The Aerospace Department at FOTEC has been developing the mN-FEEP technology under ESA research contracts for the last decades with the purpose to create a highly controllable and efficient propulsion technology for future science missions. The mN-FEEP thrusters use a crown of sharpened porous Tungsten needles which are wetted with liquid Indium. This crown is raised to a high positive potential to emit and accelerate In + ions. This thruster technology has undergone extensive testing in recent years, including performance mapping of more than hundred emitters and lifetime testing up to more than 13.000 h. Based on this technology, the IFM Nano thruster has been developed as a commercial product for small satellites. This integrated ion propulsion system fits into a volume of less than a single unit CubeSat. In 2017, the first flight model has been manufactured to be flown on an in-orbit demonstration mission, supported by the ESA IOD program ATLAS. This paper presents the results from the extensive test campaigns on proto-flight model level, including efficiency mapping of all subsystems and the validation of the neutralization strategy. The results show that the IFM Nano thruster design is fully functional and provide an outlook on the performance to be expected during in-orbit operation.

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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 € 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.