The Dense Plasma Focus Fusion Thruster for Space Propulsion

A space propulsion system has been proposed which may use the dense plasma focus (DPF) as its source of power.¹ Three modes of operation were identified and each was investigated for its usefulness in space travel with special attention paid to a manned Mars mission. Using fusion products to directly produce thrust resulted in I_sp's around 10⁶ sec, but produced system thrust-to-weight ratios (F/W) less than 10^-5. This F/w is many orders of magnitude less than a typical value of 0.2 for a manned Mars mission which is presently possible with chemical and nuclear thermal rockets.² Exhausting additional hydrogen propellant over a time period comparable to the flight time results in F/W ratios of 0.003 at I_sp's of 10,000 sec. Using large quantities of propellant to burn “impulsively” gave I_sp's of 4,000 sec with F/w equal 0.05 for one thruster and 0.132 if 5 thrusters are used.³