Solar Impulse

Bertrand Piccard initiated the Solar Impulse project in November 2003 after undertaking a feasibility study in partnership with the École Polytechnique Fédérale de Lausanne (EPFL).{{cite web|url=http://www.solarimpulse.com/timeline/view/6652|work=Solar Impulse|title=What happened between 2001 and 2003?|date=31 December 2003|url-status=dead|archive-url=https://web.archive.org/web/20130820013235/http://www.solarimpulse.com/timeline/view/6652|archive-date=20 August 2013|df=dmy-all}} As a mechanical engineer, co-founder André Borschberg directed the construction of each aircraft and oversees the preparation of the flight missions.{{cite news|url=http://edition.cnn.com/video/?/video/tech/2011/11/29/solar-impulse-aircraft.cnn|archive-url=https://web.archive.org/web/20111215134347/http://edition.cnn.com/video/?/video/tech/2011/11/29/solar-impulse-aircraft.cnn|url-status=dead|archive-date=15 December 2011|access-date=29 November 2011|publisher=CNN|title=Can solar power fuel future flight| date=29 November 2011}} By 2009, they had assembled a multi-disciplinary team of 50 engineers and technical specialists from six countries, assisted by about 100 outside advisers and 80 technological partners.{{cite web|url=http://www.solarimpulse.com/en/airplane/major-steps/|title=Major steps|publisher=Solar Impulse|access-date=5 December 2009|url-status=dead|archive-url=https://web.archive.org/web/20120915070035/http://solarimpulse.com/en/airplane/major-steps/|archive-date=15 September 2012|df=dmy-all}}

The project is financed by a number of private companies and individuals, as well as receiving around CHF 6 million (US$6.4 million) in funding from the Swiss government.{{cite web| url=http://www.swissinfo.ch/eng/government-supports-solar-impulse-with-chf6m/41279522|title=Government supports Solar Impulse with CHF6m|publisher=SwissInfo.ch|date=18 February 2015|access-date= 24 March 2015}} The project's private financial backers include Omega SA, Solvay, Schindler, ABB{{cite web|last=Piccard|first=Bertrand|title=Solar Impulse gets a lift!|url=http://www.solarimpulse.com/timeline/view/7401|date=4 April 2014|access-date=4 April 2014|url-status=dead|archive-url=https://web.archive.org/web/20140717023500/http://www.solarimpulse.com/timeline/view/7401|archive-date=17 July 2014|df=dmy-all}} and Peter Diamandis.{{cite web|url=http://www.solarimpulse.com/timeline/view/7292|publisher=Solar Impulse|title=Peter Diamandis our New Patron|first=Viktoria|last=Dijakovic|date=10 October 2013|access-date=22 March 2015|url-status=dead|archive-url=https://web.archive.org/web/20141216143328/http://www.solarimpulse.com/timeline/view/7292|archive-date=16 December 2014|df=dmy-all}} The EPFL, the European Space Agency and Dassault have provided technical expertise, while SunPower provided the aircraft's photovoltaic cells.{{cite web| url=http://global.sunpowercorp.com/about/sponsor/solar-impulse/| title=Solar Impulse – Around the world in a solar airplane| publisher=SunPower| access-date=24 January 2013| archive-url=https://web.archive.org/web/20120503074601/http://global.sunpowercorp.com/about/sponsor/solar-impulse/| archive-date=3 May 2012| url-status=dead}}; and {{cite web| last1=Dijakovic| first1=Viktoria| title=Construction HB-SIB Solar Cells| url=http://info.solarimpulse.com/timeline/view/6544| publisher=Solar Impulse| date=17 July 2012}}{{cite web| url=http://www.solarimpulse.com/common/documents/partner.php?lang=en&group=partner| title=Partners, Financing Structure| publisher=Solar Impulse| access-date=25 February 2010| url-status=dead| archive-url=https://web.archive.org/web/20110106124812/http://solarimpulse.com/common/documents/partner.php?lang=en&group=partner| archive-date=6 January 2011| df=dmy-all}}

Piccard stated that the entire project from its beginnings in 2003 until mid-2015 had cost €150 million.{{cite web| url=https://www.theguardian.com/environment/2015/jul/27/solar-impulse-round-the-world-flight-raise-20-million-euros| work=The Guardian| title=Solar Impulse's troubled round-the-world flight: 'We need to raise €20m'|first=Joshi |last=Herrmann| date=27 July 2015|access-date=28 July 2015 }} It raised another €20 million in late 2015 to continue the round-the-world flight.Al Wasmi, Naser. [http://www.thenational.ae/uae/exclusive-solar-impulse-headed-back-to-abu-dhabi-the-long-way-round "Exclusive: Solar Impulse headed back to Abu Dhabi the long way round"], The National, 8 January 2016

• 2002:Solar Impulse. 2020. Solar Impulse - Around The World To Promote Clean Technologies. [online] Available at: [Accessed 10 March 2020]. Feasibility study at the École Polytechnique Fédérale de Lausanne
• 2004–2005: Development of the concept
• 2006: Simulation of long-haul flights
• 2006–09: Construction of first prototype (HB-SIA; Solar Impulse 1)
• 2009: First flight of Solar Impulse 1
• 2009–11: Manned test flights{{cite web|author=Lipsey, Sid|url=https://www.yahoo.com/travel/secrets-of-the-solar-powered-plane-that-might-make-110026751682.html|title=Secrets of the Solar-Powered Plane That Might Make History|publisher=Yahoo|date= 4 February 2015|access-date=22 March 2015}}
• 2011–12: Further test flights through Europe and North Africa
• 2011–13: Construction of second prototype (HB-SIB; Solar Impulse 2)
• 2013: Continental flight across the US by Solar Impulse 1{{cite web| url=http://www.solarimpulse.com/en/across-america/| title=Across America| publisher=Solar Impulse| year=2013| access-date=13 June 2013| url-status=dead| archive-url=https://web.archive.org/web/20130629085555/http://www.solarimpulse.com/en/across-america/| archive-date=29 June 2013| df=dmy-all}}
• 2014: First flight of Solar Impulse 2
• 2015–2016: Circumnavigation of the Earth by Solar Impulse 2, conducted in seventeen stages over 16-1/2 months

