Power System for the Eu:CROPIS Satellite - Results from Design Trade-Offs, Analysis, Simulation and Testing

The Eu:CROPIS satellite is the first satellite to be launched as part of the DLR Compact Satellite Program. The mission is currently in Phase D and is scheduled to be launched in 2017. The Eu:CROPIS satellite is a small satellite of about 1m3, and a mass of 250kg. The nominal power consumption in science mode is approximately 200W from which ~50% is provided to the payloads. The design of the Eu:CROPIS power system design is driven by the primary payload which is a biological payload that has a very narrow temperature range, and the attitude control system which utilizes only magnetic torquers as actuators. The power system has been optimized in order to provide as much power as possible during the Launch and Early Operations Phase (LEOP) of the mission resulting in a design which for the nominal part of the mission is over-dimensioned. This paper captures the trade-offs affecting the power system carried out on system level, which were made in the design phase of the mission, and will explain in more detail the analysis, simulation and testing related to the LEOP of the mission. Based on the simulations and resulting design iterations performed for the LEOP the probability of power balance in this phase has been increased significantly compared to the power system which was optimized for the nominal mission