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#401 2019-03-18 22:16:35

RobertDyck
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From: Winnipeg, Canada
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Re: Air. Shelter. Water. Food.

Wikipedia says exhaled breath contains 13.6% to 16.0% oxygen. Earth's atmosphere contains 20.946% oxygen. I find that amazing efficiency. And Wikipedia says atmosphere has 0.0407% CO2, although global climate change documents claim it fluctuates between 0.0409% and 0.0413%. Exhaled breath has 4% to 5% CO2 by volume. Again amazing.

That confirms your figures. I had tried to estimate power required for life support in thread updating Mars Direct

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#402 2019-03-18 22:27:02

tahanson43206
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Re: Air. Shelter. Water. Food.

For SpaceNut #400 ....

Your reminder about Nitrogen inspired a search for Nitrogen in space ... Google came up with numerous citations (of course) but I followed one about Titan. Then I put "titan and nitrogen" into the NewMars search tool, and found LOTS of posts by void, and this one:

From: Index >> Human missions >> Analog(ue) air

Tom Kalbfus wrote:

I always thought terraforming would be a touch nut to crack, but Titan has lots of nitrogen, and a low gravity as well, despite its size, the surface gravity on Titan is less than out Moon. By the time we're ready to terraform Mars, the tech should be available to obtain nitrogen from Titan. Titan has more than enough. Probably th easiest way to transport it is to collect the nitrogen at the Saturn-Sun L1 Point, and then give the big ball of nitrogen a shove when the planets are light up just right for a gravity assist trajectory to impact Mars. Well need some insulation to get the stuff closer to the Sun while keeping it frozen, and then we unpack it prior to impact. The native atmosphere on Mars will intercept it and we'll end up with an atmosphere that is 50% carbon-dioxide and 50% nitrogen, we then send another package to Mars upping the atmosphere to 25% carbon-dioxide and 75% nitrogen and we keep on sending more and more nitrogen until we can get the carbon-dioxide percentage to under 1% of the atmosphere. Along wit the nitrogen de also deliver enough water to fill the ancient Ocean basin on Mars.

I'd like to key off of this idea with a less ambitious proposal to collect Nitrogen from the stratosphere of Titan and float it back to Mars for use in habitats.

The celestial mechanics of that operation are beyond my capability, but perhaps someone can compare the "cost" of energy of supplying Nitrogen for habitat use in the ways which seem most competitive:

1) Collect Nitrogen from atmosphere of Mars
2) Bring Nitrogen from Earth
3) Extract Nitrogen from minerals on Mars
4) Collect Nitrogen from Titan

(th)

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#403 2019-03-19 16:33:41

SpaceNut
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Re: Air. Shelter. Water. Food.

While the nitrogen is a buffer gas for humans to breath and is used in plant growth the first only needs enough to prime the living area as its not changed in amount with only plant life need a little. Its the oxygen and co2 build up which requires effort to maintain in a healthy living level.
The numbers for each person is different with regards to lung volume and efficiency of using that breath so a system that is to tightly regulated will be an issue for the crews survival.
That said we need computed numbers for a given source to allow for man to deliver the system to make it work with given margin for safety. Each system plus source will have different numbers for energy, mass and so forth.
The average total lung capacity of an adult human male is about 6 litres of air.

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#404 2019-03-20 16:47:48

SpaceNut
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Re: Air. Shelter. Water. Food.

The level of co2 at which it becomes toxic to humans can be a slow rise in levels from 1000 to 2000 ppm, the air quality is low. From 2000 to 5000 ppm, CO2 concentration starts to cause problems (headaches, insomnia, nausea). It is a dirty air. From 5000 ppm, the presence of other gases in air is altered, arising a toxic atmosphere or poor in oxygen with fatal effects as the concentration increases. Hypercapnia, or hypercarbia, as it is sometimes called, is a condition arising from too much carbon dioxide in the blood. It is often caused by hypoventilation or disordered breathing where not enough oxygen enters the lungs and not enough carbon dioxide is emitted.

When you start counting over 10,000ppm, most scientists and manufacturers change from ppm to percent concentration. So instead of describing a 10,000ppm CO2 sensor, we talk about a 1% CO2 sensor instead. (10,000/1,000,000 = 0.01) – the terms are synonymous. In other words, 1ppm = 0.0001% gas.

