People who think about space colonization tend to follow the same path Eric Drexler did: manufacturing of "bottom of pyramid" substances such as aluminum and methane depends on being self-sufficient for "middle of pyramid" and "top of pyramid" manufacturing. Drexler's molecular assembler seems to have failed, but you could put together something like it with different pieces, the existence proof of which is that commodities like horses can build themselves by molecular assembly out of nucleic and amino acids.<p>"Advanced manufacturing" is of interest here on Earth for the reasons headlined and for many others (how can a country like Argentina escape the trap it is in?)<p>Fermentation combined with synthetic biology is an attractive approach but struggles in terms of cost. Anything that comes out of a petrochemical plant costs about 50 cents a pound [1] whereas carbohydrates of plant origin cost about $1 a pound [2]. One of the renewable energy "El Dorado" technologies is ethanol from cellulosic biomass [3] which is straightforward to demo but is nowhere near being cost competitive -- during WWII there was a revolution in fermentation that got the cost of penicillin down by orders of magnitude but cellulase production has been worked on for decades and seems to be near the limit.<p>[1] <a href="https://www.statista.com/statistics/1171072/price-benzene-forecast-globally/" rel="nofollow">https://www.statista.com/statistics/1171072/price-benzene-fo...</a><p>[2] <a href="https://www.statista.com/statistics/236628/retail-price-of-white-rice-in-the-united-states/" rel="nofollow">https://www.statista.com/statistics/236628/retail-price-of-w...</a><p>[3] <a href="https://en.wikipedia.org/wiki/Cellulosic_ethanol" rel="nofollow">https://en.wikipedia.org/wiki/Cellulosic_ethanol</a>