The dismantled Solar Impulse 2 aircraft is pictured before being loaded into a Cargolux Boeing 747 cargo aircraft at Payerne airport January 5, 2015. The Solar Impulse 2 aircraft and its team relocates to Abu Dhabi from where an attempt to fly around the world in stages using only solar energy will be made from March 2015. The aircraft, weighing 2.4 tons with a wingspan of 72 meters, is fitted with more than 17,000 solar cells. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT ENVIRONMENT SCIENCE TECHNOLOGY)

An element of a wing of the dismantled Solar Impulse 2 aircraft is loaded into a Cargolux Boeing 747 cargo aircraft at Payerne airport January 5, 2015. The Solar Impulse 2 aircraft and its team relocates to Abu Dhabi from where an attempt to fly around the world in stages using only solar energy will be made from March 2015. The aircraft, weighing 2.4 tons with a wingspan of 72 meters, is fitted with more than 17,000 solar cells. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT ENVIRONMENT SCIENCE TECHNOLOGY)

The wings of the dismantled Solar Impulse 2 aircraft are pictured before being loaded into a Cargolux Boeing 747 cargo aircraft at Payerne airport January 5, 2015. The Solar Impulse 2 aircraft and its team relocates to Abu Dhabi from where an attempt to fly around the world in stages using only solar energy will be made from March 2015. The aircraft, weighing 2.4 tons with a wingspan of 72 meters, is fitted with more than 17,000 solar cells. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT ENVIRONMENT SCIENCE TECHNOLOGY)

The dismantled Solar Impulse 2 aircraft is pictured before being loaded into a Cargolux Boeing 747 cargo aircraft at Payerne airport January 5, 2015. The Solar Impulse 2 aircraft and its team relocates to Abu Dhabi from where an attempt to fly around the world in stages using only solar energy will be made from March 2015. The aircraft, weighing 2.4 tons with a wingspan of 72 meters, is fitted with more than 17,000 solar cells. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT ENVIRONMENT SCIENCE TECHNOLOGY)

The solar-powered Solar Impulse 2 experimental aircraft, piloted by Swiss Bertrand Piccard, prepares to take off for a test flight in Payerne November 13, 2014. The aircraft, weighing 2.4 tons with a wingspan of 72 meters, is fitted with more than 17,000 solar cells. An attempt to fly around the world in stages using only solar energy will be made in 2015. REUTERS/Ruben Sprich (SWITZERLAND - Tags: TRANSPORT ENVIRONMENT SCIENCE TECHNOLOGY) 

The solar-powered Solar Impulse 2 experimental aircraft, piloted by Swiss Bertrand Piccard, is pictured during a test flight in Payerne November 13, 2014. The aircraft, weighing 2.4 tons with a wingspan of 72 meters, is fitted with more than 17,000 solar cells. An attempt to fly around the world in stages using only solar energy will be made in 2015. REUTERS/Ruben Sprich (SWITZERLAND - Tags: TRANSPORT ENVIRONMENT SCIENCE TECHNOLOGY) 

Solar Impulse co-founders and pilots Bertrand Piccard (bottom L) and Andre Borschberg (bottom R) pose with staff members at their base in Payerne December 16, 2014. The aircraft (SI2), which was unveiled April 9, weighs 2.4 tons with a wingspan of 72 metres (236 ft.) and has more than 17,000 solar cells. The attempt to fly around the world in stages using only solar energy will be made from March 2015 starting from Abu Dhabi. Picture taken December 16, 2014. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT ENVIRONMENT SCIENCE TECHNOLOGY)

Swiss pilot Bertrand Piccard prepares for a test flight of the solar-powered Solar Impulse 2 experimental aircraft in Payerne November 13, 2014. The aircraft, weighing 2.4 tons with a wingspan of 72 meters, is fitted with more than 17,000 solar cells. An attempt to fly around the world in stages using only solar energy will be made in 2015. REUTERS/Ruben Sprich (SWITZERLAND - Tags: TRANSPORT ENVIRONMENT SCIENCE TECHNOLOGY) 

