1 Overview of Chang'e-5 project
As the final step of the"three-step"development strategy(i.e.,orbiting,landing and sample returning)of the Chinese Lunar Exploration Program,the Chang'e-5 project aims to achieve moon surface sampling and retrieving for the first time in China.It was initiated with the approval of the State Council in January 2011.Through nearly a decade of conceptual design,prototype development and flight model development,the Long March 5 launch vehicle and a totally new probe composed of a lander,an ascender,an orbiter and a re-entry capsule,have been developed.Ground-based facilities such as the comprehensive test site for landing and take-off,the sampling and sealing ground test facilities,the Argentina 35 m deep-space station,the re-entry radar,and the lunar sample laboratory,have been constructed.Hence,China has the ability to fulfill the lunar sample return mission(Pei et al.,2015).