Harvesting Asteroids - Economics and Practice of

tahanson43206 · 2021-11-08 11:20:22

for SpaceNut .... there are already a great number of topics with numerous posts about asteroids

Some came close to covering the subject matter I have in mind for this new topic, so I'll begin this topic with a list of all related topics:

Index» Search» Topics with posts containing 'asteroid*'
Pages:1
Search results
Topic Forum Replies Last post
Colonizing / terraforming small asteroids by Calliban [ 1 2 3 … 10 ]
Terraformation 241 2021-10-06 12:44:41 by Mars_B4_Moon
Asteroid/off-Earth mining by louis
Science, Technology, and Astronomy 14 2021-10-03 12:18:41 by tahanson43206
Asteroids Size Comparison by louis
Science, Technology, and Astronomy 0 2020-03-17 19:56:36 by louis
Launch Loop for Moon or Asteroids by tahanson43206
Interplanetary transportation 18 2020-03-07 10:24:42 by SpaceNut
New weekly educational series focuses on comets and asteroids by ChaseC
Science, Technology, and Astronomy 0 2020-01-13 11:50:35 by ChaseC
Manufacturing Solar Power Satellites within Near Earth Asteroids by Calliban
Human missions 10 2019-11-12 20:35:19 by SpaceNut
Aldrin Cyclers and Asteroid Belt Cyclers by tahanson43206 [ 1 2 ]
Interplanetary transportation 34 2019-09-10 17:16:38 by SpaceNut
Rubble Piles, Asteroids, Moons, the inhabitation of. by Void
Life support systems 22 2019-03-27 20:04:00 by SpaceNut
Giant Metallic Asteroid Psyche may have water by Tom Kalbfus
Human missions 10 2018-04-20 20:29:10 by SpaceNut
Asteroids & Shells by Antius
Terraformation 17 2017-10-30 06:01:51 by Antius
Terraformation through Asteroids & comets by Shashi Ranjan
Terraformation 7 2017-05-14 05:48:21 by karov
What is the source of metal asteroids/meteors? by RobertDyck
Science, Technology, and Astronomy 5 2017-04-03 17:31:15 by SpaceNut
NASA's Asteroid redirect/retrieval mission; should it be cancelled? by Oldfart1939 [ 1 2 ]
Human missions 48 2017-02-03 18:04:29 by SpaceNut
"Terraforming" the Asteroid Belt by Tom Kalbfus [ 1 2 ]
Terraformation 34 2014-11-11 09:17:47 by Void
Scavenging Asteroids to Terraform Mars by sanman
Terraformation 5 2014-09-25 02:07:07 by knightdepaix
Asteroid mining / Mass for propulsion & structures. by Void
Interplanetary transportation 6 2013-04-09 03:19:13 by Void
Terraformation by Asteroid Impactor by sanman
Terraformation 14 2013-03-05 18:52:18 by louis
Pages:1

The intention for this new topic is to provide a convenient collection point for knowledge about, and best practices for, harvesting asteroid and comet materials, and securing them for economic benefits to the ventures that carry them out, and to human society as a whole.

(th)

tahanson43206 · 2021-11-08 11:25:57

To open this new topic with a concrete example, I would like to offer a vision of an alternative to the (somewhat desperate) vision of trying to deflect asteroids or comets that might be on a collision course with Earth.

As a perfectly viable alternative, I am proposing to follow the tried and true Army Ant procedure.

A large problem is divided into small work pieces that can be managed by individual workers.

In this case, the "individual workers" would be "Unmanned probes" that would arrive at the object, collect one metric ton of material, and head "home" with that payload, using solar wind as the primary driver and occasional mass ejection when necessary. The small worker devices need not be in a hurry, and they may take years or even many years to deliver their cargo to the desired destination.

An "army" of such workers would make short work of any object that is a threat to Earth, and collect all that might be valuable as a reward.

