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Mars NASA Space Science Technology

NASA Designs 'Ice Dome' For Astronauts On Mars (phys.org) 126

An anonymous reader quotes a report from Phys.Org: The "Mars Ice Home" is a large inflatable dome that is surrounded by a shell of water ice. NASA said the design is just one of many potential concepts for creating a sustainable home for future Martian explorers. The idea came from a team at NASA's Langley Research Center that started with the concept of using resources on Mars to help build a habitat that could effectively protect humans from the elements on the Red Planet's surface, including high-energy radiation. The advantages of the Mars Ice Home is that the shell is lightweight and can be transported and deployed with simple robotics, then filled with water before the crew arrives. The ice will protect astronauts from radiation and will provide a safe place to call home, NASA says. But the structure also serves as a storage tank for water, to be used either by the explorers or it could potentially be converted to rocket fuel for the proposed Mars Ascent Vehicle. Then the structure could be refilled for the next crew. Other concepts had astronauts living in caves, or underground, or in dark, heavily shielded habitats. The team said the Ice Home concept balances the need to provide protection from radiation, without the drawbacks of an underground habitat. The design maximizes the thickness of ice above the crew quarters to reduce radiation exposure while also still allowing light to pass through ice and surrounding materials.
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NASA Designs 'Ice Dome' For Astronauts On Mars

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  • I'm afraid (Score:3, Funny)

    by Anonymous Coward on Saturday December 31, 2016 @02:21AM (#53583693)

    that astronauts will face a frosty reception on Mars.

  • ...do they believe that only one of these many alternatives will be the way to live on Mars.

    • by Brett Buck ( 811747 ) on Saturday December 31, 2016 @03:18AM (#53583771)

      I am sure that your country's highly successful space program, that has done multiple successful manned landings on other celestial bodies, and sent many successful probes to land on Mars, knows much better. Which country was that again?

      • by Anonymous Coward

        We managed to colonize other solar systems. And it's not a country, it's the Alliance.

      • by gweihir ( 88907 )

        You mean that country that did a lot of stunts, but never managed to get anything manned permanently into space (except LEO)? That country that does not have a reliable launch vehicle at this time?

    • by Jack9 ( 11421 ) on Saturday December 31, 2016 @03:24AM (#53583781)

      This, like most plans about survivability on Mars, is fantasy level design. Just have to carry the water in supply ships or bring it with you around each transport ship (once we make ships that do that) or mine the water from the Martian surface (hopefully it's about the same as what we need, right?).

      I believe, the only way to live on Mars, in the forseeable future, is underground. That has enough problems to make it impractical in the next century. It's been particularly biting that In the 80's we thought we'd have flying cars and instead we got the "don't pokemon and drive" freeway warnings.

      If we can get something long-term set up on the Moon, we can handle Mars. Humans haven't been willing or able to try yet. It should net some tasty govt grants though, eventually (eco-dome experiments primarily resulted in a terrible movie).

      • by wierd_w ( 1375923 ) on Saturday December 31, 2016 @03:43AM (#53583797)

        I still think they need to look into solar sintering based glass fiber production. Sinterable dust is all over on mars, and already loaded with melt temp reducing salts. The median bulk composition of Martian dust needs to be released for materials research, to see if viable glasses can be produced this way. (You just need a bead of glass and a centrifuge to spin off glass fiber. Even with the lower light levels, this should be doable on Mars. That gives the raw material for sandbag based habitat construction.)

        So far though, I have yet to see a good bulk mineral assay of martian dust, only formulations for simulants that simulate texture for landings. That is not useful for evaluating glass quality for fiber production.

        • by Rei ( 128717 ) on Saturday December 31, 2016 @06:48AM (#53584085) Homepage

          I assume you mean basalt fiber, not glass fiber. Quartz sand is not readily available on Mars.

          Not every basalt is suitable for use in production of basalt fiber. I have no clue how well Martian regolith would suit, and I doubt anyone else does. Either way, it's a very energy intense process involving some pretty heavy hardware; you have to basically create a molten pool of basalt (aka lava) at about 1400C and blast it through tiny nozzles into air (which is extremely thin to begin with on Mars) moving at hurricane speeds.

