NASA Picks Winners For 3D-Printed Mars Habitat Design Contest (space.com)

schwit1 writes: NASA has picked the three winners in a design contest for 3D-printed habitats that could help future astronauts live on Mars. The $25,000 first prize in NASA's 3D-Printed Habitat Challenge Design Competition went to Team Space Exploration Architecture and Clouds Architecture Office for the 'Mars Ice House' design, which looks like a translucent, smooth-edged pyramid. That pyramid would be built of Martian ice and serve as a radiation shield, protecting the lander habitat and gardens inside it, team members said. The Mars Ice House's ribbed interiors and exteriors glow with diurnally determined hues at various times of sol (Martian day). In one illustration from the team's proposal, the outer shell is washed in Mars’ inky blue sunset, and in another it looks like it was dipped in the tea-tinged pink of the high noon on Mars.

Comments

Re:It makes no sense.

[oic0]

I think there is meant to be a good amount of insulation betwee the internal and the ice.

if an astronaut can still be called an astronaut

[turkeydance]

while living on a planet, then...Hey Mom! i'm an astronaut!

Let's think about this critically

[TWX]

I'm sure that some will say I'm a cynic, but if one looks at the entire history of spacefight as-imagined versus as-implemented, no functional space equipment has ever looked as sleek or smooth as the concept artists' work promised. Even the Shuttle, in its technological glory and areodynamic flight, does not look like the early prototypes of a spaceplane as envisioned by artists and dreamers.

Technology is often ugly because it is designed for function first. Form, past function, is a luxury. A nation-state that is already arguing about funding is not going to spend extra to make something that looks cool if it costs more to look cool. It will be built out of the simplest materials that are expected to achieve the desired result. If it doesn't need coverings it won't get coverings. If it's simpler to run a conduit or pipe exposed and there's no problem running it exposed, it will be run exposed.

The first Martian structures built from local materials will probably be some form of adobe or regolith-poured structure with a binder. They will be thick, they will be strong, they will match the soil of which they're constructed and will be ugly. They may even be like the anti-hurricane structures used in the Pacific, a lightweight polystyrene mold filled with the regolith and binding agent as a form of concrete. Bulky, but light and cheap, and if mass is more of a problem than volume, probably easier to transport to Mars, or if the expanded foam could be generated on-site, the blocks could be made of brought materials with equipment on-site, stacked, and filled with regolith.

It simply won't be done expensively when it can be done less expensively.

Re:Let's think about this critically

[gstoddart]

Yeah, I look at this and the first one looks like an impossible thing to build on Mars.

The second one looks cool, but still fairly complicated.

Oddly the third one looks like it could be plausible.

Is this based on anything other than being pretty and allowing NASA to have some PR? Or is there some expectation of this translating into anything real?

Because the translucent shark fin seems pretty unlikely.

Re:Let's think about this critically

[TWX]

Is this based on anything other than being pretty and allowing NASA to have some PR?

I doubt that it's more than PR, given how they're referencing 3d printing as a hot technology right now. Mind you, NASA needs PR as it is constantly threatened with being scaled-back, but I don't think that any of these concepts would do more than influence small portions of a final engineered design.

Re:Let's think about this critically

[Mr D from 63]

Curved structures look nice, but straight walled structures are much more space efficient and generally easier to construct.

Re:Let's think about this critically

[CrimsonAvenger]

Even the Shuttle, in its technological glory and areodynamic flight, does not look like the early prototypes of a spaceplane as envisioned by artists and dreamers.

Note that Shuttle looked that way, not because we couldn't make one that matched artist's conceptions, but because we were unwilling to pay the pricetag required for a fully reusable launch vehicle.

Re:Let's think about this critically

[Rei]

Actually I strongly recommend that people read the design documents (linked above). While the sleek look first comes across as an architect wildly fantasizing, the shape really comes from function.

1) You have to have radiation shielding. This means massive amounts of *something*, ideally from Mars. They identify water as the easiest "something" to work with. They're probably right.

