Advanced MEMS Components in Closed-loop Micro Propulsion Applications

This paper presents recent advances in the development of two MEMS (Micro Electro Mechanical Systems) components suitable for small satellite propulsion applications. First a cold gas MEMS thruster with proportional and closed-loop thrust control and secondly a Xenon flow control module for precision control of extremely low flow rates to Ion engines. The development of these products is ongoing but recent achievements have demonstrated that besides miniaturization also unique performance and functionality can be achieved. The components are described in terms of design, manufacturing, and test results. The flow control module can regulate flows in the range of 5-50 μg/s with a resolution better than 0.2 μg/s. By using the same closed-loop control in a MEMS-based thruster configuration, the combination of milli-Newton thrust range, sub micro-Newton resolutions, and fast response time can be achieved. In our view, using MEMS technology and integrating the flow control valve, mass flow sensor and chamber/nozzle on a single chip is the best –if not the onlyway to realize a closed-loop control thruster that can meet new tough small satellite propulsion requirements.