The primary goal of the satellites was to replace the U-2 spyplane in surveilling the Sino-Soviet Bloc, determining the disposition and speed of production of Soviet missiles and long-range bombers assess.

The KH-1 payload included the C (for Corona) single, vertical-looking, panoramic camera that scanned back and forth, exposing its film at a right angle to the line of flight.

[6] The Discoverer program began with a series of three test flights whose satellites carried no cameras, all launched in the first half of 1959.

The satellite massed 810 kilograms (1,790 lb)[1]: 236 Launched into a polar orbit[3] by a Thor-Agena A booster on 13 September 1960 at 22:13:39 GMT from Vandenberg LC 75-3-5 by a Thor DM-21 Agena-A rocket,[7] Discover 15's camera functioned properly.

[1]: 245  CORONA was declassified in 1995,[1]: 14  and a formal acknowledgement of the existence of US reconnaissance programs, past and present, was issued in September 1996.