Editing Space Shuttle (section)

== Design and development ==
===Historical background===
In the late 1930s, the German government launched the "[[Amerikabomber]]" (English: America bomber) project, and [[Eugen Sänger|Eugen Sanger]]'s idea, together with mathematician [[Irene Sänger-Bredt|Irene Bredt]], was a winged rocket called the [[Silbervogel]] (German for "silver bird").<ref>{{Cite web|last=Wall|first=Mike|date=June 28, 2011|title=How the Space Shuttle Was Born|url=https://www.space.com/12085-nasa-space-shuttle-history-born.html|access-date=March 30, 2023|website=Space.com|archive-date=March 30, 2023|archive-url=https://web.archive.org/web/20230330205213/https://www.space.com/12085-nasa-space-shuttle-history-born.html|url-status=live}}</ref> 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 [[Boeing X-20 Dyna-Soar|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.<ref name="dev_space_shuttle">{{cite book |last=Williamson |first=Ray |title=Exploring the Unknown: Selected Documents in the History of the U.S. Civil Space Program, Volume IV: Accessing Space |chapter=Developing the Space Shuttle |publisher=NASA |date=1999 |location=Washington, D.C. |chapter-url=https://history.nasa.gov/SP-4407/vol4/cover.pdf |access-date=April 23, 2019 |archive-date=May 31, 2020 |archive-url=https://web.archive.org/web/20200531171908/https://history.nasa.gov/SP-4407/vol4/cover.pdf |url-status=live}}</ref>{{rp|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-24|Martin Marietta X-24A]], and the [[Martin Marietta X-24#X-24B 2|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.<ref name="lifting_body_report">{{cite book |url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19980169231.pdf |title=Wingless Flight: The Lifting Body Story |date=January 1, 1997 |access-date=April 25, 2019 |publisher=NASA |first=R. Dale |last=Reed |isbn=9780160493904 |author-link=R. Dale Reed |archive-date=December 18, 2014 |archive-url=https://web.archive.org/web/20141218030338/https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19980169231.pdf |url-status=live}}</ref>{{rp|142}}<ref name="shuttle_manual">{{cite book |last=Baker |first=David |author-link=David Baker (author) |title=NASA Space Shuttle: Owners' Workshop Manual |publisher=[[Haynes Manual]] |date=April 2011 |location=Somerset, UK |isbn=978-1-84425-866-6}}</ref>{{rp|16–18}}

===Design process===
{{main|Space Shuttle design process}}

On September 24, 1966, as the Apollo space program neared its design completion, NASA and the Air Force released a joint study concluding that a new vehicle was required to satisfy their respective future demands and that a partially reusable system would be the most cost-effective solution.<ref name="dev_space_shuttle" />{{rp|164}} The head of the NASA Office of Manned Space Flight, [[George Mueller (NASA)|George Mueller]], announced the plan for a reusable shuttle on August 10, 1968. NASA issued a [[request for proposal]] (RFP) for designs of the Integral Launch and Reentry Vehicle (ILRV) on October 30, 1968.<ref>{{Cite book |last=Guilmartin JF, Mauer JW |title=A shuttle chronology 1964–1973: Abstract concepts to letter contracts (5 vols.) |publisher=NASA Lyndon B. Johnson Space Center, Houston, TX. |year=1988 |location=Houston, TX. |publication-date=1988}}</ref> Rather than award a contract based upon initial proposals, NASA announced a phased approach for the Space Shuttle contracting and development; Phase A was a request for studies completed by competing aerospace companies, Phase B was a competition between two contractors for a specific contract, Phase C involved designing the details of the spacecraft components, and Phase D was the production of the spacecraft.<ref name=lindroos>{{cite web|url=http://www.pmview.com/spaceodysseytwo/spacelvs/index.htm|title=Introduction to Future Launch Vehicle Plans [1963–2001]|last=Lindroos|first=Marcus|publisher=Pmview.com|date=June 15, 2001|access-date=April 25, 2019|archive-date=July 17, 2019|archive-url=https://web.archive.org/web/20190717122307/http://www.pmview.com/spaceodysseytwo/spacelvs/index.htm|url-status=live}}</ref><ref name= shuttle_manual />{{rp|19–22}}

