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Comment by taneq | Hacker News Reader

The Moon's gravity well is smaller but, with no atmosphere, it's both much easier to escape, and much harder to land softly on. If anything, I'd guess our best bet is a propellant factory on the Moon, using a magnetic launcher to shoot the fuel into lunar orbit to supply an orbiting fuel station.

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Giving the moon magnetic catapults is giving the moon weapons for their eventual war for freedom from earth.

TANSTAAFL!

Silence, Comrad - you will blow our cell! Or are you working for Warden - Catapulthead-svinoi!

Magnetic launchers can be used in reverse as catchers too as a sort of atmosphere replacement.

How so? Would you have to "land" by going back down the barrel of the launch device?

That'd be quite a trick if you could pull it off - the precision required seems formidable, though.

Like trying to land a rocket upright back on its launchpad. Lunacy.

The rocket gets to 'fly' in, taking advantage of the atmosphere for control and braking. Not that it's not a bonkers achievement but the speeds are much higher and the tolerances much lower to slot an orbiting payload back into a linear rail.

Magnetic Lander might be a decent smartphone game...

How is that that much different than landing on an aircraft carrier?

Should be easier if we can assume that the vehicle is powered because the landing stage is not moving.

It's occuring at orbital velocity in a vacuum.

Would the vacuum piece make it much easier than landing on a carrier

At least there wouldn't be a crosswind

You should look up proposals for Venusian cloud cities. In many senses Venus is more hospitable than Mars.

On Mars, or on Moon, you have a lot of local materials to build from. A Venusean floating city needs to be brought in completely from the outside.

I can see how you might think that, I suppose, but you do actually have an entire planet full of useful resources at hand, even if they're not ones that you might immediately think of. There are many things that you can reasonably extract or synthesize from the Venusian atmosphere, particularly plastics. This StackExchange answer has more details: https://space.stackexchange.com/questions/9158/what-useful-m...

How about a space elevator?

Actually can be built with existing materials I remember reading

Unfortunately the moon turns very slowly. It is tidally locked to Earth. The cable of a moon space elevator would have to be the length of the moon-earth distance.

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