Before the first astronauts flew, Kranz literally wrote the first book on the rules of space flight.

In total, 355 astronauts will have flown on the shuttle since the inaugural mission in 1981.

These astronauts flew aboard weather reconnaissance aircraft to provide support at the selected landing site.

After four futile attempts, the astronauts abandoned the test and flew back to Earth.

All four astronauts flew them dozens of times each, and they got so used to the instability that we nearly forgot it was there.

In return, Soviet astronauts would fly on several shuttle missions.

Today Columbia's astronauts flew back to Houston to await word on the fate of the mission.

Besides simulator training, astronauts must fly at least 15 hours a month in the T-38, including slightly more than an hour at night.

The mission also marked the first time two female astronauts had flown together.

The astronaut flew on shuttle flights in 1988, 1990 and 1992, accumulating 440 hours in space.