Space Shuttle Challenger Disaster


The Challenger disaster occurred on January 28, 1986, shortly after the launch of the US space shuttle Challenger from Cape Canaveral, Florida, killing seven astronauts: Francis (Dick) Scobee, pilot Michael Smith, mission specialists Ellison Onizuka, Judith Resnik, and Ronald McNair, Hughes Aircraft engineer Gregory Jarvis, and Christina McAuliffe.
 
AIM OF THE MISSION:
• Shuttle mission 51-L's primary goal was to launch the second Tracking and Data Relay Satellite (TDRS-B).
• Challenger was to launch the Spartan Halley spacecraft, a small satellite that would be picked up two days later after observing Halley's Comet during its closest approach to the Sun.
• In-Space-Teacher Christina McAuliffe was supposed to conduct at least two lessons from space and then lecture students across the United States for the next nine months. The goal was to emphasise the value of teachers and to pique students' interest in high-tech careers.
 
Space Shuttle Challenger DisasterABOUT THE MISSION
• The launch was postponed for several days at the start of the mission, partly due to delays in getting the previous shuttle mission, 61-C (Columbia), back on the ground.
• A severe cold wave swept through central Florida the night before the launch, depositing thick ice on the launch pad.
• Liftoff was delayed on launch day, January 28. Everything seemed normal until the vehicle exited "Max-Q," the period of greatest aerodynamic pressure.
• At an altitude of 14,000 metres, the vehicle vanished in an explosion just 73 seconds after taking off (46,000 feet).
• Debris rained into the Atlantic Ocean for more than an hour after the explosion, and no sign of the crew could be found.
• The Challenger was shattered in the explosion, but the forward section with the crew cabin remained intact.
• The crew was thought to have survived the initial breakup, but because they were not wearing pressure suits, the loss of cabin pressure rendered them unconscious within seconds. Minutes before impact, death was most likely caused by a lack of oxygen.
 
AFTERMATH
• The shuttle programme was immediately halted as a result of the incident.
• The National Aeronautics and Space Administration (NASA) conducted an extensive investigation, as did a commission appointed by US President Ronald Reagan and chaired by former Secretary of State William Rogers.
• Astronauts Neil Armstrong and Sally Ride, test pilot Chuck Yeager, and physicist Richard Feynman were among the commission's other members.
• What emerged was a shocking pattern of assuming the vehicle could withstand minor mishaps and be pushed even further. The ill-fated launch brought to light the difficulties NASA had been having for years in attempting to do too much with too little money.
• Nasa's space shuttle programme, which ran from 1981 to 2011, was put on hold for 32 months after the Challenger disaster, and it became a national scandal for Nasa, whose decision-making policies, bureaucratic culture, and safety protocols were all scrutinised after the disaster.
 
ROGERS COMMISSION
• According to Commission, the  accident was caused by a failure in the O-rings sealing a joint on the right solid rocket booster, which allowed pressurized hot gases and eventually flame to "blow by" the O-ring and make contact with the adjacent external tank, causing structural failure.
• The O-ring failure was attributed to a faulty design, whose performance was too easily jeopardised by factors such as the low ambient temperature on launch day. The O-rings wouldn't work properly at temperatures below 50 degrees Fahrenheit (10 degrees Celsius)—and it was 36 degrees Fahrenheit (2 degrees Celsius) on the morning of the launch.
• A number of engineers testified before the Rogers Commission that they had been concerned about the seals' reliability for at least two years and had warned superiors about a possible failure the night before 51-L was launched.
• Tightening the communication gap between shuttle managers and working engineers was one of the Rogers Commission's strongest recommendations.
• In response to the implied criticism that its quality-control measures had become lax, NASA increased the number of checkpoints in the shuttle bureaucracy, including a new NASA safety office and a shuttle safety advisory panel, in order to avoid another "flawed" launch decision.
• The shuttle programme lacked the personnel and spare parts necessary to maintain such a high rate of flight without taxing its physical resources or overworking its technicians.
 
Space Shuttle Challenger DisasterU.S. HOUSE COMMITTEE HEARINGS
• The United States House Committee on Science and Technology held hearings and issued its own report on the Challenger disaster on October 29, 1986.
• As part of its investigation, the committee reviewed the Rogers Commission's findings and agreed with the Rogers Commission on the technical causes of the accident.
• Its assessment of the accident's contributing causes differed from that of the committee.
• The Committee believes that the underlying issue that led to the Challenger disaster was not a lack of communication or a lack of procedures, as the Rogers Commission concluded. Rather, the fundamental issue was poor technical decision-making by top NASA and contractor personnel over a period of several years, who failed to act decisively to resolve the growing number of serious anomalies in the Solid Rocket Booster joints.
• The accident's contributing causes were also considered in the report. The failure of both NASA and Morton-Thiokol (Contractor) to adequately respond to the danger posed by the deficient joint design was particularly noteworthy. They decided to define the problem as an acceptable flight risk rather than redesigning the joint.
• According to the report, Marshall managers had known about the flawed design since 1977, but never discussed it with Thiokol outside of their reporting channels, which was a clear violation of NASA regulations.

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