The Solar Impulse 2, a solar-powered plane, flies over the Sheikh Zayed Grand Mosque in Abu Dhabi during preparations for next month's round-the-world flight, February 26, 2015. Swiss pilots Bertrand Piccard and Andre Borschberg will attempt to fly around the world in the Solar Impulse 2, in a bid to prove that such a flight is possible without the use of fossil fuels. The solar-powered plane has a wingspan of 72 metres, larger than that of a Boeing 747, but weighs only 2.3 tons, about as much as a family car. More than 17,000 solar cells on the wing power lithium-ion batteries in four electric motors. The airframe makes use of carbon fiber, which is three times lighter than paper, to keep the plane as light as possible. The 35,000 km flight is expected to take about five months, with stops in Oman, India, Myanmar, China, the United States, and in Southern Europe or North Africa depending on the weather. The Solar Impulse 2 is expected to land back in Abu Dhabi in late July or early August. [Photo/Agencies]