Skylab

The Skylab space station was launched on May 14, 1973 in the program designed for the conduct of scientific experiments in zero gravity, earth resources experiments, and solar observations in long-duration missions. Three separate crews were launched in Apollo-type command modules on May 25, July 28, and November 16, 1973. These crews remained, respectively, for mis­sion periods of 28 days, 59 days, and 84 days. The Skylab mission also proved that humans can remain for extended periods of time in space without adverse health or psychological conse­quences and that resupply of space vehicles is workable.

Skylab’s orbit deteriorated because there were no spacecraft, nor any program ready (the Space Shuttle had been delayed), to boost its orbit. On July 11, 1979, Skylab reentered the earth’s atmosphere and disintegrated over the Indian Ocean and across Western Australia.

Apollo-Soyuz Mission

This mission was the first international manned space flight and had as one of its main goals the proving of the reliability of rescue plans of international crews. The Apollo spacecraft used was essentially the same as that used in the lunar program and the Soviet Soyuz was the same that had been in use since 1967. The flight was conducted between July 15 and July 24, 1975, with launches in the United States and the Soviet Union, docking over a two-day period, and return of the spacecraft to their respective countries after separation.

The return of Apollo marked the beginning of a six-year hiatus in the American manned space flight program. In addition to the human space flight program, NASA also maintained a small aeronautics research program, a space sci­ence program (including deep space and inter­planetary exploration), and an earth observation program.