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{{short description|1986 inflight breakup of U.S. Space Shuttle}}{{distinguish|Space Shuttle Columbia disaster{{!}}Space Shuttle Columbia disaster}}{{pp-move}}{{italic title|string=Challenger}}{{featured article}}{{Use American English|date=January 2014}}{{Use mdy dates|date=January 2023}}

factoids

s Space Shuttle Solid Rocket Booster>solid rocket boosters fly uncontrollably after the breakup of the external tank separated them from the shuttle stack. The remains of the orbiter and tank leave thin white contrails as they fall toward the Atlantic Ocean.Eastern Time Zone>EST (16:39:13 UTC)| place = Atlantic Ocean, off the coast of Florida28248048region:US-FL_type:event_scale:1500000|display=title,inline}}O-ring seal failure in right Space Shuttle Solid Rocket Booster>SRB due to cold weather and wind shear1=

• F. Richard Scobee, commander
• Michael J. Smith, pilot
• Ronald McNair, mission specialist
• Ellison Onizuka, mission specialist
• Judith Resnik, mission specialist
• Gregory Jarvis, payload specialist
• Christa McAuliffe, payload specialist, teacher

}}|inquiries = Rogers Commission Report|outcome = {{bulleted list }}}}On January 28, 1986, the Space Shuttle Challenger broke apart 73 seconds into its flight, killing all seven crew members aboard. The spacecraft disintegrated {{convert|46000|ft|km}} above the Atlantic Ocean, off the coast of Cape Canaveral, Florida, at 11:39{{nbsp}}a.m. EST (16:39{{spaces}}UTC). It was the first fatal accident involving an American spacecraft while in flight.WEB, Lotito, Jennifer, 3 Leadership Lessons From The Challenger Space Shuttle Disaster,weblink January 28, 2024, Forbes, January 28, 2024,weblink live, WEB, Challenger explosion was 38 years ago today; Naples' readers recall event,weblink January 28, 2024, Naples Daily News, en-US, January 28, 2024,weblink live, The mission, designated STS-51-L, was the 10th flight for the orbiter and the 25th flight of the Space Shuttle fleet. The crew was scheduled to deploy a communications satellite and study Halley's Comet while they were in orbit, in addition to taking schoolteacher Christa McAuliffe into space under the Teacher In Space program. The latter task resulted in a higher-than-usual media interest in and coverage of the mission; the launch and subsequent disaster were seen live in many schools across the United States.The cause of the disaster was the failure of the primary and secondary redundant O-ring seals in a joint in the shuttle's right solid rocket booster (SRB). The record-low temperatures on the morning of the launch had stiffened the rubber O-rings, reducing their ability to seal the joints. Shortly after liftoff, the seals were breached, and hot pressurized gas from within the SRB leaked through the joint and burned through the aft attachment strut connecting it to the external propellant tank (ET), then into the tank itself. The collapse of the ET's internal structures and the rotation of the SRB that followed threw the shuttle stack, traveling at a speed of Mach 1.92, into a direction that allowed aerodynamic forces to tear the orbiter apart. Both SRBs detached from the now-destroyed ET and continued to fly uncontrollably until the range safety officer destroyed them.The crew compartment, human remains, and many other fragments from the shuttle were recovered from the ocean floor after a three-month search-and-recovery operation. The exact timing of the deaths of the crew is unknown, but several crew members are thought to have survived the initial breakup of the spacecraft. The orbiter had no escape system, and the impact of the crew compartment at terminal velocity with the ocean surface was too violent to be survivable.The disaster resulted in a 32-month hiatus in the Space Shuttle program. President Ronald Reagan created the Rogers Commission to investigate the accident. The commission criticized NASA's organizational culture and decision-making processes that had contributed to the accident. Test data since 1977 demonstrated a potentially catastrophic flaw in the SRBs' O-rings, but neither NASA nor SRB manufacturer Morton Thiokol had addressed this known defect. NASA managers also disregarded engineers' warnings about the dangers of launching in cold temperatures and did not report these technical concerns to their superiors.As a result of this disaster, NASA established the Office of Safety, Reliability, and Quality Assurance, and arranged for deployment of commercial satellites from expendable launch vehicles rather than from a crewed orbiter. To replace Challenger, the construction of a new Space Shuttle orbiter,{{OV|105|full=no}}, was approved in 1987, and the new orbiter first flew in 1992. Subsequent missions were launched with redesigned SRBs and their crews wore pressurized suits during ascent and reentry.

Background

Space Shuttle

File:STS-51-L - Space Shuttle Challenger on the Crawler-Transporter.jpg|thumb|Space Shuttle Challenger – assembled for launch along with the ET and two SRBs – atop a crawler-transportercrawler-transporterThe Space Shuttle was a partially reusable spacecraft operated by the US National Aeronautics and Space Administration (NASA).{{r|rogers_com}}{{rp|5, 195}} It flew for the first time in April 1981,{{r|jenkins2016}}{{rp|III–24}} and was used to conduct in-orbit research,{{r|jenkins2016}}{{rp|III–188}} and deploy commercial,{{r|jenkins2016}}{{rp|III–66}} military,{{r|jenkins2016}}{{rp|III–68}} and scientific payloads.{{r|jenkins2016}}{{rp|III–148}} At launch, it consisted of the orbiter, which contained the crew and payload, the external tank (ET), and the two solid rocket boosters (SRBs).BOOK, Jenkins, Dennis R., Space Shuttle: The History of the National Space Transportation System, Voyageur Press, 2001, 978-0-9633974-5-4, {{rp|363}} The orbiter was a reusable, winged vehicle that launched vertically and landed as a glider.{{r|jenkins2016}}{{rp|II-1}} Five orbiters were built during the Space Shuttle program.{{r|rogers_com}}{{rp|5}} Challenger (OV-099) was the second orbiter constructed after its conversion from a structural test article.{{r|jenkins2016}}{{rp|I-455}} The orbiter contained the crew compartment, where the crew predominantly lived and worked throughout a mission.{{r|jenkins2016}}{{rp|II-5}} Three Space Shuttle main engines (SSMEs) were mounted at the aft end of the orbiter and provided thrust during launch.{{r|jenkins}}{{rp|II-170}} Once in space, the crew maneuvered using the two smaller, aft-mounted Orbital Maneuvering System (OMS) engines.{{r|jenkins}}{{rp|II-79}}When it launched, the orbiter was connected to the ET, which held the fuel for the SSMEs.{{r|jenkins}}{{rp|II-222}} The ET consisted of a larger tank for liquid hydrogen (LH2) and a smaller tank for liquid oxygen (LOX), both of which were required for the SSMEs to operate.{{r|jenkins}}{{rp|II-222, II-226}} After its fuel had been expended, the ET separated from the orbiter and reentered the atmosphere, where it would break apart during reentry and its pieces would land in the Indian or Pacific Ocean.{{r|jenkins}}{{rp|II-238}}Two solid rocket boosters (SRBs), built by Morton Thiokol at the time of the disaster,{{r|mcdonald}}{{rp|9–10}} provided the majority of thrust at liftoff. They were connected to the external tank, and burned for the first two minutes of flight.{{r|jenkins}}{{rp|II-222}} The SRBs separated from the orbiter once they had expended their fuel and fell into the Atlantic Ocean under a parachute.{{r|jenkins}}{{rp|II-289}} NASA retrieval teams recovered the SRBs and returned them to the Kennedy Space Center (KSC), where they were disassembled and their components were reused on future flights.{{r|jenkins}}{{rp|II-292}} Each SRB was constructed in four main sections at the factory in Utah and transported to KSC, then assembled in the Vehicle Assembly Building at KSC with three tang-and-clevis field joints, each joint consisting of a tang from the upper segment fitting into the clevis of the lower segment. Each field joint was sealed with two ~20 foot (6 meter) diameter Viton-rubber O-rings around the circumference of the SRB and had a cross-section diameter of {{convert|0.280|in|mm}}.{{r|rogers_com}}{{rp|48}} The O-rings were required to contain the hot, high-pressure gases produced by the burning solid propellant and allowed for the SRBs to be rated for crewed missions.{{r|mcdonald}}{{rp|24}}BOOK, Heppenheimer, T.A., The Space Shuttle Decision: NASA's Search for a Reusable Space Vehicle,weblink live, NASA, SP-4221, 1998, July 19, 2021,weblink" title="web.archive.org/web/20210812050335weblink">weblink August 12, 2021, {{rp|420}} The two O-rings were configured to create a double bore seal, and the gap between segments was filled with putty. When the motor was running, this configuration was designed to compress air in the gap against the upper O-ring, pressing it against the sealing surfaces of its seat. On the SRB Critical Items List, the O-rings were listed as Criticality 1R, which indicated that an O-ring failure could result in the destruction of the vehicle and loss of life, but it was considered a redundant system due to the secondary O-ring.{{r|rogers_com}}{{rp|126}}

