Underground Habitats of Ceres

Tom Kalbfus · 2015-01-22 00:17:04

th?&id=HS.277989655638&w=300&h=300&c=0&pid=1.9&rs=0&p=0
•MEAN RADIUS: 487.3 km
•MASS: 0.013 (Earth=1)
•DENSITY: 2.077 (g/cm^3)
•GRAVITY: 0.028 (Earth=1)
•ORBIT PERIOD: 1679.819 (Earth days)
•ROTATION PERIOD: 0.3781 (Earth days)
•SEMIMAJOR AXIS OF ORBIT: 2.765 au
•ECCENTRICITY OF ORBIT: 0.07976017

Basically the idea is to dig 500 meter wide cylindrical tunnels into the Dwarf Planet Ceres and bury Kalpana One Space Colonies within them, in which they rotate twice a minute for 1 full gravity on their inner surfaces, The tunnels in which these habitats are embedded are verticle. Unlike the diagram above, these cylinders aren't limited to a length of 550 meters as Ceres itself provides the stability Each cylinder needs. The inhabited tunnels are fully pressurized and verticle, transverse tunnels move horizontally underground parallel to the surface of Ceres to provide a means of traveling from one rotating inhabited cylinder to another. the cylinder in the diagram above provides living space for about 5000 people, assuming a length of 550 meters and a radius of 250 meters. Some quick calculations can determine the amount of living space, the first 550 meters of Ceres subsurface could provide, I'm a bit tired now, so I'll save that for another post, when I fresher. I think two or more of these cylinders can be connected by pressurived exterior tunnels. I expect the energy source would be either nuclear fusion or fission, probably a fusion reactor would be a realistic assumption by the time we are able to build these things and dig 500 meter wide and 550 meter deep tunnels into Ceres. We are going to find out a lot more about Ceres in the next three months as the space probe draws nearer. Excavating tunnels should be easier in Cere's low gravity.

I think the thermal rejection system in the diagram won't be needed, as the rotating cylinders share the same atmosphere as the tunnels they rotate inside of, the air will carry the heat away from the rotating cylinders (1400 watts per square meter of absorbed artificial sunlight) and come in contact with the rock and ice strata of Ceres crust which will be very cold. The fusion reactors will also generate electricity by exchanging heat with the cold crust of Ceres.

Last edited by Tom Kalbfus (2015-01-23 14:46:43)

Spaniard · 2015-01-22 02:39:49

Tom Kalbfus wrote:

Basically the idea is to dig 500 meter wide cylindrical tunnels into the Dwarf Planet Ceres and bury Kalpana One Space Colonies within them

Ceres has gravity. Small, but enough to complicate things.

The logical configuration is a inverted and truncated cone, perpendicular to the Ceres gravity. In fact, it would not exactly a cone. The curve of the cone should be vector result of the centrifugal pseudoforce and Ceres gravity. Because Ceres gravity is small, the structure would be almost cilindrical, but not completely.
Because centrifugal force is smaller with less radius, it is not a cone but more like a bowl.
On the center, the gravity is not zero but Ceres surface gravity.

This configuration could be replicated in other moon or planets, with some differences. For example, on Mars, the gravity is too strong to make too deep. It is better a quasi-torus configuration, like a train travel very fast on a near perpendicular camber.
It will not rotate as fast as zero gravity, because the sense force is the sum of vectors of native gravity and centrifugal force.
If you move through a stairs "up", really you are moving to the center. The stairs must curve to maintain each stair perpendicular to the vectors of its position, and the stair becomes into a corridor when you approach the center.

The bodies with very little gravity like Phobos/Deimos could build structures very similar to cilinders. But bodies like Moon/Mars/Mercury/Callisto... needs narrow configurations more similar to torus.

Tom Kalbfus · 2015-01-22 08:40:20

Well Ceres has a gravity of 0.028 of Earth's, I was thinking of having a straight cylinder and a number of gently sloping hills on the inside, if we build houses and buildings on the outwards face of each hill, the resultant slope would be level. For the cylinder as a hole, going towards the center of Ceres along the Cylinder would be the equivalent of going down hill, I figure we can just live with it as the effective slope would be rather slight, and besides I don't want the cylinders getting narrower as one travels down. I figure one can hollow out significant portions of Ceres. I think under this gravity, we can dig about 35.7 times as deep as we can on Earth. A shaft that was 550 meters deep on Ceres would be the equivalent of one that was 15.4 meters deep on Earth, and I know we can dig deeper than that here on Earth. The advantage of Ceres is that we can inhabit more of her interior volume that we can of Earth, we also have to consider that the deeper we dig towards the center, the less gravity there is. So if we can dig 1 km down on Earth, we can dig 35.7 km down on Ceres, we could probably even push it to 48.7 km, which is one tenth the distance to the core of Ceres. Gravity there would probably be around 0.0252g. The deepest mine on Earth is the Tau Tona mine in South Africa, which is 3.9 km deep The first kilometer would be 35.7 km deep, the second would be 40 more kilometers for a total of 75.7 km which is 15.5% of the way to the core where the gravity would be 0.02366 g. The third kilometer on Earth would be equivalent of going 42.3 km deeper on Ceres for a total depth of 118 kilometers. Also keep in mind the average density of Ceres is about 2/5ths that of Earth, this means we can dig even deeper still to 295 kilometers. That is 60.7% of the distance to the center of Ceres Gravity there would be around 1.106% that of Earth We have 0.9 km to go on Earth. This will get us 204.5 km deeper, when you consider that Ceres is less dense than Earth, for a total depth of 500 km, as this is greater than Cere's mean radius, we could literally dig to the center of that dwarf planet Though the pressure would be enormous at that depth, we have the technology that is capable of dealing with it. Practically speaking though, we probably won't be digging that deep to place our habitats, though smaller tunnels for mining purposes might be so dug. Probably we won't build rotating habitats deeper that 50 km, and all the material we'd excavate would be deposited on the surface of Ceres.

