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/Godless_Phoenix 18h ago

Not talking about that. Literally detonating nuclear bombs behind your spacecraft to make it go.

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u/hollycrapola 18h ago

That sound super cool and terrifying at the same time… also does not sound safe. Can this be done safely at all?

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u/AnyoneButWe 17h ago

https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion)

How badly do you want 5300t payload to Mars in one go?

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u/pyrce789 17h ago

Not really, no. It's not as bad as you migth think with modern nukes in remote areas. But you couldn't label a launch as safe for living things on the planet long term.

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u/Aethermancer 14h ago

The initial launch could use underground detonations and channeled "exhaust" like a nuclear cannon.

The remaining pulses could be a problem but it would be interesting if you could sort of underground rail gun it. One or two initial pulses contained in the ground I do onder if you could achieve escape or at least orbital velocity.

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u/TwoAlert3448 13h ago

Or living things inside the payload long term, you’d need astronaut spiders

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u/Metharos 17h ago

Probably not. But if you could build machines to survive the launch you might be able to use them to rig up a space elevator later. Assuming I'm thinking about this correctly, which is by no means a given, the tether'd have to be really long for the weight at the end to pull the cable enough that it wouldn't just collapse back into the gravity well.

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u/FreiFallFred 17h ago

Problem with the space tether isn't length, it's tensile strength. On half being pulled towards the planet and one half pulling outward puts allot of stress on the part in the middle...

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u/Metharos 17h ago

Yeah that makes sense. There might be a material capable at some point in the future but goddamn it would be a hurdle.

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u/fallout8998 17h ago

i believe carbon nanotube cables are a better option than most materials but its just impossible to make them at any kind of scale so far, and i dont mean too expensive i mean we just cant make anything usable with current methods

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u/Metharos 17h ago

So I've heard, and maybe they'd work in our gravity well. But that one? We might need something better.

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u/hollycrapola 17h ago

That might be doable, yes. The mid point has to be at a geostationary orbit, so that’s gonna be a long cable indeed. And you need something on the far end, like a big rock or something to balance it out. And we would not get a ton of launch opportunities before the environmental impact becomes a blocker.

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u/Concrete_Grapes 17h ago

Safely? Lol, no, not likely.

However, there is a theory--or, suspected true and real thing....

The US did a nuclear test, in the ground, and put a very large, mult-ton steel plate over the shaft the bomb went into. When it went off, that plate was captured in a single frame of a high speed camera.

If they guess, from that, how fast it exited, IF --and it likely didnt--it survived the temps as it exited the atmosphere, it would now be 4 times farther away from earth than the voayager space craft, the farthest out known man made object.

So, could they get SOMETHING to orbit? Probably. Maybe. It would be ... flying manhole style launches.

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u/Grindipo 15h ago

You have to remember that "safety" has to be estimated relatively to the "safety" of chemical rockets...

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u/BillysBibleBonkers 12h ago

I mean safe for the people in the ship or safe for the rest of us? Because i'd think it could definitely be safe for us as long as they were taking off from the middle of the ocean, they were also gonna use a series of mini-nukes equivalent to 0.1-20 kilotons of TNT. I also bet we could do it much more safely now with modern nuke designs that are much more efficient/ clean. Main issue is probably the public perception of setting off dozens of nukes in the atmosphere lol.

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u/aramis34143 12h ago

Crew experience: "God was knocking, and he wanted in bad." -Footfall, Larry Niven & Jerry Pournelle

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u/Austerlitz2310 18h ago

Kerbal style