Aircraft dubbed “Solar Impulse”, HB-SIA prototype flies, just before landing, for the first time with test pilot Markus Scherdel on board in the military airport in Payerne, Switzerland, Wednesday, April 7, 2010. After six years of research, modelling and simulation training the Solar Impulse prototype with a 63.40 metres wingspan aircraft, registered as HB-SIA, is performing a flight of more of 1hour and reaching the altitude of 1000 meters. The Solar Impulse project aims to circumnavigate the world with an aircraft powered only by solar energy. (KEYSTONE/POOL/Laurent Gillieron)