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Thread: How long until we have colonize Mars?

  1. #961
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    Quote Originally Posted by Roger E. Moore View Post
    Use silica aerogel to colonize regions of Mars, if not the whole world?

    https://phys.org/news/2019-07-silica...habitable.html
    More details on the above. I'm not sure that I get this.

    https://arxiv.org/abs/1907.09089

    Enabling martian habitability with silica aerogel via the solid-state greenhouse effect

    R. Wordsworth, L. Kerber, C. Cockell
    (Submitted on 22 Jul 2019)

    The low temperatures and high ultraviolet (UV) radiation levels at the surface of Mars today currently preclude the survival of life anywhere except perhaps in limited subsurface niches. Several ideas for making the martian surface more habitable have been put forward previously, but they all involve massive environmental modification that will be well beyond human capability for the foreseeable future. Here we present a new approach to this problem. We show that widespread regions of the surface of Mars could be made habitable to photosynthetic life in the future via a solid-state analogue to Earth's atmospheric greenhouse effect. Specifically, we demonstrate via experiments and modelling that under martian environmental conditions, a 2 to 3-cm thick layer of silica (SiO2) aerogel will simultaneously transmit sufficient visible light for photosynthesis, block hazardous ultraviolet radiation, and raise temperatures underneath permanently to above the melting point of water, without the need for any internal heat source. Placing silica aerogel shields over sufficiently ice-rich regions of the martian surface could therefore allow photosynthetic life to survive there with minimal subsequent intervention. This regional approach to making Mars habitable is much more achievable than global atmospheric modification. In addition, it can be developed systematically starting from minimal resources, and can be further tested in extreme environments on Earth today.
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  2. #962
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    Quote Originally Posted by Roger E. Moore View Post
    More details on the above. I'm not sure that I get this.

    https://arxiv.org/abs/1907.09089

    Enabling martian habitability with silica aerogel via the solid-state greenhouse effect

    R. Wordsworth, L. Kerber, C. Cockell
    (Submitted on 22 Jul 2019)

    The low temperatures and high ultraviolet (UV) radiation levels at the surface of Mars today currently preclude the survival of life anywhere except perhaps in limited subsurface niches. Several ideas for making the martian surface more habitable have been put forward previously, but they all involve massive environmental modification that will be well beyond human capability for the foreseeable future. Here we present a new approach to this problem. We show that widespread regions of the surface of Mars could be made habitable to photosynthetic life in the future via a solid-state analogue to Earth's atmospheric greenhouse effect. Specifically, we demonstrate via experiments and modelling that under martian environmental conditions, a 2 to 3-cm thick layer of silica (SiO2) aerogel will simultaneously transmit sufficient visible light for photosynthesis, block hazardous ultraviolet radiation, and raise temperatures underneath permanently to above the melting point of water, without the need for any internal heat source. Placing silica aerogel shields over sufficiently ice-rich regions of the martian surface could therefore allow photosynthetic life to survive there with minimal subsequent intervention. This regional approach to making Mars habitable is much more achievable than global atmospheric modification. In addition, it can be developed systematically starting from minimal resources, and can be further tested in extreme environments on Earth today.
    Or you could build greenhouses with a couple layers of appropriately-filtered plastic for a few orders of magnitude lower cost. As a bonus, those could contain environments habitable to humans, not just lichens.

    The description of aerogel as something that can be developed from minimal resources is a usage of the word "minimal" I'm not familiar with.

  3. #963
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    An article that needs to be read: "Death on Mars".

    https://blogs.scientificamerican.com...eath-on-mars1/

    It's not the air, not the gravity -- it's the radiation.
    Last edited by Roger E. Moore; 2020-Jan-26 at 12:12 AM.
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  4. #964
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    Quote Originally Posted by Roger E. Moore View Post
    An article that needs to be read: "Death on Mars".

    https://blogs.scientificamerican.com...eath-on-mars1/

    It's not the air, not the gravity -- it's the radiation.
    The radiation environment is similar to that in LEO...the atmosphere of Mars is roughly equivalent to Earth's magnetic field. That's without any shielding, and settlers and researchers are not going to be spending their entire time walking about the surface naked, they'll be in shielded habitats.

