Comment by giraffe_lady
4 hours ago
We have never, even as a proof of concept, been able to develop a closed system capable of supporting mammalian life separate from earth's ecosystems. We assume it's possible based on no particularly rigorous evidence and in spite of our numerous failures to even come close. "Mars as backup" is not a credible plan based on science within even our optimistic grasp.
The technology & social systems capable of doing this would be incredibly valuable long before any permanent mars settlement became feasible so if we can do it we should and then we can see.
They did a year in the moon base simulator Yuegong-1, apparently.
Peaked at about half the food produced internally iirc and it’s like three people. It’s a good and necessary start but shows just how incredibly far we are from the real deal.