Cheep simulation of low gee environment

Quaoar · 2014-04-16 03:52:27

We know a lot of body modification in microgravity, and almost nothing in law gee environment like a Mars 0.38 gee. To save mass for a space mission, it can be very useful to know how much gee fraction astronauts need to avoid negative effects of microgravity, and if periodic centrifugation in a short arm centrifuge can be enough or not (it's easier and cheeper fitting a 2.5 - 3 meters radius centrifugue in a Falcon H/Delta IV launched module that building a spinning ship).

I propose a way to study the issue on Earth with low cost stuff.

1) Instead of 6° head down bed rest, microgravity can be better simulated with head-up bathing in a swimming pool: differential hydrostatic pressure give a very good body fluid shift, and floating in the water, subjects can moove almost like astronaut do in microgravity.

2) low gee environment can be either simulated on Earth in this way: subjects have to be suspended orizontally to the roof with some kind of climbing harness, keeping the feet on a horizontal centrifuge: we can choose from a 2.5-3 meters radius that can be fitted in a Falcon H/Delta IV module or a 15-20 meters that can give a better simulation of Mars surface.

Last edited by Quaoar (2014-04-16 03:59:33)

Void · 2014-04-21 10:12:03

From my point of view, estimating the psychology of parties who might take actions, and what actions are possible, I would as a choice
promote a 2 person lunar base, under an international sponsorship, with the strong involvement of businesses if possible.

A reason it that we have 1 Gee data, and we have some micro gravity data on the rate of deterioration of humans in those two environments
over time.

The Moon would give data also, and finding the rate of deterioration for Muscle, Skeleton, and eyes, for the Moon would give a third
data point, and a form of graphing to make a Mars estimate might be possible. And of course data that applies to the Moon itself would
be obtained.

International sponsorship would reduce legal issues, and it appears that there are parties that have an interest in the Moon, and who
will want data on human performance in the environment also. So, perhaps shared costs.

I would suggest a rotation of one person at a time. Perhaps a lander without a enclosed cabin. Perhaps the person arriving would put
the lander in some type of resting but not shut down mode, and that person would climb off, and the departing person would climb on
and leave immediately.

The Moon would provide crude materials for partial radiation shielding, I would also suggest that when inside their habitat, they might
wear suits with padding of Paraffin wax as more shielding.

Experiments on the Lunar materials might be done to test some manufacturing notions. Certain items manufactured on Earth could be
deployed, and then retrieved and analyzed at the base or returned to Earth for analysis, to determine how well they hold up under the Lunar
conditions.

This would be a precursor to an actual Lunar economy. Companies and nations would gain some fame from being involved, perhaps advertizing
fodder.

I persume that the lander would originate from a space station in a Lagrangian point, and that that station may have a rescue craft to assist
if the lander has a mishap other than actually impacting the lunar surface.

http://en.wikipedia.org/wiki/Lagrangian_point

Last edited by Void (2014-04-23 08:13:39)

Quaoar · 2014-04-23 04:39:45

It's very interesting but a bit expensive and very difficoult to do, because you need to lobby politician of many states. My stuff is very cheep and can be done now with less than 50000 $.

Last edited by Quaoar (2014-04-23 04:41:25)

Void · 2014-04-23 08:34:25

Oh I appologize, I did not get what you were proposing. Clever. Of course it is not the same, as the head would experience significantly less synthetic gravity than the legs, but never-the-less, some data similar to an actual artificial spinning world in space. If the person does not get sick. Couldn't you use one of those Merry-Go-Rounds (Modified) such as they have for children, to run some preliminary tests, and then invest in a built system?

If the person were suspended sideways, of course the Earths gravitation would act on their arms, but perhaps they could run and jump a bit.

I believe that the space program did do something like that with a wall for training crews, early in the program.

If what you propose would prove to work, and give useful data then I might also suggest:

A large circular hovercraft that spins on it's air cushion might work, with a walkway around it's perimeter, where when spinning centrifugal force could hold the persons feet to the walkway (Wall). And the anchor point for the harness being on a track above the platform, so that once spinning, the person could walk around the track, and perhaps even run, if the anchor wheels were free enough.

