ANALYSIS OF PROPELLANT INJECTION IN A LOW-POWER ELECTRODELESS THRUSTER FOR CUBESATS

Resumo

Miniaturized satellites, particularly CubeSats, have revolutionized access to space by enabling low-cost scientific and technological missions. However, their operational capabilities are strongly limited by the lack of efficient, compact propulsion systems. In this context, electrodeless plasma thrusters, such as low-power helicon devices, emerge as promising alternatives due to their simplicity, robustness, and scalability. This work investigates the effect of propellant injection configuration on the performance of a low-power electrodeless thruster designed for CubeSats. Numerical simulations were carried out using the Molecular Flow Module of COMSOL Multiphysics to analyze the neutral gas distribution in two propellant injection modes: normal and vortex. The results reveal that the vortex mode significantly enhances the neutral gas density inside the discharge chamber, achieving a 43% increase compared to the normal mode. This improvement is attributed to the radial injection geometry and longer gas residence time, which increases the probability of ionization events. The neutral density profiles obtained from the simulations were fitted with a fourth-degree polynomial function and subsequently implemented as input for particle-in-cell (PIC) simulations, allowing for a self-consistent analysis of plasma behavior under realistic neutral distributions. The findings highlight the critical role of injection configuration in improving thruster efficiency and demonstrate that optimizing propellant injection is a cost-effective strategy for enhancing electrodeless plasma propulsion systems for CubeSats and other miniaturized spacecraft operating under severe power, mass, and volume constraints.