2) Gantry cranes are heavy. You don't want to ship big heavy cranes to Mars. So it's best if you can build it up from bottom to top with a small device that ascends as it makes the wall. Hence their "3d printing bot" - yes, I know 3d printing is such a buzzword, but the bot design isn't actually that complex. It prints the tracks that it drives on into the wall it's making. Hence that "rippled" look to the walls. The shape doubles as a fresnel lens to focus light, which is neat and useful - but it stems from something much simpler, the need for the wall to be climbable.

3) This approach of printing tracks into walls is easiest done if the structure is highly vertical. For simplicity, the structure is also to be printed around the landing vehicle that brings all of the hardware and materials to print the shell - the vehicle also doubling as the habitat once it's been emptied out (reuse, reuse, reuse). Rockets tend to also be highly vertically-oriented vehicles. So you get - no shock - a highly vertical structure. It's function, not style - it's just that the function happens to also be stylish.

4) So you've got an outer pressure/radiation shell and an inner vehicle to be your habitat... but obviously you have to have insulation somewhere. What's the lightest insulation you could have? Aerogel. Okay, so you're going to bring aerogel. You can't just have it on your lander's exterior, it'll burn off on entry, so it's better to print it on when you get down to the surface - after all, you've already designed and built print bots. But if you're going to spray up a wall with your robots already designed for printing shells, why not leave a gap between the lander/habitat and the aerogel insulation, giving you more useful, room-temperature space? And another gap between the insulation shell and the ice - so now you have three independent domes providing redundancy? So right there again, function dictates form - even though the resulting form looks neat.

5) So you have room-temperature space outside your lander/habitat. And you have light filtering in through aerogel and ice, since they're mostly transparent. So why not grow plants there? Hence the greenhouse - it comes at almost no cost.

So while at a first glance it just looks like some fanciful design by a wannabe art/architecture student, there's actually solid reasoning behind it. Even the size of the habitat and its payload for making the shells was dictated by existing in-development launch vehicles (designed to fit on a Falcon Heavy or SLS).

Re:Let's think about this critically

[Rei]

A sphere has the minimum ratio of surface area (and thus material) to volume. It's also the shape you get when you inflate the simplest shape of balloon to act as the surface you're going to print against. Modifying the ideal sphere for a number of practical constraints leads to a more domed shape as in the winning design.

Corners are also an impediment to a robot designed to ride a self-printed track around the inside of a wall, as in the design.

Re:Let's think about this critically

[TheDarkMaster]

Engineers and designers are two species doomed to live in eternal conflict :-)

Re:Let's think about this critically

[Mr D from 63]

If you've ever tried to furnish the inside of a round room, or fill storage space with round walls, you'd know how much space is difficult to use. Making it spherical jsut makes it worse. Just because round is a natural shape does not mean anything. Crystals have a naturally rhombic elemental structure.

Actually, autonomous straight wall construction is simpler because the robot only needs to operate horizontally an vertically in the plane, then you just re-orient for each wall. Even with spherical structures, you will have interior walls and therefor corners, and curved corners are certainly more problematic that straight ones. Bringing closure to the top of the sphere becomes a challenge as well. Yes, there is the benefit of arcing support during construction, but you can put an arched roof on a straight wall structure if you want.

Re:Let's think about this critically

[werepants]

This is actually a pretty brilliant design, because water is easy to come by on Mars, and easier to work with than regolith or any other local material. The easiest way is to bring hydrogen from Earth, then obtain water via Sabetier reaction, using your hydrogen with CO2 from the martian atmosphere. Oxygen is the heaviest part of water, so a little bit of hydrogen goes a long way if you can get oxygen locally.

So, essentially all you need to do is create liquid water, and then deposit it and let the Martian temperatures solidify it. You don't need to get anything up to very high temperatures. Liquid water is very benign to work with as well, you aren't going to be gumming up printing nozzles, etc. Finally, water is very effective radiation shielding and has the added bonus of being transparent, so your astronauts don't feel stuck living in a cave. A bit of insulation as-needed on the interior will allow a comfortable temperature for the astronauts, and a sub-freezing temperature to be maintained by the ice.

