The money saved by retiring the shuttles was supposed to have been channeled into a renewed mission to the moon. Funding for that was cut in 2010, however, leaving U.S. manned spaceflight (beyond the International Space Station's orbit) in limbo.
Could the private sector pick up the slack? What would its motivation be? Even if an extraordinary wealth of minerals were found within reach of terrestrial vessels, it would have to be excavated and transported back to Earth. Given the colossal expense of manned spaceflight and the relative ease of earthly mining, the prospects for moneymaking missions of this sort are scant.
True, private space tourism is expected to expand. Note, though, that it's expected to involve short excursions, only dozens of miles above Earth's surface - a tiny fraction of the distance to the moon, let alone to Mars and other planets. Once again, given the costs, there would be little incentive for larger private ventures. It's up to government to expand Kennedy's quest for discovery.
One of the vital roles of the shuttle program was servicing the Hubble Space Telescope, replacing worn-out or outdated components. Throughout its decades of service, the Hubble has offered an extraordinarily valuable window into the depths of space, helping astronomers understand the history and fate of the cosmos to an unprecedented degree. No one would doubt its importance.
Like any instrument, however, the Hubble has a limited lifetime. Eventually, it will no longer produce the crystal-clear images of galaxies and other objects that have brought it acclaim.
