Editing Whipple shield

{{Short description|Impact shield to protect spacecraft from micrometeoroids and orbital debris}}
[[Image:WhippleShield.jpg|thumb|right|upright=1.2|Whipple shield used on [[NASA]]'s ''[[Stardust (spacecraft)|Stardust]]'' probe]]

The '''Whipple shield''' or '''Whipple bumper''', invented by [[Fred Whipple]],<ref name="Whipple47">{{Citation |last=Whipple |first=Fred L. |title=Meteorites and Space Travel |journal=Astronomical Journal |volume=52 |page=131 |year=1947 |bibcode=1947AJ.....52Q.131W |doi=10.1086/106009 |doi-access=free}}.</ref> is a type of [[spaced armor]] shielding to protect crewed and uncrewed [[spacecraft]] from [[hypervelocity]] impact / collisions with [[micrometeoroid]]s and [[orbital debris]] whose velocities generally range between {{convert|3|and|18|km/s}}. According to NASA, the Whipple shield is designed to withstand collisions with debris up to 1&nbsp;cm.<ref>{{cite web | url=https://solarsystem.nasa.gov/stardust/spacecraft/whipple.html | title=STARDUST Whipple Shield }}</ref>

==Shield==
In contrast to monolithic shielding of early spacecraft, Whipple shields consist of a relatively thin outer bumper spaced some distance from the main spacecraft wall. The bumper is not expected to stop the incoming particle or even remove much of its energy, but to break up and disperse it, dividing the original particle energy among many fragments that fan out between bumper and wall. The original particle energy is spread more thinly over a larger wall area, which is more likely to withstand it. Although a Whipple shield lowers total spacecraft mass compared to a solid shield (always desirable in spaceflight), the extra enclosed volume may require a larger [[payload fairing]].

There are several variations on the simple Whipple shield. [[Multi-shock shields]],<ref name="C-P89">{{Citation |last1=Cour-Palais |first1=Burton G. |title=A Multi-Shock Concept for Spacecraft Shielding |journal=International Journal of Impact Engineering |volume=10 |issue=1–4 |pages=135–146 |year=1990 |doi=10.1016/0734-743X(90)90054-Y |last2=Crews |first2=Jeanne L.|bibcode=1990IJIE...10..135C }}.</ref><ref name="Crews91">{{cite patent|country-code=US|patent-number=5067388|title=Hypervelocity Impact Shield|issue-date=November 26, 1991|inventor1-last=Crews|inventor2-last=Cour-Palais|inventor1-first=Jeanne L.|inventor2-first=Burton G.}}.</ref> like the one used on the ''[[Stardust (spacecraft)|Stardust]]'' spacecraft, use multiple bumpers spaced apart to increase the shield's ability to protect the spacecraft. Whipple shields that have a filling between the rigid layers of the shield are called ''stuffed Whipple shields''.<ref name="Christiansen95">{{citation |last1=Christiansen |first1=Eric L. |title=Enhanced Meteoroid and Orbital Debris Shielding |journal=International Journal of Impact Engineering |volume=17 |issue=1–3 |pages=217–228 |year=1995 |url=https://zenodo.org/record/1258555 |doi=10.1016/0734-743X(95)99848-L |last2=Crews |first2=Jeanne L. |last3=Williamsen |first3=Joel E. |last4=Robinson |first4=Jennifer H. |last5=Nolen |first5=Angela M.|bibcode=1995IJIE...17..217C }}.</ref><ref name="Crews97">{{cite patent|country-code=US|patent-number=5610363|title=Enhanced Whipple Shield|issue-date=March 11, 1997|inventor1-last=Crews|inventor2-last=Christiansen|inventor3-last=Robinson|inventor4=Joel E. Williamsen, Angela M. Nolen|inventor1-first=Jeanne L.|inventor2-first=Eric L.|inventor3-first=Jennifer H.}}.</ref> The filling in these shields is usually a high-strength material like [[Kevlar]] or Nextel [[aluminium oxide]] fiber.<ref name="3M">{{citation |title=3M Nextel Ceramic Fabric Offers Space Age Protection |url=http://www.3m.com/market/industrial/ceramics/pdfs/CeramicFabric.pdf |publisher=[[3M Company]] |archiveurl=https://web.archive.org/web/20040205073017/http://www.3m.com/market/industrial/ceramics/pdfs/CeramicFabric.pdf |archivedate=2004-02-05}}.</ref> The type of shield, the material, thickness and distance between layers are varied to produce a shield with minimal mass that will also minimize the probability of penetration. There are over 100 shield configurations on the [[International Space Station]] alone,<ref name="Christiansen03">{{citation |last=Christiansen |first=Eric L. |title=Meteoroid/Debris Shielding |page=13 |year=2003 |url=http://ston.jsc.nasa.gov/collections/TRS/_techrep/TP-2003-210788.pdf |url-status=dead |location=Washington, DC |publisher=National Aeronautics and Space Administration |format=Technical Report |id=TP−2003-210788 |archiveurl=https://web.archive.org/web/20130225001045/http://ston.jsc.nasa.gov/collections/TRS/_techrep/TP-2003-210788.pdf |archivedate=2013-02-25}}.</ref> with important and high-risk areas having better shielding.

== See also ==
* [[Double hull]]
* [[Micrometeoroid shielding]]
* [[Spaced armor]]

==References==
{{Reflist}}

== External links ==
*[https://web.archive.org/web/20081211000227/http://hitf.jsc.nasa.gov/hitfpub/shielddev/basicconcepts.html Brief descriptions of spacecraft shielding by NASA]
*[https://historycollection.jsc.nasa.gov/JSCHistoryPortal/history/oral_histories/Cour-PalaisBG/Cour-PalaisBG_3-1-04.pdf NASA Oral History Project - B.G. Cour-Palais' reminisces of the Apollo meteoroid protection program]
*[https://historycollection.jsc.nasa.gov/JSCHistoryPortal/history/oral_histories/CrewsJL/CrewsJL_8-6-07.pdf NASA Oral History Project - J.L. Crews' recounting of the invention of the multi-shock shield, pp. 21–29]
*[https://history.nasa.gov/skylabrep/SRcover.htm The Skylab meteoroid shield design and development]
*[https://web.archive.org/web/20111024145836/http://www.esa.int/export/SPECIALS/Space_Year_2007/SEMIZWXTVKG_0.html ESA Giotto dust shield]
*[https://web.archive.org/web/20120325000204/http://mediaarchive.ksc.nasa.gov/detail.cfm?mediaid=21624 Installing the Nextel/Kevlar blankets in the Destiny laboratory stuffed Whipple Shields]
*[http://www.esa.int/TEC/Structures/SEM1TQLJC0F_0.html Meteoroid/Debris Protection System Development at ESA for ATV and Columbus]
*[http://iss.jaxa.jp/iss/kibo/develop_status_09_e.html Hyper-velocity impact test at JAXA of Kibo's debris shield]

[[Category:Spacecraft components]]
[[Category:Shields]]