The plume-surface interaction that occurs as a result of a variable-thrust engine exhaust plume impinging on soil during landings is critical for future lunar mission design. Unique lunar environmental properties, such as low gravity, high vacuum, and the regolith layer, make this study complex and challenging. In this paper, we build a reliable simulation model, with constraints based on landing photos, to characterize the erosion properties induced by a low-thrust engine plume. We focus on the low-thrust plume-surface erosion process and erosion properties during the Chang’E-5 mission, aiming to determine the erosion difference between high- and low-thrust conditions; this is a major concern, as the erosion process for a low-thrust lunar mission is rarely studied. First, to identify the entire erosion process and its relative effect on the flat lunar surface, a one-to-one rocket nozzle simulation model is built; ground experimental results are utilized to verify the simulated inlet parameters of the vacuum plume flow field. Following that, plume flow is considered using the finite volume method, and the Roberts erosion model, based on excess shear stress, is adopted to describe plume-surface interaction properties. Finally, a Lagrangian framework using the discrete phase model is selected to investigate the dynamic properties of lunar dust particles. Results show that erosion depth, total ejected mass, and the maximum particle incline angle during the Chang’E-5 landing period are approximately 0.2 cm, 335.95 kg, and 4.16°, respectively. These results are not only useful for the Chang’E-5 lunar sample analysis, but also for future lunar mission design.

It was suspected that the horizon glow observed over the lunar terminator was caused by electrostatically‐levitated dust particles, but do high concentrations of dust particles really exist over the lunar terminator? This is an important question that cannot be answered even today. In fact, no in‐situ investigations about the lunar dust have been conducted on lunar surface since Apollo. Here we first report in‐situ investigations of lunar dust at Chang’E‐3 (CE‐3) landing site using solar cell probe (SCP). The results show that, different from Apollo’s observation, the short‐circuit current of SCP did not decrease sharply during the first several lunations except the first lunation, indicating the recently developed minimalist qualitative model of sunrise‐driven dust transport might not be applicable at the geologically young CE‐3 landing site. In addition, within detector’s detection limit, no abrupt changes in dust concentration were observed above the sharp sunlight/shadow boundaries on lunar surface.

The intensity of low-energy cosmic rays on the lunar farside is consistent with that observed in the near-earth space.