On 28 January 1986, Space Shuttle Challenger exploded just 73 seconds after lift-off killing all seven astronauts on board. Watch the tragic video…
The cause of explosion was determined to be an o-ring failure in the right solid rocket booster. Cold weather was determined to be a contributing factor. The STS-51L Mission Profile gives a detailed account of Challenger’s launch and the accident.
Soon after the fateful day, Dr Joseph P Kerwin, biomedical specialist from the Johnson Space Centre in Houston, Texas, was commissioned to investigate the cause of death of the Challenger astronauts.
After a thorough review of the wreckage and all other available data from the Challenger flight, Nasa was unable to determine positively the cause of death of the Challenger astronauts but established that it was possible, but not certain, that loss of consciousness did occur in the seconds following the orbiter breakup.
Source: Nasa History