And space exploration solves happiness for a significant portion of the human population? If we're talking about minimizing the repugnant conclusion we're generally talking about resources and how they're distributed.
Well, because space travel would enable more resource acquisition and more humans to then use those resources productively to be happy. If we limit ourselves to Earth, we quickly run out.
Basically the old argument about expanding the size of the pie vs. fighting over the current one.
Let's be real though. There are enough resources now. There is really no reason to believe that if the resources of another world fell under Earth's control that those resources would be used to enrich more people than would be exploited to extract them. And in a situation where these new resources would be behind the most significant barrier to entry in human history, they would almost certainly be controlled by the wealthy.
That's why I'm saying that at this point, it's not about how much, it's about us making a positive choice to orient society so that the resources we do have are used to enrich as many human lives as possible. Without that, you're just creating even more wealth for the elite.
I don't think this is true or likely at all. Space is pretty much infinite and while it may take a few hundred years (or even a thousand) for personal space travel to be possible, that's nothing on a longer timeline.
