IRECIN Nano-satellite communication system and ground segment

Abstract

On board resources necessary to perform the mission tasks are very limited in nano-satellites. This paper proposes a real-time multi-processing system for the communication system between ground segment and IRECIN nano-satellite. The first microprocessor is devoted to interface to the rice-transceiver subsystem decoding packet information and the second one is in charge to communicate with the other subsystems through I 2 C bus. It uses UHF band and less than 1 W in RF. All electronic components are SMD technology in order to reduce weight and size. The realized electronic boards are completely developed, realized and tested at the Vitrociset S.P.A. under control of Research and Develop Group. This multi-processor system even allows managing the tasks of the microprocessor eventually damaged, the microprocessor still working takes the functionalities of the first one using simpler algorithms. This choice assures an increasing nano-satellite life time. Moreover, the depicted method allows to free the on-board main microprocessor from the control functions of the communication data, increasing its communication capabilities with the other subsystems. The proposed system is implemented on the IRECIN, a modular nano-satellite weighing less than 1.5 kg, constituted by 16 external sides with surface-mounted solar cells and three internal Al plates, kept together by four steel bars. Lithium-ion batteries are added for eclipse operations. Attitude is determined by two three-axis magnetometers and the solar panel data. Control is provided by an active magnetic control system. The spacecraft will be spin-stabilized with the spin-axis normal to the orbit.