Solar Sail Body-Fixed Hovering over Elongated Asteroids

Solar sail spacecraft are proposed to accomplish body-fixed hovering missions over elongated asteroids. The body-fixed hovering flight is to maintain a fixed position relative to the surface of the spinning asteroid. A solar sail without fuel consumption can greatly expand the range of hovering locations in a variable lightness number for an extended period. A rotating mass dipole is used to produce the gravitational field created by an elongated asteroid. Dynamic equations are obtained for the approximate model in terms of the specified hovering conditions. Feasible hovering regions over elongated asteroids are presented and analyzed via numerical simulations. A parametric study is made to investigate the influence of solar latitude angles and the lightness number on the feasible hovering region. The hovering orbits around the realistic asteroid 951 Gaspra are performed to evaluate the effectiveness of the method in this paper.