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Mars ISS Moon NASA

Self-Replicating Chernobyl Mold Tested on ISS as a Space Radiation Shield (cnet.com) 130

Humans on the moon and Mars would face the problem of damaging space radiation.

But new research suggests one possible solution to the fact that "Space wants to kill you," according to CNET: To protect astronauts, scientists have been studying an unusually hardy organism, discovered in one of the most radioactive places on the planet: Chernobyl... In some parts of the plant, the level of radiation spiked so high that exposure would kill a human in about 60 seconds. But several species of fungi have been discovered in the reactor. And they're thriving, "feeding" on the extreme levels of radiation. A new study, yet to undergo peer review, was published on the pre-print repository bioRxiv on July 17 and examines one of these species, Cladosporium sphaerospermum. It suggests the fungi could be used as a self-healing, self-replicating shield to protect astronauts in deep space...

Researchers placed the fungi aboard the ISS for 30 days and analyzed its ability to block radiation... The proof-of-concept study showed that the fungi was able to adapt to microgravity and thrive on radiation. It was able to block some of the incoming radiation, decreasing the levels by almost 2%. One of the major advantages, the researchers write, is the fungi self-replicates from microscopic amounts. You would only need to send a small amount to orbit, give it some nutrients and let it replicate, forming a biological radiation shield. With some tweaking, the fungi could be used to shield bases on the moon or Mars.

It's a long while until we put boots on the red planet, but the groundwork is being laid now.

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Self-Replicating Chernobyl Mold Tested on ISS as a Space Radiation Shield

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  • by gijoel ( 628142 ) on Monday July 27, 2020 @06:45AM (#60335515)
    It'll build a massive FTL ring gate out around Neptune.
  • Because nothing bad ever came of spores from space...

  • by hattig ( 47930 ) on Monday July 27, 2020 @06:49AM (#60335521) Journal

    If it only absorbs 2% of the incoming, then you probably need a lot of layers. 35 layers would absorb 50% of the incoming radiation. 150 layers would get you under 5% getting through. Obviously there may be other materials that can help this a lot. And the nutrient provision and other support mechanisms would probably require a quite complex wall design.

    Multiple layers or a thick layer isn't a problem if it only needs nutrients and natural radiation. Especially if you only need to seed the spores onto the surfaces to protect and let it grow over time until the protection is ready.

    • by klik ( 93694 ) on Monday July 27, 2020 @07:02AM (#60335549)

      you don't need a complex design, just a thick one - a low density foamed concrete with lots of internal channels would make sense - let the fungus loose in the walls and it will spread throughout the internal foam structure, producing an equivalent to multiple layers.
       

      • by HiThere ( 15173 )

        Styrofoam or polystyrene foam would probably be better than concrete. Possibly, though, foamed steel would be even better. Or perhaps foamed agar gel or paraffin (US, not UK usage). Somehow, though, the idea of a spaceship as a giant dip candle seems a bit weird.

        • by klik ( 93694 )

          This fungus ( or its modified descendants ) will probably be most useful on Mars. Partially buried habitats with a rough ceramic foam structure with a number of fungal strains to protect against radiation and possibly filter toxins out of the air.

          Spacecraft-wise, its probably a longer term goal to repurpose an asteroid as a cycler between the earth/moon system and mars - and this can be used in the same way. keep it fed nutrients from inside and it will protect against radiation from the outside.

    • by tinkerton ( 199273 ) on Monday July 27, 2020 @07:19AM (#60335581)

      What would the benefit be of a living layer of material absorbing radation as opposed to a dead layer of, say dirt , rock or metal? I see none. It's not like the fungi are magically sucking radiation from around you.

      An interesting part about a fungus which survives hard radiation is that it can allow you to grow things in bad places without elaborate effort to protect them. So you could hope to use genetic engineering to create all kinds of chemical factories with little protection.

      The principle of life in hard radiation seems easy enough: it's like sending messages over very long distances with a lot of errors creeping in. Just add a lot of error correction and redundancy.

      • by TWX ( 665546 )

        Probably a mass/density issue, in that one wants to construct the craft as light as possible to reduce the demands for fuel.

