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#1 2019-11-02 12:46:23

kbd512
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Registered: 2015-01-02
Posts: 3,106

Practical Water Extraction Methods for Starship Missions

I was unable to obtain any responses in other threads that amounted to a practical plan to extract water for SpaceX's proposed Mars mission, so I'm starting this topic to discuss this vital component to SpaceX's plan to refuel their Starships on Mars.  I believe they require something in the range of 750t of water to refuel a Starship.

I've read through a number of very vague assertions that there's usable water on the surface of Mars, which have never been subjected to the rigor of a single test.  Nobody knows what's in the ice, meaning what solids or dissolved minerals it might contain, the total volume of surface reserves, nor how much regolith and rock we'd need to excavate to get at that ice.  We also know that there are large buried glaciers, but again, there's no precise map indicating how deep those glaciers are buried.  The resolution of the radars that mapped this stuff from orbit is not precise enough to provide this information and we've never sent a rover to such locations to confirm anything.

Here on Earth, we frequently use drills to create wells and then use pumps to transport liquid water.  We also obtain fresh water from lakes or desalinate brine from the oceans by flashing sea water to steam when fresh water is not available.  The one thing we don't do to obtain water, beyond small quantities of drinking water in survival situations, is melt blocks of ice, even though the technology and power to do that is readily available.  That process must be pretty inefficient, aptly explaining why we don't use it even though there's no shortage of ice available at the poles.

The amount of power required to pump liquid water pales in comparison to the amount of power required to excavate and melt ice, which is why we never do that unless we absolutely have to.  There's an endless supply of ice in Antarctica, but the station we have there still uses a well that was drilled under one of the buildings to draw fresh liquid water.  As a function of the power required, we don't desalinate brine when fresh water is available, either.

This SpaceX mission will be severely mass and power constrained, especially if it's limited to solar power and batteries, so a power and mass efficient method to extract water is required and candidate well sites identified that likely have liquid water that may be pumped.  Basically, this means drilling wells to a depth where there is liquid water available.

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#2 2019-11-02 12:58:41

SpaceNut
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Re: Practical Water Extraction Methods for Starship Missions

The three rovers now down to 1 and the 2 landers also down to 1 have done some cursery evidence that water is at some levels where they are locally of which the orbiting satelites have also done inferred work via sensing that water does exit but at what level or depth.

I am under the assumption that at least 1 mission must be made with small landers and crew that have picked a prime location based on the sensing in order to set up shop for the much larger mission to come.

These courageous first mission crew will know the risk that they might not be able to comeback on the first mars cycle but will be supplied with more cargo to be able to dig in like a tick such that when the large craft does come they will be able to leave. They will hopefully gain the level of expience and knowledge that will give the degree of safety for the future mission.

I do not feel that a full robotic mission can do what a man can do in a shorter period of time with the same equipment as we can see without delay and select other locations to test without others helping.

Edit:
Pulling topic content from Starships a go

SpaceNut wrote:
Oldfart1939 wrote:

One acre of land is 43,560 square feet of area, and if we simply for ease of calculations, assume 1 foot deep soil, that's 43,560 cubic feet of dirt. Divided by 27 cubic feet per cubic yard, that yields 1613 cubic yards of Mars dirt needing processed.  Taking the density of 90 pounds per cubic foot x 27, we arrive at 2430 pounds.

The level of water in the mars soils are in the 1 to 5% or for a cubic foot of Mars soil, you can harvest around two pints of water give or take.
The fact that we need water for making fuel shows that if we must rely on this source we will be processing a larger amount of soil with very little in comparison going into a greenhouse.

One acre is 43,560 cubic ft at 2 pt. a ft cube = 87,120 Pt. possible water yield
70 ton is    150,647 pints ouch we are moving a huge amount of soil to get the water.....
Amount of fuel in quest for full is 1200 tonnes
Seems we will process 35 acres....

We can only hope that we do not need a full fuel loading to go home....

SpaceNut wrote:

Ground in the shade which will have the most water content will be hard and will make it difficult for a bull dozer to move. Ground in the sunlight will be softer for the bulldozer to move until it gets down to the forst line or bed rock which ever comes first. A bulldozer will also need to be made heavier by moving soil onto a basket to add to the mass to offset the lower gravity for the machine so that it can push more effectively.

GW Johnson wrote:

It's hard to figure out what all you must take,  when you do not really understand what is actually there beneath the surface.  Ain't it?

Did it ever occur to anybody that not doing an exploratory robot drill mission is one way to put off ever sending people there?

As for alternatives to buried glaciers,  bear in mind that processing large volumes or masses will be a very energy-hungry effort. 

