On January 28, 1986, the Space Shuttle Challenger broke apart 73 seconds into its flight, killing all seven crew members. The spacecraft broke apart about 46,000 feet (14 km) above the Atlantic Ocean, near Cape Canaveral, Florida, at 16:39:13 UTC (11:39:13 a.m. EST, local time). This was the first fatal accident involving an American spacecraft during flight.
The mission, called STS-51-L, was the 10th flight for the orbiter and the 25th flight of the Space Shuttle program. The crew was scheduled to launch a commercial communications satellite, study Halley’s Comet, and take schoolteacher Christa McAuliffe into space as part of the Teacher in Space Project. This mission received more media attention than usual, and many schools across the United States watched the launch and the disaster live.
The disaster happened because the primary and secondary O-ring seals in a joint of the right Solid Rocket Booster (SRB) failed. Cold temperatures on the morning of the launch made the rubber O-rings stiff, reducing their ability to seal the joint. After liftoff, hot gas from inside the SRB leaked through the joint, damaged the structure connecting it to the external fuel tank, and entered the tank. This caused the tank to collapse and the SRB to rotate, sending the shuttle stack at a speed of Mach 1.92 in a direction that led to the orbiter breaking apart. Both SRBs separated from the damaged tank and continued flying until a range safety officer sent a signal to destroy them.
The crew compartment, which contained human remains, and other pieces of the shuttle were recovered from the ocean floor after a three-month search. The exact time the crew members died is unknown, but some may have survived the initial breakup. The orbiter had no escape system, and the force of the crew compartment hitting the ocean at high speed made survival impossible.
The disaster caused a 32-month pause in the Space Shuttle program. President Ronald Reagan formed the Rogers Commission to investigate the accident. The commission found that NASA’s decision-making processes and organizational culture had contributed to the disaster. Test data since 1977 had shown a serious problem with the SRB’s O-rings, but NASA and the manufacturer, Morton Thiokol, did not fix the issue. NASA managers ignored warnings from engineers about the risks of launching in cold weather and did not share these concerns with higher officials.
Because of the disaster, NASA created the Office of Safety, Reliability, and Quality Assurance. It also began using expendable launch vehicles to send commercial satellites into space instead of using crewed shuttles. A new Space Shuttle orbiter, Endeavour, was built in 1987 to replace Challenger and first flew in 1992. Later missions used redesigned SRBs, and astronauts wore pressurized suits during launch and reentry. In February 2003, the Space Shuttle Columbia broke apart during reentry. The Columbia Accident Investigation Board found that NASA had not learned lessons from the Challenger disaster, leading to the second accident.
Background
The Space Shuttle was a spacecraft that could be used more than once. It was operated by NASA, the United States space agency. The first flight happened in April 1981. The shuttle was used to do research in space and to carry satellites, tools, and equipment for science, the military, and businesses. At launch, the shuttle had three parts: the orbiter, which carried the crew and supplies; the external tank (ET), which held fuel; and two solid rocket boosters (SRBs), which provided power during liftoff. The orbiter was a reusable, winged vehicle that launched upward and landed like a glider. Five orbiters were built during the Space Shuttle program. Challenger (OV-099) was the second orbiter made after it was changed from a test model. The orbiter had a crew compartment where the astronauts lived and worked during missions. Three main engines were attached to the back of the orbiter and helped the shuttle rise into space. After reaching orbit, the crew used two smaller engines, called the Orbital Maneuvering System (OMS), to move around in space.
At launch, the orbiter was connected to the external tank, which stored fuel for the main engines. The external tank had two sections: one for liquid hydrogen and one for liquid oxygen. These were needed for the main engines to work. Once the fuel was used up, the external tank separated from the orbiter and fell back to Earth. It broke apart during reentry and its pieces landed in the Indian or Pacific Ocean.
The two solid rocket boosters (SRBs), made by Morton Thiokol, provided most of the power during liftoff. They were attached to the external tank and burned for the first two minutes of flight. After their fuel was used, the SRBs separated from the orbiter and fell into the Atlantic Ocean. NASA teams recovered the SRBs and sent them back to the Kennedy Space Center (KSC), where they were taken apart and reused for future missions.
Each SRB was built in four parts at a factory in Utah and sent to KSC. There, they were put together in a building called the Vehicle Assembly Building. Each joint between the parts used a tang and a clevis. Around each joint, two large rubber rings called Viton-rubber O-rings were placed. These rings were needed to keep hot, high-pressure gases from escaping during the SRB’s burn. The two O-rings created a double seal, and the space between the parts was filled with putty. When the SRB burned, the design was meant to push air against the upper O-ring, pressing it tightly into place. On the SRB Critical Items List, the O-rings were labeled as Criticality 1R, meaning a failure could destroy the shuttle and cause loss of life. The secondary O-ring was considered a backup system.
