First Discharge of a Bismuth-Fueled Vacuum Arc Thruster for Spacecraft Momentum Management

This work details the design, integration, and early testing of a small vacuum arc thruster (VAT) for small sat attitude control systems (ACS). Vacuum arc thrusters have demonstrated operational characteristics that make it a potentially effective electric propulsion thruster for spacecraft momentum management [1]. This work is comprised of a theoretical discussion of thruster performance characteristics, and mechanical design of the VATACS thruster produced at ERAU Prescott. Next, the experimental setup will be detailed, including vacuum system, power, and data collection instrumentation. The V-I characteristics of the discharge are presented for the current experiment and discussed. Finally, based on these results, detailed design of an appropriate power processing unit (PPU) and thermal provision can proceed. In future work additional important operational characteristics must be determined including: steady-state voltage and current characteristics, inrush current characteristics, thermal soak-back heat flux and steady-state operational temperature in the chamber.