|The Solar Impulse HB-SIA in Dübendorf during its first "flea hop" test flight on 3 December 2009.|
|Role||Experimental solar powered aircraft|
|Manufacturer||Solar Impulse Project|
|First flight||3 December 2009|
Solar Impulse is a Swiss long-range solar powered aircraft project being undertaken at the École Polytechnique Fédérale de Lausanne. The project eventually hopes to achieve the first circumnavigation of the Earth by a piloted fixed-wing aircraft using only solar power. The project is led by Swiss psychiatrist and aeronaut Bertrand Piccard, who co-piloted the first balloon to circle the world non-stop, and Swiss businessman André Borschberg.
The first aircraft, bearing the Swiss aircraft registration code of HB-SIA, is a single-seater monoplane, capable of taking off under its own power, and intended to remain airborne up to 36 hours. This aircraft first flew an entire diurnal solar cycle, including nearly nine hours of night flying, in a 26-hour flight on 7–8 July 2010. In 2012, Piccard and Borschberg conducted successful solar flights from Switzerland to Spain and Morocco, and conducted a multi-stage flight across the USA in 2013.
Building on the experience of this prototype, a slightly larger follow-on design (HB-SIB) is planned to make a circumnavigation of the globe in 20–25 days. This flight was initially planned for 2014, but following a structural failure of the aircraft's main spar during static testing, a more likely date is 2015.
Design and development
Piccard initiated the Solar Impulse project in 2003. By 2009, he had assembled a multi-disciplinary team of 50 specialists from six countries, assisted by about 100 outside advisers. The project is financed by a number of private companies. The four main partners are Deutsche Bank, Omega SA, Solvay, and Schindler. Other partners include Bayer MaterialScience, Altran, Swisscom and Swiss Re (Corporate Solutions). Other supporters include Clarins, Semper, Toyota, BKW and STG. The EPFL, the European Space Agency (ESA) and Dassault have provided additional technical expertise, while SunPower provided the aircraft's photovoltaic cells.
- Achieved timeline
- 2003: Feasibility study at the École Polytechnique Fédérale de Lausanne
- 2004–2005: Development of the concept
- 2006: Simulation of long-haul flights
- 2006–09: First prototype (HB-SIA)
- 2009: First flight of prototype
- 2009–11: Manned test flights with prototype
- 2011–12: Further test flights through Europe and North Africa in 7 legs
- 2011–13: Construction of second prototype (HB-SIB)
- Planned timeline
- 2013: Continental flight across United States (Mission Across America)
- 2014: Start of flight testing in HB-SIB
- 2015: Attempt world tour in several stages
Prototype aircraft (HB-SIA)
With a non-pressurized cockpit and a limited flight ceiling, the HB-SIA is primarily a demonstrator design. The plane has a similar wingspan to the Airbus A340 airliner. Under the wing are four nacelles, each with a set of lithium polymer batteries, a 10 hp (7.5 kW) motor and a twin-bladed propeller. To keep the wing as light as possible, a customised carbon fibre honeycomb sandwich structure is used. 11,628 photovoltaic cells on the upper wing surface and the horizontal stabilizer generate electricity during the day. These both propel the plane and charge its batteries to allow flight at night, theoretically enabling the single-seat plane to stay in the air indefinitely. The first manned flight overnight lasted about 26 hours in July 2010.
The aircraft's major design constraint is the capacity of the lithium polymer batteries. Over an ideal 24-hour cycle, the motors will deliver a combined average of about 8 hp (6 kW), roughly the power used by the Wright brothers' pioneering Flyer in 1903. As well as the charge stored in its batteries, the aircraft uses the potential energy of height gained during the day to power its night flights.
Maiden flight and other early flights
On 26 June 2009, the Solar Impulse was first presented to the public in Dübendorf, Switzerland. Following taxi testing, a short-hop test flight was made on 3 December 2009, piloted by Markus Scherdel. André Borschberg, co-leader of the project team, said of the flight:
"It was an unbelievable day. The airplane flew for about 350 metres (1,150 ft) and about 1 metre (3 ft 3 in) 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 HB-SIA conducted an extended 87-minute test flight, piloted by Markus Scherdel. This flight reached an altitude of 1,200 m (3,937 ft). On 28 May 2010, the aircraft made its first flight powered entirely by solar energy, charging its batteries in flight.
