Prototype of a Workflow for a Digital Twin in Small Satellite Operations

Kurzfassung

The Digital Twin (DT) is a concept where a physical object is linked to a digital representation of itself. This digital representation consists of the data generated by the real object. This paper presents how a DT could be defined for satellite operations starting from a characterisation from literature. The developed prototype workflow shows exemplarily how a DT can be introduced into satellite operations to achieve a high level of automation and autonomy. This includes to be able to analyse the received telemetry data of a satellite automatically. To demonstrate the proposed architecture and workflow, the NASA Operational Simulator for Small Satellites (NOS3) is used. With NOS3 a satellite can be simulated orbiting the earth. Commands can be sent to the satellite and telemetry is received from it. A simulation model for the Electrical Power System (EPS) including solar panels and battery was implemented into NOS3. The resulting telemetry of the EPS is analysed automatically by a machine learning algorithm, which was trained with data for nominal operation of the EPS. In a first step, a failure of a solar panel is introduced to simulate incorrect behaviour of the satellite. Using the implemented architecture of the DT, the satellite telemetry is analysed and the abnormal behaviour of the satellite is detected. A prepared command is sent to the satellite. In comparison to an onboard fault detection, isolation, and recovery mechanism, the anomaly detection can identify the anomaly without a limit of a parameter is violated. This first prototype shows how the automation workflow with a DT can be implemented and tested for small satellite operations.