Enabling Sustained Lunar Presence: Advances and Innovations in Radioisotope Power Systems for Surviving the Lunar Night

The new race to the Moon has begun with recent landings by Japan, China, and the U.S. The new finish line is a sustained presence on the Moon enabled by technologies that allow infrastructure to survive the lunar night. Radioisotope Power Systems (RPS) provide reliable thermal energy in extreme environments, ensuring critical systems remain operational during the prolonged lunar nights. Some estimates of the thermal power required for a sustained lunar presence are as high as several thousand watts. To meet this demand, abundant and readily available radioisotopes are necessary to create robust, scalable solutions that align with both NASA and commercial mission timelines and operational requirements. This challenge must be balanced with the desire for high volume of lightweight and cost-effective RPS systems. Three trends will be influential in considering which radioisotopes can support this capability over the next decade. First, private companies and international space agencies are developing novel radioisotope power systems, providing additional options and freeing up the U.S. Department of Energy's plutonium-238 systems to support more NASA marquee missions. Second, the development of heavy-lift launch vehicles like SpaceX's Starship and Blue Origin's New Glenn over the next several years will drastically increase the mass capacity for space systems. This shift implies that power, rather than mass, will become the primary constraint for future space systems, necessitating a pivot away from traditional mass-constrained architectures. Third, NASA is developing a new radiation-hardened electronics technology that greatly increases the processing speed and radiation tolerance of electronic components - enabling electronics to endure much longer in the high-radiation environment on the lunar surface. This paper will explore these design trades in more detail and discuss the portfolio of radioisotope options that can support sustained lunar night survivability. It will discuss how emerging technologies, increased launch capacities, and advanced electronics standards collectively contribute to overcoming the challenges of maintaining a long-term human presence on the Moon.