Optimal Solar Sail Phasing Trajectories for Circular Orbit

The article discusses the performance of a small (ideal) solar sail subjected to a piecewise constant steering law, comparing its effectiveness with a situation in which a chemical (high-thrust) propulsion system is employed to perform the same maneuver. The two-dimensional repositioning problem of an ideal solar sail has been discussed in an optimal framework. Starting from a circular heliocentric parking orbit, an analytical expression for the optimal steering law was derived using an indirect approach, under the assumption that the spacecraft equations of motion may be described through a linear approximation. The available results have been collected within suitable tables to obtain a simple and accurate estimate of the obtainable performances that link the flight time and the phase angle for a given value of the sail lightness number.