CRRES (Combined Release and Radiation Effects Satellite) is a NASA and Department of Defense satellite to study the electrical, magnetic, and particle environment of near-Earth space. The Air Force Geophysics Laboratory's Spacerad (Space Radiation Effects) experiment investigated the radiation environment of the inner and outer radiation belts and measured radiation effects on state-of-the-art microelectronics devices. Other magnetospheric, ionospheric, and cosmic ray experiments were supported by NASA and the Office of Naval Research. Marshall Space Flight Center's project involved the release of chemicals from onboard canisters at low altitudes near dawn and dusk perigee (low orbit) times and at high altitudes near local midnight. These releases were monitored with optical and radar instrumentation by ground-based observers to measure the bulk properties and movement of the expanding clouds of photoionized plasma along field lines. Contact with the spacecraft was lost on 12 October 1991, following a battery failure.