Numerical Simulation of the Lunar Polar Environment: Implications for Rover Exploration Challenge

• Published in: Aerospace
• Main Authors: Hong Gan, Chengxuan Zhao, Guangfei Wei, Xiongyao Li, Guojun Xia, Xiao Zhang, Jingjing Shi
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2023
• Subjects: lunar south pole; illumination condition; electric-field environment; Chang’E-7; lunar rover; Motor vehicles. Aeronautics. Astronautics; TL1-4050; South Pole; South pole
• Online Access: https://doi.org/10.3390/aerospace10070598; https://doaj.org/article/53c55854935e41ae9cc27d5496fd3a70

The lunar polar regions are key areas for future exploration due to the long-term continuous illumination and persistently shadowed regions that can cold trap abundant water and other volatiles. However, the complex terrain, dynamic lighting, and solar wind-induced electric-field environment present multiple challenges for polar investigation and sampling missions. China’s Chang’E-7 (CE-7) will explore the Moon’s south polar region in 2026. One of the scientific goals is to drill samples in a wide area with a rover for in situ analysis. This study analyzes the engineering constraints of the polar illumination condition, slopes, and electric field for landing and sampling-site selection. Then, we create a 3D model of CE-7’s lunar rover in three operating environments by employing the Spacecraft Plasma Interaction Software, with the rover sampling (i) on a flat surface, (ii) in a shadow, and (iii) near a meter-scale crater under different solar altitude angles. The results show that the rover can be charged to different potentials under the combined effects of solar wind incident angles and surrounding terrains. We find that a favorable traversing and/or sampling site of the rover for future polar exploration is in the upwind direction of a bulge (positively elevated terrains, such as the lander or boulders) or crater, which will cause a minimum charging effect on the rover. Our results have important implications for minimizing the risk of charging effects and guiding the lunar polar region exploration.