A Primer on Long-Duration Life Support

(mceglowski.substack.com)

39 points | by zdw 4 days ago

6 comments

  • emptybits 1 hour ago

        "The limiting factor in urine distillation is actually the high level of calcium 
        from disintegrating astronaut bone, a nice example of how problems in space find 
        ways to compound one another."
    
    Sobering. One of the many long term effects of life away from Earth.[1]

    With humanity's future probably (?) driving more of us to leave the planet, I'm glad these things are being studied. Where there's a will, there's a way.

    [1] "Long-term space missions’ effects on the human organism: what we do know and what requires further research" https://pmc.ncbi.nlm.nih.gov/articles/PMC10896920

    • PowerElectronix 25 minutes ago
      They need to come up with either spinning ships or suits that compress you enough to activate the bones (they are piezoelectric so they naturally catch calcium ions when under stress).
    • imglorp 57 minutes ago
      They mention a botched drug study but I'm curious why that wasn't redone correctly given how many years we've been at this. And growing plants for that matter. Hop to it guys, we have to get this figured out while we have a station.
  • billfor 42 minutes ago
    The most interesting thing I learned is that we let people who need Zoloft on the ISS. The FAA will disqualify you for that unless you jump through hoops.
  • oersted 52 minutes ago
    Curious that both average inputs and outputs match to exactly 5.74 kg. I had intuitively assumed there would be a significant difference, but I suppose that even if a lot of energy is extracted, the mass difference will be negligible, mc2 and all.

    I'm also surprised that the vast majority of the output carbon is in the form of CO2 rather than feces.

    It's all rather obvious in retrospect, it was just nice to see crystallized like this.

    • birdsongs 24 minutes ago
      > I'm also surprised that the vast majority of the output carbon is in the form of CO2 rather than feces.

      Not sure if you know, but in the same vein, I was shocked when I learned ~50% of the biomass of trees is carbon (right, we knew that), but also that the carbon came from CO2 the tree respirated. Also makes total sense in hindsight, but still think it's so cool.

      The trees literally build their mass from the air and sunlight (and yes, obviously also water and trace minerals from the roots).

  • buildsjets 1 hour ago
    A note on their section on fire extinguishing - just about all aerospace fire extinguishing systems use agents with a fluorine based chemistry. Putting out a fire dissociates some of the agent, and in the presence of humidified air it recombines and forms hydroflouric acid, which will eat you from the inside out. So your air scrubbers had best do a good job at removing acid gasses.

    https://www.researchgate.net/publication/280646417_Acid_gas_...

    • XorNot 34 minutes ago
      It doesn't really eat you though: HF is so small that the problem is it just traverses straight through the skin into your blood and causes fluoridosis.

      There's been more then a few metallurgy lab deaths because someone spilled a substantial amount of HF on themselves and didn't realize it.

  • isoprophlex 1 hour ago
    On water reclamation:

    > On the Mir space station, this used to happen organically. Collecting water was a grubby job that involved chasing beach-ball sized spheres of condensate around the colder parts of the spacecraft with trash bags before they could climb into the walls and cause mayhem. Crew members spent three to four hours a day on this dirty and difficult task.

    That sounds, frankly, horrible.

    It made me think that the average space module probably smells like moist, reheated ass, too.

    • malfist 18 minutes ago
      Mir famously stank. Though you'd be glad to know without gravity your nose doesn't work as well
  • adolph 1 hour ago
    This is a great read and unironically I want to subscribe to the substack, which is titled "Mars for the Rest of Us." The author is that Ceglowski of Pinboard and occasional space essays at idlewords.com, both of which make this self-recommending for me at least.

    It's a cliche that space exploration creates discoveries that improve life back here on Earth. In the topics discussed in this essay, water reclamation and waste recycling especially, the future solutions developed I think will lead to improvements for terrestrial living.