Roger Boisjoly was an engineer at solid rocket booster manufacturer Morton Thiokol and had begun warning as early as 1985 that the joints in the boosters could fail in cold weather, leading to a catastrophic failure of the casing. Then on the eve of the Jan. 28, 1986, launch, Boisjoly and four other space shuttle engineers argued late into the night against the launch.
In cold temperatures, o-rings in the joints might not seal, they said, and could allow flames to reach the rocket’s metal casing. Their pleas and technical theories were rejected by senior managers at the company and NASA, who told them they had failed to prove their case and that the shuttle would be launched in freezing temperatures the next morning. It was among the great engineering miscalculations in history.