An anonymous reader writes "Can a blimp propelled entirely by solar power cross the English Channel? We're about to find out! Nephelios, the world's first solar blimp, was built by Projet Sol'r — a collaboration between students at engineering and technical schools in France. Now, almost a year after its debut (and a year after it was supposed to launch), the helium-filled airship is ready for action, with its inaugural flight set to take place next week. The blimp is covered in semi-flexible solar cells that can generate up to 2.4 kilowatts — enough to keep the blimp moving at 25 mph as it crosses la Manche."