experimental
An experiment is a procedure carried out to support or refute a hypothesis, or determine the efficacy or likelihood of something previously untried. Experiments provide insight into cause-and-effect by demonstrating what outcome occurs when ...
solar-powered aircraft
An electric aircraft is an aircraft powered by electricity.
Electric aircraft are seen as a way to reduce the environmental effects of aviation, providing zero emissions and quieter flights.
Electricity may be supplied by a variety of methods, ...
project, and also the name of the project's two operational aircraft. The privately financed project is led by Swiss engineer and businessman
André Borschberg
André Borschberg Royal Scottish Geographical Society, FRSGS (born December 13, 1952) is a Swiss entrepreneur, explorer, pilot, and speaker. He is the co-founder of the Solar Impulse project, the first ever round-the-world solar flight, success ...
and Swiss psychiatrist and balloonist
Bertrand Piccard
Bertrand Piccard FRSGS (born 1 March 1958) is a Swiss explorer, psychiatrist and environmentalist. Along with Brian Jones, he was the first to complete a non-stop balloon flight around the globe, in a balloon named Breitling Orbiter 3. He was t ...
, who co-piloted ''
Breitling Orbiter 3
''Breitling Orbiter'' was the name of three different Rozière balloons made by the Bristol based balloon manufacturer Cameron Balloons to circumnavigate the globe, named after the Swiss watchmakers Breitling. The third was successful in Marc ...
'', the first
balloon
A balloon is a flexible bag that can be inflated with a gas, such as helium, hydrogen, nitrous oxide, oxygen, and air. For special tasks, balloons can be filled with smoke, liquid water, granular media (e.g. sand, flour or rice), or light so ...
to circle the world non-stop. The Solar Impulse project's goals were to make the first
circumnavigation
Circumnavigation is the complete navigation around an entire island, continent, or astronomical object, astronomical body (e.g. a planet or natural satellite, moon). This article focuses on the circumnavigation of Earth.
The first recorded circ ...
of the Earth by a piloted
fixed-wing aircraft
A fixed-wing aircraft is a heavier-than-air flying machine, such as an airplane, which is capable of flight using wings that generate lift caused by the aircraft's forward airspeed and the shape of the wings. Fixed-wing aircraft are distinc ...
using only solar power and to bring attention to
clean technologies
Clean technology, in short cleantech, is any process, product, or service that reduces negative environmental impacts through significant energy efficiency improvements, the sustainable use of resources, or environmental protection activities. Cle ...
.
The aircraft is a single-seated
monoplane
A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes.
A monoplane has inherently the highest efficiency and lowest drag of any wing confi ...
powered by
photovoltaic cell
A solar cell, or photovoltaic cell, is an electronic device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physics, physical and Chemical substance, chemical phenomenon.diurnal solar cycle, including nearly nine hours of night flying, in a 26-hour flight. Piccard and Borschberg completed successful solar-powered flights from Switzerland to Spain and then Morocco in 2012, and conducted a multi-stage flight across the US in 2013.
A second aircraft, completed in 2014 and named ''Solar Impulse 2'', carries more solar cells and more powerful motors, among other improvements. On 9 March 2015, Piccard and Borschberg began to circumnavigate the globe with ''Solar Impulse 2'', departing from
Abu Dhabi
Abu Dhabi (, ; ar, أَبُو ظَبْيٍ ' ) is the capital and second-most populous city (after Dubai) of the United Arab Emirates. It is also the capital of the Emirate of Abu Dhabi and the centre of the Abu Dhabi Metropolitan Area.
...
in the United Arab Emirates. The aircraft was scheduled to return to Abu Dhabi in August 2015 after a multi-stage journey around the world. By June 2015, the plane had traversed Asia, and in July 2015, it completed the longest leg of its journey, from Japan to Hawaii. During that leg, the aircraft's batteries sustained thermal damage and took months to replace. A battery cooling system was installed and ''Solar Impulse 2'' resumed the circumnavigation in April 2016, when it flew on to California.Berger, Noah "Solar-powered plane completes journey across Pacific Ocean" , ''
The Charlotte Observer
''The Charlotte Observer'' is an American English-language newspaper serving Charlotte, North Carolina, and its metro area. The Observer was founded in 1886. As of 2020, it has the second-largest circulation of any newspaper in the Carolinas. I ...
