Mitigating plume surface interactions using lunar craters

Launching and landing spacecraft on the lunar surface mobilizes regolith at high velocities which will likely cause damage to nearby objects and infrastructure, a phenomenon known as plume surface interactions (PSIs) that must be mitigated for sustainable lunar surface exploration. While some mitigation strategies prescribe the construction of walls and landing pads using locally sourced regolith and additive manufacturing techniques, cheaper and more immediately available approaches may be required. We introduce a novel concept that uses small lunar craters (<1.5 km) as unprepared landing sites to mitigate the hazards posed by PSIs. We simulated the ballistic trajectories of regolith grains ejected by PSIs from the centers of 238 lunar craters and find that many could completely shield nearby areas from ejected regolith, with some of these protected "umbrella zones" being large enough to host either a 16 m-tall Blue Moon Mk. 2 lander or a lunar outpost. These examined craters are also conducive to safe landings as they retain sufficiently large and flat crater floors, as well as crater walls that are traversable by the Artemis program's proposed Lunar Terrain Vehicle. However, much work remains for this approach to be fully relied upon as a mitigation strategy.