In December 1968, NASA created the Space Shuttle Task Group to determine the optimal design for a reusable spacecraft, and issued study contracts to [[General Dynamics]], [[Lockheed Corporation|Lockheed]], [[McDonnell Douglas]], and [[North American Rockwell]]. In July 1969, the Space Shuttle Task Group issued a report that determined the Shuttle would support short-duration crewed missions and space station, as well as the capabilities to launch, service, and retrieve satellites. The report also created three classes of a future reusable shuttle: Class I would have a reusable orbiter mounted on expendable boosters, Class II would use multiple expendable rocket engines and a single propellant tank (stage-and-a-half), and Class III would have both a reusable orbiter and a reusable booster. In September 1969, the Space Task Group, under the leadership of U.S. vice president [[Spiro Agnew]], issued a report calling for the development of a space shuttle to bring people and cargo to low Earth orbit (LEO), as well as a [[space tug]] for transfers between orbits and the Moon, and a reusable [[Nuclear propulsion#Spacecraft|nuclear upper stage]] for deep space travel.<ref name="dev_space_shuttle" />{{rp|163–166}}<ref name=space_task_group_1969 />

After the release of the Space Shuttle Task Group report, many aerospace engineers favored the Class III, fully reusable design because of perceived savings in hardware costs. [[Max Faget]], a NASA engineer who had worked to design the [[Project Mercury|Mercury]] capsule, patented a design for a two-stage fully recoverable system with a straight-winged orbiter mounted on a larger straight-winged booster.<ref name="faget_bio">{{cite web |last= Allen |first= Bob |title= Maxime A. Faget |publisher= NASA |date= August 7, 2017 |url= https://www.nasa.gov/langley/hall-of-honor/maxime-a-faget |access-date= April 24, 2019 |archive-date= December 19, 2019 |archive-url= https://web.archive.org/web/20191219065416/https://www.nasa.gov/langley/hall-of-honor/maxime-a-faget/ |url-status= live}}</ref><ref name="faget_patent">{{cite patent |country=United States |number=3,702,688 |status= |title=Space Shuttle Vehicle and System |pubdate=November 14, 1972 |gdate= |fdate=January 4, 1971 |pridate= |inventor=[[Maxime Faget|Maxime A. Faget]] |invent1= |invent2= |assign1= |assign2= |class= |url=https://patentimages.storage.googleapis.com/eb/f9/60/879c61bb6df70a/US3702688.pdf}} {{Webarchive|url=https://web.archive.org/web/20190424100336/https://patentimages.storage.googleapis.com/eb/f9/60/879c61bb6df70a/US3702688.pdf |date=April 24, 2019}}</ref> The Air Force Flight Dynamics Laboratory argued that a straight-wing design would not be able to withstand the high thermal and aerodynamic stresses during reentry, and would not provide the required cross-range capability. Additionally, the Air Force required a larger payload capacity than Faget's design allowed. In January 1971, NASA and Air Force leadership decided that a reusable delta-wing orbiter mounted on an expendable propellant tank would be the optimal design for the Space Shuttle.<ref name="dev_space_shuttle" />{{rp|166}}

After they established the need for a reusable, heavy-lift spacecraft, NASA and the Air Force determined the design requirements of their respective services. The Air Force expected to use the Space Shuttle to launch large satellites, and required it to be capable of lifting {{convert|65000|lb|kg|sigfig=2|sp=us|order=flip|adj=on|abbr=on}} to an eastward LEO or {{convert|40000|lb|kg|sigfig=2|sp=us|order=flip|adj=on|abbr=on}} into a [[polar orbit]]. The satellite designs also required that the Space Shuttle have a {{convert|15|by|60|ft|m|sigfig=2|sp=us|order=flip|adj=on|abbr=on}} payload bay. NASA evaluated the [[Rocketdyne F-1|F-1]] and [[Rocketdyne J-2|J-2]] engines from the [[Saturn (rocket family)|Saturn rockets]], and determined that they were insufficient for the requirements of the Space Shuttle; in July 1971, it issued a contract to [[Rocketdyne]] to begin development on the [[RS-25]] engine.<ref name="dev_space_shuttle" />{{rp|165–170}}

