The Space Shuttle orbiter family comprised six reusable winged vehicles built by Rockwell International for NASA. Enterprise performed atmospheric approach-and-landing and ground-interface testing; Columbia, Challenger, Discovery, Atlantis, and Endeavour then flew 135 orbital missions from 1981 through 2011. The orbiters carried crews and payloads, deployed and serviced spacecraft, supported Spacelab and Shuttle-Mir, and assembled the International Space Station.