DISTRIBUTED TEMPERATURE SENSING FOR LARGE DEPLOYABLE REFLECTORS - EXPRO+

Objective: To develop a breadboard of a distributed temperature sensor using a fibre optic to measure the temperature of large deployable reflectors.Description: Missions such as CIMR which use a Large Deployable Reflectors (LDR) for radiometry require knowledge of the reflector temperature during observation in order to increase the accuracy of the measurement. This is a very challenging temperature measurement, both on orbit and on-ground, due to the very thin wires of the mesh structure, together with the gold coating of the wires. Contact thermometers, infra-red thermography and electrical techniques have all been proposed, each coming with their own set of challenges. The use of a fibre optic Distributed Temperature Sensor (DTS) is an alternative approach to infer LDR temperature both on-ground and in-orbit. The use of a gold-plated fibre - which matches the thermo-optical properties of the mesh wires -allows the fibre to act as a temperature measurement proxy for the LDR itself. In addition, the DTS allows temperature to be read out continuously along the fibre over a long distance (e.g. very 2.5cm over tens of metres) from a single interrogator. The use of Raman scattering DTS with a gold coated fibre has already been proposed for the CIMR-like use case with basic feasibility demonstrated. The activity aims to test and characterize at a representative scale this measurement method and build a breadboard which can be developed for future EO mission. The use of a fibre optic does raise a number of practical challenges, for example the safe handling of the fibre during AIT, and the integration with a deployable structure for flight application. The activity will therefore assess the practical feasibility of the technique in a realistic industrial setting. The activity encompasses the following tasks: - Requirements consolidation and assessment of state of the art - Design of breadboard and associated test bench - Manufacture of breadboard, test bench - Execution of tests and exploitation of results - Roadmap for further development towards a flight applicationDeliverables: Breadboard, Report, Software