Gradient-index solar sail and its optimal orbital control

Solar sails with the capability of generating a tangential radiation pressure at sun-pointing attitude, such as refractive can provide more efficient methods for attitude and orbital control sailcraft. This paper presents concept gradient-index sail an advanced class sail, which operates by guiding solar through structure made graded index material. The design sail's distribution is performed transformation optics, resultant realized effective non-resonant bulk metamaterials silica. performance was evaluated using ray tracing broad spectrum under normal incidence angle, showed efficiency 90.5% generation pressure. We also studied tangential-radiation-pressure-generating sails, that full control, including modification axes, eccentricity, inclination be applied changing merely around sun-sail axis, while keeps every point orbit.