Author Topic: Human "mars gravity" experiment in orbit  (Read 10563 times)

Offline AlexCam

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Human "mars gravity" experiment in orbit
« on: 08/31/2011 08:00 pm »
Have there been concepts of such an experiment/mission yet? Basically a small Salyut-type space station module as a free-flyer that is put into spin with a tether to the upper stage of the rocket that put it in orbit or some other counterweight.

Crew of 2 (or more) dock with the module and start the spinning to simulate Mars gravity. Crew stays there for several months to study the effects of Mars gravity.

Anyone know of any plans for such a mission?

Offline Jim

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Re: Human "mars gravity" experiment in orbit
« Reply #1 on: 08/31/2011 08:12 pm »
No requirement for such missions

Offline AlexCam

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Re: Human "mars gravity" experiment in orbit
« Reply #2 on: 08/31/2011 08:18 pm »
No requirement for such missions

Why? Do we have enough data on the long-term effects of Mars gravity on the human body (or any low gravity environment)?

Offline aquanaut99

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Re: Human "mars gravity" experiment in orbit
« Reply #3 on: 08/31/2011 08:22 pm »
No requirement for such missions

Why? Do we have enough data on the long-term effects of Mars gravity on the human body (or any low gravity environment)?

Why would we need that? We're not going to Mars, not before the end of this century.
« Last Edit: 08/31/2011 08:22 pm by aquanaut99 »

Offline AlexCam

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Re: Human "mars gravity" experiment in orbit
« Reply #4 on: 08/31/2011 08:25 pm »
No requirement for such missions

Why? Do we have enough data on the long-term effects of Mars gravity on the human body (or any low gravity environment)?

Why would we need that? We're not going to Mars, not before the end of this century.

It's a fairly cheap experiment. It's still novel and the data gained is valuable, at least as far as I see it. Humans will go to Mars at some point. Knowing how quickly (or if) we adapt to Mars gravity is quite important.

Offline Robotbeat

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Re: Human "mars gravity" experiment in orbit
« Reply #5 on: 08/31/2011 08:33 pm »
No requirement for such missions

Why? Do we have enough data on the long-term effects of Mars gravity on the human body (or any low gravity environment)?

Why would we need that? We're not going to Mars, not before the end of this century.
It's impossible for you to project that far ahead. People said the same thing about flight to the Moon a century ago... there's no way they could've predicted WWI leading to WWII leading to the Cold War (which is what provided the impetus for going to the Moon).

Going to Mars is FAR less outlandish now than going to the Moon was a century ago.

I know, I know, you like to say how space exploration is dead, the world is ending, etc, etc, etc.
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Offline Will

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Re: Human "mars gravity" experiment in orbit
« Reply #6 on: 08/31/2011 08:36 pm »
No requirement for such missions

Why? Do we have enough data on the long-term effects of Mars gravity on the human body (or any low gravity environment)?

Why would we need that? We're not going to Mars, not before the end of this century.

Note that the same module, spun slower, can answer similar questions about the long term affect of  lunar gravity.

Offline Patchouli

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Re: Human "mars gravity" experiment in orbit
« Reply #7 on: 08/31/2011 08:37 pm »
Going with a high ball figure of 3 rpm for the angular velocity the radius could be 32 meters.

Very easy for a tether and possibly even doable for reasonable costs with a rigid truss.

Low cost a BA330 tethered to a Dragon might work.

Cons there would be no way to visit the Dragon spacecraft during the experiment.

I don't think a Dragon tether to the upper stage would really do this experiment justice as they crew would not have much room which would skew the data.

Though it might be possible to use an extendable truss to link the hab with it's upper stage  and have docking located at the barycenter of the two masses.

Most of the truss length would be empty and lack a pressurize tunnel.
« Last Edit: 08/31/2011 08:41 pm by Patchouli »

Offline AlexCam

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Re: Human "mars gravity" experiment in orbit
« Reply #8 on: 08/31/2011 08:49 pm »
Going with a high ball figure of 3 rpm for the angular velocity the radius could be 32 meters.

At 3 rpm vertigo will occur in most subjects. 1 rpm is what we should strive for.

Offline Patchouli

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Re: Human "mars gravity" experiment in orbit
« Reply #9 on: 08/31/2011 09:03 pm »
Going with a high ball figure of 3 rpm for the angular velocity the radius could be 32 meters.

