It's your obsession to bring riches back to Earth. My intention was to point out the best mining opportunity was not on Earth, or on the Moon, but in the Asteroids. No, you can't use yourself as an example of future excellence. Some things must be built in space before they can be brought to Earth's surface. ...
No, I am certainly not obsessed with bringing riches back to Earth from asteroids because it is not economical to do so and never will be.
I was only replying to your post:
{post 285, in part} If the products or resources procured from asteroid extraction were to return to Earth orbit, it could be a matter of barging or tether-pulling the load from the Asteroids to Earth orbit, in a low gravitational journey, which is the shipping cost of containment, and fuel to get the load to speed, and fuel to brake at destination. ...
Because few who suggest this have even the slightest idea how lacking in economic feasibility (for fundamental reasons) it is; I spoke of returning mass from the moon as people do have some feeling for the cost of that. - The “to huge for humans to really comprehend” costly program Kennedy proposed did bring a few pound of moon rocks back, which were just picked up with no mining or refining expenses.
Very few understand that the doing the same (even with un-manned robots) returning mass just to only a near Earth orbit (never landing it back on Earth) from an asteroid would be dozens, if not 100s of times more costly per pound returned. This is not due to the need to climb up out of Earth's gravity well but due to the speed changes required, which few, including you, understand is the main (and FUNDAMENTAL) problem.
Landing on the moon and returning to near Earth orbit is very easy compared to doing the same with an asteroid, because both moon and Earth are orbiting the sun with the same speed (~107,000 km/h) and at essentially the same point in the sun’s “gravitational well.” (less than 0.1% difference in potential energy when extreme and exactly the same every14 days) All those gigantic Apollo rockets had to do was give the space ships a little less speed wrt to Earth than Earth’s escape speed (40,200 km/h) to go to the moon. This speed is also all you need to crash into an “earth orbit crossing” asteroid if you time the encounter to be when the asteroid is at1AU from the sun (same distance as the earth is) BUT if you want to land on the asteroid that is an entirely different and much more expensive story as you must have fuel, lifted from earth, (with 100s of times more than that fuel’s weight burnt during launch to give the fuel taken to the asteroid a speed wrt Earth of 40,200 km/h) adequate to change the velocity (speed and direction) of the rocket to be the same as that of the asteroid.
Assuming you do land on the asteroid as it passes thru the same point in the sun’s gravity well as Earth is in and spend only a week setting up, exploring for the richest ore to reduce refining costs and delays and then mining (a very optimistic assumption as doing that on Earth always takes more than a year) then when you launch for the return trip to Earth, you are at very different place in the sun’s gravity potential well, and will need fuel to get back to even just cross Earth’s orbit (even with the speed of the asteroid. i.e. changing only the potential energy) Compared to this fuel requirement, we can neglect the tiny amount of fuel needed to pull away from the weak gravity field of the asteroid; however, note this “return to the 1AU point” fuel also had to be lifted off earth during the original launch from Earth.
After pulling away from the asteroid with your “pay load mass” you again need to make a huge expenditure of more fuel to change your velocity (speed back to ~107,000 km/h around the sun) and make the direction of it to be along the Earth’s orbital path in the Earth’s orbital plain. All this fuel also was in the original rocket you launched from Earth and greatly increasing the size and cost of the launch rocket.
It is this fuel, lifted off from Earth, for these necessary (regardless of any advances of “capitalism” like your Fred example had) velocity changes that makes the asteroid mission rocket returning a few pounds of matter to only near Earth orbit dozens, if not 100s, of times larger and more costly than Apollo’s rockets were. That is what dreamers of “mining asteroids” usually fail to understand. (If they concern themselves with any of the physics, it is usually only with the relatively unimportant energy and fuel requirement to climb away from earth’s gravity.)
Those velocity change requirements are why there is nothing on or in an asteroid worth* returning to even only a near earth orbit. (Near Earth orbit objects also are travelling around the sun at 107,000 km/h and in the exact same direction as Earth is.) Returning mass to Earth’s surface instead of just leaving it in near Earth orbit is only a relatively minor increase original launch rocket’s fuel lift off mass requirement compared to these “velocity change” fuel requirements, especially if one dips in and out of the atmosphere to lose speed wrt Earth's surface where the landing site is.
None of these “asteroid velocity change” requirements were needed to make a round trip to the moon. That is why it is dozens, if not 100s of times cheaper to return mass from the moon.
* I.e. Nothing which is not much more cheaply available on Earth.
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The part of your post I made bold is totally uncalled for and without any foundation in fact. I should not be blamed for understanding this problem better than you do. I have been fortunate to get a good education, especially in classical physics, but do NOT think myself any better than others who did not. There are many valuable things others can do that I cannot. For example, paint wonderful pictures, write good poetry, heal the sick, compose beautiful music, etc. whereas I cannot do any of this, not even play the piano, crudely.
- For probably more than 10 million dollars the weight of less than a flea's legs was returned in a tiny re-entry capsule that did not burn up with re-entry!