Engineers at NASA’s Dryden Flight Research Center chalked up another first for the center recently when they flew a scale-model sailplane that was towed aloft by one of NASA’s small Dryden Remotely Operated Integrated Drones – DROID for short.
The January flights of the two small unmanned aircraft were intended to validate systems and procedures and to reduce risk en route to a full-scale demonstration of the innovative Towed Glider Air-Launch Concept demonstration.
The flights marked the first time the DROID towed another aircraft into the air and the first autonomous towed flight ever at NASA Dryden.
The DROID and the glider were flown from the north end of Rogers Dry Lake at Edwards Air Force Base, Calif., in both remotely controlled mode by pilots using standard model-airplane radio controllers and autonomously via a pre-programmed autopilot. Flight objectives included validation of the towing technique, tests of the tow release system and autopilot, transition from manual to autonomous flight and demonstration of the remote pilot’s ability to fly the glider from a ground-based cockpit using visual input transmitted from a miniature video camera on board the aircraft.
“The flights were primarily flown to evaluate the research pilots’ ability to control and position the glider under tow behind the DROID, and also to evaluate the performance of the flight avionics and video systems on the DROID and the single fuselage glider that enabled the piloting task,” said TGALC project manager Gerald “Jerry” Budd.
The DROID flew nine flights during the tests, five of which towed the sailplane into the air. Budd said about 85 percent of the goals for the preliminary flight evaluation were accomplished.
Additional flights using the sub-scale conventional single-fuselage glider and lessons learned during the initial flights will pave the way for the next phase of the project, which will involve towing a custom-made twin-hulled sailplane model representative of the proposed TGALC configuration.
A long-time aerospace engineer who is currently a business development manager in NASA Dryden’s Advanced Planning and Partnerships Office, Budd initiated the concept of optimizing launch of small space satellites from a glider towed aloft by a powered aircraft as a much cheaper alternative to present-day launch methods. NASA Dryden’s Center Innovation Fund supports the small-scale project.