Energy Optimization in Nuclear Electric Propulsion: Solar-Nuclear Integration for Mars Missions
- Paper ID
99292
- DOI
- author
- company
Universidad Nacional Mayor de San Marcos; Universidad Nacional de Ingeniería (Lima, Perù)
- country
Peru
- year
2025
- abstract
The optimization of energy consumption in long-duration space missions is crucial for the sustainable exploration of the solar system. Nuclear electric propulsion (NEP) stands out for its high specific impulse (Isp), but its reliance on nuclear reactors poses challenges in terms of sustainability and fissile resource management. This study evaluates the feasibility of a hybrid solar-nuclear NEP system, integrating solar energy and modular microreactors (MMR) to enhance energy efficiency and reduce nuclear fuel consumption. The performance of various propulsion technologies is compared, including NEP, solar electric propulsion (SEP), nuclear thermal propulsion (NTP), and chemical propulsion (CP). While CP enables high thrust levels, its low Isp (~4500 m/s) limits its efficiency for interplanetary missions. NTP, with an Isp of ~9000 m/s, offers better performance but still requires significant amounts of propellant. In contrast, NEP maximizes efficiency by minimizing propellant mass, at the cost of sustained high energy demand. SEP is highly efficient within 1.5 AU due to solar irradiance (~1367 W/m2 at 1 AU), but its performance decreases drastically beyond Mars. Since both NEP and SEP present advantages and limitations in efficiency and resource availability, this study proposes a hybrid solar-nuclear NEP system. This approach aims to reduce fissile material consumption through solar energy support, optimizing energy management without compromising sustainability in crewed missions to Mars and exploration beyond 1.5 AU. Preliminary estimates suggest that this system could improve energy efficiency by a factor of 4 to 8 compared to conventional NEP, with refinements as the research progresses. The study employs an energy balance model and mass-power feasibility analysis, incorporating up-to-date information from NASA and SpaceX regarding Mars missions. The impact of the solar-nuclear combination is evaluated without relying on high-computational-demand simulations or laboratory experimentation. This research aims to identify strategies for enhancing NEP efficiency through complementary solar energy, reducing reliance on nuclear reactors, and extending mission autonomy. Furthermore, it will assess its contribution to sustainable deep-space exploration. This study highlights the importance of sustainable energy solutions in space, essential for cost reduction, resource optimization, and laying the foundation for self-sustaining space settlements, aligning with the vision of a "Sustainable Space and Resilient Earth.”