In a paper published in the journal Advances in Space Research, Jonathan Whitlow and Jesus Dominguez present a process in which the Marangoni effect would allow non-mechanical transportation of the extraterrestrial mineral to feed an also in-situ pyrolysis-based refinery unit.
The researchers seek to establish that the Marangoni effect, which is crucial for welding metals, manufacturing integrated circuits and growing crystals, has the potential to be important for supporting lunar habitats and other extraterrestrial endeavours. They contend that vacuum and reduced gravity are expected to augment the Marangoni effect on extraterrestrial molten soil leading to sustainable extraterrestrial in-situ resources utilization.
To reach their conclusion, the authors conducted a Marangoni effect assessment on molten lunar regolith via JSC-1A lunar regolith simulant under vacuum yielding a spontaneous upwards migration of a uniform molten thin-film front as well as at bulk scale that climbed the crucible wall covering the entire wall’s surface and reaching the crucible’s top end.
In their view, this unique formation and self-migration of a thin-film front could enable key in-situ resources utilization processes such as thin-film coating, crystal growth, and feedstock generation for additive 3D printing.
“Further assessment on higher-temperature vacuum-driven decomposition of the uniform thin-film front as it climbed the crucible’s wall revealed a significant decomposition of various simulant’s metal-oxide components into their respective oxygen and metal elements strengthening the feasibility of extraterrestrial generation and fractional separation of oxygen and metals/alloys with none or minimal need for terrestrial precursors,” the authors write in the paper.
For Whitlow and Dominguez, these two-coupled phenomena, spontaneous material transportation at both thin-film and bulk scales via the Marangoni effect and vacuum-driven decomposition open novel pathways in space mining and manufacturing.
“Future extraterrestrial mining will require an operational approach completely different from the terrestrial one that heavily relies on not only mechanical excavation and transportation but also on a stand-alone refinery process to extract the mineral components,” the study reads.
