How Humans Conquered The Ocean | History's Greatest Machines (S1)

By the early 2000s, people have mapped the earth and even the moon, but there's one place they don't know much about, the bottom of the ocean, until a Hollywood director decides to go there in a sub engineered to take the pressure. In June of 2023, the U.S. Coast Guard is exploring one of the most infamous areas of the North Atlantic Ocean, the site of the doomed Titanic, which lies 12,500 feet beneath the surface on the ocean bottom. Then, about 1600 feet from the bow of the Titanic, they find what they most feared, a debris field strewn across the seafloor is the carbon fiber remnants of the submersible, the Titan. The Titan is an experimental submarine that takes paying customers down to the wreck of the Titanic, and it has been missing for days. It's immediately apparent that the hull was pulverized by a catastrophic implosion. The pressure at that depth is over 5,000 pounds per square inch. The Titan shows how dangerous deep ocean pressure can be. 10 years earlier, James Cameron faces similar challenges when he envisions diving even deeper. In 2005, Cameron sets out to become the first person to go alone to the Challenger Deep. He teams up with a group of engineers to build a special submarine to achieve that audacious goal. The Challenger Deep is the deepest spot in the Mariana Trench, 36,000 feet from the ocean surface to its bottom. That's like seven miles. It's so deep that if you sunk Mount Everest to the bottom, there would still be a mile more of water between its peak and the atmosphere. Sunlight has never touched it, and creatures that live there must thrive at a pressure of 16,000 pounds per square inch. That's three times the pressure that imploded the Titan submarine. Cameron and his team create a machine that can reach the bottom and stay down long enough to film and study it. They dub it the Deep Sea Challenger. The Deep Sea Challenger stands 24 feet tall and weighs nearly 24,000 pounds. It's shaped like a torpedo to cut through the water and reach the bottom quickly. But the real innovation is at the bottom of that torpedo shape, a spherical pilot chamber barely big enough for one person. And that sphere is the key to surviving seven miles of crushing ocean pressure. At 16,000 pounds per square inch, that's a lot of pressure. So you need a shape that is incredibly strong. And the strongest shape is a sphere. So it's harder to crush. A sphere distributes pressure equally. Just think like a ping pong ball. If you try to crush it, it's really hard. Now think of a soda can. It's a cylinder. So when you try to crush it, it has weak points because of that pressure, and it's easy to crush. The Titan sub had a cylindrical shape, which means that the crushing force was not equally distributed across its surface, and it had weak points, making it vulnerable. While the sphere is rigid, the outer hull is flexible. It's designed to give with the extreme pressure and prevent the cracks that can lead to a sudden implosion. They equip the hull with lights, HD cameras, and a robotic arm to take samples from the ocean floor. They also include a reinforced window so Cameron can pilot the craft and see the world around him. Cameron knows he's not the first one to attempt the dive. In 1960, a Navy sub and its crew reach Challenger Deep. But after 20 minutes, their viewport cracks, and they're forced to abandon the dive. For 50 years, no one dares go back. On March 26th, 2012, he's ready to complete the mission. The torpedo shape descends quickly, exactly as designed. By 5,000 feet down, it's pitch black. By 10,000 feet, the pressure is so high, it will crush any submarine that's not designed exactly like this one. You really have to wonder what he's feeling at this time. Is he excited? Is he terrified? Because when you watch him on the onboard cameras, he's all business. Way up bottom. Touchdown. The Deepsea Challenger does what no other sub has done before. It reaches Challenger Deep, the deepest point on Earth, and stays operational. He's collecting sediment samples, snapping high-res photographs, filming in 3D, scanning for signs of life. Every second down there is pure scientific gold. Seven hours in with oxygen dwindling, Cameron makes the call. It's time to head back up. The first solar-piloted machine to attempt Earth's most extreme environment makes it back. The Deepsea Challenger may have had only a single dive, but its legacy continues. It cracked some serious engineering challenges, and it has inspired a whole new generation of explorers to continue the mission. In the 21st century, the U.S. Navy decides it needs a new kind of warship, one that uses the latest tech to counter emerging threats. Lots of people have heard of stealth planes, but how about a stealth destroyer? By the early 2000s, America's enemies have changed drastically. They're no longer fighting big Navy battles against other major powers on the world. They're fighting terrorists, rogue states, and coastal threats that can hide among civilian populations. Here's the problem. America's massive Cold War-era destroyers are not suited to these new tasks. It's like bringing a sledgehammer to somewhere where you're going to need a scalpel. Even U.S. modern destroyers are huge, loud, and easy to see on enemy radars. You can see them coming from hundreds of miles away. They need a destroyer that can sneak close to enemy coastlines undetected and then rain down precision fire on land targets. The military has perfected stealth aircraft, and they've experimented with smaller stealth warships, but they never tried to make a 600-foot destroyer stealthy. The Navy decides that they need to build this new stealth destroyer from scratch. That means new hull, new weapons, new everything. And the price tag? $22 billion for three ships. And I said billion with a B. This is the USS Zumwalt, the first in a new class of stealth destroyers. Her hull angles inward and her surfaces are sharp and geometric, the opposite of traditional ships. The ship is designed with sharply angled sides that slope inward, so that incoming radar doesn't bounce back off the ship, they bounce away. And that makes it 50 times harder to detect than a ship with vertical sides, where the radar signal just bounces straight back to the source. She's also wrapped in radar-absorbing materials, all designed to make her invisible. Those changes confuse enemy radar, but they're not space-efficient. That's why she's over 600 feet long. A 15,000-ton warship that's 50 percent larger than all other destroyers looks like a little fishing boat on enemy screens. It's like wrapping a skyscraper in an invisibility cloak. You never know what hit you until it was too late. In 2023, the Navy installs hypersonic missiles hidden inside an angular compartment on the deck, with holes for the missiles to blast through. These weapons strike targets at five times the speed of sound. By the time the enemy sees it coming, it's already hit. Each caster carries multiple hypersonic missiles that can hit targets 1,700 miles away. That means the Zumwalt can park off of New York and hit something in Denver in minutes. This is what the future of naval warfare looks like. Stealth ships that sneak up to enemy coastlines fire unstoppable hypersonic missiles at targets deep within enemy territory. Those old-school battleship duels, they're done. The Zumwalt hasn't seen combat yet, but it's already won the war that matters, proving that all this crazy tech actually works. Today, it's basically the Navy's floating laboratory for tomorrow's weapons. The Navy is still trying to figure out what this ship can do. Maybe shooting down enemy missiles, controlling swarms of unmanned drones from the bridge. The sky may not be the limit. The Zumwalt's showing us the future in visible ships that can hit nearly anything from nearly anywhere.