Electric Propulsion Microsatellites in a Versatile Constellation for Remote Sensing Applications

The paper presents the study of a microsatellites constellation equipped with electric thrusters to support land use monitoring and management while reducing mission cost and retaining high performance. The activity was carried out in collaboration between Alta SpA and University of Pisa. The usage of electric thrusters to compensate atmospheric drag and perform orbital maneuver enables microsatellites to maintain low-altitudes (below 500 km) and achieve autonomously operational orbits. This approach allows at selecting a wide range of orbits and designing a constellation based on standard platforms equipped with various optical instruments (multispectral, hyperspectral and thermal infrared). Alta’s HT100, a 100W Hall thruster, was assumed as reference propulsion system for this study. The 60 kg class platform designed may host a wide range of possible Earth observation payloads in terms of available volume (up to 20 liters), mass (up to 12 kg), power (30 W at least), data transfer speed (up to 100 Mbit/s), and pointing accuracy (down to 0.025 deg). As a result of the study, we show that the combination of microplatforms and electric propulsion outclasses classical larger spacecraft platforms based on chemical propulsion systems, with better operational flexibility, revisit frequencies and geographical coverage performance