NASA reviewed 29 potential designs for the Space Shuttle and determined that a design with two side boosters should be used, and the boosters should be reusable to reduce costs.<ref name="dev_space_shuttle" />{{rp|167}} NASA and the Air Force elected to use [[solid-propellant rocket|solid-propellant boosters]] because of the lower costs and the ease of refurbishing them for reuse after they landed in the ocean. In January 1972, President [[Richard Nixon]] approved the Shuttle, and NASA decided on its final design in March. The development of the Space Shuttle Main Engine (SSME) remained the responsibility of Rocketdyne, and the contract was issued in July 1971, and updated SSME specifications were submitted to Rocketdyne that&nbsp;April<!-- 1972-->.<ref>{{cite web |last1=Lethbridge |first1=Cliff |title=SPACE SHUTTLE |url=https://www.spaceline.org/united-states-manned-space-flight/space-shuttle-program-history/#:~:text=The%20first%20goal%20of%20the,by%2012%20to%2024%20people. |website=Spaceline.org |access-date=March 31, 2023 |archive-date=March 31, 2023 |archive-url=https://web.archive.org/web/20230331193408/https://www.spaceline.org/united-states-manned-space-flight/space-shuttle-program-history/#:~:text=The%20first%20goal%20of%20the,by%2012%20to%2024%20people. |url-status=live}}</ref> The following August<!-- 1972-->, NASA awarded the contract to build the orbiter to North American Rockwell, which had by then constructed a full-scale mock-up, later named ''[[Space Shuttle Inspiration|Inspiration]]''.<ref name="Campa 2024">{{cite web | last=Campa | first=Andrew J. | title='This is where it all happened.' Downey's space shuttle prototype begins move to future home | website=Los Angeles Times | date=October 17, 2024 | url=https://www.latimes.com/california/story/2024-10-17/downey-space-shuttle-model-moves-to-site-near-future-home | access-date=January 19, 2025}}</ref><ref name="Lost LA S7E1">{{cite web | title=Lost LA season 7, episode 1: Space Shuttle | website=PBS | date=January 7, 2025 | url=https://www.pbs.org/video/space-shuttle-jraw1j/ | access-date=January 19, 2025}}</ref> In August 1973, NASA awarded the external tank contract to [[Martin Marietta]], and in November the solid-rocket booster contract to [[Morton Thiokol]].<ref name="dev_space_shuttle" />{{rp|170–173}}

=== Development ===
[[File:566175main columbia-opf.jpg|thumb|right|alt=The Space Shuttle Columbia under construction|[[Space Shuttle Columbia|''Columbia'']] undergoing installation of its ceramic tiles]]

On June 4, 1974, Rockwell began construction on the first orbiter, OV-101, dubbed Constitution, later to be renamed [[Space Shuttle Enterprise|''Enterprise'']]. ''Enterprise'' was designed as a test vehicle, and did not include engines or heat shielding. Construction was completed on September 17, 1976, and ''Enterprise'' was moved to the [[Edwards Air Force Base]] to begin testing.<ref name="dev_space_shuttle" />{{rp|173}}<ref name="enterprise_overview">{{cite web |last= Howell |first= Elizabeth |title= Enterprise: The Test Shuttle |publisher= Space.com |date= October 9, 2012 |url= https://www.space.com/17983-space-shuttle-enterprise.html |access-date= April 24, 2019 |archive-date= August 6, 2020 |archive-url= https://web.archive.org/web/20200806144504/https://www.space.com/17983-space-shuttle-enterprise.html |url-status= live}}</ref> Rockwell constructed the [[MPTA-098|Main Propulsion Test Article (MPTA)-098]], which was a structural truss mounted to the ET with three RS-25 engines attached. It was tested at the [[Stennis Space Center|National Space Technology Laboratory]] (NSTL) to ensure that the engines could safely run through the launch profile.<ref name=jenkins2016 />{{rp|II-163}} Rockwell conducted mechanical and thermal stress tests on Structural Test Article (STA)-099 to determine the effects of aerodynamic and thermal stresses during launch and reentry.<ref name=jenkins2016 />{{rp|I-415}}

The beginning of the development of the RS-25 Space Shuttle Main Engine was delayed for nine months while [[Pratt & Whitney]] challenged the contract that had been issued to Rocketdyne. The first engine was completed in March 1975, after issues with developing the first throttleable, reusable engine. During engine testing, the RS-25 experienced multiple nozzle failures, as well as broken turbine blades. Despite the problems during testing, NASA ordered the nine RS-25 engines needed for its three orbiters under construction in May 1978.<ref name=dev_space_shuttle />{{rp|174–175}}

NASA experienced significant delays in the development of the Space Shuttle's [[Space Shuttle thermal protection system|thermal protection system]]. Previous NASA spacecraft had used [[Atmospheric entry#Ablative|ablative]] heat shields, but those could not be reused. NASA chose to use ceramic tiles for thermal protection, as the shuttle could then be constructed of lightweight [[aluminum]], and the tiles could be individually replaced as needed. Construction began on [[Space Shuttle Columbia|''Columbia'']] on March 27, 1975, and it was delivered to the KSC on March 25, 1979.<ref name=dev_space_shuttle />{{rp|175–177}} At the time of its arrival at the KSC, ''Columbia'' still had 6,000 of its 30,000 tiles remaining to be installed. However, many of the tiles that had been originally installed had to be replaced, requiring two years of installation before ''Columbia'' could fly.<ref name=shuttle_manual />{{rp|46–48}}

On January 5, 1979, NASA commissioned a second orbiter. Later that month, Rockwell began converting STA-099 to OV-099, later named [[Space Shuttle Challenger|''Challenger'']]. On January 29, 1979, NASA ordered two additional orbiters, OV-103 and OV-104, which were named [[Space Shuttle Discovery|''Discovery'']] and [[Space Shuttle Atlantis|''Atlantis'']]. Construction of OV-105, later named [[Space Shuttle Endeavour|''Endeavour'']], began in February 1982, but NASA decided to limit the Space Shuttle fleet to four orbiters in 1983. After the [[Space Shuttle Challenger disaster|loss of ''Challenger'']], NASA resumed production of ''Endeavour'' in September 1987.<ref name=shuttle_manual />{{rp|52–53}}