    Everything needed to make breathable air is accessible with just a compressor, a fairly simple processing plant, and energy. We know a few meters of regolith is the worst case for what we'll need to deal with the radiation. The gravity is actually the one thing we don't know about and which will be difficult to deal with if it proves to be a problem...centrifugal gravity is possible but would be a pain.

  5. #965
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    Cut-and-cover tunnels would be one rather low-tech solution (except for the fact that we'd need to develop excavation machinery to work on Mars. Straightforward, but not trivial). Another would be to toss surface material on top of a structure. All that's needed for radiation shielding on the surface of Mars (or the Moon) is mass, and these are conveniently on the surface of bodies that are made up of rock, much of which has been broken down into sand or gravel.
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  6. #966
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    Quote Originally Posted by swampyankee View Post
    Cut-and-cover tunnels would be one rather low-tech solution (except for the fact that we'd need to develop excavation machinery to work on Mars. Straightforward, but not trivial). Another would be to toss surface material on top of a structure. All that's needed for radiation shielding on the surface of Mars (or the Moon) is mass, and these are conveniently on the surface of bodies that are made up of rock, much of which has been broken down into sand or gravel.
    Yup. There's not much discussion about the radiation because there's not really that much interesting discussion left to have about it. We know what needs to be done, we know roughly how to do it. Planning of the habitats is going to have to take it into account, and will do so when the time comes. It will require solving some difficult problems involving heavy machinery, but those problems will have to be solved anyway if we're to set up anything more than a temporary campsite.

  7. #967
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    What are your crewmates going to do with you if you die on Mars? https://www.space.com/how-to-die-on-...nt-ritual.html
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  8. #968
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    Quote Originally Posted by Roger E. Moore View Post
    What are your crewmates going to do with you if you die on Mars? https://www.space.com/how-to-die-on-...nt-ritual.html
    There are actually non-space precedents as to what to do, including cannibalism (one presumes there won't be a food shortage on a Mars mission, but it's not impossible for a permanent settlement), preserving the corpse to return (this seems to be the present tradition in most armed forces), and burial in situ. This is something that would need to be planned for and put into procedures, but I suspect what will be done is to take a lot of photos of the corpse, tissue samples unless the death is from a catastrophic accident, and put the body under a cairn or bury it.
    Information about American English usage here. Floating point issues? Please read this before posting.

    How do things fly? This explains it all.

    Actually they can't: "Heavier-than-air flying machines are impossible." - Lord Kelvin, president, Royal Society, 1895.



  9. #969
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    ‘Spacefarers’ book tries to predict how space colonization will happen. The book offers an "optimistic yet realistic" take on future space travel.
    https://www.sciencenews.org/article/...on-will-happen

    QUOTE: Experiments in the 1990s provide a humbling illustration of how space missions could go awry. Inside a prototype Mars colony dubbed Biosphere 2 in Arizona, bugs multiplied, crops failed and crew members split into factions. After the disaster that was the first two-year mission, a second attempt in 1994 lasted just six months before dissolving into “vandalism, foul language, lawsuits, finger-pointing, shaming,” Wanjek writes. “You know, typical Mars colonization kind of stuff.”
    Do good work. —Virgil Ivan "Gus" Grissom

  10. #970
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    Quote Originally Posted by Roger E. Moore View Post
    ‘Spacefarers’ book tries to predict how space colonization will happen. The book offers an "optimistic yet realistic" take on future space travel.
    https://www.sciencenews.org/article/...on-will-happen

    QUOTE: Experiments in the 1990s provide a humbling illustration of how space missions could go awry. Inside a prototype Mars colony dubbed Biosphere 2 in Arizona, bugs multiplied, crops failed and crew members split into factions. After the disaster that was the first two-year mission, a second attempt in 1994 lasted just six months before dissolving into “vandalism, foul language, lawsuits, finger-pointing, shaming,” Wanjek writes. “You know, typical Mars colonization kind of stuff.”
    A "realistic" take on Mars colonization, that cites Biosphere 2?

