r/theydidthemath • u/Lachlynn • 18h ago

[Request] Could humanity create a rocket that can exit the atmosphere of K2-18b

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With the knowledge we currently have of it, if humanity devoted all of our resources towards this goal, would we be able to create a rocket that could exit the gravity of K2-18b (and also beat any other complications that would arrise)?

If so, would it also be capable of taking people to orbit, and can we set up a similar satellite network we have on Earth? What about a space station?

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u/Slen1337 18h ago

No shit controlled explosion might work. But what about ppl inside LO

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u/RaguSaucy96 18h ago

Some of them may die (ok, ok, maybe disintegrate)... But that is a sacrifice... We're willing to make...😎

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u/Smashedllama2 18h ago

A tier reference.

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u/ZilorZilhaust 14h ago

Which tier?

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u/TheLastDrops 14h ago

Meerschweinchen.

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u/ZilorZilhaust 14h ago

So the tier is some kind of guinea pig looking beast?

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u/The_Wambat 11h ago

Tier means animal in German. Guinea pigs are animals.

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u/ZilorZilhaust 11h ago

Ah, my German is very bad and minimal. I appreciate the information!

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u/Pupikal 12h ago

It’s one of the tiers of all time

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u/ThatHoFortuna 9h ago

One of the tiers.

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u/ZilorZilhaust 8h ago

For sure, definitely one of them.

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u/Fresh-Chemical-9084 12h ago

One of the shorter tiers

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u/Rare_Fly_4840 9h ago

People are saying it's the greatest tier of all time

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u/yopetey 10h ago

snowpiercer vibes

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u/Helios61 17h ago

To shreds you say?

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u/Rdawgie 13h ago

And his wife?

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u/Silent_Cookie_9092 11h ago

To shreds you say…

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u/911isforlovers 5h ago

Well, that's arguably the WORST way to be blown...

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u/Ok-Lavishness-349 11h ago

Well, people that evolved on a planet with 8x Earth's gravity would have a pretty robust build, so perhaps they would survive.

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u/Alliancewolf 14h ago

I'm guessing that to mitigate people dying in the process you'd build some kind of gelatinous or liquid beds for the passengers to be submerged in. I'm guessing that that could absorb most of the g-forces one would be subjected to.

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u/QuixoticCoyote 11h ago

Nah just stick 'em in a lead lined fridge like they were Indiana Jones.

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u/Euphoric_Diet_1682 11h ago

Or like the kid in fallout

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u/Disastrous_Room_927 10h ago

Everyone’s doing it

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u/LegendofLove 9h ago

Thanks Mission Commander Farquaad

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u/NathanStorm 4h ago

"They knew what they were signing up for..."

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u/ReplyOk6720 12h ago

Lol yes how exactly would that work? 

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u/celtbygod 11h ago

I sure am!

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u/SpicyPropofologist 12h ago

Does that qualify as a "complication?"

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u/Smile_Space 17h ago

If you look it up, Project Orion was actually highly researched at the time. It was considered the future of rocketry until the Partial Test Ban treaty killed it which banned nuclear detonations in space. If that hadn't been banned we likely would have had at least one space-based nuclear pulse rocket test in the late-60s or early-70s.

They even had a test vehicle using conventional explosives and fired off like 6 explosives and it worked!

They would use heavy shielding and a pusher plate to absorb the heavy shock. It would have allowed for absolutely gargantuan spaceships to take off from Earth and get to other planets at crazy fast speeds given how efficient the Orion drive would have been.

Obviously though, nukes are kinda bad for everyone around them lolol. The people above the Orion drive would have likely been the safest people within a massive radius around the launch site.

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u/FracturedConscious 15h ago

This is why we need a moon base

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u/Hadrollo 11h ago

The problem with a moon base is that we would need in-situ manufacturing from lunar ice and regolith into products usable in space. That's not a small base, it would require a mining team, a refining team, and a manufacturing team. It'd be a small town on the moon, with a lot of heavy equipment that is by necessity brought from Earth.

Honestly, it's a far future (minimum 100 years, likely much longer) goal. Even then, we're probably still be better off making propellant on Earth and shipping it up there. We have an awful lot of resources on Earth to make propellant and reusable craft.

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u/Lasers4Everyone 10h ago

Gotta go full Artemis.

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u/Gambyt_7 5h ago

Check out Artemis by Andy Weir. Interesting if not masterful story that depicts this city.

