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Space Elevator

(neal.fun)
1773 points kaonwarb | 1 comments | | HN request time: 0s | source
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isgb ◴[] No.45643283[source]
> Space elevators are actually a possible idea being considered by scientists. > The hard part is making a strong enough cable. And finding enough elevator music...

Most engineers would bring up a lot more issues than just finding a strong cable. Also, most attempts with e.g. carbon nanotubes have been abandoned ages ago https://www.newscientist.com/article/2093356-carbon-nanotube....

- We don't have a good ascent mechanism other than rockets - and then we might just use rockets without building an elevator. - We don't have a good (and safe) descent mechanism. - Maintenance? Protection from space debris? Protection from oscillations? Ground-protection if the elevator collapses?

This is dyson-sphere level of fiction. We can do back-of-the-napkin calcualtions on how things would work, but the practicalities make it completely impossible or impractical.

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gizmo686 ◴[] No.45644414[source]
Isn't the entire point of the space elevator to be the ascent/descent mechanism?

Once you have the cable up, you can grab onto it and pull yourself up.

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bisby ◴[] No.45644930[source]
A space elevator doesnt just take you to the karman line (like in the OP website), to get to orbit, you'd need to get up to geostationary height. That's 22,000 miles.

What's the best way to pull yourself directly vertical along a cable for 22,000 miles?

What's the best way to descend 22,000 miles quickly, but also with a braking mechanism that isn't going to require a heat shield?

Some sort of slow cable car going at 10mph even is going to take 2200 hours... 1000mph is going to take 22 hours still. That's a full day to orbit even going REALLY fast. And getting up to 1000mph vertically, for a sustained 22 hours... that's not an easy feat.

And if the goal is just to get up past the karman line and use the elevator as a stage 1 for a rocket launch and detaching from the elevator while suborbital is fine, then it's a one way trip, and still need to re-enter the old fashion way.

The scale of space makes all of the problems far more complicated (edit: not just the cable strength issue, but traversing the cable)

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1. oofbey ◴[] No.45645298{3}[source]
You don’t need to get to geostationary to get to orbit. The reason elevators need to get that high is because that’s the lowest place you could “anchor” the top of the elevator to something fixed relative to the earth.