Micronewton Thrust Balance for Indium FEEP Thrusters

Abstract

Thrust measurements of electric propulsion devices are essential for validating, characterizing and qualifying their performance. For this purpose a direct thrust measurement system for use with In-FEEP thrusters has been designed at ARC Seibersdorf research (ARC -sr), based on a torsional balance design. A symmetric arm is able to rotate by means of two flexural pivots. The linear displacement of the arm (which is a function of the applied thrust) is measured with an optical displacement sensor. The system also allows upscaling to measure the thrust of a new generation of In -Feep Clusters that are currently developed at ARC- sr . An electrical damping system is used to reduce oscillations of the arm. Special attention has to be given to the cables supplying the heating and operating power of the In-Feep thruster. In this paper we present the design of the thrust stand as well as preliminary measurements.