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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.
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.
Lost at C:>. Found at C.
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.
The War of 1812... the good 'ol days when the federal government actually tried to save New Orleans.
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).
The War of 1812... the good 'ol days when the federal government actually tried to save New Orleans.
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).
The War of 1812... the good 'ol days when the federal government actually tried to save New Orleans.
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.
The War of 1812... the good 'ol days when the federal government actually tried to save New Orleans.
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.
The War of 1812... the good 'ol days when the federal government actually tried to save New Orleans.
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.)
If it weren't for deadlines, nothing would be late.
Why is it so hard for people to RTFA, when it's provided in the post you're responding to?
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.
The War of 1812... the good 'ol days when the federal government actually tried to save New Orleans.