'', 24 April 2016 It continued across the US until it reached New York City in June 2016. Later that month, the aircraft crossed the Atlantic Ocean to the city of
Seville
Seville (; es, Sevilla, ) is the capital and largest city of the Spanish autonomous community of Andalusia and the province of Seville. It is situated on the lower reaches of the River Guadalquivir, in the southwest of the Iberian Peninsula ...
unmanned aerial vehicle
An unmanned aerial vehicle (UAV), commonly known as a drone, is an aircraft without any human pilot, crew, or passengers on board. UAVs are a component of an unmanned aircraft system (UAS), which includes adding a ground-based controller ...
s capable of continuous flight. It plans to use the plane for research and development flights, after which the Solar Impulse 2 is planned to be on permanent display at the
Swiss Museum of Transport
The Swiss Museum of Transport or Verkehrshaus der Schweiz (literally "Transportation House of Switzerland") in Lucerne opened in July 1959 and exhibits all forms of transport including trains, automobiles, ships and aircraft as well as communicati ...
.
Project development and funding
Bertrand Piccard
Bertrand Piccard FRSGS (born 1 March 1958) is a Swiss explorer, psychiatrist and environmentalist. Along with Brian Jones, he was the first to complete a non-stop balloon flight around the globe, in a balloon named Breitling Orbiter 3. He was t ...
initiated the Solar Impulse project in November 2003 after undertaking a feasibility study in partnership with the École Polytechnique Fédérale de Lausanne (EPFL). As a mechanical engineer, co-founder
André Borschberg
André Borschberg Royal Scottish Geographical Society, FRSGS (born December 13, 1952) is a Swiss entrepreneur, explorer, pilot, and speaker. He is the co-founder of the Solar Impulse project, the first ever round-the-world solar flight, success ...
directed the construction of each aircraft and oversees the preparation of the flight missions. 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.
The project is financed by a number of private companies and individuals, as well as receiving around CHF 6 million (
US$
The United States dollar (symbol: $; code: USD; also abbreviated US$ or U.S. Dollar, to distinguish it from other dollar-denominated currencies; referred to as the dollar, U.S. dollar, American dollar, or colloquially buck) is the official ...
6.4 million) in funding from the Swiss government. The project's private financial backers include
Omega SA
Omega SA is a Swiss luxury watchmaker based in Biel/Bienne, Switzerland. Founded by Louis Brandt in La Chaux-de-Fonds in 1848, the company formerly operated as ''La Generale Watch Co.'' until incorporating the name ''Omega'' in 1903, becoming ' ...
,
Solvay Solvay may refer to:
Companies and organizations
* Solvay Brussels School of Economics and Management, Brussels, Belgium
* Solvay Conference, founded by Ernest Solvay, deals with open questions in physics and chemistry
* Solvay Indupa, an Argentin ...
ABB
ABB Ltd. is a Swedish- Swiss multinational corporation headquartered in Zürich, Switzerland. The company was formed in 1988 when Sweden's Allmänna Svenska Elektriska Aktiebolaget (ASEA) and Switzerland's Brown, Boveri & Cie merged to create ...
and
Peter Diamandis
Peter H. Diamandis (; born May 20, 1961) is a Greek Americans, Greek-American engineer, physician, and entrepreneur best known for being founder and chairman of the X Prize Foundation, cofounder and executive chairman of Singularity University a ...
European Space Agency
, owners =
, headquarters = Paris, Île-de-France, France
, coordinates =
, spaceport = Guiana Space Centre
, seal = File:ESA emblem seal.png
, seal_size = 130px
, image = Views in the Main Control Room (1205 ...
and
Dassault
Dassault Group (; also GIM Dassault or Groupe Industriel Marcel Dassault SAS) is a French group of companies established in 1929 with the creation of Société des Avions Marcel Bloch (now Dassault Aviation) by Marcel Dassault, and led by son Ser ...
have provided technical expertise, while
SunPower
SunPower is an American provider of photovoltaic solar energy generation systems and battery energy storage products, primarily for residential customers. The company, headquartered in San Jose, California, was founded in 1985 by Richard Sw ...
provided the aircraft's photovoltaic cells.
