Contributions of Non-Destructive Testing in the Development of Dimensionally Stable Space Composite Camera Structures

The onboard cameras of Earth Observation Satellites of the Indian Space Research Organization (ISRO) that operate from low earth orbit are designed with less than 1 m spatial resolution. These space-borne optical cameras are high-precision systems that require highly dimensionally stable structures to preserve the alignment of the optics during realization, after launch and in-orbit operation to get the best possible imagery. Carbon fiber reinforced polymer (CFRP) composite materials are used in these structures because of their specific strength, specific stiffness, low coefficient of thermal expansion, tailorability of properties, etc. The in-orbit geometric stability of these structures is dependent on the temperature sensitiveness of the fiber and matrix combination. The design, development and qualification of a new 1 m class composite camera structure called for the adoption of a new design, material and processing methodologies to maintain the required dimensional accuracies from earth to space. This paper provides a brief summary of the contributions of non-destructive testing (NDT) in the development of the camera structure starting from the process feasibility studies to the qualification and acceptance for its flight use.