The night before the launch, January 27, 1986, engineers at Morton Thiokol, the booster manufacturer, raised an urgent alarm. The temperature was a record-low 2 degrees Celsius, and they feared the O-rings would fail to seal properly. Engineers like Roger Boisjoly presented data showing that the seals had never been tested below 53 degrees Fahrenheit. Despite their formal recommendation against launching, NASA managers pressured them. Morton Thiokol management ultimately overruled their engineers after a senior executive told the vice president of engineering to 'take off his engineering hat and put on his management hat'.
The Space Shuttle Challenger Disaster
The story of the Challenger's final flight on January 28, 1986, and the investigation that revealed its fatal O-ring flaw.
Chapter 1
The Warning
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Frequently Asked Questions
What was the technical cause of the Challenger disaster?
The disaster was caused by the failure of an O-ring seal in a joint of the right solid rocket booster. The record-low temperatures on launch day made the rubber O-ring stiff, preventing it from properly sealing the joint. This allowed a plume of hot gas to escape and burn through the external fuel tank, leading to the shuttle's structural breakup.
Were there any warnings before the launch?
Yes. Engineers from the manufacturer, Morton Thiokol, formally recommended against the launch the night before. They warned that the O-rings had never been tested in such cold temperatures and might fail. However, they were overruled by their own management and by NASA officials.
What changes did NASA make after the Challenger accident?
NASA grounded the shuttle fleet for 32 months to implement major changes. This included redesigning the solid rocket booster joints with a third O-ring and heaters. NASA also created a new office for safety oversight and required astronauts to wear pressurized launch suits for added protection.
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