An elastic pendulum thrust stand for evaluating six-degree-of-freedom thrust of 10 mN-class propulsion systems.

This article presents the design, implementation, and demonstration of an elastic pendulum six-degree-of-freedom (six-DoF) thrust stand employing the null-balance method to measure all thrust and torque components of CubeSat propulsion systems in the millinewton (mN) class. The thrust stand supports the propulsion system on a triangular mounting plate suspended by three springs, enhancing the effective thrust-to-weight ratio and enabling precise six-DoF measurements using six displacement sensors and six voice coil motors (VCMs) within a vacuum chamber. Experimental validation was conducted using a 10 mN-class cold-gas thruster, achieving measurement uncertainties within 0.82 mN for thrust and 0.13 mN·m for torque components, with results consistent with theoretical predictions. The study also includes a detailed uncertainty analysis, mechanical characterization, and discussion of the thrust stand’s applicability to various CubeSat propulsion systems, highlighting its potential for comprehensive thrust profiling in advanced CubeSat missions.