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NASA Designs 'Ice Dome' For Astronauts On Mars (phys.org)
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.
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?
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).
Often wrong but never in doubt.
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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.
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.
... 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.
For the love of Crom, am I the only one here who wants to keep the U.S. technologically competitive?
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)
For the love of Crom, am I the only one here who wants to keep the U.S. technologically competitive?
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.
For the love of Crom, am I the only one here who wants to keep the U.S. technologically competitive?
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.