Northrop Grumman [NOC], the Defense Advanced Research Projects Agency (DARPA), and NASA Dryden Flight Research Center said they have successfully completed a series of flights moving DARPA’s Autonomous High-Altitude Refueling (AHR) program closer to demonstrating the first autonomous aerial refueling between two unmanned, high-altitude aircraft.
The goal of the $33 million DARPA AHR program is to demonstrate autonomous fuel transfer between two Global Hawks, thus enabling flights of up to one-week endurance.
The flights, which used two NASA Global Hawk unmanned aircraft–one configured as a tanker and the other as a receiver–were conducted at Edwards AFB, Calif.
The flights took place between Jan. 11 and May 30 and reached several milestones including: the lead receiver aircraft extended and retracted its aerial refueling hose several times, completing all planned tests to validate the associated program hardware and software, the company said in a statement. Also, the trail tanker aircraft successfully demonstrated precision control in formation with manual and automated breakaway maneuvers, important safety features and criteria of the test program.
Additionally, for the first time, the two Global Hawks successfully flew in close formation–as close as 30 feet. During flight, the aircraft rendezvoused and flew for more than 2.5 hours under autonomous formation control with the majority of the time within 100 feet, or one wingspan, of each other.
“The technical developments that enabled these two high-altitude, long-endurance unmanned Global Hawks in close formation is an outstanding accomplishment for the AHR program,” said Fred Ricker, vice president and deputy general manager for Northrop Grumman Aerospace Systems’ Advanced Programs & Technology. “Coupled with the advanced design and technical implementation of aerial refueling systems on board both aircraft, the demonstration has truly brought a concept to life, which has the potential to change the operations for unmanned aircraft utility and enable mission flexibility never before realized.”
AHR is a follow-on to a 2006 DARPA Autonomous Aerial Refueling Demonstration (AARD), a joint effort with NASA Dryden that used an F/A-18 Hornet as a surrogate unmanned aircraft to autonomously refuel via a probe and drogue from a 707 tanker.
As part of the Navy’s Unmanned Combat Air System Carrier Demonstration program, Northrop Grumman is also developing AAR technology to help extend the operating range and flight duration of future carrier-based unmanned systems. The company plans to conduct AAR demonstrations in 2014 using the Navy’s X-47B unmanned demonstrator aircraft.
In partnership with NASA in the Space Act Agreement, Northrop Grumman supports the operations and maintenance of the two Global Hawks used in the AHR program and is responsible for all engineering design, as well as modification of both aircraft.