‘Clic’, a rather interesting pseudo science reportage program from the ubiquitous BBC channel was showing, in one way, the shortage of materials on Earth. Mining for metals here is becoming a more expensive because we have to look further afield. So, the program was showing whether asteroid mining was actually a proposition, was it worthwhile. Well, it could be of course but from my point of view it would depend on two things, the remaining availability on Earth and the difference in costs. The deposits on Earth are finite, particularly as economies of countries are using more and more, it will become necessary to look elsewhere.
It is interesting because it will almost certainly involve human beings. But are we really fit for living in space? Where is the food supply, water, vitamins? You can only take so much with you. After all it still takes some nine months to fly to Mars and the asteroid belt is much further away! So, this will throw up another conundrum. It is now known that human muscle deteriorates, even when exercising in space. After all we are used to a constant 1G on Earth, our muscular system is completely in tune with it.
It is one of the reasons, I think, we will never see aliens. We might encounter robotic beings but not flesh and blood in space. The reason is, again it is my personal opinion, that after a very prolonged travel time human beings would not be able to move much at all. Nor will any alien. For that reason interplanetary wars fought by sentient beings of the flesh and blood type, is not really possible. I laughed at some American SF films, such as ''Starship Troopers' as complete hogwash, funny yes but totally unrealistic. Call it brain-fodder. Indeed, for that reason I believe asteroid mining would have to be entirely robotic and as such pretty expensive. And as with everything else, money will dictate whether these efforts are feasible.
The other side of the coin is why do we not more on recycling? Most materials can be salvaged and re-used. But as there is a cost associated with it which is more expensive than mining new resources we lack the will to recycle properly. It is believed that the electronic waste mountain exists of 18 million tons of discarded equipment at this moment and increasing (see this url - https://www.theworldcounts.com/challenges/planet-earth/waste/electronic-waste-facts) Thrown away and just mostly clogging up our living space. What we are doing is continually looking up but forgetting to look down. We are deluding ourselves about space thinking it will save everything but in the meantime our base, the planet Earth, is withering and rotting under our feet. Well, we will reap what we sow, so let it be grain on Earth and not ideas about how to sow that on Mars or some Godforsaken asteroid!