Station-keeping strategy for real translunar libration point orbits using continuous thrust

In this paper, we investigate the station-keeping strategy for translunar libration point orbits (LPOs) using the continuous thrust in the ephemeris model. Ephemeris models with and without the solar radiation pressure (SRP) are proposed for the numerical simulation. Three kinds of translunar LPOs, including halo orbits, vertical Lyapunov orbits, and Lissajous orbits, are used as nominal orbits. A station-keeping strategy based on the backstepping technique is extended to the ephemeris model. Then station keeping under practical constraints, caused by the navigation system and the executive system, is studied in ephemeris models with and without the SRP. Using numerical simulations, influences of the dead-band scheme, navigation errors, the navigation interval time and the area-to-mass ratio on station keeping are discussed, respectively. Furthermore, numerical simulations indicate that if the SRP is taken into account, LPOs obtained in the ephemeris model with the SRP is more preferable as nominal orbits than those without the SRP. More Monte-Carlo simulations testify that our control strategy can be applied to the long-term station keeping for different translunar LPOs.