Solar 3D printing of lunar regolith

Abstract

The authors demonstrated the feasibility of sintering lunar regolith layer-by-layer solely using concentrated sunlight. First trials using actual concentrated sunlight led to an inhomogeneous sintering of individual layers of lunar regolith simulant, due to the significant flux density variations caused by atmospheric fluctuations. Tests focusing Xenon light demonstrated however the concept with the manufacturing of the first solar 3D printed brick made of lunar regolith simulant. The use of artificial light enabled steady illumination conditions over several hours as required to sinter lunar regolith layer-by-layer. Actual compressive strength of the sintered bricks, below 5 MPa, might be currently too low for a direct lunar application. High porosity levels and weak layer-to-layer bonding were observed on the micro-scale, but ways of improving the technology were found by reducing the thermal gradient and the cooling time between consecutive layers, thus showing the potential of the process. Adaptation of the technology on the Moon is presented to illustrate the suitability of solar additive manufacturing on the lunar surface, as a possible technique for shielding habitats and building roads prior to arrival of the astronauts.