system.
4.4.2.2.1
T
HERMAL
S
UBSYSTEM
The Thermal Subsystem, which is really a subset of active thermal management, acquires waste thermal loads at
or near the site of origin and transports those loads to sites where they are rejected. The Thermal Subsystem also
redistributes heat for reuse by other processes when necessary as part of the defined life support system. Typical Thermal
Subsystem technologies often include heat exchangers, coldplates, pumps and fans, valves, working fluids,
accumulators, and fluid lines.
4.4.2.2.2
C
OOLING
E
XTERNAL
I
NTERFACE
The Cooling External Interface, which is also a subset of active thermal management, rejects waste thermal
loads from the spacecraft. Cooling technologies include rejection hardware such as radiators, phase change devices, and
devices that reject expendable materials carrying thermal loads.
4.4.2.3
General Thermal Management Architecture
In addition to dividing active thermal management as a Thermal Subsystem plus a Cooling External Interface,
active thermal management may be divided into internal thermal control and external thermal control. In this
arrangement, the internal thermal control system (ITCS)
114
initially acquires thermal loads from the crew cabin. The
ITCS transports the thermal loads and releases them to a heat exchanger common to both the ITCS and the external
thermal control system (ETCS).
115
The ETCS acquires thermal loads from the heat exchanger in common with the
ITCS and from heat sources outside the crew cabin. The ETCS transports the combined heat loads to the vehicle heat
rejection devices.
This architecture, using an ITCS with an ETCS, allows a non-toxic working fluid to circulate in all thermal
management hardware located inside the crew cabin while allowing a more appropriate fluid, from an engineering
perspective, to be used in thermal management hardware outside the crew cabin. With recent NASA vehicles, such as the
Shuttle Orbiter and ISS, the ITCS working fluid is water, which is non-toxic and has ideal properties for transporting
thermal loads, except that it has a relatively high freezing point compared to the external environment in low-Earth orbit.
The Shuttle Orbiter and ISS both use more toxic working fluids in their ETCS that have lower freezing point
temperatures. The Shuttle Orbiter uses Freon 21 while ISS relies on anhydrous liquid ammonia.
While this architecture, using an ITCS with an ETCS, allows use of more toxic, freeze-resistant working fluids
in the ETCS while circulating a non-toxic fluid in the ITCS, this approach carries additional expenses compared with a
system using a common loop to both acquire thermal loads from the crew cabin and reject them to the external
environment. In particular, a thermal management system using both an ITCS and an ETCS has the added mass of the
heat exchanger common to the ITCS and ETCS plus the added mass of an additional pump for the additional loop.
Noting that both the Shuttle Orbiter and ISS use two ITCS and two ETCS loops, for redundancy, this arrangement
actually adds two extra heat exchangers and two extra pump packages. Further, while the ITCS and ETCS loops are
cross-linked or plumbed in a manner that any heat load may be acquired and rejected by either of the two loops serving a
particular location in the spacecraft, loss of either an ITCS loop or an ETCS loop degrades the overall heat transport and
rejection capabilities of the thermal control system. Consequently, the additional inherent complexity actually reduces
overall system reliability.
4.4.2.3.1
I
NTERNAL
T
HERMAL
C
ONTROL
S
YSTEM
The internal thermal control system (ITCS) acquires thermal loads from thermal acquisition sites within the
crew cabin and transports those loads to a heat exchanger in contact with the ETCS. The ITCS acquires thermal loads
through specified interfaces. These interfaces are usually coldplates, where the heat loads are cooled by conduction
114
Likewise, this may be designated as the “internal thermal control subsystem.â€
115
At assembly complete, International Space Station also uses the terminology “internal thermal control system†for its
corresponding water coolant loops. However, the corresponding International Space Station “external thermal control system†is
referred to as the “external active thermal control system†(EATCS). Combined, the ITCS and EATCS are the “active thermal
control system†(ATCS).
70
through the hardware’s external structure, or heat exchangers, where the heat loads are initially cooled by convection to a
working fluid. In the second case, the most common working fluid within a crew cabin is the enclosed atmosphere
because many heat loads release their waste heat to the cabin atmosphere either by convection or radiant transfer. Gas-
liquid heat exchangers transfer the atmospheric heat loads to the ITCS.
Cabin atmospheric thermal loads are removed by the gas-liquid heat exchanger through two approaches.
Sensible heat is released from cabin atmospheric gases by convection to the gas-liquid heat exchanger. Latent heat is
released by condensing water vapor, also called humidity, from the cabin atmospheric gases, removing both humidity
and thermal energy by convection with phase change.
Though removal of sensible and latent thermal loads from the cabin atmosphere is a necessary function, because
the cabin atmospheric gases and extracted condensate are involved in this process, it is possible that the cabin
condensing heat exchanger may organizationally be grouped in whole or in part outside of the Thermal Subsystem even
though the underlying processes remove heat. In this document, for completeness, the condensing heat exchanger is
grouped with the Thermal Subsystem.
4.4.2.3.2
E
XTERNAL
T
HERMAL
C
ONTROL
S
YSTEM
The external thermal control system (ETCS) acquires thermal loads from the ITCS and from thermal acquisition
sites outside of the crew cabin. Because the equipment outside of the crew cabin is almost universally in an
unpressurized environment, thermal acquisition interfaces are almost universally coldplates. The ETCS rejects thermal
loads to the environment using specified heat rejection devices, such as radiators, phase change devices, and devices that
reject expendable materials carrying thermal loads. Mixing warm and cooled working fluid in the return line adjusts the
temperature of the ETCS working fluid returning from the heat rejection suite to a prescribed set-point temperature.
While the heat-rejection suite thermally cools working fluid, warm working fluid is routed around the heat rejection suite
using a flow bypass as necessary to meet the set-point temperature for the ETCS heat acquisition devices.
Figure 4.4.1 illustrates the interrelationship between the various component definitions for the ATCS. The
ITCS, denoted in black with plain type, acquires thermal loads within the crew cabin and rejects those thermal loads to
the ETCS. The ETCS, denoted in red with italicized type, acquires thermal loads from the ITCS and equipment outside
of the crew cabin and rejects those thermal loads to the environment. The Thermal Subsystem hardware is displayed on a
green background and includes all ITCS hardware and ETCS hardware not dedicated to heat rejection. Finally, the
Cooling External Interface, displayed on a blue background with underlined type, includes ETCS hardware dedicated to
heat rejection.
71
Condensing Heat Exchangers
Cabin Cold Plates
Other Heat Exchangers
Cabin Atmospheric Heat Loads
Equipment Heat Loads
Pump Package
Water
ITCS
ITCS
ETCS
Pump Package
Cabin Cold Plates
Equipment Heat Loads
Radiators
Rejection with Consumables
Thermal Storage
Flow
Bypass
Consumables
Heat to Environment
Ejected Consumables
ETCS
Thermal
Cooling
Common
ITCS/
ETCS
Heat Exchanger
Figure 4.4.1 Active thermal control system component definitions. Internal thermal control system components are
designated with black lines and plain type. External thermal control system components are designated with
red lines and italicized type. Cooling External Interface hardware is presented on a blue background with
underlined type. Thermal Subsystem hardware is presented on a green background without additional
adjustments to the type font.
72
4.4.3
Thermal Management Technology
4.4.3.1
Historical Thermal Management Approaches
While all NASA human-rated vehicles to date have used thermal management hardware to control the crew
cabin atmospheric temperature and humidity, recent concerns over safety prohibit all but the most recent designs. In
particular, some older spacecraft, such as Apollo, used a mixture of ethylene glycol with water as a working fluid within
an active thermal control system loop that entered the crew cabin. Recent flight rules strongly advise against using
ethylene glycol in any application within a vehicle in which a crewmember may contact it. Accordingly, the discussion
of historical thermal management approaches is limited to designs for the Shuttle Orbiter and the ISS.
4.4.3.1.1
S
HUTTLE
T
HERMAL
M
ANAGEMENT
Figure 4.4.2 shows the ordering of components for one of two ETCS loops in a Shuttle Orbiter. A mechanical
pump package, with two identical units plumbed in parallel, drives the single-phase Freon 21 working fluid. For this
application, one pump is active and the second is a spare. The accumulator sets the low pressure for the fluid loop. When
the working fluid contracts, the accumulator adds fluid, and when the working fluid expands, the accumulator stores any
excess fluid. Because even liquid material properties are not truly invariant to temperature variations, the accumulator
most often compensates for working fluid density variations associated with temperature changes.
The Shuttle was designed to reject heat through several means depending on the mission segment. On the
launch pad and after the ground crew can make connections following landing, the ETCS rejects heat to ground facilities
through the ground service equipment heat exchanger. On launch, re-entry, and when necessary on-orbit, the flash
evaporator allows excess water to evaporate from the outside of the ETCS working fluid line, expelling the vapor, with
its waste heat, to space. Upon re-entry, when the external atmospheric pressure is too great to operate the flash
evaporator efficiently, the ammonia boiler evaporates anhydrous ammonia to cool the ETCS working fluid lines, again
expelling the vapor to the environment.
116
The radiators, which are mounted on the inside of payload bay doors, reject
heat by radiant transfer to space while the Shuttle is on-orbit. Shuttle controls the ETCS working fluid temperature from
the radiators with a bypass loop as depicted. Varying internal flowrates or expendable fluid consumption rates controls
the other heat rejection devices.
Heat is gathered by the ETCS from many sites throughout the vehicle. Those listed as heat exchanger are
liquid/liquid devices where the second operating fluid is the coolant for the attached hardware. The water/Freon
interchanger is the common ITCS/ETCS heat exchanger, while the oxygen restrictor is a heat exchanger between the
ETCS loop and the pressurized cabin oxygen supply.
116
In practice, the ammonia boiler is rarely used as designed. Rather, just before the radiators are removed from service by closing
the payload bay doors, the Shuttle flies an attitude so that the radiators face deep space. This maneuver fills the radiator panels
with chilled Freon 21 and chills the metallic panels as well. Following this maneuver, the radiators are completely bypassed and
the flash evaporator rejects the entire vehicle thermal load. When the flash evaporator ceases operations high in the atmosphere,
flow through the now-stowed radiators is re-established, releasing the previously cooled working fluid. This approach provides
sufficient cooling from when the flash evaporator ceases operations until about 15 minutes after touch down. If all proceeds on
schedule, the ground-cooling cart that interfaces with the ground service equipment heat exchanger is operational by 15 minutes
after touch down, and the ammonia boiler is not used. The ammonia boiler is provided on each mission as a contingency for heat
rejection, and would provide primary cooling if the ground-cooling cart was not available in time or the Shuttle executed a
launch abort.
73
Figure 4.4.2 Active thermal control system hardware for the Shuttle Orbiter. This diagram represents one of two
Freon 21 loops in the Shuttle Orbiter ETCS. Coolant flow is clockwise. Because the ETCS loops run
through an unpressurized portion of the vehicle, the heat exchangers are integral with the devices they cool.
The Water/Freon Interchanger and the Oxygen Restrictor are heat exchangers between the ITCS water loop
and the pressurized cabin oxygen supply, respectively. The Accumulator maintains pressure within the flow
loop. The Radiator, Ground Service Equipment Heat Exchanger, Ammonia Boiler, and Flash Evaporator
are all heat rejection devices.
4.4.3.1.2
I
NTERNATIONAL
S
PACE
S
TATION
T
HERMAL
M
ANAGEMENT
The external active thermal control system (EATCS) for ISS at Assembly Complete is very similar to the
architectures presented above. The ISS EATCS uses single-phase, anhydrous liquid ammonia as its working fluid,
although the corresponding ITCS uses water. The radiators are mounted on booms that connect to the P1 and S1
117
truss
segments through a thermal radiator rotary joint (TRRJ). The TRRJs orient the radiator panels so that they display their
thinnest face, their “edges,†to the Sun, allowing their radiant face-sheets to be exposed only to relatively cooler
environments
118
. While not depicted in Figure 4.4.3, many of the fine details are similar to those in earlier diagrams.
117
The ISS truss segments are numbered in ascending order from the center of the vehicle. The S0, “starboard zero,†truss segment
forms the base for the other truss segments and connects directly to the other ISS modules through the U. S. Laboratory. The
first starboard segment outboard of S0 is S1, while the first port segment outboard is P1, or “port one.â€
118
In rare situations, the TRRJs are not able to completely orient the radiator edges at the Sun, but this case is not common and
only occurs for brief periods.
74
Figure 4.4.3 Active thermal control system hardware for ISS at Assembly Complete. As noted by the arrows, ammonia
flows from radiators to the common ITCS/EATCS heat exchanger then to the warmer thermal loads
associated with electronics mounted on coldplates. Each Thermal Radiator Rotary Joint (TRRJ) rotates to
position the radiator panels so that they face anti-Sun, or “edge-on†to the Sun. The bulk of the EATCS is
located on truss segments S0, S1, and P1.
4.4.3.2
Advanced Thermal Management Approaches
There are many concepts to increase the efficiency of thermal management hardware. Several of the more
common ideas are summarized in the paragraphs below. Please note, however, this is not an exhaustive discussion and
other viable approaches exist.
As noted above, the active thermal control system (ATCS) is the summation of both the ITCS and ETCS
119
.
Further, dividing the ATCS into two loops when, physically, only one loop is required, adds inefficiency to the process
of removing thermal loads from the vehicle even when there are benefits from this approach. An alternate approach
employs only a single ATCS loop in place of each ITCS / ETCS combination. The working fluid requirements are more
stringent because the working fluid may not be a significant hazard to the crew if leaked into the crew cabin, nor may it
be overly susceptible to freezing when flowing through heat rejection equipment. While not employed currently, such
systems are under development and the concept is mentioned here as background.
Another possible advanced concept is a two-phase thermal management working fluid. Thermal management
loops using single-phase working fluids rely on the heat capacity of the working fluid to accept and transport thermal
loads. However, single-phase working fluids are limiting in practice because acquiring a thermal load raises the
temperature of the working fluid, so hardware downstream must reject their thermal loads to a working fluid at a higher
temperature than hardware upstream, and this concern can lead to other inefficiencies. Secondly, a single-phase working
fluid generally can acquire less heat over its entire liquid temperature range than is required to change the phase of the
same mass of working fluid from a liquid to a vapor. If the thermal management working fluid is allowed to vaporize as
it acquires thermal loads, the working fluid remains at a constant temperature and actually less fluid mass is required to
carry the same thermal load. Issues associated with two-phase flows under non-terrestrial gravitational fields remain as
challenges to this approach so far.
Heat pumps also offer promise as advanced thermal management technologies. While terrestrial heat pumps
move heat either into or out of a volume, heat pumps as part of an advanced thermal management system move heat
from the vehicle to the environment only. Specifically, heat pumps use work, either thermal or mechanical, to raise the
temperature of waste heat loads so as to increase the ease of rejecting those loads by radiant heat transfer. While heat
pumps add hardware and use power, the increased temperature of the heat load for radiant emission from the vehicle
119
Or the “external active thermal control system†(EATCS) when using International Space Station nomenclature.
75
decreases the required radiator size so that the overall system may be less massive than a thermal management system
without a heat pump.
4.4.4
Radiant Energy Balance
Heat transfer is a broad topic and any in depth treatment is beyond the scope of this document. Reference a heat
transfer text such as Incropera and DeWitt (1985) for a more complete introduction. However, several definitions and
assumptions are common when analyzing radiant heat transfer for space applications within NASA. Except as
specifically noted, the development below follows Incropera and DeWitt (1985).
In general, heat emitted by a perfectly black body, q
bb
[W], may be described by the Stefan-Boltzmann
equation.
q
bb
=
σ
A T
4
Equation 4.4-1
where
σ
is the Stefan-Boltzmann constant with a value of 5.67
×
10
–8
W/(m²
•
K
4
), A is the body’s surface area [m²], and
T is the body’s absolute temperature [K]. A black body is a perfect emitter and its emittance is a function only of its
temperature once its geometry is fixed.
In practice, most real surfaces are not perfect emitters, and their surface emittance may be described as some
fraction of the emittance from a perfectly black body. For a non-ideal body whose emittance fraction is constant, a
slightly modified relation applies.
q
e
=
σ
ε
A T
4
Equation 4.4-2
where q
e
is emittance [W], and
ε
is the emissivity or the fraction of the surface’s actual emittance compared to its ideal or
black body emittance at its current absolute temperature, T. Alternately,
ε
is unity only for an ideal or black body.
As noted earlier, radiant exchange of thermal energy does not depend on intervening matter for transfer. Rather,
radiant exchange is possible between any two surfaces with a view of each other. Physically, according to one theory,
thermal energy transfers between the surfaces via electromagnetic waves.
120
According to classic physics, thermal
radiation, which is a subset of a broader phenomenon know as electromagnetic radiation, varies between wavelengths of
0.1 and 100
µ
m. Visible light, according to the human eye, is confined to a range varying from 0.40 to 0.70
µ
m. In
addition to visible radiation, classic physics defines thermal radiation at wavelengths less than 0.40
µ
m is also ultraviolet
radiation, and thermal radiation at wavelengths greater than 0.70
µ
m is also infrared radiation. As context,
electromagnetic radiation at wavelengths less than 0.1
µ
m is classified, depending on its wavelength, as ultraviolet
radiation
121
, x-rays, or gamma rays. Electromagnetic radiation at wavelengths immediately greater than 100
µ
m is
classified as microwaves.
When thermal radiation strikes a solid object, it may be absorbed, reflected from the surface, or transmitted
through the object. If the surface is opaque to the incident radiation, transmittance is zero and only absorbance or
reflectance is possible.
α
+
Ï
= 1
Equation 4.4-3
where
α
is the absorptivity and
Ï
is the reflectivity. For an ideal or black body, reflectivity is zero and absorptivity is
unity.
At any given wavelength,
λ
, according to Kirchhoff’s Law, absorptivity and emissivity are equal for a particular
surface if (1) the incident irradiation is invariant with respect to direction, or diffuse, and (2) the surface properties are
invariant with respect to direction, or diffuse.
α
λ
=
ε
λ
Equation 4.4-4
Additionally, if (3) the incident irradiation is diffuse and if (4) the surface properties, the absorptivity and
emissivity, are independent of wavelength,
λ
, the surface is called a gray surface.
120
Alternate theories describe the transfer via photons or quanta, but the image of an electromagnetic wave is most applicable to
the current discussion.
121
Ultraviolet radiation varies from 0.01 to 0.40
µ
m, and so overlaps the range classified as thermal radiation.
76
α
=
ε
Equation 4.4-5
While most real surfaces do not abide by this final requirement to qualify as gray surfaces, many are effectively
gray over some subset of the range of thermal radiation. At Johnson Space Center, two thermal radiation sub ranges are
often defined for radiant transfer calculations (Conger and Clark, 1997). Thermal irradiation between 0.25
µ
m and
2.5
µ
m, inclusive, is designated as solar thermal radiation (AZ Technology, 1993), while thermal irradiation above
2.5
µ
m is designated as infrared thermal radiation. Over each of these sub ranges, material surface properties are
assumed gray.
α
s
=
ε
s
α
ir
=
ε
ir
Equation 4.4-6
where the subscript “s†denotes surface properties over the range of solar thermal radiation and the subscript “ir†denotes
surface properties over the range of infrared thermal radiation. This does not imply that
α
s
equals
α
ir
or that
ε
s
is equal to
ε
ir
. This approach effectively considers Equation 4.4-5 applicable in a piecewise manner over two sub ranges for thermal
radiation.
Physically, except during re-entry or similar operations with extremely high aerodynamic drag, the surface
temperatures of spacecraft in space do not approach the range where surfaces emit in the solar range. So, surface
emissions from spacecraft, planetary surfaces, and other non-glowing physical bodies have surface properties as defined
by the second relation in Equation 4.4-6. Irradiation coming from the Sun, or reflected irradiation that originated from
the Sun, however, emit in the solar range. Because of this, incident or reflected irradiation from the Sun uses surface
properties as defined by the first relation in Equation 4.4-6.
From the perspective of a spacecraft, which emits infrared thermal radiation but likewise absorbs incident solar
thermal radiation, it is meaningful to define the
ε
ir
, for both infrared thermal emittance and absorptivity, and
α
s
, for solar
thermal absorptivity.
4.4.5
Thermal Management Values
This section provides values necessary to estimate heat transfer both within a spacecraft and between a
spacecraft and its environment. Thermal exchange with the environment is more correctly identified as Cooling, but to
ease use of this material, all similar values are grouped below. In fact, many values below may apply both to thermal
management within a spacecraft as well as to heat rejection from the spacecraft.
Table 4.1.1 presents solar absorptivities and infrared emissivities for several common aerospace structural
materials. The end-of-life properties reflect changes associated with external usage in near-Earth space and are not
applicable within the crew cabin. While surfaces within the crew cabin certainly wear, aging mechanisms differ from
those in the vacuum of space or even on the Martian surface. Accordingly, as a first approximation, emissivities for new
materials apply even for a used interior.
Within the crew cabin, thermal considerations are dictated by two concerns. The first is crew comfort and
maintaining equipment within its thermal bounds. The second concern is to maintain humidity within an acceptable
range. If the overall cabin atmospheric temperature drops below the local dew-point temperature, allowing water vapor
to condense. Because liquid water poses a significant hazard to electronics especially in weightless situations,
maintaining cabin atmospheric and humidity within prescribed limits is important.
Table 4.4.2 presents applicable thermal limits from current ALS requirements (Duffield, 2003).
77
Table 4.4.1
Surface Optical Properties for Common Exterior Space Material
New
End-of-Life
122
Material
α
s
ε
ir
α
s
ε
ir
References
Silverized
Teflon
0.07 0.80 0.14 0.80
Aluminized
Teflon
0.12 0.80 0.20 0.80
Ortho Fabric
123
0.18 0.84
Beta Cloth
0.26
0.90
A276
White
Paint
0.28 0.87 0.36 0.90
Clear
Anodized
Aluminum
0.38 0.83 0.58 0.79
Gold
Anodized
Aluminum
0.55 0.81 0.63 0.81
Black
Anodized
Aluminum
0.81 0.88 0.84 0.79
Alodine Aluminum
0.45
0.35
Bare Stainless Steel
0.42
0.11
Sand-Blasted Stainless Steel
0.58
0.38
Bare Titanium
0.52
0.12
Tiodized Titanium
0.82
0.51
From Conger and Clark
(1997) unless otherwise
noted.
Table 4.4.2
Crew Cabin Thermal Ranges
Assumptions
Parameter Units
Lower
Nominal Upper
References
Air Temperature
124
K 291.5
299.8
Dew-Point Temperature
K
277.6
288.7
Relative Humidity
%
25
70
Ventilation m/s
0.076
0.347
From Duffield (2003)
unless otherwise noted
Transport properties for several common thermal management working fluids are tabulated in Table 4.4.3 at
likely operating temperatures. These values support basic thermal loop energy balances.
122
These values apply to external applications only because aging and wear mechanisms within the crew cabin differ considerably
from external aging and wear mechanisms. As a first approximation, surface properties for materials within the crew cabin do
not change with time.
123
The exterior fabric on the EMU.
124
The cabin “dry bulb†atmospheric temperature.
78
Table 4.4.3
Transport Properties for Common Thermal Management Loop Working Fluids
Temperature = 280.0 K
Temperature = 297.0 K
Temperature = 300.0 K
Fluid Hazards
Density
[kg/m³]
Specific
Heat
[kJ/kg
•
K]
Viscosity
[kg/m
•
s]
Density
[kg/m³]
Specific
Heat
[kJ/kg
•
K]
Viscosity
[kg/m
•
s]
Density
[kg/m³]
Specific
Heat
[kJ/kg
•
K]
Viscosity
[kg/m
•
s]
References
Water
1,002.08
4.204 0.00148
998.35
4.187 0.00083
30 % Ethylene
Glycol/70 % Water
Irritant 1,042.15
3.741 0.00311
1,033.34
3.788 0.00176
60 % Ethylene
Glycol/40 % Water
Irritant 1,083.84
3.130 0.00796
1,071.70
3.216 0.00417
30 % Propylene
Glycol/70 % Water
1,027.79
3.800 0.00542
1,018.36
3.861 0.00212
60 % Propylene
Glycol/40 % Water
1,050.18
3.264 0.02090
1,036.12
3.369 0.00710
30 % Glycerin
/70 % Water
1,072 3.656
0.00223
60 % Glycerin
/40 % Water
1,147 3.176
0.00819
Potassium
Acetate/Water
1,196 3.300
0.00270
Fluorinert
72
1,722.12
1.025 0.00117
1,669.92
1.056 0.00092
Hydrofluoroether
HFE-7100
1,522.76
1.147 0.00088
1,477.38
1.187 0.00071
Ammonia
(liquid)
Toxic
628.20
4.679 0.000232
600.46
4.854 0.00021
D Limonene
Flammable
847.5
2.05
0.00091
From Schoppa (1997) unless
noted otherwise.
79
Table 4.4.4 and Table 4.4.5 provide appropriate thermodynamic values to compute energy balances of
phase-change materials for representative materials. Of the materials available, both here and more generally, water
requires the greatest heat input for the least mass and is the “best†phase-change material available (although the
temperatures at which it transitions from one phase to the next sometimes prohibits its use.) While the temperature at
which a liquid boils varies directly with pressure, melting point temperatures are effectively invariant with pressure
for applications likely to see use in spaceflight.
Table 4.4.4
Thermodynamic Properties of Common Thermal Management Phase-Change Materials
for Liquid-Vapor Transitions
Material Formula
Liquid
Density
[kg/m³]
Saturation
Pressure
[kPa]
Saturation
Temper-
ature
[K]
Heat of
Vapori-
zation
[kJ/kg]
Reference
Ammonia NH
3
702.2
(1)
40.7
(1)
223.2
(1)
1,425.8
(1)
690.1
(1)
71.6
(1)
233.2
(1)
1,392.5
(1)
677.5
(1)
119.5
(1)
243.2
(1)
1,361.1
(1)
Water H
2
O 1,000
(1)
0.61
(1)
273.2
(1)
2,500.0
(1)
1,000
(1)
1.23
(1)
283.2
(1)
2,478.4
(1)
998
(1)
2.34
(1)
293.2
(1)
2,455.0
(1)
(1)
Howell and Buckius
(1987)
Table 4.4.5
Thermodynamic Properties of Common Thermal Management Phase-Change Materials
for Solid-Liquid Transitions
Material Formula
Solid
Density
[kg/m³]
Liquid
Density
at 20°C
[kg/m³]
Melting
Temper-
ature
[K]
Heat of
Fusion
[kJ/kg]
References
Water H
2
O 920
(1)
998
(2)
273.2
(3)
333.5
(3)
Waxes (Paraffin)
n-Dodecane C
12
H
26
748.7
(3)
263.6
(4)
210.5
(4)
n-Tetradecane C
14
H
30
762.8
(3)
279.1
(4)
229.9
(4)
n-Hexadecane C
16
H
34
773.3
(3)
291.4
(4)
228.9
(4)
n-Octadecane
125
C
18
H
38
776.8
(3)
301.4
(4)
243.5
(4)
(1)
Incropera and DeWitt
(1985)
(2)
Howell and Buckius
(1987)
(3)
Weast and Astle (1979)
(4)
Humphries and Griggs
(1977)
4.5
Waste Subsystem
The Waste Subsystem collects waste materials from life support subsystems and interfaces. Commonly,
wastes are perceived as materials with no further utility. However, because ALS focuses on increased material loop
closure, “wastes†encompass a variety of materials with varying degrees of possible future utility. Wastes might
include crew metabolic wastes, food packaging, wasted food, paper, tape, soiled clothing, brines, inedible biomass,
expended hygiene supplies, and equipment replacement parts from the other subsystems. The traditional definition
of a waste within ALS and within this document excludes most gases, depending on the system configuration. For
example, crew-expelled carbon dioxide might not be recycled within a given life support system architecture. In
such a case, although carbon dioxide is technically a waste material, the Air Subsystem typically assumes the
responsibility for waste gases. However, the Waste Subsystem might ultimately collect the expended carbon dioxide
scrubbing materials and trapped gases if those gases are not vented. To further complicate subsystem definitions, a
waste-processing device might incorporate trace contaminant control hardware which is usually an Air Subsystem
function, to control the release of potentially harmful gases. Further information related to waste types and
characteristics is included below.
125
The liquid density for n-octadecane is evaluated at 28°C.
