Editing Space Shuttle Challenger (section)

==History==
''Challenger'' was named after [[HMS Challenger (1858)|HMS ''Challenger'']], a British [[corvette]] that was the command ship for the [[Challenger expedition|''Challenger'' Expedition]], a pioneering global marine research expedition undertaken from 1872 through 1876.<ref name="bg">[http://www-pao.ksc.nasa.gov/shuttle/resources/orbiters/Challenger.html "Orbiter Vehicles"] {{webarchive|url=https://web.archive.org/web/20090203035705/http://www-pao.ksc.nasa.gov/shuttle/resources/orbiters/Challenger.html |date=February 3, 2009 }}, [[Kennedy Space Center]], [[NASA]], 2000-10-03, retrieved November 7, 2007.</ref>  The [[Apollo 17]] [[Apollo Lunar Module|Lunar Module]], which landed on the Moon in 1972, was also named ''Challenger''.<ref name="bg"/>

===Construction===
[[File:Challenger 1A.jpg|thumb|upright|''Challenger'' being prepared in 1985 for its penultimate flight, [[STS-61-A]]]]
[[File:STS-51-L - Space Shuttle Challenger on the Crawler-Transporter.jpg|thumb|''Challenger'' atop a [[Crawler-transporter]], en route to the launch site for its final flight, [[STS-51-L]]]]
Because of the low production volume of orbiters, the Space Shuttle program decided to build a vehicle as a [[Test article (aerospace)|Structural Test Article]], STA-099, that could later be converted to a flight vehicle. The contract for STA-099 was awarded to North American Rockwell on July 26, 1972, and construction was completed in February 1978.<ref>{{cite web|title=NASA – Space Shuttle Overview: Challenger (OV-099)|url=http://www.nasa.gov/centers/kennedy/shuttleoperations/orbiters/challenger-info.html|access-date=November 7, 2012|archive-date=June 11, 2017|archive-url=https://web.archive.org/web/20170611063127/http://www.nasa.gov/centers/kennedy/shuttleoperations/orbiters/challenger-info.html|url-status=dead}}</ref> After STA-099's rollout, it was sent to a [[Lockheed Corporation|Lockheed]] test site in Palmdale, where it spent over 11 months in vibration tests designed to simulate entire shuttle flights, from launch to landing.<ref name="Lardas 2012 36">{{cite book|last=Lardas|first=Mark|title=Space Shuttle Launch System: 1972–2004|year=2012|publisher=[[Osprey Publishing]]|pages=36}}</ref> To prevent damage during structural testing, qualification tests were performed to a [[safety factor]] of 1.2 times the design limit loads. The qualification tests were used to validate computational models, and compliance with the required 1.4 factor of safety was shown by analysis.<ref>NASA Engineering and Safety Center (2007). [http://www.nasa.gov/pdf/189071main_RP-06-108_05-173_DDT%26_E_Volume_II_(MASTER)08-07-2007_Final_%5B1%5D.pdf Design Development Test and Evaluation (DDT&E) Considerations for Safe and Reliable Human Rated Spacecraft Systems, Vol. II] {{Webarchive|url=https://web.archive.org/web/20201025055455/https://www.nasa.gov/pdf/189071main_RP-06-108_05-173_DDT%26_E_Volume_II_(MASTER)08-07-2007_Final_%5B1%5D.pdf |date=October 25, 2020 }}, June 14, 2007, p. 23.</ref> STA-099 was essentially a complete airframe of a Space Shuttle orbiter, with only a mockup crew module installed and [[thermal insulation]] placed on its forward fuselage.<ref>{{cite book|last=Evans|first=Ben|title=Space Shuttle Challenger: Ten Journeys Into the Unknown|year=2007|publisher=Praxis Publishing|isbn=978-0-387-46355-1|page=8}}</ref>
[[File:STS Challenger on 747 SCA.jpg|thumb|''Challenger'' being transported by [[Shuttle Carrier Aircraft]] 905, shortly before being delivered in 1982]]

NASA planned to refit the prototype orbiter [[Space Shuttle Enterprise|''Enterprise'']] (OV-101), used for flight testing, as the second operational orbiter; but ''Enterprise'' lacked most of the systems needed for flight, including a functional propulsion system, thermal insulation, a life support system, and most of the cockpit instrumentation. Modifying it for spaceflight was considered to be too difficult, expensive, and time-consuming. Since STA-099 was not as far along in the construction of its airframe, it would be easier to upgrade to a flight article. Because STA-099's qualification testing prevented damage, NASA found that rebuilding STA-099 into a flightworthy orbiter would be less expensive than refitting ''Enterprise''. Work on converting STA-099 to operational status began in January 1979, starting with the crew module (the pressurized portion of the vehicle), as the rest of the vehicle was still being used for testing by Lockheed. STA-099 returned to the Rockwell plant in November 1979, and the original, unfinished crew module was replaced with the newly constructed model. Major parts of STA-099, including the payload bay doors, body flap, wings, and vertical stabilizer, also had to be returned to their individual subcontractors for rework. By early 1981, most of these components had returned to Palmdale to be reinstalled. Work continued on the conversion until July 1982, when the new orbiter was rolled out as ''Challenger''.<ref name="Lardas 2012 36"/>

