Skylab was America's first experimental space station. Designed for long duration missions, Skylab program objectives were twofold: To prove that humans could live and work in space for extended periods, and to expand our knowledge of solar astronomy well beyond Earth-based observations.

Skylab was launched May 14, 1973. It was the last mission of the legendary Saturn V launch system which had been developed for the moon landing program in the 1960s. Successful in all respects despite early mechanical difficulties, three three-man crews occupied the Skylab workshop for a total of 171 days, 13 hours.

After the last crew departed on February 8, 1974, NASA had hoped to rejunvinate the station for continued experiments using the developing Space Shuttle Transport Sytem. Delays in the Space Shuttle program made this impossible before the orbit of the giant station decayed and it re-entered the atmosphere.

Apollo Soyuz was the first international manned spaceflight. It was designed to test the compatibility of rendezvous and docking systems for American and Soviet spacecraft, to open the way for international space rescue as well as future joint manned flights.