DEVELOPMENT OF A LOW COST PPU FOR FEEP ELECTRIC PROPULSION USING COTS COMPONENTS

In the frame of the development of an electric-propulsion thruster for Micro- and Nanosatellites, FOTEC has put forward the in-house development of a low cost PPU, capable of driving the thruster with up to 10 kV emitter and -10 kV extractor voltage. After 5 generations of development, the PPU currently used in a thruster testing and qualification campaign has achieved 85% total efficiency including high voltage multiplier stages and protection circuitry. The PPU includes the functionality of the step-up conversion for emitter and extractor, propellant heating and neutralizer-operation within a volume of 90 x 94 x 78 mm, at a weight of less than 230 g and a total cost in production of less than sic 1,000. This low cost approach using COTS components is targeting constellations and mega-constellations and is certainly the other extreme compared to the conventional design approach for spacecraft PPUs. In the light of the ongoing discussions of a change in the philosophy of designing spacecraft, going from fail-safe components to a "mass production" strategy which aims for fail-safety by redundancy. This paper also gives a starting point for the discussion on how a possible tradeoff between cost and reliability can be achieved.