cheap lunar gear & base (spin-off of superhero flight)
Leonard Erickson
setting up a "base" on the moon. (An idea I'd already had)
It's a great place to stash stuff you don't want folks to find.
Thing is, while she can protect stuff from the local conditions while
she carries it, that doesn't help when she leaves.
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?
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.
Third, cheap pressure suit for any visitors she might haul up there.
Mike Williams
>Third, cheap pressure suit for any visitors she might haul up there.
Definitely not. Space suits will never be cheap. You can't convert
something like a deep sea diving suit into a space suit because it will
end up like a suit-shaped balloon. The guy inside can't bend the arms
and legs because the pressure inside the suit is forcing it into a
preferred configuration.
The best you might be able to achieve for a reasonable price is some
sort of rigid container, like a toughened zorb ball or an iron lung.
However, they're not going to be cheap either, and the iron lung exceeds
your carrying capacity.
--
Mike Williams
Gentleman of Leisure
Leonard Erickson
Well, I know that the old USAF high altitude suits (which worked at
100,000 feet) showed up as surplus from time to time. Those ought to
be usable. Though making sure they are still up to snuff could get
interesting.
As for the rigid container bit, there are existing designs for "rescue
balls" which amount to a fabric bag you crawl into, zip shut behind
you and have an air supply and some stuff to deal with CO2 and excess
humidity.
An iron lung is overkill.
Bryan Derksen
> 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.
> 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.
> 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.
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.
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.
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?
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.
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.
Leonard Erickson
<bryan....@shaw.ca> 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.
Teleportation 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 teleporter 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 support against
the internal pressure, it might just do.
Crown-Horned Snorkack
> On Mon, 14 Apr 2008 07:45:07 GMT, Bryan Derksen
>
> >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.
to be hard rock.
Pick regolith instead. It seems to bear some resemblance to soft
sandstone, tuff or loess. Slightly indurated, so that it will support
holes excavated in it, and cave ceilings can stand without props, but
also soft and fragile enough that it crumbles under pickaxe blows.
> >http://www.iht.com/articles/1992/02/13/moon.phphad some tantalizing
Do not bury at all. Just excavate.
The important part is leaving a roof which will support its weight -
and which will not be lifted out of place when the interior is
pressurized.
1 atm matches the weight of 60 m water in the feeble gravity of the
Moon, or of 20 m solid rock, or considerably thicker layer of
regolith.
Bryan Derksen
> On Mon, 14 Apr 2008 07:45:07 GMT, Bryan Derksen
> <bryan....@shaw.ca> 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 Support 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 teleporter is
switching air pressures instantaneously. Perhaps she should teleport to
a mountaintop first in order to give her ears and sinuses a few seconds
to drain of excess air. Can she teleport 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 teleporter can help with some things.
If the teleporter 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 teleporter 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.
Steve Hix
Bryan Derksen <bryan....@shaw.ca> 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.
Just remember to plug the vent.
I wonder what the leakage rate would be through the main gasket, and
through the blowout plug? There is always a little bit of steam leaking
through the blowout plug when my pressure cookers are working, although
it takes 15-30 minutes for the pressure to drop far enough to let the
main valve drop, and most of the pressure drop is just from cooling,
rather than leaking steam.
Crown-Horned Snorkack
There is no source of carbon monoxide unless you set fires.
Carbon dioxide is monitored by breathing centre.
Steve Hix
Leonard Erickson <sha...@shadowgard.com> wrote:
> On Mon, 14 Apr 2008 07:45:07 GMT, Bryan Derksen
> <bryan....@shaw.ca> 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.
What are you trying to store? (I wandered in late...)
Pressure canners are pretty much the same thing as a cooker sans some of
the decoration, a 40qt model would have an interior volume of a cylinder
about 15" dia. x 14" tall.
Wayne Throop
::: pressure cookers sold in the US can hold a one-atmosphere difference
::: and there's probably a goodly safety margin there.
Would the gaskets on a standard pressure cooker last long under lunar
conditions? They might, but I wouldn't be confident. The pressure
cookers of my distant yoot had valves that regulated pressure based on
weight of a little metal widget that fit over a vent; is that still that
case? If so, lunar gravity would cause problems for an unmodified cooker.
And therefore you'd probably have to be careful to plug up the vent
in such a way that the plug would well withstand lunar conditions, and
also not leak (ie, ou couldn't just crimp it shut... braizing or welding
might work, but then there's less reason to start with a pressure cooker).