File:Cockpit HB-SIA.jpg

File:Prototype HB-SIA.jpg

The first Solar Impulse aircraft, registered as HB-SIA, was primarily designed as a demonstration aircraft. It has a non-pressurized cockpit and a single wing with a wingspan similar to that of the Airbus A340 airliner. Under the wing are four nacelles, each with a set of lithium polymer batteries, a {{convert|10|hp|kW|1|abbr=on|order=flip}} electric motor and one twin-bladed propeller. To keep the wing as light as possible, a customised carbon fibre honeycomb sandwich structure was used. 11,628 photovoltaic cells on the upper wing surface and the horizontal stabilizer generate electricity during the day to power the electric motors and to charge the batteries allowing flight at night, theoretically enabling the single-seat plane to stay in the air indefinitely.{{cite news|last=Engeler|first=Eliane|title=Solar plane lands after completing 24-hour flight|url=http://www.businessweek.com/ap/financialnews/D9GQS2FG2.htm|agency=Associated Press|date=8 July 2010|access-date=27 May 2015|url-status=dead|archive-url=https://web.archive.org/web/20150527103858/http://www.businessweek.com/ap/financialnews/D9GQS2FG2.htm|archive-date=27 May 2015|df=dmy-all}}{{Cite web|url=http://www.solarimpulse.com/common/documents/challenge_solar.php?lang=en&group=challenge|title=Plane|access-date=18 June 2011|publisher=Solar Impulse|url-status=dead|archive-url=https://web.archive.org/web/20110628112009/http://solarimpulse.com/common/documents/challenge_solar.php?lang=en&group=challenge|archive-date=28 June 2011|df=dmy-all}}

The aircraft's major design constraint is the capacity of the lithium polymer batteries. Over an optimum 24-hour cycle, the motors can deliver a combined average of about {{convert|8|hp|kW|0|abbr=on|order=flip}}, roughly the power used by the Wright brothers' Flyer, the first successful powered aircraft, in 1903. In addition to the charge stored in its batteries, the aircraft uses the potential energy of height gained during the day to power its night flights.{{cite web|url=http://www.solarimpulse.com/common/documents/blog.php?lang=en&group=media&id=105&comment=visible|title=Description of HB-SIA|publisher=SolarImpulse.com|date=22 June 2010|access-date=9 July 2010|url-status=dead|archive-url=https://web.archive.org/web/20110726022519/http://www.solarimpulse.com/common/documents/blog.php?lang=en&group=media&id=105&comment=visible|archive-date=26 July 2011|df=dmy-all}}

{{Aircraft specs

|prime units? = met

|ref = Solar Impulse Project{{cite web|url=http://www.solarimpulse.com/pdf/hb-sia/hb-sia_en.pdf|archive-url=https://web.archive.org/web/20110726022440/http://www.solarimpulse.com/pdf/hb-sia/hb-sia_en.pdf|url-status=dead|archive-date=26 July 2011|title=Around the World in a Solar Airplane|publisher=Solar Impulse|year=2009|access-date=24 June 2013}} and Diaz{{cite web|url=https://gizmodo.com/262940/solar-impulse-around-the-world-in-a-100-sun+powered-airplane|title=Solar Impulse: Around the World in a 100% Sun-powered Airplane|last=Diaz|first=Jesus|date=23 May 2007|publisher=Gizmodo|access-date=25 February 2010|archive-date=14 August 2009|archive-url=https://web.archive.org/web/20090814030654/http://gizmodo.com/262940/solar-impulse-around-the-world-in-a-100-sun+powered-airplane|url-status=dead}}

|crew = 1

|length m = 21.85

|length ft = 71.7

|span m = 63.4

|span ft = 208

|height m = 6.40

|height ft = 21.0

|wing area sqm = 200

|wing area note = covered with 11,628 photovoltaic cells rated at 45 kW peak

|airfoil =

|aspect ratio = 19.7

|empty weight main =

|empty weight alt =

|gross weight kg = 1,600

|gross weight lb = 3,500

|useful load main =

|useful load alt =

|max takeoff weight kg = 2,000

|max takeoff weight lb = 4,400

|more general =
Take-off speed: {{cvt|35|km/h}}

|fuel capacity = {{cvt|21|kW.h}} lithium-ion battery

|eng1 name = {{cvt|10|hp|order=flip}}

|eng1 type = electric motors

|eng1 number = 4

|prop blade number = 2

|prop dia m = 3.5

|prop dia ft = 11

|max speed main =

|max speed alt =

|cruise speed kmh = 70

|cruise speed alt =

|stall speed main =

|stall speed alt =

|never exceed speed main =

|never exceed speed alt =

|endurance = approximately 36 hours

|ceiling m = 8,500

|ceiling ft = 27,900

|ceiling note = with a maximum altitude of {{cvt|12000|m}}

|climb rate main =

|climb rate alt =

|wing loading main =

|wing loading alt =

|thrust/weight =

|power/mass =

|more performance =

}}

File:Flea Hop HB-SIA - Solar Impulse.jpg on 3 December 2009]]

On 26 June 2009, Solar Impulse 1 was first presented to the public at the Dübendorf Air Base, Switzerland. Following taxi testing, a short-hop test flight was made on 3 December 2009,{{cite news|url=http://news.bbc.co.uk/1/hi/sci/tech/8393688.stm|title=Record solar plane's first 'hop'|date=3 December 2009|publisher=BBC|access-date=4 December 2009|first=Jason|last=Palmer}} piloted by Markus Scherdel.{{cite web|url=https://www.newscientist.com/article/dn18233-solarpowered-piloted-plane-makes-its-first-flea-hop.html|title=Solar-powered piloted plane makes its first 'flea hop'|first=Tom|last=Simonite|date=3 December 2009|work=New Scientist|access-date=5 December 2009}} Borschberg, co-leader of the project team, said of the flight:

{{blockquote|"It was an unbelievable day. The airplane flew for about {{convert|350|m}} and about {{convert|1|m}} above the ground ... The aim was not to get high but to land on the same runway at a speed to test its controllability and get a first feeling of its flying characteristics ... the craft behaved just as the engineers had hoped. It is the end of the engineering phase and the start of the flight testing phase."}}

On 7 April 2010, the plane conducted an 87-minute test flight, piloted by Markus Scherdel. This flight reached an altitude of {{convert|1200|m|ft|0|abbr=on}}.{{cite news|url=http://www.latimes.com/technology/sns-ap-eu-switzerland-solar-adventure,0,3199191.story|title=Swiss team makes 1st test flight of prototype for round-the-world solar flight|work=Los Angeles Times|date=1 July 2010|access-date=9 July 2010}}{{dead link|date=June 2021|bot=medic}}{{cbignore|bot=medic}}{{cite magazine|url=https://www.wired.com/autopia/2010/04/solar-airplane-completes-maiden-voyage|title=Solar Airplane Completes Maiden Voyage|magazine=Wired|date=7 April 2010|access-date=9 July 2010}} On 28 May 2010, the aircraft made its first flight powered entirely by solar energy, charging its batteries in flight.{{cite web|url=http://www.avweb.com/avwebflash/news/SolarImpulseFliesOnPureSunlight_202647-1.html|title=Solar Impulse Flies on Pure Sunlight|access-date=3 June 2010|last=Grady|first=Mary|date=May 2010|archive-url=https://web.archive.org/web/20100604034523/http://www.avweb.com/avwebflash/news/SolarImpulseFliesOnPureSunlight_202647-1.html|archive-date=4 June 2010|url-status=dead|df=dmy-all}}

On 8 July 2010, Solar Impulse 1 achieved the world's first manned 26-hour solar-powered flight.{{cite news| last=Maron|first=Dina Fine|title=Swiss Team to Launch Solar Night Flight|url=https://www.nytimes.com/cwire/2010/07/06/06climatewire-swiss-team-to-launch-solar-night-flight-9738.html|work =The New York Times|agency=ClimateWire| date=6 July 2010|access-date=8 July 2010}}{{cite news|title=Solar Impulse completes record-breaking flight| url=https://www.telegraph.co.uk/earth/energy/solarpower/7878526/Solar-Impulse-completes-record-breaking-flight.html| archive-url=https://web.archive.org/web/20100709160249/http://www.telegraph.co.uk/earth/energy/solarpower/7878526/Solar-Impulse-completes-record-breaking-flight.html| url-status=dead| archive-date=9 July 2010| work=The Daily Telegraph|date=8 July 2010|access-date=8 July 2010|location=London}}{{cite magazine| last=Paur| first=Jason|title=Solar Airplane to Fly Through the Night (Tonight!)|url=https://www.wired.com/autopia/2010/07/solar-airplane-to-fly-through-the-night-tonight|magazine=Wired|date=7 July 2010|access-date=8 July 2010}} The airplane was flown by Borschberg, and took off at 06:51 Central European Summer Time (UTC+2) on 7 July from Payerne Air Base, Switzerland. It returned for a landing the following morning at 09:00 local time.{{cite news|last=van Loon|first=Jeremy|title=Solar-Powered Plane Lands Safely After Overnight Flight|url=http://news.businessweek.com/article.asp?documentKey=1377-a4lM164962iU-6B58GM9T9AIUVKONT5V3EIC6KO|work=Bloomberg BusinessWeek|date=8 July 2010|access-date=8 July 2010|url-status=dead|archive-url=https://web.archive.org/web/20100713014428/http://news.businessweek.com/article.asp?documentKey=1377-a4lM164962iU-6B58GM9T9AIUVKONT5V3EIC6KO|archive-date=13 July 2010|df=dmy-all}} During the flight, the plane reached a maximum altitude of {{convert|8700|m|abbr=on}}.{{cite news|title=Solar-powered plane lands safely after 26-hour flight|url=http://news.bbc.co.uk/2/hi/world/europe/10550430.stm|publisher=BBC|date=8 July 2010|access-date=8 July 2010}} At the time, the flight was the longest and highest ever flown by a manned solar-powered aircraft; these records were officially recognized by the Fédération Aéronautique Internationale (FAI) in October 2010.{{cite news| url=https://www.nytimes.com/2010/07/09/world/europe/09plane.html|access-date=8 July 2010|work=The New York Times| first=Alan|last=Cowell|title=Solar-Powered Plane Flies for 26 Hours|date=8 July 2010}}{{cite web|url=http://www.fai.org/news-of-records/35101-the-fai-ratifies-solar-impulses-world-records|title=The FAI ratifies Solar Impulse's World Records|access-date=22 October 2010|url-status=dead|archive-url=https://web.archive.org/web/20120127143011/http://www.fai.org/news-of-records/35101-the-fai-ratifies-solar-impulses-world-records|archive-date=27 January 2012|df=dmy-all}}

File:Solar Impulse Bruxelles 2011.jpg in May 2011]]