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#405 2019-03-20 17:48:56

tahanson43206
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Re: Air. Shelter. Water. Food.

For SpaceNut ... Your post below may have been in response to my earlier listing of possible sources of Nitrogen for use on Mars.

The post inspired me to ask Mr. Google for information about use of Nitrogen on the International Space Station:

https://www.nasa.gov/pdf/146558main_Rec … _10_06.pdf

6. Nitrogen, a gas that makes up 78 percent of breathable air on Earth, is inert and can therefore be safely stored
onboard spacecraft. Despite its high concentration within ambient air, nitrogen serves no particular physiological
benefit to humans and only serves to keep the Space Station pressure at 1 atmosphere (14.7 psia). Prior to extra
vehicular activities (EVA or space walking), astronauts purge nitrogen from their blood supply to prevent
decompression sickness (“the bends”). It is neither important nor practical to reclaim this nitrogen.

The editorial comment in the close of the paragraph above may be appropriate for a space station in Earth orbit, but I consider it reckless in the context of Mars.

The quantity of Nitrogen that must be shipped to Mars from Earth with explorers or settlers needs to be sufficient to comfortably fill all volumes where individuals are expecting to be able to go in a shirtsleeve environment.  That volume could be (would be) substantial (for example) if Louis builds his dome covered recreation facility.  Another example is the volume to be cleared for living space underground (whether under the surface or covered by regolith).

Another example is the tunnel complex which will likely come to pass under communities.  If the tunnel complex is pressurized for shirtsleeve travel, then the volume of Nitrogen required will be 80% of the volume of the tunnel complex.

In short, it seems to me that there is a business opportunity for those who will supply Nitrogen for explorers and settlers.

(th)

SpaceNut wrote:

While the nitrogen is a buffer gas for humans to breath and is used in plant growth the first only needs enough to prime the living area as its not changed in amount with only plant life need a little. Its the oxygen and co2 build up which requires effort to maintain in a healthy living level.
The numbers for each person is different with regards to lung volume and efficiency of using that breath so a system that is to tightly regulated will be an issue for the crews survival.
That said we need computed numbers for a given source to allow for man to deliver the system to make it work with given margin for safety. Each system plus source will have different numbers for energy, mass and so forth.
The average total lung capacity of an adult human male is about 6 litres of air.

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#406 2019-03-20 18:06:47

RobertDyck
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Re: Air. Shelter. Water. Food.

tahanson43206 wrote:

The quantity of Nitrogen that must be shipped to Mars from Earth with explorers or settlers needs to be sufficient to comfortably fill all volumes where individuals are expecting to be able to go in a shirtsleeve environment.  That volume could be (would be) substantial (for example) if Louis builds his dome covered recreation facility.  Another example is the volume to be cleared for living space underground (whether under the surface or covered by regolith).

There's sufficient nitrogen in Mars atmosphere to fill any pressurized habitat. An exploration mission will bring everything, but the first Mars base or reusable Mars habitat will harvest in-situ resources. Mars has sufficient nitrogen to fill a Mars Direct habitat, or even a dome covered recreation facility. We would have to find another source of nitrogen to terraform the entire planet, but enclosed habitation spaces can be filled with nitrogen harvested from Mars right now.

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#407 2019-03-20 19:32:45

SpaceNut
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Re: Air. Shelter. Water. Food.

Here is why the purge cycle is required in that the Spacesuits for the space shuttle era are pressurized at 4.3 pounds per square inch (psi), but because the gas in the suit is 100 percent oxygen instead of 20 percent, the person in a spacesuit actually has more oxygen to breathe than is available at an altitude of 10,000 feet or even at sea level without the spacesuit and is why they do not need as much.

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#408 2019-03-21 20:16:44

SpaceNut
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Re: Air. Shelter. Water. Food.

Humans tend to suffer from altitude sickness at elevations higher than 8000 feet. Commercial jetliners are required to maintain cabin pressurization at a cabin altitude of not greater than 2,400 m (8,000 ft).