At 3 rpm vertigo will occur in most subjects. 1 rpm is what we should strive for.

Lowest quote I seen was 2 rpm which was suggested by Robert R. Gilruth in 1969.
A 74M radius could provide this but you may loose the option of a rigid truss.
The 3 rpm figure I used was arrived at by D. Bryant Cramer in 1985.

1 rpm is doable but you'll have to use a tether.
« Last Edit: 08/31/2011 09:12 pm by Patchouli »

Offline AlexCam

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Re: Human "mars gravity" experiment in orbit
« Reply #10 on: 08/31/2011 09:06 pm »
Going with a high ball figure of 3 rpm for the angular velocity the radius could be 32 meters.

At 3 rpm vertigo will occur in most subjects. 1 rpm is what we should strive for.

Lowest quote I seen was 2 rpm which was suggested by Robert R. Gilruth in 1969.
A 74M radius could provide this but you may loose the option of a rigid truss.
The 3 rpm figure I used was arrived at by D. Bryant Cramer in 1985.

1 rpm is doable but you'll have to use a tether.

I would think a tether is preferable anyway. Practically no mass requirement or structural problems with it.

Offline Patchouli

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Re: Human "mars gravity" experiment in orbit
« Reply #11 on: 08/31/2011 09:24 pm »


I would think a tether is preferable anyway. Practically no mass requirement or structural problems with it.

 1 rpm needs a radius of 295M for .33g you'll need a tether over a half a KM long.

On one end will be a mass of 20 tons if the counter weight is lighter then the hab the cable will have to be longer.

I think the experiment needs to be sized for one F9 and one EELV heavy class LV.

Still the cable mass would be only 296kg assuming two kevlar cables with 28,000kg break strength.

« Last Edit: 08/31/2011 09:37 pm by Patchouli »

Offline Jim

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Re: Human "mars gravity" experiment in orbit
« Reply #12 on: 08/31/2011 09:28 pm »

It's a fairly cheap experiment. It's still novel and the data gained is valuable, at least as far as I see it. Humans will go to Mars at some point. Knowing how quickly (or if) we adapt to Mars gravity is quite important.

It isn't cheap and no one has the money for it.

Offline Patchouli

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Re: Human "mars gravity" experiment in orbit
« Reply #13 on: 08/31/2011 09:46 pm »

It's a fairly cheap experiment. It's still novel and the data gained is valuable, at least as far as I see it. Humans will go to Mars at some point. Knowing how quickly (or if) we adapt to Mars gravity is quite important.

It isn't cheap and no one has the money for it.

A basic experiment could be done for a few hundred million if all COTS hardware was used.

One Dragon plus F9 105M
One BA330 maybe 200M
One Delta IV-H  280M
Cables R&D etc maybe 15 to 20M

The whole experiment could be done for around 600 million USD.

If a Falcon heavy is used to launch everything at once the price would go down by 150M.

The BA 3300 is bigger then needed but it probably would be far cheaper then  anything custom made.
Plus the extra space could be utilized by stocking all the supplies needed for the duration of the experiment and trying some partial g plant growth experiments.

The experiment would be more then covered by the cost of one day of the Iraq war.
« Last Edit: 08/31/2011 09:58 pm by Patchouli »

Offline kevin-rf

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Re: Human "mars gravity" experiment in orbit
« Reply #14 on: 09/01/2011 12:36 am »
No requirement for such missions

How biological systems react to zero, and low g's (less than 1g) is still a big unknown. Of course we know so little, that even doing the experiments on mice would fill in many of the gaps.

If there was no need for this data, Japan would never have built the now canceled ISS, Centrifuge Accommodations Module for smaller bio experiments.
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Offline Patchouli

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Re: Human "mars gravity" experiment in orbit
« Reply #15 on: 09/01/2011 12:53 am »
No requirement for such missions

How biological systems react to zero, and low g's (less than 1g) is still a big unknown. Of course we know so little, that even doing the experiments on mice would fill in many of the gaps.

If there was no need for this data, Japan would never have built the now canceled ISS, Centrifuge Accommodations Module for smaller bio experiments.

It might be possible to do a Mars gravity experiment with mice just by fitting a Dragon lab with a centrifuge.

Though some of the money used in extending ISS could be used to procure a new centrifuge for ISS.

