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With help from the Defense Advanced Research Projects Agency (DARPA), an unmanned aerial vehicle (UAV) manufacturer is developing a weapon that could be used for surveillance during urban warfare, area illumination, chemical and biological detection, target marking, flare dispensing and as a weapons platform, just to list some of the possibilities.
The GoldenEye-50 (GE-50) UAV with vertical take-off and landing (VTOL) capabilities is being developed by Aurora Flight Sciences and a sister company, Athena Technologies. With a gross take-off weight of just 20 pounds and a 4.5-foot wingspan (with removable wings), the GE-50 is ideal for small units, backers say.
“This system would be intended for small-unit use,” said Brad C. Tousley, program manager, Tactical Technology Office, DARPA. “Small units could emplace small sensors and do local area reconnaissance.”
“GoldenEye is an emerging technology versus a sustaining technology,” said Edward T. Smith, business development senior staff member at Aurora. “Global Hawk replaced the U-2 and helped sustain and improve existing surveillance methods. GoldenEye, with its VTOL capability and autonomous flight controls, will create altogether new methods that will be applied directly by the end-user. It is at the forefront of an emerging capability.”
Military and civil infrastructure protection will eventually rely heavily on small UAVs, Smith said, adding that major defense transformation programs, like the Army’s Future Combat Systems and the Navy’s Littoral Combat Ship, support this assertion. Architectures for these systems rely on distributed surveillance capabilities provided with small UAVs.
Aurora reached a key milestone in April, with the successful completion of a series of test flights by the GoldenEye-100 (GE-100) UAV, GE-50’s big brother. The barrel-shaped autonomous vehicle, viewed close-up, looks unwieldy. Yet even in its first test flight in September 2003, it executed a smooth VTOL and transition to a stable hover at Manassas Regional Airport, VA.
Ducted-Fan Engine
GoldenEye is able to level into horizontal flight by virtue of rotating wings. Its engine, known as a ducted fan, is a propeller shrouded within a cylindrical body that integrates advanced lightweight structures and a patented flight control system known as GuideStar, which was developed by Athena. It stands 5.5 feet tall and has a gross take-off weight of 150 pounds.
The GE-100 can be used for low-altitude reconnaissance, surveillance or target-acquisition programs. This spring, Aurora will use the GE-100 in a government effort to demonstrate detection, location and identification of radioactive targets with robotic systems, according to Smith.
Seeing the potential of the GE-100, DARPA provided limited funding for the development of GoldenEye through its Small Business Innovation Research (SBIR) program, as a clandestine UAV (CUAV) project. The original CUAV design-mission was covert deployment of unattended sensors in denied areas, including urban warfare areas, where sensors must be precisely positioned.
The three-phase process of the SBIR program consists of: phase one—feasibility studies; phase two—development; and phase three—commercialization.
Tousley indicated that a typical DARPA investment in phase one of a project is anywhere from $75,000 to $100,000, and the phase two limit is $750,000. DARPA is funding Athena and Aurora as an adjunct to the phase two SBIR. Aurora and Athena independently developed the GE-50 to address a clear military need for a small, quiet, distributed area surveillance tool for small units. This is exactly the type of innovation DARPA hopes to help foster.
Now, DARPA’s focus has shifted to the GE-50, with funding for Athena to develop a vision system called Vision Augmented Inertial Navigation (VAINS) for the GE-50. “This will give the 50 robotic vision and allow it to track and land autonomously on a moving target, cooperative target,” said Smith. VAINS will also aid in collision avoidance.
Performance Challenges
Any small UAV program must meet three key challenges, according to Tousley. They are:
- Performance and range. Current specifications indicate that the GE-50 has one hour of endurance with a flight ceiling of 10,000 feet.
- Flight controls. “They must be autonomous and able to react to high winds or whatever might be encountered on a flight. We don’t want to saddle a 21-year-old soldier with manning flight controls,” explained Tousley. A joystick could be used to plot waypoints in advance, but would not be used otherwise.
