DARPA's Autonomous High-Altitude Refueling (AHR) program hopes
to bring autonomous refueling to the Global Hawk and other
flying robots. A recent DARPA news release says the AHR program
has completed a test flight that brings their goal one step
closer. During the test, two Global Hawks flew within 100 feet
or less of each other for 2.5 hours at 44,800 feet. The aircraft
were fitted with a refueling probe and a receiver drogue, which
were brought into the correct orientation to connect but were
not actually connected during this test flight. According to Jim
McCormick of DARPA: "The goal of this demonstration was to
create the expectation that future HALE aircraft will be
refueled in flight. Such designs should be more affordable to
own and operate across a range of mission profiles than systems
built to satisfy the most stressing case without refueling. The
lessons from AHR certainly extend beyond the HALE flight regime,
and insights into non-traditional tanker concepts may offer
further operational advantag