Semi-Automated Bonding of OSR – Qualification of a novel Process
Résumé
Optical Solar Reflectors (OSR) are efficient thermal emitter glass tiles with a typical size of 40x40mm. They cover spacecraft radiator panels to reduce absorption of solar radiation and to dissipate internally generated heat into space. On modern high-power telecom satellites total radiator areas reach sizes of more than 20m². State-of-the-art processes to apply such OSR tiles are labour intensive and involve application of two-component adhesives, manual placing of tiles and long duration temperature controlled adhesive curing cycles. This paper presents the qualification campaign of a sophisticated OSR application method using electrically conductive pressure sensitive adhesive (PSA) and a semi-automated OSR pick-and-place facility. Compared to standard OSR application using electrically conductive filled silicone resins, the new process is resulting in radiator surfaces with up to 27% lower mass. After manual application of the PSA the panel is placed in the 3-axis controlled gantry system, where a precise manipulator takes each tile and places it on the CAD pre-defined position on the panel. When the panel is covered with OSR an automated rolling process applies the required pressure to activate tape adhesion. The application process in the pick-and-place system guarantees high degree of reproducibility and increased precision at decreased radiator through-put durations. For qualification, samples prepared with the automated process were subjected to a thorough space environmental test campaign. This campaign involved vacuum thermal-cycling and exposures to electrons, protons and UV-radiation simulating a 15 year GEO mission, followed by tile pull-off testing. Since successful completion of the qualification campaign a number of spacecraft radiators have been equipped with single sizes up to 2,1 x 2,2 meters including radiators of the SmallGEO, Exomars and EDRS-C programs.
Origine : Fichiers produits par l'(les) auteur(s)