I like the idea of putting a sub scale Nautilus-X centrifuge on ISS.
« Last Edit: 09/01/2011 12:54 am by Patchouli »

Offline Jim

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Re: Human "mars gravity" experiment in orbit
« Reply #16 on: 09/01/2011 02:50 am »

The experiment would be more then covered by the cost of one day of the Iraq war.

That tired argument again.  Ending the war is not going to increase NASA's budget.  How many times does that have to be stated.  They are completely independent.
« Last Edit: 09/01/2011 02:50 am by Jim »

Offline Jim

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Re: Human "mars gravity" experiment in orbit
« Reply #17 on: 09/01/2011 02:52 am »
No requirement for such missions

How biological systems react to zero, and low g's (less than 1g) is still a big unknown. Of course we know so little, that even doing the experiments on mice would fill in many of the gaps.

If there was no need for this data, Japan would never have built the now canceled ISS, Centrifuge Accommodations Module for smaller bio experiments.

Didn't say that research wasn't needed just the mission defined on this thread.

Offline AlexCam

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Re: Human "mars gravity" experiment in orbit
« Reply #18 on: 09/01/2011 08:52 am »
No requirement for such missions

How biological systems react to zero, and low g's (less than 1g) is still a big unknown. Of course we know so little, that even doing the experiments on mice would fill in many of the gaps.

If there was no need for this data, Japan would never have built the now canceled ISS, Centrifuge Accommodations Module for smaller bio experiments.

Didn't say that research wasn't needed just the mission defined on this thread.

Do you know alternative methods to gain insights on the effects of long-term Mars gravity exposure to humans?

Offline MagDes

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Re: Human "mars gravity" experiment in orbit
« Reply #19 on: 09/01/2011 01:25 pm »
I think Jim meant that there are no missions like this that are currently funded, or in the pipeline. Sorry if I'm wrong Jim.
« Last Edit: 09/01/2011 01:26 pm by MagDes »

Offline Warren Platts

Re: Human "mars gravity" experiment in orbit
« Reply #20 on: 09/01/2011 01:31 pm »
No requirement for such missions

How biological systems react to zero, and low g's (less than 1g) is still a big unknown. Of course we know so little, that even doing the experiments on mice would fill in many of the gaps.

If there was no need for this data, Japan would never have built the now canceled ISS, Centrifuge Accommodations Module for smaller bio experiments.

Didn't say that research wasn't needed just the mission defined on this thread.

Do you know alternative methods to gain insights on the effects of long-term Mars gravity exposure to humans?

Sure. Just go to the Moon. If people can survive long-term in 1/6 g, then it's a pretty good bet they'll be able to survive in 1/3 g....
"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."--Leonardo Da Vinci

Offline Jim

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Re: Human "mars gravity" experiment in orbit
« Reply #21 on: 09/01/2011 01:31 pm »

Do you know alternative methods to gain insights on the effects of long-term Mars gravity exposure to humans?

Why anyways?  There are no missions to Mars for decades.  Need to figure out many other things before worrying about that like:
Propulsion
life support
zero g effects
and finally money.

Offline kevin-rf

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Re: Human "mars gravity" experiment in orbit
« Reply #22 on: 09/01/2011 01:39 pm »
Because we need to fill in the gap between 0g and 1g. We know the effects of 0g and we know the effects of 1g, but we really have no data on partial g's. If 1/3g is as bad as 0g there is no sense in really planning missions that use partial g's.On the flip side if all we need is 1/3 a g, well for long term mission, maybe it should be designed in.
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Offline AlexCam

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Re: Human "mars gravity" experiment in orbit
« Reply #23 on: 09/01/2011 01:52 pm »

zero g effects


Not required if a long-term artificial gravity experiment proves to be successful. 

Offline go4mars

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Re: Human "mars gravity" experiment in orbit
« Reply #24 on: 09/01/2011 03:46 pm »
Do you know alternative methods to gain insights on the effects of long-term Mars gravity exposure to humans?

1)  My preference:  Send some humans to Mars, monitor them, draw inferences.   

2)  If the budget is less than $100M, then try some tether spin-gravity experiments with an upper stage and a recoverable mouse habitat (dare I say, a used dragon that's been tricked out)? 

