If we have to go to outer space to get the raw materials we need for our technology, there's no "sustaining" in sight. Like, ever.
Exploiting what we have down here is a lesson we have to learn first, or space mining is for naught. If we can't make spaceships without lithium, we aren't worthy of spaceships - but we certainly can make automobiles and cell phones without it, if we just bother to try.
Timo Saloniemi
There's by definition no indefinite sustaining at all, though. Raw materials of any sort on Earth are finite, and every recycling process suffers loss. Thermodynamics is even more tyrannical than the rocket equation.