Small-amplitude Periodic Orbit around Sun-Earth L1/L2 Controlled by Solar Radiation Pressure

Abstract

The L1 and L2 points of the Sun-Earth system attract much attention for various space uses, such as observation and communication. Deploying the spacecraft just on L1/L2 is, however, not convenient, because L1 always overlaps with the Sun as seen from the Earth and L2 is hidden behind the shadow of the Earth. Adopting a small-amplitude periodic orbit around the L1/L2 points is one option to solve this problem. The orbit can be achieved by low continuous maneuvering. The required magnitude of acceleration is at a level that can be managed by solar radiation pressure. Utilizing solar radiation pressure has the possibility of saving maneuvering to keep the spacecraft near a L1/L2 orbit. Acceleration due to solar radiation pressure depends on the surface area of the spacecraft and thus the spacecraft should be equipped with a large flat surface. A spacecraft equipped with a solar sail is appropriate. This paper presents two station-keeping examples of solar sails in the vicinity of SE L1/L2 using acceleration resulting from solar radiation pressure. The orbit control laws are built into the linear system about the equilibrium, and we confirm that they are applicable in the non-linear system through numerical calculation.