Extensive Lunar Surface Disturbance at the Chang'e-5 Mission Landing Site: Implications for Future Lunar Base Design and Construction

Lunar surface disturbances by spacecraft engine jets are of particular concern in the current new phase of lunar exploration, when dozens of landing missions and permanent bases are being planned. Some of these exploration efforts will involve multiple landings and liftoffs around the same lunar site; thus, it is essential to evaluate their effect on astronauts and assets on the lunar surface. Here, we assess the surface disturbances during the Chang'e-5 landing and liftoff procedures through the photometric analysis of high-resolution multi-temporal surface and orbital images. Centimeter-scale surface images reveal a four-stage evolution of the landing plume impingement over a period of similar to 50 s, which involves phenomena such as dust devils and streaks, and displacement of cobbles. Temporal-ratio calculation of orbital images (including one acquired between landing and liftoff) enables the first direct observation of ascent plume effects. The ascent blast zone consists of two separated sub-areas (similar to 3,400 km(2) in total), which is nearly twice larger than that of the landing blast zone. The final disturbed surface is characterized by a central main zone (similar to 2,300 m(2)) surrounded by a marginal diffuse zone (similar to 15,300 m(2)). Phase-ratio analyses suggest that plume impingement destroys the micro-porous structure of the uppermost regolith. We estimate that future lunar landers (e.g., SpaceX's Starship) may cause significant lunar surface disturbances over an area of square kilometers. Our results provide unique insights into Chang'e-5 mission activities, and instructive references for the planning of future lunar endeavors, including the design and construction of surface experiment packages and permanent lunar bases. Plain Language Summary When spacecraft land on or liftoff from the lunar surface, the release of huge volumes of gases from retrorocket engines significantly disturbs the lunar surface beneath it. These surface disturbance effects are of particular concern as several landing missions and permanent lunar bases are being planned. It is necessary to evaluate how people and instruments will be affected by these disturbances. Here, we study the surface modifications at the Chang'e-5 mission landing site using high-resolution surface and orbital images. Centimeter-scale Chang'e-5 images reveal dramatic surface phenomena during the landing procedure over a period of similar to 50 s, including dust devils and movements of cobbles. Orbital images obtained at different times enable the first direct observation of surface disturbances during liftoff, which are unexpectedly about twice more extensive than those during landing. The final disturbed surface is composed of a central main zone and a marginal diffuse zone. We predict that future lunar landers (e.g., SpaceX's Starship) may disturb the lunar surface over an area of several square kilometers. Our results provide unique insights into an understudied aspect of the Chang'e-5's mission, and important references for future lunar explorations, including the design and emplacement of lunar surface instruments and permanent lunar bases.