It seems what some people fail to realize is that these 'projects' are far from a waste of taxpayer money. They are a stimulus to financial growth because not only does it employ people directly on the project, but the raw materials for the rockets need to be mined, then made into usable materials, assembled, etc, etc, etc and all of these people need to eat, and have houses. whatever tax money goes into the project works it's way down to creating lots of employment which puts money back into the growth of the economy.
And on top of that, the money being spent now is laying the groundwork for the industries and jobs of tomorrow. If this didn't happen, we would still be watching TVs that have vacuum tubes.
I have a hard time thinking of a better use of tax money than employing people today in work that develops new technology and advancements, and creates new industries that will employ people in the future.