Abstract:
According to the requirements of near-Earth Asteroid kinetic impact mission, an autonomous GNC scheme is proposed, which contains the high-precision extraction method for the line of sight (LOS) of the asteroid center, high-precision autonomous relative navigation based on LOS measurement of the asteroid center, and iterative prediction guidance method. In this scheme, the LOS measurement of the asteroid center is used to estimate the relative position and velocity between the impactor and the asteroid in the direction perpendicular to the LOS. Although the elative position and velocity errors along the LOS are not estimated, the high-precision impact can be realized by the iterative prediction guidance method. The mathematical simulation shows that the proposed scheme can ensure the impactor to hit a near-Earth asteroid with the diameter 50 meter, the impact accuracy is better than 4 meter, which meets the mission requirements.