1973 - The United States launches the Skylab space station, the second orbiting platform to be manned by crews.

The space station is seen, with Earth in the background, from the Skylab 3 Command/Service Module during station-keeping maneuvers prior to docking. The station was occupied for a total of 171 days during three separate missions. Its orbit deteriorated and it fell to Earth, in pieces, in July 1979. (NASA)