Towed Glider Air Launch System (TGALS)

Armstrong researchers successfully flight-tested a prototype twin-fuselage towed glider that could lead to rockets being launched from
NASA TechPort Data Collection - AFRC Page 2 of 9 TechPort Field Notes Data understandable to all audiences pilotless aircraft at high altitudes. This technology could significantly reduce the cost and improve the efficiency of launching small satellites into a low Earth orbit (LEO). The towed glider is just one element of the novel rocket-launching concept of the TGALS project. The ultimate goal is to build a relatively inexpensive remotely piloted glider that will be towed aloft by a large transport aircraft or minimally modified business jet. Following its release, the glider will launch a booster rocket into an optimal trajectory to place its payload into LEO, resulting in a more than 50 percent increase in performance to orbit at a greatly reduced cost and schedule. Additionally, the TGALS project opens the small launch vehicle (LV) market to small companies that would otherwise find launch costs prohibitive.

Work to date: The TGALS project is a proof-of-concept demonstration using radio-controlled, one-third scale models of both glider and rocket. Researchers built a 27-foot-wingspan, twin-fuselage glider and towed it aloft with one of Armstrong's small unmanned aircraft. Test flights in 2014 demonstrated that both single- and twin-fuselage gliders are airworthy. Flight objectives included validation of towing techniques, 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 from a miniature camera aboard the aircraft.

Looking ahead: Data collected from the twin-fuselage flights will be used in the development of a scale-model rocket being built under NASA's Small Business Innovation Research (SBIR) program. Funding for future testing will come from the Space Technology Mission Directorate's Game Changing Development Program.

Partner: Whittinghill Aerospace LLC is fabricating a scale-model of its Mini-Sprite rocket for an air launch flight demonstration, under a Phase III SBIR project.

Benefits:

• Economical: Provides an inexpensive air-launch platform 
• Affordable: Provides small aerospace firms with access to optimized air launch conditions
• Safer: Offers a substantial safety perimeter from high-energy systems inherent in rocket boosters (as compared to other air-launch methodologies)

Applications: This air lift and launch capability would greatly enhance the ability to carry unique, experimental research vehicles to altitude and release them to conduct aeronautical flight research in the areas of propulsion, hypersonics, structures, aerodynamics, and flight controls.