Solar radiation pressure used for formation flying control around the Sun-Earth libration point (Q735324)

The goal of this paper is to describe a control algorithm that permits a formation of two satellites to orbit the L2 libration point in the perturbed Earth-Sun system. This problem has been addressed several times in the past, but the main difficulty has been that tight formations require av ery low thrust (less than 3.5 nano Newtons). The authors of this paper suggest the use of solar sails and provide a corresponding control algorithm. Pressure from the solar wind is one of the main perturbations of motion near the libration point, and the direction of the solar wind is restricted to a certain range. The authors determine that not all two-sattelite formations can be controlled by solar sails, but they identify the formations that are feasible. They also provide control schemes and describe the resulting dynamical behavior. The authors' analysis is based on a circular restricted three-body problem model and a simple model of the solar sail. The control algorithm they use is based on an input feedback linearized method. Simulation results are provided to illustrate the control system's performance.