CHALLENGER: A CASE STUDY

A mere 73 seconds after lift-off, on 28 January 1986, NASA’s Challenger space shuttle blew apart, killing all seven astronauts aboard. A review commission found a few edge cases that contributed to the spacecraft’s demise, but most notably, exceptionally cold temperatures were to blame. Challenger’s solid rockets were rated for temperatures of 4°C or higher, but ground temperature at launch was just -4.5°C. That, in turn, caused a seal located on the shuttle’s right solid rocket booster – known as an O-ring – to malfunction at launch, letting out hot, pressurised gas. The gas ruptured a strut connecting the booster to the external fuel tank, destroying both.