Tests in the 1970s showed that the gaps between the SRB parts could cause the O-rings to be pushed out instead of compressed. NASA and Morton Thiokol decided this was acceptable, even though engineers had concerns. A 1977 test showed that the parts could move up to 0.052 inches during a simulated launch. This movement reduced pressure on the O-rings, weakening their ability to seal and allowing hot gases to damage them. NASA engineers suggested adding shims around the O-rings, but no action was taken. In 1980, NASA requested more tests on joint strength, including tests in different temperatures and with only one O-ring. Program managers decided current testing was enough. In 1982, the Critical Items List was updated to say the secondary O-ring could not act as a backup, and the O-rings were labeled as Criticality 1, meaning they were no longer considered a backup system.
The first sign of O-ring damage happened on the right SRB during the STS-2 mission in November 1981. In August 1984, an inspection of the left SRB on STS-41-D found soot between the O-rings, showing the primary O-ring was not sealing properly. The damage was not enough to stop the O-ring from working, but it showed the O-rings were not sealing well. In January 1985, the coldest shuttle launch occurred when the air temperature was 62 °F (17 °C) and the O-rings were 53 °F (12 °C). Post-flight analysis found erosion on both SRBs’ primary O-rings. Engineers said the cold made the O-rings less flexible, reducing their ability to seal. O-ring erosion happened on most 1985 shuttle flights, and both O-rings were damaged on STS-51-B.
To fix the O-ring problems, engineers at Morton Thiokol, including Allan McDonald and Roger Boisjoly, designed a new joint with a metal lip to limit movement. They also suggested adding a spacer for better heat protection and using a larger O-ring. In July 1985, Morton Thiokol ordered new SRB casings to be used for upcoming launches until redesigned parts were ready the next year.
The Space Shuttle mission named STS-51-L was the 25th shuttle flight and the 10th flight of the Challenger. The crew was announced on January 27, 1985, and led by Dick Scobee. Michael Smith was the pilot, and the mission specialists were Ellison Onizuka, Judith Resnik, and Ronald McNair. The payload specialists were Gregory Jarvis, who worked for Hughes Aircraft Company, and Christa McAuliffe, who was part of the Teacher in Space Project.
The main goal of the Challenger crew was to use an Inertial Upper Stage (IUS) to launch TDRS-B, a satellite for sending data back to Earth. The crew also planned to study Halley’s Comet and deploy and retrieve the Spartan Halley satellite.
The mission was originally planned for July 1985 but was delayed until November and then January 1986. The launch date was first set for January 22 but was postponed several times. On December 23, 1985, the launch was moved to January 23 due to delays with another mission, STS-61-C. On January 22, the mission was postponed again because of dust storms at the emergency landing site in Senegal. NASA chose an alternative site in Morocco, but the lack of runway lights there meant the shuttle could only launch when it was daytime in Morocco and morning in Florida.
Decision to launch
On January 28, the air temperature was expected to reach a record low for a Space Shuttle launch. The temperature was predicted to drop to 18 °F (−8 °C) overnight, rise to 22 °F (−6 °C) at 6:00 a.m., and reach 26 °F (−3 °C) at the scheduled launch time of 9:38 a.m. Engineers from Morton Thiokol were worried about how cold temperatures might affect the O-rings, which are rubber seals on the Space Shuttle’s solid rocket boosters (SRBs). These O-rings had shown signs of erosion during previous launches at higher temperatures, and engineers feared that the cold might make the O-rings less flexible, preventing them from forming a proper seal during launch. Morton Thiokol engineers stated they lacked enough data to confirm if the O-rings would work properly at temperatures colder than 53 °F (12 °C), the lowest temperature for a Space Shuttle launch at that time.
During a three-way teleconference on January 27 between Morton Thiokol in Utah, NASA’s Kennedy Space Center (KSC) in Florida, and the Marshall Space Flight Center in Alabama, Morton Thiokol engineers shared their concerns. Lawrence Mulloy, NASA’s SRB project manager, questioned whether Morton Thiokol would delay the launch until April for warmer temperatures. Morton Thiokol’s Vice Presidents, Robert Lund and Joe Kilminster, recommended waiting until temperatures reached above 53 °F (12 °C) before launching.
