The United States developed the Space Shuttle system to improve its access to space. Since the first flight in April 1981, the Shuttle has carried more than 1.5 million pounds of cargo and over 600 major payloads into orbit. The Shuttle is the first and only reusable space vehicle, and is the world's most reliable and versatile launch system. The Shuttle can be configured to carry many different types of equipment, spacecraft and scientific experiments. In addition to transporting people, materials, equipment and spacecraft to orbit, the Shuttle allows astronauts to service and repair satellites and observatories in space, as was demonstrated with the successful repair of the Hubble Space Telescope in December 1993.
The Space Shuttle has three major components: the Orbiter, which carries the crew (typically 7 people) and the payload in its 60-foot long cargo bay, a 154-foot tall external fuel tank which stores nearly one-half million gallons of liquid hydrogen and liquid oxygen propellants, and twin 150-foot-tall solid rocket boosters which are strapped to the external tank.
The boosters generate over 6 million pounds of thrust at liftoff and are jettisoned 2 minutes into the flight. They are recovered and reused. The main engines produce nearly 1 million pounds of thrust and operate about 8 and one-half minutes, from liftoff until the Shuttle achieves orbit. The external tank is jettisoned and burns up in the Earth's atmosphere.
The primary objective of the Shuttle is to support NASA launch requirements safely and successfully. Because of its unique and well-established capabilities, the Shuttle remains a key element of America's space program. Shuttle flights will operate well into the 21st century at a rate of 7 to 8 missions a year.
NASA Shuttle Web - info on current missions, media, realtime data
Space Shuttle Launches - information on specific missions
Space Shuttle Photographs - a collection of Shuttle images
* This text was adapted from the NASA Spacelink: Shuttle home page.