On 13 May 2011 at 21:30 local time, the plane landed at Brussels Airport, after completing a 13-hour flight from its home base in Switzerland. It was the first international flight by the Solar Impulse, which flew at an average altitude of {{convert|6000|ft|m|sigfig=2|abbr=on|order=flip}} for a distance of {{convert|630|km|mi|0|abbr=on}}, with an average speed of {{convert|50|km/h|mph|0|abbr=on}}. The aircraft's slow cruising speed required operating at a mid-altitude, allowing much faster air traffic to be routed around it.{{cite web|url=http://www.planet-techno-science.com/ciel-et-espace/solar-impulse-premier-vol-international-reussi-pour-lavion-solaire/|title=Solar Impulse: Premier vol international réussi pour l'avion solaire|publisher=Planet Techno Science|date=14 May 2011|access-date=15 June 2013|language=fr}} The aircraft was piloted by Borschberg. The project's other co-founder, Piccard, said in an interview after the landing: "Our goal is to create a revolution in the minds of people...to promote solar energies – not necessarily a revolution in aviation."{{cite news|title=Solar-Powered Airplane Makes Historic Flight|url=https://blogs.forbes.com/oshadavidson/2011/05/13/breaking-solar-airplane-about-to-make-historic-landing.html|archive-url=https://archive.today/20120709112224/http://blogs.forbes.com/oshadavidson/2011/05/13/breaking-solar-airplane-about-to-make-historic-landing.html|url-status=dead|archive-date=9 July 2012|access-date=13 May 2011|work=Forbes|first=Osha Gray|last=Davidson|date=13 May 2011}}{{Cite news|url=http://www.avweb.com/avwebflash/news/Solar_Impulse_Crosses_Borders_204657-1.html|title=Solar Impulse Crosses Border|access-date=16 May 2011|last=Niles|first=Russ|date=May 2011|work=AvWeb|archive-url=https://web.archive.org/web/20110519092326/http://www.avweb.com/avwebflash/news/Solar_Impulse_Crosses_Borders_204657-1.html|archive-date=19 May 2011|url-status=dead|df=dmy-all}}

A second international flight to the Paris Air Show was attempted on 12 June 2011, but the plane turned back and returned to Brussels because of adverse weather conditions.{{cite news|title=A setback for Solar Impulse: the solar plane favours safety and heads back to Brussels|url=http://www.solarimpulse.com/common/documents/news_affich.php?lang=en&group=news&IdArticle=90|access-date=15 June 2011|date=June 2011|url-status=dead|archive-url=https://web.archive.org/web/20110726022858/http://www.solarimpulse.com/common/documents/news_affich.php?lang=en&group=news&IdArticle=90|archive-date=26 July 2011|df=dmy-all}} In a second attempt on 14 June, Borschberg successfully landed the aircraft at Paris' Le Bourget Airport after a 16-hour flight.{{cite news|title=Solar Impulse Plane: A Rare Treat For Crowds in Paris|url=http://tv.ibtimes.com/solar-impulse-plane-a-rare-treat-for-crowds-in-paris/890.html|archive-url=https://archive.today/20120723122419/http://tv.ibtimes.com/solar-impulse-plane-a-rare-treat-for-crowds-in-paris/890.html|url-status=dead|archive-date=2012-07-23|access-date=15 June 2011|last=Marisa|first=Krystian|date=June 2011}}

On 5 June 2012, the Solar Impulse successfully completed its first intercontinental flight, a 19-hour trip from Madrid, Spain, to Rabat, Morocco.{{cite web|url=https://www.reuters.com/article/aviation-solar-idUSL5E8H5A4U20120605|title=Solar plane completes maiden intercontinental trip|work=Reuters|date=5 June 2012|access-date=6 June 2012}} During the first leg of the flight from Payerne Air Base to Madrid, the aircraft broke several further records for solar flight, including the longest solar-powered flight between pre-declared waypoints ({{convert|1099.3|km|mi|0|abbr=on|disp=or}}) and along a course ({{convert|1116|km|mi|0|abbr=on|disp=or}}).[http://www.solarimpulse.com/timeline/view/6636/en Solar Impulse’s HB-SIA obtains two new world records] {{webarchive|url=https://web.archive.org/web/20130315003539/http://www.solarimpulse.com/timeline/view/6636/en |date=15 March 2013 }}. SolarImpulse.com. 26 September 2012. See also: [http://www.fai.org/fai-record-file/?recordId=16558 FAI Record ID #16558] {{webarchive|url=https://web.archive.org/web/20131104130158/http://www.fai.org/fai-record-file/?recordId=16558 |date=4 November 2013 }} and [http://www.fai.org/fai-record-file/?recordId=16560 FAI Record ID #16560] {{webarchive|url=https://web.archive.org/web/20131104130306/http://www.fai.org/fai-record-file/?recordId=16560 |date=4 November 2013 }}.

File:Solar Impulse JFK July 14 2013.jpg, New York, on 14 July 2013]]

On 3 May 2013, the plane began its cross-US flight with a journey from Moffett Field in Mountain View, California, to Phoenix Goodyear Airport in Arizona. Successive legs of the flight ended at Dallas-Fort Worth airport, Lambert–St. Louis International Airport,{{cite web|url=https://www.bbc.co.uk/news/science-environment-22754126|title=Solar Impulse lands in St Louis in trans-America bid|publisher=BBC|date=4 June 2013|access-date=13 June 2013}} Cincinnati Municipal Lunken Airport to change pilots and avoid strong winds,{{cite web|url=https://www.bbc.co.uk/news/science-environment-22902402|title=Two hops for trans-US solar plane|publisher=BBC| date=14 June 2013|access-date=14 June 2013}} and Washington Dulles International Airport.{{cite web| url=https://www.bbc.co.uk/news/science-environment-22902402|title=Trans-US solar plane reaches Dulles|publisher=BBC|date=16 June 2013|access-date=16 June 2013}} On 6 July 2013, following a lengthy layover in Washington, Solar Impulse completed its cross-country journey, landing at New York City's JFK International Airport at 23:09 EDT.{{cite web|title=Solar Powered Plane Finishes Journey, Lands in NYC|url=http://bigstory.ap.org/article/solar-powered-plane-final-leg-flight-nyc|agency=Associated Press|date=7 July 2013|access-date=7 July 2013|archive-date=7 September 2013|archive-url=https://web.archive.org/web/20130907011644/http://bigstory.ap.org/article/solar-powered-plane-final-leg-flight-nyc|url-status=dead}} The landing occurred three hours earlier than originally intended, because a planned flyby of the Statue of Liberty was cancelled as a result of damage to the covering on the left wing.

