Space Shuttle

NASA's Space Shuttle, officially called Space Transportation System (STS), is the United States government's current manned launch vehicle. There were a total of five usable orbiters built, of which three remain active.

The winged shuttle orbiter is launched vertically, usually carrying five to seven astronauts (although eight have been carried and eleven could be accommodated in emergency) and up to 50,000 lb (22,700 kg) of payload into low earth orbit. When its mission is complete, it fires its maneuvering thrusters to drop out of orbit and re-enters the Earth's atmosphere. During the descent and landing, the shuttle orbiter acts as a glider and makes a completely unpowered landing.

The Shuttle is the first orbital spacecraft designed for partial reusability. It carries large payloads to various orbits, provides crew rotation for the International Space Station (ISS), and performs servicing missions. The orbiter can also recover satellites and other payloads from orbit and return them to Earth, but this capacity has not been used often.

However, it has been used to return large payloads from the ISS to Earth, as the Russian Soyuz spacecraft has limited capacity for return payloads. Each Shuttle was designed for a projected lifespan of 100 launches or 10 years' operational life.
NASA announced in 2004 that the Space Shuttle will be retired in 2010 and replaced by the Orion, a new vehicle that is designed to take humans to the Moon and beyond.

When the approach and landing phase begins, the Orbiter is at 10,000 ft (3048 m) altitude, 7.5 miles (12.1 km) to the runway. The pilots apply aerodynamic braking to help slow down the vehicle. The Orbiter's speed is reduced from 424 mph (682 km/h) to approximately 215 mph (346 km/h), (compared to 160 mph for a jet airliner), at touch-down.

The landing gear is deployed while the Orbiter is flying at 267 mph (430 km/h). To assist the speed brakes, a 40 ft (12.2 m) drag chute is deployed once the nose gear touches down at about 213 mph (343 km/h). It is jettisoned as the Orbiter slows through 69 mph (111 km/h).

For more information about the STS visit http://www.nasa.gov/mission_pages/shuttle