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
See my post #34.
At current platinum prices ($1500+ per oz) I’m getting over a billion and a half dollars for a shuttle bay full of platinum which is one of the common metals in space. (Obviously that’s processed price in a shuttle that wouldn’t be used)