Discoverer 31

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Discoverer 31
Mission type Optical reconnaissance
Operator US Air Force/NRO
Harvard designation 1961 Alpha Beta 1
Mission duration 2 days
Spacecraft properties
Spacecraft type KH-3 Corona'''
Bus Agena-B
Manufacturer Lockheed
Launch mass 1,150 kilograms (2,540 lb)
Start of mission
Launch date 17 September 1961, 21:00 (1961-09-17UTC21Z) UTC
Rocket Thor DM-21 Agena-B 324
Launch site Vandenberg LC-75-1-1
End of mission
Decay date 26 October 1961 (1961-10-27)
Orbital parameters
Reference system Geocentric
Regime Low Earth
Perigee 233 kilometers (145 mi)
Apogee 380 kilometers (240 mi)
Inclination 82.7 degrees
Period 90.7 minutes
The launch of Discoverer 31

Discoverer 31, also known as Corona 9024, was an American optical reconnaissance satellite which was launched in 1961. It was a KH-3 Corona''' satellite, based on an Agena-B.[1]

The launch of Discoverer 31 occurred at 21:00 UTC on 17 September 1961. A Thor DM-21 Agena-B rocket was used, flying from Launch Complex 75-1-1 at the Vandenberg Air Force Base.[2] Upon successfully reaching orbit, it was assigned the Harvard designation 1961 Alpha Beta 1.

Discoverer 31 was operated in a low Earth orbit, with a perigee of 233 kilometres (145 mi), an apogee of 380 kilometres (240 mi), 82.7 degrees of inclination, and a period of 90.7 minutes.[3] The satellite had a mass of 1,150 kilograms (2,540 lb),[4] and was equipped with a panoramic camera with a focal length of 61 centimetres (24 in), which had a maximum resolution of 7.6 metres (25 ft).[5] Images were recorded onto 70-millimeter (2.8 in) film, and were to have been returned in a Satellite Recovery Vehicle. The Satellite Recovery Vehicle carried aboard Discoverer 31 was SRV-552. During the spacecraft's thirty-third orbit, the attitude control and power systems malfunctioned, and as a result Discoverer 31 was unable to complete its mission or return images.[4][6] It decayed from orbit on 26 October 1961.[3]


  1. ^ Krebs, Gunter. "KH-3 Corona". Gunter's Space Page. Retrieved 29 June 2010. 
  2. ^ McDowell, Jonathan. "Launch Log". Jonathan's Space Page. Retrieved 29 June 2010. 
  3. ^ a b McDowell, Jonathan. "Satellite Catalog". Jonathan's Space Page. Retrieved 29 June 2010. 
  4. ^ a b Wade, Mark. "KH-3". Encyclopedia Astronautica. Retrieved 29 June 2010. 
  5. ^ "Corona". Mission and Spacecraft Library. NASA. Retrieved 29 June 2010. 
  6. ^ Lindborg, Christina; Pike, John (9 September 2000). "KH-3 Corona". Federation of American Scientists. Retrieved 29 June 2010.