Unmanned Refueling

Unmanned Refueling

Military aviation relies on aerial refueling to conduct numerous combat, reconnaissance, and transport missions. Increasingly, unmanned aircraft are conducting these types of missions, yet they are not designed for in-flight refueling. Armstrong researchers have developed a system that allows two UAVs to fly in formation so that refueling can occur. The system consists of an image processing and control system on the receiving UAV that syncs with the GPS on the tanker UAV to enable formation flight. Subsequently, the image processing system collects azimuth, elevation, and range information so that the control system can provide commands to link the two aircraft and UAV-to-UAV refueling can commence. This research is part of NASA's Autonomous Aerial Refueling Demonstration (AARD) effort.

Work to date: The technology performed successfully in flight tests with manned aircrafts operating as surrogate UAVs (an F/A-18 and a KC-707 tanker). The initial Phase 1 test used manned aircraft operating with an automated flight control system and demonstrated two out of six successful refueling attempts. Phase 2 improved on this 'plug success ratio' and tested different configurations, such as evaluating different sun angles to the optical tracker and engaging in a turn.

Looking ahead: Next steps involve flight tests with unmanned aircraft. The team is looking for an industry partner to further development efforts.

Partner: Sierra Nevada Corporation

Benefits

 Stable: Offers excellent relative station-keeping capabilities

 Accurate: Cues the receiving UAV aircraft to the position of the tanker UAV

 Safe: Reliably retreats in a controlled and predictable manner to prevent contact in instances of declared 'misses'

Applications

 UAV refueling

 Automated manned aircraft refueling  Formation flight

Efficient Aerospace Vehicle Technologies

Increasing efficiency in aerospace systems is a key goal across the spectrum of NASA operations.

Armstrong researchers are constantly striving to build efficiency into all phases of flight projects, through development, fabrication, and operations processes.

From a new wing design that could exponentially increase total aircraft efficiency to a novel test stand for single-engine electric aircraft, our researchers are finding unique solutions that increase efficiency.