Each flight leg took between 14 and 22 hours.{{cite web|title=Solar plane leaves Calif. on cross-country trip|url=http://hosted.ap.org/dynamic/stories/U/US_SOLAR_PLANE?SITE=FLDAY&SECTION=HOME&TEMPLATE=DEFAULT|work=Daytona Beach News Journal|access-date=3 May 2013}}{{dead link|date=March 2018 |bot=InternetArchiveBot |fix-attempted=yes }} The aircraft's second leg of its trip on 23 May to Dallas-Fort Worth covered {{convert|1541|km|mi}} and set several new world distance records in solar aviation.{{cite web|title=Solar plane completes 2nd leg of trip in Texas|url=http://bigstory.ap.org/article/solar-plane-completes-2nd-leg-trip-texas|agency=Associated Press|date=23 May 2013|access-date=10 July 2013|archive-date=4 November 2013|archive-url=https://web.archive.org/web/20131104072425/http://bigstory.ap.org/article/solar-plane-completes-2nd-leg-trip-texas|url-status=dead}}; {{cite web|title=Solar Plane Completes Longest Leg of Cross-Country Flight|url=https://news.yahoo.com/solar-plane-completes-longest-leg-cross-country-flight-143703130.html|publisher=Yahoo News|date=23 May 2013|access-date=10 July 2013}}; {{cite web|title=FAI Record ID #16815 – Straight distance, pre-declared waypoints|url=http://www.fai.org/fai-record-file/?recordId=16815|publisher=FAI|access-date=9 July 2013|url-status=dead|archive-url=https://web.archive.org/web/20131104130238/http://www.fai.org/fai-record-file/?recordId=16815|archive-date=4 November 2013|df=dmy-all}}; {{cite web|title=FAI Record ID #16817 – Free Distance|url=http://www.fai.org/fai-record-file/?recordId=16817|publisher=FAI|access-date=9 July 2013|url-status=dead|archive-url=https://web.archive.org/web/20131104130334/http://www.fai.org/fai-record-file/?recordId=16817|archive-date=4 November 2013|df=dmy-all}}; and {{cite web|title=FAI Record ID #16816 – Distance along a course, pre-declared waypoints|url=http://www.fai.org/fai-record-file/?recordId=16816|publisher=FAI|access-date=9 July 2013|url-status=dead|archive-url=https://web.archive.org/web/20131104130155/http://www.fai.org/fai-record-file/?recordId=16816|archive-date=4 November 2013|df=dmy-all}} Solar Impulse 1 was placed on public display at JFK after its landing. In August 2013, it was disassembled, then transported via a Cargolux B-747-400F to Dübendorf Air Base, where it was placed in storage in a hangar.

;Detailed route

Source:{{cite web|title=Across America Event Summary|url=http://info.solarimpulse.com/en/solar-flights/across-america/|publisher=Solar Impulse|access-date=9 March 2015|archive-date=5 March 2015|archive-url=https://web.archive.org/web/20150305085713/http://info.solarimpulse.com/en/solar-flights/across-america|url-status=dead}}

In March 2015, the plane was transported by truck to Paris to be part of the permanent exhibition at Cité des Sciences et de l'Industrie.{{cite web|title=Solar Impulse 1 s'expose|url=http://www.cite-sciences.fr/fr/au-programme/evenements/solar-impulse-1-sexpose/|access-date=21 January 2019|archive-date=21 January 2019|archive-url=https://web.archive.org/web/20190121234131/http://www.cite-sciences.fr/fr/au-programme/evenements/solar-impulse-1-sexpose/|url-status=dead}}

File:Solar Impulse SI2 pilote Bertrand Piccard Payerne November 2014.jpg in November 2014]]

Construction started in 2011 on the second aircraft, known as Solar Impulse 2, which carries the Swiss registration HB-SIB. Completion was initially planned for 2013, with a 25-day circumnavigation of the globe planned for 2014. A structural failure occurred on the aircraft's main spar during static tests in July 2012, leading to delays in the flight testing schedule to allow repairs. Solar Impulse 2{{'}}s first flight took place at Payerne Air Base on 2 June 2014.{{cite journal| journal=Sport Aviation|date=July 2014|page=14|title=First Flight for Solar Impulse 2}}

The wingspan of Solar Impulse 2 is {{convert|71.9|m|ft|abbr=on}}, slightly less than that of an Airbus A380, the world's largest passenger airliner, but compared with the 500-tonne A380,{{cite news|url=http://www.aljazeera.com/news/2015/03/solar-impulse-swiss-plane-uae-150309032941002.html|title=Solar-powered Swiss plane attempts flight around world|date=9 March 2015|publisher=Al Jazeera|access-date=26 July 2016}} the carbon-fibre Solar Impulse weighs only about {{convert|2.3|t|lb}}, little more than an average SUV.{{cite news|url=https://www.theguardian.com/environment/2016/jul/13/solar-impulse-2-lands-in-egypt-in-penultimate-stop-of-its-world-tour|title=Solar Impulse 2 lands in Egypt in penultimate stop of its world tour|work=The Guardian|date=13 July 2016|access-date=26 July 2016}} It features a non-pressurized cockpit {{Convert|3.8|m3|}} in sizeReisinger, Don. [http://www.cnet.com/au/news/solar-powered-plane-embarks-on-longest-leg-of-round-the-world-flight "Solar-powered plane embarks on longest leg of round-the-world flight"], CNET, 29 June 2015 and advanced avionics, including limited functionality of an autopilot that allows the pilot to sleep for up to 20 minutes at a time,{{Cite magazine|last=Paur|first=Jason|url=https://www.wired.com/2012/02/after-60-hours-solar-impulse-pilot-feeling-better-than-expected/|title=After 60 Hours in Cockpit, Pilot of Solar Impulse Feels 'Better Than Expected'|date=2012-02-23|magazine=Wired|access-date=2020-02-17|issn=1059-1028}} enabling multi-day transcontinental and trans-oceanic flights. Supplemental oxygen and various other environmental support systems allow the pilot to cruise up to an altitude of {{convert|12000|m}}.

