FemtoSatellite communication system: performance analysis, implementation and test of possible technical solutions for swarm applications

This master’s thesis aims to identify system requirements and performance for telecommunication, tracking and control system to ensure communication between satellite and ground or inter-satellite link for FemtoSatellites missions. FemtoSatellites are a specific class of satellites weighing less than 100g. Today small satellites are widespread in space missions due to their lower cost but also for new possible applications they can offer. After a review of existing FemtoSatellites prototypes, a newer approach to Distributed Space Mission is investigated in order to identify capabilities to adopt swarms of miniaturized spacecraft as a platform for new and unprecedent range of applications. Communication result to be a key factor to enable such kind of capabilities and for sure one of the most important challenges on small satellites systems development. In this research, Radio frequency and optical communication are presented and compared in order to identify pros and cons of these two different technologies. In terms of Radio Frequency communication, a sensitivity analysis of link and data budgets is performed and then a possible mission scenario with a large number of miniaturized satellites has been simulated in MATLAB. Genetic algorithms are implemented to optimize problem's design variables (orbital parameters and number of satellites) and found a set of optimal solutions, which maximize the total amount of downlink data sent to a ground station and at the same time minimize the mission cost. In addition, System Tools Kit environment is used to perform more accurate analysis on perturbations, eclipse time and more precise link budgets to better understand the effective constellation performance. For optical communications analysis, a literature review about existing solutions and a possible set up for intersatellite links has been analyzed and presented. The thesis concludes with experimental tests performed on communication system, pointing out possible technical solutions to ensure a stable inter-satellite link using Commercial-Off-The-Shelf components.