Before the teleconference paused for private discussion, Allan J. McDonald, Morton Thiokol’s director of the Space Shuttle SRM Project, reminded his colleagues to consider how the primary and secondary O-rings might interact. He believed this analysis could help address concerns about the O-rings’ reliability. When the call resumed, Morton Thiokol leadership changed their position, stating the evidence about O-ring failures was inconclusive and that there was a safety margin if a failure occurred. They decided to proceed with the launch. McDonald, as the onsite representative at KSC, refused to approve the decision, but Kilminster confirmed he would sign a recommendation to launch and fax it immediately. The teleconference ended, and Mulloy informed Arnold Aldrich, NASA’s Mission Management Team Leader, about the launch decision without mentioning the O-ring discussion. Aldrich agreed to proceed with the launch.
An overnight measurement by the KSC Ice Team showed the left SRB was 25 °F (−4 °C) and the right SRB was 8 °F (−13 °C). These temperatures were recorded for engineering data but not reported because SRB temperatures were not part of the Launch Commit Criteria. Cold temperatures also caused ice to form on the fixed service structure. To prevent pipes from freezing, water was slowly drained from the system but not fully removed due to the upcoming launch. Ice formed from 240 feet (73 m) down in the freezing temperatures. Engineers from Rockwell International, which built the orbiter, worried that ice might break loose during launch and damage the orbiter’s thermal protection system or enter one of the engines. Rocco Petrone, head of Rockwell’s space transportation division, and his team concluded the mission was unsafe due to the ice risk. Arnold Aldrich consulted with engineers at KSC and the Johnson Space Center (JSC), who said ice did not pose a threat to the orbiter. Aldrich decided to proceed with the launch.
The launch was delayed for an additional hour to allow more ice to melt. At T−20 minutes, the ice team inspected the area and found the ice was melting. At 11:38 a.m. EST, with an air temperature of 36 °F (2 °C), the Challenger was cleared for launch.
Launch and failure
At T+0, the Challenger spacecraft launched from the Kennedy Space Center Launch Complex 39B (LC-39B) at 11:38:00 a.m. From T+0.678 to T+3.375 seconds, nine puffs of dark gray smoke were recorded coming from the right-hand solid rocket booster (SRB) near the aft strut, which connected the booster to the external tank (ET). Later, it was found that these smoke puffs were caused by movement in the joint of the right-hand SRB at the moment of ignition.
Cold temperatures in the joint prevented the O-rings from sealing properly. Rain that had fallen earlier on the launchpad likely collected in the joint, making it harder for the O-rings to work. This allowed hot gas to escape and damage the O-rings. Molten aluminum oxides from the burning fuel temporarily sealed the joint again. The Space Shuttle main engines (SSMEs) reduced their power as planned to handle the highest aerodynamic pressure (max q). During the flight, the shuttle faced wind shear starting at T+37, but these conditions were within the shuttle’s design limits and were managed by the guidance system.
At T+58.788, a camera recorded the start of a plume near the right SRB’s aft strut, just before the shuttle reached max q at T+59.000. Strong aerodynamic forces and wind shear likely broke the temporary seal, letting flame escape through the joint. Within one second, the plume became clear, and the hole caused a drop in pressure inside the right SRB. A leak began in the liquid hydrogen (LH2) tank of the ET at T+64.660, as shown by changes in the plume’s shape.
The SSMEs adjusted their power to balance the unexpected thrust from the SRB burn-through. Pressure in the LH2 tank started dropping at T+66.764, showing that the flame had burned from the SRB into the tank. The crew and flight controllers did not show they noticed the problems. At T+68, CAPCOM Richard O. Covey told the crew, “Challenger, go at throttle up,” meaning the SSMEs had increased power to 104% thrust. Pilot Michael Smith responded, “Roger, go at throttle up,” which was the last communication from Challenger.
At T+72.284, the right SRB separated from the strut connecting it to the ET, causing a sideways force felt by the crew. At the same time, pressure in the LH2 tank dropped. Pilot Mike Smith said, “Uh-oh,” which was the last crew comment recorded. At T+73.124, white vapor was seen coming from the ET, and the aft dome of the LH2 tank fell off. The explosion of hydrogen in the tank pushed it forward into the liquid oxygen (LOX) tank with a force equal to about 3,000,000 pounds (13 MN), while the right SRB hit the intertank structure. This caused a boiling liquid expanding vapor explosion (BLEVE), where most of the liquid turned into gas almost instantly.