File:Solar Impulse-IMG 8410.jpgs worn on Solar Impulse]]

{{Aircraft specs

|prime units? = met

|ref=Solar Impulse Project[http://www.solarimpulse.com/en/our-adventure/building-a-solar-airplane "Building a Solar Airplane"] {{webarchive |url=https://web.archive.org/web/20140413143309/http://www.solarimpulse.com/en/our-adventure/building-a-solar-airplane |date=13 April 2014 }}. Solar Impulse. Retrieved 19 January 2015.

|crew=1

|length m=22.4

|length ft= 73.5

|span m=71.9

|span ft=236

|height m=6.37

|height ft= 20.9

|gross weight kg= 2,300

|gross weight lb= 5,100

|more general=*Take-off speed: 36 km/h (22.4 mph)

• Wing area: 17,248 photovoltaic solar cells cover the top of the wings, fuselage and tailplane for a total area of {{convert|269.5|m2|abbr=on}} (rated at 66 kW peak)

|eng1 number=4

|eng1 name=electric motors with 4 x {{cvt|41|kW.h}} lithium-ion batteries ({{convert|633|kg|abbr=on|disp=or}}), providing

|eng1 note=

|eng1 hp= 17.4

|prop dia m= 4

|prop dia ft= 13.1

|max speed kmh= 140

|max speed mph= 87

|cruise speed kmh= 90

|cruise speed mph= 56

|cruise speed note= 60 km/h (37 mph) at night to save power

|ceiling m= 8,500

|ceiling ft= 27,900

|ceiling note= with a maximum altitude of {{cvt|12,000|m|ft}}

}}

Solar Impulse 2 was first publicly displayed on 9 April 2014. Its inaugural flight took place on 2 June 2014, piloted by Markus Scherdel.{{cite web|title=Solar plane makes inaugural flight|url=https://www.bbc.co.uk/news/science-environment-27659068|publisher=BBC|date=2 June 2014|access-date=2 June 2014}} The aircraft averaged a ground speed of {{convert|30|knots|km/h}}, and reached an altitude of {{convert|5500|ft|m|order=flip}}.{{cite news|work=Aviation Week & Space Technology|title=Solar Impulse Flies Aircraft For Round-the-World Attempt|date=9 June 2014|page=14}} The first night flight was completed on 26 October 2014, and the aircraft reached its maximum altitude during a flight on 28 October 2014.

File:SolarImpulse2Route.jpg

The repair work to the aircraft's main spar delayed Solar Impulse 2{{'}}s circumnavigation of the Earth from 2012 to 2015.[http://www.solarimpulse.com/en/airplane/hb-sib Timeline: "Without a spar, what's next?"] {{webarchive|url=https://web.archive.org/web/20120915075659/http://solarimpulse.com/en/airplane/hb-sib/ |date=15 September 2012 }}, Solar Impulse, 19 July 2012. Retrieved 28 June 2013 The aircraft was delivered to Masdar City in Abu Dhabi for the World Future Energy Summit in late January 2015,{{cite web|url=http://www.solarimpulse.com/en/our-adventure/the-first-round-the-world-solar-flight|title=Our Adventure|publisher=Solar Impulse|access-date=19 January 2015|url-status=dead|archive-url=https://web.archive.org/web/20150120193029/http://www.solarimpulse.com/en/our-adventure/the-first-round-the-world-solar-flight/|archive-date=20 January 2015|df=dmy-all}} and it began the journey from Al Bateen Executive Airport on 9 March 2015.{{cite web| author=Schreck, Adam| url=https://finance.yahoo.com/news/solar-plane-pioneers-lay-round-world-flight-plan-080306681.html| title=Solar plane pioneers lay out round-the-world flight plan| agency=Associated Press| date=20 January 2015| access-date=21 January 2015| url-status=dead| archive-url=https://web.archive.org/web/20150120203222/http://finance.yahoo.com/news/solar-plane-pioneers-lay-round-world-flight-plan-080306681.html| archive-date=20 January 2015| df=dmy-all}} It was scheduled to return to the same location in August 2015. A mission control centre for the circumnavigation was established in Monaco, using satellite links to gather real-time flight telemetry and remain in constant contact with the aircraft and the support team.{{cite web|url=http://www.abb-conversations.com/2015/02/solar-impulse-launches-mission-control-center-in-monaco/|title=Solar Impulse launches Mission Control Center in Monaco|publisher=ABB Conversations|date=23 February 2015| access-date=21 March 2015}} The route followed by Solar Impulse 2 was entirely in the Northern Hemisphere. It left Abu Dhabi, then it headed east to nearby Oman and India.{{cite web|author=Mudallal, Zainab| url=http://qz.com/325922/watch-this-solar-powered-airplanes-first-around-the-world-flight/|title=This solar-powered airplane is about to take its first around-the-world flight| publisher=Quartz| date=16 January 2015|access-date= 19 January 2015}}[https://www.bbc.com/news/science-environment-36122618 "Solar Impulse lands in California after Pacific crossing"], BBC, 24 April 2016 Twelve stops were originally planned along the route, with pilots Borschberg and Piccard alternating; at each stop, the crew awaited good weather conditions along the next leg of the route.Molko, David. [http://www.cnn.com/2015/04/16/tech/solar-impulse-plane-china/ "Solar-powered plane on round-the-world flight gets stuck in China"], CNN, 17 April 2015 For most of its time airborne, Solar Impulse 2 cruised at a ground speed of between {{convert|50|and|100|kph}}, usually at the slower end of that range at night to save power. Legs of the flight crossing the Pacific and Atlantic oceans were the longest stages of the circumnavigation, taking up to five days and nights.{{cite web|author=Keyrouz, Wissam| url=https://news.yahoo.com/solar-plane-revs-historic-round-world-flight-180504805.html |title=Solar plane revs up for historic round-the-world flight|publisher=AFP via Yahoo|date= 7 March 2015|access-date=22 March 2015}} On multi-day flights, the pilots took 20-minute naps and used yoga or other exercises to promote blood flow and maintain alertness.

