In 1963, a saucer-shaped, yellow submarine returned from the depths of the Red Sea and docked to an underwater research center, 26 miles off the coast of Port Sudan and 33 feet below the surface. Aboard it was legendary explorer and oceanographer Jacques Cousteau, who captured the imagination of millions with his Oscar-winning documentary World Without Sun. "This is the first time an undersea boat has had an undersea base," Cousteau narrated as his slender figure climbed out of the submarine and into Continental Shelf Station Two, the underwater station that served as home and laboratory to five aquanauts for one month.

With Conshelf Two—a starfish-shaped habitat with bunk beds and infrared lamps as heaters—Cousteau proved that human beings can live under the sea for long periods of time. With its four rooms branching out from the center, it was a significant improvement from Conshelf One—a 16-foot long, 8-foot wide steel cylinder that could only fit two people. Funded by the French petrochemical industry, Cousteau’s Conshelf mission was halted just two years later, after Conshelf Three was set up at a record depth of 330 feet, and Cousteau shifted his focus from petrol-funded research to ocean conservation.

Jacques Cousteau's Grandson Wants to Build the International Space Station of the Sea
Fabien Cousteau Carrie Vonderhaar
Jacques Cousteau's Grandson Wants to Build the International Space Station of the Sea
Jacques Cousteau's Yellow Submarine The Cousteau Society

Much like the slew of single-mission habitats that followed Conshelf, not much remains of these underwater innovations. Plagued, in part, by a shift in public interest that triggered greater funding for space exploration, some have been pulled out of the water, others have become diving sites encrusted with coral growth. Today, the only operating underwater habitat remaining is 34 years old.

Cousteau's grandson, Fabien, is hoping to change that. The founder of the Fabien Cousteau Ocean Learning Center, a nonprofit dedicated to protecting and preserving the planet’s oceans, coastal areas and marine habitats, is building the world’s largest underwater research station.

Jacques Cousteau's Grandson Wants to Build the International Space Station of the Sea
Fabien Cousteau with his grandfather Jacques Cousteau Courtesy of Fabien Cousteau
Jacques Cousteau's Grandson Wants to Build the International Space Station of the Sea
Legendary explorer and oceanographer Jacques Cousteau captured the imagination of millions with his Oscar-winning documentary World Without Sun. The Cousteau Society

Named after the prophetic sea-god Proteus, the station will be located at a depth of 60 feet, in a biodiverse, Marine Protected Area off the coast of Curaçao. Imagined as the underwater version of the International Space Station, it will be the first underwater research habitat built in decades, marking a new chapter in their tumultuous history. “We're now in a new evolution of consciousness of ocean exploration,” says Fabien. “Thanks to modern technology, we're able to communicate the importance of ocean exploration.”

Fabien learned to scuba dive when he was four. An oceanographic explorer, environmental advocate and aquanaut (he was trained to live and work underwater), he explains that one of his biggest frustrations is the significant limitations of scuba diving as a research tool for ocean scientists. When scuba diving from the surface, the amount of time safely spent in deeper waters is limited to an average of two hours per day. With Proteus, he says, "Now, all of a sudden, we have a house at the bottom of the sea, and we're able to go into the water, and dive 10 to 12 hours a day to do research, science and filming."

Sylvia Earle, an oceanographer and pioneer in testing the viability of underwater habitats, sees promise in Fabien’s vision. “Proteus is a hopeful step forward in spreading the message that we must protect the ocean as if our lives depend on it,” she says. “Living underwater gives us the gift of time and the incredible perspective of being a resident on the reef. You’re not just a visitor anymore.”

In 2014, Fabien spent 31 days in the Aquarius Reef Base, the last remaining research station. Built in 1986, the 400-square foot base sits on the seabed off Key Largo in the Florida Keys. There, he experienced the challenges of living underwater firsthand: high humidity levels, low light, no fresh food, no physical exercise and extreme isolation. "I wanted to address all the shortcomings and offer something that is much more conducive to future exploration and research by taking as many elements from the topside world and bringing it down to a state-of-the-art marine research center," he says. "This requires a different layout."

With very few exceptions, previous underwater laboratories (there have been over 65) have been cylinders, segmented into smaller areas for living and working. Proteus, which was designed by industrial designer Yves Béhar and his firm fuseproject, is unlike any other habitat.

