Solar sail formation flying around displaced solar orbits

The characteristics of the relative motion around a displaced solar orbit are discussed and the control strategies are proposed by linearizing the equation of motion in the vicinity of a displaced solar orbit. Based on linearized equation, two types of formations, seminatural and controlled formations are discussed that are performed with only sail attitude variations, to meet special demands on the relative orbit configurations. The relative stability for seminatural formations is defined as a follower stays in the vicinity of the leader, and neither diverges from nor converges to it. The obtained formations shows that the normal vector of the follower sail is always the same as that of the leader, which is assumed to be constant vector in the rotating frame. The formation configurations of the seminatural formations are found to depend on the leader's orbit.