          Yes, the simulants like JSC Mars-1A are pretty poor. It's just sifted Pu’u Nene tephra. MMS is a bit better (not as weathered), but still, they just (roughly) match major elemental concentrations, they don't have any of the "Mars specific" things like hexavalent chromium, perchlorates, etc, nor do they guarantee particular mineral forms. And "roughly" is a key term to emphasize about the ratios. But for something where you're just going to be melting it down, that probably doesn't matter too much. Again, though, "Martian basalt", like basalt on Earth, is not a single universal thing; the dust from the particular site would need to be sampled and analyzed on its own.

          Were you talking about fiber production for use as loose-fill reinforcing fibers (like are used in some types of concrete) or for making into cloth to make into bags? Either way it's probably just easier to send from Earth, at least in the early phases.

          • by wierd_w ( 1375923 ) on Saturday December 31, 2016 @07:24AM (#53584131)

            The idea I had in mind is more akin to a high temp version of a cotton candy machine.

            A central vessel at the spin axis is under the focal point of a Fresnel lens. A small shaker chute dispenses more dust to this crucible as material is removed. The crucible has two or three small holes through which material may be expelled, and it rotates at several hundred rpm. The mechanical stretching needed for glass fiber comes from the fiber hitting the side of the hopper, while the axis continues to rotate. This should produce a cotton wool like glass fiber, which should be workable into simple construction forms.

            Due to the aridity, even water soluble glasses may end up being useful, if nothing else but for creating dust collection filters for atmospheric concentrators.

            • by Rei ( 128717 ) on Saturday December 31, 2016 @08:17AM (#53584211) Homepage

              Have you seen any basalt fiber production process that actually works like that? I haven't. I would hesitate to say that it "should", because if it did, I'd expect people to use it.

              As for the heating: it's hard enough to melt things like zinc with sunlight. Hot enough to melt basalt with just sunlight? On Mars? Now that's a very tall order.

              Again, you keep saying "glass". Mars is basaltic, not rhyolitic. You're talking basalt fiber. And the main mechanical properties you need for most applications are tensile/yield strength and young's modulus, as well as creep and flexural behavior. And getting the desired properties means using an appropriate source material.

              And I'm still not sure for what purpose you brought this up in relation to building habitats. Basalt fiber reinforced concrete is very much a real thing (I'm actually getting ready to build a basalt fiber reinforced house), but again, it'd be much simpler/cheaper/more reliable just to import your fiber from Earth, at least while one is just getting a colony established.

              • by wierd_w ( 1375923 ) on Saturday December 31, 2016 @08:28AM (#53584243)

                When I say "glass", it is not necessarily "amorphous silicon dioxide". It is more " amorphous phase metal oxide". It need not be silicon oxide.

                "glass" refers to its structure, not composition.

                glass thus does not require silicon to be created. an example is oxide glass, made from 90% alumina.

                there ARE clay formations and claystone formations on mars, which would produce viable glasses.

                • by wierd_w ( 1375923 ) on Saturday December 31, 2016 @08:38AM (#53584269)

                  As for solar only based sintering (on mars), I still think it is doable, and could be simulated on earth with appropriate feedstocks, and occultation of the Fresnel lens to model the 60% or so reduction of solar intensity.

                  A Fresnel lens from a big screen rear projection TV produces a focal point suitable for this purpose on earth. (It can melt pure silicon oxide without a flux, which has a vitreous transition temp of 1475k) We would need a significantly larger one on mars, but still within the realm of being sent there rolled up in a shipping tube.

                  • by Rei ( 128717 ) on Saturday December 31, 2016 @09:18AM (#53584351) Homepage

                    I don't doubt that it's possible; it's the rate that's the issue. Not knowing what your goal is (aka, what the fibers are for), it's hard to get a sense of how rapidly you'd need to melt it, and thus how big of a system you'd have to have.

                  • As for solar only based sintering (on mars), I still think it is doable,

                    You do realise that useful fibres for construction need a fibre diameter less than their Griffith fracture length? Which is precisely why sintering isn't used in the real world, but full-on fusion, to some hundreds of degrees above the fusion temperature range, to reduce the melt viscosity. How many hundreds of samples of sintered materials did you examined under the microscope before you realised how their microstructure differs from a

                • by Rei ( 128717 )

                  You can use terms however you want. However, to the rest of the world who deals with engineering fibers, glass fiber is made from blowing quartz, and basalt fiber is made from blowing basalt.

