The maiden voyage of the space shuttle Columbia marked an epoch in space travel, for Columbia -- launched April 12, 1981 -- was rocket, spaceship and airplane all in one.
Mission commander John Young and pilot Bob Crippen were the first astronauts who could bring their craft back from space and land on a runway. The Columbia is also the first space shuttle to have reusable boosters.
But just when the space shuttle missions started to become routine, the program was dealt a setback by the Challenger disaster, in which seven crew members died when one of the ship's booster rockets exploded 73 seconds into the mission. Among those who died was Christa McAuliffe, who was to have been the first teacher in space.
Just before the explosion, astronaut Michael J. Smith realized something had gone wrong. His last words over the radio were simply, "Uh-oh."
