Electrodeless Magnetic Reconnection Thruster Technology for Generating High-Performance Plasma Propulsion

Background

Spacecraft propulsion is a critical field underpinning both current and future space exploration missions. Traditional chemical rockets, while reliable, are limited by their low specific impulse, which restricts spacecraft speed and necessitates carrying large amounts of propellant—an inefficient solution for long-duration or deep-space missions. In response, electric propulsion technologies such as ion thrusters, Hall-effect thrusters, and magnetoplasmadynamic (MPD) thrusters have been developed to achieve higher specific impulses, enabling more efficient use of propellant and extended mission capabilities. However, as mission demands grow—especially for high-power, high-thrust-density applications—there is an increasing need for propulsion systems that offer both high performance and long operational lifetimes, with the flexibility to use a variety of propellants and to adjust thrust parameters as required.

Despite their advantages, current plasma-based propulsion systems face significant limitations. Most notably, they rely on electrodes to drive plasma acceleration, which leads to electrode erosion over time—a primary factor limiting the operational lifetime of these thrusters. Electrode erosion not only reduces efficiency but also increases maintenance requirements and mission risk. Additionally, these systems often lack flexibility in adjusting thrust density and specific impulse, constraining their adaptability to different mission profiles. The dependence on specific ion species for optimal performance further restricts propellant choices, while the need for direct plasma-electrode contact can introduce contamination and reliability issues. These challenges underscore the need for a new propulsion approach that can overcome the inherent drawbacks of electrode-based designs while delivering high thrust density, high specific impulse, and robust operational flexibility.

Technology

The electrodeless magnetic reconnection thruster (e-MRT) is an advanced spacecraft propulsion system that generates thrust by harnessing the plasma process of magnetic reconnection, all without the use of electrodes. Instead, it employs inductively driven coils and flux cores to create dynamic magnetic fields that ionize propellant gas and accelerate plasma, producing high-speed outflows. The system is designed to ensure asymmetric plasma ejection—directing thrust away from the spacecraft—through a combination of physical barriers, magnetic buffer coils, permanent magnets, counterhelicity reconnection, or spheromak formation and ejection. The e-MRT’s operation is highly flexible, accommodating various propellants and allowing precise control over thrust and specific impulse by adjusting coil current waveforms and ionization fractions. Gas puffing is synchronized with the magnetic reconnection cycle, and the system can operate with partially ionized plasma, optimizing performance and minimizing propellant waste.

What sets the e-MRT apart is its electrodeless design, which eliminates the primary limitation of conventional plasma thrusters: electrode erosion. This innovation extends operational lifetime and enables higher thrust densities and specific impulses than traditional ion, Hall-effect, or magnetoplasmadynamic thrusters. The e-MRT’s ability to generate thrust through purely inductive means allows for greater scalability and adaptability to different mission requirements, including high-power deep space missions. Its independence from ion species mass offers unmatched propellant flexibility, while the use of advanced magnetic field configurations and tailored current waveforms ensures efficient energy conversion and precise control over plasma dynamics. Collectively, these features position the e-MRT as a transformative propulsion technology, capable of meeting the demanding needs of future space exploration.

Benefits

• Eliminates electrode erosion, significantly extending thruster operational lifetime
• Achieves high thrust densities (10² to 10³ N/m²) and wide-ranging specific impulses (100 to over 10,000 seconds)
• Enables flexible use of various propellants due to ion mass independence
• Generates efficient plasma acceleration through inductively driven magnetic reconnection without direct plasma-electrode contact
• Provides multiple methods to produce asymmetric plasma outflows, ensuring effective net thrust
• Optimizes plasma generation and thrust via synchronized gas puffing and tailored coil current waveforms
• Scalable for high-power applications, suitable for deep space and manned missions
• Reduces propellant waste and improves thrust-to-power ratio through controlled partial ionization

Applications

• Deep space exploration propulsion
• Manned Mars mission propulsion
• Satellite orbit raising and stationkeeping
• High-power cargo spacecraft propulsion

Additional info

The electrodeless magnetic reconnection thruster propels spacecraft by generating high-speed plasma and neutral particle outflows. It utilizes inductively driven electromagnetic fields, coils, and flux cores to induce magnetic reconnection, converting magnetic energy into particle kinetic energy. Asymmetric plasma outflow, controlled by specific coil current waveforms and synchronized gas puffing, ensures net thrust without electrodes, enhancing lifetime and performance.