80
Wastes sent to the Waste Subsystem may be handled in many ways. Wastes accepted by the Waste
Subsystem may be collected and stored, prepared for long-term storage, processed to recover resources, processed to
render them safe for disposal, and/or disposed of, depending on the mission-specific requirements and constraints.
The mission requirements and constraints consider cost, safety, planetary protection if applicable, integration with
other subsystems, resource recovery, and any other pertinent issues defined for a specific vehicle.
Current NASA spacecraft waste-handling approaches essentially rely on dumping and storage. On Shuttle
missions, most waste is stored and returned to Earth with little or no processing. Consequently, the volume of wastes
can be significant. Waste processing on Shuttle includes drying fecal material by exposure to the vacuum of space.
Waste from ISS is returned to Earth either via a controlled re-entry aboard the Shuttle, either in the orbiter mid-deck
or within a multi-purpose logistics module in the payload bay, or aboard Progress cargo modules. If the wastes are
removed from ISS using a Progress module, they are incinerated along with the vehicle during destructive re-entry.
Wastewater, excess fuel cell product water, urine, and condensate are dumped, as necessary, from Shuttle according
to the mission schedule.
In future long-duration missions, wastes may be disposed directly, or they may be processed. For example,
during transit to Mars, jettisoning trash might be acceptable, though waste might be retained for radiation shielding
or resource recovery. However, jettisoning waste on the Martian surface may be constrained by planetary protection
protocols for exploration missions. Organic materials and microbial agents could threaten to biologically
contaminate the Martian environment. Wastes may be processed to recover useful resources, such as water and
carbon dioxide. Wastes might also be processed in preparation for long-term storage or disposal, for example,
microbial inactivation/elimination. Specific waste processing operations depend upon the mission scenario and the
system-level costs versus the system-level benefits.
4.5.1
Historical Data on Skylab
The first NASA medium-duration missions were performed aboard Skylab. Prior to Skylab, the longest
duration missions were Gemini 7, 14 days, and Apollo 17, 13 days. Within the Gemini and Apollo programs, wastes
were either returned to Earth in the vehicle, or dumped, most notably on the Lunar surface. On Skylab, the Saturn
S-IVB
126
oxygen tank was used for waste disposal. The tank was vented to space through non-propulsive vents.
Wastes were placed in the tank through an airlock and off gassed to space. This eliminated the possibility of
contamination of the crew areas through off-gassing and stored the wastes in a safe manner for an indefinite time.
However, off-gassing may have contaminated the Skylab’s exterior surfaces.
4.5.2
Historical Waste Loads from Shuttle Missions
On Shuttle missions, waste is contained and stowed for return to Earth in either “dry†trash bags, or in the
volume F “wet†trash.
127
Waste stream characterization and water content studies have been performed for each of
six Shuttle missions: STS-29, STS-30, STS-35, STS-51D, STS-99, and STS-101. The waste analyses for STS-29
through STS-51D were conducted to improve solid waste management for the Shuttle program. The waste analyses
for STS-99 and STS-101 provided data to develop a waste model to support the Waste Subsystem analysis within
the ALS Project.
In 1985, wastes for STS-51D were analyzed at NASA Ames Research Center to determine the chemical
composition of wastes and characterize the trash (Wydeven and Golub, 1991). This study found that for 49.2 kg of
total waste, 27.8 kg was food-related trash. Approximately 22 %, or 10.8 kg, of the trash recovered was comprised
of food-related plastic packaging materials. Another 12.2 kg of other plastics and paper brought the total for
packaging materials within the trash to almost 47 %. These data are presented in Table 4.5.1 and summarized in
Table 4.5.2. STS-51D supported seven crewmembers for seven days,
128
which is equivalent to 49 CM-d.
126
The Skylab space station was fabricated from a modified Saturn S-IVB rocket stage.
127
Shuttle stores trash generated within the vehicle itself in plastic bags or liners that are housed within designated storage
areas on the middeck. Volume F is one such trash storage cabinet.
128
Officially, the mission duration for STS-51D is six days, 23 hours, 55 minutes, and 23 seconds.
See http://www-pao.ksc.nasa.gov/kscpao/chron/sts51-d.htm
81
Table 4.5.1
Waste Analysis for STS-51D Trash
Trash Item
Mass
[kg]
Moisture
Content
[%]
Fraction of
Total Mass
[%]
Reference
Food and Food Packaging
Plate Waste
4.8
70
9.8
Plastic Food Containers
10.8
0.2
22.0
Uneaten Food and Beverages
129
12.2 0.2 24.7
Biomedical 6.4
13.0
Aluminum and Tape
Grey Duct Tape
1.6
3.3
Aluminum Cans
1.2
2
2.4
Plastic and Paper
Paper (mixed)
6.4
10.2
13.0
Plastic Bags
3.2
0.2
6.5
Miscellaneous Plastic
2.6
0.2
5.3
Total 49.2
100.0
Wydeven and Golub
(1991)
Storage of wastes on-orbit during early Shuttle missions of 30 CM-d or less posed no challenge for the
allotted resources of the Obiter vehicle. However, as Shuttle missions lengthen for Extended Duration Orbiter of
112 CM-d or more, the volume allocated is inadequate for the safe stowage of trash. Research to determine future
waste stowage requirements for Shuttle missions was initiated in 1989 by the Personal Hygiene and Housekeeping
Laboratory at Johnson Space Center. The study objectives were to determine the mass and volume of waste
generated per crewmember per day, and the amount of liquid stored in trash per crewmember per day (Grounds,
1990). Trash from Shuttle missions STS-29 (Garcia, 1989), STS-30 (Garcia, 1989), and STS-35 were analyzed.
STS-35 differed from the two previous missions because STS-35 used pouches, not boxes, for beverages, and
carried a prototype trash compactor (Grounds, 1990). Subsequently, there is a marked decrease in the volume of
trash from STS-35 compared with the previous missions, probably in large part due to the change in drink
packaging. This reduction in volume was consistent with data collected for STS-99 and STS-101 (Maxwell, 2000a
and 2000b). The data from these missions are summarized in Table 4.5.2.
Not included in the trash data for Shuttle missions are dirty laundry or life support expendables, such as
filters, that return to Earth separately from the trash. STS-101 generated ~50 kg of dirty laundry, consisting of
clothing and towels, occupying ~0.5 m³ (Maxwell, 2000b). Laundry returns to Earth in a mesh laundry bag. Storage,
stabilization, and odor control for laundry, some of it wet, will require dedicated facilities on longer duration
missions if no change is made to the current storage process. No data were available on life support system
expendables for STS-101.
Table 4.5.2 summarizes waste stream analyses completed for STS-99 and STS-101, as well as historical
data from STS-29, STS-30, and STS-51D.
129
This value corresponds to food and drink food packages that were never opened.
82
Table 4.5.2
Shuttle Crew Provision Wastes from Past Missions
Trash
(Solids)
Water
Mission
Duration
[CM-d]
[kg
/CM-d]
[m
3
/CM-d]
[kg
/CM-d]
Percent of
Total Trash
(by mass)
[%]
References
STS-29
(1)
25
1.49
0.0139
0.345 27.35
STS-30
(1)
20
1.63
0.0133
0.417 35.35
STS-35
(2)
63
1.14
0.0067
0.218 26.80
STS-51D
(3)
49 1.01 0.096 9.61
STS-99
(4)
66
1.47
0.0029
0.290 19.75
STS-101
(5)
63 1.62 0.0041
0.439 27.09
Average 48
1.39
0.0082
0.301
24.33
(1)
Garcia (1989)
(2)
Grounds (1990)
(3)
Wydeven and Golub
(1991)
(4)
Maxwell (2000a)
(5)
Maxwell (2000b)
4.5.3
Solid Waste Management for the International Space Station Mission
While limited containment and stowage planning is acceptable for Shuttle, with a 90-day resupply
schedule, ISS may benefit from more robust containment options, additional dedicated storage compartments, and
resource recovery plans to reduce mission costs.
ISS solid waste management today is similar to that for
Mir
. Wastes are contained either in metal
containers, for human wastes, or plastic bags, for crew provision and housekeeping wastes. Filled containers are
returned to Earth either by Progress, which incinerates upon re-entry, or within Shuttle on the middeck or in a multi-
purpose logistics module in the orbiter payload bay. Planned additions to the ISS waste processing hardware include
only a urine processor scheduled for late in the assembly sequence.
Calculated overall waste generation rates, according to the life support subsystem and external interface
categories, using data from ISS human missions through Expedition 3, are provided in Table 4.5.3 (for reference
missions associated with ISS) and Table 4.5.4 (for reference missions associated with near-term exploration
missions to Mars using the Mars Dual Lander Architecture). Stafford, et al. (2001) details the assumed reference
missions. Some data here are inferred, such as air filters. These tables present generation of storable or disposable
wastes based on the assumed configurations. A common list of hardware is used for all vehicles. In cases where
particular hardware is not part of the configuration for a specific reference mission, the location within the table is
marked with an “
2
.†When hardware is present, but a storable or disposable waste is not produced, a “
5
â€appears.
When hardware is present and a storable or disposable waste is produced, a rate, in terms of mass per crewmember
per day, is listed. These tables list only wastes delivered from the hardware or elements for disposal or storage listed,
including any containers. Thus, wastes should not be counted more than once.
The technology suite for segments or vehicles in Table 4.5.3 and Table 4.5.4 are denoted by prefixes.
Vehicles or segments with a prefix of “ISS†assume a hardware suite using primarily technologies listed in
Carrasquillo, et al. (1997) for ISS. Vehicles or segments with a prefix of “ALS†use advanced and current
technologies, as appropriate. Segments listed as Russian On-Orbit Segments of ISS use Russian ISS hardware and
are provided as a reference. See Stafford, et al. (2001) for details.
Possible types of waste are virtually unbounded, so Table 4.5.3 and Table 4.5.4 do not encompass all
possible types of waste within a space mission. Further, the waste types are organized according to the subsystems
and external interfaces defined in Section 2.4 and detailed in Stafford, et al. (2001). The configurations are not
unique, nor are they necessarily complete. However, they provide a documented baseline.
The crew contribution to the waste stream can enter more than one subsystem or interface. For example, the
crew respiration and perspiration load is first received by the life support system within the Air Subsystem, in the
form of water vapor, or by the Human Accommodations Interface on the clothing or as the result of crew hygiene
maintenance such as bathing. Consequently, it is difficult to account for all crew-generated wastes when they are
divided between, and applied to, various subsystems and interfaces, and even more difficult to calculate percentages
accepted by those subsystems and interfaces.
References:
(1)
Jones (2000);
(2)
Wieland (1998a and 1998b);
(3)
Flynn (2003);
(4)
Carrasquillo, et al. (1997);
(5)
This current document;
(6)
Lange (1998);
(7)
Lin (1998).
83
Table 4.5.3
International Space Station Reference Mission Vehicle Wastes
Assumptions
[kg/CM-d]
Component
Russian
On-Orbit
Segment,
Phase 2
Russian
On-Orbit
Segment,
Phase 3
ISS
United
States
On-Orbit
Segment,
Phase 3
ALS
United
States
On-Orbit
Segment,
Post-
Phase 2
ALS
United
States
On-Orbit
Segment,
Phase 3
Notes
Waste
Subsystem
Hardware
Compactor
2
2
5
5
5
Compactors reduce waste volume and waste storage
containment mass
Commode
5
5
5
5
5
Dryer
2
2
2
2
5
Fecal Storage
0.50
(1)
0.50
(1)
0.50
(1)
0.50
(1)
0.13
(1)
This entry includes the Russian KBO (Russian solid
waste container). Usage is based on mass of waste.
Mass of waste depends on moisture content, which
varies between options.
Lyophilization
2
2
2
2
2
This technology yields a dry, stable solid waste and a
separate greywater component.
Solid Waste Storage
5
5
5
5
5
Urinal
5
5
5
5
5
Urine Pretreatment
0.04
(2)
0.04
(2)
0.01
(2)
0.01
(2)
2
(3)
This entry reflects chemical pretreatment, whether
Russian or U.S. This is the mass of chemicals only.
Subtotal
0.54 0.54 0.51 0.51 0.13
References:
(1)
Jones (2000);
(2)
Wieland (1998a and 1998b);
(3)
Flynn (2003);
(4)
Carrasquillo, et al. (1997);
(5)
This current document;
(6)
Lange (1998);
(7)
Lin (1998).
84
Table 4.5.3
International Space Station Reference Mission Vehicle Wastes (continued)
Assumptions
[kg/CM-d]
Component
Russian
On-Orbit
Segment,
Phase 2
Russian
On-Orbit
Segment,
Phase 3
ISS
United
States
On-Orbit
Segment,
Phase 3
ALS
United
States
On-Orbit
Segment,
Post-
Phase 2
ALS
United
States
On-Orbit
Segment,
Phase 3
Notes
Waste
Subsystem
Interfaces
Air Subsystem
0.13
(4)
0.13
(4)
0.13
(4)
0.13
(4)
0.13
(4)
Based on ISS data at Assembly Complete. Reflects
spares for the Air Subsystem.
Biomass
Subsystem
Inedible Biomass
2
2
2
2
2
EVA Support External Interface
Wastes
0.02
(5)
0.02
(5)
0.02
(5)
0.02
(5)
0.02
(5)
The difference in values reflects variations in EVA
workload.
Food Subsystem Wastes
0.32
(5)
0.32
(5)
0.32
(5)
0.32
(5)
0.28
(5)
Assumption: Biomass production reduces prepackaged
food mass slightly.
Human Accommodations External Interface Wastes
Expended Clothing
0.82
(5)
0.82
(5)
0.82
(5)
0.82
(5)
0.02
(5)
Clothing mass reduced by a factor of 40 with laundry.
Assumption: 50% initial water content.
Hygiene Wipes
0.23
(5)
0.23
(5)
0.23
(5)
0.23
(5)
0.15
(5)
Thermal Subsystem Wastes
0.03
(4)
0.03
(4)
0.03
(4)
0.03
(4)
0.03
(4)
Based on ISS data for Assembly Complete.
Waste Subsystem to Environment
Urine to Earth
1.83
(1)
0.16
(1)
2
2
2
Assumption: Stowage in EDV.
Solid Waste to Earth
5
5
5
5
5
Vacuum Vent (Lyophilizer)
2
2
2
2
2
Mass losses for Air and Water to be determined.
Subtotal
3.38 1.71 1.55 1.55 0.63
References:
(1)
Jones (2000);
(2)
Wieland (1998a and 1998b);
(3)
Flynn (2003);
(4)
Carrasquillo, et al. (1997);
(5)
This current document;
(6)
Lange (1998);
(7)
Lin (1998).
85
Table 4.5.3
International Space Station Reference Mission Vehicle Wastes (concluded)
Assumptions
[kg/CM-d]
Component
Russian
On-Orbit
Segment,
Phase 2
Russian
On-Orbit
Segment,
Phase 3
ISS
United
States
On-Orbit
Segment,
Phase 3
ALS
United
States
On-Orbit
Segment,
Post-
Phase 2
ALS
United
States
On-Orbit
Segment,
Phase 3
Notes
Water Subsystem
Air Evaporator Wicks
2
2
2
0.08
(6)
0.04
(6)
This value includes air evaporator wicks and urine
solids. Assumption: Cases with a biological water
processor are 50% less massive.
Flush Water
0.00
(2)
0.00
(2)
0.00
(2)
0.00
(2)
0.00
(2)
None identified to date.
Greywater from Dryer to
Water Subsystem
2
2
2
2
Urine Processing System Brine
to Waste Subsystem
2
5
5
2
2
Urine to Water Subsystem
2
5
5
5
5
Urine Processor
2
5
0.33
(1,7)
5
5
This entry based on vapor compression distillation
performance. Brine is stored in an EDV (Russian
wastewater container).
Water Processor Spares
0.33
(4)
0.33
(4)
0.33
(4)
TBD TBD
Miscellaneous 0.89
(5)
0.89
(5)
0.89
(5)
0.89
(5)
0.89
(5)
Based on ISS data for Assembly Complete.
Subtotal
1.22 1.22 1.55 0.97 0.93
Overall
Total
5.14 3.47 3.61 3.03 1.69
References:
(1)
Jones (2000);
(2)
Wieland (1998a and 1998b);
(3)
Flynn (2003);
(4)
Carrasquillo, et al. (1997);
(5)
This current document;
(6)
Lange (1998);
(7)
Lin (1998).
86
Table 4.5.4
Advanced Mars Exploration Reference Mission Vehicle Wastes
Assumptions
[kg/CM-d]
Component
ISS
Mars
Transit
Vehicle
ISS
Surface
Habitat
Lander
ISS
Mars
Decent
/ Ascent
Lander
ALS
Mars
Transit
Vehicle
ALS
Surface
Habitat
Lander
Notes
Waste
Subsystem
Hardware
Compactor
5
5
2
5
5
Compactors reduce waste volume and waste storage
containment mass
Commode
5
5
5
5
5
Dryer
2
2
2
2
5
Fecal Storage
0.50
(1)
0.50
(1)
0.50
(1)
0.50
(1)
0.13
(1)
This entry includes the Russian KBO (Russian solid
waste container). Usage is based on mass of waste.
Mass of waste depends on moisture content, which
varies between options.
Lyophilization
2
2
2
2
5
This technology yields a dry, stable solid waste and a
separate greywater component.
Solid Waste Storage
5
5
5
5
5
Urinal
5
5
5
5
5
Urine Pretreatment
0.01
(2)
0.01
(2)
0.01
(2)
0.01
(2)
2
(3)
This entry reflects chemical pretreatment, whether
Russian or U.S. This is the mass of pretreatment
chemicals only.
Subtotal
0.51 0.51 0.51 0.51 0.13
References:
(1)
Jones (2000);
(2)
Wieland (1998a and 1998b);
(3)
Flynn (2003);
(4)
Carrasquillo, et al. (1997);
(5)
This current document;
(6)
Lange (1998);
(7)
Lin (1998).
87
Table 4.5.4
Advanced Mars Exploration Reference Mission Vehicle Wastes (continued)
Assumptions
[kg/CM-d]
Component
ISS
Mars
Transit
Vehicle
ISS
Surface
Habitat
Lander
ISS
Mars
Decent
/ Ascent
Lander
ALS
Mars
Transit
Vehicle
ALS
Surface
Habitat
Lander
Notes
Waste
Subsystem
Interfaces
Air Subsystem
0.13
(4)
0.13
(4)
0.13
(4)
0.13
(4)
0.13
(4)
Based on ISS data at Assembly Complete. Reflects
spares for the Air Subsystem.
Biomass
Subsystem
Inedible Biomass
2
2
2
0.01 0.01
Estimates assume 1 m² of growing area producing
0.1 kg/d fresh biomass with at 90% harvest index and
90% moisture content.
EVA Support External Interface
Wastes
2
0.25
(5)
0.25
(5)
2
0.25
(5)
The difference in values reflects variations in EVA
workload.
Food Subsystem Wastes
0.32
(5)
0.32
(5)
0.32
(5)
0.32
(5)
0.28
(5)
Assumption: Biomass production reduces prepackaged
food mass slightly.
Human Accommodations External Interface Wastes
Expended Clothing
0.82
(5)
0.82
(5)
0.82
(5)
0.02
(5)
0.02
(5)
Clothing mass reduced by a factor of 40 with laundry.
Assumption: 50% initial water content.
Hygiene Wipes
0.23
(5)
0.23
(5)
0.23
(5)
0.23
(5)
0.15
(5)
Thermal Subsystem Wastes
0.03
(4)
0.03
(4)
0.03
(4)
0.03
(4)
0.03
(4)
Based on ISS data for Assembly Complete.
Waste Subsystem to Environment
Urine to Earth
2
2
2
2
2
Assumption: Stowage in EDV.
Solid Waste to Earth
2
2
2
2
2
Vacuum Vent (Lyophilizer)
2
2
2
2
5
Mass losses for Air and Water to be determined.
Subtotal
1.53 1.78 1.78 0.74 0.87
References:
(1)
Jones (2000);
(2)
Wieland (1998a and 1998b);
(3)
Flynn (2003);
(4)
Carrasquillo, et al. (1997);
(5)
This current document;
(6)
Lange (1998);
(7)
Lin (1998).
88
Table 4.5.4
Advanced Mars Exploration Reference Mission Vehicle Wastes (concluded)
Assumptions
[kg/CM-d]
Component
ISS
Mars
Transit
Vehicle
ISS
Surface
Habitat
Lander
ISS
Mars
Decent
/ Ascent
Lander
ALS
Mars
Transit
Vehicle
ALS
Surface
Habitat
Lander
Notes
Water Subsystem
Air Evaporator Wicks
2
2
2
0.08
(6)
0.04
(6)
This value includes air evaporator wicks and urine
solids. Assumption: Cases with a biological water
processor are 50% less massive.
Flush Water
0.00
(2)
0.00
(2)
0.00
(2)
0.00
(2)
0.00
(2)
None identified to date.
Greywater from Dryer to
Water Subsystem
2
2
2
2
5
Urine Processing System Brine
to Waste Subsystem
5
5
2
2
2
Urine to Water Subsystem
5
5
5
5
5
Urine Processor
0.33
(1,7)
0.33
(1,7)
2
0.33
(1,7)
5
This entry based on vapor compression distillation
performance. Brine is stored in an EDV (Russian
wastewater container).
Water Processor Spares
TBD TBD TBD TBD TBD
Miscellaneous 0.89
(5)
0.89
(5)
0.89
(5)
0.89
(5)
0.89
(5)
Based on ISS data for Assembly Complete.
Subtotal
1.22 1.22 0.89 1.30 0.93
Overall
Total
3.26 3.51 3.18 2.55 1.93
89
The overall waste generation rates, including both Russian and United States On-Orbit Segments, listed in
Table 4.5.3 include all currently known waste streams. This table should be close to actual waste loads for future
long-duration missions. There are, however, significant gaps in the data, and the total will be greater than what is
listed here.
4.5.4
Solid Waste Management for Future Long-Duration Missions
Waste treatment and removal for missions to Mars and other likely near-term destinations will be more
challenging due to the longer mission duration, regardless of complications from the environment. Waste
management for such missions may employ more efficient versions of technologies developed for Shuttle and ISS—
or, completely different approaches may be more cost effective. Future missions may also generate significant
amounts of inedible biomass. In later or far-term missions, inedible biomass may dominate all other trash sources
(see Table 4.2.9). Finally, depending on the mission protocols, indefinite stable storage for the end products of any
waste-processing scheme may be necessary.
Wastes generated during human spaceflight are materials with no further utility, yet require storage at least
until the mission is complete. However, advanced Waste Subsystems may reclaim valuable resources from input
wastes to allow greater closure within the overall life support system.
The following tables provide mass data for various waste products, organized by references. Though
unavailable here, waste volumes can be significant. Further, although wastes are listed separately below, some
wastes may be contained in or associated with other wastes. For example, feces may adhere to toilet paper, wasted
food may adhere to corresponding food packaging, and miscellaneous body wastes may adhere to hygiene wipes and
dissolve or suspend in hygiene water. Also, various degrees of source separation are possible. For example,
contaminated toilet paper might be collected in a container separate from the feces collector, or contaminated food
packages might be collected separately from wasted food.
These tables do not list all possible waste types for human spaceflight. Because many spacecraft systems
routinely replace parts during scheduled maintenance on long-duration missions, a comprehensive list of wastes
varies with the hardware and configurations used throughout the vehicle. Thus, for a full understanding of
equipment-related wastes during a particular mission, the replaceable units for each piece of hardware must be
known, including any associated packaging. The list must contain detailing of wastes that are commonly of interest
to advanced waste technology developers, due to an anticipated presence or processing potential. Processing
potential may be related to resource recovery potential and anticipated pre-disposal treatment requirements. The
tables list materials that have historically been sent to the Waste Subsystem. Consequently, wastes such as carbon
dioxide gas and trace contaminants are not included here.
As noted above, most wastes depend upon the life support system or vehicle design. For example, the rate
of clothing supply and associated waste generation depends on the presence of a laundry system. The rate at which
waste is generated from food packaging depends on the degree of food bioregeneration, or crop growth, within the
vehicle. Furthermore, the quantity and composition metabolic wastes depend on the composition and quantity of
food consumed; greater metabolic demands and greater consumption of dietary fiber, for example, will result in a
greater generation rate for feces.
The tables present several mass values for some wastes. In such cases, an asterisk denotes the “preferredâ€
or suggested value for waste models if there is an appropriate entry for that particular waste with other important
defining factors about the waste being unknown. The suggested values are also summarized in Table 4.5.5. The
variability between sources is somewhat indicative of the variability in data collection methods. When known, the
data variability is provided below. Additionally, when known, variation of waste mass and composition with
particular environmental parameters are noted, allowing for customization of waste characteristics for a specific
purpose. The degree of confidence in data values is highly variable and often unknown. In some cases, data have not
been diligently collected, and mass estimates are included. In other cases, the values are contingent upon
environmental variables. Finally, the original or earliest data source available for a particular value is listed first,
followed by other sources that reference the earliest source.
90
Table 4.5.5
Summary Information on Wastes for Developing Waste Models
for Future Long-Duration Missions
Assumptions
[g/CM-d]
Waste Lower
Nominal
Upper
References
Equipment Wastes
TBD
(1)
Experiment Wastes
TBD
(1)
Extravehicular Activity Maximum
Absorption Garments (MAGs)
130
173
(1) 132
Feminine Wastes:
131
Menstrual Hygiene Products
104
(2) 133
Menses
113.4
(2) 133
Food Packaging and Adhered Food
324
(3)
Gloves
7
(4)
Grey or Duct Tape
33
(5)
Greywater
TBD
(6)
Greywater Brine
TBD
(6)
Human Detritus:
Finger and Toe Nails
0.01
(7)
Hair
0.33
(7)
Mucus
0.4
(7)
Saliva Solids
0.01
(7)
Skin Cells
3
(7)
Skin Oils
4
(7)
Sweat Solids
8
(7)
Hygiene Products, Miscellaneous
TBD
(5)
Inedible Biomass and Wasted Crop
Materials
TBD
(3)
Laundry: Clothing, Towels and
Wash Cloths
TBD
(5)
Medical Wastes
TBD
(1)
Metabolic Wastes:
Feces
123
(8)
Urine
1,562
(9)
Paper
77
(5)
Wipes:
Toilet Paper
28
(10)
Wipes, Detergent
58
(4)
Wipes, Disinfectant
56
(4)
Wipes, Dry
13
(4)
Wipes, Wet
51
(4)
(1)
See Table 4.5.14.
(2)
See Table 4.5.8
(3)
See Table 4.5.12
(4)
See Table 4.5.11
(5)
See Table 4.5.13
(6)
See Section 4.5.4.9
(7)
See Table 4.5.10
(8)
See Table 4.5.6
(9)
See Table 4.5.7
(10)
See Table 4.5.9
130
Units for this category: grams per crewmember per EVA event [g/CM-EVA].
131
The waste production rates in this category exist only for a woman during her menstrual period.
Units for this category are: grams per crewmember per menstrual period [g/CM-
℘
].
* An asterisk denotes a suggested value. If a particular waste component is essential for a waste model, but details
on the waste component’s generation are unknown, the suggested value is recommended.
91
4.5.4.1
Feces
The mass and composition of feces varies with the quantity and composition of consumed food, among
other factors. Additional fiber in the diet is known to increase daily stool mass (Tucker, et al., 1981). Wydeven and
Golub (1990) provide general detailed estimates of dry human feces. Hawk (1965) states “…the amount of fecal
discharge varies with the individual and diet. Various authorities claim that on an ordinary mixed diet the daily
excretion by an adult male will aggregate 110-170g with a solid content ranging between 25 and 45g; the fecal
discharge of such an individual on a vegetable diet will be much greater and may even be as great as 350 g and
possess a solid content of 75g.â€
NASA (1995) states that the fecal collection system shall have the capacity to accommodate fecal matter of
400g/CM-d by mass and 300 mL/CM-d by volume and a maximum bolus length of 330mm. NASA (1995) also
states that the fecal collection device shall have the capacity to accommodate a maximum of 1000mL of diarrhea
discharge.
Finally, depending on the post-defecation cleansing methods, portions of feces may adhere to toilet paper
or wipes. Table 4.5.6 summarizes information on feces.
Table 4.5.6
Information on Feces
Waste Units
Value
Comments
Feces
g/CM-d *
123
(1)
Composition: 32g/CM-d solids and 91g/CM-d water.
