Is a glider practical for an economically significant mass of minerals?
Considering the fact that it doesn’t require fuel, I can’t think of a more economic means. After all, why would you need to do it any other way?
Also there’s the fact that we’ve been thinking of this stuff in terms of government which is always wildly overpriced.
Platinum is significant in small masses. So are some of the rare earths.
Water would be stupid to return, except as fuel to be used to slow a spacecraft, as would some others, unless they had been worked into valuable end items.
Meter long carbon nano-tubes might be a case for value returning.
But the bottom line is that we don't know until we get there and do it.
What use is a baby? What is the economic return? Maybe a lot, or maybe none.
Same here. Folks will fail, we will learn, and we'll move forward.
/johnny