🌙 What lies beneath the Moon's surface? Water ice? Mineral resources? Stable ground for lunar bases? A "walking stick" developed in Japan will help uncover these mysteries. This staff-like device, wielded by astronauts on the lunar surface, could revolutionize humanity's approach to Moon exploration.
Japanese Technology Selected for NASA's Lunar Mission
In December 2025, NASA officially announced that PASS (Portable Active Seismic Source), a compact seismic device developed by Professor Takeshi Tsuji and his team at the University of Tokyo's Graduate School of Engineering, has been selected for the Artemis IV mission.
The Artemis program is NASA's flagship human spaceflight initiative, conducted in partnership with Japan and other international partners. It aims to return humans to the Moon for the first time since the Apollo missions ended in 1972—making this one of the most significant space exploration efforts in half a century.
Artemis IV, the mission where PASS will be deployed, is scheduled for launch in late 2028 or later. It will be the first mission where astronauts conduct comprehensive geological surveys on the lunar surface. There's even a possibility that Japanese astronauts will participate, potentially making them the first to use Japanese-made equipment on the Moon.
What is PASS: A Staff-Like Seismic Source
PASS stands for "Portable Active Seismic Source." The device resembles a walking stick or staff, compact enough for astronauts to operate by hand while wearing bulky spacesuits.
Here's how it works:
- Astronauts deploy seismometers on the lunar surface
- Using PASS near the seismometers, they repeatedly generate small artificial vibrations
- These vibrations travel through the Moon's interior as waves
- The seismometers record changes in wave velocity and intensity
- Scientists analyze the data to create "cross-sectional maps" of the subsurface structure
Traditional seismic survey equipment is large and heavy—far too bulky for space missions. PASS achieved the necessary miniaturization and weight reduction while incorporating space-grade features: resistance to vacuum conditions, extreme temperature fluctuations (ranging from minus 280°F to plus 250°F), and the fine lunar dust known as "regolith."
Interestingly, NASA refers to PASS as "Thumper" in official communications—the same name used for a similar device during the Apollo program. This naming suggests NASA views the Japanese-developed PASS as a worthy successor to that historic technology.
What Will Be Explored on the Moon
Artemis IV's PASS-equipped surveys aim to visualize subsurface structures up to approximately 16 feet (5 meters) deep. The data gathered will serve several crucial purposes:
Water and Mineral Resource Exploration The Moon's south polar region is believed to contain water ice in permanently shadowed craters—areas where sunlight never reaches. Finding water would be transformative: it could serve as drinking water for astronauts and, through electrolysis, be split into hydrogen and oxygen for rocket fuel. Producing fuel on the Moon rather than transporting it from Earth could dramatically reduce space exploration costs.
Foundation Assessment for Lunar Bases Plans exist for establishing permanent human habitations on the Moon. Building safely requires precise knowledge of ground conditions—hardness, composition, and structural integrity. PASS survey data will be essential for selecting optimal construction sites.
Understanding Lunar Formation The Moon's formation remains incompletely understood. Subsurface data provides valuable scientific insights into how our nearest celestial neighbor came to be.
Proven Technology on Earth
PASS wasn't originally developed for space. It was created for terrestrial subsurface exploration and has already accumulated an impressive track record:
Carbon Capture Monitoring As nations pursue carbon neutrality, injecting CO₂ deep underground has emerged as a key strategy. PASS monitors these storage sites to ensure the captured carbon isn't leaking back to the surface.
Geothermal Exploration In Japan's geothermal regions, PASS-based elastic wave surveys have successfully mapped fault structures at depths of approximately 3,300 feet (1,000 meters), improving the efficiency of geothermal resource development.
Tunnel Construction Safety The technology can detect underground cavities and monitor collapse risks during tunnel construction—a growing concern as infrastructure ages.
Infrastructure Inspection PASS enables non-destructive examination of aging levees, bridges, and other structures.
A University of Tokyo spinoff company called "Wavelet" is commercializing this technology, with the goal of making subsurface investigation accessible to anyone.
International Collaboration in Lunar Exploration
PASS will operate as part of SPSS (South Pole Seismic Station), a packaged system combining the seismic source with seismometers. This station exemplifies international collaboration:
- NASA (USA): Jet Propulsion Laboratory (JPL) leads overall project coordination
- CNES (France): French National Space Agency develops seismometers
- IPGP (France): Paris Institute of Earth Physics develops seismometers
- JAXA & University of Tokyo (Japan): Provides PASS and conducts elastic wave surveys
Japan's contribution through tangible exploration equipment marks a significant milestone—following the successful lunar landing of the SLIM probe in January 2024—in the nation's growing role in lunar exploration.
The Artemis Timeline
The Artemis program is progressing through several phases:
- Artemis I (completed 2022): Uncrewed flight test
- Artemis II (planned 2026): Crewed lunar orbit mission
- Artemis III (planned 2027-2028): First crewed lunar landing in approximately 50 years
- Artemis IV (late 2028 onwards): Comprehensive geological surveys begin using PASS
PASS's selection validates Japanese space technology on the international stage. It also demonstrates the "spinoff" phenomenon—how technology developed for space can solve terrestrial challenges and vice versa.
