The Griffiths Nuclear Powered, Microwave–Thermal Relativistic Propulsion Architecture

This paper presents the Griffiths Microwave–Thermal Nuclear Propulsion System, a hybrid architecture that couples a compact nuclear heat source with high‑intensity microwave energy deposition to achieve rapid propellant heating, high thermal efficiency, and thrust levels suitable for deep‑space and interplanetary missions. The concept integrates nuclear thermal propulsion principles with resonant microwave cavity engineering, enabling controlled volumetric heating of propellant without direct contact between reactor components and the working fluid. The system is designed to address limitations in conventional NTP designs by reducing thermal stress on reactor materials, improving energy transfer uniformity, and enabling higher propellant temperatures through distributed microwave absorption. The paper outlines the core physical mechanisms, reactor–cavity coupling strategy, thermal management approach, and expected performance envelope. Conceptual mission applications and scalability considerations are also discussed. This work forms part of an ongoing series exploring advanced propulsion architectures that blend nuclear, electromagnetic, and regenerative thermal processes to expand the feasible design space for future crewed and uncrewed missions beyond Earth orbit. Follow me on LinkedIn: www.linkedin.com/comm/mynetwork/discovery-see-all?usecase=PEOPLE_FOLLOWS&followMember=wayne-griffiths-22a52a36