January 28, 1986

The space shuttle Challenger explodes 73 seconds after liftoff, killing all seven astronauts, including schoolteacher Christa McAuliffe. Others on Mission 51-L are Francis R. Scobee, Navy Cmdr. Michael J. Smith, Judith A. Resnik, Ronald E. McNair, Air Force Lt. Col. Ellison S. Onizuka, and Gregory B. Jarvis. The manned space program will be halted for two years while vehicular and management flaws are corrected.