Piccard stated that the entire project from its beginnings in 2003 until mid-2015 had cost €150 million. It raised another €20 million in late 2015 to continue the round-the-world flight.Al Wasmi, Naser "Exclusive: Solar Impulse headed back to Abu Dhabi the long way round" ''The National'', 8 January 2016
Timeline
* 2002: 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
* 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''
* 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
''Solar Impulse 1'' (HB-SIA)
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
The Airbus A340 is a long-range, wide-body passenger airliner that was developed and produced by Airbus.
In the mid-1970s, Airbus conceived several derivatives of the A300, its first airliner, and developed the A340 quadjet in parallel with ...
airliner. Under the wing are four
nacelle
A nacelle ( ) is a "streamlined body, sized according to what it contains", such as an engine, fuel, or equipment on an aircraft. When attached by a pylon entirely outside the airframe, it is sometimes called a pod, in which case it is attached ...
s, each with a set of
lithium polymer batteries
A lithium polymer battery, or more correctly lithium-ion polymer battery (abbreviated as LiPo, LIP, Li-poly, lithium-poly and others), is a rechargeable battery of lithium-ion technology using a polymer electrolyte instead of a liquid electrolyt ...
, a electric motor and one twin-bladed propeller. To keep the wing as light as possible, a customised
carbon fibre
Carbon fiber-reinforced polymers (American English), carbon-fibre-reinforced polymers (Commonwealth English), carbon-fiber-reinforced plastics, carbon-fiber reinforced-thermoplastic (CFRP, CRP, CFRTP), also known as carbon fiber, carbon compo ...
honeycomb sandwich structure was used. 11,628
photovoltaic cells
A solar cell, or photovoltaic cell, is an electronic device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon.
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.
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 , 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
In physics, potential energy is the energy held by an object because of its position relative to other objects, stresses within itself, its electric charge, or other factors.
Common types of potential energy include the gravitational potentia ...
of height gained during the day to power its night flights.
Specifications
Operational history
Maiden flight and other early flights
On 26 June 2009, ''Solar Impulse 1'' was first presented to the public at the
Dübendorf Air Base
Dübendorf Military Airport (german: Militärflugplatz Dübendorf) was a military airfield of the Swiss Air Force northeast of Dübendorf in Switzerland, located east of Zürich.
History
The search for a suitable site for an airfield started i ...
, Switzerland. Following taxi testing, a short-hop test flight was made on 3 December 2009, piloted by Markus Scherdel. Borschberg, co-leader of the project team, said of the flight:
On 7 April 2010, the plane conducted an 87-minute test flight, piloted by Markus Scherdel. This flight reached an altitude of . On 28 May 2010, the aircraft made its first flight powered entirely by solar energy, charging its batteries in flight.
First overnight flight
On 8 July 2010, ''Solar Impulse 1'' achieved the world's first manned 26-hour solar-powered flight. The airplane was flown by Borschberg, and took off at 06:51
Central European Summer Time
Central European Summer Time (CEST), sometimes referred to as Central European Daylight Time (CEDT), is the standard clock time observed during the period of summer daylight-saving in those European countries which observe Central European Time ...
(UTC+2) on 7 July from
Payerne Air Base
Payerne Airport is a military airfield of the Swiss Air Force north of Payerne in Switzerland, located approximately halfway between Lausanne and Bern.
History
In 2004 the International Air Show Air04 was held at Payerne.
On 8 July 2010, Paye ...
, Switzerland. It returned for a landing the following morning at 09:00 local time. During the flight, the plane reached a maximum altitude of . 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
The (; FAI; en, World Air Sports Federation) is the world governing body for air sports, and also stewards definitions regarding human spaceflight. It was founded on 14 October 1905, and is headquartered in Lausanne, Switzerland. It maintai ...
(FAI) in October 2010.
International and intranational flights
=Belgium and France (2011)
=
On 13 May 2011 at 21:30 local time, the plane landed at
Brussels Airport
Brussels Airport, nl, Luchthaven Brussel, vls, Vliegpling Brussel, german: Flughafen Brüssel is an international airport northeast of Brussels, the capital of Belgium. In 2019, more than 26 million passengers arrived or departed at Bruss ...
