Development of a hanging pendulum thrust stand for pulsed plasma thrusters

Thrust stands are essential tools for evaluating the performance of propulsion systems, including Hall effect thrusters, ion thrusters, and pulsed plasma thrusters (PPTs). Our thrust stand supports a prototype weighing up to 0.8 kg and measures impulses from 150 to 550 μN·s. It generates voltage oscillations with peaks between 5 mV and 35 mV, which, combined with NI voltage modules, minimizes weight constraints on the propulsion system while maintaining accurate measurements under low thrust-to-weight conditions. This design introduces a novel approach compared to conventional torsional thrust stands. By aligning the propulsion system’s center of mass with the pendulum arm, we eliminate the need for spring torque. Instead, gravitational torque provides the necessary equivalent spring constant for damping. The eddy-current damper, featuring a copper plate, doubles as both a damping mechanism and a counterweight, allowing adjustments for different propulsion system weights. Unlike elastic pivots, this design avoids performance degradation from material fatigue or thermal effects. Challenges in the current system include non-linear spring and damping coefficients caused by PPT power cables and pulse-width errors during calibration. Future improvements will consist of cable feed-throughs to isolate vibrations without introducing unwanted coefficients. Additionally, the improvement aims to optimize the impulse generator’s power supply to eliminate calibration errors caused by high-voltage pulse-width fluctuations. • Novel hanging pendulum thrust stand for micro pulsed plasma thruster measurements. • High-precision impulse measurement in the 150–550 μN·s range using ESC calibration. • Eddy current damping and optimized wiring reduce parasitic stiffness and damping. • Validated linear impulse-angular displacement correlation with uncertainty analysis. • Measured PPT impulse with an energy-to-impulse ratio of 2.92 μN·s/J in vacuum.