Spacecraft Attitude and Reaction Wheel Desaturation Combined Control   Method
  Two popular types of spacecraft actuators are reaction wheels and magnetic torque coils. Magnetic torque coils are particularly interesting because they can be used for both attitude control and reaction wheel momentum management (desaturation control). Although these two tasks are performed at the same time using the same set of actuators, most design methods deal with only one of the these tasks or consider these two tasks separately. In this paper, a design with these two tasks in mind is formulated as a single problem. A periodic time-varying linear quadratic regulator design method is then proposed to solve this problem. A simulation example is provided to describe the benefit of the new strategy. 
Yaguang Yang
math.OC