If the regolith really is 1-5% water content by mass,  then each kg (liter) of water means you process 20-100 kg of regolith.  The energy to scoop that up must come from somewhere.  The energy to cart it over to the processing equipment must come from somewhere.  The energy to process it (usually by heating the regolith in a confined space) must come from somewhere.  The energy to liquify it might be the cheapest,  because of the cold.  But to separate out salts and perchlorates will require energy. 

And just how many liters will you need?  Thousands?  Tens of thousands?  Hundreds of thousands?  So you process hundreds to thousands of tons of regolith to get a few thousand liters of water?  Doesn't sound very attractive to me.

It's worse for extracting water from the near-vacuum of an atmosphere.  It's not so much the tonnages as the volumes you must process.  Cold air holds very little water.  Low pressure makes that even worse.  6-7 mbar "air" at 10-100 C below zero holds a very minute moisture content.  As a wild guess 0.001% by volume.  That's 1 part in 100-thousand.  That means I process something like 100,000 cubic meters of Martian air to get 1 cubic meter of water VAPOR,  AT 6-7 mbar!  Not much mass there,  only around half a kg.  Now condense that liquid phase so you can actually use it.  It's way less than a liter for all that near-vacuum air you have to process for it.   

If you compress first,  that's seemingly better,  except that an air compressor on Mars will NOT look like an Earthly compressor,  but more like an Earthly vacuum pump. Lots of machinery mass and energy consumption,  for a very tiny mass throughput.

You're way better off mining ice from some buried glacier.  Whether you dig it out,  or drill and steam extract it,  you get a lot more mass for the least expenditure.  But,  you need to know it really is there before you commit to staking lives on it.

The Mars Polar Observer probe dug a few centimeters down,  in a region where they expected massive permafrost.  What it found was a few ice-cube-sized lozenges scattered in the otherwise-dry regolith.  NEAR THE POLE!  They figured out it really was ice,  because it sublimed away in about a day after being unburied.   My point:  ground truth vastly at variance with what they expected based on remote observation.  Vastly at variance indeed!

Mining ice by digging it up risks that same sublimation loss mechanism.  Unless the ice is truly massive,  not just scattered small lozenges. 

But you won't know that until you get there and dig or drill.

And THAT ugly place is where we are.

GW

louis wrote:

Well that's not what I am proposing. I am proposing that you drill out chunks of ice using drills mounted on rovers. 

How quickly does ice sublimate? Does it really matter as long as you can grab a big enough chunk? This video would suggest that the water ice does not sublimate that quickly even in a vaccuum:

https://www.youtube.com/watch?v=G6XrAtp9WvM

Some interesting stuff in this NASA paper re ice drilling and melting to obtain water.

https://www.nasa.gov/sites/default/file … elease.pdf

But I would prefer the method of surface digging out  rather than drilling down - NASA appears to be following both lines.


SpaceNut wrote:

The ground water wells on earth require large diameter which go as deep as the water table but on mars that not only needs to be lined to the depth but capped to keep the water from boiling off as its exposed by the digging. This holds true for the drilled small diameter well also. It also assumes a ground water table. It also assumes underground water pockets as found on earth that fill caverns. These occur from subduction of the crust which does not happen on mars.

Digging into ice coverd by regolith will cause heating as the drill goes to depth in which the water must be captured as before from its uncovering and obsortion of heat from the operation. All situations would require at a minimum some sort of dome over the drilling operations to aid in capture but also for pressurization to slow vapor change.

Post #428 estimated ground soil water provided it stays in the same concentration throughout for just a 1 ft depth and nothing so far shows that it stays constant as depth increase for testing thus far.

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#3 2019-11-02 13:39:36

louis
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From: UK
Registered: 2008-03-24
Posts: 5,329

Re: Practical Water Extraction Methods for Starship Missions

I welcome this thread as it is of course one of the most crucial issues to be addressed for a Mars Mission One.

I did respond to the points you raised on the Starship Is Go thread. I won't repeat everything but I did dispute your assumption in point 2 that we have to drill down to get to ice.  My conception is that we will be removing regolith on inclines to reveal the ice walls of buried glaciers or crater ice lakes. This approach seems in line with the sorts of robot  mining machines NASA have been looking at:

https://www.philipmetzger.com/challenge-of-mars-mining/

We know there are buried glaciers in the region of the landing sites in Amazonis/Arcadia...I think people are underestimating just how accurate the surveillance of the landscape is. It's not just spectrometer readings and ground radar, but also understanding the geology and topography, looking for tell tale signs of sublimation and so on and visual assessment of ice exposure. It's true "we" don't have a precise map of where the glaciers are but that doesn't mean there isn't one. It will basically take a lot of time and effort and multi-disciplinary co-operation to draw up the map but I expect it to be very accurate.

