Thermal model development for a CubeSat

CubeSats provide a cost-effective means of several functions of satellites due to their small size, mass, relative simplicity and short development time. Therefore, CubeSat technologies have been widely studied and developed by space organizations, companies and educational institutions all over the world. These satellites have certain drawbacks. Small surface areas are a consequence of their small size which often imply thermal and power constraints. A novel development of CubeSats known as PW-Sat has been developed by Warsaw University of Technology. A control-oriented lumped thermal model of this satellite containing a fuel tank in the form of nonlinear ordinary differential equations is proposed in this paper. The model is able to simulate the thermal behavior of the surface and fuel tank of the satellite in its orbit. For the PW-Sat to operate reliably, the temperature of the fuel tank has to be maintained within given safety limits. Because of the limited power, passive thermal control is assumed in this case. Several simulation results are presented for different surface compositions to determine whether they are able to guarantee the prescribed temperature range throughout the entire orbit or not.