Experimental investigations of plasma accelerators for space vehicle guidance and propulsion

Abstract

A description is given of experimental studies concerning the possible application of a plasma accelerating device as a small thrust electric drive for space propulsion and attitude control. The particular laboratory model discussed employs a capacitor discharge across the gap between two electrodes to create a highly ionized but electrically neutral plasma which is electromagnetically accelerated into a chamber in which an attempt has been made to simulate the pressure conditions of outer space. A novel valve has been devised which serves the dual purpose of introducing the minute amounts of propellant required while obviating the need for external switching of the discharge. As a result of this development, a considerable improvement in the efficiency of energy conversion of earlier models has been affected. Specific impulses obtained with the T-tube accelerator have been in the range of 1000–20,000 sec, with calculated efficiency of conversion of stored electrical energy to mechanical energy as high as 60 per cent. Although the measurements discussed are of a preliminary nature, it is believed that they clearly demonstrate that more detailed and advanced research into plasma acceleration problems is fully justified.