        I'm wondering if it would just make more sense to use almost foil-thin sheets, stacked with calculated gaps between stacks, at extreme angles. When engineers designing armor for war vehicles like tanks sloped the armor, they found that the armor's effectiveness increased because the equivalent thickness for a shell comiing in at, from the armor's perspective, was an oblique angle, had

        • The fungus needs nutrients to grow though. To actually save weight they have to get these nutrients from Mars, otherwise they have to carry more than the fungal weight in nutrients.
          Ok, maybe this is just a matter of doing the right chemistry.
          • by mspohr ( 589790 )

            Main nutrient is CO2 and the ISS should have a lot of waste CO2 from the astronauts.

            • CO2 could also be used to grow plants instead though.
              Are you sure it is CO2? It makes sense for a radiation-absorbing process, although fungus normally needs organic matter as nutrient. Pretty interesting then
              • by mspohr ( 589790 )

                You are right. Fungi live on carbohydrates, not CO2. You would need an intermediate step of growing plants to turn the waste CO2 into carbohydrates to feed the fungi. (Also could be food for the astronauts.) It might also be possible to feed the fungi on the astronauts toilet waste.

                • This fungi in particular converts the radiation directly into cellular energy. That's why it's so interesting. It's not blocking the radiation, it's absorbing it and using it.

                  Its also why the first post was a reference to "The Expanse" series of books that was turned into a TV series by SciFi channel which was later picked up by Amazon.

            • by dvice ( 6309704 )

              Plants eat CO2 (and oxygen, but mostly CO2). Animals and fungi eat oxygen and produce CO2. For fungi to eat CO2, they need symbiosis or parasitic relationship with plants that actually eat the CO2 and transform that into nutrients for the fungi.

          • Yeah, that's what I was thinking. Radiation shielding is mostly based on mass, and on the moon or Mars sand is going to be a lot easier to acquire than an equivalent mass of water and nutrients to feed your mold.

            Now, it's not impossible that the mold might be doing something clever that, pound-for-pound, makes it substantially better radiation shielding than rock. But unless it does, it seems rather counterproductive to try to use it for radiation shielding. A binding agent for regolith would be far more

        • It's organic material. The only parameters which affect absorption/scattering of high energy radiation(higher than x rays) are the atoms, not how they are stacked. So a mixture of the right amounts of carbon, hydrogen, oxygen, nitrogen will have the same screening function.

          • We need different things to block different types of radiation. And they need to be in the right order. We need dense elements like lead, tungsten and beryllium to shield against gamma radiation. But we need low density elements like paraffin, lithium hydride or even frozen astronaut poop to block particle radiation. This is because gamma radiation is stopped by electrons while particle radiation is stopped by neutrons. And we absolutely need the lightweight elements on the outside or we get bremsstrahlung radiation generated as charged particles slam into the dense nuclei. That turns the radiation shield into an x-ray generator. So yeah, it absolutely matters how things are stacked.

            • In principle a layer of light elements will reduce brake radiation but I doubt if it is worthwhile to stack layers in an environment of hard radiation. Lead may create brake radiation but it will also stop it better than it stops gamma rays. Not that I can prove it that easily. Maybe you know instances where its usefulness is proven.
              I think In an environment with UV but nothing beyond melanin makes sense. When there is a layer of gamma protection melanin is superfluous.

              • by spun ( 1352 )

                I don't think any plans I've seen use layers, just lightweight materials on the outside, dense materials on the inside two layer designs. Just trying to point out that the arrangement of atoms does in fact make a difference. And we don't really know what other effects, like low angle incidence, might come into play with a nanostructure developed by evolution.

        • When engineers designing armor for war vehicles like tanks sloped the armor, they found that the armor's effectiveness increased because the equivalent thickness for a shell comiing in at, from the armor's perspective, was an oblique angle, had more material it had to chew through. This meant a 1" thick plate could act more like a 1.5" thick plate.

