Space and the open ocean: On the surface, it seems like two more wildly contrasting places couldn’t possibly exist. But on the contrary, the two are more closely tied than you think. And people who have been to the farthest reaches of both can attest to the fact. Because as it turns out, the types of training and experience required and the environments you find in both have impressive parallels.
Just ask aeronautical engineer, astronaut, and aquanaut Nicole Stott. She’s spent 104 days in space on the Space Station and Space Shuttle and plenty of time underwater, partially in preparation for space travel, but also for fun and education now that she spends most of her time on planet Earth.
The PADI-certified (Professional Association of Diving Instructors) diver confirms that under sea and outer space have a lot in common. After all, both are extreme environments that are not only hard to access, but often outright dangerous, require ultra specialized equipment to navigate, and are inhospitable to humans. Which turns out to be pretty convenient, because while simulating the lack of gravity and the vacuum of space can be tricky, the ocean offers a legitimate analog and impressively simulative training grounds.
In fact, astronauts, before they even think about setting foot in a shuttle to travel beyond Earth’s atmosphere, have to spend time underwater. There’s even a dedicated training center for it: the Neutral Buoyancy Laboratory in Houston that exists to train astronauts for space walks. Inside, one of the world’s largest indoor pools—measuring 202 feet long, 102-feet wide, and 40 feet deep and containing 6.2 million gallons of water—is also home to replicas of International Space Station components, as well as other man-made structures in space.
In this pool, astronauts don 300-pound suits plus plenty of other equipment to achieve neutral buoyancy, and submerge themselves, surrounded by a team of support divers, to learn and feel like what it will be like to operate and move about in space. In fact, according to Stott, it’s the closest feeling you can achieve on Earth that simulates what it’s like to move in space (minus the drag and weight you experience underwater).
After all, in both places, you’re floating—though in the water because you’re buoyant and in space because there’s no gravity—and in neither can you simply call it a day, throw off your helmet or respirator, and walk home.
Which is why Stott and others have also trained in the Aquarius Lab, an underwater habitat and aquanaut basecamp 60 feet under the surface of the ocean off the Florida Keys. She spent 18 days beneath the surface. Down there, “you’re in a real, true, extreme environment,” Stott explains, just like you would be in space—though with much more atmospheric pressure. But being at those depths doesn’t just simulate the movements and teamwork required outside Earth’s atmosphere, it mimics the sense of isolation and self-reliance, too.
“You can’t just bail,” Stott explains. When you’re underwater at significant depths, your body and blood become too saturated with nitrogen to quickly retreat to the surface if you run into trouble. Do so, and the excess nitrogen can cause bubbles in your blood and/or lungs, causing serious bodily harm and decompression illness or even death via arterial gas embolism. At Aquarius’ depth, Stott explains, saturation happens once you’re down there for just 60 minutes.
Sure, there’s a relatively safe “indoor” environment to retreat to—similar to being inside a spaceship—but in either location, “If something goes wrong, you and your crew have to figure out how to get into a safe configuration, including accounting for your crewmates.”
Everything about it is a perfect analog for space, she goes on: How you communicate, act with your crew and mission control team, live in cramped quarters, use specialized equipment, and the way you are required to deal with emergency situations. It’s just that in one case you’re under pressure surrounded by water and the other you’re dealing with the deadly vacuum of space.
“It’s the ultimate parallel of the extreme environment of space,” Stott says, even more so than other training astronauts have to endure, including cold weather and wilderness survival. But in those situations, she explains, you know that help is only a satellite phone call away. Deep in space or deep underwater, it all comes down to self-survival, working as a team, and knowing how to manage stress in a high-stakes environment. “It’s a totally diff psychological experience,” Stott adds.
Diver certification isn’t required for those dreaming of becoming astronauts, either professionally or as space tourists. But Stott says if you don’t have dive experience already and your astronaut application is accepted, you’ll get that certification and experience soon.
For those who prefer to go in prepared or want to experience what space feels like here on Earth, Stott is more than thrilled to make an introduction. In fact, she just completed her second Island Astronaut Camp in partnership with PADI and COMO Maalifushi in the Maldives. Together, kids snorkeled, built bottle rockets, designed space suits, and learned the importance of acting like a crew member, not just a passenger, whether they head to space, stay firmly rooted on terra firma, or explore underwater environments. It’s just one way she helps connect the space curious with the space serious via her Space for A Better World and Space for Art Foundation.
“It’s pretty cool that we can spend time undersea—living and working in inner space—to best prepare for what it’s going to be like to live and work in outer space,” Stott says. So if you want to experience what it’s like in space, head underwater.