ON ORBIT DESIGN AROUND A MICRO GRAVITY ASTEROID

摘要

The interest of exploring small body has been growing over these years, especially the near Earth asteroids which have potential threat to the Earth. The masses of the asteroids are mostly very small compared with that of the planets, so the asteroids’ central gravity is too small to have the probe orbit them directly all the time. Therefore, it is necessary to study the orbits around a micro gravity asteroid. In the paper, two kinds of nominal orbits are proposed. One is the quasi-period orbits around the collinear libration point; the other is the formation flying orbits around the asteroid. Due to the inevitable existence of errors, station keeping of the probe is necessary. Solar sails propulsion is used to provide station-keeping at nominal orbits. There are two control techniques including solar sail area variation and solar sail pitch and yaw angle variation considered. Also optimal control laws are used to minimize the control requirements in this paper. Finally, the control results are displayed.