Para Terra formation in Orbit, with orbital services.

Calliban · Yesterday 15:19:21

Void, that is interesting. I hadn't seen that graphic before, but it does suggest that there is plenty of space around Ceres to orbit things. A Ceres synchronous orbit is 722km above its surface. That would be a good place for an orbital ring, with space elevators descending to the surface. Ceres gravity is so weak that elevators could be made from steel.

I think the idea of Ceres being tunnelled out like Swiss cheese is feasible eventually, as it is the single largest water body in the inner solar system, Earth included. That water will have value. An orbital ring attached to space elevators, allows that water to be transfered to low thrust spacecraft docked at the ring without wasting propellant. I think ultimately, the ring will have a number of rotating habitats tethered to it. Workers in the Ceres mines would probably live in these habitats and ride the elevator down to the surface each day. The ring also allows propellant free transport between any two habitats.

Last edited by Calliban (Yesterday 15:25:29)

Void · Yesterday 18:51:16

You have stimulated my thinking, you and Isaac Arthurs video. What I was working with may be less attainable and/or stable than I would like. It was an attempt to conserve volatiles. But if the human race eventually develops fusion of isotopes of Hydrogen and perhaps Helium, or if they learn how to beam power extremely long distances, then, and endless flow of volatiles can come inward from the Kuiper belt and even the Oort Cloud.

So, conservation of volatiles does not have to be quite so stringent. This then allows the entertainment of what you have suggested, and perhaps also some embellishments of it.

A practical path is to make something that can be in harmony with its surroundings, and also which is not too vulnerable to terrorists, and idiot savants who may see a path to a parasitic damage of what is built to benefit themselves.

Unfortunately, we will likely always have some people who refuse to walk on their two hind paws.

So, you suggest a "Nulled Ring" where gravitation of Ceres and the centrifugal spin will balance to keep stability.

Looking at Isaac Arthurs work, I notice that Ceres has a 4-degree tilt of axis, and it thought to be variable in that aspect between 2 to 20 degrees tilt.

We might consider building a mini version of what he suggested without artificial gravity induced on the ring, but rather artificial gravity on spin gravity devices attached to the ring. If the ring is properly built than spinners with axis parallel to the axis of Ceres could spin for artificial gravity but mirrors also on the ring could convey light into them if that was desired. In a similar manner, solar power devices could swivel on such an axis as well, but only one spin per rotation of Ceres, synchronous, so that much of the time they gather solar energy.

But we have another game we can play. If we move mass from Ceres out to the ring, then the spin should be reduced. But then you need to expand the circumference of the ring to compensate, but the gravity of Ceres is reduced, and the spin rate of Ceres may be reduced.

Here are some images of Banks Orbit, but what is being discussed here has similarity but are not Banks Orbitals: https://www.bing.com/images/search?q=Ba … C3&first=1

So, one could go as far as they like, even eventually consuming all of Ceres to build a very big one. So, then the gravitational field would be dispersed. But perhaps only a partial conversion would make sense.

If we say that Ceres or another asteroid has a north and south rotational pole, then the ring would have a north and south edge/mooring point. Then the Satellite axis of the individual devices would have bearings one on the north edge of the ring and one on the south edge of the ring. This could be true for synthetic gravity machines, and for solar power devices, whatever type you like of those.

And the ring being like a ladder with rungs connecting the north and south rims, could allow sunshine to these devices much of the time. In the case of the solar devices, they may pivot once for each orbit of Ceres, and in the case of the space habitats, mirrors might convey light into them much of the time, and maybe it can be a bit like variations in sunlight during a partly cloudy day. So, you might fake a day/night balance.

Does that seem to be reasonable?

Done

Last edited by Void (Yesterday 19:13:36)

Void · Today 09:19:30

Well, I feel that that segway stimulated by Calliban helped in the formation of a "Ladder" geostationary hoop. Such would be two rigid rails, a north and a south, that would be joined by rigid ladder rungs. And swiveling devices could be connected by some sort of bearing to the two rails, in places between the rigid ladder rungs. This would be a form of "Nesting" of small elements into a larger superstructure.