Swiss pilot Bertrand Piccard prepares for a test flight of the solar-powered Solar Impulse 2 experimental aircraft in Payerne November 13, 2014. The aircraft, weighing 2.4 tons with a wingspan of 72 meters, is fitted with more than 17,000 solar cells. An attempt to fly around the world in stages using only solar energy will be made in 2015. REUTERS/Ruben Sprich (SWITZERLAND - Tags: TRANSPORT ENVIRONMENT SCIENCE TECHNOLOGY) 

Numbers indicating the motor power are pictured in the cockpit of the solar-powered Solar Impulse 2 aircraft after a training flight at its base in Payerne November 8, 2014. The aircraft, which was unveiled April 9, weighs 2.4 tons with a wingspan of 72 meters (236 ft.) and more than 17,000 solar cells. The attempt to fly around the world in stages using only solar energy will be made from March 2015 starting from Abu Dhabi. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT ENVIRONMENT SCIENCE TECHNOLOGY) 

A red button is pictured on the control yoke in the cockpit of the solar-powered Solar Impulse 2 aircraft after a training flight at its base in Payerne November 8, 2014. The aircraft, which was unveiled April 9, weighs 2.4 tons with a wingspan of 72 meters (236 ft.) and more than 17,000 solar cells. The attempt to fly around the world in stages using only solar energy will be made from March 2015 starting from Abu Dhabi. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT ENVIRONMENT SCIENCE TECHNOLOGY) 

Fuses are pictured in the cockpit of the solar-powered Solar Impulse 2 aircraft after a training flight at its base in Payerne November 8, 2014. The aircraft, which was unveiled April 9, weighs 2.4 tons with a wingspan of 72 meters (236 ft.) and more than 17,000 solar cells. The attempt to fly around the world in stages using only solar energy will be made from March 2015 starting from Abu Dhabi. . REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT ENVIRONMENT SCIENCE TECHNOLOGY) 

German test pilot Markus Scherdel lands the solar-powered Solar Impulse 2 aircraft after a training flight at its base in Payerne November 8, 2014. The aircraft, which was unveiled April 9, weighs 2.4 tons with a wingspan of 72 metres (236 ft.) and has more than 17,000 solar cells. The attempt to fly around the world in stages using only solar energy will be made from March 2015 starting from Abu Dhabi. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT ENVIRONMENT SCIENCE TECHNOLOGY)

The cockpit of the solar-powered Solar Impulse 2 aircraft is pictured after a training flight at its base in Payerne November 8, 2014. From left to right instruments are : fuses, throttle, power management, autopilot, motor control, flying instruments and telecomunication. The aircraft, which was unveiled April 9, weighs 2.4 tons with a wingspan of 72 meters (236 ft.) and more than 17,000 solar cells. The attempt to fly around the world in stages using only solar energy will be made from March 2015 starting from Abu Dhabi. Picture taken with a fisheye lens. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT ENVIRONMENT SCIENCE TECHNOLOGY) 

The Solar Impulse 2 aircraft is pulled out of its base for tests by pilot Bertrand Piccard in Payerne, November 1, 2014. The aircraft weighs 2.4 tons with a wingspan of 72 meters, fitted with more than 17,000 solar cells. The attempt to fly around the world in stages using only solar energy will be made in 2015. REUTERS/Pierre Albouy (SWITZERLAND - Tags: TRANSPORT ENVIRONMENT SCIENCE TECHNOLOGY) 

The Solar Impulse 2 aircraft is pulled out of its base for tests by pilot Bertrand Piccard in Payerne, November 1, 2014. The aircraft weighs 2.4 tons with a wingspan of 72 meters, fitted with more than 17,000 solar cells. The attempt to fly around the world in stages using only solar energy will be made in 2015. REUTERS/Pierre Albouy (SWITZERLAND - Tags: TRANSPORT ENVIRONMENT SCIENCE TECHNOLOGY) 

