Servo - July 2008

Robytes

by Jeff Eckert

The Vulture Seldom Comes Home to Roost

On a more celestial level, DARPA is also funding a competition to develop an unmanned aerial vehicle that will shatter endurance records. The bird will draw 5 k W of power, carry a 1,000 lb (450 kg) payload, stay aloft for at least five years, and remain in its assigned airspace 99 percent of the time while fighting winds encountered at operating altitudes, reportedly ranging from 60,000 to 90,000 ft ( 18,000 to 27,000 m). The goal is to provide long-term intelligence, surveillance, reconnaissance, and communication missions over locations of interest.

Contractors for phase one are Aurora Flight Sciences ( www.aurora. aero), Boeing ( www.boeing.com), and Lockheed Martin (www.lock heedmartin.com). A variety of propulsion approaches — including solar and internal combustion — will be considered; however, nuclear and lighter-than-air designs have been ruled out. The winning design must comply with space — not aviation — industry standards, because only a “pseudo-satellite” will handle the demanding requirements. A supervisory engineer at NASA observed,

“What you don’t want to build is a fragile, expensive pain in the butt.”

The Aurora offering will be based on its “Odysseus” design, which uses solar power during daylight hours and stored energy at night. It combines three “constituent aircraft” in a 500 ft (150 m), intriguing Z-wing configuration. Boeing is expected to field a design based on the existing British-built Zephyr high-altitude, long-endurance UAV, from partner QinetiQ ( www.qinetiq.com). Lockheed Martin is still mum on the subject.

The competitors have 12 months to come up with their initial designs for DARPA review. Phase two will end with a three-month flight test of a subscale demonstrator, and the final phase will require a 12-month test of a full-scale vehicle.

Aurora’s Odysseus design: A possible configuration of the Vulture UAV. Photo courtesy of Aurora Flight Sciences.

million over three years from the Defense Advanced Research Projects Agency ( www.darpa.gov) — is iRobot ( www.irobot.com). Under the grant, the company will develop the LANdroid robot, a portable communications relay device. According to the contractor, “This robot will be small enough that a single dismounted warfighter can carry multiple robots, inexpensive to the point of being disposable, robust enough to allow the warfighter to drop and throw them into position, and smart enough to autonomously detect and avoid obstacles while navigating in the urban environment.”

The objective is to enable networking in urban areas where buildings and other pesky objects can block wireless operations. In operation, each of the little guys will wander around until it finds a good spot to function as a node and then join the rest of the swarm to form the network. If one is destroyed, the others will adjust their positions to keep the system up and running.