The purpose of the Cosmic Background Explorer (COBE) mission was to take precise measurements of the diffuse radiation between 1 micrometer and 1 cm over the whole celestial sphere. The following quantities were measured: the spectrum of the 3 K radiation over the range of 100 micrometers to 1 cm; the anisotropy of this radiation from 3 to 10 mm; and, the spectrum and angular distribution of diffuse infrared background radiation at wavelengths from 1 to 300 micrometers.
Instrument operations were terminated on 1993-12-23. Engineering operations were to conclude in January 1994, after which the operation of the spacecraft was transferred to Wallops for use as a test satellite.