These events changed the shuttle’s direction and movement, hiding it from view by the vapor from the destroyed ET. Traveling at Mach 1.92, Challenger faced forces it was not built to handle and broke into large pieces, including the wing, main engines, crew cabin, and leaking fuel. The disaster happened at 46,000 feet (14 km). Both SRBs survived the breakup and continued flying until their flight termination systems were activated at T+110.
At T+73.191, a burst of static on the communication loop was later linked to ground radios searching for a signal from the shuttle. NASA Public Affairs Officer Steve Nesbitt was unaware of the explosion and continued sharing flight updates. At T+89, after seeing video of the explosion in Mission Control, the Ground Control Officer reported, “negative contact (and) loss of downlink,” meaning no signals from Challenger were received. Nesbitt said, “Flight controllers here are looking very carefully at the situation. Obviously a major malfunction. We have no downlink.” Soon after, he added, “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.”
In Mission Control, flight director Jay Greene ordered emergency procedures, including locking doors, shutting off phone lines, and freezing computer terminals to save data.
The crew cabin, made of reinforced aluminum, separated from the rest of the orbiter and traveled in an arc, reaching a height of 65,000 feet (20 km) about 25 seconds after the explosion. The maximum force during separation was estimated to be between 12 and 20 times gravity (g). Within two seconds, the force dropped below 4 g, and within ten seconds, the cabin was in free fall. The forces were likely not strong enough to harm the crew.
Some crew members were alive and conscious after the breakup, as Personal Egress Air Packs (PEAPs) were activated for Mike Smith and two others but not for Richard Scobee. PEAPs were not meant for use during flight, and the astronauts had no training for in-flight emergencies. Smith’s activation switch was on the back of his seat, suggesting another crew member may have turned it on for him. Investigators found unused air supplies matching expected use during the cabin’s fall.
During the investigation, switches on Smith’s panel were found moved from their usual positions. These switches had locks that needed to be pulled before moving. Tests showed the explosion or ocean impact could not have moved them, meaning Smith likely changed the switches, possibly to restore power to the cockpit after the cabin separated.
On July 28, 1986, NASA’s Associate Administrator for Space Flight, former astronaut Richard H. Truly, released a report from physician Joseph P. Kerwin about the crew’s deaths:
The cabin may have remained pressurized long enough for the crew to be conscious until impact. The cabin hit the ocean at 207 mph (333 km/h) about 2 minutes and 45 seconds after the breakup. The force of impact was estimated at 200 g, far beyond what the crew compartment or human survival could handle. The mid-deck floor showed no signs of damage from rapid decompression, but stored equipment showed signs of decompression, and debris between the forward windows may have caused pressure loss. The impact damage to the cabin was so severe that it was unclear if the cabin had been damaged earlier, leading to pressure loss.
Unlike other spacecraft, the Space Shuttle did not have a system to
Recovery of debris and crew
Immediately after the disaster, the NASA Launch Recovery Director sent two recovery ships, MV Freedom Star and MV Liberty Star, to the impact area to collect debris. The director also asked the US military for help with aircraft and ships. Because of falling debris from the explosion, the Range Safety Officer (RSO) kept recovery teams away from the impact area until 12:37 p.m. By 7:00 p.m., the recovery effort had grown to include 12 aircraft and 8 ships. Teams on the surface collected debris from the orbiter and external tank. Surface recovery operations ended on February 7.
On January 31, the US Navy was assigned to recover debris from the ocean floor. The search focused first on recovering the right SRB, then the crew compartment, and finally other debris, including parts of the orbiter and external tank. The search officially began on February 8 with the ship USS Preserver and later expanded to 16 ships, including three managed by NASA, four by the US Navy, one by the US Air Force, and eight by independent contractors. Surface ships used sound equipment to search for debris and covered an area of 486 square nautical miles (1,670 km²) in water depths between 70 and 1,200 feet (20 and 370 meters). The equipment found 881 possible debris locations, of which 187 were confirmed to be from the orbiter.
Debris from the SRBs spread far because of the explosion of their special explosives. Crewed submarines and underwater vehicles identified SRB material. These vehicles were sent to examine debris found during the search. Surface ships used technical divers and remote-controlled machines to attach slings to debris, which were then lifted with cranes. The solid fuel in the SRBs became more dangerous after being submerged. Recovered SRB parts were kept wet during recovery, and unused fuel was burned once they reached land. The damaged joint on the right SRB was first found by sonar on March 1. Later dives by the NR-1 submarine and the SEA-LINK I submersible confirmed it was the damaged joint, which was recovered on April 13. Of the 196,726 lb (89,233 kg) of SRB shells, 102,500 lb (46,500 kg) was recovered, 54,000 lb (24,000 kg) was found but not recovered, and 40,226 lb (18,246 kg) was never found.
