GURPS O'Neill Cylinder Design

[Rupert]

Originally Posted by Anthony

I would avoid uses that run the risk of maintenance issues for the rectenna structure. Depending on the opacity of the rectenna, I might put a conventional solar farm under it -- there's some loss of efficiency because of light blocked by the rectenna, but you make up for it with simplifying your power grid.

It's true that cow-proofing your rectenna array's supports would probably raise the cost a bit. Proofing it against idiots driving farm machinery too fast would cost even more.

[Prince Charon]

Originally Posted by Rupert

It's true that cow-proofing your rectenna array's supports would probably raise the cost a bit. Proofing it against idiots driving farm machinery too fast would cost even more.

Have the farm machinery driven by computers, perhaps?

[Rupert]

Originally Posted by Prince Charon

Have the farm machinery driven by computers, perhaps?

If you can make that cheaper than minimum-wage workers, perhaps. It might just not be worth the expense, and it's just easier to use Anthony's solar array option, or run something relatively unlikely to hurt the recenna and cheap/low labour, like sheep.

[Prince Charon]

Originally Posted by Rupert

If you can make that cheaper than minimum-wage workers, perhaps. It might just not be worth the expense, and it's just easier to use Anthony's solar array option, or run something relatively unlikely to hurt the recenna and cheap/low labour, like sheep.

I'm not sure that the minimum wage workers on farms are the ones driving farm equipment anymore.

[martinl]

Originally Posted by Anthony

It would actually be decently dangerous, but so is taking control of the power supply of a small country...

That is also a good RPG plot.

For OP's purposes, having folks in orbit for powersat maintenance is probably sufficient to justify the habitat, but adding powersat security to that is good adventure fodder.

Nuke the burrito from orbit, it's the only way to be sure.

[AlexanderHowl]

If you have SPS arrays, you will likely need lunar mines for the construction materials. Since they would use mass drivers to deliver materials into orbit, you would want substantial security, meaning a decent population on the Moon, which will likely need to go back to experience normal gravity after 6 months on the surface of the Moon. It is cheaper, easier, and safer to send them to an orbital habitat than to the surface of the Earth, so your space habitat would also support your lunar mines.

[Proteus]

Originally Posted by AlexanderHowl

If you have SPS arrays, you will likely need lunar mines for the construction materials. Since they would use mass drivers to deliver materials into orbit, you would want substantial security, meaning a decent population on the Moon, which will likely need to go back to experience normal gravity after 6 months on the surface of the Moon. It is cheaper, easier, and safer to send them to an orbital habitat than to the surface of the Earth, so your space habitat would also support your lunar mines.

Or you could have asteroidal mines sending regular packets of refined material in large, slow-moving transfer orbits, to be "caught" locally and then used.

I'm willing to believe that environmental / artistic / traditionalist concerns could scotch most attempts at mining the near side of the Moon, and that scientific concerns (radio-antenna placement and stability, etc.) might be enough to hinder far-side exploitation.

Then you have to have security way out in the Belt, and you've still got rotating stations out there, but it is a different dynamic.

[martinl]

Originally Posted by Proteus

Or you could have asteroidal mines ...

I'm willing to believe that ... concerns could scotch most attempts at mining the near side of the Moon..

Then you have to have security way out in the Belt, and you've still got rotating stations out there, but it is a different dynamic.

In RPG settings, you generally want more potential mayhem, not less, so I say include both, and that they are in cutthroat competition with each other.

[AlexanderHowl]

Lunar mines end up being a lot cheaper than asteroid mines due to the ability to use mass drivers for transporting materials into orbit. The close proximity also helps to catch mistakes before too much damage can be done. Of course, asteroids have more easily accessible precious metals, so they would likely exist and would produce industrial metals as a byproduct.

[Proteus]

Originally Posted by AlexanderHowl

Lunar mines end up being a lot cheaper than asteroid mines due to the ability to use mass drivers for transporting materials into orbit. The close proximity also helps to catch mistakes before too much damage can be done. Of course, asteroids have more easily accessible precious metals, so they would likely exist and would produce industrial metals as a byproduct.

My point was not an economic one but an aesthetic one.

Attempts at lunar mining are going to run into a buzzsaw of opposition from traditionalists who can't imagine tampering with the "Man in the Moon," from romantics who can't imagine blemishing the light associated with countless love songs and poems, and from plain old curmudgeons who don't want an age-old component of human nights altered.

In a future with generous space development, asteroidal resources could be relatively cheap, if you don't mind a long delay between when they're ordered and when they arrive. A multi-kiloton "package" equipped with a small, automatic mass driver could gently nudge itself into the inner system over a period of several months.