Metabolic Energy: 11.82 MJ/CM-d.
Ingested Food Composition: not available.
g/CM-d 114
(2)
Composition: 32g/CM-d “dehydrated residue†(4.5g/CM-d fat,
4.5g/CM-d protein, 1.8g/CM-d cellulose, 9.5g/CM-d inorganic
matter, 11.4g/CM-d bound water) and 82g/CM-d water.
Metabolic Energy: not available.
Ingested Food Composition: not available.
g/CM-d 120
(3,4)
Composition: 20g/CM-d solids and 100g/CM-d water.
Metabolic Energy: 11.82 MJ/CM-d (assumed).
Ingested Food Composition: not available.
g/CM-d 95.5
(5,6)
Composition: 20.5g/CM-d solids (19.5g/CM-d standard deviation)
and 75g/CM-d water.
Metabolic Energy: not available.
Ingested Food Composition: “relatively low fiber diet, not unlike
that eaten while in space.â€
Note: 24 h mean sample; standard deviation of 95.7g/CM-d.
g/CM-d 132
(7)
Composition: 21g/CM-d solids and 111g/CM-d water.
Metabolic Energy: not available.
Ingested Food Composition: not available.
g/CM-d 30
(8)
Composition: 30g/CM-d solids.
Metabolic Energy: not available.
Ingested Food Composition: not available.
Note: Dry mass only. Wet mass unavailable.
Table References:
(1)
NASA (1991),
(2)
LSDB (1962),
(3)
Parker and West (1973),
(4)
Parker and Gallagher (1992),
(5)
Wydeven and Golub (1990),
(6)
Diem and Lentner (1970),
(7)
Schubert, et al. (1984),
(8)
Tucker, et al. (1981).
4.5.4.2
Urine
The mass and composition of urine varies with the individual, with the quantity and composition of water
and food consumed, as well as with other factors. Wydeven and Golub (1990) provide general detailed estimates of
human urine.
NASA (1995) states the urine collection devices shall have the capacity to accommodate a maximum urine
output volume of 4,000 mL/CM-d and a discharge up to 800 mL in a single urination event at a delivery rate of
50 mL/s.
* An asterisk denotes a suggested value. If a particular waste component is essential for a waste model, but details
on the waste component’s generation are unknown, the suggested value is recommended.
92
Depending on the post-urination-event cleansing methods, urine may adhere to toilet paper or wipes.
Depending on the life support system configuration, urine may or may not be included with greywater. Table 4.5.7
summarizes information on urine.
Table 4.5.7
Information on Urine
Waste Units
Value
Comments
Urine
g/CM-d *
1,562
(1-4)
Composition: 59g/CM-d solids and 1,503g/CM-d water.
Ingested Food Composition: not available.
g/CM-d 1,700
(5)
Composition: 70g/CM-d solids and 1,630g/CM-d water.
Ingested Food Composition: not available.
g/CM-d 1,470
(6)
Composition: 70g/CM-d solids and 1,400g/CM-d water.
Ingested Food Composition: not available.
g/CM-d 2,107
(7,8)
Composition: not available.
Ingested Food Composition: not available.
Note: 24 h mean sample; standard deviation of 1,259g/CM-d.
132
The wet mass was calculated from urine volumes assuming a
density of 1.02g/mL.
g/CM-d 1,390
(9)
Composition: not available.
Ingested Food Composition: not available.
Note: The wet mass was calculated from urine volumes assuming a
density of 1.02g/mL.
Table References:
(1)
Parker and West (1973),
(2)
NASA (1991),
(3)
Wydeven and Golub (1990),
(4)
Schubert, et al.
(1984),
(5)
NASA (1995),
(6)
LSDB (1962),
(7)
Parker and Gallagher (1988),
(8)
Diem and Lentner (1970),
(9)
Leach
(1983).
4.5.4.3
Menstruation
Normally, adult female human beings menstruate once every 26 to 34 days for a duration of 4 to 6 days
(NASA, 1995). These excretion products provide another possible waste generation mechanism. Menstrual flow is
highly variable between individuals. Consequently, menstrual pad and tampon use is also highly variable between
individuals. Female crewmembers on ISS use medication before flight to prevent menstruation for up to six months
during flight. This approach, for many reasons, may not be acceptable for longer duration flights. Depending on the
menstruation management and cleansing method used, menses may adhere to tampons, menstrual pads, toilet paper,
or wipes. Table 4.5.8 summarizes information on menstruation using units of grams per crewmember per menstrual
cycle [g/CM-
℘
].
Table 4.5.8
Information on Menstruation
Waste Units
Value
Comments
g/CM-
℘
*
113.4
(1)
Composition: 80% is released during the first 3 d of menstruation.
Note: Menstrual period duration is 4 to 6 d every 26 to 34 d.
Menses
g/CM-
℘
28
(2,3)
Composition: 10 g/CM-
℘
solids (estimated).
Menstrual
Pads and
Tampons
g/CM-
℘
104
(3)
Note: Mean estimated tampon or menstrual pad usage is
16.2 products/CM-
℘
. The average menstrual product (menstrual
pads or tampons) is 6.4 g/product (clean).
Table References:
(1)
NASA (1995),
(2)
Hallberg and Nilsson (1964),
(3)
Parker and Gallagher (1992).
4.5.4.4
Toilet Paper
Toilet paper usage varies with production rates and consistency of metabolic waste excretions. For all
crewmembers, toilet paper is an important cleansing agent following a bowel movement. Additionally, female
132
78% of the variation in urine output could be explained by variations in fluid consumed.
* An asterisk denotes a suggested value. If a particular waste component is essential for a waste model, but details
on the waste component’s generation are unknown, the suggested value is recommended.
93
crewmembers use toilet paper following urination events and menstrual discharges. Because of relatively frequent
resupply, toilet paper usage on current human missions, such as ISS, may not be as frugal as necessary for longer-
duration missions with limited or no resupply. The value provided in Table 4.5.9 may be an upper limit.
NASA (1995) states, “In microgravity,
133
many more tissues are needed for cleansing the anal areas after
defecation, because gravitational forces are not present to aid in separation of the feces from the body.â€
If used as a means for post-defecation, post-urination and menstruation cleansing, toilet paper may contain
feces, urine, and menses. Table 4.5.9 summarizes information on toilet paper usage.
Table 4.5.9
Information on Toilet Paper
Waste Units
Value
Comments
g/CM-d * 28
(1)
134
Toilet Paper
g/CM-d 5.1
(2,3)
Note: Value computed assuming 6.0 g per bowel movement and
0.86 bowel movements/CM-d based on statistical data. Additionally,
for female crewmembers, add 36 g/CM-d to support post-urination
cleansing following each of 6 urinations/CM-d.
Table References:
(1)
Maxwell (2001a),
(2)
Parker and Gallagher (1992),
(3)
Wydeven and Golub (1990).
4.5.4.5
Miscellaneous Body Wastes
In addition to metabolic excretions, human beings also shed various wastes from the exposed surfaces of
their bodies. These include sweat solids, dead skin cells and associated oils, hair, saliva solids, mucus, fingernails,
and toe nails. Estimates and data for these waste stream components are detailed in Table 4.5.10.
Sweat solids may adhere to clothing, hygiene wipes, towels, wash cloths, and dissolve or suspend in
hygiene greywater. Wydeven, and Golub (1990) and Parker and West (1973) provide approximate compositions for
dry solids in sweat.
Dead skin cells, once free from the surface of the body, exist as cabin “dust†and collect in the cabin air
filter. However, some skin cells may adhere to clothing, hygiene wipes, towels, washcloths, or suspend in hygiene
greywater. Wydeven, et al. (1989) provides estimates for particle and dust generation rates by human beings within
a space station.
Finally, skin oils, hair, saliva solids, and mucus may adhere to clothing, hygiene wipes, towels, washcloths,
or suspend in hygiene greywater. Estimated generation rates for all these human byproducts are provided in
Table 4.5.10.
Table 4.5.10
Information on Miscellaneous Body Wastes
Waste Units
Value
Comments
g/CM-d *
18
(1)
Sweat Solids
g/CM-d 3
(2,3)
Skin Cells
g/CM-d
3
(2,3)
Skin Oils
g/CM-d
4
(2,3)
Hair
g/CM-d 0.33
(2,3)
Composition: 0.3 g/CM-d for facial shaving and 0.03 g/CM-d for
depilation.
Note: The study used only male subjects.
Saliva Solids
g/CM-d
0.01
(2,3)
Mucus g/CM-d
0.4
(2,3)
Finger and Toe
Nails
g/CM-d 0.01
(2,3)
Table References:
(1)
NASA (1991),
(2)
LSDB (1962),
(3)
NASA (1995).
133
See Footnote 33.
134
Charmin (2002) claims “the average person uses 57 sheets [of toilet paper] per day,†or 23 g/CM-d.
* An asterisk denotes a suggested value. If a particular waste component is essential for a waste model, but details
on the waste component’s generation are unknown, the suggested value is recommended.
94
4.5.4.6
Consumable Hygiene Products
Aboard ISS, crewmembers use a variety of wipes and gloves for various housekeeping and hygiene tasks.
Maxwell (2001a) estimates consumption rates for these items based on ISS usage.
Though confirmed only verbally, gloves are used at a rate of one glove per day to clean the toilet after
defecation. These gloves are non-powdered, medium, latex laboratory gloves. Following use, human metabolic
wastes, such as feces or urine, may adhere to the gloves.
Wipes are essential to many tasks aboard ISS and the estimated consumption rates here are based on ISS
usage. Four types of wipes are listed below, though detergent and disinfectant wipes are the same as wet wipes with
a commercial detergent or disinfectant solution applied to them. Because of relatively frequent resupply, wipe usage
on current human missions, such as ISS, may not be as frugal as necessary for longer-duration missions with limited
or no resupply. The values provided in Table 4.5.11 may be an upper limit.
Table 4.5.11
Information on Consumable Hygiene Products
Waste Units
Value
Comments
Gloves g/CM-d
7
(1)
Usage: 1 glove/CM-d to clean the toilet following defecation.
Wipes
Dry
g/CM-d 13
(1)
Usage: This is equivalent to 3 Kimwipe® brand, low-lint 29.2 cm by
30.5 cm wipes/CM-d.
Wet
g/CM-d 51
(1)
Usage: This is equivalent to 4.7 Huggies® brand wet baby
wipes/CM-d. Clark (2003) states that Huggies® wet baby wipes at
75% moisture have a mass of 10.9 g/wipe.
Detergent
g/CM-d 58
(1)
Disinfectant
g/CM-d 56
(1)
Table Reference:
(1)
Maxwell (2001a).
4.5.4.7
Food Packaging, Inedible Biomass, and Wasted Food
The food system, whether prepackaged or based on the conversion of crops, invariably generates a
significant and unique waste stream. Prepackaged food systems generate waste streams including packaging,
comprised of plastic bonded to a metallic layer, with adhered food. Crop-based food systems generate wastes
associated with the crops and with the conversion of crops to finished entrees. Finally, the crew, for many reasons,
may waste food in either system.
The first estimate in Table 4.5.12 provides an estimate of the minimal waste stream from a prepackaged-
food system. Levri, et al. (2001) assumed ambient-stored, prepackaged food, similar in nature to the Shuttle Training
Menu. Further, each crewmember requires metabolic energy from food of 11.82 MJ/CM-d and only 3% of all
prepackaged food and rehydration water is wasted. This is a lower practical wastage limit to estimate the material
wasted if the crew attempted to eat all of the food in every package that is opened. The food wastage represents
approximately 3% of prepackaged food and rehydration water adheres to the sides of the packaging. Additionally,
this study assumed that a small salad crop provides less than 1% of the crew’s food energy needs.
The second estimate, from Maxwell (2001b), an unpublished source to date, studied actual ISS food usage
rates. This study collected information on the preferred menus of three ISS occupants during one expedition and
computed the daily average per crewmember usage rates for food, packaging, and rehydration water. This study
additionally assumed that 15% of all food packages shipped to ISS were unopened and discarded and that 5% of all
opened food with any rehydration water was discarded while adhered to the food packaging. The actual values in
Table 4.5.12 assume modified packaging numbers to reflect more recent food packaging mass data as presented in
Levri, et al. (2001). Further, because actual crewmembers are not nominal crewmembers, the nominal metabolic
energy of 11.82 MJ/CM-d does not apply to these data. Lastly, food wastage assumptions for future long-duration
missions are usually more conservative than ISS usage values because resupply may be more limited or completely
nonexistent.
Crops and food processing may generate wastes during crop production, in the form of inedible biomass
and expended nutrient solution or other growth support agents, and post-harvest during the production of food
products and meals from the crops, in the form of wasted edible biomass, cleansing agents, food preparation fluids
and agents, and even plate waste. These waste generation rates are highly variable and mission dependent.
* An asterisk denotes a suggested value. If a particular waste component is essential for a waste model, but details
on the waste component’s generation are unknown, the suggested value is recommended.
95
Table 4.5.12 summarizes information on food packaging, inedible biomass, and wasted food.
Table 4.5.12
Information on Food Packaging, Inedible Biomass, and Wasted Food
Waste Units
Value
Comments
g/CM-d *
324
(1)
Composition: 62g/CM-d adhered food (~73% moisture content,
including beverages) and 262g/CM-d plastic packaging.
Metabolic Energy: 11.82 MJ/CM-d.
Ingested Food Composition: ambient-stored, prepackaged food
system.
Food
Packaging and
Adhered Food
g/CM-d 508
(2)
Composition: 206g/CM-d unopened food (175 g/CM-d food and
31 g/CM-d plastic packaging) and 302g/CM-d adhered food and
packaging waste (58 g/CM-d food, 176g/CM-d plastic packaging,
and 68g/CM-d rehydration water).
Metabolic Energy: not available.
Ingested Food Composition: ambient-stored, prepackaged food
system.
Inedible
Biomass and
Wasted Crop
Materials
g/CM-d TBD
Note: Highly mission dependent. See Table 4.2.7 for inedible
biomass productivity under typical crop growth chamber conditions.
See Table 4.2.6 for suggested application based on the mission. See
Table 4.2.9 for examples of diets using crops.
Table References:
(1)
Levri, et al. (2001),
(2)
Maxwell (2001b).
4.5.4.8
Paper, Tape, Miscellaneous Hygiene Products, and Clothing
Human activities generate a number of waste streams not related to metabolic activity. In particular,
documentation generates waste paper, tape is used to seal plastic garbage bags, crew hygiene activities contribute
many items to the waste stream, and clothing, when used, adds another waste stream for long-duration missions.
ISS uses paper for documentation and the data point in Table 4.5.13 is based on ISS usage rates. Waste
paper generation rates can vary significantly between ISS increments and may not be closely correlated to the
number of crewmembers. It is theorized that the relatively frequent upload and download of supplies to ISS is
strongly related to the somewhat high rate of waste paper generation from documentation. Much lower waste paper
generation rates for documentation are likely on longer-duration missions with little or no resupply.
Grey or duct tape has traditionally been used on Shuttle and ISS missions to bind bags of trash. On future
missions, the crew may utilize other approaches for sealing trash bags and other tasks where tape might be used.
Consequently, tape usage is contingent on vehicle design.
As noted in Table 4.5.13, waste generation rates associated with personal hygiene products can be
significant. The data here are based on ISS usage rates. These values may include items such as dental floss,
toothbrushes, containers for toothpaste, shave cream, razors, mouthwash, shampoo, moisturizing lotion, deodorant,
sun block, chap stick, makeup, and similar personal hygiene products. The value here should probably be considered
a historical point, and future long-duration missions with little or no resupply will be much lower. Theoretically, the
relatively frequent resupply schedule for ISS is strongly correlated to the surprisingly high rate of miscellaneous
hygiene product waste generation.
Clothing usage and associated dirty clothing generation rates are also significant historically, as
documented in Table 5.3.1 for ISS. Actual expended clothing generation rates are strongly correlated to how long
clothing may be used before it is sufficiently worn or dirty and no longer fit for use. A laundry can increase clothing
life, reducing waste generation rates associated with discarded clothing, at a cost of other vehicle resources such as
power, crewtime, and water usage.
As a simplifying assumption, clothing is comprised of 100% cotton and has 8.5% moisture content when
clean and dry, an industry standard for cotton. Actual clothing may be comprised of other materials that are more
efficient and fire retardant, but historically, crewmembers preferred clothing with higher cotton content. Clothing
will likely not be discarded in clean form. Rather: clothing, towels, and washcloths will likely contain skin cells,
sweat solids, skin oil, hair, and other miscellaneous body wastes. Towels and washcloths will likely also contain
* An asterisk denotes a suggested value. If a particular waste component is essential for a waste model, but details
on the waste component’s generation are unknown, the suggested value is recommended.
96
moisture from sweat and bathing. McGlothlin (2000) reports that the average 49-g Class III
135
Shuttle washcloth,
measuring 30.5 cm by 30.5 cm and comprised of 100% cotton, retains up to 202g of water when completely soaked.
Table 4.5.13 summarizes information on waste streams from paper, tape, miscellaneous hygiene products,
and clothing.
Table 4.5.13
Information on Paper, Tape, Miscellaneous Hygiene Products, and Clothing
Waste Units
Value
Comments
Paper g/CM-d
77
(1)
Composition: 6% moisture content.
Grey or Duct
Tape
g/CM-d 33
(2)
Note: This value is highly design contingent.
The value here represents ISS usage.
Misc. Hygiene
Products
g/CM-d 781
(1)
Note: This value is highly design contingent. The value here
represents ISS usage. Future missions may allow much lower waste
generation rates from miscellaneous hygiene products.
Clothing,
Towels, and
Wash-cloths
g/CM-d TBD
Composition: 100% cotton solids, with 8.5% moisture content
(clean and dry).
Note: See Table 5.3.1 for expended clothing generation rates.
Table References:
(1)
Maxwell (2001b),
(2)
Wydeven, et al. (1989).
4.5.4.9
Greywater and Brine
Wastewater and brines, though historically processed by the Water Subsystem, may initially or post-
processing pass to the Waste Subsystem. Section 4.6 lists wastewater generation rates and stream compositions.
However, these tables do not provide greywater generation data for configurations with crop production or food
processing. Greywater production from such activities depends on the crops produced, the growing techniques, the
crop processing approaches following harvest, the food processing technology, and the processing equipment and
crop cleansing approaches. Finally, greywater may also include urine.
In general, greywater production rates and, more importantly here, the rate of wastewater transfer to the
Waste Subsystem, are highly dependent upon the vehicle design. The individual greywater production rates are
variable, and decisions about how the wastewater streams are managed significantly influence the wastewater and
brine loads passed to the Waste Subsystem.
Brine production rates depend primarily upon the architecture of the water system. If greywater is
processed for reuse, the degree of recovery determines the composition of the brine remaining after treatment. Most
advanced physicochemical water processors recover 95% to more than 99% of the water within the input greywater
stream.
4.5.4.10
Other Waste Streams
Several other notable waste streams are possible. Wastes associated with extravehicular activities depend
on the frequency of extravehicular activities. Other waste streams from equipment, experiments, and medical tests
are highly variable and depend on the vehicle and mission architecture.
Extravehicular activities (EVA) supply waste streams to the life support system. While some wastes are
gaseous, others are solid wastes. Most significantly, crewmembers are provided with a maximum absorption
garment (MAG) to catch metabolic wastes. A used garment may be contaminated with urine, feces, and other wastes
associated with exposure to human skin. The data in Table 4.5.14 are based on ISS equipment and production rates
in terms of grams per crewmember per EVA sortie [g/CM-EVA]. Data on other likely EVA wastes, such as food
sticks, drink pouches, and batteries, were unavailable. EVA consumption rates for consumables are given in
Table 5.2.5, although these values do not reflect solid waste production rates.
Equipment wastes are highly variable with the overall vehicle design. Equipment wastes include supplies
for life support hardware, such as filters and plastic bags. Generally, the Waste Subsystem design varies with the life
support system architecture, including the degree of resource recovery and containment for pre-processing storage,
post-processing storage, and disposal. For example, a system in which there is no recovery from solid wastes, such
135
Note: “Class III†hardware is dimensionally the same and functionally similar to flight, or “Class I,†hardware. However,
Class III hardware is not, in general, identical to Class I hardware.
* An asterisk denotes a suggested value. If a particular waste component is essential for a waste model, but details
on the waste component’s generation are unknown, the suggested value is recommended.
97
as on ISS, may require more Waste Subsystem resupply items than a system that reuses or recovers resources.
Regarding storage options, some equipment wastes might be returned to its original stowage volumes, although
cleaning may be required before such an approach is acceptable. For example, contaminated membranes from the
Water Subsystem might be cleaned to remove water wastes and then stowed in the original stowage volume for
membranes.
Experimental wastes are highly variable in experimental procedures and mission objectives. Some waste
materials may be hazardous.
Medical wastes are also highly variable with medical protocol. These waste loads could be very sporadic
and may require special handling. Some waste product materials may even be biohazardous.
Table 4.5.14 summarizes information on EVA, equipment, experiment, and medical waste streams.
Table 4.5.14
Information on Other Waste Streams
Waste Units
Value
Comments
EVA Wastes
g/CM-
EVA
173
(1)
Note: This value represents the maximum absorption garment (clean
and dry)
Equipment
Wastes
g/CM-d TBD
Note: Highly variable and dependent on vehicle design.
Experiment
Wastes
g/CM-d TBD
Note: Highly variable and dependent on mission design. Waste
streams delegated to the Waste Subsystem will depend on mission
protocols. Some wastes may be hazardous.
Medical
Wastes
g/CM-d TBD
Note: Highly variable and dependent on mission medical protocol.
Waste streams delegated to the Waste Subsystem will depend on
mission protocols. Some wastes may be biohazards.
Table Reference:
(1)
EDCC (1998).
98
4.6
Water Subsystem
Water may not be the most time-critical life support commodity, but water regeneration streams are the
most massive. Further, water quality is also of great concern with respect to crew safety. No single technology has
proven adequate for water regeneration to date. Instead, a suite of complementary technologies must be employed.
In the past, power use has driven water regeneration. However, other infrastructure costs are also important.
4.6.1
Design Values for Water Subsystems
Clean water is required for drinks, food preparation, personal hygiene, and possibly for cleaning clothes
and equipment. Water quality standards will vary, but they might include potable, hygiene, technical, and plant-
transpired water. The tables here provide anticipated usage rates for several possibilities. The values here are
averages during nominal operation of the life support system. Degraded or emergency life support system values
may be different. Table 4.6.1 lists steady-state water usage estimates for missions of 30 days or less. Table 4.6.2 lists
steady-state water usage estimates for longer duration missions. More importantly here, Table 4.6.3 details
anticipated wastewater generation rates to be processed by the Water Subsystem for long-duration missions. Please
note the water usage rates and wastewater generation rates sometimes differ, as a quick comparison of Table 4.6.2 to
Table 4.6.3 confirms. In some cases, either the water usage or wastewater generation rates are unknown. In other
cases, water usage does not correspond to wastewater generated and sent to the Water Subsystem, varying with the
configuration of the system using the water.
The mission scenarios are defined as: assembly complete ISS, assumed as lacking a waste and hygiene
compartment; a transit mission, currently assumed to have similar hygiene capabilities as ISS; Early Planetary Base,
assumed to have the capability for limited hygiene water use; and Mature Planetary Base, assumed to have the
capability for full hygiene water use as well as a biomass production chamber for food cultivation.
Table 4.6.1
Steady-State Values for Vehicle Water Usage for Short-Duration Missions
136
Assumptions
Parameter Units
Lower
Nominal
Upper
References
Crew Water Allocation,
assuming Minimal Hygiene Water
for a Mission Less Than 30 days
kg/CM-d 2.9
(1)
4.5
(2)
7.7
(2)
(1)
From Apollo Program via
Ewert and Drake (2000)
(2)
Ewert and Drake (2000)
136
For
information
only.
July 2004
99
Table 4.6.2
Typical Steady-State Water Usage Rates for Various Missions
137
Parameter Units
International
Space Station
Transit
Vehicle
Early
Planetary
Base
Mature
Planetary
Base
References
Crew Drinks
kg/CM-d
2.00
(2)
2.00
(2)
2.00
(2)
2.00
(2)
Total Metabolic and Related Consumption kg/CM-d
2.00 2.00 2.00 2.00
Urinal Flush
kg/CM-d
0.30
(1)
0.30
(1)
0.50
(2)
0.50
(2)
(1)
NASA (2004)
(2)
NASA (1991)
(3)
Architecture dependent.
Oral Hygiene
kg/CM-d
0.37
(2)
0.37
(2)
0.37
(2)
0.37
(2)
Hand Wash
kg/CM-d
n/a
n/a
4.08
(2)
4.08
(2)
Shower
138
kg/CM-d
n/a n/a
2.72
(2)
2.72
(2)
Laundry
kg/CM-d
n/a n/a n/a
12.47
(2)
Dish
Wash
kg/CM-d
n/a n/a n/a
5.44
(2)
Food Processing and Preparation
kg/CM-d
TBD
TBD
TBD
TBD
Total Hygiene Consumption
kg/CM-d
0.67
0.67
7.67
25.58
Payload kg/CM-d
2.18
(1)
TBD
(3)
TBD
(3)
TBD
(3)
Total Payload Consumption
kg/CM-d
2.18
Total Water Consumption
kg/CM-d
4.85 2.67 9.67 27.58
Biomass Production Water
Consumption
139
kg/m²
•
d
n/a n/a n/a 4.00
137
For
information
only.
138
Assuming one shower per two days.
139
The water quality may differ from the standards for crew use for water provided to plants as nutrient solution. In fact, plants might provide some water reclamation functions
even while providing raw agricultural products.
July 2004
100
Table 4.6.3
Typical Steady-State Wastewater Generation Rates for Various Missions
Parameter Units
International
Space Station
Transit
Vehicle
Early
Planetary
Base
Mature
Planetary
Base
References
Urine kg/CM-d
1.20
(1)
1.50
(2)
1.50
(2)
1.50
(2)
Urinal Flush
kg/CM-d
0.30
(1)
0.30
(1)
0.50
(2)
0.50
(2)
Total Urine Wastewater Load
kg/CM-d
1.80
1.80
2.00
2.00
(1)
NASA (2004)
(2)
NASA (1991)
(3)
Architecture dependent.
Oral Hygiene
kg/CM-d
n/a
n/a
0.37
(2)
0.37
(2)
Hand Wash
kg/CM-d
n/a
n/a
4.08
(2)
4.08
(2)
Shower
140
kg/CM-d
n/a n/a
2.72
(2)
2.72
(2)
Laundry
kg/CM-d
n/a n/a n/a
11.87
(2)
Dish
Wash
kg/CM-d
n/a n/a n/a
5.41
(2)
Food Preparation and Processing
kg/CM-d
n/a
n/a
n/a
TBD
Total Hygiene Wastewater Load
kg/CM-d
0.00
0.00
7.17
24.45+
Crew Latent Humidity Condensate
kg/CM-d
2.27
(2)
2.27
(2)
2.27
(2)
2.90
(2)
Animal Latent Humidity Condensate kg/CM-d
n/a
n/a
TBD
TBD
Total Latent Wastewater Load
kg/CM-d
2.27
2.27
2.27+
2.90+
Payload kg/CM-d
n/a
n/a
TBD
(3)
TBD
(3)
Total Payload Wastewater Load
kg/CM-d
0.00
0.00
0.00+
0.00+
Total Wastewater Load
kg/CM-d
4.07 4.07
11.44+
29.35+
Biomass Production Wastewater
141
kg/m²
•
d
n/a n/a n/a TBD
140
Assuming one shower per two days.
141
The water quality may differ from the standards for crew use for water provided to plants as nutrient solution. In fact, plants might provide some water reclamation functions
even while providing raw agricultural products.
101
4.6.2
Wastewater Component Contaminant Loading
Studies by Carter (1998) and Putnam (1971) provide the data for Table 4.6.4 through Table 4.6.9, which
present wastewater stream aqueous contaminant loadings. Work by Carter (1998) focuses on anticipated wastewater
streams from ISS systems to aid sizing the ISS water processor. Consequently, some contaminants, especially those
associated with ISS cleansing agents in the shower (Table 4.6.6) and hygiene (Table 4.6.7) streams, may be unique
to ISS. Likewise, wastes listed for the EMU (Table 4.6.4) are specific to equipment employed by the Shuttle and ISS
programs. However, such loadings are likely representative. Work by Putnam (1971) characterized only human
urine. The corresponding values given by Carter (1998) for urine reflect the urine processor product stream, as
passed to the other ISS water processing equipment, and not an untreated urine stream.
