| Discoverer 31 | |
| Mission Type: | Optical reconnaissance |
| Operator: | US Air Force/NRO |
| Harvard Designation: | 1961 Alpha Beta 1 |
| Mission Duration: | 2 days |
| Spacecraft Type: | KH-3 Corona| spacecraft_bus = Agena-B| manufacturer = Lockheed| launch_mass = | launch_date = UTC| launch_rocket = Thor DM-21 Agena-B 324| launch_site = Vandenberg LC-75-1-1 | decay_date = | landing_date = | landing_site = | orbit_epoch = | orbit_reference = Geocentric| orbit_regime = Low Earth| orbit_periapsis = 233km (145miles)| orbit_apoapsis = 380km (240miles)| orbit_inclination = 82.7 degrees| orbit_period = 90.7 minutes| apsis = gee}}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, an apogee of, 82.7 degrees of inclination, and a period of 90.7 minutes.[3] The satellite had a mass of,[4] and was equipped with a panoramic camera with a focal length of, which had a maximum resolution of .[5] Images were recorded onto 70mm 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.[6] It decayed from orbit on 26 October 1961. References} |