Challenges in Control and Autonomy of Communications Satellites

Abstract The rapid growth, predicted in space communications stimulated ideas beyond present solutions. In addition to geosynchronous satellites, which presently carry nearly all space transponders in use, new low and intermediate orbit constellations of satellites and even constellations in eccentric orbits are in design and planning. The paper gives an overview of this scenario to derive the new and challenging requirements on the satellites attitude and orbit control system (AOeS) and presents solutions, based on examples from current projects. For the first time, commercial AGCS have to be produced in series and the technologies employed are driven equally by performance, quality and effort (cost and schedule). With the high number of satellites, to be operated simultaneously in constellations, on-board autonomy with minimum ground intervention during operation becomes a “must”. This concerns nominal operation as well as reconfiguration and repair in case of failures. New methods for autonomous failure management, and autonomous orbit detennination and station keeping are therefore a central subject of the paper.