tldr: Simple/small thrusters getting within order of magnitude of performance of bigger/more complicated. Introduction: > “Electrodeless” RF thrusters are dis

tldr: Simple/small thrusters getting within order of magnitude of performance of bigger/more complicated. Introduction: > “Electrodeless” RF thrusters are distinct from Hall effect thrusters, gridded ion engines, and gridded RF thrusters ... in that they do not use grids, anodes, cathodes, or high voltages to accelerate the propellant, greatly simplifying the thruster architecture. Their electrical and mechanical simplicity allows for electrodeless RF thrusters to be designed for the production requirements of the next generation of large satellite constellations. > Despite their promise, electrodeless RF thrusters have not gained wide acceptance due to their sub-par measured performance compared to state of the art Hall effect and gridded ion systems. > The Phase Four RFT approaches the concept of electrodeless RF plasma acceleration by acknowledging that the primary technological advantage of RF lies in the minaturazation of RF power electronics by the wireless power industry. Discussion: > To the authors’ knowledge, the specific impulse and thrust efficiency levels measured in the Phase Four RFT presented here represent the highest performance electrodeless thruster results ever demonstrated, by a significant margin. Specifically, the electrodeless RFT-X engine produced specific impulse on par with state of the art low power Hall effect thrusters, within 50% the thrust output at the same power level [17, 18]. This is as opposed to previous electrodeless thrusters that could not achieve the same order of magnitude thrust and/or specific impulse as their traditional Hall effect and gridded ion counterparts. > The performance improvement highlights improved understanding of the thruster ion acceleration and energy transfer mechanisms, which are captured in proprietary unified design rules that extend across thruster variants.