(th)

louis · 2021-11-08 18:15:58

https://en.wikipedia.org/wiki/4179_Toutatis

Toutatis at only 2.5 kms average diameter masses at 5.5 trillion kgs, which I make 5.5 billion tonnes. So for that asteroid you'd have to have 5.5 billion robot sorties. Not practical really. Even for quite small asteroids you might be talking about a million or so visits. Still not practical I would say! Probably an atom bomb exploding and directing the material away from Earth is the only practical option.
This is something the UN could usefully plan for but I've never heard any proposal from it.

tahanson43206 wrote:

To open this new topic with a concrete example, I would like to offer a vision of an alternative to the (somewhat desperate) vision of trying to deflect asteroids or comets that might be on a collision course with Earth.
As a perfectly viable alternative, I am proposing to follow the tried and true Army Ant procedure.
A large problem is divided into small work pieces that can be managed by individual workers.
In this case, the "individual workers" would be "Unmanned probes" that would arrive at the object, collect one metric ton of material, and head "home" with that payload, using solar wind as the primary driver and occasional mass ejection when necessary. The small worker devices need not be in a hurry, and they may take years or even many years to deliver their cargo to the desired destination.
An "army" of such workers would make short work of any object that is a threat to Earth, and collect all that might be valuable as a reward.
(th)

SpaceNut · 2021-11-08 19:25:27

Eat the material from it and use nuclear ion power and engines which can use the fuel to push it away from our orbit towards a place that could use the extra mass.
Then once its there either smash it into the place or put it into orbit so that short distances can be used.

tahanson43206 · 2021-11-08 20:01:02

For Louis re #3 ... thank you for picking up on the idea, and showing the relative numbers of robot devices that would be needed.

The human population has grown from a very small number to nearly 8 billion people.

The number you cited is less than the total number of people we already have on Earth.

As the population of Earth becomes more wealthy, assuming we can avoid major setbacks, we should be able to acquire wealth from the surrounding Solar System, and distribute it back to the population (if we can figure out how to do that equitably).

(th)

tahanson43206 · 2022-03-23 11:56:31

For SpaceNut ... there are numerous topics that contain the word "asteroid", but none seemed a perfect fit for this item:

