Aurora Flight Sciences unveils Odysseus unmanned aircraft

Aurora Flight Sciences is developing a new unmanned aircraft that can stay aloft for up to five years.

Aurora Flight Sciences (Bridgeport, W.V.) has announced details of its new solar-powered airplane called Odysseus. Aurora and its partners BAE Systems, Draper Laboratory, and Sierra Nevada were recently awarded a contract from the Defense Advanced Research Projects Agency (DARPA) for the development of a new unmanned aircraft that can stay aloft for up to five years.

Aurora Flight Sciences has received a Phase 1 contract to begin developing a new aircraft, under a U.S. Defense Advanced Research Projects Agency (DARPA) program known as "Vulture.”

DARPA's goals for Vulture are not trivial: 5 years on station with a 450kg/1,000lb payload, 5 kW of onboard power, and sufficient loiter speed to stay on station for 99 percent of the time against winds encountered at 60,000-90,000 feet. The system could act as a satellite substitute for communications relay or reconnaissance, as long as the payload fit within the weight limit. Vulture would be more vulnerable to anti-aircraft missiles than a satellite, and could be targeted by fighter jets as well given the right launch profile; on the other hand, that closeness would improve sensor resolution and communications capability.

Aurora is involved in building Northrop Grumman's high-altitude Global Hawk UAV, has worked on a "Mars Flyer”/ARES vehicle for NASA, and is also collaborating with Boeing and with General Dynamics on the hydrogen fuel cell powered, high altitude Orion HALL. Other award competitors were not mentioned, but Aerovironment builds the hydrogen powered Global Observer with its 1 week flight times, and has considerable experience with very advanced high-altitude solar UAVs like the Pathfinder Plus and the record-setting Helios.

Aurora's winning design is called "Odysseus,"using solar energy to power the aircraft during daylight, and stored solar energy to power the aircraft at night. In selecting Aurora's Odysseus, DARPA appears to have chosen a single ultra-reliable system rather than a "modular shuttling"approach, and a solar thermal approach that also uses fuel cells and has a "refuel on station"option. Aurora's teammates on the program include BAE Systems (payloads, sensors, and concept of operations and employment); C.S. Draper Laboratories (extremely high reliability electronics and control systems), and Sierra Nevada Corporation (specialist in autonomous refueling systems).

The engineering challenges ahead are formidable, as one would expect for a DARPA project. The power system in particular must be extremely reliable, and the aircraft's materials will require advances of their own. Odysseus will be exposed to far more warming and cooling than satellites, and more ultraviolet radiation which will affect the aircraft's materials. The design is also likely to require very large wings, both to help keep it aloft and to accommodate the number of solar cells required. Conditions at altitude can challenge the durability of those wings, especially with hydrogen storage tanks attached. Aerovironment's Helios (1998-2003) demonstrated this the hard way in its 2003 crash.

During Vulture's Phase 1 conceptual system definition (12 months, 2008-2009), Aurora will define the system, plus full-scale and subscale demonstrators. A Phase 2 risk reduction development and testing phase (2009 – mid-2012) go-ahead would build and testing a subscale demonstrator notionally capable of flying for 3 months, and would end with a system flight. Phase 3 fabrication would involve a full-scale aircraft demonstrator capable of staying up for 12 months, and a program that reaches a Technology Readiness Level standard of TRL 6. This would let it enter System Design & Development as a program of record, if the military wished to pursue the project.

If Vulture reached those goals, it would become a very potent lower-cost competitor to the USA's $20+ billion TSAT satellite program. DARPA projects aren't like normal military system development projects, however, and have different goals. Several breakthroughs will be required for complete success, but even 1-2 breakthroughs in areas like materials durability at 60-90 thousand feet will deliver advantages that can be carried over to other programs.