Table 4.6.4 through Table 4.6.9 have a similar format. The first column of each table provides the
contaminant name. When the common name differs from IUPAC nomenclature, the IUPAC name appears in
brackets. The next two columns, when checked with an “
×
,†identify those compounds in the wastewater stream that
are defined as either controlled inorganic compounds (CI) for potable water streams or have an associated SMAC
for the cabin atmosphere
142
. The molecular weight (MW) and percent carbon are listed next. The loading density
provides the concentration in milligrams of contaminant per liter of wastewater stream. Finally, the last column
provides the percentage of the specific contaminant with respect to the total contaminant loading.
Each table is organized in order of descending concentration, or loading density. Those components in
aggregate comprising less than five percent of the total contaminant loading, or trace components, are listed below
the thick line near the bottom of each table. Trace components that are CI or have a SMAC are listed individually
while all other trace components are listed under the generic heading of “constituents totaling less than 5%.â€
Table 4.6.4 details the anticipated aqueous contaminants in the greywater stream from an EMU. This
stream reflects Shuttle or ISS program technology, so a similar stream for an advanced spacesuit may differ. Carter
(1998) developed this list based on the ISS program.
Table 4.6.4
Wastewater Contaminants in Extravehicular Mobility Unit Stream
Component
C
I
S
M
A
C
MW
Percent
Carbon
[%C]
Loading
Density
[mg/L]
Percent
of
Stream
[%]
acetone [2-propanone]
×
58.1 62.0 0.0256 34.4
Caprolactam
113.2 63.7 0.0227 30.6
Freon 113 [1,1,2-trichloro-1,2,2-trifluoroethane]
×
×
187.4 12.8 0.0108 14.5
ethylene glycol [1,2-ethandiol]
×
62.1 38.7 0.0035 4.7
tetraoxadodecane [2,5,8,11-tetraoxadodecane]
178.2 53.9 0.0035 4.7
tetradecanol [1-tetradecanol]
214.4 78.4 0.0029 3.9
sulfolane [tetrahydrothiophene-1,1-dioxide]
120.2 40.0 0.0020 2.7
constituents totaling less than 5%
0.0029
3.9
Benzene
×
78.1 92.3 0.0002 0.3
Toluene
×
92.1 91.2 0.0002 0.3
Total
0.0742
100
Table 4.6.5 lists the anticipated contaminants from the latent condensate derived from the crew cabin.
Carter (1998) developed this list based on the ISS program.
142
See Duffield (2003) for CI and SMAC requirements.
102
Table 4.6.5
Wastewater Contaminants in Crew Latent Condensate
Component
C
I
S
M
A
C
MW
Percent
Carbon
[%C]
Loading
Density
[mg/L]
Percent
of
Stream
[%]
2-propanol
×
60.1 60.0 46.297 18.6
1,2 propanediol
76.1 47.4 45.234 18.2
bicarbonate
61.0 19.7 33.170 13.3
acetic acid [ethanoic acid]
×
60.1 40.0 14.614 5.9
ammonium
×
18.0 0.0 13.527 5.4
caprolactam
113.2 63.7 11.834 4.8
ethylene glycol [1,2-ethandiol]
×
62.1 38.7 10.224 4.1
glycolic acid [hydroxy acetic acid]
76.1 31.6 10.194 4.1
ethanol
×
46.1 52.1 8.181 3.3
formaldehyde [methanal]
×
30.0 40.0 8.136 3.3
formic acid [methanoic acid]
46.0 26.1 7.239 2.9
propanoic acid
74.1 48.6 3.916 1.6
methanol
×
32.0 37.5 3.737 1.5
lactic acid [2-hydroxy-propanoic acid]
90.1 40.0 3.079 1.2
4-ethyl morpholine
115.2 62.6 2.516 1.0
urea
60.1 20.0 2.415 1.0
chloride
×
35.5 0.0 1.465 0.6
4-hydroxy-4-methyl-2-pentanone
116.2 62.0 1.247 0.5
2-butoxyethoxy-ethanol
162.2 59.2 1.130 0.5
4-acetyl morpholine
129.2 55.8 1.092 0.4
1-butanol
×
74.1 64.8 0.937 0.4
2-butoxyethanol
118.2 61.0 0.803 0.3
carbon disulfide
×
×
76.1 15.8 0.785 0.3
octanoic acid
144.2 66.6 0.665 0.3
zinc
×
65.4 0.0 0.650 0.3
N,N-dimethylformamide [N,N-dimethyl formic acid amide]
73.1 49.3 0.608 0.2
total protein
3,206.3 53.0 0.600 0.2
hexanoic acid
116.2 62.0 0.582 0.2
isocitric acid [1-hydroxy-1,2,3-propanetricarboxylic acid]
192.1 37.5 0.576 0.2
dibutyl amine
129.2 74.3 0.566 0.2
potassium
×
39.1 0.0 0.542 0.2
constituents totaling less than 5%
9.546
3.8
nitrite
×
46.0 0.0 0.517 0.2
2-ethoxyethanol
×
90.1 53.3 0.504 0.2
acetone [2-propanone]
×
58.1 62.0 0.348 0.1
magnesium
×
24.3 0.0 0.282 0.1
phenol
×
94.1 76.6 0.204 0.1
silver
×
107.9 0.0 0.200 0.1
acetaldehyde [ethanal]
×
44.1 54.5 0.098 0.0
cyclohexanone
×
98.1 73.4 0.089 0.0
nickel
×
58.7 0.0 0.087 0.0
acetophenone
×
120.2 80.0 0.083 0.0
calcium
×
40.1 0.0 0.060 0.0
sulfate
×
96.1 0.0 0.052 0.0
methylene chloride [dichloromethane]
×
×
84.9 14.1 0.050 0.0
manganese
×
54.9 0.0 0.035 0.0
methyl ethyl ketone [2-butanone]
×
72.1 66.6 0.023 0.0
iron
×
55.9 0.0 0.008 0.0
tetrachloroethene
×
×
165.8 14.5 0.005 0.0
copper
×
63.6 0.0 0.004 0.0
isobutyl methyl ketone [4-methyl-2-pentanone]
×
100.2 72.0 0.002 0.0
cadmium
×
112.4 0.0 0.001 0.0
lead
×
207.2 0.0 0.001 0.0
toluene
×
92.1 91.2 0.001 0.0
ethyl benzene
×
106.2 90.5
trace
0.0
benzene
×
78.1 92.3
trace
0.0
chloroform [trichloromethane]
×
×
119.4 10.1
trace
0.0
Total
248.76
100
103
Table 4.6.6 details the contaminants from the crew shower stream. Subject to the cleansing agent
employed, actual components in a shower greywater stream may vary. Carter (1998) developed this list based on the
ISS program. Verostko, et al. (1989) and Wydeven and Golub (1990) also provide crew shower greywater models.
Table 4.6.6
Wastewater Contaminants in Crew Shower Stream
Component
C
I
S
M
A
C
MW
Percent
Carbon
[%C]
Loading
Density
[mg/L]
Percent
of
Stream
[%]
sodium coconut acid-n-methyl taurate
341.0 58.0 449.96 47.6
chloride
×
35.5 0.0
106.54 11.3
sodium
23.0 0.0
106.10 11.2
bicarbonate
61.0 19.7 39.10
4.1
total protein
3,206.3 53.0 36.77
3.9
urea
60.1 20.0 36.15
3.8
acetic acid [ethanoic acid]
×
60.1 40.0 30.11
3.2
propanoic acid
74.1 48.6 30.00
3.2
lactic acid [2-hydroxy-propanoic acid]
90.1 40.0 24.16
2.6
potassium
×
39.1 0.0 17.50 1.9
ammonium
×
18.0 0.0 16.80 1.8
sulfate
×
96.1 0.0 12.33 1.3
constituents totaling less than 5%
32.39 3.4
ethanol
×
46.1 52.1 3.08
0.3
ethylene glycol [1,2-ethandiol]
×
62.1 38.7 2.51
0.3
methanol
×
32.0 37.5 0.90
0.1
phenol
×
94.1 76.6 0.37
0.0
acetone [2-propanone]
×
58.1 62.0 0.21
0.0
formaldehyde [methanal]
×
30.0 40.0 0.10
0.0
propionaldehyde [propanal]
×
58.1 62.0 0.09
0.0
Total
945.2
100
104
Table 4.6.7 details the contaminants from the crew hygiene stream derived from hand and oral cleansing
operations. Subject to the cleansing agent employed, actual components in a hygiene greywater stream may vary.
Carter (1998) developed this list based on the ISS program. Wydeven and Golub (1990) also provides a crew
hygiene greywater model.
Table 4.6.7
Wastewater Contaminants in Crew Hygiene Stream
Component
C
I
S
M
A
C
MW
Percent
Carbon
[%C]
Loading
Density
[mg/L]
Percent
of
Stream
[%]
sodium coconut acid-n-methyl taurate
341.0 58.0 638.85 62.8
sodium
23.0 0.0 85.00 8.3
chloride
×
35.5 0.0 76.12 7.5
lactic acid [2-hydroxy-propanoic acid]
90.1 40.0 34.34
3.4
acetic acid [ethanoic acid]
×
60.1 40.0 28.59
2.8
total protein
3,206.3 53.0 25.04
2.5
bicarbonate
61.0 19.7 24.44
2.4
sulfate
×
96.1 0.0 11.09 1.1
formic acid [methanoic acid]
46.0 26.1 11.05
1.1
potassium
×
39.1 0.0 10.78 1.1
propanoic acid
74.1 48.6 9.56
0.9
ethanol
×
46.1 52.1 8.57
0.8
phosphate
95.0 0.0 7.20 0.7
constituents totaling less than 5%
32.09 3.2
methanol
×
32.0 37.5 6.36
0.6
ammonium
×
18.0 0.0 5.81 0.6
ethylene glycol [1,2-ethandiol]
×
62.1 38.7 1.58
0.2
1-propanol
×
60.1 60.0 0.58
0.1
2-propanol
×
60.1 60.0 0.26
0.0
phenol
×
94.1 76.6 0.16
0.0
dimethyl disulfide
×
94.2 25.5 0.13
0.0
acetone [2-propanone]
×
58.1 62.0 0.09
0.0
pentane
×
72.2 83.2 0.09
0.0
formaldehyde [methanal]
×
30.0 40.0 0.07
0.0
propionaldehyde [propanal]
×
58.1 62.0 0.05
0.0
1-butanol
×
74.1 64.8 0.05
0.0
dimethyl sulfide
×
×
62.1 38.7 0.05
0.0
carbon disulfide
×
×
76.1 15.8 0.02
0.0
Total
1,018.0
100
105
Table 4.6.8 lists the composition of unprocessed urine as derived from the human metabolic process. The
reference is Putnam (1971).
Table 4.6.8
Wastewater Contaminants in Crew Urine Stream
Component
C
I
S
M
A
C
MW
Percent
Carbon
[%C]
Loading
Density
[mg/L]
Percent
of
Stream
[%]
urea
60.1 20.0 13,400 36.2
sodium chloride
×
58.4 0.0 8,001 21.6
potassium sulfate
×
174.3 0.0 2,632 7.1
potassium chloride
×
74.6 0.0 1,641 4.4
creatinine
113.1 42.5 1,504 4.1
ammonium hippurate
×
196.2 55.1 1,250 3.4
magnesium sulfate
×
120.4 0.0 783 2.1
ammonium nitrate
×
80.0 0.0 756 2.0
ammonium glucuronate
×
211.2 34.1
663 1.8
potassium bicarbonate
×
100.1 12.0
661 1.8
ammonium urate
×
185.1 32.4
518 1.4
ammonium lactate
×
107.1 33.6
394 1.1
uropepsin (as tyrosine)
181.2 59.7
381 1.0
creatine
131.1 36.6
373 1.0
glycine
75.1 32.0
315 0.9
phenol
×
94.1 76.6
292 0.8
ammonium L-glutamate
×
164.2 36.3
246 0.7
potassium phosphate
×
212.3 0.0 234 0.6
histidine
155.2 46.4
233 0.6
androsterone
290.4 78.6
174 0.5
1-methylhistidine
169.2 49.7
173 0.5
glucose
180.2 40.0
156 0.4
imidazole
68.1 52.9
143 0.4
magnesium carbonate
×
84.3 14.2
143 0.4
taurine [2-aminoethanesulfonic acid]
125.1 19.2
138 0.4
constituents totaling less than 5%
1,487 4.0
ammonium aspartate
×
150.1 32.0
135 0.4
ammonium formate
×
63.1 19.0
88 0.2
calcium phosphate
×
310.2 0.0
62 0.2
ammonium pyruvate
×
105.1 34.3
44 0.1
ammonium oxalate
×
124.1 19.4
37 0.1
Total
37,057
100
106
Table 4.6.9 lists anticipated contaminants from the latent condensate derived from experimental animals.
Carter (1998) developed this list based on the ISS program.
Table 4.6.9
Wastewater Contaminants in Animal Latent Condensate
Component
C
I
S
M
A
C
MW
Percent
Carbon
[%C]
Loading
Density
[mg/L]
Percent
of
Stream
[%]
ammonium
×
18.0 0.0
581.88 81.9
acetic acid [ethanoic acid]
×
60.1 40.0 33.58
4.7
2-propanol
×
60.1 60.0 14.76
2.1
acetone [2-propanone]
×
58.1 62.0 14.69
2.1
phosphate
95.0 0.0 12.09 1.7
glycerol [1,2,3-propanetriol]
92.1 39.1 11.23
1.6
total protein
3,206.3 53.0 8.81
1.2
constituents totaling less than 5%
16.36 2.3
potassium
×
39.1 0.0 5.07 0.7
ethylene glycol [1,2-ethandiol]
×
62.1 38.7 4.18
0.6
sulfate
×
96.1 0.0 1.47 0.2
methanol
×
32.0 37.5 1.25
0.2
nitrate
×
62.0 0.0 0.87 0.1
chloride
×
35.5 0.0 0.74 0.1
calcium
×
40.1 0.0 0.74 0.1
2-butanol
×
74.1 64.8 0.60
0.1
magnesium
×
24.3 0.0 0.56 0.1
barium
×
137.3 0.0 0.53 0.1
zinc
×
65.4 0.0 0.41 0.1
acetaldehyde [ethanal]
×
44.1 54.5 0.33
0.0
formaldehyde [methanal]
×
30.0 40.0 0.12
0.0
nickel
×
58.7 0.0 0.08 0.0
copper
×
63.6 0.0 0.07 0.0
phenol
×
94.1 76.6 0.04
0.0
arsenic
×
74.9 0.0 0.03 0.0
iron
×
55.9 0.0 0.02 0.0
silver
×
107.9 0.0 0.01 0.0
manganese
×
54.9 0.0 0.01 0.0
Total
710.55
100
4.6.3
Wastewater and Intermediate Water System Solution Formulations for Testing
The following formulations provide standardized feed solutions for developmental hardware. Please see
Verostko, et al. (2004) for additional details. Sections 4.6.3.1 and 4.6.3.2 present projected input wastewater streams
from the crew cabin for a transit vehicle and an early planetary base, respectively. The concentrations and volumes
for the transit mission wastewater stream are originate in literature describing wastewater for ISS. The wastewater
volumes for the early planetary base originate from flowrates measured during the Advanced Water Recovery
System test. These formulations provide researchers with two different feed wastewater streams for testing
developmental water processing hardware. For completeness, both streams should be considered.
Sections 4.6.3.3, 4.6.3.4, and 4.6.3.5 detail product streams from the biological water processor (BWP), a
reverse osmosis (RO) system, and the air evaporation subsystem (AES), respectively, to provide authentic pre-
processed input streams for downstream hardware. These formulations of hardware product streams are based on
data taken at Johnson Space Center during an Integrated Advanced Water Recovery Systems test. The tested
configuration included a BWP coupled with a RO system. The BWP included a packed-bed denitrification reactor
and a tubular nitrification reactor. An AES dewatered brine from the RO system. Though not represented in the data
below, the dewatered brine and RO-system permeate were post-processed during testing with a mixed-media ion
exchange bed and a series of ultraviolet-light lamps. Because water quality from actual water processing hardware
may vary, nominal and worst-case formulations are listed for both the RO permeate and the AES condensate. The
BWP effluent is an appropriate feed stream for developmental secondary processors while the RO permeate and the
AES condensate formulations provide appropriate feed streams for developmental post-processors.
107
4.6.3.1
Transit Mission Wastewater Ersatz
4.6.3.1.1
T
RANSIT
M
ISSION
W
ASTEWATER
E
RSATZ
C
ONCENTRATE
C
ONSTITUENT
T
ABLES
Table 4.6.10 through Table 4.6.14 describe the components of the transit mission (TM) wastewater ersatz.
The state of each constituent is indicated by its measured value. For solid constituents, a mass is listed. For liquid
constituents, a volume is listed. In all cases, when applicable, the constituent purity or concentration is noted in the
first column following the constituent name. When not otherwise noted, all constituent purities are greater than 99%.
Final solution properties are listed in Table 4.6.15. The preparation instructions are presented in Section 4.6.3.1.2.
For the original source, see Verostko, et al. (2004)
Table 4.6.10
Concentrate 1: Urine 1 – Organic Compounds for TM Wastewater Ersatz (C1)
143
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
urea NH
2
CONH
2
60.06 52.021
-
creatinine (98%)
C
4
H
7
N
3
O 113.10
5.221
-
histidine, soluble (98%)
C
6
H
9
N
3
O
2
155.20
0.958
-
taurine C
2
H
5
NSO
3
125.10
0.556
-
glutamic acid
C
5
H
9
NO
4
147.10
1.660
-
glucose (96%)
C
6
H
12
O
6
390.40
2.636
-
ammonium citrate (99%)
(NH
4
)
2
C
6
H
5
O
7
226.20 12.340 -
ammonium formate (97%)
NH
4
HCO
2
63.10 1.466 -
ammonium oxalate monohydrate (NH
4
)
2
C
2
O
4
142.10
0.665
-
Table 4.6.11
Concentrate 2: Urine 2 – Inorganic Compounds for TM Wastewater Ersatz (C2)
144
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
sodium chloride
NaCl
58.40
23.126
-
magnesium chloride hexahydrate
MgCl
2
•
6H
2
O
203.31 5.483 -
potassium bicarbonate
KHCO
3
100.10
2.197
-
potassium carbonate
K
2
CO
3
138.21
0.474
-
potassium monobasic phosphate
KH
2
PO
4
136.09
1.069
-
potassium
chloride
KCl
74.60 5.436 -
potassium sulfate
K
2
SO
4
174.29
7.424
-
calcium chloride
CaCl
2
110.99
0.221
-
sodium sulfate
Na
2
SO
4
142.00
4.144
-
143
This solution is 10 times more concentrated than will be its constituents in the final TM wastewater ersatz.
144
This solution is 10 times more concentrated than will be its constituents in the final TM wastewater ersatz.
108
Table 4.6.12
Concentrate 3: Humidity Condensate for TM Wastewater Ersatz (C3)
145
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
acetic acid
CH
3
CO
2
H 60.05
- 0.441
benzoic acid
C
6
H
5
CO
2
H 122.20
0.046
-
benzyl alcohol
C
6
H
5
CH
2
OH 108.14
-
0.259
ethanol C
2
H
6
O 46.07
-
1.506
acetone CH
3
COCH
3
58.08
- 0.030
caprolactam C
6
H
11
NO 113.16
0.191
-
phenol C
6
H
5
OH 94.11
0.027
-
N,N-dimethylformamide HCON(CH
3
)
2
73.10
- 0.035
ethylene glycol
HOCH
2
CH
2
OH 62.07 -
0.157
4-ethyl morpholine
C
6
H
13
NO 115.18
- 0.072
formaldehyde (37%)
HCHO
30.03
-
0.461
formic acid (96%)
HCO
2
H 46.03
-
0.208
lactic acid
CH
3
CH(OH)CO
2
H 90.08 -
0.187
methanol CH
3
OH 32.04
-
0.218
1,2-propanediol C
3
H
8
O
2
76.09
-
0.013
2-propanol (CH
3
)
2
CHOH 60.10
- 0.042
propionic acid
CH
3
CH
2
CO
2
H 74.08
-
0.042
urea NH
2
CONH
2
60.06
0.101
-
Table 4.6.13
Concentrate 4: Sabatier Product Water for TM Wastewater Ersatz (C4)
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
ammonium bicarbonate
NH
4
HCO
3
79.06
2.611
-
Table 4.6.14
US Urine Pretreatment (per liter of wastewater) for TM Wastewater Ersatz
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
oxone 2KHSO
5
•
KHSO
4
•
K
2
SO
4
614.80 1.671 -
potassium benzoate
C
7
H
5
KO
2
160.22
0.334
-
sulfuric acid, concentrated (96%, 36 Normal) H
2
SO
4
98.08
-
0.615
4.6.3.1.2
T
RANSIT
M
ISSION
W
ASTEWATER
E
RSATZ
F
ORMULATION
P
ROCEDURE
1) Concentrate Preparation:
•
Label four (4) 1-liter flasks “C1,†“C2,†“C3,†and “C4.†Add 750 mL of deionized water to each.
•
For each concentrate, add the constituents listed in Table 4.6.10 through Table 4.6.14 above, one at a time
and in the order listed. Mix thoroughly between constituents until each dissolves.
•
Dilute each flask to 1 liter with deionized water and mix thoroughly to complete preparation of the
concentrate mixes.
•
Cap all concentrates and store under ambient conditions. (In other words,
DO NOT REFRIGERATE
.)
NOTE: DO NOT MAKE a Urine Pretreatment concentrate. (These constituents are added directly to the 1-Liter
Working Solution in Step 3)
145
This solution is 10 times more concentrated than will be its constituents in the final TM wastewater ersatz.
109
2) 1-Liter Working Solution Preparation:
•
Add 300 mL deionized water, 100 mL of solution C1, and 100 mL of solution C2 to a 1-liter flask, dilute to
500 mL with deionized water, and mix thoroughly.
3) 1-Liter Working Solution Preparation (continued):
•
Add 1.671g oxone and 0.334 g potassium benzoate, and mix thoroughly.
•
Slowly add 0.615 mL concentrated sulfuric acid. Mix thoroughly.
•
The solution pH should be less than 2.4.
4) 1-Liter Working Solution (concluded):
•
Now add 100 mL of solution C3, and 50 mL of solution C4.
•
Dilute with deionized water to 1 liter and mix thoroughly.
5) Verification:
•
Analyze working solution for cation, anion, pH, conductivity, total organic carbon (TOC), and total inorganic
carbon (TIC).
•
Target values for these solution properties are listed in Table 4.6.15.
Table 4.6.15
Average Solution Properties for Transit Mission Wastewater Ersatz
Property or
Concentration
Formula Units
Average
Value
Standard
Deviation
Reference
potential of hydrogen
pH
2.6
± 0.2
Verostko, et al. (2004)
Conductivity µS
12,352
±
1,853
total organic carbon
TOC
mg/L
2,209
± 221
total inorganic carbon
TIC
mg/L
-
-
Chloride Cl
-
mg/L 1,870 ±
281
Nitrite NO
2
-
mg-N/L
-
-
Nitrate NO
3
-
mg-N/L
-
-
Phosphate PO
4
–3
mg/L
75
±
11
Sulfate SO
4
–2
mg/L
2,864
±
430
Sodium Na
+
mg/L 1,045 ±
157
Ammonium NH
4
+
mg-N/L 221
±
33
potassium K
+
mg/L 1,387 ±
208
calcium Ca
+2
mg/L
7.95
±
1.2
magnesium Mg
+2
mg/L
64.0
±
10
4.6.3.2
Early Planetary Base Wastewater Ersatz
4.6.3.2.1
E
ARLY
P
LANETARY
B
ASE
W
ASTEWATER
E
RSATZ
C
ONCENTRATE
C
ONSTITUENT
T
ABLES
Table 4.6.16 through Table 4.6.21 describe the components of the early planetary base (EPB) wastewater
ersatz. The state of each constituent is indicated by its measured value. For solid constituents, a mass is listed. For
liquid constituents, a volume is listed. In all cases, when applicable, the constituent purity or concentration is noted
in the first column following the constituent name. When not otherwise noted, all constituent purities are greater
than 99%. Final solution properties are listed in Table 4.6.22. The preparation instructions are presented in
Section 4.6.3.2.2. For the original source, see Verostko, et al. (2004)
110
Table 4.6.16
Concentrate 1: Inorganic Compounds 1 for EPB Wastewater Ersatz (C1)
146
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
ammonium bicarbonate
NH
4
HCO
3
79.06
23.002 -
sodium bicarbonate
NaHCO
3
84.01
2.118 -
potassium bicarbonate
KHCO
3
100.10 0.462 -
Table 4.6.17
Concentrate 2: Inorganic Compounds 2 for EPB Wastewater Ersatz (C2)
147
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
potassium chloride
KCl
74.60
1.968
-
sodium chloride
NaCl
58.40
6.942
-
potassium monobasic phosphate
KH
2
PO
4
136.09 1.661 -
potassium sulfate
K
2
SO
4
174.29 1.595 -
ammonium hydroxide, concentrated (29.34%)
NH
4
OH 35.05 - 10.000
Table 4.6.18
Concentrate 3: Humidity Condensate for EPB Wastewater Ersatz (C3)
148
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
acetic acid
CH
3
CO
2
H 60.05 - 0.927
benzoic acid
C
6
H
5
CO
2
H 122.20 0.096 -
benzyl alcohol
C
6
H
5
CH
2
OH 108.14
-
0.542
ethanol C
2
H
6
O 46.07 - 3.164
acetone CH
3
COCH
3
58.08 -
0.039
caprolactam C
6
H
11
NO 113.16 0.401 -
phenol C
6
H
5
OH 94.11 0.057 -
N,N-dimethylformamide HCON(CH
3
)
2
73.10
-
0.073
ethylene glycol
HOCH
2
CH
2
OH 62.07
-
0.330
4-ethyl morpholine
C
6
H
13
NO 115.18 -
0.150
formaldehyde (37%)
HCHO
30.03
-
0.967
formic acid (96%)
HCO
2
H 46.03 - 0.438
lactic acid
CH
3
CH(OH)CO
2
H 90.08
-
0.393
methanol CH
3
OH 32.04 - 0.457
1,2-propanediol C
3
H
8
O
2
76.09 - 1.980
2-propanol (CH
3
)
2
CHOH 60.10
-
0.195
propionic acid
CH
3
CH
2
CO
2
H 74.08
-
0.236
urea NH
2
CONH
2
60.06 0.290 -
Table 4.6.19
Concentrate 4: Sabatier Product Water for EPB Wastewater Ersatz (C4)
149
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
ammonium bicarbonate
NH
4
HCO
3
79.06
0.389 -
146
This solution is 10 times more concentrated than will be its constituents in the final EPB wastewater ersatz.
147
This solution is 10 times more concentrated than will be its constituents in the final EPB wastewater ersatz.
148
This solution is 100 times more concentrated than will be its constituents in the final EPB wastewater ersatz.
149
This solution is 10 times more concentrated than will be its constituents in the final EPB wastewater ersatz.
111
Table 4.6.20
Concentrate 5: Hygiene Water for EPB Wastewater Ersatz (C5)
150
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
NASA Whole Body Shower Soap (40%)
151
-
30.076
-
acetic acid
CH
3
CO
2
H 60.05 -
0.681
urea NH
2
CONH
2
60.06 0.180 -
ethanol C
2
H
6
O 46.07
- 0.130
lactic acid
CH
3
CH(OH)CO
2
H 90.08
1.627
-
methanol CH
3
OH 32.04
-
0.060
propionic acid
CH
3
CH
2
CO
2
H 74.08 -
0.246
Table 4.6.21
Concentrate 6: Urine Organics for EPB Wastewater Ersatz (C6)
152
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
urea NH
2
CONH
2
60.06 1.595
-
creatinine (98%)
C
4
H
7
N
3
O 113.10 1.585
-
histidine, soluble (98%)
C
6
H
9
N
3
O
2
155.20 0.291
-
taurine C
2
H
5
NSO
3
125.10 0.170
-
glutamic acid
C
5
H
9
NO
4
147.10 0.509
-
glucose (96%)
C
6
H
12
O
6
390.40 0.783 -
ammonium citrate (99%)
(NH
4
)
2
C
6
H
5
O
7
226.20 3.712
-
ammonium formate (97%)
NH
4
HCO
2
63.10 0.445 -
ammonium oxalate monohydrate (NH
4
)
2
C
2
O
4
142.10 0.182
-
4.6.3.2.2
E
ARLY
P
LANETARY
B
ASE
W
ASTEWATER
E
RSATZ
F
ORMULATION
P
ROCEDURE
1) Concentrate Preparation:
•
Label six (6) 1-liter flasks “C1,†“C2,†“C3,†“C4,†“C5,†and “C6.†Add 750 mL of deionized water to
each.
