Skylab 4 was the third manned Skylab mission and placed the third and final
crew aboard the first American space station.
The mission started on November 16, 1973 with the launch of three astronauts on a
Saturn IB rocket from the Kennedy Space Center, Florida and lasted 84 days, one
hour and 16 minutes. A total of 6,051 astronaut-utilization hours were tallied
by Skylab 4 astronauts performing scientific experiments in the areas of
medical activities, solar observations, Earth resources, observation of the
Comet Kohoutek and other experiments. The manned Skylab missions were
officially designated Skylab 2, 3, and 4. Mis-communication about the numbering
resulted in the mission emblems reading Skylab I, Skylab II, and Skylab 3
respectively. Crew
Skylab 4 was the fourth all-rookie crew that NASA launched.
= Backup crew = = Support crew =
Robert L. Crippen Henry W. Hartsfield, Jr
Bruce McCandless II F. Story Musgrave
Russell L. Schweickart William E. Thornton
Richard H. Truly Mission parameters
Mass: 20,847 kg Maximum Altitude: 440 km
Distance: 34.5 million miles Launch Vehicle: Saturn IB
Perigee: 422 km Apogee: 437 km
Inclination: 50.04° Period: 93.11 min
= Docking = Docked: November 16, 1973 – 21:55:00 UTC
Undocked: February 8, 1974 – 02:33:12 UTC
Time Docked: 83 days, 4 hours, 38 minutes, 12 seconds
= Space walks = Gibson and Pogue – EVA 1
EVA 1 Start: November 22, 1973, 17:42 UTC
EVA 1 End: November 23, 00:15 UTC Duration: 6 hours, 33 minutes
Carr and Pogue – EVA 2 EVA 2 Start: December 25, 1973, 16:00
UTC EVA 2 End: December 25, 23:01 UTC
Duration: 1 hour, 01 minute Carr and Gibson – EVA 3
EVA 3 Start: December 29, 1973, 17:00 UTC
EVA 3 End: December 29, 20:29 UTC Duration: 3 hours, 29 minutes
Carr and Gibson – EVA 4 EVA 4 Start: February 3, 1974, 15:19 UTC
EVA 4 End: February 3, 20:38 UTC Duration: 5 hours, 19 minutes
Mission highlights Skylab 4 was the last Skylab mission.
The crew arrived aboard Skylab to find that they had company – three figures
dressed in flight suits. Upon closer inspection, they found their companions
were three dummies, complete with Skylab 4 mission emblems and name tags which
had been left there by Al Bean, Jack Lousma, and Owen Garriott at the end of
Skylab 3. The all-rookie astronaut crew had
problems adjusting to the same workload level as their predecessors when
activating the workshop. Things got off to a bad start after the crew attempted
to hide Pogue's early space sickness from flight surgeons, a fact discovered
by mission controllers after downloading onboard voice recordings. The crew's
initial task of unloading and stowing the thousands of items needed for their
lengthy mission also proved to be overwhelming. The schedule for the
activation sequence dictated lengthy work periods with a large variety of
tasks to be performed, and the crew soon found themselves tired and behind
schedule. As the activation of Skylab progressed,
the astronauts complained of being pushed too hard. Ground crews disagreed;
they felt that the astronauts were not working long enough or hard enough.
During the course of the mission, this culminated in a radio conference to air
frustrations. Following this, the workload schedule was modified, and by
the end of their mission the crew had completed even more work than had been
planned before launch. The experiences of the crew and ground controllers
provided important lessons in planning subsequent manned spaceflight work
schedules. On Thanksgiving Day, Gibson and Pogue
accomplished a 61⁄2 hour spacewalk. The first part of their spacewalk was spent
replacing film in the solar observatory. The remainder of the time was used to
repair a malfunctioning antenna. The crew reported that the food was
good, but slightly bland. The crew would have preferred to use more condiments to
enhance the taste of the food. The amount of salt they could use was
restricted for medical purposes. The quantity and type of food consumed was
rigidly controlled because of their strict diet.
