Cheap building material on the Moon and Mars

[rocksolver]

Hello, this is my first post.<br /><br />I was wondering if the very old and basic technology of dry-stone walling could be combined with modern computer science and 3D scanning techniques to turn ordinary unprocessed rock into a valuable building material. I suppose buildings on the Moon and Mars will need to be protected from radiation and meteorites by some sort of solid shield and there will be the need for landscaping. The cost of manufacturing large amounts of suitable building material would be very high so maybe the local, unprocessed rocks could be used if there was an easy way to fit them together.<br /><br />I imagine the process would be something like the following; several rocks first pass through some sort of 3D scanner then when enough rocks have been scanned a computer starts fitting them to each other and to the design wall shape in the virtual world. The computer outputs instructions to the builder/robot as to the position and orientation of each rock and more rocks are scanned as building progresses. There are lots of technical issues to sort out but because unprocessed rock is such a readily available resource on the Moon and Mars then I'm sure ways will be found to use it.<br /><br />I have started developing such a method for more mundane uses here on Earth but it's still just a concept (and a patent specification) so I'd be happy to hear anyone's views about it's potential use in space.<br /><br />Have a look at www.rocksolver.com to see what I've done so far.<br /><br />Thanks.

 

[chriscdc]

Well merely using unprocessed rocks would be far too difficult to be concidered. However you could use a minimal amount of grinding to allow rocks to slot together. Just like those walls, made from boulders, made by that south american civilisation whose name escapes me. <br /><br />Also the amount of rocks available to just pick up is likely to be limited, and so even with easy scanning, a robot or astronaut would have to travel along way to pick up a rock, just the right shape. The same energy would probably be better used in changing the shape of nearby rocks. Although I could be wrong and the space agencies could select a landing site with plenty of such nearby rocks.<br /><br />Thinking further about it, it would seem difficult to create roofs using this method. The actual need for thick walls is minimal compared to a thick roof, due to the lack of substantial wind on mars and any (although there is a wierd levitating charged particle wind) on the moon. <br /><br />Anyway, the moon has an easier construction method. You take the regolith and use microwaves to sinter the particles together.<br /><br />Overall there may be a place for it out there, but I can't really see it. Although there are groups that want to go to mars and they might be able to see a place for this method.

 

[rocksolver]

Thanks c.<br />You are right about the roof being difficult as the right shaped rocks to form a dome would be scarce. Perhaps a combination of fitting irregularly-shaped rocks when it's possible, and shaping them when it's not.<br /><br />I haven't heard about the regolith. I'll check it out. The easiness of a method might be related to how cheap is the energy to perform it. I've still got lots of sums to do.

 

[owenander]

I think it's an extremely innovative idea, but the problem is the rocks on the surveyor belt through the scanner. They will need to use some sort of cementing agent either way to fit in the cracks. So if it's small rocks it's not an issue, but then again you really wouldn't need this advanced technology anyways because you can easily move around rocks (and there's only so many options). Then I thought of application here on Earth and I'm currently building some condominiums where retention rock walls are needed, but those rocks are much to large to put onto a belt and transport through a scanner.

 

[j05h]

A rock "solver" is a cool idea but I think would be mostly useful for lower retaining walls and foundations. The best concept I'm aware of for near-term in-situ space habitats is Dr. Nadir Khalili's Earth Dome. Insert sand/concrete/regolith into a sandbag, stack like bricks with a layer of barbed wire in between. Wet down and let set, then burn the building into a lovely ceramic (on Earth). He has differing methods for extraterrestrial use. <br /><br />The advantage is that you can use easy to manage loose material stuffed into pre-shaped bags. <br /><br />The South American culture that the walls by sand-shaping were the Moche and Chimu on the west coast. A lot of the monumental building in Peru started well before the Inca came about by these ancients. The technique was adapted by Hopi and other Uto-Aztecans in northern Mesoamerica (see Mesa Verde kiva construction for example) and a similiar technique was used by the Khmer empire to build Angkor Wat in ancient Cambodia. Lay a run of rock, pile sand on top and rub a roughly-shaped rock across it until they fit together. Some building foundations in Cuzco have survived the old kingdoms, the Inca, the Spanish Destroyers and modern life, no worse for the wear. That is construction for the ages.<br /><br />I'm still voting for sandbag domes as the enabling tech for in-situ habitats. http://www.calearth.org/<br /><br />josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[barrykirk]

Just look at all those stone walls in New England,<br /><br />they were made in a similar manner but without being scanned.

