
Standard Space Habitats - luu
https://halcanary.org/vv/2020/07/14/3017/
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jandrese
The subtitle of the article is a better title for the HN post.

> A refinement of O'Neill's colonies.

Basically just increasing the robustness of an O'Neill colony by removing the
windows and giant mirrors. Also bolted on the power generation and cooling
requirements that the original design mostly overlooked. I'm not sure the
cooling requirements have been fully considered however, since it involves
pumping hot coolant through 32+km of pipes. As described the colony is going
to have a hot side and a cold side.

And honestly, the O'Neill cylinder is going to be covered in gold foil. I
fully agree that the windows and gigantic mirrors are not a good idea.
Electric lights run off of a massive solar array avoid many of the problems of
the original design.

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wedn3sday
The back side of solar arrays make for good radiator placements. I dont see
any reason why all the solar arrays and radiators need to be on opposite ends,
why not have both on both sides?

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programd
Why bother connecting the solar arrays to the habitat? Just hook them up to
microwave transmitters and beam the power to the cylinders. That way you can
have the solar arrays anywhere it's convenient, maybe even in position to
shade the entire colony so that the heat disposal problem is less of an issue.

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throwaway316943
Fair point but you needn’t bother with microwaves when a cable and some good
ol’ fashion brushes will do. It’s just a rotor after all.

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HuShifang
One of the major observations in Kim Stanley Robinson's _Aurora_ [0] (which is
excellent, well-informed, and worth a read) is that "99.9%" self-sufficient
isn't going to cut it, at least for a multigenerational interstellar mission.

[0]:
[https://en.m.wikipedia.org/wiki/Aurora_(novel)](https://en.m.wikipedia.org/wiki/Aurora_\(novel\))

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philwelch
Well of course not, but building colonies inside the solar system is much more
forgiving. In fact much of the potential benefit lies precisely in trade
between Earth and the colonies.

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goda90
Maybe there can be some of the advantages of a system sent along. A
multigenerational fleet with multiple ships, capable of trading among them,
but also providing a degree of separation and differentiation. You could even
try attaching some engines to asteroids and comets full of useful materials to
send along side the fleet, ready to be used if the self sufficient systems
fail, and for the colony when they finally arrive.

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vhodges
Steel is a poor material for radiation protection (because of high energy
scattering effects causing secondary high energy particles - but I am no
Physicist). Hyrdogen rich (eg water, polyethelene, etc) make better shielding.

See also this paper on a potential location that requires little or no
shielding:

[http://space.alglobus.net/papers/Easy.pdf](http://space.alglobus.net/papers/Easy.pdf)

A related paper proposes a faster rotaion (upto 4 rpm) vs. the conservative
2rpm selected in the '70s which allows for smaller (easier, cheaper) colonies
to be built sooner.

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arijun
I was hoping for something a bit more innovative or comprehensive, this seems
to be just an oneil cylinder with no windows.

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abecedarius
Right. They justify this by radiation and impacts, but without giving any
numbers. Those were certainly considered back in the 70s.
[https://en.wikipedia.org/wiki/O%27Neill_cylinder#Atmosphere_...](https://en.wikipedia.org/wiki/O%27Neill_cylinder#Atmosphere_and_radiation)

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vhodges
Addendum: If you like Space art (including a possible rendition of the Kalpana
1 and 2 designs) visit

[https://spacehabs.com/](https://spacehabs.com/)

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tln
I don't get why "if [the diameter] is an order of magnitude larger, the
structure won't hold together when it spins". The centripetal force is the
same, 9.8N/kg, so it's kg / m^2 that matters. Right?

Wikipedia lists other design updates:
[https://en.wikipedia.org/wiki/O%27Neill_cylinder#Design_upda...](https://en.wikipedia.org/wiki/O%27Neill_cylinder#Design_update_and_derivatives)

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1958325146
Imagine cutting a cylinder in half from top to bottom, then taping the halves
back together. As you spin it, the tape has to stop the two halves from flying
apart. If you make the cylinder bigger and keep the centripetal acceleration
the same, the tape has a harder job do because it has heavier things trying to
fly apart.

Every strip of the cylinder has to keep the opposing halves from flying apart.
For a big enough cylinder, the material will not be strong enough. You can
make the cylinder walls thicker, but now you've made the flying-apart halves
heavier too.

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tln
But if you just consider equal size strips, with the larger cylinder just
having more of them, then the force on each will be the same... unless you're
saying the imaginary tape have to deal with forces from other strips. I don't
see why

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rini17
I believe habitat with natural light and view of the stars will be much more
attractive than without.

The windows could contain sandwiched several meters of clear water for
radiation/meteor protection, with self-sealing chemicals/a system to
continuously automatically repair leaks. The water will also provide emergency
water supply and thermal stability.

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jkmcf
Another person addressed the window material problem (the tech doesn't exist).

Given that, I think it would be more attractive to have more spacious
interiors, namely higher ceilings and wider corridors.

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ncmncm
Alexis Gilliland explored similar ideas in more depth and with interesting
politics alongside, in "Revolution from Rosinante" and two sequels.
Recommended. (Available as an e-book.)

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choeger
The usual question would be: how would one build such a structure. And why
should someone create the infrastructure to do so in the first place?

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Sosh101
> The frequency of revolution is about two minutes

period

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choeger
Hmm, yes, I think you are right. Revolutions from standstill every two minutes
might be a little uncomfortable in the long run, but certainly would be
entertaining for a short while. Much like a washing machine.

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nojokes
How do you make war between habitats?

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ceejayoz
High speed rocks.

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wishinghand
Coated in vanta black

