Motion modeling and formation form analysis of spacecraft near collinear libration points

To meet the increasing research demand for deep space exploration, especially for the second libration point (L₂) conditional periodic orbit (Halo orbit) in the Sun-Earth system, the methods to get analytical Halo orbit and differential-correction Halo orbit were described firstly, and the corresponding orbits accuracy was analyzed. Then, based on the results of third-order and differential-correction Halo orbits, the formation form was studied. Analysis was carried out to discuss the influence of system amplitude, initial phase, and phase difference on the formation form, as well as that of initial orbit values on form accuracy. Finally, some simulation results demonstrate the validity of the proposed methods.