Basic civil engineering on the Moon or Mars

[nicp]

It troubles me that lots of plans for future bases on the Moon or Mars 'simply' dig a really big hole so people can live safe from meteorites and solar and cosmic radiation, or, suddenly, out of nowhere there's a square kilometre of solar panels generating enough power for an early colony.

That cannot happen by magic. You need machines familiar to us all, or at least cousins of those machines.

I would call such a machine a JCB - because I am British, you might call it a backhoe, mechanical excavator, you get the idea. Just one without the necessary support infrastructure is in the multiple tons. You get it there how? Would the tracks grip in lower gravity? How do you maintain it? Will it work in a total or near vacuum?

So, for example, one day you land an automated vehicle or 10 of them on the lunar south pole to recover water ice. Gonna need them diggers! Well at least something like them.

Oh and wait a minute, maybe you need conveyer belts to shift all that resource poor source material and then extract the water in some ill defined machine.... This is not a trivial problem. Many tons of rock/regolith going into a clever box to recover a rather small fraction of water.

And no diesel engines! Fine, fine, all electric. Tesla can do all the power trains... OR electric motors can perhaps provide the pressure to drive the hydraulics. Works already, no sweat. A solved problem.

But would those overheat? No air-cooling!

How do you dissipate the excess heat?

My point is there are wonderful suggestions of how to live on Mars or the Moon, but if you have watched a small housing development in construction it _is_ trivial. HERE. Now try it on the Moon. Just getting the existing kit to the Moon (where it would be useless) would be a monumental task

I contend the technology does not exist.

EDIT: Missing word

[ZChris13]

Caterpillar and NASA have some sort of agreement already, although I'm not the man to ask if you want details.
The weight issue is real, which is why SpaceX are attempting to develop a 100-ton class payload delivery system to the surface of Mars.

[sierra tango]

Great topic!  I agree with nicp on this.  I am a civil engineer with over 30 years of experience in heavy civil construction and I am awed by the challenges moon/mars construction and resource mining present.  I am confident NASA is concerned with these issues but not so confident that traditional NASA R&D efforts (with CAT or other manufacturers) will provide timely and cost efficient solutions.  I suspect some type of paradigm shift is needed to encourage (and reward) hundreds (thousands?) of entrepreneurs to start to tackle the many...many challenges. Here is an example: A mundane, routine operation for heavy equipment is changing out ground engaging tools (GETs).  Depending on the work and the material, this can be a monthly, weekly, daily, or even hourly operation (trenching/drilling in hard rock can require several cutting bit changes per day).  The GET attachment hardware is often pretty beat up, bolts sometimes have to be torched off to remove the old items.  Doing this routine task on another celestial body, in a vacuum or near vacuum in cryogenic conditions...seems hard.  However this GET problem is probably an easy one to solve compared to others...(how to get traction in 1/6th gravity, dust exclusion, lubrication stability in vacuum conditions, etc.).  Then there is the universal truth: "Stuff that works in dirt (regolith) & rock breaks."  As I said,  great topic!
 

[TrevorMonty]

When comes to water extraction the School  Of Mines has developed system that doesn't involve earthworks. They place inflatable tent over area and heat it with reflected concentrated sunlight with mirrors on crater rim. The evaporated water and other volatiles are captured for further refining.


 

[Eka]

I'm pretty sure Tesla has put some thought into how to cool their propulsion systems on Mars, and maybe Moon too. It ends up needing heat radiator panels instead of the traditional finned radiators we use on Earth. They already have liquid cooling for all the vital components, including the computer. Of course when out of the sun there is the opposite problem of keeping them warm.

What is a heat radiator panel. It is designed to radiate heat via IR radiation, instead if mater to mater conduction. In practice this method sucks. It takes a lot of area to get rid of the same amount of heat a small finned radiator plus fan can. Also big heat sources like the sun can defeat a panel's radiating ability by overwhelming it with solar heat gain. Panels out in the daylight need to be orientated edge on to the sun. Even then it still helps to shade them. Panels that have high input temperatures are more efficient. This is why some systems use a compressor to up the pressure of a vapor coolant to concentrate the heat, much like a compressor based air conditioner or refrigerator does. And that's about my limit on cooling in a vacuum. My cooling knowledge is mostly related to keeping semiconductors cool in a terrestrial environment. Even then it isn't extensive.