''Challenger'', as did the orbiters built after it, had fewer tiles in its [[Space Shuttle thermal protection system|Thermal Protection System]] than ''Columbia'', though it still made heavier use of the white LRSI tiles on the cabin and main fuselage than did the later orbiters. Most of the tiles on the payload bay doors, upper wing surfaces, and rear fuselage surfaces were replaced with [[DuPont]] white [[Nomex]] felt insulation. These modifications and an overall lighter structure allowed ''Challenger'' to carry 2,500&nbsp;lb (1,100&nbsp;kg) more payload than ''Columbia.'' ''Challenger''{{'}}s fuselage and wings were stronger and lighter than ''Columbia''{{'}}s.<ref name="Lardas 2012 36"/> The hatch and vertical-stabilizer tile patterns were different from those of the other orbiters. ''Challenger'' was the first orbiter to have a [[heads-up display]] (HUD) system for use in the [[Space Shuttle#Re-entry and landing|descent]] phase of a mission, and the first to feature [[Space Shuttle Main Engine#Upgrades|Phase I main engines]] rated for 104% maximum thrust.

====Construction milestones (as STA-099)====
{| class="wikitable"
|-
! style="background:#efefef;" | Date
! style="background:#efefef;" | Milestone<ref name="NASA/KSC">{{cite web|title=Shuttle Orbiter ''Challenger'' (OV-099)|url=http://science.ksc.nasa.gov/shuttle/resources/orbiters/challenger.html|publisher=NASA/KSC|access-date=November 7, 2012|archive-date=May 23, 2019|archive-url=https://web.archive.org/web/20190523112035/https://science.ksc.nasa.gov/shuttle/resources/orbiters/challenger.html|url-status=dead}}</ref>
|-
| July 26, 1972
| Contract Award to [[Rockwell International|North American Rockwell]]
|-
| November 21, 1975
| Start structural assembly of crew module
|-
| June 14, 1976
| Start structural assembly of aft fuselage.
|-
| March 16, 1977
| Wings arrive at Palmdale from [[Grumman]]
|-
| September 30, 1977
| Start of Final Assembly
|-
| February 10, 1978
| Completed Final Assembly
|-
| February 14, 1978
| Rollout from Palmdale
|}

====Construction milestones (as OV-099)====
{| class="wikitable"
|-
! style="background:#efefef;" | Date
! style="background:#efefef;" | Milestone<ref name="NASA/KSC"/>
|-
| January 5, 1979
| Contract Award to [[Rockwell International]], Space Transportation Systems Division
|-
| January 28, 1979
| Start structural assembly of crew module
|-
| November 3, 1980
| Start of Final Assembly
|-
| October 23, 1981
| Completed Final Assembly
|-
| June 30, 1982
| Rollout from Palmdale
|-
| July 1, 1982
| Overland transport from Palmdale to Edwards
|-
| July 5, 1982
| Delivery to KSC
|-
| December 18, 1982
| Flight Readiness Firing (FRF)
|-
|January 25, 1983
|Second FRF (performed due to a hydrogen leak having occurring during the first FRF)<ref>{{cite web |date=April 6, 2013 |title=30 Years Since STS-6: The Rise of the Challenger (Part 1) |url=http://www.americaspace.com/?p=33504}}</ref>
|-
| April 4, 1983
| First Flight ([[STS-6]])
|}

===Flights and modifications===
 	
After its [[STS-6|first flight]] in April 1983, ''Challenger'' quickly became the workhorse of [[NASA]]'s [[Space Shuttle]] fleet, flying six of nine Space Shuttle [[list of space shuttle missions|missions]] in 1983 and 1984. Even when the orbiters [[Space Shuttle Discovery|''Discovery'']] and [[Space Shuttle Atlantis|''Atlantis'']] joined the fleet, ''Challenger'' flew three missions a year from 1983 to 1985. ''Challenger'', along with ''Atlantis'', was modified at [[Kennedy Space Center]] to be able to carry the [[Centaur (rocket stage)|Centaur-G]] upper stage in its payload bay. If flight [[STS-51-L]] had been successful, ''Challenger''{{'}}s next mission would have been the deployment of the [[Ulysses (spacecraft)|''Ulysses'' probe]] with the Centaur to study the polar regions of the Sun.

