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#276 2024-01-24 06:38:19

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 3,793

Re: Colonizing / terraforming small asteroids

I thought it might be time to revive this topic, given the likely impending success of Starship and the options it opens to us.  My original idea was wrap asteroids in a cocoon of glass fibre, like a spider wrapping up a bug.  The asteroud would then be spun up to provide spin gravity in pressurised tunnels.  This turns out to be a bad idea.  It is a lot of work building a web of fibres that can hold together a loosely aglomerated pile of rubble.  Better to mine the asteroid and use the materials to build a space station that is structurally optimised for pressure and rotation.  But the question then comes, how do we mine something that has almost no gravity?  What do the shovels and jack hammers push against?  How do we prevent materials from floating off into space when disturbed, given the asteroid's meagre gravity and escape velocity?  All things to think about here.

Bennu is well studied and is about the right size to be a baseline candidate for this topic.  The asteroid is a rubble pile, which makes it easier to mine using shovels, without need for explosives or mechanical drills.  It has mass 73 million tonnes.  Enough to construct twenty Island 1 type habitats and hundreds of solar power satellites in the 5GWe range.  It also contains plentiful carbon and at least some hydrogen.  This makes it a good first target.
https://en.m.wikipedia.org/wiki/101955_Bennu

Last edited by Calliban (2024-01-24 06:46:52)


"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."

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#277 2024-01-24 07:42:46

tahanson43206
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Registered: 2018-04-27
Posts: 19,405

Re: Colonizing / terraforming small asteroids

This post is reserved for a work session with ChatGPT4 and DALL-E.

Post #276 by Calliban renews our long running discussion of how to work with asteroids. 

In post #276, Calliban renews and re-evaluates the discussion of enclosure of a rubble pile in a web.

Among the points included in #276 is the question of what kind of tool might be best suited to collecting material from rubble piles.

Japan and NASA have both collected small samples of material from rubble pile objects in deep space. I suspect that machines with similar designs will become common in the asteroid mining industry.  Today, I'll as ChatGPT4 to ask DALL-E to create images showing asteroid mining tools. Based upon recent experience, since DALL-E is a free agent with a "mind" of it's own, I have expectation that whatever is produced will be surprising. 

SearchTerm:DALL-E image of asteroid rubble pile mining equipment

(th)

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#278 2024-01-24 07:50:02

tahanson43206
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Registered: 2018-04-27
Posts: 19,405

Re: Colonizing / terraforming small asteroids

This post introduces the possibility of use of electrostatic force as a mechanism for efficiently mining rubble pile solar system objects.

Electrostatic force is the force upon which much (if not most) of the world we see about is depends.  We take it for granted, but it is the force that holds us and all the rest of the objects we see and interact with together.

In the case of a rubble pile mining operation, I am wondering if there might be a way to deliver a quantity of electrons to an area on a rubble pile so that a positively charged collection plate would attract mass from the area of interest. 

An example of what that might look like is available from our experiments with the comparable force, magnetism.

It is possible to introduce a small permanent magnet into a pile of iron particles. Upon withdrawal of the magnet from the iron particles, a number of the particles will remain visible on the magnet, due to the attraction of the iron by the magnet.

Something similar may be possible with the electrostatic force for asteroid mining.

(th)

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#279 2024-01-24 08:59:51

Void
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Registered: 2011-12-29
Posts: 7,820

Re: Colonizing / terraforming small asteroids

Please forgive me, I only want a contributing touch here, not to envelope and control the conversation.

It seems likely that you are on to something.  Bennu, not being very Oxidized, may have significant magnetite in it.

A magnetic solar wind sail may be able to intercept it and bind to it.

This could block the solar wind from it.  Bennu rotates, so if the solar sail is in an orbit bonded by magnetism more than gravitation, as the sail is presented towards the sun, it would be pushed towards Bennu, and as presented behind Bennu, will pull away from it.

The intensity of the magnetic field can be throttled to suit desires.  It could be possible to increase the spin of Bennu or decrease it by changing the magnetic fields intensity, as larger when the solar wind is aiding the existing spin or opposing the existing spin.

Methods to fluff up Bennu could be employed.  That could be magnetic, electrostatic or mechanical.