Very high level, no technical details descriptions of overall thermal control methods used in space:


Interesting tech highlighted in this video: Temporarily store heat in a phase change material. I guess a rover could store heat while operating, then use it to keep the batteries warm when idle.

[Eka]

Early on and a few times since I've mentioned a basic construction rover based off of a Tesla skateboard and telehandler boom with quick attack system. I generically call it the telehandler. I thought of it as I was figuring out what Tesla should leave behind on the Moon for NASA.

This was one post:

I expect even the first Starships to land on the moon will return. NASA wants more real regolith. A Starship could return tons. A telehandler boom system placed on a Tesla truck skateboard would be able to move containerized cargo a safe distance away allowing takeoff. Give the boom a quick attach system, and it could be used for all sorts of uses. Possible attachments include, but are not limited to, forklift forks, payloader buckets, bulldozer blades, augers, object gripers, jackhammer heads, cable trencher/layer, arc welder head, and even NASA Science Modules. Astronauts could teleoperate the rovers from inside their habitats, or let the rovers do their work autonomously. A science module could even instruct the rover where to go.

A combined Communications and Power Tower provides communications back to Earth, and cell service for rovers, etc. It also has chargers for charging the rovers. Remember that snake like automatic charger hookup video? A large self deploying solar array is used for generating power it uses, and stores excess in a space ready Powerwall. Many of these towers could be placed around the area to provide redundancy.

Tesla snake automatic charger hookup video.


I kinda went crazy with an ecosystem of equipment over the past couple days which the above is just part of. I think it got too large to post in this thread. The core of it is simplicity, redundancy, reusability for other uses. Redundancy is paramount due to possible failures due to unanticipated issues. Reusability is also fundamental. We can't anticipate all possible needs.

A couple telehandlers with grippers could hold tank sections in place while a telehandler with a welding head welds them together. A telehandler with a griper could place large fussed regolith bricks to make a landing pad. Of course one would need a kiln to fuse the bricks, and a loader to put the regolith into the forms. A drying and sorting plant for extracting water and other volatile compounds from the regolith, then sort it into fine, medium, and coarse piles. Different brick shapes can be made for other uses. The water can be frozen into large blocks, and moved to a shaded place by a telehandler. No need for containers.

[floss]

For the moon raised roads to keep machinery out of the dust would be of massive advantage and allow lower cost commercial and commuter vehicles to be developed the only vehicles that touches the lunar surfaces directly should be mining rigs and dump trucks .

[Eka]

On the Moon it may be better to tunnel.

On Mars I've wondered about dust issues. What is the mixture of fines, mediums, and large particles in the regolith. Are there enough mediums to larges for the surfaces of roads? Fines can be used in 3D printed building construction. You don't want fines on the roads because the mesh tires will kick them up. Once kicked up could they lead to more dust storms? Will rovers in a caravan need to space themselves out? Dust control may also limit rover speeds.

Note: with enough energy, washed regolith could be fused into pavers for landing pads and road construction. Huge multi ton pavers for landing pads, and smaller ones for roads and spacecraft parking areas. Tiles can also be made for interior floors.

[Cherokee43v6]

I actually brought this very issue up several years ago on a Mars colonization thread here.  Created about three pages of discussion before the whole thing got nixed as 'off topic'.  I'll dig back in my posting history and see if I can find the topic and add it here as an edit.

That said, the OP raises an entirely valid point.  Sure transportation is important.  So is your purpose for the base/colony.  But infrastructure is CRITICAL.  If you have no means to build it, no one can come.

Resolving the very real problems of basic dirt moving in a lunar or martian environment is a vastly overlooked critical path item.

Below is the first relevant message I posted in that thread and a link back to it:

After some consideration, there is one key element missing from the plan.

A 'pure play', possibly disposable, cargo transporter.

