America's first experimental space station. Designed for long
duration mission, 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.
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
The empty Skylab spacecraft returned to Earth July 11,
1979 scattering debris over the Indian Ocean and the sparsely settled region of
Launched: May 14, 1973
Highlights: The station was launched into orbit by a Saturn V booster. Almost immediately, technical problems developed due to vibrations during lift-off. A critical meteoroid shield ripped off taking one of the craft's two solar panels with it; a piece of the shield wrapped around the other panel keeping it from deploying.
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.
Launched: May 25, 1973
Landed: June 22, 1973
Highlights: First manned mission. The crew rendezvoused with Skylab on the fifth orbit. After making substantial repairs, including deployment of a parasol sunshade which cooled the inside temperatures to 23.8 degrees C (75 degrees F), by June 4 the workshop was in full operation. In orbit the crew conducted solar astronomy and Earth resources experiments, medical studies, and five student experiments; 404 orbits and
392 experiment hours were completed; three EVAs totalled six hours, 20 minutes. Flight duration: 28 days, 50 minutes.
The Skylab 2 astronauts were:
- Charles C. Conrad Jr., Commander
Paul J. Weitz, Pilot
Joseph P. Kerwin, Scientist Pilot
Launched: July 28, 1973
Landed: September 25, 1973
Highlights: Second manned mission. Continued maintenance of the space station and extensive scientific and medical experiments. Completed 858 Earth orbits and 1,081 hours of solar and Earth experiments; three EVAs totalled 13 hours, 43 minutes. Flight duration: 59 days, 11 hours.
The Skylab 3 astronauts were:
- Alan L. Bean, Commander
Jack R. Lousma, Pilot
Owen K. Garriott, Scientist Pilot
Launched: November 16, 1973
Landed: February 8, 1974
Highlights: The third manned mission and the last of the Skylab missions; included observation of the Comet Kohoutek among numerous experiments. Completed 1,214 Earth orbits and four EVAs totalling 22 hours, 13 minutes. Flight duration: 84 days, 01 hour.
The Skylab 4 astronauts were:
- Gerald P. Carr, Commander
William R. Pogue, Pilot
Edward G. Gibson, Scientist Pilot
SKYLAB OPERATIONS SUMMARY
The Skylab space station was launched May 14, 1973, from the NASA
Kennedy Space Center by a huge Saturn V launch vehicle, the moon
rocket of the Apollo Space Program. Sixty-three seconds after liftoff,
the meteoroid shield--designed also to shade Skylab's
workshop--deployed inadvertently. It was torn from the space station
by atmospheric drag. This event and its effects started a ten-day
period in which Skylab was beset with problems that had to be
conquered before the space station would be safe and habitable for the
three manned periods of its planned eight-month mission.
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
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
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.