Astronomy and Space
What was one of the worst disasters in the U.S. space program and what caused it?
Challenger mission STS 51L was launched on January 28, 1986, but exploded 73 seconds after liftoff. The entire crew of seven was killed, and the Challenger was completely destroyed. The investigation of the Challenger tragedy was performed by the Rogers Commission, established and named for its chairman, former secretary of state, William Rogers.
The consensus of the Rogers Commission (which studied the accident for several months) and participating investigative agencies was that the accident was caused by a failure in the joint between the two lower segments of the right solid rocket motor. The specific failure was the destruction of the seals that are intended to prevent hot gases from leaking through the joint during the propellant burn of the rocket motor. The evidence assembled by the commission indicated that no other element of the space shuttle system contributed to this failure.
Although the commission did not affix blame to any individuals, the public record made clear that the launch should not have been made that day. The weather was unusually cold at Cape Canaveral, and temperatures had dipped below freezing during the night. Test data had suggested that the seals (called O-rings) around the solid rocket booster joints lost much of their effectiveness in very cold weather.