Spacelab

Spacelab was a reusable laboratory developed by the European Space Agency and flown on certain Space Shuttle missions. It was not a single vehicle but a kit of components carried in the orbiter cargo bay: a pressurized habitable module, unpressurized pallets for experiments in vacuum, and a pressurized Igloo holding the subsystems for pallet-only flights. Eight flight configurations were qualified. The work grew from an August 1973 memorandum of understanding between NASA and the European Space Research Organisation, and construction began in 1974 at ERNO, a subsidiary of VFW-Fokker. The first laboratory module was donated to NASA in exchange for flight opportunities for European astronauts, and NASA bought a second. Spacelab hardware flew on about 32 Shuttle missions, with at least 22 major Spacelab missions between 1983 and 1998 and some pallets flying as late as 2008, letting scientists run microgravity experiments in Earth orbit.