Editing Skylab 4 (section)

==Communications break==
An unplanned communications break occurred during the Skylab 4 mission: its crew did not communicate with mission control for the portion of one orbit during which Skylab had line of sight to its tracking stations.<ref>{{cite news|last=Broad|first=William J.|title=On Edge in Outer Space? It Has Happened Before|newspaper=[[The New York Times]]|url=https://www.nytimes.com/1997/07/16/world/on-edge-in-outer-space-it-has-happened-before.html|date=July 16, 1997|accessdate=January 29, 2017}}</ref> Before the midpoint of the mission, the Skylab 4 crew had started to become fatigued and behind on the work. In order to catch up, they decided that only one crew member needed to be present for the daily briefing instead of all three, allowing the other two to complete ongoing tasks.<ref name="bbc gibson"/> At one point, according to both Carr and Gibson, the crew forgot to turn their radios on for the daily briefing, leading to a lack of communications between the crew and ground control during that orbit's period of communications availability. By the next planned period, the crew had reaffirmed radio contact with ground control.<ref name="bbc gibson">{{cite web |url = https://www.bbc.com/news/stories-56346001 |title = Skylab: The myth of the mutiny in space |first= Kirstie |last =Brewer |date = March 20, 2021 |accessdate= March 22, 2021 |publisher = [[BBC]] }}</ref><ref name="carr oral history">{{cite report |url = https://historycollection.jsc.nasa.gov/JSCHistoryPortal/history/oral_histories/CarrGP/GPC_10-25-00.pdf |title = Oral History Transcript - Gerald Carr |date = October 25, 2000 |accessdate = March 26, 2021 |first = Kevin |last = Rusnak |publisher = [[NASA Johnson Space Center]] }}</ref> Both Carr and Gibson stated that this event partially contributed to a discussion on December 30, 1973, in which the crew and ground control [[capsule communicator]] [[Richard H. Truly]] revisited the astronauts' schedule in light of their fatigue. Carr called this meeting "the first sensitivity session in space".<ref name="bbc gibson"/><ref name="carr oral history"/> NASA agreed to assign the crew a more relaxed schedule, and productivity for the remaining mission significantly increased, surpassing that of the prior [[Skylab 3]] mission.<ref name="nasa strike"/>

===Consequences===
[[File:HHPS Figure 3-2.jpg|thumb|Performance lapses for time in bed (TIB) over 14 days of sleep restriction<ref name="Van Dongen" />]]

NASA spent time studying the causes and effects of the unintentional lack of communications to avoid its replication in future missions.<ref name=":1" /> At the time, only the crew of Skylab 3 had spent six weeks in space. It was unknown what had happened psychologically. NASA carefully worked with crew's requests, reducing their workload for the next six weeks. The incident took NASA into an unknown realm of concern in the selection of astronauts, still a question as humanity considers human missions to Mars or returning to the Moon.<ref name="AutoFP-4" /> Among the complicating factors was the interplay between management and subordinates. On Skylab 4, one problem was that the crew was pushed even harder as they fell behind on their workload, creating an increasing level of stress.<ref name="AutoFP-5" /> Even though none of the astronauts returned to space, there was only one more NASA spaceflight in the decade and Skylab was the first and last American space station.<ref name="armaghplanet.com" /> NASA was planning larger space stations but its budget shrank considerably after the Moon landings, and the Skylab orbital workshop was the only major execution of [[Apollo Applications Program|Apollo Applications]] projects.<ref name="armaghplanet.com" />

The final Skylab mission became known for the incident, and also known for the large amount of work that was accomplished in the long mission.<ref name=":0" /> Skylab orbited for six more years before its orbit decayed in 1979 due to solar activity that was higher than expected.<ref name=":1" /> The next crewed U.S. spaceflights were the [[Apollo–Soyuz Test Project]] in July 1975, then the first Space Shuttle orbital flight [[STS-1]] in April 1981.

