MIDIM, an UV imager for the monitoring of aerosols for future missions to Mars
Authors: Willame Yannick , Robert Séverine , Pereira Nuno , Antoine Philippe , Lecat Jean-Hervé , Ligot Renaud , Vandaele Ann Carine , Bolsée David 
Published: July 2024

Past and present Mars orbiters have been able to provide great information on Mars surface and atmosphere, focusing mostly on targeted high resolution measurements but lacking continuous global coverage. However, Mars atmospheric phenomena (clouds and dust storms in particular) and space weather environment require continuous, simultaneous, global observations to fully understand the dynamic variability and extension of meteorological and environmental conditions at Mars [Montabone, 2021]. In the next decade, spacecrafts monitoring Mars will embark on a new generation of instruments.In a collaboration between the Royal Belgian Institute for Space Aeronomy (BIRA-IASB) and the Lambda-X company, an instrument for future Martian orbiter missions, MIDIM is being developed. The &#8220;Mars Imager for Dust and Ice clouds Monitoring&#8221; will be a multispectral band UV imager able to monitor dust and ice clouds.Dust and ice clouds are key compounds in the Martian climate as they modulate the dynamical and thermal structure of the atmosphere. They absorb and scatter sunlight, which can result in local warming or cooling of the atmosphere. A constant monitoring of aerosols around Mars would help us to assess the physical processes that control the onset, growth and decay of dust storms, the interannual variability of global dust storms, the global budget of dust and its evolution over time, as these processes are not yet fully understood in the martian atmosphere [Kahre, 2024]. The impact on the water ice cycle also needs to be better constrained.The MIDIM imager will have an extended field of view covering a large portion of Mars, depending on the orbit of the spacecraft. It will be suited for high altitude or stationary orbits. The instrument design will be partly based on the heritage of the NOMAD/UVIS instrument [Patel et al., 2017] on board ExoMars Trace Gas Orbiter, using the same CCD camera, as well as in state-of-the-art CubeSat compatible optical design solutions [Schifano 2022]The NOMAD/UVIS dataset is used in this work to assess the science requirements related to the objectives of this instrument [Willame et al. in prep, Willame et al. 2017]&#160;In the poster, we will present our progress about the design and preliminary studies of the MIDIM development.&#160;ReferencesKahre (2024), Dust on Mars. Oxford Research Encyclopedia of Planetary Science, Oxford University Press, article id. 119.Montabone (2021), A Paradigm Shift in Mars Meteorology. EPSC 2021, 625.Patel MR et al. (2017) NOMAD spectrometer on the ExoMars trace gas orbiter mission: part 2&#8212;design, manufacturing, and testing of the ultraviolet and visible channel. Appl Opt, AO 56:2771&#8211;2782Schifano L. et al. (2022) Freeform Wide Field-of-View Spaceborne Imaging Telescope: From Design to Demonstrator. Sensors 2022, 22, 8233.Willame et al. in prep. Dust and ice cloud retrieval from NOMAD/UVIS.Willame et al. (2017). Retrieving cloud, dust and ozone abundances in the Martian atmosphere using SPICAM/UV nadir spectra Planet. Space Sci., 2017. 142: p. 9-25.