Aurora Flight Sciences has begun construction of a hydrogen-powered high-altitude, long-endurance (HALE) unmanned air vehicle as it works with Boeing to pursue a US Department of Defense advanced concept technology demonstration.

The Orion high-altitude, long-loiter (HALL) UAV now under construction at Aurora's Columbus, Mississippi plant will have a four-day endurance at 65,000ft (19,800m), while the larger HALE vehicle under study would stay aloft for 10 days.

The 33.8m (111ft)-span, 2,360kg (5,200lb) gross-weight Orion is powered by a Ford four-cylinder automotive engine modified and supercharged to burn hydrogen stored in the bulbous, 3.05m-diameter fuselage. Aurora has conducted long-endurance testing of the powerplant at a simulated 65,000ft, and run the engine at 110,000ft. Boeing, with Aurora, is looking at a 61m-span, twin-engine HALE vehicle with a 10-day endurance at 65,000ft.

Aurora says the first Orion HALL vehicle will fly in 2008 and be owned by Mississippi State University's Raspet Flight Research Laboratory.

Source: Flight International