Radiation transfer thrusters for low thrust applications

A thruster assembly is disclosed which includes a removable filament mounted in a heat exhange cavity which isolates propellent from the filament and transfers energy from the filament to the propellant. The filament may comprise a single winding of wire or may if desired comprise a bifilar wound helix. Also disclosed are a number of ways of powering the filament including a plurality of power supplies provided for redundancy as well as variability of operation. The thruster assembly housing includes sophisticated heat conduction structure including a tortuous internal heat conduction path which minimizes heat loss from the thruster for a variety of disclosed purposes. Also disclosed is structure for providing energy transfer to propellant both through radiation and emission. Further, a test bed facility for testing the inventive thruster assembly is set forth.