Some Finish people have suggested a Megga Satellite around Ceres which would also foster "Nesting": https://www.sciencealert.com/could-huma … anet-ceres
Image Quote:
Quote:

(P. Janhunen, arXiv, 2020)

But these are not "Hill Sphere Shells". I wonder if other asteroids could support such shells.

https://en.wikipedia.org/wiki/List_of_e … _asteroids
Quote:

List of exceptional asteroids

Scrolling down:
The "S", "M", and "X" asteroids may well lack an abundance of volatile substances, but the others may have much.
But even volcanic Vesta is thought to be covered with Carbonaceous dust on much of its surface.

Some questions emerge.

A hill sphere shell may be easier with a smaller asteroid. And also, the notion of perhaps a "Beyond Hill Sphere" shell.

You could even have a shell that has no world inside of it at all.

If such shells were thought of as a digestive system, they might ingest small asteroids and process them.

Unless I am in a mistake(s), then I think that a shell equal or larger than a hill sphere, will not suffer from gravity induced warping and collapse, if the world object contained can be kept centered.

My intention for these shells would not be that they would hold a high air pressure, but rather thin gasses subject to molecular flow.
https://en.wikipedia.org/wiki/Free_molecular_flow
Quote:

Free molecular flow
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From Wikipedia, the free encyclopedia
Free molecular flow describes the fluid dynamics of gas where the mean free path of the molecules is larger than the size of the chamber or of the object under test. For tubes/objects of the size of several cm, this means pressures well below 10−3 mbar. This is also called the regime of high vacuum, or even ultra-high vacuum. This is opposed to viscous flow encountered at higher pressures.[1] The presence of free molecular flow can be calculated, at least in estimation, with the Knudsen number (Kn). If Kn > 10, the system is in free molecular flow,[2] also known as Knudsen flow.[3]

So, a bit like an exosphere, but perhaps a thick one.

In this condition a hole in the shell will let some gas escape, but not from collective molecular motion but just because that hole was in the path the molecule was traveling in a straight line.

There is a question as to if the pressures from solar emissions will push the shell outward. Photons, and the Solar Wind. I don't know the answers yet. I suspect that there is an aligning force from the major planets that may tend to keep objects in place, if their gravity dimple is large enough, relative to the other forces exerted on the object, such as from the sun. So, there may be value in anchoring on a large enough of the tiny worlds, if that is true.

The purposes of such a shell are to contain things, to provide a solar exposed surface for solar power devices, and a sphere where nested objects can be associated into.

And I am not sure of all of this. A shell on its own may not have a large enough gravity dimple to be "Noticed" by the larger objects of the solar system, so it may be free to obey the solar wind and the photon pressure on it. So, an advantage may exist for holding a significant mass inside of it, so that perhaps the shell and the mass it encloses, may stay in an appointed orbit.

But as I have said I am not sure. This is where perhaps we learn more.

If a shell is solar locked, with one side facing the sun and the other facing the outwards from the sun, then considerable cold may exist on the outward portions of the shell. This may be used to condense molecules of gas that are in Molecular flow inside of the shell. Adsorption could be used.

https://en.wikipedia.org/wiki/Adsorption

OK, perhaps sorption then: https://en.wikipedia.org/wiki/Sorption
Quote:

Sorption is a physical and chemical process by which one substance becomes attached to another. Specific cases of sorption are treated in the following article

So, then an object in the shell could be heated as desired to gas off, but not at a rate faster than your sorption methods can handle.

And this leaves the problem, how do you keep the treated object centered in the shell? Magnetics might work. Maybe some complex mechanical method, The object may likely spin and we do not want to spin this shell.

Possibly air pressure might help, if you could shoot jets of compressed air from the inside of the shell, or inversely have a second interior shell that encases the object and spins with it, and then that shell emits jets of gas into the region between shells.

I would like to see if magnetics could do it.

In process, I guess.

Done

Keep in mind that one of the values of the shell is the amount of sunlight it can intercept.

Done

Last edited by Void (Today 10:24:51)

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#51 Yesterday 15:19:21

Re: Para Terra formation in Orbit, with orbital services.

#52 Yesterday 18:51:16

Re: Para Terra formation in Orbit, with orbital services.

#53 Today 09:19:30

Re: Para Terra formation in Orbit, with orbital services.

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