Minimum-impact-error correction strategy for [formula omitted]-constrained small-sized asteroid impactor

Abstract

The Asteroid (469219) 2016 HO3, one of the targets of the potential small celestial body missions, is a typical small-sized stable quasi-satellite of the Earth. Compared with the targets of previous impact missions, it is more challenging for a hypervelocity impact on 2016 HO3 due to its much smaller size. Besides, the time durations for autonomous navigation and maneuver correction are greatly narrowed because the impactor can hardly capture the small-sized target until they are close enough. This paper suggests a high-precision autonomous navigation system and proposes a minimum-impact-error correction strategy for the targeting maneuver to solve the challenges. The navigation system utilizes traditional optical navigation assisted by a radar ranging measurement unit, which has been proved of high precision and short convergence time during the approach phase (better than 10 m in 100.0 s). After obtaining the relative positions and velocities, the targeting maneuvers are needed to correct the impactor’s orbit for a final successful impact. Therefore, a minimum-impact-error correction strategy is proposed to determine the optimal number and correction schedule of targeting maneuvers, which can minimize the impact error under the condition that the total velocity increments are limited. In the case of the 2016 HO3 impactor, this paper conducts numerical Monte-Carlo simulations for validation. The results are encouraging, and the proportion of successful impact is above 99.1 percent. The correction strategy proposed in this paper is meaningful for future hypervelocity impact on small celestial bodies.