Spinning nets could collect the fluffed-up materials.  For instance, an X like propeller with nets on each end of each spoke of the X, could then collect the materials and hold them with centrifugal force.  Each spoke of the propellers could have a slide like nature so that particles could be collected to the sliding process and slide into the nets.  Or instead of four nets you could have a torus with an open trough shape, and then give vibration to that so that the collected particles would flow like a fluid.

Force factors could include gravitation, magnetism, and electrostatic.  But also inertia.

The main device that deploys the magnetic field would be attached so some object with significant inertia.

One method of fluffing would be to have the device punch the asteroid when the solar wind would be pushing the device towards the asteroid.  Then that would fluff things up and the spinning netting devices would collect some of the materials.  Perhaps one punch for one orbit.

As materials would collect into a torus trough then you would increase inertia.

Obviously you don't want the materials to drift completely away from Bennu, so this needs to be appropriately gentile.

The magnetic field may prevent the solar wind from snatching dust particles, I hope.

I don't have the whole thing but I have some parts for you to perhaps enhance and add to.

Done

Last edited by Void (2024-01-24 09:15:49)


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#280 2024-01-24 09:24:22

tahanson43206
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Posts: 19,405

Re: Colonizing / terraforming small asteroids

For Void re #279

It is fun to imagine development of your idea, and I hope you will pursue it further.

The method may not be ideal for Bennu, because a quick check reveals absence of iron.

However, there is a solar system full of objects, and some of those appear to contain iron, and ** those ** should respond well to your capture devices designed to employ magnetic force.

Please do continue developing this idea. 

In addition, since the idea is fresh in mind, your drawing talents might find additional expression via the free trial version of DALL-E. I understand that you may be given up to 15 images per month, based upon the date of your registration with DALL-E.

To save you some time, you are welcome to look at the prompts I have posted in the Teleoperation topic.

DALL-E works only with words. it does not have the ability to accept numeric instructions.

It does understand small vs large.

(th)

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#281 2024-01-24 09:44:27

Void
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Registered: 2011-12-29
Posts: 7,820

Re: Colonizing / terraforming small asteroids

Thanks (th).

Actually I am expecting Bennu to have some Magnetite as it was not formed from an Oxidizing environment but lets see about it in the future.  Your point may be correct.  (Or not).

Done

https://www.sciencedirect.com/science/a … 3518302252
Quote:

Magnetite-bearing lithologies are common in aqueously-altered carbonaceous chondrites (e.g., Brearley and Jones, 1998), where the magnetite occurs as a reaction product of the aqueous alteration of olivine and to a lesser extent pyroxene.

Done

Last edited by Void (2024-01-24 09:47:42)


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#282 2024-01-24 11:56:05

tahanson43206
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Posts: 19,405

Re: Colonizing / terraforming small asteroids

For Void re Post #281

Thank you for a link to follow, to find out what the authors are offering as guidance.

I took for my message a report of NASA findings of the assay of actual material from Bennu.

No iron was reported, but perhaps that was an oversight (or not).

(th)

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#283 2024-01-24 14:08:44

tahanson43206
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Registered: 2018-04-27
Posts: 19,405

Re: Colonizing / terraforming small asteroids

This post is intended to offer the first of what I hope will be interesting attempts by DALL-E to show various ideas for mining an asteroid in space.  As usual, DALL-E took the opening request and ran with it in whatever direction it "thought" suitable.  Also as usual, I gave the setup to ChatGPT4, which composed the prompt given to DALL-E.  I used the example of a "shovel" to try to get the process started, and DALL-E ignored that, and delivered what looks like a vacuum cleaner instead. Of course a vacuum cleaner is not a reasonable idea in space, but I thought the image was so well done our forum audience might like to see it.

Here is the prompt:

DALL-E 3 Image Generation Prompt

A futuristic small spacecraft equipped with a mechanical shovel, designed for asteroid mining. The spacecraft is hovering above the surface of Asteroid Bennu, which is a rubble pile asteroid with boulders and dust. The shovel is extended towards the surface, gently attempting to collect material. The scene captures the microgravity environment of space, showing some small rocks and dust particles floating around due to the gentle movement of the shovel. The spacecraft is sleek, with solar panels and advanced technology, illustrating a sophisticated design for space exploration and mining in zero gravity. The background shows the darkness of space with distant stars.

