Shepard, Glenn set first two milestones __ 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.