Space Transportation System (STS) AKA Space Shuttle
NASA/US Air Force Space Shuttle, officially named the Space Transportation System (STS), is the spacecraft currently used by the United States government for its human spaceflight missions and is scheduled to be retired from service in 2010. At launch, it consists of a rust-colored external tank (ET), two white, slender Solid Rocket Boosters (SRBs), and the orbiter.
The shuttle stack launches vertically like a conventional rocket from a mobile launch platform. It lifts off under the power of its two solid rocket boosters (SRBs) and its three main engines (SSMEs), the latter fueled by liquid hydrogen and liquid oxygen from the external tank. The space shuttle has a two stage ascent. The boosters are used only for the first stage, while the main engines burn for both stages. About two minutes after liftoff, staging occurs: the SRBs are released, and shortly begin falling into the ocean to be retrieved for reuse. The shuttle orbiter and external tank continue to ascend under power from the three main engines and their inertia. Upon reaching orbit, the main engines are shut down, and the external tank, the only non-reusable major component, is jettisoned downward and falls to burn up in the atmosphere. At this point, the orbital maneuvering system (OMS) engines may be used to adjust or circularize the achieved orbit.
The orbiter carries astronauts and payload such as satellites or space station parts into low earth orbit, into the Earth's upper atmosphere or thermosphere.[1] Usually, five to seven crew members ride in the orbiter. Two crew members, the Commander and Pilot, are sufficient for a minimal flight, as in the first four "test" flights, STS-1 through STS-4. The payload capacity is 22,700 kilograms (50,000 lb). To carry its payload, the orbiter has a large cargo bay with doors that open along the entire length of its top, a feature which makes the space shuttle unique among present spacecraft. This feature made possible the deployment of large satellites such as the Hubble Space Telescope.