, 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 for a distance of , with an average speed of . The aircraft's slow cruising speed required operating at a mid-altitude, allowing much faster air traffic to be routed around it. 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."
A second international flight to the
Paris Air Show
The Paris Air Show (french: Salon international de l'aéronautique et de l'espace de Paris-Le Bourget, Salon du Bourget) is a trade fair and air show held in odd years at Paris–Le Bourget Airport in north Paris, France. Organized by the French ...
was attempted on 12 June 2011, but the plane turned back and returned to Brussels because of adverse weather conditions. In a second attempt on 14 June, Borschberg successfully landed the aircraft at Paris' Le Bourget Airport after a 16-hour flight.
=First intercontinental flight (2012)
=
On 5 June 2012, the Solar Impulse successfully completed its first intercontinental flight, a 19-hour trip from
Madrid
Madrid ( , ) is the capital and most populous city of Spain. The city has almost 3.4 million inhabitants and a metropolitan area population of approximately 6.7 million. It is the second-largest city in the European Union (EU), and ...
, Spain, to
Rabat
Rabat (, also , ; ar, الرِّبَاط, er-Ribât; ber, ⵕⵕⴱⴰⵟ, ṛṛbaṭ) is the capital city of Morocco and the country's seventh largest city with an urban population of approximately 580,000 (2014) and a metropolitan populati ...
, Morocco. During the first leg of the flight from
Payerne Air Base
Payerne Airport is a military airfield of the Swiss Air Force north of Payerne in Switzerland, located approximately halfway between Lausanne and Bern.
History
In 2004 the International Air Show Air04 was held at Payerne.
On 8 July 2010, Paye ...
to Madrid, the aircraft broke several further records for solar flight, including the longest solar-powered flight between pre-declared waypoints () and along a course ().
=United States (2013)
=
On 3 May 2013, the plane began its cross-US flight with a journey from
Moffett Field
Moffett Federal Airfield , also known as Moffett Field, is a joint civil-military airport located in an Local government in California#Counties, unincorporated part of Santa Clara County, California, Santa Clara County, California, United States, ...
in
Mountain View, California
Mountain View is a city in Santa Clara County, California, United States. Named for its views of the Santa Cruz Mountains, it has a population of 82,376.
Mountain View was integral to the early history and growth of Silicon Valley, and is the ...
, to
Phoenix Goodyear Airport
Phoenix Goodyear Airport (formerly Goodyear Municipal Airport) is a public airport southwest of Goodyear, in Maricopa County, Arizona, United States.
It was built during World War II as a naval air facility, NAF Litchfield Park, then upgrade ...
Lambert–St. Louis International Airport
St. Louis Lambert International Airport is the primary commercial airport serving metropolitan St. Louis, Missouri, United States. Commonly referred to as Lambert Field or simply Lambert, it is the largest and busiest airport in the state o ...
,
Cincinnati Municipal Lunken Airport
Cincinnati Municipal Airport – Lunken Field (Cincinnati Municipal Lunken Airport) is a public airport in Cincinnati, Ohio, three miles (5 km) east of Downtown Cincinnati. It is owned by the city of Cincinnati and serves private aircr ...
to change pilots and avoid strong winds, and
Washington Dulles International Airport
Washington Dulles International Airport , typically referred to as Dulles International Airport, Dulles Airport, Washington Dulles, or simply Dulles ( ), is an international airport in the Mid-Atlantic (United States), Eastern United States, loc ...
. 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. The landing occurred three hours earlier than originally intended, because a planned flyby of the
Statue of Liberty
The Statue of Liberty (''Liberty Enlightening the World''; French: ''La Liberté éclairant le monde'') is a List of colossal sculpture in situ, colossal neoclassical sculpture on Liberty Island in New York Harbor in New York City, in the U ...
was cancelled as a result of damage to the covering on the left wing.
Each flight leg took between 14 and 22 hours. The aircraft's second leg of its trip on 23 May to Dallas-Fort Worth covered and set several new world distance records in solar aviation. ''Solar Impulse 1'' was placed on public display at JFK after its landing. In August 2013, it was disassembled, then transported via a
Cargolux
Cargolux, legally ''Cargolux Airlines International S.A.'', is a Luxembourgian flag carrier cargo airline with its headquarters and hub at Luxembourg Airport. With a global network, it is one of the largest scheduled all-cargo airlines in Europe ...