O-ring concerns

File:RogersCommission-v1p57 cropped.jpg|thumb|Cross-sectional diagram of the original SRB field joint. The top end of the lower rocket segment has a deep U-shaped cavity, or alt=Diagram from the Rogers Commission depicting a cross-section of the solid rocket booster field jointEvaluations of the proposed SRB design in the early 1970s and field joint testing showed that the wide tolerances between the mated parts allowed the O-rings to be extruded from their seats rather than compressed. This extrusion was judged to be acceptable by NASA and Morton Thiokol despite concerns of NASA's engineers.{{r|rogers_com}}{{rp|122–123}}JOURNAL, The history of the flawed joint, IEEE Spectrum, 1987, 24, 2, 39–44, 10.1109/MSPEC.1987.6448025, 26828360,weblink August 6, 2021, August 5, 2021,weblink live, A 1977 test showed that up to {{convert|0.052|in|mm}} of joint rotation occurred during the simulated internal pressure of a launch. Joint rotation, which occurred when the tang and clevis bent away from each other, reduced the pressure on the O-rings, which weakened their seals and made it possible for combustion gases to erode the O-rings.{{r|rogers_com}}{{rp|123–124}} NASA engineers suggested that the field joints should be redesigned to include shims around the O-rings, but they received no response.{{r|rogers_com}}{{rp|124–125}} In 1980, the NASA Verification/Certification Committee requested further tests on joint integrity to include testing in the temperature range of {{convert|40|to|90|F|C}} and with only a single O-ring installed. The NASA program managers decided that their current level of testing was sufficient and further testing was not required. In December{{nbsp}}1982, the Critical Items List was updated to indicate that the secondary O-ring could not provide a backup to the primary O-ring, as it would not necessarily form a seal in the event of joint rotation. The O-rings were redesignated as Criticality{{nbsp}}1, removing the "R" to indicate it was no longer considered a redundant system.{{r|rogers_com}}{{rp|125–127}}{{r|mcdonald}}{{rp|66}}The first occurrence of in-flight O-ring erosion occurred on the right SRB on {{nowrap|STS-2}} in November{{nbsp}}1981.{{r|rogers_com}}{{rp|126}} In August{{nbsp}}1984, a post-flight inspection of the left SRB on {{nowrap|STS-41-D}} revealed that soot had blown past the primary O-ring and was found in between the O-rings. Although there was no damage to the secondary O-ring, this indicated that the primary O-ring was not creating a reliable seal and was allowing hot gas to pass. The amount of O-ring erosion was insufficient to prevent the O-ring from sealing, and investigators concluded that the soot between the O-rings resulted from non-uniform pressure at the time of ignition.{{r|rogers_com}}{{rp|130}}{{r|mcdonald}}{{rp|39–42}} The January{{nbsp}}1985 launch of {{nowrap|STS-51-C}} was the coldest Space Shuttle launch to date. The air temperature was {{convert|62|F|C|sigfig=2}} at the time of launch, and the calculated O-ring temperature was {{convert|53|F|C|sigfig=2}}. Post-flight analysis revealed erosion in primary O-rings in both SRBs. Morton Thiokol engineers determined that the cold temperatures caused a loss of flexibility in the O-rings that decreased their ability to seal the field joints, which allowed hot gas and soot to flow past the primary O-ring.{{r|mcdonald}}{{rp|47}} O-ring erosion occurred on all but one ({{nowrap|STS-51-J}}) of the Space Shuttle flights in 1985, and erosion of both the primary and secondary O-rings occurred on {{nowrap|STS-51-B}}.{{r|rogers_com}}{{rp|131}}{{r|mcdonald}}{{rp|50–52, 63}}To correct the issues with O-ring erosion, engineers at Morton Thiokol, led by Allan McDonald and Roger Boisjoly, proposed a redesigned field joint that introduced a metal lip to limit movement in the joint. They also recommended adding a spacer to provide additional thermal protection and using an O-ring with a larger cross section.{{r|mcdonald}}{{rp|67−69}} In July{{nbsp}}1985, Morton Thiokol ordered redesigned SRB casings, with the intention of using already-manufactured casings for the upcoming launches until the redesigned cases were available the following year.{{r|mcdonald}}{{rp|62}}File:Challenger flight 51-l crew.jpg|thumb|STS-51-L crew: (back) Onizuka, McAuliffe, Jarvis, Resnik;(front) Smith, Scobee, (Ronald McNair|McNair]].WEB, Tonguette, Peter, 'Ohioans in Space' painting features Neil Armstrong, John Glenn, Jim Lovell, Judith Resnik,weblink live,weblink January 28, 2024, 2024-01-28, The Columbus Dispatch, |alt=Picture of the seven crew members in flight suits and holding their helmets)

Mission

The Space Shuttle mission, named {{nowrap|STS-51-L}}, was the twenty-fifth Space Shuttle flight and the tenth flight of{{OV|099|full=no}}.WEB, Rogers, William P., William P. Rogers, Armstrong, Neil A., Neil Armstrong, Acheson, David C., David Campion Acheson, Covert, Eugene E., Eugene E. Covert, Feynman, Richard P., Richard Feynman, Hotz, Robert B., Kutyna, Donald J., Donald Kutyna, Ride, Sally K., Sally Ride, Rummel, Robert W., June 6, 1986, Report of the Presidential Commission on the Space Shuttle Challenger Accident,weblink live,weblink July 13, 2021, July 13, 2021, NASA, Sutter, Joseph F., Joe Sutter, Walker, Arthur B.C., Arthur B. C. Walker Jr., Wheelon, Albert D., Yeager, Charles E., Chuck Yeager, 1, {{rp|6}} The crew was announced on January{{nbsp}}27,{{nbsp}}1985, and was commanded by Dick Scobee. Michael Smith was assigned as the pilot, and the mission specialists were Ellison Onizuka, Judith Resnik, and Ronald McNair. The two payload specialists were Gregory Jarvis, who was assigned to conduct research for the Hughes Aircraft Company, and Christa McAuliffe, who flew as part of the Teacher in Space Project.{{rp|10–13}}The primary mission of the Challenger crew was to use an Inertial Upper Stage (IUS) to deploy a Tracking and Data Relay Satellite (TDRS), named TDRS-B, that would have been part of a constellation to enable constant communication with orbiting spacecraft. The crew also planned to study Halley's Comet as it passed near the Sun,{{r|jenkins2016}}{{rp|III-76}} and deploy and retrieve a SPARTAN satellite.WEB The mission was originally scheduled for July{{nbsp}}1985, but was delayed to November and then to January{{nbsp}}1986.{{r|rogers_com}}{{rp|10}} The mission was scheduled to launch on January{{nbsp}}22, but was delayed until January 28.NEWS, Broad, William J., 24-Hour Delay Called for Shuttle Flight As Wind And Balky Bolt Bar Launching,weblink live, The New York Times, January 28, 1986, July 13, 2021,weblink July 16, 2021,