German test pilot Markus Scherdel steers the solar-powered Solar Impulse 2 aircraft with the Mont-Blanc in background during a training flight at its base in Payerne September 27, 2014. The aircraft, which was unveiled April 9, weighs 2.4 tons with a wingspan of 72 meters (236 ft.) and has more than 17,000 solar cells. The attempt to fly around the world in stages using only solar energy will be made from March 2015 starting from Abu Dhabi. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT ENVIRONMENT SCIENCE TECHNOLOGY TPX IMAGES OF THE DAY) 

German test pilot Markus Scherdel steers the solar-powered Solar Impulse 2 aircraft over the Lake Murten during a training flight at its base in Payerne September 27, 2014. The aircraft, which was unveiled April 9, weighs 2.4 tons with a wingspan of 72 meters (236 ft.) and has more than 17,000 solar cells. The attempt to fly around the world in stages using only solar energy will be made from March 2015 starting from Abu Dhabi. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT ENVIRONMENT SCIENCE TECHNOLOGY) 

German test pilot Markus Scherdel steers the solar-powered Solar Impulse 2 aircraft over the Lake Neuchatel during a training flight at its base in Payerne September 27, 2014. The aircraft, which was unveiled April 9, weighs 2.4 tons with a wingspan of 72 meters (236 ft.) and has more than 17,000 solar cells. The attempt to fly around the world in stages using only solar energy will be made from March 2015 starting from Abu Dhabi. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT ENVIRONMENT SCIENCE TECHNOLOGY TPX IMAGES OF THE DAY) 

German test pilot Markus Scherdel steers the solar-powered Solar Impulse 2 aircraft over the Lake Murten during a training flight at its base in Payerne September 27, 2014. The aircraft, which was unveiled April 9, weighs 2.4 tons with a wingspan of 72 meters (236 ft.) and has more than 17,000 solar cells. The attempt to fly around the world in stages using only solar energy will be made from March 2015 starting from Abu Dhabi. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT ENVIRONMENT SCIENCE TECHNOLOGY) 

German test pilot Markus Scherdel steers the solar-powered Solar Impulse 2 aircraft during its maiden flight at its base in Payerne June 2, 2014. The aircraft, which was unveiled on April 9, has a wingspan of 72 metres (236 ft), and weighs 2.4 tons, bearing in total more than 17,000 solar cells. The attempt to fly around the world in stages using only solar energy will be made in 2015. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT ENVIRONMENT SCIENCE TECHNOLOGY) 

People work on the new experimental solar-powered Solar Impulse 2 aircraft, with a wingspan of 72 metres (236 ft), in Payerne June 2, 2014. REUTERS/Fabrice Coffrini/Pool (SWITZERLAND - Tags: TRANSPORT ENVIRONMENT SCIENCE TECHNOLOGY) 

Solar Impulse project co-founder Andre Borschberg (R) checks from his helicopter as German test pilot Markus Scherdel steers the solar-powered Solar Impulse 2 aircraft during its maiden flight at its base in Payerne June 2, 2014. The aircraft, which was unveiled April 9, weighs 2.4 tons with a wingspan of 72 meters (236 ft.) and more than 17,000 solar cells. The attempt to fly around the world in stages using only solar energy will be made in 2015, according to the project. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT ENVIRONMENT SCIENCE TECHNOLOGY) 

German test pilot Markus Scherdel steers the solar-powered Solar Impulse 2 aircraft for its maiden flight at its base in Payerne June 2, 2014. The aircraft, which was unveiled April 9, weighs 2.4 tons with a wingspan of 72 meters (236 ft.) and more than 17,000 solar cells. The attempt to fly around the world in stages using only solar energy will be made in 2015, according to the project. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT ENVIRONMENT SCIENCE TECHNOLOGY) 

Solar Impulse co-founder Bertrand Piccard (L) congratulates German test pilot Markus Scherdel (R) after steering the solar-powered Solar Impulse 2 aircraft on its maiden flight at its base in Payerne June 2, 2014. The aircraft, which was unveiled April 9, weighs 2.4 tons with a wingspan of 72 meters (236 ft.) and more than 17,000 solar cells. The attempt to fly around the world in stages using only solar energy will be made in 2015, according to the project. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT ENVIRONMENT SCIENCE TECHNOLOGY) 

