[nitrogen]

under the threshold of people that would be required to establish a self-sustaining colony

Such a small group of people, armed with current genetic engineering and future artificial means of reproduction, could bring with them enough genetic diversity and reproductive capacity to reach colonizing scale.

You can hop one time or one billion times, you won't clear the building because after each failed hop you're back to square one.

Despite the first part of my reply, this point about minimum activation energy is relevant to a lot of contexts, from escaping poverty to switching careers, from getting fit to overcoming medical conditions. This is a pretty good analogy that I might use in the future.

[slipframe]

I think genetics is actually the easy part. A few dozen or so people, selected for strong health, probably contain enough genetic material in their groins to start a colony. More would doubtlessly be better, but I think such things have been done by humans on earth before. Frozen eggs/sperm and women willing to be surrogate mothers help a lot too; you wouldn't need artificial womb technology, necessarily.

The hard part I think is "playing factorio IRL" on a planet we weren't evolved to cope with. Bootstrapping industry sufficient even to create additional shelters would be very challenging. Maybe we could practice this on Mars.

[erik_seaberg]

I want to see it, but does a Mars colony have any chance before we’ve tested solutions for the major issues that Biosphere 2 quickly ran into?

[slipframe]

Maybe not, though a Mars colony might not have to run as a totally isolated system. Perhaps solar power could be used to extract oxygen from the rocks or something. It's definitely a tricky nut to crack though and I'm far from confident that it will happen.

[mikewarot]

NASA has already extracted enough oxygen (out of the atmosphere) for about 5 minutes of breathing, on Mars. The nut is already cracked. 8)