Low gravities and colonization. A show stopper? - Any suggestions apart from exercising?

atitarev · 2004-07-06 20:45:04

Most solid planets/moons have gravity lower than Earth, which will put off people from settling permanently on smaller bodies. This includes Mars with its 3.71 m/s2 surface gravity and the Moon with 1.62 m/s2. The smaller the body, the more danger to health. Well, if somebody decides to settle permanently on a moon, they will feel comfortably there but coming back to Earth might be a problem. Is there anything we can do about it with the current knowledge of medicine? Or, does anybody know about the research results? I've heard about about experiments with mice (exposed to low and 0 G) but don't know what happened.

Planet/Satellite Name Surface Area (square km) Observed surface gravity (m/s2)
Mercury 74,815,144 3.7
Venus 460,234,317 8.87
Earth 511,209,977 9.81
Moon 37,958,532 1.62
Mars 145,011,003 3.71
Io 41,396,452 1.79
Europa 30,935,401 1.31
Ganymede 86,986,441 1.42
Callisto 72,382,295 1.23
Titan 83,322,891 1.36
Titania 7,822,830 0.372
Oberon 7,277,449 0.346
Triton 22,902,210 0.783
Pluto 16,245,414 0.651
Charon 4,315,241 0.334

Here are some FAQ about gravity (and other health hazards) answered by an astrobiologist. Exercise is the only method used so far.
http://weboflife.ksc.nasa.gov/faq.htm]Ask the astrobiologist

MarsDog · 2004-07-06 21:18:04

Sitting and watching TV in an Artificial Gravity Machine for several hours a day is not a great hardship. Artificial Gravity swimming pool next?
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There are people who get no exercise, and then do 30 chin-ups. Not your average person, but then, space pioneers will self select.
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I am suprised that athletes do not train under artificial gravity.

atitarev · 2004-07-06 23:40:03

Sitting and watching TV in an Artificial Gravity Machine for several hours a day is not a great hardship. Artificial Gravity
swimming pool next?
-
There are people who get no exercise, and then do 30 chin-ups. Not your average person, but then, space pioneers will self select.
-
I am surpassed that athletes do not train under artificial gravity.

Yeah, an artificial gravity machine should be a must-have on domed asteroids for sure.

I wonder, why NASA haven't done any tests on animals yet, as if they are not planning to send humans to Mars, the Moon, etc. We could have a few generations of mice or monkeys bred in Martian or Lunar G.

karov · 2004-07-07 01:47:13

Low gravity tolerability of the human body really could impose a barrier to free colonisation of environments under 1 G.

Now is planned an Australian experiment where the full lifecycle of rats will be tested in martian-equivalent of gravity.
I hope that at least about 30% of gees would be enough for complete lifecycle of human beings to deploy... But appart of home centrifuges and excessive eexcersising, there are several ideas for compensating the effects of low or microgravity, allowing longduration or all-life stay. I mean technics and technologies which do not need permanent alienation from the earth-model of human organism.

The immediate harms on the human physics come from: bone and muscle loss + some cardio-vascular problems derived from the different blood presure distribution in the body which in low G has not the ability to stay errect.

First: reversible or irreversible genetic alteration of the basic human body design ( indistinguishable on surface by naked eye, i.e. no cosmetic or esthetic problems ). The genethic reprograming of mature human organisms, appear to be easier and more programable, than prenatal one, according to recent studies in the field of organ cloning and tissue engineering. Such genes-complex material could be borrowed, say, from certain water inhabiting vertebrates which it seems don`t suffer from micro-g problems; or written from scratch...

Second: a swarm of nanobots in the body which to repair it constantly from the damages caused by the low G, i.e. internal 1 G emulation.

Third: 'Utility Fog' in the habitats directing force in such way - to generate 1 G equivalent push - consisting of trillions of tiny smart robots fine dust... indeed perfect for simulating gravity in closed environments -- rooms, space ships and small non-rotating stations... If the necessary density of the Fog is too big for air transperancy, the Fog should play the role to pretend 'non-present' projecting the light of the surroundings like passing in pure air...

Indeed it could occur that treatment with cetain medicines could do the work for counter-measuring the effects of long stay in low G.