Antius · 2015-01-22 12:22:26

If the crust turns out to be thin, you could site such structures within the icy mantle. Nuclear powered tunnelling machines could literally melt their way through the ice. A similar proposal was made for the moon 'the nuclear subselene'. This would have been much more difficult, as the operating temperature of the core would have to exceed the melting point of rock. It would work much better on an icy body.

You could make the job easier by producing a non-rotating cave habitat with rotating buildings within it. That way the rotating structures can be kept quite small, compact and lightweight and you only provide the gravity where there is a clear economic benefit. If each crew member is afforded 200m3 of rotating habitation space, then a cylinder 40m wide and 40m long could house 250 people.

Last edited by Antius (2015-01-22 12:32:22)

Tom Kalbfus · 2015-01-22 22:32:20

Well actually my original idea was to have 200 meter wide rotating cylinders that rotate 3 times per minute creating 1 full gravity on their inner surfaces. The tunnels they are in are just a little wider that the rotating cylinders, and they have tracks in their walls to hold the cylinders in place while they rotate. The relative tangential velocity at which the cylinders rotate within the tunnels comes to about 67.5 miles per hour, which is about the speed of a car driving down a US highway. Each cylinder is about 1 km long and 200 meters wide. The rotating cylinders are oriented in the up and down direction relative to Ceres, that is they point towards the planetoids center and towards its crust, that way the perceived gravitation forces inside the cylinder won't vary by 2.4% once every 20 seconds, as it would if the cylinder was placed horizontally, people might not like that Every kilometer up and down a cylinder ends and there is 6-way intersection of tunnels, 4 of them lead out horizontally and 2 vertically, the vertical ones lead to rotating cylinders one above, the other below, the other 4 horizontal tunnels lead North, South, East, and West, you take one of the horizontal tunnels to another similar 6-way intersection, with the up and down ones leading to more rotating habitation cylinders.

There is the problem with the relative velocity of the constantly spinning cylinders and the not spinning tunnels through rock. My idea is to have a circular water basin, or a circular river, the water is propelled around the circle by water jets, that keep the water moving at a constant 33.75 miles per hour, about the speed of a fast flowing river, this is half the speed of the rotating cylinders, and within this ring-shaped circular river are 4 tear-shaped islands, at the center of each island is a 10 meter wide tunnel. One can from the rotating cylinders jump into the river and be carried around once every 40 seconds until one reaches one of the tear-shaped islands, one can climb ashore, and when one does this one would be nearly weightless, a series of hand holds would then allow one to climb into one of the horizontal tunnels. Water from the river that splashed over the banks would tend to fall into the rotating cylinder below it. The weak gravity of Ceres would tend to cause water to flow down streams from the upper end to the lower end and then to pour into the next circular river intersection. For people who don't like to get wet or use boats there are bridges that cross over the intersections from one rotating cylinder to the next. From the perspective of the rotating cylinder a person would see a raging river, swirling around in a loop once every 40 seconds and within that river 4 tear shaped islands with circular tunnel entrances 10 meters wide moving twice as fast down the center of that river, one circuit every 20 seconds. Down the center of every cylinder and tunnel is a tube, either florescent or some other means of illumination to simulate daylight. Through the smaller tunnels similar illumination so people floating through them can see where they are going. Perhaps wider horizontal tunnels can be used for agriculture if 2.4% gravity isn't too little for those plants. I think near zero-gee agriculture may prove to be a little awkward though.

GW Johnson · 2015-01-23 09:37:45

Your whole habitat does not need to spin. The bed rest microgravity studies do in fact show that we do not benefit from gravity while sleeping. There's no need for artificial gravity in sleeping quarters. There is for your daily work shift. I'd guess that off-hours leisure time should have some spent under artificial gravity, but some could be spent in microgravity. The real question, unanswered even today, is how much artificial gravity is enough to be therapeutic? That really has a huge impact upon designs and their fundamental feasibilities.

