One of the sillier aspects of criticism of (say) Mars missions is applying terrestrial opportunity costs logic (if you spend $X on A, you can't spend it on B).
Earth's economy stops at GEO. Only hunks of metal go beyond. All economic impact, good or bad, REMAINS ON EARTH
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If they want to do X you can't make they do Y. It's not a chain gang. Their attention and motivation remains earthbound for you to entice.
Many socialist mistakes comes from viewing free people as equipment. Attention opportunity cost is for the individual to think about.
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Like I said I don't think opportunity costs apply in that way to humans. I make no assumption abou you

