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Calliban

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From: Northern England, UK

Registered: 2019-08-18

Posts: 3,768

Re: Harvesting Asteroids - Economics and Practice of

If the rubble pile is a few hundred metres in diameter, then it could be encased in a single bag, or two hemispheric bags which are connected together around the equator.

But I prefer the idea of having an equatorial rotating ring that has no direct contact with the surface.  Opposable shovels attached to manipulator arms mounted on the ring can take bites out of the surface, without needing to exert very much parallel pressure.  As this progresses, the volume of the asteroid will shrink.  But in a loose rubble pile, which behaves like a liquid, gravity will draw its shape back to a sphere.

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"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."

SpaceNut

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From: New Hampshire

Registered: 2004-07-22

Posts: 29,428

Re: Harvesting Asteroids - Economics and Practice of

I remember the topic but a quick look for it only turned up the "Compressed gas balloon rocket for Mars launch" which was a woven basalt bag for mars.

Void

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Registered: 2011-12-29

Posts: 7,754

Re: Harvesting Asteroids - Economics and Practice of

I will continue to intrude here.

I consider Calliban's notions as good, at least for small objects.  Of course, I am myself interested in objects that may be larger, so the solutions may be different, or perhaps may borrow from other solutions for other objects.

In my case Phobos and Deimos, even if they are moons, to some extent resemble asteroids, quite a lot, but they may be a bit more porous.

Here might be a basis for a useful tool: Query: "corkscrew yard anchor for dogs"
https://www.bing.com/shop?q=corkscrew+y … 540FE1303B
These will need to be used in counter orientations, as at least pairs.  In other words, one designed to spin in one direction clockwise, and the other in counterclockwise.

In this manner they may be able to attach to a rubble pile.  They would have to be presented to the rubble pile perhaps a first action would be to spear the rubble pile using the inertia of the mining vessel.  Then the spin to get an anchorage.

Additional anchors might be used subsequently to provide additional anchoring.

If a rubble asteroid were subjected to a strong magnetic field, this would both attract to both the projector of magnetism, and the ship itself if it had magnetic qualities.  This would also cause the rubble asteroid to clinch together like a fist, as the magnetic particles in the rubble asteroid would be attracted to the field and each other.

If you vibrated the ship, then a fluidization process may be induced, and it may even be that the mining ship might become enveloped in particles with some magnetic portions in them.  I don't know if that is useful or a problem.  It could be useful as to provide some radiation shielding.

Phobos and Deimos being where I think that this type of mining might be pioneered, I don't really know how much magnetic materials are in them.  There are probably some.
Query: "Magnetic iron in rubble asteroids"
https://sservi.nasa.gov/articles/astero … -the-moon/
https://physics.stackexchange.com/quest … etic-field

I think that in any case that Phobos and Deimos were created, there should be at least some magnetic Iron, maybe Nickle?

The mining vessel could have a very powerful magnet, similar to those contemplated for magnetic plasma bubble space drives.

My posts #23 and #24 can be referenced for additional things that might be done.

If it turns out that somehow Phobos and Deimos have some kind of Hydrogen resources, then Eureka!

You may have already established a set of holdfasts on the surface of the objects and might then access these Hydrogen resources.

It seems likely that Deimos at least has some Carbon on its surface.  The interior, we cannot be sure of.

This is simply of interest: https://screenrant.com/mars-moon-phobos … olar-wind/

I will make the point that if materials of Phobos and Deimos contain anything of value to Earth/Moon, that may be possible to carry back in a returning Starship(s).

Done.

Last edited by Void (2022-09-17 11:08:29)

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Mars_B4_Moon

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Registered: 2006-03-23

Posts: 9,776

Re: Harvesting Asteroids - Economics and Practice of

Didymos is Spinning So Quickly That Rocks are Detaching at its Equator and Going Into Orbit

https://www.universetoday.com/160574/di … nto-orbit/

Last fall, when NASA’s DART mission impacted Didymos’ moon Dimorphos in a dramatic (and successful) attempt to change the object’s orbit, DART got a quick look at the Didymos system before the probe was purposefully smashed to pieces.

Alongside demonstrating the capability to prevent future asteroid strikes on Earth, DART also gathered new information about the dynamics of the pair of asteroids. The data collected suggests that Didymos is actively throwing material out into space, and there are likely millions of other small asteroids doing the same across the Solar System, all the time.

