Staff members riding bicycles follow as German test pilot Markus Scherdel lands the solar-powered Solar Impulse 2 aircraft after its maiden flight 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/Fabrice Coffrini/Pool (SWITZERLAND - Tags: TRANSPORT SCIENCE TECHNOLOGY ENVIRONMENT)