Seven days into their mission, a problem developed in the Skylab gyroscope
attitude control system, which threatened to bring an early end to the
mission. Skylab depended upon three large gyroscopes, sized so that any two
of them could provide sufficient control and maneuver Skylab as desired. The
third acted as a backup in the event of failure of one of the others. The
gyroscope failure was attributed to insufficient lubrication. Later in the
mission, a second gyroscope showed similar problems, but special
temperature control and load reduction procedures kept the second one
operating, and no further problems occurred.
The crew spent many hours studying the Earth. Carr and Pogue alternately manned
controls, operating the sensing devices which measured and photographed selected
features on the Earth's surface. The crew also made solar observations,
recording about 75,000 new telescopic images of the Sun. Images were taken in
the X-ray, ultraviolet, and visible portions of the spectrum.
As the end of their mission drew closer, Gibson continued his watch of the solar
surface. On January 21, 1974, an active region on the Sun's surface formed a
bright spot which intensified and grew. Gibson quickly began filming the
sequence as the bright spot erupted. This film was the first recording from
space of the birth of a solar flare. On December 13, the crew sighted Comet
Kohoutek and trained the solar observatory and hand-held cameras on it.
They gathered spectra on it using the Far Ultraviolet Camera/Spectrograph.
They continued to photograph it as it approached the Sun. On December 30, as
it swept out from behind the Sun, Carr and Gibson spotted it as they were
performing a spacewalk. The crew also photographed the Earth
from orbit. Despite instructions not to do so, the crew photographed Area 51,
causing a minor dispute between various government agencies as to whether the
photographs showing this secret facility should be released. In the end, the
picture was published along with all others in NASA's Skylab image archive,
but remained unnoticed for years. The Skylab 4 astronauts completed 1,214
Earth orbits and four EVAs totaling 22 hours, 13 minutes. They traveled 34.5
million miles in 84 days, 1 hour and 16 minutes in space.
The three astronauts had joined NASA in the mid-1960s, during the Apollo
program, with Pogue and Carr becoming part of the likely crew for the
cancelled Apollo 19. Ultimately none of the crew of Skylab 4 flew in space
again, as all three retired from NASA before the first Space Shuttle launch.
Gibson, who had trained as a scientist-astronaut, resigned from NASA
in December 1974 to do research on Skylab solar physics data, as a senior
staff scientist with the Aerospace Corp. of Los Angeles, California.
Gallery Spacecraft location
The Skylab 4 command module is on display at the National Air and Space
Museum in Washington, D.C. Mission insignia
The triangular emblem features a large number 3 and a rainbow circling three
areas of study the astronauts pursued. At the time of the flight, the
astronauts issued the following description:
"The symbols in the patch refer to the three major areas of investigation in
the mission. The tree represents man's natural environment and refers to the
objective of advancing the study of earth resources. The hydrogen atom, as
the basic building block of the universe, represents man's exploration
of the physical world, his application of knowledge, and his development of
technology. Since the sun is composed primarily of hydrogen, the hydrogen
symbol also refers to the Solar Physics mission objectives. The human silhouette
represents mankind and the human capacity to direct technology with a
wisdom tempered by his regard for his natural environment. It also relates to
the Skylab medical studies of man himself. The rainbow, adopted from the
Biblical story of the Flood, symbolizes the promise that is offered to man. It
embraces man and extends to the tree and hydrogen atom, emphasizing man's pivotal
role in the conciliation of technology with nature by a humanistic application
of our scientific knowledge." Some versions of the patch included a comet
in the top curve because of studies made of the comet Kohoutek.
See also Extra-vehicular activity
List of spacewalks Splashdown
References Further reading
Gilles Clement, Fundamentals of Space Medicine, Microcosm Press, 2003. pp.
212. Lattimer, Dick. All We Did was Fly to
the Moon. Whispering Eagle Press. ISBN 0-9611228-0-3.
External links Skylab: Command service module systems
handbook, CSM 116 – 119 April 1972 Skylab Saturn 1B flight manual September
1972 NASA Skylab Chronology
Marshall Space Flight Center Skylab Summary
Skylab 4 Characteristics SP-4012 NASA HISTORICAL DATA BOOK
Astronauts and Area 51: the Skylab Incident
Skylab, "The Third Manned Period", NASA History
Voices of Oklahoma interview with William Pogue. First person interview
conducted with William Pogue on August 8, 2012. Original audio and transcript
archived with Voices of Oklahoma oral history project.