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The MIDAS 4 (MIssile Defense Alarm System) satellite was designed primarily to detect the exhaust heat from a recently launched ICBM by use of infrared sensors. Secondary objectives included the measurement of cosmic radiation and the ejection of 350 million copper needles into orbit around the earth (Project West Ford). The needles were to serve as an artificial scattering medium for radio signals in the centimeter band. The spacecraft was cylindrical in shape and measured approximately 6 m in length and 1.5 m in diameter. The IR sensors and communication subsystem were chemical battery powered. Once in orbit, the spacecraft was stabilized in a nose-down attitude so that the IR sensors and telemetry antenna were always facing earthward. The satellite was successfully launched into a near polar orbit on October 21, 1961; however, the needles failed to release.

Alternate Names

  • Alpha Delta
  • West Ford (1)
  • Missile Defense Alarm System 4
  • 00192
  • MIDAS4

Facts in Brief

Launch Date: 1961-10-21
Launch Vehicle: Atlas
Launch Site: Point Arguello, United States
Mass: 1800 kg

Funding Agency

  • Department of Defense-Department of the Air Force (United States)


  • Surveillance and Other Military
  • Space Physics
  • Astronomy

Additional Information

Questions and comments about this spacecraft can be directed to: Coordinated Request and User Support Office



NameRoleOriginal AffiliationE-mail
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