WHAT WE LEARNED FROM THE CHALLENGER DISASTER

The first loss of a Space Shuttle and its crew was a preventable disaster, but it would go onto largely change NASA for the better

- Ian Evenden

Just 73 seconds was all it took from the launch of Space Shuttle mission STS-51-L on 28 January 1986 to the Shuttle’s disintegration over the Atlantic and the loss of all seven of its crew. It was a routine mission to deploy a data relay satellite and test a probe designed to observe Halley’s Comet, but was notable for the presence of Christa McAuliffe – the first teacher in space, and a civilian, in the crew. She had been chosen for the mission out of an initial application pool of more than 11,000, and was planning to carry out experiments and beam back lessons to Earth in order to rekindle interest in the US space program, remind Americans of the role teachers play in society and demonstrate the reliability of spaceflight.

Challenger was completely destroyed in the disaster, which was traced to the failure of an O-ring seal in the Shuttle’s right-hand solid rocket booster. This allowed hot gases to flare out, burning through the strut attaching the booster to the external fuel tank and causing the two to clash together, eventually leading to structural failure of the fuel tank and allowing all parts of the launch vehicle to fly apart, disintegrating under the pressure of aerodynamic forces.