I think this is a really hot topic debate.
On one side, space exploration is amazing. We are exposing ourselves to the chance of colonization, and breaking new barriers in physics.
On the other hand, many countries are poverty-stricken. Even first world nations have health care and poverty issues that aren't dealt with.
That being said, all these problems could be fixed at a fraction of military expenditure costs. Can't imagine anyone doing that anytime soon though :(