THE ATTITUDE AND ORBIT CONTROL SUBSYSTEMS AND THE ANTENNA POINTING PERFORMANCE OF THE SESAT SPACECRAFT

摘要

This paper describes the SESAT Attitude Determination and Control subsystem and Propulsion subsystem. It describes the ADCS and associated equipment, the ADCS operational modes (including antenna mapping mode), key performance parameters and an overview of ADCS dynamic testing. The SESAT satellite is three axis stabilized during all phases of the mission and has two fixed (deployable) antennae and one steerable antenna. The ADCS is based on a standard configuration of sensors (earth sensor, sun sensor, precise gyroscope) and a momentum bias reaction wheel, mounted on two degrees of freedom gimbals, as the nominal actuator. Electric plasma thrusters are used for station keeping, hydrazine thrusters for attitude control.