  11. #971
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    Quote Originally Posted by cjameshuff View Post
    A "realistic" take on Mars colonization, that cites Biosphere 2?
    Perhaps points out the value of picking the right colonists, ones who have been long trained to work together, without media exposure.
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  12. #972
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    Quote Originally Posted by Roger E. Moore View Post
    Perhaps points out the value of picking the right colonists, ones who have been long trained to work together, without media exposure.
    Biosphere 2 was an ideologically driven, incompetently designed and managed stunt that had almost nothing to do with Mars colonization.

  13. #973
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    So, imagine sending a 3-D printer to Mars, digging up a lot of iron ore, then printing perfect steel from it.

    https://phys.org/news/2020-04-uncove...rd-steels.html
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  14. #974
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    On a simulated Mars base in Utah, it seems humans still waste food.

    https://www.abc.net.au/news/2020-04-...waste/12140680
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  15. #975
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    Go to Mars, risk >3% death by cancer. Not good.

    https://cvmbs.source.colostate.edu/r...tion-missions/
    New clues to predict the risks astronauts will face from space radiation on long missions
    Date: April 16, 2020
    Source: Colorado State University
    Summary: Researchers used a novel approach to test assumptions in a model used by NASA to predict health risks for astronauts.
    QUOTES: A team led by researchers at Colorado State University used a novel approach to test assumptions in a model used by NASA to predict these health risks. The NASA model predicts that astronauts will have more than a three percent risk of dying of cancer from the radiation exposures they will receive on a Mars mission. That level of risk exceeds what is considered acceptable. The study, "Genomic mapping in outbred mice reveals overlap in genetic susceptibility for HZE ion- and gamma-ray-induced tumors," was published April 15 in Science Advances.

    Original paper: https://advances.sciencemag.org/content/6/16/eaax5940
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  16. #976
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    Quote Originally Posted by Roger E. Moore View Post
    Go to Mars, risk >3% death by cancer. Not good.

    https://cvmbs.source.colostate.edu/r...tion-missions/
    New clues to predict the risks astronauts will face from space radiation on long missions
    Date: April 16, 2020
    Source: Colorado State University
    Summary: Researchers used a novel approach to test assumptions in a model used by NASA to predict health risks for astronauts.
    QUOTES: A team led by researchers at Colorado State University used a novel approach to test assumptions in a model used by NASA to predict these health risks. The NASA model predicts that astronauts will have more than a three percent risk of dying of cancer from the radiation exposures they will receive on a Mars mission. That level of risk exceeds what is considered acceptable. The study, "Genomic mapping in outbred mice reveals overlap in genetic susceptibility for HZE ion- and gamma-ray-induced tumors," was published April 15 in Science Advances.

    Original paper: https://advances.sciencemag.org/content/6/16/eaax5940
    The paper finds that HZE particle radiation (which we have little human data on) has effects in rats similar to gamma radiation, which we do have human data on and which the NASA risk model is based on gamma radiation as a best approximation. It isn't finding that radiation is any more dangerous than thought, it basically concludes that the current NASA risk model is accurate, as far as we can tell by looking at rats. It also finds that genetic susceptibility is a significant enough factor that the risk for selected individuals could be meaningfully lower.

    The paper doesn't actually say much about Mars. There is a single assertion that "0.4 Gy of HZE ions represents a realistic dose, received over 20 to 30 months, for a flight crew traveling to Mars". This is rather vague and confusing...one would not spend 20-30 months traveling to Mars (or even there and back), and the surface is a very different radiation environment. It also does not actually state that this would exceed the 3% limit anywhere that I saw.

    Also, one of the notable differences they find is the way the dose is distributed among the cells. In particular, where a comparable dose of gamma radiation would affect all cells, HZE radiation would affect tracks through tissue while leaving surrounding tissue untouched. This makes certain types of cancers (lymphomas and some others) less likely to result from HZE radiation.

