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Space Elevator

(neal.fun)
1773 points kaonwarb | 1 comments | 20 Oct 25 04:42 UTC | HN request time: 0s | source
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tempestn ◴[20 Oct 25 06:49 UTC] No.45640679[source]▶
TIL it's estimated that over 48 tons of meteors hit the atmosphere every day.

Regarding actual space elevators though, while they're not sci-fi to the extent of something like FTL travel - ie. they're technically not physically impossible - they're still pretty firmly in the realm of sci-fi. We don't have anything close to a cable that could sustain its own weight, let alone that of whatever is being elevated. Plus, how do you stabilize the cable and lifter in the atmosphere?

A space elevator on the moon is much more feasible: less gravity, slow rotation, no atmosphere, less dangerous debris. But it's also much less useful.

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pbmonster ◴[20 Oct 25 08:34 UTC] No.45641321[source]▶
> A space elevator on the moon is much more feasible: less gravity, slow rotation

The slow rotation is a minus, it means you've got to string the tether up to L1 instead of "just" up to geo/luna-stationary orbit. A lunar space elevator needs to be at least 56000 km long, more than 20000 km longer than the one to earth.

> But it's also much less useful.

Yeah, especially because all the things that make lunar space elevators a little more attainable also make lunar mass drivers a lot more attainable. Why ride in an elevator for a week if you also can just be fired from a cannon?

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1. pfdietz ◴[20 Oct 25 11:55 UTC] No.45642883[source]▶
A space elevator is kind of like a vertical mass driver, so just build one of those along the surface of the moon with modest acceleration, survivable by passengers.

Rotating cables ("rotavators") on the moon seem much more practical than full space elevators.

https://en.wikipedia.org/wiki/Momentum_exchange_tether#Rotov...