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| Brian Gaff... |
 Posted: Thu Jul 23, 2009 4:07 am |
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I would have thought that drinking more fluids might help a canister work
as you would sweat it out more. One does not want to dehydrate for many
reasons. co2 however is a silent killer and they were right to catch it
early.
These cannisters do need some humidity to work well from what I recall.
Brian
--
Brian Gaff - briang1 at (no spam) blueyonder.co.uk
Note:- In order to reduce spam, any email without 'Brian Gaff'
in the display name may be lost.
Blind user, so no pictures please! |
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| Craig... |
| Posted: Thu Jul 23, 2009 5:49 am |
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What runs out first by design? Suit Oxygen or the CO2 scrubbers?
If the CO2 scrubbers run out first, CO2 poisoning. Although this could
be delayed by continuously venting the suit to be replenished with
whatever available oxygen is left. Do the suits have adjustable vents?
If the Oxygen, then the astronaut could potentially breath the suit down
to a vacuum. Probably this is the case.
Brian Gaff wrote:
[quote:db946af7b2]I would have thought that drinking more fluids might help a canister
work as you would sweat it out more. One does not want to dehydrate
for many reasons. co2 however is a silent killer and they were right
to catch it early.
These cannisters do need some humidity to work well from what I
recall.
Brian
[/quote:db946af7b2] |
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| Craig... |
| Posted: Thu Jul 23, 2009 7:46 am |
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If the CO2 scrubber is working, there will never be high CO2 levels.
The O2 regulator is continually cycling open to keep the pressure up in
the suit, as the CO2 is taken out. When the O2 tank runs dry, there is
nothing to maintain the pressure. As the Astronaut continues to breath
and convert O2 to CO2, CO2 is scrubbed, the pressure will drop. Hypoxia
will occur, as the pressure drops. It wouldn't go to a complete vacuum,
but would probably drop to the boiling point of water (at 96F) that the
Astronaut is exhaling.
I also wonder about Methane scrubbers. If the Astronaut has a gas
attack, and the bacteria is of a kind that produces large quantities of
methane, the percentage of oxygen in the suit would go down as the
methane would just be recirculated like nitrogen and would continue to
build up. A large enough methane buildup would be explosive. Do the
suits have methane scrubbers? They must.
André, PE1PQX wrote:
[quote:10138af21e]Craig drukte met precisie uit :
If the Oxygen, then the astronaut could potentially breath the suit
down to a vacuum. Probably this is the case.
Explait this please... after every inhale, a person exhales, so no
vacuum will be created. The only thing happening then is the O2 level
drops, and the CO2 levels rises.
Before any chance of vacuum, the astronaut already dies by high levels
of CO2, and low levels of O2.
[/quote:10138af21e] |
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| Craig... |
| Posted: Thu Jul 23, 2009 8:47 am |
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LiHo...
http://en.wikipedia.org/wiki/Lithium_hydroxide
....a chemical reaction with CO2 to produce Li2CO3...
http://en.wikipedia.org/wiki/Li2CO3
.... a solid.
André, PE1PQX wrote:
[quote:a23f30d73e]Craig formuleerde de vraag :
If the CO2 scrubber is working, there will never be high CO2 levels.
The O2 regulator is continually cycling open to keep the pressure up
in the suit, as the CO2 is taken out. When the O2 tank runs dry,
there is nothing to maintain the pressure. As the Astronaut continues
to breath and convert O2 to CO2, CO2 is scrubbed, the pressure will
drop. Hypoxia will occur, as the pressure drops. It wouldn't go to a
complete vacuum, but would probably drop to the boiling point of
water (at 96F) that the Astronaut is exhaling.
I also wonder about Methane scrubbers. If the Astronaut has a gas
attack, and the bacteria is of a kind that produces large quantities
of methane, the percentage of oxygen in the suit would go down as the
methane would just be recirculated like nitrogen and would continue
to build up. A large enough methane buildup would be explosive. Do
the
suits have methane scrubbers? They must.
the CO2 scrubbers do not lower any pressure in the suit (A.F.A.I.K.),
it's just a filter.
