**4. Conclusion**

Summarize the current status of micro-impulse measurement. To improve measurement accuracy, the following key technologies remain to be explored.

### **4.1 Environmental noise control technology**

The system response measurement error caused by environmental noise interference is the dominant factor that causes thrust or impulse measurement errors. Therefore, environmental noise interference suppression technology is one of the key technologies for thrust or impulse measurement.

The challenge in suppressing environmental noise interference lies in its multisource and diverse effects. Therefore, the research on the control technologies for environmental noise interference should focus on the identification of noise sources. These sources can be complex, including displacement hidden excitation interference, external force excitation interference, thrust or impulse loading interference, as well as the sight and drag interference caused by thruster connecting pipelines and cables, and the measurement error of displacement sensors.

### **4.2 High compensation system response measurement technology**

The thrust or impulse is obtained from the inverse calculation of the measurement system response. The precision regarding the response of the measurement system will directly affect the accuracy of the thrust or impulse measurements. Therefore, high-precision system response measurement technology is one of the key technologies for thrust or impulse measurement.

The challenge of high-precision system response measurement is the measurement of small system response under environmental noise interference and small thrust-toweight ratio. Spaceborne thruster (e.g., micro-thruster) has a very small thrust-toweight ratio, which means that when carrying a thruster to measure thrust, the rotational inertia of the rotating parts of the measuring system is large, and the thrust that the thruster can generate is relatively small, so the displacement generated by thrust is very small, and there is also the impact of environmental noise interference, involving environmental noise interference and high-precision measurement of small displacement under small thrust-to-weight ratio.
