No offense intended but, um, what have those samples that were [brought back by a manned mission and analyzed in a meaningful way] done to provide a concrete, tangible, material benefit to the taxpayers who involuntarily funded it all (ALL the taxpayers; not just those who were employed to retrieve or analyze them)?
Like I said in an earlier post, if all you are interested in is an immediate return in money (which I think is what you really mean when you say "concrete, tangible, material benefit"), then you are displaying the hallmarks and characteristics of a people well on the road to decay and decadence. When we place material comfort and monetary gain above all else, when we worship money as God, then we have truly lost our collective souls.
No, I can't tell you what discoveries will come of what we've learned so far in our honest and gainful efforts in space exploration and development. No more than Columbus could have foreseen the establishment of the freest and greatest nation the world has ever seen, when he set off to find a trade route to the East and stumbled upon some islands in the Caribbean. Nor could James Clerk Maxwell have foreseen the establishment of a vast and complex system of wireless communication when he took it upon himself to scribble down some equations on a piece of paper. Or those (taxpayer-funded) persons who labored in developing an electronic method of calculating ballistic trajectories could have foreseen the growth of a computer industry that would make calculating machines as commonplace in households today as radios and TVs were a few decades ago.
Like I said, think small, be small. Limit yourself to holding onto every penny you can, and pennies is what you will end up with when you crawl away to your hole to die. Meanwhile, others will forge a destiny in the stars. I just hope those are people of the great and free nations of the West. We can do it, if only we have the will and the vision to look beyond our own petty comforts.