                  Neither are produced from clays.

                  • Not my definition. It is the definition used in chemistry, AND material science.

                    No silicon to be found in "metallic glass" for instance.

                    http://engineering.jhu.edu/mat... [jhu.edu]

                    The requirement that it be silica glass to be called "glass" is a fabrication made entirely by yourself. I used the term correctly. A glass is any solid substance lacking an orderly molecular arrangement. That's why metals can be glasses, as noted above.

                    • by Rei ( 128717 )

                      It is not the definition used. "Glass fiber" refers to fibers of silicon dioxide plus various additives to lower the melting point. "Basalt fiber" refers to fiber made from basalt, without additives. These terms aren't up for debate; that's what they actually mean. That's how they're actually used. I don't give a rat's arse if basalt fiber is "a glass" from a chemical standpoint; if you go place an order on glass fiber, it will never, ever be made from basalt. If you find a place that is melting down b

                    • by Rei ( 128717 )

                      Words matter. To put it in terms familiar to Slashdotters, it's as if the other person was using the term "RAM" to mean both RAM and hard drives, using the argument that hard drives are "random access" and "memory", and thus RAM. You don't just sit there and pretend that it's okay to grossly misuse product names, particularly for products that you actually use.

                      For your "steel nails" analogy, it's as if the other person was calling copper nails "steel nails" on the justification there's a couple-percent ir

                • glass thus does not require silicon to be created. an example is oxide glass, made from 90% alumina.

                  Congratulations for raising the necessary temperature from about 1400 C to 1900 C and so the radiative heat loss from (relative) 1 to about 3.39. i.e., you've made the energy requirements over 3 times harder.

                  Can you point me towards the reports of high grade (say, 10% v/v) alumina deposits on Mars? I seem to have missed the reported analyses.

                  there ARE clay formations and claystone formations on mars,

                  Well cl

              • As for the heating: it's hard enough to melt things like zinc with sunlight. Hot enough to melt basalt with just sunlight? On Mars? Now that's a very tall order. I don't think so.

                There is a nice youtube video https://www.youtube.com/watch?... [youtube.com]

                Showing how to use a Fresnel lens to have a 3D printer using sand.

                There are a few more/better videos but I could not find them quickly.

                it'd be much simpler/cheaper/more reliable just to import your fiber from Earth, at least while one is just getting a colony establishe

                • by Rei ( 128717 )

                  Indeed - but as I mentioned above, it depends on the quantity that they're talking about (which they never spelled out). Also, making tiny beads is very different from a large, uniformly heated crucible.

                  Really? I mean, we are talking about tons, hundreds of tons of "building material"

                  Again, the person never specified what exactly the fibers were to be for. But there's no reason you'd expect them to be the majority or even a significant fraction of the total system mass. Reinforcing fibres in concrete are

                  • Well, I did not think about the development costs on earth, in case there is a new "autonomous fabrication robot" needed.

                    I only considered the transportation/launch costs.

                    Then again: that perhaps would be a project to try to establish on the Moon?

          • it's a very energy intense process

            Energy, like comes from Plutonium piles?

            involving some pretty heavy hardware

            bigger problem, potentially best solved by building from local materials.

            As others have stated: knowing the properties of the readily available materials in the area where the colony will be located is critical. Assume we need water (ice), first we need some extensive surveys of the non-ice materials in the general vicinity of the ice.

            • by Rei ( 128717 )

              Energy, like comes from Plutonium piles?

              A "pile of plutonium" does not a nuclear reactor make. If you're talking 239Pu, a pile of plutonium is either a "pile of nothing useful" or a "pile of soon to be a nuclear disaster". If you're talking 238Pu, depending on how fast you're talking expensive to obscene proportions. And neither generally run hot enough to melt basalt, by design; you generally try to avoid meltdown.

              Engineering a new nuclear reactor designed to operate in a Mars environment at temperature

              • Just say "Mars" and you can run into the tens of billions of dollars on administrative overhead alone.