B-747-400F to
Dübendorf Air Base
Dübendorf Military Airport (german: Militärflugplatz Dübendorf) was a military airfield of the Swiss Air Force northeast of Dübendorf in Switzerland, located east of Zürich.
History
The search for a suitable site for an airfield started i ...
, where it was placed in storage in a hangar.
;Detailed route
''Source:''
Aircraft on display
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
The Cité des Sciences et de l'Industrie ("City of Science and Industry", abbreviated la CSI) or simply CSI is the biggest science museum in Europe. Located in the Parc de la Villette in Paris, France, it is one of the three dozen French Cultur ...
.
''Solar Impulse 2'' (HB-SIB)
Construction history
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
SPAR, originally DESPAR, styled as DE SPAR, is a Dutch multinational that provides branding, supplies and support services for independently owned and operated food retail stores. It was founded in the Netherlands in 1932, by Adriaan van Well, ...
during static tests in July 2012, leading to delays in the flight testing schedule to allow repairs. ''Solar Impulse 2s first flight took place at
Payerne Air Base
Payerne Airport is a military airfield of the Swiss Air Force north of Payerne in Switzerland, located approximately halfway between Lausanne and Bern.
History
In 2004 the International Air Show Air04 was held at Payerne.
On 8 July 2010, Paye ...
on 2 June 2014.
Design
The wingspan of ''Solar Impulse 2'' is , slightly less than that of an
Airbus A380
The Airbus A380 is a large wide-body airliner that was developed and produced by Airbus. It is the world's largest passenger airliner and only full-length double-deck jet airliner.
Airbus studies started in 1988, and the project was annou ...
, the world's largest passenger
airliner
An airliner is a type of aircraft for transporting passengers and air cargo. Such aircraft are most often operated by airlines. Although the definition of an airliner can vary from country to country, an airliner is typically defined as an ...
, but compared with the 500-ton A380, the carbon-fibre Solar Impulse weighs only about , little more than an average
SUV
A sport utility vehicle (SUV) is a car classification that combines elements of road-going passenger cars with features from off-road vehicles, such as raised ground clearance and four-wheel drive.
There is no commonly agreed-upon definitio ...
avionics
Avionics (a blend word, blend of ''aviation'' and ''electronics'') are the Electronics, electronic systems used on aircraft. Avionic systems include communications, Air navigation, navigation, the display and management of multiple systems, ...
, including limited functionality of an
autopilot
An autopilot is a system used to control the path of an aircraft, marine craft or spacecraft without requiring constant manual control by a human operator. Autopilots do not replace human operators. Instead, the autopilot assists the operator' ...
that allows the pilot to sleep for up to 20 minutes at a time, enabling multi-day transcontinental and trans-oceanic flights.
Supplemental oxygen
Oxygen therapy, also known as supplemental oxygen, is the use of oxygen as medical treatment. Acute indications for therapy include hypoxemia (low blood oxygen levels), carbon monoxide toxicity and cluster headache. It may also be prophylactical ...
and various other environmental support systems allow the pilot to cruise up to an altitude of .
Specifications
Operational history
''Solar Impulse 2'' was first publicly displayed on 9 April 2014. Its inaugural flight took place on 2 June 2014, piloted by Markus Scherdel. The aircraft averaged a
ground speed
Ground speed is the horizontal speed of an aircraft relative to the Earth’s surface. It is vital for accurate navigation that the pilot has an estimate of the ground speed that will be achieved during each leg of a flight.
An aircraft diving ve ...
of , and reached an altitude of . The first night flight was completed on 26 October 2014, and the aircraft reached its maximum altitude during a flight on 28 October 2014.
