Bertrand Piccard (L) celebrates with Andre Borschberg after the Solar Impulse 2 airplane, piloted by Borschberg, landed at Kalaeloa airport after flying non-stop from Nagoya, Japan, in Kapolei, Hawaii, July 3, 2015. The aircraft, powered only by the sun's energy and piloted alternatively by Swiss explorers Borschberg and Piccard, has broken a world record for the longest non-stop solo flight, the project team said on Thursday. REUTERS/Hugh Gentry 

The Solar Impulse 2 airplane is greeted by hula dancers after it landed at Kalaeloa airport after flying non-stop from Nagoya, Japan in Kapolei, Hawaii, July 3, 2015. The aircraft, powered only by the sun's energy and piloted alternatively by Swiss explorers Andre Borschberg and Bertrand Piccard, has broken a world record for the longest non-stop solo flight, the project team said on Thursday. REUTERS/Hugh Gentry 

Crew members push the solar-powered plane Solar Impulse 2 to its parking position at Nagoya airport after changing weather conditions thwarted a planned take-off, June 24, 2015. The solar-powered plane attempting a round-the-world flight cut short the seventh leg of its 35,000-km global (22,000-mile) journey earlier this month, landing in Nagoya, western Japan, due to bad weather. REUTERS/Thomas Peter
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Solar Impulse spokeswoman Elke Neumann (C) informs journalists that a planned flight of the solar powered plane Solar Impulse 2 from Nagoya airport was canceled due to a change in weather conditions, June 24, 2015. The solar-powered plane attempting a round-the-world flight cut short the seventh leg of its 35,000-km global (22,000-mile) journey earlier this month, landing in Nagoya, western Japan, due to bad weather. REUTERS/Thomas Peter

The Solar Impulse 2, a solar powered plane, is parked in an inflatable hangar after an unscheduled landing at Nagoya airport in Japan June 3, 2015. The solar-powered plane attempting a round-the-world flight will cut short the seventh leg of its 35,000-km global (22,000-mile) journey, landing in Nagoya, western Japan, due to bad weather. REUTERS/Thomas Peter
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The Solar Impulse 2, a solar powered plane, approaches at Nagoya airport in Japan June 1, 2015. The solar-powered plane, which is attempting a round-the-world flight, will cut short the seventh leg of its 35,000-km global (22,000-mile) journey, landing in Nagoya, western Japan, due to bad weather. REUTERS/Thomas Peter

The Solar Impulse 2, a solar powered plane, circles above Nagoya airport in Japan before a planned landing, June 1, 2015. The solar-powered plane attempting a round-the-world flight will cut short the seventh leg of its 35,000-km global (22,000-mile) journey, landing in Nagoya, western Japan, due to bad weather. REUTERS/Thomas Peter
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The Solar Impulse 2 (foreground), a solar powered plane, sits on the tarmac after it landed at Nagoya airport in Japan June 1, 2015. The solar-powered plane, which is attempting a round-the-world flight, will cut short the seventh leg of its 35,000-km global (22,000-mile) journey, landing in Nagoya, western Japan, due to bad weather. REUTERS/Thomas Peter

The Solar Impulse 2 is seen taking off at the Mandalay international airport March 30, 2015. Pilots Bertrand Piccard and Andre Borschberg will take turns at the controls of Solar Impulse 2, which began its journey in Abu Dhabi in the United Arab Emirates on March 9, as it makes its way in the first round-the-world solar-powered flight in about 25 flight days at speeds of between 50 kph and 100 kph (30 mph to 60 mph). Picture taken with slow shutter speed. REUTERS/Soe Zeya Tun 

Ground staff prepare to push the "Solar Impulse 2", a solar powered plane, into a hangar after it landed at the airport in the western Indian city of Ahmedabad March 11, 2015. The Swiss-built solar aircraft took off from Muscat in Oman earlier on Tuesday to begin the second leg of its epic journey. The unprecedented attempt at the first flight around the world seeks to prove that flying is possible without using fossil fuel. On its five-month journey of 35,000 km (22,000 miles), the engines will be powered only by solar energy. Two Swiss pilots, Bertrand Piccard and Andre Boschberg, will take turns at the controls in the tiny cabin for five consecutive days and nights in the air. REUTERS/Amit Dave (INDIA - Tags: TRANSPORT SCIENCE TECHNOLOGY ENVIRONMENT) 

The Solar Impulse 2 takes off at Al Bateen airport in Abu Dhabi, at the start of an attempt to fly around the world in the solar-powered plane March 9, 2015. Two Swiss pilots, Bertrand Piccard and Andre Borschberg, on Monday embarked on the attempt to fly around the world on the solar-powered airplane that is expected to last for five months and is aimed at promoting clean technology in the aviation sector. On its five-month journey of 35,000 km (22,000 miles), the engines will be powered only by solar energy. REUTERS/Ahmed Jadallah (UNITED ARAB EMIRATES - Tags: TRANSPORT ENVIRONMENT ENERGY) 

Swiss pilots Andre Borschberg and Bertrand Piccard (L) smile before flying the Solar Impulse 2, at Al Bateen airport in Abu Dhabi, March 9, 2015. Piccard and Borschberg, attempting the first flight around the world in a solar-powered plane began the maiden leg of their voyage on Monday, the mission's official website said. Solar Impulse 2 took off from Abu Dhabi in the United Arab Emirates en route to the Omani capital Muscat at the start of a five-month journey of 35,000 km (22,000 miles) organised to focus the world's attention on sustainable energy. REUTERS/Ahmed Jadallah (UNITED ARAB EMIRATES - Tags: TRANSPORT ENERGY) 

SOLAR-PLANE/ - Reissue. Diagram of the Solar Impulse 2, a solar powered plane which is attempting the world's first round-the-world flight of its kind. Includes route map. (SIN03)