Of course, just doing 1 instead of 2 and 1 saves $100 megabucks, and gets you lots of other interesting data as well. 
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Offline savuporo

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Re: Human "mars gravity" experiment in orbit
« Reply #25 on: 09/01/2011 04:09 pm »
Have there been concepts of such an experiment/mission yet?

No, but even the proposal to fly mice in martian gravity environment never flew.

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

Incredible that something so fundamental just keeps getting ignored, it would be a very small investment to answer very important questions about our future, or lack of it, in space.

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Offline Jim

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Re: Human "mars gravity" experiment in orbit
« Reply #26 on: 09/01/2011 09:48 pm »

zero g effects


Not required if a long-term artificial gravity experiment proves to be successful. 

There isn't any and hence the inclusion on the list.
« Last Edit: 09/01/2011 09:48 pm by Jim »

Offline manboy

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Re: Human "mars gravity" experiment in orbit
« Reply #27 on: 09/20/2011 09:11 am »
Have there been concepts of such an experiment/mission yet? Basically a small Salyut-type space station module as a free-flyer that is put into spin with a tether to the upper stage of the rocket that put it in orbit or some other counterweight.

Crew of 2 (or more) dock with the module and start the spinning to simulate Mars gravity. Crew stays there for several months to study the effects of Mars gravity.

Anyone know of any plans for such a mission?
This isn't entirely the same as your concept but it is a proposal for a small A-g spacecraft and the intro has some info that may be relevant to you.

http://www.spacearchitect.org/pubs/NASA-JSC-EX-02-50.pdf
« Last Edit: 09/20/2011 09:18 am by manboy »
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Offline Solarsail

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Re: Human "mars gravity" experiment in orbit
« Reply #28 on: 09/22/2011 05:20 pm »

zero g effects


Not required if a long-term artificial gravity experiment proves to be successful. 

There isn't any and hence the inclusion on the list.

...There isn't a long-term artificial gravity experiment in the works?  If that's what you are referring to, that would be the point of the original post (spinning the habitat to 'simulate gravity' from the perspective of the crew on board).

If we know partial g is possible and better for the crew than weightlessness, a mars bound craft should be built to spin.  If it's never studied (or studied and shown to be unworkable) then a trip's probably just going to be extended weightlessness.  All this remains irrelevant with no manned trip to Mars planned, but so is everything else.

Offline jee_c2

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Re: Human "mars gravity" experiment in orbit
« Reply #29 on: 09/24/2011 10:08 am »
Actually, for going to Mars, it is probably a good idea to test the artifical gravity technology, because it would be needed for that (if we are not supposing some nice high energy/speed transfer/propulsion).

I was just wondering, if it would be possible to alter the orbit (could be Sun orbit) of a vehicle, which consists of two large part connected with cables, and rotated to generate enough G to maintain the astronauts health.
So, what should be the requrement for that? More thrusters on the two parts, a very well, computer controlled thrust sequence.

I mean: for course modification, and for acceleration, slowing down the spacecraft system.

How would that be possible? What should be the disadvantages - in efficiency. ARe there any study about this subject?

Offline michaelwy

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Re: Human "mars gravity" experiment in orbit
« Reply #30 on: 10/01/2011 02:57 am »
Have there been concepts of such an experiment/mission yet? Basically a small Salyut-type space station module as a free-flyer that is put into spin with a tether to the upper stage of the rocket that put it in orbit or some other counterweight.

Crew of 2 (or more) dock with the module and start the spinning to simulate Mars gravity. Crew stays there for several months to study the effects of Mars gravity.

Anyone know of any plans for such a mission?

Wasn't there a gravity simulator as part of the suggested Nautilus X plan, which was to start by adding a test centrifuge to the ISS?
The Nautilus plan was really brilliant as it combined the best of what we currently have of space vehicles. There would be several inflatable Bigelow modules to store stuff in, a Canada arm just like at the ISS and a 14 X 6 meter fixed module. The only new thing really was the centrifuge or gravity simulator. The plan was not too expensive either, they say.

But I don't think anyone would put up the money in these recession times.

I would like to see several Nautilus X ships built. Then it could be used to ship people back and forth between bases at mars or in orbit.
I wish there was something in space that didn't exist on earth, some rare metal or something that could justify investment. Are there no rare metals on the moon or on Mars?

http://news.bbc.co.uk/2/hi/sci/tech/401227.stm

« Last Edit: 10/01/2011 03:00 am by michaelwy »

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