No, they aren't. There's tons of asteroids in Earth-crossing orbits. And Mars-crossing orbits too. It'll be a long time before we use those up.
>You need to move a lot of bulk material which means heavy Delta V problems.
No, you don't. You process the ores near the asteroids; you don't have to ship it all to the point-of-use.
>Micro gravity means you can't have humans in the area for long without giant structures.
So what? You don't need a lot of humans there; this stuff needs to be automated (or at least remote-controlled). And artificial gravity doesn't need a giant structure; you can do it with a small structure on a tether.
>Finally, economically resources are just not that scarce.
That depends on what resources, and where you want them. If you want a lot of platinum, it's very scarce here on Earth, but mining one Earth-crossing asteroid could provide a huge amount of it relatively cheaply.
>As to mining Mars's moon's they don't really have a lot of useful material that is not on Mars in the first place.
How do you know that? Mars's moons are really just captured asteroids and likely have no geological relation to Mars at all.
Anyway, back to your argument. Processing ore is not light weight. Total mass of asteroids inside earths orbit is actually surprisingly low relative to planetary manufacturing needs. Sure the asteroid belt is ~4% of the moons mass, but inner planets have mostly cleared their orbits.
Yea, there are KM sized objects, which might be rich in stuff we want. But consider, Bingham Canyon Mine for example is 0.6 miles deep and 2.5 miles wide and that's just for copper. And even if you processed it all you still need Delta V on 19 million tonnes of copper.
Look at a periodic table. Mines can only really provide you with that stuff. Now exclude the useless elements and the stuff and what's abundant and there really is not a huge niche for asteroid mining. Futher ateriods regularly impacted mars after it had a solid surface so all the same elements are there much like they are on earth.
So, you really need asteroid mining to stand on it's own independent of colonizing Mars.
PS: Artificial gravity only gets you part of the way to dealing with micro gravity You need life support, food, water etc. Spin all that stuff and you need an even stronger tether with a larger counter weight.
>You need life support, food, water etc.
We figured all that stuff out ages ago. We can already recycle air and water and have been doing so on space stations for decades. Food can be supplied by resupply missions, and also grown on-site; it's not that hard. You're completely overstating the problem. If you think that running a small space station is somehow far harder than running a habitat on Mars (where you cannot control the gravity at all), which seems to be what you're implying here, you have no idea what you're talking about, and I think you're being intellectually dishonest to boot.
To put things in perspective if we knew about a 1,000 ton 100% gold asteroid at say 1.2 AU, getting that to earth right now would cost more than it was worth. Add on top of that the need to refine stuff in space or send back less valuable material and it's a pipe dream until we get a lot better at spaceflight.
PS: You can increase the gravity of living spaces on mars 'easily' by rotating the habitat. Though we don't expect that to be necessary.
How is Planetary Resources a scam? Citation needed.
We can easily do 20g on earth: https://en.wikipedia.org/wiki/High-G_training
1g is much easier in mars gravity as you can simply tilt the chamber at an angle while spinning it. Training centrifuges generally have the chamber on a hinge so you automatically get the correct angle.
Now, sure you lose some energy to friction. But, not all that much further, we have a lot of experience dealing with very heavy rotating objects for decades. EX: Power plants.
Rotating a habitat is a hard problem in space or on a planet. But, Mars's is gravity would make the problem easier not harder. The atmosphere might be a problem, scale might be a problem etc etc, but gravity is not. Further, there may be little need for 24/7 1g, perhaps a tiny room to work out in is enough, perhaps you should sleep in 1g or perhaps 1/3 is enough for sleep etc.
But, again gravity is not the problem. And yes such a massive fundamental failure in understanding is a clear sign of incompetence.
https://en.m.wikipedia.org/wiki/List_of_revolving_restaurant...
The example on that list that I had been to most recently is the Westin in Atlanta.
It's 57M in diameter and it's upper floor spins at once every 30 minutes. Plugging that into Mω²r, you end up with 0.0000354084g.
Not exactly the best example.
The delta V issues are more reasonable when you want stuff to end up in space. But, that's not an issue for a Mars colony. As to mining Mars's moon's they don't really have a lot of useful material that is not on Mars in the first place.
PS: Space X's slightly lower the cost to orbit actually makes Asteroid mining even less viable.