If anyone can point me to a (simple) explantanion of those
scrubbers... please do!
[/quote:a23f30d73e] |
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| Brian Gaff... |
| Posted: Thu Jul 23, 2009 3:17 pm |
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The reaction is reversible then or seems to be, Where does the co2 go when
they bake them out?
Brian
--
Brian Gaff....Note, this account does not accept Bcc: email.
graphics are great, but the blind can't hear them
Email: briang1 at (no spam) blueyonder.co.uk
______________________________________________________________________________________________________________
"Craig" <WeBeGood at (no spam) GMail.Com> wrote in message
news:iMSdndbtDtWJ5fXXnZ2dnUVZ_iydnZ2d at (no spam) earthlink.com...
[quote:cd1627ccc3]LiHo...
http://en.wikipedia.org/wiki/Lithium_hydroxide
...a chemical reaction with CO2 to produce Li2CO3...
http://en.wikipedia.org/wiki/Li2CO3
... a solid.
André, PE1PQX wrote:
Craig formuleerde de vraag :
If the CO2 scrubber is working, there will never be high CO2 levels.
The O2 regulator is continually cycling open to keep the pressure up
in the suit, as the CO2 is taken out. When the O2 tank runs dry,
there is nothing to maintain the pressure. As the Astronaut continues
to breath and convert O2 to CO2, CO2 is scrubbed, the pressure will
drop. Hypoxia will occur, as the pressure drops. It wouldn't go to a
complete vacuum, but would probably drop to the boiling point of
water (at 96F) that the Astronaut is exhaling.
I also wonder about Methane scrubbers. If the Astronaut has a gas
attack, and the bacteria is of a kind that produces large quantities
of methane, the percentage of oxygen in the suit would go down as the
methane would just be recirculated like nitrogen and would continue
to build up. A large enough methane buildup would be explosive. Do
the
suits have methane scrubbers? They must.
the CO2 scrubbers do not lower any pressure in the suit (A.F.A.I.K.),
it's just a filter.
If anyone can point me to a (simple) explantanion of those
scrubbers... please do!
[/quote:cd1627ccc3] |
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| JD in TX... |
| Posted: Thu Jul 23, 2009 6:55 pm |
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Craig <WeBeGood at (no spam) GMail.Com> wrote in
news:TNmdney-5_Ki0_XXnZ2dnUVZ_tednZ2d at (no spam) earthlink.com:
[quote:c3f9a02fd9]If the Oxygen, then the astronaut could potentially breath the suit
down to a vacuum.
[/quote:c3f9a02fd9]
LMAO!!! You're really smart! BWHAHAHAHAHAHAHAHA! |
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| Craig... |
| Posted: Sun Jul 26, 2009 7:12 am |
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André, PE1PQX wrote:
[quote:50c79abcda]Before any chance of vacuum, the astronaut already dies by high levels
of CO2, and low levels of O2.
[/quote:50c79abcda]
Looks like you are right, the CO2 scrubbers are sized smaller than the
O2 tank. The same excited astronaut used up the CO2 scrubbers on two
space walks.
http://www.msnbc.msn.com/id/32123770/ns/technology_and_science-space/ |
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| Craig... |
| Posted: Sun Jul 26, 2009 7:51 am |
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I believe that is a different type of CO2 scrubber, some mineral that
absorbs it as opposed to a chemical reaction.
It seems the CO2 scrubber run out first, then why do they have
additional 30 minute O2 reserve tanks in the suits? They would supply
much less than 30 minutes of O2 because the suit would have to be vented
to let the CO2 out so that the O2 regulator would open and supply the
additional Oxygen? Venting the suit would be the only way to get rid of
the CO2 buildup once the scrubbers run out, and that would let O2 out at
the same time.
Brian Gaff wrote:
[quote:dc3c48f396]The reaction is reversible then or seems to be, Where does the co2 go
when they bake them out?
Brian
[/quote:dc3c48f396] |
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| John Doe... |
| Posted: Sun Jul 26, 2009 1:00 pm |
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Craig wrote:
[quote:28f57e7459]It seems the CO2 scrubber run out first, then why do they have
additional 30 minute O2 reserve tanks in the suits?
