Predictions in years are less and less meaningful to me as I go along. I'd give .6 confidence that we're no more than 5 tech-generations away from being able to build a fully automated mining facility (just to pick a concrete example), and no more than 3 generations from there to being able to build one in a way that would be cost-effective (given current-day labor costs and raw materials prices) for at least some application... perhaps underwater mining of rare earths.

I also expect that along the way, selected raw materials prices will increase enough (in inflation-adjusted currency) that using current-day prices is absurdly conservative. Then again, I also expect that along the way we'll see several failures of such equipment that cause as much as half a commute-year (current-day) of environmental damage, which might set the whole project back by decades. So, who knows?

A commute-year, incidentally, is a measure of risk (e.g., death and property/environmental damage) equal to that caused by people commuting to and from their jobs in a given year. My guess is that half a commute-year is typically more than enough to cause the majority of Americans to insist that a new project is way too dangerous to even consider. (Of course, that doesn't apply to the project of actually commuting to work.)