File:Solar Impulse 2 Oahu Hawaii April 2016.jpg

By the end of May 2015, the plane had traversed Asia.Amos, Jonathan. [https://www.bbc.com/news/science-environment-32946874 "Solar Impulse plane begins Pacific crossing"], BBC News, 31 May 2015 It made an unscheduled stop in Japan to await favourable weather over the Pacific, increasing the expected number of legs of the journey to 13.Randall, Tom. [https://www.bloomberg.com/news/features/2015-06-15/solar-impulse-sun-powered-plane-is-about-to-smash-some-records "This Plane Runs on Sun and Is About to Smash Some Records"], Bloomberg L.P., 15 June 2015 The aircraft began the flight from Japan to Hawaii on 28 June 2015 (29 June, Japan local time).Morelle, Rebecca. [https://www.bbc.com/news/science-environment-33244912 "Solar Impulse begins second bid to cross Pacific Ocean"], BBC News, 28 June 2015 With Borschberg in the cockpit, it reached Hawaii on 3 July, setting new records for the world's longest solar-powered flight both by time (117 hours, 52 minutes) and distance (7,212 km; 4,481 mi). The flight's duration was also a record for longest solo flight, by time, for any aircraft.Archangel, Amber.{{cite news|url= http://cleantechnica.com/2015/07/06/solar-impulse-sets-world-record-117-hours-52-minutes-longest-solo-flight-ever-video/ |title= Solar Impulse Sets World Record: 117 Hours & 52 Minutes – Longest Solo Flight Ever |website= cleantechnica.com |date= 6 July 2015}}The Fédération Aéronautique Internationale (FAI) website states that the "Free distance along course" was 7,039.9 km. [http://www.fai.org/fai-record-file/?recordId=17595 FAI Record ID #17595] {{webarchive|url=https://web.archive.org/web/20150924045155/http://www.fai.org/fai-record-file/?recordId=17595 |date=24 September 2015 }}, Fédération Aéronautique Internationale. Retrieved 29 July 2015The FAI does not record this record as official, since the FAI does not have an "any aircraft" category. See [http://www.fai.org/records "FAI records page"], Fédération Aéronautique Internationale, 29 July 2015 During that leg the plane's batteries were damaged by overheating because they were packed in too much insulation. New parts had to be ordered, and as it was late in the season, with days shortening in the northern hemisphere, the plane was grounded in Hawaii. The US Department of Transportation stored the aircraft in a hangar at Kalaeloa Airport on Oahu.Amos, Jonathan. [https://www.bbc.com/news/science-environment-33538442 "Solar Impulse grounded until 2016"], BBC, 15 July 2015Molko, Davis. [http://www.cnn.com/2015/07/15/travel/solar-impulse-grounded-until-2016/ "Solar Impulse: Plane's pilots ground record-setting attempt until 2016"], CNN, 15 July 2015 New batteries were made and installed in the plane. Test flights began in February 2016[http://phys.org/news/2016-02-solar-impulse-plane-maintenance-flight.html "Solar Impulse plane makes first maintenance flight in Hawaii"], Phys.org, 28 February 2016 to prepare for resumption of the circumnavigation once northern hemisphere days lengthened enough to permit multi-day solar-powered flights.Al Wasmi, Naser. [http://www.thenational.ae/uae/technology/after-months-long-hiatus-solar-impulse-2-gets-set-to-fly-again "After months-long hiatus, Solar Impulse 2 gets set to fly again"], The National, 11 March 2016 A favourable weather window opened in April 2016, and the plane resumed its journey,Delony, Jennifer. [http://www.renewableenergyworld.com/content/rew/en/articles/2016/04/solar-impulse-live-solar-airplane-pilot-gives-interview-while-flying-from-hawaii-to-california.html "Solar Impulse Live: Solar Airplane Pilot Gives Interview While Flying from Hawaii to California"], RenewableEnergyWorld.com, 22 April 2016 landing at Moffett Field, in California, on 23 April. During that flight, Piccard, via a live videolink, spoke with Ban Ki-moon and Doris Leuthard before the General Assembly of the United Nations, from the cockpit of Solar Impulse 2, commenting on that day's historic signing of the Paris Agreement and discussing how using clean technologies can create jobs and fight global warming.Morosini, Marco. [http://www.huffingtonpost.com/marco-morosini/a-majestic-solar-dragonfl_b_9781484.html "A majestic solar dragonfly landed in San Francisco – Is this the future?"], The Huffington Post, 28 April 2016; and [https://www.youtube.com/watch?v=r1EVfr0diZY "Live conversation between UN Secretary-General Ban Ki-moon & Bertrand Piccard"], Solar Impulse, YouTube, 22 April 2016 Additional legs of the flight were added in the US as Solar Impulse 2 flew to Phoenix, Arizona,{{cite news |url=https://www.bbc.com/news/science-environment-36186227 |date=2 May 2016 |title=Solar Impulse aeroplane reaches Phoenix, Arizona |first=Jonathan |last=Amos|work=BBC News }}{{cite web |url=https://www.npr.org/sections/thetwo-way/2016/05/03/476569334/solar-airplane-lands-in-phoenix-after-flight-from-silicon-valley |title=Solar Airplane Lands in Phoenix After Flight From Silicon Valley |first=Bill |last=Chappell |date=3 May 2016 |access-date=5 May 2016 |publisher=NPR}} Tulsa, Oklahoma,Ryburn, Stacy. [http://www.tulsaworld.com/news/local/solar-plane-lands-at-tulsa-international-airport/article_e6b25fc8-9704-51d2-97d5-de8b2fd6339c.html "Solar plane lands at Tulsa International Airport"], Tulsa World, 12 May 2016 Dayton, Ohio,[http://www.nbcnews.com/tech/innovation/solar-impulse-2-lands-ohio-complete-latest-leg-global-trip-n578171 "Solar Impulse 2 Lands in Ohio to Complete Latest Leg of Global Trip"], NBC, 21 May 2016 Lehigh Valley, Pennsylvania[http://www.nbcnews.com/tech/innovation/solar-impulse-2-lands-pennsylvania-latest-leg-global-journey-n580576 "Solar Impulse 2 Lands in Pennsylvania in Latest Leg of Global Journey"], NBC, 25 May 2016 and New York City, arriving there on 11 June 2016.Rice, Doyle. [https://www.usatoday.com/story/tech/sciencefair/2016/06/11/solar-impulse-2-solar-powered-plane-new-york-city/85701316 "Solar Impulse 2 lands in New York City, final U.S. destination"], USA Today, 11 June 2016 Piccard piloted the aircraft across the Atlantic Ocean, arriving in Seville, Spain, on 23 June. The aircraft next stopped in Cairo, Egypt, on 13 July, and landed in Abu Dhabi on 26 July, completing the around-the-world trip in a total of 17 stages and 16-1/2 months; it was the first circumnavigation of the Earth by a piloted fixed-wing aircraft using only solar power.

