A slender, glider-like plane has completed the first night flight powered by solar energy, staying aloft for 26 hours and flying higher and longer than any previous solar flight. The Solar Impulse, with a 193-foot wingspan and weighing only 3,500 pounds, completed its record-breaking flight over Switzerland, soaring to 28,000 feet and achieving an average speed of 23 knots. The project is the brainchild of Bertrand Piccard, who completed the first round-the-world flight in a hot air balloon in 1999.
The Solar Impulse has 12,000 solar cells in its wings, which feed energy to high-performance batteries and four electric motors. Piccard said that the plane’s flight — using energy stored during the day to power the plane after dark — is proof that “we are on the verge of the perpetual flight.” The Solar Impulse is the prototype of an aircraft that Piccard hopes will circumnavigate the globe in 2012.