I think we are looking for a not too steep incline where we can be fairly confident the regolith covering the ice is between 1 and 5 metres width. I propose using small bull dozer rovers to remove the regolith and reach the ice at which point we either drill out ice chunks (my favoured solution) or we melt the ice and collect it as water.  Basically the whole mining operation would be overseen by humans in a  human-rated rover capable of operating the robot rovers or watching over them as they undertake automated, self-drive operations.

I think the "drill down" approach is wrong and will add hugely to the complexity of the mission. Once again, rather as with nuclear power, it is not a flexible solution. What happens if your drill goes kaput for some reason? That's it - retrieving it, examining it, replacing it will all take precious time.

Something like you suggest may well be done in later missions. But for Mission One, I think the answer is to have a flexible, simple approach that guarantees access to the ice.

I'm not convinced you've made the case for drilling down and pumping being more energy efficient overall. Are you proposing piping this water to the PP facility? Because the landing sites and PP facility are very unlikely to be where the water is, since the Starships will need to land on solid rock. It's likely the two locations will be separated by kms meaning you will have to be laying down pipes, and probably heating them I imagine. Again, it just seems unnecessarily complex to me.

How much water ice do we need? I'm assuming maybe a couple of tons per day. To melt that requires less than 200 KwHs. Given we are talking about a 1 Mw operation, that's only 20% of the energy output over one hour.

The water mining operation might take something like  200 Kws over maybe 4 hours - harvesting 500 Kgs of ice an hour or about 8 Kgs a minute. You might need 2 robot rovers operating at the ice face, and a couple of scoop rovers to collect the ice. A transporter rover would take ice from the scoop rovers periodically and deposit the ice at the propellant production facility.

Space X's mission does not have a tight mass constraint. The whole ice mining operation might weigh in at 15 tons max out of a 500 ton mission.

Last edited by louis (2019-11-02 17:10:18)


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#4 2019-11-02 15:34:57

kbd512
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Re: Practical Water Extraction Methods for Starship Missions

Louis,

Yes, you did respond in the Starship thread.  You just didn't answer any of the questions I posed.  That seems to be a running theme whenever I start asking pertinent questions.  That's also where the logical fallacies typically start showing up, such as the difficulty of pushing a berm of regolith up against a trash can versus excavating thousands of tons of materials with unknown compositions.  In any event, hand-waving all the problems with what you proposed doing still doesn't make them go away.

Regarding the mapping of Martian ice, I think you're vastly over-stating what we actually know.  NASA doesn't keep this sort of information secret just to play games with people.  Whenever they actually know something, they publish it.  That's how a government agency not acting under any cloak of secrecy operates.  If they don't know something or have more questions that need to be answered, then they ask for more money to investigate further.  We give it to them because they're the only organization on the planet that has any real program to explore other planets and they have a track record of delivering results whenever engineers are making decisions about how to accomplish something.  You keep making statements of belief about this without supporting data.

I proposed drilling to obtain liquid water, not ice.  If the first mission would be enabled by obtaining ice, then we'd simply land at either of the Martian poles on a solid block of ice.  There's more ice there, that's not covered by anything, than you can shake a stick at.  Speaking of flexibility as it pertains to the use of nuclear power, this doesn't work at all for this solar power scheme.  So much for the flexibility of solar power and batteries.  As long as you're in the Goldilocks Zone, solar power and batteries can be made to work if mass and money is no object.  Unfortunately, only the "money is no object" applies to space exploration efforts.

Every year NASA has a running contest for these regolith excavation robots, but has never sent a single one of them to the moon, which is much closer than Mars, to actually excavate anything at all; nor has any other government space agency.  Speaking of complexity, it's fascinating to see the complexity of a drilling rig blown out of all proportion, yet the complexity of multiple self-driving excavating robots hand-waved for sake of argument.  Precisely zero such robotic vehicles have ever been to Mars.  All of NASA's rovers are remotely programmed by an operator sitting in a control room on Earth, whereupon the rovers then execute those driving instructions.  They have minimal collision avoidance software and they move at a snail's pace.  Something tells me that that won't cut it for a mining operation.

On that note, you haven't made any case at all for why ice mining will work, just provided another string of assertions and personal beliefs without evidence.  We don't do anything like what you're proposing here on Earth where there aren't any mass or power constraints and we have research stations at the poles that could operate robot rovers as you described to obtain their drinking water, but that's not how they do it.  I could be persuaded to take your proposal more seriously if you can come up with anything indicating that SpaceX or NASA or any other space exploration organization has developed, tested, and sent one of these ice mining robots to the moon or Mars.  Currently, your proposal is to go to Mars with something that's never been tested on Mars and not used here on Earth.  That doesn't sound like a viable plan to me.

Unless this technology has been properly tested, even once, then there's no way our government will green-light sending people to Mars who are relying on that technology to function as intended.  I'd love to get NASA to actually test all of these ideas, but if I was a mission planner I wouldn't start betting lives on it before the test program has positive results.