  17. #977
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    Will the astronauts who go to and colonize Mars have to be genetically different from us?

    https://www.livescience.com/mars-col...rdigrades.html
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  18. #978
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    Quote Originally Posted by Roger E. Moore View Post
    Will the astronauts who go to and colonize Mars have to be genetically different from us?

    https://www.livescience.com/mars-col...rdigrades.html
    From the article:
    Coming soon?

    Genetic enhancement may not be restricted to the pages of sci-fi novels for much longer. For example, scientists have already inserted genes from tardigrades — tiny, adorable and famously tough animals that can survive the vacuum of space — into human cells in the laboratory. The engineered cells exhibited a greater resistance to radiation than their normal counterparts, said fellow webinar participant Christopher Mason, a geneticist at Weill Cornell Medicine, the medical school of Cornell University in New York City.
    A few genes in a few cell cultures that survive is a good first step, but to go from that to in vivo success in large scale human genetic modifications will be a very large way down the road, if it works out at all, and if it's legally allowed at all. By then we might have Mars colonists already, the hard way. Just accepting the higher cancer rates the way we currently accept high deaths from traffic accidents.
    "I'm planning to live forever. So far, that's working perfectly." Steven Wright

  19. #979
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    Quote Originally Posted by Noclevername View Post
    From the article:


    A few genes in a few cell cultures that survive is a good first step, but to go from that to in vivo success in large scale human genetic modifications will be a very large way down the road, if it works out at all, and if it's legally allowed at all. By then we might have Mars colonists already, the hard way. Just accepting the higher cancer rates the way we currently accept high deaths from traffic accidents.
    That study mentioned a few posts back also found that genetic predisposition was a significant factor. Simple screening could reduce the risk to those selected, and show who needs to be watched more closely.

  20. #980
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    Quote Originally Posted by cjameshuff View Post
    That study mentioned a few posts back also found that genetic predisposition was a significant factor. Simple screening could reduce the risk to those selected, and show who needs to be watched more closely.
    Screening, drugs, medical intervention (surgery, etc.), and new therapies I cannot imagine will probably make it safer, but the screening strikes me as a top-drawer solution. Cancer surgery in space will have to be an option. Dr. McCoy's job is safe.
    Last edited by Roger E. Moore; 2020-May-25 at 03:00 PM.
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    Quote Originally Posted by cjameshuff View Post
    That study mentioned a few posts back also found that genetic predisposition was a significant factor. Simple screening could reduce the risk to those selected, and show who needs to be watched more closely.
    Which is true and has nothing to do with the article I cited.
    "I'm planning to live forever. So far, that's working perfectly." Steven Wright

  22. #982
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    Quote Originally Posted by Noclevername View Post
    Which is true and has nothing to do with the article I cited.
    It has plenty to do with the points you raised about it. Screening would provide the Martian population some degree of resistance to radiation damage without large scale genetic modification, and can be done before the first person ever sets foot there.

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    Quote Originally Posted by cjameshuff View Post
    It has plenty to do with the question you asked about it.
    I did not ask a question.
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    Quote Originally Posted by cjameshuff View Post
    It has plenty to do with the points you raised about it. Screening would provide the Martian population some degree of resistance to radiation damage without large scale genetic modification, and can be done before the first person ever sets foot there.
    Cool. But the article was about human genetic modifications using Tardigrade genes in anticipation of Mars colonization. That was what I was addressing.
    "I'm planning to live forever. So far, that's working perfectly." Steven Wright

  25. #985
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    Go to Mars, by way of Venus!

    https://arxiv.org/abs/2006.04900
    Human Assisted Science at Venus: Venus Exploration in the New Human Spaceflight Age
    Noam R. Izenberg, Ralph L. McNutt Jr., Kirby D. Runyon, Paul K. Byrne, Alexander Macdonald
    [Submitted on 8 Jun 2020]
    Some human mission trajectories to Mars include flybys of Venus. These flybys provide opportunities to practice deep space human operations, and offer numerous safe-return-to-Earth options, before committing to longer and lower-cadence Mars-only flights. Venus flybys, as part of dedicated missions to Mars, also enable human-in-the-loop scientific study of the second planet. The time to begin coordinating such Earth-to-Mars-via-Venus missions is now.
    Do good work. —Virgil Ivan "Gus" Grissom

