Development and experimental validation of a two-axis thrust stand for the characterization of electric thruster...

Area of Science:

• Aerospace Engineering
• Experimental Physics

Background:

• Accurate measurement of electric thruster performance is crucial for spacecraft propulsion development.
• Existing thrust stands face challenges in simultaneously measuring multi-component thrust vectors and mitigating environmental effects.

Purpose of the Study:

• To develop and validate a two-axis thrust stand for direct, simultaneous measurement of electric thruster thrust vector components.
• To implement a calibration method and assess the accuracy of the thrust stand's angular resolution and uncertainty.
• To evaluate the instrument's ability to mitigate thermal and magnetic effects from electric propulsion systems.

Main Methods:

• Construction of a two-axis thrust stand using piled-up single-axis stages with a deformable parallelogram geometry.
• Calibration using a mass deposition method, including crosstalk correction between axes.
• Implementation of a new methodology to compare theoretical and experimental angular uncertainties.
• Experimental validation using a rotating cold gas thruster with known operating angles and thrust levels.

Main Results:

• The thrust stand achieves a theoretical angular resolution of 0.1° for total thrusts above 645 μN within a 10° half-angle cone.
• Experimental uncertainties were measured at 0.7° (below 630 μN) and 1.2° (above 630 μN), with identified sources of systematic error.
• Potential for achieving the theoretical 0.2° uncertainty at total thrusts above 250 μN with further improvements.
• Demonstrated effective mitigation of thermal and magnetic effects from an Electron Cyclotron Resonance (ECR) thruster.

Conclusions:

• The developed two-axis thrust stand provides accurate and simultaneous thrust vector component measurements.
• The study identified sources of systematic error and outlined paths for achieving higher precision.
• The instrument is suitable for characterizing electric thrusters, including ECR thrusters, by effectively managing environmental interference.