Development of inverted pendulum thrust stand with spring-shaped wire for high power electric thrusters

Area of Science:

• Spacecraft propulsion systems
• Aerospace engineering
• Measurement instrumentation

Background:

• Pendulum thrust stands are crucial for measuring spacecraft electric propulsion system thrust.
• Nonlinear tensions from wiring and piping in traditional stands reduce measurement accuracy, especially for high-power systems.
• Accurate thrust measurement is vital for spacecraft performance and mission success.

Purpose of the Study:

• To develop an improved thrust stand design that mitigates measurement inaccuracies caused by wiring and piping tensions.
• To establish design guidelines for creating spring-shaped elements for thrust stands.
• To validate the performance of the novel thrust stand with a high-power thruster.

Main Methods:

• Derived design guidelines for spring-shaped wires, formulating conditions for sensitivity, responsivity, spring shape, and electrical wiring.
• Designed and fabricated an inverted pendulum-type thrust stand utilizing pipes and wirings as springs.
• Evaluated the thrust stand's performance through calibration and thrust measurements using a 1 kW-class magneto-plasma-dynamics thruster.

Main Results:

• The developed thrust stand demonstrated a sensitivity of 17 mN/V.
• The normalized standard deviation of structural variations was measured at 1.8 × 10^-3.
• Thermal drift during long-term operation was approximately 4.5 × 10^-3 mN/s.

Conclusions:

• The inverted pendulum thrust stand effectively minimizes tension-induced errors, enhancing measurement accuracy for electric propulsion systems.
• The derived design guidelines provide a framework for optimizing future thrust stand development.
• The fabricated thrust stand performed well, validating its suitability for high-power electric propulsion testing.