https://www.yahoo.com/entertainment/nas … 42242.html

NASA predicted an asteroid impact — and they got it right
Elizabeth Rayne
Tue, March 22, 2022, 2:11 PM
Earth has been punched in the face by asteroids before. It has seen everything from undetectable rock shards that burn up in the atmosphere to the monster-oid that triggered a mass extinction 66 million years ago.
NASA wasn’t there to do anything about the dinosaurs getting vaporized. However, the space agency was able to predict an impact with the type of accuracy that could prevent any sort of Deep Impact situations in the future (that was a comet in the movie, but you get the idea). Detect the offender and launch a spacecraft like DART to deflect it. Maybe this space rock was too small to be hazardous, but it could mean big things for predicting, well, bigger things.
Asteroid 2022 EB5 was first seen heading for us by astronomer Krisztián Sárneczky at the Piszkéstető Observatory in Hungary. After the observations were reported to the Minor Planet Center, NASA’s Scout impact hazard assessment system figured out the thing was going to come plummeting through Earth’s atmosphere. It zapped alerts to the NASA Planetary Defense Coordination Office and Center for Near Earth Object Studies (CNEOS).
Scout, which was developed by NASA JPL navigation engineer Davide Farnocchia, also flagged the object on its own webpage. Other observatories soon became aware it was on its way.
“Given a short arc of optical observations of a newly discovered object, Scout computes possible trajectories that are compatible with the observational data,” Farnocchia told SYFY WIRE. “It then projects them into the future to assess how close the asteroid may come close to, or even reach, Earth in the near future.”
The program doesn’t actually collect its own data. It relies on observations from anyone who can identify a flying object coming at Earth, from professionals to hardcore space geeks checking a sky watching app. What is pretty amazing is that Scout only had 14 observations, from only one observatory, all taken in less than an hour, to work with — at least until more observatories got in on the asteroid and increased the accuracy of those observations. Then everyone involved could get a better idea of its trajectory and where it was going to crash.
So where was it headed? Just two hours after 2022 EB5 was first observed, Scout predicted it would zoom through the atmosphere southwest of the Norwegian island Jan Meyen, which is about 300 miles off Greenland’s east coast, at exactly 5:25 p.m. Optical observations measured its position and brightness. Infrasound detectors were able to make out its approximate size to be some 6 1/2 feet. The only reason it was detected at the last minute was because it was such a faint micro-asteroid, at least compared to behemoths like dinosaur killer Chicxulub.
“From its brightness and orbit, we can derive a range of possible sizes depending on how much sunlight is reflected by the asteroid,” said Farnocchia. "Infrasound detectors measure impact energy, which is a function of the asteroid's mass and the impact velocity.”
You might not realize it, but smaller space rocks fall to Earth all the time. Random ones seem to fall out of nowhere about once a year. Scouring the sky for huge asteroids is also going to turn up smaller ones. These are only close enough, meaning bright enough, to be detected hours before they hit. Larger objects would be brighter and therefore detectable from further away. An asteroid’s trajectory gives away its impact velocity, which makes it possible to figure out the mass and size. Something threatening Earth in the future may be caught in time to be deflected.
Anything on a collision course with Earth will be spotted with even more accuracy in the near future. When the Vera Rubin Observatory in Chile starts watching what is going on above us in a few years, it will be able to see objects fainter than any current technology can squint at. NASA’s upcoming NEO Surveyor mission will also be on the lookout. This space telescope will have infrared vision that was also developed for discovering more near-Earth asteroids.
For now, Farnocchia is optimistic after what Scout was able to pull off.
“We confirmed that we can accurately model the trajectory and predict the impact location for an incoming asteroid,” he said. “The fact that the asteroid community could detect and recognize the upcoming impact for such a small object gives us a positive outlook.”

(th)

Mars_B4_Moon · 2022-03-25 10:00:55

Ryugu be a remnant of an extinct comet

https://www.spacedaily.com/reports/Ryug … t_999.html

Asteroids hold many clues about the formation and evolution of planets and their satellites. Understanding their history can, therefore, reveal much about our solar system. While observations made from a distance using electromagnetic waves and telescopes are useful, analyzing samples retrieved from asteroids can yield much more detail about their characteristics and how they may have formed. An endeavor in this direction was the Hayabusa mission, which, in 2010, returned to Earth after 7 years with samples from the asteroid Itokawa.

The successor to this mission, called Hayabusa2, was completed near the end of 2020, bringing back material from Asteroid 162173 "Ryugu," along with a collection of images and data gathered remotely from close proximity. While the material samples are still being analyzed, the information obtained remotely has revealed three important features about Ryugu. Firstly, Ryugu is a rubble-pile asteroid composed of small pieces of rock and solid material clumped together by gravity rather than a single, monolithic boulder. Secondly, Ryugu is shaped like a spinning top, likely caused by deformation induced by quick rotation. Third, Ryugu has a remarkably high organic matter content.

Of these, the third feature raises a question regarding the origin of this asteroid. The current scientific consensus is that Ryugu originated from the debris left by the collision of two larger asteroids. However, this cannot be true if the asteroid is high in organic content (which will confirmed once the analyses of the returned samples are complete). What could, then, be the true origin of Ryugu?

GW Johnson · 2022-03-26 10:55:38

I've said this before, but I don't think anybody else yet believes this. It is a wrong-headed idea to distinguish between comets on the one hand and asteroids on the other. There is merely a spectrum of small bodies that are poorly consolidated, if at all, which are partly chunks of solid minerals and partly ices of various volatiles. The ice-vs-rock budget they start out with depends upon how far out they formed. Colder further out there is more ice to agglomerate with the mineral pieces.