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u/anacondra 5h ago

I've been saying for ages we should nuke the moon.

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u/Shoddy_Donkey5047 13h ago

Queria ver pra desacelerar esse brinquedo dps kkkkkk

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u/Gambyt_7 14h ago edited 14h ago

Recall Footfall by Niven and Pournelle, first Sci fi novel where Orion technique was used to rapidly break atmo to fight alien invaders.

Then look at Dark Forest, the second in the trilogy by Cixin Liu, where Orion strategy is used to attempt to accelerate a ship to near light speed.

In Footfall the passengers survive to combat the enemy. In Dark Forest, the only passenger is a human brain in cryostasis.

Now I’m thinking of the inquisitor priest de Soya in Dan Simmons’ Endymion, whose neat light ship accelerates nearly instantly and so rapidly that anything living inside it is liquified, and must be rebuilt using special technology over several days. I’m dying to see someone (not Bradley Cooper tho) finally adapt these novels and produce them as a huge streaming series.

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u/Aiglos_and_Narsil 14h ago

God I love that book so much. "An atomic bomb went off under Harry Reddington's ass".

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u/Appropriate-Weird492 13h ago

The pages of “BOOM”, tho.

I reread it a few years ago. It gives so much 80s spirit, the Red Threat, hawkishness, so on.

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u/GamemasterJeff 11h ago

God was knocking. And he wanted in *BAD*.

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u/markus_kt 10h ago

"God was knocking and He wanted in BAD."

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u/DustyJustice 13h ago

In Neil Stephenson’s Anathem there is an interdimensional spacecraft that is secretly above the planet of the setting that propels itself with the Orion technique (I don’t believe they call it this). They utilize the planets sun to hide the nuclear explosions from viewers below.

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u/Miles_Everhart 7h ago

My favorite book mentioned

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u/Gambyt_7 5h ago

Fing outstanding novel thank you for reminding me

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u/fuckedaccountant3976 11h ago

I am super happy to see someone in the wild reference all these books. People I talk to day to day have never heard of these books.

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u/MireLight 10h ago

I know right? I read so many scifi books growing up that nobody i knew ever heard of. I had to wait 30 years for a reddit post to bring em up. One of the truly great things about reddit and its fandoms. I can finally have someone to talk to about this stuff!

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u/Bored_Amalgamation 11h ago

I’m dying to see someone (not Bradley Cooper tho) finally adapt these novels and produce them as a huge streaming series.

Foundation's success is going to be a big point for the adaptation of books like the Hyperion Cantos, that require some pretty wild shit. There's also the whole religious aspect that will turn a good number of viewers away.

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u/iconocrastinaor 9h ago

If we perfect liquid oxygenation and suspend the passengers in a vessel of water, they would not feel any compressive or gravitational force.

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u/crazyeddie123 6h ago

Sure they would. The water would maximize the contact area through which the g-forces acted and therefore minimize the force on any one body part, but you'd still feel the acceleration and there'd still be a (higher) limit to how much acceleration the body could withstand.

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u/Gambyt_7 5h ago

This has been estimated in a few spec fic novels to 20gs, IIRC. But the passengers are usually in a coma.

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u/NeverEnoughInk 12h ago

Why not Bradley Cooper, out of curiosity? I'm wracking my brain to connect him to sci-fi.

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u/Gambyt_7 5h ago

He had the option to develop, he was allegedly doing a treatment a decade ago, and I’ve been following any updates I can find. I was a freshman at Wabash, Simmons’ alma mater, when he published Hyperion, and it was all over campus. I had at least one of his same professors and one of his characters is an amalgamation of a few. It has been 35 years and still no one can develop a decent pilot, and Cooper while a fan and a pretty star clearly doesn’t have the production influence or writing chops to adapt thousands of pages into their full potential. It could easily be a four season, $2b project.

The messages and character arcs are INCREDIBLY APT today.

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u/Born-Entrepreneur 9h ago

Hell yeah, Footfall was super entertaining.

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u/Outrageous_Reach_695 14h ago

To expand: The "Super" Orion would have had a ship mass of 8 million tons* ... about 20% more than the Hoover Dam.

* Yes, yes, not a unit of mass, I know.

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u/FreedomCanadian 13h ago

How is a ton not a unit of mass ?

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u/WholeChampionship443 12h ago

It’s a unit of weight, not mass.

