µFCU - A New Miniaturized Xenon Flow Control Unit

Gas consuming thrusters in the µNewton thrust range show a demand for controlled Xenon gas flows below 0.1 sccm.

Today, Europe has some development activities but no own high TRL technology for miniaturized flow control units. Even for normal sized FCUs the design of most suppliers rely on valves with US origin due to the lower leakage rates compared to European solutions. This brings Europe into dependency from external countries. Therefore a flow control unit for EP systems has been rated as critical space technology (Urgent Action List ID 13, ESTER ref. T-8117, T-8119). 

A novel flow control unit (µFCU) is under development by AST Advanced Space Technologies GmbH together with a partner network and funded by the European Commission.

The µFCU design is based on a commercial component-of-the-shelf (COTS) approach. The core components and technologies have already been developed for ground applications. They have a high reliability background like medicine, chemical industry or even space. These components will be modified for space applications and for the changed operational and environmental parameter range.

The flow control capability covers the range from 0.001 to 0.1 sccm in the low flow regimes. A cost effective development and production of a flow control unit is only possible, if the full market potential is addressed. Therefore the basic design of the FCU shall be scalabe to thrusters and neutralizers for satellite station keeping (typ. 50-100 mN thrust).

This new development shall outperform existing technologies with respect to mass reduction, leak tightness, drift and long term stability. Furthermore, it shall reduce complexity, driver electronics requirements and AIT effort and therefore will reduce cost. Further cost reduction shall be achieved by modularity, use of COTS and integration of for flow lines controllers into one device.

The µFCU will cover a large temperature range from -40°C to +110°C and shall be tolerant to inlet flow overpressure conditions of up to 4 times the nominal inlet pressure of 2.2 bar.

The design of the µFCU is driven by costumer requirements. Key customer already agreed to join an Advisory Board. The Advisory Board shall support the project by defining reference missions and by reviewing the design.