They DO NOT retain the ice budgets over geologic time. Those materials have a non-zero vapor pressure, even at cryogenic temperatures. It is quite low, yes, but it is NOT zero. Icy deposits exposed to the vacuum of space are NOT stable over geologic time. Period. But, the loss rates depend upon both temperature exposures and size. Here's why size matters:

These bodies are quite porous. There are torturous paths between the particles leading in all directions from the center to the surface. Vapors can flow against considerable friction through these torturous paths, with an accompanying pressure drop due to the flow friction. That pressure drop has to be the vapor pressure of the ice in the center, and zero (vacuum of space) at the surface. That drop and the combined areas of the zillions of flow passages sets the massflow getting released (as vapor) at the surface.

The bigger the body, the longer those paths, and the higher the friction effect. Bigger ones located reasonably far from the sun (about the main belt on out) where there is little warmth being applied by sunlight, will take geologic time to vent all their ices as vapor. Smaller ones may well have dessicated by now, leaving dry, loose rubble piles. We have seen a lot of such dry rubble piles out there, and yet also some larger ones that still show faint comet tails among the "asteroids".

Given the mechanism that I described, why should those observations be surprising in any way, shape, or form?

Closer in to the sun, there's more warmth to drive up internal temperatures, in turn driving up vapor pressure of the ice content. That raises the flow rate of vented vapor, and shortens the time to dry out the body to a loose dry rubble pile. After 4.5 billion years, one would expect NO ice content among smaller bodies that stay closer to the sun. One might expect to find a lot more ice content among even the smaller bodies, way far out in the cold outer solar system. And in point of fact, that is EXACTLY the trend we have observed.

So, if you are looking for volatiles, you must go out to at least the main asteroid belt, and likely out to, or past Jupiter, to find significant icy content inside smaller bodies. It would take a larger body to still have significant ice content, in the inner solar system, and there simply aren't any.

That being said, there are the solids. These look like a mix of charcoal, and various kinds of rock dust and sand, with some stones mixed in. Yeah, there's oxygen, hydrogen, and carbon bound up in that rock dust/sand/stones. But it's NOT free for the taking, any more than it is here on Earth from the rocks around us.

The minerals that we mine here on Earth to make engineering materials are mostly associated with oceans, or to some extent volcanoes. The small bodies in space have neither. The great bulk of the minerals around us are pretty useless to us, except as landfill or road base.

So, somebody tell me how to turn rock dust and sand, plus a bit of charcoal, into useful engineering materials? Without expending vast amounts of power? It takes a whale of a lot of heat to process iron ore, or aluminum ore, or any other ore. You have to melt the stuff, and cook it. That's 1500+ C stuff. And the specific heat of these materials is large.

GW

Last edited by GW Johnson (2022-03-26 11:01:53)

Mars_B4_Moon · 2022-05-09 07:56:30

Is Goldman Sach's lying once again, seems the Queen and Saudi are already Trillionaires

China to conduct asteroid deflection test around 2025
https://spacenews.com/china-to-conduct- … ound-2025/

NASA Shows Off Psyche Spacecraft to Media
https://www.jpl.nasa.gov/news/nasa-show … t-to-media

US Space Force Releases Decades of Bolide Data to NASA for Planetary Defense Studies
https://www.jpl.nasa.gov/news/us-space- … se-studies

Can Electric Fields Lift Particles Off an Asteroid’s Surface?
https://aasnova.org/2022/04/22/lofty-go … s-surface/

Asteroid Mining Corporation's Walking Robots Take First Steps Towards Resource Independence
https://finance.yahoo.com/news/asteroid … 00154.html

Future of Earth's Defense is Ground-Based Planetary Radar
https://public.nrao.edu/news/planetary- … eed-radar/

Asteroid mining will produce the world’s first trillionaire, according to Goldman Sachs
https://bgr.com/science/asteroid-mining … hs-report/

