I thought about the Nina...Pinta St Maria argument for a bit and although that sounds like a logical defense for exploration, some factors invalidate it.
Would the Spanish pay for the 20th, 21st, or 22nd trip to the same place after they have lost over half of what was previously launched with the supreme hope of coming back with a thimble of dust?....um, nope;they have more sense than that.
Columbus lost his flagship and abandoned a crew at La Navidad that was eventually massacred. He returned with a few trinkets, parrots, hammocks and a few bewildered "indians."
The native American population plunged by an estimated 20 million from the "portmantea biota" of diseases in the next century...ask them if they think it was worth the visit
Regarding that argument that we will eventually run out of resources...thus we MUST explore...that is a seemingly logical outcome of our current growth. BUT
I just read that sperm counts have dropped by 30% in a study of several thousand men over the past decade. Numerous developed countries have a negative growth rate and the nations that seem to be growing quickly have been subject to SARS, Aids, and internal massacres (Sudan etc) that restrict growth rates.
As resources thin out...so does our population.
Launching folks on a 3 month trip to a unbearable wasteland will NOT solve our resource problems here....
WE DO NEED SPACE technology: but we need it hovering in our troposhere...not with a 55% destruction rate, millions of miles away searching for answers to questions that really don't matter.