Decision to launch

The air temperature on January 28 was predicted to be a record low for a Space Shuttle launch.{{r|mcdonald}}{{rp|47, 101}} The air temperature was forecast to drop to {{convert|18|F|C|}} overnight before rising to {{convert|22|F|C|}} at 6:00{{spaces}}a.m. and {{convert|26|F|C|}} at the scheduled launch time of 9:38{{spaces}}a.m.{{r|rogers_com}}{{rp|87}}{{r|mcdonald}}{{rp|96}} Based upon O-ring erosion that had occurred in warmer launches, Morton Thiokol engineers were concerned over the effect the record-cold temperatures would have on the seal provided by the SRB O-rings for the launch.{{r|mcdonald}}{{rp|101–103}} Cecil Houston, the manager of the KSC office of the Marshall Space Flight Center, set up a conference call on the evening of January 27 to discuss the safety of the launch. Morton Thiokol engineers expressed their concerns about the effect of low temperatures on the resilience of the rubber O-rings. As the colder temperatures lowered the elasticity of the rubber O-rings, the engineers feared that the O-rings would not be extruded to form a seal at the time of launch.{{r|mcdonald}}{{rp|97–99}}NEWS,weblink Remembering Roger Boisjoly: He Tried To Stop Shuttle Challenger Launch, All Things Considered, February 6, 2012, July 27, 2021, Berkes, Howard, NPR, April 30, 2015,weblink" title="web.archive.org/web/20150430062751weblink">weblink live, The engineers argued that they did not have enough data to determine whether the O-rings would seal at temperatures colder than {{convert|53|F|C}}, the coldest launch of the Space Shuttle to date.{{r|mcdonald}}{{rp|105–106}} Morton Thiokol employees Robert Lund, the Vice President of Engineering, and Joe Kilminster, the Vice President of the Space Booster Programs, recommended against launching until the temperature was above {{convert|53|F|C}}.{{r|rogers_com}}{{rp|107–108}}(File:Icicles on the Launch Tower - GPN-2000-001348.jpg|thumb|Ice on the launch tower hours before Challenger launch|alt=The underside of the orbiter wing and the SRB behind the structure of the service tower. The service tower has numerous icicles.)The teleconference held a recess to allow for private discussion amongst Morton Thiokol management. When it resumed, Morton Thiokol leadership had changed their opinion and stated that the evidence presented on the failure of the O-rings was inconclusive and that there was a substantial margin in the event of a failure or erosion. They stated that their decision was to proceed with the launch. Morton Thiokol leadership submitted a recommendation for launch, and the teleconference ended.{{r|rogers_com}}{{rp|97, 109}} Lawrence Mulloy, the NASA SRB project manager,{{r|mcdonald}}{{rp|3}} called Arnold Aldrich, the NASA Mission Management Team Leader, to discuss the launch decision and weather concerns, but did not mention the O-ring discussion; the two agreed to proceed with the launch.{{r|rogers_com}}{{rp|99}}{{r|mcdonald}}{{rp|116}}An overnight measurement taken by the KSC Ice Team recorded the left SRB was {{convert|25|F|C|}} and the right SRB was {{convert|8|F|C|}}.{{r|rogers_com}}{{rp|111}} These measurements were recorded for engineering data and not reported, because the temperature of the SRBs was not part of the Launch Commit Criteria.{{r|mcdonald}}{{rp|118}} In addition to its effect on the O-rings, the cold temperatures caused ice to form on the fixed service structure. To keep pipes from freezing, water was slowly run from the system; it could not be entirely drained because of the upcoming launch. As a result, ice formed from {{convert|240|ft|m}} down in the freezing temperatures. Engineers at Rockwell International, which manufactured the orbiter, were concerned that ice would be violently thrown during launch and could potentially damage the orbiter's thermal protection system or be aspirated into one of the engines. Rocco Petrone, the head of Rockwell's space transportation division, and his team determined that the potential damage from ice made the mission unsafe to fly. Arnold Aldrich consulted with engineers at KSC and the Johnson Space Center (JSC) who advised him that ice did not threaten the safety of the orbiter, and he decided to proceed with the launch.{{r|rogers_com}}{{rp|115–118}} The launch was delayed for an additional hour to allow more ice to melt. The ice team performed an inspection at T–20 minutes which indicated that the ice was melting, and Challenger was cleared to launch at 11:38 a.m. EST, with an air temperature of {{convert|36|F|C|}}.{{r|rogers_com}}{{rp|17}}

Launch and failure

{{Further|Timeline of the STS-51-L mission}}

Liftoff and initial ascent

File:STS-51-L grey smoke on SRB.jpg|thumb|Gray smoke escaping from the right-side solid rocket boostersolid rocket boosterAt T+0, Challenger launched from the Kennedy Space Center Launch Complex 39B (LC-39B) at 11:38:00{{nbsp}}a.m.{{r|rogers_com}}{{rp|17}}BOOK, Jenkins, Dennis R., Space Shuttle: Developing an Icon – 1972–2013, 978-1-58007-249-6, Specialty Press, 2016, {{rp|III–76}} Beginning at T+0.678 until T+3.375 seconds, nine puffs of dark gray smoke were recorded escaping from the right-hand SRB near the aft strut that attached the booster to the ET.{{r|rogers_com}}{{rp|19}}{{r|jenkins2016}}{{rp|III-93}} It was later determined that these smoke puffs were caused by joint rotation in the aft field joint of the right-hand SRB at ignition.{{r|mcdonald}}{{rp|136}}The cold temperature in the joint had prevented the O-rings from creating a seal. Rainfall from the preceding time on the launchpad had likely accumulated within the field joint, further compromising the sealing capability of the O-rings. As a result, hot gas was able to travel past the O-rings and erode them. Molten aluminum oxides from the burned propellant resealed the joint and created a temporary barrier against further hot gas and flame escaping through the field joint.{{r|mcdonald}}{{rp|142}} The Space Shuttle main engines (SSMEs) were throttled down as scheduled for maximum dynamic pressure (max q).{{rp|III–8–9}}{{r|timeline}} During its ascent, the Space Shuttle encountered wind shear conditions beginning at {{nowrap|T+37}}, but they were within design limits of the vehicle and were countered by the guidance system.{{r|rogers_com}}{{rp|20}}

Plume

(File:Booster Rocket Breach - GPN-2000-001425.jpg|thumb|Plume on right SRB at {{nowrap|T+58.788}} seconds|alt=Space Shuttle challenger in-flight with an anomalous plume of fire from the side of its right solid rocket booster)At {{nowrap|T+58.788}}, a tracking film camera captured the beginnings of a plume near the aft attach strut on the right SRB, right before the vehicle passed through max q at {{nowrap|T+59.000}}.WEB,weblink STS-51L, CBS News, 2015, Harwood, William, July 29, 2021, June 11, 2021,weblink" title="web.archive.org/web/20210611125941weblink">weblink live, The high aerodynamic forces and wind shear likely broke the aluminum oxide seal that had replaced eroded O-rings, allowing the flame to burn through the joint.{{r|mcdonald}}{{rp|142}} Within one second from when it was first recorded, the plume became well-defined, and the enlarging hole caused a drop in internal pressure in the right SRB. A leak had begun in the liquid hydrogen (LH2) tank of the ET at {{nowrap|T+64.660}}, as indicated by the changing shape of the plume.The SSMEs pivoted to compensate for the booster burn-through, which was creating an unexpected thrust on the vehicle. The pressure in the external LH2 tank began to drop at {{nowrap|T+66.764}} indicating that the flame had burned from the SRB into the tank. The crew and flight controllers made no indication they were aware of the vehicle and flight anomalies. At {{nowrap|T+68}}, the CAPCOM, Richard O. Covey, told the crew, "Challenger, go at throttle up," indicating that the SSMEs had throttled up to 104% thrust.{{refn|group=note|The RS-25 engines had several improvements to enhance reliability and power. During the development program, Rocketdyne determined that the engine was capable of safe, reliable operation at 104% of the originally specified thrust. To keep the engine thrust values consistent with previous documentation and software, NASA kept the originally specified thrust at 100%, but had the RS-25 operate at higher thrust.BOOK, Baker, David, David Baker (author), NASA Space Shuttle: Owners' Workshop Manual, Haynes Manual, 2011, Somerset, UK, 978-1-84425-866-6, {{rp|106–107}}}} In response to Covey, Scobee said, "Roger, go at throttle up"; this was the last communication from Challenger on the air-to-ground loop.{{r|timeline}}

