JSC2007-E-18102 (9 April 2007) --- United Space Alliance (USA) crew trainer Adam Flagan (left) briefs astronaut Douglas H. Wheelock, STS-120 mission specialist, on the usage of a special pulley device, used to lower oneself from a trouble-plagued shuttle. The briefing came during an emergency egress training session in the Space Vehicle Mockup Facility at the Johnson Space Center. Wheelock is wearing a training version of his shuttle launch and entry suit. jsc2007e18102

The Space Shuttle program was the United States government's manned launch vehicle program from 1981 to 2011, administered by NASA and officially beginning in 1972. The Space Shuttle system—composed of an orbiter launched with two reusable solid rocket boosters and a disposable external fuel tank— carried up to eight astronauts and up to 50,000 lb (23,000 kg) of payload into low Earth orbit (LEO). When its mission was complete, the orbiter would re-enter the Earth's atmosphere and lands as a glider. Although the concept had been explored since the late 1960s, the program formally commenced in 1972 and was the focus of NASA's manned operations after the final Apollo and Skylab flights in the mid-1970s. It started with the launch of the first shuttle Columbia on April 12, 1981, on STS-1. and finished with its last mission, STS-135 flown by Atlantis, in July 2011.