While it's easy to be naive about space exploration when one spends time watching SciFi but doesn't spend time on cosmology, the reality is that we humans will never be a "space faring species." We aren't adapted to live in tiny artificial cages in low or zero gravity. There are no Earth-like worlds that have been discovered, and if there ever are any there is no reason to believe we'd be able to colonize them. Furthermore, the cosmic radiation experienced during even a short 6-month trip to Mars will likely condemn anyone making the trip to an ultimate death by cancer, as we have no practical way to shield a capsule within the mass limitations imposed by fuel/distance/speed tradeoffs. We will explore space - by robotic missions. These missions have already yielded 99% of what we know. They are cheap, no one has to die of horrible cancers, and they yield huge benefits. If we stopped playing Star Trek and put a fraction of the money being wasted on human exploration into robotic exploration our knowledge would expand dramatically. As it is, human space flight is a dead-end in all senses of the phrase.