AeroVironment has become the first company to fly a stratospheric, very-long-endurance UAV as part of the U.S. government’s Global Observer initiative. The 175-foot-wingspan aircraft took off from Edwards Air Force Base on August 5 and flew for one hour, reaching 4,000 feet. The airplane’s four airscrews were turned by battery power on this maiden flight, but AeroVironment will substitute a liquid-hydrogen system later this year for the high-altitude, long-endurance (HALE) tests. Six U.S. government agencies are providing more than $120 million in funding for the Global Observer joint capability technology demonstration. Interest in UAVs and small airships that can remain airborne for at least four days at altitudes up to 65,000 feet is growing fast, as lightweight composite structures and lighter-weight payloads make practical applications possible. AeroVironment said that its Global Observer UAV can provide “valuable communications and reconnaissance at a lower cost to military and nonmilitary customers.” Boeing has developed the liquid-hydrogen-powered Phantom Eye to meet similar requirements, and has teamed with Aurora Flight Sciences to develop the Orion, a smaller UAV with even longer endurance.