The air cushion for the spinning hover craft could come out of a conduit in the ground benieth the skirted spinning hover craft, so that it would not need engines on it. That would reduce cost I would think.

This larger size would allow a better simulation, where the synthetic gravitation experienced by the head would be closer to that experienced by the legs.

I would be tempted to return to the Moon though. The point of that being that there are many organizations interested in the Moon, and they might through in on some sort of Moon station, even if it was 2 people for 6 months, one time. Then we would have the Moon data, and if your centrifuge idea was also done for Moon gravitation with 2 people for 6 months, then you could compair the data, and understand just how good your Earth based simulation was at simulation of Lunar gravity's effects on the human body.

The Moon would be somewhat of a freebee, since it might be sponsored by countries like Japan and China and Russia, and also private interests. I don't expect that the US would contribute unless the next elected government was of a much different nature than this one.

It would not hurt to have Moon data and Earth-Centrifuge data. (If possible).

Assuming that so called civilization does not collapse, then eventually given enough time we (Or the inheritors) would have both.

Again I appologize, I should have read more carefully. I am glad you are patient.

Last edited by Void (2014-04-23 08:38:20)

Terraformer · 2014-04-23 16:44:43

http://www.popsci.com/scitech/article/2 … ates-mouse

I don't know what the results were, or whether they managed to achieve partial effective gravity.

Quaoar · 2014-04-24 08:13:58

Terraformer wrote:

http://www.popsci.com/scitech/article/2 … ates-mouse
I don't know what the results were, or whether they managed to achieve partial effective gravity.

This is diamagnetic levitation: animal and human body is composed mostly of water, that is diamagnetic and can be repelled by a very strong magnetic field of almost 16 Tesla (1-2 Tesla is the field of a NMR devicie).
If you put a big superconductive coil on the roof of an ISS module, you can repell the astronauts on the floor, simulating a 1 gee gravity environment, and have also a very good cosmic ray magnetic shielding, both with the same devicie. It sounds fantastic?

But there are four little issues:

1) the coils and the cooling hardware are very massive

2) there are no data on health effect of long term exposition to 10-20 Tesla range magnetic fields

3) in case of cooling failure, the superconductive coils become resistive and will explode like a bomb, realeasing all the energy stored inside (see magnetic quench http://en.wikipedia.org/wiki/Supercondu … net_quench )

4) every ferromagnetic object inside such a field is turned in a bullet.

Last edited by Quaoar (2014-04-24 08:21:39)

Quaoar · 2014-04-24 09:02:05

Void wrote:

Oh I appologize, I did not get what you were proposing. Clever. Of course it is not the same, as the head would experience significantly less synthetic gravity than the legs, but never-the-less, some data similar to an actual artificial spinning world in space. If the person does not get sick.

I imagine a 2.4 m radius centrifuge that can be fitted in a Falcon 9 or Delta IV launced module: astronauts will live in microgravity (if the study is performed on Earth, "ground astronauts" will float head-up in a swiming pool douring the day and stay at bed douring the night) and willl periodically exercise in high gee environment, following a training protocol to be determinated.

At 25 RPM a 1.8 m tall astronaut will experience almost 1.6 gee at the feet, 0.8 gee at the belly, 0.4 gee at the head. At 30 RPM our astronaut will have 2.4 gee at the feet (elastic sox will be needed), 1.2 gee at the belly and 0.6 gee at the head.

They will experience drizzines, but we can try to fix it using augmented reality.
Dizziness is mostly due to disagreement between visual and vestibular inputs, that cause an overstimulation of vestibular nuclei, extended to the dorsal nucleus of the vagus nerve. It can also be experienced reading a book on a moving car: the book doesn’t move but the car does, so there is discordant inputs that may cause dizziness. The same happen in a short arm high spin centrifuge, where dizziness is due of vestibular stimulation by strong Coriolis acceleration, but I think it's possible to correct the discordant sensorial input using some device like google glass and a proper software.

Last edited by Quaoar (2014-04-24 09:16:04)

JoshNH4H · 2014-04-24 09:09:12

Quaoar, as a doctor what is your opinion on the notion that slow spin-up and anti-nausea medication can be used to ease adaptation to high-spin rate environments?

