Solar Sail Hybrid Trajectory Optimization for Non-Keplerian Orbit Transfers

SOLAR sails have long been seen as an attractive concept for low-thrust propulsion.They transcend reliance on reaction mass and have the ability to provide a small, but continuous, acceleration. Because propellant mass is not an issue, high-performance sails can enable new exotic non-Keplerianor bits (NKOs)1 that are not feasible for conventional chemical or electric propulsion.A constant out-of plane sail force is utilized to raise the spacecraft's orbit high above the ecliptic plane in two- or three-body systems. Potential beneŽfits to the science community are large. Circular, displaced orbits can be used to provide continuous observation of the solar poles or to provide a unique vantage point for infrared astronomy. (There is much less resolution-limiting dust out of the ecliptic plane enabling smaller telescope mirror dimensions for equivalent performance.) Very high performance sails can even levitate, in equilibrium, at any point in space.