Thermal Modelling of ECO Satellite Radiometer

The Earth Climate Observatory (ECO) mission is a proposal for the European Space Agency (ESA) Earth Explorer 12 program. Its main goal is to measure the Earth's Energy Imbalance (EEI) from space using a constellation of satellites equipped with radiometers and Short Wave (SW) and Long-Wave (LW) cameras. Since the EEI signal is extremely small, on the order of 1 W/m2, maintaining a highly stable thermal environment for the radiometers is essential to ensure measurement accuracy.

This thesis focuses on the thermal modelling of the ECO payload, with particular attention to the radiometers. A theoretical background on spacecraft thermal control and environmental fluxes is first provided, followed by an overview of the EEI measurement concept and the ECO mission architecture. A detailed thermal model of the payload was developed using Systema Thermica (Airbus) to simulate the spacecraft’s behaviour in orbit. Parametric analyses were conducted on orbital inclination, radiator size, heater power, and surface properties to identify the optimal configuration. Results show that a 40×40 cm2 radiator combined with 10÷25 W heaters can maintain the radiometer temperature within 1 K of the thermostat set-point under varying orbital conditions.