This "walking stick" for probing the Moon's interior will be a crucial tool supporting humanity's next giant leap in space exploration.
In Japan, there's considerable pride that university-developed basic research has been selected for major international space projects. How is your country contributing to space exploration and lunar development? What applications do you see for subsurface investigation technology? Share your thoughts in the comments!
References
Reactions in Japan
Amazing that technology from a UTokyo lab got selected for NASA's lunar mission! Seeing basic research bear fruit like this shows how shortsighted discussions about cutting research funding really are.
Love the 'walking stick' description. The image of astronauts wielding a staff on the Moon like wizards is so sci-fi and exciting!
The successor to Apollo's Thumper being Japanese-made is deeply moving. Really feel the half-century of technological advancement.
They say it can explore up to 5m underground, but honestly isn't that insufficient for water resource exploration? Maybe we shouldn't get our hopes too high.
Professor Tsuji's lab is impressive. From CO2 storage to space exploration—the beauty of research is how one technology can have such diverse applications.
Japanese astronauts potentially using Japanese equipment on the Moon? That's straight out of a movie. Can't believe I'm alive to hear this news.
2028 huh... Still a ways off. Just have to hope the plan proceeds without issues until then. Delays are par for the course in space development.
Seismometers from France, source device from Japan, coordination by USA. A textbook example of international cooperation. But I wonder if they ever clash over budget allocation or credit for results.
Wonder if we could use this tech to inspect our company's aging infrastructure. Non-destructive testing is expensive, so if costs come down, that'd be helpful.
The idea that lunar water could be used to make fuel—I read that in sci-fi novels as a kid. Surreal to see those stories becoming reality.
First time learning there's a lunar simulation facility in Cologne, Germany. An ESA facility. Wish Japan would develop more testing facilities like this too.
Read the article—so 'regolith' is lunar dust? Sounds like a nightmare for equipment. Impressive they managed to design around it.
Great that a UTokyo startup is commercializing this for terrestrial use too. Important to bring space tech back to solve Earth's problems.
Honestly 'Thumper' is catchier and easier to remember than PASS. Marketing-wise, NASA's naming might be better.
When they talk about 'foundation assessment for lunar bases,' it suddenly feels real. An era when humans live on the Moon is actually coming.
So it's being used for geothermal surveys too. Japan's a volcanic country, so hopefully this tech can help address domestic energy issues.
Checked out Prof. Tsuji's lab page. Impressive publication record and the students look talented. Labs like this are Japan's strength.
Space exploration is dreamy but honestly felt irrelevant to my life. But if subsurface tech can help disaster prevention, that's real value.
China's accelerating lunar exploration too, and competition is fierce. Japan demonstrating presence through niche technology seems like a good strategy.
From SLIM's success to PASS selection, Japan's space development has momentum lately. Hope they keep nurturing the space industry like this.
Didn't expect Apollo's Thumper successor to come from Japan. Really shows 50 years of tech evolution. If NASA approved it, must have serious reliability.
Love this collaboration—France handling seismometers through IPGP and CNES, Japan handling the seismic source. Science truly has no borders.
Impressed that Japanese university research directly connects to space development. China is working hard on Chang'e program too, but there's much to learn from this miniaturization tech.
Lunar water exploration is crucial for humanity's future. If Japan's tech succeeds, it could significantly reduce Mars mission costs.
Happy to hear it was tested at LUNA facility in Cologne. Proud that Germany is contributing to lunar exploration projects too.
Japan follows SLIM success with this. Korea started lunar exploration with Danuri, but Japan's ahead in providing concrete equipment. Motivating for us.
Interesting idea to apply seismic survey tech to space. Italy's also earthquake-prone, so I'm curious about terrestrial applications too.
Seeing tech from different countries come together for NASA's Artemis really shows it's a global project. Different from Apollo era.
India's Chandrayaan-3 also surveyed the lunar south pole. Combined with Japan's tech, we might create more detailed subsurface maps.
Honestly 5 meters depth feels limited, but hoping future versions can explore deeper.
The spinoff effect—space tech being used for ground infrastructure inspection—is wonderful. Could this be applied to Poland's aging infrastructure too?
Combining Taiwan's semiconductor tech with Japan's precision equipment could lead to exciting developments in space. Hope for more East Asian collaboration.
Foundation assessment for lunar bases—it's like surveying construction sites on Earth. Civil engineering for the space age!
Cheering from Brazil! Japan's technical prowess is truly impressive. Hope South America can participate more in space development someday.
Happy that Dutch ESA contributions and Japan's PASS will be used in the same project. Space exploration is a common goal for humanity.
2028 is still a ways off, but I'm looking forward to following Artemis progress. Watching how Japanese tech performs will be exciting.
Japanese living in the US here. Feels proud seeing Japanese tech featured in NASA announcements. Cheering for my home country's achievements.
Interesting that this tech works for CO2 storage monitoring. CCS is a challenge in Australia too—would love to see this technology adopted here.
Only a few countries have lunar exploration tech. Japan being in this club proves its status as a technological powerhouse.
Sweden is investing in space industry too, but producing concrete results like Japan will take time. This is good motivation for us.