Lief, how much science could have been funded more cheaply had we not wasted so much money on manned space flight after Apollo. Up to and including Apollo manned space flight made sense as there was no way to know how advanced and lightweight remotely controlled systems would become.
The USAF MOL program was canceled without being flown and the Soviet Almaz program was also canceled because it not only became cheaper to use unmanned satellites to do their reconnaissance roles, but they could do it better because they didn't have to deal with human cargo.
There's been a lot of helpful research done on the human body that could've only been done in space.
