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May 5, 1961: Alan Shepard becomes first American in space.
Feb. 20, 1962: John Glenn becomes first American in orbit.
Jan. 27, 1967: Gus Grissom, Edward White II and Roger Chaffee die in Apollo 1 spacecraft fire on launch pad.
July 20, 1969: Apollo 11's Neil Armstrong and Buzz Aldrin land on moon.
July 17, 1975: American Apollo and Soviet Soyuz spacecraft link in orbit.
April 12, 1981: Columbia soars on first space shuttle flight.
June 18, 1983: Sally Ride becomes first American woman in space.
Jan. 28, 1986: Challenger explodes, killing all seven on board.
April 25, 1990: Hubble Space Telescope is released into orbit.
Dec. 2, 1993: First Hubble repair mission is launched.
March 14, 1995: Norman Thagard is first American to be launched on a Russian rocket. Two days later, he becomes first American to visit Mir.
June 29, 1995: Atlantis docks with Mir in first shuttle-station hookup.
Sept. 26, 1996: Shannon Lucid returns to Earth after 188-day Mir mission, a U.S. space endurance record and a world record for women.
Nov. 19, 1996: Story Musgrave, at age 61, becomes oldest man in space.
Oct. 29, 1998: Discovery is scheduled to blast off, carrying 77-year-old John Glenn back into orbit and making him oldest man in space.