Development and testing of a new thrust stand for micro-thrust measurement in vacuum conditions

Abstract

A miniature thrust stand in man-made vacuum environment, based on the principle of leaf spring bending deformation, capable of supporting testing of thrusters having a total mass of up to 300 g and producing thrust levels between 1 μN and 760 μN has been developed and tested. A case-study measurement was conducted for a Colloid Micro-Newton Thruster (CMNT) to investigate the feasibility of the proposed system under vacuum conditions. Displacement of the leaf spring deforming was measured using a linear capacitive displacement sensor (LCDS). An in situ calibration rig allows for steady-state calibration before, during and after thruster operation. To validate this method, extensive thrust measurements were carried out on a colloid thruster that produces μN magnitude level thrust under vacuum conditions. Results show that the measurements were very repeatable, producing results that compare favorably with measured data with an uncertainty of approximately 10%.