Link to image via imgur.com:
h92r67A.png

(th)

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#284 2024-01-24 16:17:39

Void
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Registered: 2011-12-29
Posts: 7,820

Re: Colonizing / terraforming small asteroids

In time I will attempt to use your method.

https://www.nationalgeographic.co.uk/sp … s-for-life
Quote:

In its time orbiting the asteroid, OSIRIS-REx has revealed all sorts of unexpected details. For one, it’s seen bizarre “popping rocks” eject from Bennu’s surface, likely due to the sun’s heating. The spacecraft even spotted chunks of another asteroid, Vesta, among Bennu’s asphalt-coloured boulders by picking out rocks that contained Vesta’s calling-card mix of minerals.

Bennu may or may not have significant magnetic materials.  Time will tell, but it appears to be a mixture of asteroid materials.

I think that half of NASA is obsessed about life in space, so they are most interested in the organic chemicals.

Done

OK, now I will be a bit of a jerk, but not too much: https://www.nature.com/articles/d41586- … %20history.
Quote:

The Bennu samples also contain iron-rich minerals with large flat surfaces, which might have helped to catalyse chemical reactions early in the asteroid’s history.

So, chances are some of it may be magnetic.

Done

https://www.cnn.com/2023/10/11/world/os … index.html
Quote:

The analysis also revealed sulfide minerals, “a critical element for planetary evolution and biology,” iron oxide minerals called magnetite that react to magnetic fields, and other minerals that could be important for organic evolution, Lauretta said.

Of course, I am very familiar with magnetic iron like magnetite.  I used to work in a Taconite processing facility.

Done

Last edited by Void (2024-01-24 16:26:45)


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#285 2024-01-24 18:32:38

tahanson43206
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Posts: 19,405

Re: Colonizing / terraforming small asteroids

For Void .... re #284 and concept of using a magnet to pull material out of an asteroid ...

Your idea deserves a field test.   Please try to find some material that matches what you have convinced yourself exists on Bennu. 

You may well be right, because NASA brought back only a tiny part of the surface of the asteroid, and there may be iron a short distance away.

You can do your part by obtaining some material that matches what you think is to be found on Bennu, and testing it with a small magnet.

if the material jumps to the magnet, then you will have evidence that NASA and other researchers can use to justify a request for funding to try your idea at Bennu.

There is no need to use words to continue this discussion.  A simple experiment will provide evidence that your idea has merit.

Here is an experiment you can perform at home: put a quantity of ordinary rust near a magnet.

Can Magnets Rust?
Iron-oxide aka rust is not magnetic, and since the actual magnet becomes smaller, it becomes weaker as well. Rust buildup can also create a larger gap between the magnet and what it is attracting to which will lower pull force.

Can Magnets Rust?

K&J Magnetics
https://www.kjmagnetics.com › blog › p=can-magnets-rust
About featured snippets

Feedback

If the material in an asteroid is present in the form of iron-oxide, then it will not jump to a magnet, if the quote Google found above is accurate.

(th)

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#286 2024-01-24 20:37:14

Void
Member
Registered: 2011-12-29
Posts: 7,820

Re: Colonizing / terraforming small asteroids

By your criteria, I may reply and so will.

Your data is insufficient.  Magnetite is not rust.

Hematite, which is red like rust, and really quite similar is not magnetic: https://en.wikipedia.org/wiki/Hematite
formula>Fe2O3

Magnetite, which is brown or blackish, is magnetic: https://en.wikipedia.org/wiki/Magnetite
formula>Fe2+Fe3+2O4.

