21 of 22:
This is the official NASA photo of the crew of the space shuttle Challenger mission 51L. All seven members of the crew were killed when the shuttle exploded during launch on Jan. 28, 1986. From front left, are: astronauts Michael J. Smith, Francis R. (Dick) Scobee, and Ronald E. McNair. Rear left are: Ellison Onizuka, Christa McAuliffe, Gregory Jarvis and Judith Resnik.
(AP Photo/ NASA)