GW

Tom Kalbfus · 2015-01-23 14:43:40

GW Johnson wrote:

Your whole habitat does not need to spin. The bed rest microgravity studies do in fact show that we do not benefit from gravity while sleeping. There's no need for artificial gravity in sleeping quarters. There is for your daily work shift. I'd guess that off-hours leisure time should have some spent under artificial gravity, but some could be spent in microgravity. The real question, unanswered even today, is how much artificial gravity is enough to be therapeutic? That really has a huge impact upon designs and their fundamental feasibilities.
GW

Problem is, these centrifuges need to be huge in order not to cause spin-induced nausea, The ones I am talking about are two football fields in diameter, and they are so big, they might as well encompass one's entire living quarters. But if you are suggesting that people sleep at the tunnel intersections with the swirling water, well to each his own. I think humans are evolved for a 1 gravity environment, they can tolerate short durations of near weightlessness, but for health reasons, some gravity is required. the near weightless conditions inside of Ceres allow more of its volume to be used for habitation.

Void · 2015-01-23 17:09:08

If it were me designing the synthetic gravity devices, I would have caves filled with CO2, and at the bottom a water pool. The cylinder would have a skirt with a fractional diameter that projected into the water. (The diameter would be much less than the diameter of the cylinder. Like an upside down cup in the kitchen sink filled with air (Almost filled). Then projecting into this air bubble (Not CO2), a right side up cylinder of small diameter. This being the method of entrance and exit to the greater community.

So, floating in CO2 like proposed for Venus, but held to a narrow band vertical by the air bubble in the water.

As for sleeping arrangements, I am sure that can be worked out in accordance to economic and medical necessity.

Tom Kalbfus · 2015-01-23 17:55:24

Void wrote:

If it were me designing the synthetic gravity devices, I would have caves filled with CO2, and at the bottom a water pool. The cylinder would have a skirt with a fractional diameter that projected into the water. (The diameter would be much less than the diameter of the cylinder. Like an upside down cup in the kitchen sink filled with air (Almost filled). Then projecting into this air bubble (Not CO2), a right side up cylinder of small diameter. This being the method of entrance and exit to the greater community.
So, floating in CO2 like proposed for Venus, but held to a narrow band vertical by the air bubble in the water.
As for sleeping arrangements, I am sure that can be worked out in accordance to economic and medical necessity.

Are you aware that CO2 is a solid at the orbital distance of Ceres from the Sun?
Other than that, why would you need CO2, except for plants, and plants don't need that much! I mean the tunnels have walls and you can mount spinning cylinders within them. I'd rather have the caves filled with breathable gases rather than pure CO2, why would you want to do that anyway? Its not like there is much gravity to deal with anyway.

Void · 2015-01-23 19:43:19

I am giving you my design. You may make your own.

A cave. Fill it with CO2 (Gas) not solid.

Fill the bottom with liquid water.

Now put a pipe large enough for a human to walk up a staircase in it. A center that a hoist cable can pull a package up or lower down.

Now put a hab inside the cave fill the hab with O2 and N2.

Put a skirt under the spinning cylinder, attached to the spinning cylinder, with a much less radius than that of the spinning cylinder. The skirt projects into the surface of the pool. The skirt is filled with a bubble of O2 and N2. The skirts bubble is an envelope that the pipe that projects into from the non-rotating main tunnel system.

Just like on a floating Venus hab, the interior being a mix of O2 and N2, it floats in an atmosphere of mostly CO2.

Some more floatation is provided by the skirt bubble floating in the water pool.

Let me list the potential problems.

CO2 may leak through the water into the skirt bubble. Solutions: 1) Gas Mask, 2) CO2 removal, 3) Mechanical devices float on top of the water of the pool, limiting the permeation of CO2 into the water, and out of it into the skirt bubble.

Also, like a washing machine it could become out of balance. That would require stupidity on the part of the humans, but I suppose it has to be considered.

So, it is a possible method. Tell me of another. How do you do your bearings?

Tom Kalbfus · 2015-01-23 22:49:26

Void wrote:

I am giving you my design. You may make your own.
A cave. Fill it with CO2 (Gas) not solid.
Fill the bottom with liquid water.
Now put a pipe large enough for a human to walk up a staircase in it. A center that a hoist cable can pull a package up or lower down.
Now put a hab inside the cave fill the hab with O2 and N2.
Put a skirt under the spinning cylinder, attached to the spinning cylinder, with a much less radius than that of the spinning cylinder. The skirt projects into the surface of the pool. The skirt is filled with a bubble of O2 and N2. The skirts bubble is an envelope that the pipe that projects into from the non-rotating main tunnel system.
Just like on a floating Venus hab, the interior being a mix of O2 and N2, it floats in an atmosphere of mostly CO2.
Some more floatation is provided by the skirt bubble floating in the water pool.
Let me list the potential problems.
CO2 may leak through the water into the skirt bubble. Solutions: 1) Gas Mask, 2) CO2 removal, 3) Mechanical devices float on top of the water of the pool, limiting the permeation of CO2 into the water, and out of it into the skirt bubble.
Also, like a washing machine it could become out of balance. That would require stupidity on the part of the humans, but I suppose it has to be considered.
So, it is a possible method. Tell me of another. How do you do your bearings?