Mars_B4_Moon

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Registered: 2006-03-23

Posts: 9,776

Re: Harvesting Asteroids - Economics and Practice of

NASA aims to perform lunar mining trial within 10 years

https://interestingengineering.com/inno … l-10-years

Mars_B4_Moon

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Registered: 2006-03-23

Posts: 9,776

Re: Harvesting Asteroids - Economics and Practice of

Ryugu samples reveal traces of rock from before the Sun existed

https://arstechnica.com/science/2023/08 … n-existed/

SpaceNut

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From: New Hampshire

Registered: 2004-07-22

Posts: 29,428

Re: Harvesting Asteroids - Economics and Practice of

Mention in the topic NASA sends spacecraft to “God of Darkness” asteroid Apophis before it flies by Earth

This celestial body is set to make a historic flyby of Earth in 2029, an event unseen since the advent of recorded history.

The spacecraft, now renamed OSIRIS-APEX (Origins, Spectral Interpretation, Resource Identification, and Security – Apophis Explorer), leverages its successful past to venture into new cosmic territories.

The journey of OSIRIS-REx is nothing short of extraordinary. After a seven-year, 4 billion-mile expedition, it returned to Earth with a sample from asteroid Bennu.

This feat in September marked a pinnacle in space exploration. With its instruments still in excellent condition and a quarter of its fuel remaining, the decision to repurpose the spacecraft for a new mission was a natural progression.

Apophis, an "S-type" asteroid composed of silicate materials and nickel-iron, starkly contrasts with the carbon-rich, "C-type" Bennu.

On April 13, 2029, Apophis will pass within 20,000 miles (32,000 kilometers) of Earth's surface, closer than some satellites and potentially visible to the naked eye in the Eastern Hemisphere.

Asteroids of Apophis' size, roughly 367 yards (340 meters) across, only come this close to Earth approximately once every 7,500 years. This rarity presents an invaluable opportunity for scientific exploration and understanding.

close encounter as that within the geo satellite orbits.

GW Johnson

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From: McGregor, Texas USA

Registered: 2011-12-04

Posts: 5,784

Website

Re: Harvesting Asteroids - Economics and Practice of

Apophis comes by every 7 years or so,  periodically.  2036 is next one,  and it is supposed to be a "close shave",  too.

GW

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GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

tahanson43206

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Registered: 2018-04-27

Posts: 19,221

Re: Harvesting Asteroids - Economics and Practice of

It appears to be time to bring this topic back into view....

In a series of posts launched by Void, and supported by Calliban and others, we seem to have arrived at a resolution of the question:

Can magnetic force be used to harvest material from an asteroid?

The discussion went off into left field for a while, because moving an entire asteroid is an objective of Planetary Defense.

It turns out that a magnetic field cannot reach out to enclose an entire asteroid, based upon two observations:

1) By calculation, it would take a magnet of 65,000Tesla to exert a 1 Tesla force at a distance of 40 meters (Inverse Cube Law) and...
2) The largest magnet build on Earth through 2023 is 54 Tesla, and that one resides in a two story building.

However, since Void reminded me that his original thoughts were about asteroid **mining** and NOT about moving them, and with Calliban's input in another topic about harvesting material from an asteroid, it now appears reasonable to imagine an electromagnet of modest strength collecting a batch of material from the surface of an asteroid, moving the collection to a receptacle, removing the current, and thus releasing the collected material.

A modest sized harvesting robot could chew it's way through a suitable asteroid at a rate that could translate into tons per 24 hour interval.

I note the reminder by GW Johnson and SpaceNut that Apophis is coming by in a few years.

That is plenty of time  to prepare a probe with an electromagnet on board, to characterize the material of the asteroid.

About 2,050,000 results (0.32 seconds)
Size and Distance Apophis is about 1,100 feet (340 meters) in width. It's expected to safely pass close to Earth – within 19,794 miles (31,860 kilometers) from our planet's surface – on April 13, 2029. This will be the closest approach to Earth by an asteroid of this size that scientists have known about in advance.

Apophis - NASA Science

For GW Johnson ... 2036 will be an excellent follow up opportunity.

Update: Void has recently reminded us of ways to sail around the Solar System. Sailing small batches of asteroid material might be an inexpensive way of delivering harvested material from an asteroid to a processing location.  The investors would need to fund the equipment and shipment to the asteroid to be harvested. but the Sun or other Solar Systems agents would handle delivery to a processing location.