''Challenger'' flew the [[Sally Ride|first American woman]], [[Guion Bluford|African-American]], [[Wubbo Ockels|Dutchman]], and [[Marc Garneau|Canadian]] into space; carried three [[Spacelab]] missions; and performed the [[STS-8|first night launch and night landing]] of a Space Shuttle.

=== Final mission and destruction ===
[[File:Challenger explosion.jpg|thumb|''Challenger'' breaks apart after launch in 1986, killing all crew on board, including [[Christa McAuliffe]], a teacher with the NASA [[Teacher in Space Project]]]]
{{Main|Space Shuttle Challenger disaster}}

[[STS-51-L]] was the orbiter's tenth and final flight, initially planned to launch on January 26, 1986 (after several technical and paperwork delays). The mission attracted huge media attention, as one of the crew was a civilian schoolteacher, [[Christa McAuliffe]], who was assigned to carry out live lessons from the orbiter (as part of NASA's [[Teacher in Space Project]]). Other members would deploy the [[TDRS-B]] satellite and conduct comet observations.

''Challenger'' blasted off at 11:38 am EST on January 28, 1986. Just over a minute into the flight, a faulty booster joint opened up, leading to a flame that melted securing struts which resulted in a catastrophic structural failure and explosion of the [[External Tank]]. The resulting pressure waves and aerodynamic forces destroyed the orbiter, resulting in the loss of all of the crew.

''Challenger'' was the first Space Shuttle to be [[Space Shuttle Challenger disaster|destroyed]] in a mission disaster.<ref>{{cite web | last=Ware | first=Doug G. | title = Engineer who warned of 1986 Challenger disaster still racked with guilt, three decades on | date=January 28, 2016 | publisher=[[United Press International]] | url = http://www.upi.com/Top_News/US/2016/01/28/Engineer-who-warned-of-1986-Challenger-disaster-still-racked-with-guilt-three-decades-on/4891454032643/ | access-date=January 28, 2016}}</ref> The collected debris of the vessel is currently buried in decommissioned [[missile launch facility|missile silos]] at [[Cape Canaveral Air Force Station Launch Complex 31|Launch Complex 31]], [[Cape Canaveral Air Force Station]]. A section of the fuselage recovered from Space Shuttle ''Challenger'' can also be found at the "Forever Remembered" memorial at the Kennedy Space Center Visitor Complex in Florida. Debris from the orbiter sometimes washes up on the Florida coast.<ref name="cnn">{{Cite web|url=http://www.cnn.com/TECH/9612/17/challenger.debris/index.html|title=Shuttle Challenger debris washes up on shore|access-date=November 7, 2007|publisher=[[CNN]]|year=1996}}</ref> This is collected and transported to the silos for storage. Because of its early loss, ''Challenger'' was the only Space Shuttle that never wore the NASA [[NASA insignia|"meatball" logo]], and was never modified with the MEDS "glass cockpit". The tail was never fitted with a drag chute, which was fitted to the remaining orbiters in 1992. ''Challenger'' and sister ship ''Columbia'' are the only two shuttles that never visited the Mir Space Station or the International Space Station. In September 2020 [[Netflix]] released ''[[Challenger: The Final Flight]]'', a four-part miniseries created by Steven Leckart and Glen Zipper documenting the tragedy firsthand.

=== Lawsuits ===

In March 1988 the federal government and Morton Thiokol Inc. agreed to pay $7.7 million in cash and annuities to the families of four of the seven ''Challenger'' astronauts as part of a settlement aimed at avoiding lawsuits in the nation's worst space disaster, according to government documents. Morton Thiokol, the company that manufactured the faulty solid rocket booster that caused the accident, paid 60 percent, $4,641,000. The remainder, $3,094,000, was paid by the government.<ref>{{cite news|title=Challenger Settlements Disclosed : U.S. and Rocket Maker Paid $7.7 Million to 4 Families |date=March 8, 1988 |url=https://www.latimes.com/archives/la-xpm-1988-03-08-mn-614-story.html |publisher=LA Times |access-date=May 10, 2025}}</ref>

In September 1988 a federal judge dismissed two lawsuits seeking $3 billion from Space Shuttle rocket-maker Morton Thiokol Inc. by [[Roger Boisjoly]], a former company engineer who warned against the ill-fated 1986 ''Challenger'' launch.<ref>{{cite news| url = https://www.washingtonpost.com/archive/business/1988/09/03/judge-dismisses-lawsuits-against-maker-of-shuttle-rocket-by-former-employee/c5b0a4c4-80a6-428e-9980-10376e9e0daf/| title = JUDGE DISMISSES LAWSUITS AGAINST MAKER OF SHUTTLE ROCKET BY FORMER EMPLOYEE - The Washington Post| newspaper = [[The Washington Post]]}}</ref>