<h2>AAS 99-126</h2>
<h2>Dynamics and Control of Cluster Orbits for Distributed Space Missions                                                                            </h2>
<h4>C.C. Chao, J. Pollard, S. Janson                                                                                                                                                    </h4>
The Aerospace Corporation, Los Angeles, Ca                                                                                                                                
<h2> Abstract </h2>
Space missions in which the payload functions are distributed among several satellites may benefit from the use of cluster orbits where the satellites fly in a tightly locked formation with a relatively small required to maintain the cluster. This paper consists of two parts. Part I describes a method for determining the cluster orbital elements, and the relative geometry and dynamics of satellites under a two-body force field with the secular J2 influence. Part II examines the disruption of the formation due to all the major natural perturbations, and the feasibility of a formation-keeping strategy. The proposed strategy blends four state of the art techniques: differential GPS measurement, micro electromechanical systems, frozen orbits, and auto-feedback control. Results show that it only requires 10 to 30 m/s per year per satellite in to control a 1 km radius cluster for LEO.