Editing Skylab (section)

=== Solar activity ===
[[File:Skylab Solar flare.jpg|left|thumb|Skylab captured this view of the Sun]]
[[File:False Color Isophote of a Solar Eruption.jpg|thumb|right|Solar prominence recorded by Skylab on August 21, 1973<ref>{{cite web |url=http://mix.msfc.nasa.gov/abstracts.php?p=1375|archive-url=https://web.archive.org/web/20131112194856/http://mix.msfc.nasa.gov/abstracts.php?p=1375|url-status=dead|archive-date=2013-11-12|title=A Solar Prominence Taken by the Skylab Telescope}} {{PD-notice}}</ref>]]

British mathematician [[Desmond King-Hele]] of the [[Royal Aircraft Establishment]] (RAE) predicted in 1973 that Skylab would de-orbit and crash to Earth in 1979, sooner than NASA's forecast, because of increased [[solar cycle|solar activity]].<ref name="ap19790704">{{cite news |url=https://news.google.com/newspapers?nid=1876&dat=19790704&id=Bj8sAAAAIBAJ&pg=5468,1065536|title=Foreign Astrologers, Soothsayers Make Skylab Predictions|work=Spartanburg Herald|date=July 4, 1979|agency=Associated Press|page=B8|access-date=September 1, 2016}}</ref> Greater-than-expected solar activity<ref>{{harvp|Benson|Compton|1983|p=362}}.</ref> heated the outer layers of Earth's atmosphere and increased drag on Skylab. By late 1977, [[NORAD]] also forecast a reentry in mid-1979;<ref name="harvp|Edelson|1979|p=65"/> a [[National Oceanic and Atmospheric Administration]] (NOAA) scientist criticized NASA for using an inaccurate model for the second most-intense sunspot cycle in a century, and for ignoring NOAA predictions published in 1976.<ref>{{harvp|Benson|Compton|1983|pp=362–363}}.</ref>

The reentry of the USSR's nuclear powered [[Cosmos 954]] in January 1978, and the resulting radioactive debris fall in [[northern Canada]], drew more attention to Skylab's orbit. Although Skylab did not contain radioactive materials, the [[United States Department of State|State Department]] warned NASA about the potential diplomatic repercussions of station debris.<ref>{{harvp|Benson|Compton|1983|p=363}}.</ref> [[Battelle Memorial Institute]] forecast that up to 25 tons of metal debris could land in 500 pieces over an area {{convert|4000|mi}} long and {{convert|1000|mi}} wide. The lead-lined film vault, for example, might land intact at {{convert|400|ft/s|m/s}}.<ref name="lewis1984">{{cite book |title=The Voyages of Columbia: The First True Spaceship |publisher=Columbia University Press |last=Lewis |first=Richard S. |year=1984 |url=https://books.google.com/books?id=v0cG1SdLkP0C |isbn=0-231-05924-8 |pages=80–82 |via=Google Books}}</ref>

Ground controllers re-established contact with Skylab in March 1978<ref>{{harvp|Edelson|1979|pp=65-66}}.</ref> and recharged its batteries.<ref name="time19790716"/> Although NASA worked on plans to reboost Skylab with the Space Shuttle through 1978 and the [[Teleoperator Retrieval System|TRS]] was almost complete, the agency gave up in December 1978 when it became clear that the shuttle would not be ready in time;<ref name="time19790101">{{cite news |url= http://www.time.com/time/magazine/article/0,9171,916583,00.html|archive-url= https://web.archive.org/web/20101022031830/http://www.time.com/time/magazine/article/0,9171,916583,00.html|url-status= dead|archive-date= October 22, 2010|title=Science: Skylab Will Come Tumbling Down|magazine=Time|date=January 1, 1979|page=72}}</ref><ref>{{harvp|Benson|Compton|1983|pp=363–367}}.</ref> its first flight, [[STS-1]], did not occur until April 1981. Also rejected were proposals to launch the TRS using one or two uncrewed rockets<ref name="oberg199202">{{cite magazine|author-link=James Oberg|last=Oberg|first=James |url=http://www.astronautix.com/s/skylabsuntimelyfate.html|title=Skylab's Untimely Fate|magazine=Air & Space|date=February–March 1992|pages=73–79 |url-status=dead |archiveurl=https://web.archive.org/web/20200807043634/http://www.astronautix.com/s/skylabsuntimelyfate.html|archivedate=2020-08-07}}</ref> or to attempt to destroy the station with missiles.<ref name=lewis1984/>