1957 Oct. 4 The Soviet Union launches the first artificial satellite, the 184-lb. Sputnik 1
 Nov. 3 Sputnik 2 carries a dog named Laika into orbit. She lives for seven days, proving that animals (and presumably humans) can survive in space

1958 JAN. 31 Launch of Explorer 1, the first U.S. satellite

1961 April 12 Soviet cosmonaut Yuri Gagarin is the first person to orbit Earth.

1963 June 16 Cosmonaut Valentina Tereshkova becomes the first woman in space

1969 July 20 "That's one small step for man, one giant leap for mankind." Apollo 11 astronauts Neil Armstrong and Edwin ("Buzz") Aldrin walk on the moon

1971 April 19 The Soviet Union launches the first space station, an orbiting laboratory named Salyut 1

1975 July 17 The Apollo-Soyuz rendezvous, highlight of the first international manned space mission

1976 July 20 Viking 1 lands on Mars and transmits the first pictures from the planet's surface. Viking 2 will arrive in September 1976

1979 March 5 Voyager 1 makes its closest approach to Jupiter, relaying images of the planet and its moons. Voyager 2 follows four months later

 July 11 After losing altitude for nearly two years, Skylab falls out of the sky and crashes, scattering debris from the southeastern Indian Ocean to western Australia

1981 April 12 Inaugural launch of the U.S. space shuttle Columbia, the first reusable manned spacecraft

1986 Jan. 24 Voyager 2 arrives at Uranus 
 Feb. 20 space station Mir launched into Earth orbit

1987 Feb. 8 Mir becomes the first continuously inhabited space station

1990 April 25 Astronauts on the shuttle Discovery place the Hubble Space Telescope into Earth orbit.

1998 Nov. 20 First piece of the International Space Station launched

1999 June Mir falls out of orbit and crash to Earth