My proposition here is not that space exploration is zero-sum but rather that space travel is wildly inefficient for solving problems here on earth. The trouble

My proposition here is not that space exploration is zero-sum but rather that space travel is wildly inefficient for solving problems here on earth. The trouble with your suggestion (and, prior, mine) is that we don't really know what could have been done with the same resources had there been a moonshot to, say, solving the climate crisis. As a huge lover of space travel, I have shared that very letter from Ernst Stuhlinger. What it really only proves is that if you throw enough money at something, you will get some returns. The rest of the arugment is borderline religious in nature; that through some mysterious process if we just get into space we'll suddenly realize oh, we should fix that planet, simply because we can see ourselves as one small planet. Peak space travel was arguably right when this letter was written. If it were at all true, we would not in the position we're in now. Instead, the opposite has happened, and it's not because we're not travelling in space - it's because we continue to ignore the problems we alone are causing. Running away from those problems into space will not somehow, magically, solve them.