Here are my assumptions:
1. Each spinning cylinder is 500 meters in diameter and 500 meters long.

2. Each spinning cylinder is in a section of tunnel that is 1000 meters long and slightly more that 500 meters wide so the spinning cylinders can fit inside and rotate.

3. Using the formula Velocity - (Accel{9.81 meters/sec}*r{250 meters})^0.5 I have calculated that the tangential velocity of the spinning cylinder is 49.5 meters per second or 110.8 miles per hour relative to the wall of the tunnel. A train consisting of ordinary wheels on rails can go this speed, as could a car.

2. Reconsidering the spinning cylinders, lets make them spinning spheres in stead, Each sphere is the size of an Island One Space Colony, about 500 meters in diameter, the tangential velocity relative to the tunnel wall is 110.8 miles per hour.

3. The tunnels bulge out to form a partial sphere slightly larger than the Island One spinning habitat. If the axis of spin can be considered the sphere's equator at 0 degrees latitude, Cut out the sphere at 60 degrees from the equator, this will create a hole that is 250 meters in radius, the tunnels contours follow that of the spinning sphere, meaning that the tunnel narrows to 270 meters wide, The spinning surface of the Sphere at this cut out opening is only half that at the equator, or about 55.4 miles per hour.

4. Filling this tunnel is a swirling vortex of water 10 meters deep, this water is moving at a speed of 27.7 miles per hour in a circle relative to the wall of the tunnel, since this is half the spin velocity of the Sphere edge opening, the water is also moving 27.7 miles per hour in the opposite direction relative to the sphere at the 60 degree openings, this is the velocity of a raging river. The air on top of the water is also moving at 27.7 miles per hour while the air inside the sphere is more or less moving with the sphere. So as one approaches the opening of the sphere it gets windy with the air moving at about the relative speed of the water.

there are 4 islands in the middle of this 500 meter wide river, each island is a tear drop shape to allow the water to flow around it and it rises 10 meters above the water surface and is 20 meters wide (in a tunnel that is 250 meters in diameter) In the center of each island is a 10 meter wide opening. One can enter into this opening and travel through the tunnel in 0.024 g gravity ( walking is kind of awkward in such low gravity, so a person would just grab hand holds along the wall of the tunnel and pull himself along, the tunnels are filled with breathable air that it shares with the Island One Sphere through the circular openings at the 60 degree latitude lines of each sphere. At the 70 to 90 degrees, above the opening to the tunnel, is a panel that emits artificial sunlight to the opposite side of the Island One Sphere, this is attached to the tunnel walls outside the sphere and is powered by a fusion reactor, it does not rotate, but this does not matter due to radial symmetry of the rotating sphere.

This is the inside of a Bernal Sphere to give you an idea of what this looks like. Where you see those windows to let in sunlight, that is where the opening to the tunnel would be. That island in the center of that circular window in the picture, that is where the artificial sunlight would come from, behind that circle as seen from inside the sphere is a fusion reactor, both the fusion reactor and the light panel are mounted to the tunnel wall and do not rotate with the sphere. One climbs the walls of the sphere to gain access to the tunnel Travel over the river ( 500 meters wide) to the next Island One Sphere is accomplished by cable car, by despinning the cable car can lower itself from the central cable towards one of the tear shaped islands holding the entrance to a horizontal tunnel. The ISland Threes aren't air tight, they share the same air as the tunnel, the tunnel is sealed at the top by a dome at the surface of Ceres, to which access to a spaceport is granted.

Last edited by Tom Kalbfus (2015-01-23 22:52:31)

Void · 2015-01-23 23:18:24

Ok nice ideas, supported with math. At one point you cite metal wheels on rails for your bearings. Not impossible.

I am not indicating that there is something wrong with your plan. I am just indicating that this is what your communication has said to me about bearings.

For my part, I would dispense with trying to convey sunlight into such an apparatus, but would put it somewhat deeper, perhaps even allowing more than 1 bar of pressure (More floatation in CO2). I would perhaps include house plants of value using artificial light.

As for agriculture, of course there would be methods previously discussed not too different than solutions for Mars or the Moon. Again, only one persons view. You are quite welcome to share further how you would do things.

Tom Kalbfus · 2015-01-24 09:06:05

I don't know what the deal with Carbon Dioxide is, I would prefer that the atmosphere would be breathable if I could help it. I mean in Venus, you don't have a choice, you have to work with the atmosphere you've got, in a tunnel in an asteroid, you could create whatever atmosphere you want from surrounding materials, because there is none. I was sort of lost in your description of the thing, but it seems to me that rock can support more weight than a carbon-dioxide atmosphere. I mean basically there is a shaft, you have a hollow in the rock where you place the Bernal Sphere, it literally can't fall down the shaft because the tunnel is too narrow for it to fall down through As such the Bernal would probably be built within the hollowed out cavity in the Dwarf Planet The way I look at it, if you have shafts 50 kilometers deep, with one Bernal Sphere placed in a hollow cavity for every kilometer of the shaft and have each shaft spaced one tenth of a degree apart from neighboring shafts oriented in a straight North-south and East-West lines, there would be enough interior land surface area equal to one fifth the surface of the Earth. Now one of two things can be done with the excavated material from these tunnels, it can either be pied up on the surface or exported to Mars and Venus for terraforming projects.

