On 15 apr, 10:52, Leonard Erickson <sha...@[EMAIL PROTECTED]
> wrote:
> On Mon, 14 Apr 2008 16:38:28 GMT, Bryan Derksen
>
>
>
> <bryan.derk...@[EMAIL PROTECTED]
> wrote:
> >Leonard Erickson wrote:
> >> On Mon, 14 Apr 2008 07:45:07 GMT, Bryan Derksen
> >> <bryan.derk...@[EMAIL PROTECTED]
> wrote:
> >>> 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.
>
> >The Apollo 1 fire happened not just because of a pure oxygen
atmosphere,
> >but because they used a _16 psi_ pure oxygen atmosphere. They needed to
> >test the spacecraft's ability to hold pressure in a vacuum, but since
> >they were testing it at sea level they had to pump it up with
> >higher-than-sea-level pressure inside to do that. In space, pure oxygen
> >atmospheres are only around 3 psi. The lack of nitrogen as a buffer gas
> >would make fires a bit hotter but you wouldn't get an instant
> >all-consuming infero like Apollo 1 did.
>
> No, but it'll be at least as bad as an oxygen tent fire.
>
> Gibven that the materials easily scrounged may be things like wood and
> plastics, I'd not want to risk it.
>
> >> Besides,
> >> plants will do an okay job of air renewal once they've got reliable
> >> power.
>
> >It's actually a lot trickier than it seems to get this to work. Google
> >for "CELSS" (Controlled Ecological Life Sup****t System) to find work
> >that's been done on this area. Plants will certainly be nice to have
> >around, for psychological reasons if nothing else, but you're still
> >going to need to worry about CO2 scrubbers and bringing more oxygen up
> >from Earth over the long haul. When your ecosphere is only the size of
a
> >small house it's got too little inertia to strike a balance easily.
>
> They'll help a lot. And if you pick things that are edible raw, it's
> nice for snacking. (Fond memories of the tomato "bush" a friend had.
> The tomatos varied from pea sized to grape sized and were delicious.
> Also bore them for *months* ripening a handful or so a day. :-)
>
> >> You want higher pressure for that as well as well as avoiding
> >> decompression problems.
>
> >You're unlikely to get the bends from a 0.8-atmosphere drop in
pressure.
> >That's the equivalent of coming up from a dive of 26 feet depth.
Digging
> >around a bit, I found a website suggesting that divers don't need to
> >bother with decompression unless they go under 130 feet down.
> >There'll be unpleasant ear-popping, perhaps, if your tele****ter is
> >switching air pressures instantaneously. Perhaps she should tele****t to
> >a mountaintop first in order to give her ears and sinuses a few seconds
> >to drain of excess air. Can she tele****t into mid-air higher than that?
>
> Also not good for sodas, many packaged foods and even a lot of
> computer stuff.
>
> >Alternately, since mass is so cheap in this scenario, you can just
> >over-engineer everything to such a degree that holding a full
atmosphere
> >of pressure isn't a major concern. :)
>
> See my multilayered wall idea in the original thread.
>
> Though I'm wondering if a concrete sealer that's rated for arctic
> conditions might not be a good start.
>
>
>
> >>> 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.
>
> >If the tele****ter is able to take the super as a passenger and is
always
> >available when the super will need to get inside the base, it might be
> >best to not bother with hatches at all. Dig the cave in a vacuum, bring
> >in the tele****ter to familiarize her with the location, then seal the
> >entrance completely. If you want solar power make sure to leave a cable
> >running through the plug.
>
> I thought about that, but she needs to be able to get in on her own.
> This may be easier to solve if it takes long enough because I do
> figure on her getting stronger as she figures out some "tricks" of the
> "forcefield" on the skin that does the "invulnerable" bit.
>
> More strength means more cargo. As well as the ability to use some
> brute force solutions.
>
> >> Either way, hauling up enough pressure tanks for "just in case" will
> >> be a chore, but doable.
>
> >What would worry me most is carbon dioxide and monoxide buildup. Just
> >adding more O2 to the air doesn't get rid of that, and plants are very
> >slow. Make sure to bring some monitoring equipment with you to keep an
> >eye on that.
>
> Compressed air. Much easier to get refills for.
>
> CO is easy, just buy (or shoplift) a monitor.
>
> CO2 is harder. But easily handled by bubbling air thru a calcium
> hydroxide solution.
>
Still bad. Because then you will run out of oxygen. Breathing centre
senses excess carbon dioxide, not lack of oxygen.
> Activated charcoal to deal with all the *nasty* trace gases that build
> up is another need. Especially with non-space rated sealers and
> materials.
>
> A dehumidifer will be needed if they spend much time there.
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