Update: To return to Planetary Defense ... a benefit of harvesting material from an asteroid is that there is left material left to threaten the Earth.

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SpaceNut

Administrator

From: New Hampshire

Registered: 2004-07-22

Posts: 29,428

Re: Harvesting Asteroids - Economics and Practice of

Artificial Magnetosphere - Electromagnetic Induction

tahanson43206

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Registered: 2018-04-27

Posts: 19,221

Re: Harvesting Asteroids - Economics and Practice of

Here is a suggestion that came in from our correspondent who lives in Alaska...

Temporary title:

Alaska Taffy Pull

Regarding harvesting a rubble pile asteroid...

RE Magnetism... As understand it, the challenge is to latch onto a "rubble pile asteroid"... do you mean a dense cloud of rubble? Or a lot of rubble sitting on a solid core?

Could a foaming agent be interjected among the rubble that sets in some >0 PSI bond, possibly with a towing ring bonded in? I was just watching this video on AIrcrete, so am thinking about such things. The concept seems generalizable to plenty of other solutions.

https://www.youtube.com/watch?v=9r57zn08fNc

There might be a foaming alternative in crystal growth... inject super-saturated solution and kick it off for self-sustaining state-change. Convert the pile into a crystalline conglomerate.

One of the interesting things about towing in space is that acceleration and deceleration can be very slow, ergo low stress. The ties that bind don't need to be terribly strong to stand up to low-G forces. Might be a good application for autonomous solar sail propulsion, with pick-up at the far end of the flight?

This is the sort of far out idea that might come from Void.  To my knowledge Void has not published this idea, but Void has been here a ** lot ** longer than I have, and I have not read all of his creative posts.

Temperatures in the middle of an asteroid like Apophis are on the cold side, so if a substance is introduced into the asteroid material by a long rod with tiny ports, that substance might freeze or congeal and provide a strong chemical bond with itself, while enclosing all the asteroid material it encounters while expanding into free space between clumps of asteroid material.

After the material has congealed, the rod might be boosted away from the asteroid and carried off to Earth without further work.

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tahanson43206

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Registered: 2018-04-27

Posts: 19,221

Re: Harvesting Asteroids - Economics and Practice of

I asked ChatGPT4 to evaluate the suggestion from our Alaskan correspondent:

Alaska Taffy Pull: Innovative Asteroid Material Collection Technique

The concept of harvesting material from rubble pile asteroids presents unique challenges and opportunities. Drawing inspiration from a construction technique used on Earth, an innovative idea has emerged from Alaska, proposing the use of a water injection system to collect asteroid materials. This system, adapted for space, uses water as a cohesive agent, exploiting the low temperatures in space to freeze water and bind asteroid materials together. Below is a summary of our detailed discussion on this topic.

Water Injection System Design
- The system employs heating coils within an injection pipe to ensure water remains liquid as it travels through the pipe, despite the cold vacuum of space.
- Exit ports along the pipe allow even distribution of water into the asteroid material, increasing the efficiency of material collection.

Water Heating and Management
- An onboard water heating mechanism is crucial for thawing water stored during transit. Precise temperature control is necessary to maintain the water in a liquid state for injection.
- The concept emphasizes energy efficiency and the need for a robust system that can heat and inject water without excessive energy consumption.

Thermal Management for Return Journey
- Reflective materials, such as aluminum foil, are proposed to shield the collected material and ice from solar radiation during the return journey to Earth.
- The use of solar sails for propulsion offers a sustainable method to return the harvested material, with traditional propulsion systems as a backup for precise maneuvering.

Automation and Robotics
- Automation and robotic systems are essential for the operation, given the vast distances and communication delays involved in space missions.
- Robots could assist in the precise deployment and management of the injection system, ensuring the success of the material collection process.

This idea, dubbed the "Alaska Taffy Pull," represents a blend of terrestrial engineering techniques adapted for the unique challenges of space exploration. It offers a potential method for efficiently collecting material from asteroids, leveraging the natural environment of space to facilitate the process. The concept underscores the importance of innovative approaches in advancing our capabilities for asteroid mining and resource utilization beyond Earth.

Feel free to discuss further or share your thoughts on this innovative concept!

Here is a link to the image created by DALL-E to show this concept: https://imgur.com/a/l5WLFHA

And  here is the image:

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tahanson43206

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Registered: 2018-04-27

Posts: 19,221

Re: Harvesting Asteroids - Economics and Practice of

I asked Google to look for any companies that might be set up to pursue Asteroid Mining ...

