System Architecture of the SMART-1 Electric Propulsion Monitoring Tool

Abstract

The Special Projects Division, within the European Space Operations Centre (ESOC), has developed an Electric Propulsion Monitoring Tool (EPMT), which will complement SMART-1’s Mission Control System and its Science and Technology Operations Coordination facility, located at the European Space Research and Technology Centre (ESTEC). Since SMART-1 is the first mission utilizing a solar electric propulsion subsystem (EPS) as primary propulsion to orbit raise through the radiation belts, it is important to see if the spacecraft, or the EP itself, will be affected. The MCS alone cannot point quickly to EP-radiation belt-spacecraft interaction issues. The scenario at hand presents a need to support a spacecraft operations engineer to monitor, evaluate and forecast the EP performance throughout SMART-1’s mission. Also, this type of monitoring is completely new, needing constant feedback from users, throughout the tool’s development and implementation phases. Therefore, it is almost a necessity to use an adaptive approach for its development, such as, Dynamic System Development Method (DSDM). The tool has been designed to fuse five different data inputs: 1. Electric Propulsion live house keeping telemetry 2. Dedicated scientific payloads, the Electric Propulsion Diagnostic Package (EPDP) and the Spacecraft Potential, Electron and Dust Experiment (SPEDE) 3. Spacecraft attitude and orbit position 4. Model of the plasma space environment (primarily the near-Earth (Van Allen) Radiation Belts) 5. ACE space weather data The tool will be able to monitor and indicate interactions between any combination of: the plasma environment, the thruster and the spacecraft. Its cutting edge advantage is in using fuzzy logic to produce an output for each severity level (graded alarms) by identifying time-correlations between similar events, coming from the five inputs mentioned above. Also, it will provide further graphical outputs, in the form of graphs, etc., to provide key information such as plasma flux trend with time. Subsequently, this should increase the understanding of the behaviour of static plasma thrusters, nominally and while it interacts with the space plasma environment. Ultimately, in case there are any on-board anomalies, this should lead to more efficient and effective recoveries, especially during critical moments while SMART-1 flies through the radiation belts.