Comment by PaulHoule
19 days ago
Manufacturing is hard, even for something “simple” like a pencil:
https://www.amazon.com/Pencil-History-Design-Circumstance/dp...
Those big machines have lots of little parts and if you have to wait three years to get a spare part that’s a big problem. (Never mind anything that Earth sends to a Mars colony is a gift because it is inconceivable that it would be profitable to bring anything back)
Anyone who starts sketching out what a space manufacturing complex looks like (e.g. Drexler, myself [1]) comes to the same conclusion Drexler did —- there is this diverse residue of difficult to manufacture small but complex things. The good news is that we have molecular assemblers, they built you, and now that people are decoding the “junk DNA” we are getting a handle on genetic regulation networks and will be able to make them much more productive and reliable.
[1] unpublished study on manufacturing sunshades on an asteroid which is rich in something which is more-or-less “coal”, out of a lack of imagination I assumed it was going to use a pyrolysis system like https://www.netl.doe.gov/research/Coal/energy-systems/gasifi... and I can tell you that sort of thing on Earth has almost as many things that can go wrong with it as a fast reactor
You use your pile of lathes and mills to make replacement little parts. Probably skip making integrated circuits on-planet at first, but anything metal or plastic can be done by the huge group of machinists.
And for every fifty people on mars you can have a thousand people back on earth figuring out the best way to make every component.
The hard part is building chemical stocks of all these different things. And while that's a huge task, it's so much less hard than a make-anything machine. Once you have graphite, clay, rubber, and wood, making it into a pencil is simple. Cut, mix, extrude, clamp. Wood (and rubber if that's the easiest way) can be grown on-site, wood can be turned into graphite, and clay shouldn't be amazingly hard to get from martian soil. Oh and glue, we can figure out a glue.
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