On March 7, Air Force divers found possible debris from the crew compartment, which was confirmed the next day by divers from the USS Preserver. The damage to the crew compartment showed it had stayed mostly intact during the initial explosion but was heavily damaged when it hit the ocean. The remains of the crew were badly damaged from the impact and submersion and were not whole. The USS Preserver made several trips to return debris and remains to port, and recovery of the crew compartment continued until April 4. During this process, Jarvis’s body floated away and was not found until April 15, weeks after other remains had been identified. Once remains reached port, pathologists from the Armed Forces Institute of Pathology worked to identify them, but could not determine the exact cause of death for any of the crew. Medical examiners in Brevard County disagreed with transferring human remains to the US military for autopsies and refused to issue death certificates. NASA officials eventually released the death certificates for the crew members.
The IUS, which was meant to help launch the TDRS-B satellite, was one of the first pieces of debris recovered. There was no sign that the IUS had ignited too early, which had been one of the suspected causes of the disaster. Debris from the three SSMEs was recovered from February 14 to 28, and analysis showed the engines had suddenly lost their fuel supply. Deepwater recovery operations continued until April 29, with smaller, shallow recovery efforts lasting until August 29. On December 17, 1996, two pieces of the orbiter were found at Cocoa Beach. On November 10, 2022, NASA announced a 20-foot (6 m) piece of the shuttle was found near a World War II-era aircraft wreckage off the coast of Florida. The discovery was shown on the History Channel on November 22, 2022. Most recovered non-organic debris from Challenger is buried in missile silos at Cape Canaveral Space Force Station, at LC-31 and LC-32.
On April 29, 1986, the astronauts’ remains were transported by a C-141 Starlifter aircraft from Kennedy Space Center to the military mortuary at Dover Air Force Base in Delaware. Each casket was covered with an American flag and passed by an honor guard, followed by an astronaut escort. After arriving at Dover Air Force Base, the remains were given to the families of the crew members. Scobee and Smith were buried at Arlington National Cemetery. Onizuka was buried at the National Memorial Cemetery of the Pacific in Honolulu, Hawaii. McNair was initially buried in Rest Lawn Memorial Park in Lake City, South Carolina, but his remains were later moved to the Dr. Ronald E. McNair Memorial Park. Resnik was cremated, and her ashes were scattered over water. McAuliffe was buried at Calvary Cemetery in Concord, New Hampshire. Jarvis was cremated, and his ashes were scattered in the Pacific Ocean. Unidentified crew remains were buried at the Space Shuttle Challenger Memorial in Arlington on May 20, 1986.
Public response
President Ronald Reagan had planned to give the 1986 State of the Union Address on January 28, 1986, the same day as the Challenger disaster. After talking with his advisors, Reagan decided to delay the speech and instead gave a message about the disaster from the Oval Office. On January 31, Ronald and Nancy Reagan went to the Johnson Space Center to speak at a memorial service for the Challenger crew. During the event, an Air Force band played "God Bless America" while NASA jets flew over the space center in a traditional formation called the missing-man formation.
Soon after the disaster, some Democratic politicians said that White House officials, including Chief of Staff Donald Regan and Communications Director Pat Buchanan, had encouraged NASA to launch Challenger before the State of the Union speech because Reagan planned to mention the launch in his remarks. In March 1986, the White House shared the original version of the State of the Union speech. In that speech, Reagan had planned to mention an X-ray experiment launched on Challenger and designed by a guest invited to the speech, but he did not talk about the launch itself. In the rescheduled speech on February 4, Reagan spoke about the Challenger crew members and changed his remarks about the X-ray experiment to say it was "launched and lost." In April 1986, the White House released a report stating that no pressure had been placed on NASA to launch Challenger before the State of the Union.
The launch and explosion of Challenger were shown live on TV by CNN. To support the Teacher in Space program, which included a teacher named McAuliffe as a crew member, NASA arranged for students across the United States to watch the launch at school with their teachers. Other TV networks, like CBS, also joined in to broadcast the disaster and its effects. News coverage of the event grew quickly; the number of reporters at the Kennedy Space Center increased from 535 on the day of the launch to 1,467 three days later. After the accident, NASA was criticized for not allowing important staff members to speak with reporters. Without clear information, reporters wrote articles suggesting the external tank caused the explosion. Until 2010, CNN's live broadcast was the only known video recorded at the launch site. More videos from amateur and professional sources have since been made public. In the Soviet Union, news coverage of the disaster was described as "sad and caring" and mostly free of political comments.
