Discoverer 20

Discoverer 20, also known as Corona 9014A, was an American area survey optical reconnaissance satellite which was launched in 1961. It was a KH-5 Argon satellite, based on an Agena-B. Discoverer 20 was the first KH-5 to be launched, however it failed towards the end of its mission, when its film return capsule failed to separate from the main spacecraft.

The launch of Discoverer 20 occurred at 20:25 UTC on 17 February 1961. A Thor DM-21 Agena-B rocket was used, flying from Launch pad 75-3-4 at the Vandenberg Air Force Base. Upon successfully reaching orbit, it was assigned the Harvard designation 1961 Epsilon 1.

Discoverer 20 was operated in a low Earth orbit, with a perigee of 283 km, an apogee of 770 km, 80.9 degrees of inclination, and a period of 95.2 minutes. The satellite had a mass of 1110 kg, and was equipped with a frame camera with a focal length of 76 mm, which had a maximum resolution of 140 m. Images were recorded onto 127 mm film, and were to have been returned in an SRV before the satellite ceased operations. Due to a problem with the systems controlling the flight program, the spacecraft failed to eject its film capsule, and hence no images were returned. Discoverer 20 decayed from orbit on 28 July 1962.