Lockheed Martin has pulled the lid off of a secret, stealthy, high-flying drone. Built and flown by its famous "Skunk Works" division, the unmanned aerial vehicle (UAV) could serve as a model for a new generation of robotic aircraft that hits targets halfway around the world.
With a 90-foot wingspan and a tailless design, the "Polecat" UAV looks like a smaller version of the B-2 stealth bomber. And like the B-2, the drone has been built to be stealthy and sneaky. But the twin-engine Polecat is "90 percent composite materials, rather than metal," the L.A. Daily News notes. "The vehicle is also made from less than 200 parts," adds Aviation Week. "Adhesives are used rather than rivets, decreasing the amount of labor needed to construct it -- that approach also contributed to a lower radar cross section inherent in the design."The Polecat has taken two subsonic flights, around 15,000 ft. But, eventually, the idea is to fly it 60,000 and higher -- and break the sound barrier. Up there, contrails don't form, Jane's observes, so the plane can stay hidden even better. Plus, Lockheed wants to see how its composites hold up at high altitudes.Skunk Works is also trying to rig Polecat up with "a fully autonomous flight control and mission-handling system that will allow future UAVs to conduct their missions, from take-off to landing, without the intervention of human operators," Jane's adds.Already hard at work on a number of shape-shifting planes, Lockheed is working on ways for the Polecat and future UAVs to alter their structure -- and change their roles mid-mission, Jane's continues. An "extended-wing long-loitering [recon] planform" could suddenly change into "a swept-wing attack configuration."
The addition of a tail, for example, that could morph from a horizontal into a vertical configuration - to allow a laminar-flow wing to fly and manoeuvre without undue risk in the thin air above 60,000 ft. A morphing tail might also be a desirable feature for a carrier-borne UAV.The company built the plane with $27 million of its own money over an 18-month period. But with the Air Force already pouring money in to high-altitude drone development -- and looking to put a new, multi-billion dollar fleet of long-range bombers in the air by 2018, that could be money extremely well spent.UPDATE 2:49 PM: Lockheed is doing more than building giant drones. The company is making itty-bitty, teeny-weeny UAVs, too. Darpa just gave Lockheed a $1.7 million, 10-month contract to build a drone "similar in size and shape to a maple tree seed."
A chemical rocket enclosed in its one-bladed wing will power a sensor payload module more than 1,100 yards. Delivered from a hover and weighing up to 0.07 ounces, the module will be interchangeable based on mission requirements. Besides controlling lift and pitch, the wing will also house telemetry, communications, navigation, imaging sensors, and battery power. The NAV [nano air vehicle] will be about 1.5 inches long and have a maximum takeoff weight of about 0.35 ounces.In typical operation, a warfighter will launch the NAV and fly it toward the target by viewing its flight path through a camera embedded in the wing. Like a maple tree seed, the one-bladed device will rotate in flight, but its camera will provide a stable forward view and transmit images back to a small, hand-held display. As the system matures, a simple autopilot aboard the NAV will provide limited autonomous operations. Once the NAV delivers its payload, it will return to the warfighter for collection and refurbishment.UPDATE 07/24/06 4:06 PM: It turns out this secret UAV wasn't built, -- it was printed, New Scientist notes.
In rapid prototyping, a three-dimensional design for a part - a wing strut, say - is fed from a computer-aided design (CAD) system to a microwave-oven-sized chamber dubbed a 3D printer. Inside the chamber, a computer steers two finely focussed, powerful laser beams at a polymer or metal powder, sintering it and fusing it layer by layer to form complex, solid 3D shapes.The technique is widely used in industry to make prototype parts - to see if, for instance, they are the right shape and thickness for the job in hand. Now the strength of parts printed this way has improved so much that they can be used as working components.About 90 per cent of Polecat is made of composite materials with much of that material made by rapid prototyping.(Big ups: Eric)