Oh, and of course, pressure cookers with gasket and vent aren't really
designed to prevent long-term slow leakage. Indeed, the vent as I recall
it wasn't really totally air/steam-proof; just slowed down losses enough
to raise the pressure.
Wayne Throop thr...@sheol.org http://sheol.org/throopw
Michael Ash
> 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.
It is not uncommon for pilots to go to pretty extreme altitudes with
nothing but an oxygen mask. The only limit is when the air pressure is no
longer enough to push sufficient oxygen into the blood when breathing 100%
O2. (The limit is actually slightly higher than this, because there are
systems which give you a bit higher pressure in the lungs than outside,
but it's not a big difference in the end.) These altitudes are attained
pretty quickly and unless you've recently gone diving there are no
problems with decompression.
> There'll be unpleasant ear-popping, perhaps, if your teleporter is
> switching air pressures instantaneously. Perhaps she should teleport to
> a mountaintop first in order to give her ears and sinuses a few seconds
> to drain of excess air. Can she teleport into mid-air higher than that?
From what I've read about explosive decompressions it sounds as though
an immediate change is doable. Air leaves these cativies relatively
easily, although making it a gradual change would be better.
Coming back could be worse. Air escapes a lot more easily than it returns.
When you have low pressure outside and high pressure inside, the excess
just forces its way out. But when you have high pressure outside and low
pressure inside, the outside pressure forces the channels closed.
Digressing slightly here... this can mean that you may have mild
congestion that you don't discover until you return to the high pressure
environment. I had this happen to me a couple of months ago. I had the
beginnings of a cold but didn't think it would be a problem. Going up was
fine. Coming back down I discovered that my ear no longer wanted to accept
incoming air, even with lots of encouragement. It was extremely painful
although not quite debilitating, and it finally cleared overnight. This
was with a pressure differential of only about 0.3 atmospheres.
It would be interesting to see Our Hero come urgently back from his secret
moonbase only to be taken down by a mild upper respiratory infection he
didn't even realize he had yet.
> 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.
If your structure leaks then replenishing it with O2 will result in your
CO2 level reaching some sort of equilibrium, with faster leaks leaving you
with less CO2. I don't know if this will be a reasonable way to deal with
the situation, but if you can easily bring up air from Earth then it may
well be the simplest solution. Getting too stuffy in your secret moonbase?
Just open the door a bit....
--
Michael Ash
Rogue Amoeba Software
Bryan Derksen
> There is no source of carbon monoxide unless you set fires.
Maybe not, but you'll be exposing a lot of moonrock to an oxygen
atmosphere for the first time ever so I expect there'd be all sorts of
odd reactions and trace gases being emitted at first. Since oxygen and
volatiles will be pretty cheap I'd want to fill the cave up with air and
then flush it all out again before setting it up for "permanent"
habitation. Hose the place down with water first too.
A carbon monoxide alarm will still be good to have. You never know when
some piece of equipment is quietly shorting out somewhere.
> Carbon dioxide is monitored by breathing centre.
I'd rather notice that CO2 levels are increasing _before_ the nausea and
headaches start. Especially since nausea and headache are pretty vague
symptoms that could mean a variety of things. CO2 monitors can be
purchased cheaply and aren't big or power-hungry so it's not a big expense.
Steve Hix
wrote:
> ::: A pressure cooker is the first thing that comes to mind.
> ::: http://en.wikipedia.org/wiki/Pressure_cookersays most standard
> ::: pressure cookers sold in the US can hold a one-atmosphere difference
> ::: and there's probably a goodly safety margin there.
>
> Would the gaskets on a standard pressure cooker last long under lunar
> conditions? They might, but I wouldn't be confident.
The old natural rubber ones wouldn't, but these days they're usually
either silicone rubber or neoprene. As long as they don't see huge
temperature swings (lunar) daily, they should last quite a while.
> The pressure
> cookers of my distant yoot had valves that regulated pressure based on
> weight of a little metal widget that fit over a vent; is that still that
> case?
Pretty much, although there's some variation on how it's implemented.
The rocking weight is still around, but a lot of cookers use other sorts
of weights or spring-loaded valves.
> If so, lunar gravity would cause problems for an unmodified cooker.
Since you're probably not going to be cooking whatever you've got
stashed in the cooker, it's likely you'd just plug the vent and be done
with it.
