An integrated temperature sensor network for satellite sandwich panels

Large telecommunication satellites are equipped with hundreds of sensors including strain sensors, accelerometers and especially temperature sensors for the measurement during testing, launch and operation. The huge amount of sensors is very expensive in terms of integration effort, harness complexity and weight. To reduce this negative impact on large telecommunication satellites the use of fiber optic sensors for the distributed sensing in satellites is investigated. Here we show the integration of a fiber optic sensor network into satellite sandwich panel structures for the purpose of hot spot detection. The developed sensor system enables temperature measurement without any disturbance by static or dynamic mechanical loads or electro-magnetic fields. The integration technique of the sensor system between the face-sheet and the honeycomb core has only negligible impact on the structural integrity of the panel. Ideally the very sensitive fiber optic temperature sensors lead to temperature resolutions of 0.01°K. First experiments showed the possibility to achieve resolutions in that range. However the designed sensors showed a slightly inert behavior. The simulation of a demonstrator panel with a sensor density of even only 9 sensors per square meter showed the possible reconstruction of the temperature field with an error of 6.9%.