Quaoar · 2014-04-24 09:29:21

JoshNH4H wrote:

Quaoar, as a doctor what is your opinion on the notion that slow spin-up and anti-nausea medication can be used to ease adaptation to high-spin rate environments?

I think it may be work very well: starting with low spin rate, some scopolamine if needed, and gradually spinning-up, I guess astronauts will quickly adapt to Coriolis accelerations, almost like sailors adapts to pitch and roll motion sikness. But I also think we can enhance their comfort in the first days using some kind of augmented reality sofware, to minimize discordant sensorial input

Last edited by Quaoar (2014-04-24 09:30:14)

JoshNH4H · 2014-04-24 09:47:16

Sounds like a good idea to me. My feeling is that if astronauts can adapt to microgravity, they can also probably adapt to high spin rates over time. Either way, with modern medicine as it is I bet the process of adaptation (if for whatever reason we can't simply stick to spinning habitats with larger radii) won't be as bad as the effects of space sickness upon astronauts in the past.

GW Johnson · 2014-04-24 16:17:25

The only problem with an extreme gee gradient is fainting from reduced blood flow to the head, when sitting up or standing. Putting on a gee suit to counter this screws up the deal for experimenting with artificial gravity.

Large-radius artificial gee avoids this, as the gradient is essentially negligible. For 56 m at 4 rpm, I had a rather low number for the gradient, one not much different from sitting vs standing, in terms of cranial blood pressure change. And 4 rpm should be tolerable even to untrained civilians.

You get a much better experiment with a big rig, even if it has to be cable-connected, which is a real bitch to start and stop spinning. Sounds like something we should be building in LEO. Maybe something we should have built instead of the ISS that we did build.

Hindsight is always 20-20, ain't it?

GW

Void · 2014-04-25 08:05:26

For your large radius desires but on Earth:

I would suggest that you try to design a mock up of your baton synthetic gravity device and do it on the surface of the Earth. The bearings for this could be provided as I suggested before with a hovercraft air cushion. The air input for this could occur from air handlers outside of the device and by feeding the output of the air handlers into the center pivot point. The “Baton” could have multiple centrifuge “Floors”. 1) Asteroid simulations. 2) Dwarf Planet Simulation (Ceres). 3)Lunar simulation. 4)Mars simulation.
So as has been stated a harness and/or frame (With wheels) could counteract the actual Earth Gravitational field. A flexible neck brace (Maybe with a cable system attached to a counterweight with pulleys that counteracts 1 gee for the head, and similar methods for the arms and legs. The system would need to allow the person to rotate from left side down to right side down, and from face down to face up (Actual gravity as the reference for this). The frame with counterweight compensators should also have wheels/slides, so that the person with their feet planted against the centrifugal floor could walk a bit.
This would not only allow testing of synthetic gravitation against the long axis of a human body, but would also allow you to actually estimate just how large the radius needs to be to keep humans comfortable, and it also might help in determining which people can deal with a shorter radius.

But a different and more simple method. I have seen that some unfortunate people have stayed in bed to simulate zero gee?
What about tilting the bed so that their feet push against the “Foot Board” to the value of 1/3 gee?
Make a “V” structure and tilt the “V” in the Earth’s gravitational field, thus dividing the field into a 1/3 part that is applied to the long axis of the human body, and the remaining 2/3 being applied to hold the shorter axis of the human body against the “Mattress”. But not a mattress actually a hard floor that wheels can work on. Build a body frame, with wheels, and counterweight/ pulley systems to help levitate the most movable body parts (Head, arms, legs).

Last edited by Void (2014-04-25 14:12:26)

Quaoar · 2014-04-26 07:13:04

JoshNH4H wrote:

Sounds like a good idea to me. My feeling is that if astronauts can adapt to microgravity, they can also probably adapt to high spin rates over time. Either way, with modern medicine as it is I bet the process of adaptation (if for whatever reason we can't simply stick to spinning habitats with larger radii) won't be as bad as the effects of space sickness upon astronauts in the past.

