Some Approaches to Mass Reduction of the Gasdynamic Mirror Fusion Rocket

Previous studies have shown that the gasdynamic mirror (GDM) fusion propulsion system is capable of producing specific impulses in excess of 105 seconds and thrusts in the tens of kilonewtons. These propulsive capabilities arise from the ability of this magnetic fusion system to confine a hot plasma long enough to produce fusion energy while allowing a certain fraction of its charged particle population to escape through one end (a magnetic nozzle) to generate thrust. Earlier investigations have revealed that the optimum performance arise from the use of large mirror ratios which require large magnets and result in very massive vehicles. Major contributors to the large mass, in addition to the magnetic fields, are the large radiators required to dispose of waste heat. In this paper we address the question of mass reduction by investigating the role of magnetic field reversal near the mirror region, on the one hand, and the utilization of the liquid droplet radiator design on the other. We find that significant reduction in the mass of the vehicle can be achieved, and a reduction in cost and travel time are the direct beneficiaries of this reduction