Thermal Testing of Bonded Joints for a Hyper Hemispheric Panoramic Camera

In any space mission, observation of the surrounding scenario is one of the most important activities. Through high-performance imaging systems, space instruments allow the acquisition of new information about the observed environment and improve scientific studies. However, traditional cameras by which space instruments are typically equipped, show a limited field of view, requiring the presence of actuators coupled with moving elements to acquire the entire scenario. Indeed, moving elements increase the risk of failure, especially in the space environment, which is characterized by very harsh conditions, and where any maintenance is critical or impossible. Hyper-hemispheric panoramic cameras provide a compact solution to this issue because, thanks to their large field of view, they can acquire the surrounding scenario with a single image acquisition. Within the framework of this research, the validation of the thermo-mechanical design of the catadiopter, one of the main optics of the Hyper Hemispheric camera, was performed in the expected working temperature range from - 120 °C to 100 °C. Some mockups representative of the connection area between the mechanics and the optics were manufactured and tested with thermal cycling to assess the baseline holding strategy, which requires gluing of materials with different Coefficients of Thermal Expansion. The activity allowed the validation of the selected composite adapters (Torlon 7130) to be used as intermediate material between the optics and the holder.