Boeing's new Phantom Eye UAV is powered by hydrogen, making it a very fuel efficient vehicle capable of flying at more than 12 miles of altitude for 4 days at a time. From the company's press release:
"The program is moving quickly, and it’s exciting to be part of such a unique aircraft," said Drew Mallow, Phantom Eye program manager for Boeing. "The hydrogen propulsion system will be the key to Phantom Eye's success. It is very efficient and offers great fuel economy, and its only byproduct is water, so it's also a 'green' aircraft."
Phantom Eye is powered by two 2.3-liter, four-cylinder engines that provide 150 horsepower each. It has a 150-foot wingspan, will cruise at approximately 150 knots and can carry up to a 450-pound payload.
Link via Gizmodo | Photo: Boeing