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#5 2019-11-02 18:06:13

louis
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From: UK
Registered: 2008-03-24
Posts: 5,329

Re: Practical Water Extraction Methods for Starship Missions

Many of the points you were raising were based on the assumption that in order to get an adequate supply of water we have to drill down to find liquid water.

My understanding is that there are very few locations on Mars where there is a suggestion of liquid water. It's more of a hypothesis, so built on much shakier ground than the detailed assessments of Amazonis-Arcadia being undertaken.

This paper gives a flavour of how scientists are mapping this area for water ice:

https://www.researchgate.net/publicatio … nitia_Mars

Clearly, further more detailed work can be done analysing potential ice mining sites. I'm not sure what you are saying - are you saying that NASA have got it all wrong and there is no readily accessible water ice in this area?  I would be looking for a flexible mission - one of the reasons I favour a PV energy system.  You can set up a water exploration camp away from the main base if necessary with its own power supply. People could live on board the human-passenger rover for several sols while exploration is undertaken. The HPR might be prospecting to a 20 km range. My point is we aren't necessarily requiring NASA or whoever to identify a precise spot where water ice will definitely be found.  If they identify 100 potential locations and they are 50% correct, that will be more than good enough.

Landing at the north pole (I think it's only in the north we have the large supply of water...but I may be wrong) would create a whole host of other problems not least having to cope with even more extreme temperatures. It would be no good for a PV energy system either, and your nuclear reactors might have a problem with waste heat.

Robots are now used extensively in mining operations on Earth:

https://www.nbcnews.com/mach/science/ro … ncna831631

My previous link referenced water ice mining on Mars:

https://www.philipmetzger.com/challenge-of-mars-mining/

This paper regarding propellant production on the moon has a section on "Rover Mounted Drills" and states that "As discussed in the Surface and Subsurface Samplingsection, Honeybee Robotics has explored several on-site water-extraction concepts that utilize a rover-mounted rotary-percussive drill." Rover-mounted drills are clearly therefore a practical proposition that people are giving serious consideration to. They have many advantages as stated in the paper. So I am not sure why you are trying to dismiss my proposal.  (See page 20 of the paper - page 38 of the electronic document.)

https://www.philipmetzger.com/wp-conten … ecture.pdf

My understanding, BTW,  is that on the Moon they are not expecting the sort of very pure water ice we expect to find on Mars.

The Apollo lander had never been "tested on the Moon"  - it worked because there was good planning, good co-operation and a creative approach. I think once again you and others are putting up barriers to a successful mission that don't need to be there. We've had 50 years' experience of putting rovers on the Moon and Mars. We can put any design through its paces back here on Earth in Mars analog conditions and I would expect Rovers to be tested on the Moon as well before the Mars Mission.

kbd512 wrote:

Louis,

Yes, you did respond in the Starship thread.  You just didn't answer any of the questions I posed.  That seems to be a running theme whenever I start asking pertinent questions.  That's also where the logical fallacies typically start showing up, such as the difficulty of pushing a berm of regolith up against a trash can versus excavating thousands of tons of materials with unknown compositions.  In any event, hand-waving all the problems with what you proposed doing still doesn't make them go away.

Regarding the mapping of Martian ice, I think you're vastly over-stating what we actually know.  NASA doesn't keep this sort of information secret just to play games with people.  Whenever they actually know something, they publish it.  That's how a government agency not acting under any cloak of secrecy operates.  If they don't know something or have more questions that need to be answered, then they ask for more money to investigate further.  We give it to them because they're the only organization on the planet that has any real program to explore other planets and they have a track record of delivering results whenever engineers are making decisions about how to accomplish something.  You keep making statements of belief about this without supporting data.

I proposed drilling to obtain liquid water, not ice.  If the first mission would be enabled by obtaining ice, then we'd simply land at either of the Martian poles on a solid block of ice.  There's more ice there, that's not covered by anything, than you can shake a stick at.  Speaking of flexibility as it pertains to the use of nuclear power, this doesn't work at all for this solar power scheme.  So much for the flexibility of solar power and batteries.  As long as you're in the Goldilocks Zone, solar power and batteries can be made to work if mass and money is no object.  Unfortunately, only the "money is no object" applies to space exploration efforts.

Every year NASA has a running contest for these regolith excavation robots, but has never sent a single one of them to the moon, which is much closer than Mars, to actually excavate anything at all; nor has any other government space agency.  Speaking of complexity, it's fascinating to see the complexity of a drilling rig blown out of all proportion, yet the complexity of multiple self-driving excavating robots hand-waved for sake of argument.  Precisely zero such robotic vehicles have ever been to Mars.  All of NASA's rovers are remotely programmed by an operator sitting in a control room on Earth, whereupon the rovers then execute those driving instructions.  They have minimal collision avoidance software and they move at a snail's pace.  Something tells me that that won't cut it for a mining operation.

