Natural and non-natural spacecraft formations near the L₁and L₂libration points in the Sun–Earth/Moon ephemeris system

Space-based observatory and interferometry missions, such as Terrestrial Planet Finder (TPF), Stellar Imager, and MAXIM, have sparked great interest in multi-spacecraft formation flight in the vicinity of the Sun–Earth/Moon (SEM) libration points. The initial phase of this research considered the formation keeping problem from the perspective of continuous control as applied to non-natural formations. In the present study, closer inspection of the flow corresponding to the stable and centre manifolds near the reference orbit, reveals some interesting natural relative motions as well as some discrete control strategies for deployment. In addition, some implementation issues associated with discrete formation keeping of natural versus non-natural configurations are addressed in the present study.