- Propulsion system. The propulsion system must be adequate for the job and not too noisy, said Tousley, adding that developers will use standard aviation fuel for testing. “But that has a high flash point and wouldn’t be safe in the field. Eventually, diesel fuel would be the ideal.”
Smith is certain that Aurora and Athena will more than meet all the requirements. “Even in its maiden flight, the GE-100 was able to operate autonomously,” he said, noting that a user can intervene with manual inputs, such as up, down, left, right, faster, slower or stop, if desired.
No pilot skills required to use the GE-50, he said. And with a completely enclosed ducted fan, GoldenEye can bump into things when running and not be stopped. “For example, it would bounce off power lines, as opposed to helicopters, which would crash,” said Smith. “Other small UAV ducted-fan efforts have been plagued with autonomy problems.”
Smith pointed out that ground safety handling is also critical in a tactical, uncontrolled environment. In windy, turbulent conditions, or when recovering onto a ship or boat, GE-50’s resilience with respect to bumping into objects unlocks the possibility for all kinds of simple recovery methods, according to Smith. “For example, a soldier could catch it with a pole tipped with a Velcro hook. This simplicity is impossible with a fixed-wing aircraft.”
The variable geometry nozzle gives the unit remarkable control authority, while its ability to fly with or without wings greatly increases its maneuverability. “A downside to fixed wing aircraft is that you need a launch and recovery area,” said Smith. “Or, if it’s small enough to be handheld, it’s limited operationally.”
Unlike fixed-wing UAVs, GoldenEye can be operated out of a small area, allowing for concealment of both the operator and the aircraft. “GoldenEye could easily be used to operate in an urban environment,” said Smith.
As for the noise level of the UAV, the ducted-fan design allows for a very sophisticated muffler to be used. “Although we haven’t optimized the system yet, the GE-100 has a 57 decibel sound level at 500 feet—sufficient to go unnoticed above ambient noise in most situations,” said Smith.
A baseline GE-50 system would consist of the UAV, an integrated field pack and preferably two operators, one to carry the aircraft and one to carry the tactical data link. The GoldenEye’s parts are simple, few and well known, according to Smith.
“We used commercial-off-the-shelf products for the servos and engines, as well as a production flight control computer,” he said. In addition, the GE-50 is durable and modular in design, so it’s easy to put back into service. “Another aspect of the GE-50 is that it creates backpressure to balance the prop, which makes it much simpler and less expensive. There’s very little that can go wrong with it,” said Smith.
And while there have been concerns about the attrition of large, expensive UAVs such as Global Hawk, Smith doesn’t anticipate that being a problem with the GE-50. The target price for the production GE-50 is approximately $50,000.
Tousley also doesn’t regard crash potential as much of a factor with the GE-50. “While a big emphasis on small UAVs is to keep the costs down, it’s a question of cost accountability—if it’s important to use the UAV, then it should be used,” he said. “For example, you could take a small UAV, send it into a threat area and allow it to get shot at to locate a sniper.”
“The money spent for 20 hours of flying time in a Huey helicopter would buy one GoldenEye vehicle,” Smith added.
Bandwidth Concerns
One other concern revolves around bandwidth for missions involving transmission of imagery. “Smaller UAVs can send some information line-of-sight. I’m not concerned with point-to-point communications,” said Tousley. “But what network will be used? When you put a networked vehicle in the air, it acquires the nodes in the area and becomes a wireless router.”
This is an area that’s being worked on. “There are small network-capable data links we’ll be able to use in three to four years,” said Tousley.
After the GE-50 completes a successful flight test, it will then be used in a ground-air teaming operation with an unmanned ground vehicle.
Smith is already thinking about the next generation of GoldenEye, in which the flight control system will be slaved to the camera. That will allow for collision avoidance and for operation off a moving platform without human interaction. The ability to fold the wings is also on the drawing board, which would make the vehicle more compact and allow greater mission endurance.
Full production of GoldenEye vehicles is expected to begin this year. “I can certainly see them being used in complex environments like Iraq and Afghanistan, as long as we can keep them affordable,” concluded Tousley.
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