Discoverer 31


Discoverer 31
Mission typeOptical reconnaissance
OperatorUS Air Force/NRO
Harvard designation1961 Alpha Beta 1
COSPAR ID1961-026A
SATCAT no.00186Edit this on Wikidata
Mission duration2 days
Spacecraft properties
Spacecraft typeKH-3 Corona'''
Launch mass1,150 kilograms (2,540 lb)
Start of mission
Launch date17 September 1961, 21:00 (1961-09-17UTC21Z) UTC
RocketThor DM-21 Agena-B 324
Launch siteVandenberg LC-75-1-1
End of mission
Decay date26 October 1961 (1961-10-27)
Orbital parameters
Reference systemGeocentric
RegimeLow Earth
Perigee altitude233 kilometers (145 mi)
Apogee altitude380 kilometers (240 mi)
Inclination82.7 degrees
Period90.7 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. Archived from the original on 18 September 2010. Retrieved 29 June 2010.
  5. ^ "Corona". Mission and Spacecraft Library. NASA. Archived from the original on 3 October 2007. Retrieved 29 June 2010.
  6. ^ Lindborg, Christina; Pike, John (9 September 2000). "KH-3 Corona". Federation of American Scientists. Retrieved 29 June 2010.