The Challenger Spacecraft Explosion

34 years ago, NASA management and engineering were widely criticized after space shuttle Challenger broke apart 73 seconds into flight and killed seven astronauts aboard it. This event resulted in intense criticism against NASA.

Christa McAuliffe was one of the victims and had been chosen by NASA as the inaugural teacher in space; her death sent shockwaves through the nation.

What Happened?

On January 28th 1986, Space Shuttle Challenger exploded in an explosive disaster witnessed by millions of viewers watching live on television. It was the worst tragedy ever experienced by NASA and all seven astronauts aboard died – including Christa McAuliffe, who had become the first civilian in space.

An independent committee was convened to investigate the incident and established that its cause lay in a pair of rubber O-rings used to seal joints between segments on the rocket booster’s lower sections, failing due to cold temperatures during launch which reduced their resilience and caused them to fail prematurely.

At a commission hearing, Nobel prize-winning physicist Richard Feynman immersed an O-ring into a glass of ice water to demonstrate how quickly its resilience was lost at low temperatures. Additionally, he presented evidence that NASA managers ignored pre-launch warnings from Morton Thiokol’s solid rocket booster design company.


After just minutes after launch, NASA and millions of TV viewers across the nation experienced an unthinkable tragedy: seven astronauts perished. Millions more viewers, including students in schools nationwide, also witnessed this event with great sadness.

Investigators soon determined that two rubber O-rings had failed due to cold temperatures. Their purpose was to seal segments of the right-hand solid rocket booster; however, due to severe cold, their resilience had decreased, providing a pathway for hot exhaust gases to escape and trigger an explosion.

NASA was unprepared for such a catastrophic failure, which led to an investigation that focused on NASA’s culture and decision-making procedures following the Challenger accident. Nobel Prize-winning physicist Richard Feynman played a prominent role during these hearings – famously immersing an O-ring piece into cold water to demonstrate its loss of resilience at low temperatures; also being highly critical of NASA’s overreliance on past successes while not prioritizing safety as organizational practices that did not promote wellbeing were often in the spotlight during these hearings.


Spacecraft are devices and robots designed to leave Earth’s atmosphere and travel through outer space, from satellites that orbit Earth to planet-hopping robots sent on missions, vehicles that carry human astronauts and research vessels carrying experiment capsules or research station in orbit. Some spacecraft, like Voyager 1 & 2, Pioneer 10 and 11 and New Horizons are on trajectories that will eventually take them beyond our Solar System; one early explosion was caused by a 16mm film camera falling off a satellite which hit astronaut Alan Bean on the head causing him mild injuries but served as an alarming reminder of what may lay ahead when traveling through space – its dangers were only partly evident!


Note from Editor’s Desk: This article first appeared in IEEE Spectrum magazine in June 1989 and has become widely referenced in histories of spaceflight and risk analyses. Today, 30 years since Challenger’s destruction, it is being republished to remember this event and remind all of us the value of openness within safety culture.

Morton Thiokol engineers had long understood that cold temperatures could impact the rubber O-rings that sealed gases on solid rocket boosters nozzles, yet NASA managers didn’t grasp this concept: they believed blow-by gasses that eroded previous shuttle flights had no correlation to temperature changes.

Rogers’ commission discovered, as it investigated potential causes for the accident, that some NASA high-ranking managers did not grasp basic engineering principles. Feynman’s report was so critical of NASA that he threatened not to sign it unless Rogers included it as part of his final report as an appendix. Eventually Rogers accepted this suggestion and included it.

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