Re:Let's think about this critically

[Rei]

I did not say because it's a "natural" shape. I said because it's the ideal shape for maximizing internal area while reducing surface area, and it's the shape naturally reached by inflating a membrane (which is what this concept is based on). Furthermore, "internal space" != "living space". The outer shell is a pressure vessel and radiation shielding. This creates a cold but breathable and pressurized area which can function as storage space, a place for holding external equipment, an EVA prep area, etc. The next shell in is the insulation shell (also with its own airlock, adding redundancy). Inside this (also domed) structure is a greenhouse / livable "outdoor" area for people to spend time in. Plants don't give a rat's arse what shape greenhouse they're being grown in, and you don't put beds and the like in the greenhouse. The actual living area isn't a dome. It's a cylinder. Why? Because it's the rocket sent from Earth, and rocket housings are cylindrical. You deal with what you've got.

You clearly have not read the construction process proposed for building these domes, hence your comments are not applicable. Please read the proposed construction method, *then* come back here and discuss it. Your "straight walls with corners" approach would require a far more complicated wheel assembly than the one that they use to go along curved, cornerless walls, which is akin to a common assembly used by roller coasters to hang onto a track. When was the last time you saw a roller coaster traversing a sharp 90 degree corner? As for the top of the dome, each of the printing bots has an arm from which the material (mostly water, but also aerogel and reinforcing fibers) is sprayed.

Re:Let's think about this critically

[Mr D from 63]

I was not concerned with the specific construction method. I was just saying that curved walls make interior space use less efficient, and rectangular structures allow more complete use of that interior space. I honestly don't think the robotics one way or the other is going to be an issue once you've already overcome the challenge of getting to Mars. Decide what structure is best, then determine the robotics required, not the other way around.

As for an automated building, there are already prototypes of building robots out there, and the ones that are working the best so far build straight walls. Just search on house building robots and you'll see how simple they can be.

Re:Let's think about this critically

[FatdogHaiku]

...It simply won't be done expensively when it can be done less expensively.

I have to agree. but what I don't understand is why build at all... DIG. Find a shelf of something similar to limestone or even thick sandstone and tunnel under it. If done properly you could have large areas supported by wrapped and bound pillars of what ever it is you are removing. Spray a humidity barrier on the walls and ceiling to keep your water from going away. Transfer excess heat to the surface and use the temperature difference to capture some electricity. The idea of growing things using sunlight is going to need augmentation at the very least, so just use the pink LED method already working here. Then you have to fab airlocks... LOTS of them. Most of the nasty stuff that can happen is at the surface, so I would not spend more time up there than is needed for exploring, testing, and of course real estate promotion.
I can already see the billboard:
If You Lived Here,
You'd Be Frozen By Now.
Great place to ship the cryogenically inclined among us... may need to work on the slogan...

Re:Let's think about this critically

[ClickOnThis]

On Mars, hurricanes and tornadoes do not pack anywhere near the wallop that they do on Earth, because the Martian atmosphere is so thin (less than 2% of the density of Earth's atmosphere.)

Re:Let's think about this critically

[Rei]

So your basic argument is "don't worry about how hard the habitat you want to build is, just make sure that you can fit a piece of furniture anywhere in it"?

If so, I've got a wall to hit my head against.

Curved walls on the radiation shielding/pressure vessel are the best shape for the walls of a radiation-shielding pressure vessel. We're not talking about someone's bedroom here, we're talking about the thing that stops your bedroom from getting fried by high energy protons. And you want to complicate the construction process - both the ability of the printers to traverse it, and the complexity of the membrane - so that simply your *shield* (not your living space) isn't round? And again, as for the bedrooms themselves, the shapes are to be dictated by the shape of the rocket (cylinder, not dome nor box) because, well, what you're sending to Mars is a rocket, and it's far, far easier to make something complex (like the actual area a person will be living in and all of the fixtures therein) on Earth than to try to build it on Mars. And if that means rounded external walls, people will live with rounded walls, just like they've done in every habitat we've ever launched into space.

