Oh, okay. Personally I lean much more towards average utilitarianism as opposed to total, but I haven't really thought through the issue that much. I was unaware that total utilitarianism was popular enough that it alone was sufficient for so many people to endorse space colonization.

But, now that I think about it, even if you wanted to add as many happy people to the universe as possible, couldn't you do it more efficiently with ems?