SOMETHING ABOUT SPACE SHUTTLE

Space Shuttle

Space Shuttle Discovery begins liftoff at the start of STS-120.
Function	Manned orbital launch and reentry
Manufacturer	United Space Alliance: Thiokol/Alliant Techsystems (SRBs) Lockheed Martin/Martin Marietta (ET) Boeing/Rockwell (orbiter)
Country of origin	United States of America
Size
Height	56.1 m (184.2 ft)
Diameter	8.7 m (28.5 ft)
Mass	2,030 t (4,470,000 lbm)
Capacity
Payload toLEO	24,400 kg (53,600 lb)
Payload to GTO	3,810 kg (8,390 lbm)
Payload to Polar orbit	12,700 kg (28,000 lb)
Payload to Landing[1]	14,400 kg (32,000 lb)[1] (Return Payload)
Launch history
Status	Retired
Launch sites	LC-39, Kennedy Space Center SLC-6, Vandenberg AFB (unused)
Total launches	135
Successes	134 successful launches 133 successful re-entries
Failures	2 (launch failure, Challenger; re-entry failure, Columbia)
Maiden flight	April 12, 1981
Last flight	July 21, 2011
Notable payloads	Tracking and Data Relay Satellites Spacelab Great Observatories (including Hubble) Galileo, Magellan, Ulysses Mir Docking Module ISS components
Boosters (Stage 0) - Solid Rocket Boosters
No. boosters	2
Engines	1 solid
Thrust	12.5 MN each, sea level liftoff (2,800,000 lbf)
Specific impulse	269 s
Burn time	124 s
Fuel	solid
First stage - External Tank
Engines	3 SSMEs located on Orbiter
Thrust	5.45220 MN total, sea level liftoff (1,225,704 lbf)
Specific impulse	455 s
Burn time	480 s
Fuel	LOX/LH2
Second stage - Orbiter
Engines	2 OME
Thrust	53.4 kN combined total vacuum thrust (12,000 lbf)
Specific impulse	316 s
Burn time	1,250 s
Fuel	MMH/N2O4

The Space Shuttle was a partially reusable launch system and orbital spacecraft operated by the U.S. National Aeronautics and Space Administration (NASA) for human spaceflight missions. The system combined rocket launch, orbital spacecraft, and re-entry spaceplane with modular add-ons. The first of four orbital test flights occurred in 1981 leading to operational flights beginning in 1982. It was used on a total of 135 missions from 1981 to 2011 all launched from the Kennedy Space Center, Florida.

Major missions included launching numerous satellites, interplanetary probes, Hubble Space Telescope (HST), conducting space science experiments, and constructing and servicing the International Space Station. Major components included the orbiters, recoverable boosters, external tanks, payloads, and supporting infrastructure. Five space-worthy orbiters were built; two were destroyed in accidents.

The Space Shuttle at launch consisted of the Orbiter Vehicle (OV), one external tank (ET), and two Solid Rocket Boosters (SRBs). It was launched vertically like a conventional rocket with thrust from the two SRBs and three main engines. During launch, the external tank provided fuel for the orbiter's main engines. The SRBs and ET were jettisoned before the orbiter reached orbit. At the conclusion of the orbiter's space mission, it fired its thrusters to drop out of orbit and re-enter the lower atmosphere. The orbiter decelerated in the atmosphere before flying like a glider but with reaction control system thrusters before landing on a long runway.

Contents   [hide]  1 Overview 2 Early history 3 Description 3.1 Orbiter vehicle 3.2 External tank 3.3 Solid rocket boosters 3.4 Orbiter add-ons 3.4.1 Spacelab 3.5 Flight systems 3.6 Orbiter markings and insignia 3.7 Upgrades 3.8 Technical data 4 Mission profile 4.1 Launch 4.1.1 Ascent tracking 4.2 In orbit 4.3 Re-entry and landing 4.3.1 Final approach and landing phase 4.4 Post-landing processing 4.5 Landing sites 4.6 Risk contributors 5 Fleet history 5.1 Shuttle disasters 6 Retirement 6.1 Distribution of orbiters and other hardware 7 Space Shuttle successors and legacy 8 In culture 8.1 U.S. postage commemorations 9 See also 9.1 Physics 9.2 Similar spacecraft 10 References 11 Further reading 12 External links

