This is one small step for a man, one giant leap for mankind.
[Space travel] will come, but only when there is a high enough demand so that you can have a “public highway” system. To support today’s air traffic network, you’ve got to have a million passengers constantly on the move. The same will be true in space: It’s not really a technology problem, it’s more a sort of chicken-and-egg economic problem. I hope that it will grow, probably on the back of the military. The military has needs for all kinds of space launching and is prepared to pay for it. So with luck something like this space highway will develop. It doesn’t matter who pays for it initially. In the end it will belong to everybody.
~Freeman Dyson, Discover Magazine, June 2008
All civilizations become either spacefaring or extinct.
~Carl Sagan, Pale Blue Dot