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To ensure the success of surface missions and the eventual habitation of the Lunar and Martian surfaces, construction materials for machine components, tools, plumbing, and more must be considered for the long-term supportability of astronauts. The financial burden of launching these materials from Earth is far too great; therefore, in-situ resource utilization (ISRU) technology will be required. The Martian environment contains numerous elements for producing bulk metal components; however, these elements are almost exclusively found as compounds. The use of ionic liquids (ILs) for elemental metal harvesting is being researched by NASA's Marshall Space Flight Center (MSFC) to extract feedstock materials from local regolith and meteorites. Studied at MSFC as a life support system, the Boschprocess produces a byproduct elemental carbon (C) during oxygen (O 2) regeneration from metabolic or environmental carbon dioxide (CO 2). This study details the refinement of a ductile iron (DI) designed to simulate the combination of IL-harvested iron (IL-Fe) and Bosch C by investigating the effects of Ni and Mn addition on IL-DI properties. Dilatometry was used to evaluate how the properties of the IL-DI might vary when produced in the Martian environment. DIs were cast using commercial elements with C produced via a C formation reactor (C–Fr) at MSFC with microstructural, hardness, and phase diagram analyses completed. Results suggest that the combination of IL-Fe and Bosch C could be a viable means of producing DI alloys in-situ and, with the quantities used here, the use of Ni could be more beneficial to alloy customization than Mn additions for IL-DI alloys. • Ionic liquids iron and Bosch carbon is further studied for ductile iron production. • Nickel and manganese additions investigated for property variation. • Dilatometry used to study how microstructure might vary when produced on Mars. • 4% nickel content provided more significant hardenability than 1% manganese. • Results suggest satisfactory ductile irons could be cast with the ISRU materials. [ABSTRACT FROM AUTHOR]

• Ionic liquids iron and Bosch carbon is studied for ductile iron production. • The produced material was compared to a commercially available material. • Analyses reveal similar metallurgical properties. • The variations are attributable to the greater nickel content of the IL DI. • Results suggest a satisfactory ductile iron could be cast with the ISRU materials. As researchers continue to study methods to facilitate long-term missions beyond low-Earth orbit, the ability to manufacture high-quality mechanical and structural components on the Lunar and Martian surfaces remains a crucial piece to the puzzle for a sustained presence. Due to the immense cost of sending supplies to extraterrestrial bodies, in-situ resource utilization (ISRU) methods are critical for the success and feasibility of these habitation missions. Ionic liquids (ILs) are currently being studied at NASA's Marshall Space Flight Center (MSFC) to harvest elemental metals from meteorites and regolith minerals. Additionally, the Bosch process is being explored as a life support system at MSFC for oxygen (O 2) regeneration, rendering a byproduct of elemental carbon (C). In this investigation, the viability of casting ductile iron (DI) using IL-sourced iron (IL-Fe) and Bosch C was studied given the range of applications and performance of DI as an as-cast alloy. Ingots were produced using commercial elements to simulate the use of IL-Fe with C sourced from the byproduct C of the Bosch process. Samples were cast and compared to commercially available 65–45-12 DI with phase transformation diagrams, microstructures, and hardness. Results showed that IL-sourced elements are a viable source of elemental alloying materials for a range of DI alloys, with some limitations. [ABSTRACT FROM AUTHOR]

Element recovery from the Martian regolith using ionic liquids (ILs) is an active area of research within the field of in-situ resource utilization. In this work, we performed a classical molecular dynamics (MD) simulation study to better understand the solvation thermodynamics and structures of potential cationic and anionic species originating from the Martian regolith in two select ILs, i.e., 1-ethyl-3-methylimidazolium acetate ([emim][Ac]) and 1-ethyl-3-methylimidazolium hydrogen sulfate ([emim][HSO 4 ]), at two temperatures of 298.15 and 473.15 K. The studied cationic and anionic species represent the stable ions, i.e., a series of tetra-, tri-, di-, and monovalent cations, as well as several silicate, phosphate, chromate, titanate, and select halide anions, based on the mineral composition of the Martian regolith. We calculated the solvation free energies (SFEs) of these ionic species in the ILs using the free energy perturbation method. Moreover, we investigated the solvation environment of these ionic solutes by generating the relevant radial distribution functions and calculating the running coordination numbers of ILs' anions and cations surrounding the solutes. Overall, the average absolute values of the SFEs for cationic solutes increase with increasing ion valency (charge) and size of the solute at both temperatures. For anionic solutes, a more complex effect of anion molecular size and charge is responsible for the trends observed in the absolute values of the SFEs. For example, we found orthosilicate to be the most soluble anionic species in both ILs. On the other hand, the dichromate anion was found to be essentially insoluble in both ILs. Comparing between the solvation efficiencies of the ILs, [emim][Ac] shows larger negative SFE values than [emim][HSO 4 ] for all cationic solutes at both temperatures. While the temperature effect on the solvation of cationic solutes is mixed, higher temperatures generally favor the dissolution of the anionic solutes in both ILs. Our results provide molecular insights into the solvation thermodynamics of various potential ionic species that may be extracted from the Martian regolith using suitable ILs. Unlabelled Image • Solvation free energies of Martian regolith ions in ionic liquids were determined. • [emim][Ac] and [emim][HSO 4 ] were selected as ionic liquids solvent. • Cations with higher charges and sizes were more soluble in [emim][Ac]. • Anions were slightly more soluble in [emim][Ac] showing a reverse trend with size. • Raising the temperature improved the solvation of the anions in both ILs. [ABSTRACT FROM AUTHOR]