CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, a tractor-trailer carrying the Alpha Magnetic Spectrometer, or AMS, at the Space Station Processing Facility, where it will be processed for launch. AMS arrived on Kennedy's Shuttle Landing Facility aboard an Air Force C-5M aircraft from Europe. AMS, a state-of-the-art particle physics detector, is designed to operate as an external module on the International Space Station. It will use the unique environment of space to study the universe and its origin by searching for dark matter. The STS-134 crew will fly AMS to the International Space Station aboard space shuttle Endeavour, targeted to launch Feb. 26, 2011. Photo credit: NASA/Frankie Martin KSC-2010-4496

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.