2015–16 circumnavigation of the Earth
The repair work to the aircraft's main spar delayed ''Solar Impulse 2s circumnavigation of the Earth from 2012 to 2015.Timeline: "Without a spar, what's next?" , Solar Impulse, 19 July 2012. Retrieved 28 June 2013 The aircraft was delivered to
Masdar City
Masdar City ( ar, مدينة مصدر, Madīnat Maṣdar, lit=Source City) is a planned city project in Abu Dhabi, in the United Arab Emirates. Its core is being built by Masdar, a subsidiary of Mubadala Development Company, with the majority ...
in Abu Dhabi for the
World Future Energy Summit
The World Future Energy Summit (WFES) is an annual event hosted in the United Arab Emirates, aiming to advance future energy, energy efficiency, and clean technologies. It began in 2008, held under the patronage of Sheikh Mohammed Bin Zayed Al Nah ...
in late January 2015, and it began the journey from
Al Bateen Executive Airport
Al Bateen Executive Airport ( ar, مطار البطين, ) is a dedicated business jet international airport located south east of the city centre of Abu Dhabi, United Arab Emirates. The airport is on the Abu Dhabi island. Other tenants include ...
on 9 March 2015. It was scheduled to return to the same location in August 2015. A mission control centre for the circumnavigation was established in
Monaco
Monaco (; ), officially the Principality of Monaco (french: Principauté de Monaco; Ligurian: ; oc, Principat de Mónegue), is a sovereign city-state and microstate on the French Riviera a few kilometres west of the Italian region of Lig ...
, using satellite links to gather real-time flight telemetry and remain in constant contact with the aircraft and the support team.
The route followed by ''Solar Impulse 2'' was entirely in the
Northern Hemisphere
The Northern Hemisphere is the half of Earth that is north of the Equator. For other planets in the Solar System, north is defined as being in the same celestial hemisphere relative to the invariable plane of the solar system as Earth's Nort ...
. It left Abu Dhabi, then it headed east to nearby Oman and India. 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. For most of its time airborne, ''Solar Impulse 2'' cruised at a ground speed of between , 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. On multi-day flights, the pilots took 20-minute naps and used yoga or other exercises to promote blood flow and maintain alertness.
By the end of May 2015, the plane had traversed Asia. 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. The aircraft began the flight from Japan to Hawaii on 28 June 2015 (29 June, Japan local time).Morelle, Rebecca "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.The
Fédération Aéronautique Internationale
The (; FAI; en, World Air Sports Federation) is the world governing body for air sports, and also stewards definitions regarding human spaceflight. It was founded on 14 October 1905, and is headquartered in Lausanne, Switzerland. It maintai ...
(FAI) website states that the "Free distance along course" was 7,039.9 km FAI Record ID #17595 ,
Fédération Aéronautique Internationale
The (; FAI; en, World Air Sports Federation) is the world governing body for air sports, and also stewards definitions regarding human spaceflight. It was founded on 14 October 1905, and is headquartered in Lausanne, Switzerland. It maintai ...
. Retrieved 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
The United States Department of Transportation (USDOT or DOT) is one of the executive departments of the U.S. federal government. It is headed by the secretary of transportation, who reports directly to the President of the United States and ...
stored the aircraft in a hangar at
Kalaeloa Airport
Kalaeloa Airport , also called John Rodgers Field (the original name of Honolulu International Airport) and formerly Naval Air Station Barbers Point, is a joint civil-military regional airport of the State of Hawaii established on July 1, 1999, ...
on
Oahu
Oahu () (Hawaiian language, Hawaiian: ''Oʻahu'' ()), also known as "The Gathering place#Island of Oʻahu as The Gathering Place, Gathering Place", is the third-largest of the Hawaiian Islands. It is home to roughly one million people—over t ...
Moffett Field
Moffett Federal Airfield , also known as Moffett Field, is a joint civil-military airport located in an Local government in California#Counties, unincorporated part of Santa Clara County, California, Santa Clara County, California, United States, ...
, in California, on 23 April. During that flight, Piccard, via a live videolink, spoke with
Ban Ki-Moon
Ban Ki-moon (; ; born 13 June 1944) is a South Korean politician and diplomat who served as the eighth secretary-general of the United Nations between 2007 and 2016. Prior to his appointment as secretary-general, Ban was his country's Minister ...
and
Doris Leuthard
Doris Leuthard (born 10 April 1963) is a Swiss politician and lawyer who served as a Member of the Swiss Federal Council from 2006 to 2018. A member of the Christian Democratic People's Party (CVP/PDC), she was elected as President of the Swiss ...
before the
General Assembly of the United Nations
The United Nations General Assembly (UNGA or GA; french: link=no, Assemblée générale, AG) is one of the six principal organs of the United Nations (UN), serving as the main deliberative, policymaking, and representative organ of the UN. Curr ...