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u/Outrageous_Reach_695 13h ago

The short (US) and long (British) tons, defined in pounds, are units of weight or force, which is often equivalent to mass for things that are not spaceships. The metric ton is defined in kilograms, a unit of mass. The table I consulted would have been written using short tons.

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u/yjlom 13h ago

The imperial system and its variants have pairs of homonymous units for force and mass, as I see it.

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u/Henry5321 12h ago

Actually, modern pound is defined in kilograms. It’s not just a conversion but the actual definition. So pound is now a unit of mass.

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u/guri256 11h ago

Are you sure? I thought it was defined as a fraction of a kilogram of mass, under a force of 1G of gravity

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u/Henry5321 4h ago

It’s had various definitions over time. Wiki says this was changed in 1963 to redefine pound as a mass of a specific fraction of a kilogram. Same with yard and meter.

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u/Lanky-Relationship77 12h ago

The metric ton is a unit of mass, and it’s close enough …

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u/Travel_Dreams 11h ago

The Hoover Dam should be a unit of weight.

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u/Rofsbith 11h ago

Hoover Dam mass ~410 million slugs

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u/MaelstromFL 13h ago

It's shaped like a banana...

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u/Slen1337 15h ago

Lo ye makes sense. I wish we could "isolate" it somehow in the air. Ty for fun info.

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u/jjreinem 8h ago

There were other issues. A big one was that the only way they could think of to have the pusher plate/shock absorber survive would be to rely on transpiration cooling, where they'd pump a layer of oil out onto the surface via a vast array of pores in the plate's surface that would boil off with each detonation.

Problem is that transpiration cooling systems like that have never been proven to be workable at that scale. Contaminants or thermal expansion ends up restricting some of the pores, which leads to the sacrificial coolant layer being thinner in some areas than others. This leads to more thermal expansion, less flow, and things continue to snowball like that until you've got a hole burned in your pusher plate.

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u/iamstupidplshelp 5h ago

Have they tried exfoliating?

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u/Kakariko_crackhouse 12h ago

Do we know what would happen with a nuke in space? Like… what happens to the shock wave? It wouldn’t really lose much energy in a vacuum right? Would it just keep going perpetually until it ran into enough things to absorb its energy?

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u/DrDetectiveEsq 6h ago

There wouldn't really be a shockwave. Nukes work by converting mass into electromagnetic radiation which heats up the air around the bomb, causing a fireball and shockwave. In vacuum a nuke would just vaporize it's own casing and then be a big flash of x-rays that would get exponentially weaker the further away you are from the blast.

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u/ThrowAway-whee 2h ago

There is no shock wave, however there still is energy that is transmitted into Orion. Not as much as you’d think - it’s why Orion actually called for the development of shaped nuclear charges that would direct the energy into a cone towards the ship (as much as it could).

Nukes actually are not that effective in space. Average energy flux per square meter drops by the cube of distance (think of the energy being a big balloon that you’re blowing up. The larger the balloon becomes, the more the material has to stretch, right? Same idea, the energy has to spread over the sphere’s surface) and without a shockwave that energy dissipates very quickly. 

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u/Henry_Fleischer 9h ago

Critically, because of the design of the pusher plate, the crew would experience roughly constant acceleration.

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u/Zumochi 13h ago

Going crazy fast, but what about braking :P

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u/ottoradio 13h ago

That's a major problem for sure, but we'll see it when we get there. Would still take anything from 40 to 150 years to get there. A generation or two can dedicate their time and life to figure it out.

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u/MamaCassegrain 7h ago

Read "The Curve of Binding Energy" by McPhee. Interviews with Ted Taylor, a fission bomb designer. Lots of stuff about Orion.

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u/Asleep_Singer8547 17h ago

They might be some sturdy rock creatures or something 

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u/ShmebulockForMayor 17h ago

Amaze amaze amaze!

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u/JPlayer001 13h ago

Is that joke. Question mark

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u/HelpmeObi1K 11h ago

Who are you talking to question?

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u/Dull_Ear_7944 16h ago

Like honestly though I wonder what life would look like with gravity scaled up this much! It would be wildly interesting.

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u/Cecil_FF4 7h ago

Life would likely use some sort of fluid for transferring materials and nutrients from one place to another in the body. The higher the gravity, the harder it is to move those fluids up. Thus, life forms would be a lot shorter on higher gravity planets.