Re:Let's think about this critically

[Mr D from 63]

So your basic argument is "don't worry about how hard the habitat you want to build is, just make sure that you can fit a piece of furniture anywhere in it"?

That is not at all what I said, that is your attempt to distort what I said to make a point. I said it makes sense to decide what structure is best first, when the building of it is not likely to be significantly more difficult either way. Your assumption that curved building is tremendously easier than straight is not one that I share with you.

I recognize that curved structures are better in general for pressure boundaries. But that implies a continuous curve and not varying ones as shown in the artist's depiction. But a straight wall can be an effective pressure boundary as well.

So, yes, there could be a case where internal space efficiency is sacrificed for other factors. That does not mean that is the best way to go, nor does is negate my point that round interior spaces are less efficient for use.

And another very good reason to use straight wall construction is for adding adjacent structures that share walls with existing ones. If you are starting a new habitat in space, you are likely better off starting small and adding. For that approach, a hexagonal straight wall structure might be optimal.

http://www.mathsinthecity.com/...

Re:Let's think about this critically

[TWX]

If humans are going to live on Mars, as opposed to just going on a very expensive camping trip, heavy equipment will be necessary beyond the construction of a settlement.

Re:Let's think about this critically

[TWX]

I don't disagree with having a large portion of the habitat underground, but for the long term mental health of the occupants there would need to be above-ground portions and probably portions with windows.

Re:Let's think about this critically

[FatdogHaiku]

Digging != Mining
You dig in soft material, which is often found under karst type layers like limestone, sandstone, gypsum, salt, etc.... That's why we get sink holes, soft layers under karst.

Ummm ....

[gstoddart]

In one illustration from the team's proposal, the outer shell is washed in Mars' inky blue sunset, and in another it looks like it was dipped in the tea-tinged pink of the high noon on Mars.

What the actual fuck? Is this actual NASA language?

Are these things being selected on the basis of color or something?

Seriously? Tea-tinged pink of the high noon? What is this drivel?

Re:Ummm ....

[Rei]

That's actually correct. Ambient light on Mars is pinkish when dim, butterscotch/oolong-tea colored when bright - except near the sun at sunrise/sunset where it's bluish.

Dupe story

[tomhath]

This was discussed a couple of weeks ago. But I suppose since it's both 3D printing and humaned mission to Mars it's worth discussing a few more times.

Re:It makes no sense.

[Rei]

It's not that simple of a design - there are multiple layers, not all of them ice, and different temperature zones. It's not even pure ice, it's an ice/fiber/aerogel composite, layered onto the inside of an inflated EFTE membrane in a modified fresnel lens shape to control where the light that filters through goes. This provides the "pressure vessel" as well as radiation shielding and some degree of insulation. A person can walk around in this area without a space suit, although it's quite cold. The next shell inward is printed using just the aerogel and binder. Inside this shell it's kept warm enough for living and plant growth; basically the whole area around the living quarters is a vertical greenhouse. The innermost section, the living quarters, isn't made on Mars. It's the landing craft that contained all of the excavation/printing hardware and supplies. It's sized to be launched on a Falcon Heavy. There's basically three separate airtight shells with airlocks leaving each one (the outer ice shell, the inner aerogel shell, and the inner living quarters/spacecraft, providing a great deal of redundancy against leaks. They even did actual 3d printing prototypes with their ice composite to test its properties, and have a pretty clever concept for how to have the printer be able to climb the walls its printing (it basically uses paired wheels (upper and lower) to grab onto the ridges of the fresnel lens structure it's printing, sort of like how some roller coasters hang into their tracks.

Really, it's not that bad of a concept, IMHO. There were certainly far worse in the competition.

technically, Mars is international waters...

[Thud457]

Technically, Mark Watney is the best architect on Mars.
So logically, early period Martian colonial architecture would look like the parts of Fred Sanford's junkyard that didn't get blow away by a recent hurricane.

Re:It makes no sense.

