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#26 2019-11-04 14:51:11

louis
Member
From: UK
Registered: 2008-03-24
Posts: 5,851

Re: Practical Water Extraction Methods for Starship Missions

There is certainly "till" in glaciers but when you get beyond the ice-regolith boundary, I think the ice on Mars is pretty pure (researchers deduce this from radar reflections). I don't think ground ice is a good indication for purity of ice in glaciers or crater ice lakes. Basal ice is nearly always very dirty, from what I've read but above that layer ice can be very pure.

I am not saying "no EVAs" and you make a good point about getting away from the sense of confinement. I think for me that would be catered for by exploration missions which would involve EVAs and "something to look at".

I think the main work activities will be: 1. Propellant plant production and fuelling of return Starship - monitoring and maintenance. 2. Water ice mining. 3. Exploration missions. 4. Energy system monitoring and maintenance. 5. Small experimental farm facility. 6. Coms. 7. Hab cleaning and maintenance. 8. 3D printing/industrial processing. 9. Return launch preparedness. 10. Kitchen duties. 11. Archiving of finds. In addition, pioneers will need to carry out a scheduled hygiene and exercise regime which might take up a couple of hours per day.

GW Johnson wrote:

Re Louis Post 19:

I rather doubt that there will be pure water ice available just under the surface.  That was what they expected to find with the polar lander,  and the ground truth was vastly different.  You will find rocks,  boulders,  sand,  and gravel,  all thoroughly mixed with the ice.  There will be layers with more ice content,  and there will be other layers with less ice content. 

Each layer will be very,  very inhomogenous,  because of the history of meteor impacts.  This stuff will more-than-likely look like permafrost soil full of rocks,  with an ice content under 50% by volume. 

That's pretty much what real ice-containing glacial deposits and permafrost-type ground look like on Earth.  Mars should be similar,  except for more rocky debris strewn about by the meteor impacts. 

You ain't gonna successfully mine that (or drill it) with some damned robot.  This is the "more-art-than-science" thing that cannot effectively be automated at this time in history.  At this time,  robots still cannot cope with art or even highly-variable science.

Besides,  your preference for no EVA work is going to drive a crew crazy from confinement.  They were cooped up in a tin can for months getting there (big payloads do not go with fast trips,  so says physics!),  and you want to coop them up inside tin can habitats once there?  Not only no,  but hell,  no!  They have to go outside to feel unconfined,  even if the spacesuit is a clumsy one.  Necessary for mental health. 

Besides,  what do you expect them to do,  sit on their butts watching some computer screen all day?  EVERY day?  If you're going to go to all the fuss and bother to send people to Mars,  then let them go outside and EXPLORE the place!.  You cannot do that sitting in a building or a pressurized vehicle.  You have to go and dig and put your (gloved) hands in the dirt,  and poke your (helmeted) nose into nooks and crannies to see what is there. 

If you cannot tell,  I quite agree with Kbd512 about this!

GW


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

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#27 2019-11-04 17:38:29

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 18,958

Re: Practical Water Extraction Methods for Starship Missions

I was reminded that ice would after the surface freeze would lack the steering effects that would make it contaminated and would result as it cools more pure over time as it descends with continued temperatures remaining cold. But once you get towards the bottom that will not hold true as the contamination levels will increase.

https://en.wikipedia.org/wiki/Ice

The oxygenation or in this case CO2 would slowly stop making the ice less strong over time as the gas will seperate out of the liquid water to form bubbles.

From https://www.sciencedirect.com/science/a … 2X11000395 I see from the information that the colder it is the harder the ice will be.


https://books.google.com/books?id=R_Q6j … th&f=false

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#28 2019-11-04 20:17:23

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 18,958

Re: Practical Water Extraction Methods for Starship Missions

Here is the drill for the life search on mars
1-marsrovertes.jpg

https://www.technology.org/2019/09/20/n … n-its-own/

But if you are thinking of using this for water you would be dead wrong as its not heavy enough and the drill diameter is tiny for what we are looking to do.

Then again if you think this is going to mars anytime soon you would be wrong again
mars_exploring_vehicle_by_novaillusion-d94pt1a.jpg

Of course what Nasa would build would be closer to this
isru_marsice_close_copy.jpg

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#29 2019-11-04 20:28:58

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 18,958

Re: Practical Water Extraction Methods for Starship Missions

Now to be honest if the ice is sheets under the dirt of mars even at a depth of a foot or two once cleared I am thinking that you would do more like new englanders have done for centuries with blocks of ice being cut from the lake ice with cutting saws. The saw would need mass to allow for the blade to cut into the ice straight or at angles to make chunks that could be pulled from where it rests and then dumped into a collection truck to be hauled to the processing plant.

Sure this is a bit old tech but it works
ice-block-cutting-machine-underwood-archives.jpg

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#30 2019-11-05 04:06:26

louis
Member
From: UK
Registered: 2008-03-24
Posts: 5,851

Re: Practical Water Extraction Methods for Starship Missions

Great images. Personally I am favouring a rover-mounted hydraulic hammer coming down at 45 degrees or thereabouts on ice exposed on an incline, the regolith having first been removed by a small bull dozer. The bull dozer rover could have both blade and hydraulic hammer - maybe one on "front" and one on "rear".


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

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#31 2019-11-05 08:02:01

elderflower
Member
Registered: 2016-06-19
Posts: 1,255

Re: Practical Water Extraction Methods for Starship Missions

The mass (therefore weight) of a drilling rig could be enhanced by fitting hoppers to it and filling them with loose rocks/regolith/sand. They can be emptied before relocating the rig and refilled at the new site.

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#32 2019-11-05 08:28:24

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 18,958

Re: Practical Water Extraction Methods for Starship Missions

Which is also true for the other earth moving designs that we would send to mars. The electric drive systems will need a very powerfull energy source to be able to get the work we need done with them.

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