A proposed magnetic-coupling scheme would afford additional degrees of freedom to optimize the designs of gas-driven catapults or launchers. The scheme could be applied to gas guns in diverse applications, including launching spacecraft or aircraft, propelling various objects at high speeds along the ground, and accelerating objects to high speeds for research on hypervelocity impacts.

Heretofore, the usual approach to designing a gas-driven launcher has involved designing a launching tube to accommodate the projectile; the rear end of the projectile would be configured as a piston, and pressurized gas would be introduced into the tube behind the piston to accelerate the projectile to the desired muzzle velocity. If the projectile is a spacecraft, aircraft, or other large object, then this approach entails major disadvantages in that the tube must be made very wide and the amount of pressurized gas that must be supplied is correspondingly large.

The proposed magnetic-coupling scheme would make it possible to launch a projectile by use of one or more launching tube(s) narrower than the projectile. Thus, one could design a launching system that would function with a smaller amount of gas (albeit at a higher pressure needed to generate the required accelerating force over a smaller piston area). By making it possible to use a narrower tube or tubes, the proposed scheme would also make it possible or easier to design a staged compressed-gas system that would utilize compressed gas and compression energy more efficiently.

This work was done by Glen A. Robertson of Marshall Space Flight Center.

This invention is owned by NASA, and a patent application has been filed. Inquiries concerning nonexclusive or exclusive license for its commercial development should be addressed to

Sammy Nabors
MSFC Commercialization Assistance Lead
at (256) 544-5226 or This email address is being protected from spambots. You need JavaScript enabled to view it..

Refer to MFS-31184.

NASA Tech Briefs Magazine

This article first appeared in the September, 2000 issue of NASA Tech Briefs Magazine.

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