STS-7

Two communications satellites – Anik C2 for Telesat of Canada, and Palapa B1 for Indonesia – were successfully deployed during the first two days of the mission. The mission also carried the first Shuttle Pallet Satellite, SPAS-1, which was built by the West German aerospace firm Messerschmitt-Bolkow-Blohm. SPAS-1 was unique in that it was designed to operate in the payload bay or be deployed by the Remote Manipulator System (RMS) as a free-flying satellite. It carried 10 experiments to study formation of metal alloys in microgravity, the operation of heat pipes, instruments for remote sensing observations, and a mass spectrometer to identify various gases in the payload bay.