GPS micro navigation and communication system for clusters of micro and nanosatellites

Formation flying will quickly revolutionize the way science, remote sensing and surveillance missions are performed in space, enabling a whole new range of applications for small satellites. Currently, there are numerous missions in the planning stages involving formation flying of a constellation of micro or nanosatellites. However, to truly achieve the goals of these formation-flying missions, an accurate means of relative ranging, determining time and position measurements, intersatellite communications, and controlling the formation states is becoming critical. Today, while there are very expensive products available for positioning and attitude determination, none of them are capable of meeting the precise positioning accuracy and attitude determination requirements of formation flying, let alone the mass and power restrictions of these tiny space vehicles. This paper addresses the needs of future formation flying missions by discussing a technology with integrated capabilities for communicating, relative ranging, and exchanging precise timing among spacecraft within the constellation. This system is being developed by integrating a Carrier Phase Differential GPS (CDGPS) navigation sensor with a low power, inexpensive, compact ranging and communications system. The result of this integration is a low-cost, robust, secure GPS micro navigation and communication system for micro and nanosatellite constellations.