Editing Skylab (section)

== Film vaults and window radiation shield ==
[[File:P188skylabfilmvault.jpg|thumb|A labeled illustration of a Skylab film vault, from ''Skylab: A Guidebook'' (EP-107) by NASA]]

Skylab had certain features to protect vulnerable technology from [[radiation]].<ref name="ntrs.nasa.gov">{{cite conference |author1=John E. Braly |author2=Thomas R. Heaton |date=1972 |title=Radiation Problems Associated with Skylab |publisher=NASA |book-title=Proceedings of the National Symposium on Natural and Manmade Radiation in Space |url=https://ntrs.nasa.gov/citations/19720010052}} {{cite web |title=PDF |url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19720010052.pdf |url-status=dead |archive-url=https://web.archive.org/web/20170108093705/https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19720010052.pdf|archive-date=2017-01-08}} {{PD-notice}}</ref> The window was vulnerable to darkening, and this darkening could affect experiment S190.<ref name="ntrs.nasa.gov"/> As a result, a light shield that could be open or shut was designed and installed on Skylab.<ref name="ntrs.nasa.gov"/> To protect a wide variety of films, used for a variety of experiments and for astronaut [[photography]], there were five film vaults.<ref name="ntrs.nasa.gov"/> There were four smaller film vaults in the [[Multiple Docking Adapter]], mainly because the structure could not carry enough weight for a single larger film vault.<ref name="ntrs.nasa.gov"/> The orbital workshop could handle a single larger safe, which is also more efficient for shielding.<ref name="ntrs.nasa.gov"/> A later example of a radiation vault is the [[Juno Radiation Vault]] for the [[Juno (spacecraft)|Juno]] Jupiter orbiter, launched in 2011, which was designed to protect much of the uncrewed spacecraft's electronics, using 1&nbsp;cm thick walls of [[titanium]].<ref name="nasa.gov">{{cite web|url=https://www.nasa.gov/mission_pages/juno/news/juno20100712.html|title=NASA – Juno Armored Up to Go to Jupiter|website=nasa.gov|access-date=6 January 2017|archive-date=January 7, 2017|archive-url=https://web.archive.org/web/20170107100649/https://www.nasa.gov/mission_pages/juno/news/juno20100712.html|url-status=dead}} {{PD-notice}}</ref>

The large vault in the orbital workshop had an empty mass of {{convert|2398|lb|kg}}.<ref name="ntrs.nasa.gov"/> The four smaller vaults had combined mass of {{convert|1545|lb|kg|abbr=on}}.<ref name="ntrs.nasa.gov"/> The primary construction material of all five safes was aluminum.<ref name="ntrs.nasa.gov"/> When Skylab re-entered there was one {{convert|180|lb|kg}} chunk of aluminum found that was thought to be a door to one of the film vaults.<ref>{{cite book |last=Shayler |first=David |date=May 28, 2001 |url=https://books.google.com/books?id=X4WaYqQDVKwC&pg=PA313 |page=313 |title=Skylab: America's Space Station |publisher=Springer Science & Business Media |isbn=9781852334079}}</ref> The large film vault was one of the heaviest single pieces of Skylab to [[Atmospheric entry|re-enter]] [[Atmosphere of Earth|Earth's atmosphere]].<ref>{{cite news|last=O'Toole |first=Thomas |url=https://www.washingtonpost.com/archive/politics/1979/07/11/latest-forecast-puts-skylab-over-southern-canada/840063eb-9870-42ef-8e24-093837b3e780/|title=Latest Forecast Puts Skylab Over Southern Canada|newspaper=The Washington Post |issn=0190-8286|date=11 July 1979|access-date=8 January 2017}}</ref>

The Skylab film vault was used for storing film from various sources including the [[Apollo Telescope Mount]] solar instruments.<ref name="nasa.gov2">{{cite web |url=https://history.nasa.gov/SP-402/ch4.htm |title=4: The Solar Telescopes on Skylab |work=SP-402 A New Sun: The Solar Results from Skylab |access-date=9 January 2017}} {{PD-notice}}</ref> Six ATM experiments used film to record data, and over the course of the missions over 150,000 successful exposures were recorded.<ref name="nasa.gov2"/> The film canister had to be manually retrieved on crewed spacewalks to the instruments during the missions.<ref name="nasa.gov2"/> The film canisters were returned to Earth aboard the Apollo capsules when each mission ended, and were among the heaviest items that had to be returned at the end of each mission.<ref name="nasa.gov2"/> The heaviest canisters weighed 40&nbsp;kg and could hold up to 16,000 frames of film.<ref name="nasa.gov2"/>