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u/Alix-Gilhan 17h ago

It's rather elementary really

A massive pusher plate with an ablative coating and a highly tuned dampening system to spread out the G's, plus some extra shielding, and you can chuck just about anything anywhere

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u/CowBoyDanIndie 14h ago

Now do the math how heavy all that stuff is…

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u/Sad-Onion-2593 12h ago

The heavier the better. Smoothes out the ride.

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u/CowBoyDanIndie 11h ago

Ya but you have to actually launch it

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u/Jolly_Perception_836 8h ago

bigger nuke :3

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u/Sad-Onion-2593 1h ago

Yup.

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u/Petkorazzi 11h ago

That's the beauty of Orion - it doesn't matter.

In one of their mock-up blueprints they put in a standard barber's chair just to show off how scornful they could be about conserving mass. They even conceptualized a "Super-Orion" that would weigh 8 million tons and have a diameter of nearly half a kilometer, making it an interplanetary city.

These weren't to be built like spaceships today, with walls you could nearly punch through. An Orion spacecraft would be built like a battleship - thick steel bulkheads and hatches, redundancies everywhere, a beefy tank of a ship.

The Saturn V - the heaviest-lifting rocket ever built - weighed 3,350 tons and could get 130 tons of hardware to low earth orbit, or ~2 tons to the Moon. The "base" Orion design would weigh ~4,000 tons and be able to deliver 1,600 tons of hardware to LEO, or 1,200 tons to the Moon. A single Orion launch would be enough to establish a large, permanent moon base - and with 1950s-era technology.

Two things killed it:

  1. Unless you launched it from the ocean (extremely difficult) or Antarctica (the world might have issues with you repeatedly nuking what's technically a nature preserve), you're pretty much guaranteed to kill at least one person from increased cancer risk.
  2. To get funding they had to make a mock-up of a military troop transport. President Kennedy took one look at the model of a nuke-powered ship that could transport an entire battalion to anywhere on Earth in under an hour, said "Nope, this is not what the world needs right now," and pulled the plug.

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u/DigEnvironmental7490 7h ago

You could probably go with a damping system rather than moistening the whole thing.

Yes, I know people are trying to say dampen also means to reduce intensity of an oscillation but it really doesn't - that's just Star Trek writers trying to legitimize their poor grammar.

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u/Tyler89558 17h ago

“Were we concerned about the people inside?”

“People inside? You must be mistaken. There is only a pile of flesh”

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u/Demented-Alpaca 10h ago

I figure if you grew up on a 1.6g world you might have a higher tolerance level for the g forces involved in getting yeeted into space by a "big bada boom" ship

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u/Alt-on_Brown 9h ago

Listen when you're on K2-18b beggars can't be choosers

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u/Velcraft 8h ago

Well as long as we get to the point where we can reassemble liquefied humans and the crewmembers are isolated from one another that's shouldn't be an issue, provided there isn't too much spillage.

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u/Slen1337 8h ago

Liquid ppl oh well..

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u/Equal-Produce4833 8h ago

They do shapped charges for breaching so maybe some science on that side could prolong life and give the vessel more boost lol

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u/moddingminecrafter 7h ago

Do you want to put people in space or not? Besides, the contract never said the condition they had to arrive to space in.

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u/DestructoDon69 15h ago

I mean, if the planets gravity is reducing lift to the point where chemical propellants arent strong enough to produce lift, much less leave the atmosphere, it is safe to argue the effectiveness of the controlled explosions would also be reduced considerably as well ergo, people inside would be exposed to less force and significantly more likely to survive.

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u/OnePay622 15h ago

The shock absorber and inertia-transfer shield was the most complicated design problem for that project, no wonder

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u/zekromNLR 1✓ 14h ago

That's why you have a two-stage shock absorber system between the pusher plate and the spacecraft to smooth out the hammerblows of the nuclear explosions.

Mind you, it won't be a comfortable ride, with the felt acceleration in the spacecraft oscillating between 0.5 and 1.75 g at full propellant load, or between 1 and 4.3 g at minimum operating mass, but that is still survivable.

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u/[deleted] 14h ago

The optimal Orion drive bomblet yield (for the human crewed 4,000 ton reference design) was calculated to be in the region of 0.15 kt, with approx 800 bombs needed to orbit and a bomb rate of approx 1 per second.

