A family of low-cost transfer orbits for rendezvous-type missions to NEAs

Abstract

AbstractWe develop a family of transfer orbits suitable for the peculiarity of NEAs orbits. They involve one or more carefully planned deep-space maneuvers and one or more close encounters with the Earth. Basically, it is a gravity assist technique, but only Earth is used as the driving planet. In this manner, the orbit of the spacecraft stays near the Earth, as the orbits of NEAs. The idea is to obtain a large relative velocity in respect to the Earth, using these impulsive maneuvers. Next, successive rotations of this relative velocity vector due to resonant encounters with the Earth will, finally, shape the orbit of the spacecraft, in order to match the inclination and the orientation of apsidal line of the asteroid's orbit.With a velocity budget less than 9 km/s most of NEAs orbits are reachable, even highly inclined ones, or orbits with relatively large nodal distances. An example is given: a rendezvous mission to asteroid (1036) Ganymed.