Plane Flies on Power of Five Light Bulbs (SPACE.com / LiveScience.com)

Sara Goudarzi LiveScience Staff Writer LiveScience.com 2 hours, 50 minutes ago The largest unmanned aircraft to rely solely on hydrogen fuel has flown successfully during tests. The plane, with a 22-foot-wingspan, is powered by a fuel-cell system that generates 500-watts—equal to five bright light bulbs . “That raises a lot of eyebrows,” said Adam Broughton, a research engineer at the Georgia Institute of Technology's Aerospace Systems Design Laboratory. “Five hundred watts ...