[Rei]

No. Picture the following: Room temperature space, 20C -> start of insulation (20C) -> end of insulation (-50C) -> beginning of ice (-50C) -> end of ice (-60C) -> outdoors on Mars (-60C). How is ice at temperatures between -50C and -60C supposed to melt?

The actual design is more complex than that, of course (multiple shells, airspaces, etc).

Dust?

[necro81]

How well is a habitat intended to be made of translucent ice going to do once it is inevitably covered with dust?

Re:Dust?

[Rei]

It will reduce the transparency. But Mars also undergoes wind scouring events - which is why Opportunity is still roving on Mars to this day.

Good transparency isn't a key aspect of the design. The basic issue is, you need radiation shielding from something, ideally something local. What's easier to work with that's local on Mars than water? Yeah, what's on Mars is really more like a salty, silty frozen muck than the pure fresh water ice that most people picture. But turning that to consistent-quality building material is assuredly easier than doing the same with bedrock, regolith, or whatnot. And much easier to spray/cast/etc while minimizing the amount of material you have to bring from Earth to do so.

Be sure to tell the droids...

[Dutch Gun]

"I didn't ask you to turn on the thermal heater. I merely commented that it was freezing in the princess's chamber..."

*bleep* *boop*

"But it's SUPPOSED to be freezing! How we are ever going to dry out her clothes, I really don't know!"

Re:It makes no sense.

[Rei]

Insulation does not regulate temperature. A closed box needs to have active temperature regulation for long term use.

You do have active temperature regulation. It's called "thousands of square meters of external surface area convecting with the atmosphere and radiating into space". It's a well pretty known thing that things on Mars tend to get cold. Usually there's far more challenge to have them not get too cold than to cool them down - hence, even Mars missions that don't use RTGs still tend to use smaller radiothermal heaters.

Any temperature gradient moving across the ice (in the above, -50C to -60C) means heat loss. The greater the gradient, the faster the heat loss - if you wanted more heat loss you could reduce the insulation and bump the inside of the ice's temperature up to say -10C and get a 50-degree delta-T instead of a 10-degree delta-T and thus 5x higher heat flow. But again, with this large of a structure, "getting too hot" is not your problem. Avoiding getting too cold is.

Re:Dumb design

[Rei]

Best of luck with your simple to operate and maintain, affordable-to-launch Martian tunnel borer. And I'm sure you'll only go through oh-so-predictable strata.

3D is so old tech, we do 4D nowadays

[WillAffleckUW]

Seriously. Only 1AME people use 3D.

Wake me when you realize you're using last century's tech.

If your flip phone still works.

A small step, much more required...

[swell]

The habitat is the second and lesser of two projects for humans to live on mars. A balanced approach is to adapt mars for human occupation, and also adapt humans to life on mars.

The first, most important, most time consuming project is to modify some humans so they have the best chance to survive. Eager volunteer space cadets may not be sufficient for this daunting adventure.

The obvious choice is to begin with the unborn. Ancestry will be important- people of the arctic circle who are adapted to cold, relative isolation and weak sunlight might be a good choice. Then there will be some genetic adjustments, funded by the department of defense, that we cannot discuss publicly for a few generations. The fetus/infant/child will have physical and psychological preparation throughout its development. When existing science has done all it can for this specimen, we shoot him/her off to mars.

Is existing science ready for this? Are social, political and religious leaders willing to accept this requirement? It's one thing to fantasize about gee whiz hardware and tech, it's quite another to properly prepare people to live a life we can barely imagine.

(I suspect that none of this will happen in our lifetimes. I sense that mars is a distraction the government wants us to think about when they are quietly doing evil things.)

The real question is ...

[140Mandak262Jamuna]

... Will it grow potatoes?

Re:The real question is ...

[Rei]

It does have a greenhouse built in, yes. So you could grow potatoes there (unlike the approach used in the book, which wouldn't actually work ;) )

One thing that the ice house site mentions in passing, without going into the implications, is that the shape of the ice shell will act as a fresnel lens. One of the neat aspects about that is that you can have it function as basically a passive solar concentrator, boosting the effective solar constant in the greenhouse/living area..

