Crater Profile Roughness Tool That Predicts PSI Physics

Gaseous or solid impactors can disrupt the regolith-covered surfaces of small bodies or the moon, causing extensive surface modification and posing a severe risk to on-surface structures. Gas-granular plume surface interactions (PSI) cross multiple physics regimes, featuring a mixture of viscous (Navier-Stokes assumptions are valid) and rarefied flow (particle-particle collisions dominate; the plume behaves as a granular gas), high turbulence, and fluidization of the soil. Understanding the behaviors of these granular materials in vacuum and microgravity environments is vital for mitigation of unwanted plume surface interaction effects. This proposal focuses on developing the innovative use of crater profile roughness as an indicator of the PSI physics behaviors and regimes at play during any given landing scenario. Development of this model in 2D (Phase I), expansion into 3D space (Phase II), and development of a software product (“Lunar CPR”) to allow access to this data for commercial applications and NASA missions (Phase III) will result in a robust model (Phase I-II) and tool (Phase III) which can be used to predict the PSI physics of cratering and surface erosion in low-pressure and rarefied environments. This tool, validated with experimental data, will allow customers to access geotechnical properties of landing zone regolith, only requiring (a) information about the lander such as thrust, descent rate and height over time, and total mass, and (b) a camera capable of imaging the surface, both of which are available for historical landings of record and will be available for any future commercial or private landers. Much like the maps referenced when building on Earth, this data would allow for creation of geotechnical maps vital for making informed geoengineering decisions on the Moon or remote locations on Earth.