On that note, you haven't made any case at all for why ice mining will work, just provided another string of assertions and personal beliefs without evidence.  We don't do anything like what you're proposing here on Earth where there aren't any mass or power constraints and we have research stations at the poles that could operate robot rovers as you described to obtain their drinking water, but that's not how they do it.  I could be persuaded to take your proposal more seriously if you can come up with anything indicating that SpaceX or NASA or any other space exploration organization has developed, tested, and sent one of these ice mining robots to the moon or Mars.  Currently, your proposal is to go to Mars with something that's never been tested on Mars and not used here on Earth.  That doesn't sound like a viable plan to me.

Unless this technology has been properly tested, even once, then there's no way our government will green-light sending people to Mars who are relying on that technology to function as intended.  I'd love to get NASA to actually test all of these ideas, but if I was a mission planner I wouldn't start betting lives on it before the test program has positive results.

Last edited by louis (2019-11-02 18:09:48)


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#6 2019-11-02 19:53:24

SpaceNut
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Posts: 17,360

Re: Practical Water Extraction Methods for Starship Missions

Nasa did several test of the lander before comitting men to landing on the moon...
Committing to a polar landing site means no solar for the mission to suceed.
Nasa and others will need to contend with the landings where these glaciers are and due to the location being in the high ground areas of mars we can not land near them.
https://en.wikipedia.org/wiki/Glaciers_on_Mars

Evidence of glaciers are from Radar studies with the SHAllow RADar (SHARAD) on the Mars Reconnaissance Orbiter combined radar observations with ice flow modelling to say that ice in all of the Martian glaciers is equivalent to what could cover the entire surface of Mars with 1.1 meters of ice. Which means no real ice has been confirmed...

http://www.esa.int/Science_Exploration/ … rs_on_Mars

Simular devices were used to do the same detailed observations of which the glaciers are at the edges of the transitions from the highland to low....
Topography_of_Colles_Nili_pillars.jpg

https://marsed.mars.asu.edu/sites/defau … oposal.pdf

http://marsed.asu.edu/sites/default/fil … %20Cap.pdf

topography-mars-1000x593.jpg

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#7 2019-11-02 20:30:59

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 17,360

Re: Practical Water Extraction Methods for Starship Missions

Each of the lines for topographical features are several hundred feet in verticle change.

https://phys.org/news/2016-10-glaciers-mars.html

Buried glaciers on Mars. This jumble of eroded blocks lies along the distinctive boundary between the Red Planet's southern highlands and the northern lowlands, with remnants of ancient glaciers flowing around them. This boundary is one of the oldest and most prominent features on Mars, marking a height difference of several kilometres.

Cold-based mountain glaciers on Mars: Western Arsia Mons
http://www.planetary.brown.edu/pdfs/2837.pdf

https://dps.aas.org/sites/dps.aas.org/f … aciers.pdf

http://marsed.asu.edu/sites/default/fil … 20Mons.pdf

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#8 2019-11-02 21:12:20

kbd512
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Re: Practical Water Extraction Methods for Starship Missions

Louis,

I'm saying your proposal is entirely predicated on assumptions that have no actual testing to back them up.  I'm 100% in favor of testing this proposal, so show me the results from a single practical test with something that's either been to Mars or operated under Mars-like conditions.  I don't think one silly little test is asking for very much.  A single test result is a more constructive predictor of future results than all the assertions in the world.  We have a total lack of testing here.  When I start seeing test results come in for all the technology to make this work, then I'll begin to believe that we're serious about doing this.

Your glittering generalities about there being ice somewhere under the surface at different places on Mars isn't precise enough to actually dig or drill for water.  Someone stating that there's oil in the ground in Texas, while technically correct, without being more specific, hasn't told me anything useful.  I can't afford to drill a well the size of Texas to figure out where the oil is, nor can the astronauts we send to Mars afford to dig around endlessly looking for enough water to get home.

From actual direct measurement, how much ice is actually located at those sites and what's mixed in with it?

I'm not interested in what you wish to believe because you're enamored with the idea.  I'm equally enamored with the idea, but I also wouldn't sign off on the mission if I were a mission planner or government agency without first seeing the results of one silly little test.  I'm still waiting to see those results.

Edit:

We put the "drill" on the Mars InSight lander through its paces back here on Earth.

How well did that work out?

Last edited by kbd512 (2019-11-02 21:14:41)

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#9 2019-11-02 22:27:30

tahanson43206
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Registered: 2018-04-27
Posts: 1,627

Re: Practical Water Extraction Methods for Starship Missions

For kbd512 re topic ...