Quote:

Magnetite is a mineral and one of the main iron ores, with the chemical formula Fe2+Fe3+2O4. It is one of the oxides of iron, and is ferrimagnetic;[6] it is attracted to a magnet and can be magnetized to become a permanent magnet itself.[7][8] With the exception of extremely rare native iron deposits, it is the most magnetic of all the naturally occurring minerals on Earth.[7][9] Naturally magnetized pieces of magnetite, called lodestone, will attract small pieces of iron, which is how ancient peoples first discovered the property of magnetism.[10]

Magnetite is black or brownish-black with a metallic luster, has a Mohs hardness of 5–6 and leaves a black streak.[7] Small grains of magnetite are very common in igneous and metamorphic rocks.[11]

The chemical IUPAC name is iron(II,III) oxide and the common chemical name is ferrous-ferric oxide.[12]

Here is a quote from my previous post here. (It is about Bennu):

https://www.cnn.com/2023/10/11/world/os … index.html
Quote:

The analysis also revealed sulfide minerals, “a critical element for planetary evolution and biology,” iron oxide minerals called magnetite that react to magnetic fields, and other minerals that could be important for organic evolution, Lauretta said.

Of course, I am very familiar with magnetic iron like magnetite.  I used to work in a Taconite processing facility.

As I told you I worked in taconite processing for 10.5 years and before that I worked with Hematite.  I know the difference.  At that time the whole process was to extract Magnetite from Taconite to create a concentration of Iron to send to the blast furnaces.

I request that in the future you ask questions about why a member may think that something is true.  This is not about ego or status, just truth, which is why I have to make this post.

Done

Last edited by Void (2024-01-24 20:51:16)


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#287 2024-01-24 21:05:53

tahanson43206
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Registered: 2018-04-27
Posts: 19,405

Re: Colonizing / terraforming small asteroids

For Void re #286

It appears that you will be well able to advise an asteroid miner who discovers magnetite in a body.

It was not my intent to question that certain materials respond to magnetic fields.

My intent was and still is to question whether there is any magnetite in Asteroid Bennu. 

Samples of Bennu have been distributed to research facilities.

Here is a link to a report from the University of Arizona.

I scanned the article, but you may be able to read it more carefully and find iron anywhere in the sample.

https://news.arizona.edu/story/sweating … vestigator.

I have no objection to using a magnetic device to harvest magnetite from asteroids where it is present. That sounds like a sensible thing to do.  You may be able to find such an asteroid in the literature. 

However, if you are planning to encourage miners to invest in equipment to find magnetic material in Bennu, it seems possible you will be asked to provide evidence that such material is present, and in sufficient quantity to justify investment in the tool.

Thank you for continuing to develop this interesting topic!

(th)

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#288 2024-01-24 21:10:57

tahanson43206
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Registered: 2018-04-27
Posts: 19,405

Re: Colonizing / terraforming small asteroids

In a short work session with ChatGPT4, we decided to change the wording of our prompt so it would be accessible to a third grade student. In the US, such a person would be 9 years old (or so).  Here is the revised wording of the prompt:

DALL-E 3 Image Generation Prompt for Children

Imagine a special space robot that flies to a big space rock called Bennu. This space robot is trying to pick up tiny pieces of the rock. It has a space shovel but is being very careful. The rock is floating in space where there is no gravity, so things can float away. The robot is using its tools to gently collect the rock pieces without making them float away into space. We can see stars and darkness all around because this is happening far away in space.

The image DALL-E 3 produced was dramatically different.  One significant element was rendering of the shovel.  I'm not sure how useful this image would be for a book for this age group, but it is certainly different!

Link to image from imgur.com: eXi5f0W.png

(th)

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#289 2024-01-24 21:24:33

Void
Member
Registered: 2011-12-29
Posts: 7,820

Re: Colonizing / terraforming small asteroids

Please examine this article and find the following: https://www.cnn.com/2023/10/11/world/os … index.html


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#290 2024-01-24 21:26:42

Void
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Registered: 2011-12-29
Posts: 7,820

Re: Colonizing / terraforming small asteroids

Please examine this article and find the following: https://www.cnn.com/2023/10/11/world/os … index.html

Quote:

The analysis also revealed sulfide minerals, “a critical element for planetary evolution and biology,” iron oxide minerals called magnetite that react to magnetic fields, and other minerals that could be important for organic evolution, Lauretta said.

Done


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#291 2024-01-24 21:29:33

tahanson43206
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Re: Colonizing / terraforming small asteroids

For Void re #290 ...