Vehicle breakup

(File:LOX Tank Rupture - GPN-2000-001426.jpg|thumb|Challenger is enveloped in flaming liquid propellant after rupture of the liquid oxygen tank)At {{nowrap|T+72.284}}, the right SRB pulled away from the aft strut that attached it to the ET, causing lateral acceleration that was felt by the crew. At the same time, pressure in the LH2 tank began dropping. Pilot Mike Smith said "Uh-oh," which was the last crew comment recorded. At {{nowrap|T+73.124}}, white vapor was seen flowing away from the ET, after which the aft dome of the LH2 tank fell off. The resulting release of all liquid hydrogen in the tank pushed the LH2 tank forward into the liquid oxygen (LOX) tank with a force equating to roughly {{Convert|3000000|lbf|MN|abbr=off}}, while the right SRB collided with the intertank structure.These events resulted in an abrupt change to the shuttle stack's attitude and direction, which was shrouded from view by the vaporized contents of the now-destroyed ET. As it traveled at Mach 1.92, Challenger took aerodynamic forces it was not designed to withstand and broke into several large pieces: a wing, the (still firing) main engines, the crew cabin and hypergolic fuel leaking from the ruptured reaction control system were among the parts identified exiting the vapor cloud. The disaster unfolded at an altitude of {{convert|46000|ft|km}}.{{r|timeline}}{{r|rogers_com}}{{rp|21}} Both SRBs survived the breakup of the shuttle stack and continued flying, now unguided by the attitude and trajectory control of their mothership, until their flight termination systems were activated at {{nowrap|T+110}}.{{r|rogers_com}}{{rp|30}}

Post-breakup flight controller dialogue

File:STS-51L riadiace stredisko.jpg|thumb|alt=View along the computers banks in the mission control center and a flight controller sitting in front of a terminalAt {{nowrap|T+73.191}}, there was a burst of static on the air-to-ground loop as the vehicle broke up, which was later attributed to ground-based radios searching for a signal from the destroyed spacecraft. NASA Public Affairs Officer Steve Nesbitt was initially unaware of the explosion and continued to read out flight information. At {{nowrap|T+89}}, after video of the explosion was seen in Mission Control, the Ground Control Officer reported "negative contact (and) loss of downlink" as they were no longer receiving transmissions from Challenger.{{r|timeline}}Nesbitt stated, "Flight controllers here are looking very carefully at the situation. Obviously a major malfunction. We have no downlink." Soon afterwards, he said, "We have a report from the Flight Dynamics Officer that the vehicle has exploded. The flight director confirms that. We are looking at checking with the recovery forces to see what can be done at this point."{{r|timeline}}In Mission Control, flight director Jay Greene ordered that contingency procedures be put into effect,{{r|timeline}} which included locking the doors, shutting down telephone communications, and freezing computer terminals to collect data from them.{{r|mcdonald}}{{rp|122}}

Cause and time of death

(File:Challenger breakup cabin.jpg|thumb|The forward section of the fuselage after breakup, indicated by the arrow|alt=A trapezoidal gray section of the shuttle among several plumes of smoke and vapor against the blue sky)The crew cabin, which was made of reinforced aluminum, separated in one piece from the rest of the orbiter.WEB, Barbree, Jay, Jay Barbree, January 1997, Chapter 5: An eternity of descent,weblink live,weblink" title="web.archive.org/web/20200923225813weblink">weblink September 23, 2020, October 31, 2020, NBC News, It then traveled in a ballistic arc, reaching the apogee of {{convert|65000|ft|km}} approximately 25 seconds after the explosion. At the time of separation, the maximum acceleration is estimated to have been between 12 and 20 times that of gravity (g). Within two seconds it had dropped below 4{{nbsp}}g, and within ten seconds the cabin was in free fall. The forces involved at this stage were probably insufficient to cause major injury to the crew.At least some of the crew were alive and conscious after the breakup, as Personal Egress Air Packs (PEAPs) were activated for Smith{{r|Mullane}}{{rp|246}} and two unidentified crewmembers, but not for Scobee. The PEAPs were not intended for in-flight use, and the astronauts never trained with them for an in-flight emergency. The location of Smith's activation switch, on the back side of his seat, indicated that either Resnik or Onizuka likely activated it for him. Investigators found their remaining unused air supply consistent with the expected consumption during the post-breakup trajectory.{{r|Mullane}}{{rp|245–247}}While analyzing the wreckage, investigators discovered that several electrical system switches on Smith's right-hand panel had been moved from their usual launch positions. The switches had lever locks on top of them that must be pulled out before the switch could be moved. Later tests established that neither the force of the explosion nor the impact with the ocean could have moved them, indicating that Smith made the switch changes, presumably in a futile attempt to restore electrical power to the cockpit after the crew cabin detached from the rest of the orbiter.BOOK, Mullane, Mike, Mike Mullane, Riding Rockets: The Outrageous Tales of a Space Shuttle Astronaut,weblink live, Simon and Schuster, 2006, December 31, 2018,weblink June 12, 2020, 978-0-7432-7682-5, {{rp|245}}On July 28, 1986, NASA's Associate Administrator for Space Flight, former astronaut Richard H. Truly, released a report on the deaths of the crew from physician and Skylab 2 astronaut Joseph P. Kerwin:{{blockquote|The findings are inconclusive. The impact of the crew compartment with the ocean surface was so violent that evidence of damage occurring in the seconds which followed the disintegration was masked. Our final conclusions are:

• the cause of death of the Challenger astronauts cannot be positively determined;
• the forces to which the crew were exposed during Orbiter breakup were probably not sufficient to cause death or serious injury; and
• the crew possibly, but not certainly, lost consciousness in the seconds following Orbiter breakup due to in-flight loss of crew module pressure.}}

Pressurization could have enabled consciousness for the entire fall until impact. The crew cabin hit the ocean surface at {{convert|207|mph|km/h|abbr=on}} approximately two minutes and 45 seconds after breakup. The estimated deceleration was {{val|200|u=g}}, far exceeding structural limits of the crew compartment or crew survivability levels. The mid-deck floor had not suffered buckling or tearing, as would result from a rapid decompression, but stowed equipment showed damage consistent with decompression, and debris was embedded between the two forward windows that may have caused a loss of pressure. Impact damage to the crew cabin was severe enough that it could not be determined whether the crew cabin had previously been damaged enough to lose pressurization.WEB, Kerwin, Joseph P., Joseph P. Kerwin, Joseph P. Kerwin to Richard H. Truly, July 28, 1986,weblink NASA, August 2, 2021, January 3, 2013,weblink live,

Prospect of crew escape

{{further-text|Shuttle ejection escape systems, Post-Challenger abort enhancements}}Unlike other spacecraft, the Space Shuttle did not allow for crew escape during powered flight. Launch escape systems had been considered during development, but NASA's conclusion was that the Space Shuttle's expected high reliability would preclude the need for one.{{r|rogers_com}}{{rp|181}} Modified SR-71 Blackbird ejection seats and full pressure suits were used for the two-person crews on the first four Space Shuttle orbital test flights, but they were disabled and later removed for the operational flights.{{r|jenkins2016}}{{rp|II-7}} Escape options for the operational flights were considered but not implemented due to their complexity, high cost, and heavy weight.{{r|rogers_com}}{{rp|181}} After the disaster, a system was implemented to allow the crew to escape in gliding flight, but this system would not have been usable to escape an explosion during ascent.WEB, Implementation of the Recommendations of the Presidential Commission on the Space Shuttle Challenger Accident, Recommendation VII, June 1987,weblink NASA, August 3, 2021, February 24, 2021,weblink live,