Thank you for starting this important topic.

It caused me to wonder if a water rich asteroid could be directed to Mars, so that a supply of water could be in a known location.

I'll continue this line of inquiry in Calliban's topic, since it has to do with asteroids.

However, if an asteroid iceberg were to be deposited on Mars, this topic would apply directly.

(th)

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#10 2019-11-03 08:12:38

louis
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From: UK
Registered: 2008-03-24
Posts: 5,329

Re: Practical Water Extraction Methods for Starship Missions

The earliest Space X will be putting humans on Mars is 2024/25. It seems unreasonable to me to keep demanding evidence of advanced testing as opposed to accepting what I propose is perfectly reasonable within the scope of our knowledge.

This is a good guide to water mapping on Mars currently being undertaken. More and more detailed and accurate maps are being produced for the Arcadia region.  This paper includes photos of recent impact sites which show exposed ice. These can be used to verify the radar, thermal and geological analyses being used to map water ice presence.

https://www.nasa.gov/sites/default/file … des_v6.pdf

For me, this sort of detailed mapping will be good enough for mission planning. Yes, you might have to start up digs at several sites before you hit payload and that might take 10 or 20 sols - who knows? I think it's unlikely, you'll probably hit ice first time, but let's be conservative in our assumptions - but it is pure obduracy to maintain there is a high level of risk in this approach. There isn't: we know the water ice is there, just below the surface. To keep missing it would be like missing the egg in a cheese omlette.

So, as far as I am concerned, I am with NASA on this. We will know where the water is to be found.

Next, I have already posted links to (a) the extensive use of robot vehicles and machines in mining on Earth and (b) the NASA programme for developing robot mining machines for use on Mars.

Add to that, we have 50 years' experience of rover technology on the Moon and Mars and NASA has been developing a human-rated rover for Mars over several years now, and that is well advanced having been tested in Mars-like ground conditions.

As regards the "purity" of the ice, this is dealt with in the NASA paper. They can detect levels of purity from the radar info- very pure and solid ice gives back very different signals from loose regolith or regolith-ice mixtures.

Drills have been used successfully on Mars. The problems with the Mars InSight drill seem pretty irrelevant to my proposal. The InSight drill is now operational again but I think the fact it found it so difficult to drill through the ground layer suggests your proposal for drilling down is more problematic than mine.

https://www.digitaltrends.com/cool-tech … -progress/

What I would say about the use of drills on Mars, as regards my proposal, is that these would be heavy duty and their use would be overseen directly by humans.  With a 500 ton mission we can afford to use heavy duty drills.  But of course melting the ice is an alternative technology or one that can be combined with drilling.

kbd512 wrote:

Louis,

I'm saying your proposal is entirely predicated on assumptions that have no actual testing to back them up.  I'm 100% in favor of testing this proposal, so show me the results from a single practical test with something that's either been to Mars or operated under Mars-like conditions.  I don't think one silly little test is asking for very much.  A single test result is a more constructive predictor of future results than all the assertions in the world.  We have a total lack of testing here.  When I start seeing test results come in for all the technology to make this work, then I'll begin to believe that we're serious about doing this.

Your glittering generalities about there being ice somewhere under the surface at different places on Mars isn't precise enough to actually dig or drill for water.  Someone stating that there's oil in the ground in Texas, while technically correct, without being more specific, hasn't told me anything useful.  I can't afford to drill a well the size of Texas to figure out where the oil is, nor can the astronauts we send to Mars afford to dig around endlessly looking for enough water to get home.

From actual direct measurement, how much ice is actually located at those sites and what's mixed in with it?

I'm not interested in what you wish to believe because you're enamored with the idea.  I'm equally enamored with the idea, but I also wouldn't sign off on the mission if I were a mission planner or government agency without first seeing the results of one silly little test.  I'm still waiting to see those results.

Edit:

We put the "drill" on the Mars InSight lander through its paces back here on Earth.

How well did that work out?


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

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#11 2019-11-03 12:51:34

kbd512
Moderator
Registered: 2015-01-02
Posts: 3,106

Re: Practical Water Extraction Methods for Starship Missions

Louis,

2024 is only 4 years away.  That's an incredibly short period of time for "We have this idea for a giant new rocket" (that continues to change as engineering reality begins to set in) to "We have a complete deep space transportation and habitation system that's been tested, at least once, in the environments it's expected to operate in".  It just is.  It doesn't matter what you believe about that.  I'm sure it's great for rallying the troops, but nobody with any good sense should ever expect that to happen.  If it does happen, then great.  I'd be ecstatic if it did.

