I'd argue on humanitarian and moral grounds that the best evaluation
criteria should be on lives saved / $ spent (or more accurately years
of potential life saved / $ spent). In that respect the $ going to the
NIH or the EPA probably far exceed those going to the NSF or NASA.
Bottom line is -- if you want a billion dollar Europa mission -- how
many human lives are on the line if the available $ are diverted from
NIH research to NASA development? It isn't a nice question but it needs
to be asked to *focus* your attention on priorities.
Don't be ridiculous. In a world of 6.5 billion people, lives are cheap.
What we're talking is not quantity of lives, but the quality of them. That requires money, which is really just another way of prioritizing efforts, by spreading the decision making to as many people as possible.
Again, if you're talking billion dollar missions, you should be funding those projects which have some opportunity of return on your investment. Getting a major company or ten involved in the space decisions game would tend to raise this issue to paramount importance. Pseudo science projects would wither away, and economical projects would flourish.
Space exploration, if it happens, won't be to 'save human lives'. It'll be to make money. Just like the conquest of the Americas.
It's gonna happen. It's just a question of when.
-- JHB