Reason for the possibly disposable.  Every shot shows the Spaceship landed on its tail, with all the engines and tankage between the cargo and the ground.  This will create serious hardships for the early colonist in removing necessary cargo from the ship to the ground.  It will also limit the size of any specific element of cargo to the maximum capability of whatever crane system were to be incorporated (weight and stability of total stack).

Additionally, to handle the construction of a permanent base, certain heavy machinery would be required on site.  Particularly mars( ) moving equipment and other construction machinery (Cement mixers, cranes, etc).

As such, a cargo ship that lands in a horizontal position would seem to be a necessity.  A ship capable of transporting and landing something probably on the order of a (Mars Optimized) Caterpillar D11 as a maximum single weight item.

And the following, after which the discussion kicked in:

regarding cargo and offloading:

I'm sure the cargo will be in standard modules, like shipping containers. I assume that the containers will either be repurposed for living quarters or could be assembled into structures or equipment.

offloading wouldn't require much more than a hoist, 5 people and a week (probably less). I'm not sure why some here think it needed to be explained in detail in this presentation.

Because the presentation was about creating a Mars Colony transportation infrastructure.  That infrastructure is intended for the development of a permanent habitation on Mars.  In order to develop that habitation, you're going to need cargo that far exceeds the size and weight that can be shifted through a cargo hatch on the 100 person spacecraft and dropped 30+ feet to the ground.

The specific example referenced in my original question was 'heavy construction equipment'.  Something that will be mandatory for site prep and development of the permanent colony.

https://en.wikipedia.org/wiki/Caterpillar_D11

[Eka]

While D11s are often used in large projects here on earth, I don't see it for Mars. A D11 is just way to heavy to transport. Their bodies could be made on Mars, and then fitted out with controls, motors, etc from Earth. But that is still a ways off. It would be much more efficient for a rover running a large tiller to loosen the soil, then have a bunch of rovers with loader buckets move it. A tiller breaks up the soil, but doesn't need massive weight to do so. This allows light weight rovers to move it around and sculpt it as needed. Note, none of these rovers will have anybody in them. They will all be automated with a person watching over them. This should give you an idea of the type and size of tiller I'm thinking of. https://youtube.com/watch?time_continue=79&v=kQAmFcsnYhg

[Cherokee43v6]

Well, the D-11 was merely used as an example, and yes, it is on the large size for construction purposes, but the ability to transport that weight of cargo, as indicated in my original quoted post, and offload it in a remote environment with minimal infrastructure was the key point.

Thing is, moving dirt requires mass in the vehicle.  Now, something that was brought up in the other discussion was adding that mass in the form of rocks/dirt at the end site to reduce the transported mass of the vehicle.  You still have to transport the motive frame and handling equipment, plus the tools to do any assembly on-site that is necessary.

Hmm... sounds like the first thing needed is a mid-capacity mobile crane.  Followed by either a bucket loader or a backhoe, both designed to run in the martian environment (electrically driven hydraulics? Methane based IC with an independent O^2 supply.  Red squirrels in a cage?).  With those, then assembly of other mars-moving equipment should be possible.

[Deepunder]

This approach might be a little more realistic:

https://deeepunderground.com/construction.html

[Eka]

Hmm... sounds like the first thing needed is a mid-capacity mobile crane.  Followed by either a bucket loader or a backhoe, both designed to run in the martian environment (electrically driven hydraulics? Methane based IC with an independent O^2 supply.  Red squirrels in a cage?).  With those, then assembly of other mars-moving equipment should be possible.

Exactly, my telehandler idea. Based off of a Tesla Semi skateboard. Telehandler boom with automated quick attachment system. Attachments include, but not limited to, loader buckets, scraper blades, forklift tines, jackhammer, welder, grippers, rototiller, auger, trencher/pipe/wire layer, etc. For the weight of that D11, one could send up a dozen telehandlers and dozens of attachments for them to use. One telehandler could fill the ballast bins on another telehandler. Ones with different lengths and strengths of booms could be sent. Two with grippers could hold the parts of a tank, while the one with a welder welds them together. It is a good first wave multi use construction machine. More specialized equipment can be sent later, or built on Mars/Moon.