I look at how long it took Falcon Heavy, something that "seemed" like a simple matter of bolting three Falcon 9 cores together in Elon Musk's own words, to first launch.  The amount of effort that actually required equated to designing a completely new vehicle core.  In the end, that's exactly what SpaceX had to do.  Elon had an idea in his head, but real engineering is what dictated what would actually be required to make it a reality.  It wasn't nearly as fast or as cheap as he thought it'd be, but yes, it was a monumental achievement and I was cheering it on as I watched it ascend to orbit.

So, any time someone says "I'm going to build a super heavy lift launch vehicle and have it land humans somewhere on another planet in 4 years", I simply look at past similar efforts and note that not a single one of them were pulled off that fast.  There's on a single example available for a point of comparison, but there it is.  It just so happens that it's a very complex and costly task.

Regarding what you're "with" or "not with" with NASA on, that seems to be entirely dependent on whether or not they tell you exactly what you want to hear.  Whenever they don't, you claim they're inept / corrupt / whatever other disparaging descriptors you attribute to the only group who simply presents actual data.  It's not done with the intent to agree or disagree with your assertions or beliefs.

You also have this way of ignoring established and proven ways to go about accomplishing a task in the simplest way possible, which also tends to be the most reliable way to do something.  Again, I can only surmise that that's because it disagrees with some part of your ideation about why we do things the way we do.

There are an endless number of more technologically sophisticated ways of screwing a bolt into a socket, but in the end the lowly wrench or socket set tends to be the simplest and most reliable way to do it, irrespective of circumstances.  Sure, we have robots that can do the same thing, provided the work piece is precisely positioned, the robot knows exactly where it is, and an entire list of other caveats.  With all of those pre-conditions met, the robot can likely do the job faster than a human.  However, when last I checked, motor vehicle service centers were still staffed with humans using hand tools, not robots in automated work cells.

Robots really shine when performing highly repetitive and simplistic tasks, such as drilling a hole in an engine block in the precise spot it should be located at, and doing that thousands of times per day.  Some of the most advanced robots, such as those created by Boston Dynamics, while being much more generally useful than a drill robot in a specialized work cell, also have a habit of simply falling on their faces from time to time when they're not otherwise moving or doing something else- because all that sophisticated software is real complexity, every bit as real as any mechanical complexity from greater parts count, whether you believe it or not.

I hope you can understand why someone who's interested in the general reliability of some set of equipment used to perform some specific task wouldn't want to rely on such technology functioning properly when lives are at stake.  It has nothing at all to do with trying to dash your dreams of a robot-enabled future.  At the very least, I hope you know you're not the only person who wished they could simply press the "easy button" and have the robot take care of something.  That's really a tacit admission that such tech is still experimental in nature and I don't want to perform a science experiment with the lives of the astronauts on their first mission to Mars.  I want them to prove that the fundamental ideas about what we can do are sound, that we've demonstrated we can apply those concepts to enable future missions, and that we have a reliable way to send people to and from Mars.  We can still go buck-wild with automation on the second mission.

Here are my favorite examples:

A rope an pulley is too complicated or takes too long, therefore we need to design an inflatable slide and air mattress to bounce sensitive power generation equipment off of that to get all of it to the ground faster because otherwise my ideation about whether or not it's faster to unload 100 fission reactors or 1,000's of solar panels and batteries isn't satisfied.  Well, yeah, of course it takes longer to unload 10 times as much equipment.  Why would we even need to argue about that?

If you had countered with, "Well, while that's true, I can also temporarily set some of them up near my Starship to start producing power immediately and I don't need to immediately transport a reactor a kilometer or two from my ship", then I would've thought to myself, okay, he's actually thought this through and he has reasonable and practical solutions to actual problems.  Instead, we veered off onto one of these tangents that any engineer I know would just scratch their head over.  Sometimes it just looks like argumentation for sake of arguing what would seldom, if ever, be argued over if we were trying to accomplish the same task here on Earth.

I don't accept that we will probably have to drill to obtain water, therefore I'm going to assert we need a team of autonomous excavating robots that are going to get at the ice faster with laser drills and then we're going to have other robots that scoop up the ice and possibly more robots that take it back to the ship, all while being overseen by a small team of humans in a rover that needs to provide for their every need while they're operating it.

Whereas, we could send a single exploration mission to one of these ice deposits to take samples of the water, find out what's in it, determine how much is in some specific area we want to land in, decide what extraction methods would work best, and then design / test equipment to do that.  Doesn't that seem like a more reasonable approach to using a natural resource that's also more likely to result in success?  That's exactly how we do it here on Earth.  The idea that the entire engineering rule book gets thrown out because we're operating on another planet seems a bit peculiar to me.

I just want to know what problems you're trying to solve with these solutions that are so highly dependent on complex autonomous or semi-autonomous systems.  Do you understand that software complexity is just as real as any mechanical complexity and the results can be every bit as deleterious to accomplishing a task?  When we watch those Boston Dynamics robots fall on their faces while sitting / standing in place, do you understand what just happened (complete failure of the computer control systems that cause them to remain upright)?

