Tuesday, March 22, 2011

NASA-Space Shuttle Program

The National Aeronautics and Space Administration (NASA) is an Executive Branch agency of the United States government, responsible for the nation's civilian space program and aeronautics and aerospace research. Since February 2006, NASA's self-described mission statement is to "pioneer the future in space exploration, scientific discovery and aeronautics research".
NASA was established by the National Aeronautics and Space Act on July 29, 1958, replacing its
predecessor, the National Advisory Committee for Aeronautics (NACA). The agency became operational on October 1, 1958. NASA has led U.S. efforts for space exploration since, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and has been developing the manned Orion spacecraft.

Space Shuttle Program

NASA's Space Shuttle program, officially called Space Transportation System (STS), is the United States government's current manned launch vehicle. The winged Space Shuttle orbiter is launched vertically, usually carrying five to seven astronauts (although eight have been carried) and up to 50,000 lb (22 700 kg) of payload into low earth orbit. When its mission is complete, the shuttle can independently move itself out of orbit using its Maneuvering System (it orients itself appropriately and fires its main OMS engines, thus slowing it down) and re-enter the Earth's atmosphere. During descent and landing the orbiter acts as a re-entry vehicle and a glider, using its OMS system and flight surfaces to make adjustments.
The shuttle is the only winged manned spacecraft to achieve orbit and land, and the only reusable space vehicle that has ever made multiple flights into orbit. Its missions involve carrying large payloads to various orbits (including segments to be added to the International Space Station), providing crew rotation for the International Space Station, and performing service missions. The orbiter has also recovered satellites and other payloads from orbit and return them to Earth, but its use in this capacity was rare. However, the shuttle has previously been used to return large payloads from the ISS to Earth, as the Russian Soyuz spacecraft has limited capacity for return payloads. Each vehicle was designed with a projected lifespan of 100 launches, or 10 years' operational life.