Abstract
The future of sustained human space exploration is likely to rely on the use of local resources on the respective planetary bodies. The continuing exploration of the Moon via orbiter, lander and sample return makes it the next logical destination for setting up human outposts, laboratories, and observatories. Its proximity to Earth also makes it an ideal first destination before we explore further out in the Solar System. Lunar soil is a potential construction resource which can be melted or sintered for building structures [1]. To process the lunar soil, some form of compact, lightweight, electrically powered heat source is required and for this work microwave energy has been selected as it fulfils these criteria well. This research focusses on understanding the interaction of microwave energy with lunar soil. The heat-treated soil can then be fed into a 3D printing apparatus, enabling robotic missions to build structures on the Moon [2]. Lunar soil simulants JSC-1A (lunar mare soil simulant) and NU-LHT-3M (lunar highlands soil simulant) have been used for the experiments in this research. Lunar soil [3] is abundant in silicate minerals and glasses with traces of some other minerals. JSC1A [4] and NU-LHT-3M [5] also has silicates, glass and other minerals. Previous research has shown that lunar soils and lunar soil simulants (LSS) melt during sustained exposure to microwave radiation at a frequency of 2.45 GHz [1, 6]. The melting of lunar soil under microwave heating is commonly attributed to the presence of nano phase Fe0(np-Fe0) [1, 7-9]. However, JSC-1A being a terrestrially manufactured lunar soil simulant, does not contain np-Fe0; however, it melts under microwave heating [6].