The Fabien Cousteau Ocean Learning Center had been holding workshops and symposiums with academics, corporations and engineers to validate the scientific need for Proteus for two years when Fabien was introduced to Béhar in 2018. The two met at Helena, an organization that brings global leaders together to discuss and implement solutions to global issues. Last month, Béhar unveiled his design for Proteus.

Jacques Cousteau's Grandson Wants to Build the International Space Station of the Sea
Named after the prophetic sea-god Proteus, the station will be located at a depth of 60 feet, in a biodiverse, Marine Protected Area off the coast of Curaçao. Concept designs by Yves Béhar and fuseproject

At 4,000 square feet, Proteus will be ten times the size of the Aquarius Reef Base. Circular in shape, the two-story structure will revolve around a central curving ramp that connects the two floors. "You're living under tremendous amount of pressure, literal, but also scientific pressure," says Béhar. To mitigate that, he has envisioned a social space at the center, surrounded by various extensions housed in pods, where the living quarters, research laboratories, medical bays and bathrooms will be.

At 60 feet below the surface, natural light is another challenge, reduced to half the visible spectrum. The circular floors will therefore be offset from each other, with porthole windows and skylights allowing as much natural light as possible. Inside, full spectrum lights will fulfill the human need for a minimum of ten minutes of UV rays a day.

To facilitate ocean exploration, the structure will also include a moon pool, or as Jacques Cousteau once called it—"a liquid door." This specially engineered opening, situated at the bottom of the habitat, will allow divers to exit through a pressurized chamber. Unlike a space station or a submarine, the air pressure inside underwater structures is kept equal to the water pressure outside, preventing seawater from entering the habitat. This allows aquanauts to easily slip out and conduct underwater research using saturation diving—a technique that reduces the risk of decompression sickness. After 24 hours at any depth, the human body becomes saturated with nitrogen and aquanauts can remain in underwater habitats for an indefinite amount of time. (Bruce Cantrell and Jessica Fain hold the current record: 73 days in Jules’ Undersea Lodge, a former research habitat turned underwater hotel). When they are ready to resurface, the time required for decompression is the same no matter the length of the stay.

Jacques Cousteau's Grandson Wants to Build the International Space Station of the Sea
Circular in shape, the two-story structure will revolve around a central curving ramp that connects the two floors. Concept designs by Yves Béhar and fuseproject

Proteus is still in the concept phase. Fabien is raising $135 million to build the habitat and operate it for the first three years. Yet Béhar and Fabien have already discussed using composite building technology for the hull and 3D-printed coral tiles—which Fabien’s foundation has used to regenerate sea reefs—to create a living reef on the structure. And when the time comes to build, “there's no way to bring a structure underwater without sinking it,” says Béhar. “You need to fill the structure with water, sink it, and attach it to bottom of the ocean.”

For the design of Proteus, Béhar looked at the way science fiction portrayed underwater habitats, but history was his strongest muse. "Jules Verne's book, watching Cousteau's underwater adventures, were a key part of my imagination," he says.

In 1872, Verne popularized the idea of underwater life with his epic novel Twenty Thousand Leagues Under the Sea. Six decades later, American scientist William Beebe and engineer Otis Barton made science fiction a reality. In the 1930s, the pair collaborated on experimental submersibles called bathyspheres. These tiny, pressurized capsules, which dangled from a ship, took the duo more than 3,000 feet down off the coast of Bermuda, and kickstarted a surge of deep-sea exploration.

Auguste Piccard took deep-sea submarine development to the next level. The Swiss physicist and inventor, who had risen to record heights in the pressurized capsule of a balloon, realized that airships and underwater vehicles weren't so different after all. Instead of using a cable to lower and raise his submarine, Piccard used detachable ballast weights and a buoyancy tank filled with petrol, akin to the helium-filled envelope of an airship. In 1960, his invention took Piccard and American oceanographer Don Walsh on a journey to the deepest known point of the Earth—35,814 feet into the Pacific Ocean’s Mariana Trench.

Thanks to these pioneers, humans had visited the deep sea, but the advances prompted a new question: Could we live in it, too? Jacques Cousteau, the inventor of scuba, the diving regulator and an underwater vehicle known as the “diving saucer,” sparked a public fascination for the ocean (and from there, underwater living) with his documentaries about life onboard his research ship, Calypso. "When I was a kid, Calypso was a home away from home," says Fabien. "It was an amazing classroom. It made me realize these pioneers are pushing the limits every day."

