In Poland, there's a Mars-like base being built right now, though not aimed at testing self-sufficient ecosystems but equipment and work procedures of potential off-world colonists. My guess is there's more of such little-known projects happening.
The point being, the number of projects related to living off-world is slowly increasing, and my guess it will only go up as the perspective of Mars mission comes closer (SpaceX is doing a lot of good work making this close to "very soon" in peoples' minds). So we're definitely not "giving it one little shot".
https://en.wikipedia.org/wiki/Biosphere_2#See_also
So that's at least five.
In Poland, there's a Mars-like base being built right now, though not aimed at testing self-sufficient ecosystems but equipment and work procedures of potential off-world colonists. My guess is there's more of such little-known projects happening.
The point being, the number of projects related to living off-world is slowly increasing, and my guess it will only go up as the perspective of Mars mission comes closer (SpaceX is doing a lot of good work making this close to "very soon" in peoples' minds). So we're definitely not "giving it one little shot".