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. 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. 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. The satellite had a mass of , and was equipped with a panoramic camera with a focal length of , which had a maximum resolution of . Images were recorded onto 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. It decayed from orbit on 26 October 1961. References Spacecraft launched in 1961 Spacecraft which reentered in 1961