When Shepard and, later, Armstrong flew, American Exceptionalism wasn't a litmus test for would-be Congressmen, a cliché to be delivered from the stump to gauge patriotism.

Americans didn't talk of their exceptionalism. They did exceptional things, and the world talked about it. In many places around the world, in science labs and classrooms, the NASA "meatball" was as recognizable as the Stars and Stripes.

People remember that President Kennedy said, "I believe that this nation should commit itself to achieving the goal, before this decade [of the 1960s] is out, of landing a man on the moon and returning him safely to the Earth."

Forgotten is that just before that challenge, he said this as a preamble to it: "I believe we possess all of the resources and talents necessary [to lead the world into space]. But the facts of the matter are that we have never made the national decisions or marshaled the national resources required for such leadership. We have never specified long-range goals on an urgent time schedule, or managed our resources and our time as to insure their fulfillment."

Ask those involved in whatever the future of space exploration will be for their fondest wish? It's not for a heavy-lift vehicle to ferry an astronaut to Mars, or a habitat to colonize the planet.

It's for a consistent policy that guarantees a flow of resources for as long as it takes to develop that heavy-lift vehicle or that habitat. A policy that can allow scientists and engineers of today -- and those who will follow, young people now in middle school -- to start something with the knowledge that it can be completed.

The Martian equivalent of Armstrong's first step on the moon will take time. It's forecast in about 2035, and that's with a fair fiscal wind powering it.

Between now and then, as many as six presidents and a dozen Congresses will weigh in with their political priorities and preferences, which means that under the current way of doing business, the NASA "meatball" will continue being a volleyball, hit back and forth across that political net.

And those future aerospace engineers and scientists will wonder why they should be paying attention in science and math classes?

Fifty years since Gagarin, whither the United States in space?

Or wither it?

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