Jacques Cousteau's Grandson Wants to Build the International Space Station of the Sea
Conshelf Two was a starfish-shaped underwater “village” built in 1963. Didier Brandelet/Gamma-Rapho via Getty Images

And push the limits they did. In 1962, Cousteau built Conshelf One—a steel, drum-shaped structure the size of a shipping container that was suspended 33 feet underwater off the coast of Marseilles. Together with George F. Bond, the father of saturation diving, Cousteau went on to build two more underwater stations.

Conshelf Two was the starfish-shaped underwater “village” that served as backdrop for World Without Sun. Built in 1963, it was sited in Sha’ab Rumi—where Cousteau’s coral-encrusted shark cages have created a diving mecca—while a smaller and deeper cabin housed two aquanauts for a week at 100 feet. Two years later, Conshelf Three was born. Resembling a black-and-yellow checkered disco ball, the station provided six divers, including Cousteau’s son Philippe, a self-sufficient environment, 330 feet under the Mediterranean Sea.

Jacques Cousteau's Grandson Wants to Build the International Space Station of the Sea
Resembling a black-and-yellow checkered disco ball, Conshelf III provided six divers a self-sufficient environment 330 feet under the Mediterranean sea. The Cousteau Society

The Conshelf stations triggered a wave of underwater building. From the Baltic to the Gulf of Mexico, single-mission undersea habitats sprouted like mushrooms. Between 1964 and 1969, the U.S. Navy’s SeaLab I, II and III descended to greater and greater depths—193 feet, 203 feet and 600 feet respectively—until the tragic death of an aquanaut put an end to Sealab III. In 1968, Helgoland—built by German company Dräger—became the first underwater laboratory built for cold waters and rough sea conditions (it was used in the Baltic Sea, the North Sea and in the Gulf of Maine). And in 1969 and 1970, NASA teamed up with the Navy and the Department of the Interior to launch Tektite I and II—the first nationally sponsored scientists-in-the-sea program. Deployed to a depth of 50 feet in the U.S. Virgin Islands’ Great Lameshur Bay, and built by General Electric, the Tektite habitat was made up of two, 20-foot tall silos connected by a watertight tunnel and dotted with dome-shaped windows.

Jacques Cousteau's Grandson Wants to Build the International Space Station of the Sea
The NASA Extreme Environment Mission Operations (NEEMO) 21 mission began on July 21, 2016, as an international crew of aquanauts splashed down to the undersea Aquarius Reef Base, 62 feet below the surface of the Atlantic Ocean. NASA

Tektite was eventually pulled from the water, but NASA’s interest in underwater structures continues to this day. Designed to simulate life onboard the ISS and test new concepts for future interplanetary missions, NASA's Extreme Environment Mission Operations (NEEMO) sends groups of astronauts, engineers and scientists to live in Key Largo’s Aquarius Reef Base. In this extreme environment, where mobility is limited to a confined space and water provides a near-zero gravity experience, astronauts are afforded a convincing analog for space exploration.

At the peak of deep-sea exploration, Fabien estimates there were 20 truly habitable underwater structures. Today, Aquarius remains the only operating underwater research station in the world—a proud survivor that has lasted 34 years when it was built to last five. "After the '70s, ocean exploration hasn't evolved in a way that space exploration has," says Fabien. With Proteus, he hopes to shift public interest back to the ocean—and he isn’t the only one looking to do so.

Jacques Cousteau's Grandson Wants to Build the International Space Station of the Sea
Built to sail the oceans, the SeaOrbiter was designed—after a seahorse—to float vertically and drift with the ocean currents. Rougerie Architectes Associes

The French architect Jacques Rougerie has devoted his entire career to building underwater structures, citing Jacques Cousteau as the impetus for his pursuit of architecture and oceanography. Since 2009, his foundation has hosted annual competitions for young architects to design underwater and space habitats. Rougerie believes that our future lies with the blue economy, or what the World Bank defines as the “sustainable use of ocean resources for economic growth, improved livelihoods, and jobs while preserving the health of the ocean ecosystem.” But first, he says, we need a blue society. “We must motivate the young generation,” he says. “We have to instill this passion in them. They have to feel involved.” To do this, we need supporting platforms, “strong symbols” like Proteus, or his very own proposal, SeaOrbiter.

