Skylab was a manned space station launched into Earth orbit by the United States in May 1973. It was made from the third stage of a Saturn V launch vehicle. A crew of three astronauts occupied Skylab during each of three missions. The longest mission, which ended in February 1974, lasted almost three months. The Skylab missions obtained vast amounts of scientific data, and they demonstrated to the American public that people could live and work productively in space for months at a time. The Orbital workshop (OWS) was a modified Saturn 4B stage that served as crew quarters. It could hold provisions for a three-man crew for up to 84 days each. Skylab crews lived and did most of their scientific research in the workshop.