The Settlement Fitness Function
A scoring model for Moon and Mars settlements that judges a habitat by its weakest system, the way a design review does.
Run the fitness function
Open in a new tabSet the weights and the inputs, and the model scores a settlement design against them.
The idea
A settlement on the Moon or Mars is only as safe as its weakest life-support system. A strong power system does not make up for weak radiation shielding, and plenty of water does not help if the air cannot be kept clean.
The Settlement Fitness Function scores a habitat the way a design review does: not by its best system, but by whether every system clears the bar that keeps a crew alive.
From thesis to tool
The model began in 2018 as part of Anastasia Prosina’s graduate thesis on Mars settlement systems, as a way to compare habitat concepts that were otherwise judged on renderings and intuition.
In 2025 it was rebuilt as an interactive tool, with updated weights, clearer thresholds and a companion model for site selection. The core idea has not changed: a settlement is evaluated as a system of dependencies, not a list of features.
How the score works
Each life-support domain is scored on its own: air, water, food, power, thermal control, radiation protection, waste and crew health. Every domain has a minimum threshold, the level below which a crew cannot safely stay.
A domain that falls below its threshold pulls the whole score down, whatever the strength of the others. Only once every domain clears its bar do strengths start to count. This mirrors how a real habitat fails: through its weakest link, not its average.
The result is a single number that a design team can track as a concept develops, alongside a breakdown that shows exactly which system is holding the settlement back.
Choosing a site on Mars
A companion model asks where on Mars to put the first permanent human presence. It weights six factors.
Water ice and radiation shielding carry the most weight because a settlement cannot design around them. The model does not resolve the trade-offs between sites. It makes them visible, so they are made on purpose.
Who it is for
Mission planners can use it to compare habitat architectures early, before designs are locked. Architects and engineers can use it to see how a change in one system ripples through the rest. Students and educators can use it to learn why settlements are designed as integrated systems.
For the Lab, it is a way to place crew health on the same footing as power and air: a system with its own threshold, not an afterthought once the hardware is chosen.
What it does not do
This is a simplified, illustrative version of a much more detailed multi-criteria model. Real site selection involves dozens of sub-factors, mission-specific constraints and data that is often incomplete or contested. The weights are a starting framework, not a final answer.
