The Global Hawk unmanned aerial vehicle lands after an eight-hour mission Feb. 28, 2008 at Edwards Air Force Base, Calif. The flight marked the 10th anniversary of the Global Hawk's first flight at Edwards AFB, where the aircraft flew for one hour and reached an altitude of 32,000 feet. The Global Hawk is also stationed at Beale Air Force Base, Calif., where the program is a total force effort between the active duty and Air Force Reserve. (U.S. Air Force photo/Jim Shryne)