Right off the top, we have a company with the appropriate name ... founded in 2016 ... It has a web site:

https://www.asteroidminingcorporation.co.uk/contact-9

Contact
3 Pan Peninsula Square,

Canary Wharf, London, UK

E14 9HQ

enquire@asteroidminingcorporation.co.uk

I filled out the contact form and will let you know if I hear anything back.

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tahanson43206

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Registered: 2018-04-27

Posts: 19,221

Re: Harvesting Asteroids - Economics and Practice of

Our Alaskan correspondent added some thoughts about the general subject of asteroid mining ....

I wonder if the interior of the rubble pile needs to be bonded? If the exterior is bonded to some sufficient depth, it makes its own container. So long as transport acceleration and deceleration (if any of that is required at all!) are gradual, stress can be lowered almost indefinitely.

Ditto a surface foam... it could be of much higher viscosity/surface-tension if it needn't be injected but rather deployed. Kind of like Spiderman's webbing.

New thought based on 'tractor beams':

Make a large 'parachute' whose suspension lines converge to the towing point. It should be big enough to contain the rubble pile (some more than half its diameter), with lines running free to the tow(s).

If a direct connect is undesirable (though I can't see why with offset motors), a magnetic focal point could be drawn after the tug via its own magnetic field without physical contact. After acceleration, the field could be de-energized or the tow slipped.

A ring of small, ionizing motors could be used for acceleration, obviating the need for a tug entirely. Solar powered reactive motors? Maybe refueling with matter from the pile?

The advantage of this approach is that it can use tech already considered for solar sails and/or space-based PV.

Some of these are on the ambitious side. The parachute reminds me of Calliban's net concept.

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tahanson43206

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Registered: 2018-04-27

Posts: 19,221

Re: Harvesting Asteroids - Economics and Practice of

For Calliban re Alaskan's inquiry...

When you opened your first topic in this forum, it was about asteroid mining.

That was (and remains) a topic filled with interesting and potentially workable ideas. 

The idea of enclosing the rubble pile object in a net, or in a cocoon of windings of filament would allow an externally provided restraint to accept force to move the object. 

One of the suggestions by Alaskan in Post #39 is to turn the entire exterior of the rubble pile into a solid able to accept (modest) force.

The method would appear (as I read it) to involve spraying the exterior of the object with material that would solidify on the exterior of the rubble pile and bond to itself laterally, and to the surface of the object vertically.

While chemistry is not necessarily a field with which most of us have deep familiarity, I'm hoping that someone in the forum can evaluate the concept of a thin skin around a rubble pile, able to accept a load in tension, to enable an external force to be applied to the enclosed mass.  As force is applied at a point, the momentum of the material inside the enclosure would press on the inside of the enclosure, and that pressure would result in tension on the artificial skin.

I'm wondering if there is any way to put numbers to this conjecture?

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tahanson43206

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Registered: 2018-04-27

Posts: 19,221

Re: Harvesting Asteroids - Economics and Practice of

I asked ChatGPT4 for assistance in thinking about the spray idea for asteroid enclosure:

Summary of Nanotechnology and Asteroid Surface Modification Discussion

• Nanotechnology's Potential: Discussed the revolutionary implications of nanotechnology for asteroid mining, inspired by Feynman's 1959 lecture and Drexler's work in 1986.

• Structural Reinforcement: Explored how nanotechnology could strengthen asteroid structures for planetary defense, emphasizing self-replicating machines and material processing.

• Material Options: Reviewed materials like Aerogels, Polyurea Coatings, Metallic Foams, Self-healing Materials, and Graphene for creating a cohesive shell around asteroids.

• Robotics and Renewable Energy: Investigated developments in solar-powered robotics for material manipulation, hinting at future technologies for asteroid modification.

This conversation explores innovative intersections between nanotechnology, material science, and renewable energy, underscoring the potential for future advancements in space exploration and planetary defense.

Here is a suggestion for further reading:

Recommended Reading

For those interested in the integration of renewable energy and robotics, a valuable resource is provided by Cambridge Core. It offers insights into "Renewable Energy for Robots and Robots for Renewable Energy," discussing the potential for solar-powered robots in various applications, including environmental manipulation and material processing. This review might offer foundational knowledge for imagining the future of asteroid surface modification technologies.

Reference: Renewable Energy for Robots and Robots for Renewable Energy – A Review | Robotica | Cambridge Core

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