•
For each concentrate, add the constituents listed in Table 4.6.16 through Table 4.6.21 above, one at a time in
the order listed, and mix thoroughly between constituents until each dissolves.
•
Dilute each flask to 1 liter with deionized water and mix thoroughly to complete preparation of the
concentrate mixes.
•
Cap all concentrates and store under ambient conditions. (In other words,
DO NOT REFRIGERATE
.)
2) Working Solution:
NOTE: DO NOT ADD solution C1 now. See Step 3 below.
•
Add 300 mL deionized water, 100 mL of solution C2, 10 mL of solution C3, 100 mL of solution C4, 50 mL
of solution C5, and 100 mL of solution C6 to a 1-liter flask.
•
Dilute to 850 mL with deionized water and mix thoroughly.
3) Working Solution (continued):
•
Now slowly add 100 mL of solution C1. NOTE: Be sure to add C1 last to prevent TIC loss.
NOTE: Be sure to add solution C1 last to prevent loss of total inorganic carbon (TIC).
4) pH Adjustment:
•
If required, adjust pH to 8.9 ± 0.2 with 1.5 Normal
ammonium hydroxide
(NH
4
OH), using less than 7 mL.
•
Add deionized water to make 1 liter and mix.
150
This solution is 20 times more concentrated than will be its constituents in the final EPB wastewater ersatz.
151
“Geropon TC-42,†formerly “Igepon TC-42,†is manufactured by Rhodia North American Chemicals and is approximately
60% water. See Ecolab (1998).
152
This solution is 10 times more concentrated than will be its constituents in the final EPB wastewater ersatz.
112
5) Verification:
•
Analyze working solution for cation, anion, pH, conductivity, total organic carbon (TOC), and total inorganic
carbon (TIC).
•
Target values for these solution properties are listed in Table 4.6.22.
Table 4.6.22
Average Solution Properties for Early Planetary Base Wastewater Ersatz
Property or
Concentration
Formula Units
Average
Value
Standard
Deviation
Reference
potential of hydrogen
pH
8.9
± 0.2
Verostko, et al. (2004)
conductivity
µS
6,869
±
1,030
total organic carbon
TOC
mg/L
631
± 63
total
inorganic
carbon TIC mg/L
391
±
59
chloride Cl
-
mg/L
514
±
77
nitrite NO
2
-
mg-N/L
- -
nitrate NO
3
-
mg-N/L
- -
phosphate PO
4
–3
mg/L
116
±
17
sulfate SO
4
–2
mg/L
88
±
13
sodium Na
+
mg/L
331
±
50
ammonium NH
4
+
mg-N/L
852
±
128
potassium K
+
mg/L
240
±
36
calcium Ca
+2
mg/L
- -
magnesium Mg
+2
mg/L
- -
4.6.3.3
Biological Water Processor Effluent Ersatz
4.6.3.3.1
B
IOLOGICAL
W
ATER
P
ROCESSOR
E
FFLUENT
E
RSATZ
C
ONCENTRATE
C
ONSTITUENT
T
ABLES
Table 4.6.23 through Table 4.6.27 describe the components of the biological water processor (BWP)
effluent ersatz. The state of each constituent is indicated by its measured value. For solid constituents, a mass is
listed. For liquid constituents, a volume is listed. In all cases, when applicable, the constituent purity or
concentration is noted in the first column following the constituent name. When not otherwise noted, all constituent
purities are greater than 99%. Final solution properties are listed in Table 4.6.28. The preparation instructions are
presented in Section 4.6.3.3.2. For the original source, see Verostko, et al. (2004)
Table 4.6.23
Concentrate 1: Inorganic Compounds 1 for BWP Effluent Ersatz (C1)
153
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
ammonium bicarbonate
NH
4
HCO
3
79.06 36.214
-
153
This solution is 50 times more concentrated than will be its constituents in the final BWP effluent ersatz.
113
Table 4.6.24
Concentrate 2: Inorganic Compounds 2 for BWP Effluent Ersatz (C2)
154
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
ammonium chloride
NH
4
Cl 53.49
5.001 -
sodium chloride
NaCl
58.40
31.614
-
sodium nitrite
NaNO
2
69.00
1.230 -
sodium nitrate
NaNO
3
84.99
14.271 -
potassium monobasic phosphate
KH
2
PO
4
136.09 8.591 -
potassium bisulfate
KHSO
4
136.20 8.286 -
potassium chloride
KCl
74.60
13.681
-
hydrochloric acid (concentrated, 37%)
HCl
36.46
-
7.900
Table 4.6.25
Concentrate 3: Soluble Organic Compounds for BWP Effluent Ersatz (C3)
155
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
dextran (C
6
H
10
O
5
)
n
(15k-20k)
27.220
-
glucuronic acid
C
6
H
10
O
7
194.10 2.690 -
creatinine (98%)
C
4
H
7
N
3
O 113.10 2.350
-
urea NH
2
CONH
2
60.06 2.500
-
Table 4.6.26
Concentrate 4: Insoluble Organic Compounds for BWP Effluent Ersatz (C4)
156
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
fructan (xanthan gum)
-
-
0.450
-
tyrosine C
9
H
11
NO
3
181.20 0.596
-
ibuprofen C
13
H
18
O
2
206.30 0.757
-
bis-2-ethylhexyl phathalate
C
24
H
38
O
4
390.60 0.736
-
ethyl morpholine
C
6
H
13
NO 115.17 0.626
-
Table 4.6.27
Concentrate 5: Volatile Organic Carbon Compounds for BWP Effluent Ersatz (C5)
157
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
acetic acid
CH
3
CO
2
H 60.05 - 2.390
lactic acid
CH
3
CH(OH)CO
2
H 90.08
-
2.360
2-propanol (CH
3
)
2
CHOH 60.10
-
2.140
acetone CH
3
COCH
3
58.08
- 2.060
ethanol C
2
H
6
O 46.07 - 2.850
4.6.3.3.2
B
IOLOGICAL
W
ATER
P
ROCESSOR
E
FFLUENT
E
RSATZ
F
ORMULATION
P
ROCEDURE
1) Concentrate Preparation:
•
Label five (5) 1-liter flasks “C1,†“C2,†“C3,†“C4,†and “C5.†Add 750 mL of deionized water to each.
•
For each concentrate, add the constituents listed in Table 4.6.23 through Table 4.6.27 above, one at a time in
the order listed, and mix thoroughly among constituents until each dissolves, except as noted below.
NOTE: The constituents of solution C4 WILL NOT DISSOLVE completely.
154
This solution is 50 times more concentrated than will be its constituents in the final BWP effluent ersatz.
155
This solution is 1,000 times more concentrated than will be its constituents in the final BWP effluent ersatz.
156
This solution has variable concentration based on the solubility of its constituents. This solution is more concentrated than
will be its constituents in the final BWP effluent ersatz.
157
This solution is 100 times more concentrated than will be its constituents in the final BWP effluent ersatz.
114
•
Dilute each flask to 1 liter with deionized water and mix thoroughly to complete preparation of the
concentrate mixes.
•
Cap all concentrates and store under ambient conditions. (In other words,
DO NOT REFRIGERATE
.)
2) Working Solution:
NOTE: DO NOT ADD solution C1 now. See Step 3 below.
•
Add, to a 1-liter flask, 300 mL deionized water, 20 mL of solution C2, and 3.6 mL of solution C3
•
Add, to the solution above, 10.22 mL of solution C4 filtered through a #4 Whatman filter paper.
•
Add, to the solution above, 0.094 mL of solution C5.
•
Dilute to 950 mL with deionized water and mix thoroughly.
3) Working Solution (continued):
•
Now slowly add 20 mL of solution C1.
NOTE: Be sure to add solution C1 last to prevent loss of total inorganic carbon (TIC).
4) pH Adjustment:
•
If required, adjust pH to 6.6 ± 0.2 with 1.5 Normal
ammonium hydroxide
(NH
4
OH), using less than 500 µL.
•
Add deionized water to make 1 liter and mix.
5) Verification:
•
Analyze working solution for cation, anion, pH, conductivity, total organic carbon (TOC), and total inorganic
carbon (TIC).
•
Target values for these solution properties are listed in Table 4.6.28.
Table 4.6.28
Average Solution Properties for Biological Water Processor Effluent Ersatz
Property or
Concentration
Formula Units
Average
Value
Standard
Deviation
Reference
potential of hydrogen
pH
6.6
± 0.2
Verostko, et al. (2004)
conductivity
µS
3,802
±
570
total organic carbon
TOC
mg/L
51
± 5.1
total
inorganic
carbon TIC mg/L 110
±
17
chloride Cl
-
mg/L 608
±
91
nitrite NO
2
-
mg-N/L 5.0
±
0.7
nitrate NO
3
-
mg-N/L
47
±
7.1
phosphate PO
4
–3
mg/L 120
±
18
sulfate SO
4
–2
mg/L 117
±
18
sodium Na
+
mg/L 334
±
50
ammonium NH
4
+
mg-N/L 154
±
23
potassium K
+
mg/L 240
±
36
calcium Ca
+2
mg/L
-
-
magnesium Mg
+2
mg/L
-
-
4.6.3.4
Reverse Osmosis Subsystem Permeate Ersatz
The reverse osmosis subsystem permeate ersatz is presented for both nominal and worst-case possibilities.
4.6.3.4.1
R
EVERSE
O
SMOSIS
P
ERMEATE
(N
OMINAL
)
E
RSATZ
C
ONCENTRATE
C
ONSTITUENT
T
ABLES
Table 4.6.29 through Table 4.6.33 describe the components of the nominal reverse osmosis (RO) permeate
ersatz. The state of each constituent is indicated by its measured value. For solid constituents, a mass is listed. For
liquid constituents, a volume is listed. In all cases, when applicable, the constituent purity or concentration is noted
in the first column following the constituent name. When not otherwise noted, all constituent purities are greater
than 99%. Final solution properties are listed in Table 4.6.34. The preparation instructions are presented in
Section 4.6.3.4.2. For the original source, see Verostko, et al. (2004)
115
Table 4.6.29
Concentrate 1: Inorganic Compounds 1 for RO Permeate (Nominal) Ersatz (C1)
158
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
ammonium bicarbonate
NH
4
HCO
3
79.06 9.221 -
Table 4.6.30
Concentrate 2: Inorganic Compounds 2 for RO Permeate (Nominal) Ersatz (C2)
159
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
sodium nitrite
NaNO
2
69.00 0.896 -
magnesium sulfate
MgSO
4
120.40
0.005
-
potassium sulfate
K
2
SO
4
174.29
0.449
-
sodium
chloride
NaCl
58.40 3.857 -
potassium monobasic phosphate
KH
2
PO
4
136.09
0.152
-
calcium chloride
CaCl
2
110.99
0.031
-
potassium nitrate
KNO
3
101.10
3.142
-
nitric acid (0.1 Normal)
HNO
3
63.01
-
51.140
hydrochloric acid (concentrated, 37%)
HCl
36.46
-
1.500
Table 4.6.31
Concentrate 3: Soluble Organic Compounds for RO Permeate (Nominal) Ersatz (C3)
160
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
dextran (C
6
H
10
O
5
)
n
(15k-20k)
27.220
-
glucuronic acid
C
6
H
10
O
7
194.10
2.690
-
creatinine (98%)
C
4
H
7
N
3
O 113.10
2.350
-
urea NH
2
CONH
2
60.06 2.500 -
Table 4.6.32
Concentrate 4: Insoluble Organic Compounds for RO Permeate (Nominal) Ersatz (C4)
161
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
fructan (xanthan gum)
-
-
0.450
-
tyrosine C
9
H
11
NO
3
181.20
0.596
-
ibuprofen C
13
H
18
O
2
206.30
0.757
-
bis-2-ethylhexyl phathalate
C
24
H
38
O
4
390.60
0.736
-
ethyl morpholine
C
6
H
13
NO 115.17
0.626
-
Table 4.6.33
Concentrate 5: Volatile Organic Compounds for RO Permeate (Nominal) Ersatz (C5)
162
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
acetic acid
CH
3
CO
2
H 60.05
- 2.390
lactic acid
CH
3
CH(OH)CO
2
H 90.08
-
2.360
2-propanol (CH
3
)
2
CHOH 60.10 -
2.140
acetone CH
3
COCH
3
58.08
-
2.060
ethanol C
2
H
6
O 46.07
-
2.850
158
This solution is 100 times more concentrated than will be its constituents in the final nominal RO permeate ersatz.
159
This solution is 100 times more concentrated than will be its constituents in the final nominal RO permeate ersatz.
160
This solution is 1,000 times more concentrated than will be its constituents in the final nominal RO permeate ersatz.
161
This solution has variable concentration based on the solubility of its constituents. This solution is more concentrated than
will be its constituents in the final nominal RO permeate ersatz.
162
This solution is 1,000 times more concentrated than will be its constituents in the final nominal RO permeate ersatz.
116
4.6.3.4.2
R
EVERSE
O
SMOSIS
P
ERMEATE
(N
OMINAL
)
E
RSATZ
F
ORMULATION
P
ROCEDURE
1) Concentrate Preparation:
•
Label five (5) 1-liter flasks “C1,†“C2,†“C3,†“C4,†and “C5.†Add 750 mL of deionized water to each.
•
For each concentrate, add the constituents listed in Table 4.6.29 through Table 4.6.33 above, one at a time in
the order listed, and mix thoroughly between constituents until each dissolves, except as noted below.
NOTE: The constituents of solution C4 WILL NOT DISSOLVE completely.
•
Dilute each flask to 1 liter with deionized water and mix thoroughly to complete preparation of the
concentrate mixes.
•
Cap all concentrates and store under ambient conditions. (In other words,
DO NOT REFRIGERATE
.)
2) Working Solution:
NOTE: DO NOT ADD solution C1 now. See Step 3 below.
•
Add, to a 1-liter flask, 300 mL deionized water, 10 mL of solution C2, and 0.040 mL of solution C3.
•
Add, to the solution above, 1.023 mL of solution C4 filtered through a #4 Whatman filter paper.
•
Add, to the solution above, 0.070 mL of solution C5.
•
Dilute to 950 mL with deionized water and mix thoroughly.
3) Working Solution (continued):
•
Now slowly add 10 mL of solution C1.
NOTE: Be sure to add solution C1 last to prevent loss of total inorganic carbon (TIC).
4) pH Adjustment:
•
If required, adjust pH to 6.6 ± 0.2 with 0.14 Normal
hydrochloric acid
(HCl), using less than 300 µL.
•
Add deionized water to make 1 liter and mix.
5) Verification:
•
Analyze working solution for cation, anion, pH, conductivity, total organic carbon (TOC), and total inorganic
carbon (TIC).
•
Target values for these solution properties are listed in Table 4.6.34.
Table 4.6.34
Average Solution Properties for Reverse Osmosis Permeate (Nominal) Ersatz
Property or
Concentration
Formula Units
Average
Value
Standard
Deviation
Reference
potential of hydrogen
pH
6.6
± 0.2
Verostko, et al. (2004)
conductivity
µS
285
±
43
total organic carbon
TOC
mg/L
1.4
± 0.5
total inorganic carbon
TIC
mg/L
14
± 2.1
chloride Cl
-
mg/L
32
±
4.8
nitrite NO
2
-
mg-N/L
1.8
±
0.3
nitrate NO
3
-
mg-N/L
5.1
±
0.8
phosphate PO
4
–3
mg/L 1.06
±
0.2
sulfate SO
4
–2
mg/L 2.5
±
0.4
sodium Na
+
mg/L 18
±
2.7
ammonium NH
4
+
mg-N/L
16
±
2.5
potassium K
+
mg/L
14
±
2.0
calcium Ca
+2
mg/L
- -
magnesium Mg
+2
mg/L
- -
117
4.6.3.4.3
R
EVERSE
O
SMOSIS
P
ERMEATE
(W
ORST
-
CASE
)
E
RSATZ
C
ONCENTRATE
C
ONSTITUENT
T
ABLES
Table 4.6.35 through Table 4.6.39 describe components of the worst-case reverse osmosis (RO) permeate
ersatz. The state of each constituent is indicated by its measured value. For solid constituents, a mass is listed. For
liquid constituents, a volume is listed. In all cases, when applicable, the constituent purity or concentration is noted
in the first column following the constituent name. When not otherwise noted, all constituent purities are greater
than 99%. Final solution properties are listed in Table 4.6.40. The preparation instructions are presented in
Section 4.6.3.4.4. For the original source, see Verostko, et al. (2004)
Table 4.6.35
Concentrate 1: Inorganic Compounds 1 for RO Permeate (Worst-case) Ersatz (C1)
163
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
ammonium bicarbonate
NH
4
HCO
3
79.06 11.878
-
Table 4.6.36
Concentrate 2: Inorganic Compounds 2 for RO Permeate (Worst-case) Ersatz (C2)
164
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
sodium nitrite
NaNO
2
69.00
1.364
-
sodium chloride
NaCl
58.40
5.373
-
magnesium sulfate
MgSO
4
120.40
0.130
-
potassium nitrate
KNO
3
101.10
4.136
-
potassium sulfate
K
2
SO
4
174.29
0.456
-
calcium chloride
CaCl
2
110.99
0.146
-
potassium monobasic phosphate
KH
2
PO
4
136.09 0.188
-
nitric acid (0.1 Normal)
HNO
3
63.01
-
63.520
ammonium hydroxide (1.5 Normal)
NH
4
OH 35.05
-
46.000
hydrochloric acid (concentrated, 37%)
HCl
36.46
-
6.500
Table 4.6.37
Concentrate 3: Soluble Organic Compounds for RO Permeate (Worst-case) Ersatz (C3)
165
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
dextran (C
6
H
10
O
5
)
n
(15k-20k)
27.220
-
glucuronic acid
C
6
H
10
O
7
194.10 2.690
-
creatinine (98%)
C
4
H
7
N
3
O 113.10 2.350
-
urea NH
2
CONH
2
60.06 2.50
-
Table 4.6.38
Concentrate 4: Insoluble Organic Compounds for RO Permeate (Worst-case) Ersatz (C4)
166
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
fructan (xanthan gum)
-
-
0.450
-
tyrosine C
9
H
11
NO
3
181.20 0.596
-
ibuprofen C
13
H
18
O
2
206.30 0.757
-
bis-2-ethylhexyl phathalate
C
24
H
38
O
4
390.60 0.736
-
ethyl morpholine
C
6
H
13
NO 115.17 0.626
-
163
This solution is 100 times more concentrated than will be its constituents in the final worst-case RO permeate ersatz.
164
This solution is 100 times more concentrated than will be its constituents in the final worst-case RO permeate ersatz.
165
This solution is 1,000 times more concentrated than will be its constituents in the final worst-case RO permeate ersatz.
166
This solution has variable concentration based on the solubility of its constituents. This solution is more concentrated than
will be its constituents in the final worst-case RO permeate ersatz.
118
Table 4.6.39
Concentrate 5: Volatile Organic Compounds for RO Permeate (Worst-case) Ersatz (C5)
167
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
acetic acid
CH
3
CO
2
H 60.05 - 2.390
lactic acid
CH
3
CH(OH)CO
2
H 90.08
-
2.360
2-propanol (CH
3
)
2
CHOH 60.10
-
2.140
acetone CH
3
COCH
3
58.08
- 2.060
ethanol C
2
H
6
O 46.07 - 2.850
4.6.3.4.4
R
EVERSE
O
SMOSIS
P
ERMEATE
(W
ORST
-
CASE
)
E
RSATZ
F
ORMULATION
P
ROCEDURE
1) Concentrate Preparation:
•
Label five (5) 1-liter flasks “C1,†“C2,†“C3,†“C4,†and “C5.†Add 750 mL of deionized water to each.
•
For each concentrate, add the constituents listed in Table 4.6.35 through Table 4.6.39 above, one at a time in
the order listed, and mix thoroughly between constituents until each dissolves, except as noted below.
NOTE: The constituents of solution C4 WILL NOT DISSOLVE completely.
•
Dilute each flask to 1 liter with deionized water and mix thoroughly to complete preparation of the
concentrate mixes.
•
Cap all concentrates and store under ambient conditions. (In other words,
DO NOT REFRIGERATE
.)
2) Working Solution:
NOTE: DO NOT ADD solution C1 now. See Step 3 below.
•
Add, to a 1-liter flask, 300 mL deionized water, 10 mL of solution C2, and 0.30 mL of solution C3.
•
Add, to the solution above, 1.53 mL of solution C4 filtered through a #4 Whatman filter paper.
•
Add, to the solution above, 0.094 mL of solution C5.
•
Dilute to 950 mL with deionized water and mix thoroughly.
3) Working Solution (continued):
•
Now slowly add 10 mL of solution C1.
NOTE: Be sure to add solution C1 last to prevent loss of total inorganic carbon (TIC).
4) pH Adjustment:
•
If required, adjust pH to 7.3 ± 0.2 with 1.5 Normal
ammonium hydroxide
(NH
4
OH), using less than 30 µL. Add
deionized water to make 1 liter and mix.
5) Verification:
•
Analyze working solution for cation, anion, pH, conductivity, total organic carbon (TOC), and total inorganic
carbon (TIC).
•
Target values for these solution properties are listed in Table 4.6.40.
167
This solution is 1,000 times more concentrated than will be its constituents in the final worst-case RO permeate ersatz.
119
Table 4.6.40
Average Solution Properties for Reverse Osmosis Permeate (Worst-case) Ersatz
Property or
Concentration
Formula Units
Average
Value
Standard
Deviation
Reference
potential of hydrogen
pH
7.3
± 0.2
Verostko, et al. (2004)
conductivity
µS
382
±
57
total organic carbon
TOC
mg/L
5
± 1.5
total inorganic carbon
TIC
mg/L
17.9
± 2.7
chloride Cl
-
mg/L
62
±
9.3
nitrite NO
2
-
mg-N/L
2.8
±
0.4
nitrate NO
3
-
mg-N/L
6.6
±
1.0
phosphate PO
4
-3
mg/L 1.32
±
0.2
sulfate SO
4
-2
mg/L 3.6
±
0.5
sodium Na
+
mg/L 26
±
3.8
ammonium NH
4
+
mg-N/L
26
±
4.0
potassium K
+
mg/L
17.5 ±
2.6
calcium Ca
+2
mg/L
- -
magnesium Mg
+2
mg/L
- -
4.6.3.5
Air Evaporation Subsystem Condensate Ersatz
The air evaporation subsystem condensate ersatz is presented for both nominal and worst-case possibilities.
4.6.3.5.1
A
IR
E
VAPORATION
C
ONDENSATE
(N
OMINAL
)
E
RSATZ
C
ONCENTRATE
C
ONSTITUENT
T
ABLES
Table 4.6.41 through Table 4.6.44 describe the components of the nominal air evaporation condensate
subsystem (AES) ersatz. The state of each constituent is indicated by its measured value. For solid constituents, a
mass is listed. For liquid constituents, a volume is listed. In all cases, when applicable, the constituent purity or
concentration is noted in the first column following the constituent name. When not otherwise noted, all constituent
purities are greater than 99%. Final solution properties are listed in Table 4.6.45. The preparation instructions are
presented in Section 4.6.3.5.2. For the original source, see Verostko, et al. (2004)
Table 4.6.41
Concentrate 1: Inorganic Compounds for AES Condensate (Nominal) Ersatz (C1)
168
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
ammonium bicarbonate
NH
4
HCO
3
79.06
34.308 -
ammonium hydroxide, concentrated (29.34%)
NH
4
OH 35.05
-
1.000
Table 4.6.42
Concentrate 3: Soluble Organic Compounds for AES Condensate (Nominal) Ersatz (C3)
169
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
dextran (C
6
H
10
O
5
)
n
(15k-20k)
27.222
-
glucuronic acid
C
6
H
10
O
7
194.10 2.694
-
creatinine (98%)
C
4
H
7
N
3
O 113.10 2.354
-
urea NH
2
CONH
2
60.06 2.500
-
168
This solution is 100 times more concentrated than will be its constituents in the final nominal AES condensate ersatz.
169
This solution is 1,000 times more concentrated than will be its constituents in the final nominal AES condensate ersatz.
120
Table 4.6.43
Concentrate 4: Insoluble Organic Compounds for AES Condensate (Nominal) Ersatz C4)
170
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
fructan (xanthan gum)
-
-
0.450
-
tyrosine C
9
H
11
NO
3
181.20 0.596
-
ibuprofen C
13
H
18
O
2
206.30 0.757 -
bis-2-ethylhexyl phathalate
C
24
H
38
O
4
390.60 0.736 -
ethyl morpholine
C
6
H
13
NO 115.17 0.626
-
Table 4.6.44
Concentrate 5: Volatile Organic Compounds for AES Condensate (Nominal) Ersatz (C5)
171
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
acetic acid
CH
3
CO
2
H 60.05 - 2.390
lactic acid
CH
3
CH(OH)CO
2
H 90.08
-
2.360
2-propanol (CH
3
)
2
CHOH 60.10
-
2.140
acetone CH
3
COCH
3
58.08
- 2.060
ethanol C
2
H
6
O 46.07 - 2.850
4.6.3.5.2
A
IR
E
VAPORATION
C
ONDENSATE
(N
OMINAL
)
E
RSATZ
F
ORMULATION
P
ROCEDURE
1) Concentrate Preparation:
•
Label four 1-liter flasks “C1,†“C3,†“C4,†and “C5.†Add 750 mL of deionized water to each.
•
For each concentrate, add the constituents listed in Table 4.6.41 through Table 4.6.44 above, one at a time in
the order listed, and mix thoroughly between constituents until each dissolves, except as noted below.
NOTE: The constituents of solution C4 WILL NOT DISSOLVE completely.
•
Dilute each flask to 1 liter with deionized water and mix thoroughly to complete preparation of the
concentrate mixes.
•
Cap all concentrates and store under ambient conditions. (In other words,
DO NOT REFRIGERATE
.)
2) Working Solution:
•
Add, to a 1-liter flask, 300 mL deionized water, 10 mL of solution C1, and 0.24 mL of solution C3.
•
Add, to the solution above, 2.04 mL of solution C4 filtered through a #4 Whatman filter paper.
•
Add, to the solution above, 0.094 mL of solution C5.
•
Dilute to 980 mL with deionized water and mix thoroughly.
3) pH Adjustment:
•
If required, adjust pH to 8.1 ± 0.2 with 1.5 Normal
ammonium hydroxide
(NH
4
OH), using less than 250 µL.
•
Add deionized water to make 1 liter and mix.
4) Verification:
•
Analyze working solution for cation, anion, pH, conductivity, total organic carbon (TOC), and total inorganic
carbon (TIC).
•
Target values for these solution properties are listed in Table 4.6.45.
170
This solution has variable concentration based on the solubility of its constituents. This solution is more concentrated than
will be its constituents in the final nominal AES condensate ersatz.
171
This solution is 1,000 times more concentrated than will be its constituents in the final nominal AES condensate ersatz.
