New multiwire temperature sensor for space applications

The paper reports about a new temperature sensor which is going to be used in the forthcoming space mission of ESA-NASA, called Cassini-Huygens. A prototype of the sensor has been designed and manufactured in the Heat Transfer Laboratory. Thermal calibration has been performed in the same laboratory while fluid dynamics tests have been carried out in wind tunnels of other laboratories. The flight version of the sensor, to be used in the space mission, has been manufactured by a company specialised in flight measurement sensors. Thermal and fluid dynamics calibrations have been conducted in order to allow accurate temperature measurements and to know the time constant of the sensor. A small time constant is required for the sensor to respond quickly to changes in the atmospheric gas temperature during the descent of the space probe into Titan, the satellite of Saturn. Heat transfer tests have been done in order to correlate the time constant of the sensor to the basic convective heat transfer coefficients between air and wires of the sensor. Conduction thermal analysis has been carried out in order to compare theoretical and experimental temperature measurements.