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.

[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.

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: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.)