A Microwave Heating Demonstrator (MHD) payload concept for lunar construction and volatiles extraction

For an extended stay on the Moon, humans will require habitation with substantial shielding for protection from radiation and micrometeorites. Lunar regolith (soil) is a readily available in-situ resource, which can be thermally treated to extract oxygen and water, as well as for construction. For example, lunar habitats and infrastructure can be built by robots using additive manufacturing techniques. Due to the volumetric heating characteristic, intrinsic to microwave heating, it is a more energy-efficient process than solar or laser sintering for large-scale manufacturing and construction purposes. Proof of concept experiments have demonstrated that microwaves couple efficiently with lunar regolith simulants; therefore, microwaves could be an efficient mechanism to sinter and melt lunar regolith to build 3D structures and also enable the extraction of volatiles. These experiments are based on simulated conditions and materials; thus, there is missing information on microwave heating of lunar regolith, which includes the effects of nanophase iron (np-Fe0) produced via space weathering, the highly electrostatic nature of the particles, and irregular particle geometries of the real lunar soil. Through a UK Space Agency (UKSA) grant (NSTP GEI) we are developing a conceptual design of the Microwave Heating Demonstrator (MHD) payload that could be delivered to the lunar surface for in-situ experiments via the ESA’s HERACLES mission or NASA’s CLPS programme. Here, we provide further details of our conceptual design of a MHD payload.