          It's not just thickness, it's also deflection. Less of the energy is absorbed by the armor to begin with. You can see the same logic at work in earthworks and fortresses designed after the invention of the cannon. Instead of being nominally square in shape (which is efficient and easy to build) they are sort of star-shaped. That way incoming projectiles are deflected, instead of all of the force going into the wall. The same is true of the bottoms of modern military vehicles, compare hummer vs. mrap

        • by jcochran ( 309950 ) on Monday July 27, 2020 @10:36AM (#60336087)

          Mass is the only thing that stops gamma. Specifically electrons. Unfortunately, each electron has a bit of baggage in the form of an proton, which is relatively useless in stopping radiation. And of course, groups of protons have their own baggage in the form of neutrons, which once again, are relatively useless as radiation shielding. But, if you look at the periodic table, up until calcium, the ratio of protons to neutrons is approximately 50/50. After calcium the percentage of neutrons gets larger and larger. So what does that mean from a radiation shielding point of view? It means that on a mass basis, a kg of shielding comprised of light elements is more effective than a kg of shielding comprised of dense elements like lead. And living organisms like mold are comprised of mostly light elements like hydrogen, carbon, oxygen, nitrogen, etc. Such shielding may take up more volume than an equivalent mass of lead, but will be more effective in stopping radiation. And in space, mass is more important than volume.

      • What would the benefit be of a living layer of material absorbing radation as opposed to a dead layer of, say dirt , rock or metal?...>

        The advantage is it would weigh less and be self-healing, and thus require less maintenance.

        • Unfortunately, what stops ionizing radiation such as gamma is mass. Specifically electrons. The more of them the better. So the mold isn't going to result in an effective radiation shield that's lighter than a more conventional shield. But it can result in a shield that's easier to maintain. If a crater or divot is blasted out of the shield due to a micrometeorite, with a conventional shield, that specific gap needs to filled with replacement material. And the resulting patch is likely to have more mass tha

          • by spun ( 1352 )

            Depends on whether that ionizing radiation is gamma rays or charged particles. For charged particles, you want more neutrons than electrons, so low density shielding like paraffin works better. And you want it on the outside of the dense metal shielding. Otherwise, your dense metal shielding turns into a giant x-ray machine from the bremsstrahlung radiation created as the charged particles slam into it.

            • And you're contradicting yourself.

              You claim that for charged particles you want neutrons, and then claim therefor low mass, high volume materials are better for shielding against charged particles. Take a look at the periodic table. Specifically, take note of the atomic mass of each element vs the atomic number. You'll see that the percentage of neutrons increases as a function of the total mass at higher atomic numbers. So if you want more neutrons, you want denser materials such as lead, tungsten, etc. Ye

      • It's self healing.

        When cement crumbles, you need to go out and replace it.

      • by K. S. Kyosuke ( 729550 ) on Monday July 27, 2020 @07:58AM (#60335669)

        What would the benefit be of a living layer of material absorbing radation as opposed to a dead layer of, say dirt , rock or metal?

        Probably the fact that it grows into shape? You don't need to launch a heavy large module if you can grow its shielding over time using spare capacity of your supply ships for its nutrients. Alternatively you could use plastic injection for this, of course.

      • by Kisai ( 213879 )

        The problem I see is that since they require nutrients, they will require some constant feeding, and then we get into that entire "isn't this how The Last of Us started?" type of situation.

        It's not so much I think we shouldn't, but that I think if we make some radiation-proof mold, we also have no way to kill it, since you can kill things one of three ways:
        a) UV Radiation
        b) Chemical Bleach
        c) Thermal cooking

        If exposure to the vacuum of space doesn't kill it, then it really has a way of escaping.

        • So basically it's suitable stuff for SciFi horror movies :)

          • by fazig ( 2909523 )
            With all the stuff the anti science crowd is afraid of these days, almost anything is suitable stuff for SciFi horror movies.

            Also there are different ways to kill things. One additional way would be to dehydrate an organism. Because as far as we know, every single living organism requires liquid water as a solvent to carry nutrients within the organisms and for other things. Deprive them of a water source and they can't grow further or they may even die from dehydration.


            And this is not a new technique
        • getting some vibes of Halo and the flood
      • It's not like the fungi are magically sucking radiation from around you.

        If you'd bother to read even the summary, you'd find out that it is literally doing exactly that.

        I mean it's tradition around here to not read TFA, but it's also tradition to base shit only on TFS.

