Quote from: LMT on 10/10/2022 12:59 pmQuote from: mikelepage on 10/10/2022 09:07 am...Fe-rich asteroids are a particularly bad example to choose if one was making the case for asteroid mining and export (because Earth/Mars have iron in abundance)....eventually - will be able to export some of the most valuable mined products...What are highly siderophile elements?Current prices?Really…? Okay. You win.
Quote from: mikelepage on 10/10/2022 09:07 am...Fe-rich asteroids are a particularly bad example to choose if one was making the case for asteroid mining and export (because Earth/Mars have iron in abundance)....eventually - will be able to export some of the most valuable mined products...What are highly siderophile elements?Current prices?
...Fe-rich asteroids are a particularly bad example to choose if one was making the case for asteroid mining and export (because Earth/Mars have iron in abundance)....eventually - will be able to export some of the most valuable mined products...
Quote from: mikelepage on 10/10/2022 05:23 pmQuote from: LMT on 10/10/2022 12:59 pmQuote from: mikelepage on 10/10/2022 09:07 am...Fe-rich asteroids are a particularly bad example to choose if one was making the case for asteroid mining and export (because Earth/Mars have iron in abundance)....eventually - will be able to export some of the most valuable mined products...What are highly siderophile elements?Current prices?Really…? Okay. You win.You created the "Exodus financial model". You can spreadsheet space-commerce ROI and breakeven, CEO Mike.Years of asteroid posts, but now, no numbers? What's the story there?
I'm remembering why I stopped responding to LMT the first time, but for anyone wondering, I'm just going to leave this here.https://www.reddit.com/r/explainlikeimfive/comments/b2wu1d/eli5_what_does_it_mean_to_argue_in_bad_faith/If anyone actually wants to talk about asteroid mining architectures, I'll be around.
...asteroids are rubble piles and the tunnel has to have both strength and rigidity for this to work, but there's upside if you combine this tunnel construction effort with asteroid mining: ...combine the regolith with a polymer substrate to make bricks of a substance very similar to concrete (has already been done with Lunar regolith).Step 1) An autonomous tunnelling machine + solar array/power craft to arrive at the asteroid. I envisage this as a pair of craft, connected by a detachable power umbilical. Step 2) After the asteroid has been characterised, the pair take a circuit around the outside of the asteroid, where the tunnelling machine makes a number of radial bore holes down to the planned tunnel "depth".Step 3) The tunnelling machine then creates the toroidal tunnel itself, harvesting water and other elements of value, reinforcing the walls of the tunnel with "regocrete" bricks, all while detaching and reattaching the power umbilical as necessary.Step 4) Humans arrive with extra equipment to add value to the mined materials and reinforce the tunnels, since the "regocrete" would need bolstering by steel cables. Effectively the entire structure is a suspension bridge wrapped over on itself, so you would have some cables going through the centre of the asteroid too. Step 5) Human habitat modules - hosting the crew doing the work - are moved into the tunnel itself. Step 6) Train tests, at low speed, for low G. The habitat modules are probably already part of a spin-G habitat, so they are already designed to be part of a spin G station.
Robots fabricating pressurized tunnel-habs from and within microgravity debris are not mechanically plausible, or needed. Polymer can give a reliable pressurized hab by itself. There's no need to risk the production mysteries, mechanical strength variability, and hazard of gritty polymer "bricks". Also, a meter of water gives cosmic-ray protection for year+ hab transits; no need for rocky mess there, either. Explore efficient mining and distribution of water outside of gravity wells.
Years of asteroid posts, but now, no numbers? What's the story there?
I'd note that I think those plots of Fe-rich asteroids are a particularly bad example to choose if one was making the case for asteroid mining and export...
ECOCELa database for the aspiring asteroid miner
[The other question is: how does one cast large Fe-rich structures in space, using Solar Thermal technology?
Quote from: JohnFornaro on 11/24/2022 02:51 pmHow does one cast large Fe-rich structures in space, using Solar Thermal technology?1. Vapor deposition. 2. The other alternative is make wire feed stock for 3D printers.3. Checkout Mond Process can be used on other metals beside Nickel. 4. Electrostatic Separator (works best in zero G).Space provides high vacuum, zero G and extreme temperature ranges for free. All of which are very useful for these processes.
How does one cast large Fe-rich structures in space, using Solar Thermal technology?