Part of what your describing sounds like a hovercraft with a skirt underneath. I just have to say that carbon dioxide is hazardous to breath, I don't see the purpose of creating another hazardous environment in which one needs a suit to operate in. As for my swirling water tunnel, the water has a number of uses, for one is serves as a fuel tank for the fusion power plant, some of that water contained deuterium, from which tritium can be made and from which fusion reactions release neutrons from which more tritium is made from Deuterium. Of course water is a vital ingredient for life and agriculture, and of course you can have a fish farm in the water tunnel. The Water tunnels will be lit by a central tube powered by the fusion power plant, also the power is used to keep the habitants spun up against air and wheel friction, the wheels are retractable so the wheels can be replaced and repaired as the habitat keeps on spinning.

Void · 2015-01-24 10:34:09

Were talking apples and oranges Tom.

You want to use a heavy brute force method, which has some strengths, I think.

I am looking for a minimum solution with a lightweight construction which might more likely get humans to be able to live on Ceres more early and often.

So, I claim that what I proposed is easier to do. But the cost of that is some risk. Honestly I also would need to figure out how you plan to have massive weight of rails, and those rails on top of a layer of ice. I am not saying it is not possible, but I have reservations.

Visualize a spinning balloon, of relatively light weight materials, filled with O2 and N2. Instead of a gondola, it would have a tube which extends downward from it. The habitat tunnels, being a network would have a tube in the chamber the extends upward into the chamber. The balloon tube surrounds the top of the tunnel tube which is a smaller diameter. The space between the two and surround the two can be a liquid, first proposal is that it be water. The cave above is filled with CO2 which being heavier will displace the spinning floating habitat ideally in a null value +/- some variations.

Then the rather small hovercraft function formed by the two joining tubes may be able to handle the +/- variation.

I am thinking construction about the character of an airliner. Strong but light. Just enough so that people can maintain health.

Later on if they have the engineering smarts that are needed and the construction materials for it, they can try to approach what you intend.

Of course on a segway, I can say that we hope that the gravitation of Mars will be sufficient for human health, but we don't have a firm confirmation on that. So the design I have suggested here would be adaptable for Mars perhaps, whereas the design you have proposed I think would be too heavy. But we are talking Ceres, so fine continue. I do like to know what your plans are on this.

Tom Kalbfus · 2015-01-24 11:53:29

I think I understand what you intend, Basically a tunnel carved out of the rock and inside the tunnel is a sleeve, made out of plastic or rubber. The space between the tunnel and the sleeve is filled with carbon dioxide, the atmosphere inside the sleeve is a breathable mixture. the sleeve rotates, the bare rock tunnel does not. The gravitation makes large rotating structures on Mars a little impractical, it would be easier on Ceres with hardly any gravity.

Void · 2015-01-24 15:44:09

So, two approaches, maybe more. That's fine with me.

Spaniard · 2015-01-26 16:52:03

I suggest you use magnetic levitation instead of bearings. Only rails on the base would be used on case of catastrophic stop of the colony.

A configuration of magnetic rings using hall bach arrays like in inductrack configuration should be enough, not only to regulate the rotation but to transfer weight load like in a arc or a cupola, but weight translate through the repulsion of the inner rings (in the rotation section) and outer rings (in the outside part of the tunnel, fixed). With the adecuate magnetic configuration it should be possible.
Because the possibility of stack rings, fixed and rotated sections, the weight can be distributed and it could be build as deep as needed. The stacked rings will be in the outer part of the colony. From inner perspective, "underground" below the perceived floor of the ground level.

That's imply a constant flux of energy, but that would be inevitable on a body with gravity. Magnetic rings or rails, all dissipate energy.
In any case, the environment would be very cold, so energy is a necessity.
I suggest enough redundant configuration in energy source.

Tom Kalbfus · 2015-01-27 12:34:36

Spaniard wrote:

I suggest you use magnetic levitation instead of bearings. Only rails on the base would be used on case of catastrophic stop of the colony.
A configuration of magnetic rings using hall bach arrays like in inductrack configuration should be enough, not only to regulate the rotation but to transfer weight load like in a arc or a cupola, but weight translate through the repulsion of the inner rings (in the rotation section) and outer rings (in the outside part of the tunnel, fixed). With the adecuate magnetic configuration it should be possible.
Because the possibility of stack rings, fixed and rotated sections, the weight can be distributed and it could be build as deep as needed. The stacked rings will be in the outer part of the colony. From inner perspective, "underground" below the perceived floor of the ground level.
That's imply a constant flux of energy, but that would be inevitable on a body with gravity. Magnetic rings or rails, all dissipate energy.
In any case, the environment would be very cold, so energy is a necessity.
I suggest enough redundant configuration in energy source.

