Formation flying along unstable Libration Point Orbits using switching Hamiltonian structure-preserving control

Orbits for spacecraft formation flight along an unstable orbit are designed. The Hamiltonian structure-preserving (HSP) control is used to stabilize the motion of the spacecraft. Using a simple switching control strategy, the size of a circular orbit relative to a nominal trajectory can be systematically designed. To perform station-keeping of a spacecraft, the proposed HSP control is repeatedly applied. The nonlinear stability of the controller is also analyzed using Lagrange-Dirichlet criterion. To demonstrate the performance of the proposed switching HSP controller, a numerical simulation is performed for the formation flight of the spacecraft in Earth-Moon system's L-2 halo orbit.