Light-Levitated Geostationary Cylindrical Orbits Are Feasible

摘要

This paper discusses a new family of non-Keplerian orbits for solar sail spacecraft displaced above or below thernEarth’s equatorial plane. The work aims to prove the assertion in the literature that displaced geostationary orbitsrnexist, possibly to increase the number of available slots for geostationary communications satellites. The existence ofrndisplaced non-Keplerian periodic orbits is first shown analytically by linearization of the solar sail dynamics aroundrna geostationary point. The full displaced periodic solution of the nonlinear equations ofmotion is then obtained usingrnaHermite–Simpson collocationmethodwith inequality path constraints.The initial guess to the collocationmethod isrngiven by the linearized solution, and the inequality path constraints are enforced as a box around the linearizedrnsolution. The linear and nonlinear displaced periodic orbits are also obtained for the worst-case sun-sail orientationrnat the solstices. Near-term and high-performance sails can be displaced between 10 and 25 km above the Earth’srnequatorial plane during the summer solstice, and a perforated sail can be displaced above the usual station-keepingrnbox (75 u0001 75 ) of nominal geostationary satellites. Light-levitated orbit applications to space solar power are alsornconsidered.