The Zephyr flew non-stop for 82 hours, 37 minutes. The latest flight was conducted at the US Army’s Yuma Proving Ground in Arizona. However, the Yuma mark remains “unofficial” because QinetiQ did not involve the FAI (Federation Aeronautique Internationale), the world air sports federation, which sanctions all record attempts.
The 30kg Zephyr was guided by remote control to an operating altitude in excess of 18km (60,000ft), and then flown on autopilot and via satellite communication. It tested a communications payload weighing approximately 2kg.
Its structure uses ultra-lightweight carbon-fibre material; and the plane flies on solar power generated by amorphous silicon solar arrays no thicker than sheets of paper. These are glued over the aircraft’s wings. To get through the night, the propellers are powered from lithium-sulphur batteries which are topped up during the day. “Lithium sulphur is more than double the energy density of the best alternative technology which is lithium polymer batteries.
The engineers from the Farnborough-based company are now collaborating with the American aerospace giant Boeing on a defence project codenamed Vulture. This would see the biggest plane in history take to the sky, powered by the sun and capable of carrying a 450-kilo (1,000lb) payload.
– from BBC
This is a good news for renewable technology. Now people can participate in Green wars.