Editing Solar sail (section)

===IKAROS 2010===
{{Main|IKAROS}}
[[File:IKAROS IAC 2010.jpg|thumb|220px|The model of IKAROS at the 61st [[International Astronautical Congress]] in 2010]]

On 21 May 2010, [[Japan Aerospace Exploration Agency]] (JAXA) launched the [[world]]'s first [[Interplanetary spaceflight|interplanetary]] solar sail [[spacecraft]] "[[IKAROS]]" (Interplanetary Kite-craft Accelerated by Radiation Of the Sun) to Venus.<ref>{{cite web|url=http://www.jspec.jaxa.jp/e/activity/ikaros.html |archive-url=https://web.archive.org/web/20080922170700/http://www.jspec.jaxa.jp/e/activity/ikaros.html |url-status=dead |archive-date=2008-09-22 |title=IKAROS Project｜JAXA Space Exploration Center |publisher=Jspec.jaxa.jp |date=2010-05-21 |access-date=2011-01-18 }}</ref> Using a new solar-photon propulsion method,<ref>{{cite book|url=https://books.google.com/books?id=c4vJpFCs1kQC&pg=PA308|title=Protection of Materials and Structures From the Space Environment|first1=Jacob|last1=Kleiman|first2=Masahito|last2=Tagawa|first3=Yugo|last3=Kimoto|date=22 September 2012|publisher=Springer Science & Business Media|via=Google Books|isbn=9783642302299}}</ref> it was the first true solar sail spacecraft fully propelled by sunlight,<ref>[https://www.newscientist.com/article/mg20627603-800-maiden-voyage-for-first-true-space-sail/ Maiden voyage for first true space sail], ''[[New Scientist]]''</ref><ref>{{cite book|url=https://books.google.com/books?id=jaExBQAAQBAJ&pg=PA169|title=Solar Sails: A Novel Approach to Interplanetary Travel|first1=Giovanni|last1=Vulpetti|first2=Les|last2=Johnson|first3=Gregory L.|last3=Matloff|date=5 November 2014|publisher=Springer|via=Google Books|isbn=9781493909414}}</ref> and was the first spacecraft to succeed in solar sail flight.<ref>{{cite book|url=https://books.google.com/books?id=9tP-CgAAQBAJ&pg=PA32|title=Human Spaceflight: From Mars to the Stars|first=Louis|last=Friedman|date=5 November 2015|publisher=University of Arizona Press|via=Google Books|isbn=9780816531462}}</ref>

JAXA successfully tested IKAROS in 2010. The goal was to deploy and control the sail and, for the first time, to determine the minute orbit perturbations caused by light pressure. Orbit determination was done by the nearby [[Akatsuki (spacecraft)|AKATSUKI probe]] from which IKAROS detached after both had been brought into a transfer orbit to Venus. The total effect over the six month flight was 100&nbsp;m/s.<ref>{{cite web|url=http://www.isas.jaxa.jp/e/forefront/2011/tsuda/index.shtml|title=Solar Sail Navigation Technology of IKAROS|last=Tsuda|first=Yuichi|year=2011|publisher=[[JAXA]]}}</ref>

Until 2010, no solar sails had been successfully used in space as primary propulsion systems. On 21 May 2010, the Japan Aerospace Exploration Agency (JAXA) launched the IKAROS spacecraft, which deployed a 200 m<sup>2</sup> polyimide experimental solar sail on June 10.<ref name="jaxa.jp/press/2010/06/20100611_ikaros_e">{{cite web| title = Small Solar Power Sail Demonstrator 'IKAROS' Successful Solar Sail Deployment | work = JAXA website press release | publisher = Japan Aerospace Exploration Agency | date = 2010-06-11 | url = http://www.jaxa.jp/press/2010/06/20100611_ikaros_e.html | access-date = 2010-06-17}}</ref><ref name=Nature>{{Cite news| title=News briefing: 27 May 2010 | url=http://www.nature.com/news/2010/100526/full/465402a.html | work= NatureNEWS | date=26 May 2010 | access-date= 2 June 2010}}</ref><ref>{{cite web | author=Samantha Harvey | title=Solar System Exploration: Missions: By Target: Venus: Future: Akatsuki | url=http://solarsystem.nasa.gov/missions/profile.cfm?MCode=Akatsuki | publisher=NASA | date=21 May 2010 | access-date=2010-05-21 | archive-date=2010-05-27 | archive-url=https://web.archive.org/web/20100527210311/http://solarsystem.nasa.gov/missions/profile.cfm?MCode=Akatsuki | url-status=dead }}</ref> In July, the next phase for the demonstration of acceleration by radiation began. On 9 July 2010, it was verified that IKAROS collected radiation from the Sun and began photon acceleration by the orbit determination of IKAROS by range-and-range-rate (RARR) that is newly calculated in addition to the data of the relativization accelerating speed of IKAROS between IKAROS and the Earth that has been taken since before the Doppler effect was utilized.<ref name="http://www.jaxa.jp/press/2010/07/20100709_ikaros_j.html">{{cite web| title = About the confirmation of photon acceleration of "IKAROS" the small solar-sail demonstrating craft ('''There is not English press release yet''')| work = JAXA website press release | publisher = Japan Aerospace Exploration Agency | date = 2010-07-09 | url = http://www.jaxa.jp/press/2010/07/20100709_ikaros_j.html| access-date = 2010-07-10 }}</ref> The data showed that IKAROS appears to have been solar-sailing since 3 June when it deployed the sail.

IKAROS has a diagonal spinning square sail 14×14 m (196 m<sup>2</sup>) made of a {{convert|adj=on|7.5|μm|mm}} thick sheet of [[polyimide]]. The polyimide sheet had a mass of about 10 grams per square metre.<!-- calculated from polyimide density 1430 kg/m^3 --> A thin-film solar array is embedded in the sail. Eight [[liquid crystal display|LCD]] panels are embedded in the sail, whose reflectance can be adjusted for [[Spacecraft attitude control|attitude control]].<ref name=jaxa20100311>{{cite web | title=Small Solar Power Sail Demonstrator | url=http://www.jaxa.jp/projects/sat/ikaros/index_e.html | publisher=JAXA | date=11 March 2010 | access-date=2010-05-07 | archive-date=2013-10-30 | archive-url=https://web.archive.org/web/20131030175323/http://www.jaxa.jp/projects/sat/ikaros/index_e.html | url-status=dead }}</ref><ref>{{cite web|url=http://www.jspec.jaxa.jp/e/activity/ikaros.html |archive-url=https://web.archive.org/web/20080922170700/http://www.jspec.jaxa.jp/e/activity/ikaros.html |url-status=dead |archive-date=22 September 2008 |title=IKAROS Project |year=2008 |publisher=JAXA |access-date=30 March 2010 }}</ref> IKAROS spent six months traveling to Venus, and then began a three-year journey to the far side of the Sun.<ref>{{cite magazine| last = McCurry | first = Justin | title = Space yacht Ikaros ready to cast off for far side of the Sun | magazine = The Guardian Weekly | date = 2010-05-17 | url = https://www.theguardian.com/world/2010/may/17/space-yacht-ikaros-japan-venus | access-date = 2010-05-18 | location=London}}</ref>