Sea Dragon - The Saturn V's big brother?

"For All Mankind" uses a rocket known as "Sea Dragon" to carry modules and supplies to the moon. Where did the idea of Sea Dragon come from, and how would it have worked?
Sea Dragon Concept Volume 1 (Summaryy)
web.archive.org/web/200512260...
Sea Dragon Concept Volume 3 (Preliminary Program Plan)
web.archive.org/web/200512261...
@Eager_Space on Twitter
Triabolical_ on Reddit
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[@chengong388]

Maybe when the engine is so big, instability is no longer a problem because there will be multiple instabilities occurring at the same time and averaging out the thrust

[@EagerSpace]

Ah. The "so unstable that it ends up being stable" hypothesis.

[@ThatAdamIsMild]

This is also the basis for my dancefloor moves 😅

[@Tysca_]

​@@EagerSpace​@EagerSpace actually, yes. There's a similar problem and conjecture in biology regarding large animals with long lifespans that theoretically should be entirely cancer, yet aren't. Since mammal cells are approximately the same size, or at least larger mammals are larger mostly by way of simply having more cells, the odds that any one becomes cancerous should be astronomically high in animals like whales and elephants, yet they live long lives anyway. One hypothesis is 'hypertumors' or equivalent mechanisms, where cancer feeds off of other cancer, sort of canceling it out in the end. In a similar way, the combustion chamber being quite large could in theory generate turbulent flows in a much more laminar fashion overall throughout the combustion chamber, decreasing the significance of any shocks experienced in the F-1; or to put it more simply: The so-unstable-it-becomes-stable hypothesis. I for one am also skeptical about this (among many other principles of Sea Dragon), but I don't know that it's quite "and then a miracle occurs"-levels of dismissal. The real miracle would probably be the metallurgy, manufacturing, and corrosion.. Great vid! ❤

[@uru4123]

project orion - the sea dragons big brother

[@GuardsmanBass]

I'd love the idea of them fixing the big combustion instability issue by replacing with a vast number of small pressure fed engines, like some hilarious Kerbal rocket.

[@EagerSpace]

You could fit 29 F-1 engines in that space, with no gimballing. Use the aux motors to do that for you. If you shrunk their bells to 9' in diameter, you could fit 51 of them in the first stage. But - of course - nobody would ever think of putting more than 5 engines on a first stage, much less more than 25...

[@TheNheg66]

​@@EagerSpace 🤣🤣🤣🤣

[@Hungary_0987]

@@EagerSpace*laughs in starships 33 engines* 😂

[@evodinoboy3285]

​@@EagerSpace laughs in n1😂😂

[@Gold3nAng3l]

It’s a good day when the Eager Network publishes a video!

[@vincentgrinn2665]

every other rocket: our second stage engine is smaller to allow for the larger vacuum bell traux: what if it was BIGGER?

[@franciscomaiorodrigues6960]

Best video about the sea dragon I have ever seen. Most videos just cover the general OP characteristics, not the problems and how a mission would go

[@Vinnie_728]

The script feels a little stiff, but I found your video entertaining and very well made. Fantastic work :)

[@mskiptr]

6:36 millinewton engines lol

[@kargaroc386]

I mean with this you could probably start work on that solar shield to keep the earth cool. Or that fancy rotating wheel space station like in 2001. There's many organizations that could build this out of their own pockets, but they decided they wanted more yachts instead, at the expense of the entire universe.

[@robdonnelly6537]

First i ever learned of sea dragon i felt it was a bit ridiculous....that is until the scene from For All Mankind, that changed everything lol

[@EagerSpace]

It was a ridiculous idea, but it's a fun ridiculous idea.

[@robdonnelly6537]

@@EagerSpace oh definitely, just the shear size and engineering that it would have taken to build it, alone. But had they built it and flown it, holy cow that woulda been a show! 😍

[@markoj3512]

Don’t write mN for Meganewtons, because a small m stand for milli and not Mega. A capital M stand for Mega!

[@Hungary_0987]

True

[@waynemccormick4773]

Would something "similar" have worked as an expendable booster? If you could reliably launch something weighing 200-300 tons in one shot, that would be a pretty big deal!