If you go in a marina and observe desembarking yachtsmen, you can see single hull sailors waiving left and right while walking and catamaran sailors raising and crouching like kangaroos. This beacuse douring cruise, theiy have developed some kind of motor program to minimize the roll of a single hull sailboat or the up-down motion of a catamaran. And now that they are programmed to cancel boat motion, after disembarking they may experience "ground sikness", because now the not moving ground gives them discordant sensorial inputs.
I guess for astronaut will be the same. Douring a 6 month cruise on a 25 meter of radius, 6 RMP spinning spaceship (slightly shorter than GW's modular spaceship), astronauts will learn how to move in a way to compensate Coriolis accelerations: automatically shifting their barycenter anti-spinward when they rise to not fall spinward or shifting barycenter spinward when they crouch to not fall anti-spinward. When they return to Earth, having spent the criuse in artificial gravity, their bones and muscles would be perfect but their brains would be still programmed to neutralize Coriolis acceleration and would need some days to change program. Douring this days, they probably would have "Earth sickness".

To help astronauts enproving adaptation in artificial gravity, it may be useful some kind of google glass, that sligly distort their vision to compensate Coriolis acceleration.

But there is another consideration about differences between individuals: there are people who can read in a mooving car without problems and people who have motion sickness if not looking outside. People that never experienced sea sickness even in a gale and people who start to vomit just when they board a boat in a harbor. I guess the cause may be in the connections between vestibular nuclei and dorsal nucleus of the vagus nerve: people with many connections would experience dizziness very easly and people with few connections would be very resistant.

Last edited by Quaoar (2014-04-26 07:18:13)

Quaoar · 2014-04-26 07:43:33

GW Johnson wrote:

The only problem with an extreme gee gradient is fainting from reduced blood flow to the head, when sitting up or standing. Putting on a gee suit to counter this screws up the deal for experimenting with artificial gravity.

Douring 20-30 RPM cicle, if not a gee-suit, astronaut will surely need some kind of elastic garmet to counteract fluid shift in the lower limbs. But I guess a short arm-centrifuge will be used at high RPM high gee for multiple short periods to mantain bones and muscle and low RPM low gee for longer period in order to avoid microgravity body fluid shift. Optimal centrifugation protocol has to be determinated.

GW Johnson wrote:

Large-radius artificial gee avoids this, as the gradient is essentially negligible. For 56 m at 4 rpm, I had a rather low number for the gradient, one not much different from sitting vs standing, in terms of cranial blood pressure change. And 4 rpm should be tolerable even to untrained civilians.

Your spinning spaceship is the top, but I think even with her, a short arm centrifuge may be useful as an auxiliary artificial gravity devicie: there are still situations where your ship cannot spin. For example, if you want to couple chemical rockets with electric propulsion, it may be difficoult to spin when ion thrusters are firing.

GW Johnson wrote:

You get a much better experiment with a big rig, even if it has to be cable-connected, which is a real bitch to start and stop spinning. Sounds like something we should be building in LEO. Maybe something we should have built instead of the ISS that we did build.
Hindsight is always 20-20, ain't it?
GW

If spin and despin operations are computer controlled and done with RCS perfectly syncronized and cable kept in tension by canted outward retrorockets, it may be not such a bitch... Or not?

Last edited by Quaoar (2014-04-26 09:35:14)

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#1 2014-04-16 03:52:27

Cheep simulation of low gee environment

#2 2014-04-21 10:12:03

Re: Cheep simulation of low gee environment

#3 2014-04-23 04:39:45

Re: Cheep simulation of low gee environment

#4 2014-04-23 08:34:25

Re: Cheep simulation of low gee environment

#5 2014-04-23 16:44:43

Re: Cheep simulation of low gee environment

#6 2014-04-24 08:13:58

Re: Cheep simulation of low gee environment

#7 2014-04-24 09:02:05

Re: Cheep simulation of low gee environment

#8 2014-04-24 09:09:12

Re: Cheep simulation of low gee environment

#9 2014-04-24 09:29:21

Re: Cheep simulation of low gee environment

#10 2014-04-24 09:47:16

Re: Cheep simulation of low gee environment

#11 2014-04-24 16:17:25

Re: Cheep simulation of low gee environment

#12 2014-04-25 08:05:26

Re: Cheep simulation of low gee environment

#13 2014-04-26 07:13:04

Re: Cheep simulation of low gee environment

#14 2014-04-26 07:43:33

Re: Cheep simulation of low gee environment

#15 2022-07-09 05:07:36

Re: Cheep simulation of low gee environment

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