Colin Greenwood

What is it? Magnetic propulsion uses the concepts and applications of electromagnets in order to propel an object. This technology is not necessarily a new one, the idea and research on using magnetic propulsion has been researched in the US since the 1920’s. The technology is advancing in three main fields:  Magnetic levitation trains (Maglev)  Weaponry (Rail gun)  Propulsion systems for space travel Transrapid 05, Hamburg, German 1979

Magnetic Levitation Train  Trains have no steel wheels or traditional tracks, use magnetic forces to “float” above track.  The car’s float on a cushion of air 1- 10cm thick, this eliminates friction allowing trains to safely reach speeds of 310mph. At this speed you could travel from Denver to LA in just over two hours.  The trains obtain thrust from the alternating currents flowing through the propulsion coils acting on the large magnets mounted to the train undercarriage.  Maglev trains use large amounts of power, typically 3-4 times what a typical subway train uses.  Several Japanese companies have started using super-cooled superconducting electromagnets to cut electricity costs. First commercial maglev train, Pudong International Airport, Shanghai. 2003

Electromagnetic Rail Gun  A rail gun is basically a large electric circuit, made up of three parts: a power source, a pair of parallel rails and a moving armature.  The power supply for a large rail gun is in the millions of amps, propelling projectiles at speeds approaching mach 7, hitting at miles away.  New generation all-electric naval ships can produce amperage needed by diverting power from their propulsion systems temporarily.  Major problems to overcome: Excessive heat is produced in the rails causing deformation Extreme polar forces will cause rails to bend and deform away from each other Huge power requirements need equally huge capacitors Research is costly, total research costs by 2011 predicted at $276 million.

Potential future Space Propulsion  The US Department of Energy, NASA and Boeing are working on using superconductors and high power solid state switches to harness the power magnetic propulsion.  Superconductors cooled to -450 F with liquid helium vibrate rapidly for 100 nanoseconds after a current is applied.  The goal is to harness this vibration directionally producing thrust.  Advanced solid state switches switch the power supply on and off 400,000 times per second producing steady thrust.  Predictions put the systems capable of 1% the speed of light.  System requires 30 amps and 9,000 volts planned to be powered by a small nuclear reactor.