The Machines that make it Possible

Even to reach space we need incredibly complex machines. To live there we will need machines that can do any physical task we can, see as well or better, that anticipate, compensate, and make judgement calls. Recent advancements in robotics stand beside reusable rockets as new factors accelerating our advance into space. The Moon’s harsh surface is no place for a human to work. Spacesuits make you very clumsy, and a ton of infrastructure is needed to keep you alive and safe. Bring on the robots.

Rovers and Robots - the Workhorses

In this project, the approach is taken that the first missions to settle the Moon will focus on developing the robotic infrastructure needed to do construction entirely without humans present. Such robots do not yet exist, but the field is advancing quickly. Development of that technology has a wealth of applications here on Earth, it would make sense to make such R&D a central part of a settlement space program. A few missions would be needed where a minimal crew go to support the prototype robots, testing and fixing them, until there is confidence the robots can be operated remotely from Earth. After that, the robots build the first permanent habitat and its infrastructure without anyone on-site. Once that hab is near completion, again a crew arrives. They test everything, maybe make some minor final touches. Then they stay. After that the human population ramps up quickly and they operate the robotic machinery from within the habs.

So, great things come from great robots. Rovers in space are already designed to handle factors not present on Earth. Rovers and robots on the Moon will have extra challenges that have not yet been solved. The list below takes them in ascending order of difficulty:

  • The high radiation environment, which requires special design of computer components. This technology is well developed, but does add cost and increases the bulk of components.
  • The 290 K temperature swing between day and night. Two key things are important here:
    • Thermal wadis - which are masses of solid stone that store the sun's heat far better than the powdery soil. If a rover can snuggle up to one at sundown and throw a reflective tarp over itself to slow heat loss, the cold it has to withstand overnight is greatly reduced.
    • Nuclear power - there is no reason to fear nuclear power on the Moon. It is a great way to get through the long cold night, when there is no solar power. Robots working at night can run their heaters by drawing power beamed to them as microwaves from the nuclear power plant
  • The extremely abrasive, finely powdered soil that will grind away at any moving part it gets into. And it comes with static cling. Some things can be wrapped to minimize the dust that enters. Magnetic brushes seem quite effective for dusting things off, though they haven't been tested on-site. Ultimately, the best thing is to fuse the surface soil into a solid cap of stone wherever robots work (or people).
  • The 3 second round-trip transmission delay between Earth and Moon, that will need to be designed for to make remote operation work. So, if a robot is tipping over, it needs to look after that itself. It needs to be able to handle simple, repetitive tasks on its own. It needs protocols for collision avoidance. It needs to understand what it is looking at well enough to direct itself as it moves around and manipulates things.

The videos in the sidebar show we've made big advances on these things, but there is a ways to go. It is hard to overstate how much of a difference robots with these capabilities make. They are absolutely necessary for success.

Construction and Fabrication - the Road to Big Business

If there was a way to build a habitable shelter on the Moon that wasn't super hard, we'd already be there. It is important not to underestimate how hard it is to do this. But, the needed technology is coming together and turns out to change the equation of what the best method is.

Most designs for lunar construction up to now have focused on batch processes that don't require much finesse (such as making lunar concrete blocks). Few designs have contemplated use of in situ materials, though, because of the difficulty of delivering the machinery to work them, and the probability such machinery wouldn't last long in such a harsh environment. Almost all serious designs send finished modules built on Earth.

If you plan to stay, you have to be able to build there. If you can build there, you have something you can sell. If you are good at it, you can build for space, too, and that's our whole idea.

All construction designs here are centered around the use of melted regolith, in particular the basalt of the lunar maria. When basalt is drawn into fibers it has good tension strength. A material that is strong in tension is the key to space development. Holding in an atmosphere requires it. Basalt rope and cloth can be made with no additives other than a thin application of a sizing chemical to the surface of the threads. This makes construction with basalt much easier.

Some highlands materials spun into fibers will also have good tension strength, but likely need to be processed to change their chemical composition before that is true, and such processing would take considerable infrastructure. Once they are, they might also need to be embedded in a matrix, like fiberglass is embedded in plastics on Earth. Glass fibers aren't used for rope or fabric on Earth because it only takes slight damage to cause the fibers to lose their strength. On the other hand, quite possibly the different chemistry and environment of the Moon means that they would work well without needing a protective matrix. Still, unless deposits very high in silica are found, resource-intensive processing will be needed in the highlands to produce materials capable of containing an atmosphere. That complicates construction of habitats a great deal, a principal reason why only a small human colony will be made at the pole, and then construction will be concentrated at Lalande.

All these designs absolutely depend on the use of agile robots. They don't have to be carpenters, but they do need the manual skills of your typical 5 year old. Guided by human operators on Earth, that would be enough. Several development missions would need to go to the Moon to test and refine that technology.

If you have those robots, what follows is the best way to build. By far, no contest. It is far less energy intensive, and far more adaptable, than anything else I've seen. The equipment needed to start is far less, and less complex. Except for the robots, of course, which are so broadly useful they are still quite mass-efficient, even if they need a bunch of modular drop-in replacement parts shipped with them.

So, if you perhaps calculate that such robots are a long way off, still by the time Cernan's Promise was fully developed, they would exist and have been used for the bulk of that construction. We can quibble later about the most plausible way to present the first few missions, when those robots are in development and can't be relied on. The winds blow very strongly towards their development, so it is sound policy to explore what they can do.

Interactive 3d models

Click the play arrow to load the 3d models below. Check out the controls at the bottom of the model window - especially the bar to click through the annotations, and the double arrows in the corner to make it full screen.

These models are in development, both in what is in them, and in how it is presented. They go through spurts of changes, which should become more frequent and dramatic with time. Right now they are at a pretty early stage.
The production of basalt fiber is critical technology for large construction. Cable can perhaps be imported for the first hab, after that this has to be made to work.
The Melt-In-Place stations need to be the backbone of early construction. They can produce a wide range of useful items, a very wide range if the rovers are agile enough to assist. They can produce materials in bulk, so if the materials have some weaknesses, you can simply use more to compensate.
The hangars will be filled up with lots more things. This early draft gives some sense that industrial scales are sought, and the work flow will be complex.