[spacenick88]

I don't see why this realization should be regarded as a counter argument to establishing a Mars colony. It's really really hard and a lot of problems need to be solved.

The most important thing for me is that most if not all of these problems are extremely relevant on earth and for dealing with climate change and overpopulation. Now one could say that we should then solve them for Earth first, but that's not how things work. We only have solar panels today because there wasn't any better way to power satellites. Earth makes things so easy that we won't go for >99% water reclamation, 0 waste green houses and so on.

[jcranmer]

> I don't see why this realization should be regarded as a counter argument to establishing a Mars colony. It's really really hard and a lot of problems need to be solved.

The point is that, right now in 2019, we do not know how to build a self-sustaining colony outside of Earth's biosphere. If you want such a thing to exist, you have to do a lot of research first to enable it. But, in general, the space enthusiast crowd isn't interested in pushing for that kind of research. And without that research, a lot of the arguments for space travel are very moot.

[spacenick88]

I'm such a space enthusiast and I'd absolutely love a Biodome 3. That said, I think that people tend to confuse "sustainable colony" and "self-sustaining colony". If it ever comes to it, we will have a sustained presence on Mars for decades before it becomes self-sustaining. That said even with supplies from Earth a Mars base will need a lot of sustainability tech that can be applied on earth too.