So what will we be able to survive for lower pressures.
pressure_vs_altitude_sm.gif


https://en.wikipedia.org/wiki/Carbon_dioxide_scrubber

Economic and energetic analysis of capturing CO2 from ambient air

https://ieaghg.org/docs/General_Docs/Re … ubbing.pdf

Still looking at what would be the lowest energy needed.

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#409 2019-03-21 20:45:42

kbd512
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Re: Air. Shelter. Water. Food.

SpaceNut,

Take a look at CAMRAS.  It's already extremely energy efficient.  That's what's going into Orion.  It's already been flown aboard ISS.  I believe I posted documents about it some time ago.

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#410 2019-03-22 11:50:59

GW Johnson
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From: McGregor, Texas USA
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Re: Air. Shelter. Water. Food.

When I was younger,  airliner cabin altitudes of 10,000 feet were quite common.  Maybe they do it a bit lower now,  but higher is still feasible.  There are lots of tourists visiting Quito,  a big city,  at about 13,000 feet.  Few seem to have much of a problem. 

As for CO2,  we evolved during the Pleistocene ice ages,  at levels varying between just about 200 to 280 ppm,  according to the gas bubbles preserved in the ice cores.  We did okay in the centuries since,  at about 280 to 300 ppm,  and in the last half century,  a rise to 400 ppm. 

Given 1000 ppm is considered to be the start of bad air,  it might be wiser to stay under 500 ppm,  anyway. 

The diluent gas we evolved with is nitrogen.  Traces like argon hurt nothing.  Dive experience says helium also works,  except that voices are distorted dramatically,  and decompression times increase significantly.  Better to stick with nitrogen.

That being said,  synthetic air at 20.94 volume % oxygen and 79.06 volume % nitrogen should serve nicely as an equivalent to what we evolved in.  Total pressures as low as that at about 13,000 feet should be easily feasible.  Anywhere from 5000 to 13,000 feet equivalent could serve well.

GW


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#411 2019-03-22 16:10:08

RobertDyck
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Re: Air. Shelter. Water. Food.

Carbon Dioxide Exposure Effects - Fact Sheet

  • 1,000 ppm - Less than 2½ hrs - Impairs judgment, decision-making ability, and thinking skills on a short-term basis, even for healthy individuals.

  • 2,500 ppm - Less than 2½ hrs - Many individuals are rendered cognitively marginal or dysfunctional.

  • 5,000ppm with 20.9% Oxygen - Headache, lethargy, mental slowness, emotional irritation, and sleep disruption.

  • 6% - 1-2 mins - Hearing and visual disturbances

  • 7% (70,000 ppm) with 20.9% Oxygen - 5 mins - death

  • 10% to 15% - Dizziness, drowsiness, severe muscle twitching, unconsciousness and death within a few minutes.

  • 17% to 30% - Within 1 min - Loss of controlled and purposeful activity, unconsciousness, coma, convulsions, and death

  • 30% carbon dioxide, with 70% oxygen - 30secs - Unconsciousness, with some subjects having seizures that were characterized as decerebrate (no cerebral functioning).

These are the actual effects. Notice absolutely no effect less than 1,000 ppm.  (Note 1,000 ppm = 0.1%, 10,000 ppm = 1%)

Some historical data: 80 million years ago, when dinosaurs roamed the Earth, CO2 was 1,000 ppm.
500 million years ago CO2 was 6,000 to 7,000 ppm. That was the Cambrian period, major diversification of life known as the Cambrian Explosion.

Last edited by RobertDyck (2019-03-22 16:34:46)

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#412 2019-03-22 17:25:19

kbd512
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Re: Air. Shelter. Water. Food.

The Navy tries to keep the CO2 levels aboard submarines below 5,000ppm.  The CO2 levels measured on 10 of our submarines apparently averaged out around 4,100ppm, but were measured at over 11,000ppm in some instances.  If the partial pressure of CO2 is as low as it is aboard ISS, then everyone who goes to Mars should be just fine.  If they're not, then maybe they shouldn't go to Mars.

NASA says they're worried that increased CO2 levels are increasing intracranial pressure and causing headaches.  If they were really worried about that, then maybe they'd at least attempt an artificial gravity experiment, which would bring intracranial pressure far below what it presently is in microgravity, with or without any CO2.

