New Methodologies for the Thermal Modelling of CubeSats

One of the main threats for the success of a CubeSat mission is the unbalanced distribution of thermal loads caused by internal and external heat sources. In order to design an appropriate thermal subsystem that can cope with these loads a detailed analysis is required. However, currently available thermal software is considered as being less convenient for the application with CubeSats, mainly due to the complexity of the modelling process. This paper examines thermal engineering issues for CubeSats and describes the development of new methodologies to realise a more appropriate thermal modelling and analysis specifically for such systems. This includes the utilisation of a component database and new approaches to create thermal couplings in the modelling process. A thermal software tool based on MATLABR was developed which implements these approaches to build the thermal model. Furthermore, the development of specific ray-tracing algorithms is presented to compute external radiation on the CubeSat. Application of the software for the thermal analysis of the UKube-1 CubeSat showed that the computational and methodological approaches provide good modelling capabilities and result similar temperature distributions as the professional software ESATAN TMSR