Roger Boisjoly, a 27-year veteran of the U.S. Aerospace Industry, worked as a technical troubleshooter for Morton Thiokol, Inc., the company contracted by NASA to build rocket boosters for the space shuttle. His responsibility was the production and testing of the o-ring that prevents hot, combustible gasses from leaking from the rocket boosters.

In January of 1986, Boisjoly had been studying evidence of o-ring failure in previous shuttle launches. On January 27, the night before the Space Shuttle Challenger was due to launch, he learned that the temperature at Cape Canaveral would drop below...