===Testing===
[[File:OV-101 first flight.jpg|thumb|alt=Enterprise being release from the Shuttle Carrier Aircraft for the Approach and Landing Tests|''Enterprise'' during the [[Approach and Landing Tests]]]]
[[File:Space Shuttle Columbia launching cropped 2.jpg|thumb|upright|alt=The Space Shuttle Columbia launching on the first Space Shuttle mission|[[Space Shuttle Columbia|''Columbia'']] launching on [[STS-1]]{{efn|[[STS-1]] and [[STS-2]] were the only Space Shuttle missions that used a white fire-retardant coating on the external tank. Subsequent missions did not use the latex coating to reduce the mass, and the external tank appeared orange.<ref name=shuttle_manual />{{rp|48}}}}]]

After it arrived at Edwards AFB, ''Enterprise'' underwent flight testing with the [[Shuttle Carrier Aircraft]], a Boeing 747 that had been modified to carry the orbiter. In February 1977, ''Enterprise'' began the [[Approach and Landing Tests]] (ALT) and underwent captive flights, where it remained attached to the Shuttle Carrier Aircraft for the duration of the flight. On August 12, 1977, ''Enterprise'' conducted its first glide test, where it detached from the Shuttle Carrier Aircraft and landed at Edwards AFB.<ref name="dev_space_shuttle" />{{rp|173–174}} After four additional flights, ''Enterprise'' was moved to the [[Marshall Space Flight Center]] (MSFC) on March 13, 1978. ''Enterprise'' underwent shake tests in the Mated Vertical Ground Vibration Test, where it was attached to an external tank and solid rocket boosters, and underwent vibrations to simulate the stresses of launch. In April 1979, ''Enterprise'' was taken to the KSC, where it was attached to an external tank and solid rocket boosters, and moved to [[Kennedy Space Center Launch Complex 39|LC-39]]. Once installed at the launch pad, the Space Shuttle was used to verify the proper positioning of the launch complex hardware. ''Enterprise'' was taken back to California in August 1979, and later served in the development of the [[Vandenberg AFB Space Launch Complex 6|SLC-6]] at [[Vandenberg AFB]] in 1984.<ref name=shuttle_manual />{{rp|40–41}}

On November 24, 1980, ''Columbia'' was mated with its external tank and solid-rocket boosters, and was moved to LC-39 on December&nbsp;29<!--, 1980-->.<ref name=jenkins2016 />{{rp|III-22}} The first Space Shuttle mission, [[STS-1]], would be the first time NASA performed a crewed first-flight of a spacecraft.<ref name=jenkins2016 />{{rp|III-24}} On April 12, 1981, the Space Shuttle launched for the first time, and was piloted by [[John Young (astronaut)|John Young]] and [[Robert Crippen]]. During the two-day mission, Young and Crippen tested equipment on board the shuttle, and found several of the ceramic tiles had fallen off the top side of the ''Columbia''.<ref name=into_the_black>{{cite book |last = White |first = Rowland |title = Into the Black |publisher = Touchstone |date = 2016 |location = New York |isbn = 978-1-5011-2362-7}}</ref>{{rp|277–278}} NASA coordinated with the Air Force to use satellites to image the underside of ''Columbia'', and determined there was no damage.<ref name=into_the_black />{{rp|335–337}} ''Columbia'' reentered the atmosphere and landed at Edwards AFB on April 14.<ref name=jenkins2016 />{{rp|III-24}}

NASA conducted three additional test flights with ''Columbia'' in 1981 and 1982. On July 4, 1982, [[STS-4]], flown by [[Ken Mattingly]] and [[Henry Hartsfield]], landed on a concrete runway at Edwards AFB. President [[Ronald Reagan]] and his wife [[Nancy Reagan|Nancy]] met the crew, and delivered a speech. After STS-4, NASA declared its Space Transportation System (STS) operational.<ref name="dev_space_shuttle" />{{rp|178–179}}<ref>{{cite web
 |last = Dumoulin
 |first = Jim
 |title = Space Transportation System
 |publisher = NASA
 |date = August 31, 2000
|url = https://science.ksc.nasa.gov/shuttle/technology/sts-newsref/sts_overview.html
 |access-date = June 21, 2020
|archive-date = February 5, 2021
|archive-url = https://web.archive.org/web/20210205085519/https://science.ksc.nasa.gov/shuttle/technology/sts-newsref/sts_overview.html
 |url-status = live
}}</ref>