Lifesupport System in Outer Space

[guckyfan]

I have been thinking about emergencies with not enough time to don spacesuits.

A globe of maybe 80cm to 1m, maybe of Kevlar or some similar high stress material. Stored it would be quite small and no expensive tech so many of them could be available, like live vests on a ship. When pressure drops or it is activated it inflates. You can enter through an opening and zip it airtight from the inside. That should take much less than a minute. Inflate it to habitat pressure with pure oxygen. That would mitigate any depressurization effects. If the habitat does not deflate instantly there should be time enough to get into it.

You would be immobile, but with some water and maybe a simple manually driven CO2 scrubber you can wait many hours for rescue to arrive.

[RanulfC]

On the topic of spacesuits that don't require pre-breathe, what happened to the biosuit? is it still under development, or were there any show-stoppers?

Biosuits don't provide higher pressure than spacesuits. At least according to the info I have seen. So they require similar pre-breathing.

A better general descriptor for the suit is the Mechanical Counter-Pressure Space Suit, (MCP) and they are generally assumed to have a lower pressure than Earths surface to keep the mechanical constraints down. There's still a lot of interest in the MCP but there's also a lot of institutional inertia to overcome in their use. As long as suits are few and far between there isn't much call for a major change which the MCP would be.

Randy

[Stormbringer]

I have been thinking about emergencies with not enough time to don spacesuits.

A globe of maybe 80cm to 1m, maybe of Kevlar or some similar high stress material. Stored it would be quite small and no expensive tech so many of them could be available, like live vests on a ship. When pressure drops or it is activated it inflates. You can enter through an opening and zip it airtight from the inside. That should take much less than a minute. Inflate it to habitat pressure with pure oxygen. That would mitigate any depressurization effects. If the habitat does not deflate instantly there should be time enough to get into it.

You would be immobile, but with some water and maybe a simple manually driven CO2 scrubber you can wait many hours for rescue to arrive.

they already had these on the shuttle.

http://www.astronautix.com/craft/reseball.htm

though the internal air supply would last only ten minutes they could be connected to an external air supply i think.

[Stormbringer]

hatchback suits


http://www.dailymail.co.uk/sciencetech/article-2179908/Nasa-designs-new-space-suit-20-years--hatchback-doesnt-hour-like-todays-models.html

The new suit will also effectively be its own airlock, doing away with the need to spend time getting the pressure right.

[guckyfan]

I have been thinking about emergencies with not enough time to don spacesuits.

A globe of maybe 80cm to 1m, maybe of Kevlar or some similar high stress material. ...........

they already had these on the shuttle.

http://www.astronautix.com/craft/reseball.htm

though the internal air supply would last only ten minutes they could be connected to an external air supply i think.

Thanks. I had never heard of it. It seems with 80cm my estimate was too low. It sounds like at least one meter would be necessary.

[hop]

hatchback suits

http://www.dailymail.co.uk/sciencetech/article-2179908/Nasa-designs-new-space-suit-20-years--hatchback-doesnt-hour-like-todays-models.html

If you want to get factual information about NASAs advanced suit design projects just about anything, the daily mail is not a good place to start. Wikipedia will at least get you some links to original sources: http://en.wikipedia.org/wiki/Z_series_%28space_suits%29

The "suitport" idea may reduce the time to get outside, but that doesn't mean you will just be able to jump in and go.

[Stormbringer]

that may be but I hve seen other articles; different media sources.

speaking of which; I have also seen articles about rovers with a couple of suits similar to this docked to a big rover. the idea being you drive somewhere in the rover and the crew jumps through the port into the exterior mounted suits, detach and go do some EVA tasks.

[Stormbringer]

Topical:  a new video article on the MIT Bio-suit.

http://www.sciencedaily.com/videos/e950c41a1fc78ba24169dd9022c829b9.htm

[RanulfC]

Topical:  a new video article on the MIT Bio-suit.

http://www.sciencedaily.com/videos/e950c41a1fc78ba24169dd9022c829b9.htm

The "print" article is here:
http://www.sciencedaily.com/releases/2014/09/140919094833.htm

I wonder why no one is revisting the "capstan" type MCP suit:
http://www.astronautix.com/craft/s2pesuit.htm

The overall limitations were mostly design and could easily be "fixed" today, especially since the suit wouldn't be "non-breathing" as the original suit was. Information on the type here:
http://www.oiresource.com/capstan.htm

Randy

[tlesinsk]

and i also vaguely recall that pure o2 damages biological tissue in various ways. I don't recall from where i read that but that is the feeling i get from the vast swamp of my memory.

