Optimal spin rate control of a spinning solar sail for orbital inclination change

Abstract

Solar sails are a form of spacecraft which deploys a large sail in space and uses solar radiation pressure for propulsion. They are expected to be a promising technology for future deep space exploration since they do not require any propellant for propulsion. It is known that the spin-axis direction of a spinning solar sail rotates around an equilibrium direction near the Sun direction due to the effect of solar radiation pressure. This attitude motion can be controlled by the spin rate of a spacecraft. Since the solar radiation pressure force on the sail, hence the acceleration of the spacecraft, is dependent on the attitude with respect to the Sun, the orbit of a spinning solar sail can be controlled indirectly by the spin rate. In this paper, the spin rate control of a spinning solar sail for orbital inclination change is investigated. It is assumed that a spacecraft is initially in a circular orbit around the Sun in the ecliptic plane, and the orbital inclination is maximised by spin rate control.