1972    U.S. President Richard Nixon orders the development of a space shuttle program.

1976    The first Space Shuttle, Enterprise, is unveiled by NASA.

1979    The first fully functional space shuttle orbiter, ''Columbia'', is delivered to the John F. Kennedy Space Center to be prepared for its first launch.

1981    The first launch of a Space Shuttle: ''Columbia'' launches on the STS-1 mission. thumb

1982    NASA's Space Shuttle ''Columbia'', is launched from the Kennedy Space Center on its third mission, STS-3.

1982    Space Shuttle Columbia launched from the Kennedy Space Center on the final research and development flight mission, STS-4.

1983    During STS-6, astronauts Story Musgrave and Don Peterson perform the first space shuttle spacewalk.

1984    STS-41-D: The Space Shuttle ''Discovery'' takes off on its maiden voyage.

1984    Marc Garneau becomes the first Canadian in space, aboard the Space Shuttle ''Challenger''.

1988    The PEPCON disaster rocks Henderson, Nevada, as tons of space shuttle fuel detonates during a fire.

1988    Space Shuttle: NASA launches STS-26, the return to flight mission, after the Space Shuttle ''Challenger'' disaster. 160px

1994    Space shuttle STS-62 (''Columbia'' 16) launches into orbit.

1996    Space Shuttle program: STS-72 launches from the Kennedy Space Center marking the start of the 74th Space Shuttle mission and the 10th flight of ''Endeavour''.

2000    NASA launches STS-92, the 100th Space Shuttle mission, using Space Shuttle Discovery.

2005    STS-114: NASA grounds the Space Shuttle, pending an investigation of the continuing problem with the shedding of foam insulation from the external fuel tank. During ascent, the external tank of the Space Shuttle Discovery sheds a piece of foam slightly smaller than the piece that caused the Space Shuttle Columbia disaster; this foam does not strike the spacecraft.