Electric Propulsion for Space Exploration: Principles, Technologies, Challenges, and Future Directions

Abstract

Electric propulsion (EP) represents a transformative alternative to conventional chemical propulsion by utilizing electrical energy to accelerate propellant to extremely high exhaust velocities. This results in significantly higher specific impulse (Isp) and reduced propellant mass requirements, making EP particularly suitable for long-duration and deep-space missions. This review provides a comprehensive overview of major EP technologies, including ion thrusters, Hall-effect thrusters, and magnetoplasmadynamic thrusters. It examines their operating principles, performance characteristics, historical evolution, and current state-of-the-art developments. Additionally, the paper discusses system-level integration challenges, particularly in power generation and thermal management. Emerging innovations, mission design considerations, and future research directions are also analyzed. The potential of EP in enabling interplanetary cargo transport, sustained lunar operations, and human missions beyond Earth orbit is critically assessed.