A burning mixture of air and natural gas propels a heavy piston. The piston compresses and heats hydrogen gas. A metal diaphragm bursts under pressure and releases hydrogen to the launch tube. The diaphragm is scored so that it fails in a predictable manner. The projectile rests on a nylon sabot which is propelled by hydrogen. The sabot reduces abrasion and makes it possible to use low hydrogen pressure and a slender projectile. Maximum velocity is limited to the speed of sound in very hot hydrogen, which is about 4 km/s. The minimum mass (for 1-ton cargo) is 104 tons.
W. D. Crozier and William Hume, "High-Velocity, Light-Gas Gun," Journal of Applied Physics, Vol. 28, August 1957, pp. 892-894.
Roy A. Taylor, "A Space Debris Simulation Facility for Spacecraft Materials Evaluation," SAMPE Quarterly, Vol. 18, No. 2, January 1987, pp. 28-34.
John W. Hunter and Rod A. Hyde, "A Light Gas Gun System for Launching Building Material into Low Earth Orbit," AIAA Paper 89-2439, July 1989.
Breck W. Henderson, "Livermore Proposes Light Gas Gun for Launch of Small Payloads," Aviation Week and Space Technology, Vol. 133, No. 4, July 23, 1990, pp. 78-79.
David W. Bogdanoff and Robert J. Miller, "Improving the Performance of Two-Stage Gas Guns by Adding a Diaphragm in the Pump Tube," International Journal of Impact Engineering, Vol. 17, 1995, pp. 81-92.
Pavel V. Kryukov, "Review of Investigations Under Way on the Large-Scale TsNIIMASH Ballistic Facility," Ballistic Technologies Scientific Venture, Box 92, Korolev, Moscow Region, 141070, Russia.
SHARP gas gun at Lawrence Livermore National Laboratory.