This is an excerpt from EERE Network News, a weekly electronic newsletter.

July 28, 2010

Unmanned Solar-Powered Aircraft Soars Nonstop for 14 Days

Photo of a long-winged aircraft being prepared for flight by several assistants.

A flight crew preps the solar-powered QinetiQ Zephyr before its record-breaking 14-day flight over Arizona.
Credit: QinetiQ

The Zephyr, an unmanned solar-powered aircraft, landed safely on July 23 after flying nonstop for 14 days, unofficially smashing long-standing world records, according to its manufacturer QinetiQ. The craft, which launched from the U.S. Army's Yuma Proving Ground in Arizona on July 9, touched down there after a journey that quadrupled its own unofficial world record for longest unmanned flight (82 hours, 37 minutes) set in 2008. The company, which said Zephyr also surpassed the official world record for the longest flight for an unmanned air system (30 hours, 24 minutes) set by Northrop Grumman's RQ-4A Global Hawk in March 2001, is awaiting official confirmation of the new mark. Zephyr also bettered the record for non-stop flight, passing the Rutan Voyager milestone of 9 days set in December 1986.

The drone flies on solar power delivered by amorphous silicon solar arrays on its 74-foot wingspan. The energy collected during the day recharges lithium-sulfur batteries, allowing it to fly during darkness without refueling. Zephyr's ultra-lightweight carbon-fiber frame weighs about 110 pounds. This is the second notable solar-powered feat this month. On July 7-8, a pilot kept the solar-powered Solar Impulse aloft over Switzerland through an entire 24-hour cycle, the first time this was accomplished with a manned craft, according to sponsors. See the QinetiQ press release.