Ian Flint · 2004-07-07 08:23:46

Karov, those ideas sound good...for a sci-fi novel. Maybe they will be possible in a century or two, but I don't see nano technology or genetic alterations playing any part in space colonization in the near future. For now I would be ok with using a centrifuge.

MarsDog · 2004-07-07 13:08:29

Substituting for the effects of gravity may get as small as a large rubber hammer or medicine ball impacting on effective body locations. Fire the Mars settler, several times a day, from a circus cannon ?

BWhite · 2004-07-07 13:19:09

Fetal development is the mission critical issue.

clark · 2004-07-07 13:37:14

So here is the thing, why is it so important that we be able to have children born in space, or off earth?

We could still conceivably colonize Mars- perhaps Martian parents would adopt Earth children (at whatever safe developmental age) as a proxy to having their own- or martian mothers would make the trek back to earth to bear a child (like salmon swimming up stream).

I'll grant you that it will limit how far we can go... but at least the solar system.

Cobra Commander · 2004-07-07 13:37:48

Limiting ourselves to immediately available technology, a few possibilities stand out. Large centrifuges could be useful, they don't even have to be used in an "exercise program" per se, colonists may be able to work in them at times, read in them, watch a movie, just make every colonist sleep in one if all else fails. Though long-term use may cause other problems...

On a more mundane level, use weighted clothing and encourage manual labor. As much as possible, do everything manually, it's good for the colonists and every task performed by humans is one less machine to break down. Intentionally take a low-tech approach to everything that can accomodate it, particularly if it involves some physical exertion. Rotate the colonists through these tasks, instill a healthy respect for manual work. One could even make tools heavier than they need to be for certain tasks, just to increase the health benefits, though this would have to wait until some Martian manufacturing ability was established. No sense launching 4 kilo pipe wrenches when a pair of 5 ounce channel-locks will do... And of course such "unnecessary" exertion will require a modest increase in food as each colonist burns more calories going about their daily business.

Efficiency may be a rather subjective term in some respects.

dicktice · 2004-07-07 17:18:41

Is one gee optimum for the human-type organism: Isn't that the question? How to determine this on Earth, at least to start with, with later confirmation budgeted for the ISS, should be discussed. Using horizontal centrifuges, overspeeding with inner occupation, underspeeding with outer occupation. Remain prone to minimize the vertical component. Range between 0.6 gee and 1.4 gees, say.

atitarev · 2004-07-07 21:33:15

Thanks all for posting. I guess, the research of low G impact on human health and ways to reduce it should be of high priority. It will determine the way we go in space exploration and settlement. I don't think we will be settling gas giants (thanks Karov, it sounds interesting but I just can't get my head around this possibility ). I like your optimism, though. Things are done by optimists. In my opinion we can settle only on solid planets/moons.

If we are limited to the minimum of 30% Earth G - we have only Venus, Mars and Mercury to work with. Settlements somewhere else will only be possible if we get enough artificial gravity machines or come up with the method to counter the impact. The lowest limit of about 10% of Earth gravity would give us the Moon, Ganymede, Callisto, Europa, Io and Titan - not bad. On these moons even heavy suits and boots could work for extra exercise. I imagine the gravity machines could be quite big and expensive.

Should we go about terraforming small moons if we know that people who settle there would have it hard to return to Earth? They would have new plant and animal species adjusted to the low gravity. I mean, we could get a new human race raised on the Luna type of moons who feel quite comfortable where they are. Do you think, it's inhumane? Everyone would be aware of the risks, so it's a free choice. What's your opinion on this?

As for people going to low gravity objects for work - a research would explain how long people can live on a particular body. A record stay in 0 G was over a year - the Russian cosmonaut who did it required some adaptation back on Earth but recovered well. Low G is better than 0 G and enhanced with vitamins and exercise would mean a permissable stay on a Luna type object could reach 5-10 years - sufficient time if we want to go Jupiter's and Saturn's moons - where a short stay wouldn't make sense.

Let's not say what is possible and what is not until it's proven. I'm eager to see how the experiments with animals in low gravity will go.

