Huge ‘launch ring’ to fling satellites into orbit – space – 03 October 2006 – New Scientist Space
An enormous ring of superconducting magnets similar to a particle accelerator could fling satellites into space, or perhaps weapons around the world, suggest the findings of a new study funded by the US air force.
The advantage of a circular track is that the satellite can be gradually accelerated over a period of several hours. And the setup is technologically feasible and cost effective, suggests a recent, preliminary study of the idea funded by the air force’s Office of Scientific Research.
The air force has now given the go-ahead for more in-depth research of the idea. The two-year study will begin within a few weeks and be led by James Fiske of LaunchPoint Technologies in Goleta, California, US.
The launch ring would be very similar to the particle accelerators used for physics experiments, with superconducting magnets placed around a 2-kilometre-wide ring.
The satellite, encased in an aerodynamic, cone-shaped shell that would protect it from the intense heat of launch, would be attached to a sled designed to respond to the forces from the superconducting magnets.
When the sled had been accelerated to its top speed of 10 kilometres per second, laser and pyrotechnic devices would be used to separate the cone from the sled. Then, the cone would skid into a side tunnel, losing some speed due to friction with the tunnel’s walls.
The tunnel would direct the cone to a ramp angled at 30° to the horizon, where the cone would launch towards space at about 8 kilometres per second, or more than 23 times the speed of sound. A rocket at the back end of the cone would be used to adjust its trajectory and place it in a proper orbit.
Anything launched in this way would have to be able to survive enormous accelerations – more than 2000 times the acceleration due to gravity (2000g). This would seem to be an obstacle for launching things like communications satellites, but Fiske points out that the US military uses electronics in laser-guided artillery, which survive being fired out of guns at up to 20,000g. [Article]