NASA's space shuttle flights began three decades ago with Columbia and will end this month with the final voyage of Atlantis and the retirement of the fleet.
Some of the milestones of the shuttle era:
1981: Columbia makes first shuttle flight for two days.
1982: Shuttle declared operational, no longer experimental.
1983: Challenger's first flight with first shuttle spacewalk; America's first woman in space, Sally Ride; America's first black astronaut in space, Guion Bluford.
1984: Discovery's first flight, first untethered spacewalk by Bruce McCandless, the so-called "human satellite."
1985: Atlantis' first flight; first congressman in space, Sen. Jake Garn of Utah.
1986: Challenger destroyed after lift-off, seven killed including teacher Christa McAuliffe; shuttles grounded during investigation.
1988: Shuttle flights resume with Discovery.
1989: Launch of Jupiter probe Gallileo.
1990: Launch of Hubble Space Telescope.
1992: First flight of Endeavour, replacement for Challenger.
1993: Hubble repaired by spacewalkers.
1994: First Russian cosmonaut on shuttle.
1995: First female pilot, Eileen Collins; first docking with Russia's Mir space station.
1998: Mercury astronaut John Glenn returns to orbit at 77; first U.S. piece of International Space Station launched.
1999: First female commander, Eileen Collins.
2003: Columbia destroyed during re-entry, seven killed; shuttles grounded during investigation.
2005: Shuttle flights resume with Discovery.
2007: First teacher-astronaut, Barbara Morgan.
2011: Last flights of Discovery, Endeavour, and soon, Atlantis.