It was launched on a Thor-Agena A rocket on 28 February 1959 at 21:49:16 GMT from Vandenberg Air Force Base in California.

A CIA report, later declassified, concluded that "Today, most people believe the Discoverer 1 landed somewhere near the South Pole".

[5] The Discover program was managed by the Advanced Research Projects Agency (ARPA) of the U.S. Department of Defense and the U.S. Air Force.

The primary goal of the program was to develop a film-return photographic surveillance satellite to assess how rapidly the Soviet Union was producing long-range bombers and ballistic missiles and where they were being deployed, and to take photos over the Sino-Soviet bloc to replace the Lockheed U-2 spyplanes.

The goal of the program was not revealed to the public at the time; it was presented as a program to orbit large satellites to test satellite subsystems and investigate the communication and environmental aspects of placing humans in space, including carrying biological packages for return to Earth from orbit.

The second stage engine ignited when the correct attitude was achieved, putting the spacecraft into a polar orbit where it remained until re-entry on 17 March 1959.