Excellent !!!! I too found the text you cited.

The analysis also revealed sulfide minerals, “a critical element for planetary evolution and biology,” iron oxide minerals called magnetite that react to magnetic fields, and other minerals that could be important for organic evolution, Lauretta said.

Your magnetic tool appears to have a place in the tool box!

(th)

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#292 2024-01-24 21:45:35

Void
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Registered: 2011-12-29
Posts: 7,820

Re: Colonizing / terraforming small asteroids

Thankyou (th), and please have a restful evening.

Done


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#293 2024-01-25 05:40:29

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 3,793

Re: Colonizing / terraforming small asteroids

What I had in mind, looks like this:
20240125-112946.jpg

We surround a rubble pile asteroid with a rigid ring structure, which is stationary w.r.t to the surface of the asteroid but its radius is greater than the stationary orbit radius for the asteroid.  This means that anything attached to the ring will experience outward centrifugal force away from the ring.  Habitats and ore processing facilities hang off the ring from cables.  We ballast the ring such that its centre of mass lines up with the centre of gravity of the asteroid.  This means that if the ring is deflected and one part of it is pushed closer to the asteroid, there will be a restoring force that realigns the ring centre of mass to the centre of gravity of the asteroid.  This gives us something we can push against as we work the asteroid surface.  We cannot easily tether the ring to the surface, because rubble piles like this appear to be unable to sustain any shear stresses and behave like liquid when disturbed.  So there is nothing to latch onto, save the weak gravity of the body.

The surface of the asteroid is mined by taking bites using grab shovels, mounted on manipulator arms.  These take bites out of the surface and drop the material into chutes, leading to the ore processing facilities.  The entrance to the chutes are above the stationary orbit point, so there will be a net outward centrifugal force acting on anything released over the chute.  So the material will fall out of the shovel once released and down the chute.  The whole asteroid is surrounded by a flexible, spherical polymer cover.  This prevents and disturbed material from escaping into space and creating a hazard.  The asteroid's own gravity will eventually pull any loose material back to the surface.

This seems to me the most practical way of mining a rubble pile asteroid with only weak gravity.  We can choose the effective gravity in the ore processing facilities and habitations, by changing their distance from the centre of rotation.  Travel between ore processing facilities and habitation will be accomplished by running cables between the different modules and running cable cars along them.

Last edited by Calliban (2024-01-25 06:07:06)


"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."

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#294 2024-01-25 07:08:01

tahanson43206
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Registered: 2018-04-27
Posts: 19,405

Re: Colonizing / terraforming small asteroids

For Calliban re #293

Thank you for you development of the shovel idea!

I'll give your description to CH4 so see what DALL-E makes of it.  I'm not particularly hopeful at this point, except that I'm confident whatever is produced will be interesting.  Whatever is produced is unlikely to have all the elements of your vision.

***
Update a bit later after the shovel/clamp/nippers/jaws post ...

A detail that may be assumed in your work is that the asteroid is rotating?

I presume all asteroids are rotating... the situation with comets is less clear, since they are influenced by Solar energy.

Update: I found the reference to rotation in 293 ...

by changing their distance from the centre of rotation.

If the asteroids you are mining are indeed rotating, then the centrifugal force you've described would be present, so the system components that depend upon gravity would be slung outward. 

(th)

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#295 2024-01-25 08:17:50

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 3,793

Re: Colonizing / terraforming small asteroids

This is roughly what I had in mind for the shovel on the end of the manipulator arm: a Selector Grab.
Resized-2.jpg

A classic open shovel like you see on an excavator on Earth won't work, because there is no gravity to hold the material within the shovel.  The manipulators need to bite off chunks of loose material from the asteroid and contain it until it is released over the chute.

The ring itself needs to be rigid, because the manipulators will be exerting reaction forces on it, which will exert both bending and torsional forces.  The ring would be loaded with various masses that would exert outward forces on the structure due to centrifugal effects.  So that ring would be under constant tension.  But point forces could still subject it to bending and torsion.  I think the best way of making the ring stable against these forces would be to build it as a cross-braced frame made from maraging steel struts.  The rigidity of the ring would be increased by bracing wires between sections of the frame.  Any forces bending the ring out of shape would result in tensile forces in the bracing cables.  These cables can be carbon fibre ropes.  They would stretch between coupling pins on the structure.

tahanson43206 wrote:

If the asteroids you are mining are indeed rotating, then the centrifugal force you've described would be present, so the system components that depend upon gravity would be slung outward. 

