Guidance Summary and Assessment of the Chang’e-3 Powered Descent and Landing

On 14 December 2013, Chang’e-3 successfully touched down on the surface of the moon, setting off its roaming exploration activities. Before this significant step, years of design, development, and testing of the Chang’e-3 powered descent and landing guidance, navigation, and control system were conducted to prepare for the most challenging robotic spacecraft landing endeavor attempted on the moon to date. In this paper, the mission and system design of Chang’e-3 are first described. Then, the guidance algorithms of powered descent and soft landing are summarized and assessed in detail. The powered descent and landing guidance technologies developed for Chang’e-3, including autonomous hazard detection and avoidance, lay the critical foundation for future lunar pinpoint soft-landing missions.