The Defense Advanced Research Projects Agency has announced that two modified Global Hawk drones have demonstrated they can "safely and autonomously operate under in-flight refueling conditions," but challenges remain. The tests actually took place several months ago, and DARPA researchers have been poring over data acquired during those tests to reach their conclusions. Researchers expected low success rates over multiple attempts because Global Hawks are designed for endurance, not refined control authority in formation flight. But DARPA this week said data analysis shows that close formation flights show that "60 percent of the attempts would achieve contact." And that could eventually lead to changes the mission profiles and capabilities of unmanned aerial systems.
This is a companion discussion topic for the original entry at https://www.avweb.com/news/darpa-steps-toward-uav-to-uav-refueling