Nanosatellite on-low-earth-orbit temperature simulation and its implication concerning extreme cases

It is common sense that nanosatellites, a new generation of small satellites, are characterized by a reduced size envelope, lower cost, and shorter design time. Nevertheless, they are confronted with various challenges, including large thermal gradients or multiple thermal loads. The thermal behavior is usually predicted through simulation which must be well conducted in order to obtain reliable results. The present paper intends to describe the various types of thermal radiation experienced by the nanosatellite, and then simulate them in a rigorous way taking into account the thermal dissipation of the nanosatellite arising mainly from the batteries. The passive thermal control of the nanosatellite was conducted taking into consideration the change of the optical coatings of the material. A first approximation consisting of a simple shape of the nanosatellite to obtain tangible results has been developed while foreseeing a more complex and complete geometry in the future. Based on the results, the temperatures in the two cases, namely the cold and the hot cases, were very distinct. Indeed, for the cold case, the detected temperatures were within the acceptable limit when the ratio α/ε did not exceed unity. As a matter of fact, when α/ε=0.29, the temperature oscillated between 15.44°C marked at the level of the batteries and 13.35°C noted on the shell. Thereafter when α/ε=1.11 the temperature swung between 64.32°C marked at the batteries and 62.37°C read on the shell. However, for the hot case, it was clear that all the temperatures detected were well above the acceptable limit, requiring for this case the intervention of a complementary thermal control to avoid high temperatures if the studied coatings should be kept. In fact, the temperatures found when α/ε=0.29 were of 86.56°C at the level of the batteries and of 80.09°C in the outer shell of the nanosatellite. Similarly when α/ε=1.11, the temperature reached 114.48°C at the level of the batteries and almost 108.2°C on the outer shell by recording 6°C of temperature difference between the inside and the outside of the nanosatellite. Consequently, it appears from the results that the temperatures are very sensitive to the surface coating of the nanosatellite as well as to the heat dissipation at the level of the batteries.