[@blacx2]

Sorry for being pedantic but, mN=millinewtons, MN=meganewtons

[@AidenHere]

Giant brother

[@AidenHere]

David Vs goliath

[@Bradstephens11]

You make comments about combustion instability, but I've been searching but I've only found references to comments by Tom Mueller on the Sea Dragon that it was going to use pintle injectors like the Merlin and that Tom believes the Sea Dragon would be stable. I believe pintle injectors have much better combustion stability than the injectors of the F1. Tom would be the one to know. I believe it was a tweet.

[@EagerSpace]

Tom would obviously know far more about it than I would. I'll only note that a) at the beginning of the F-1 they didn't think they would run into any significant issues with scaling and b) nobody has tried to build an engine that big since and c) the Russians went to multi-chamber engines which shows that they found the big combustion chambers problematic as well.

[@waynemccormick4773]

Can you provide the source for the illustrations of the cargo version of the LEM at time marker 42 seconds?

[@EagerSpace]

Took me a few minutes... www.thespacereview.com/article/4503/1

[@waynemccormick4773]

@@EagerSpace Thank You!

[@iandaniel1748]

What information volume 2 Sir ❓

[@EagerSpace]

See: kzbin.info/www/bejne/rXbOf6qZgZh3pa8 It's not really very exciting IMO.

[@michaelmoore1403]

Using pintle injectors like the SpaceX Merlins, rather than the "showerhead" injectors or F1 would reduce the instabilities. and using stainless steel rather than aluminium could solve the heat related issues. Clever design could further reduce the dry mass of the craft increasing performance. The use of solid boosters could solve some of the problems as well. I thought early on in it's development that perhaps the Superheavy may borrow more from that design.

[@discipleofra13]

A Daedalus video could be nice

[@TheBackyardChemist]

What if the first stage was a giant SRB instead?

[@EagerSpace]

It would need 24 times the thrust of the SLS boosters. Seems like that would be pretty hard to fabricate and pour. They are also really dense - the propellant is about twice as dense as water - and therefore very very heavy. You would need some sort of floating platform to keep them from sinking.

[@TheBackyardChemist]

@@EagerSpace Good points

[@Quasarnova1]

Also solid rockets are not throttleable, which gives complications as you approach max q and is why they are rare to see on main stages on large rockets.

[@TheBackyardChemist]

@@Quasarnova1 There is some "thrust profile" you can "program" into the fuel itself, via geometry and composition, but yeah that is another complication.

[@mirandahw]

@@Quasarnova1 This isn't necessarily a dealbreaker. Saturn V, Firefly Alpha and Starship-Super Heavy all punch through Max-Q without throttling; albeit, solids tend to be rougher than liquid fuelled vehicles, so it might be a little more difficult. But as someone else pointed out, you can _kinda_ get a variable thrust output from solids by just hardcoding (hardcasting?) the preferred flight profile and make it work.

[@annando]

I'm asking myself how the ignition under water would work reliably.

[@EagerSpace]

I don't know if this is tested, but if you vent a small amount of lox into the engine bell it will vaporize and that vapor will push fill the nozzle and displace the water.

[@annando]

@@EagerSpace Question is how deep the engines are under water. The engine is pressure feed, so the pressure of the water must be lower than the pressure of the LOX.

[@EagerSpace]

@@annando The rocket is 150 meters tall, and roughly 100 meters is below the surface of the water. The LOX tank is at 16 bar, but if you heat up the pressure will go up. You could also dedicate some of the liquid methane to do it. It's at 300 bar IIRC.

[@nickstonehenge]

6:40 this should be MN not mN otherwise you have millinewtons

[@Hungary_0987]

True

[@iandaniel1748]

Add aquarius rocket own vedio made company 😊 3 part

[@iandaniel1748]

More pressure fed rocket design out there . Pressure fed astronaut talk family pressure fed rocket smaller,medium, large, super large rocket. Now some pressure fed beer can rocket will try launch

[@interests3279]

Sea Dragon would only take 3 years worth of USA military "aid" gifted to Israel. (10 billion/year) Or it would only take 1/3 of military "aid" given to Ukraine so far. (100 billion as of Feb 2023. 🤡🌎

[@mudkatt2003]

I think we all know it would have cost overuns like every other government project *cough*SLS*cough*

[@yellowrose0910]

MN meganewton. mN millinewton.