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#413 2019-03-22 18:30:10

SpaceNut
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Re: Air. Shelter. Water. Food.

CAMRAS

kbd512 post consolidated:
Technolgy we need:

NASA / Paragon SDC - CAMRAS atmospheric scrubbers and IWP waste water processors

* CAMRAS and IWP for ECLSS or legacy ISS equipment

I expect life support systems to add another 872We (672We for MOXIE, 100We for CAMRAS, 50We for IWP) to the avionics and thermal control requirements

* CAMRAS / IWP / MOXIE - We simply must have more reliable and lower power consumption systems for atmospheric and water recycling for human exploration of Mars; I realize that these are lower-TRL technologies, but the greater reliability and lower power consumption is not debatable at this point- these systems simply work better than legacy life support systems and are substantially lighter and more compact.

Life Support
CAMRAS (amine bed atmospheric scrubber) - far lighter, more compact, and less electrical power than current ISS atmospheric scrubbers
MOXIE (O2 from Martian CO2) - sucks CO2 out of the Martian atmosphere and turns it into O2
IWP (ionomer membrane waste water processor) - recovers 90%+, as high as 98%, of water from waste water and turns it into potable water with very little electrical power

We have already demonstrated 98% efficient water recycling and in a few more years and Paragon should have that up to 99%.  CAMRAS is not quite that efficient, but with MOXIE replacing atmospheric losses, it really doesn't have to be.  The losses are so small that they're measured in pounds of O2 and H2O over the course of a year.  The power requirements for CAMRAS, IWP, and MOXIE are well within what solar panels and batteries can deliver. 

NASA is actively working on more reliable closed-loop life support systems.  Paragon SDC and NASA are developing the next generation of atmospheric scrubbers (CO2 And Moisture Removal Amine Swingbed or CAMRAS) and waste water processing equipment (Ionomer Water Processor or IWP).  Both systems are a very clear cut above what ISS currently uses.  During testing, CAMRAS halved CO2 levels aboard ISS for the period it was in operation and was operated longer than was required by the testing cycle as a function of its excellent performance.  IWP isn't ready for prime time yet, but in testing the system recovered 97% to 98% at a rate far above the target recovery rate.  An IWP flight demonstration unit will fly aboard ISS in 2019.  Both systems also demonstrate an extreme level of power consumption and maintenance reduction over current systems.  IWP is an in-conjunction-with, rather than a standalone water processor, but it dramatically lowers the requirement for further filtration to potable water standards.  In short, it's a lightweight plastic filter bag that filters out the nasty stuff using minimal pumping power so that more power and maintenance intensive filtration systems have less demand placed upon them.

MIT MOXIE (O2 generator): 360We - Scaled up to generate enough O2 to replace what one person consumes in one hour

Hamilton Sundstrand CAMRAS (CO2 scrubber): 12We - Dumps 17lbs of O2 during vacuum regeneration of amine bed

Paragon SDC IWP (H2O recycler): 56We - Requires 23.7kWh for one cycle of 416 hours, so multiple IWP's required for recycling


The new CAMRAS CO2 scrubbers NASA is working on for the Orion capsule vents atmosphere and moisture into space during the amine swing bed's regeneration cycle.  The engineers built features called "air save" and "water save" into the device to slow the rate of loss, but slowing the rate of loss is all that those features do.  The new Paragon IWP ionomer membrane water processors are much lighter, simpler, and recover more water using far less electrical power than the equipment currently installed aboard ISS, but the disposable plastic bags that purify the water have short lives, can and have leaked, and the process is not 80% to 90% efficient.

https://ntrs.nasa.gov/archive/nasa/casi … 006700.pdf

https://ttu-ir.tdl.org/ttu-ir/bitstream … sequence=1

CAMRAS CO2 Scrubber - I had the actual power measurements from the ISS demonstrator unit and now I can't find it, but I seem to recall the figure was at or under 200We.  The legacy CDRA units require 750We, for comparison purposes.  One unit is intended to scrub the CO2 exhaled by 6 astronauts.

Paragon IWP Waste Water / Brine Filtration Unit - 86We.  This is a jaw-dropping power consumption improvement over legacy systems and the overall mass and volume of the system is also dramatically lowered.  The cycle length is rather long (days), so I believe two units are required for four to six astronauts.

