Study of Combustion Mechanisms and Optimization of Iron- and Lunar Regolith-Based Pyrotechnic Compositions for Space Applications

Subject Description Context and Issues: Future lunar and Martian space missions will require autonomous energy systems capable of producing heat in situ, without relying on an atmosphere. Pyrotechnic compositions—energetic materials that can burn without atmospheric oxygen—offer a promising solution, but their development for space applications is currently limited by two scientific challenges: 1. Understanding the physico-chemical mechanisms governing the ignition and combustion of iron/regolith mixtures, especially in the condensed phase. 2. The lack of predictive models for designing controlled combustion systems suited to the constraints of long-duration missions. Scientific Objectives: This thesis aims to (i) experimentally characterize the combustion of composite iron/lunar regolith pellets, investigating the influence of various parameters on combustion rate (porosity, particle size, potential additives such as Mg), (ii) develop a phenomenological model correlating the structural properties of the mixtures (analyzed via electron microscopy) with their energetic performance (combustion rate, ignition energy), and (iii) validate this model through controlled environment tests (constant volume reactor, high-speed camera, photodiodes, and pyrometry). This work will contribute to advancing ISRU (In-Situ Resource Utilization) technologies by proposing a sustainable energy solution based on materials available in situ. Methodology The thesis will involve (i) manufacturing pyrotechnic composition pellets with varying compositions and compaction pressures, (ii) characterization campaigns for thermal (mass, heat flux, transport properties), structural (electron microscopy), and energetic (combustion rates, ignition energies via Langlie method) analysis, and (iii) numerical modeling of combustion phenomena, with experimental validation.