Editing Outgassing (section)

==In a vacuum==
Outgassing is a challenge to creating and maintaining clean high-[[vacuum]] environments. [[NASA]] and [[ESA]] maintain lists of materials with low-outgassing properties suitable for use in [[spacecraft]], as outgassing products can condense onto optical elements, [[thermal radiator]]s, or [[solar cell]]s and obscure them. Materials not normally considered absorbent can release enough lightweight [[molecule]]s to interfere with industrial or scientific vacuum processes. [[Moisture]], [[sealant]]s, [[lubricant]]s, and [[adhesive]]s are the most common sources, but even [[metal]]s and [[glass]]es can release gases from cracks or impurities. The rate of outgassing increases at higher [[temperature]]s because the [[vapor pressure]] and rate of chemical reaction increases. For most solid materials, the method of manufacture and preparation can reduce the level of outgassing significantly. Cleaning of surfaces, or heating of individual components or the entire assembly (a process called "[[bake-out]]") can drive off [[Volatility (chemistry)|volatiles]].

NASA's [[Stardust (spacecraft)|''Stardust'']] [[space probe]] suffered reduced image quality due to an unknown contaminant that had condensed on the [[charge-coupled device|CCD]] sensor of the navigation camera.<ref>{{Cite web |date=January 11, 2001  |title=STARDUST Vision Nearly Restored |url=https://stardust.jpl.nasa.gov/news/vision.html |url-status=dead |archive-url=https://web.archive.org/web/20090403014351/https://stardust.jpl.nasa.gov/news/vision.html |archive-date=April 3, 2009 |website=stardust.jpl.nasa.gov}}</ref> A similar problem affected the [[Cassini–Huygens|''Cassini'']] space probe's Narrow Angle Camera, but was corrected by repeatedly heating the system to 4&nbsp;°C.<ref name="jpl-20020723">{{Cite press release |date=23 July 2002 |title=Cassini Camera Haze is Removed |url=https://solarsystem.nasa.gov/news/12241/cassini-camera-haze-is-removed/ |url-status=live |archive-url=https://web.archive.org/web/20240715083900/https://solarsystem.nasa.gov/news/12241/cassini-camera-haze-is-removed/ |archive-date=15 July 2024 |access-date=14 October 2006 |publisher=[[NASA]] & [[JPL]] }}</ref> A comprehensive characterisation of outgassing effects using [[Mass spectrometry|mass spectrometers]] could be obtained for ESA's [[Rosetta (spacecraft)|''Rosetta'']] spacecraft.<ref>B. Schläppi, et al. (2010), Influence of spacecraft outgassing on the exploration of tenuous atmospheres with in situ mass spectrometry, J. Geophys. Res., 115, A12313, {{doi|10.1029/2010JA015734}}.</ref>

Natural outgassing is commonplace in [[comet]]s.<ref>{{cite journal|arxiv=1208.5480|doi=10.1051/0004-6361/201220169|title=An upper limit for the water outgassing rate of the main-belt comet 176P/LINEAR observed with ''Herschel''/HIFI|year=2012|last1=De Val-Borro|first1=M.|last2=Rezac|first2=L.|last3=Hartogh|first3=P.|last4=Biver|first4=N.|last5=Bockelée-Morvan|first5=D.|author5-link=Dominique Bockelée-Morvan|last6=Crovisier|first6=J.|last7=Küppers|first7=M.|last8=Lis|first8=D. C.|last9=Szutowicz|first9=S.|last10=Blake|first10=G. A.|last11=Emprechtinger|first11=M.|last12=Jarchow|first12=C.|last13=Jehin|first13=E.|last14=Kidger|first14=M.|last15=Lara|first15=L.-M.|last16=Lellouch|first16=E.|last17=Moreno|first17=R.|last18=Rengel|first18=M.|s2cid=118376416|journal=Astronomy & Astrophysics|volume=546|pages=L4|bibcode=2012A&A...546L...4D}}</ref>