Space resource usage could first happen with asteroids, not on the Moon or Mars. Propellants mined from asteroids can be transferred anywhere with very low delta V and low thrust. It just takes time.
Esp. the moon because you can use a cannon to launch spacecraft so you don't need to use fuel on it (if you'd do it with a magnetic cannon you could do it entirely with solar arrays).
ps. it's actually interesting concept, you could have something similar to medieval catapult on the Moon and throw rocks on Earth which would be equivalent to nuclear explosions, no?
Just launching cargo is a lot easier, we already know how to accelerate things to the speed of a bullet in a variety of ways. Scaling up a railgun to handle heavier bullets is comparatively easy.
Cargo could be made to go much, much faster.
https://www.kickstarter.com/projects/391496725/the-slingatro...
For alive payloads, the rail becomes longer.
The advantage is that on the moon the low gravity and no atmosphere make megastructures like this easier to build. Energy is also no concern either, you have pure unfiltered sunlight for about 15 days each month on each side of the moon.
That's a bit of an overstatement. We have a 3d printer on the ISS and me make great strides in producing fiber optics in space that are superior to what we can do on earth at similar price points [1].
1: https://www.nasa.gov/mission_pages/station/research/experime...
Yeah, heavy REMs are still expensive but there is really no reason to believe that they'll stay that way. New sites will be found, new extraction techniques will be tried and new processes developed and then the problem will go away. Sure, it could happen in space but it's so much easier to do here on earth that it might never be worth it to go to space for it.
I'm not an emissions system engineer so I can't evaluate the truth of the statement. If it is true, and supply existed: it would create demand, potentially it could even drive up price as potential users quit using less desirable alternatives.
No, it's not. I'm pretty sure it's silicon. Iron is relatively rare (but not as rare as platinum or gold of course).
Iron is the most abundant element in the Earth, but not on it. The core is full of iron. But that doesn't help us at all, because we can't get to that. We can only access materials in the crust, and there isn't much iron there.
If you include the biosphere, it's carbon. If you include the oceans, it's hydrogen (the hydrogen atoms in water).
Even if you just include inorganic materials in the crust, I believe oxygen is more abundant than silicon (oxygen is part of silicate rocks).
https://en.wikipedia.org/wiki/Abundance_of_the_chemical_elem...
Oxygen is #1, silicon is #2, aluminum is #3, and iron is #4 (though far less than O or Si). Carbon doesn't even rank in the top 9.
It says "in the Earth's crust". That indicates to me that the biosphere and the oceans are not being counted. Also, it's giving abundances by mass, which is not the only way to do it (I was actually thinking of abundance by atom count).
Later in the same Wikipedia article, the top eleven abundances by mass for the ocean are given: oxygen and hydrogen are the first two, carbon is #10, and silicon doesn't even make the list.
No figures are given in that article for the biosphere; my statement of carbon being the most abundant for that is based on the fact that it forms the "backbone" of all of the main types of molecules in living organisms: proteins, carbohydrates, lipids, and nucleic acids.
As for the "crust", the definition of the Earth's crust I'm pretty sure includes the oceans, the seafloor, and everything down to the mantle, so the biosphere and oceans should be counted there. Hydrogen doesn't rank highly because it has little mass compared to other elements. Atom count seems like a pretty pointless metric; we're talking about resources available for mining, in which case mass is what counts.
Of course silicon doesn't make the list for oceans because it's mostly water, and a lot of dissolved CO2. Count the seafloor and you'll find lots of silicon (and probably some iron, aluminum, titanium, etc.).
If the crust included the oceans, there wouldn't be different figures for the oceans in the same article.
You make a valid point about the seafloor being part of the crust; but I didn't intend to include the seafloor in "oceans".
> Atom count seems like a pretty pointless metric; we're talking about resources available for mining, in which case mass is what counts.
That depends on what we're mining the resource for. For example, if we're mining for metals to use in catalytic converters for vehicles, atom count is the relevant metric, since the catalytic effectiveness depends on the number of atoms, not on the total mass.
No, it isn't; each hemoglobin molecule has just four iron atoms in it (IIRC--each heme structure has one, and I think there are four heme structures in one hemoglobin molecule). Most of each such molecule, by either mass or atom count, is carbon. And each red blood cell is more than just hemoglobin molecules.
Once you have capabilities to build in space, going down gravity wells makes zero sense.
Want to build a factory or physics lab in space. You just mine things there and build them there. After a while you are looking at permanent colonies and then it's useful there.
Asimov truly was legendary.
story & characters are definitely "american-style" (very direct & aggressive), but in these cases I ended up liking quite a lot this approach (basically it fits the setup of the stories because of the fight for survival of the species).
---
---
List of books (Spoiler alert - don't read the plots):
Looking glass: https://en.wikipedia.org/wiki/Voyage_of_the_Space_Bubble
Troy rising: https://en.wikipedia.org/wiki/Troy_Rising
There is very little coherent argument for bringing space resources back down to earth.
Sure, fully automated mining, refining, QA, etc. isn’t ready yet, but it’s not implausible, and those things are all still increasingly automated even down here on Earth.
Similarly, we can expect that the early solar economy will provide opportunities for the same, though there is a lot of still undiscovered issues at hand.
Here, Mars/Moon will make the food and other 'simple' goods that are then sent to the Asteroid Belt. This is because the delta-V to get foodstuffs and goods off Mars/Moon is a lot less than on Earth and, depending on more surveying, there seems to be a fair bit of water on Mars that you can use. It seems thus far that corn-pone and beef-steaks do not grow well in 0G, though that remains to be seen.
These simple goods and food-stuffs will then be consumed by the Asteroid Belt in the use of mining for rare-earth elements and in production of vehicles and fuel for use in the outer solar system. The mined elements and materials will then be sent back to Earth for use in highly complex machines and other things.
Highly complicated machines built by people that do not want to raise their kids in the Belt or on Mars/Moon will then be sent to Mars/Moon for use in production of simpler goods.
A company with skills in (robotic?) space shipping and landing could make a profit at every gravity well.
This triangular trade is not likely to last very long as greenhouses are set-up (if possible) in the belt, manufacturing and leisure are made easier on Mars/Moon, and as techniques and science are improved on Earth.
[0] https://en.wikipedia.org/wiki/Triangular_trade
[1] https://en.wikipedia.org/wiki/John_Hawkins_(naval_commander)
For really far bases you would need spin gravity in a hollow asteroid for the staff.
Edit: hmmm... it seems that escaping Earth and the Sun would be easier from the Moon, since the Moon trajectory components include already the 9 km/s and 30 km/s of Moon and Earth's orbits. Once in Moon's orbit, with the right angle and a little push, you should be able to escape Sun.
It could make sense if you can design a spacecraft that can use Mars' atmosphere to slow down (aerocapture) without going all the way to a landing.
Being able to use the atmosphere to slow down is why in some ways it's easier to land a heavy payload (like Curiosity) on Mars than on the Moon.