Dynamic space link design and verification of the spinning spacecraft mission Eu:CROPIS

In this paper, we present a dynamical link budget approach for the verification of the communication subsystem of the Eu:CROPIS (Euglena and Combined Regenerative Organic Food Production in Space) satellite. Eu:CROPIS is a spin-stabilized satellite, which simulates the gravitational fields of Moon and Mars for on-board performed astrobiological research. For this reason, spin rates of up to 30rpm are obtained, which exert influence on the communication link between the satellite and the ground stations. From ground station perspective, the satellite antenna's far-field behaves dynamic, including amplitude variations and phase rotations. Both effects degrade the link quality and might lead to an abort of communication. With respect to satellite orbit parameters (e.g. orbit attitude and pointing direction) a dynamic link budget analysis and verification is performed, to ensure a stable communication link between the satellite and ground station under the defined worst case conditions. In this paper we introduce the evaluation and verification process to test the receiver electronics, by emulating the communication link with the pre-measured far-field pattern of the satellite antenna system and simulated orbit parameters.