First overnight flight
|Wikinews has related news: Solar-powered plane completes 26-hour flight|
On 8 July 2010, the HB-SIA achieved the world's first manned 26-hour solar-powered flight. The airplane was flown by André Borschberg, and took off at 6:51 a.m. Central European Summer Time (UTC+2) on 7 July from an airfield in Payerne, Switzerland. It returned for a landing the following morning at 9:00 a.m. local time. During the flight, the plane reached a maximum altitude of 8,700 m (28,500 ft). 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.
International and intranational flights
Belgium and France (2011)
On 13 May 2011, at approximately 21:30 local time, HB-SIA 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 6,000 ft (1,829 m) for a distance of 630 km (391 mi), with an average speed of 50 km/h (31 mph). The aircraft's slow cruising speed required operating at a mid-altitude, allowing much faster air traffic to be routed around it. </ref> The aircraft was piloted by Andre Borschberg. The project's other co-founder, Bertrand 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 was attempted on 12 June 2011, but the plane turned back half-way and landed back in Brussels, where it had taken off, due to adverse weather conditions. In a second attempt on 14 June, André Borschberg successfully landed the aircraft at Paris' Le Bourget Airport at 9:15 pm after a 16-hour flight.
First intercontinental flight (2012)
On 5 June 2012, the Solar Impulse successfully completed its first intercontinental flight, flying a 19-hour trip from Madrid, Spain, to Rabat, Morocco. During the first leg of the flight from Payerne, Switzerland, to Madrid, the aircraft broke several further records for solar flight, including the longest solar-powered flight between pre-declared waypoints (1,099.3 km (683 mi)) and along a course (1,116 km (693 mi)).
United States (2013)
On 3 May 2013, the plane began its first cross-US flight with a journey from Moffett Field in Mountain View, California, to Phoenix Sky Harbor International Airport in Arizona. Successive legs of the flight took the Solar Impulse to Dallas-Fort Worth airport, Lambert–St. Louis International Airport, Washington Dulles International Airport and finally New York's John F. Kennedy airport. Each flight leg will take about 19 to 25 hours, with 10-day stops in each city.
After the first leg to Phoenix, the plane completed the second leg of its trip on 23 May, landing at Dallas-Fort Worth International Airport. This flight, which covered 1,541 kilometres (958 mi), set a new world distance record in solar aviation. On 4 June, the plane landed in St. Louis, Missouri. It departed for Washington DC on 14 June, briefly stopping in Cincinnati, Ohio, to change pilots and avoid strong winds. On 16 June, the plane landed at Dulles International Airport in Washington DC, and will head to its final destination, New York City's JFK, after its layover.
Planned second aircraft (HB-SIB)
Construction of the second Solar Impulse aircraft, carrying the Swiss registration HB-SIB, started in 2011. It will feature a larger, pressurized cockpit and advanced avionics to allow for transcontinental and trans-oceanic flights. Supplemental oxygen and various other environmental support systems will allow the pilot to cruise at an altitude of 12,000 metres (39,000 ft).
The wingspan of HB-SIB will be 80.0 m (262.5 ft), slightly wider than an Airbus A380, the world's largest passenger airliner, but unlike the 500-ton A380, the carbon-fibre Solar Impulse will weigh little more than an average automobile.
Completion was planned for 2013, with a circumnavigation of the globe in 20–25 days in 2014. However, following a structural failure of the main spar during static tests, a more likely date for the circumnavigation is 2015. The flight would circle the world in the northern hemisphere, near the equator. Five stops are planned to allow changes of pilots. Each leg of the flight will last three to four days, limited by the physiology of each pilot. Once improved battery efficiency makes it possible to reduce the aircraft's weight, a two-seater is envisaged to make a non-stop circumnavigation.
