Boeing has won an $89 million government contract to build and fly an unmanned solar-powered plane that can--eventually--stay aloft continuously for up to five years. Yes, that's five years.
The defense contractor will develop the SolarEagle aircraft for the Vulture II program run by the U.S. Defense Advanced Research Projects Agency, better known as DARPA. Scheduled to get off the ground for its first demo flight in 2014, the plane will likely serve as an electronic sensor and military communications platform. But it could eventually turn into a less expensive alternative to communications and reconnaissance satellites.
"SolarEagle is a uniquely configured, large unmanned aircraft designed to eventually remain on station at stratospheric altitudes for at least five years," Pat O'Neil, Boeing Phantom Works program manager for Vulture II, said in a statement. "That's a daunting task, but Boeing has a highly reliable solar-electric design that will meet the challenge in order to perform persistent communications, intelligence, surveillance and reconnaissance missions from altitudes above 60,000 feet."
"Daunting" should rightly come across as understatement. To date, long-term flights for solar-powered aircraft--still a largely experimental category--have been more on the order of hours or days. In July, Bertrand Piccard's Solar Impulse made its first-ever 24-hour flight, with the plane (carrying a pilot) powering through the night on energy stored in its batteries during daylight hours. In 2007, the 66-pound, unmanned Zephyr from British defense specialist Qinetiq flew for 54 hours, and in 2008 it flew for 83 hours, or more than three days.
The more immediate endurance challenge for the SolarEagle will be more modest than the five-year ideal. Boeing says that during testing, the UAV--which will have a 400-foot wingspan--will linger in the upper atmosphere for 30 days, using "highly efficient electric motors and propellers" to run on the solar energy collected during daytime.
The actual labor on the SolarEagle will be done by Boeing's Phantom Works, a group that teams up with other businesses in Boeing's Defense, Space & Security unit to develop advanced products and technologies. Under the agreement, Boeing will create a full-scale working flight demonstrator, with help from suppliers Versa Power Systems and Qinetiq.
To win DARPA's Vulture II project, Boeing faced off against two other defense contractors--Aurora Flight Sciences and Lockheed Martin. The goal now for Boeing will be to design a solar craft that can stay above the clouds at 60,000 to 90,000 feet, withstand the high winds at that altitude, and carry a 1,000-pound payload.
Update Sept. 17 at 8:43 a.m. PDT: A reader points out that Qinetiq says the latest version its Zephyr has now logged a continuous flight that lasted 336 hours, 22 minutes--that is, 14 days--a feat that it pulled off in July of this year above the U.S. Army's Yuma Proving Ground in Arizona.