The event, which the involved astronauts have joked about,<ref name="nytimes pogue obit">{{cite news |last=Vitello |first=Paul |title=William Pogue, Astronaut Who Staged a Strike in Space, Dies at 84 |newspaper=The New York Times |url=https://www.nytimes.com/2014/03/11/science/space/william-r-pogue-astronaut-who-flew-longest-skylab-mission-is-dead-at-84.html |date=March 10, 2014 |accessdate=January 30, 2017}}</ref> has been a case study in various fields of endeavor including [[space medicine]], [[Team composition and cohesion in spaceflight missions|team management]], and [[Space psychology|psychology]]. According to ''[[Space Safety Magazine]]'', the incident affected the planning of future space missions, especially long-term missions.<ref name=":0" />

The described events were considered a significant example of "us versus them" syndrome in space medicine.<ref name="Clément" /> Crew psychology has been a point of study for Mars analog missions such as [[Mars-500]], with a particular focus on crew behavior triggering a mission failure or other issues.<ref name="Clément" /> One of the impacts of the incident is the requirement that at least one member of the International Space Station crew be a space veteran (not be on a first flight).<ref name="AutoFP-6" />

The 84-day stay of the Skylab 4 mission was a human spaceflight record that was not exceeded for over two decades by a NASA astronaut.<ref name=":3" /> The 96-day Soviet [[Salyut 6 EO-1]] mission broke Skylab 4's record in 1978.<ref>{{Cite web|url=http://www.globalsecurity.org/space/world/russia/soyuz_26_27_series.htm|title=Soyuz 26 and Soyuz 27|last=Pike|first=John|website= globalsecurity.org|access-date=2017-01-05}}</ref><ref>{{cite web |last1=Hollingham |first1=Richard |title=How the most expensive structure in the world was built |url=https://www.bbc.com/future/article/20151221-how-the-most-expensive-structure-in-the-world-was-built |website=BBC |date=December 21, 2015}}</ref>

===In the media===
{{anchor|Skylab strike}}
The communications failure has been interpreted by the media as a deliberate act<ref name="nasa strike"/><ref name="nytimes pogue obit"/><ref name="Hiltzik" /> and became known as the '''Skylab strike''' or '''Skylab mutiny'''. One of the first accounts reporting that a strike aboard Skylab had occurred was published in ''[[The New Yorker]]'' on August 22, 1976, by [[Henry S. F. Cooper Jr.|Henry S. F. Cooper]], who claimed that the crew were alleged to have stopped working on December 28, 1973.<ref>{{cite news |last=Cooper |first=Henry S. F. |author-link=Henry S. F. Cooper Jr. |title=Life in a Space Station |newspaper=[[The New Yorker]] |url=http://www.newyorker.com/magazine/1976/09/06/life-in-a-space-station-ii|date=August 30, 1976|accessdate=January 30, 2017}}</ref><ref name="nasa strike"/> Cooper also published similar claims in his book ''A House in Space'' that same year.<ref name="nasa strike"/> The [[Harvard Business School]] published a 1980 report, "Strike in Space", also claiming that the astronauts had gone on strike, but without citing any sources.<ref name="nasa strike"/>

NASA, the astronauts involved, and spaceflight historians have stated that no strike occurred. NASA has suggested the events of December 28 may have been confused with a day off that was given to the crew on December 26 following the completion of a long spacewalk by Carr and Pogue the day before.<ref name="bbc gibson"/><ref name="nasa strike">{{cite web |url = https://www.nasa.gov/feature/the-real-story-of-the-skylab-4-strike-in-space/ |title = The Real Story of the Skylab 4 "Strike" in Space |first = John |last= Uri |date = November 16, 2020 |accessdate = March 22, 2021 |publisher = [[NASA]] }}</ref> NASA added that there may also have been confusion with a known ground equipment failure on December 25; this left them unable to track Skylab for one orbit, but the crew were notified of this issue ahead of time.<ref name="nasa strike"/> Both Carr and Gibson have stated that it was a series of misjudgments and not the crew's intent that caused them to miss the briefing.<ref name="bbc gibson"/><ref name="carr oral history"/><ref name="gibson oral history">{{cite web |url =https://historycollection.jsc.nasa.gov/JSCHistoryPortal/history/oral_histories/GibsonEG/GibsonEG_12-1-00.htm |title = Oral History Transcript - Edward G. Gibson |first = Carol |last= Butler |date = December 1, 2000 |accessdate = March 26, 2021 |publisher = [[NASA Johnson Space Center]] }}</ref> Spaceflight history author [[David Hitt]] also disputed that the crew deliberately ended contact with mission control, in a book written with former astronauts [[Owen K. Garriott]] and [[Joseph P. Kerwin]].<ref name="HS">{{cite book |last=Hitt |first=David |author-link=David Hitt |title=Homesteading Space: The Skylab Story|publisher=[[University of Nebraska Press]]|url=https://books.google.com/books?id=sR5Cm_zeIekC |date=2008|accessdate=January 29, 2017 |isbn=978-0803219014}}</ref>