Superconducting Ring Accelerator to Launch Payloads Into Space

We are used to thinking of superconducting ring accelerators in the context of physics research with particle accelerators. The idea of accelerating macro-sized payloads up to 100 kgs in weight to a velocity of six miles per second in a ring accelerator, simply never occurred to most space launch theorists. The idea did occur to Jim Fiske at LaunchPoint Technologies in Goleta, CA,

The design calls for a high-speed accelerator that whips a projectile as heavy as 220 pounds around a circular 1.5-mile-radius vacuum tunnel. Powerful electromagnetic motors inside the tunnel will accelerate the unit, strapped to a magnetic sled, in circles until it reaches a velocity of six miles per second and then will eject the projectile from a launch ramp into space.

The system is still just an idea on paper, but the U.S. Air Force has awarded Launchpoint a two-year, $500,000 grant to prove it can work. Project leader Jim Fiske, an expert in magnetic levitation, believes that the magnetic forces would counteract the pulverizing G-forces generated by radial acceleration and prevent the sled from touching the tunnel wall.

As for the system’s cost, its low power requirements would allow spy micro-satellites to be slung into orbit for $50,000, a small fraction of the current $5-million launch cost. That explains the Air Force’s interest, but the system could also be a boon for space exploration. An inexpensive magnet-propelled pipeline could toss construction materials, food and other basic resources into orbit to supply tomorrow’s space colonies. “You could send a block of aluminum, water or even frozen mashed potatoes,” Fiske suggests—anything durable enough to handle the stress.

Source (hat tip Michael Anissimov)


Here is more from a Newscientist.com article:

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.

....If the ring launched hundreds of satellites a year, it would be cheaper than conventional rocket launches. With 300 launches per year, the team estimates the ring could put payloads into orbit for $745 per kilogram. If the launch rate reached 3000 launches per year, they calculate that would drop to $189 per kilogram. Today, it costs more than 100 times that to send payloads into space.

Source.

Of course this type of mass accelerator could be used to boost supplies for space exploration, scientific study of earth from space, space colonization, and certainly could boost weapons to orbital or sub-orbital velocities. Anything that could stand the extreme acceleration.

Humans are too fragile for such high accelerations, but if most of the mass humans need could be boosted cheaply in this fashion, the relatively few humans going to space could get there via chemical rocket, for now.