Development of a Direct Drive Vacuum Arc Thruster Passively Ignited for Nanosatellite

Abstract

Active attitude control systems require a non-negligible amount of space to be mounted on board satellites. For the nanosatellite case, it becomes even more difficult to accommodate an active attitude control system due to size and mass constraints, and choices of active attitude control system are therefore limited. In this paper, small size and lightweight are realized by direct drive and passive ignition of a thruster. The direct drive is a power supply system without a booster circuit. The passive ignition system is an ignition system using microdischarge generated by interaction with a plasma environment and the propellant surface. Availability of these two systems was verified. As a result, when the thruster was placed into a high-density plasma environment ( $10^{12}~\text{m}^{-3})$ , it was confirmed that the direct drive and passive ignition can operate normally. Moreover, expected performance of this vacuum arc thruster was measured. The results show that the impulse bit was of micronewtons order, and the ion velocity was measured to be approximately 12 km/s. Moreover, it was found that the impulse bit changes with the applied voltage and the capacitance value of the discharge circuit.