CAPE CANAVERAL, Fla. – In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, workers attach an overhead crane to the Lightweight Multi-Purpose Experiment Support Structure Carrier, or LMC, which holds an ammonia tank assembly. Part of the payload for space shuttle Discovery's STS-128 mission to the International Space Station, the carrier will be weighed and then installed in the payload canister. The STS-128 flight also will carry science and storage racks to the space station on Discovery. Launch of Discovery is targeted for Aug. 18. Photo credit: NASA/Tim Jacobs KSC-2009-3921

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.