Enabling High-Efficiency Cislunar Transportation: A Mission Architecture Study Based on Nuclear Thermal Propulsion Systems

Sustained cislunar logistics operations, including recurring support of the Lunar Gateway at EML1 and EML2, impose demanding propulsion requirements, including high ΔV budgets, restart capability, and long-duration propellant storage, which conventional propulsion approaches struggle to meet efficiently at scale. This study presents a novel cislunar mission architecture based on nuclear thermal propulsion (NTP), operating at a specific impulse of 900 s with liquid hydrogen as propellant and a hydrazine Reaction Control System (RCS) for proximity and docking maneuvers. The architecture is evaluated analytically through sequential application of the Tsiolkovsky rocket equation across two mission scenarios: a direct logistics transfer to EML1 (Scenario A) and a two-burn Gateway staging transfer from EML1 to EML2 (Scenario B), using a launch mass of 9000 kg, a 5% ΔV margin, and deterministic ΔV values of 3164 m/s for LEO→EML1, 160 m/s for EML1→EML2, and 37.36 m/s for RCS operations. The proposed architecture achieves a total propellant mass below 3044 kg and a total delivered mass between 5956 kg and 6071 kg across both scenarios. These results establish NTP as a technically credible foundation for scalable and sustainable cislunar transportation, with broad implications for the development of a permanent lunar economy.