A Value-Focused Evaluation of Outer Solar System Worlds for Sustained Human Presence within an Early Fusion-Driven Era

The promise of fusion energy and propulsion could open up the worlds of the solar system in the near future. In preparation for this, an evaluation of these potentially accessible worlds can be performed using a Value-Focused-Thinking (VFT) approach to develop expert-weighted desirability scores of individual attributes for each proposed world, so that resources can be allocated more responsibly. This evaluation spans approximately three dozen attributes grouped under four primary objectives that include access difficulty, environmental hazards, scientific benefits, and economic benefits and sustainability. It assumes that humanity will pursue sustained human activity on these worlds as an aggregate, collaborative framework similar to the International Space Station coalition. Using these assumptions and background as a foundation, scoring methodology utilized available literature from scientific missions and was weighted by experts at space and scientific organizations across multiple countries. Known worlds, specifically the Moon and Mars, were scored in parallel as benchmarks. Results indicate that Titan represents the most promising world in the outer solar system for sustained human exploration while Callisto and Ceres also show potential. In contrast, more distant worlds, including the moons of Uranus (Oberon was used as a representative example of that system), Triton, and Pluto (with its large moon Charon) appear to be less viable unless more advanced fusion propulsion capabilities beyond what is assumed here become possible.