Artificial Biospheres In Space

> From: Gturner6PPC@... [mailto:Gturner6PPC@...]

> The optical fiber approach becomes dreadfully expensive very
> quickly. Just illuminating a 100 by 100 meter area could result in
> a cable that costs $2.4 million dollars a meter, and that's a pretty
> conservative estimate.

Presuming this refers to using lots of little optical fibres? Why not just use one big one? It's not like it'll have to be flexible after it's installed.

> The O'Neill type windows also represent a serious problem, although
> the mylar mirrors are easy.
> Unfortunately, to cut the length of the seals
> in half and the number of windows by four, by doubling the diameter
> of each window, requires the window to be twice as thick, and the
> total weight of glass doubles.

Then use long thin windows. A 1x10m window would have a 22m 'o-ring', rather than a 31m/40m worth if it had been individual 1x1m windows, and it could keep the same thickness. That's a useful saving. 45 windows per hour may also be very practical with robotics, or just regular people - if it's an island 4 with 20,000,000 living there. ;) The habitat windows would also not be pressure critical. Sure if one gave way the colony would start to loose gass, but very slowly and no-one would be immediately threatened by it.

> Just the bulk
> cost is coming to around $2,300 per square meter, and I wouldn't be
> surprised if the final cost was ten times higher.

Using space-based manufacturing could affect the price, as could buying in the tens of square kilometers. Either could bring the price down.

> Using solar cells and the new argon sulfur sunlight bulbs would
> probably come in at a much lower cost than this, and don't require
> precision assembly in a vacuum environment. In the near term this
> might be a much easier option to adopt.

Very true and very practical, with just one draw-back: You won't be able to see the stars at night.

ANTIcarrot.