Design of line-of-sight guide law for small body high speed impactors

A Line-of-Sight(LOS) guide law is designed for small body high speed impactors. Error ellipse on the B-plane is utilized to describe confidence level of the predictive intercept point for solving the problem of the trajectory correction maneuvers execution selection. Then, the trajectory correction maneuvers execution timing is translated into design of switching curve through guiding the intercept point into appointed error ellipse. The rotation velocity and distance variety ratio are constructed by using impactors' position and velocity and the engine is driven to enable impactors to reach the aim point by restraining Line-of-Sight rate. The results of strict Monte Carlo simulations show that this guide law improves on predictive guide law in the impact precision upward of 100 meter, and maximal impact error is less than 250 meter, simultaneously economizing fuel.