Planetary science decadal survey prioritizes UArizona-led planetary defense mission
https://news.arizona.edu/story/planetar … se-mission

NASA to repurpose OSIRIS-REx for second asteroid encounter
https://spacenews.com/nasa-to-repurpose … encounter/

A NASA mission to return samples from one near Earth asteroid will get an extended mission to visit a second asteroid under a plan approved by the agency April 25.
NASA announced that the Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer, or OSIRIS-REx, spacecraft, on its way back to Earth after collecting samples from the asteroid Bennu, will travel to the asteroid Apophis after returning samples in September 2023.
The main spacecraft, after ejecting the sample return container that will land in the Utah desert, will fly by Earth on a trajectory that will bring it to Apophis in 2029, shortly after that asteroid passes just 32,000 kilometers from the Earth. The spacecraft will spend 18 months in the vicinity of Apophis, studying the 350-meter asteroid and coming close enough to use its thrusters to brush away surface rocks and expose subsurface materials.

Last edited by Mars_B4_Moon (2022-05-09 07:57:36)

Mars_B4_Moon · 2022-05-26 17:48:28

AstroForge raises $13 million to mine platinum from asteroids

https://qz.com/emails/space-business/21 … asteroids/

First human landing on an asteroid could take place by 2073, scientists say.

https://astronomy.com/news/2022/05/firs … id-by-2073

Last edited by Mars_B4_Moon (2022-05-26 17:54:32)

Mars_B4_Moon · 2022-05-31 12:48:10

Asteroid-mining startup books its first mission, launching with SpaceX

https://www.tweaktown.com/news/86499/as … index.html

Mars_B4_Moon · 2022-06-02 06:35:39

Mining on NEOs, comets, Asteroids might soon be a thing?

Startups raise millions for lunar rovers and asteroid mining
https://spacenews.com/startups-raise-mi … id-mining/

Mars_B4_Moon · 2022-08-25 06:52:12

In a world-first, NASA will slam a spacecraft into an asteroid to test planetary defense

https://interestingengineering.com/scie … o-asteroid

DART Spacecraft Will Collide With Asteroid

Lunar Mining, Moon Land Claims Dig Into International Law Gray Area
https://www.manufacturing.net/laws-regu … -gray-area

Astronauts might be able to use asteroid soil to grow crops
https://www.sciencenews.org/article/ast … food-space

Last edited by Mars_B4_Moon (2022-08-25 06:54:52)

tahanson43206 · 2022-08-25 07:24:25

For Mars_B4_Moon re #13 and DART

DART inspired at least one science fiction writer ... the current issue of Analog contains a story constructed around the interesting proposition that there is an alien monitoring station on the small moonlet at the asteroid of interest.

The story's building of suspense phase uses the proposition that the aiming mechanism of the impactor guidance system is attracted to the perfectly spherical shape of the alien dome, so that it lands precisely at the center of the dome and destroys the multiple story structure.

For the 100,000 readers of Analog who happen to read this story, the arrival of DART in September of 2022 will have special interest.

Thank you for refreshing our awareness of DART.

(th)

Mars_B4_Moon · 2022-09-14 11:02:15

DART Sets Sights on Asteroid Target
https://spaceref.com/science-and-explor … id-target/

Why Self-propagating Robots Are the Future of Space
https://www.defenseone.com/sponsors/202 … ce/374786/