Sending humans to Mars presents three problems that haven't been adequately solved.

1. Life support systems need to be far more reliable, far lighter, and use far less power than what ISS is currently using.  NASA has refined versions of OGS, new CAMRAS atmospheric scrubbers, and new IWP waste water processors in advanced stages of testing.  CAMRAS has already flown aboard ISS.  The new OGS and IWP systems should fly this year or next.  This hardware is absolutely critical to the success of the mission and nobody is going to Mars unless and until these technologies are refined to the point of being mature flight hardware.

Cygnus is assumed to use 3 OGS, 3 CAMRAS CO2 scrubbers, 3 ionomer membrane water processors, 4 ATK MegaFlex solar panels for electrical power, and 250Wh/kg lithium-ion batteries for life support and power.  All of the power and life support systems are current generation technology in the final stages of testing.  Water and oxygen recycling is required, but these current generation systems are enabling technologies that are compact, light weight, reliable, and consume substantially less electrical power than legacy ISS systems.

The first link is Amine Swingbed Payload Testing on ISS and the second is Carbon Dioxide Removal Technologies for U.S. Space Vehicles: Past, Present, and Future.

First document finally gives the acronym: CO2 And Moisture Removal Amine Swing-bed, or CAMRAS and has the removal rates

second link pg 8 shows the system used for co2 removal.

Of course we have the related topic as well in MARCO-POLO which covers some of the same system.

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#414 2019-03-22 18:36:20

SpaceNut
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Re: Air. Shelter. Water. Food.

Submarines and the ISS are very simular as they are contained volumes which must use air flow to keep co2 from rising to deadly condition levels. Lots of power is used to blow and suck the air from all over in order to keep it moving through the filtering systems which use an ionic breeze like device super sized to clean particles from the air as well as UV to kill bacteria with in the air as its processed.

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#415 2019-03-23 09:26:42

GW Johnson
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Re: Air. Shelter. Water. Food.

I was startled to see numbers as high for CO2 as Kbd512 quoted for submarines,  so I went and researched this a bit.  He's right,  and NASA's spacecraft limits are very similar to USN's submarine limits. 

NASA's continuous exposure max limits vary with time of exposure,  being 13,000 ppm for 1 hr or 24 hr,  and 7000 ppm for 30 days and for 180 days.  USN's current 90 day continuous exposure limit is 5000 ppm,  but they may raise it,  while reducing the max limits for short-term exposures. 

Bear in mind that these are supposed to be max exposure limits,  and that these limits are based on being able to still perform routine tasks and perform simple arithmetic,  without noticeable degradation.  More critical judgements may be affected,  but those effects were not included in these limits on exposure.  Other sources claim that sets in,  in the 1000-2000 ppm range.

Bear also in mind that all this was done for total atmospheric pressures near 1 atm. 

Bear also in mind that the effects of CO2 exposure definitely worsen as oxygen concentrations drop.  Without makeup oxygen,  for every drop of 1 % O2,  there is ~ 1% rise in CO2. 

Just things to think about.  I still recommend sizing enough CO2 scrubber equipment to keep the continuous exposure under 1000 ppm "for sure",  under 500 preferred. There is a risk getting too far away from what we evolved with,  and we may need to use higher-equivalent-altitude (lower) habitat pressures for any of a number of reasons,  which makes the CO2 poisoning risks worse.

Seems stupid to me to be stingy with scrubber equipment and supplies,  just because we can get away with it in submarines at ~ 1 atm.

GW

Last edited by GW Johnson (2019-03-23 09:27:43)


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#416 2019-03-23 10:01:03

SpaceNut
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#417 2019-03-23 10:30:51

GW Johnson
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From: McGregor, Texas USA
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Re: Air. Shelter. Water. Food.

Where I got my data was a book on submarine atmosphere contaminants.  The chapter on CO2 was online and I copied it.

From:  Emergency and Continuous Exposure Guidance Levels for Selected Submarine Contaminants:  Volume 1 (2007) Chapter 3 Carbon Dioxide,  National Academies Press.

NASA SMAC (spacecraft max allowable concentration) levels (ppm):  13,000 for 1 hr to 24 hr,  7000 for 30 days to 180 days. 

