space shuttle
space shuttle
space shuttle
space′ shut`tle
(often caps.)
Noun | 1. | space shuttle - a reusable spacecraft with wings for a controlled descent through the Earth's atmosphere |
单词 | space shuttle | |||
释义 | space shuttlespace shuttlespace shuttlespace′ shut`tle(often caps.)
space shuttlespace shuttle,reusable U.S. space vehicle (1981–2011). Developed by the National Aeronautics and Space Administration (NASA) and officially known as the Space Transportation System (STS), it was the world's first reusable spacecraft that carried human beings into earth orbit. It consisted of a winged orbiter (122 ft/37 m long, with a 78-ft/24-m wingspan), two solid-rocket boosters, and a large external fuel tank. As with previous spacecraft, the shuttle was launched from a vertical position. Liftoff thrust was derived from the orbiter's three main liquid-propellant engines and the boosters. After 2 min the boosters used up their fuel and separated from the spacecraft, and—after deployment of parachutes—they were recovered following splashdown in the Atlantic Ocean and reused. After about 8 min of flight, the orbiter's main engines shut down; the external tank was then jettisoned and burned up as it reentered the atmosphere. The orbiter entered orbit after a short burn of its two small Orbiting Maneuvering System (OMS) engines. To return to earth, the orbiter turned around, fired its OMS engines to reduce speed, and, after descending through the atmosphere, landed like a glider. Five different orbiters—Columbia, Challenger, Atlantis, Discovery, and Endeavour—saw service; two were lost in accidents.Following four orbital test flights (1981–82) of the space shuttle Columbia, operational flights began in Nov., 1982. On Jan. 28, 1986, the ChallengerChallenger, A second disaster struck the shuttle program on Feb. 1, 2003, when the ColumbiaColumbia, Missions of the space shuttle included the transport of the Spacelab scientific workshop and the insertion into orbit of the Hubble Space TelescopeHubble Space Telescope In 1995 that the crew of Atlantis accomplished the first of nine shuttle-Mir (Russian space stationspace station A number of nations and organizations developed proposals for shuttle-like space vehicles, but only one, the Soviet-Russian Buran, ever made it into orbital flight. A crewless Buran underwent a successful orbital test flight in 1988. Unlike the shuttle, the Buran did not incorporate main engines used during liftoff, only maneuvering engines, but otherwise the overall design was similar. The program was suspended in 1993 before a flight with a crew had been undertaken. The U.S. Air Force's X-37, whose development was begun by NASA, is a reusable, unmanned vehicle that was first launched in 2010. It is largely similar in general appearance to the space shuttle but is much smaller (29 ft/9 m long, with a 15-ft (4.5-m) wingspan). BibliographySee D. R. Jenkins, Space Shuttle: The History of Developing the National Space Transportation System (2d ed. 1996); D. M. Harland, The Space Shuttle: Roles, Missions, and Accomplishments (1998); C. Bredeson, The Challenger Disaster: Tragic Space Flight (1999); M. O. Thompson and C. Peebles, Flying without Wings: NASA Lifting Bodies and the Birth of the Space Shuttle (1999). space shuttleA partially recoverable manned space transportation system developed and tested by NASA. The first orbital test flight, by the shuttle Columbia, took place on Apr. 12 1981, and the shuttle system, officially referred to by NASA as the space transportation system (STS), was operational by 1982. The shuttles Challenger, Discovery, and Atlantis were brought into service alongside Columbia in 1983, 1984, and 1985 respectively. Challenger was destroyed, and its seven-person crew killed, in an explosion on Jan. 28 1986, shortly after liftoff. Shuttle flights were then suspended until Sept. 1988. The shuttle Endeavour was built to replace Challenger, making its first flight in 1992. On Feb. 1 2003, Columbia broke up over Texas during its return from an orbital mission and was destroyed with the loss of all on board. Space shuttle flights were again suspended and did not resume until May 2005.A shuttle consists of an Orbiter with the appearance of a delta-wing aircraft, a huge expendable external propellant tank, on which the Orbiter is mounted at launching, and two solid-fuel rocket boosters. The whole system weighs about 2000 tonnes at launch and has an overall length of about 56 meters. The Orbiter is 37 meters in length. The shuttle is launched in a vertical position by the simultaneous firing of its two rocket boosters and three very powerful liquid hydrogen/liquid oxygen main engines. About two minutes into the flight the empty rocket boosters are detached, parachute into an ocean area, and are recovered for further use. Just before the craft reaches its orbit the propellant tank is discarded and burns up in the atmosphere. The Orbiter can then maneuver by means of two on-board engines. The altitude, eccentricity, and inclination of the orbit can be varied, within limits, as can the flight duration – between about 7 and 30 days. On mission completion the Orbiter uses its rocket motors to put it into a reentry path, enters the atmosphere in a shallow glide, and finally makes an unpowered landing like a conventional glider. The Orbiter has a large cargo bay – 18.3 meters long and 4.6 meters in diameter – in which the payload is housed. Spacelab first flew in the cargo bay in 1983. Satellites can be launched into orbit from the cargo bay and can also be brought back into the bay for servicing and redeployment or for return to Earth. Since the Challenger disaster, unpiloted boosters such as the Deltas have been used as the main launch vehicles for astronomy missions. But the space shuttle was employed for carrying the Hubble Space Telescope into orbit in 1990 and later for service and repair missions to it. The shuttles are also used for medical, scientific, and technological experiments conducted by the astronauts. A total mass of 29.5 tonnes can be carried into a low-altitude orbit, with smaller loads for higher or less accessible orbits. Payloads to be placed in orbits above the shuttle ceiling, such as a geostationary orbit, require additional propulsion; the shuttle ceiling is about 1000 km in altitude. A payload of 11.5 tonnes can be returned to Earth. In 1995 a shuttle made the first of several flights to and from the Russian space station Mir, in preparation for the construction and utilization of the International Space Station (ISS). In 1998 shuttles and Russian Soyuz craft embarked upon the process of building the ISS, ferrying components into orbit and transferring personnel to and from the ISS modules as they were assembled. The suspension of shuttle flights after the loss of the Columbia temporarily halted the shuttles' contribution to this activity, but their collaboration in completing the ISS were scheduled to resume when they returned to service. space shuttle[′spās ‚shəd·əl]space shuttlespace shuttle
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