A 10 nN resolution thrust-stand for micro-propulsion devices.

Area of Science:

• Aerospace Engineering
• Applied Physics
• Instrumentation

Background:

• Measuring thrust from microthrusters is crucial for small spacecraft propulsion.
• Traditional nano-Newton thrust stands face challenges with facility vibrations and limited resolution.
• Accurate measurement of low thrust levels is essential for micropropulsion system development.

Purpose of the Study:

• To develop and validate a novel nano-Newton thrust stand capable of measuring microthruster performance.
• To achieve high resolution (10 nN) and immunity to environmental vibrations.
• To enable precise thrust measurement for diverse micropropulsion technologies.

Main Methods:

• Development of a compact thrust stand utilizing an impingement force measurement technique.
• Integration of a homodyne (lock-in) readout system for enhanced vibration immunity.
• Validation using a cold-gas thruster and subsequent testing of an electrospray propulsion system in vacuum.

Main Results:

• Achieved a thrust resolution of 10 nN and a minimum detectable thrust of 10 nN.
• Successfully measured thrust from a cold-gas thruster up to 50 μN and an electrospray thruster up to 3 μN.
• Demonstrated agreement within 50 nN to 150 nN for electrospray thruster measurements compared to beam diagnostics.

Conclusions:

• The developed thrust stand offers state-of-the-art 10 nN resolution, comparable to existing systems but with a higher natural frequency.
• It is the first impingement-based thrust stand to achieve sub-3 μN resolution, broadening its applicability to various microthrusters.
• The design is scalable for higher thrust measurements, offering a versatile tool for micropropulsion research.