USN submarine atmosphere levels are recommended for change:  90-day continuous exposure levels (ppm) are 5000,  proposed 7000,  NRC-recommended max 8000. 

I also found an old report downloadable as a pdf that had data from the diesel-electric submarine days.  That was AD - P 006362 Submarine Atmospheres,  by Knight,  et al.  It's a DTIC document from 1985,  approved for public release long ago.

The haze of hydrocarbon poisons from the diesel electric days surprisingly persisted in the nuclear sub days.  Solvents and the like,  plus lubricants in the machinery spaces.

One point to understand about all this is it's complicated.  There's not just one number you use as a guide.

GW

Last edited by GW Johnson (2019-03-23 10:32:15)


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#418 2019-03-24 07:19:56

tahanson43206
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Re: Air. Shelter. Water. Food.

This post could go in several topics.  Hopefully it will be a good fit here.

Today's local (Sunday) paper included a brief note about electrolysis and improved performance with impure water.

The section is called "Earthweek: a diary of the planet", and the topic is called "hydrogen power"

Stanford scientists have proved they can use solar power to convert salt water taken from San Francisco Bay to create hydrogen gas.  << skip >> The researchers found that by using electrodes rich in negatively charged layers of nickel-iron hydroxide and nickel sulfide over a nickel foam core, the corrosion is significantly reduced.

Assuming briny water exists on Mars, the reported discoveries may improve performance of electrolysis equipment there.

(th)

Last edited by tahanson43206 (2019-03-24 07:25:00)

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#419 2019-03-24 08:41:13

SpaceNut
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Re: Air. Shelter. Water. Food.

Some how I had missed the Next-Gen Air Scrubber Moves On to Final Phase of Testing otherwise known as CAMRAS.

Amine_Swingbed1-400x267.jpg

http://www.nasa.gov/centers/marshall/pd … _eclss.pdf
http://www.nasa.gov/mission_pages/stati … ngbed.html

This technology is being developed for Orion, and the design will control CO2 levels for a crew of six on the multi-purpose crew vehicle.

The heart of the Amine Swingbed assembly is the Carbon dioxide And Moisture Removal Amine Swingbed (CAMRAS). Hamilton Sundstrand developed the test equipment for the Crew and Thermal Systems Division at NASA’s Johnson Space Center in Houston. CAMRAS has several layers of amine-based filter beds that remove carbon dioxide and water vapor from the station’s environment. An amine is a nitrogen-containing organic compound. Once the filter beds are full, the assembly rotates to vent CO2 and moisture into space. This venting cleans the filter beds and makes for uninterrupted CO2 removal.

Amine technology is not new. It was tested first on the space shuttle. What makes the CAMRAS filter different is that it is more efficient than the ones used on the shuttle. The system also uses less power and is considerably smaller than the space station’s current carbon dioxide removal system. An update to such an assembly for future exploration vehicles could save space and reduce costs.

Nice images show its been built and tested onboard the ISS...

Also when searching forund this Methane Utlisation in Life support systems

Support of crew in one of the pages.

https://www.science.gov/topicpages/l/li … chnologies

Still searching for the energy and mass numbers and to see if its can be down scaled as well as up scaled for performance based on capability to service any size crew or area of habitation.

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#420 2019-03-24 18:44:12

SpaceNut
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Re: Air. Shelter. Water. Food.

Based on the submarine data co2 can rise so long as the amount of oxygen in the air stays at what we call the comfort zone of 22 ish% but when that drops then man has issues with in a given volume of breathing area.

The concentration of oxygen in the normal atmosphere is 20.9% of the total of the gases (mainly nitrogen and oxygen). The pressure, but not the concentration of oxygen, decreases with altitude. Oxygen deficiency is a major concern in the occupational setting and the subject of several standards and many regulations.

http://www.nwohs.com/Oxygen%20Regulator … ts%20I.pdf

https://www.physicsforums.com/threads/h … om.685796/

https://www.quora.com/How-long-will-it- … -of-oxygen

As noted the dangers of not having enough oxygen
https://www.airproducts.com/~/media/Fil … ram-17.pdf

Oxygen concentration Health effects of persons at rest
(% vol)

19 Some adverse physiological effects occur, but they may
not be noticeable.

15–19 Impaired thinking and attention. Increased pulse and
breathing rate. Reduced coordination. Decreased
ability to work strenuously. Reduced physical and
intellectual performance without awareness.

