asteroid habitats

--- In spacesettlers@yahoogroups.com, "victoriatangoman"
wrote:

> the remaining walls cannot safely be considered to be
> monolithic, and in fact there may be sections that are loose
> aglomerations, which would erupt when subjected to the forces
within
> atmospheric pressure.

The article "How to Colonize an Asteroid" (I think the site is now
defunct) mentioned this problem. The suggested answer is to be very,
very careful.

> If you have the technology to "melt" a whole asteroid, I'd simply
> redeploy it so that you melt out the metals, then remelt the metals
> into an engineered product - a Habitat shell.

The method of hollowing out the asteroid, from the article mentioned
above (and from other sources) is to drill a shaft down the length
of the asteroid, stuff it with bags full of water and a
thermonuclear bomb. The bomb goes off, and the steam and shock wave
blow the asteroid up like a balloon.

> As for your sunlight question well, let's work it through a bit.
>
> You don't specify a diameter, so I'll assume 6 km. On the cylinder
> wall, you've got 565 km^2 of area that needs to be lit. Assuming
each
> end cap is half of a sphere, the surface area of each end cap is
56.5
> km^2. If one end cap is dedicated to your window, then you need to
> light a total of 621 km^2 of area. Assuming you want to deliver
1,000
> watts of light to each meter^2 of surface area you're going to
have to
> shine 621 GW through that end cap.

Actually, the diameter is 20 km. I should have told you that. But
thank you for the calculations. Now I have to come up with over 800
GW of light. ;)

> How will you create night and day?

Night is unnecessary in my scenario. Shutters on the bedroom
windows will do nicely. I work graveyard shift, so I know.

> How much heat will be absorbed into the endcap window?
> How will the window radiate the heat?

Very good questions. Anyone have an answer?

> How will you deal with the permanent shadows created by having the
sun
> be immobile in the endcap?

Some people like to sit in the shade. And if the far endcap is
mirrored (or partly so), this might not be that much of a problem.

> There will be a differential in light intensity between the region
> immediately adjacent to the endcap window and the region 30 km
away at
> the other end of the cylinder.

There will be a temperature difference, too, which will affect wind
patterns. I have that info in my files somewhere, and can post it
at some point. Basically, it would operate pretty much the same as
in an Island 3 cylinder.

> Will people like to have their windows facing into perpetual
shadow?

I would assume that windows would face the sun, but when the sun
came up over the mountains this morning and into the coffee shop
window, I changed seats to get it out of my eyes. So perhaps some
windows will face the sun and some would not. Actually, like the
ancient Greeks, people are going to spend most of their time
outdoors.