Advancing Magnetohydrodynamic Propulsion for Sustainable and Efficient Space Exploration

This paper presents a novel theoretical investigation into magnetohydrodynamic (MHD) propulsion systems that integrate ionic liquids as propellants and advanced helical magnetic field configurations for efficient thrust generation. MHD propulsion operates by directly converting electromagnetic forces into thrust via the interaction between conductive fluids and applied electric and magnetic fields, eliminating the need for combustion or mechanical moving parts. Such systems promise high thrust-to-weight ratios, extended operational lifetimes, and simplified architectures compared to conventional propulsion technologies, making them highly attractive for future space exploration. The study emphasizes the role of the Lorentz force in accelerating and controlling plasma and liquid metal flows within MHD channels. Several conductive media, including ionized gases and ionic liquids, are analyzed with respect to their ionization energy, electrical conductivity, thermal stability, and operational safety. Specifically, the ionic liquids 1-ethyl-3-methylimidazolium chloride ([EMIM][Cl]), [BMIM][PF₆], and [TEA][NO₃] were evaluated, with [EMIM][Cl] demonstrating superior characteristics for MHD applications due to its favorable conductivity, chemical stability, and relatively low toxicity. The paper further investigates the application of novel toroidal and helical magnetic field geometries to enhance plasma confinement, stabilize flow instabilities, and optimize thrust efficiency. The scalability and adaptability of such MHD propulsion systems are assessed for a range of mission profiles, including CubeSat propulsion, orbital station-keeping, and deep-space exploration. Sustainable propellant options such as water and low-cost ionic solutions are also discussed as potential pathways for reducing resource dependency. Although this work remains theoretical, the findings establish a robust framework for future experimental validation and interdisciplinary development. With continued advancement, the proposed MHD propulsion architecture could offer a transformative approach to sustainable and efficient space transportation, addressing emerging challenges in long-duration interplanetary missions and advanced satellite operations.