Speaker
Description
The development of infrastructure on Mars is essential in future crewed missions, where ISRU will play a key role in sustainable sourcing. Here, we examine the feasibility and efficiency of robotic construction via extrusion additive manufacturing (eAM) using site-specific Mars regolith simulants. We simulate Martian atmosphere conditions and develop an eAM process that works therein. A Martian habitat built with these means could be a resource-efficient way to attenuate radiation.
The use of regolith for radiation shielding purposes has been investigated [1–3]; eAM however can produce green bodies with clay-water matrices that remain frozen under the right conditions, providing higher densities and structural integrity with tensile and compressive strengths similar to those of concrete on Earth. Additionally, clay slurries are effective absorbers of thermal neutrons, with increased performance given a higher water content [4], whereas dry Martian regolith alone can increase neutron exposure by secondary radiation production [5]. This project proposes the development of water-clay systems in different phase conditions (wet, icy, dry) to investigate the mechanical and radiation shielding properties of materials produced via eAM. We are specifically examining the porosity and heterogeneity in our samples arising from degassing and ice crystal accumulation during printing.
[1] Kim MH, Thibeault SA, Wilson JW, Heilbronn L, Kiefer RL, Weakley JA et al. Radiation protection using Martian surface materials in human exploration of Mars. Physica Medica 2001;17:81–3.
[2] Llamas HJ, Aplin KL, Berthoud L. Effectiveness of Martian regolith as a radiation shield. Planetary and Space Science 2022;218:105517. https://doi.org/10.1016/j.pss.2022.105517.
[3] Meurisse A, Cazzaniga C, Frost C, Barnes A, Makaya A, Sperl M. Neutron radiation shielding with sintered lunar regolith. Radiation Measurements 2020;132:106247. https://doi.org/10.1016/j.radmeas.2020.106247.
[4] Yoshikawa E, Komine H, Saito Y, Goto S, Narushima S, Arai Y et al. Radiation-shielding properties of heavy bentonite-based slurry for the decommissioning of the Fukushima First Nuclear Power Plant. Geo-Chicago 2016. 2016;269(269 GSP). https://doi.org/10.1061/9780784480120.031.
[5] Röstel L, et al. Subsurface Radiation Environment of Mars and Its Implication for Shielding Protection of Future Habitats. Journal of Geophysical Research 2020. https://doi.org/10.1029/2019JE006246.