, from the cockpit of ''Solar Impulse 2'', commenting on that day's historic signing of the
Paris Agreement
The Paris Agreement (french: Accord de Paris), often referred to as the Paris Accords or the Paris Climate Accords, is an international treaty on climate change. Adopted in 2015, the agreement covers climate change mitigation, Climate change a ...
and discussing how using clean technologies can create jobs and fight
global warming
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...
. Additional legs of the flight were added in the US as ''Solar Impulse 2'' flew to Phoenix, Arizona,
Tulsa, Oklahoma
Tulsa () is the second-largest city in the state of Oklahoma and 47th-most populous city in the United States. The population was 413,066 as of the 2020 census. It is the principal municipality of the Tulsa Metropolitan Area, a region with ...
,
Dayton, Ohio
Dayton () is the sixth-largest city in the U.S. state of Ohio and the county seat of Montgomery County. A small part of the city extends into Greene County. The 2020 U.S. census estimate put the city population at 137,644, while Greater Day ...
Lehigh Valley
The Lehigh Valley (), known colloquially as The Valley, is a geographic region formed by the Lehigh River in Lehigh County and Northampton County in eastern Pennsylvania. It is a component valley of the Great Appalachian Valley bound to the no ...
Seville
Seville (; es, Sevilla, ) is the capital and largest city of the Spanish autonomous community of Andalusia and the province of Seville. It is situated on the lower reaches of the River Guadalquivir, in the southwest of the Iberian Peninsula ...
, Spain, on 23 June. The aircraft next stopped in
Cairo
Cairo ( ; ar, القاهرة, al-Qāhirah, ) is the capital of Egypt and its largest city, home to 10 million people. It is also part of the largest urban agglomeration in Africa, the Arab world and the Middle East: The Greater Cairo metro ...
, 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.
Detailed route
:Notes:
* — Leg 7 was planned as a 144-hour flight from
Nanjing
Nanjing (; , Mandarin pronunciation: ), alternately romanized as Nanking, is the capital of Jiangsu province of the People's Republic of China. It is a sub-provincial city, a megacity, and the second largest city in the East China region. T ...
, China to Hawaii (). Deteriorating weather forced a diversion to
Nagoya
is the largest city in the Chūbu region, the fourth-most populous city and third most populous urban area in Japan, with a population of 2.3million in 2020. Located on the Pacific coast in central Honshu, it is the capital and the most pop ...
, Japan.
Post-flight sale
In September 2019 the Solar Impulse 2 aircraft was sold to Skydweller, a Spanish-American company that is developing autonomous
unmanned aerial vehicle
An unmanned aerial vehicle (UAV), commonly known as a drone, is an aircraft without any human pilot, crew, or passengers on board. UAVs are a component of an unmanned aircraft system (UAS), which includes adding a ground-based controller ...
s capable of continuous flight and “carrying radar, electronic optics, telecommunications devices, telephone listening and interception systems”. 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
The Swiss Museum of Transport or Verkehrshaus der Schweiz (literally "Transportation House of Switzerland") in Lucerne opened in July 1959 and exhibits all forms of transport including trains, automobiles, ships and aircraft as well as communicati ...
.
Honours
In 2016, the
Swiss Post
Swiss Post (french: La Poste suisse, it, La Posta Svizzera, german: Die Schweizerische Post, rm, La Posta Svizra) is the national postal service of Switzerland. A public company owned by the Swiss Confederation, it is the country's second larg ...
edited a special
stamp
Stamp or Stamps or Stamping may refer to:
Official documents and related impressions
* Postage stamp, used to indicate prepayment of fees for public mail
* Ration stamp, indicating the right to rationed goods
* Revenue stamp, used on documents to ...
to honour the achievement of ''Solar Impulse 2''.
World Alliance for Clean Technologies
During the final flight of their circumnavigation of the globe, Borschberg and Piccard announced the creation of a World Alliance for Clean Technologies (later renamed World Alliance for Efficient Solutions). The aim of this
non-governmental organisation
A non-governmental organization (NGO) or non-governmental organisation (see American and British English spelling differences#-ise, -ize (-isation, -ization), spelling differences) is an organization that generally is formed independent from g ...
is to promote
green energy
Energy is sustainable if it "meets the needs of the present without compromising the ability of future generations to meet their own needs". Most definitions of sustainable energy include considerations of environmental aspects such as greenho ...
