Experimental Development of a Lunar Water Simulant and System Control of a Related Lunar Water Purification System

Abstract

This master thesis deals with the selection of a lunar water simulant based on the results of dissolution experiments and the system control via LabVIEW of a related lunar water purification system. The research questions are: What is the required composition for a lunar water simulant using lunar regolith simulant? How can the related lunar water purification system be controlled using a LabVIEW program? Dissolution experiments are conducted to investigate possible contaminants of extracted water from the lunar surface. To determine a lunar water simulant, the methodology of the dissolution experiments and the results are described. For the dissolution experiments, ultrapure water or buffer solution with a pH of 5.6 are tested with the lunar regolith simulants LHS-1 and LMS-1 by Exolith Lab. This further includes lunar regolith simulant LHS-1D in an ambient and in a nitrogen atmosphere. These results provide new insights into the influences of pH, simulant to aqueous solution ratio, bulk chemistry, and simulant particle size on dissolution experiments. A lunar water simulant is selected, portraying the worst-case regarding released ions with a chosen lunar regolith simulant, simulant to aqueous solution ratio, and aqueous solution from all conducted dissolution experiments within the Synergetic Material Utilization (SMU) research group of the German Aerospace Center (DLR) Bremen. It is further investigated how to control a related lunar water purification system via a LabVIEW program. For the lunar water purification system, the methodology, including control technology, selected measuring instruments, and sedimentation experiments, is explained. The results of the sedimentation experiments, the LabVIEW program and the first test of the lunar water purification system lead to estimates of the purification ability and optimisations of the lunar water purification system and the LabVIEW program. These results can be used to test the lunar water purification system on Earth and to adapt the purification system to a fully automatic application with extracted lunar water.