                Plutonium is a product of breeder reactors, its market price is far disconnected from the actual effort required to make it. "Like Plutonium Piles" does, indeed, imply the development of a nuclear reactor for Mars deployment. Plutonium piles are mostly developed for small energy needs on "deep space" missions, you'd want basalt melting heat from something relatively lightweight and portable. Rocket launc

          • Again, though, "Martian basalt", like basalt on Earth, is not a single universal thing; the dust from the particular site would need to be sampled and analyzed on its own.

            What? you mean that the reality might actually be a little bit more complex than the daydreams of people typing on internet fora? That Areology might actually be different to geology, even if both are built on fundamental chemistry? Wow - do they breed realists up there in Iceland? You're far off message.

      • by dbIII ( 701233 ) on Saturday December 31, 2016 @03:47AM (#53583807)

        Just have to carry the water in supply ships

        Someone hasn't been paying attention over the last few years.

        • by wierd_w ( 1375923 ) on Saturday December 31, 2016 @04:00AM (#53583839)

          The martian water tends to be 2 kinds:

          So saline that it will literally burn your skin off on contact (because it is basically bleach).

          Frozen, and buried under a lot of overburden.

          The first kind avoids sublimation and freezing due to its high salinity. It is useless for astronaut/colonist use. Would require extensive reprocessing to be made useful. Not cheap.

          The second kind avoids sublimation due to the pressure exerted by the overburden, and the frigid deep soil temperatures of Mars. Mining it requires removal of the overburden (strip mining), which is not cheap. Once exposed, it will begin sublimating immediately. A great deal will be lost to this form of evaporation, and the mine strip will be geologically unstable, due to the volatility of the ice. Not cheap.

          Putting dirt into sandbags? Potentially very cheap.

          • It does not matter if it is cheap or not, as you are not competing with one who makes it cheaper than you.

            Also keep in mind, the saline water is excellent for electrolysis, hence H2, and O2 for breathing and/or clean water production and/or electricity via fuel cells and/or with CO2 from the atmosphere perfect for making CH4 and more O2.

            Regarding underground "mining" I would consider boring and not strip mining the better approach. But to be sure about that we would need some real experts that analyze a rea

            • by Rei ( 128717 ) on Saturday December 31, 2016 @04:59AM (#53583935) Homepage

              Arbitrary saline water is not "excellent for electrolysis", you'll end up destroying your electrolysis cells. Look at all the trouble they've had with the Elektron systems on the ISS, and that's under perfectly controlled conditions. Screwups are not acceptable on Mars. You can't just guess that things will be okay. For any potential ice resource, you need to have it very well quantified (and not just a tiny surface sample - and not just the water, but all of the solid matter it's mixed in with), so that engineers on Earth can create an accurate testbed for their proposed hardware to operate on.

              Re, boring: have you ever seen the size of a TBM? Don't get me wrong, nuclear-powered Martian backhoes aren't exactly a dime a dozen, but that sure sounds cheaper than martian TBMs.

              I have to agree with weird_w - the simplest means of radiation shielding is to use loose regolith (in regions where it's available in a deep enough layer... which aren't exactly rare, although they're not universal). Whether that's via bagging, binding with cement, binding with materials from Earth (a thermoplastic, epoxy, water, etc, optionally plus reinforcing fibers), or just simple loose dumping over a form, they're probably your easiest bet.

              If you are advancing to the point where you're going to be doing in-situ water harvesting for electrolysis and drinking, however, something like the ice house is probably worth consideration. It does provide for much better human factors via transmission of (and fresnel concentration of) light, and allows for some limited agriculture (without requiring vast amounts of power generation for artificial lighting). It's easy to want to ignore human factors, but they're very real. Having people live their lives inside a cramped windowless can isn't exactly good for mental health or morale.

              However, IRSU water is not a given. Pretending that harvesting of water is just "you go there and dig it up" is a vast oversimplification. To the point that even a lot of IRSU propellant proposals call for sending the hydrogen for the fuel from Earth even while they get the carbon and oxygen from the atmosphere. The atmosphere is a fairly constant, reliable, predictable fluid feedstock. The ground... isn't.

              (And yes, technically you can get water vapor from the atmosphere, but the quantities it's available in are so tiny that most analysis writes off the concept due to the amount of air you'd have to move through the system per unit water recovered, and the mass of the system you'd need to do so)

          • by Anonymous Coward

            Agreed.

