OXYGEN EXTRACTION FROM LUNAR SOILS AND PYROCLASTIC GLASS

We have conducted experiments on 16 lunar soils and three lunar pyrocl astic glass samples to study the extraction of oxygen, an important re source for a future lunar base. The samples were chosen to span the ra nge of composition,mineralogy, and maturity represented in the Apollo sample collection. Each sample was reduced in flowing hydrogen for 3 h ours at 1050 degrees C. The dominant effect was reduction of Fe2+ (as FeO) in minerals and glass to iron metal, with concomitant release of oxygen. Oxygen extraction was strongly correlated with initial Fe2+ ab undance. The data and supporting experiments also indicate extraction of oxygen from TiO2 and SiO2. No dependence of oxygen release on sampl e maturity could be identified. Oxygen was extracted, in decreasing or der of efficiency, from ilmenite, agglutinitic and pyroclastic glass, olivine, and pyroxene. The experimental reduction of lunar soil provid es a method for assessing the oxygen production potential for sites on the lunar surface from lunar orbit. Our results show that oxygen yiel d from the regolith can be predicted from knowledge of only one parame ter, total iron content. This parameter can be measured from orbit by gamma ray spectrometry or multispectral imaging. These experimental da ta also support the selection of feedstocks and operating parameters f or a lunar oxygen plant.