> And therefore you'd probably have to be careful to plug up the vent
> in such a way that the plug would well withstand lunar conditions, and
> also not leak (ie, ou couldn't just crimp it shut... braizing or welding
> might work, but then there's less reason to start with a pressure cooker).
The valves tend to be replaceable, screwed in, so unscrewing the vent
and replacing it with a machine screw of the right pitch/diameter should
be fine.
> Oh, and of course, pressure cookers with gasket and vent aren't really
> designed to prevent long-term slow leakage. Indeed, the vent as I recall
> it wasn't really totally air/steam-proof; just slowed down losses enough
> to raise the pressure.
Solved by a machine screw.
Steve Hix
Michael Ash <mi...@mikeash.com> wrote:
> Bryan Derksen <bryan....@shaw.ca> wrote:
> > 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.
>
> It is not uncommon for pilots to go to pretty extreme altitudes with
> nothing but an oxygen mask. The only limit is when the air pressure is no
> longer enough to push sufficient oxygen into the blood when breathing 100%
> O2. (The limit is actually slightly higher than this, because there are
> systems which give you a bit higher pressure in the lungs than outside,
> but it's not a big difference in the end.)
Those systems tend to be exhausting to use.
> These altitudes are attained pretty quickly and unless you've recently gone
> diving there are no problems with decompression.
And if you have, you can be in a world of hurt. I recall reading about a
Navy pilot who went flying too soon after a weekend diving/fishing party
in the Gulf of Mexico. Hadn't been diving all that deeply or long, but
the next morning shortly after takeoff he started getting symptoms of
serious bends, and getting him down and into the nearest hyperbaric
chamber wasn't enough to save him.
John Schilling
<nos...@econym.demon.co.uk> wrote:
>Wasn't it Leonard Erickson who wrote:
>>Third, cheap pressure suit for any visitors she might haul up there.
>Definitely not. Space suits will never be cheap. You can't convert
>something like a deep sea diving suit into a space suit because it will
>end up like a suit-shaped balloon.
Why would you want to, when you can buy an actual used space suit for
$10-20 thousand? And if you're skeptical about the used ones, Orbital
Outfitters will sell you a new one for a reasonable price - they aren't
saying how much, exactly, but I know some of their customers and they
aren't *that* rich.
Sure, NASA spends ten million or so per, but the only thing that really
tells you is that the commercial price is going to be somewhere under a
million, possibly very much under a million.
--
*John Schilling * "Anything worth doing, *
*Member:AIAA,NRA,ACLU,SAS,LP * is worth doing for money" *
*Chief Scientist & General Partner * -13th Rule of Acquisition *
*White Elephant Research, LLC * "There is no substitute *
*John.Sc...@alumni.usc.edu * for success" *
*661-951-9107 or 661-275-6795 * -58th Rule of Acquisition *
Leonard Erickson
<schi...@spock.usc.edu> wrote:
>On Mon, 14 Apr 2008 01:59:30 +0100, Mike Williams
><nos...@econym.demon.co.uk> wrote:
>
>>Wasn't it Leonard Erickson who wrote:
>
>>>Third, cheap pressure suit for any visitors she might haul up there.
>
>>Definitely not. Space suits will never be cheap. You can't convert
>>something like a deep sea diving suit into a space suit because it will
>>end up like a suit-shaped balloon.
>
>Why would you want to, when you can buy an actual used space suit for
>$10-20 thousand? And if you're skeptical about the used ones, Orbital
>Outfitters will sell you a new one for a reasonable price - they aren't
>saying how much, exactly, but I know some of their customers and they
>aren't *that* rich.
>
>Sure, NASA spends ten million or so per, but the only thing that really
>tells you is that the commercial price is going to be somewhere under a
>million, possibly very much under a million.
Now figure out how a teenger can afford one.
I rather expect that my two characters will start out with airtight
boxes to store stuff, then after a *lot* of work, come up with a way
to have a small pressurized space. (Think treehouse on the moon :-)
It may well have to wait until they can get help from others before
they can get a proper suit for the non-invulnerable one.
Though, given that character's power, all that's needed is something
that can be sealed quickly and support life for a minute or two.
That'd do for an emergency.
After all, as soon as he detects the problem, "blip" port to a safe
location on earth.
But that does mean that the "suit" has to stay reasonably "people
shaped" even if it starfishes you. That way you don't risk puncturing
it or other problems.