Re:Pretty, but maybe not the most practical

[Rei]

Ice isn't known for its structural properties, its prone to cracking, temperature sensitive & its not overly strong.

Which is why they're not printing out of pure ice. They're printing out of a mixture of ice, aerogel and reinforcing fibers. The *are* proposing a modern equivalent of pykrete.

but that's not going to stop it from trying to sublimate every time the sun hits it

Of course not. The EFTE exterior membrane onto which the ice is printed is what does that.

or melting if you accidentally set one of the many heat sources necessary to keep your crew alive too close to it.

Your crew doesn't live in that dome. They don't even live in the next dome inward from it (which is made of aerogel). They live inside the rocket which took the construction supplies and hardware there, located in the center of the aerogel dome. You have three spaces. The inner-most is the rocket-supplied living space (after having all of the aerogel, reinforcing fiber, etc unloaded from it) - bedrooms, kitchen, bathroom, lab, etc. The next layer out, the aerogel dome, is "outside" space at moderate temperatures, which acts as a greenhouse for growing plants and gives people place to walk around comfortably rather than being cramped inside the launched living area all the time. Outside that is the cold but still pressurized and radiation-blocking ice dome, where people can prep for EVAs, park vehicles and be as close to "walking around unsuited on Mars" as is possible for a human. Each layer provides redundancy in the event of a leak.

Its an interesting approach; I recommend you read the design document.

Re:It makes no sense.

[HeadSoft]

Seems to me Mars would have plentiful "cold" to refreeze anything which did melt... And inside, just like in an igloo, the air temperature can be quite warm while the ice itself is 32 degrees.

I'm wondering why they didn't just consider stone and dirt, which are also plentiful and probably just as good at blocking radiation, but I am sure someone thought of that. Surely?

Re:It makes no sense.

[Anonymous Coward]

If you build your habitat from ice, and if you keep the interior at a temperature that people and plants will tolerate, the ice will melt. This is common sense.

I take it you've never heard of an igloo?

Or a quinzhee?

Re:It makes no sense.

[Jarik C-Bol]

Also, ask anybody who's served on a nuke boat in the navy, iron/steel is a far better radiation shield than water. Using (scarce) water on Mars as a radiation shield, when the entire surface is rich in iron oxide seems dumb as hell to me. You'd be better off filling bags with surface material, pressing them into blocks, and using those blocks to build igloo shaped structures. This is why most of the (decent) books about mars colonization involve living underground initially.

Re:Dumb design

[Coren22]

https://www.google.com/search?...

I prefer already bored tunnels.

Look at the pictures in the Google image search.

Re:It makes no sense.

[nospam007]

"You'd be better off filling bags with surface material, pressing them into blocks, and using those blocks to build igloo shaped structures."

So your idea of 3d-printing habitats on Mars (that was the question) is to drop a brick and cement factory there together with a few builder-robots?

A better option, without 3D printing?

[dsmatthews9379]

If these guys could automate their system it would build bigger and stronger structures that could then be covered with additional layers for shielding.

http://www.monolithic.org/dome...

A double walled skin could be inflated with concrete foam, or polymer soil mix, in an automated system that would be very fast. The insulating properties of the foam material would then allow ice layers to be added to the external surface before a layer of soil to preserve the ice.

The problem with the NASA contest was the assumption that 3D printing offered the best solution. The other assumption was that the result had to be pretty, but that is designers for you. The most robust solution would have no external features other than entrances. This is assuming availability of compact fusion power by the time humans are ready to colonise Mars.

Re:A better option, without 3D printing?