            Using a very rare element, that is very unstable due to sublimation, while there is plenty of other local alternatives (yes, mars has dirt!) is plain silly.

          • by Anonymous Coward

            Any kind of agriculture is going to depend on artificial lighting no matter what. 44% of the light that reaches earth reaches mars, virtually all plants that are used by agriculture require substantially more light than this. If you don't believe me, put a heated greenhouse without any artificial lighting up in the winter in a non-equatorial latitude and see how well things grow. Things like rye and wheat may be able to survive pretty cold temperatures when sprouting and getting started but they grow bes

            • by Rei ( 128717 )

              Very good points. Note that the ice house does use a fresnel lens pattern on the outer shell to concentrate light onto the inner shell. But it's not designed to be a "farm", just a courtyard with some agricultural production potential.

              Most proposals for full-scale farms on Mars these days seem to be inflatable low-pressure domes with no radiation shielding, plus artificial lighting to function as both a light and heat source. Plants can tolerate much higher radiation levels and much lower pressures than

              • Plants can tolerate much higher radiation levels and much lower pressures than humans can.

                "tolerate" as in "survive", probably; but it's hardly thriving. Humans can (and do) survive extended periods in the 5.5 to 6.5 km altitude range which is above the practical limit of agriculture. Most Sherpa villages are a kilometre or more further down into the atmosphere than this precisely because their crops (barley, mostly) needs the additional air pressure.

                In Martian terms, you need to concentrate the atmospher

            • The solution to this is reflectors that send additional light into the greenhouses. I'm thinking of something like these linear concentrators:

              http://www.redrok.com/images/h... [redrok.com]

              but instead of focusing the light on a tube to boil water, they focus it on narrow windows in the greenhouse. Since Mars has a similar day length and axial tilt to Earth, the main thing is to increase the amount of light getting into the greenhouse. So the reflectors need to be about 2.5 times the area of the greenhouse floor. I as

          • by dbIII ( 701233 )

            The first kind avoids sublimation and freezing due to its high salinity. It is useless for astronaut/colonist use

            Apart from a use that is described in the summary above.

          • by Notabadguy ( 961343 ) on Saturday December 31, 2016 @10:40AM (#53584545)

            I just wanted to thank Rei and wierd_w for some topical, intelligent hilarity.

            Seems like most of the comments on slashdot these days are made by dumb people, are not topical to the thread they're posted in, and usually have to do with Trump or Clinton.

            It's good to see some engineers getting lippy with each other over things like the definition of glass. That's why I come to slashdot - to find people smarter than me arguing about interesting things.

        • by Kjella ( 173770 )

          It's there != we can mine it with reasonable effort. Take for example asteroid mining, how long have we heard about that? I think the biggest limitation is that if you depend on a water deposit you have to land pretty much on top of it. Mars' circumference is 21344 km, you will not be travelling geographically significant distances with it. Maybe we'd rather be near the equator for higher temperatures? Down a crater for denser atmosphere? Near resources for fuel production?

          I'm thinking we need an airtight d

          • > Take for example asteroid mining, how long have we heard about that?

            It's been a feature of science fiction since the early days. But making a serious effort at it depends on several things that are more recent:

            * The discovery of 15,000 Near Earth asteroids, 90% of which have been found in the last 15 years : http://neo.jpl.nasa.gov/stats/ [nasa.gov] The Near Earth group are much easier to reach than the Main Belt asteroids. The more of them you find, the better the chance of some of them being the right compo

          • Take for example asteroid mining, how long have we heard about that?

            About as long as we've been hearing about rockets that land on their tail and self driving cars and handheld communications devices that connect to anyone. :-)

          • I'm thinking we need an airtight dome and an almost completely closed system anyway,

            Scrub the "almost" from your design brief. Things will break and leak often enough that you don't need to go around designing holes in your system.

            If you're in a dome, with a closed ecology, what is the benefit of being at the bottom of a gravity well too? going to go outside on your break time and catch some rays?

      • Unlike the moon, Mars has plenty of ice. An underground habitat would have to extract all that ice anyway for drinking and fuel, so I don't see how the ice dome is more complicated than making an air-tight environment in a cave that can withstand high pressure and then bringing the water down into it.