:Notes:

• {{note|rw1|N1}} — Leg 7 was planned as a 144-hour flight from Nanjing, China to Hawaii ({{convert|9132|km|nmi|order=flip|abbr=on|disp=or}}). Deteriorating weather forced a diversion to Nagoya, Japan.

In September 2019 the Solar Impulse 2 aircraft was sold to Skydweller Aero, a Spanish-American company that is developing autonomous unmanned aerial vehicles capable of continuous flight and "carrying radar, electronic optics, telecommunications devices, telephone listening and interception systems".{{cite news |last1=Renfer |first1=Marc |last2=Dieuaide |first2=Yann |title=Solar Impulse to be reborn as a military-linked project |url=https://www.swissinfo.ch/eng/solar-impulse-to-be-reborn-as-a-military-linked-project/46172512 |date=November 23, 2020}} As part of this sale, the Solar Impulse 2 aircraft was transferred from Switzerland to Spain though once Skydweller completes its research and development flights the Solar Impulse 2 will be transferred back to Switzerland for permanent display at the Swiss Museum of Transport.{{cite news |title=Solar Impulse to start 'second life' in Spain |url=https://www.swissinfo.ch/eng/sustainable-technology_solar-impulse-to-start--second-life--in-spain/45222090 |date=September 11, 2019}}{{cite press release |last1=Lebleu |first1=Tristan |title=A Second Life for the Solar Impulse (Si2) Airplane |url=https://solarimpulse.com/news/a-second-life-for-the-solar-impulse-si2-airplane |publisher=Solar Impulse |date=September 11, 2019}} By February 2023, Skydweller Aero had conducted its first autonomous flight in Spain before transferring the aircraft to southern Mississippi in 2024 where it conducted the world's first uncrewed autonomous flight of a solar aircraft.{{cite news |last=Molyneaux |first=Ian |title=World's first unmanned large solar aircraft takes flight |url=https://www.aerotime.aero/articles/skydweller-aero-unmanned-solar-powered |work=Aerotime |date=5 April 2024}} The company intends to build a fleet of aircraft to operate year-round in latitudes between Miami (26°N) to Rio de Janeiro (23°S).{{cite news |url= https://aviationweek.com/aerospace/aircraft-propulsion/solar-powered-skydweller-completes-first-autonomous-flights |title= Solar-Powered Skydweller Completes First Autonomous Flights |author= Graham Warwick |date= February 7, 2023 |work= Aviation Week}} Uncrewed and autonomous, these aircraft will be able to perform military missions and commercial tasks unachievable to manned aircraft and at far less cost than satellites.{{cite news |url= https://futurride.com/2024/07/25/skydweller-on-mission-to-fly-uncrewed-solar-aircraft-autonomously-nonstop-around-the-world/|title= Skydweller on mission to fly uncrewed solar aircraft autonomously nonstop around the world|date= 25 July 2024}}

Skydweller Aero intends to fly an aircraft nonstop around the world in the coming years.{{cite news |url= https://vimeo.com/1005476561/a2383cfe27|title= Skydweller - Perpetual Flight|date= 2 September 2024}}

In 2015, Swissmint issued a special commemorative coin in anticipation of the Earth circumnavigation mission.[https://onlinecoin.club/Coins/Country/Switzerland/Twenty_Francs_2015_Solar_Impulse/ "Twenty Francs 2015 Solar Impulse"] (page visited on 21 February 2024).

In 2016, the Swiss Post edited a special stamp to honour the achievement of Solar Impulse 2.{{in lang|fr}} [https://www.post.ch/fr/notre-profil/entreprise/medias/communiques-de-presse/2016/la-poste-rend-hommage-a-solar-impulse-2-avec-un-timbre-commemoratif "La Poste rend hommage à « Solar Impulse 2 » avec un timbre commémoratif"], press release of the Swiss Post published on 27 July 2016 (page visited on 7 September 2016).

{{Columns-list|colwidth=30em|

• Electric aircraft
• List of circumnavigations
• Solar vehicle
• Renewable energy by country

;Other solar aircraft

• Gossamer Penguin
• Helios Prototype
• Qinetiq Zephyr
• Solar Challenger
• PlanetSolar, first solar vehicle (boat) to circumnavigate the Earth
• SolarStratos

;Records

• Flight endurance record
• List of firsts in aviation

}}

{{reflist|30em}}

{{Commons category}}

• [http://www.solarimpulse.com Official website]
• [https://www.youtube.com/watch?v=o_9oDFMiIhw&list=UUCSjLVJs5wD_BKaQqzXwyhg Official YouTube channel]

{{Portal bar|Aviation|Renewable energy|Energy|Switzerland}}

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Category:Vehicles introduced in 2009

Category:2009 in science

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Category:Solar power in Switzerland

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Category:Circumnavigation