DARPA tests Global Hawk UAVs for tanker role

A team from DARPA, NASA and Northrop Grumman has tested an RQ-4 Global Hawk UAV for the feasibility of using unmanned aircraft as an aerial tankers as part of the KQ-X program. The team flew Scaled Composites’ Proteus test jet 40-feet behind the drone at an altitude of 45,000-feet as part of the test.