On 14 apr, 19:38, 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.
>
> > 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.
>
> > 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?
>
> 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. :)
>
> >> 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.
>
> > 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.
There is no source of carbon monoxide unless you set fires.
Carbon dioxide is monitored by breathing centre.
|