[/quote:28f57e7459]
For one thing, different people have different breathing requirements.
And I would surmise that reserve O2 would also be there to provide
addition survival should there be a leak in the suit. And in the case of
a failed Co2 scrubber, yeah, you could vent and replace with fresh O2.
You woudl waste some O2 because it would be vented out, but in the end,
you would still lower the Co2 to O2 ratio and give additional minutes
for the crewmember to get back to airlock. |
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| Craig... |
| Posted: Mon Jul 27, 2009 6:36 am |
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John Doe wrote:
[quote:c484027c68]For one thing, different people have different breathing requirements.
[/quote:c484027c68]
and added together....
http://www.chron.com/disp/story.mpl/space/6547991.html
....the CO2 scrubber on the American side goes down.
Sounds like Mars might be to hard for NASA to handle. |
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| John Doe... |
| Posted: Mon Jul 27, 2009 11:38 am |
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Craig wrote:
[quote:efeb18d536]and added together....
http://www.chron.com/disp/story.mpl/space/6547991.html
...the CO2 scrubber on the American side goes down.
Sounds like Mars might be to hard for NASA to handle.
[/quote:efeb18d536]
While much has been said about the problems of the russian Elektron,
there has been little coverage of the USA CO2 scrubber (CDRA if I
remember correctly).
I was surprised that they allowed the crtew to reach 6 before they had
the spare CDRA installed (coming with next shuttle if I remember correctly).
Since they were able to "fix" this from the ground, I assume that they
need to reset some faulty sensor to force the unit back in operation.
Mars is exactkly why the ISS is needed. It is the ISS that will get NASA
and partners to debug systems and get MTBF numbers on that equipment so
that a mars mission will be properly outfitted with tools and enough
spare parts to get those systems to operate to keep the crews alive
until return to earth.
I still am puzzled to find some people really believing it is possible
to do a "mars direct" with no assembly in LEO. |
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| Craig... |
| Posted: Tue Jul 28, 2009 10:57 am |
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| Craig... |
| Posted: Wed Jul 29, 2009 5:44 am |
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André, PE1PQX wrote:
[quote:e3c22fa475]Craig beweerde :
..to the Moon and Mars by 2020...
http://www.wired.com/images_blogs/wiredscience/2009/07/iss-
endeavor.jpg
...photographed on it's way to Mars and land a couple...
That would be cool...
Craig
John Doe wrote:
Mars is exactkly why the ISS is needed.
I think this could be Atlantis too...
Yeah, the detail is amazing when backlite by the sun.[/quote:e3c22fa475] |
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| Craig... |
| Posted: Thu Jul 30, 2009 12:41 pm |
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Seems the LiOH is the limiting factor on the Space Shuttle's reentry. The first
consumable to go dry at End of Mission + 2 day, or Sunday. It has enough O2
for 16 hours past running out of LiOH...
http://www.nasaspaceflight.com/2009/07/endeavour-tracking-ksc-return-tps-cleared-entry/
....I wonder if they used Shuttle consumables at a larger rate because of the
Station Problems?
John Doe wrote:
[quote:76b4b89621]Craig wrote:
and added together....
http://www.chron.com/disp/story.mpl/space/6547991.html
...the CO2 scrubber on the American side goes down.
Sounds like Mars might be to hard for NASA to handle.
While much has been said about the problems of the russian Elektron,
there has been little coverage of the USA CO2 scrubber (CDRA if I
remember correctly).
I was surprised that they allowed the crtew to reach 6 before they had
the spare CDRA installed (coming with next shuttle if I remember
correctly).
Since they were able to "fix" this from the ground, I assume that they
need to reset some faulty sensor to force the unit back in operation.
Mars is exactkly why the ISS is needed. It is the ISS that will get
NASA and partners to debug systems and get MTBF numbers on that
equipment so that a mars mission will be properly outfitted with tools
and enough spare parts to get those systems to operate to keep the
crews alive until return to earth.
I still am puzzled to find some people really believing it is possible
to do a "mars direct" with no assembly in LEO.[/quote:76b4b89621] |
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