Flight Test Results of the Microgravity Active Vibration Isolation System in China's Tianzhou-1 Mission

The Microgravity Active vibration Isolation System (MAIS) was operated on China's first cargo-spacecraft Tianzhou-1, which was launched on April 20, 2017 and re-entered atmosphere and burned on September 22, 2017. In this article, the flight test results of MAIS is presented. The results are evaluated in terms of the performances of microgravity acceleration and vibration attenuation under control. Firstly, the system configuration of MAIS on Tianzhou-1 is described, including operating modes, acceleration measurement, and control schemes. Then, two control performance indices, namely, microgravity acceleration and vibration attenuation, are introduced, followed by their definitions and methods of calculation. Subsequently, the flight test results of MAIS are described in detail. The microgravity acceleration under a PID (Proportional-Integral-Derivative) controller is at the order of 10(-7) - 10(-6)m/s(2) in the frequency band of 0.01-10Hz, and the performance of vibration attenuation reaches -20dB at frequencies higher than 0.2Hz. The flight test results show that MAIS in the TZ-1 mission performed well and achieved the expected control performance of microgravity vibration isolation in orbit. Finally, some experiences and lessons learned are summarized, which can serve as a benchmark reference to develop MAIS-like devices on board China's Space Station in the near future.