Here's How Mars Could Play A Key Role In Asteroid Mining

https://www.slashgear.com/965621/heres- … id-mining/

The concept of mining asteroids for their mineral riches has long been a staple of science fiction, but the scientific expectations are realistic and private firms are already making moves to grab a piece of the pie. Even NASA is actively soliciting concepts and working models that could one day turn the dream into reality.
Take for example Mini Bee, a proposal that entered the Phase III studies within the NASA Innovative Advanced Concepts (NIAC) program back in 2019. The plan is to harvest water vapor and volatile chemical compounds from an asteroid using a technique called optical mining. The goal is to excavate the asteroid and collect target materials into a containment unit attached to the spacecraft.
However, sending a spacecraft to near-Earth asteroids is not the most economical idea, given their smaller size and mineral density. On a similar note, sending retrieval units to larger asteroids that are further away and maintaining a chain of transport between them and Earth won't exactly be cheap either.
This is where Mars and satellites come into the picture, providing closer access to the asteroid belt between Mars and Jupiter. Asteroids in our nearby asteroid belt are large and abundant, which means mining them would be easier and economically reasonable if a base was established on Mars or its natural satellites Phobos and Deimos. It might sound fantastical, but a few experts ran the numbers and propose that a Mars-based asteroid mining base would be the optimal strategy for asteroid mining.

GW Johnson · 2022-09-14 11:44:37

I have yet to see how one can secure a lander to an asteroid with almost zero surface gravity, and have any friction or any other reaction force to oppose the action of a hammer or a drill.

If it's a small enough object you can put it in a crusher press (a really big, heavy piece of machinery, not even counting its power supply), provided you have the envelope around it to catch all the rubble you create, which will be flying out of the crusher press at rather significant speeds.

If it's too big an object for that, then just how the hell are you going to bust it open and get to your ores that are supposedly there?

I have never seen those answers, not from anyone. Until I do, I will continue my harsh skepticism of the entire notion of asteroid mining.

GW

Calliban · 2022-09-14 13:41:23

GW Johnson wrote:

I have yet to see how one can secure a lander to an asteroid with almost zero surface gravity, and have any friction or any other reaction force to oppose the action of a hammer or a drill.
If it's a small enough object you can put it in a crusher press (a really big, heavy piece of machinery, not even counting its power supply), provided you have the envelope around it to catch all the rubble you create, which will be flying out of the crusher press at rather significant speeds.
If it's too big an object for that, then just how the hell are you going to bust it open and get to your ores that are supposedly there?
I have never seen those answers, not from anyone. Until I do, I will continue my harsh skepticism of the entire notion of asteroid mining.
GW

Most asteroids appear to be rubble piles and mostly quite small. For a body a few hundred metres in diameter, we could put a rigid metal ring frame around the asteroid and mount manipulator arms fitted with opposable shovels to the ring.
The shovels then bite off loose regolith. The rigidity of the ring will be maintained by bracing wires between different sections of the frame.

The centre of mass of the ring will line up with the centre of mass of the asteroid. As the manipulators exert force on the surface of the asteroid, they will push the ring out of alignment, such that it's centre of gravity is pushed away from the asteroid centre of gravity. There will be a net gravitational force restoring equilibrium. By slowly rotating the ring, such that its rate of rotation exceeds the local orbital velocity, centrifugal force will create weak gravity along the ring surface and any body that hangs outward from the ring away from the asteroid. The manipulators can release material into open chutes that lead to ore processing facilities that are hung from the ring frame by steel cables. The processing facilities will have gravity which is a function of ring rotation rate and their distance from the centre of mass. The more gravity needed, the longer the cables and chutes between the ring and the facility hanging off of it.

For this arrangement to work, mass must be reasonbly well distributed along the circumference of the ring. If centre of gravity is too skewed, then it will drag the ring onto the surface of the asteroid. This can be assured the hanging ballast from sections of the ring frame and placing equipment such that centre of mass is never too far from the geometric centre.

Last edited by Calliban (2022-09-14 13:55:31)

tahanson43206 · 2022-09-14 14:03:53

For Calliban and GW Johnson ... re discussion of technique for asteroid mining ...

SearchTerm:asteroid mining suggestion by Calliban following question by GW Johnson
SearchTerm:mining asteroid
SearchTerm:rubble pile asteroid mining

I would note that Calliban has already extensively discussed and worked out a system to wrap an asteroid with thin cable/thread, much as a caterpillar wraps a cocoon.

This discussion is available for anyone to read, in the NewMars archive.

By now I've forgotten the key search words saved with the discussion, but I am confident they were created.

