The Solar Impulse aircraft, a pioneering

The Solar Impulse aircraft, a pioneering Swiss bid to fly around the world on solar energy is flying under a commercial plane during is first test on April 7, 2010 from Payerne's air base, western Switzerland. Propelled by four 10 horsepower electric motors, the gangling single-seater aircraft and test pilot Markus Scherdel slowly gained altitude for a scheduled flight of around two hours at an altitude of around 1,000 metres (3,280 feet). The tests are due to build up to a first non-stop 36-hour flight through darkness, followed by a five-stage flight around the world in 2012. AFP PHOTO/POOL/ FABRICE COFFRINI (Photo credit should read FABRICE COFFRINI/AFP via Getty Images)