 

[j05h]

> Just look at all those stone walls in New England,<br /> /> they were made in a similar manner but without being scanned.<br /><br />LOL! We've got a stack-stone slate foundation in our house - the original section is in far better shape than the (slightly more) modern addition. There is incredible stonework throughout this region. The Stonington/Mystic area in CT has a lot of nice residential stone, mostly walls, but I still prefer the original stonework in old farms and barns. <br /><br />Actually, on a space note, this could be a great place for human input - why bother digitizing it when eyeballs are available to perform the same task? All it takes is a couple cameras in the assembly area. <br /><br />I'm still holding out for the superadobe domes. <br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[rocksolver]

Thanks for your ideas and comments.<br />Maybe I should have called this topic "cheap landscaping material on the moon and Mars".<br /><br />A friend said the rocks would scratch the glass on the scanner <img src="/images/icons/smile.gif" /> For large rocks sitting on a flat surface the bottom of the rock can be assumed to be flat and the 3D shape can be obtained by a scanner set up in 3 different places or using digital cameras...or something, I haven't quite worked it all out yet. Maybe in a couple of years. The viability of the method will be tested here on Earth in the next few years if I get my way <img src="/images/icons/smile.gif" /><br /><br />There are some fantastic stone walls around and some still being built entirely by people but I can't help but wonder if the fact that a computer can effectively remember the shape of thousands of rocks (and fit them into thousands of possible places in the virtual wall) will mean that they can build rock walls that are better. Or is that blasphemy? If the trial-and-error is carried out in the virtual world then the time and energy saving in the real world might make unprocessed rock a viable landscaping material on the moon. But I suppose landscaping is a low priority activity.

 

[JonClarke]

You should perhaps contact people at the Mars homestead project http://www.marshome.org/ - they may well be interested and have ways of testing and evaluating the proposal.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[annodomini2]

I thought NASA did research into this in the 70's and found from the rock samples they collected that they could make a form of concrete from moon dust/rock, with little additives other than water.<br /><br />If this is true, you could potentially use an inflatable structure to form a support frame and then just pour your 'mooncrete' into the mould, possibly eliminating the roof support structure problem?<br /><br />Although I am unsure if there are extra requirements for the concrete to 'go-off' and set. <div class="Discussion_UserSignature"> </div>

 

[spacester]

rocksolver, I like this idea very much!<br /><br />This is right up my alley. It took me a little while to respond because this is in fact a new twist that I do not remember hearing about before. Cool idea, nicely done.<br /><br />I have been working on a lunar dome concept. A big one. OK, it doesn't have to be a dome <img src="/images/icons/wink.gif" /> but what I seek is a viable plan to build a VERY LARGE lunar habitat, one that would support many dozens of people, and create a tourist destination. (The dome design <i>is</i> pretty cool, though ) Obviously, this requires using in-situ materials for a very large percentage of the structure and pressure integrity material.<br /><br />What I have sought is the very least initial investment of infrastructure to get started, while initiating a process that will snowball into a sustainable and successful enterprise. IOW, how can we get started on building a human settlement on the moon with just one rocket launch? IOW, given a plan that can be shown to be plausible, based on working backwards from where you want to end up, what is the very first payload delivered on site?<br /><br />Answering "the first payload question" is to me the best test of a plan for Moon and Mars: the more specific the answer, the better thought-out the plan must be. The first payload question is a short-cut to make a preliminary evaluation pending detailed investigation, and works especially well if ISRU is involved. Anyway . . . I'm not going to ask you that question - I guess I just wanted to establish a context for my remarks.<br /><br />To me, any evaluation of a building technology for the Moon must start with a discussion of the kinds of buildings you want, the purposes they will serve and their interfaces with transportation systems, power systems, comm. systems, etc. You start with a raison d'etre in order to define the purposes for the infrastructure and the buildings; then you can start talking about what building materials and technologies <div class="Discussion_UserSignature"> </div>

 

[JonClarke]

On Mars the presence of abunant gypsum (in some places) raises the possibility of using plaster of paris as a mortar. The gypsum could be partly dehydrated in a kilm, forming hemihydrite, ready for re-mixing with water.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[rocksolver]

Thanks spacester for the encouraging response.<br /><br />Stone wallers improved their technique over hundreds of years to satisfy local requirements but there haven't been many improvements in technique in the last 100 years or so. Maybe because there's a limit to the 3D calculations a human brain can do. The potential for a computer-aided stone building method is that the method becomes quantifiable in terms of forces, friction, etc and it opens itself to modern Computer Science methods of applying Computational Geometry to solving problems. As chris pointed out, domes might be difficult due to the lack of enough naturally-shaped suitable rocks but who knows what smart mathematically-minded builders will find in the future. There may be techniques yet to be discovered. Walls and foundations shouldn't be a problem. Maybe even cobble paved roads on the Moon.....OK, I'm getting carried away.<br /><br />Thanks Jon for the marshome link. I'm onto it.

 

[nexium]

Using humans to select and fit rocks on the moon or Mars may cost a million dollars per hour. Scanners, computers and robots can likely do it better at much lower cost. A tiny amount of morter/glue may be a plus. Your method has merit even if the roof is constructed in a different manner. Neil