Solar Pressure Three-Axis Attitude Control

Abstract

The feasibility of two different designs for a three-axis attitude control system is studied for a synchronousorbit communication satellite. The attitude control is achieved by torques generated by sunlight striking a set of lightweight reflective surfaces called solar sails. The design is studied via analysis as well as a computer simulation of the attitude control dynamics. A nominal trajectory for the satellite attitude is defined, and a set of dynamical equations are derived that are linearized about this nominal trajectory. A sensor scheme is proposed for sensing attitude, and this is combined with the linearized analysis to determine the overall dynamical system behavior for the attitude control system. A sensitivity analysis confirms that the design is robust to unknown disturbance torques and initial conditions far from nominal.