Testing and research is being carried out on a Boeing hydrogen aircraft engine at a facility in Manassas, Virginia, where the Aurora Flight Sciences Corporation has its headquarters.

Aurora, who design, manufacture and operate unmanned aerial vehicles (UAV) for a diverse group of federal agencies and prime aerospace contractors, have just been awarded a $6.1m Army contract for continued work on an advanced unmanned aircraft.

The aircraft in question, named Orion HALL, is serving as a test bed for a hydrogen propulsion system that would enable the machine to fly at altitudes of up to 65,000 feet for more than 100 hours. A conventionally powered version is also being studied, with an endurance level of around two weeks at altitudes of around 20,000 feet.

The Orion Hall has been in development since 2006 and is scheduled for its first flight in 2009, with surveillance and tracking targets as possible functions when in Army use.