Midas W37 Sensor

Part of a then-secret USAF program known as WS-117L, the MIDAS (Missile Defense Alarm System) program began in November 1958. It was terminated in the summer of 1966 after less than a dozen MIDAS satellites were put into orbit. MIDAS was intended to provide timely warning of an attack upon the United States by detecting and tracking the hot exhaust gases of enemy missiles at launch and during boost phase. But the sensor and processing technology of the time, and the constellation architecture, were not up to the task.

In the late 1950s, the advent of a Soviet intercontinental ballistic missile threat convinced the U.S. Air Force of the urgent need for a constellation of satellites that would provide timely warning of an imminent missile attack. MIDAS was at best a qualified success -- early problems included mistaking sunlight reflected from clouds as an enemy missile launch. The earliest satellites carried the Aerojet W-17, the first sensor to be deployed on operational MIDAS satellites. A later and more capable version, the Aerojet W-37 infrared early warning sensor, became the first space-based sensor to successfully detect a missile launched from Earth. This was the first sensor to be deployed on operational MIDAS satellites.

In the mid-1960s, MIDAS was supplanted by the USAF's Program 461 and subsequently by that service's highly successful deep space Defense Support Program early warning satellite system.

Typical orbit: 2533 km circular orbit, 83.2 deg inclination. Mass: 1,840 kg (4,050 lb).

• 1960 February 26 - Midas 1 - Launch Site: Cape Canaveral. Launch Complex: LC14. Launch Vehicle: Atlas. FAILURE: Second stage failed to separate. Mass: 2,025 kg (4,464 lb).
  Missile Defense Alarm System.

• 1960 May 24 - Midas 2 - Launch Site: Cape Canaveral. Launch Complex: LC14. Launch Vehicle: Atlas. Mass: 2,300 kg (5,000 lb). Perigee: 473 km (293 mi). Apogee: 494 km (306 mi). Inclination: 33.00 deg. Period: 94.30 min.
  Missile Defense Alarm System. Test launch with W-17 sensor.

• 1960 December 20 - Discoverer 19 - Launch Site: Vandenberg. Launch Complex: SLC1E. Launch Vehicle: Delta. Mass: 1,060 kg (2,330 lb). Perigee: 186 km (115 mi). Apogee: 359 km (223 mi). Inclination: 83.40 deg. Period: 90.00 min.
  Tested IR sensors for Midas program; did not carry camera or film capsule.

• 1961 February 18 - Discoverer 21 - Launch Site: Vandenberg. Launch Complex: SLC1E. Launch Vehicle: Delta. Mass: 1,110 kg (2,440 lb). Perigee: 212 km (131 mi). Apogee: 458 km (284 mi). Inclination: 80.60 deg. Period: 91.30 min.
  Tested IR sensors for Midas program; did not carry camera or film capsule.

• 1961 July 12 - Midas 3 - Launch Site: Vandenberg. Launch Complex: SLC3E. Launch Vehicle: Atlas. Mass: 1,600 kg (3,500 lb). Perigee: 3,343 km (2,077 mi). Apogee: 3,540 km (2,190 mi). Inclination: 91.20 deg. Period: 161.40 min.
  Missile Defense Alarm System.

• 1961 October 21 - Midas 4 - Launch Site: Vandenberg. Launch Complex: SLC3E. Launch Vehicle: Atlas. Mass: 1,800 kg (3,900 lb). Perigee: 3,482 km (2,163 mi). Apogee: 3,763 km (2,338 mi). Inclination: 95.90 deg. Period: 165.90 min.
  Missile Defense Alarm System. Deployed subsatellites.

• 1962 April 9 - Midas 5 - Launch Site: Vandenberg. Launch Complex: SLC3E. Launch Vehicle: Atlas. Mass: 1,860 kg (4,100 lb). Perigee: 2,784 km (1,729 mi). Apogee: 3,405 km (2,115 mi). Inclination: 86.70 deg. Period: 152.90 min.
  Missile Defense Alarm System.

• 1962 December 17 - TRS 3 - Launch Site: Vandenberg. Launch Complex: SLC3E. Launch Vehicle: Atlas. FAILURE: Failure.
  

• 1962 December 17 - TRS 4 - Launch Site: Vandenberg. Launch Complex: SLC3E. Launch Vehicle: Atlas. FAILURE: Failure.
  

• 1962 December 17 - Midas 6 - Launch Site: Vandenberg. Launch Complex: SLC3E. Launch Vehicle: Atlas. FAILURE: Failure. Mass: 2,000 kg (4,400 lb).
  Missile Defense Alarm System. Carried ERS-3, ERS-4 subsatellites.

• 1963 May 9 - Midas 7 - Launch Site: Vandenberg. Launch Complex: SLC3E. Launch Vehicle: Atlas. Mass: 2,000 kg (4,400 lb). Perigee: 3,609 km (2,242 mi). Apogee: 3,680 km (2,280 mi). Inclination: 87.30 deg. Period: 166.40 min.
  MIDAS 7 was the first operational MIDAS mission and the first equipped with the W-37 sensor. During its six weeks of operation, MIDAS 7 recorded nine US ICBM launches, including the first missile launch ever detected from space.

• 1963 June 12 - Midas 8 - Launch Site: Vandenberg. Launch Complex: SLC3E. Launch Vehicle: Atlas. FAILURE: Failure. Mass: 2,000 kg (4,400 lb).
  Missile Defense Alarm System. Carried ERS-7, ERS-8 subsatellites.

• 1963 June 12 - TRS 7 - Launch Site: Vandenberg. Launch Complex: SLC3E. Launch Vehicle: Atlas. FAILURE: Failure.
  

• 1963 June 12 - TRS 8 - Launch Site: Vandenberg. Launch Complex: SLC3E. Launch Vehicle: Atlas. FAILURE: Failure.
  

• 1963 July 19 - Midas 9 - Launch Site: Vandenberg. Launch Complex: SLC3E. Launch Vehicle: Atlas. Mass: 2,000 kg (4,400 lb). Perigee: 3,676 km (2,284 mi). Apogee: 3,726 km (2,315 mi). Inclination: 88.40 deg. Period: 167.90 min.
  Missile Defense Alarm System. Did not eject ERS 10 subsatellite.

• 1966 June 9 - Midas 10 - Launch Site: Vandenberg. Launch Complex: SLC3E. Launch Vehicle: Atlas. Mass: 2,000 kg (4,400 lb). Perigee: 154 km (95 mi). Apogee: 3,678 km (2,285 mi). Inclination: 90.00 deg. Period: 125.20 min.
  Missile Defense Alarm System. Left in transfer orbit.

• 1966 August 19 - Midas 11 - Launch Site: Vandenberg. Launch Complex: SLC3E. Launch Vehicle: Atlas. Mass: 2,000 kg (4,400 lb). Perigee: 3,658 km (2,272 mi). Apogee: 3,708 km (2,304 mi). Inclination: 89.70 deg. Period: 167.40 min.
  Missile Defense Alarm System.

• 1966 October 5 - Midas 12 - Launch Site: Vandenberg. Launch Complex: SLC3E. Launch Vehicle: Atlas. Mass: 2,000 kg (4,400 lb). Perigee: 3,657 km (2,272 mi). Apogee: 3,724 km (2,313 mi). Inclination: 89.80 deg. Period: 167.60 min.
  Missile Defense Alarm System.