The Challenger accident has been studied in subjects such as engineering safety, the ethics of whistleblowing, communication, group decision-making, and the dangers of groupthink. Roger Boisjoly and Allan McDonald became speakers who promoted responsible workplace decisions and engineering ethics. Information designer Edward Tufte argued that the Challenger accident happened because engineers did not communicate clearly and used complicated explanations. He said showing how cold weather affected parts of the shuttle could have made the risks clearer. Boisjoly and others disagreed, saying the data Tufte described was not as simple or available as he claimed.
Reports
The Presidential Commission on the Space Shuttle Challenger Accident, also called the Rogers Commission after its leader, was created on February 6, 1986. The commission included Chairman William P. Rogers, Vice Chairman Neil Armstrong, and members such as David Acheson, Eugene Covert, Richard Feynman, Robert Hotz, Donald Kutyna, Sally Ride, Robert Rummel, Joseph Sutter, Arthur Walker, Albert Wheelon, and Chuck Yeager.
The commission held meetings to examine the NASA accident investigation, the Space Shuttle program, and the Morton Thiokol decision to launch the shuttle despite problems with O-rings, which are rubber seals used to prevent gas leaks. On February 15, Rogers announced that the commission would now investigate the accident independently of NASA because of concerns about how NASA handled its internal processes. The commission formed four groups to study different parts of the mission. The Accident Analysis Panel, led by Kutyna, used information from search and recovery efforts and tests to find the exact cause of the accident. The Development and Production Panel, led by Sutter, studied the companies that built the shuttle hardware and their work with NASA. The Pre-Launch Activities Panel, led by Acheson, focused on the final steps of assembling the shuttle and activities before launch at NASA’s Kennedy Space Center. The Mission Planning and Operations Panel, led by Ride, examined how the mission was planned, including concerns about crew safety and pressure to meet deadlines. Over four months, the commission spoke with more than 160 people, held at least 35 meetings, and involved over 6,000 NASA employees, contractors, and support staff. The commission released its report on June 6, 1986.
The commission found that the accident happened because hot gas escaped through the O-rings in the field joint of the right solid rocket booster. It concluded that the design of the field joint was flawed and too sensitive to temperature changes, movement, and material properties. The report criticized NASA and Morton Thiokol for ignoring evidence that showed the O-rings could be dangerous. It noted that NASA accepted the risk of O-ring damage without checking how it might affect mission safety. The commission said NASA’s safety culture and management structure were not strong enough to properly report, analyze, or prevent flight problems. It also stated that the pressure to increase the number of shuttle flights reduced training, quality checks, and repair work for each mission.
The commission suggested changes to improve the safety of the Space Shuttle program. It recommended redesigning the joints in the solid rocket boosters to stop gas from escaping through the O-rings. It also proposed reorganizing the program’s management to protect project managers from being forced to meet unsafe deadlines and to include astronauts in decisions about crew safety. The commission suggested creating a safety office that would report directly to NASA’s administrator to oversee all safety, reliability, and quality checks. It also addressed issues with the shuttle’s safety and maintenance and recommended adding a way for the crew to escape during controlled gliding flight.
During a televised meeting on February 11, Feynman showed how cold temperatures made rubber lose its flexibility by putting a rubber piece into a glass of cold water. This demonstration received media attention. Feynman, a Nobel Prize-winning physicist, pushed for stronger criticism of NASA in the report and disagreed with Rogers. He threatened to remove his name from the report unless it included his observations on reliability, which were added as Appendix F. In the appendix, he praised the engineering and software achievements of the program but said that parts like the avionics and SSMEs, in addition to the solid rocket boosters, were more dangerous than NASA had originally estimated.
The U.S. House Committee on Science and Technology investigated the Challenger disaster and released its report on October 29, 1986. The committee, which had approved funding for the Space Shuttle program, reviewed the findings of the Rogers Commission. It agreed with the commission that the failed field joint in the solid rocket booster caused the accident and that NASA and Morton Thiokol failed to act despite warnings about the joint’s risks. The committee’s report also highlighted safety concerns with other parts of the shuttle and recommended a review of risks for all critical systems.
