How are you accounting for regolith variability in your designs?

Open fractures exposed and a bouldery farm.

Understanding the ground before we build is essential. Mature vs. Immature Regolith: why it matters for lunar infrastructure? From bearing capacity to dust hazards, the regolith can tell the story!

On Earth, we study soil profiles, grain sizes, and rock mechanics before building a single road or tunnel. On the Moon, we face a different challenge: a surface shaped not by water or wind, but by billions of years of micrometeorite impacts and solar wind exposure.

This process creates mature regolith: fine-grained, rich in agglutinates, with cohesive behavior that may allow steeper slopes and even some structural stability under low gravity. But it also brings significant dust hazards, low shear strength, and challenges for compaction.

In contrast, immature regolith, formed by fresh impact ejecta, is coarse, blocky (rock fragments), and unpredictable (great for ISRU aggregate) but risky for bearing capacity and prone to differential settlement.

These differences are not just academic. They are directly tied to how we plan and execute:

• Landing pads and berms

• Roadways and ramps

• Foundations for habitats, towers, buried structures and shelters

• Shielding structures and regolith-based construction

Questions I keep asking as we move closer to real lunar infrastructure development:

• How does regolith maturity influence slope design and stability in low gravity?

• Are we prepared to handle dust adhesion, thermal swings, and excavation behavior in mature regolith?

• What ground improvement techniques will work best for immature, blocky regolith zones?

Our approach to lunar site preparation needs to connect planetary science with field-proven geotechnical practices: adapted but not reinvented from scratch!!!