Nonlinear adaptive backstepping design for spacecraft attitude control using solar radiation pressure

Spacecraft and interplanetary probes orbiting at high altitudes experience forces due to solar radiation pressure, which can be used for maneuvering. This paper treats the question of large angle pitch attitude maneuvers of satellites using solar radiation torque. For pitch axis maneuver, two highly reflective control surfaces are used to generate radiation moment. Based on a backstepping design technique, a nonlinear adaptive control law is derived for the control of the pitch angle. In the closed-loop system, the pitch angle asymptotically tracks prescribed reference trajectories. Simulation results are presented to show that the adaptive control system accomplishes attitude control of the satellite in spite of the parameter uncertainties in the system.