Space Shuttle
The Space Shuttle is a retired, partially reusable low Earth orbital spacecraft system operated from 1981 to 2011 by the U.S. National Aeronautics and Space Administration (NASA) as part of the Space Shuttle program. Its official program name was Space Transportation System (STS), taken from a 1969 plan for a system of reusable spacecraft where it was the only item funded for development.[7]
This article is about a spacecraft system used by NASA. For space shuttles in general, see spacecraft and spaceplane. For the spaceplane component of the Space Shuttle, see Space Shuttle orbiter.Function
Crewed orbital launch and reentry
- United Space Alliance
- Thiokol/Alliant Techsystems (SRBs)
- Lockheed Martin/Martin Marietta (ET)
- Boeing/Rockwell (orbiter)
United States
US$211 billion (2012)
US$450 million (2011)[1]
56.1 m (184 ft)
8.7 m (29 ft)
2,030,000 kg (4,480,000 lb)
1.5[2]: 126, 140
27,500 kg (60,600 lb)
16,050 kg (35,380 lb)
10,890 kg (24,010 lb) with Inertial Upper Stage[3]
2,270 kg (5,000 lb) with Inertial Upper Stage[3]
14,400 kg (31,700 lb)[4]
Retired
133[a]
2
2 solid-fuel rocket motors
13,000 kN (3,000,000 lbf) each, sea level (2,650,000 liftoff)
242 s (2.37 km/s)[5]
124 seconds
3 RS-25 engines located on Orbiter
5,250 kN (1,180,000 lbf) total, sea level liftoff[6]
455 s (4.46 km/s)
480 seconds
The first (STS-1) of four orbital test flights occurred in 1981, leading to operational flights (STS-5) beginning in 1982. Five complete Space Shuttle orbiter vehicles were built and flown on a total of 135 missions from 1981 to 2011. They launched from the Kennedy Space Center (KSC) in Florida. Operational missions launched numerous satellites, interplanetary probes, and the Hubble Space Telescope (HST), conducted science experiments in orbit, participated in the Shuttle-Mir program with Russia, and participated in the construction and servicing of the International Space Station (ISS). The Space Shuttle fleet's total mission time was 1,323 days.[8]
Space Shuttle components include the Orbiter Vehicle (OV) with three clustered Rocketdyne RS-25 main engines, a pair of recoverable solid rocket boosters (SRBs), and the expendable external tank (ET) containing liquid hydrogen and liquid oxygen. The Space Shuttle was launched vertically, like a conventional rocket, with the two SRBs operating in parallel with the orbiter's three main engines, which were fueled from the ET. The SRBs were jettisoned before the vehicle reached orbit, while the main engines continued to operate, and the ET was jettisoned after main engine cutoff and just before orbit insertion, which used the orbiter's two Orbital Maneuvering System (OMS) engines. At the conclusion of the mission, the orbiter fired its OMS to deorbit and reenter the atmosphere. The orbiter was protected during reentry by its thermal protection system tiles, and it glided as a spaceplane to a runway landing, usually to the Shuttle Landing Facility at KSC, Florida, or to Rogers Dry Lake in Edwards Air Force Base, California. If the landing occurred at Edwards, the orbiter was flown back to the KSC atop the Shuttle Carrier Aircraft (SCA), a specially modified Boeing 747 designed to carry the shuttle above it.
The first orbiter, Enterprise, was built in 1976 and used in Approach and Landing Tests (ALT), but had no orbital capability. Four fully operational orbiters were initially built: Columbia, Challenger, Discovery, and Atlantis. Of these, two were lost in mission accidents: Challenger in 1986 and Columbia in 2003, with a total of 14 astronauts killed. A fifth operational (and sixth in total) orbiter, Endeavour, was built in 1991 to replace Challenger. The three surviving operational vehicles were retired from service following Atlantis's final flight on July 21, 2011. The U.S. relied on the Russian Soyuz spacecraft to transport astronauts to the ISS from the last Shuttle flight until the launch of the Crew Dragon Demo-2 mission in May 2020.[9]
Design and development[edit]
Historical background[edit]
In the late 1930s, the German government launched the "Amerikabomber" project, and Eugen Sanger's idea, together with mathematician Irene Bredt, was a winged rocket called the Silbervogel (German for "silver bird").[10] During the 1950s, the United States Air Force proposed using a reusable piloted glider to perform military operations such as reconnaissance, satellite attack, and air-to-ground weapons employment. In the late 1950s, the Air Force began developing the partially reusable X-20 Dyna-Soar. The Air Force collaborated with NASA on the Dyna-Soar and began training six pilots in June 1961. The rising costs of development and the prioritization of Project Gemini led to the cancellation of the Dyna-Soar program in December 1963. In addition to the Dyna-Soar, the Air Force had conducted a study in 1957 to test the feasibility of reusable boosters. This became the basis for the aerospaceplane, a fully reusable spacecraft that was never developed beyond the initial design phase in 1962–1963.[11]: 162–163
Beginning in the early 1950s, NASA and the Air Force collaborated on developing lifting bodies to test aircraft that primarily generated lift from their fuselages instead of wings, and tested the NASA M2-F1, Northrop M2-F2, Northrop M2-F3, Northrop HL-10, Martin Marietta X-24A, and the Martin Marietta X-24B. The program tested aerodynamic characteristics that would later be incorporated in design of the Space Shuttle, including unpowered landing from a high altitude and speed.[12]: 142 [13]: 16–18
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