Sailing for 54 hours more than 50,000 feet (15,240 meters) above the New Mexico desert, a solar-powered aircraft has set a new world record for longest unmanned flight.
The company acknowledged the record might not stand because the test, held at the White Sands Missile Range in New Mexico, was not witnessed by officials from the World Air Sports Federation, which keeps and certifies records.
Built from carbon fibers, the trapezoid shaped aircraft is 18 meters, or 59 feet, long and weighs only 30 kilograms, about 66 pounds - light enough to be launched, by hand, by a team of three. It uses paper-thin silicon panels to draw on the sun's power and the surplus is stored in lithium-sulphur batteries, which power the plane through the night.
QinetiQ declined to say how much the program cost, although it said Britain's Ministry of Defense had contributed several million pounds to the project.
Potential applications for Zephyr include surveillance and communications work.