January, 1986: NASA's newest space shuttle, Challenger, launches from Cape Canaveral. Seventy-three seconds later, millions of Americans watched their TVs in horror as the space shuttle was engulfed in a plume of white smoke. The Challenger tragedy was one of the darkest moments in NASA's history. Learn what happened to cause the accident, and the stories of the engineers and scientists who risked their careers to make sure that such a disaster never happened again.

January, 1986: NASA's newest space shuttle, Challenger, launches from Cape Canaveral. Seventy-three seconds later, millions of Americans watched their TVs in horror as the space shuttle was engulfed in a plume of white smoke. The Challenger tragedy was one of the darkest moments in NASA's history. Learn what happened to cause the accident, and the stories of the engineers and scientists who risked their careers to make sure that such a disaster never happened again.