Recovery of debris and crew

Immediately after the disaster, the NASA Launch Recovery Director launched the two SRB recovery ships, MV Freedom Star and MV Liberty Star, to proceed to the impact area to recover debris, and requested the support of US military aircraft and ships. Owing to falling debris from the explosion, the RSO kept recovery forces from the impact area until 12:37{{nbsp}}p.m. The size of the recovery operations increased to 12 aircraft and 8 ships by 7:00{{nbsp}}p.m. Surface operations recovered debris from the orbiter and external tank. The surface recovery operations ended on February{{nbsp}}7.BOOK, O'Connor, Jr., Edward A., Report of the Presidential Commission on the Space Shuttle Challenger Accident., Volume 3, Appendix O: NASA Search, Recovery and Reconstruction Task Force Team Report, June 6, 1986,weblink August 5, 2021, March 1, 2021,weblink live, On January{{nbsp}}31, the US Navy was tasked with submarine recovery operations.{{r|usn_salvage_report}}{{rp|5}} The search efforts prioritized the recovery of the right SRB, followed by the crew compartment, and then the remaining payload, orbiter pieces, and ET.{{r|usn_salvage_report}}{{rp|16}} The search for debris formally began on February{{nbsp}}8 with the rescue and salvage ship {{USS|Preserver|ARS-8|6}}, and eventually grew to sixteen ships, of which three were managed by NASA, four by the US Navy, one by the US Air Force and eight by independent contractors.{{r|usn_salvage_report}}{{rp|4–5}} The surface ships used side-scan sonar to make the initial search for debris and covered {{convert|486|sqnmi|km2}} at water depths between {{convert|70|ft|sp=us}} and {{convert|1200|ft|sp=us}}.WEB,weblink Space Shuttle Challenger Salvage Report, April 29, 1988, Department of the Navy, Direction of Commander, Naval Sea Systems Command, July 19, 2021, September 1, 2021,weblink live, {{rp|24}} The sonar operations discovered 881 potential locations for debris, of which 187 pieces were later confirmed to be from the orbiter.{{r|usn_salvage_report}}{{rp|24}}(File:STS-51-L Recovered Debris (Burn Marks on the SRM) - GPN-2004-00004.jpg|thumb|Right SRB debris showing the hole caused by the plume|alt=The field joint of a solid rocket booster on the deck of a ship with a large hole in it)The debris from the SRBs was widely distributed due to the detonation of their linear shaped charges. The identification of SRB material was primarily conducted by crewed submarines and submersibles. The vehicles were dispatched to investigate potential debris located during the search phase.{{r|usn_salvage_report}}{{rp|32}} Surface ships lifted the SRB debris with the help of technical divers and underwater remotely operated vehicles to attach the necessary slings to raise the debris with cranes.{{r|usn_salvage_report}}{{rp|37, 42}} The solid propellant in the SRBs posed a risk, as it became more volatile after being submerged. Recovered portions of the SRBs were kept wet during recovery, and their unused propellant was ignited once they were brought ashore. The failed joint on the right SRB was first located on sonar on March{{nbsp}}1. Subsequent dives to {{convert|560|ft|m|abbr=on}} by the {{ship|American submarine|NR-1||2}} submarine on April{{nbsp}}5 and the SEA-LINK I submersible on April{{nbsp}}12 confirmed that it was the damaged field joint,{{r|usn_salvage_report}}{{rp|42}} and it was successfully recovered on April{{nbsp}}13. Of the {{convert|196726|lbs|kg|abbr=on}} of both SRB shells, {{convert|102500|lbs|kg|abbr=on}} was recovered, another {{convert|54000|lbs|kg|abbr=on}} was found but not recovered, and {{convert|40226|lbs|kg|abbr=on}} was never found.{{r|usn_salvage_report}}{{rp|44}}On March 7, Air Force divers identified potential crew compartment debris, which was confirmed the next day by divers from the USS Preserver.{{r|usn_salvage_report}}{{rp|51}}WEB,weblink Chapter 6: Raising heroes from the sea, NBC News, Barbree, Jay, January 25, 2004, August 9, 2021, June 5, 2019,weblink" title="web.archive.org/web/20190605131432weblink">weblink live, The damage to the crew compartment indicated that it had remained largely intact during the initial explosion but was extensively damaged when it impacted the ocean.{{r|rogers o}} The remains of the crew were badly damaged from impact and submersion, and were not intact bodies.NEWS,weblink Remains of Crew Of Shuttle Found, The Washington Post, Isikoff, Michael, March 10, 1986, August 9, 2021, February 11, 2021,weblink live, The USS Preserver made multiple trips to return debris and remains to port, and continued crew compartment recovery until April{{nbsp}}4.{{r|usn_salvage_report}}{{rp|51}} During the recovery of the remains of the crew, Jarvis's body floated away and was not located until April{{nbsp}}15, several weeks after the other remains had been positively identified.{{r|msnbc_remains}}WEB, Schmidt, William E., All Shuttle Crew Remains Recovered, NASA Says,weblink live, The New York Times, April 20, 1986, August 9, 2021,weblink July 15, 2021, Once remains were brought to port, pathologists from the Armed Forces Institute of Pathology worked to identify the human remains, but could not determine the exact cause of death for any of them.{{r|wp_remains}}{{r|kerwin}} Medical examiners in Brevard County disputed the legality of transferring human remains to US military officials to conduct autopsies, and refused to issue the death certificates; NASA officials ultimately released the death certificates of the crew members.NEWS, Shuttle Crew Said to Have Survived Blast,weblink live, The Washington Post, November 12, 1988, August 11, 2021,weblink August 18, 2020, The IUS that would have been used to boost the orbit of the TDRS-B satellite was one of the first pieces of debris recovered.{{r|usn_salvage_report}}{{rp|51}} There was no indication that there had been premature ignition of the IUS, which had been one of the suspected causes for the disaster.{{r|rogers_com}}{{rp|50}} Debris from the three SSMEs was recovered from February{{nbsp}}14 to{{nbsp}}28,{{r|usn_salvage_report}}{{rp|51}} and post-recovery analysis produced results consistent with functional engines suddenly losing their LH2 fuel supply.{{r|rogers o}} Deepwater recovery operations continued until April{{nbsp}}29, with smaller scale, shallow recovery operations continuing until August{{nbsp}}29.{{r|usn_salvage_report}}{{rp|53}} On December 17, 1996, two pieces of the orbiter were found at Cocoa Beach.NEWS, December 17, 1996, Shuttle Challenger debris washes up on shore,weblink live,weblink" title="web.archive.org/web/20160806053827weblink">weblink August 6, 2016, July 15, 2021, CNN, On November 10, 2022, NASA announced that a {{convert|20|ft|m|adj=on|0}} piece of the shuttle had been found near the site of a destroyed World War II-era aircraft off the coast of Florida.NEWS, Divers discover Challenger space shuttle debris, en-GB, BBC News,weblink November 11, 2022, November 11, 2022,weblink live, WEB, Dunn, Marcia, Section of destroyed shuttle Challenger found on ocean floor,weblink AP News, November 10, 2022, November 10, 2022, November 10, 2022,weblink live, WEB, Bardan, Roxana, November 10, 2022, NASA Views Images, Confirms Discovery of Shuttle Challenger Artifact,weblink November 11, 2022, NASA, November 11, 2022,weblink live, NEWS, Diaz, Jaclyn, A piece of the wrecked 1986 Challenger space shuttle was found off Florida's coast,weblink November 13, 2022, NPR, November 11, 2022, November 13, 2022,weblink live, NEWS, Evans, Greg, Long-Missing Space Shuttle Challenger Wreckage Found On Ocean Floor By History Channel Filmmakers, Nasa Confirms,weblink November 13, 2022, Deadline Hollywood, November 10, 2022, November 13, 2022,weblink live, The discovery was aired on the History Channel on November 22, 2022.NEWS, Television, Hearst, Artifact from Space Shuttle Challenger found on ocean floor, NASA confirms,weblink November 13, 2022, Houston Chronicle, November 11, 2022, November 13, 2022,weblink live, Almost all recovered non-organic debris from Challenger is buried in Cape Canaveral Space Force Station missile silos at LC-31 and LC-32.WEB

