Seventy three seconds after blast-off, the shuttle Challenger exploded and killed all seven astronauts on board. The explosion ws the greatest loss ever for the American space program, and was later blamed on faulty o-rings in the booster rocket. In 2003 the shuttle Columbia disintegrated on reentry, killing all of its astronauts.
At 11:38 the rocket blasted off. For the first minute of the flight, the flight seemed to be fine, and later analysis would show at close to 59-second mark a leak had developed. At 68 seconds the pilot was told he was “go for throttle up” the last words of Commander Dick Scobee that were heard on the ground were “ Roger go at throttle up” two seconds later the vehicle began to break up. Later investigation showed that at least some of the crew survived the initial breakup and may have lived through a free fall to the water from 65,000 feet. Anyone alive perished on impact with the water.
President Reagan appointed an independent commission to investigate the disaster, and they concluded that the accident was caused by Rubber O rings that failed due to the cold. The O rings were used to seal the tanks and when they failed they allowed a leak that then led to the catastrophic failure. The shuttle fleet was grounded for three years until the cause was determined and the rings replaced. Killed in the accident were:
Francis R. Scobee, Commander
Michael J. Smith, Pilot
Ronald McNair, Mission Specialist
Ellison Onizuka, Mission Specialist
Judith Resnik, Mission Specialist
Gregory Jarvis, Payload Specialist
Christa McAuliffe, Payload Specialist, Teacher