1986: CHALLENGER DISASTER. The Space Shuttle Challenger explodes 73 seconds after launch, killing Astronauts Francis R. Scobee, Navy Cmdr Michael J. Smith, Dr. Judith Resnik, Dr. Ronald E. McNair, Air Force Lt Col Ellison S. Onizuka, Gregory Jarvis of Hughes Aircraft Corp., and schoolteacher Christa McAuliffe. This tragedy delays America’s manned space program for more than two years.