Development of porous emitter electrospray thruster using advanced manufacturing processes

Abstract

A UK-Austrian consortium led by AVS UK in collaboration with the University of Southampton (UoS) and RHP Technology is developing a low power porous electrospray propulsion system. Using as a baseline a thruster previously developed at UoS, the updated system design focuses on achieving higher thrust using processes suitable for high volume production. This is to meet the rapidly growing micro/nanosatellite market demand. Relying on more than 10 years of expertise in electrospray propulsion, UoS is leading the experimental test campaign and is assisting with thruster design. RHP Technology are creating the high-precision, high-volume manufacturing processes for the emitter arrays and the porous reservoir. AVS UK is designing the propulsion unit and associated High Voltage Power Processing Unit (HV-PPU) while also leading commercial exploitation. The two-year project is centred on three main goals. The first is to develop a thruster with improved performance metrics that better suit the new requirements of the micro/nanosatellite market. The second is to design an updated HV-PPU adapted to operate alongside the improved thruster. The third is to move away from the use of CNC machining in favour of sintering techniques for the manufacturing of the emitters. This paper describes the steps taken to achieve these goals with a particular emphasis on the emitter manufacturing and testing. Our initial single emitter tests demonstrate promising performance. A new single emitter demonstrated reasonably high emission current after onset, with maximum values of around 35 μA at 3500 V reached. Assuming a 50 % monomer-dimer mix, the estimated thrust and specific impulse are approximately ~3.50 μN and ~4600 s.