Design of high-accuracy Δ vega trajectory for Ivar asteroid exploration mission

Near earth small body exploration is one of the most sophisticated mission currently investigated in the world. An impending demand for exploring the small bodies such as comets and asteroids urged the Chinese Deep Space exploration mission to the near Earth asteroid Ivar. A design of high-accuracy Δ VEGA trajectory for Ivar asteroid is discussed in this paper. Ivar asteroid exploration mission analysis requires determination of a Δ VEGA trajectory for which the trajectory of the spacecraft with respect to some central body also involves close flyby of one of satellites of the central body. The whole trajectory is divided into several trajectory segments. Each trajectory segment connecting consecutive maneuver points is found by solving an N-body analog to Lambert's problem. We can also obtain state transition matrix of each trajectory segment, which will be used to optimize the trajectory. By adjusting the launch time, the arrival asteroid time, the swingby time and the periapsis position relative to the gravitating body with a quasi-Newton algorithm, the total Δ V could be reduced. In the mentioned algorithm, first order derivatives will be used, which derived from the state transition matrix of each trajectory segments. Finally several analyses of the designing result are given.