Kilopower: Space Fission Reactor with Stirling Conversion

Solar panels stop working the moment a lander loses the sun — through a two-week lunar night, deep planetary shadow, or a mission bound for the outer planets. NASA's Kilopower concept solves this with a compact fission core, passive sodium heat pipes, and free-piston Stirling engines that turn reactor heat directly into electricity, rejecting the rest to space through a radiator. This simulator models the full heat chain — core thermal balance, heat-pipe conduction capped by the number of active converters, Carnot-limited Stirling efficiency, and Stefan–Boltzmann radiative cooling — so you can push the reactor into overheating with too few converters, or watch efficiency swing between lunar day and night.