DATE2025.09.12 #Press Releases

Participation in JAXA’s “Lunar Regolith Investigation Mission”

— In Collaboration with MLIT’s “Space Unmanned Construction Innovation Technology Development” under the Space Development and Utilization Acceleration Strategy Program —

Summary

Ritsumeikan University (Kyoto, President: Yoshio Nakaya), Keio University (Tokyo, President: Kohei Itoh), and the University of Tokyo (Tokyo, President: Teruo Fujii) will participate as collaborating research institutions in the “Regolith Impact Stiffness Experiment with Orb Drops on Lunar Surface (RISE Mission),” led by the Japan Aerospace Exploration Agency (JAXA).

The experimental instruments will be installed on the Nova-C class lunar lander developed by Intuitive Machines (U.S.), scheduled for launch in the third quarter of 2027. After landing on the lunar surface, the RISE Mission will be carried out. The project is being conducted in collaboration with the Ministry of Land, Infrastructure, Transport and Tourism (MLIT)’s “Space Unmanned Construction Innovation Technology Development Project,” part of the Space Development and Utilization Acceleration Strategy Program (also known as the “Stardust Program”).

Background
As part of international efforts such as the International Space Exploration Coordination Group (ISECG) and the U.S.-led Artemis Program, humanity is preparing to return to the Moon and build a sustained lunar presence. The lunar surface is covered by regolith—a layer of fine dust and fragmented rock formed over billions of years through micrometeoroid impacts and thermal fatigue caused by extreme temperature differences between lunar day and night.

Although data has been obtained from Apollo samples, further in-situ investigations are essential to safely conduct future lunar activities, including analyzing the behavior of lunar landers, operating surface machinery, and installing habitat modules. In particular, understanding the mechanical properties of regolith—its hardness and strength (geotechnical properties)—is crucial for predicting machine performance and planning construction activities.

To address this need, the RISE Mission will deploy an ultra-compact soil investigation device aboard the lander to directly measure regolith mechanical properties on the lunar surface.

Mission Details
The RISE Mission will release spherical probes equipped with accelerometers from the lander toward the lunar surface. By analyzing the probes’ acceleration responses upon impact with the regolith, researchers will determine key mechanical characteristics of the lunar soil—such as stiffness and compressibility.

The results will provide essential parameters for the design and evaluation of construction machinery and lunar infrastructure, and will also enable the development of high-fidelity simulators. Ultimately, these advances will significantly contribute to the establishment of sustainable lunar bases in the coming decades.

Associate Professor Tomokatsu Morota of the Department of Earth and Planetary Science is participating in this research.

Figure: Image of the lunar surface ground survey(Credit: JAXA)

Related Links

Ritsumeikan University, Keio University, Japan Aerospace Exploration Agency (JAXA)