New Mars Forums

Official discussion forum of The Mars Society and MarsNews.com

You are not logged in.

Announcement

Announcement: We've recently made changes to our user database and have removed inactive and spam users. If you can not login, please re-register.

#51 2019-10-18 04:30:56

Terraformer
Member
From: Lancashire
Registered: 2007-08-27
Posts: 3,161
Website

Re: Artificial 1g Gravity on Mars vs in Space

(Also posted on My Hacienda)

If being used for exercise, how big does a centrifuge have to be? Could we do a full regimen lying down, allowing us to get away with quite a small radius?


"I guarantee you that at some point, everything's going to go south on you, and you're going to say, 'This is it, this is how I end.' Now you can either accept that, or you can get to work." - Mark Watney

Offline

#52 2019-10-18 06:18:54

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 225

Re: Artificial 1g Gravity on Mars vs in Space

Living in 1g on Mars would mean building big centrifuges with thrust bearings and electric motors to keep them spinning.  And they would need a big rotation radius in order to avoid Coriolis sickness.  Possible, but not cheap.


Interested in space science, engineering and technology.

Offline

#53 2019-10-18 06:27:05

louis
Member
From: UK
Registered: 2008-03-24
Posts: 5,333

Re: Artificial 1g Gravity on Mars vs in Space

Depends what we are talking about. In order to get the 1G effect for your muscles and bones all you would need is a suit and boots massing just under twice your body mass. That's probably not going to happen (because it might interfere with work)  but I could imagine some weighted clothing being worn in order to maximise the benefits of Mars gravity.

Later, 1G sleep pods might be developed. Also, I think for purposes of gestation and healthy foetal development, it's quite possible women will spend several months in a 1 G environment either on the surface or, more likely, in orbit.


Calliban wrote:

Living in 1g on Mars would mean building big centrifuges with thrust bearings and electric motors to keep them spinning.  And they would need a big rotation radius in order to avoid Coriolis sickness.  Possible, but not cheap.


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

Offline

#54 2019-10-18 06:33:44

Terraformer
Member
From: Lancashire
Registered: 2007-08-27
Posts: 3,161
Website

Re: Artificial 1g Gravity on Mars vs in Space

There's little point to sleeping in 1g. Particularly in space, since it makes more sense to use the central, best shielded part of the spaceship for sleeping.


"I guarantee you that at some point, everything's going to go south on you, and you're going to say, 'This is it, this is how I end.' Now you can either accept that, or you can get to work." - Mark Watney

Offline

#55 2019-10-18 06:53:52

louis
Member
From: UK
Registered: 2008-03-24
Posts: 5,333

Re: Artificial 1g Gravity on Mars vs in Space

I was thinking of on the Mars surface, if you're living there for maybe 4 or more years. It might be important to prevent eye disease, issues re the heart  and problems with the immune system - the micro effects of not living in 1G. On the other hand we might find living in 0.38 G is sufficient to overcome these issues.

Terraformer wrote:

There's little point to sleeping in 1g. Particularly in space, since it makes more sense to use the central, best shielded part of the spaceship for sleeping.


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

Offline

#56 2019-10-18 07:23:52

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 225

Re: Artificial 1g Gravity on Mars vs in Space

Terraformer wrote:

There's little point to sleeping in 1g. Particularly in space, since it makes more sense to use the central, best shielded part of the spaceship for sleeping.

Indeed.  The effects of 0g on the body are very similar to the effects of bed rest, to the extent that bed rest is used here on Earth as a reasonably good proxy for modelling the effects of zero g.  This suggests that a fully grown adult could sleep in zero g with little ill effect, provided that their waking hours were mostly spent in gravity.

But there is another less well known reason for zero g deterioration of bones.  Without the force of gravity, new bones cells cannot align themselves properly when attaching to the bone matrix.  This is likely to be especially problematic for anyone still growing, especially babies and small children.  Everyone sent into space so far has been fully grown.  Whether 0.38g is sufficient gravity to prevent issues of this type, I do not know.  I am tempted to say 'probably yes' given that 0.38g is still substantial gravity.  We won't know for sure until we carry out partial gravity experiments on developing animals in orbit.

Last edited by Calliban (2019-10-18 07:26:47)


Interested in space science, engineering and technology.

Offline

#57 2019-10-18 19:06:58

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 17,382

Re: Artificial 1g Gravity on Mars vs in Space

So how do we nail down the levels of gravity to see what the line of ailments will be along the line from 0 to 1g increments.

We have no data points and the moon while its not 0g has its own open hazards for man on its surface.

I remembered that Nasa created a microgravity device to simulate on earth what it might feel like once in orbit. I was wondering if its speed could be slowed tosimulate the other levels of gravity.

PG82S95.GIF

The Gimbal Rig Mercury Astronaut Trainer


Can we crowd fund a new effort to learn before we get there....

Offline

#58 2019-10-18 19:10:27

louis
Member
From: UK
Registered: 2008-03-24
Posts: 5,333

Re: Artificial 1g Gravity on Mars vs in Space

I disagree. I think you are confusing the issue of muscle/bone loss for which bed rest is a good 0G analog with other issues for which I don't think bed rest gives the same results. 

I think gravitational pull would give the heart muscle the right gravitational workout in your sleep. We don't fully understand the eye and immunity decline issues, but they are likely to be a direct result of 0G, so 1G sleep could help. Obviously this would all need to be tested for effectiveness. A 1G working environment on the Mars surface during hours awake is simply not a practical proposition, I think. During sollight, I think the pioneers should wear weighted suits and boots. Once the base is established, building sleep pods might become a practical possibility. 

Yes, one criticism I have of Musk is he seems to blithely assume people can move to Mars, start reproducing successfully and that children can grow up healthily there. I think it could take 50 years or more like 100 years before we have sorted out all the health issues so that humanity can live there healthily, reproduce and grow through childhood successfully.  A lot of work to be done!


Calliban wrote:
Terraformer wrote:

There's little point to sleeping in 1g. Particularly in space, since it makes more sense to use the central, best shielded part of the spaceship for sleeping.

Indeed.  The effects of 0g on the body are very similar to the effects of bed rest, to the extent that bed rest is used here on Earth as a reasonably good proxy for modelling the effects of zero g.  This suggests that a fully grown adult could sleep in zero g with little ill effect, provided that their waking hours were mostly spent in gravity.

But there is another less well known reason for zero g deterioration of bones.  Without the force of gravity, new bones cells cannot align themselves properly when attaching to the bone matrix.  This is likely to be especially problematic for anyone still growing, especially babies and small children.  Everyone sent into space so far has been fully grown.  Whether 0.38g is sufficient gravity to prevent issues of this type, I do not know.  I am tempted to say 'probably yes' given that 0.38g is still substantial gravity.  We won't know for sure until we carry out partial gravity experiments on developing animals in orbit.


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

Offline

Board footer

Powered by FluxBB