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The early 1960s was an optimistic time for space engineering. With the Space Race between the U.

S. and the Soviet Union in full swing, cameras, animals, and humans were being launched into orbit. And the world seemed headed for a space-faring future, where hundreds or even thousands of people would be living and working off-Earth. Getting that civilization into orbit, though, would require a lot of power.

And, in 1963, a team led by engineer Bob Truax proposed a solution: a supersized rocket capable of launching an entire space station in one go. They called it the Sea Dragon. And while it never launched, it was well ahead of its time — and it continues to inspire engineers today.

When the Sea Dragon was proposed, the Soviets were leading the charge with rockets that were about 50 meters long and 3 meters wide. They could carry maximum payloads of about 5 metric tons. The Sea Dragon would have been an absolute monster by comparison.

It would have been more than 150 meters tall and more than 22 meters wide, and it was designed to carry more than 500 metric tons into space. And it would have been nearly 400 times more powerful than rockets of the time, and 10 times more powerful than the future Saturn V, the rocket that eventually took humans to the Moon. And, as the name suggests, it was also intended to launch from the sea.

No, not on a floating platform or anything. Like… directly from the water. As impractical as that might sound, there are actually a few good reasons why a water launch was the best option.

For one, it would have made transporting and assembling the rocket's huge components a lot easier, since a buoyant environment would support the rocket safely as it was being constructed. Then, there was all that thrust. At ignition, the Sea Dragon's powerful engines would have caused major damage to launch pads of the time, tearing apart concrete and melting metal.

Water, on the other hand, just boils off or flows away. Finally, after launch, the Sea Dragon's huge and scalding exhaust plume would be kept far away from populated areas. Of course, while a water launch offered a ton of benefits, it did create a few potential engineering challenges, too.

For example, salt water is really good at corroding metal and messing up delicate electronic components. To get around that, engineers hoped to borrow techniques from submarines, which spend months at a time completely immersed in salt water. Their idea was to build the rocket with thick steel plates, insulation, or special paint to resist corrosion, and to place access panels for waterproofed electrical components above the waterline.

But aside from water protection, the rocket's design was really simple, a style that would become known as a “big dumb booster”. Each of the Sea Dragon's two stages would store fuel and liquid oxygen in pressurized tanks. At liftoff, simple valves would open, and the chemicals would mix, igniting on contact to produce a bunch of thrust that would carry the payload into space.

This design is less efficient than those found on the sophisticated. Saturn V, but the Sea Dragon's huge size would have made up for that, making it considerably cheaper per kilogram of payload. The simple design would have also helped ease its assembly and launch.

The main components would be built in dry docks and onshore facilities, then would be floated and assembled in a specially-made lagoon in Cape Canaveral, Florida. The rocket would then be filled with fuel and pressurized before being towed out to the launch point about 60 kilometers from the shore. When it was time to launch, ballast sacks attached to the bottom would be filled with a heavy fluid, like muddy clay.

Then, they would sink, and would pull the Sea Dragon upright. Once the engines were lit, water would be expelled from the first stage, and everything would work pretty much like any other rocket. Its massive payload would be in low Earth orbit in a few minutes.

All this is really cool, but the Sea Dragon had one more innovation up its gigantic sleeves — one that would put it way ahead of its time:. The rocket was designed to be almost entirely reusable. After launch, bags on the ballast tanks could be inflated with air to float the tank back to the surface.

And both the rocket's first and second stages would be fitted with inflatable drag skirts to point them in the right direction and slow them down enough to survive a water landing with no damage. Each Sea Dragon would have been able to make more than 100 flights, and that reuse would have massively reduced the cost of getting to space. It really was a time of infectious optimism.

Although the Sea Dragon was many times bigger than anything that had come before it, none of the engineering challenges seemed insurmountable. The team even got as far as a couple of prototypes to prove that a sea launch was possible. Unfortunately, though, the whole program just kind of fizzled out after a while.

And while Truax was asked to develop other versions of his designs over the next few decades, nothing ever really got off the ground. Or out of the water, I guess. What left the Sea Dragon adrift wasn't the engineering challenges, or even the cost, but the motivation.

Although some of the public may have looked forward to a space-faring future, NASA was more tightly focused on a single goal: getting a man on the Moon. The Sea Dragon was an incredible tool, but not one that the space agency really needed at the time. It was a workhorse for large scale settlement of space, at a time when pioneers were still making tentative steps to explore space.

Even today, we're not launching anything that needs the Sea Dragon's massive lifting power. Still, the idea of a sea launch certainly isn't dead in the water. Among the many private companies clamoring for space, several are proposing sending their rockets from the sea.

One of the main benefits is that you don't need a designated launch pad — which could become really useful as we start to launch more rockets and set our sights on a space-faring future once again. And if the day ever comes where we do want to launch a city into space… well, we have a design worth dusting off. Thanks for watching this episode of SciShow Space — and special thanks to Destin Sandlin over at Smarter Every Day for first telling our team about this sweet old rocket.

If you want to check out Destin's channel – which, you should, it's amazing – you can go to youtube.com/smartereveryday. [♪ OUTRO].