Called the Zephyr, it's an aircraft that can fly continuously using nothing but solar power and "low drag aerodynamics". The combination of solar panels on the upper wing surface and rechargeable batteries allows Zephyr to be flown for many weeks and even months. The first flight trial of the Zephyr were conducted recently by QinetiQ in White Sands Missile Range, New Mexico. Two aircraft were flown for four and a half and six hours respectively, the maximum flight times permitted under range restrictions. The maximum altitude attained was 27,000 feet above sea level. The ultra-light aircraft is designed to fly at altitudes as high as 132,000 feet (25 miles/40km), above normal commercial air-lanes and most weather.
QinetiQ believes that stratospheric platforms will rapidly become commercially viable and revolutionize future communications. High altitude platforms of this sort could provide a cheaper alternative to satellites in remote areas and developing countries. They can also enable observation of natural disasters and humanitarian crises.
Via: The Energy Blog