I believe it wasn't just coincidence that both the space race and the civil rights movement reached their respective apogees at roughly the same time: the late 1950s and early 1960s. Think about the integration of Little Rock High School starting barely a month before the Russian launch of Sputnik, which galvanized the United States, pushing it toward not just sending its own satellites, but also getting busy with improving and funding math and science education.
At the time, the tendency was to think of such events as being at best mutually exclusive. I think they are now both logical and synchronous outgrowths of the human impulse to break down barriers and move ahead. The less afraid we are to think outside the box scientifically, the less afraid we are of other barriers, other things that constrict our natures. This week, Major League Baseball celebrated the 65th anniversary of Jackie Robinson breaking the color barrier on April 15, 1947. Seven months later, almost to the day, Chuck Yeager poked a hole in the sky with a rocket plane and broke the sound barrier.
I do not say one event led directly to the other (not necessarily, anyway). But I do think both were driven by the same insistent energy to fly higher, push harder, maybe even make ourselves better people in the very long run.
I will try very hard not to consider Discovery's last touchdown as the end of something, though I still fear it may signify the beginning of the end -- not just of a dream, but of our very capacity to dream.