Narciso said:

“Getting to the Moon, in order to mine H3 for fusion is a good idea though.”

Alas, no it isn’t. The fusion cross sections for He3
are impossible to achieve with any near term controllable technology (however, we could in theory make He3 weapons). Unfortunately, mining He3 on the Moon is a pipe dream. We could mine metal on asteroids but before that becomes practical we need to first achieve cheap access to space (CAtS). At present, no one knows how to achieve CAtS (get launch costs under $1000/kg). Martian colonization is possible with current day (expensive) launch technology but the cost to colonize Mars would be comparable to the cost of a minor war (huge!).