      • Will water shield against cosmic rays? Because that's what I've heard the main problem with mars colonization is - there is no magnetosphere to shield against solar storms. One hiccup from the sun and everyone on the surface gets a lethal dose of X-rays.

        • by Rei ( 128717 )

          Yes; that's the primary point of it. You want as much material, ideally hydrogen, between you and space as you can. Water is an excellent way to do this.

        • Cosmic rays are nothing to do with solar storms. Two entirely different things.

  • Trying to colonize Mars with rocket technology is like trying to Colonize the New World with canoes. What's really needed is a way to get off the planet that can do better then 10% takeoff weight to orbit (about theoretical max). Saturn V managed about 4%
    • Trying to colonize Mars with rocket technology is like trying to Colonize the New World with canoes.

      Canoes got the Polynesians pretty far, possibly including the New World. Mars is a lot harder due to the lack of air and fish, yet easier in the sense that all you need is some really obscene amounts of money. For say 10 trillion dollars a year, you can make a pretty successful rocket-based colonization program.

  • by Rei ( 128717 ) on Saturday December 31, 2016 @04:43AM (#53583913) Homepage

    ... I do have to admit, this one seems the best thought out (it's been covered here on Slashdot before). The level of detail that they went into on their work was impressive, on every front. Some of the unique concepts are rather interesting, such as having the outer ice shell shaped as a fresnel lens, thus concentrating sunlight to higher levels in the interior. I also like the nested aspects of it - providing a large uninsulated (but pressurized) staging yard (quite useful, particularly once you start ramping up ISRU and need room for lots of industrial systems and feedstock/output stockpiles), and an insulated greenhouse/courtyard around the primary shelter (nice thought toward human factors, as well as small scale agriculture). Having the primary shelter be constructed on Earth and simply landed (with its interior space initially filled up with the hardware needed to make the outer radiation protection / pressure shell) hits all the right buttons as well. Having the "printer" slide along grooves in the shell it sprays out is also a lot more elegant of a design than many other potential alternatives.

    Still, there's a massive amount of engineering and testing that would be needed to make such a thing. And a lot of in-situ demo missions as well for each aspect of the technology, especially the (no hardware design given) vaporization-based water recovery system, but up to and including a small scale inflate-and-print testbed.

    • by Rei ( 128717 )

      I'd also note that most of what they propose could also be done with regolith + binder instead of ice, albeit giving up light transmission in the process.

      • the issue with that, is that mars is LOADED with iron in the regolith. As such, you will have loads of secondary radiation. Not a good thing.
        • by Rei ( 128717 )

          When you say "secondary radiation", what do you mean - bremsstrahlung and (x, n) reactions? It's okay to have some heavy elements so long as you have a sufficient total cross section of light elements, esp. hydrogen. In some regards it's actually better to mix both heavy and light elements; heavy elements block X-rays/gamma rays better.

    • This is actually a pretty interesting concept for Arctic / Antarctic construction. They apparently have at least a small ice-printer. The theory and engineering behind additive manufacturing is pretty well understood - there are commercial units printing concrete. You could easily imagine, for example, a wind powered device that heats the snow / ice, cleans it up and sends it to the printer (or does the same without heating, whatever). Print up your North Slope construction domes or Antarctic research s

    • considering meteorites are a constant issue (atmosphere is too thin to burn them up), I would not want to live in that.
      HOWEVER, that really would make a great topside garage for a lava tube. In fact, I wonder if this could be used to seal the lava tube to the point that it could take some decent pressure inside?
    • Still, there's a massive amount of engineering and testing that would be needed to make such a thing. And a lot of in-situ demo missions as well for each aspect of the technology

      That's true of pretty much every scheme currently on offer for surface operations on Mars.

      • We're in a post-engineering world. The MBAs know it's all about vision and making all the text light bluish-grey so you can't see it.

  • For the really really nerdy, who wants to know more about this, I can recommend the podcast Orbital Mechanics, specifically this episode about the Nasa Centennial Challenge: 3d Printed Habitats. (Which the ice dome was part of)

    http://theorbitalmechanics.com... [theorbitalmechanics.com]
  • Other concepts had astronauts living in caves, or underground, or in dark, heavily shielded habitats.

    Would we not take lights with us?

