To outer space by reducing size and cost
Electric propulsion systems are expected to play an increasingly important role for future planetary exploration and for commercial as well as military low Earth orbit satellites. These systems require much less propellant to produce the same increase in spacecraft velocity. The propellant is ejected up to 20 times faster than from chemical thrusters. Thus, while chemical thrusters can eject massive amounts of propellant, electric engines work with very small flows, so that they push the spacecraft very gently. The controlled flow of propellant at low pressure from storage at high pressure is accomplished by a combination of pressure flow control devices. The FP7-funded 'Miniaturised flow control unit' (µFCU) has proposed a flow control unit suitable for electric micropulsion systems. The µFCU project partners provided components that had been developed in Europe for ground applications in medicine or chemical industries. An advantage of the use of existing technologies was a significant cost and time reduction in the design of the miniaturised flow control unit. These components had shown at least the same performance as those from United States (US) competitors or even outperformed them. Noble gases and in particular, xenon are the favoured propellants for electric propulsion systems, because they are not corrosive. The µFCU system has been designed to fit in existing electric propulsion systems without changing their overall operation concept. The total mass of the µFCU system is below 60 g, compared with existing technologies of around 400 g. The µFCU system covers a large temperature range, from -40ο C to +110o C and is tolerant to inlet flow overpressure of up to 4 times the nominal pressure of 2.2 bar. The design of the µFCU system was driven by customer requirements who have supported the project by defining reference space missions. On the other hand, the project consortium of partners from different European countries has helped the European space industry to gain a leading position in space gas fluidic control systems.
Keywords
Space technology, flow control unit, noble gas, xenon, electric propulsion, low Earth orbit, satellite, propellant, valve