NASA is taking its next-generation Artemis moon suits into the water, using underwater training to rehearse the first human steps on the Moon in more than half a century. The new gear is built to handle the harsh lunar environment while giving astronauts far more mobility and comfort than the Apollo-era designs that defined the last age of moonwalking.
By pairing advanced suits with a massive training pool in Houston, the agency is turning simulated gravity into a proving ground for the hardware that will carry crews across the lunar south pole. I see this underwater campaign as the clearest sign yet that NASA is shifting from design on paper to full-scale rehearsal for the Artemis era.
Why NASA is taking moonwalk practice underwater
The most realistic way to prepare for walking on another world is to strip away as much of Earth’s gravity as possible, and NASA has learned that water is the most practical tool for that job. By carefully adjusting weights and flotation, trainers can make an astronaut in a spacesuit feel almost weightless, which lets crews rehearse the awkward, full-body choreography of working in a pressurized suit that will later be used on the Moon.
In the Artemis program, those underwater sessions are not a novelty, they are a core part of how NASA validates procedures, tools, and the new suits themselves before anyone leaves Earth. The agency has described how these underwater sessions are used to refine tasks for future moonwalks as the Artemis program ramps up, turning the pool into a stand-in for the rugged terrain and low gravity crews will face near the lunar south pole.
The Neutral Buoyancy Laboratory, reimagined for the Moon
For decades, the centerpiece of NASA’s underwater training has been a cavernous pool in Houston that was originally built to simulate weightlessness for spacewalks around the International Space Station. That facility, known as the Neutral Buoyancy Laboratory, is now being reconfigured to support lunar operations, with mockups and training regimes that reflect the demands of working on the Moon rather than just in orbit.
The Neutral Buoyancy Laboratory sits at The Johnson Space Center, which offers mission planning, crew training, flight product generation, and real-time flight control support alongside specialized facilities such as an ISO level 8 clean room. NASA is now using that same complex to stage Artemis-focused rehearsals in the pool, leveraging the Neutral Buoyancy Laboratory as a bridge between engineering models and real human performance in the new suits.
From Apollo to Artemis: why the AxEMU matters
The suits going into the water in Houston are not museum pieces, they are the AxEMU, a new generation of exploration gear designed specifically for the Artemis lunar surface missions. Where Apollo astronauts worked in stiff, custom-fitted suits that limited their range of motion, the AxEMU is built to offer better mobility, visibility, and overall performance so crews can do more than plant flags and collect a few rocks.
Technically, the AxEMU represents an upgrade from both the Apollo suits and the units used on the ISS, with a design that supports improved mobility, communications, and life support. NASA has highlighted that the AxEMU is built to offer better mobility, visibility, and overall performance than the Apollo and ISS suits, and that the question of What exactly makes it different is central to how Artemis will expand the scope of lunar exploration.
Inside the next-gen Artemis moon suit
At the heart of the AxEMU design is a focus on flexibility and fit, two qualities that directly affect how safely and efficiently astronauts can work on the Moon. The suit is built with more flexible joints that allow for deeper bends at the hips and knees, more natural arm motion, and better reach, which should make tasks like drilling, sampling, and climbing slopes far less punishing than they were for Apollo crews.
NASA has also emphasized that the new suit includes improved life-support systems and a design that fits a wider range of astronaut body types, a shift that broadens who can credibly be assigned to lunar surface roles. In material shared in Nov, the agency pointed to those more flexible joints, upgraded life support, and inclusive sizing as key reasons the AxEMU is better suited to long, complex moonwalks than earlier generations of hardware.
How underwater training shapes real moonwalks
Practicing in a pool might sound like a crude stand-in for the vacuum of space, but in reality it is one of the most precise tools NASA has for shaping the choreography of a moonwalk. In the Neutral Buoyancy Laboratory, trainers can script full timelines, from climbing down a ladder to deploying instruments and collecting samples, then watch in real time where astronauts struggle, where tools are hard to reach, and where the suit’s stiffness or visibility limits slow them down.
Those observations feed directly back into both suit design and mission planning, which is why the underwater sessions used for the Artemis program are as much about engineering as they are about astronaut fitness. NASA has described how these underwater sessions are used to test new spacesuits for future moonwalks as NASA refines its Artemis timelines, turning each training run into a data set that shapes the final procedures crews will follow on the Moon.
Artemis III and the stakes of getting the suit right
The urgency behind this underwater training campaign comes from a specific mission on the horizon, Artemis III, which is planned as the first crewed landing of the program. That flight is expected to put astronauts back on the Moon and, crucially, to land astronauts, including the first woman, on the lunar surface to advance long-term exploration and science at the south pole.
For Artemis III to succeed, the AxEMU has to function not just as a life-preserving shell but as a mobile laboratory that lets crews work for hours in extreme cold and low light. NASA has framed Artemis III as a pivotal step that will land astronauts, including the first woman, on the Moon and anchor a broader contract for future exploration efforts, which makes every underwater test of the AxEMU a rehearsal for a mission with historic stakes.
From ISS heritage to lunar innovation
Although the AxEMU is new, it does not start from scratch, it builds on decades of experience with the suits used for spacewalks outside the ISS. Those orbital suits proved how to keep humans alive in vacuum for hours at a time, but they were optimized for floating around a spacecraft, not hiking across a crater rim or kneeling in regolith to drill for ice.
In the Artemis context, engineers have taken that ISS heritage and reworked it for a world where gravity is one sixth of Earth’s and the terrain is jagged, dusty, and unforgiving. Reporting on the AxEMU has underscored that it represents an upgrade from the Apollo-era suits and even the current ISS units, with a build that is meant to improve mobility, communications, and overall performance for lunar surface work, a point NASA highlighted when astronauts took the new moonsuit for a swim in Space.
Public interest, polls, and the politics of moonwalking
Behind the engineering and training, there is a quieter contest playing out over public attention and political support for Artemis. NASA knows that underwater training photos and videos of astronauts in sleek new suits can do more than inspire, they can help justify budgets and keep lunar exploration in the public conversation at a time when other priorities compete for funding.
That is one reason the agency and its partners have leaned into social media and outreach, highlighting the AxEMU’s capabilities and the diversity of the crews who will wear it, and paying attention to how audiences respond. Coverage of the new suit has referenced a poll that gauges public interest in lunar exploration, and the fact that those numbers are being tracked alongside technical milestones shows how tightly NASA is tying the AxEMU story to broader support for Artemis, a dynamic that was evident in Apollo-to-Artemis comparisons that foreground what the new suit enables.
What underwater training reveals about the future of lunar work
Watching NASA return to the pool with a new generation of suits, I see more than a training exercise, I see a preview of how work on the Moon will actually feel. The AxEMU’s flexible joints, upgraded life support, and inclusive fit are not abstract features when an astronaut is trying to climb a mock boulder or manipulate a tool underwater, they are the difference between a clumsy, exhausting task and a sustainable routine that can be repeated day after day on the lunar surface.
As the Artemis program moves from design reviews to full-scale rehearsals, the underwater sessions at The Johnson Space Center’s Neutral Buoyancy Laboratory are becoming a kind of dress rehearsal for a new era of human spaceflight. In that sense, every time an astronaut in an AxEMU drops into the pool in Nov or any other month, they are not just training for a mission, they are helping to define what it will mean to live and work on the Moon for the long term.
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