(th)

Bennu, for example, rotates once every 4.3 hours.  I havn't done the maths to work out how high above the surface a stationary orbit would be.  But if we were to build a tower, say, that stretched from the surface into space, anything higher than stationary orbit, would experience a net tensile force, because its speed w.r.t the surface, would exceed the local orbital speed.  So there would be a centrifugal force pulling it away from the asteroid.  If the ring is stationary w.r.t the surface, but is above the stationary orbit height, there woukd be a net tensile force acting on the ring.  Anything that we attach to the ring, would hang out into space.  The net force acting on it would be:

F = mg - mw^2 x r

As you hang further from the ring, local gravity diminishes, w stays the same, so effective outward centrifugal force scales with radius.  But if you want 1g with a rotation rate of 4.3 hours, you would need an extremely long cable.  By my estimates it would be 59,500km long.  So I think we will be dealing with milli-g.

Last edited by Calliban (2024-01-25 10:37:24)


"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."

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#296 2024-01-25 10:59:45

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 3,793

Re: Colonizing / terraforming small asteroids

I calculate the stationary orbit radius of Bennu to be 309.65m.  This is only slightly greater than its radius of 245m.  At its present rotation rate, the asteroid is very close to flying apart!

If we make the ring radius 1km, say, then the centrifugal gravity with a 4.3h rotation rate would be 1.65E-4ms-2.  At that acceleration, it would take 18 minutes for a scoop of material to fall down a 100m long chute.  It would take about ten seconds for material just to fall out of the grab when released.  For mining, this might just be enough.  But for ore processing operations and human living arrangements, we need more gravity than that.  And building cables thousands of km long isn't going to be a mass efficient solution.

So I think the human habitat and ore processing facilities would need rotation to produce higher gravity.

Last edited by Calliban (2024-01-25 11:17:28)


"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."

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#297 2024-01-25 12:19:15

tahanson43206
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Posts: 19,405

Re: Colonizing / terraforming small asteroids

For Calliban re Engineering Drawing ... I described your Engineering Drawing to ChatGPT4 as well as I could, and ChatGPT4 prepare a prompt for DALL-E, which produced an image.  As always, DALL-E produces an image that differs from what was requested, but in this case, enough elements were generated as requested that I thought you might be willing to take a look at it.

Here is the prompt:

DALL-E 3 Image Generation Prompt

An engineering drawing laid out on a 40x40 grid. The grid lines are subdued, with a pencil sketch dominating over the grid. The grid fills the entire image. In the center, there's an asteroid outline, 12 squares in diameter, with an irregular circumference. Outside the asteroid, a perfectly formed girder ring, 18 squares in diameter and one square thick. Four articulated robot arms, like the Canadian Arm at the ISS, project in from the ring, equipped with pincers. These arms are positioned to gently pull material from the asteroid. Between the arms, there are chutes, five squares long, leading to collecting buckets outside the chutes, each four squares long and two squares wide. The scene is a top view, looking down at the rotating asteroid from the axis of rotation, in orthographic projection. The title of the scene is 'Top View'.

I'll put the link to the image here. There are several steps needed to make the image available.

XxUl9Pk.png

(th)

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#298 2024-01-25 15:14:00

tahanson43206
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Posts: 19,405

Re: Colonizing / terraforming small asteroids

In this next attempt to feed Calliban's engineering drawing into DALL-E using words, ChatGPT4 and I decided to use a clock face to try to help DALL-E to understand the bilateral symmetry at work, and the needs to show only elements we want to see and not add any new ones.

