Boeing's hydrogen-powered UAV takes to the skies

Yesterday at Edwards Air Force Base in Los Angeles County Boeing successfully completed the first test flight of its "Phantom Eye" high-altitude unmanned aerial vehicle. This particular vehicle is unique because its propulsion system is hydrogen-based. The large tanks are responsible for the aircraft's unusual girth. "The combustion produces... water, so it's about as green as it gets when flying," said Drew Mallow, the Phatom Program manager. The prototype aircraft should be able to stay aloft for four days; the final design? Ten.