Northrop Grumman Corporation, Defense Advanced Research Projects Agency (DARPA) and NASA Dryden Flight Research Center took a major step toward demonstrating autonomous aerial refueling between two unmanned, high altitude aircraft, an operation never before performed. In a key risk reduction flight test, Northrop Grumman's Proteus test aircraft and a NASA Global Hawk flew as close as 40 feet apart at an altitude of 45,000 feet, an industry-setting record.