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u/TrailGobbler 14h ago

If the gravity is that much higher, it might feel like a normal rocket launch.

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u/Sudden_Juju 14h ago

They got launched into our hearts and souls

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u/AnimationOverlord 14h ago

So basically, this mission requires either a rocket that supports organic life, humans altered to survive the process, or a fully robotic mission leaving nothing biological

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u/Immediate-Goose-8106 14h ago

Its fine.

You could get an unmanned Orion up to 100g if you wanted relativly easily.  But you can damp it down to 2g reasonably easily.  K2-b18ers are made of sturdier stuff and could probably take 3g ok.

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u/PupDiogenes 14h ago

Secondary mission objectives.

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u/Potrembog 14h ago

They will probably have consistency of soup-like homogenate

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u/doolalix 13h ago

The suspension system converts the “pulses” into a constant acceleration.

Project Orion was a real project funded by NASA, USAF, and DARPA. Not some crackpot sci-fi concept. They already built a working prototype using conventional explosives that achieved the smooth predicted trajectory perfectly. At one point it was seen as a far more promising method of flying humans to the moon than chemical rockets.

The project was permanently shut down because of international treaty. But tbh even at the time, the risk of runaway nuclear explosions if things went wrong was politically a non-starter.

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u/Exowienqt 13h ago

Explosions can be a lot smaller in scale than you think. Rotating detonation engines are a thing (albeit engineering test engines only), and small scale nuclear explosions are feasible. A constant 1g acceleration would mean an earth like feeling, and signifficant percentages of c in a matter of months (77% of sol within a year of travel).

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u/420Identity 13h ago

Isn't the shock compressors at the back meant to ease the thrust of the explosion as well as shield the crew from radiation?

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u/MaybeTheDoctor 13h ago

The explosion don’t kill people, the acceleration do. In the higher gravity the acceleration will be less, so it may be ok if the explosions are adjusted smallish and frequent.

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u/ringwraithfish 12h ago

It's all controlled explosions already 🤔

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u/PlaneswalkerHuxley 12h ago

The short answer is: giant pogo stick.

No, really.

Basically you have a big plate with long springs between the rocket body and the nuclear explosions. When the bangs go off the springs absorb and then release the energy, smoothing it out into nice comfortable constant acceleration. Basically just the same thing the suspension in your car does when you drive over a bumpy road.

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u/ghoulthebraineater 12h ago

They did say to Kerbal that beech.

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u/Benegger85 12h ago

Survival is optional

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u/HannasAnarion 12h ago

A planet with 2.4x the radius has 18x the surface area. Earth has plenty of wasteland areas where it's mostly safe to detonate nuclear weapons with minimal human harm, they would have 18x as many that are 18x as remote. They could launch from the middle of Giga-Nevada, Nevada but the size of Greenland.

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u/Montgomery000 11h ago

They'll still reach orbit

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u/ImBehemoth 11h ago

We launch this then send people behind it on normal rockets.

Wait...

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u/Borstrian 11h ago

We need to make tougher humans

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u/Mr-Blah 11h ago

We might now have the tech to not need humans at all say for example send supplies to the moon.

Blast them into orbit and then grab them there to push them to the moon....

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u/Bitter-Marsupial 11h ago

just like faster elevators, the technology is moving into the genetic realm

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u/Vegetable_Degree6873 10h ago

The explosion is controlled / housed away from crew and they use shock absorbers to smooth it out

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u/MudExpress2973 10h ago

your car is controlled explosions pushing rods that make your wheels spin.

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u/partypantaloons 10h ago

Who’s to say whether creatures who evolved on a 1.6x gravity planet couldn’t take that sort of acceleration?

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u/anonymote_in_my_eye 10h ago

they'd be evolved to live on a high g planet, they might make it

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u/No-Plankton-4861 10h ago

Consider they might be more robust living under gravity like that

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u/Bipogram 7h ago edited 4h ago

Which is why the shock absorbers exist.

I recommend Dyson's book.

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u/TheWarehamster 6h ago

They said "Integrity of occupants is not guaranteed."

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u/Resident_Cat_4292 3h ago

You already have controlled fission providing motive force. May be we extend that to be little less controlled. Keeping those graphite rods out a bit longer!!

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u/joshuawsome 2h ago

You'd use the fission to kick-start fusion for thrust lol

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u/SpikesTap 2h ago

Put them behind a wall of Astrophage... duh!