The explosion of the Antares and Virgin Galactic rockets might make us reconsider utility of space travel. Is it worth using so many resources and even endangering lives for a cause that is viewed by some as ultimately conceptually quixotic and practically superfluous? NASA has already abandoned its manned space flights and has been stripped of much of its spending while China increasingly overtakes it in terms of ambition. Since the height of the Space Race and the Apollo Program, humanity has massively regressed from the vision of the likes of Robert Goddard and Jack Parsons. But there is indeed a justification for civilian space travel and exploration in the most profound terms:
Even if we cease destroying the Earth's habitation with climate change, overpopulation or nuclear holocaust, its viability for supporting life is ultimately finite. The same thing can be said about the universe, but the planet will be destroyed by a Red Dwarfed Sun in around 7.5 billion years, whereas the entire lifespan of our known universe is estimated in the hundreds of billions. Ethical concerns about extraterrestrial life notwithstanding, with space travel humanity could be able to populate other planets, either through terraforming providing them with the correct acclimatization or that preexisting in them. Thus if our scientific knowledge and advancement keeps persisting over billions of years, then we could possibly manage to transcend the dimensions of our physical universe and find a home in alternate ones. If we really care about posterity and self-preservation, then it should be in our sights.