My question is what weight load? The Bernal Sphere is designed to spin and hold itself together, the tracks aren't there to hold it together under its own spin, what it will do is hold it up against Ceres gravity, but that is not much, about 2.4% of Earth's gravity All the tracks do is provide something to push against so it continues rotating for its own internal gravity, as it will be rotating within a breathable atmosphere at 1 atmospheric pressure, the speed at which it would be rotating against the air in the tunnel is 67.5 miles per hour, however the water in the tunnel will be spinning at half that velocity, so the relative velocity between the Bernal Sphere and the water surface will be only 33.75 miles per hour, the flow of the water relative to the tunnel walls would also be 33.75 miles per hour. the water surface allows people to transfer from the spinning habitat to the nonspinning tunnels and thus travel underground from one habitat to another without having to go into space.

Void · 2015-01-27 14:37:47

http://photojournal.jpl.nasa.gov/missio … rget:Ceres:

Spaniard · 2015-01-27 15:40:55

Tom Kalbfus wrote:

My question is what weight load? The Bernal Sphere is designed to spin and hold itself together, the tracks aren't there to hold it together under its own spin, what it will do is hold it up against Ceres gravity, but that is not much, about 2.4% of Earth's gravity All the tracks do is provide something to push against so it continues rotating for its own internal gravity, as it will be rotating within a breathable atmosphere at 1 atmospheric pressure, the speed at which it would be rotating against the air in the tunnel is 67.5 miles per hour, however the water in the tunnel will be spinning at half that velocity, so the relative velocity between the Bernal Sphere and the water surface will be only 33.75 miles per hour, the flow of the water relative to the tunnel walls would also be 33.75 miles per hour. the water surface allows people to transfer from the spinning habitat to the nonspinning tunnels and thus travel underground from one habitat to another without having to go into space.

2,4% could sounds little, but this structures are HUGE, so we are talking about a lot of energy.
The less friction, the better.

I'm not sure about your configuration. Could you provide some drawing?
A handwriting draw could be enough.

Here is the mine.

Obviously not at scale. Drawing of a centered cut. The levitation supports are circular in 3D. They could levitate each one, so it could be detached, stopped, fixed/changed, rotate again and reattach.

The number of rotation disks could be incremented to distribute the weight to the deep.

In this draw i choose a cilindrical configuration, although the effective gravity is the sum of Ceres gravity and centripetal.
Not at scale (Ceres vector is smaller), but the idea is that in this configuration are mounds with the perception of live in a slope to the bottom of the cilinder.

Last edited by Spaniard (2015-01-27 15:44:57)

Tom Kalbfus · 2015-01-27 22:38:50

Spaniard wrote:

Tom Kalbfus wrote:
My question is what weight load? The Bernal Sphere is designed to spin and hold itself together, the tracks aren't there to hold it together under its own spin, what it will do is hold it up against Ceres gravity, but that is not much, about 2.4% of Earth's gravity All the tracks do is provide something to push against so it continues rotating for its own internal gravity, as it will be rotating within a breathable atmosphere at 1 atmospheric pressure, the speed at which it would be rotating against the air in the tunnel is 67.5 miles per hour, however the water in the tunnel will be spinning at half that velocity, so the relative velocity between the Bernal Sphere and the water surface will be only 33.75 miles per hour, the flow of the water relative to the tunnel walls would also be 33.75 miles per hour. the water surface allows people to transfer from the spinning habitat to the nonspinning tunnels and thus travel underground from one habitat to another without having to go into space.
2,4% could sounds little, but this structures are HUGE, so we are talking about a lot of energy.
The less friction, the better.
I'm not sure about your configuration. Could you provide some drawing?
A handwriting draw could be enough.
Here is the mine.
http://s2.postimg.org/zbbop4a2t/image_colony_ceres_less.jpg
Obviously not at scale. Drawing of a centered cut. The levitation supports are circular in 3D. They could levitate each one, so it could be detached, stopped, fixed/changed, rotate again and reattach.
The number of rotation disks could be incremented to distribute the weight to the deep.
In this draw i choose a cilindrical configuration, although the effective gravity is the sum of Ceres gravity and centripetal.
Not at scale (Ceres vector is smaller), but the idea is that in this configuration are mounds with the perception of live in a slope to the bottom of the cilinder.

I could draw something and send it to you. I don't know how to post something of my own work here, as it needs to be already on the web for me to post the image here. I will give you a verbal description for now. Your drawing looks like a straight cylinder within a cylindrical shaft carved down into the crust. In my case I would escavate a cylindrical shaft 270 meters wide. On top would be a dome to hold in the air, along with docking ports for spaceships.

