Christa Corrigan McAuliffe was an American teacher who was chosen to be the first private citizen in space. Aboard the space shuttle Challenger, she was one of the seven astronauts killed when the rocket exploded 73 seconds after takeoff. The death of McAuliffe and her fellow crew members in the 1986 space shuttle Challenger disaster was deeply felt by the nation and had a strong effect on the U.S. space program. Space shuttle flights were suspended until 1988. An independent U.S. commission blamed the disaster on unusually cold temperatures that morning and the failure of the O-rings, a set of gaskets in the rocket boosters.