It may not have been the weeks of air time potential we were touting two years ago when we first wrote about the Zephyr——an unmanned, solar-powered aircraft developed by UK firm QinetiQ—but at the US Army's Yuma Proving Grounds in Arizona a new unofficial solar-powered flight record was set: 82 hours, 37 minutes.
Solar Powered by Day, Battery Powered by Night
Powered by amorphous silicon solar panels on its wings during the day and by lithium-sulphur batteries at night (recharged by the solar panels during the day) the Zephyr is officially a high-altitude long-endurance unmanned aerial vehicle (HALE UAV). Made of carbon fiber and weighing 30 kilograms, the Zephyr is launched by hand and can fly at altitudes of up to 60,000 feet.
Solar Aircraft Have Advantages over Satellites for Surveillance
The Zephyr project is funded by the US Department of Defense and is intended as a step towards developing an alternative surveillance system to both traditional aircraft and satellites. Chris Kelleher of QinetiQ described the advantages of the Zephyr in this regard to the BBC:
The principal advantage is persistence, that you would be there all the time. A satellite goes over the same part of the Earth twice a day—and one of those times is at night—so it's only really getting a snapshot of activity. Zephyr would be watching all day.
Kelleher went on to say that the Zephyr should be fully operational within two years, at which time the aircraft should be sufficiently developed to remain in the air for months at a time.
So why was the record unofficial? The Federation Aeronautique Internationale, the international air sports organization which sanctions world record attempts, was not present during the three day test flight.
Qinetiq and :: BBC News
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