Oxygen partial pressures above 500 mbar are toxic to the central nervous system and to the lungs in a matter of a dozen hours. You can still use pure oxygen if you keep the pressure below that.

http://en.wikipedia.org/wiki/Oxygen_toxicity

[Stormbringer]

hey, speaking of looking askance at media sources. mind the RT here; but:

http://rt.com/news/193280-crystal-breathe-underwater-oxygen/

if this is legit it means a lot for life support from space suits to space habitats to even medical therapies i think.

[Stormbringer]

Thread topic related:  http://www.space-travel.com/reports/NASA_Selects_Advanced_Oxygen_Recovery_Proposals_for_Spacecraft_Missions_999.html

[cordwainer]

I am skeptical about nitrogen being completely useless for life support. It is a necessary component in a number of biological processes, albeit one can get sufficient nitrogen from food sources as opposed to the air.
Still the long term breathing of a partial pressure oxygen environment has not been fully studied, there could be ramifications we have yet to fully understand. Also if you want to have generations of settlers then you have to study those ramifications on pregnancies and infirmity. Having lots of nitrogen in the air and soil is beneficial for plant life and bacteria if I am not mistaken. One also has to take into account the health effects that a nitrogen free atmosphere might have on symbiotic bacterial organisms in humans as well.

[cordwainer]

As to the water cycle issue, Doge. We don't actually have a perfect water cycle here on the Earth. We are running out of potable water and yet this planet supported us just fine until the industrial revolution and will go on supporting us for generations to come. Like most problems we have faced with taming our environment to meet our needs humans will no doubt find a technological fix like they have in the past. You don't have to have a 100% efficient solution to a problem just a sufficient amount of efficiency in relation to the size of the resource you are using that you can maintain a sustainable equilibrium for reasonable time. Reasonable time usually means the six generation rule, since typically a population improves their technology and increases their access to resources in that amount of time even if they are living in a subsistence existence(like the Native Americans from which the six generation rule originates).

[Vultur]

I am skeptical about nitrogen being completely useless for life support. It is a necessary component in a number of biological processes, albeit one can get sufficient nitrogen from food sources as opposed to the air.

Humans are unable to use gaseous nitrogen (N₂), so yes it is useless (except as a buffer gas) to humans.

Still the long term breathing of a partial pressure oxygen environment has not been fully studied, there could be ramifications we have yet to fully understand.

Well, pure oxygen means more fire risk, and a 100% oxygen environment means a higher O2 partial pressure than sea level (to overcome the water vapor/CO₂ partial pressure in the alveoli, if I understand correctly) which can have some effects.

It would probably be better to use a lower pressure non-pure-oxygen mix to make getting into spacesuits easier, something like 6-8psi with a high oxygen concentration but some nitrogen/argon/whatever, rather than pure oxygen.

You could even use, say, a Mexico City altitude air mix - that's significantly lower pressure (11.2 psi - about 76% of sea level pressure) just slightly enriched in oxygen (or not, most people are just fine at that altitude* and it ought to be possible to screen for those who are not).

*US airliner cabins are allowed to be depressurized to 8000 ft equivalent

Having lots of nitrogen in the air and soil is beneficial for plant life and bacteria if I am not mistaken. One also has to take into account the health effects that a nitrogen free atmosphere might have on symbiotic bacterial organisms in humans as well.

Yes, some bacteria can use ("fix") gaseous nitrogen. This is where nitrogen in the soil and biologically available nitrogen for plants and animals comes from. These bacteria are symbiotic with some plants (especially legumes - bean family). This symbiosis isn't a human thing though.

[cordwainer]

What about the reactions in the human body and soil that require fixing nitrogen in the atmosphere into nitrogen oxides that are used in human and bacterial biological processes? Yes most of this fixing is done within plants or through combustion process and then absorbed into the human body but nonetheless if you need a buffer gas for changes between different pressure gradients and to lower combustibility in an oxygen rich environment then nitrogen seems the way to go. Especially if your going to grow your own food in space.

[Stormbringer]

maybe this fits here.

http://phys.org/news/2015-03-breakthrough-energy-harvesting-power-life.html

[catdlr]

Keeping Astronauts Alive - Everything You Need To Know About Life Support In Space

Apr 26, 2025
Keeping people alive in space has been a cornerstone of spaceflight technology since before humans even went to space. Systems need to provide for all the biological needs and remove all the byproducts from life processes.
Recycling is important to minimize the amount of consumables required on long duration flights. The international space station has moved away from filters, scrubbers and solid fuel oxygen generators to racks of equipment which keep the air fresh and breathable.