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 ... more 
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) less 
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Reuters | Photo By DENIS BALIBOUSE / REUTERS
Mon, Jun 2, 2014 3:01 AM EDT