| Mission type | Optical reconnaissance |
|---|---|
| Operator | US Air Force/NRO |
| Harvard designation | 1961 Alpha Beta 1 |
| COSPAR ID | 1961-026A |
| SATCAT no. | 00186 |
| 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 UTC |
| Rocket | Thor DM-21 Agena-B 324 |
| Launch site | Vandenberg LC-75-1-1 |
| End of mission | |
| Decay date | 26 October 1961 |
| Orbital parameters | |
| Reference system | Geocentric |
| Regime | Low Earth |
| Perigee altitude | 233 kilometers (145 mi) |
| Apogee altitude | 380 kilometers (240 mi) |
| Inclination | 82.7 degrees |
| Period | 90.7 minutes |
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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]
