Bertrand Piccard has unveiled a prototype of the solar-powered plane he hopes eventually to fly around the world.
The vehicle, spanning 61m but weighing just 1,500kg, will undergo trials to prove it can fly through the night.
Piccard, who made history in 1999 by circling the globe non-stop in a balloon, says he wants to demonstrate the potential of renewable energies.
The final version of the plane will try first to cross the Atlantic in 2012. It will be a risky endeavour. Only now is solar and battery technology becoming mature enough to sustain flight through the night - and then only in unmanned planes.
The HB-SIA has the look of a glider but is on the scale - in terms of its width - of a modern airliner.
The aeroplane incorporates composite materials to keep it extremely light and uses super-efficient solar cells, batteries, motors and propellers to get it through the dark hours.
HB-SIA should be succeeded by HB-SIB. It is likely to be bigger, and will incorporate a pressurised capsule and better avionics. It is this vehicle which will attempt to circle the Earth (after first making an Atlantic crossing).
For full article and video of the solar plane prototype, visit BBC News.