Satellite attitude control using only magnetorquers

This study presents a method to control the attitude of spacecraft using only magnetorquers without the gravity gradient boom. The main challenge is that the control torque can only be generated perpendicular to the geomagnetic field. If the dynamic model is expressed in the geomagnetic frame, the system can be divided into two parts: the outer loop and the inner loop. The stability of the outer loop controller is proved by LaSalle´s and Floquet´s theorems. The inner loop has devastating disturbance torque. Considering the disturbance torque, the sliding mode controller is designed in the inner loop. The results of the simulation of this method are presented herein