121
Table 4.6.45
Average Solution Properties for Air Evaporation Condensate (Nominal) Ersatz
Property or
Concentration
Formula Units
Average
Value
Standard
Deviation
Reference
potential of hydrogen
pH
8.0
± 0.2
Verostko, et al. (2004)
conductivity
µS
507
±
76
total organic carbon
TOC
mg/L
4.5
± 1.5
total inorganic carbon
TIC
mg/L
52
± 7.8
chloride
Cl
-
mg/L
- -
nitrite
NO2
-
mg-N/L
- -
nitrate
NO3
-
mg-N/L
- -
phosphate PO4
-3
mg/L
- -
sulfate
SO4
-2
mg/L
- -
sodium
Na
+
mg/L
- -
ammonium NH4
+
mg-N/L
64.0
±
9.6
potassium K
+
mg/L
- -
calcium
Ca
+2
mg/L
- -
magnesium Mg
+2
mg/L
- -
4.6.3.5.3
A
IR
E
VAPORATION
C
ONDENSATE
(W
ORST
-
CASE
)
E
RSATZ
C
ONCENTRATE
C
ONSTITUENT
T
ABLES
Table 4.6.46 through Table 4.6.49 describe the components of the worst-case air evaporation subsystem
(AES) condensate ersatz. The state of each constituent is indicated by its measured value. For solid constituents, a
mass is listed. For liquid constituents, a volume is listed. In all cases, when applicable, the constituent purity or
concentration is noted in the first column following the constituent name. When not otherwise noted, all constituent
purities are greater than 99%. Final solution properties are listed in Table 4.6.50. The preparation instructions are
presented in Section 4.6.3.5.4. For the original source, see Verostko, et al. (2004)
Table 4.6.46
Concentrate 1: Inorganic Compounds for AES Condensate (Worst-case) Ersatz (C1)
172
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
ammonium carbonate
(NH
4
)
2
CO
3
96.09
12.501
-
ammonium hydroxide, concentrated (29.34%) NH
4
OH 35.05
- 10.000
Table 4.6.47
Concentrate 3: Effluent Soluble Organic Compounds
for AES Condensate (Worst-case) Ersatz (C3)
173
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
dextran (C
6
H
10
O
5
)
n
(15k-20k)
27.222
-
glucuronic acid
C
6
H
10
O
7
194.10
2.694
-
creatinine (98%)
C
4
H
7
N
3
O 113.10
2.354
-
urea NH
2
CONH
2
60.06 2.500 -
172
This solution is 100 times more concentrated than will be its constituents in the final worst-case AES condensate ersatz.
173
This solution is 1,000 times more concentrated than will be its constituents in the final worst-case AES condensate ersatz.
122
Table 4.6.48
Concentrate 4: Insoluble Organic Compounds
for AES Condensate (Worst-case) Ersatz (C4)
174
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
fructan (xanthan gum)
-
-
0.450
-
tyrosine C
9
H
11
NO
3
181.20
0.596
-
ibuprofen C
13
H
18
O
2
206.30
0.757
-
bis-2-ethylhexyl phathalate
C
24
H
38
O
4
390.60
0.736
-
ethyl morpholine
C
6
H
13
NO 115.17
0.626
-
Table 4.6.49
Concentrate 5: Volatile Organic Compounds
for AES Condensate (Worst-case) Ersatz (C5)
175
Constituent
Chemical
Formula
Molecular
Weight
Constituent
Mass
[g]
Constituent
Volume
[mL]
acetic acid
CH
3
CO
2
H 60.05
- 2.390
lactic acid
CH
3
CH(OH)CO
2
H 90.08
-
2.360
2-propanol (CH
3
)
2
CHOH 60.10 -
2.140
acetone CH
3
COCH
3
58.08
-
2.060
ethanol C
2
H
6
O 46.07
-
2.850
4.6.3.5.4
A
IR
E
VAPORATION
C
ONDENSATE
(W
ORST
-
CASE
)
E
RSATZ
F
ORMULATION
P
ROCEDURE
1) Concentrate Preparation:
•
Label four (4) 1-liter flasks “C1,†“C3,†“C4,†and “C5.†Add 750 mL of deionized water to each.
•
For each concentrate, add the constituents listed in Table 4.6.46 through Table 4.6.49 above, one at a time in
the order listed, and mix thoroughly between constituents until each dissolves, except as noted below.
NOTE: The constituents of solution C4 WILL NOT DISSOLVE completely.
•
Dilute each flask to 1 liter with deionized water and mix thoroughly to complete preparation of the
concentrate mixes.
•
Cap all concentrates and store under ambient conditions. (In other words,
DO NOT REFRIGERATE
.)
2) Working Solution:
•
Add, to a 1-liter flask, 300 mL deionized water, 60 mL of solution C1, and 0.56 mL of solution C3.
•
Add, to the solution above, 4.09 mL of solution C4 filtered through a #4 Whatman filter paper.
•
Add, to the solution above, 0.094 mL of solution C5.
•
Dilute to 980 mL with deionized water and mix thoroughly.
3) pH Adjustment:
•
If required, adjust pH to 9.4 ± 0.2 with 1.5 Normal
ammonium hydroxide
(NH
4
OH), using less than 6 mL. Add
deionized water to make 1 liter and mix.
4) Verification:
•
Analyze working solution for cation, anion, pH, conductivity, total organic carbon (TOC), and total inorganic
carbon (TIC).
•
Target values for these solution properties are listed in Table 4.6.50.
174
This solution has variable concentration based on the solubility of its constituents. This solution is more concentrated than
will be its constituents in the final worst-case AES condensate ersatz.
175
This solution is 1,000 times more concentrated than will be its constituents in the final worst-case AES condensate ersatz.
123
Table 4.6.50
Average Solution Properties for Air Evaporation Condensate (Worst-case) Ersatz
Property or
Concentration
Formula Units
Average
Value
Standard
Deviation
Reference
potential of hydrogen
pH
9.4
± 0.2
Verostko, et al. (2004)
conductivity
µS
1,286
±
193
total organic carbon
TOC
mg/L
9.5
± 3.0
total inorganic carbon
TIC
mg/L
94
± 14
chloride Cl
-
mg/L
- -
nitrite NO
2
-
mg-N/L
- -
nitrate NO
3
-
mg-N/L
- -
phosphate PO
4
-3
mg/L
- -
sulfate SO
4
-2
mg/L
- -
sodium Na
+
mg/L
- -
ammonium NH
4
+
mg-N/L
636
±
95
potassium K
+
mg/L
- -
calcium Ca
+2
mg/L
- -
magnesium Mg
+2
mg/L
- -
124
5
Life Support External Interface Assumptions and Values
5.1
Cooling External Interface
The Cooling External Interface takes thermal loads from the Thermal Subsystem and rejects those loads to
the environment. Accordingly, within this manuscript, the Cooling External Interface masses are treated as
infrastructure. Detailed analyses and modeling through the thermal-energy-management-mass penalty are outlined
in Section 3.2. Additional values related to the Cooling External Interface may be found in Section 4.4 Thermal
Management.
5.2
Extravehicular Activity Support External Interface
176
Extravehicular activity (EVA) for planetary exploration missions will exhibit significant differences from
current EVA in low-Earth orbit. On a planetary surface, the presence of gravity raises the importance of suit mass,
so planetary surface space suits must be much lighter than current systems. Such new space suits must also be
designed for walking, picking up surface samples, hammering, etc., to accommodate field geology and similar
activities necessary for planetary exploration. The current space suit, or EMU, does not have these attributes. It has a
mass on the order of 135 kg and is designed for weightless mobility using foot restraints. Table 5.2.1 presents local
accelerations due to gravity for planetary bodies and Table 5.2.2 presents historical EMU masses. Finally,
Table 5.2.3 presents the weight
177
of an average 70 kg crewmember plus historical and current EMU designs under
a variety of gravitational conditions. As noted, the current EMU, if not reduced in mass for Mars, would burden a
crewmember with a weight 12 % greater than the weight of a nominal, unencumbered crewmember under terrestrial
gravity.
•
Note: The analysis here is not meant to suggest that a historical Apollo EMU or the current Shuttle
Program EMU will be used for operations on the surface of Luna or Mars, but rather to compare
the effects of suits with similar mass. The current Shuttle Program EMU is inappropriate for
surface operations, while the historical Apollo EMU has many limitations and would be
inappropriate for Martian surface operations.
Table 5.2.1
Local Accelerations Due to Gravity
Locale
Mean
Acceleration
due to
Gravity
[m/s²]
Fractional
Gravity
compared to
Earth
Normal
Reference
Earth 9.807
1.000
Luna 1.620
0.165
Mars 3.740
0.381
Weast and Astle
(1979)
176
This section on advanced extravehicular activities is from Rouen (2001).
177
Weight, a force, is defined as the mass of an object [kg], which is invariant with locale, multiplied by the local acceleration
due to gravity [m/s²]. More specifically, weight is the force with which a planet pulls a mass towards its surface and,
therefore, the “on back weight†experienced by a crewmember carrying something on the surface in that gravity field.
125
Table 5.2.2
Historical Extravehicular Activity Masses
Item
Mass
[kg]
References
Nominal Human Being
70
(1)
Apollo Program Spacesuit, A7L
178
83.0
(2)
Apollo Program Spacesuit, A7LB
179
90.7
(3)
Shuttle/ISS Program Spacesuit
135
(4)
(1)
See
Section
3.3.3
(2)
NASA
(1969)
(3)
Rouen
(2002)
(4)
Rouen
(2001)
Table 5.2.3
Weights of Historical Spacesuits Under Gravitational Loadings
Locale and Loading
Total Mass
[kg]
Weight for
Human
Alone
[N]
Weight for
Human
Plus Space
Suit
[N]
Percentage of
Unencumbered,
Earth-Normal
Weight
[%]
Earth
70.0 686
100
Luna
70.0 113
16.5
Lunar Surface with Apollo A7L EMU
153.0
248
36.1
Lunar Surface with Apollo A7LB EMU
160.7
260
37.9
Lunar Surface with Shuttle EMU
205
332
48.4
Mars
70.0 262
38.2
Martian Surface with Apollo A7L EMU
153.0
572
83.4
Martian Surface with Apollo A7LB EMU 160.7
601
87.5
Martian Surface with Shuttle EMU
205
767
112
The entire EVA system, including airlocks, spacesuits, tools, and vehicle interfaces, must also be designed
to minimize the mission launch mass, requiring technology development. The final design solution depends upon the
mission architecture as well as the success of development efforts. Several possibilities are described below that
represent the best available assumptions with regard to EVA for planetary exploration missions.
5.2.1
Operations During Transit to Mars
On a Mars transit vehicle, EVA would likely be reserved for contingency only. If EVA from the transit
vehicle is minimal, then the transit vehicle airlock system should be as lightweight as possible with minimal
intrusions into the crew habitat. Solutions that use an existing volume within the cabin that can be isolated and
depressurized or a fabric, fold-up airlock stowed externally to the outer cabin wall are some possible minimum
impact solutions to provide contingency EVA capability. In an event, current EVA protocol requires at least two
crewmembers at any time, so the minimum airlock should accommodate at least two crewmembers at a time.
Accordingly, the minimum airlock internal volume is about 3.7 m³. This corresponds to the volume of the current
Shuttle airlock.
178
The value here corresponds to the Apollo A7L EMU and a –6 portable life support system and associated equipment.
Apollo 11 used this configuration on the lunar surface. The EVA surface duration per sortie was less than 8 hours in this
configuration.
179
The value here corresponds to the Apollo A7LB EMU and a –7 portable life support system and associated equipment. The
later Apollo missions used this configuration on the lunar surface. The EVA surface duration per sortie was increased to
8 hours in this configuration.
126
5.2.2
Martian Surface Operations
Because the gravity on Mars is about twice that of Luna and about a third of that on Earth, the overall mass
of a Mars spacesuit is extremely critical. A likely mission design to mitigate this problem is to reduce the standard
EVA duration to 4 hours and plan to recharge the spacesuit consumables at midday. Therefore, to maintain the same
time outside the vehicle during exploration, two 4-hour, or “half-day,†EVA sorties per workday could replace the
more traditional 8-hour EVA sortie. Assuming five workdays per week allows 520 half-day EVA sorties of two
crewmembers per year without any allowance for holidays. This is also the expected number of airlock cycles per
year. Each EVA sortie normally requires at least two crewmembers outside.
One method of reducing EVA consumables is to use a radiator to reject thermal loads from the spacesuit
backpack rather than rely solely on consuming water to reject thermal loads, as is the current practice in low-Earth
orbit. This could reduce cooling water usage to 0.19 kg/h from 0.57 kg/h, which is a typical value when a radiator is
not used. The calculation here assumes a human metabolic rate of 1.06 MJ/h (295 W). Water, which remains within
the spacesuit, also provides the thermal working fluid to transport heat from the astronaut’s skin to heat rejection
equipment in the portable life support system (PLSS).
Another concept, which would completely eliminate loss of water to the environment for cooling, is a
cryogenic spacesuit backpack. The cryogenic spacesuit backpack rejects thermal loads to the environment via
radiator and vaporizes cryogenically-stored oxygen for metabolic consumption. As above, water still provides the
heat transport working fluid.
Oxygen usage and losses during EVA depend on the technologies employed in the PLSS. If a completely
closed-loop system is used, oxygen is only consumed by metabolic activity and leakage. Under such conditions,
oxygen usage is 0.3 kg per 4-hour EVA sortie, or 0.076 kg/h. If carbon dioxide generated while on EVA is stored by
the PLSS and recycled once the crewmembers return to the vehicle actual oxygen loss is associated only with
leakage. Oxygen leakage alone accounts for a loss rate of 0.02 kg per 4-hour EVA sortie, or 0.005 kg/h. If the
spacesuit PLSS employs a swing bed carbon dioxide removal technology to reject carbon dioxide and water to the
Martian environment, then some additional oxygen is lost as a sweep gas to aid the bed’s operation. In this case,
oxygen loss rates are 0.6 kg per 4-hour EVA sortie, or 0.15 kg/h. If cryogenic oxygen is used for thermal energy
management as well as breathing, the overall oxygen usage rates are 4.0 kg per 4-hour EVA sortie, or 1.0 kg/h.
Normally, flight rules require two exits providing redundant means to enter and egress a vehicle. If
pressurized rovers are used, one exit would be dedicated to docking rovers while an airlock would support on-foot
EVA operations. Since exits are only useful if coupled with a corresponding airlock, the contingency airlock for a
secondary exit (when another pressurized vehicle is not docked) is often used to depressurize the entire vehicle
cabin.
Although the hatch size increases in an environment with gravity, the required airlock volume remains
constant. A two-crewmember airlock has an empty volume of 4.25 m³. During use, the free gas volume within the
airlock is 3.7 m³ and two suited crewmembers fill the remaining volume. Though not generally acceptable under
current rules, a single person airlock has an empty volume of 1.02 m³ and a free gas volume of roughly 0.89 m³.
About 10% of the free gas within the airlock is lost to space and not recovered by the airlock compression pump
during depressurization. These losses could be reduced to 5 % at the expense of additional time and power
consumption for the airlock pump. Other advanced concepts, however, may reduce the gas losses without
corresponding time and power penalties.
Table 5.2.4 summarizes the estimates above for EVA operations on the surface of Mars. All values are
provided by Rouen (2001). Losses in Table 5.2.4 denote mass that leaves the pressurized volume of the spacesuit
and, therefore, does not return to the vehicle at the end of EVA operations. Consumption in Table 5.2.5 denotes
usage of a commodity by the crewmember regardless of whether that commodity leaves the pressurized spacesuit
volume or is retained within that volume and later recycled. McBarron, et al. (1993) provide overall values
describing the metabolic loads and inputs for an EVA crewmember assuming an average metabolic rate of
1,055 kJ/CM-h (293 W) and a respiratory quotient of 0.90. See Table 5.2.5.
127
Table 5.2.4
Summary of Extravehicular Activity Values for Mars Surface Operations
Value Units
Low
Nominal High
Reference
MJ
/CM-h
1.06
Rouen (2001)
Human Metabolic Rate
During EVA
W/CM
295
EVA Crewmember Hours
per Week
CM-h
/wk
80 80
EVA Sorties
180
per Week
Sorties
/wk
5
181
or 10
182
5
183
or 10
184
Cooling Water Losses
kg
/CM-h
0
0.19 0.57
Oxygen Losses
kg
/CM-h
0.005
to 0.076
0.15 1.0
Airlock
Volume
m³ 1.02 4.25
Airlock Free-Gas Volume
m³
0.89
3.7
Airlock Cycles per Week
Cycles
/wk
0
5
183
or 10
184
5
183
or 10
184
Airlock Gas Losses
per Cycle as a Percentage
of Airlock Gas Volume
183
%
5 10 10
Table 5.2.5
Extravehicular Activity Metabolic Loads
Parameter Units
Rate
References
Oxygen Consumption
kg/CM-h
0.075
(1)
Potable Water Consumption
184
kg/CM-h 0.24
(1, 2)
Food Energy Consumption
185
MJ/CM-h 1.062
(3)
Carbon Dioxide Production
kg/CM-h
0.093
(1)
Respiration and Perspiration Water Production
kg/CM-h
TBD
Urine Production
kg/CM-h
TBD
(1)
McBarron, et al.
(1993); metabolic
rate of 293 W/CM
and a respiratory
quotient of 0.9.
(2)
NASA (1995); a
maximum value.
(3)
Rouen (2001)
5.2.3
Lunar Surface Operations
Future EVA scenarios on the lunar surface are likely to be similar to those described above for Mars
because lunar surface exploration is often cited as a precursor to Martian surface exploration missions. However,
due to lower gravity on Luna, it is easier to extend the EVA sorties to 8 hours, thus saving time and airlock cycle gas
losses. However, radiant heat rejection would be a greater challenge during the lunar day.
180
Each EVA sortie assumes two crewmembers.
181
Assuming 8-hour EVA sorties.
182
Assuming 4-hour, or “half day†EVA sorties.
183
As given, these values are as a percentage of the mass of gas occupying the free airlock volume when depressurization
begins.
184
For EVA sorties longer than 3 hours.
185
This is the total energy expended, and as consumed, per crewmember per hour of extravehicular activity.
128
5.3
Human Accommodations External Interface
5.3.1
Clothing
Clothes are not traditionally part of an environmental control and life support system. However, the data
here detail some of the many interfaces between crew clothing, overall crew support mass, and the Water and Waste
Subsystems. The approach for ISS is to resupply clothes as needed. Alternately, clothes could be cleaned and reused
to significantly reduce the mass of clothes allotted per mission.
The main interfaces between the life support subsystems and a traditional laundry would be the mass of
water to support an aqueous washer and the corresponding water vapor load. The water vapor load would depend on
the performance of the laundry system, but assuming that most of the wash water is removed mechanically, leaving
a mass of water within the fabric equal to the mass of the clothes, the corresponding water-vapor load would be
about 1.5kg/CM-d.
Table 5.3.1 provides a summary of clothing and laundry options. Table 5.3.2 provides values for an
aqueous laundry system originally under development for ISS (Lunsford and Grounds, 1993, and ALS Systems
Workshop, 1998), while Table 5.3.3 details a recent study of a more efficient washer/dryer prototype unit (Jeng and
Ewert, 2002). In this latter study, the authors assumed clothing would have a useful life of 40 laundry cycles.
Table 5.3.1
Clothing and Laundry Options
Mass
[kg]
Mass
[kg/CM-d]
Volume
[m
3
/CM-d]
Power
[kW]
References
ISS Approach (clothes shipped, single use):
From Chaput (2003)
0.343
(1)
186
From Rogers (1999)
0.718
(2)
0.0013
(2)
From Branch (1998)
1.69
(3)
0.00135
(3)
From Reimers and
McDonald (1992)
1.47
(4)
0.00140
(4)
Using a Laundry:
0.267
(4)
0.000351
(4)
0.0746
(6a)
0.00044
(6a)
0.0373
(6b)
0.00022
(6b)
Clothes
0.0191
(6c)
0.00011
(6c)
118
(4)
0.31
(4)
Laundry
Equipment
80
(6)
0.751
(6)
12.47
(5)
187
Interfaces (Water)
7.33
(6)
(1)
Chaput (2003). Based on
clothing allocation “as
planned†for ISS
(2)
Rodgers (1999). Based on
clothing “as planned†for ISS.
(3)
Branch (1998)
(4)
Reimers and McDonald
(1992)
(5)
NASA (1990)
(6)
Jeng and Ewert (2002)
(6a)
Jeng and Ewert (2002);
90 d mission duration
(6b)
Jeng and Ewert (2002);
180 d mission duration
(6c)
Jeng and Ewert (2002);
600 d mission duration
186
Chaput (2003) gives ISS planning values for clothing of 10.3 kg per crewmember per 30 days.
187
The laundry uses clean water and provides a waste stream of greywater to the water recovery system.
129
Table 5.3.2
Early ISS Laundry Equipment Specifications
Washer Unit
Value
Units
Comments
References
Mass 118
kg
Volume 0.66 m³
Capacity 2.7 kg/load
Water Usage
49
kg/load
Effluent is greywater. This unit
does not release water vapor.
Crewtime 0.33
CM-h/load
Load, remove, fold, and stow
clothes.
Energy 3.3 kWh/load
Consumables 0.0024 kg/load Detergent
From Lunsford and
Grounds (1993) with
updates from material
presented at the ALS
Systems Workshop
(1998). This informa-
tion is based on the
laundry originally under
development for ISS.
Table 5.3.3
Advanced Washer/Dryer Specifications
Washer Unit
Value
Units
Comments
Reference
Mass 80 kg
Volume 0.264
m³
Capacity 4.5 kg/load
Clothes
Water Usage
51.3
188
kg/load
Effluent is greywater. This unit
does not release water vapor.
Crewtime 0.42
CM-h/load
Load, remove, fold, and stow
clothes.
Energy
0.95
189
kWh/load Low
setting
Consumables 0.010
kg/load Detergent
(Igepon
soap)
From Jeng and
Ewert (2002)
5.4
In-Situ Resource Utilization External Interface
Significant quantities of local resources are available at Mars that might be used for life support. Sridhar, et
al. (1998) identified some resources that might be needed. (See Table 5.4.1) Drysdale (1998) estimated very
roughly the masses required for each resource and the cost leverage that seemed credible from in-situ resource
utilization (ISRU) based on data from John Finn (NASA Ames Research Center). (See Table 5.4.3)
Regolith may be used for radiation and meteoroid protection at a long-term base and would be available for
the cost of moving it and bagging it.
Water would be a high leverage item, particularly if bioregeneration is used extensively. It could be
available from the atmosphere, despite its dryness, from permafrost that is expected to be extensive at a meter or two
below the surface, from polar ice, or from subsurface water or ice deposits. It could also be made from atmospheric
carbon dioxide, if a source of hydrogen is available. Even if hydrogen had to be shipped from Earth, this would still
give a 5 to 1 cost advantage. The cost of acquisition would depend on the cost of extraction and purification.
Currently, the abundance and location of water on Mars is undetermined. The atmosphere of Mars carries water
vapor in minimal quantities. Likewise, large deposits of water exist at both Martian poles, but accessing that water is
complicated by the seasonal deposition of frozen carbon dioxide on top of the ice deposits.
Atmospheric carbon dioxide could support plant growth, particularly if a plant growth unit is set up and
started remotely. It could be readily extracted from the atmosphere, which is 95% carbon dioxide, though at a low
pressure.
An inert gas would be needed to dilute the cabin oxygen, assuming the base air would not be pure oxygen.
This could be extracted from the atmosphere by removing the carbon dioxide and water vapor.
188
A washer using ozone, O
3
, for the detergent will use less water. Energy usage, however, increases to support ozone
production.
189
Corresponding energy usage values: The washer cycle is 40 minutes at 300 W and the dryer cycle is 60 minutes at 750 W.
130
Finally, oxygen, for crew respiration, can be obtained from the atmosphere, either by removing the rest of
the gases or by reaction with the atmospheric carbon dioxide using either a Sabatier/electrolysis or zirconia cell
reaction.
A design reference mission (Hoffman and Kaplan, 1997) proposes using local resources to make rocket
propellant, liquid methane and liquid oxygen, for the Mars ascent vehicle from the Martian atmosphere. While
oxygen is available as a product from splitting carbon dioxide, methane production requires a source of hydrogen.
Water provides a readily used source of hydrogen, but as addressed above, it may not be readily available. The
design reference mission avoids the issue of water availability by providing liquid hydrogen from Earth for ISRU
propellant production.
Similar propellants could be used for power storage, including propelling surface or aerial vehicles,
especially if a local source of water is available. In addition, the same chemical processing plant could be used to
make life support commodities, such as listed below in Table 5.4.3. Some of these, inert gases, for example, might
be made available as by-products at minimal added cost.
Note that shipped commodities will have a negative cost leverage to account for packaging. This can be a
significant mass factor, as shown in Table 4.1.4 for permanent gases. This is in addition to any cost factor for the
shipping location as identified in Table 3.2.1.
Table 5.4.1
Nitrogen Gas Losses Associated with International Space Station Technology
Parameter
Mass
[kg/y]
Comments Reference
Nitrogen Resupplied 796
ISS Module Leakage 18 - 44
Airlock Losses
10%
mass of nitrogen lost per cycle is 1 kg
Information from Sridhar,
et al. (1998)
Table 5.4.2
Nitrogen Gas Losses for the Mars Design Reference Mission (One Cycle)
Using ISS Technologies
Mission
Phase
Event
Mass
[kg]
per
Event
Total
Mass
Lost
[kg]
Calculation
Basis
Reference
Transit Module
Leakage 0.1 day
26
260 days transit;
both ways
Surface Airlock
Usage 1 cycle 1,200
2 cycles/day for
619 days
Surface Module
Leakage 0.1 day
62 619
days
Total
1,288
Gas Mass
Excluding Tanks
Information from Sridhar,
et al. (1998)
131
Table 5.4.3
Estimation of Cost Leverages from In-Situ Resource Utilization
190
Commodity
Requirement
[kg]
Cost
Leverage
Comments / Assumptions
Likelihood
191
Regolith
620,000
3,100
Assumes a Rover is Available
Always
Water
12,000
310
From Local Permafrost
Unknown to Unlikely
Water 12,000
390
From
Local
Atmosphere
Unlikely
Water
12,000
5
Produced Using Hydrogen from Earth Always
Carbon Dioxide
528
47
For 30 days of Plant Growth; Using Local
Atmosphere
Always
Inert Gas
(Argon/Nitrogen)
508 1.6
From
Local
Atmosphere
Always
Oxygen
121
19
From Electrolysis of Local Water
Unknown to Unlikely
Hydrogen
system
dependent
1.2 From Electrolysis of Local Water
Depends on water
availability
Allen and Zubrin (1999) suggest ISRU is also available on Luna, though the variety and source of
commodities is more limited. Specifically, oxygen is available as an oxide within the lunar regolith. Further, though
very limited in extent, water, as ice, is present in deep craters at both lunar poles.
5.5
Integrated Control External Interface
5.5.1
Sensors
Sensors are critical to life support system operation. However, based on current estimates from the ALS
Systems Analysis Workshop of March 1998, the mass will not be significant compared to the overall life support
system mass.
Table 5.5.1
Sensor Mass Estimates
Assumptions [kg]
Parameter
Lower Nominal Upper
References
Low Tech
221
(1)
TBD 680
(1)
High Tech
71
(1)
TBD 165
(1)
Highest Tech
39
(1)
TBD 106
(1)
(1)
Jan (1998)
190
From Drysdale (1998) using data from J. Finn (NASA/Ames Research Center). These estimates are very preliminary.
191
Likelihood assesses how likely a particular commodity might be available based on current knowledge of Mars for a
typical site. Assessment scale: “Always†implies availability at all sites. “Likely†implies availability at most sites in
unlimited quantities. “Unlikely†implies availability at some sites in unlimited quantities or available at most sites in
limited quantities. “Unknown†implies unknown availability.
132
5.6
Power External Interface
Within this manuscript, power enters analyses and modeling through use of a power-mass penalty.
Information on power systems is provided under the description of infrastructure in Section 3.2.
5.7
Radiation Protection External Interface
Radiation Protection, according to Table 2.4.2, may impact numerous systems. While exotic life support
designs are possible, it is likely that Radiation Protection, which is effectively mass between the crew and the
external radiant environment, will remain a dedicated mass of material with a high hydrogen content such as
polyethylene or, less ideally, water. Further, vehicle structure, including the primary structure, avionics, and
propulsion system can provide varying degrees of protection just due to the nature of their mass (Duffield, 2001).
However, the most likely interaction for the Radiation Protection External Interface is with the Water Subsystem
and then only as a contingency source.
For operations in near Earth space, hydrogen mass equivalent, as detailed in Table 3.2.6, in and around any
safe haven is considered adequate for a vehicle radiation shelter to protect against solar particle events. While the
initial activity from solar particle events enters from the direction of the Sun, the radiation field soon becomes
effectively isotropic. Any effective radiation protection must provide a complete enclosure for the crew. This
radiation shelter may include the entire crew cabin. On short-duration missions, such as a lunar transit, such
protection may only encompass a portion of the crew cabin, such as the sleeping quarters, due to the added mass
associated with complete radiation shielding.
