> How exactly do you realistically think we are going to survive in outer space?

Currently, I don't think we can, but I think our odds of survival increase the sooner and more seriously we invest in research and experimentation towards that goal. We already have some pretty good concepts for things like generation ships and propulsion, but clearly we've got a long way to go. The more ships we send out the better our chances will be.

> And even if we could, why would we want to?

Because generally it's always been our nature to. Your question would have been just as relevant when it meant crossing the oceans, entering the rainforests, or mapping Earth's cave systems, but we did those things and more because we're explorers. We've usually benefited from exploration as well. We find new resources, new scientific discoveries, and new opportunities pretty much every time we put in the effort. None of us would be where we are or have what we do today if somebody else hadn't put in that work before us.

We're also generally driven to survive. Or instincts for self-preservation don't just apply at an individual level. Like many other animals we work cooperatively to preserve and advance our species and our communities even to the point where individuals become self-sacrificial at times.

> I don't think the rest of society should subsidize the escape fantasies of a small minority who find space travel exciting and worth seriously pursuing.

I disagree that it's a small minority who want humanity to continue to survive. Most people might not be interested in space travel itself, but they wouldn't suggest we should just allow ourselves to die out without even attempting to survive. I think that most people who understand that space travel is a requirement for the survival of our future generations find space travel to be worth seriously pursuing with true dissenters being those unaware that the destruction of our planet and all life on it is going to happen eventually and that it is entirely unavoidable. Everyone else understands at least on some level that space travel is worth seriously pursuing and either enthusiastically support it or would simply rather slow that pursuit down because they feel the short term gains are worth playing the odds and simply hoping that we won't kill ourselves off and none of the other life ending disasters (like giant space rocks and solar flares which could happen at any time without warning) will happen while humanity kicks the can down the road.

I think that it's a very optimistic view that in addition to us being lucky enough to avoid the kinds of disaster that would end all life on Earth before we bother to get around to investing time and resources into finding a way out of our solar system, we'll also be lucky enough to avoid any and all disasters that would make doing that kind of research later extremely difficult, unlikely, or impossible. Economic collapse, exhaustion of natural resources, plague, war, even the dumbing down of humanity either through attacks on science and education or through other means (for example leaded fuels causing average IQs to drop by several points) could mean that we're in a better position right now to tackle the challenges of space travel than future generations will be.

If we're unwilling to just lay down and die space travel is just a question of when and not if. Because the amount of time we have left is extremely uncertain and our future is generally looking more dire than it has in a very long time, it seems irresponsible to put off the work that must be done today just so that we can play, be lazy, or devote all of our increasingly limited resources to immediate pleasures and short term gains. I'm not suggesting that we drop everything else we do and devote ourselves to the problem of space travel 100% but it seems very odd to single out the relatively small investments we're making today as problematic. Even if it turns out we'll all die off in a few years time anyway, we'll have already been "wasting" a lot more money on things far less worthy.