New Plasma Engine Design Uses Atmospheric Air as Fuel

Key Takeaways

• Researchers have developed an Atmosphere-Breathing Electric Propulsion (ABEP) system that captures air molecules to fuel satellites in Very Low Earth Orbit (VLEO).
• The design solves critical issues like atomic oxygen corrosion and the need for neutralizers by utilizing a contactless Radio-Frequency (RF) Helicon Plasma Thruster.

Technical Challenges and Innovations

• Atomic Oxygen (AO) Corrosion: In VLEO, AO oxidizes metal components and destroys the cathodes required for standard ion thruster neutralization, causing system failure.
• Optimized Intake: Three designs were tested, with the 'specular intake' (a parabolic mirror coated with graphite or silicon dioxide) achieving 94.3% collection efficiency.
• Thruster Efficiency: Inspired by MRI birdcage antennas, the thruster delivers 99% of electrical power into the system, avoiding the losses typical of standard wire coils.
• Neutralizer-less Operation: A magnetic field generated by a solenoid ejects both positive and negative ions as a quasi-neutral jet, eliminating the need for a separate cathode neutralizer.

Performance and Potential Applications

• Experimental Validation: The system produced steady plasma streams using only 50-60W of RF power, consistent with standard solar panel capabilities.
• Orbital Longevity: Simulations based on the GOCE satellite suggest the engine could maintain orbit indefinitely between 190 and 250 km using less than 1.6 kW of power.
• Extraterrestrial Use: The technology has potential for Martian exploration, where it could support spacecraft operations at 120–160 km altitude by utilizing the CO2-dominated atmosphere.