Le temps
''Le Temps'' (literally "The Time") is a Swiss French-language daily newspaper published in Berliner format in Geneva by Le Temps SA. It is the sole nationwide French-language non-specialised daily newspaper of Switzerland. Since 2021, it has b ...
'', Wednesday 27 July 2016, page 13. Box part of the large article of Fabien Goubet entitled "Un tour du monde, zéro carburant : Solar Impulse réécrit l'histoire de l'aviation", ''
Le temps
''Le Temps'' (literally "The Time") is a Swiss French-language daily newspaper published in Berliner format in Geneva by Le Temps SA. It is the sole nationwide French-language non-specialised daily newspaper of Switzerland. Since 2021, it has b ...
'', Wednesday 27 July 2016, pp. 12–13 by bringing together for-profit companies creating green solutions.
World Alliance was launched in November 2017.Wei-Haas, Maya "Inside the First Solar-Powered Flight Around the World" '' Smithsonian'' magazine, 31 January 2018 Patrons of the initiative included
Albert II, Prince of Monaco
Albert II – Website of the Palace of Monaco (Albert Alexandre Louis Pierre Grimaldi; born 14 March 1958) is Prince of Monaco, since 2005.
Albert was born at the Prince's Palace of Monaco, and he is the second child and only son of Prince Rai ...
and actor
Arnold Schwarzenegger
Arnold Alois Schwarzenegger (born July 30, 1947) is an Austrian and American actor, film producer, businessman, retired professional bodybuilder and politician who served as the 38th governor of California between 2003 and 2011. ''Time'' ...
. Piccard said that he and his organization, Solar Impulse Foundation, formed the World Alliance to help draw investors' and businesses' attention to new cleantech startups. Piccard does not receive a salary for his leadership of the alliance, which is funded by donors including
Air Liquide
Air Liquide S.A. (; ; literally "liquid air"), is a French multinational company which supplies industrial gases and services to various industries including medical, chemical and electronic manufacturers. Founded in 1902, after Linde it is ...
Solvay Solvay may refer to:
Companies and organizations
* Solvay Brussels School of Economics and Management, Brussels, Belgium
* Solvay Conference, founded by Ernest Solvay, deals with open questions in physics and chemistry
* Solvay Indupa, an Argentin ...
.
In November 2017 at
COP23
The 2017 United Nations Climate Change Conference (COP23) was an international meeting of political leaders, non-state actors and activists to discuss environmental issues. It was held at UN Campus in Bonn, Germany, during 6–17 November 2 ...
, Piccard tasked the World Alliance with a project to identify 1,000 technological solutions that are both profitable and good for the planet, with the goal to bring environmentalists and industrialists together. He noted in a 2018 ''Smithsonian'' article that technologies developed for the solar-powered flight were already being repurposed in new ways, including new ceiling fans based on the solar airplane engines and refrigerators using the cockpit insulation.
When speaking to government leaders, Piccard said he was consistently told that they wanted to protect the environment but it was too expensive. To provide reassurance, in May 2018 Piccard and the Solar Impulse Foundation announced the Efficient Solutions Label, a certification involving a rigorous
Ernst and Young
Ernst & Young Global Limited, trade name EY, is a multinational professional services partnership headquartered in London, England. EY is one of the largest professional services networks in the world. Along with Deloitte, KPMG and Pricewaterh ...
-certified evaluation by independent experts to assess each solution's quality and ability to turn a profit. According to Piccard, any Solar Impulse labeled solution must be the best in its class: the most environmentally friendly as well as economically viable and available for purchase today.
In 2021 in a ''Reuters'' interview Piccard stated that his organization had assembled a portfolio of 910 vetted and labeled solutions and expected to reach 1000 by mid-April 2021. Piccard told ''Reuters'' he plans to discuss the solutions with businesses and governments, especially those in the process of funding the global economic recovery from
COVID-19
Coronavirus disease 2019 (COVID-19) is a contagious disease caused by a virus, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The first known case was COVID-19 pandemic in Hubei, identified in Wuhan, China, in December ...