Discoverer 31, also known as Corona 9024, was an American optical reconnaissance satellite which was launched in 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.

[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).

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.