Development of a 50 W porous emitter electrospray thruster towards flight

Abstract

A low power porous electrospray propulsion system (PET-50)has been developed and tested at the University of Southampton in collaboration with RHP Technology Austria and AVS UK.The thruster utilizes a 313-emitter array, a molybdenum extractor plate and stainless-steel porous reservoir, also working as distal electrode. The performance of the thruster has been characterized using electrical diagnostics, plume diagnostics, Time-of-Flight (ToF) mass spectrometry and direct thrust measurements. PET-50 demonstrated high beam current after onset, with maximum values of around +1.5/-1.5 mA at 3400 V. Assuming a 50 % monomer-dimer mix, the estimated thrust and specific impulse is ~180 μN and~5800 s with an input power of 5.5 W. The measured thrust time response depicted increase in thrust with increasing voltage, reaching ~175 μN at 5.5 W, in excellent agreement with that estimated solely from electrical measurements. Four thruster units operating together will produce a total thrust of ~0.7 mN consuming only ~22 W with thrust to power ratio of ~32 μN/W