The Largest Rocket That Never Launched
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The Largest Rocket That Never Launched

March 24, 2020

This video is supported by SurfShark. In November 1967, NASA launched the iconic
Saturn V rocket for the first time. Standing 110 meters tall and producing 7.6
million pounds of thrust, the Saturn V stillI holds the record for the largest and most
powerful rocket ever launched. But a rocket designed years before the Saturn
V would have shattered the scale of rocket design and altered the course of rocket technology. The rocket was known as the Sea Dragon. This was an enormous two staged rocket, aiming to cut costs and launch extremely heavy payloads into space. The idea for the Sea Dragon came from engineer
Robert Truax in the early 60’s. Truax envisioned a semi-reusable two-stage
launch vehicle, capable of delivering extreme payloads to the Moon and Mars. Simplicity, reusability, and cost-savings
were the guiding principles behind the rocket’s design. Sea Dragon’s first stage consisted of a
single engine rather than multiple smaller engines like the Saturn V. Instead of using
complex fuel pumps, it had liquid nitrogen tanks which would pressurize the fuel tanks
and push the propellants into the engine. Taking away the complex and unreliable fuel
pumps would make the engine cheaper to build and easier to refurbish. Since both stages of the rocket were designed
to be refurbished and reused, they had to be recovered carefully after each launch. Once the rocket launched and reached an altitude
of about 38 kilometers, the first stage engine would cut out and separate from the 2nd stage. It would continue to fall back to Earth using
an inflatable flare. This would help to slow the stage down and
orientate it in a way that wouldn’t damage the engine once it hit the ocean. The second stage would follow a similar path back to Earth after delivering the payload into orbit. Given the sheer size of the Sea Dragon, it
would have been far too big to build and transport on land. The incredible amount of sound generated during
liftoff would have created shockwaves strong enough to damage the launch pad and the rocket
itself. In order to overcome these issues, the rocket
would need to be built and launched at sea. The rocket would be built in a shipyard and
towed out to the launch site. In order to orient the rocket vertically,
6 tanks near the base of the rocket would fill with water and sink the engine into the
sea. Although sea-launched rockets had already
been used during the second World War, the technology had never been tested on such an
enormous scale. In order to begin testing the Sea Dragon,
engineers modified a rocket from the U.S. Navy nicknamed ‘Sea Horse’. Testing began in San Francisco Bay where engineers
fired the rocket’s engine on a barge above the water and slowly lowered it into the water. The engineers found that once submerged, the
engine continued to fire perfectly and the sea dampened the shockwaves substantially. The success of this test opened the door for
the Sea Dragon to become a reality. However, like many other rocket designs, Sea Dragon failed to leave the drawing boards. As the 1960’s came to a close, NASA’s
budget was slashed as the United States went to war with Vietnam. At the height of the decade, NASA’s annual
budget peaked at $5.9 billion. Over the next few years, their budget was
reduced by 37%. These cuts ended many of NASA’s experimental
research programs along with the construction of the Sea Dragon. In many ways, the sheer size of the rocket’s design contributed to the downfall of Sea Dragon. As the Saturn V rocket continued to develop,
NASA were reaping the benefits of having a rocket much larger and more powerful than
anything else that had come before. Although Sea Dragon would have opened the
door for even larger payloads, NASA couldn’t justify the cost of developing the unproven
technology required to make Sea Dragon operational. From a technical standpoint, there were also
concerns with combustion instability for a rocket this large. Sea Dragon would have generated more than 79 million pounds of thrust at liftoff, 10 times the amount of the Saturn V – which had
its own combustion instability problems. Either way, the Sea Dragon will go down in
history as one of the craziest rocket concepts that almost happened. Since the retirement of the Saturn V in 1973,
SpaceX’s Starship rocket is the closest thing we have to the Sea Dragon concept. Starship is designed to be 118 meter tall
and produce 16 million pounds of thrust. So although we never got to see what became of the incredibly ambitious Sea Dragon, we can look forward to the exciting future that lies ahead in the world of spaceflight. Thanks to SurfShark for supporting this episode
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Only registered users can comment.

  1. Little Spoiler of For All Mankind

    Aftercredit of For All Mankind Season 1, They show this rocket. I’m hyped for Season 2

  2. It's been a real privilege to contribute (a bit) to this video . Thank you for the opportunity.

  3. If you wanna say "FIRST!", do it with a sentence involving the word "first". Copypaste this if you wanna stop cringiest comments

  4. The level of sound that thing would have generated at liftoff would have been devastating to marine life in a massive area.
    Though if you want a crazier idea- Project Orion.

  5. What about comparison of the Seadragon and the Starship? You said in the video it's the closest thing we got and you even mentioned the stats, but I doubt most of the viewers remembered the stats of Seadragon to be able to compare it. This will now make me go and do the research myself as to how they compare, and I'd say this decreases the quality of the video, especially if this happened near the end as it leaves the bitter feeling of not getting the answer easily.

  6. Private development of technologies has proven to be more efficient and forward looking than if NASA had continued. Good that their budget was reduced. NASA has become an impediment to cost efficient advancement of what it says it champions. The more Political NASA becomes, the less effective and more needy of funds it becomes.
    Space-X has advanced rocket technology faster and cheaper than NASA could have. NASA should be remembered for what it did when it was important and praise worthy. Now it is time to put it to bed and turn off the lights and turn to a fresh page where man can again dream without being stifled by bureaucracy.

