Space-based free-space optical communication requires precisely coordinating the pointing of multiple subsystems. In order to manage the control interfaces and dynamics of evolving actuators and sensors, and their design limitations, a dedicated control unit has been developed and is presented in this work: the Master Attitude Controller. It facilitates integration of the satellite’s attitude determination and control system with the optical communication payload. Additionally, it incorporates an on-board inertial measurement unit to enhance the accuracy of attitude knowledge during the acquisition phase. In the subsequent tracking phase, it uses control allocation to distribute the control effort among all effectors.