Space Shuttle

The space shuttle is a reusable spacecraft that takes off like a rocket, orbits the Earth like a satellite, and then lands like a glider. The space shuttle has been essential to the repair and maintenance of the Hubble Space Telescope and to construction of the International Space Station; it has also been used for a wide variety of other military, scientific, and commercial missions. It is not capable of flight to the Moon or other planets, being designed only to orbit the Earth.

The first shuttle to be launched was the Columbia, on April 12, 1981. Since that time, two shuttles have been lost in flight: Challenger, which exploded during takeoff on January 28, 1986, and Columbia, which broke apart during reentry on February 1, 2003. Seven crew members died in each accident. The three remaining shuttles are the Atlantis, the Discovery, and the Endeavor. The first shuttle actually built, the Enterprise, was flown in the atmosphere but never equipped for space flight; it is now in the collection of the Smithsonian Museum.

A spacecraft closely resembling the U.S. space shuttle, the Aero-Buran, was launched by the former Soviet Union in November, 1988. Buran's computer-piloted first flight was also its last; the program was cut to save money and all copies of the craft that had been built were dismantled.

The STS has four main components: (1) the orbiter (i.e., the shuttle itself), (2) the three main engines integral to the orbiter, (3) the external fuel tank that fuels the orbiter's three engines during liftoff, and (4) two solid-fuel rocket boosters also used during liftoff.