Review of plasma thruster technology development for air-breathing electric propulsion missions

Air-breathing electric propulsion (ABEP) technology makes use of in-situ gas in very low Earth orbit (VLEO) as propellant, which is expected to break through the propellant carrying limitations of traditional electric propulsion spacecraft and achieve long-term on-orbit residence. However, due to the shortage of propellant and energy supply for VLEO missions, several issues need to be addressed before the air-breathing electric propulsion technology can be realized. This paper reviews the key challenges and technological progress in the development of air-breathing electric propulsion technology, especially on core issues such as low-pressure discharge, ionization of nitrogen-oxygen propellants, and high-performance requirement. It is indicated that available plasma propulsion technologies under VLEO propellant supply conditions suffer from bottlenecks including relatively high discharge pressure, low propellant utilization, and insufficient specific impulse and thrust-power ratio. In comparison, hybrid electric propulsion technologies, by integrating low-pressure discharge with high efficiency acceleration methods, provide a new approach to addressing the high-performance requirements of such missions.