German test pilot Markus Scherdel steers the solar-powered Solar Impulse 2 aircraft on its maiden flight at its base in Payerne June 2, 2014. The aircraft, which was unveiled April 9, weighs 2.4 tons with a wingspan of 72 meters (236 ft.) and more than 17,000 solar cells. The attempt to fly around the world in stages using only solar energy will be made in 2015, according to the project. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT ENVIRONMENT SCIENCE TECHNOLOGY) 

Staff members riding bicycles follow as German test pilot Markus Scherdel lands the solar-powered Solar Impulse 2 aircraft after its maiden flight in Payerne June 2, 2014. The aircraft, which was unveiled April 9, weighs 2.4 tons with a wingspan of 72 meters (236 ft.) and more than 17,000 solar cells. The attempt to fly around the world in stages using only solar energy will be made in 2015, according to the project. REUTERS/Fabrice Coffrini/Pool (SWITZERLAND - Tags: TRANSPORT SCIENCE TECHNOLOGY ENVIRONMENT) 

The new Solar Impulse 2 aircraft is pulled out of its base for the first time for tests with solar panels in Payerne April 14, 2014. The aircraft, which was unveiled on April 9, weighs 2.4 tons with a wingspan of 72 meter and more than 17,000 solar cells. The attempt to fly around the world in stages using only solar energy will be made in 2015. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT SCIENCE TECHNOLOGY ENVIRONMENT) 

The new Solar Impulse 2 aircraft is pulled out of its base for the first time for tests with solar panels in Payerne April 14, 2014. The aircraft, which was unveiled on April 9, weighs 2.4 tons with a wingspan of 72 meter and more than 17,000 solar cells. The attempt to fly around the world in stages using only solar energy will be made in 2015. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT ENVIRONMENT SCIENCE TECHNOLOGY) 

The unveiled Solar Impulse II aircraft is seen at their base in Payerne April 9, 2014. The new solar powered aircraft weighs 2.4 tons with a wingspan of 72 meter and more than 17,000 solar cells. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT ENVIRONMENT TPX IMAGES OF THE DAY) 

Pilot and co-founder of Solar Impulse Bertrand Piccard, sits with electrodes attached to his head as he awaits the start of a transatlantic 72 hour flight simulation at the airport in Duebendorf near Zurich December 17, 2013. Swiss long-range solar-powered aircraft project Solar Impulse HB-SIB airplane is expected to be completed by the end of 2013. Flight testing is planned for spring 2014, and the first solar-powered round-the-world flight for sometime between April and July 2015. REUTERS/Arnd Wiegmann (SWITZERLANDTRANSPORT TECHNOLOGY - Tags: SCIENCE TECHNOLOGY TRANSPORT HEADSHOT) 

Bertrand Piccard (C) pilot and co-founder of Solar Impulse receives an injection from a medic before the start of a transatlantic 72 hour flight simulation at the airport in Duebendorf near Zurich December 17, 2013. Swiss long-range solar-powered aircraft project Solar Impulse HB-SIB airplane is expected to be completed by the end of 2013. Flight testing is planned for spring 2014, and the first solar-powered round-the-world flight for sometime between April and July 2015. REUTERS/Arnd Wiegmann (SWITZERLANDTRANSPORT TECHNOLOGY - Tags: SCIENCE TECHNOLOGY TRANSPORT) HEADSHOT) 

Engineers assemble the 72 metre (236 feet) long wing of the solar-powered Solar Impulse HB-SIB airplane during its assembly at the airport in Duebendorf near Zurich December 17, 2013. Swiss long-range solar-powered aircraft project Solar Impulse HB-SIB airplane is expected to be completed by the end of 2013. Flight testing is planned for spring 2014, and the first solar-powered round-the-world flight for sometime between April and July 2015. REUTERS/Arnd Wiegmann (SWITZERLAND TECHNOLOGYSCIENCE TRANSPORT - Tags: SCIENCE TECHNOLOGY TRANSPORT BUSINESS EMPLOYMENT) 

