Yesterday was the 40th anniversary of the moon landing by Neil Armstrong and Buzz Aldrin. Yes it was really amazing the first time, but what would be the purpose of going again? Well, proponents say that we need it because it was so exciting the first time, and we need more excitement to unite the nation behind a common purpose. I'm all for the advancement of science, but I also know that the first time we had the space program, much of the science and engineering community became focused on this mission because that is what it takes. Clearly, if that much engineering resources are going to be devoted to more space exploration, there will be less, especially brainpower, for technological breakthroughs in energy, green manufacturing, etc.
On the other hand, if more space exploration means less R@D for making weapons, that would be good. Plus, any inventions may eventually be cleared for civilian use and perhaps could be a breakthrough for sustainable living. I'm not sure what they do with waste in space, but they certainly have to make do with fewer resources.