Battery-Aware Contact Plan Design for LEO Satellite Constellations: The Ulloriaq Case Study

Power demands of the transmission technologies for communication between LEO satellites are difficult to counterbalance by solar infeed and on-board battery storage, due to size and weight limitations in LEO. This makes the problem of battery-powered inter-satellite communication a very difficult one. Its management requires a profound understanding as well as techniques for a proper extrapolation of the electric power budget as part of the inter-satellite and satellite-to-ground communication design. We discuss how the construction of contact plans in delay tolerant networking can profit from a sophisticated model of the on-board battery behaviour. This model accounts for both nonlinearities in battery behaviour as well as stochastic fluctuations in charge, so as to control the risk of battery depletion. We take an hypothetical Ulloriaq constellation based on the GomX-4 satellites from GomSpace as a reference for our studies.