- Crew: 1
- Length: 21.85 m (71.7 ft)
- Wingspan: 63.4 m (208 ft)
- Height: 6.40 m (21.0 ft)
- Wing area: 11,628 photovoltaic cells rated at 45 kW peak: 200 m2 (2,200 sq ft)
- Loaded weight: 1,600 kg (3,500 lb)
- Max. takeoff weight: 2,000 kg (4,400 lb)
- Powerplant: 4 × electric motors, powered by 4 x 21 kWh lithium-ion batteries (450 kg), providing 7.5 kW (10 HP) each
- Take-off speed: 35 kilometres per hour (22 mph)
- Cruise speed: 70 kilometres per hour (43 mph)
- Endurance: 36 hours (projected)
- Service ceiling: 8,500 m (27,900 ft) with a maximum altitude of 12,000 metres (39,000 ft)
- Aircraft of comparable role, configuration and era
- Cardwell, Diane (1 May 2013). "Cross-Country Solar Plane Expedition Set for Takeoff". New York Times. Retrieved 2 May 2013.
- FAI entry of the 1999 record
- Solar Impulse Project. "HB-SIA Mission". Retrieved 2009-12-05.
- "Swiss solar plane makes history with night flight". Swisster. 2010-07-08. Retrieved 2010-07-13.
- "Solar plane completes maiden intercontinental trip". Reuters. 5 June 2012. Retrieved 6 June 2012.
- "Across America". SolarImpulse.com. 2013. Retrieved 13 June 2013.
- Amos, Jonathan (26 June 2009). "Round-the-world solar plane debut". BBC News. Retrieved 19 November 2009.
- Timeline, "Without a spar, what's next". Solarimpulse.com.
- Solar Impulse Project. "Major steps". Retrieved 2009-12-05.
- Piccard, Bertrand. "Solar Impulse gets a lift !". Retrieved 3 October 2011.
- "Solar Impulse - Around the world in a solar airplane". SunPower. Retrieved 24 January 2013.
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- Solar Impulse Project. "HB-SIA file". Retrieved 2009-12-05.
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- "The FAI ratifies Solar Impulse's World Records". Retrieved 22 October 2010.
- "Solar Impulse : Premier vol international réussi pour l’avion solaire" (in French). Planet Techno Science. 14 May 2011. Retrieved 15 June 2013.
- Osha Gray Davidson (13 May 2011). "Solar-Powered Airplane Makes Historic Flight". Forbes.com. Retrieved 13 May 2011}.
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- "A setback for Solar Impulse: the solar plane favours safety and heads back to Brussels". June 2011. Retrieved 15 June 2011.
- Marisa, Krystian (June 2011). "Solar Impulse Plane: A Rare Treat For Crowds in Paris". Retrieved 15 June 2011.
- Solar Impulse’s HB-SIA obtains two new world records. SolarImpulse.com. 26 September 2012; FAI Record ID #16558 and FAI Record ID #16560.
- "Solar plane leaves Calif. on cross-country trip". Daytona Beach News Journal. Retrieved 3 May 2013.
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- "Solar Plane Completes Longest Leg of Cross-Country Flight". Yahoo News. Retrieved 23 May 2013.
- "Solar Impulse lands in St Louis in trans-America bid". BBC. 4 June 2013. Retrieved 13 June 2013.
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- Diaz, Jesus (23 May 2007). "Solar Impulse: Around the World in a 100% Sun-powered Airplane". Gixmodo. Retrieved 25 February 2010.
|Wikimedia Commons has media related to: Solar Impulse|
- Official website and YouTube channel
- Bertrand Piccard's solar-powered adventure – lecture at TED (conference), July 2009 (17 min)
- Solar-powered plane aims to fly around the world. 60 Minutes. CBS News. December 2012.
- How does Solar Impulse work? How It Works magazine. 13 May 2011.
- Record-attempting solar powered plane's first 'hop'. BBC News. 4 December 2009.
- Solar Impulse plane starts 24-hour test flight . BBC News. 7 July 2010.
- Article about Solar Impulse via RobotPig.net
- Article about Solar Impulse project via GreenerMachine.org
- Article about Solar Impulse via SolarChoice.net
- Solar Impulse: The Endless Flight – slideshow by Life magazine