Galileo satellite navigation program

CAN Newsletter June 2007

The Giove experimental satellites are part of the Galileo satellite navigation program of the European Union and ESA (European Space Agency). The electronic control system platform is based on a dually redundant hardware including a redundant CAN-based network. The OBC386 on-board computers are cold-redundant and provide 32 MiB of RAM disk. Typical devices connected to the CAN network are the power system and the propulsion controller. Telemetry and telecommand devices switch between primary and secondary networks, if a look-up condition is detected. The CAN networks links each OBC386 to sensor data (e. g. sun, gyro, and earth-horizon), formatted and generated by the attitude ad orbit-control module. Via CAN the computer controls the actuators (e.g. magnetorquer, wheel, propulsion). ESA has internally released a recommended practice for CANopen in order to achieve a higher degree of plug-and-play functionality.