A Regional Microsatellite Constellation with Electric Propulsion in Support of Tuscan Agriculture

This paper presents the mission design of a microsatellite constellation with electric propulsion to monitor and support the agriculture activities in the Tuscany region. The activity was carried out in collaboration between Alta SpA and University of Pisa. Starting from the user requirements and considering the performance of existing small optical instruments, our analysis has resulted in a constellation based on four microsatellites, each equipped with a different optical instrument (multispectral, hyperspectral and thermal infrared) responding to specific spatial and spectral perfomance. In order to guarantee very frequent revisit, microsatellites are placed in Sun-synchronus Repeating Ground Track (SSRGT) orbits from 358 km to 554 km. Each microsatellite is equipped with a low power Hall effect thruster, to provide orbital maneuvering capability and drag compensation for station keeping. The software suite SATSLab (Spacecraft Attitude, Trajectory and Subsystems LABoratory), suited for Earth Observation missions analysis, has been used to evaluate platform capabilities to compensate atmospheric drag, to perform orbital transfers, and to evaluate the instantaneous balance of energy exchanges onboard due to thruster firing, operation of observation instruments and data transmission