A little-known component on the space shuttle that NASA doesn't like to talk about is the self-destruct mechanism or, as they like to call it, "Flight Termination."

In the event that the space shuttle flies out of a specific flight path over the Atlantic and it appears that it will impact a populated area, an Air Force officer would flip the switch which would detonate charges in the booster rocket, destroying the shuttle and crew.

If the shuttle manages to fly for two minutes, the booster rockets fall away taking the charges with them after which, if a problem arises, the crew can either ditch the ship into the Atlantic, evacuating via parachutes, or orbit the Earth once and land at Edwards Air Force Base.

After the destruction of Challenger, the charges were used to remotely detonate the booster rockets that continued to fly out of control after the explosion.