Relative Attitude Dynamics and Control of Spacecraft Using Electrostatic Torque

Recent years have seen an increased interest in spacecraft formation flying, with many applications requiring that the members of these formations maintain specific relative attitude configurations. One low-cost method that has been considered to accomplish this is the use of electrostatic torques, which are generated by charging the surfaces of involved spacecraft to allow interaction without physical contact. The research presented in this thesis analyzes a pair of cylindrical-bodied spacecraft operating in deep space. Specifically, the suitability of using electrostatic torques as an actuator to synchronize the two spacecraft\u27s attitude responses is under consideration. The study considers a simplified case, wherein the two spacecraft are restricted to rotate in a single plane, as well as a more practical case where the two are allowed to freely rotate in three dimensions about their centers of mass. These cases are primarily investigated to develop suitable control laws to accomplish the attitude synchronization between the two spacecraft. Additionally, the actuator dynamics required to implement one of these controllers are developed and simulated, in order to investigate the practicality of using the controller in question. Based on the findings of this study, the system was found to be controllable with the presented control laws. In addition, the actuator dynamics required to implement one of these control laws were developed and simulations show that much of the control can be accomplished with small changes in the actuating spacecraft charge. However, with the currently-considered 3D controller in the case that was simulated, the required actuator dynamics are too aggressive at one point for a practical device to accomplish the charging. Thus, future work may consider other 3D control laws