Jan 27 2011
The Global Observer UAV surveillance aircraft of the U.S. Air Force accomplished its initial flight test recently. The advanced aircraft, developed after six years of persistent efforts, features a wingspan of about 56.5 meter or 175 feet and four electrically activated propellers.
The aircraft can stay in the air for more than 160 hours in a week, flying at 21 kilometers or 65,000 feet. This unique one ton Global Observer aircraft has the capability to transport nearly 400 kg or 880 pounds of vidcams and communications gear, and utilizes liquid hydrogen to run a generator that activates the four props and sensing devices.
The aircraft is a powered glider and thus can travel nearly 250 kilometers per hour. Several long-lasting UAVs have been tried to develop, employing solar panels in the wings. But such aircrafts are not so rugged and failed to carry heavy payload or produce power, in contrast to those, which utilizes liquid hydrogen. The solar powered aircraft stays for longer time in the air. Global Observer UAVs can be used as substitutes for space satellites, and effectively provide ground-based surveillance.
Several security and durable reasons restricts Global Observer from operation in the near future. It took nearly five years in developing the creative, tiny, versions of this specific aircraft. The final model can be made huge and upon successful completion of all these trials, the aircraft can be made functional in 5 to ten years.
Source: http://www.airforce.com