[Rei]

The concept actually kind of is what you linked to :) They inflate a dome and then spray a material that will harden onto it. The differences are that what they're spraying is water+fibers+aerogel rather than cement+water+rebar+aggregate, and the spraying is done from close range rather than long range. Bringing fibers + aerogel rather than cement + rebar is obviously a lot lighter, and the former combination gives you light (amplified in the living area by the fresnel lens shape) and increases the R-value. Rather than inflating foam for the next layer (insulation), they print (aka, spray) out aerogel + binder (again, it's lighter). Spraying at close range rather than long range (ala shotcrete) reduces the power requirements on the pumping system, gives greater control over the shape/accuracy (allowing for light concentration and greater structural strength with less material), and reduces the complications of water vaporizing or freezing en route to the skin (remember that we're dealing with Mars temperatures and pressures here).

But at a fundamental level, it's basically a proposal for a high-tech, Mars-adapted version of a monolithic dome.

The "prettiness" is just a side effect of printing with water and the fresnel lens effect; I don't think it's fair to penalize them for their design *also* being pretty. That said, I am in full agreement that it's good for your crew to have natural light... not just for saving power or growing plants, but also for their mental well being. These are people basically cooped up in a can on a dead world for months to years on end who can't get away from their coworkers even if they wanted to and don't get to see their families and friends... at least give them some sunlight.

Re:It makes no sense.

[Rei]

Why is it so hard for people to RTFA, when it's provided in the post you're responding to?

3D Printing with Ice

Ice habitats on Earth and 3D Printing with ice are not without precedent. In consultation with our Team’s expert scientific advisors, astrophysicists, geologists, structural engineers and renowned 3D printing experts, we have achieved positive experimentation with one to one ice printing and successfully analyzed structural models.

Through an understanding of the physics of phase change and the temperature and pressure conditions of the Martian environment, as well as an understanding of the physical deposition techniques required we've designed a process to turn subsurface ice into water vapor, vapor used to deposit liquid water, in an environment cold enough to print a form in solid ice.

Making & Climbing the Ice Wall

The iBo is designed to deposit layers of ice with a low-volume, close-range nozzle that ensures that any water that freezes mid-trajectory melts and refreeze instantaneously via the energy of its impact (a contact weld).

It's not an obscure concept. And they've done test prints in a simulated Mars environment.

Any more questions? If so, make sure you read the design document first before asking them.

Re:Dumb design

[Rei]

They certainly warrant investigation and might ultimately prove useful, but they also present about as hazardous, difficult to access terrain as one could possibly imagine. And are a total unknown at this point in time.

Re:Inhabitant health

[Rei]

This design does call for exactly that: bringing their own habitat and using martian materials as exterior coverings. There are three segments: the inner segment (living quarters) is the rocket that brought all of the building supplies there. It's surrounded by an aerogel dome for insulation. The ice dome for radiation shielding is outside of that. There are three separate levels of air locks in the design.

Re:It makes no sense.

[Rei]

Also, ask anybody who's served on a nuke boat in the navy, iron/steel is a far better radiation shield than water.

Depends highly on the type of radiation. Iron is actually a pretty terrible shield against neutrons, for example.

As far as general purpose shielding against solar radiation and GCR, things rich in hydrogen generally are the best option. You can boost their effectiveness by borating them, especially on the inner layers, to help absorb thermal neutron secondaries.

Water is not scarce on Mars, it's actually quite abundant.

You cannot just "press regolith into blocks", any more than you can just press sand into blocks. You can sinter it into (gas-permeable) bricks, but that takes a great amount of energy - vastly more than melting water. And you want to bring a gantry crane to Mars to stack them?

This is why most of the (decent) books about mars colonization involve living underground initially.

Oh great, not only do you want to ship in a gantry crane, you also want to ship in a tunnel borer!

Don't stop there, ship in a bucket wheel excavator to do your mining, and a trained elephant to boulders around on sleds!

Re:It makes no sense.

[Jarik C-Bol]

Not really. Earth-ram blocks are a common enough building material, and can be made by hand, or with simple tools. Instead of cement, we can use any number of masonry epoxies as a mortar, which are far easier to ship than a cement factory. Additionally, the fact that Mars has just over 1/3rd the gravitational pull as earth simplifies the building process.

all this is pretty well beside the point, because these are more of a 'long term' option, not a 'first visit'. Not like we're going to Mars any time soon anyways.