Developed by the European Space Agency, Spacelab was a modular laboratory system installed in the payload bay of the Space Shuttle orbiter. Two laboratory modules were flown on a total of 16 missions from 1983 through 1998. This one, Module #1, was used nine times, first on the Spacelab 1 mission in 1983 and last on the Microgravity Science Laboratory missions in 1997.