    • by Rei ( 128717 )

      Can't (realistically) beat the sun's several hundred watts per square meter. To get that much light would take multi-kilowatt spotlights every square meter**. Plus the outer ice dome is designed as a fresnel reflector to concentrate light onto the inner insulated dome.

      ** Offsetting this is the cosine of the angle of the sun from the horizon, and the fact that the sun provides you no light at night. But overall, it's very difficult to match the light output of the sun!

      • Well, it takes a lot, but not multi-kilowatts/m. Even here on Earth, sunlight only offers about 1.4kw/m^2, and that only when it's directly overhead on a perfectly clear day, and not all of that is in the visible spectrum. A single kW/m will best it most of the time. And on Mars that number falls to only about 0.6 kW/m^2 since it's so much further away.

        • by Rei ( 128717 )

          1,4kW/m^2 at Earth in space. 1kW/m^2 on the surface on a clear day. 600W at Mars in space. A bit less on the surface on a clear day, vastly less during a dust storm.

          You do need multi-kW lights per square meter because even LED lights release much more energy as heat than light, and almost any setup loses a significant amount of stray light.

          It gets even worse (from an area perspective, at least) if you go PV->electricity->lights because then you need another big loss mechanism (~80% of the energy fo

      • You quoted many facts, but still failed to answer my question. If we take lights – and use them – the habitats won't be dark. Why would we choose to live in dark habitats?
        • by Rei ( 128717 )

          It depends on what you mean by dark. If you mean "living in pitch black", no, they won't be. If you mean "living without light comparable to sunlight", then that is absolutely true.

  • by Anonymous Coward

    I've been reading about plans for manned spaceflight to Mars since I was a kid and saw an article in the newspaper about it the day after the Apollo 11 moon landing. That article quoted a NASA source saying we would be on Mars by 1990. No human has been beyond low Earth orbit since the 70s and I fear we may not have the resources or technology to achieve such a dream right now. I hope I'm wrong. It's still worth planning for it - but practically the cost of such a mission, not to mention a permanent se

    • by Rei ( 128717 )

      If the Apollo budgets had held, there's little doubt that humans would have been on Mars by 1990. It's all about where you focus your budget priorities. The US gutted NASA to pay for Vietnam.

      The US isn't really at odds with the EU. But the EU spends only a pittiance on space exploration. Russia is increasingly a shadow of its former self in regards to space exploration budgets as well. If there's going to be a new space race, it'd have to be between the US and China. Or as the new president might say,

      • by gweihir ( 88907 )

        Keep kidding yourself, you obviously are not living in the real world. It is not a question of money.

    • by gweihir ( 88907 )

      I think your estimate is way low. Get something on the moon that is self-sustaining over a few decades, and then we can talk about doing it somewhere really far away like Mars.

  • Came here expecting to see posts recommending transparent aluminum.
    Was competely disappointed.

    Will now jump into time machine to read a /. post from 1998 suggesting coating the dome with hot grits.

  • Seriously, a lava tube while being darker, would be relatively even-keel on temps. In addition, it would do a better job of protecting from meteorites. Finally, with a lava tube, simple seals can let in light, but increase the pressure just a little bit to the point where plants can survive ( with artificial lighting obviously ). With a bit of genetics, we can figure out what plants can actually exists on Mars surface.

    One thing that would be nice to see Musk do is send a couple of large wing flyers that
  • Comment removed based on user account deletion
    • by Rei ( 128717 )

      The structure is not "just ice", and you should really read the linked articles before you comment. The outer shell is dyneema-reinforced ETFE membrane coated in ice. The inner shell is aerogel. The habitat (inside the inner shell) is the rocket landing stage (presumably carbon fiber or aluminum).

      And ice + regolith would be permafrost, not pykrete, which is based around wood fibers. And would defeat one of the main purposes, translucency.

  • Let's just assume the following...

    We haven't colonized the moon yet, and that's just a few days away. What makes anyone think that a manned mission to Mars (let alone any attempt at colonization) would be anything more than a multi-billion dollar suicide mission? Apollo missions were all just a simple malfunction from certain death. That Apollo 13 made it back alive was part luck, part good timing of when the service module exploded, and part *real* men (not millennial snowflakes) working 24/7 back on ea

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