Adding Spin Gravity on Small Worlds.

Void · 2023-08-12 10:46:40

I am still a bit ill, (Not too bad), but have to limit contact with people so I guess I will do this:

Adding Spin Gravity Simulation On Small Worlds: (This is the best article I have encountered for it, it is sort of about the Moon).
https://www.science20.com/robert_invent … how-176169

To their credit, Japan seems to have an interesting imagination on the topic of very grand instances of this notion, for the Moon, here is an example: https://www.gearrice.com/update/japan-w … %20gravity.

The Europeans seem to be contemplating a space station with a floor with a Centrifuge in it: https://www.impactlab.com/2023/05/05/gr … 0of%20four.

It is not made for the Moon, but I do wonder if with better bearings it could do something on the surface of the Moon.

Last edited by Void (2023-08-12 10:55:01)

tahanson43206 · 2023-08-12 10:54:08

For Void ....

First, best wishes for recovery from whatever you are dealing with ....

Second, best wishes for this interesting (to me for sure) new topic!

While the topic will inevitably contain details that seem (or are) similar to those in topics about building rotating habitats from scratch, the scope of this topic seems equally likely to occur, and the kind of habitat this topic is about may actually have a GREATER chance of success, because all the materials to be used are already assembled by various natural forces.

I am hoping this new topic wins support by other members of the forum.

If there is someone ** out there ** who would like to contribute but is not currently a member, please see Recruiting Topic for procedure.

(th)

Void · 2023-08-12 10:58:01

Thanks (th), I am actually going to link this to my other topic that I often post in, but I thought that the materials of the 1st post are already valuable as reference, so I thought I would give this its own topic. "Index» Terraformation» Worlds, and World Engine type terraform stuff."

Perhaps others will add to it over time.

I believe that in the old days ~70's putting spin gravity onto the Moon was not though to be practical, but it appears that it might be done in limited ways.

This is already quite interesting: https://www.science20.com/robert_invent … how-176169

Quote:

Artificial gravity only intermittently during the day.
Or we might need gravity only intermittently during the day for health. Here is a study that found that full gravity in a centrifuge for just one hour a day made a big difference to muscle loss in bed rest volunteers lying with head slightly lower than their feet to simulate zero g. Other studies come to similar conclusions. Other experiments use "dry immersion" to simulate zero g, where a volunteer is immersed in warm water with an elastic suit to keep them dry, which has similar physiological effects to head down bed rest, but the changes take effect more quickly.

I decided to query for this from the above paragraph: "Here is a study that found that full gravity in a centrifuge for just one hour a day made a big difference to muscle loss in bed rest volunteers lying with head slightly lower than their feet to simulate zero g."

General Response: https://www.bing.com/search?q=Here+is+a … 60CFF086D8

Very good case:
https://www.wired.com/2009/07/humancent … htlessness. Quote:

SCIENCEJUL 23, 2009 8:59 PM
Human Centrifuge Preserves Muscle at Zero-G
Preventing muscle loss in space is simple: Just spend an hour a day in a giant human centrifuge that’s spinning at 30 rotations per minute. And don’t lose your lunch. In the first human experiment looking at the effects of artificial gravity on muscle mass, researchers discovered that a force of 2.5 g’s applied to […]

So, that is very promising for adult humans to "Serve" a hitch on the Moon. I am sure some will think military, but maybe also if you work in Antartica, you may often have to agree to some terms of how you will be there for a certain time period.

Artificial gravity will not make the Moon more military oriented, not more than may be so for NASA missions, I would think.

Done.

Last edited by Void (2023-08-12 11:15:42)

Void · 2023-08-12 11:17:58

In post #2, (th) posted this:

While the topic will inevitably contain details that seem (or are) similar to those in topics about building rotating habitats from scratch, the scope of this topic seems equally likely to occur, and the kind of habitat this topic is about may actually have a GREATER chance of success, because all the materials to be used are already assembled by various natural forces.

I agree, and I feel that if we can come up with reasonable methods to bring more volatile materials to the Moon, it can perhaps really assist in human reach out into the solar system.

I have to wonder if something like Neuralink could modify what a humans inner ear does as per motion sickness. In that case we would have a great deal more liberty in creating spin gravity.

Neuralink:
https://neuralink.com/

Done.

Last edited by Void (2023-08-12 11:20:50)

Void · 2023-08-12 11:26:33

I am very satisfied with this so far. Lots of reason to think adult humans could be kept reasonably healthy on the Moon for extended periods of time. Not proven but seeming like a good chance's situation. At least the materials of posts #1-#5 so far, are encouraging for it.

Done.

Last edited by Void (2023-08-12 11:28:41)

tahanson43206 · 2025-01-21 14:03:41

GW Johnson provided a spreadsheet for anyone interested in evaluating various rotation systems.

http://newmars.com/forums/viewtopic.php … 41#p229241

The spreadsheet covers G force from 1 down to .1, and RPM from 3 to 20

Separately Terraformer found a study funded by NASA that shows that humans can be trained to tolerate spin, if they are give time to get used to the state.

The NASA funded study found that on average, people were able to increase RPM at the rate of 1.75 RPM per day of training.

I note that this "training" is not overly complex.

There is a topic where the study Terraformer found is linked. Look for topics that contain "rotation" in the title.

(th)

Calliban · 2025-01-22 01:12:52

This is interesting for a number of applications. The centrifuge featured on the film 2001: A Space Odyssey, was some 9m in diameter. This formed the habitation area of the ship and was internal to the pressure hull. This is an easier arrangement, as it means: (1) The ship itself does not need to rotate; (2) Bearings and their lubricants are not exposed to vacuum. Vacuum rated bearings have presented some difficulty to spacecraft designers in the past. All other work areas of the ship were zero-g. One thing that isn't clear to me is if there are problems exposing the human body to repeated changes between zero-g and full / partial g. Would this cause repeated dizziness or nausea every time someone goes back into zero-g?

