On 28 January, 1986 at around 11-38am local time, the Challenger Space shuttle lifted off from the NASA Kennedy Space Centre in Florida. 73 seconds later the space vehicle exploded, claiming the lives of seven astronauts.
The crew included a teacher, who was to have talked to school children from space, a vital factor in launching on a school day. A desperate struggle to delay the launch occurred, based on engineers' fears that vital 'O' ring rocket seals would fail at low temperatures.
Former chief engineer Roger Boisjoly and colleagues argued with NASA management, but were overruled by a decision based on 'acceptable risk'.
A final pressure was placed on the head engineer, who was told: "Take off your engineering hat and put on your management hat…" Thus the fateful decision to over-ride that of the engineers, and to go ahead and launch.