The first flight of the Theseus unmanned aircraft, designed to support NASA's Mission to Planet Earth initiative, was cut short by propulsion problems after it lifted off from Rogers Dry Lake, California, on 24 May.
"It was a propeller controller issue from what we can tell right now," says NASA Dryden Theseus project manager, John DelFrate. A new attempt will be made in the first week of July pending high-speed-taxi trials, he says. The 43m-span aircraft flew for 61s and reached an altitude of 60ft (18m) before the ground-based pilot brought it back to land. The aircraft, which was built by Virginia-based Aurora Flight Sciences and two local universities, weighed about 2,600kg on take-off for the first flight.
It is powered by two modified 60kW (80shp) Rotax 912 piston engines, which drive twin 2.7m-diameter propellers. The fuel-injected engines have three-stage turbochargers, to enable them to maintain 120kW at altitudes of over 70,000ft. The test team expects to investigate the full flight envelope over the next year.
The $4.9 million Theseus was designed and built to fly autonomously at high altitudes for over 24h with a scientific payload of up to 320kg. It will support research of stratospheric ozone depletion and the effects of future high-speed commercial-transport engines. Collected data will be used to validate satellite-based global-environmental measurements made by NASA's planned Earth Observing System.
Source: Flight International
