And I can't come up with a economically defensible reason to go back,
You understand that the only option in 1968 for finding out whether or not there is a good reason to explore the moon is actually going to the moon, right? And despite your objectivist baloney, human beings do things without a profit motive. Sometimes, great things. How much did Isaac Newton profit when he was working out optics? You think Galileo or Copernicus were doing their rather unpopular work for the sweet sweet coin?
What is money except a measure of economic value? What is capital except a measure of society's perceived value in making a task possible?
Late stage capital is a complete refutation of this purely materialistic vision.
If you have to force people to do something via the application of the government's power of life and death, it probably isn't worth doing.
Wait, you think the guys that went to the moon or the guys that built the Apollo rockets or the people who paid a minuscule share of their tax money to pay for the space program were only doing it because of the "government's power of life and death"?
Maybe you're too young to remember this: https://youtu.be/g25G1M4EXrQ
I was too young to remember it, though I was alive at the time. What I do remember is that the space program inspired generations and it cost less than Americans were spending on cigarettes and cigars every year. We're talking about a people that were only 16 years from having saved their bacon grease and string to be able to help the war effort. We're talking about a generation of people who had come out of a very dark chapter in human history, having sacrificed universally for something they believed in. They didn't scrimp for war bonds and enlist in the military because they thought, "what profit is there in this?" but because they were inspired to do so by larger events. And the larger events of the US space program similarly inspired generations of young people to set their sights beyond just going to work selling insurance or vacuum cleaners door-to-door. During the space program, interest in the sciences - all of the sciences - exploded, and set the route that led to almost all of the technological innovation that followed in the decades hence.
I'm not sure what happened to you. When did you lose your ability to be inspired by something besides selfish financial gain? Though you demonstrate the symptoms of someone who fell in love with the pseudo-intellectual pursuit known as "objectivism", most likely as an undergrad, clearly something else went wrong as well.
[in case anyone is interested, here is the entirety of the JFK speech excerpted above: