Heterodyne OH Lunar Miniature Spectrometer (HOLMS), a miniature ultra-sensitive UV spectrometer for future lunar and planetary missions

Here, we report the development of an ultra-miniature high-sensitive near UV spectrometer to determine the abundance or the upper limit of the water in the lunar atmosphere and investigate the processes that control its distribution and variability. Heterodyne OH Lunar Miniature Spectrometer (HOLMS) is based on the Michelson design Spatial Heterodyne Spectrometry (SHS) technique, a novel approach for high R in a compact, low-cost, low-mass, low-power architecture. HOLMS is designed to observe Hydroxyl (OH) molecules in the lunar exosphere in 311-317 nm and 0.1 nm spectral resolution. OH radicals are key lunar water surrogate molecules produced during solar UV-light dissociation; therefore, measuring it reveals critical information about the lunar water cycle and resources. Acknowledgments: This work has been conducted at the Jet Propulsion Laboratory, California Institute of Technology, under contract to NASA: copyright 2024, California Institute of Technology. Government sponsorship acknowledged.