RTGs are sophisticated and unique power sources for deep space science missions. These systems are subject to launch vibrations, extreme thermal cycling, and exposure to radiation environments. Furthermore, each RTG must operate during its maintenance‐free lifetime of decades in space. These demanding performance requirements and resultant engineering complexities demand the utmost confidence in understanding an RTG’s lifetime behavior, system performance, reliability, and associated operational phenomena.
To meet this need, computational modeling tools and analytical methods to evaluate and predict RTG performance have been developed over several decades. This chapter explores some of the modern modeling tools and analytical methods used to understand various phenomena associated with RTGs. These tools and methods predict thermoelectric couple physics, generator performance, thermal management, ionizing radiation effects, and more. While the topics presented here represent important capabilities of modern RTG modeling techniques, they represent only a subset of the vast array of tools and methods available for modeling these complex systems.