Only one man has ever traveled alone to the darkest corner of the Earth: the deepest part at the bottom of the Pacific Ocean. Tuesday, he was in Washington, D.C. asking lawmakers to pay more attention to it in hopes it might hold the secret to staving off climate change and understanding extreme weather.
The Deepsea Challenger mission, started in secret nearly a decade ago by filmmaker James Cameron, might at first seem like an $8 million pet project of a man who has made the two most successful films of all time. But Cameron says he didn't spend seven years developing the submarine just to become the first person since Jacques Piccard and Don Walsh traveled together to the Mariana Trench in 1960.
"We've got to put vehicles into the ocean to understand it," Cameron says. "This vehicle was done not to set a record but to be a science platform, to go down and do real science."
On that front, Cameron's mission appears to have been a success: Its robotic arms have taken samples of the Challenger Deep, which is more than 7 miles below the water's surface. On March 26, 2012, Cameron spent several hours exploring Challenger Deep, which is located at the southern tip of the Mariana Trench, about 200 miles southwest of Guam. Using Deepsea Challenger's 3-D cameras, Cameron discovered 68 new species. He's currently working on a 3-D film of his mission.
In March, Cameron donated Deepsea Challenger to Cape Cod's Woods Hole Oceanographic Institution, where researchers will study the submarine in order to design better robotic and manned submarines. David Gallo, director of special projects at the institution, says scientists there hope Deepsea Challenger and future vessels based on the sub will help them better understand phenomena such as climate change and major earthquakes.
"We think of the oceans as a big blue fishbowl," he says. "But they've got the world's greatest mountain range, the world's deepest valleys. They're an important part of the world."
Gallo says that scientists are just beginning to learn more about the Hadal Zone, a general term for the deepest parts of the oceans, which starts at about 20,000 feet deep. It's a region where there is believed to be very little life and no light. It's named after the Greek god Hades.
"The most dynamic and energetic earthquakes come from those regions," Gallo says. "Every time we go down there and turn on a camera, we're finding out something new about the Earth and our relationship with Earth. The clues to the origins of life and the keys to the future of life on this planet, those answers are down there at the bottom."
Says Cameron, who recently announced he is forming a company that hopes to mine asteroids for resources: "As much as I love space exploration, we don't have to go into space to find great exploration horizons. We can do it right here on Earth. It's critical we understand the oceans faster than we're changing the oceans."
Tuesday, Cameron made waves on Capitol Hill as he pitched the importance of ocean exploration to lawmakers such as Sen. Sheldon Whitehouse, D-R.I., a founding member of the Senate Oceans Caucus. It's a shame "we know more about the backside of the moon than we know about our own oceans on this planet," Whitehouse said.
Cameron famously became a deep-sea explorer before directing "Titanic," when he took submarines to examine and film the ship's wreckage.
Not surprisingly, Cameron's vessel was completely privately funded. To get to the bottom of the trench without crushing Cameron or its scientific equipment, it had to be designed unlike any other submarine.
Piccard and Walsh's vessel, the Trieste bathyscaphe, consisted primarily of gasoline tanks to provide it buoyancy (gas is less dense than water and uncompressible even at high pressures), a pressure sphere that held Piccard and Walsh, and 9 tons of iron pellets to help speed its descent. Cameron's vessel, on the other hand, weighs one tenth of the Trieste and is much more maneuverable. The filmmaker explored the trench for about three hours; Trieste had essentially no scientific equipment and lasted at the bottom for just 20 minutes.
Cameron enlisted engineers at Australia's Acheron Project Pty, specifically co-designer Ron Allum, who Cameron called the "only other parental supervision" on the project, and student engineers.
"We did this in secrecy because we didn't want to tell the world we were doing something we didn't know we could do until we were confident we could do it," Cameron says.
Allum says Deepsea Challenger had to be built to withstand more than 16,500 pounds per square inch of pressure, meaning several tons of force is exerted on each part of the sub. Allum says it's enough to "compress a block of steel."
"At that depth, everything compresses, even the sea water compresses," he says. That means that submerging can get difficult (think of trying to push a basketball to the bottom of a pool). To get it to the bottom, the team affixed a 1,100 pound weight, which has to be released on the way up.
"When we're descending, we're gaining buoyancy, but when we're ascending, we're losing it," he says. "That means if we got our calculations wrong, we might only come up three fourths of the way and we'd just be drifting in the currents indefinitely."
Allum says it's unlikely many more manned submarines designed to reach the deepest parts of the ocean will be built as robotic subs get more sophisticated, cheaper and come without the inherent risk that manned exploration brings. But robotic subs won't ever be able to replicate the feeling that comes with being miles beneath the ocean, he says.
"I've been down in this vehicle [on test missions to a depth of about a mile] and it's a tremendous experience. To go caving and experience it with your own eyes – to bring back a rock sample you've selected rather than doing it robotically – is absolutely amazing," he says. "I think in the future most of it will be robotic, but I still think we should have manned vessels."
Though Woods Hole doesn't have any immediate plans to put Deepsea Challenger back into the water, Gallo says Cameron's trip to the bottom of the Mariana Trench won't be its last mission. Cameron is coy about his plans, but Gallo says the director almost certainly will pilot it once again.
"We're looking at who will dive this next – my bet is it will be James Cameron himself," Gallo says. "I know he's working on Avatar 2, 3 and 4, but if he can stay away from Deepsea Challenger for a few years I'd be very surprised."