Karov, could you give me a link describing the test with rats, you were talking about?

karov · 2004-07-08 02:10:37

The simulated Martian gravity project link:

http://www.marssociety.org/translife/re … 5Feb02.PDF

karov · 2004-07-08 03:04:04

Karov, those ideas sound good...for a sci-fi novel. Maybe they will be possible in a century or two, but I don't see nano technology or genetic alterations playing any part in space colonization in the near future. For now I would be ok with using a centrifuge.

Yes, we can not talk about any kind of 'space colonisation in the near future'. If we regard the next 50 years as near future it is obvious that it will be a time of robotic probing, some 'permanent' earth-orbital, lunar and with low possibility martian crewed basing... + space tourism -- suborbitals and short stays in LEO 'hotels'. BTW, the major human traffic should consist namely from these space tourists - pushed to 100 km hight and minor part of them shortstaying for weeks in LEO stations.

Grand scale human presence, habitats building, colonisation and terraforming is job to be done in the next millennium or two, when huge industrial infrastructure is establihed off-earth and substantial part of the Gross Human Product is made out there, i.e. when it is economically profitable and necessary to be commited such activities.

Even in the case of Mars after a century it will has not enough population to occur in their minds that it is their immediate task to terraform the planet -- because the terraforming of Mars is job of its fuiture inhabitants in their favour, not to the earthlings.

Rxke · 2004-07-08 03:26:37

Just to point out that sleeping in centrifuge doesn't help much... You have to be active under G-loads. ESA did some long-time low-g simulations, to compare with Rusian long-duration stays in LEO... And they did it with people just laying in bed for weeks, never sitting up, not to eat, wash etc.
The effects are virtually the same as low-g... Bone-loss etc, while they were of course on Earth, in a 1g enviro!

karov · 2004-07-08 03:39:51

So here is the thing, why is it so important that we be able to have children born in space, or off earth?
We could still conceivably colonize Mars- perhaps Martian parents would adopt Earth children (at whatever safe developmental age) as a proxy to having their own- or martian mothers would make the trek back to earth to bear a child (like salmon swimming up stream).
I'll grant you that it will limit how far we can go... but at least the solar system.

If the martian gravity has harmfull consequences on human pregnancy and fetal development, the colonist`s mother aren`t due to go to Earth. Rotating space colony wide enough the Corioliss effect to be insignificant close to Mars is OK for pregnancy and birth place or even kindergarden under 1 G at the 'floor'.

But the whole point is that if such measures appear to be necessary. If on Mars the humans can`t be born and rased without harm why at all to bother terraforming and inhabiting it.

If lower than 1 G environment occurs to be uninhabitable for humans lifelong (birth-growth-dying) cycle than it is obvious that the low-gees planets are not suitable for unmodified human ( or just humans ) and we`ll have to occupy only -- solid bodies, rotating tube worlds + eventually artificial solid shells around bigger bodies. Both the last -- fully artificial wolds -- offer enormously bigger living area than earthlike planets: the Supra-Sun multilayered shell structure could have 300 000 000 000 times the earth area, the same figure as with the Pat Gunkle`s makaroni habitat of continuous rotating tube 1000 to 5000 km wide and many light years long messed around the central star -- the upper limit is the total energy output of the Sun.

My personal bet, although, is that with reversible, cheap and non-freaking measures the human permanent settlement of low G environments shall be practical + everything necessary for traveling between the different gees colonies of their inhabitants with minor means of adaptation.

Shaun Barrett · 2004-07-08 08:24:21

Hi Rik!
This is off-topic. The subject of your English has come up recently and I repeated what I said before, that I think your command of the language is extremely good. (Better than half the native English-speakers I know! )

But I think you are falling into a trap which ensnares probably the majority of even people whose first language is English. Without wishing in any way to be critical, may I point out a small error in your recent post, which happens to be a pet hate of mine among English-speakers?

" ... people just laying in bed for weeks .. "

There are two verbs which are constantly being muddled up: 'To lie' and 'to lay'. (And we're ignoring another version of 'to lie', which is used to express the relaying of untruths! )

'To lie' is an intransitive verb which has no object. It's main tenses are:-
I lie (down)
I lay (down)
I have lain (down)
This is the verb you were using in your post and the correct usage in the context of your sentence was: " ... people just lying in bed for weeks .. "

'To lay' is a transitive verb which has an object. It's main tenses are:-
I lay (my burden down)
I laid (my burden down)
I have laid (my burden down

You can lay carpet on the floor or lay flowers on a grave but you can't lay in bed.

