New Design and Stability Analysis of Gravity Stabilized Solar Sail in Earth Orbit

A new solar sail model that can be controlled passively using gravity stabilization and black-coating was designed. In this paper, a long boom with a tip-mass was used to realize gravity-gradient stabilization when a solar radiation pressure (SRP) was applied. The solar sail does not require extra controllers or fuel sources to maintain proper attitude for orbit raising schemes. In an orbit mission, attitude dynamics and control analysis of a solar sail are critical issues for successful performance. This paper investigated analytically and numerically the stability of 1-dof pitch motion of the solar sail model. Ignoring the SRP and conducting analytic interpretation, among the four equilibrium points of the solar sail, the solar sail was marginally stable in the standing attitude aligned along the direction of gravity or in the standing attitude upside down. The computation, including an SRP, showed that the state near two of the four equilibrium points (standing attitude and standing attitude upside down) were oscillating within a certain boundary if the perturbation was small and stable. The validation was verified by checking the phase portrait and the power spectral density. The simulation of 3-dof orbit demonstration mission of the presented model with translation motions shows the result of increased orbital altitude change, implying the feasibility of mission performance.