On Mon, 14 Apr 2008 07:45:07 GMT, Bryan Derksen
<bryan.derksen@[EMAIL PROTECTED]
> wrote:
>Leonard Erickson wrote:
>> So first need is some sort of relatively cheap, easy to obtain
>> container that can hold a 1 bar pressure difference.
>>
>> Any chance that any of the amo cases or the like you can find at gun
>> shows might work?
>
>A pressure cooker is the first thing that comes to mind.
>http://en.wikipedia.org/wiki/Pressure_cooker
says most standard pressure
>cookers sold in the US can hold a one-atmosphere difference and there's
>probably a goodly safety margin there.
They tend to be inconveniently small, and a sub optimal shape.
>> Second, suggestions on how to build a shelter to even out temp
>> differences. Assume no parts bigger than a standard sheet of plywood
>> or heavier than a couple of hundred kilos.
>
>Bring a shovel and dig a deep hole. Or carve a cave into the base of a
>cliff face - you probably won't even need tools for that, just keep
>repeatedly flying at high speed into it and chisel it out with your
>invulnerable head. :) This will have the added benefit of providing
>radiation protection, too.
>
>You may be able to find ready-made caves, evidence of lava tubes has
>been found in photos from orbit. Also, if a constant _cold_ temperature
>is okay, there are the shadowed craters at the poles.
Ah, I used to know some folks in the L-5 Society and related groups
who were working on a project to try building a "mockup" base in one
of the lava tubes down near Klamath Falls tp test some of the problems
that might be encountered.
Got any urls for the locations of those suspected lava tubes? They'd
be high on the list of places to scout.
>> Third, cheap pressure suit for any visitors she might haul up there.
>
>Much, much harder, as pointed out elsewhere in the thread. But if all
>you want to do is store someone up there, without letting them wander
>around on the surface, there are probably easier ways.
>With a weight limit of a couple of hundred kilos you won't be able to
>bring up much of a pressurized habitat module in one trip. You could
>perhaps haul up a big propane tank, but something like that would be
>really claustrophobic - I'd have to _really really_ trust the super to
>be left in something like that.
Well, the most likely "companion" can get back on their own.
Tele****tation is handy, but if you have to be there before you can
target it, there are problems.
>Instead, I'd focus on enhancing the cave idea I mentioned earlier. If
>you dig a cave in suitably hard rock, it should be able to hold
>pressure. You'll just need to add a door. That's still going to be
>pretty hard, a door and surrounding steel doorframe capable of holding
>that pressure won't come cheap and won't be easy to install. Keep it as
>small as possible, a hatch just big enough to crawl through.
Assuming theres a way to seal things to the rock (needed as insurance
for the pressurized section anyway) and if the lava tube is reasonably
long, it might be easier to build a number of "hatches". Each would
only have to handle a few psi. Adds a safety factor as well as being
easier to build.
>Anchoring your hatch's steel wall to the rock will require some holes to
>be drilled; pneumatic tools should work fine on the Moon, though you'll
>need to fly all the way back to Earth to replenish the pressurized air
>so super-powered hand tools might be better.
Heck, go back to the "John Henry" type rock drill. Steel rod with a
properly shaped end. Place it against the rock, hit with big hammer
(or a an invulnerable fist with some super strength behind it.) Rotate
rod slightly, repeat.
Remove rock chips and dust as needed.
This will be tedious but doable. Very tedious as the rock is likely to
be basalt and that stuff is pretty tough. Not like granite, but not
fun either.
>http://www.iht.com/articles/1992/02/13/moon.php
had some tantalizing
>suggestions about the possibility of making concrete on the Moon and
>setting it in a vacuum. Not sure how well it'll work with regular
>commercial stuff. Concrete would be good for sealing up the gaps around
>the edges of the door frame. Failing that, perhaps use a gas torch to
>solder the edges with something meltable?
Heck, *thermite* will burn quite happily in a vacuum. Bring along some
fireclay or the like to channel the liquid iron (or use your
invulnerable hands) and you could probably seal things fairly well.
>If you use pure oxygen to fill the habitat you'll have much less than a
>full atmosphere of pressure, so that'll help ease the stress on your
>door too.
No thanks. I'm old enough to remember the Apollo 1 fire. Besides,
plants will do an okay job of air renewal once they've got reliable
power. You want higher pressure for that as well as well as avoiding
decompression problems.
I can just see our supers getting in trouble because all the
hydroponics gear and grow lights gets them suspected of starting a
marijuana growing operation. :-)
>An airlock will probably be needed; if the super isn't super-strong he
>won't be able to open the hatch against atmospheric pressure, and the
>super needs to be able to get in and out without blowing all the air and
>killing the visitor in the process. This should be just a matter of
>installing a second hatch and putting valves in them to allow pressures
>to be equalized.
Well, depending on difficulty of making the hatches, the multiple
hatch solution might be good.
And once it's airtight and has decent supply of air and is at a
reasonable temp, the tele****ter can help with some things.
Either way, hauling up enough pressure tanks for "just in case" will
be a chore, but doable.
Drat. Gotta be able to seal against a full 1 atm pressure, because
lava tubes are apt to be a *lot* longer than is practical to use.
A quick google search says that lunar tubes are apt to be large. Much
larger than the ones on earth. This is a problem.
Looks like the best bet may be the old "buried quonset hut" with a
pressure tight liner.
Framerwork pieces should be easy to carry. A bit harder to assemble
(note: erect sunshade so they don't expand too much, but reflect
enough light that they don't shrink too much either.)
Attaching the corrugated tin (or whatever) cover panels won't be too
bad either. Burying it will be a pain. Probably best to find a small
"valley" or something so you don't have to excavate and *then* bury.
Just bury.
Doh!
Just build the silly thing inside a lava tube. No need to bury it.
Hmm. I wonder what materials (especially things like heavy sheet
plastic) will be ok in a vacuum?
Come to think of it, welding, say 1/8" aluminum in a vacuum ought to
be easy. And with some steel framing on the outside to sup****t against
the internal pressure, it might just do.
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