From the BBC: "Record-breaking aviators Brian Jones and Bertrand Piccard hope to harness the Sun's power to fly round the world.
The pair gained worldwide recognition in 1999 when they became the first to circumnavigate the globe in a balloon.

Now they plan to repeat the journey in a solar-powered aeroplane which will have to use batteries to fly at night.

A feasibility study has confirmed the viability of the Solar Impulse project and experts are now preparing to design the craft for launch some time in 2006."