An Open Database of Lunar Regolith and Simulants Properties

TL;DR

This paper addresses the fragmentation of lunar regolith data by introducing an open, centralized database that integrates in-situ measurements, returned-sample analyses, remote-sensing inferences, and simulant data. It presents a unified data model, explicit testing-method metadata, and an interactive web interface for filtering, visualization, and export, enabling rapid, site- and method-specific comparisons. The database covers key geotechnical parameters such as the angle of internal friction, cohesion, bulk density, and bearing capacity, across multiple missions and simulants, with clear distinctions among data sources. The resource enhances accessibility and reproducibility for mission planning and scientific analysis, supporting rover mobility, landing-site selection, excavation strategies, and simulant selection, and it is designed to evolve with new data from Artemis, Chandrayaan, and other programs.

Abstract

Lunar regolith, the layer of unconsolidated material covering the Moon's surface, is central to the science and technology developed for the Moon, notably related to in-situ science investigations, resource utilization, surface infrastructure, and mobility systems. However, data on lunar soil properties remain fragmented across decades of mission reports, often in formats that are difficult to access or interpret. We present a newly compiled database of lunar regolith physical and geotechnical properties, including data collected by direct in-situ measurements from crewed missions, estimates inferred from surface interactions on the Moon and using remote sensing, as well as laboratory analyses of samples returned to Earth. The data collected include, among others, the angle of internal friction and cohesion (both Mohr-Coulomb model parameters), bulk density, and static bearing capacity, extracted from Luna and Apollo-era historical mission documentation all the way to contemporary Lunar programs. The dataset specifies the type and location of the tests from which each value was obtained. Our database also includes parameters for lunar regolith simulants, providing a direct link between mission data and laboratory studies. In addition to centralizing this information, we developed a user interface that facilitates data retrieval, filtering, and visualization. This interface enables users to generate customized plots for comparative analysis. Developed in an open-science perspective, it is designed to evolve in response to the community's needs. The database and its associated tools significantly enhance the accessibility and usability of lunar regolith and simulants data for scientific and engineering research.

Figures (6)

• Figure 1: Schematic of the database architecture. Overview of the data files, processing scripts, and user interface forming the lunar regolith database.
• Figure 2: Moon map with missions landing sites. The global lunar albedo map shows the contrast between the dark lunar maria and the lighter highland regions. The cylindrical projection uses the selenographic coordinate system, spanning from -180°E to 180°E (left to right) and 90°N (North pole, top) to 90°S (South pole, bottom), centered on the mean sub-Earth point (0°N, 0°E). The map is reproduced with permission from NASA's Scientific Visualization Studio CGI Moon kit ernie_moonmap_2019. Each mission landing site is placed on the map (see legend for specific mission identification). This map, including the mission landing sites, is directly extracted from the database website.
• Figure 3: Geomechanical properties of lunar regolith depending on type of lunar terrain. Internal friction angle (top) and cohesion (bottom), both parameters of the Mohr-Coulomb failure model, are shown as functions of bulk density. Cohesion values are plotted on a logarithmic scale ($y$-axis) to capture their wide range, spanning two orders of magnitude, from 100Pa to 10kPa. Filled symbols indicate data obtained during the Apollo missions, while open symbols represent data from all other missions.
• Figure 4: Moon map showing the geographic locations of missions as a function of lunar terrain. Locations are classified as mare (blue disks) and highland (orange squares); the points highlight the spatial spread of the location of data collection.
• Figure 5: Comparison of geomechanical properties measured on Earth versus the Moon. We compare three typical geomechanical properties (internal friction angle, cohesion, bearing capacity), as a function of bulk density, for true regolith tested in-situ, returned samples tested on ground, and properties estimated remotely.