Skylab was the largest craft launched into orbit up to that point, with laboratories and living quarters for three astronauts, first led by Commander Charles 'Pete' Conrad. Three separate crews inhabited the station for a collective 171 days.
But that success came after a rocky start. During the station's lift-off, crucial shielding and a solar panel were ripped off. Electrical systems weren't functioning properly and temperatures inside the Skylab workshop, which was facing the Sun, reached 125 degrees.
The crew was able to deploy a parasol called the Skylab sun shade, bringing temperatures down to 75 degrees. By June 4th, 10 days after the crew had arrived, the station was fully operational.
Joseph Kerwin, Charles Conrad and Paul Weitz launched on May 25, 1973, spending 28 days aboard Skylab. Owen Garriott, Jack Lousma and Alan Bean launched on July 28, 1973, spending 59 days aboard. Gerald Carr, Edward Gibson and William Pogue lauched on Nov. 16, 1973, spending 84 days aboard.
By 1978, the abandoned Skylab was falling out of orbit. Solar heating had expanded Earth’s atmosphere, increasing friction and dragging it down. NASA was hoping to use its new shuttle program to boost the station into a higher orbit, but Skylab fell to Earth in 1979, before the shuttle was complete.