LIRIS - A Small Satellite Concept to Provide High Resolution Maps of Water on the Moon

LIRIS – A small satellite concept to provide high resolution maps of water on the Moon. N. E. Bowles1, H. Eshbaugh1, R. Evans1, T. Warren1, K. A. Shirley1, F. Clarke1, A. Harvey2, L. Middlemass2, J. Friend2, S. Eckersley2, S. Knox2, B. Hooper2, A. da Silva Curiel2, M. Sweeting2. 1University of Oxford, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, UK, [email protected] (2)Surrey Satellite Technology Limited, Tycho House, 20 Stephenson Road, Surrey Research Park, Guildford, United Kingdom, GU2 7YE, [email protected] Introduction: The detection of possible widespread surficial H2O/OH on sunlit and shadowed regions of the lunar surface was one of the most unexpected discoveries of the 2000’s. Remote sensing measurements of the H2O/OH absorption 3 µm feature from data sets from e.g. the Moon Mineralogy Mapper (M3) [1] on the Chandrayan-1 spacecraft in 2009 also gave an indication of possible spatial and temporal variations in surficial water concentration. The identification of water and determining its abundance at scales from <75 m will provide critical new knowledge on a possible “lunar water cycle” and support future human and robotic exploration. With advancements in technology, improved lunar infrastructure (including services such as ESA’s Moonlight) and increased accessibility enabled by lower cost rideshares, fast (e.g. <4 year), focused mission development is now possible to answer this and other critical questions about the lunar environment to further science and better enable future human exploration. Mission Concept: The Lunar InfraRed Imaging System (LIRIS) small satellite concept builds on experience from the Lunar Pathfinder development at SSTL towards designing a variant of the Carb+ platform series tailored for the lunar environment. Building on heritage from the DarkCarb imager flown in 2023, the multispectral imager will be capable of providing sub-meter resolution images of the lunar surface in spectral bands around 3 microns. The spacecraft will host a thermal infrared imager, capable of imaging in the 6-25 microns range, which is an evolution of the University of Oxford’s Lunar Thermal Mapper flown on NASA’s Lunar Trailblazer mission [2] to provide thermal context for environment and surface composition characterisation. This presentation will describe the details of the concept and science case, as well as the current status. Figure 1: Lunar Infra-Red Imaging System Mission Concept (image credit SSTL) Figure 2: Lunar Infra-Red Imaging System 3 µm camera based on the SSTL DarkCarb Camera, clear aperture ~315mm ((image credit SSTL)) Figure 1. (left) The LTM flight unit, a multispectral TIR mapper. (right) the LTM FM prior to the cover being locked in place. Dimensions 215 x 100 x 250 mm without Multi-Layer Insulated blankets fitted. (image credit Univ. Oxford) References: [1] Pieters et al. 2009 Science 326, 565-568. [2] Ehlmann et al. 2022 IEEE Aerospace Conference (AERO), pp. 1-14. IEEE, 2022, https://doi.org/10.1109/AERO53065.2022.9843663