There are a number of known effects on the human body resulting from zero-g. Bone demineralisation has been well documented and is replicated in bed rest studies. Muscle loss as well. Another problem unique to zero-g is that without gravity, newly created bone cells (and potentially other tissues) cannot orient themselves properly within the tissue matrix. So longterm effects of weightlessness include improper development of bone microstructure and potentially, other organs as well. How much gravity is needed to avoid these effects? Would 0.1g be enough? 0.01g? Nobody knows. Do we need full time exposure to gravity for these effects to be avoided, or just a few hours aday? Unknown.

If humans can live on low-g worlds by spending some fraction of their time in rotating structures, this has profound implications for the habitability of the cosmos. We have discussed at length the possibilities of using shell world techniques to create habitable 'terraformed' environments on small worlds like asteroids, moons and KBOs. These environments cannot simulate Earth gravity. Depending upon the specific environment, gravity could be anywhere between 0 and 0.1g for these terraformed worlds. For these environments to be useful to humanity, we must be able to live within them. If it is a simple case of working or piving within a rotating structure for a portion of the day, then this is relatively straightforward. We could have entire cities with individual rotating buildings mounted on thrust bearings. The ecosystem itself would still be in microgravity. But maybe there will be evolutionary adjustment?

Last edited by Calliban (2025-01-22 01:41:16)

Terraformer · 2025-01-22 05:03:25

It makes sense; humans typically spend a third of their day in bed rest conditions, and a substantial amount sat down, our full exposure is already intermittent. There may be other health issues to consider from microgravity such as fluid distribution, but bone and muscle loss should be straightforward to mitigate. The other issues I *suspect* will not require anywhere close to 1g to deal with, just enough that the body knows which way is down.

Void · 2025-01-22 08:21:03

I agree to the greater part of what has recently been said.

I think we will have the tools to answer some of those questions fairly soon. Because Dr. Johnson indicated in the past that Starship might be able to go up to .5 g in a baton tumble method.

Such testing would not require refilling the ship. Just LEO.

So I would start with a "Half Down Spiral Test".

You would likely load the ship in LEO with a set of humans, using Dragon. Then you would kick it to a .5 g rotation gravity simulation. Then over a time period you would bring the level down in small gradients to microgravity. I will presume life support sufficient to have a mission to the Moon and back, which is what is expected to be available to support the Artimus, intentions for the Moon.

While this will not do a 6 month or 1 year test of bone and muscle, it will be possible to have a look at blood pooling in the upper body. Also, the typical body chemistry tests could be performed. You should be able to see if the body is shedding Calcium, I think.

You also could do a "Half Up Spiral Test". Start at or near microgravity and increase the spin over a period of time in small increments.

My suspicion is that upper body blood pooling will not be exactly the same for all people, and that it will kick in at some level of gravity simulation between microgravity and .5 g simulation.

During such testing you could also find out information about sanitation. Plumbing. And you would be stress testing the ship as well.

This would test for any level of gravity simulation for worlds humans might visit in the next few decades except Venus.
And if you wanted to test for Venus, then just hook two Starships together at the tail, and you might be able to spiral up and down from Microgravity to close to 1 g.

Again, this could be done while the Starship is still not matured yet, as the Dragon exists, and Dream Chaser might become human rated, if there is a push to do that.

It would also be possible to do animal tests in this way, but really, I don't think any animal other than humans stands on it's two hind paws as much as humans. So, for animal testing you could do the tests longer term to see what bone losses are.

Eventually as the Starship becomes reliable as per life support, you might get test data from humans who have been in microgravity for 6-9 months. You might move them to a Starship and see how well they recondition as you spiral up the gravity simulation. This could be important for trips to Mars.

Someone is testing aerobraking, which might be a method of accessing Mars in increments: https://www.spaceforce.mil/News/Article … -maneuver/
Quote:

The X-37B Orbital Test Vehicle (OTV-7) will begin executing a series of novel maneuvers, called aerobraking, to change its orbit around Earth and safely dispose of its service module components in accordance with recognized standards for space debris mitigation.

So, my best guess would be that for a trip to Mars, you might have a fraction of 1 g for sanitary reasons, and perhaps to keep the blood pooling as favorable. Then as would be useful, you might tumble the ship at intervals to get the humans prepared for multiple aerobraking events, and finally to be conditioned to work on the surface of Mars.

But we do not yet know what level of gravity simulation would be enough to keep blood pooling as favorable, and we do not know what the sanitary gravity level is that would work best.

Ending Pending

Last edited by Void (2025-01-22 08:48:50)

New Mars Forums

Announcement

#1 2023-08-12 10:46:40

Adding Spin Gravity on Small Worlds.

#2 2023-08-12 10:54:08

Re: Adding Spin Gravity on Small Worlds.

#3 2023-08-12 10:58:01

Re: Adding Spin Gravity on Small Worlds.

#4 2023-08-12 11:17:58

Re: Adding Spin Gravity on Small Worlds.

#5 2023-08-12 11:26:33

Re: Adding Spin Gravity on Small Worlds.

#6 2025-01-21 14:03:41

Re: Adding Spin Gravity on Small Worlds.

#7 2025-01-22 01:12:52

Re: Adding Spin Gravity on Small Worlds.

#8 2025-01-22 05:03:25

Re: Adding Spin Gravity on Small Worlds.

#9 2025-01-22 08:21:03

Re: Adding Spin Gravity on Small Worlds.

Board footer