The shaft from the surface would go down 250 meters then it would form a bulb - a spherical cavity probably 510 meters in diameter within which a 500 meter wide Bernal Sphere would fit within snugly, the spin plane of the bernal sphere would be parallel to the surface of Ceres above it. Below the Bernal and the spherical cavity is another shaft which continues downward, it is 270 meters wide, and it continues another 500 meters down before ending at another spherical cavity just like the one above, with another bernal inside that is 500 meters wide and rotating 1.9 times a minute for a full gravity at its equator, below that one is another 270 meter wide cylindrical passage that continues another 500 meters down to meet yet another spherical cavity with bernal sphere rotating inside. In each 270 meter wide spherical tunnel is a layer of water 10 meters deep, the water flow keeps the water to the sides of the tunnel by centrifugal force, the centrifugal force is one eighth of Earth's gravity at the water surface, and it has to contend with the 2.4% Ceres gravity that is pulling the water downward. This pattern repeats until the shaft with 50 Bernal spheres inside reach a depth of 50 kilometers, total population of 50 Bernals works out to be about half a million if occupied to capacity, and new shafts can be dug all over the surface of Ceres. Horizontal tunnels connect the various shafts and allow for lateral transport underground rather than having to come up to the surface for travel. All the shafts are filled with breathable air, so no need for spacesuits. The lateral tunnels connect to each shaft segment in the center of islands rising about the centrifugal flow of water at the midpoints of each shaft.

Spaniard · 2015-01-28 02:00:53

Tom Kalbfus wrote:

I could draw something and send it to you. I don't know how to post something of my own work here, as it needs to be already on the web for me to post the image here. I will give you a verbal description for now. Your drawing looks like a straight cylinder within a cylindrical shaft carved down into the crust. In my case I would escavate a cylindrical shaft 270 meters wide. On top would be a dome to hold in the air, along with docking ports for spaceships.

In my design, the colony is closed too obviously. It could be usign a dome, or buried deep in the ground, or anything similar. While materials could support the pressure of the zone where is excavated, there is no limit to the place where it could be built, while the align is correct.
It's a design we could adapt to any low mass body, including Mars. With more gravity, more levitation rings are needed, and the perceived slope will be greater, but all others things remain the same.
To have colonies with artificial 1g it could be critical to fetal development and it will be an advantage to greater health for sure.

Tom Kalbfus wrote:

The shaft from the surface would go down 250 meters then it would form a bulb - a spherical cavity probably 510 meters in diameter within which a 500 meter wide Bernal Sphere would fit within snugly, the spin plane of the bernal sphere would be parallel to the surface of Ceres above it. Below the Bernal and the spherical cavity is another shaft which continues downward, it is 270 meters wide, and it continues another 500 meters down before ending at another spherical cavity just like the one above, with another bernal inside that is 500 meters wide and rotating 1.9 times a minute for a full gravity at its equator, below that one is another 270 meter wide cylindrical passage that continues another 500 meters down to meet yet another spherical cavity with bernal sphere rotating inside. In each 270 meter wide spherical tunnel is a layer of water 10 meters deep, the water flow keeps the water to the sides of the tunnel by centrifugal force, the centrifugal force is one eighth of Earth's gravity at the water surface, and it has to contend with the 2.4% Ceres gravity that is pulling the water downward.

I don't understand this configuration.
Why stack spheres? which advantage gets over simply using more surface on Ceres?
Or even fragility. I think that not aligned shafts are more robust, even they are buried deep in Ceres, filling the planet.
And we don't know by now how is the deep crust. Perhaps, at some deep, the ice become liquid.

And the water... The water between the sphere and the walls, it's like liquid rails. A lot of friction i think.

Perhaps i'm mistaking the model.

Tom Kalbfus · 2015-01-28 08:13:04

Spaniard wrote:

Tom Kalbfus wrote:
I could draw something and send it to you. I don't know how to post something of my own work here, as it needs to be already on the web for me to post the image here. I will give you a verbal description for now. Your drawing looks like a straight cylinder within a cylindrical shaft carved down into the crust. In my case I would escavate a cylindrical shaft 270 meters wide. On top would be a dome to hold in the air, along with docking ports for spaceships.
In my design, the colony is closed too obviously. It could be usign a dome, or buried deep in the ground, or anything similar. While materials could support the pressure of the zone where is excavated, there is no limit to the place where it could be built, while the align is correct.
It's a design we could adapt to any low mass body, including Mars. With more gravity, more levitation rings are needed, and the perceived slope will be greater, but all others things remain the same.
To have colonies with artificial 1g it could be critical to fetal development and it will be an advantage to greater health for sure.
Tom Kalbfus wrote:
The shaft from the surface would go down 250 meters then it would form a bulb - a spherical cavity probably 510 meters in diameter within which a 500 meter wide Bernal Sphere would fit within snugly, the spin plane of the bernal sphere would be parallel to the surface of Ceres above it. Below the Bernal and the spherical cavity is another shaft which continues downward, it is 270 meters wide, and it continues another 500 meters down before ending at another spherical cavity just like the one above, with another bernal inside that is 500 meters wide and rotating 1.9 times a minute for a full gravity at its equator, below that one is another 270 meter wide cylindrical passage that continues another 500 meters down to meet yet another spherical cavity with bernal sphere rotating inside. In each 270 meter wide spherical tunnel is a layer of water 10 meters deep, the water flow keeps the water to the sides of the tunnel by centrifugal force, the centrifugal force is one eighth of Earth's gravity at the water surface, and it has to contend with the 2.4% Ceres gravity that is pulling the water downward.
I don't understand this configuration.
Why stack spheres? which advantage gets over simply using more surface on Ceres?
Or even fragility. I think that not aligned shafts are more robust, even they are buried deep in Ceres, filling the planet.
And we don't know by now how is the deep crust. Perhaps, at some deep, the ice become liquid.
And the water... The water between the sphere and the walls, it's like liquid rails. A lot of friction i think.
Perhaps i'm mistaking the model.