Quote from: TrevorMonty on 11/24/2022 04:21 pmQuote from: JohnFornaro on 11/24/2022 02:51 pmHow does one cast large Fe-rich structures in space, using Solar Thermal technology?1. Vapor deposition. 2. The other alternative is make wire feed stock for 3D printers.3. Checkout Mond Process can be used on other metals beside Nickel. 4. Electrostatic Separator (works best in zero G).Space provides high vacuum, zero G and extreme temperature ranges for free. All of which are very useful for these processes.1 & 2 require high temperatures, just like casting does. My 3D printer guy tells me that 3D printing is very slow in space. He had done a BOTE for the tension ring structure I proposed for a ring station; he guessed it would take 8 years to print it here on Earth, if one could imagine printing pieces that large. He suggested casting in a large rotating mold of refractory material.3. A cursory look at the Mond Process suggests it's for Nickel only.4. A quick look at Electrostatic Separation suggests it could be a way to get the Fe out of ilmenite, which is found on the Moon in good quantities.https://www.sciencedirect.com/topics/earth-and-planetary-sciences/electrostatic-separation If anybody's working on in-space metals refinement and foundries, they are way below the radar.
The other question is: how does one cast large Fe-rich structures in space, using Solar Thermal technology?
Quote from: JohnFornaro on 11/24/2022 02:51 pmThe other question is: how does one cast large Fe-rich structures in space, using Solar Thermal technology?"large Fe-rich structures' are usually steel, not cast iron. ...
I'm in the 'enrich is place' camp. Moving slag from the asteroids seems costly in deltaV versus moving it from the Moon's surface for most construction projects. And it can always be re-used later when the belt is settled, it doesn't go away.Most interesting minerals are in PPM or small % concentrations, Minerals required in larger concentrations are readily available from the Moon, except for carbon and lithium, perhaps.Psyche might be the exception, and I am really looking forwards to that mission. https://www.jpl.nasa.gov/missions/psyche
Vapor deposition...Space provides high vacuum, zero G and extreme temperature ranges for free. All of which are very useful...
During this mission, AstroForge will demonstrate their refinery capabilities with the goal of validating our technology and performing extractions in zero gravity. The spacecraft will launch pre-loaded with an asteroid-like material that the refinery payload will vaporize and sort into its elemental components.
...your "proprietary unobvious (sic) method" of shifting asteroids around... if it actually worked... could become the go-to method for planetary defence...
...The other question is: how does one cast large Fe-rich structures in space, using Solar Thermal technology?
Quote from: JohnFornaro on 11/24/2022 02:51 pm...The other question is: how does one cast large Fe-rich structures in space, using Solar Thermal technology?Curious why you want to cast 316L in stead of drawing it and then welding it into the shapes for your designs? Less weight (i.e. less material), which might be important.But if you want to cast, why not use space versions of investment casting?
Quote from: Coastal Ron on 12/12/2023 02:49 pmQuote from: JohnFornaro on 11/24/2022 02:51 pm...The other question is: how does one cast large Fe-rich structures in space, using Solar Thermal technology?Curious why you want to cast 316L in stead of drawing it and then welding it into the shapes for your designs? Less weight (i.e. less material), which might be important.But if you want to cast, why not use space versions of investment casting?I would think that what we want to produce as far as steel goes may have more to do with I beam and plates, and not complex parts?
Quote from: Coastal Ron on 12/12/2023 02:49 pmQuote from: JohnFornaro on 11/24/2022 02:51 pm...The other question is: how does one cast large Fe-rich structures in space, using Solar Thermal technology?Curious why you want to cast 316L in stead of drawing it and then welding it into the shapes for your designs? Less weight (i.e. less material), which might be important.But if you want to cast, why not use space versions of investment casting?(1) I would think that what we want to produce as far as steel goes may have more to do with I beam and plates, and not complex parts? (2) We can mine for low volume high value, or low value high volume. If we are mining steel, we might move some of the other minerals as well for low mass penalties, as we might have 20-50% iron ores. But if we are mining materials at 50-100 ppm, we would want to remove the largest amounts of material possible so we only move a few percent of the mineral mass.If we are mining high value metals, we are probably not yet in an intensive space occupation paradigm. But if we are mining iron to make steel, then even the silica becomes valuable as radiation shielding. (3) The only elements in a space occupation scenario that we might want to do away with are oxygen and possibly sulfur or chlorine? As we are likely to have an overabundance of these. Carbon and nitrogen, however, will be valuable bulk materials.
(1) My station design still imagines large cast sections that are bolted together. Even investment casting wouldn't be appropriate at that scale.