Crew members check the Solar Impulse plane after it landed following a 19-hour flight from Madrid at Rabat's International airport, June 5, 2012. The plane landed in Morocco on Tuesday, completing the world's first intercontinental flight powered by the sun to show the potential for pollution-free air travel. REUTERS/Youssef Boudlal (MOROCCO - Tags: TRANSPORT SCIENCE TECHNOLOGY ENERGY) BEST QUALITY AVAILABLE 

The Solar Impulse plane's project president and pilot, Bertrand Piccard (L) celebrates with co-founder and CEO Andre Borschberg (R) and Moroccan Agency for Solar Energy (MASEN) CEO Mustapha Bakkoury after the plane landed following a 19-hour flight from Madrid at Rabat's International airport, June 5, 2012. The plane landed in Morocco on Tuesday, completing the world's first intercontinental flight powered by the sun to show the potential for pollution-free air travel. REUTERS/Youssef Boudlal (MOROCCO - Tags: TRANSPORT SCIENCE TECHNOLOGY ENERGY) 

The Solar Impulse aircraft is being pulled out of the hangar for take off at Payerne airport May 24, 2012. The Solar Impulse HB-SIA prototype aircraft, which has 12,000 solar cells built into its 64.3 metres (193 feet) wings, attempted its first intercontinental flight from Payerne to Rabat in Morocco with a few days for a technical stop and a change of pilot in Madrid. This flight will act as a final rehearsal for the 2014 round-the-world flight. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT SCIENCE TECHNOLOGY SOCIETY) 

Solar Impulse project CEO and pilot Andre Borschberg looks at the sky before take off at Payerne airport May 24, 2012. The Solar Impulse HB-SIA prototype aircraft, which has 12,000 solar cells built into its 64.3 metres (193 feet) wings, attempted its first intercontinental flight from Payerne to Rabat in Morocco with a few days for a technical stop and a change of pilot in Madrid. This flight will act as a final rehearsal for the 2014 round-the-world flight. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT SCIENCE TECHNOLOGY SOCIETY BUSINESS) 

The suit and boots of Solar Impulse project CEO and pilot Andre Borschberg puts are pictured before take off at Payerne airport May 24, 2012. The Solar Impulse HB-SIA prototype aircraft, which has 12,000 solar cells built into its 64.3 metres (193 feet) wings, attempted its first intercontinental flight from Payerne to Rabat in Morocco with a few days for a technical stop and a change of pilot in Madrid. This flight will act as a final rehearsal for the 2014 round-the-world flight. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT SCIENCE TECHNOLOGY SOCIETY) 

Solar Impulse project president and pilot Bertrand Piccard sits in the solar-powered HB-SIA prototype airplane before a test flight at Payerne airport April 17, 2012. The Solar Impulse HB-SIA, which has 12,000 solar cells built into its 64.3-meter (193-foot) wings, is a prototype for an aircraft that its creators hope will carry out its first circumnavigation of the globe from 2014. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT ENERGY BUSINESS) 

A technician measures the speed of wind with a nanometer in front of the solar-powered HB-SIA prototype airplane before a test flight at Payerne airport April 17, 2012. The Solar Impulse HB-SIA, which has 12,000 solar cells built into its 64.3-meter (193-foot) wings, is a prototype for an aircraft that its creators hope will carry out its first circumnavigation of the globe from 2014. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT ENERGY BUSINESS SCIENCE TECHNOLOGY) 

Pilot and CEO of Solar Impulse, Andre Borschberg (L) shakes hands with the head of the recovery crew, Tahan Pangaribuan after the landing of the Swiss solar-powered airplane at Le Bourget Airport, near Paris, June 14, 2011, where it will be exhibited at the Paris Air Show, which opens on June 20. REUTERS/Michel Euler/Pool (FRANCE - Tags: TRANSPORT SCI TECH) 

Solar Impulse's Chief Executive Officer and pilot Andre Borschberg takes off with the solar-powered HB-SIA prototype aircraft during a flight from Brussels to Paris, June 11, 2011. REUTERS/Francois Lenoir (BELGIUM - Tags: TRANSPORT ENERGY ENVIRONMENT SCI TECH) 