For longer duration missions, either for extended operations on Luna or to transit to Mars, the crew cabin
must also provide protection versus galactic cosmic radiation. Again this radiation source is, by nature, isotropic. As
implied above in the Section 3.2.1 on infrastructure, galactic cosmic radiation is much more difficult to stop. For
extended duration transit missions, all mass to protect against galactic cosmic radiation must be transported with the
spacecraft. On a planetary surface, local resources, such as regolith packed into “sandbags†or underground caverns
may be used to protect against radiation. Additionally, the carbon dioxide atmosphere of Mars, as well as the mass
of the planet itself, provides some protection.
Here, Radiation Protection External Interface costs are integrated with the primary structure penalty for
volume as noted above in Section 3.2.1.
133
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7
Appendices
7.1
Appendix A: Acronyms and Abbreviations
AES
air evaporation subsystem
ALS
Advanced Life Support
ARC
Ames Research Center
ATCS
active thermal control system
BIO-Plex Bioregenerative
Planetary
Life
Support Systems Test Complex
BPC
Biomass Production Chamber at
Kennedy Space Center
BVAD
Baseline Values and Assumptions
Document (This Document)
BWP
biological water processor
CI controlled
inorganic
(compound)
CO
2
carbon
dioxide
COP
S
overall
system
thermodynamic
coefficient of performance
CTMP crewtime-mass-penalty
[kg/CM-h]
CTSD
Crew and Thermal Systems Division
(at NASA JSC)
dw
dry mass (dry “weightâ€)
EATCS external
active thermal control
system
EMU extravehicular
mobility
unit
(space suit)
EPB
early planetary base
ESM equivalent
system
mass
ETCS
external thermal control system
EVA extravehicular
activity
ffm
frozen food mass
fw
fresh mass (fresh “weightâ€)
HPS
high pressure sodium, a type of lamp
ISRU
in situ resource utilization
ISS
International Space Station
IST Invariantly-Scheduled
Time
ITCS
internal thermal control system
IUPAC
International Union of Pure and
Applied Chemistry
IVA
intra vehicular activity
JSC
Johnson Space Center
KSC
Kennedy Space Center
LMLSTP
Lunar Mars Life Support Test
Program (integrated human life
support system test at JSC)
MAG
Maximum Absorption Garment (for
the EMU)
MEC
Modified Energy Cascade models
MPR
multivariable polynomial regression
MSFC
Marshall Space Flight Center
MW molecular
weight
or Megawatt if used as a unit
n/a not
applicable
NASA
National Aeronautics and Space
Administration
O
2
oxygen
p(gas)
partial pressure exerted by gas
PAR
photosynthetically active radiation
pH
potential of hydrogen
PLSS
portable life support system
PPF
photosynthetic photon flux
PV photovoltaic
RO reverse
osmosis
(system)
R
S
system composite thermal resistance
SI
Système Internationale d’Unités, or
International System of Units
(Metric System)
SIMA
Systems Integration, Modeling, and
Analysis element (of the
ALS Project)
SMAC
spacecraft maximum allowable
concentration
SP100
type of nuclear reactor
STS
space transportation system
SVCHp
solar vapor-compression heat pump
TBD
to be determined
TIC total
inorganic
carbon
TM transit
mission
TOC
total organic carbon
TRRJ
thermal radiator rotary joint
VST Variably-Scheduled
Time
RF
W
ˆ
specific power consumption for a
cooled volume within a cabinet
Note: Symbols specific to the crop models in Section 4.2.3 are
defined in Table
4.2.14 and The
canopy surface
conductance, gC [molWater/m²
•
s], is based on the
canopy stomatal conductance, gS [molWater/m²
•
s],
and the atmospheric aerodynamic conductance, gA
[molWater/m²
•
s].
144
7.2
Appendix B: Abbreviations for Units
Symbol Actual
Unit
Physical
Correspondence
°C degrees
Centigrade
temperature
CM crewmember
person
CM-d crewmember-day
crewtime
CM-h crewmember-hour
crewtime
CM-wk crewmember-week
crewtime
CM-
℘
crewmember-menstrual period
crewtime
c centi-
prefix
d day
time
g gram
mass
h hour
time
J Joule
energy
k kilo-
prefix
kW kilowatt
power
kW
e
kilowatt electric
electric power
L liter
volume
M mega-
prefix
m meter
length
m² square
meter
area
m
3
cubic meter
volume
m milli-
prefix
meq/L
milli-equivalents per liter
concentration
mol mole
mole
N Newton
force
Pa Pascal
pressure
ppm parts
per
million
concentration
S Siemens
conductivity
s second
time
W Watt
power
wk week
time
y year
time
µ micro-
prefix
References:
(1)
de Vera (1999);
(2)
Calculation;
(3)
MADS (2001);
(4)
de Vera (1998b);
(5)
NASA (2001b);
(6)
Niehuss (2001);
(7)
NASA (2001c);
(8)
de Vera (1998a).
Note: Hardware entries in
italics
are components of assembly entries in
bold
type.
145
7.3
Appendix C: Life Support Equipment Parameters from the Advanced Life Support Database
192
7.3.1
International Space Station
Table 7.3.1
International Space Station Atmosphere Control and Supply
Assembly or Component
Mass
[kg]
Volume
[m³]
Length
[m]
Width or
Diameter
[m]
Height
[m]
Peak
Power
[W]
Operational
Average
Power
[W]
MTBF
[h]
CMMTTR
[h]
Life Limit
[y] No.
Cabin Pressure Sensor
193
0.3316
(1)
0.000369
(2)
0.0444
(1)
0.0762
(1)
0.1092
(1)
1
Manual Pressurization Equalization Valve
(MPEV)
194
1.0795
(1)
0.002394
(2)
0.1143
(1)
0.1676
(1)
0.1249
(1)
9
MPEV with Muffler
196
0.1134
(1)
0.000151
(2)
0.0355
(1)
0.0762
(1)
0.0558
(1)
1
Negative Pressure Relief Valve
195
0.9343
(1)
0.002836
(2)
0.163
(1)
0.163
(1)
0.1066
(1)
6
Nitrogen / Oxygen Manual Isolation Valve
196
3.928
(3)
1
Nitrogen Manual Isolation Valve
1.0432
(3)
0.002548
(7)
0.1905
(4)
0.0355
(4)
0.08
(4)
1.0
×
10
6
0.5 1
Oxygen Manual Isolation Valve
0.9616
(3)
0.002548
(7)
1.0
×
10
6
0.5 3
Nitrogen / Oxygen Pressure Restrictor
196
0.9071
(4)
0.000189
(2)
0.0355
(4)
0.1905
(4)
1
Nitrogen / Oxygen Pressure Sensor
195
0.8436
(3)
0.002548
(3)
0.0317
(4)
0.1778
(4)
4
Nitrogen / Oxygen Pressure Vessel
197
108.8616
(4)
0.9804
(4)
1.397
(4)
1
Nitrogen / Oxygen Regulator / Relief Valve
Assembly
197
7.8
1
Low Pressure Nitrogen Regulator / Relief Valve
Assembly
1.9504
(4)
0.002548
(3)
0.2095
(4)
0.1333
(4)
0.0889
(4)
300,000
(3)
0.52
(3)
1
(3)
Low Pressure Oxygen Regulator / Relief Valve
Assembly
1.9504
(4)
0.002548
(3)
0.2095
(4)
0.1333
(4)
0.0889
(4)
300,000
(3)
0.92
(3)
2
(3)
Medium Pressure Oxygen Regulator / Relief Valve
Assembly
1.9504
(4)
0.002548
(4)
0.2095
(4)
0.1333
(4)
0.0889
(4)
300,000
(3)
0.92
(3)
1
(7)
Oxygen / Nitrogen Latching Motor Valve
198
4.9
(3)
1
Nitrogen Latching Motor Valves
1.6329
(3)
0.004531
(3)
0.2032
(4)
0.1841
(4)
0.1196
(4)
500,000
0.84
1
Oxygen Latching Motor Valves
1.6329
(3)
0.004531
(3)
0.2032
(4)
0.1841
(4)
0.1196
(4)
500,000
0.95
2
192
See Database (2002)
193
Function:
atmospheric pressure monitoring
194
Function:
pressure
equalization
195
Function:
pressure
relief
196
Function: nitrogen and oxygen flow distribution
197
Function: nitrogen and oxygen storage
References:
(1)
de Vera (1999);
(2)
Calculation;
(3)
MADS (2001);
(4)
de Vera (1998b);
(5)
NASA (2001b);
(6)
Niehuss (2001);
(7)
NASA (2001c);
(8)
de Vera (1998a).
Note: Hardware entries in
italics
are components of assembly entries in
bold
type.
146
Table 7.3.1
International Space Station Atmosphere Control and Supply (continued)
Assembly or Component
Mass
[kg]
Volume
[m³]
Length
[m]
Width or
Diameter
[m]
Height
[m]
Peak
Power
[W]
Operational
Average
Power
[W]
MTBF
[h]
CMMTTR
[h]
Life Limit
[y] No.
Oxygen Generation
Assembly
198
446
1
Hydrogen
161.6176
(6)
0.146697
(6)
0.7874
(6)
0.4318
(6)
0.4318
(6)
27,156
(6)
1.1
(6)
2.38
(6)
1
(6)
Hydrogen Sensor
4.3545
(6)
0.003398
(6)
0.1778
(6)
0.1524
(6)
0.127
(6)
61,845.6
(6)
0.6
(6)
0.25
(6)
1
(6)
Inlet Deionizing Bed
28.6675
(6)
0.029452
(6)
0.6146
(6)
0.2362
(6)
0.2032
(6)
296,701.2
(6)
0.233
(6)
6
(6)
1
(6)
Nitrogen Purge ORU
34.2468
(6)
138,408
(6)
1
(6)
Oxygen Outlet
48.1723
(6)
0.031152
(6)
0.3556
(6)
0.3175
(6)
0.2768
(6)
98,112
(6)
0.65
(6)
10
(6)
1
(6)
Power Supply Module
42.6384
(6)
0.064852
(6)
0.6096
(6)
0.381
(6)
0.2794
(6)
47,479.2
(6)
0.583
(6)
4.17
(6)
1
(6)
Process Controller
47.0836
(6)
0.083827
(6)
0.7213
(6)
0.4445
(6)
0.2616
(6)
103,280.4
(6)
1.05
(6)
7.72
(6)
1
(6)
Pump
17.9625
(6)
0.010152
(6)
0.2794
(6)
0.2286
(6)
0.1574
(6)
144,540
(6)
0.583
(6)
1
(6)
1
(6)
Water
61.0545
(6)
0.075614
(6)
0.4572
(6)
0.4521
(6)
0.3657
(6)
33,288
(6)
0.966
(6)
2.92
(6)
1
(6)
Oxygen Relief Valve
Assembly
199
1.9504
(4)
0.000849
(3)
0.1524
(4)
0.2189
(4)
0.0533
(4)
1
Portable Breathing Apparatus
Quick Disconnect
200
0.1514
(1)
0.0177
(1)
0.019
(1)
0.0508
(1)
1
Positive Pressure Relief
Valve
201
1.3607
(1)
0.179
(1)
0.1143
(1)
0.1524
(1)
1
Pressure Control Panel
201
22.68
(5)
0.035116
(3)
0.4826
(3)
0.3149
(3)
0.2311
(3)
1
Firmware Controller
4.8897
(8)
0.005608
(8)
0.2057
(8)
0.1651
(8)
0.1651
(8)
15
(8)
12
(8)
1
Nitrogen Isolation Valve
1.2927
(8)
0.000849
(8)
0.0095
(8)
50
(8)
38
(8)
1
Oxygen Isolation Valve
1.2927
(8)
0.000849
(8)
0.0095
(8)
50
(8)
38
(8)
1
Vent and Relief Valve
201
5.4432
(8)
0.01416
(8)
0.0558
(8)
30
(8)
1
Vent and Relief Control Valve
(VRCV)
0.0558
(8)
1
Vent and Relief Isolation (VRIV)
0.0558
(8)
1
198
Function:
oxygen
generation
199
Function:
pressure
relief
200
Function: emergency equipment
201
Function:
atmospheric pressure control
References:
(1)
de Vera (1999);
(2)
Calculation;
(3)
MADS (2001);
(4)
de Vera (1998b);
(5)
NASA (2001b);
(6)
Niehuss (2001);
(7)
NASA (2001c);
(8)
de Vera (1998a).
Note: Hardware entries in
italics
are components of assembly entries in
bold
type.
147
Table 7.3.2
International Space Station Atmosphere Revitalization Subsystem
Assembly or Component
Mass
[kg]
Volume
[m³]
Length
[m]
Width or
Diameter
[m]
Height
[m]
Peak Power
[W]
Operational
Average
Power
[W]
MTBF
[h]
CMMTTR
[h]
Life Limit
[y] No.
3-way Sample Valve
202
1.9731
(1)
0.002322
(1)
0.1778
(1)
0.1143
(1)
0.1143
(1)
1
Carbon Dioxide Removal Assembly
203
195.3793
(8)
0.387984
(8)
1,487
(8)
860
(8)
1
Air Pump, Two-Stage, ORU
10.8861
(8)
0.004531
(3)
0.084
(3)
0.234
(3)
0.234
(3)
245
(8)
23
(8)
156,200
(3)
1.53
(3)
15.29
(3)
1
(3)
Blower
5.5792
(8)
0.025488
0.61
(3)
0.203
(3)
0.203
(3)
170
(8)
170
(8)
129,700
(3)
1.67
(3)
10
(3)
1
Check Valves
39.9159
(8)
0.178416
(8)
960
(8)
346
(8)
1
Desiccant Beds
42.6384
(3)
0.08496
(3)
1.0922
(3)
0.3048
(3)
0.254
(3)
77,100
(3)
2.28
(3)
2
Heat Controller
3.3112
(8)
0.008496
(3)
0.178
(3)
0.142
(3)
0.216
(3)
32
(8)
19
(8)
242,700
(3)
0.55
(3)
2
(3)
Precooler
5.5792
(8)
0.025488
0.61
(3)
0.203
(3)
0.203
(3)
129,700
(3)
1.67
(3)
10
(3)
1
Pump Fan Motor Controller
2.7215
(8)
0.005664
(3)
0.14
(3)
0.089
(3)
0.165
(3)
20
(8)
2
(8)
2.272
×
10
6 (3)
0.52
(3)
2
(3)
Selector Valves
3.039
(8)
0.001699
(8)
0.155
(3)
0.109
(3)
0.109
(3)
60
(8)
1
(8)
117,000
(3)
0.94
(3)
10.61
(3)
6
(3)
Sorbent Beds (Zeolite)
42.6384
(3)
0.08496
(3)
1.0922
(3)
0.3048
(3)
0.254
(3)
77,100
(3)
2.28
(3)
2
Catalyst Element Assembly
204
5.2616
(1)
0.004729
(1)
0.0939
(1)
0.6604
(1)
0.0762
(1)
4
Major Constituent Analyzer
205
54.7483
(8)
0.43896
(8)
87.6
(8)
1
ORU 1-Data and Control Assembly
8.0196
(3)
0.013214
(3)
0.1905
(3)
0.2844
(3)
0.2438
(3)
34.9
(8)
43,500
(3)
0.84
(3)
10
(3)
1
(5)
ORU 2-Mass Spectrometry Assembly
13.304
(3)
0.023794
(3)
0.254
(3)
0.4191
(3)
0.2235
(3)
31.8
(8)
8,180
(3)
0.8
(3)
4.5
(3)
1
ORU 4-Low Voltage Power Supply Assembly
5.67
(3)
0.005333
(3)
0.1574
(3)
0.1778
(3)
0.1905
(3)
30.8
(8)
199,000
(3)
0.82
(3)
1
(3)
ORU 5-Series Sample Pump Assembly
3.1298
(3)
0.004961
(3)
0.2209
(3)
0.1016
(3)
0.1981
(3)
4
(8)
11,900
(3)
0.71
(3)
2
(3)
1
(5)
ORU 6-Sample Distribution Assembly
2.1092
(3)
0.003613
(3)
0.16
(3)
0.127
(3)
0.1778
(3)
0.1
(8)
70,900
(3)
0.71
(3)
15
(3)
1
(5)
ORU 7-EMI Filter Assembly
1.4515
(3)
0.001699
(3)
0.1752
(3)
0.0744
(3)
0.1303
(3)
1.8
(8)
1.16
×
10
6 (3)
0.71
(3)
1
(3)
ORU 8-Verification Gas Assembly
5.7607
(3)
0.013722
(3)
0.3098
(3)
0.1981
(3)
0.2235
(3)
0.1
(8)
52,100
(3)
0.74
(3)
1.5
(8)
1
(3)
Manual Sample Valve
204
0.2267
(1)
0.000589
(1)
0.1016
(1)
0.0762
(1)
0.0762
(1)
1
Sample Distribution Assembly
204
1
Trace Contaminant Control Subsystem
206
79.8318
(8)
0.271866
(2)
0.6461
(8)
0.4508
(8)
0.9331
(8)
250
(8)
180
(8)
1
Activated Charcoal Bed
36.65
(8)
0.075699
(8)
0.8255
(3)
0.3886
(3)
0.3505
(3)
215,000
(3)
0.7
(3)
1
(3)
Blower
2.9392
(8)
0.005899
(8)
51.75
(8)
34.5
(8)
121,500
(3)
0.38
(3)
5
(3)
1
Catalytic Oxidizer
11.0449
(8)
0.024312
(8)
0.2413
(3)
0.2463
(3)
0.4089
(3)
168
(8)
120.96
(8)
89,500
(3)
0.6
(3)
1
(3)
Electronic Interface Assembly
3.4201
(3)
0.003749
(3)
0.254
(3)
0.2235
(3)
0.066
(3)
7.64
(8)
7.64
(8)
483,000
(3)
0.59
(3)
1
(3)
Flowmeter
1.0886
(8)
0.000196
(8)
0.1778
(3)
0.0635
(3)
0.1651
(3)
11.5
(8)
11.5
(8)
936,000
(3)
0.35
(3)
1
(3)
Lithium Hydroxide Sorbent Bed
4.1049
(8)
0.007823
(8)
0.3759
(3)
0.16
(3)
0.2082
(3)
241,000
(3)
0.59
(3)
1
202
Function:
air
sampling
203
Function: carbon dioxide control
204
Function: control gaseous contaminants
205
Function: monitor atmospheric partial pressure
206
Function: control gaseous contaminants
References:
(1)
de Vera (1999);
(2)
Calculation;
(3)
MADS (2001);
(4)
de Vera (1998b);
(5)
NASA (2001b);
(6)
Niehuss (2001);
(7)
NASA (2001c);
(8)
de Vera (1998a).
Note: Hardware entries in
italics
are components of assembly entries in
bold
type.
148
Table 7.3.3
International Space Station Temperature and Humidity Control
Assembly or Component
Mass
[kg]
Volume
[m³]
Length
[m]
Width or
Diameter
[m]
Height
[m]
Peak
Power
[W]
Operational
Average
Power
[W]
MTBF
[h]
CMMTTR
[h]
Life Limit
[y] No.
Avionics Air Assembly
207
12.519
(3)
0.033134
(3)
0.5969
(3)
0.2794
(3)
0.1981
(3)
175
(8)
1
Bacteria Filter Assembly
208
26.36
(5)
0.018781
(5)
0.785
(5)
0.145
(5)
0.165
(5)
1
Bacteria Filter Element
2.0275
(3)
0.009062
(3)
0.7112
(3)
0.1016
(3)
0.127
(3)
2.0
×
10
8 (3)
0.1
(3)
13
Cabin Diffuser Assembly
209
0.82
(5)
0.003398
(3)
0.0635
(3)
0.1676
(3)
0.3175
(3)
6
Charcoal Catalytic Filter Element
210
4.46 0.00921 0.711 0.102 0.127
1
Common Cabin Air Assembly
210
96.161
(8)
705
(8)
469
(8)
1
Condensing Heat Exchanger
49.71
(5)
0.393293
(5)
1.016
(5)
0.762
(5)
0.508
(5)
832,600
(3)
1.56
(3)
1
Electronic Interface Box (EIB)
4.037
(3)
0.017275
(3)
0.3302
(3)
0.2286
(3)
0.2286
(3)
2.3506
×
10
6 (3)
0.83
(3)
2
Fan Delta Pressure Sensor
0.4535
(8)
0.000163
(8)
0.0558
(3)
0.0406
(3)
0.1473
(3)
0.24
(8)
1.25
×
10
6 (3)
0.94
(3)
1
Heat Exchanger Liquid Sensor
0.635
(8)
0.000566
(8)
0.098
(3)
0.0546
(3)
0.0995
(3)
0.009
(8)
1.1363
×
10
6 (3)
0.47
(3)
2
Inlet ORU
25.31
(5)
0.130875
(3)
0.5905
(8)
0.4826
(8)
0.4889
(8)
469
(8)
332,900
0.39
1
Pressure Transducer
0.4762
(3)
0.000283
(3)
0.1524
(3)
0.0406
(3)
0.0406
(3)
0.24
(8)
1.25
×
10
6 (3)
0.92
(3)
15
1
Temperature Control Check Valve (TCCV)
7.4526
(3)
0.00708
(3)
0.381
(3)
0.1905
(3)
0.0965
(3)
32,880
(3)
0.44
(3)
2
Temperature Sensor
0.263
(3)
0.001416
(3)
0.1046
(3)
0.1206
(3)
0.1016
(3)
3.7594
×
10
7 (3)
0.53
(3)
4
Water Separator
11.93
(3)
0.058285
(3)
0.371
(3)
0.356
(3)
0.434
(3)
130,800
(3)
0.79
(3)
5
2
Water Separator Liquid Sensor
0.635
(8)
0.000566
(8)
0.009
(8)
1
Damper Valve Assembly
211
2.7215
(1)
0.006125
(1)
0.1682
(1)
0.1574
(1)
0.2311
(1)
4
Intermodule Ventilation Muffler
213
0.000237
(1)
0.0762
(1)
0.0558
(1)
0.0558
(1)
9
Intermodule Ventilation Caps
213
1.9
1
IMV cap
0.635
(1)
0.00192
(1)
0.1587
(1)
0.1587
(1)
0.0762
(1)
1
IMV Cap Flange Saver
0.4989
(1)
0.00192
(2)
0.1587
(1)
0.1587
(1)
0.0762
(1)
1
IMV Leak Check Cap
0.7257
(1)
0.00192
(2)
0.1587
(1)
0.1587
(1)
0.0762
(1)
1
Intermodule Ventilation Fan
213
4.1657
(1)
0.009283
(2)
0.2413
(1)
0.226
(1)
0.1701
(1)
55
(1)
1
Intermodule Ventilation Valve
213
5.2162
(1)
0.008284
(2)
0.3256
(1)
0.1579
(1)
0.161
(1)
20
(1)
7.68
(1)
1
Node 1 Cabin Fan
211
24.9474
(1)
0.13935
(1)
0.5905
(1)
0.4826
(1)
0.4889
(1)
1,000
(1
)
180
(1)
1
Cabin Fan Delta Pressure Sensor
0.4535
(1)
0.000163
(1)
0.24
(1)
1
207
Function:
heat
removal
208
Function: particulate and microbial growth control
209
Function: intramodule atmosphere circulation
210
Function: temperature and humidity control
211
Function: intermodule atmosphere circulation
References:
(1)
de Vera (1999);
(2)
Calculation;
(3)
MADS (2001);
(4)
de Vera (1998b);
(5)
NASA (2001b);
(6)
Niehuss (2001);
(7)
NASA (2001c);
(8)
de Vera (1998a).
Note: Hardware entries in
italics
are components of assembly entries in
bold
type.
149
Table 7.3.4
International Space Station Fire Detection and Suppression
Assembly or Component
Mass
[kg]
Volume
[m³]
Length
[m]
Width or
Diameter
[m]
Height
[m]
Peak
Power
[W]
Operational
Average
Power
[W]
MTBF
[h]
CMMTTR
[h]
Life
Limit
[y] No.
Portable Fire Extinguisher
212
7.7563
(1)
0.038409
(5)
0.4851
(1)
0.2606
(1)
0.2606
(1)
1
Smoke Detector
213
1.5422
(1)
0.001968
(2)
0.1143
(1)
0.1301
(1)
0.1323
(1)
1.48
(1)
1
Table 7.3.5
International Space Station Vacuum Services
Assembly or Component
Mass
[kg]
Volume
[m³]
Length
[m]
Width or
Diameter
[m]
Height
[m]
Peak
Power
[W]
Operational
Average
Power
[W]
MTBF
[h]
CMMTTR
[h]
Life Limit
[y]
No.
Load Control Assembly
214
10.8861
(8)
0.01246
(3)
0.2794
(3)
0.2209
(3)
0.2032
(3)
1
On-orbit Support
Equipment
216
3.5
1
VES/VRS jumper
2.13
(5)
0.002556
(5)
0.991
(5)
0.051
(5)
0.051
(5)
1
VS Equalization tool
1.37
(5)
0.000932
(5)
0.206
(5)
0.069
(5)
0.066
(5)
1
Vacuum Exhaust System
(VES)
216
35.02
(8)
150
(8)
80
(8)
1
Cold Cathode Transducer
2.5401
(8)
0.002832
(3)
0.3429
(3)
0.1041
(3)
0.0787
(3)
10
(8)
5
(8)
400,384
(3)
1.22
(3)
0.5
(3)
1
(3)
Flexible Metal Bellows
0.8436
(8)
0.0635
(8)
1
Non-Propulsive Vent (NPV)
1.7917
(3)
0.005947
(3)
0.1524
(3)
0.3048
(3)
0.127
(3)
2.0
×
10
8 (3)
0.19
(3)
1
(3)
Pirani Gauge Transducer
1.1339
(8)
0.001132
(3)
0.2184
(3)
0.1041
(3)
0.0482
(3)
3
(8)
1.5
(8)
307,800
(3)
1.11
(3)
1
(3)
Positive Pressure Transducer
0.4535
(8)
0.000283
(3)
0.1016
(3)
0.0254
(3)
0.0254
(3)
682,611
(3)
1.11
(3)
1
(3)
Rack Isolation Valve (1 inch)
1.8143
(8)
0.002548
(3)
0.1371
(3)
0.0939
(3)
0.2032
(3)
30
(8)
428,700
(3)
4.54
(3)
13
(3)
Vent Valve (2.5 inch)
4.672
(3)
0.00538
(3)
0.2794
(3)
0.1727
(3)
0.1143
(3)
30
(8)
347,425
(3)
0.43
(3)
1
(3)
Vacuum Resource System
(VRS)
216
8.8
(8)
150
(8)
80
(8)
1
Cold Cathode Transducer
2.5401
(8)
0.002832
(3)
0.3429
(3)
0.1041
(3)
0.0787
(3)
10
(8)
5
(8)
400,384
(3)
1.22
(3)
0.5
(3)
1
(3)
Pirani Gauge Transducer
1.1339
(8)
0.001132
(3)
0.2184
(3)
0.1041
(3)
0.0482
(3)
3
(8)
1.5
(8)
307,800
(3)
1.11
(3)
1
(3)
Positive Pressure Transducer
0.4535
(8)
0.000283
(3)
0.1016
(3)
0.0254
(3)
0.0254
(3)
682,611
(3)
1.11
(3)
1
(3)
Vent Valve (2.5 inch)
4.672
(3)
0.00538
(3)
0.2794
(3)
0.1727
(3)
0.1143
(3)
30
(8)
347,425
(3)
0.43
(3)
1
(3)
212
Function:
fire
suppression
213
Function:
fire
detection
214
Function: supply vacuum services
References:
(1)
de Vera (1999);
(2)
Calculation;
(3)
MADS (2001);
(4)
de Vera (1998b);
(5)
NASA (2001b);
(6)
Niehuss (2001);
(7)
NASA (2001c);
(8)
de Vera (1998a).
Note: Hardware entries in
italics
are components of assembly entries in
bold
type.
150
Table 7.3.6
International Space Station Water Recovery and Management
Assembly or Component
Mass
[kg]
Volume
[m³]
Length
[m]
Width or
Diameter
[m]
Height
[m]
Peak
Power
[W]
Operational
Average
Power
[W]
MTBF
[h]
CMMTTR
[h]
Life Limit
[y] No.