Just trying to be helpful, Rik. Hope you aren't insulted or anything. I'll go away now!

MarsDog · 2004-07-08 11:39:15

Just to point out that sleeping in centrifuge doesn't help much... You have to be active under G-loads. ESA did some long-time low-g simulations, to compare with Rusian long-duration stays in LEO... And they did it with people just laying in bed for weeks, never sitting up, not to eat, wash etc.
The effects are virtually the same as low-g... Bone-loss etc, while they were of course on Earth, in a 1g enviro!

If you slam your hand on a table, the hand, including the bones, will become stronger. Can banging your head against the wall improve your thinking ?

Rxke · 2004-07-08 14:25:08

*Thanks, Shaun. I kinda knew i was making a mistake when i wrote it, but was too tired, and thought "lying there" was telling lies in bed at that point (Oh, language, fuzzy-headedness... What a combination!) So instead of re-phrasing my sentence to avoid the problem (like saying 'reclined position prolonged studies' or something similar high-brow...) i just put it up.

*Marsdog, don't have the faintest clue what you mean, referring to my misspelt post, though...
Or do you mean you're hoping that the current state you're in (actively banging your hand against a wall in desperation from hearing this bad news) might have some positive side-effects?

MarsDog · 2004-07-08 14:37:57

I was trying to make a joke of the remedies to a low G environment. Some martial artists do bang their hands on a hard surface. But, having their heads banged may increase the calcium content while decreasing their intelligence.

atitarev · 2004-07-08 18:44:43

The simulated Martian gravity project link:
http://www.marssociety.org/translife/re … 5Feb02.PDF

Thanks a lot, Karov! It's a great 20 page document.

Here's a summary:

The science produced by this proposed mission will be groundbreaking in a number of respects: it will be the first to gather systematic data on the effects of 3/8-g on mammals; the first to study the effect of prolonged rotation of mice in orbit; the first to study mammalian birth and postnatal development in orbit; and the longest rodent mission ever flown. With all of these innovations, the true challenge is to develop a mission that produces statistically significant science with distinct relevance both to human habitation at Martian g-levels and to the use of artificial gravity as a countermeasure to the physiological deconditioning currently seen in microgravity flight.

http://www.marsgravity.org/main/]Mars Gravity - main page.

Rxke · 2004-07-09 02:03:15

It's crazy this stuff has not been done on ISS ages ago... With lower life-forms at least.
How difficult would it be to build a simple as possible mini-centrifuge, w/o all the whizz-bang stuff they always want to incorporate, and wich breaks down ... containing newts, frogs, ants, spiders or other smaller stuff...
Esp. frogs would be interesting, looking how they evolve from egg to 'full-frog' in different G's...

atitarev · 2004-07-09 02:35:52

It's crazy this stuff has not been done on ISS ages ago... With lower life-forms at least.
How difficult would it be to build a simple as possible mini-centrifuge, w/o all the whizz-bang stuff they always want to incorporate, and wich breaks down ... containing newts, frogs, ants, spiders or other smaller stuff...
Esp. frogs would be interesting, looking how they evolve from egg to 'full-frog' in different G's...

I agree with you 100%, Rik.

dicktice · 2004-07-09 10:17:30

Just to point out that sleeping in centrifuge doesn't help much... You have to be active under G-loads. ESA did some long-time low-g simulations, to compare with Rusian long-duration stays in LEO... And they did it with people just laying in bed for weeks, never sitting up, not to eat, wash etc.
The effects are virtually the same as low-g... Bone-loss etc, while they were of course on Earth, in a 1g enviro!

Wouldn't it be great if somewhat less than 1-g could lead to longer useful lifetimes? The ESA finding suggests a way to find out without involving the ISS, if staying flat in bed for weeks produces results simular to Russian long-duration stays in LEO. For instance:
If you were to lie flat in a molded bed (to prevent sliding off) at the end of a centrifudge, head inward, and spun-up to 1/6th-g, wouldn't that be a first approximation of Moon gravity? 1/3rd-g, for Mars gravity? 1-g, for Earth gravity (to see if health remains okay)? 1+g ,with increases in small increments (to see how health degrades with increasing gravity)? Wouldn't this be a way to determine [to a first approximation] if 1-g is optimum? And, what if it isn't. . . ?

