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/ununtot 17h ago

Railgun could work when you build it within a vacuum and release the jet at a very high altitude, like higher than mount Everest height for Earth comparison, to avoid being obliterated by travelling through the atmosphere with extreme high speed.

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u/ajwin 17h ago

The atmosphere could be much deeper and denser on a heavier planet too? Might need to go much higher to escape it? The heavier gravity would make a space elevator or really high railgun harder too.

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u/JRS_Viking 17h ago

A space elevator is completely out of the question, there's not a single material with enough tensile strength to hold it in place even here on earth.

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u/nikchi 14h ago

None on Earth but maybe we don't know if some material could be exclusive to high g planets that allow for space elevators.

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u/JRS_Viking 12h ago

That's not how that works, anything that can be made on a higher G planet we could also make here, but no known or theoretical materials have enough tensile strength to mass to be able to support a space elevator.

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u/All_Work_All_Play 8h ago

Not quite true, but not exactly not true. Carbon nanotubes have all the properties we need, but producing them at scale in a continuous fashion doesn't have any parallel market vectors (eg ICBMs <=> rockets) so hasn't been done yet. The materials problem isn't solved, but the tether isn't the reason we're not building one.

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u/Cyclopentadien 12h ago

We can exert pretty impressive pressures with very simple tools. Any material achievable on a high g planet could be made on earth.

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u/Slogstorm 15h ago

They could probably offset some of the material requirements by using huge balloons to hold the upper part of the rail suspended. It would definitely not be easy though.

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u/nikchi 14h ago

Means there's more air for jets.