NASA response
After the commission's recommendations, NASA redesigned the solid rocket booster (SRB), later called the redesigned solid rocket motor (RSRM), with oversight from an independent group. The redesigned joint included a feature on the tang inside the clevis to stop rotation. The space between this feature and the clevis was sealed with an additional O-ring. This design reduced joint rotation risk to 15% of what occurred during the disaster. If rotation happened, it would weaken the O-ring seal on one side but strengthen it on the other. Heaters were added to keep O-rings at higher, more stable temperatures. The RSRM was first tested on August 30, 1987. In 1988, tests with intentional flaws were conducted to check if the improved joint prevented rotation. After successful tests, the RSRM was approved for use on the Space Shuttle.
NASA also improved safety standards for other Space Shuttle components. Updates were made to critical item lists and failure modes for the space shuttle main engines (SSMEs), along with 18 hardware changes. SSME thrust was limited to 104%, with 109% only allowed during an emergency. Landing gear was upgraded to improve steering and handling. An escape system was added, allowing astronauts to jettison the side hatch, extend a pole, and slide down it to avoid hitting the orbiter before deploying parachutes. Software was modified to ensure stable flight if all crew members left controls during an escape. This method would not have helped during the Challenger disaster but was added for future emergencies.
In 1986, NASA created a new Office of Safety, Reliability, and Quality Assurance, led by a NASA associate administrator reporting directly to the NASA administrator, as the commission requested. Former Challenger flight director Greene became head of the Safety Division. After the Columbia disaster in 2003, the Columbia Accident Investigation Board (CAIB) found that NASA had not established a truly independent safety office. The CAIB also noted that the weak safety culture from the Challenger accident contributed to the Columbia disaster.
The Teacher in Space program, which selected Christa McAuliffe, was canceled in 1990 due to the Challenger disaster. In 1998, NASA replaced it with the Educator Astronaut Project, requiring teachers to become trained mission specialists rather than short-term payload specialists. Barbara Morgan, McAuliffe’s backup, joined NASA Astronaut Group 17 and flew on STS-118.
The Rogers Commission criticized NASA’s goal of 24 launches per year as unrealistic, creating pressure to meet schedules. In 1986, President Reagan approved building a new orbiter, later named Endeavour, to replace Challenger. Construction began in 1987 and ended in 1990. Endeavour first flew on STS-49 in 1992. Reagan also announced that the Space Shuttle would no longer carry commercial satellites, shifting that responsibility to commercial launch vehicles to reduce pressure on NASA.
The Space Shuttle fleet was grounded for two years and eight months for investigation, redesign, and restructuring. On September 29, 1988, Discovery launched on STS-26 with five veteran astronauts. Its payload, TDRS-3, replaced the satellite lost with Challenger. The mission tested the redesigned boosters, and crew members wore pressure suits during ascent and reentry. The mission succeeded, and the program resumed flights.
On February 1, 2003, the Space Shuttle Columbia disintegrated during reentry on STS-107, killing all seven crew members. The cause was foam from the external tank striking the orbiter’s left wing during launch. Again, NASA’s culture was criticized for not treating foam strikes as a risk, despite past incidents. Scheduling pressures also arose due to the need to meet International Space Station assembly goals. The CAIB concluded that NASA had not fixed the issues from the Challenger disaster, stating, “NASA’s response to the Rogers Commission did not meet the Commission’s intent” and “the causes of the institutional failure responsible for Challenger have not been fixed.” The Space Shuttle returned to flight in 2005 with STS-114.
Legacy
In 2004, President George W. Bush gave the Congressional Space Medals of Honor to all 14 crew members who died in the Challenger and Columbia accidents. A plain oval area in the Brumidi Corridors of the United States Capitol was completed with a portrait of the crew by artist Charles Schmidt in 1987. The painting was made on canvas and then placed on the wall. The "Forever Remembered" exhibit at the Kennedy Space Center Visitor Complex opened in July 2015. It includes a 12-foot (3.7 m) piece of Challenger's recovered fuselage. The exhibit was opened by NASA Administrator Charles Bolden and family members of the crew. Trees were planted in NASA's Astronaut Memorial Grove at the Johnson Space Center for each astronaut from the Challenger, Apollo 1, and Columbia disasters. Seven asteroids were named after the crew members: 3350 Scobee, 3351 Smith, 3352 McAuliffe, 3353 Jarvis, 3354 McNair, 3355 Onizuka, and 3356 Resnik. The approved naming was published by the Minor Planet Center on March 26, 1986 (M.P.C. 10550). In 1988, seven craters on the far side of the Moon, within the Apollo Basin, were named after the astronauts by the IAU. The Soviet Union named two craters on Venus after McAuliffe and Resnik. The landing site of the Opportunity Mars rover was named Challenger Memorial Station.