Ian Flint · 2004-07-09 10:31:17

I don't think that would work, because from the report it seems that you have to be moving around and using your muscles. But hey, let's get some human guinnea (sp?) pigs and try it!

dicktice · 2004-07-09 11:00:14

They weren't lying horizontal in bed, at the end of a centrifuge, which says to me that the body-height aligned force of gravity is vital. So, by adding calibrated amounts of horizontally-applied force aligned with the body height-axis, it should work. I'm not volunteering, myself, but there must be lots of warm bods out there who wouldn't mind being paid to lie down for a few weeks at a time, being fed and entertained and attended-to as required. I wouldn't mind being on the team that figures out how to go about it though. Another project of the Mars Society, perhaps? Worth discussing in a new thread? ???

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#1 2004-07-06 20:45:04

Re: Low gravities and colonization. A show stopper? - Any suggestions apart from exercising?

#2 2004-07-06 21:18:04

Re: Low gravities and colonization. A show stopper? - Any suggestions apart from exercising?

#3 2004-07-06 23:40:03

Re: Low gravities and colonization. A show stopper? - Any suggestions apart from exercising?

#4 2004-07-07 01:47:13

Re: Low gravities and colonization. A show stopper? - Any suggestions apart from exercising?

#5 2004-07-07 08:23:46

Re: Low gravities and colonization. A show stopper? - Any suggestions apart from exercising?

#6 2004-07-07 13:08:29

Re: Low gravities and colonization. A show stopper? - Any suggestions apart from exercising?

#7 2004-07-07 13:19:09

Re: Low gravities and colonization. A show stopper? - Any suggestions apart from exercising?

#8 2004-07-07 13:37:14

Re: Low gravities and colonization. A show stopper? - Any suggestions apart from exercising?

#9 2004-07-07 13:37:48

Re: Low gravities and colonization. A show stopper? - Any suggestions apart from exercising?

#10 2004-07-07 17:18:41

Re: Low gravities and colonization. A show stopper? - Any suggestions apart from exercising?

#11 2004-07-07 21:33:15

Re: Low gravities and colonization. A show stopper? - Any suggestions apart from exercising?

#12 2004-07-08 02:10:37

Re: Low gravities and colonization. A show stopper? - Any suggestions apart from exercising?

#13 2004-07-08 03:04:04

Re: Low gravities and colonization. A show stopper? - Any suggestions apart from exercising?

#14 2004-07-08 03:26:37

Re: Low gravities and colonization. A show stopper? - Any suggestions apart from exercising?

#15 2004-07-08 03:39:51

Re: Low gravities and colonization. A show stopper? - Any suggestions apart from exercising?

#16 2004-07-08 08:24:21

Re: Low gravities and colonization. A show stopper? - Any suggestions apart from exercising?

#17 2004-07-08 11:39:15

Re: Low gravities and colonization. A show stopper? - Any suggestions apart from exercising?

#18 2004-07-08 14:25:08

Re: Low gravities and colonization. A show stopper? - Any suggestions apart from exercising?

#19 2004-07-08 14:37:57

Re: Low gravities and colonization. A show stopper? - Any suggestions apart from exercising?

#20 2004-07-08 18:44:43

Re: Low gravities and colonization. A show stopper? - Any suggestions apart from exercising?

#21 2004-07-09 02:03:15

Re: Low gravities and colonization. A show stopper? - Any suggestions apart from exercising?

#22 2004-07-09 02:35:52

Re: Low gravities and colonization. A show stopper? - Any suggestions apart from exercising?

#23 2004-07-09 10:17:30

Re: Low gravities and colonization. A show stopper? - Any suggestions apart from exercising?

#24 2004-07-09 10:31:17

Re: Low gravities and colonization. A show stopper? - Any suggestions apart from exercising?

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Re: Low gravities and colonization. A show stopper? - Any suggestions apart from exercising?

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