        • The summary is pure shit. The fungus (which is dangerous to humans) uses radiosynthesis so it does "feed" on radiation but that's not what matters here. The interesting bit is the byproduct which is what was sent into space to be tested as a potential sunscreen for people to wear, not as spacecraft shielding like most of the comments here are assuming.
      • by Compuser ( 14899 )

        The benefit is mostly self-healing as far as I can tell. Radiation will degrade any dead material over time but a living material will rebuild itself on the fly. Considering that any space travel beyond basic orbiting in the Earth-Moon system is slow and takes a long while, this could indeed be an advantage. It could also be an advantage for structures on Mars and elsewhere outside of Earth assuming they would be built to last.

      • by Kaenneth ( 82978 )

        self-repair, if a micrometeorite dings the surface, it will fix itself.

    • by iroll ( 717924 )

      From a mile-high perspective, of course the average engineer should see promise here... unless they work with microbiologists implementing bioengineering solutions, whether waste treatment, energy production, or biomass production. Then all of the complexity of even relatively simple earth-bound bioreactors will temper expectations.

      The nutrients that a fungus needs are carbohydrates and oxygen. Everything I've seen indicates that radiotrophy (using radiation for energy) is just bonus energy; I really doubt

    • by Dr. Tom ( 23206 )
      using polyethelene as a substrate would help with that
  • Why The Mold? (Score:5, Interesting)

    by rtb61 ( 674572 ) on Monday July 27, 2020 @06:51AM (#60335525) Homepage

    The old is arbitrary, what is important is the molecular structure that allows the conversion of high frequency energy to lower frequencies, that the mold can make use of. Probably a molecular crystalline structure, now if that can be readily reproduced, it will become an insulating coating, as thick as you need it (generating heat).

  • This is quite the amazing adaptation. What will be even more interesting is when they examine the inner workings of what enables it to thrive. Doing so could enable trees to be engineered to thrive on Mars which gets heavy radiation (yes, the temperature swings are still a problem but babysteps).

    • Re:Evolution! (Score:5, Insightful)

      by ledow ( 319597 ) on Monday July 27, 2020 @07:03AM (#60335553) Homepage

      Anywhere there is an abundant energy source, something will change in order to take advantage of it.

      Thermal vents in the ocean, sunlight, radiation, warmth of human houses, waste in sewers, etc.

      To be honest, this is not at all surprising. "Radiation" is almost literally direct energy - in the form of gamma rays, beta and alpha radiation. That's why it's so damaging. Gamma rays are just the same as UV but in a different part of the spectrum. The particles direct interact with matter.

      Anything that survives their bombardment with them will find them a powerful and useful energy source almost directly if they already photosynthesise or work by breaking down other chemicals.

      Trees need far more than a bit of strange light, though. They need tons of carbon dioxide, deep well-integrated root systems, soil nutrients, abundant light, tons of water, and a fairly stable climate in many cases, not to mention a host of interdependent organisms to help them thrive.

      • To be honest, this is not at all surprising. "Radiation" is almost literally direct energy - in the form of gamma rays, beta and alpha radiation. That's why it's so damaging.

        And why it's so surprising that some biological thing can use it. Plants have discovered photosynthesis, but everything more or less animal needs some chemical energy carrier AND protein as physical building block for the biomass they are growing. Some amphibic lifeforms still use direct radiation energy, but that brings a whole bag of thermal regulation problems.

      • Trees need far more than a bit of strange light, though.

        Yeah... but I like trees. :)
        If I just wanted a chemical factory then single celled organisms are the obvious choice.

    • Re:Evolution! (Score:4, Interesting)

      by wierd_w ( 1375923 ) on Monday July 27, 2020 @07:49AM (#60335641)

      It is just a reconformation of melanin.

      http://large.stanford.edu/cour... [stanford.edu]

      Understanding how the fungi have coopted melanin as a metabolic energy converter (rather than just as a passive diffuser, like humans use it) could lead to more interesting plantlife for extreme environments.

  • Anyone else think this sounds like the start of a sci-fi horror movie plot?

  • by Zak3056 ( 69287 ) on Monday July 27, 2020 @07:40AM (#60335619) Journal

    Not going to make bad horror movie jokes, but using fungi in space seems like a terrible idea, given what happened to Mir [slashdot.org].

  • In other words, the margin of error. Try again.

    O yea. Is it edible? Asking for a friend.