Several memorials honor the Challenger disaster. Peers Park in Palo Alto, California, includes the Challenger Memorial Grove with redwood trees grown from seeds carried aboard Challenger in 1985. Schools and streets have been renamed to include the crew's names or "Challenger." In 1990, a 1/10 scale model of Challenger in liftoff position was built in Little Tokyo, Los Angeles, California. Challenger Point is a mountain peak in the Sangre de Cristo Range. The McAuliffe-Shepard Discovery Center, a science museum and planetarium in Concord, New Hampshire, is named after McAuliffe, a Concord High School teacher, and Alan Shepard, who was from Derry, New Hampshire. The crew's families created the Challenger Center for Space Science Education, a nonprofit educational organization.
An American flag, later called the Challenger flag, was carried aboard Challenger. It was sponsored by Boy Scout Troop 514 of Monument, Colorado, and was recovered intact, still sealed in its plastic container. Onizuka included a soccer ball with his personal items, which was recovered and later taken to the International Space Station by American astronaut Shane Kimbrough during Soyuz Expedition 49. The ball is displayed at Clear Lake High School in Houston, where Onizuka's children attended school.
The 1986 movie Star Trek IV: The Voyage Home was dedicated to the Challenger crew with an opening message stating, "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…"
The last track on French musician Jean-Michel Jarre's 1986 album Rendez-Vous was originally planned to include a saxophone recording by Ron McNair aboard Challenger. This would have made it the first piece of music recorded in space.
In media
After the Challenger disaster, many books were written to explain the causes of the accident, the investigation, and the changes that followed. In 1987, Malcolm McConnell, a journalist who saw the disaster, wrote Challenger–A Major Malfunction: A True Story of Politics, Greed, and the Wrong Stuff. His book was criticized for suggesting a secret plan involving NASA Administrator Fletcher giving a contract to Morton Thiokol because it was based in his home state, Utah. In the same year, Joseph Trento published Prescription for Disaster: From the Glory of Apollo to the Betrayal of the Shuttle, which claimed the Space Shuttle program had problems and was influenced by politics from the beginning. In 1988, Richard Feynman’s book What Do You Care What Other People Think? was released. The second part of the book discusses his role in the Rogers Commission and his work with Kutyna.
Books about the disaster were also written later. In 1996, Diane Vaughan published The Challenger Launch Decision: Risky Technology, Culture, and Deviance at NASA, which suggests that NASA’s overall structure and goals, not just how the Space Shuttle program was managed, led to a culture where risks were accepted, which caused the disaster. That same year, Claus Jensen released No Downlink: A Dramatic Narrative About the Challenger Accident and Our Time, which focuses on the history of rocketry before the disaster. However, the book was criticized for relying mostly on other people’s research instead of original work. In 2009, Allan McDonald, with help from space historian James Hansen, wrote Truth, Lies, and O-Rings: Inside the Space Shuttle Challenger Disaster. The book describes McDonald’s role in the launch, disaster, investigation, and return to flight, and criticizes NASA and Morton Thiokol leaders for agreeing to launch Challenger despite engineers’ warnings about the O-rings.
In 1990, the ABC television movie Challenger aired. It features Barry Bostwick as Scobee and Karen Allen as McAuliffe. The movie criticizes NASA and shows engineers who opposed the launch in a positive light. However, the widows of Smith, McNair, and Onizuka said the movie did not accurately describe events. In 2013, the BBC docudrama The Challenger Disaster was broadcast. It stars William Hurt as Feynman and focuses on the investigation into the disaster. A film titled The Challenger Disaster, directed by Nathan VonMinden, was released in 2019. It includes fictional characters involved in the decision to launch.
The 11th episode of the American sitcom Mixed-ish, titled “When Doves Cry,” shows characters dealing with grief and trauma after watching the Challenger disaster.
The four-part docuseries Challenger: The Final Flight, created by Steven Leckart and Glen Zipper, was released on Netflix in 2020. It uses interviews with NASA and Morton Thiokol workers to argue that poor decisions by these organizations caused a disaster that could have been prevented.
In 2021, the first episode of the Australian drama The Newsreader showed the disaster from the perspective of a television newsroom. It includes a character hosting a news report that connects to a storyline about changes in how news was presented.
The first episode of Season 6 of This Is Us, titled “The Challenger,” shows children in school watching coverage of the disaster, their reactions, and a parent’s concern about explaining the event to them.