In the early morning of November 24, 2020, the Chang'E 5 lunar probe was launched from the Wenchang Space Launch Center and successfully executed a 23-day journey of lunar sample return (LSR) mission. In a review paper recently published in Space: Science & Technology , Dr. Zhong-Sheng Wang and his colleagues from the Beijing Institute of Spacecraft System Engineering, addresses three key orbit design technologies in the Chang'E 5 mission, including orbit design for lunar orbit rendezvous and docking (RVD), orbit design for precision lunar landing and inclination optimization, orbit design for Moon-to-Earth transfer.
First, an overview of the Chang'E 5 mission profile is presented. The Chang'E 5 spacecraft was composed of four modules: an orbiter, a lander, an ascent module, and a reentry capsule. After the spacecraft completed a 112-hour Earth-to-Moon transfer, two lunar orbit insertion (LOI) maneuvers were conducted within a one-day interval between the two LOIs, followed by the process of which the spacecraft entering a near-circular lunar orbit with an altitude of approximately 200km. After approximately 8 hours, the lander and ascent module assembly was separated from the orbiter and reentry capsule assembly. Approximately one day after the second LOI, the lander and ascent module assembly performed two consecutive descent maneuvers (DM) in order to lower its perilune altitude to 15km. One day after the DMs, the assembly made a powered descent to land at the expected location in the Storm Ocean.
After landing process, the lunar sample collecting operation was conducted. Two days later, the ascent module was launched from the lunar surface. Within only two days, four maneuvers were conducted by the ascent module before the initial aim point was achieved, when the ascent module was flying in a 210km×210km circular orbit, 50km ahead of the orbiter along-track. The orbiter also performed four phasing maneuvers between the separation of the two assemblies and the lunar launch, in order to ensure that it arrived at the desired orbital location at the prescribed time of the initial aim point. The far-range, close-range, and docking operations were completed in approximately 3.5 hours after the initial aim point, followed by the transfer of the lunar sample from the ascent module to the reentry capsule. Subsequently, the ascent module was separated from the orbiter and reentry capsule assembly and eventually collides with the Moon surface, whereas the assembly continued to fly in a circular lunar orbit of altitude 210 km. After approximately 5-6 days, two trans-Earth insertion (TEI) maneuvers were conducted with a one-day interval between them, and the orbiter and reentry capsule assembly enters the Moon-to-Earth transfer orbit. After 4-5 days, the reentry capsule was separated from the orbiter, reentered the atmosphere, and shortly landed in the chosen landing field of Inner Mongolia.
Afterwards, Dr. Wang focused on three main challenges in the orbit design for the precision lunar landing, the lunar orbit rendezvous and docking and the Moon-to-Earth transfer.
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Reference
Author: Zhong-Sheng Wang, Zhanfeng Meng, Shan Gao, and Jing Peng
Title of original paper: Orbit Design Elements of Chang'E 5 Mission
Article link: https://spj.sciencemag.org/journals/space/2021/9897105/
Journal: Space: Science & Technology
DOI: 10.34133/2021/9897105
Affiliations: Beijing Institute of Spacecraft System Engineering, China Academy of Space Technology
About Dr. Zhong-Sheng Wang
Dr. Wang received his PhD in Aerospace Engineering from the University of Cincinnati in 2001. Dr. Wang had been teaching engineering mechanics at Embry-Riddle Aeronautical University (Daytona Beach) from 2003 to 2011, and was promoted to Associate Professor in 2009. Since 2011, Dr. Wang has been working on orbit and mission design of Moon, Mars and asteroid missions as a senior space engineer at Beijing Institute of Spacecraft System Engineering.
Space: Science & Technology
Data/statistical analysis
Not applicable
Orbit Design Elements of Chang’e 5 Mission
16-Nov-2021
The authors declare that they have no conflicts of interest.