Sling launch of a mass using superconducting levitation

Abstract

A sling concept is discussed in which a projectile could be slowly accelerated around a circular path to extremely high velocity (>10 km/s) in a closed evacuated cryogenic tube that guides it around the circular path. A high normal conductivity layer is maintained on the inner surface of the guide tube, and a launch package with superconducting magnets is levitated in the tube so that EM drag is minimized and it moves in a nearly frictionless state. An accelerating coriolis force is then experienced inside the tube by driving a smooth low-speed displacement motion of the entire accelerator tube using rotating machinery distributed outside the closed tube around the circular path. The projectile accelerates under a force proportional to its mass and in a manner equivalent to sliding down an inclined plane of very small angle in a gravitational field of strength increasing as the square of the projectile velocity. This accelerating wave can be programmed to travel around the accelerator at extremely high speed. The kinetic energy invested in moving the circular guide tube is small compared with that in the projectile, although the tube momentum is dominant. Future applications depend on advances in the technology of strong superconducting levitation, but could range from hypervelocity impact research using small masses to the launch of large masses (tons) into space from the surface of the earth or moon.