This is an excerpt from EERE Network News, a weekly electronic newsletter.
Aeronaut's Goal: Around the World on Solar Power
A team of aeronauts — the first to circumnavigate the globe in a hot-air balloon without stopping — now aims to repeat the feat in a solar-powered aircraft. Dr. Bertrand Piccard announced on November 28th that he will team with Brian Jones, his former balloon co-pilot, and Andre Borschberg, an engineer and jet pilot, to accomplish the task. To develop a solar-powered airplane capable of flying continuously, the Piccard team will receive scientific assistance from the Swiss Federal Institute of Technology in Lausanne. A team of 30 experts from several departments of that institute has been investigating the feasibility of the solar-powered aircraft, called the "Solar Impulse," since March.
As envisioned by the team, the Solar Impulse aircraft will have an extremely long wingspan, advanced aerodynamics, and a revolutionary structure in order to capture and store sufficient solar energy during the day to be able to maintain itself in flight during the night. Piccard's plans call for the design and construction of a prototype aircraft over the next two years, followed by initial test flights in 2006. The team expects to achieve its first overnight flight in 2007, but they have not yet set a date for their flight around the world. See the Solar Impulse Web site and press release (PDF 140 KB). Download Acrobat Reader.
The closest thing yet to the Solar Impulse was the Helios, an unmanned solar-powered aircraft developed by AeroVironment, Inc. for the National Aeronautics and Space Administration (NASA). The Helios was designed to use a fuel cell to maintain flight overnight, but it crashed in June before accomplishing that goal. The crash investigation is still underway. Meanwhile, NASA is investigating the use of ground-based lasers to power an aircraft that has solar cells mounted on the bottom of its wings. See the Helios project page and the laser-powered aircraft press release on NASA's Dryden Flight Research Center Web site.