Quasi-periodic orbits of small solar sails with time-varying attitude around Earth–Moon libration points

This paper proposes new quasi-periodic orbits around Earth–Moon collinear libration points using solar sails. By including the time-varying sail orientation in the linearized equations of motion for the circular restricted three-body problem (CR3BP), four types of quasi-periodic orbits (two types around L1 and two types around L2) were formulated. Among them, one type of orbit around L2 realizes a considerably small geometry variation while ensuring visibility from the Earth if (and only if) the sail acceleration due to solar radiation pressure is approximately of a certain magnitude, which is much smaller than that assumed in several previous studies. This means that only small solar sails can remain in the vicinity of L2 for a long time without propellant consumption. The orbits designed in the linearized CR3BP can be translated into nonlinear CR3BP and high-fidelity ephemeris models without losing geometrical characteristics. In this study, new quasi-periodic orbits are formulated, and their characteristics are discussed. Furthermore, their extendibility to higher-fidelity dynamic models was verified using numerical examples.