Long-range vision: In quest for 5-year UAV flights developers think 'beyond the airplane'

摘要

Derek Bye remembers the titter that ran through the audience when the U.S. Defense Advanced Research Projects Agency (DARPA) held an industry day in Arlington, Va, to announce its latest aeronautics research effort, a program called Vulture. There was "the giggle factor," said Bye, who designs airplanes for Lockheed Martin. DARPA wanted an unmanned plane that would fly at altitudes as high as 90,000 feet for five years without landing, carry a halfton of payload and draw 5 kilowatts of power. It sounded like an idea right out of H.G. Wells' science fiction but, in fact, the idea sprang in part from NASA's aeronautics record books. Seven years earlier, a strange-looking, unmanned solar-powered plane called Helios set an altitude record for propeller-driven craft of 96,863 feet. The California company AeroVironment built Helios under a NASA research effort aimed at developing a new class of high-flying environmental sensing aircraft. In a 2003 flight, the Helios flying wing bowed under the weight of a newly added 520-pound fuel-cell pod and hydrogen tanks, and the craft broke apart off Hawaii.