1
$\begingroup$

If there's one thing that solid celestial bodies have, it's dust. Dust plus water is mud. Mud plus heat is brick (and recoverable water vapor). The heat can come from a reflective solar array. Easy, right?

Would it be feasible to build brick and mortar habitats on other planets or moons with little or no atmosphere? Is it possible to make an airtight, pressurized brick building?

$\endgroup$
  • $\begingroup$ Better off making concrete walls. Fewer joints to seal. $\endgroup$ – user2448131 Aug 8 '15 at 3:27
  • $\begingroup$ Concrete needs form works. No wood in space, next best thing is metal forms. Got to make them or ship them in. Making them requires smelting, rolling, machining, etc., really complex for an early settlement. Shipping them in is a big deal. Bricks you just bake and glue. $\endgroup$ – master_gibber Aug 8 '15 at 6:36
1
$\begingroup$

Short answer: Likely.

Maybe techniques from powder metallurgy can be used to sift carefully selected grain sizes together for high density bricks. Depending on the microscopic shape of the mineral particles, it might be possible to have them fit together nicely. (I imagine that mineral particles that were formed in space might have remarkably different microstructures than those on earth.) Dry dust in a vacuum could be carefully sieved and deposited into a vibrating mold in layers to get close packing. Particle sizes could be selected so that successively smaller particles fill the voids left by larger ones.

With little or no atmosphere, it's trivially easy to get perfectly dry powder, which is important for the sintering. If there is any offgassing during the bake, the final material is likely to be porous and open-celled. In fact, the near-complete lack of gas in a lunar environment would mean there would be no gas entrained in the microstructure, at all, when it comes time to bake. It's perfect!

With dense, water- and gas-free powder, and long baking times one might be able to get sinterred bricks that are almost non-porous, or at least closed-cell so that they can be air-tight. A thin coat of sealant might be needed on the interior surface in case of wormholes.

I don't know about mortar though. It might have to be a polymer mortar because most other types of mortar will offgas as they set, so they will definitely be porous and open-celled.

This type of structure might be preferable to the plastic bubble construction we often see in science fiction. With non-porous brick and polymer mortar you get a sturdy, insulating structure that is not prone to accidental damage. As a bonus, because the polymer is between the bricks or inside the structure, it will not be exposed to UV radiation, so it will not degrade by that UV denaturation.

A structure like this doesn't have to be a tomb either. It can have glass windows, provided the windows are well sealed and are thick enough. (They don't have to be very thick, either. Imagine windows that can keep water out of a submarine at 3 meters depth.) Sure, glass is fragile, but it's a lot tougher than a sheet of polyethylene and it will last much longer. Again, glass is something that can be made on site with a solar oven, provided there is silica dust to be found. Silica is pretty common throughout the solar system. Organic compounds might be hard to come by in a space colony so it's best to minimize the need for them.

$\endgroup$
  • $\begingroup$ Much of glass' brittleness is due to stress concentrations from microfractures caused by water etching its surface. If the glass were fabricated in vacuum and coated with a plastic on the atmosphere facing side (prior to being exposed to atmosphere), the glass could be quite tough indeed. $\endgroup$ – Jim2B Aug 8 '15 at 2:08
  • $\begingroup$ If you have enough energy to bake the bricks with a solar furnace, it may be possible to increase the amount of energy on the bricks by tightening the focus and melting the inner and outer surfaces of the bricks to make them gas tight. For a structure in free space, you could literally spin the habitat under the glare of a mirror and glaze the entire exterior surface to make it seamless and gas tight. $\endgroup$ – Thucydides Aug 8 '15 at 2:37

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.