A solar-powered plane that will be taken on a round-the-world journey in 2015 has taken off on its inaugural flight.
The Solar Impulse 2 vehicle lifted off from Payerne airfield in Switzerland on Monday, with adventurers Bertrand Piccard and Andre Borschberg at the controls, the BBC reports.
It is a larger, upgraded version of the aircraft that flew across the United States last year, setting a number of records including the longest manned solar-powered flight at 26 hours.
Mr Piccard and Mr Borschberg want to push the boundaries for alternative energy and believe their plane can be a standard bearer.
For the maiden flight, test pilot Markus Scherdel was in the cockpit. Wheels up occurred just after 03.35 GMT.
It follows weeks of ground and taxi tests, which have seen the vehicle run up to near take-off speed. This had satisfied project leaders that the craft's systems were ready to go airborne.
The tops of the plane's wings are covered by 17,000 solar cells, which drive four brushless electric motors at speeds of up to 140km/h.
During the day, the solar cells will recharge lithium batteries, which can then be used to keep the plane's propellers turning through the night.