Here is the prompt:

DALL-E 3 Image Generation Prompt

Create a 2D engineering drawing on engineering paper, with a 40x40 grid. In the center, a 12-square diameter asteroid with an irregular edge. Around it, an 18-square diameter girder ring. The drawing is symmetrical, resembling a clock. At 12, 3, 6, and 9 o'clock, there are solid chutes, 2 blocks wide at the bottom, narrowing to 1 block at the top, leading to catch buckets (2 blocks wide, 4 blocks long). At 1, 4, 7, and 10 o'clock, solid blocks on the ring, each with a robotic arm with two joints, two sections, and jaws, fitting between the ring and the asteroid. At 2, 5, 8, and 11 o'clock, identical solid blocks. The scene is a top view, with bilateral symmetry, in an orthographic projection. The drawing is functional, with no ornamentation, every line representing force flowing through the structure.

The link to the image goes here:
6lRFzWZ.png

(th)

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#299 2024-01-25 16:42:51

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 3,793

Re: Colonizing / terraforming small asteroids

TH, that is impressive and is not a million miles from what I actually drew.  Was the software able to construct this from the word description you gave?

The ring would be a much more slender structure than is shown in the AI reconstruction, probably no more than 6" thick.  It would be a beam with triangulated cross braces and bracing cables stretched between different sections.  It doesn't need to be tremendously strong, because the forces involved are modest, with the greatest point load no more than about 1KN, or 100kg-force.  But it does need to retain its shape under all forseeable loads and under uneven load distribution.  Most of the forces on the ring will act outward, resulting in tension within the structural members, which help improve its stiffness.

I am uncertain at present, how the mined materials will actually be processed.  The shovels will drop material down the chutes that are shown in the diagram.  But even if the ring has a radius of 1km and the ore receipt facility hangs hundreds of metres further outward, centrifugal gravity remains less that 1 milli-g.  This is far too weak to allow conventional ore crushing and smelting operations.  We either need to bag the excavated material and transport it to a rotating factory unit away from the asteroid, or somehow attach that rotating unit to the ring.  That would be the easiest option logistically.  But the rotating unit needs to be designed to avoud exerting gyroscopic forces on the ring.

Last edited by Calliban (2024-01-25 16:46:46)


"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."

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#300 2024-01-25 18:26:45

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 19,405

Re: Colonizing / terraforming small asteroids

For Calliban re #299

Thank you for your encouragement and feedback.

I'd like to emphasize that you can experiment with DALL-E yourself, at no charge.  You are eligible for 15 free images per month.  As an experiment, you can copy and paste the Prompts that ChatGPT4 has prepared, exactly as I have quoted them. What you will experience is different from what I have shown.  DALL-E always starts with a clean slate, and uses some sort of randomizing process, so no two images are ever the same.

On the ** other ** hand, your encouragement is helpful to me, because I am enjoying this new capability of ChatGPT4.  I would like to draw your attention to the differences between the two attempts posted in this topic.  The Prompt for each is given with the image, so you can see the effect of small changes between the versions. 

Before I try the next version, with a thinner ring, please think about how wide you want that ring.  We are working with a 2D drawing, but the ring must have width to hold all that hardware for robot arms and for the chutes.

Regarding your observation about the low gravity for the chutes ... I don't see any reason why the robot arm can't give the load a bit of momentum as it enters the chute... Your computer controls are already managing the robot arm to collect material from the asteroid, so they can be instructed to fling the load (gently) into the chute.

I agree that the processing can (and probably should) be done away from the harvester.

For comparison, a wheat or corn harvester collects material and places it (not so gently) in a transport vehicle. That vehicle carries the load to a location where it can be processed efficiently.  You have the option of delivering all that collected material to a Lunar or LEO facility.

If you are looking for funding (and I trust you are) then the harvesting method you're considering should be of great interest to the US Homeland Security department.  Your method, if implemented well ahead of the time of need, would harvest all the material from threatening Solar system objects, and deliver it in small lots to the processing facility. 

It is even possible that some similar agency exists in the UK, although I have no idea where in the bureaucracy it might reside.

In my next attempt, I will attempt to persuade DALL-E to shrink the ring to half a block (remember, it knows nothing about numbers) and stop extruding unneeded projections all over the place.  DALL-E has a built-in need to decorate everything, as you can see in both images.

You can also see some of DALL-E's creativity in the teleprocessing topic, where I am attempting to create marketing material.

(th)

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