Lorentz actuated propulsion would require no propellant. However, recent experiments simulating orbit conditions resulted in explosions.
The team tested the ability of various objects to hold a charge in a vacuum while being bombarded with plasma, as would be the case in orbit. To generate the charge on the test object, they attached it to a sample of radioactive Americium-24, an alpha-particle emitter, and applied a voltage. The electric field carries away the positively charged alpha particles leaving the object highly charged. Microscopic arcing was observed at voltages as low as -300 V. This arcing caused solder to explode off of the object.
Experimental Study of a Lorentz Actuated Orbit, preprint paper
The arcing that occurs at low voltages is a serious problem but can essentially be eliminated if the wires and solder are well insulated. The object can easily be charged in plasma only if it is insulated in such a way that it is not in direct contact with the plasma. The only problem then is the net zero charge that is observed by the magnetic field. The plasma itself, created in the lab, is not exactly identical to that of outer space or the upper atmosphere. Even though the electron temperature closely relates to those regions, the electron density is four orders of magnitude higher and may cause different results than one would obtain in a lower electron density environment. Experimental research on a Lorentz Actuated Orbit is still ongoing with the hope that one day we will be able to establish an experimental basis for sizing a propellantless propulsion system.
SpaceX Conducts First Five Engine Firing of Falcon 9 Rocket
Space Exploration Technologies Corp. (SpaceX) conducted the first five-engine firing of its Falcon 9 medium to heavy lift rocket at its Texas Test Facility outside McGregor on Thursday, May 29. At full power the engines generated almost half a million pounds of force, and consumed 1,750 lbs of fuel and liquid oxygen per second. This five engine test again sets the record as the most powerful test yet on the towering 235-foot tall test stand.
The first Falcon 9, contracted to launch a US government payload, will arrive at the SpaceX launch site at Cape Canaveral by the end of 2008, according to vice-president for propulsion Tom Mueller.
The maiden flight is expected late in the first quarter of 2009, some six months later than originally planned. The next flight of SpaceX's smaller Falcon 1 rocket is scheduled for late June or July of 2008.
Last month, SpaceX secured a NASA launch services contract that could be worth up to $1 billion and last from June 2010 to the end of 2012.