Main reason for any of that is so he can take things to or from the
"base" without needing the other one along to provide life support.
Leonard Erickson
<chorned...@hush.ai> wrote:
>On 14 apr, 13:33, Leonard Erickson <sha...@shadowgard.com> wrote:
>> On Mon, 14 Apr 2008 07:45:07 GMT, Bryan Derksen
>>
>> 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.
>>
>Which is why natural lava caves are not so good idea. They are likely
>to be hard rock.
>
>Pick regolith instead. It seems to bear some resemblance to soft
>sandstone, tuff or loess. Slightly indurated, so that it will support
>holes excavated in it, and cave ceilings can stand without props, but
>also soft and fragile enough that it crumbles under pickaxe blows.
It's a major hazard though in that it's really hard to keep it outside
(though the flyer won't pick any up coming in so that's a maybe. It's
not healthy for long term exposure. Hard on equipment too.
>> 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.
>>
>Do not bury at all. Just excavate.
>
>The important part is leaving a roof which will support its weight -
>and which will not be lifted out of place when the interior is
>pressurized.
>
>1 atm matches the weight of 60 m water in the feeble gravity of the
>Moon, or of 20 m solid rock, or considerably thicker layer of
>regolith.
Except you *have* to bury it under a minimum of several meters both
for thermal control and for radiation shielding. If you don't, a solar
flare will ruin a lot of things and be fatal to anybody who is there
at the time (or than the flyer)
Leonard Erickson
<bryan....@shaw.ca> wrote:
>Leonard Erickson wrote:
>> On Mon, 14 Apr 2008 07:45:07 GMT, Bryan Derksen
>> <bryan....@shaw.ca> 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 Support 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 teleporter is
>switching air pressures instantaneously. Perhaps she should teleport to
>a mountaintop first in order to give her ears and sinuses a few seconds
>to drain of excess air. Can she teleport 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 teleporter can help with some things.
>
>If the teleporter 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 teleporter 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.
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.
Leonard Erickson
>Crown-Horned Snorkack wrote:
>> There is no source of carbon monoxide unless you set fires.
>
>Maybe not, but you'll be exposing a lot of moonrock to an oxygen
>atmosphere for the first time ever so I expect there'd be all sorts of
>odd reactions and trace gases being emitted at first. Since oxygen and
>volatiles will be pretty cheap I'd want to fill the cave up with air and
>then flush it all out again before setting it up for "permanent"
>habitation. Hose the place down with water first too.
Also, furnishings and our bodies release an *amazing* number of
volatiles into the air.
>A carbon monoxide alarm will still be good to have. You never know when
>some piece of equipment is quietly shorting out somewhere.
>
>> Carbon dioxide is monitored by breathing centre.
>
>I'd rather notice that CO2 levels are increasing _before_ the nausea and
>headaches start. Especially since nausea and headache are pretty vague
>symptoms that could mean a variety of things. CO2 monitors can be
>purchased cheaply and aren't big or power-hungry so it's not a big expense.
Alas, pulse oximeters aren't cheap. But one would be handy to have.
Leonard Erickson
Books, storage media, snacks, this and that.
Figure what a teen might want to hide from adults. Add in what a super
teen might want to hide from authorities.
Crown-Horned Snorkack
> Crown-Horned Snorkack wrote:
> > There is no source of carbon monoxide unless you set fires.
>
> Maybe not, but you'll be exposing a lot of moonrock to an oxygen
> atmosphere for the first time ever
Only outside. The regolith is porous so it will not hold air. It will,
however, support a plastic airproof sheet.The only air in contact with
regolith is the air which has leaked out and is not coming back.
Crown-Horned Snorkack
senses excess carbon dioxide, not lack of oxygen.
Bryan Derksen
> On Mon, 14 Apr 2008 07:51:08 -0700 (PDT), Crown-Horned Snorkack
> <chorned...@hush.ai> wrote:
>> Pick regolith instead. It seems to bear some resemblance to soft
>> sandstone, tuff or loess. Slightly indurated, so that it will support
>> holes excavated in it, and cave ceilings can stand without props, but
>> also soft and fragile enough that it crumbles under pickaxe blows.
>
> It's a major hazard though in that it's really hard to keep it outside
> (though the flyer won't pick any up coming in so that's a maybe. It's
> not healthy for long term exposure. Hard on equipment too.
If you've got lots of water available it's not so bad, you can keep the
dust under control by washing. Maybe set up a HEPA filter for the small
stuff that's still airborne.
