Long duration exposure facility - A free-flying experiment carrier

The Long Duration Exposure Facility (LDEF) will complement and extend Shuttle operations with Spacelab and pallets. The LDEF is a passive stabilized structure which can accommodate a wide variety of users who have experiments which require a free-flying carrier for exposure in space. The experiments are contained in trays which are attached to the LDEF. This paper describes the LDEF concept and operation, the facility, mission characteristics, and plans for the selection of experiments to fly on LDEF.