CAPE CANAVERAL, Fla. – At NASA's Kennedy Space Center in Florida, this aerial view of the mobile launcher park site area north of the 525-foot-tall Vehicle Assembly Building shows a new mobile launcher, or ML, for the Constellation Program under construction. In the background are the Atlantic Ocean and Launch Complex 41 on Cape Canaveral Air Force Station, at upper left, from which Atlas V rockets are launched. When completed, the tower will be approximately 345 feet tall and have multiple platforms for personnel access. Its base is being made lighter than space shuttle mobile launcher platforms so the crawler-transporter can pick up the heavier load of the tower and a taller rocket. For information on the Constellation Program, visit http://www.nasa.gov/constellation. Photo credit: NASA/Cory Huston KSC-2009-6975

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.