The COMET Interceptor mission, chosen by the European Space Agency (ESA) in 2019 as a fast-class mission within the Cosmic Vision Programme, features a primary spacecraft and two probes, performing a fly-by with a comet. These three spacecraft will be first positioned at the L2 point, awaiting the identification of a yet undiscovered comet, and then move to a transfer orbit to perform the close-encounter. This paper focuses on the thermal analysis and design of Probe B2 and how the thermal model is structured at a system level to ease the iteration process. The thermal environment during the cruise and encounter phase proves challenging due to factors such as deep space radiation, solar radiation ranging from 0.85 to 1.2 astronomical units, and the impact of the primary spacecraft, which can act as a shadowing or reflective body during different mission phases. Overcoming this challenge requires some iterations conducting 19 analysis cases and using three geometrical models to dimension the thermal design of the probe. The thermal design mainly features a structured baseplate that houses all units and scientific instruments and ensures thermal control. The entire probe is covered with a Multi-Layer Insulator (MLI), with the structure being thermally regulated through heaters for warming and external radiators for cooling. A hierarchical structure was used for both thermal and geometrical mathematical models to facilitate implementation and to automate the execution. All results were post-processed using Python.
González-Bárcena et al. (Sun,) studied this question.