(th)

Calliban · 2022-09-14 14:31:25

Those initial discussions seem a bit naive now. Why go to the trouble of cocooning an asteroid in glass fibre, just to burrow into it with mines? Building stuff in orbit around the body would appear to be a more promising approach.

Building on the previous post. The ring could actually be a tensile cable. The cable would be both stationary above the surface and in tension, simply by having a radius that is greater than the geostationary orbital radius of the asteroid. The loop of cable would literally hang in the sky above the equator of the asteroid like a planetary ring. As the ring is rotating at the same angular velocity as the asteroid, it would be stationary w.r.t the surface and centrifugal force would keep it taut. Manipulator arms would be mounted on ore processing factories that hang off of the cable, out towards space. These would grab rocks and regolith from the asteroid surface, dropping the material into chutes. Material would fall down the chutes into the ore processing facilities due to centrifugal force.

As the mass hanging from the ring grows, it will eventually be neccesary to reinforce it with additional cables. Eventually, the industrial infrastructure and living spaces around the asteroid will resemble a disc. Human habitats will be spherical pressure vessels, covered shells of silicate waste material some 2m thick. The steel pressure vessels will rotate within the shells, which will be suspended from the cable rings, rather like Christmas tree baubles.

Last edited by Calliban (2022-09-14 14:49:33)

GW Johnson · 2022-09-15 09:15:10

For the dry rubble piles, my "sand bag in free-fall without the bag" argument still applies. Do the thought experiment for yourself. There is no pushing against such a thing with any kind of line, net, or solid structure of any kind. It just flies apart in response.

GW

tahanson43206 · 2022-09-15 09:20:46

For GW Johnson re #20

Calliban "solved" the problem you've described long ago (in NewMars forum terms)...

Now he has (quite recently) disowned his own creative thinking by pronouncing it "naive" ....

This may be a result of subsequent over-thinking, which is an occupational hazard for a working engineer.

Wrapping a rubble pile in kevlar (or similar) thread is perfectly do-able, and the resulting cocoon an be pushed anywhere you need it to go.

What we seem to lack around here is whatever it takes to move from sensible idea to Real Universe achievement, without backsliding when difficulty appears, as it ** always ** is going to do.

(th)

tahanson43206 · 2022-09-15 09:26:32

For GW Johnson ...

You will have five opportunities to introduce Calliban's cocoon asteroid wrapping idea as a bonus for your audiences at the upcoming conference.

It would be perfectly reasonable for you to publicly scorn the idea, and even to affirm Calliban's judgement it is "naive"

What is needed is to get the idea out into the thought universe of people who are motivated enough to attend (or to tune into) the convention.

All it takes is ** ONE ** individual with the right connections to make the idea happen in the Real Universe.

Your opportunity (if you agree to take it on) is to cast the idea out into the Mars Society audience in hopes of catching the waiting mind.

For Terraformer (a ** real ** writer) .... Calliban's Cocoon might be the basis of a thrilling (or at least thought provoking) story that could be published in Analog. It could not be published anywhere else, unless it contained a lot of fantasy, which (it seems to me) would not reach the right minds.

(th)

Void · 2022-09-15 12:04:15

On my way from up north, I pondered some of the posts. I have my own notions, in part in response to those posts. I see this as an evolving possibility(s), and it would be quite wrong, in my opinion to lock down to an absolute opinion(s) about this. So, I will offer my thoughts for what they are worth, just an alternate and perhaps compatible set.

Spin effects can be of worth, air jets, and thrusters also but those then consume resources.

I feel that electrostatic, magnetic, and other forces can be explored.

I would like to scale the initial operation down, as per input resources required in order to get a useful output.

Rubble piles being the probable targets. Phobos and Deimos and some NEO's probably qualify as potential targets. It does not matter where the mass for these came from. In each case, it is likely to have come from various sources.

