Abstract
At the Moon, the regolith (soil) is a readily available resource, which can be thermally treated for extracting oxygen and water, as well as, for fabricating construction components. Due to the volumetric heating characteristic, intrinsic to microwave heating, it is considered as a more energy-efficient process than solar or laser sintering for large- scale manufacturing and construction purposes. Proof of concept experiments and numerical modelling 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-printed structures, while also enabling the extraction of volatiles. In the context of In-Situ Resource Utilisation (ISRU) to offset the need to transport all materials from Earth, it is highly desirable and timely to align with the current Solar System exploration road maps of international space agencies.
At the Open University, we have been leading the development of a microwave heating-based 3D printing technique to be used as a preferred fabrication method in extra-terrestrial construction processes and resource extraction, including oxygen, water and iron. As part of this research, a series of experiments were conducted to understand the microwave sintering/melting behaviour of lunar regoith and simulants. In this contribution, we describe different microtextures that were observed in microwave heated lunar simulant JSC-1A specimens under different input powers. This is important because it would allow us to utilise a specific input power of microwave for specific applications.