12–15 Poor judgment. Faulty coordination. Abnormal fatigue
upon exertion. Emotional upset.

10–12 Very poor judgment and coordination. Impaired
respiration that may cause permanent heart damage.
Possibility of fainting within a few minutes without
warning. Nausea and vomiting.

<10 Inability to move. Fainting almost immediate.
Loss of consciousness. Convulsions. Death.

So its a drop of oxygen and a rise of co2 that is the issue for man going to space.
Dangers of to much oxygen
http://www.airproducts.com/~/media/down … 09-010.pdf

We will need to measure both to ensure proper levels are retained for health at all times.

Sure we will be more percise but this is a way to do it.
How to Measure the Oxygen Level in the Air

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#421 2019-03-24 19:48:45

kbd512
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Re: Air. Shelter. Water. Food.

SpaceNut,

The link below should indicate what kind of power consumption would be required for the same technology incorporated into a space suit:

Rapid Cycle Amine (RCA 2.0) System Development

The technology is now 6 years further advanced than it was, but 6 years ago the electrical power requirement for a space suit amine swing bed CO2 scrubber was 3We idle, 12We peak, and 3.1We averaged over 8 hours.  A nuclear battery and a super capacitor could easily provide that kind of power for at least a decade.

Edit:

Look at what CAMRAS did to the CO2 levels aboard ISS:

Amine Swingbed Payload Technology Demonstration

Edit #2:

The power consumption from CAMRAS is negligible.  I'd conservatively estimate that a 0.5We to 1kWe nuclear power source could provide all the power required for life support equipment for a dozen people for at least a decade, if not several decades.  The newer flight avionics would require similar levels of power provisioning.  Combining current nuclear battery, rather than RTG's or fission reactors, with super capacitors, could provide more than enough power for life support, avionics, and communications.  The ISRU and ISPP technologies would require solar panels and Lithium-ion batteries or fission reactors to supply sufficient power.  In the end, the power requirements for life support are all about fan and pump power requirements to move a given number of cubic feet per minute of air or water.  If you need to move more, then you need more power.  At some point, only photovoltaics and batteries or fission reactors are practical solutions.

Last edited by kbd512 (2019-03-24 20:11:18)

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#423 2019-03-25 19:32:34

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 23,903

Re: Air. Shelter. Water. Food.

Another document LIFE SUPPORT SYSTEM for EXTRAVEHICULAR ACTIVITY page 5 give city in the good air breathing channel on the graph.

From the document

Humans can survive for about 3 days without water and about 30 days without food.

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#424 2019-03-26 06:34:37

tahanson43206
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Registered: 2018-04-27
Posts: 8,088

Re: Air. Shelter. Water. Food.

For SpaceNut ...

This document includes a detailed discussion of requirements for a Martian EVA suit.  Some elements proposed for a self-adjusting complex of fabrics of various kinds appear (to me at least) to be aspirational, but they point the way forward for those who will be (or perhaps are now) engaged in designing and manufacturing these garments.

(th)

SpaceNut wrote:

Another document LIFE SUPPORT SYSTEM for EXTRAVEHICULAR ACTIVITY page 5 give city in the good air breathing channel on the graph.

From the document

Humans can survive for about 3 days without water and about 30 days without food.

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#425 2019-03-26 17:55:14

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 23,903

Re: Air. Shelter. Water. Food.

The complex fabric is the MCP suit design which GW has referred to as well. The amine design is applicable to the Quadra cycle topic for keeping the air inside the crew area good for breathing for a long duration time under the pedal power backup condition.

Spacesuits - personal spaces
Lets brainstorm on suit design - We will need suits after all
Spacesuits - Its about time we came back to them
New idea for Mechanical CounterPressure suit
Powered Spacesuits
Pressurized Air in Suits
What we need to go to Mars - short term projects

Mars is a harsh place and what we bring must be able to do the job its designed for. The requirement for man is minimal Energy use, Minimal Mass and volume area, and made durable for the duration of many mission cycles.

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