Condensate Water Storage Assembly
215
21.3373
(3)
0.145848
(3)
0.9296
(3)
0.3962
(3)
0.3962
(3)
1
Contingency Water Container
217
1.18
(5)
0.017663
(5)
0.61
(5)
0.381
(5)
0.076
(5)
1
Fuel Cell Water Tank
217
72.1224
(3)
0.381187
(3)
1
Overboard Water Vent
216
1.4605
(3)
0.007363
(3)
0.1955
(3)
0.193
(3)
0.193
(3)
2
Urine Processor Assembly
217
291
1
Distillation Assembly
92.7612
(6)
0.142166
(6)
0.762
(6)
0.4318
(6)
0.4318
(6)
142,525.2
(6)
0.95
(6)
2
(6)
1
(6)
Firmware Controller Assembly
23.0882
(6)
0.028603
(6)
0.2921
(6)
0.3835
(6)
0.2565
(6)
27,331.2
(6)
1.15
(6)
2.4
(6)
1
(6)
Fluids Control and Pump Assembly
47.5826
(6)
0.073065
(6)
0.6883
(6)
0.4216
(6)
0.2514
(6)
90,140.4
(6)
2.066
(6)
4
(6)
1
(6)
Pressure Control and Pump Assembly
49.0795
(6)
0.115828
(6)
0.7416
(6)
0.4622
(6)
0.3378
(6)
181,507.2
(6)
0.916
(6)
2
(6)
1
(6)
Recycle Filter Tank Assembly
15.377
(6)
0.101102
(6)
0.8382
(6)
0.4318
(6)
0.2794
(6)
199,640.4
(6)
0.916
(6)
0.08
(6)
1
(6)
Separator Plumbing Assembly
16.7832
(6)
0.022939
(6)
0.8178
(6)
0.1727
(6)
0.1625
(6)
384,651.6
(6)
0.816
(6)
1
(6)
1
(6)
Wastewater Storage Tank Assembly
45.9496
(6)
0.039364
(6)
0.8255
(6)
0.2184
(6)
0.2184
(6)
184,222.8
(6)
1.716
(6)
10
(6)
1
(6)
Water Processor Assembly
218
781
1
Catalytic Reactor
67.042
(6)
0.115545
(6)
0.7874
(6)
0.4191
(6)
0.3505
(6)
25,579.2
(6)
1.183
(6)
2.25
(6)
1
(6)
Gas Separator
39.1456
(6)
0.065985
(6)
0.7112
(6)
0.4064
(6)
0.2286
(6)
84,008.4
(6)
0.716
(6)
1
(6)
1
(6)
Ion Exchange Bed
13.0183
(6)
0.017275
(6)
0.8128
(6)
0.1905
(6)
0.1117
(6)
296,701.2
(6)
0.266
(6)
0.16
(6)
1
(6)
Microbial Check Valve
5.7607
(6)
0.006513
(6)
0.3175
(6)
0.1473
(6)
0.1397
(6)
143,488.8
(6)
0.266
(6)
1
(6)
1
(6)
Multifiltration Bed #1
149.2344
(6)
0.065702
(6)
0.7442
(6)
0.4394
(6)
0.2006
(6)
296,701.2
(6)
0.383
(6)
0.36
(6)
1
(6)
Multifiltration Bed #2
149.2344
(6)
0.065702
(6)
0.7442
(6)
0.4394
(6)
0.2006
(6)
296,701.2
(6)
0.383
(6)
0.36
(6)
1
(6)
Particulate Filter
32.2509
(6)
0.071649
(6)
0.6172
(6)
0.508
(6)
0.2286
(6)
717,356.4
(6)
0.25
(6)
0.22
(6)
1
(6)
pH Adjuster
2.5401
(6)
0.002548
(6)
0.2032
(6)
0.127
(6)
0.1016
(6)
137,181.6
(6)
0
(6)
1
(6)
1
(6)
Process Controller
44.9971
(6)
0.083827
(6)
0.7213
(6)
0.4445
(6)
0.2616
(6)
87,950.4
(6)
0.683
(6)
7.72
(6)
1
(6)
Pump Separator
31.3437
(6)
0.086942
(6)
0.7543
(6)
0.4318
(6)
0.2667
(6)
42,398.4
(6)
0.7
(6)
2
(6)
1
(6)
Reactor Health Sensor
16.8285
(6)
0.04248
(6)
0.6604
(6)
0.254
(6)
0.254
(6)
56,677.2
(6)
0.666
(6)
1
(6)
1
(6)
Sensor
4.8081
(6)
0.003398
(6)
0.1778
(6)
0.1524
(6)
0.127
(6)
143,664
(6)
0.65
(6)
10
(6)
1
(6)
Separator Filter
7.6658
(6)
0.010195
(6)
0.3429
(6)
0.1778
(6)
0.1676
(6)
359,072.4
(6)
0.233
(6)
0.84
(6)
1
(6)
Start-up Filter
9.4348
(6)
0.018408
(6)
0.635
(6)
0.2286
(6)
0.127
(6)
226,884
(6)
0
(8)
19.92
(6)
1
(6)
Wastewater
103.2847
(6)
0.163123
(6)
0.7772
(6)
0.4775
(6)
0.4394
(6)
53,611.2
(6)
0.65
(6)
4.71
(6)
1
(6)
Water Delivery
47.5372
(6)
0.09742
(6)
0.7874
(6)
0.4394
(6)
0.2819
(6)
64,561.2
(6)
0.633
(6)
5
(6)
1
(6)
Water Storage
56.7453
(6)
0.175017
(6)
0.8077
(6)
0.4394
(6)
0.4927
(6)
44,676
(6)
0.65
(6)
3.92
(6)
1
(6)
215
Function:
water
storage
216
Function:
water
venting
217
Function:
process
urine
218
Function:
process
wastewater
References:
(1)
Doinier;
(2)
Calculation.
Note: Hardware entries in
italics
are components of assembly entries in
bold
type.
151
7.3.2
Spacelab
Table 7.3.7
Spacelab Atmosphere Revitalization Subsystem
Assembly or Component
Mass
[kg]
Volume
[m³]
Length
[m]
Width or
Diameter
[m]
Height
[m]
Peak
Power
[W]
Operational
Average
Power
[W]
MTBF
[h]
CMMTTR
[h]
Life
Limit
[y]
No.
Cabin Fan Assembly
219
18.96 0.081622 0.4612 0.3027 0.5844 399
1
Cabin Fan
2.7 0.00562 0.1428
0.1868
0.2105 395
2
Check Valve
0.205 0.004299 0.0421 0.1802
2
Debris Trap Filter
0.85 0.001482 0.381 0.2286 0.017
1
Power Factor Corrector
0.93 0.001032 0.1524 0.0889 0.0762
2
1
Carbon Dioxide Control
Assembly
220
24.1
(1)
0.191135
(2)
0.7
(1)
0.635
(1)
0.43
(1)
0.2
(1)
1
Carbon Dioxide Control
Assembly
222
3.06
1
Carbon Dioxide Absorber Element
3.06 0.025968 0.2872 0.1696
1
Humidity and Temperature
Control Assembly
221
19.43 0.078403 0.2529 0.5751 0.5389
0.85
1
Condensing Heat Exchanger
17.77 0.078401 0.2529 0.5751 0.5389
0.85
1
Temperature Control Valve
2.3 0.0272 0.4351
0.2159
0.2895
1
Water Separator Assembly
222
97.6 0.040714
0.5003
0.3048
0.2669 48
1
Liquid Check Valve
0.055 0.000102 0.0508 0.0254
2
Power Factor Corrector
0.759 0.001032 0.1524 0.0889 0.0762
1
1
Rotary Separator
2.55 0.015127 0.1524 0.1778
43
2
Table 7.3.8
Spacelab Active Thermal Control Subsystem
Assembly or Component
Mass
[kg]
Volume
[m³]
Length
[m]
Width or
Diameter
[m]
Height
[m]
Peak
Power
[W]
Operational
Average
Power
[W]
MTBF
[h]
CMMTTR
[h]
Life
Limit
[y] No.
Freon Pump Package
223
22.4 0.044586
0.48 0.2997
0.0988 315
1
Water Pump Package
225
21.09 0.036565 0.3937 0.2997 0.3098
66
1
219
Function: intramodule atmosphere circulation
220
Function: carbon dioxide control
221
Function: temperature and humidity control
222
Function: humidity control
223
Function:
heat
removal
References:
(1)
Doinier;
(2)
Calculation.
Note: Hardware entries in
italics
are components of assembly entries in
bold
type.
152
Table 7.3.9
Spacelab Temperature and Humidity Control
Assembly or Component
Mass
[kg]
Volume
[m³]
Length
[m]
Width or
Diameter
[m]
Height
[m]
Peak
Power
[W]
Operational
Average
Power
[W]
MTBF
[h]
CMMTTR
[h]
Life
Limit
[y] No.
Avionics Fan
224
20
(1)
0.0516
(2)
0.5
(1)
0.43
(1)
0.24
(1)
670
130
(1)
225
1
Avionics Heat Exchanger
Assembly
226
15.6
(1)
0.039525
(2)
0.383
(1)
0.43
(1)
0.24
(1)
4,510
(1)
1
Cabin Fan
226
18.7
(1)
0.126449
(2)
0.85
(1)
0.483
(1)
0.308
(1)
403
(1)
1
Humidity and Temperature
Control Assembly
226
19.4
(1)
0.104147
(2)
0.539
(1)
0.582
(1)
0.332
(1)
51
(1)
1
Table 7.3.10
Spacelab Water Recovery and Management
Assembly or Component
Mass
[kg]
Volume
[m³]
Length
[m]
Width or
Diameter
[m]
Height
[m]
Peak
Power
[W]
Operational
Average
Power
[W]
MTBF
[h]
CMMTTR
[h]
Life
Limit
[y]
No.
Condensate Overboard Dumping
Assembly
227
4.5
(1)
0.00896
(2)
0.4
(1)
0.14
(1)
0.16
(1)
150
(1)
1
Condensate Storage Assembly
228
9.9
(1)
0.52
(1)
1
Water Separator Assembly
229
9.8
(1)
0.04272
(2)
0.5
(1)
0.32
(1)
0.267
(1)
48
(1)
1
224
Function: temperature and humidity control
225
The values here are for high-speed and low-speed settings, respectively.
226
Function: intramodule atmosphere circulation
227
Function:
water
venting
228
Function:
water
storage
229
Function:
process
wastewater
References:
(1)
Doinier;
(2)
Calculation.
Note: Hardware entries in
italics
are components of assembly entries in
bold
type.
153
7.3.3
Space Shuttle Program
Table 7.3.11
Space Shuttle Atmosphere Revitalization Subsystem
Assembly or Component
Mass
[kg]
Volume
[m³]
Length
[m]
Width or
Diameter
[m]
Height
[m]
Peak
Power
[W]
Operational
Average
Power
[W]
MTBF
[h]
CMMTTR
[h]
Life Limit
[y]
No.
Ambient Temperature Catalytic
Oxidizer
230
1.5422 0.011163 0.3444 0.1016
1
ARS Instrumentation
231
1.421
1
Cabin Temperature Controller
4.4452 0.010222 0.2603 0.1849 0.2123
16
1
Carbon Dioxide Partial Pressure
Sensor
0.3855 0.000145 0.0635 0.0635 0.1524
0.2
1
Humidity Sensor
0.36
(1)
0.5
(1)
1
IR Carbon Dioxide Sensor
0.6
(1)
2.4
(1)
1
Pressure Sensor
0.25
(1)
0.000291
0.092 0.0317
0.5
(1)
1
Quantity Sensor
0.2268 0.000238 0.064 0.0576 0.0645
0.01
1
Speed Sensor
0.0453 0.000032 0.0254 0.0254 0.0508
1
Temperature Sensor
0.0771 0.000015 0.0731 0.0082
1
Temperature Sensor, Thermistor
0.0407
(1)
0.000054
0.0546
0.0177
1
Water Quantity Sensor
0.17
(1)
1
Avionics Cooling Assembly
232
12.787 0.056609 0.3556 0.5969 0.2667 185
3
Avionics Check Valve
0.3538 0.007953 0.1041 0.1559
2
Avionics Fan
1.8597 0.010127 0.1388 0.1524
180
2
Avionics Heat Exchanger
6.3957 0.023644 0.353 0.3337 0.2006
1
Signal Conditioner
0.8618 0.002457 0.1778 0.16
0.0863
5
1
Beam Assembly
233
7.9969 0.063857 0.1747 0.6096 0.5994
1
Cabin Air Fan
234
18.6
(1)
0.038198
(2)
0.4699
(1)
0.3556
(1)
0.2286
(1)
70
(1)
20.5
(1)
1
Cabin Air Fan and Debris Trap
Assembly
236
17.191 0.1914 0.9042 0.3078 0.6876 495
1
Cabin Air Fan
2.6989 0.00562 0.1428 0.1868 0.2105 495
2
Check Valve
0.2041 0.003742 0.0393 0.1734
2
Debris and Filter Trap
0.1134 0.000492 0.2148 0.2148 0.0106
1
Signal Conditioner-ARS
0.9979 0.002465 0.1607 0.1785 0.0858
4
1
Nitrogen Storage Tank
235
0.137337
(1)
4
Oxygen Auxiliary Tank
237
0.13677
(1)
230
Function: carbon monoxide control
231
Function: temperature and humidity control
232
Function:
heat
removal
233
Function:
equipment
mounting
234
Function: intramodule atmosphere circulation
235
Function: nitrogen and oxygen storage
References:
(1)
Doinier;
(2)
Calculation.
Note: Hardware entries in
italics
are components of assembly entries in
bold
type.
154
Table 7.3.11
Space Shuttle Atmosphere Revitalization Subsystem (continued)
Assembly or Component
Mass
[kg]
Volume
[m³]
Length
[m]
Width or
Diameter
[m]
Height
[m]
Peak
Power
[W]
Operationa
l Average
Power
[W]
MTBF
[h]
CMMTTR
[h]
Life Limit
[y] No.
Carbon Dioxide Absorber and
Temperature Control Assembly
236
17.355
0.258958
0.635
0.6634
0.6146
1
Cabin Temperature Selector
0.2494 0.000585 0.0838 0.0838 0.0833
0.01
1
Carbon Dioxide Absorber Element
(with LiOH Canister)
2.903
0.025968
0.2872
0.1696
2
Electric Actuator
0.4989 0.000561 0.1173 0.0627 0.0762 57.5 34.5
1
Temperature Control Valve
2.2952 0.035743 0.4351 0.2402 0.3418
1
Emergency Breathing Provisions
237
5.6
1
Breathing Regulator
0.1
(1)
1
Oxygen System
5.5
(1)
0.00131
(1)
0.4318
(1)
0.0698
(1)
1
Humidity Control Heat Exchanger
Assembly
238
20.0718 0.092732 0.5384 0.5199 0.3312
0.003
1
Humidity Control Heat Exchanger
19.913 0.092583 0.5384 0.5207 0.3302
1
Signal Conditioner
1.8597
0.004358
0.207 0.207 0.1016
8
1
IMU Fan Assembly
239
10.9317 0.068252 0.889 0.3556 0.2159
50
1
Check Valve
0.0408
0.000761
0.0447
0.0736
3
Filter
0.0095
0.476538
0.3479
0.6604
1
IMU Fan
2.1273 0.004817 0.2032 0.0889 0.2667
3
IMU Fan Motor
1.1793 0.001389 0.0762 0.0762
50
3
IMU Heat Exchanger
3.2886 0.008117 0.1892 0.2095 0.2047
1
Self Sealing Coupling
0.2268
0.000272
0.0685
0.0355
1
Signal Conditioner
0.9298 0.002464 0.1785 0.1607 0.0858
4
3
Multi-Purpose Heat Exchanger
240
2.1772 0.005473 0.3131 0.1965 0.0889
1
Primary Water Pump Package
241
14.4879 0.035708 0.4599 0.319 0.2433 239.5
1
Accumulator
2.0412
0.027972
0.2794
0.1785
1
Filter
0.0589
0.00042
0.0599
0.0472
1
Self-Sealing Couplings
0.17
0.000154
0.0762
0.0254
3
Water Bypass Controller
1.7917 0.00598 0.2329 0.2329 0.1102
8
1
Water Bypass Valve
1.2746 0.001839 0.1778 0.1163 0.0889 57.5 34.5
1
Water Pump
1.8824 0.001045 0.1651 0.0683 0.0927
197
2
Water Pump Check Valve
0.9072 0.000488 0.1407 0.0899 0.0386
1
236
Function: carbon dioxide control
237
Function: emergency equipment
238
Function: humidity control
239
Function: intermodule atmosphere circulation
240
Function:
heat
removal
241
Function:
temperature
control
References:
(1)
Doinier;
(2)
Calculation.
Note: Hardware entries in
italics
are components of assembly entries in
bold
type.
155
Table 7.3.11
Space Shuttle Atmosphere Revitalization Subsystem (concluded)
Assembly or Component
Mass
[kg]
Volume
[m³]
Length
[m]
Width or
Diameter
[m]
Height
[m]
Peak
Power
[W]
Operational
Average
Power
[W]
MTBF
[h]
CMMTTR
[h]
Life Limit
[y] No.
Regenerative Carbon Dioxide
Removal System
242
147
(1)
0.309998
(2)
0.4635
(1)
0.6794
(1)
0.9842
(1)
311
(1)
110
(1)
1
Canister Assembly
42.5
(1)
0.096816
(2)
0.8699
(1)
0.254
(1)
0.4381
(1)
1
Controller
8.8
(1)
0.014984
(2)
0.164
(1)
0.3238
(1)
0.2819
(1)
2
(1)
Crew Setting Valve
0.5
(1)
0.000514
(2)
0.0787
(1)
0.1186
(1)
0.0551
(1)
1
(1)
Fan
2.13
(1)
0.004817
(2)
0.2032
(1)
0.0889
(1)
0.2667
(1)
56
(1)
1
(1)
Inlet Muffler and Filter
1
(1)
Odor Filter: Charcoal, Shell
Cartridge, Cloth Liner
2.5
(1)
0.011328
(1)
0.1696
(1)
0.287
(1)
0.0246575
(1)
1
Outlet Muffler
0.35
(1)
0.0762
(1)
0.3556
(1)
1
(1)
Pressure Equalization Valve
0.73
(1)
0.0508
(1)
0.1422
(1)
6
(1)
System Sensors
1
(1)
Ullage Save Compressor
6.21
(1)
0.005649
(2)
0.1143
(1)
0.1955
(1)
0.2527
(1)
250
(1)
180
(1)
1
(1)
Vacuum Cycle Valve (VCV)
1.23
(1)
0.001364
(2)
0.1056
(1)
0.1104
(1)
0.1168
(1)
2
(1)
Vacuum Cycle Valve Actuator
0.89
(1)
0.000469
(2)
0.0736
(1)
0.0533
(1)
0.1193
(1)
2
(1)
Secondary Pump and
Accumulator Assembly
243
12.6735 0.035708 0.4599 0.319 0.2433 239.5
1
Water Separator Assembly
244
7.8472 0.024189 0.2656 0.448 0.2032
1
Fan / Separator
2.5401 0.015127 0.1524 0.1778
43
2
Fan / Separator Motor
1.0659 0.001389 0.0762 0.0762
40
1
Gas Check Valve
0.009 0.000145
0.0276
0.0408
2
Liquid Check Valve
0.0498 0.000102 0.0508 0.0254
2
Signal Conditioner
0.9208 0.002464 0.1785 0.1607 0.0858 4
1
Table 7.3.12
Space Shuttle Airlock Support Subsystem
Assembly or Component
Mass
[kg]
Volume
[m³]
Length
[m]
Width or
Diameter
[m]
Height
[m]
Peak
Power
[W]
Operational
Average
Power
[W]
MTBF
[h]
CMMTTR
[h]
Life Limit
[y] No.
LCVG Heat Exchanger
245
0.001966
(2)
0.0762
(1)
0.2032
(1)
0.127
(1)
242
Function: carbon dioxide control
243
Function:
temperature
control
244
Function: humidity control
245
Function: temperature and humidity control
References:
(1)
Doinier;
(2)
Calculation.
Note: Hardware entries in
italics
are components of assembly entries in
bold
type.
156
Table 7.3.13
Space Shuttle Active Thermal Control Subsystem
Assembly or Component
Mass
[kg]
Volume
[m³]
Length
[m]
Width or
Diameter
[m]
Height
[m]
Peak
Power
[W]
Operational
Average
Power
[W]
MTBF
[h]
CMMTTR
[h]
Life Limit
[y] No.
Ammonia Boiler Subsystem
246
0.346881
(2)
1.0668
(1)
0.6096
(1)
0.5334
(1)
1
Cold Plates
1
Evaporator / Control
0.224028
(2)
0.5334
(1)
0.5334
(1)
0.7874
(1)
1
(1)
Flash Evaporator Subsystem Water
Accumulator
0.1676
(1)
0.0914
(1)
1
(1)
Flash Evaporation Assembly
248
26.2543 0.130535 0.5461 0.4953 0.4826 200
1
Evaporator
7.4844 0.149054
0.4191 0.3365
2
Flash Evaporator Controller
1.7463 0.001769 0.1524 0.1524 0.0762
8
1
Flash Evaporator, Controller No.3
1.7463 0.001769 0.1524 0.1524 0.0762
9
1
High Load Duct Assembly
10.9
1
High Load Valve / Nozzle Assembly
0.4989 0.00043 0.0889 0.0762 0.0635
35
1
Nozzle Heater
0.254
0.3048
25
1
Sonic Nozzle Assembly
1.2247 0.015217
0.1778 0.1651
25
1
Topping Duct Assembly
25.7191
1
Topping Valve / Nozzle Assembly
0.5443 0.000399 0.0825 0.0762 0.0635
35
1
Flow Proportioning Module
248
1.7236 0.004244
(2)
0.1778
(1)
0.1016
(1)
0.2495
(1)
57.5
34.5
1
Flow Proportioning Valve
0.004244 0.1778 0.1016 0.2495
2
Flow Sensor
0.7484 0.001721 0.1778 0.0645 0.1501
0.84
2
Signal Conditioner
2.0865 0.004034 0.1656 0.1498 0.1625
10
1
Freon Pump Package, Single
Pumps
248
19.0466 0.0854
(2)
0.7226
(1)
0.3276
(1)
0.3606
(1)
360
2
Check Valve
1.8144
0.019
1
Filter
0.136 0.000106
0.1016
0.0182
1
Freon Accumulator
10.8864 0.238894 0.6913 0.3317
1
Freon Pump
1.769 0.001585 0.2006 0.0889 0.0889 360
1
Freon Pump Package, Two
Pumps
248
20.294 0.0854
(1)
0.7223 0.3276 0.3606 360
2
Freon To Water Interchanger
248
14.3791 0.023819
(2)
0.7467
(1)
0.2616
(1)
0.1219
(1)
1
Fuel Cell Heat Exchanger
248
7.6114 0.010406
(2)
0.4114
(1)
0.2032
(1)
0.1244
(1)
0.002
1
Ground Support Equipment Heat
Exchanger
248
0.007039
(2)
0.3429
(1)
0.1879
(1)
0.1092
(1)
1
Hydraulics Heat Exchanger
248
11.1132 0.020808
(2)
0.4699
(1)
0.2614
(1)
0.1676
(1)
Payload Heat Exchanger
248
19.6408 0.013225
(2)
0.5359
(1)
0.2159
(1)
0.1143
(1)
1
Radiator System
248
246
Function:
heat
removal
References:
(1)
Doinier;
(2)
Calculation.
Note: Hardware entries in
italics
are components of assembly entries in
bold
type.
157
Table 7.3.13
Space Shuttle Active Thermal Control Subsystem (continued)
Assembly or Component
Mass
[kg]
Volume
[m³]
Length
[m]
Width or
Diameter
[m]
Height
[m]
Peak
Power
[W]
Operational
Average
Power
[W]
MTBF
[h]
CMMTTR
[h]
Life Limit
[y] No.
Water Boiler, Thermal Control,
Hydraulic
247
71.6824 0.345493 0.8636 0.7874 0.508
150
100
3
Heater
0.1134 0.000032 0.2984 0.085 0.0012
14.7-31.7
1
Hydraulic Pressure Relief Valve
1.134 0.000201 0.1041 0.0762 0.0254
1
Water Boiler
33.0493 0.096167 0.4445 0.3111 0.6953
1
Water Shutoff Valve
0.6441 0.000225 0.1082 0.0482 0.0431
50
1
Water Spray Boiler Controller
4.3092 0.009107 0.1134 0.2413 0.3302
42
1
Water Tank
5.4432 0.258479 0.6906 0.3589
1
Water Spray Boiler Subsystem
249
82.4644 0.388839 0.4826 1.0226 0.7879
3
Electrical Heater-1
0.2177
51
1
Electrical Heater-2
0.0453
33.5
1
Electrical Heater-3
0.0453
11.5
1
Hydraulic Bypass Relief Valve
4.8399 0.004144 0.3357 0.1468 0.084
57.5
34.5
1
Liquid Level Sensor
0.1134 0.00005 0.0508 0.0177
0.3
1
Liquid Level Sensor Electronics
0.068 0.000506 0.0571 0.0698 0.127
1
Nitrogen Regulator
0.6804 0.000644 0.0967 0.0873 0.0762
1
Nitrogen Shutoff Valve
0.6804 0.000558 0.1135 0.0787 0.0624
50
1
Nitrogen Storage Tank
0.9072 0.016351
0.1574
1
Spray Boiler
21.5097 0.0482
0.6985 0.3959 0.2032
1
Steam Dump Nozzle
2.1772 0.01681 0.1905 0.1676
51
1
Water Supply Valve
0.5307 0.000617 0.1097 0.0805 0.0698
50
1
Water Tank for Water Spray Boiler
21.4099 0.111143 0.7409 0.4051 0.3708
1
Table 7.3.14
Space Shuttle Water Recovery and Management
Assembly or Component
Mass
[kg]
Volume
[m³]
Length
[m]
Width or
Diameter
[m]
Height
[m]
Peak
Power
[W]
Operational
Average
Power
[W]
MTBF
[h]
CMMTTR
[h]
Life Limit
[y] No.
Potable Water Tank
248
3.3
(1)
1
Wastewater Tank
250
3.3
(1)
1
247
Function:
heat
removal
248
Function:
water
storage
REPORT DOCUMENTATION PAGE
Form Approved
OMB No. 0704-0188
Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and
maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including
suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302,
and to the Office of Management and Budget, Paperwork Reduction Project (0704-0188), Washington, DC 20503.
1. AGENCY USE ONLY
(Leave Blank)
2. REPORT DATE
3. REPORT TYPE AND DATES COVERED
August 2004
NASA Contractor Report
4. TITLE AND SUBTITLE
5. FUNDING NUMBERS
Advanced Life Support Baeline Values and Assumptions Document
6. AUTHOR(S)
Anthony J. Hamford
7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)
8. PERFORMING ORGANIZATION
REPORT NUMBERS
Lockheed Martin, Houston
S-927
9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)
10. SPONSORING/MONITORING
AGENCY REPORT NUMBER
National Aeronautics and Space Administration
Washington, DC 20546-0001
CR-2004-208941
11. SUPPLEMENTARY NOTES
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Category: 54
13. ABSTRACT
(Maximum 200 words)
The Advanced Life Support (ALS) Baseline Values and Assumptions Document (BVAD) provides analysts and modelers as well as
other ALS researchers with a common set of initial values and assumptions called a baseline. This baseline provides a common point
of origin from which all systems integration, modeling, and analysis element studies will depart. The BVAD identifies quantities that
define life support systems from an analysis and modeling perspective; provides a nominal or baseline value plus a range of possible
or observed values for each physical quantity identified; and documents each entry with a description of the use, value selection
rationale, and appropriate references of that quantity. Specifically, the BVAD allows the life support analysis community to carefully
review and evaluate input study assumptions. Each study can benefit from the "best" available input values and assumptions by
drawing on information collected by a group of researchers rather than an individual researcher. The BVAD process identifies
quantities that are not well-defined by current information, allows researchers from multiple disciplines to effectively and quickly
compare results from multiple studies, and allows these researchers to conduct a follow-on study to any previous work because
assumptions from each study are clearly available and carefully recorded.
14. SUBJECT TERMS
15. NUMBER OF
PAGES
16. PRICE CODE
systems analysis; analogs; life support systems; human factors engineering;
environmental engineering; aerospace environments; mathematical models
158
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