Solar-Powered UAV Can Stay Aloft for Years

The SolarEagle, Boeing’s newly announced unmanned airborne vehicle (UAV), has a 400-foot wingspan and will be capable of remaining aloft in the stratosphere for at least five years.

SolarEagle is designed to be a “zero-maintenance, launch-and-leave” UAV, Boeing's Pat O'Neil said.

Boeing says the aircraft offers many of the same capabilities as orbiting assets such as satellites but has a higher degree of flexibility and a lower cost, which makes it attractive for a variety of intelligence, communications and commercial applications.  Potential customers include the Department of Defense, Department of Homeland Security and various telecommunications operators.

The solar-electric-powered aircraft can cruise at altitudes above 60,000 feet at a speed of 70 to 80 knots while performing communications, intelligence, surveillance and reconnaissance missions.

Boeing is developing this high-altitude, long-endurance (HALE) aircraft under an $89 million contract with the U.S. Defense Advanced Research Projects Agency (DARPA) for the agency’s Vulture II demonstration program.

During the day, the SolarEagle will harvest solar energy and store it in fuel cells for use at night. The aircraft will have solar arrays attached to its plastic skin that cover more than 50 percent of its surface.

It has highly efficient electrical motors and propellers and a high aspect-ratio wing similar to a glider for increased solar power and aerodynamic performance.

The SolarEagle, which is being developed by Boeing’s Phantom Works’ rapid prototyping shop, will be able to carry payloads of up to 1,000 pounds. The goal of rapid prototyping is to get new technologies off the drawing board and into the air as soon as possible.

Before the five-year SolarEagle is launched, a demonstrator will test the aircraft’s flight characteristics, flying 30-to-90-day missions at the same altitudes. The demonstrator is scheduled to make its first flight in 2013.

The SolarEagle will take off from NASA’s Dryden Flight Research Center at Edwards Air Force Base in the Mojave Desert in California.

“We’ll likely be flying during the winter solstice in 2013,” said O'Neil, who is also Boeing’s Phantom Works program manager for Vulture II. “It’s meant to be a stressing situation.”

Because those first missions will be flown during the winter, with shorter days and weaker sunlight, the aircraft’s power system will face its maximum challenge.

“That’s a daunting task, but Boeing has a highly reliable, solar-electric design that will meet the challenge,” O’Neil said.