Ground staff prepare the solar-powered HB-SIA Solar Impulse prototype aircraft before a test flight at Payerne airport early morning April 18, 2011. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT SCI TECH ENVIRONMENT BUSINESS IMAGES OF THE DAY) 

A staff member rides a bike in the Solar Impulse's solar-powered HB-SIA prototype airplane hangar at Payerne airport April 11, 2011. The Solar Impulse HB-SIA, which has 12,000 solar cells built into its 64.3-meter (193-foot) wings, is a prototype for an aircraft that its creators hope will carry out its first circumnavigation of the globe from 2012. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT SCI TECH ENERGY BUSINESS) 

Solar Impulse's solar-powered HB-SIA prototype airplane test pilot Markus Scherdel of Germany arrives for a test flight at Payerne airport April 11, 2011. The Solar Impulse HB-SIA, which has 12,000 solar cells built into its 64.3-meter (193-foot) wings, is a prototype for an aircraft that its creators hope will carry out its first circumnavigation of the globe from 2012. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT SCI TECH ENERGY BUSINESS) 

Solar Impulse's solar-powered HB-SIA prototype airplane with test pilot Markus Scherdel performs a low altitude go-round procedure during a test flight at Payerne airport April 11, 2011. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT SCI TECH ENVIRONMENT BUSINESS) 

Solar Impulse's Chief Executive Officer and pilot Andre Borschberg flies in the solar-powered HB-SIA prototype airplane above Lake Leman near Vevey during a test flight from its base in Payerne to Geneva International airport September 21, 2010. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT SCI TECH ENVIRONMENT IMAGES OF THE DAY) 

Staff push the solar-powered HB-SIA prototype after it successful landing on the tarmac of Cointrin International airport in Geneva September 21, 2010. The plane landed for the first time on a commercial airport, causing traffic to he halted for 20 minutes to avoid turbulence. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT SCI TECH ENVIRONMENT) 

Solar Impulse's solar-powered HB-SIA prototype airplane stands still after its first successful night flight attempt at Payerne airport July 8, 2010. The aircraft took off July 7 at 06:51 am and reached an altitude of 8,700 meters (28,543 feet) by the end of the day. It then slowly descent to 1,500 meters (4,921 feet) and flew during the night on the batteries, charged during the day by 12,000 solar cells, which powered the four electric motors. It landed July 8 at 09.00 am (GMT+2) for a flight time of 26 hours and nine minutes, setting the longest and highest flight ever made by a solar plane. REUTERS/Denis Balibouse (SWITZERLAND - Tags: TRANSPORT SCI TECH ENVIRONMENT IMAGES OF THE DAY) FOR BEST QUALITY IMAGE ALSO SEE: GM1E9BB0NL301 

A helicopter flies over the solar-powered Solar Impulse HB-SIA prototype airplane steered by German test pilot Markus Scherdel, during his first flight over Payerne April 7, 2010. The propeller plane, with a 61 metres (200 feet) wingspan, is powered by four electric motors and designed to fly day and night by saving surplus energy from its 12,000 solar cells in high-performance batteries. Wednesday's flight follows six years' work by 50 engineers and technicians led by Swiss adventurer Bertrand Piccard on the so-called Solar Impulse project. REUTERS/Ruben Sprich (SWITZERLAND - Tags: TRANSPORT ENVIRONMENT SCI TECH) 

Bertrand Piccard (L), pilot and president of Solar Impulse and Andre Borschberg, CEO and pilot of the company, unveil the solar-powered 61 metres (200 feet) wingspan HB-SIA prototype airplane at the airport in Duebendorf near Zurich June 26, 2009. REUTERS/Christian Hartmann (SWITZERLAND ENVIRONMENT SOCIETY SCI TECH) 

A technician removes a part of a model of a cockpit of the 61 metres (200 feet) wingspan prototype airplane Solar Impulse during a presentation in the town of Duebendorf near Zurich November 5, 2007. After four years of research and simulations, the solar-fired Solar Impulse plane project has entered a concrete phase with the construction of an initial prototype, referred to by its registration number 'HB-SIA'. REUTERS/Arnd Wiegmann (SWITZERLAND)