"I find it hard to understand how we justify the billions spent in the name of research and exploration to grow crystals in zero gravity or something EQUALLY as VITAL to mankind's very ability to sustain life, rather than focus that money on curing diseases or alleviating hunger or.....?"
The spinoffs from the research and development in the space effort have resulted in many of the improvements in today's medical technology. Even by the 1970s, NASA's return on investment was running above 10:1 per year. simplest put, NASA hired private-sector folks to solve problems. Those solutions had spinoffs which translated into all manner of uses never foreseen at the time of the first efforts. We've wound up with a lot of new techniques in eye surgery, cancer/brain/heart surger--and an incredible amount of diagnostic equipment.
Not to mention the micro-miniatureization of computers and the Internet--Al Gore notwithstanding.
As far as alleviating hunger, that's not a money thing. That's a regime-change thing. Whether socialist or just plain thugocracy, it's governments which are at the root of that problem. Insofar as food itself, there's an annual surplus, worldwide. The biggest mistake that's being made in many places is the foreign aid to help the poverty-stricken. Most of the money which is not piddled away in administrative expenses is stolen by local governemnts, winding up in Swiss or Cayman banks. When people are trained to expect handouts, they lose the ambition to do for themselves--and their governments don't care.
Art