Product assurance management and coating qualification of the Telescope Assembly mirrors in the Ariel mission

The Atmospheric Remote-sensing Infrared Exoplanet Large-survey (Ariel), selected as ESA’s fourth medium-class mission in the ‘Cosmic Vision’ programme, is set to launch in 2029. The objective of the mission is to conduct spectroscopic observations of approximately one thousand exoplanetary atmospheres enhancing our understanding of planetary system formation and evolution. Additionally, it seeks to establish a clear link between the characteristics of exoplanets and their parent stars. The realization of the Ariel’s telescope is a challenging task that is still ongoing. It is an off-axis Cassegrain telescope (M1 parabola, M2 hyperbola) followed by a re-collimating off-axis parabola (M3) and a plane fold mirror (M4). The Telescope Assembly is made of EN AW 6061 and designed to operate at visible and infrared wavelengths, between 0.5 µm and 1.95 µm. The aluminum mirrors of the telescope are coated with a protected silver recipe, qualified to operate at cryogenic temperatures, to enhance reflectivity performance. Object of this thesis work is the study of Product Assurance/ Quality Assurance (PA/QA) responsibilities applied in the context of the Ariel space mission, highlighting the importance of stringent quality controls in ensuring mission success. Moreover, the activities carried out at CNR-IFN in Padua, Italy, concern the verification of the ageing effect on the mirrors coating which pose a specific technological challenge. The mirrors samples has been analyzed through Atomic Force Microscopy (AFM) for morphological characterization and with the aid of Fourier Transform Infrared (FTIR) spectroscopy for reflectance measures.