Funeral ceremonies

On April 29, 1986, the astronauts' remains were transferred on a C-141 Starlifter aircraft from Kennedy Space Center to the military mortuary at Dover Air Force Base in Delaware. Their caskets were each draped with an American flag and carried past an honor guard and followed by an astronaut escort.WEB , Resnik was cremated and her ashes were scattered over the water.WEB, Some Fear Learning How Loved Ones Died : Crew Discovery Upsets Shuttle Kin, Los Angeles Times, March 16, 1986,weblink February 11, 2024

Public response

White House response

(File:President Ronald Reagan's Speech on Space Shuttle Challenger, January 28, 1986.webm|thumb|President Ronald Reagan's Speech on Space Shuttle Challenger, January 28, 1986)President Ronald Reagan had been scheduled to give the 1986 State of the Union Address on January{{nbsp}}28,{{nbsp}}1986, the evening of the Challenger disaster. After a discussion with his aides, Reagan postponed the State of the Union, and instead addressed the nation about the disaster from the Oval Office.BOOK, Words of a Century: The Top 100 American Speeches, 1900–1999, Stephen E., Lucas, Martin J., Medhurst, 978-0-19-516805-1, 2008, Oxford University Press, WEB, Ronald Reagan Presidential Library,weblink Address to the Nation on the Explosion of the Space Shuttle Challenger, January 28, 1986, July 29, 2021, March 22, 2021,weblink live, On January{{nbsp}}31, Ronald and Nancy Reagan traveled to the Johnson Space Center to speak at a memorial service honoring the crew members. During the ceremony, an Air Force band sang "God Bless America" as NASA T-38 Talon jets flew directly over the scene in the traditional missing-man formation.NEWS, Weintraub, Bernard, February 1, 1986, Reagan Pays Tribute to 'Our 7 Challenger Heroes',weblink live,weblink" title="web.archive.org/web/20170201045658weblink">weblink February 1, 2017, February 12, 2017, The New York Times, A1, File:President Ronald Reagan and Nancy Reagan and families of the "Challenger" victims at the memorial service for the space shuttle crew in Houston Texas.jpg|thumb|President Reagan and First LadyFirst LadySoon after the disaster, US politicians expressed concern that White House officials, including Chief of Staff Donald Regan and Communications Director Pat Buchanan, had pressured NASA to launch Challenger before the scheduled January 28 State of the Union address, because Reagan had planned to mention the launch in his remarks.WEB, Boyd, Gerald M., White House Finds no Pressure to Launch,weblink live, The New York Times, April 4, 1986, August 11, 2021,weblink August 11, 2021, WEB, Hunt, Terence, NASA Suggested Reagan Hail Challenger Mission in State of Union,weblink live, Associated Press, March 13, 1986, August 24, 2021,weblink August 30, 2021, In March 1986, the White House released a copy of the original State of the Union speech. In that speech, Reagan had intended to mention an X-ray experiment launched on Challenger and designed by a guest he had invited to the address, but he did not further discuss the Challenger launch.BOOK,weblink Ronald Reagan and the Space Frontier, Logsdon, John M., 2018, Springer, 978-3-319-98962-4, 283, November 21, 2020, February 4, 2021,weblink live, In the rescheduled State of the Union address on February 4, Reagan mentioned the deceased Challenger crew members and modified his remarks about the X-ray experiment as "launched and lost".WEB,weblink Address Before a Joint Session of Congress on the State of the Union – 1986, July 19, 2021, February 4, 1986, Reagan, Ronald, Ronald Reagan, Ronald Reagan Presidential Library & Museum, July 19, 2021,weblink live, In April{{nbsp}}1986, the White House released a report that concluded there had been no pressure from the White House for NASA to launch Challenger prior to the State of the Union.{{r|nyt_sotu}}

Media coverage

Nationally televised coverage of the launch and explosion was provided by CNN.WEB

Engineering case study

The Challenger accident has been used as a case study for subjects such as engineering safety, the ethics of whistleblowing, communications and group decision-making, and the dangers of groupthink.JOURNAL

Reports

Rogers Commission Report

The Presidential Commission on the Space Shuttle Challenger Accident, also known as the Rogers Commission after its chairman, was formed on February{{nbsp}}6.{{r|rogers_com}}{{rp|206}} Its members were Chairman William P. Rogers, Vice Chairman Neil Armstrong, David Acheson, Eugene Covert, Richard Feynman, Robert Hotz, Donald Kutyna, Sally Ride, Robert Rummel, Joseph Sutter, Arthur Walker, Albert Wheelon, and Chuck Yeager.{{r|rogers_com}}{{rp|iii-iv}}The commission held hearings that discussed the NASA accident investigation, the Space Shuttle program, and the Morton Thiokol recommendation to launch despite O-ring safety issues. On February{{nbsp}}15, Rogers released a statement that established the commission's changing role to investigate the accident independent of NASA due to concerns of the failures of the internal processes at NASA. The commission created four investigative panels to research the different aspects of the mission. The Accident Analysis Panel, chaired by Kutyna, used data from salvage operations and testing to determine the exact cause behind the accident. The Development and Production Panel, chaired by Sutter, investigated the hardware contractors and how they interacted with NASA. The Pre-Launch Activities Panel, chaired by Acheson, focused on the final assembly processes and pre-launch activities conducted at KSC. The Mission Planning and Operations Panel, chaired by Ride, investigated the planning that went into mission development, along with potential concerns over crew safety and pressure to adhere to a schedule. Over a period of four months, the commission interviewed over 160 individuals, held at least 35 investigative sessions, and involved more than 6,000 NASA employees, contractors, and support personnel.{{r|rogers_com}}{{rp|206−208}} The commission published its report on June 6, 1986.{{r|rogers_com}}{{rp|iii-iv}}File:Rogers Commission members arrive at Kennedy Space Center.jpg|thumb|Members of the Rogers Commission arrive at alt=Black-and-white photo of a group of individuals at the Kennedy Space Center with the rocket garden behind themThe commission determined that the cause of the accident was hot gas blowing past the O-rings in the field joint on the right SRB, and found no other potential causes for the disaster.{{r|rogers_com}}{{rp|71}} It attributed the accident to a faulty design of the field joint that was unacceptably sensitive to changes in temperature, dynamic loading, and the character of its materials.{{r|rogers_com}}{{rp|73}} The report was critical of NASA and Morton Thiokol, and emphasized that both organizations had overlooked evidence that indicated the potential danger with the SRB field joints. It noted that NASA accepted the risk of O-ring erosion without evaluating how it could potentially affect the safety of a mission.{{r|rogers_com}}{{rp|149}} The commission concluded that the safety culture and management structure at NASA were insufficient to properly report, analyze, and prevent flight issues.{{r|rogers_com}}{{rp|162}} It stated that the pressure to increase the rate of flights negatively affected the amount of training, quality control, and repair work that was available for each mission.{{r|rogers_com}}{{rp|177}}The commission published a series of recommendations to improve the safety of the Space Shuttle program. It proposed a redesign of the joints in the SRB that would prevent gas from blowing past the O-rings. It also recommended that the program's management be restructured to keep project managers from being pressured to adhere to unsafe organizational deadlines, and should include astronauts to address crew safety concerns better. It proposed that an office for safety be established reporting directly to the NASA administrator to oversee all safety, reliability, and quality assurance functions in NASA programs. Additionally, the commission addressed issues with overall safety and maintenance for the orbiter, and it recommended the addition of the means for the crew to escape during controlled gliding flight.{{r|rogers_com}}{{rp|198–200}}During a televised hearing on February{{nbsp}}11, Feynman demonstrated the loss of rubber's elasticity in cold temperatures using a glass of cold water and a piece of rubber, for which he received media attention. Feynman, a Nobel Prize-winning physicist, advocated for harsher criticism towards NASA in the report and repeatedly disagreed with Rogers. He threatened to remove his name from the report unless it included his personal observations on reliability, which appeared as Appendix F.WEB