Install carpeting and vacuum regularly. :)
Bryan Derksen
> Also, furnishings and our bodies release an *amazing* number of
> volatiles into the air.
Heh. Perhaps "airing out" your furnishings in a vacuum for a while will
help get rid of the worst of it.
> Alas, pulse oximeters aren't cheap. But one would be handy to have.
http://search.ebay.com/search/search.dll?from=R40&_trksid=m37&satitle=oximeter&category0=
has a lot of them available in the $100 range. There were some carbon
dioxide monitors available in the $200 range when I checked, too.
A lot of the monitoring gear that would be nice to have is the same sort
of thing that would be used in mines, perhaps that would be a good angle
to follow when looking for this sort of thing. In a pinch, theft remains
an option here too.
Bryan Derksen
Which is why you'll have an oxygen supply to replenish it.
Bryan Derksen
> On 15 apr, 00:23, Bryan Derksen <bryan.derk...@shaw.ca> wrote:
>> Maybe not, but you'll be exposing a lot of moonrock to an oxygen
>> atmosphere for the first time ever
>
> Only outside. The regolith is porous so it will not hold air. It will,
> however, support a plastic airproof sheet.The only air in contact with
> regolith is the air which has leaked out and is not coming back.
Moonrock will get inside in the form of dust. According to Apollo
astronauts Moon dust smelled like spent gunpowder, and since it abraded
the seals on the containers that were supposed to bring pristine samples
back to Earth for study we don't actually know _why_ it smelled that way
yet; the stuff we got back was exposed to air and had lost its odor by
the time it landed.
Michael Ash
>> 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.
Your breathing is driven by the level of CO2 *in your blood*, which will
still become appreciable even when breathing air which has none. As should
be fairly easy to see, otherwise anyone breathing pure oxygen would
suffocate.
You still have the problem of detecting when O2 levels become too low, but
that's a separate problem. Starting from a reasonable pressure, you can
lose a lot more O2 than you can gain in CO2 before it becomes dangerous,
and if O2 is the only significant input into the system then you can
regulate O2 levels simply by monitoring air pressure.
Leonard Erickson
HEPA filters in vacuums are useful for a lot of things. For example,
they drastically change the design of home fallout shelters. :-)
Leonard Erickson
<bryan....@shaw.ca> wrote:
>Leonard Erickson wrote:
>> Also, furnishings and our bodies release an *amazing* number of
>> volatiles into the air.
>
>Heh. Perhaps "airing out" your furnishings in a vacuum for a while will
>help get rid of the worst of it.
>
>> Alas, pulse oximeters aren't cheap. But one would be handy to have.
>
>http://search.ebay.com/search/search.dll?from=R40&_trksid=m37&satitle=oximeter&category0=
>has a lot of them available in the $100 range. There were some carbon
>dioxide monitors available in the $200 range when I checked, too.
Rats. When I had the money and looked, they were $300. Wasn't cheap
enough to justify getting just then, even though I could use one. If
I'd seen one at that price, I['d have grabbed it.
Leonard Erickson
<chorned...@hush.ai> wrote:
>On 15 apr, 10:52, Leonard Erickson <sha...@shadowgard.com> wrote:
>> On Mon, 14 Apr 2008 16:38:28 GMT, Bryan Derksen
>> >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.
Thing is, you can add oxygen. It's getting rid of the stuff you don't
want that's a problem.
But yes, some sort of oxygen meter is needed. I don't know anything
about meters that can directly monitor oxygen levels (other than
knowing they were part of the hazmat team's gear at one place I
worked).
But a pulse oximeter will at least register the oxygen level in a
visitor's blood, and sound an alarm if it goes too low. And they are
widely available, just spendy.
Monitoring for too high an oxygen level is important though. Don't
want extra fire hazards.
Crown-Horned Snorkack
exhausted while nitrogen builds up.
Michael Ash
Well then, don't do that.
Pure oxygen isn't particularly difficult to obtain. Last time I paid to
get one refilled I think it was under $20. The tank itself isn't
particularly cheap but I'm seeing ones targeted toward pilots for under
$200. I don't know whether medical tanks would be cheaper or more
expensive, since both "medical" and "aviation" are automatic price
increasing words. There may be cheaper sources, maybe welding suppliers?
If you do want to use regular air, it's even cheaper to get, so you should
be able to just deliberately vent the room from time to time.