Rougerie has designed dozens of underwater habitats, four of which have been built. His very first was Galathée, a 56-ton, semi-mobile habitat launched in 1977, off the coast of Japan. Until Galathée, the architect explains, most previous structures were built on the seabed. Rougerie changed the course by designing a structure with a variable ballast that allows suspended anchoring at different depths (from 30 to 200 feet) and with no impact on the underwater ecosystem.

Jacques Cousteau's Grandson Wants to Build the International Space Station of the Sea
Galathée was a 56-ton, semi-mobile habitat launched in 1977 off the coast of Japan. Rougerie Architectes Associes

His later habitats were even more mobile, culminating in his most ambitious design to date—SeaOrbiter. Built to sail the oceans, the semi-submersible vessel was designed—after a seahorse—to float vertically and drift with the ocean currents.

"The sea is an incredible source. A field of hope for startups around the world,” Rougerie says. “We still don’t know about the abyssal zone [the deepest layer of the ocean near the sea floor]. We don’t know about the hydrothermal vents. We know very little.”

According to the National Ocean Service, more than 80 percent of our ocean remains "unmapped, unobserved and unexplored." But even the parts that have been explored haven’t been mapped to a resolution high enough to detect objects such as airplane wreckage or the spire of an undersea volcano. With Proteus, Fabien will be able to map the surrounding area to a radius of a mile and a resolution of ¼ inch. "That gives us a really, really neat mosaic that we can revisit on a regular basis to show the changes on a yearly and decade-long basis," he says.

Fabien envisions the station to cater to a wide variety of studies, from biochemistry to pharmaceuticals to climate change. “Studying the historical responses of ecosystems like coral reefs to past changes in climate provides a useful guide. But these methods only get us so far,” says Brian Helmuth, a professor of marine and environmental sciences and public policy at Northeastern University. “Using a combination of experimental approaches coupled with observations in nature, we can use an understanding of the mechanisms by which reefs are impacted by environmental change to forecast future responses with much finer detail.”

In Proteus, Helmuth sees an opportunity to study an intact coral reef over a prolonged period of time and without the limitations of surface diving. “It would allow scientists to study the undersea environment by becoming a part of it, rather than working as casual interlopers,” he says.

Famously, Fabien’s month-long mission in Aquarius Reef Base yielded three years’ worth of research, but there were shortcomings, like the lack of an on-site laboratory for real-time studies. The state-of-the-art laboratories on Proteus will allow for advanced research on-site, with no degradation of samples in transit, while its full-scale video production facility will provide continuous livestreaming for educational purposes. “There are countless teachers and students who, like me growing up in New York, don’t have easy access to the ocean,” says Helmuth. “Proteus really will be a game changer in ocean education, providing an inner space station that not only offers exciting new opportunities to the scientific community, but also reinvigorates that passion for the ocean that launched so many people from my generation into careers in science and exploration.”

Since the start of modern ocean exploration, the ocean has changed drastically. Vast swaths are now completely devoid of oxygen, leading to “dead zones” that are now four times larger than they were in 1950. "When I was a teenager, I would go to the Florida Keys, and it was a playground of color, texture and movement,” says Fabien. “And now, comparatively, it's a ghost town.”

Underwater habitats like Proteus, or SeaOrbiter, can help deepen our culture of exploration and experimentation. These undersea laboratories can help discover new species, understand how climate change affects the ocean, and allow for testing of green power, aquaculture and robotic exploration. "The concept of robot-human teams is especially compelling for Proteus,“ says Mark Patterson, a professor and associate dean at Northeastern University, whose research focuses on the development of autonomous underwater robots for civil infrastructure and marine sensing. “This approach, of humans working with fast-swimming, tough robots, will overcome the problem that has plagued oceanography since the days of the HMS Challenger expedition: namely, the ocean changes faster than we have had the ability to observe.”

Sixty years after Cousteau filmed his adventures into the Red Sea, ocean exploration has yet to reach its full potential. “We have lived in the bosom of the sea,” Cousteau said as his yellow diving saucer rose from the darkness. “The sea has indulged us, but we have taken only the first steps into our new space. Further adventures await oceanauts in the world without sun."

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