THE SILFELA MISSION TO ARISTARCHUS PLATEAU ON THE MOON

Silfela is a low-cost lunar PRISM mission concept designed to study the regolith properties of the Aristarchus Plateau on the Moon. The mission will make use of the PRISM mobility capability (rover) to assess regoliths in two different geological units (mare and highland) on either side of a geologic contact along the edge of the Herodotus E impact crater, along with a fresh ejecta blanket. The instrument suite consists of the SPARTA regolith sampling toolkit, the NIRVSS imager/spectrometer, the NSS neutron spectrometer and a high-resolution hand-lens imager (Heimdall).

Regolith properties foundationally inform on wide-ranging planetary science topics, including surface evolution through impact gardening; erosional processes; the delivery and distribution of water in the inner solar system; the distribution of potential habitable zones; and thermal histories of planetary bodies. Silfela will introduce a standardized set of geomechanical measurements for the bulk and shear strength, dielectric and thermal properties of the near-surface lunar regolith ( to ~15cm depth). These measurements address several goals and questions in the NRC 2007 report and in the 2022 Decadal Survey. Silfela will study crustal composition, heat production, and origin of crustal dichotomies (if any) on the Moon by in situ geochemical, mineralogical and heat flow measurements; regolith heterogeneity; and geophysical parameters that control past and present material fluxes in rocky subsurfaces, such as porosity, permeability, and heat flux.

The geotechnical measurements pioneered by the Silfela mission will also serve engineering functions, not only at the Moon but on other rocky bodies as well. Future exploration of planetary bodies such as the Moon (e.g., NASA’s Artemis program) will require an understanding of regolith strengths for landing site suitability, vehicle mobility and traversability, ISRU development, or even for construction using local resources. Past planetary missions have failed or have had difficulties because planners did not understand basic surface properties such as regolith shear strength, triboelectric charging , or regolith bulk strength in a reduced-gravity environment. Silfela represents a development toward a standardized payload to address these objectives and build a basic understanding of planetary regoliths throughout the Solar System.