[1] The satellite was equipped with a frame camera with a focal length of 76 millimetres (3.0 in), which had a maximum resolution of 140 metres (460 ft).

[1] Discoverer 20 was placed in a near-polar orbit to continue evaluation of the Agena-B system, with particular emphasis on the spacecraft's stabilization system in order to overcome instability problems encountered on the previous DISCOVERER and to attempt ejection, deceleration, reentry through the atmosphere, and recovery of an instrument package.

The satellite's scientific experiment package of radiation dosimeters, infrared radiometers, and microwave band detectors was identical to that of Discoverer 18 (launched 7 December 1960).

The recovery capsule payload included photographic film packs, nuclear track plates, and biological specimens.

Recovery of the capsule was not attempted due to a system malfunction, and thus the scientific experiment data obtained were limited.