[edit]Overview

The Space Shuttle was a partially reuseable^[2] launch system and orbital spacecraft operated by the U.S. National Aeronautics and Space Administration (NASA) for human spaceflight missions from 1981 to 2011. The system combined rocket launch, orbital spacecraft, and re-entryspaceplane with modular add-ons. The first of four orbital test flights occurred in 1981 leading to operational flights beginning in 1982, all launched from the Kennedy Space Center, Florida. The system was retired from service in 2011 after 135 missions;^[3] on July 8, 2011, with Space Shuttle Atlantis performing that 135th launch - the final launch of the three-decade Shuttle program.^[4] The program ended after Atlantis landed at the Kennedy Space Center on July 21, 2011. Major missions included launching numerous satellites and interplanetary probes,^[5] conducting space science experiments, and servicing and construction of space stations. Enterprise was a prototype orbiter used for atmospheric testing during development in the 1970s, and lacked engines and heat shield. Five space-worthy orbiters were built—two were destroyed in accidents and the others have been retired.

It was used for orbital space missions by NASA, the U.S. Department of Defense, the European Space Agency, Japan, and Germany.^[6][7] The United States funded Space Transportation System (STS) development and Shuttle operations except for Spacelab D1 and D2 — sponsored by West Germany and reunified Germany respectively.^{[6][8][9][10][11]} In addition, SL-J was partially funded by Japan.^[7]

At launch, it consisted of the "stack", including a dark orange-colored external tank (ET);^[12][13] two white, slender Solid Rocket Boosters (SRBs); and the Orbiter Vehicle (OV), which contained the crew and payload. Some payloads were launched into higher orbits with either of two different booster stages developed for the STS (single-stage Payload Assist Module or two-stage Inertial Upper Stage). The Space Shuttle was stacked in the Vehicle Assembly Building and the stack mounted on a mobile launch platform held down by four explosive bolts on each SRB which are detonated at launch.^[14]

The Shuttle stack launched vertically like a conventional rocket. It lifted off under the power of its two SRBs and three main engines, which were fueled by liquid hydrogen and liquid oxygen from the external tank. The Space Shuttle had a two-stage ascent. The SRBs provided additional thrust during liftoff and first-stage flight. About two minutes after liftoff, explosive bolts were fired, releasing the SRBs, which then parachuted into the ocean, to be retrieved by ships for refurbishment and reuse. The Shuttle orbiter and external tank continued to ascend on an increasingly horizontal flight path under power from its main engines. Upon reaching 17,500 mph (7.8 km/s), necessary for low Earth orbit, the main engines were shut down. The external tank was then jettisoned to burn up in the atmosphere.^[15] After jettisoning the external tank, the orbital maneuvering system (OMS) engines were used to adjust the orbit.

The orbiter carried people and payload such as satellites or space station parts into low Earth orbit, into the Earth's upper atmosphere orthermosphere.^[16] Usually, five to seven crew members rode in the orbiter. Two crew members, the commander and pilot, were sufficient for a minimal flight, as in the first four "test" flights, STS-1 through STS-4. The typical payload capacity was about 22,700 kilograms (50,000 lb), but could be increased depending on the choice of launch configuration. The orbiter carried its payload in a large cargo bay with doors that opened along the length of its top, a feature which made the Space Shuttle unique among spacecraft. This feature made possible the deployment of large satellites such as the Hubble Space Telescope, and also the capture and return of large payloads back to Earth.

When the orbiter's space mission was complete, it fired its OMS thrusters to drop out of orbit and re-enter the lower atmosphere.^[16] During descent, the orbiter passed through different layers of the atmosphere and decelerated from hypersonic speed primarily by aerobraking. In the lower atmosphere and landing phase, it was more like a glider but with reaction control system (RCS) thrusters and fly-by wire-controlled hydraulically-actuated flight surfaces controlling its descent. It landed on a long runway as a spaceplane. The aerodynamic shape was a compromise between the demands of radically different speeds and air pressures during re-entry, hypersonic flight, and subsonic atmospheric flight. As a result, the orbiter had a relatively high sink rate at low altitudes, and it transitioned during re-entry from using RCS thrusters at very high altitudes to flight surfaces in the lower atmosphere.