  • by dotancohen ( 1015143 ) on Monday July 27, 2020 @08:32AM (#60335761) Homepage

    You would only need to send a small amount to orbit, give it some nutrients and let it replicate

    Due to conservation of mass, I have a hard time believing that the nutrients could weigh less than more of the mold itself. The question remains if any of the needed nutrients might be endemic to Mars, which I highly doubt.

    • Depends..

      Nitrogen is going to be the issue. Carbon and oxygen? Yup, already there. Hydrogen? Yup, there's lots of hydrated silica clays there.

      So-- You send liquid nitrogen, soil nitrogen fixating microbes, some bubbler tanks, and samples of this mold.

    • by phayes ( 202222 )

      I fail to see how furnishing nutrients is in any way better than designing water tanks around a solar flare lifeboat or bulldozing regolith over a hab.

      It's not just "nutrients", it's air, temperature control, etc for this stuff to live and grow.

  • by burtosis ( 1124179 ) on Monday July 27, 2020 @09:12AM (#60335843)
    Did you hear about the astronaut with a biological radiation shield? He was a fun guy!
  • ...and can kill people with compromised immune systems? Is this really a tradeoff that'll be worth it?
  • So if you place 50 layers of this thing, you get radiation down to 36% and humans die a little slower!

    In other news, articles about Science written by people that do neither understand Physics nor Mathematics can be exceptionally dumb.

  • So a major premise of Star Trek: Discovery is not so far fetched after all? Mind blown.
  • by pesho ( 843750 ) on Monday July 27, 2020 @10:03AM (#60335981)

    That study is really shoddy [nih.gov]. The work is so bad that is inconsistent with itself. The claim is that the fungus can absorb radiation trough melanin and use it in chemical reactions. This is not shown directly. Here is a short list of the most significant problems:

    1. They get exactly the same result when they use ionizing radiation, UV light, visible light, or simply heat the bug.

    2. They use indirect assays to measure metabolic activity: XTT and MTT assay. The two assays use exactly the same chemical reaction, it is just that the two reagents, XTT and MTT, have different side groups. The reactive cores of XTT and MTT are identical. The expectation is that they should produce the same result, but they do not: XTT shows effect of radiation and MTT does not.

    3. Comically the XTT assay shows increase of metabolic activity regardless if the fungus is dead or alive.

    4. To prove that radiation supports the growth of the fungus they look how it grows in presence of chemical energy source (sugar) compared to when the only source of energy is the radiation. Irradiated fungus grows faster than non irradiated fungus when grown on sugar. The effect of the radiation is gone when they remove the sugar. To me the logical conclusion is that the fungus is not using the radiation as energy source (in their words not "feeding on radiation"), otherwise they should have seen much larger effect on growth when radiation was the only energy source.

    • by pz ( 113803 )

      Hmm.... the article you linked to was published in PNAS in 2007. Is it really the same as the one from the summary?

      Here's the preprint from the summary:

      https://www.biorxiv.org/conten... [biorxiv.org]

      • Hmm.... the article you linked to was published in PNAS in 2007. Is it really the same as the one from the summary?

        He's complaining about the original study that purports to describe the radiation-eating fungus in the first place. Given that the alleged molecule being used to convert the radiation is melanin, the fungus could be using it the same way it's used in human skin, as a passive diffuser, and it's not functioning remotely like chlorophyll. Or it's using the melanin as a diffuser in combination with an algae to photosynthesize the resulting frequency-shifted energy and isn't a fungus at all, but a lichen. Wit

  • Self-Replicating is part of the very definition of life, so I'm not sure why we need to be reminded of that trait for this specific type of mold.

  • Better shielding can be had by material that doesn't require feeding. polyethelene or similar light nuclei materials do a great job, water being another.

  • "It's a long while until we put boots on the red planet,"

    Some boots have the fungi built-in.

  • That's creep ffs...
    Someone wake me up already, 2020 has gotten too weird!
  • I get that it will self replicate because it's alive. Also, it requires mass to do so, at least carbon atoms. So unless this fungus can transform solar radiation into matter, you're still subject to the tyranny of the rocket equation.

  • So we're supercharging space mold with killer space radiation?

    My moneys on space orks. With Cockney accents. EXTERMINATUS!

//GO.SYSIN DD *, DOODAH, DOODAH

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