Skylab 4

Infobox Space mission
mission_name = "Skylab IV"
insignia = Skylab3-Patch.png sign = Skylab 4
crew_members = 3
launch_pad = Kennedy Space Center, Florida
LC 39B
launch = November 16, 1973
14:01:23 UTC
landing = February 8, 1974
15:16:53 UTC
coord|31|18|N|119|48|W|
mass = CSM: ~20,000 kg
crew_photo = S73-33208.jpg
crew_caption = L-R: Carr, Gibson and Pogue
previous =
next =
duration = 84d/01:15:30
apogee = 437 km
perigee = 422 km
period = 93.11 min
inclination = 50.0°
orbits = 1214
distance = ~55,500,000 km|

Skylab 4 (also SL-4 and SLM-3 [cite web | url = http://williampogue.com/skylab-numbering-mixup.html | title = Skylab Numbering Fiasco | publisher = williampogue.com] ) was the fourth Skylab mission and placed the third crew on board. It started November 16, 1973, with the launch of three astronauts on a Saturn IB rocket, and lasted 84 days, 1 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.

Crew

Number in parentheses indicates number of spaceflights by each individual prior to and including this mission.
*Gerald P. Carr (1) - Commander
*William R. Pogue (1) - Pilot
*Edward G. Gibson (1) - Science Pilot

Backup Crew

*Vance D. Brand - Commander
*Don L. Lind- Pilot
*William Lenoir - Science Pilot

upport Crew

*Robert L. Crippen
*Richard H. Truly
*Henry W. Hartsfield, Jr
*William E. Thornton

Mission parameters

*Mass: 20,847 kg
*Maximum Altitude: 440 km
*Distance: 34.5 million miles (55,500,000 km)
*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

pace 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

ee also

*Extra-vehicular activity
*List of spacewalks
*Splashdown

Mission highlights

Skylab 4 was the last Skylab mission.

The crew arrived on Skylab to find that they had company up there - three figures dressed in flight suits. Upon closer inspection, they found their companions were three dummies, complete with Skylab 4 mission patches 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 one astronaut's early motion 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 the crew announcing an unscheduled day off, mutinying against Mission Control by turning off the communications radio while getting some rest. After a radio conference to air frustrations, their 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 6 1/2 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 attitude control gyroscope 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 looking at the Earth. Carr and Pogue alternately manned controls, operating the sensing devices which measured and photographed selected features on the Earth's surface. When not otherwise occupied, they watched through the workshop window as the Earth rolled steadily beneath them.

Solar observations were made, with about 75,000 new telescopic images of the Sun recorded. 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 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 (perhaps inadvertently) 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. [ [http://www.thespacereview.com/article/1010/1 The Space Review: Secret Apollo] published November 26th, 2007]

Skylab 4 completed 1,214 Earth orbits and four EVAs totalling 22 hours, 13 minutes.They traveled 34.5 million miles (55,500,000 km) in 84 days, 1 hour and 16 minutes in space.

None of the three astronauts in this crew would ever fly in space again. Whether or not this was the result of their 'mutiny' is somewhat debatable, as there was only the ASTP mission left between Skylab-4 and STS-1. Both Carr and Gibson retired from NASA before the Shuttle flew.

Mission insignia

The triangular patch 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 insignia include a comet in the top curve because of studies made of the Comet Kohoutek but these were not apparently worn during the flight.

References

* [http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19720067844_1972067844.pdf Skylab: Command service module systems handbook, CSM 116 - 119 (PDF) April 1972]
* [http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19740021163_1974021163.pdf Skylab Saturn 1B flight manual (PDF) September 1972]
* [http://history.nasa.gov/SP-4011/contents.htm NASA Skylab Chronology]
* [http://history.nasa.gov/SP-4011/app2.htm Marshall Space Flight Center Skylab Summary]
* [http://history.nasa.gov/SP-4012/vol3/table2.51.htm Skylab 4 Characteristics SP-4012 NASA HISTORICAL DATA BOOK]
* [http://www.thespacereview.com/article/531/1]
*Source: [http://history.nasa.gov/SP-400/ch9.htm]
*Gilles Clement, "Fundamentals of Space Medicine," Microcosm Press, 2003. pp. 212.
*Lattimer, Dick (1985). "All We Did was Fly to the Moon". Whispering Eagle Press. ISBN 0-9611228-0-3.