Successful in all respects despite early mechanical difficulties, three three-man crews occupied the Skylab workshop for a total of 171 days, 13 hours. It was the site of nearly 300 scientific and technical experiments: medical experiments on humans' adaptability to zero gravity, solar observations, and detailed Earth resources experiments.

The empty Skylab spacecraft returned to Earth July 11, 1979 scattering debris over the Indian Ocean and the sparsely settled region of Western Australia.

Skylab was maneuvered so its Apollo Telescope Mount (ATM) solar panels faced the Sun to provide as much electricity as possible. Because of the loss of the meteoroid shield, however, this positioning caused workshop temperatures to rise to 52 degrees Celsius (126 degrees F). The launch of Skylab 2 was postponed while NASA engineers, in an intensive 10-day period, developed procedures and trained the crew to make the workshop habitable. At the same time, engineers "rolled" Skylab to lower the temperature of the workshop.

• Charles C. Conrad Jr., Commander
  Paul J. Weitz, Pilot
  Joseph P. Kerwin, Scientist Pilot

• Alan L. Bean, Commander
  Jack R. Lousma, Pilot
  Owen K. Garriott, Scientist Pilot

• Gerald P. Carr, Commander
  William R. Pogue, Pilot
  Edward G. Gibson, Scientist Pilot

When the meteoroid shield ripped loose, it disturbed the mounting of workshop solar array "wing" two and caused it to partially deploy. The exhaust plume of the second stage retro-rockets impacted the partially deployed solar array and literally blew it into space. Also, a strap of debris from the meteoroid shield overlapped solar array "wing" number one such that when the programmed deployment signal occurred, wing number one was held in a slightly opened position where it was able to generate virtually no power.

In the meantime, the space station had achieved a near-circular orbit at the desired altitude of 435 kilometers (270 miles). All other major functions including payload shroud jettison, deployment of the Apollo Telescope Mount (Skylab's solar observatory) and its solar arrays, and pressurization of the space station occurred as planned.

Scientists, engineers, astronauts, and management personnel at the NASA Marshall Space Flight Center and elsewhere worked throughout the first ten-day period of Skylab's flight to devise the means for its rescue. Simultaneously, Skylab--seriously overheating--was maneuvered through varying nose-up attitudes that would best maintain an acceptable "holding" condition. During that ten-day period and for some time thereafter, the space station operated on less than half of its designed electrical system, in the partially nose-up attitudes, was generating power at reduced efficiency. The optimum condition that maintained the most favorable balance between Skylab temperatures and its power generation capability occurred at approximately 50 degrees nose-up.

Skylab's achievements are a summary of the accomplishments of many ground-based persons as well as its three separate crews who were launched in Apollo-type command modules by Saturn IB vehicles on May 25, July 28, and November 16, 1973. In Skylab, both the man-hours in space and the man-hours spent in performance of extravehicular activities (EVA) under micro-gravity conditions exceeded the combined totals of all of the world's previous space flights up to that time.

By deploying the parasol-type sun shield through Skylab's solar scientific airlock and later releasing workshop solar array wing number one during EVA, the first crew made the remainder of the mission possible. The second crew, also during EVA, erected another sun shield, a twin-pole device.

The effectiveness of Skylab crews exceeded expectations, especially in their ability to perform complex repair tasks. They demonstrated excellent mobility, both internal and external to the space station, showing man to be a positive asset in conducting research from space. By selecting and photographing targets of opportunity on the Sun, and by evaluating weather conditions on Earth and recommending Earth Resources opportunities, crewmen were instrumental in attaining extremely high quality solar and Earth oriented data.

All three crews demonstrated technical skills for scientific, operational, and maintenance functions. Their manual control of the space station, their fine pointing of experiments, and their reasoning and judgment throughout the manned periods were highly effective.

The capability to conduct longer manned missions was conclusively demonstrated in Skylab, first by the crew returning from the 28 day mission and, more forcefully, by the good health and physical condition of the second and third Skylab crews who stayed in weightless space for 59 and 84 days respectively. Also, resupply of space vehicles was attempted for the first time in Skylab and was proven to be effective.

During their time in space, all three crews exceeded the operational and experimental requirements placed upon them by the pre-mission flight plan and schedule. In addition, the third crew performed a number of sightings of Comet Kohoutek which were not initially scheduled.

Following the final manned phase of the Skylab mission, ground controllers performed some engineering tests of certain Skylab systems--tests that ground personnel were reluctant to do while men were aboard. Results from these tests helped to determine causes of failures during the mission and to obtain data on long term degradation of space systems.

Upon completion of the engineering tests, Skylab was positioned into a stable attitude and systems were shut down. It was expected that Skylab would remain in orbit eight to ten years. However, in the fall of 1977, it was determined that Skylab was no longer in a stable attitude as a result of greater than predicted solar activity.

On July 11, 1979, Skylab impacted the Earth surface. The debris dispersion area stretched from the Southeastern Indian Ocean across a sparsely populated section of Western Australia.