US House Committee report

The US House Committee on Science and Technology conducted an investigation of the Challenger disaster and released a report on October{{nbsp}}29, 1986.WEB, October 29, 1986, Investigation of the Challenger Accident; Report of the Committee on Science and Technology, House of Representatives,weblink live,weblink August 13, 2021, August 26, 2021, US House Committee on Science and Technology, US Government Printing Office, {{rp|i}} The committee, which had authorized the funding for the Space Shuttle program, reviewed the findings of the Rogers Commission as part of its investigation. The committee agreed with the Rogers Commission that the failed SRB field joint was the cause of the accident, and that NASA and Morton Thiokol failed to act despite numerous warnings of the potential dangers of the SRB. The committee's report further emphasized safety considerations of other components and recommended a risk management review for all critical systems.{{r|House Committee}}{{rp|2–5}}

NASA response

SRB redesign

In response to the commission's recommendation, NASA initiated a redesign of the SRB, later named the redesigned solid rocket motor (RSRM), which was supervised by an independent oversight group.{{r|rogers_com}}{{rp|198}}{{r|jenkins2016}}{{rp|III-101}}WEB, Report to the President: Actions to Implement the Recommendations of the Presidential Commission on the Space Shuttle Challenger Accident, NASA, July 14, 1986,weblink July 19, 2021, February 24, 2021,weblink live, The redesigned joint included a capture feature on the tang around the interior wall of the clevis to prevent joint rotation. The space between the capture feature and the clevis was sealed with another O-ring. The capture feature reduced the potential of joint rotation to 15% of that which had occurred during the disaster. Should joint rotation occur, any rotation that reduced the O-ring seal on one side of the clevis wall would increase it on the other side. Additionally, heaters were installed to maintain consistent, higher temperatures of the O-rings.{{r|mcdonald}}{{rp|429–430}} The RSRM was first tested on August 30, 1987. In April and August 1988, the RSRM was tested with intentional flaws that allowed hot gas to penetrate the field joint. These tests permitted the engineers to evaluate whether the improved field joint prevented joint rotation. Following the successful tests, the RSRM was certified to fly on the Space Shuttle.{{r|jenkins2016}}{{rp|III-101}}

Space Shuttle modifications

In addition to the SRBs, NASA increased the safety standards on other Space Shuttle program components. The critical items lists and failure modes for the SSMEs were updated, along with 18 hardware changes. The maximum thrust of the SSMEs was limited to 104%, with 109% only allowed in an abort scenario.{{r|jenkins2016}}{{rp|II-172}} The landing gear was updated to improve its steering and handling abilities while the Space Shuttle was landing.{{r|jenkins2016}}{{rp|III-104}} NASA implemented an escape option in which the astronauts would jettison the side hatch and extend a pole out of the orbiter; they would slide down the pole to avoid hitting the orbiter as bailed out before they activated their parachutes. The orbiter's software was modified to maintain stable flight while all of the flight crew left the controls to escape.{{r|jenkins2016}}{{rp|III-103}} This escape method would not have saved the crew in the Challenger disaster, but was added in the event of another emergency.{{r|jenkins2016}}{{rp|III-102}}

Safety office

In 1986 NASA created a new Office of Safety, Reliability, and Quality Assurance, headed by a NASA associate administrator who reported directly to the NASA administrator, as the commission had specified.{{r|rogers_com}}{{rp|199}}{{r|recommendation_7}}WEB

Teacher in Space

The Teacher in Space program, which McAuliffe had been selected for, was canceled in 1990 as a result of the Challenger disaster. In 1998, NASA replaced Teacher in Space with the Educator Astronaut Project, which differed in that it required the teachers to become professional astronauts trained as mission specialists, rather than short-term payload specialists who would return to their classrooms following their spaceflight. Barbara Morgan, who had been the backup teacher for McAuliffe, was selected to be part of NASA Astronaut Group 17 and flew on STS-118.{{r|jenkins2016}}{{rp|III-116}}

Return to flight

{{Further-text| Space Shuttle program | STS-26 }}The projected launch schedule of 24 per year was criticized by the Rogers Commission as an unrealistic goal that created unnecessary pressure on NASA to launch missions.{{r|rogers_com}}{{rp|165}} In August 1986, President Reagan approved the construction of an orbiter, which would later be named {{OV|105|full=no}}, to replace Challenger. Construction of Endeavour began in 1987 and was completed in 1990, and it first flew on STS-49 in May 1992.WEB The Space Shuttle fleet was grounded for two years and eight months while the program underwent investigation, redesign, and restructuring. On September 29, 1988, Discovery launched on STS-26 mission from LC-39B with a crew of five veteran astronauts.WEB, John A., Logsdon,weblink NASA, Return to Flight: Richard H. Truly and the Recovery from the Challenger Accident, July 27, 2021, 1998, February 24, 2021,weblink live, Its payload was TDRS-3, which was a substitute for the satellite lost with Challenger. The launch tested the redesigned boosters, and the crew wore pressure suits during the ascent and reentry. The mission was a success, and the program resumed flying.WEB