  7. For a more modern depiction of the Sea Dragon, it appeared at the end of "For All Mankind", an alt-history show where the Soviets beat America to the moon and the space race kept going. The reveal is pretty damn epic (

  8. if you are wondering how they deal with the massive sound generated by rockets today
    the answer is still water 😀
    just not that they launch from the sea
    but rockets get sprayed down with huge amounts of water during liftoff
    this creates water vapor and muffles the sounds substantially

  9. Always hope for a breakthrough with new kind of engine.Or imagine some kind of enormous slingShot to support start.Not mention some crazy sky platform /skytower elevator/or flying ^^ xD

  10. Well, not sure about some points regarding the Sea Dragon. The budget cuts was not really a stopper for the production of the rocket, it was more the anti-water lauches (as would Ken Mason put it, guy who worked with Robert Truax) People did not want to get their rockets wet in simple terms. The second thing would be the sheer payload capabilities of 500 tons to LEO (There was not a demand for such a heavy payload).
    Also regarding the combustion stability, Truax wasn't concerned with it because the engine was going to be a pintle injector type. In this paper by TRW (Apollo lander rockets manufracturers) { } they point out that pintle injectors have demonstrated stable combustion with motors varying in scale by 50,000:1.
    It was tested this idea of scaling the pintle injector in the now retired TR-201 engine for the Delta rocket.

  11. One small detail not explained in the video, but that explain why starship is compable to the sea dragon.

    All our currents rocket and most rocket in history are made of a component : carbon fiber, a really lightweight and strong material, but quite brittler.

    Sea dragon and startship use the same material : stainless steel (even though it's a different type of steel between the 2)

  12. 0:20
    Well… The story is a little more complicated then that.
    About "largest":
    If its by hight then yes , but there were several rockets that were wider like the N1, space shuttle and buran-energia.
    About "most powerful":
    If its payload to LEO you are talking about then yes , but if you mean thrust (at lift of) then both N1 and buran-energia had more.

  13. The unpredictability of how waves could alter the rocket's angle of attack is probably why every rocket is launched from land-based launch sites.

  14. I THINK they need to @ NASA on this one boys. Jesus SLS is retarded… massive price for what 4 launches that are 6 yrs behind schedule???

  15. If NASA had a warehouse full of ET tanks and SRBs. They would have been able to launch a space shuttle every two weeks or so.

  16. Sea Dragon will become a reality one day once the hunger for lifting bigger things, even entire cities to orbit becomes a necessity

  17. A Sea Dragon-type rocket with a methane-powered first stage could transport the fuel needed to refuel Starship in orbit until LOX could be produced on the Moon. With the fuel capacity of Starship at around 1200 mt, a payload capacity close to Boeing´s Large Multipurpose Launch Vehicle (LMLV) would be needed. In the 1960s Boeing was still run by engineers and was a legitimate contractor. Go, Starship.

  18. Apple TV production For all Mankind, includes Sea Dragon in series one, episode 10, closing scene after the credits.

  19. 2 things: 1: is 1:34 Kerbal Space Program?! And 2: this is the first time I’ve every heard the F-1 referred to as “smaller”

  20. It wasn’t the Vietnam was that cut NASA’s budget, it was v largely the hostility of the Left which opposed virtually all spending not directed at social welfare.

    It was the Energy Crises in 1973-1983 plus double digit inflation that really did it in.

    The 70s was dominated by a political culture of hostility to American greatness and general sense of malaise and hopelessness.

    Such a culture does not fund big, future oriented space programs.

  21. No ,sea dragon was possible considering nasa’s budget and logistics. But no Vietnam war was more important to 🇺🇸, which was a huge loss and jaw breaking defeat. Rather it had allocated that resources there had been multiple ISS, moon missions and even colonies on mars. Sea dragon was immensely capable. Unfortunate 😣

  22. And now we can see this at the end of the first season, and hopefully in the whole of the second season of For All Mankind.

  23. I think the N1 was heavier, taller and definitely more powerful when it launched.

    So much more powerful, in fact, that it exploded all 4 times in less than a minute after those launches.

  24. I have never heard of that rocket…what a behemoth it would have been….simplicity, ease of use and reusability…now where i have heard that before ?…but that dude was thinking that way back in the 60s. A man ahead of his time i would say….peace.

  25. SeaDragon could of made Rods from God a real weapon but it should still be looked at for launching water, fuel and fully built reactors to orbit even if you send the reactive mass up on a more reliable rocket. Would you rather have toxic or heavy loads fail near land or out in the middle of the ocean?

  26. According to the previous videos on this topic sea dragon is supposed to use kerosene and liquid oxygen on the first stage , pushed by gaseous methane , the second one would use hidrolox but with turbopoms, I don't see how liquid nitrogen can push the liquid hidrogen into combustion chamber without pomps, if you introduce into fuel tank would freeze and clogging the pipe.

  27. Sea Dragon didn't flew because there was never a need to deliver so much payload into orbit, regular small rockets like Saturn V were capable of doing the required job.

  28. Still not the largest or most capable rocket ever designed. Onto largest by an official NASA team. Russia and Convair had far crazier and capable designs.

  29. I think there was an additional idea to build an artificial lagoon for it to launch from, so you wouldn't need to take it all the way out to sea.

    I love the design, but the combustion instability would have been something else.

  30. Unfortunately the closest we’ll ever get to seeing the Sea Dragon fly, will be in the second season of For All Mankind.

  31. The propellant tanks of the first stage look pitifully tiny compared to the engine. I wonder for how long can they feed that monster.

  32. The same principles with that is spacex building their rockets, either Falcon 9, Falcon Heavy or super heavy/starship:

    E.g. using a default Linux and standard computer components as their launch steering and control systems

    The only rocket at the moment that is reusable

    Cost savings:
    Is coming with the first two points

  33. Don't know why they never tried to get an Apollo sized sea dragon program into service or testing. I can see why the scale of sea dragon turned NASA off from it.

  34. Would kill so many whales and dolphins by deafening them. Might be ok if launched from an enclosed atoll lagoon

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