A torsional thrust balance with asymmetrical configuration for microthruster performance evaluation

Area of Science:

• Aerospace Engineering
• Mechanical Engineering
• Instrumentation

Background:

• Microthruster performance evaluation is crucial for spacecraft propulsion systems.
• Existing thrust stands often require significant space, limiting their use in vacuum facilities.
• Accurate and reliable thrust measurement is essential for micropropulsion development.

Purpose of the Study:

• To design and test a compact torsional thrust balance for microthruster performance evaluation.
• To develop an optimization method for key thrust balance parameters.
• To introduce a novel calibration method using a printed circuit board electrostatic comb.

Main Methods:

• Design of a torsional thrust balance featuring an asymmetrical arm for enhanced resolution.
• Optimization of critical thrust balance parameters.
• Calibration using a novel printed circuit board electrostatic comb capable of generating forces from 30 μN to 3300 μN.

Main Results:

• The asymmetrical arm design allows for high resolution with a reduced arm length.
• The electrostatic comb successfully calibrated the thrust balance, demonstrating steady force generation.
• Experimental results show reliable performance with repeatability and an estimated total uncertainty of 3.33% in the 1 μNs range.

Conclusions:

• The developed asymmetrical torsional thrust balance is effective for microthruster performance evaluation in space-constrained vacuum facilities.
• The novel calibration method provides reliable and repeatable force and impulse bit measurements.
• The system demonstrates potential for extended measurement ranges, including the nano-Newton second scale.