Take the moon landing -- The entire space race costs the US hundreds of billions of dollars (in 1960s dollars) and resulted in a nice piece of propaganda to use against the Soviets. And the argument that technological bleed-over from NASA to private industry was worth it are unfounded. If the US government didn't claim a monopoly on space travel, perhaps private industry would have been more active, and we would be even better off now.
Didn't we get Tang out of the deal?
There are ways to do a “man on the moon” without the government creating a new administration to do it. How about some R&D tax moratoriums? Or some seed money to private sector companies with rigorously defined new energy programs. Etc etc.