Validation of the Galileo scan platform control design using DISCOS

The flexibility of the Galileo spacecraft's scan platform control system stator structure, which lies between the scan platform and one of the control actuators, has been a major design consideration. Tests have been conducted to verify the prevention of undesirable interactions between the structure and the control loop, by means of the Dynamic Interaction Simulation of Controls and Structure (DISCOS) program. The scan platform's control design has been validated for the achievement of 140-microradians maximum position deviation and 50 microradians of jitter over 1-sec intervals.