Not too bad I think, submarines move through water without too much trouble, and the speeds we are talking about aren't too incredible. One option is the have the Spherical chambers filled with water, the water moves in the direction of the sphere's spin at the equator at 67.5 miles per hour against the wall of the chamber, the tangential velocity of the sphere at the equator is 134 miles per hour, but it is only moving against the water at 67.5 miles per hour. The thing about water is it can flow, and it is only an object's water speed that counts. Also having a symmetric object spinning in water is easier than having something move through water pushing it aside as it goes. Both of these velocities can be reached by a car on a highway.

Tom Kalbfus · 2015-01-28 08:31:42

Spaniard wrote:

...
I don't understand this configuration.
Why stack spheres? which advantage gets over simply using more surface on Ceres?
Or even fragility. I think that not aligned shafts are more robust, even they are buried deep in Ceres, filling the planet.
And we don't know by now how is the deep crust. Perhaps, at some deep, the ice become liquid.
And the water... The water between the sphere and the walls, it's like liquid rails. A lot of friction i think.
Perhaps i'm mistaking the model.

Why stack spheres? That's easy, because Ceres has less surface area than Earth because it is small, you can create more surface area by digging tunnels into Ceres, and you can make maximum use of this super-asteroid. I've calculated that if you dig these shafts with 50 Bernals per shaft and covered the entire surface of Ceres allowing for separations of shafts from their neighbors by one tenth of a degree, then there would be the equivalent surface area of one fifth of Earth's surface, and that is only by digging down to a depth of 50 km, if you dig deeper, you get more. One fifth of the Earth's surface area is about the total usable land on Earth, not counting Antarctica for instance. If you want the equivalent of another Earth, then you start by making Ceres look like "Swiss cheese".

Spaniard · 2015-01-30 08:55:08

Tom Kalbfus wrote:

Not too bad I think, submarines move through water without too much trouble, and the speeds we are talking about aren't too incredible.

A submarine, something a lot smaller, needs a huge power to move. I'm afraid that your system would require a lot more energy than a levitation one. And heat rejection is a problem in Ceres. It would need a web of pipes around the colony to distribute the heat and avoid overheat the surface too much to avoid massive evaporation.

Tom Kalbfus wrote:

Why stack spheres? That's easy, because Ceres has less surface area than Earth because it is small, you can create more surface area by digging tunnels into Ceres.

I'm not even consideration a number of colonies so huge. I was thinking about some little colonies to work in it. To live, I suppose that it has more sense space colonies.

New Mars Forums

Announcement

#1 2015-01-22 00:17:04

Underground Habitats of Ceres

#2 2015-01-22 02:39:49

Re: Underground Habitats of Ceres

#3 2015-01-22 08:40:20

Re: Underground Habitats of Ceres

#4 2015-01-22 12:22:26

Re: Underground Habitats of Ceres

#5 2015-01-22 22:32:20

Re: Underground Habitats of Ceres

#6 2015-01-23 09:37:45

Re: Underground Habitats of Ceres

#7 2015-01-23 14:43:40

Re: Underground Habitats of Ceres

#8 2015-01-23 17:09:08

Re: Underground Habitats of Ceres

#9 2015-01-23 17:55:24

Re: Underground Habitats of Ceres

#10 2015-01-23 19:43:19

Re: Underground Habitats of Ceres

#11 2015-01-23 22:49:26

Re: Underground Habitats of Ceres

#12 2015-01-23 23:18:24

Re: Underground Habitats of Ceres

#13 2015-01-24 09:06:05

Re: Underground Habitats of Ceres

#14 2015-01-24 10:34:09

Re: Underground Habitats of Ceres

#15 2015-01-24 11:53:29

Re: Underground Habitats of Ceres

#16 2015-01-24 15:44:09

Re: Underground Habitats of Ceres

#17 2015-01-26 16:52:03

Re: Underground Habitats of Ceres

#18 2015-01-27 12:34:36

Re: Underground Habitats of Ceres

#19 2015-01-27 14:37:47

Re: Underground Habitats of Ceres

#20 2015-01-27 15:40:55

Re: Underground Habitats of Ceres

#21 2015-01-27 22:38:50

Re: Underground Habitats of Ceres

#22 2015-01-28 02:00:53

Re: Underground Habitats of Ceres

#23 2015-01-28 08:13:04

Re: Underground Habitats of Ceres

#24 2015-01-28 08:31:42

Re: Underground Habitats of Ceres

#25 2015-01-30 08:55:08

Re: Underground Habitats of Ceres

Board footer