  26. #986
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    A proposal to give Mars a magnetic field that won't involve destroying Mars to save it.

    https://arxiv.org/abs/2006.05546
    Fundamental Physical and Resource Requirements for a Martian Magnetic Shield
    Marcus DuPont, Jeremiah W. Murphy
    [Submitted on 9 Jun 2020]
    Mars lacks a substantial magnetic field; as a result, the solar wind ablates the Martian atmosphere, making the surface uninhabitable. Therefore, any terraforming attempt will require an artificial Martian magnetic shield. The fundamental challenge of building an artificial magnetosphere is to condense planetary-scale currents and magnetic fields down to the smallest mass possible. Superconducting electromagnets offer a way to do this. However, the underlying physics of superconductors and electromagnets limits this concentration. Based upon these fundamental limitations, we show that the amount of superconducting material is proportional to B^−2ca^−3, where Bc is the critical magnetic field for the superconductor and a is the loop radius of a solenoid. Since Bc is set by fundamental physics, the only truly adjustable parameter for the design is the loop radius; a larger loop radius minimizes the amount of superconducting material required. This non-intuitive result means that the "intuitive" strategy of building a compact electromagnet and placing it between Mars and the Sun at the first Lagrange point is unfeasible. Considering reasonable limits on Bc, the smallest possible loop radius is ~10 km, and the magnetic shield would have a mass of ~10^19 g. Most high-temperature superconductors are constructed of rare elements; given solar system abundances, building a superconductor with ~10^19 g would require mining a solar system body with several times 10^25 g; this is approximately 10% of Mars. We find that the most feasible design is to encircle Mars with a superconducting wire with a loop radius of ~3400 km. The resulting wire diameter can be as small as ~5 cm. With this design, the magnetic shield would have a mass of ~10^12 g and would require mining ~10^18 g, or only 0.1% of Olympus Mons.
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  27. #987
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    Quote Originally Posted by Roger E. Moore View Post
    Therefore, any terraforming attempt will require an artificial Martian magnetic shield.
    Not a given. Any spacefaring society that can terraform a planet, can easily perform regular maintenance on the atmosphere.

    With this design, the magnetic shield would have a mass of ~10^12 g and would require mining ~10^18 g, or only 0.1% of Olympus Mons.
    Or, the materials might come from a nameless asteroid that is not going to be Mars' biggest tourist attraction.
    "I'm planning to live forever. So far, that's working perfectly." Steven Wright

  28. #988
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    Quote Originally Posted by Noclevername View Post
    Not a given. Any spacefaring society that can terraform a planet, can easily perform regular maintenance on the atmosphere.



    Or, the materials might come from a nameless asteroid that is not going to be Mars' biggest tourist attraction.
    A planetary magnetic field also comes with inconveniences like radiation belts (though with a superconducting loop, you could at least turn it off periodically to dissipate them).

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    Maybe I missed it, but I don’t see an estimate of atmosphere loss due to lack of a magnetic field anywhere in that article. Estimates I’ve seen before were small. If it would amount to a large percentage loss in centuries it probably would make sense. If it would take many tens of millions of years for significant loss, as I suspect, not so important. Though it still might be nice if it can be made self repairing. I wouldn’t want to count on a human civilization maintaining repair over tens of millions of years.

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  30. #990
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    Quote Originally Posted by Van Rijn View Post
    Maybe I missed it, but I don’t see an estimate of atmosphere loss due to lack of a magnetic field anywhere in that article. Estimates I’ve seen before were small. If it would amount to a large percentage loss in centuries it probably would make sense. If it would take many tens of millions of years for significant loss, as I suspect, not so important. Though it still might be nice if it can be made self repairing. I wouldn’t want to count on a human civilization maintaining repair over tens of millions of years.
    Does anyone think the superconducting magnetic loops of the article could be made self maintaining over long term?
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