Thermo-mechanical design feasibility study of an Imaging Spectrometer for the Jovian system

The Moons And Jupiter Imaging Spectrometer is an experiment designed for the Jupiter Icy Moons Explorer ESA mission. The instrument will perform imaging spectroscopy in the visible and near infrared ranges to study the Galilean System. This work focuses on the thermo-mechanical design study performed to assess the instrument feasibility. The thermal design is based on a completely passive cooling, providing operational temperatures lower than 90 K, for the infrared detector, and lower than 140 K for the optical bench. These are required to reduce detector noise and background radiation disturbances on the measured signals. The instrument is mounted on a spacecraft whose temperature during operation is between -10 to 20 °C. Therefore, structural design is driven by the requirement of minimizing the thermal conductance of the instrument supporting structure, which, on the other hand, has to provide strength and stiffness required to hold the instrument optical head and radiators. Different mechanical and thermal layouts have been studied and compared. All the conceived configurations allow achieving the expected design requirements although with different margins with respect to the imposed constraints.