Legacy

(File:Challenger Disaster Memorial KSC-9.jpg|thumb|Fragment of Challenger{{'}}s fuselage on display at the Kennedy Space Center Visitor Complex|alt=A portion of the Challenger's fuselage hanging vertically, displaying the American flag.)In 2004, President George W. Bush conferred posthumous Congressional Space Medals of Honor to all 14 crew members killed in the Challenger and Columbia accidents.WEB,weblink Congressional Space Medal of Honor, NASA, April 28, 2006, July 19, 2021, February 20, 2011,weblink" title="web.archive.org/web/20110220213828weblink">weblink live, An unpainted decorative oval in the Brumidi Corridors of the United States Capitol was finished with a portrait depicting the crew by Charles Schmidt in 1987. The scene was painted on canvas and then applied to the wall.WEB, Brumidi Corridors Murals, 2021,weblink Architect of the Capitol, July 19, 2021, August 31, 2021,weblink live, The "Forever Remembered" exhibit at the Kennedy Space Center Visitor Complex opened in July 2015 and includes a display of a {{convert|12|ft|m|adj=on}} section of Challenger{{'}}s recovered fuselage. The exhibit was opened by NASA Administrator Charles Bolden along with family members of the crew.{{r|jenkins2016}}{{rp|III-97}} A tree for each astronaut was planted in NASA's Astronaut Memorial Grove at the Johnson Space Center, along with trees for each astronaut from the Apollo 1 and Columbia disasters.NEWS Seven asteroids were named after the crew members: {{MoMP|3350|3350 Scobee}}, {{MoMP|3351|3351 Smith}}, {{MoMP|3352|3352 McAuliffe}}, {{MoMP|3353|3353 Jarvis}}, {{MoMP|3354|3354 McNair}}, {{MoMP|3355|3355 Onizuka}}, and {{MoMP|3356|3356 Resnik}}. The approved naming citation was published by the Minor Planet Center on March 26, 1986 ({{small|M.P.C. 10550}}).WEB , In 1988, seven craters on the far side of the Moon, within the Apollo Basin, were named after the astronauts by the IAU.BOOK, Byrne, Charles,weblink The Far Side of the Moon A Photographic Guide, 2014, Springer Science, 978-1-4899-8806-5, 1244446759, June 27, 2022, January 28, 2024,weblink live, The Soviet Union named two craters on Venus after McAuliffe and Resnik.WEB File:ChallengerPlaque-20231125.jpg|thumb|Plaque at TRW's Space ParkSpace ParkSeveral memorials have been established in honor of the Challenger disaster. The public Peers Park in Palo Alto, California, features the Challenger Memorial Grove including redwood trees grown from seeds carried aboard Challenger in 1985.WEB,weblink January 14, 2021, City of Palo Alto, California, Peers Park, July 19, 2021, July 19, 2021,weblink live, Schools and streets have been renamed to include the names of the crew or Challenger.WEB The crew's families established the Challenger Center for Space Science Education as an educational non-profit organization.WEB An American flag, later named the Challenger flag, was carried aboard the Challenger. It was sponsored by Boy Scout Troop 514 of Monument, Colorado, and was recovered intact, still sealed in its plastic container.WEB,weblink Rising from the ashes, Garmon, Jay, January 24, 2006, Tech Republic, July 19, 2021, July 12, 2021,weblink live, Onizuka had included a soccer ball with his personal effects that was recovered and later flown to the International Space Station aboard Soyuz Expedition 49 by American astronaut Shane Kimbrough. It is on display at Clear Lake High School in Houston, which was attended by Onizuka's children.WEB, Malinowski, Tonya, June 29, 2018, NASA astronaut Ellison Onizuka's soccer ball that survived the Challenger explosion,weblink ESPN, July 19, 2021, August 20, 2021,weblink live, The 1986 motion picture (Star Trek IV: The Voyage Home) was dedicated to the crew of the Challenger with an opening message which stated "The cast and crew of Star Trek wish to dedicate this film to the men and women of the spaceship Challenger whose courageous spirit shall live to the 23rd century and beyond..."WEB,weblink Star Trek IV The Voyage Home (1986), Musings From Us, January 25, 2011, January 28, 2022, February 2, 2022,weblink live,

In media

Books

In the years immediately after the Challenger disaster, several books were published describing the factors and causes of the accident and the subsequent investigation and changes. In 1987, Malcolm McConnell, a journalist and a witness of the disaster, published Challenger–A Major Malfunction: A True Story of Politics, Greed, and the Wrong Stuff. McConnell's book was criticized for arguing for a conspiracy involving NASA Administrator Fletcher awarding the contract to Morton Thiokol because it was from his home state of Utah.{{r|mcdonald}}{{rp|588}}JOURNAL, Tomayko, James E., June 1987, Challenger: A Major Malfunction,weblink Aerospace Historian, 34, 2, 139, October 5, 2021, Air Force Historical Foundation, 44524264, October 5, 2021,weblink live, The book Prescription for Disaster: From the Glory of Apollo to the Betrayal of the Shuttle by Joseph Trento was also published in 1987, arguing that the Space Shuttle program had been a flawed and politicized program from its inception.{{r|mcdonald}}{{rp|588–589}}JOURNAL, Hallion, Richard P., June 1987, Prescription for Disaster: From the Flory of Apollo to the Betrayal of the Shuttle,weblink Aerospace Historian, 345, 2, 151, October 5, 2021, Air Force Historical Foundation, 44525431, October 5, 2021,weblink live, In 1988, Feynman's memoir, (What Do You Care What Other People Think?|"What Do You Care What Other People Think?": Further Adventures of a Curious Character), was published. The latter half of the book discusses his involvement in the Rogers Commission and his relationship with Kutyna.{{r|mcdonald}}{{rp|594}}JOURNAL, Shair, Frederick H., June 1989, What Do You Care What Other People Think? Further Adventures of a Curious Character,weblink American Scientist, 77, 3, 267–268, October 5, 2021, Sigma Xi, 27855729, October 5, 2021,weblink live, Books were published long after the disaster. In 1996, Diane Vaughan published The Challenger Launch Decision: Risky Technology, Culture, and Deviance at NASA, which argues that NASA's structure and mission, rather than just Space Shuttle program management, created a climate of risk acceptance that resulted in the disaster.{{r|mcdonald}}{{rp|591–592}}JOURNAL, Weick, Karl E., June 1997, The Challenger Launch Decision: Risky Technology, Culture, and Deviance at NASA,weblink Administrative Science Quarterly, 42, 2, 395–401, October 5, 2021, Sage Publications, 10.2307/2393925, 2393925, October 5, 2021,weblink live, Also in 1996, Claus Jensen published No Downlink: A Dramatic Narrative About the Challenger Accident and Our Time that primarily discusses the development of rocketry prior to the disaster, and was criticized for its reliance on secondary sources with little original research conducted for the book.{{r|mcdonald}}{{rp|592}}WEB

Film and television

The ABC television movie titled Challenger was broadcast on February 25, 1990.WEB The four-part docuseries (Challenger: The Final Flight), created by Steven Leckart and Glen Zipper, was released by Netflix on September 16, 2020. It uses interviews with NASA and Morton Thiokol personnel to argue against their flawed decision-making which produced a preventable disaster.WEB The first episode of the Australian television drama The Newsreader, broadcast on August 15, 2021, depicts the disaster from the perspective of the television industry, specifically the journalists and crew within, and of, an Australian television newsroom at the time; a co-lead character's hosting of a newsflash weaving in with an overarching background storyline about the shift in news presentation from serious to that of allowing emotion into its delivery.EPISODE, Three, Two, One..., The Newsreader#ep1, The Newsreader, Michael, Lucas, ABC (Australian TV network), ABC Television, August 15, 2021, 1, 1, The first episode of Season 6 of the television drama series This Is Us, titled "The Challenger"EPISODE, The Challenger, This Is Us#ep89, This Is Us, NBC, January 4, 2022, 6, 1, features the incident of the explosion in 1986 in the flashback scenes.

See also

• Criticism of the Space Shuttle program
• Normalization of deviance
• Engineering disasters
• List of spaceflight-related accidents and incidents
• PEPCON disaster

Notes

{{reflist|group=note}}

References

{{Reflist}}

External links

{{Commons category|Space Shuttle Challenger disaster}}

• Rogers Commission Report NASA webpage (crew tribute, five report volumes and appendices)
• {{librivox book | title=Report to the President by the Presidential Commission on the Space Shuttle Challenger Accident}}
• Complete text and audio and video of Ronald Reagan's Shuttle Challenger Address to the Nation
• {{YouTube|id=oEifG9H8eWs|title=Space Shuttle Challenger Tragedy}} – video of shuttle launch and Reagan's address
• {{YouTube|id=2FehGJQlOf0|title=Challenger: A Rush to Launch}}, an Emmy Award-winning documentary about flight STS-51-L and what caused the Challenger explosion
• weblink" title="web.archive.org/web/20060127122917weblink">7 myths about the Challenger shuttle disaster: It didn't explode, the crew didn't die instantly and it wasn't inevitable MSNBC.com
• CBS Radio news bulletin of the Challenger disaster anchored by Christopher Glenn from January 28, 1986: Part 1, Part 2, Part 3, and Part 4
• Videos of the disaster
  • {{YouTube|id=peT-j9wE5gs|title=NASA video recording showing the breakup}}
  • {{YouTube|id=WIMsolc3wvY|title=video from Winter Haven, Florida}}
  • {{YouTube|id=8rkox1-c6JQ|title=from a plane leaving from Orlando International Airport}}
  • {{YouTube|id=m2nFZzLlZwU|title=8 film recorded at the Kennedy Space Center}}
  • {{YouTube|id=0ABi1YjD4CM|title=at the Kennedy Space Center}}

{{STS-51L}}{{Space Shuttle Challenger}}{{Space Shuttle}}{{Authority control}}