Two-impulse transfer orbits connecting equilibrium points of irregular-shaped asteroids

The transfer orbits connecting equilibrium points of irregular-shaped asteroids are studied. A new method is proposed to generate the transfer orbits connecting any two equilibrium points near an arbitrary irregular asteroid. This new method has three steps, including the approximate searching, the first transfer orbit correction and the flight time continuation. Specially, this method is applied to the asteroid 433 Eros and all twelve families of transfer orbits connecting every two of its four equilibrium points are founded in its vicinity. The results indicate that the tendency of the total velocity-increment with respect to the flight time is decreasing and the transfer orbits with the lowest total velocity-increment have the longest flight time in each family. Besides, the velocity-increments required for transferring between two equilibrium points can be larger than the one obtained by the difference of the orbital energy. Moreover, four minimum-velocity-increment tours of equilibrium points starting at each equilibrium point are obtained by patching the generated transfer orbits and the minimum-velocity-increment tour cost about 18 m/s.