It’s a safe bet that 100 years from now most half-way educated people will know about Neil Armstrong. It’s also a safe bet that in a century the name Michael Jackson will be familiar only to five or six cultural anthropologists and, possibly, a medical historian. So what does it say about the United States in 2009 that the late moon-walker is a household name but the living one is not?

Plenty has been written about the Apollo program: the technological wonder; its place in history; the fact that we haven’t gone very far since. Not enough has been written about the Apollo astronauts and, in particular, about their place in the history of American character. That’s a pity: What they have, or had, is something Americans could use.

That something is “The Right Stuff,” which in the movie version means fearlessness, ambition, unblinking patriotism and a penchant for understated irony. Most of us would probably think of the Right Stuff as some combination of piloting skills and a barrelful of guts.

But the really essential ingredient is personal modesty, if not in private than certainly in public. “One day you’re just Gene Cernan, young naval aviator, whatever,” recalls the commander of Apollo 17 in the documentary, “In the Shadow of the Moon.” “And the next day you’re an American hero. Literally. And you have done nothing.”

Mr. Cernan is the last man to have walked on the moon. Nobody can accuse him of lacking for courage. He is simply expressing the very human bewilderment of a sentient person caught in the blandishments of modern celebrity culture. Does America make men like Gene Cernan anymore?