STS-51B | Three-Tenths of a Second from Disaster
Forty years ago today, Challenger lifted off LC-39A on a science mission that nobody outside Morton-Thiokol would call dangerous. Years later, after the orbiter and seven other astronauts were gone, investigators looked at the recovered boosters from STS-51B and realized the crew had come within a fraction of a second of dying first. This is the story of the launch that should have been a warning.