Water from Lunar Regolith: Reduction by Hydrogen for a Small-scale Demonstration of in situ Resource Utilisation for the Moon

Abstract

Water is a critical resource required for long-duration space exploration missions, and in situ water production will be key to enabling a sustained human presence on and around the Moon. There are two potential sources of lunar water: from frozen ice deposits in polar craters; and from the extraction of oxygen from regolith. The Package for Resource Observation and in Situ Prospecting for Exploration, Commercial exploitation and transportation (PROSPECT) will be used to investigate both sources of water when it is flown on the Luna-27 mission to a high-latitude region of the Moon. The aim of this work was to determine whether a static system, such as that found on the onboard Sample Processing and Analysis suite (ProSPA), could be used to perform hydrogen reduction of lunar regolith to produce water. If successful, it would be one of the first in situ resource utilisation (ISRU) demonstrations to be performed on the Moon. To achieve this aim, the movement of gases in a static system was modelled and then trialled experimentally on a breadboard, where ilmenite, a common lunar mineral, was successfully reduced. A second breadboard with improved thermal control was developed and evaluated, and then used to perform ilmenite reduction experiments where the reaction temperature and hydrogen pressure were optimised to produce the highest yields of water. Finally, the optimised procedure was applied to the reduction of lunar-like and lunar materials, including a lunar highland simul…