Satellite Formation Flying Initial Configuration Maintenance Using Impulsive Maneuvers

On-orbit service missions are increasingly gaining interest among the aerospace community, driven by a growing commercial space sector that has developed a market for servicing Earth-orbiting satellites. Such missions may require a formation of satellites to maintain a precise shape with mission-appropriate tolerances, depending on the tasks to carry out. Indeed, over the past two decades, space agencies have questioned the need to use single platforms with a high level of complexity, which is not always associated with a high degree of reliability, a key driver in any space mission. Several studies have shown that spacecraft formations can perform tasks previously accomplished with single space platforms, often large and complex, but employing smaller satellites and therefore significantly lower costs. Spacecraft formation flying consequently represents an emerging technology with high potential for future commercial and scientific space missions. The purpose of this work is the analysis of a formation of four satellites (deputies) in a tetrahedral configuration, orbiting around a main spacecraft (chief). The formation is deployed in a circular Low Earth Orbit (LEO), at an altitude of 350 km. In order to perform scientific or commercial tasks, the formation is required to maintain its original shape as unaltered as possible. It is therefore necessary to apply periodic impulsive maneuvers for each deputy individually to counteract the natural dynamics of the spacecraft. In this regard, an algorithm has been developed to determine the best set of initial conditions, able to guarantee the lowest amount of deconfiguration. Orbital perturbations such as J2 and atmospheric drag were also taken into account to perform more accurate simulations. In the last part of the work, an analysis was conducted in order to observe the effects of variation in altitude or formation size. This thesis work is the result of an internship conducted in collaboration with NASA's Jet Propulsion Laboratory.