Harpoons might be used as electrodes and to hold things. The harpoons, may have retractable tines, probably motorized or solenoid in nature. Still a motor of sorts.

I have the notion of a fish. Modern fish can have mobile jaws. I think the most primitive fish simply somehow had non-mobile open mouths.

So, then you may have a chamber with an open mouth and attached to it methods to move the device around relative to the object to be mined.

Harpoons with lines may help to hold the mouth to the asteroid surface.

A centrifuge or centrifuges can be in the volume of the "Fish". We then need mechanisms to hold attract any stirred-up materials into the centrifuge. I think that both electrostatic and magnetic methods can be included. And also, vibration to fluidize the materials in the centrifuge.

The harpoons while being to some degree holdfasts, can also be electrodes allowing electrons to either be pushed into the target object or withdrawn from the target object. The Centrifuges may then be given an opposite electric charge. Magnetism of large magnitude can then also be employed at one end of the centrifuge(s), and also vibration added to the centrifuge to produce fluidization of materials collected. This in part may create a partial segregation of magnetic from non-magnetic materials.

Both the electrostatic and magnetic forces in the "Fish" are likely to further attract the "Fish" to the object to be mined.

A stirring method may be applied like puffs of air. Or, like a lamprey fish, mechanical rasps could be applied. If spinning perhaps there are two which counter spin with each other. Also needed might be a linear in and out motion.

Once the "Fish Belly" was filled, you would bring up the centrifugal force enough that you could turn off the electrostatic force and the magnetic force. Withdraw the harpoons if possible, and then perhaps even reverse the polarity of electrostatic force and magnetic force to push the "Fish" off.

It is not impossible that this might become a bit of a tunneling machine, if you used explosive charges to push it in, and also employed liners with horizontal anchors pushed into the regolith.

It may be that these objects may have large chunks in their interiors, so that might give access, but they also might block further tunneling. But you might build a radiation shelter as well by working in this direction. Eventually perhaps even a void(s) large enough to put a spin gravity device into.

Not perfected, but we should not be seeking perfection yet, just trying options.

If it is Phobos and Deimos perhaps on-site processing could occur with common metals such as Iron remaining in orbit of Mars or even perhaps brought down to Mars. If there are any valuable materials, they might even travel back to the Earth/Moon on returning spacecraft.

Done.

Last edited by Void (2022-09-15 12:30:55)

Void · 2022-09-15 12:36:00

And pertaining to my just previous post, of course withdrawing the "Fish" there may be a door that could be closed over the "Mouth", and even the possibility of pressurizing the interior to make working with the materials easier in some ways, but of course working in vacuum might also be preferable in some ways.

Done.

GW Johnson · 2022-09-15 14:29:20

The notion of just wrapping lines about a dry rubble-pile object seems out-of-touch with reality to me, as the line will just slice through the object, the same way it would through a "sand bag without a bag" in free fall (in vacuum). Again, do the thought experiment!

You can contain such an object within a solid container, or within a "soft" container, if it resembles a fabric bag. A net will not do! The average size of the porosity of the fabric will let through particles smaller in diameter. Any sort of mesh will let through any particles of the mesh dimension or smaller. Like a filter, just a different application.

There are pebbles, cobbles, and boulders out there; we have already seen them. There is also "regolith", meaning particles like sand or dust. All these are part of the dry rubble piles, which also fly apart if they spin too fast (centrifugal forces exceed mutual gravity). We have seen that, too.

There are bodies out there with significant "ice" content, meaning frozen volatiles. These are bound together by very significant cohesion forces (many orders of magnitude stronger than gravity), because the ice sticks to the particles, the same way that cement sticks to the aggregate in concrete. These are all large bodies (many dozens or more miles in dimension), or else located in the cold outer solar system (out past Jupiter), or both. We've already seen this.

Such cohesively-bound bodies you could indeed lasso with a line, or drive a stake into.

But not the dry rubble piles. Those lie outside your Earthly experience.

Simple as that.

GW

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