Abstract DGP2026-67

This contribution presents the fundamentals of Molten Regolith Extrusion (MREx), a concept based on the extrusion of molten lunar regolith for additive manufacturing under vacuum conditions. In this approach, regolith simulant is heated above its liquidus temperature inside a controlled chamber and allowed to flow through a nozzle onto a substrate. The deposited material solidifies layer by layer, enabling the fabrication of solid structures using only in-situ resources, an essential requirement for sustainable lunar construction.

The MREx process relies on gravity-driven melt flow, reducing mechanical complexity and enhancing robustness for operation in harsh extraterrestrial environments. By adjusting process parameters such as temperature and extrusion rate, the stability of the molten stream and the geometry of deposited beads can be controlled. Experimental investigations in both ambient and vacuum conditions provide insight into material flow behavior, wetting, and layer formation.

A key aspect of MREx is the fluid dynamics of high-viscosity regolith melt during free-fall deposition. As the molten stream exits the nozzle, it can exhibit phenomena such as liquid rope coiling, governed by the interaction between viscosity and gravity. Understanding these mechanisms, particularly under reduced gravitational acceleration as expected on the Moon, is essential for predicting deposition patterns and ensuring geometric accuracy and structural integrity in additively manufactured lunar components.