Laser Direct Additive Manufacturing of Natural Inorganic Minerals for Space and Terrestrial Applications (LAMISTA)

Renewed international ambitions to establish a permanent human presence on the Moon — driven notably by NASA's Artemis program, whose Artemis II mission marks a recent milestone — place in-situ resource utilization (ISRU) at the centre of exploration strategy. Sustaining astronauts and lunar infrastructures in such a resource-scarce environment requires minimizing dependence on materials shipped from Earth. Lunar regolith, abundant and readily available on site, together with solar energy, constitutes one of the very few exploitable local resources and is therefore a natural feedstock for on-site manufacturing and repair of technical parts. Most experimental work on regolith-based additive manufacturing to date has focused on Mare-type simulants, yet current lunar base scenarios point toward a South Pole location dominated by Highland-type terrain. This PhD project addresses this under-explored question: how does Highland regolith behave under a direct, binder-free additive manufacturing process such as Selective Laser Melting (SLM), and how must the process be adapted to it? Unlike indirect routes (vat photopolymerization, binder jetting, fused filament fabrication), which require an organic binder transported from or produced on the Moon and a subsequent debinding/sintering stage reaching temperatures above 1500°C, SLM proceeds in a single step without added binder or waste heat — a decisive advantage for a resource- and energy-constrained lunar environment, though one that raises major scientific challenges, since ceramics are poor heat conductors with brittle behaviour, prone to cracking, warping and porosity. The project is organized in five work packages. WP1 selects and characterizes a reference Highland simulant (thermal, thermo-optical and phase-transformation behaviour by FTIR, DTA/TGA/DSC, laser-flash diffusivity, SEM/TEM and XRD), benchmarked against the Mare simulants (BPY, EAC-1) already studied at ICA. WP2 develops optimized metal-ceramic and/or carbon-metal-ceramic composite feedstocks that valorise the metallic and carbon-based by-products of regolith reduction processes (pyrolysis, molten-salt electrolysis), improving toughness while limiting brittleness. WP3 optimizes the SLM process itself for the Highland simulant and its composites, addressing thermal-gradient management to limit cracking, in-process monitoring of the melt pool (thermal and optical instrumentation), and an in-situ post-processing protocol (a second, non-melting laser pass replacing ex-situ furnace annealing). WP4 validates the manufactured parts through geometric (3D scanning), volumetric (X-ray computed tomography), microstructural (SEM/EDS) and mechanical (compressive, flexural, fracture-toughness, Weibull statistics) qualification, against functional specifications co-defined with ESA for target applications such as heat exchangers, irrigation pipes or particle filters. WP5 quantifies the environmental impact and energy balance of the process through a Life Cycle Assessment (ISO 14040-14046) and identifies realistic terrestrial applications, particularly in construction and resource-constrained industrial contexts. This work is carried out within an international, multidisciplinary framework bridging the Toulouse ISRU Task Force (ICA, IRAP, LGC, TBI, CNES), University of Cologne (DE), ESA's European Astronaut Center (EAC, Cologne (DE)) and Cologne university, and is expected to take the form of a co-supervision and a one-year stay at the EAC, with further collaboration opportunities with Hochschule Aalen and the Laser Zentrum Hannover Institute. Beyond its space application, the project directly answers the sustainable-transitions pillar of the BEST program: manufacturing parts directly from local mineral resources and solar energy, with no organic binder and minimal waste, offers a model of resource-efficient production whose relevance extends to Earth, reinforcing the project's dual Moon-to-Earth impact. École doctorale : MEGEP - Mécanique, Energétique, Génie civil, Procédés Direction : Thierry SENTENAC Financement : MSCA COFUND BEST