In a science fiction setting, in the not-too-distant future, people want to send robotic probes out into space - both to explore and to set up boostrap space colonies. They need to be designed to be as minimal as possible, while being able to gather their own material (likely from asteroids), process it, and create their own products (e.g., gear, goods, starship parts). The end result should be small colonies throughout the galaxy, ready for humans to move in.

The probes would be able to extend themselves, and make copies of themselves, but let's assume their A.I. is well designed so they don't become grey goo or evolve into super-intelligences. If we mostly ignore the concerns of time and space, but otherwise stay grounded in actual science, what gear and technology would a probe need in order to become a generic, self-sustaining builder?

  • $\begingroup$ What exactly do you mean by "what technology"? What I mean is, what kind of answer do you expect, other than "self sustaining colony constructor technology"? $\endgroup$
    – AlexP
    Jan 12, 2021 at 17:39
  • $\begingroup$ Something more specific than "what-you-asked-for technology". Current probes can think somewhat, fly around, scan things, and land on asteroids. But what tech would them to independently collect resources, process them, and build useful items? $\endgroup$
    – LukeN
    Jan 12, 2021 at 17:57
  • $\begingroup$ Take a smartphone for instance, so many technologies went into making it functional. You really need to narrow it down to which aspect of functionality you would like to explore otherwise the list goes on forever. $\endgroup$
    – user6760
    Jan 12, 2021 at 18:28
  • $\begingroup$ I mean "technology" mainly as "machinery and equipment developed from the application of scientific knowledge". What machinery or equipment do you bolt onto a Rosetta or OSIRIS-REx probe in order to achieve the goals I outlined? $\endgroup$
    – LukeN
    Jan 12, 2021 at 18:40
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    $\begingroup$ @cowlinator One meat bag's galaxy wide genocide is another machine's golden age of exploration and colonization. $\endgroup$
    – DKNguyen
    Jan 13, 2021 at 5:27

1 Answer 1



This question is far, far too broad as it involves either compressing everything in the manufacturing and technological chain down into a relatively tiny space and then combining it with a power source that can actually run everything.


If you're not going to miniaturize everything we already have, then you're going to need to find equivalents for all of those.

This covers virtually every technology in existence, as well as a very large number of those that don't yet exist.

It involves everything from start to end:

  • Mining (surveying, analysis, drilling, digging, smelting, refining, processing)
  • Forming (cutting, grinding, lapping, honing, forging, casting, welding, etching, weaving, growing (crystals))
  • Post-treatments (hardening, plating, painting, doping, etc).
  • Assembly (actually grasping, moving, and fastening everything together)

For example, it's not just good enough to have the technology to cut screw threads. You need to be able to cut ANY screw thread on ANY material ANYWHERE. Virtually every technology we have is not good enough as is due to either taking up too much space, requiring too much power, requiring too much stuff, or being too special-purpose.

I know there's talk about 3D printer being able to make "everything", and its true they have the potential to eliminate a lot of other machinery. But even if you assume they have advanced to a point where limitations in workable materials is no longer an issue, there are so many more processes involved in making something just not covered by 3D printers. And 3D printers do nothing for mining and processing of raw materials.

The only example that even comes close is biological organisms, and we all know those succumb to the rigours of space.


The next time you eat an apple, think about what it takes for your body to turn that apple into something that both provides the energy to run your body, and materials with which to build your body with. Then think about what it takes for your body to turn that apple into something that can provide it with energy AND materials to construct itself with. And that's an apple; It's not even the raw material. That apple has been pre-processed by an apple tree into a form that is suitable for your body. Think about what it took for the apple tree to grab sunlight, soil, and air to make that apple. You need that, but better because in space there is no biosphere to support you; You need to be self-sufficient.

Going back to biology, there's a reason biological organisms are mostly made of hydrogen, carbon, oxygen, nitrogen, and phosphorus rather than copper or iron. The former elements are far more abundant and you don't have cover a huge area to find them. Whereas with metals you have to process huge amounts of ore to get enough bulk material to work with. So the initial stages might actually have less metal machinery (other than what you brought with you) and look more like wood, plastics, or carbon fiber which are all made of far more abundant elements. Asteroids do help though with the scarce metals though.

The caveat is that you need to pump energy into those molecular bonds, and unlike a block of iron where you can pump the energy into it rather crudely to smelt it, to form wood or plastic from elemental carbon and hydrogen takes finesse. The question might become whether it is more efficient to search far and wide for metal ore (though asteroids help), then dig down and refine it or whether to use more abundant non-metallic elements in-situ and use energy to very precisely form the bonds to produce a construction material.

There's also the question about whether it takes more energy to smelt and refine a block of iron than it does to pour energy into hydrogen, carbon, oxygen, nitrogen, and phosphorus bonds to form wood or plastic. A wood or plastic fire can't melt iron so I assume the wood and plastic are more energy efficient but require more finesse to form. Current technology can't synthesize real wood, but what it can do is turn produce oil from carbon and hydrogen, and of course we know how to turn oil into plastic. Is that entire process more energy efficient than the whole processing of finding, digging, and refining iron? I do not know. It could go either way. But if you have a limitless fusion reaction with you, the abundance of raw material could become more important than the amount of energy it takes to process it.

This starts steering things back to nanotech and molecular engineering again which I don't like to do. But it might be unavoidable because there is great incentive to travel light, but the paradigm of our industrial production is to do things big, but doing big things requires big equipment with big resources.

Hard-science wise there's not much room to budge because we are so far from it as we know it. You would either have to ignore the issue, hand-wave it away as something that's taken for granted, or come up with ClarkTech like Star Trek replicators.

  • $\begingroup$ Improvements to 3D printing might save tons if pains for the custom stuff, while standardising most other things. Example: astronauts now have 3D printers in space so they can make important items that might pop up suddenly. But also companies starting 3D printed buildings or more recent examples of 3D printed bridges in the Netherlands. $\endgroup$
    – Trioxidane
    Jan 12, 2021 at 19:53
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    $\begingroup$ Obviously, whenever you have a big problem, a way to solve it is to split it into multiple smaller problems which are hopfeully easier to solve. All you need are: 1. a way to turn arbitrary matter into paper clips, and 2. a way to assemble aribrary things out of paper clips. Easy! $\endgroup$
    – Mike Caron
    Jan 12, 2021 at 21:13
  • $\begingroup$ I like the breakdown you did of Mining, Forming, Post-treatments, and Assembly. Seems like it would have to contain mining tools at a minimum, but perhaps it could have some rudimentary forming/printing process which would allow it to slowly build up it's capabilities in all the other areas? Perhaps it could collect atoms at a time, and slowly assemble them to make more efficient items? $\endgroup$
    – LukeN
    Jan 12, 2021 at 21:25
  • $\begingroup$ @LukeN It would need to. One problem is that one area might not have enough resources to build mining equipment to get started, even if you brought along your own mining equipment to start. Without a better way around this, it could only be solved by literally importing your own fully functioning mine. Of course, this also applies to every other piece of equipment as well. $\endgroup$
    – DKNguyen
    Jan 12, 2021 at 22:45
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    $\begingroup$ @LukeN Now that I think about it, I would actually expect the initial stages to look very different from our metal-laden machines. It might actually start with a lot more woody or plastic materials because things like wood and plastic are made from elements far more abundant than iron or copper. Things like hydrogen, carbon, oxygen, nitrogen and phosporus are far more abundant and if you pump energy into them the right way, you make materials more like plastic, wood, or carbon fiber. Ultimately, it might look a lot more like growing something than machining something. $\endgroup$
    – DKNguyen
    Jan 12, 2021 at 23:09

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