Remotely Controlled Thrust Stand Calibration for Milli-Newton Plasma Thrusters

We implemented a calibration system for a thrust stand which will be used for characterization of low-power Hall thrusters. These thrusters are designed for operation at low power levels of less than 200 W. They include a cylindrical geometry Hall thruster [1] and a wall-less Hall thruster [2], both generate a thrust at the level of a few mN. With the thrust to the thruster mass ratio of 1-10mN/kg accurate thrust measurement is not a trivial task. There are several requirements for the design of the thruster stand: high thrust resolution and sensitivity (~0.05 mN [2]), minimized thermal drift during the thruster operation and in situ calibration of the thrust stand. As the thruster is tested in a vacuum chamber, calibration must be performed remotely without the need to open the chamber. In this work, we will discuss how this, and the other challenges of the accurate and reliable thrust measurements are addressed for these low power Hall thrusters.