PRORIS: Science-Driven Instrumentation for In Situ Lunar Resource Exploration

The PRORIS (Programma di Ricerca Spaziale di base) Strategic Project, coordinated by the Italian National Research Council (CNR) and the National Institute for Astrophysics (INAF), is a national initiative dedicated to the development of advanced methodologies and instrumentation for in situ resource prospecting in preparation for their exploration on the Moon. The goal of PRORIS is the design, integration, and validation of an integrated approach based on sensor systems and autonomous platforms for the identification and characterization of key lunar resources, with a focus on water ice, rare earth elements (REEs), and rare metals. The objective is to provide scientific and technological tools for upcoming surface missions—such as those under NASA’s Artemis program—by enabling targeted resource identification, site characterization, and operational strategies that support sustainable exploration and in situ resource utilization (ISRU).

Although PRORIS is a technology-driven project, establishing a scientific context is a foundational and mandatory step. The internal scientific driving plan within PRORIS is constituted by the “Science Node”, a working group focused on a roadmap for identifying relevant geological targets on the Moon, clarifying a mineralogical context within the selected target areas, as well as designing and simulating mission scenarios that reflect real world operational constraints in order to fulfill the exploration goals. This activity ensures that the instrument development is performed in accordance with the current state-of-the-art lunar ground-truth knowledge, and paying particular attention to the polar regions—home to cold-trapped volatiles—and to the Procellarum KREEP Terrain (K potassium, REE rare-earth elements, P phosphorus) known to host higher REE contents. Other rare chemical elements will also be considered.

The PRORIS Science Node will provide the scientific context guidelines by benefiting from the analyses of previous missions’ publicly available datasets (such as Clementine, Lunar Prospector, LRO, Chandrayaan-1, SELENE, and Chang’e). It will also provide sound constraints related to the lunar environment relevant to both scientific requests and payload deployment and operations. The dataset analyses will inform the selection of regions of interest and guide the definition of mission profiles, including potential landing sites and surface operations. By correlating orbital data with analog studies and laboratory work, PRORIS contributes to a science-based prioritization of exploration targets.

The project’s core technological developments include a multi-sensor approach for surface and subsurface characterization. A geophysical tomography suite integrates instruments such as a ground-penetrating radar (GPR), an electrical resistivity meter, a magnetic gradiometer, and a passive seismometer in order to allow the 3D reconstruction of the subsurface stratigraphic sequences down to tens of meters, aimed at detecting ice deposits. A complementary broadband microwave radiometer will survey the regolith dielectric properties and thermal gradients, improving the identification of ice-bearing layers.

Surface mineralogy surveys are planned using a suite of instruments, including a visible reflectance hyperspectral stereo imaging camera (SHY-4D), a Raman spectrometer, an UV-induced fluorescence hyperspectral imager optimized for REE detection (RESCUE), and a LIDAR-induced fluorescence spectrometer for other elements detection. A combined X- and gamma-ray spectrometer (PROGReX), and quartz crystal microbalance sensors complete the suite, enabling quantitative in situ elemental analysis.

PRORIS aims to create an instrumental and modeling ecosystem that allows a comprehensive assessment of lunar resources at the in situ scale. The technologies developed are designed to be compatible with deployment on autonomous platforms, such as future rover or lander systems, and will include edge computing capabilities and machine learning algorithms to enable real-time data processing and adaptive exploration strategies. While PRORIS does not develop rover systems directly, its instrumentation is tailored for integration with such platforms to optimize science return under mission constraints.

Although the project’s primary follow-up is technological, PRORIS relies on a strong scientific rationale to ensure that the developed solutions address relevant questions and are compatible with the physical and geological conditions of the operational scenario. This science-technology feedback loop also includes field validation activities in analogous environments, which are key to testing instrument performance and simulating surface operations.

By bridging instrumentation development with geoscientific context, PRORIS exemplifies a mission-enabling approach to lunar resource prospecting. In this frame, PRORIS Science Node provides essential inputs for designing effective payloads and exploration architectures, while the technologies developed are tailored to operate in the real conditions at high-priority lunar sites. Through this integration, PRORIS will support the advancement of planetary science and the implementation of concrete ISRU strategies, making a contribution to the global effort for a sustainable and scientifically informed presence at the Moon.

 

Acknowledgements: The authors gratefully acknowledge support from INAF-CNR under the ‘Programma di Ricerca Spaziale di Base (PRORIS), DM 789/2023’ initiative.