Design Drivers for Formation Flying Near Collinear Libration Points in the Circular and Elliptic Restricted Three-Body Problems

The study of formations of spacecraft in a three-body environment represents one of the most promising challenges for future space mission design. Two or more cooperating spacecraft can greatly answer some very complex mission goals, not achievable by a single spacecraft. In addition, the dynamical properties of a low acceleration environment such as the vicinity of libration points associated to a three-body system, can be effectively exploited to design spacecraft configurations able of satisfying tight relative position and velocity requirements. This work studies the evolution of an uncontrolled formation orbiting periodic orbits about collinear libration points under the Circular and Elliptic Restricted Three-Body Problems. A three spacecraft triangularly-shaped formation is assumed as a representative geometry to be investigated. Initial configurations, which provide good performance in terms of formation keeping, have been investigated and key parameters, which mainly control the formation dynamics within the three-body system, have been identified. Formation keeping performance is quantified by monitoring shape and size changes of the triangular formation. The analysis has been performed under five degrees of freedom to define the geometry, the orientation and the location of the triangle in the synodic rotating frame.