So, I'll ask again.

If we could send a small team of humans to operate a small drilling rig to drill a well that we could either pump liquid water out of the ground after drilling down to the water table, or even drilling a small hole in a block of surface ice and then melting the surrounding ice with steam so we can pump out liquid water, then why would we resort to using a team of laser-drill-equipped semi-autonomous excavation machines and more robots that break up the ice and cart it back to the ship, while still requiring human oversight?

Are we more likely to be successful using a simple plan executed with simple tools, specifically selected with foreknowledge of the problems we'll face, or a comparatively more complicated plan using more complex tools and only cursory knowledge of the problems we'll encounter?

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#12 2019-11-03 14:19:33

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 17,360

Re: Practical Water Extraction Methods for Starship Missions

Arcadia region said to be smooth lava flow area high in altitude surrounding a volcano are small dips where water ice is covered.
https://en.wikipedia.org/wiki/Arcadia_Planitia

PIA00163_hires.jpg

Sure it looks smooth but so did the other nasa landing sites which have been found to not be true.

https://www.teslarati.com/spacex-starsh … sa-photos/

nasa gathered 6 updated locations for space x

aHR0cDovL3d3dy5zcGFjZS5jb20vaW1hZ2VzL2kvMDAwLzAzMi8zOTUvb3JpZ2luYWwvaW5zaWdodC1tYXJzLWxhbmRpbmctc2l0ZXMuanBn

Notice where Nasa has been able to land on mars in the blue and green areas of topograhical hieght. That's due to amount of fuel and engine thrust that must be carried to be able to land in the 1km distance to the surface once the heat shield and parachutes have done there job. With the sensing of the ground coming in less than 20 seconds which pushes the thrust even further up for the payload to be able to slow to a soft landing.

Trying to land in the red yellow zones will put the thrust even higher and also the fuel will also need to grow which will cut into the payload.

EDIT:

To tally: Arcadia Planitia offers (somewhat) warmer summers and winters due to its latitude, augmented by a low relative altitude that insulates the region from weather extremes and enables more efficient propulsive spacecraft landings.

However, perhaps more important than any of the above features is the fact that Arcadia Planitia is host to a vast wealth of water ice resources, ranging from frozen aquifers to glaciers in the adjacent Erebus Montes mountains. Of central importance to SpaceX’s strategy of affordably colonizing and exploring Mars is the decision to produce return propellant – needed for Starships to return to Earth – on Mars, known as in-situ resource utilization (ISRU). Starship’s use of methane and oxygen is almost entirely a result of this – methane is far easier to work with than hydrogen and can also be easily produced from water, as can oxygen.

The cleaner and more accessible the Martian water ice is, the easier it will be for SpaceX robots or astronauts to set up a propellant plant on Mars. Additionally, clean water is extremely expensive to transport in space, and a near-infinite supply of ice-derived water would be extremely useful for all sorts of human outpost needs.

Until we mine and process the ice or water we will not know how many and which contaimants we will be dealing with. Electrolysis needs contanimnent free water.

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#13 2019-11-03 15:29:43

louis
Member
From: UK
Registered: 2008-03-24
Posts: 5,329

Re: Practical Water Extraction Methods for Starship Missions

I think Space X is looking to land in the green blobs to the north west of Olympus Mons on your map - green blobs in a sea of blue.


SpaceNut wrote:

Arcadia region said to be smooth lava flow area high in altitude surrounding a volcano are small dips where water ice is covered.
https://en.wikipedia.org/wiki/Arcadia_Planitia

https://www.jpl.nasa.gov/spaceimages/images/largesize/PIA00163_hires.jpg

Sure it looks smooth but so did the other nasa landing sites which have been found to not be true.

https://www.teslarati.com/spacex-starsh … sa-photos/

nasa gathered 6 updated locations for space x

https://img.purch.com/w/660/aHR0cDovL3d … l0ZXMuanBn

Notice where Nasa has been able to land on mars in the blue and green areas of topograhical hieght. That's due to amount of fuel and engine thrust that must be carried to be able to land in the 1km distance to the surface once the heat shield and parachutes have done there job. With the sensing of the ground coming in less than 20 seconds which pushes the thrust even further up for the payload to be able to slow to a soft landing.

Trying to land in the red yellow zones will put the thrust even higher and also the fuel will also need to grow which will cut into the payload.


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

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#14 2019-11-03 16:42:38

louis
Member
From: UK
Registered: 2008-03-24
Posts: 5,329

Re: Practical Water Extraction Methods for Starship Missions

We can all see the giant rocket being built...it's not a fantasy. Either it will work or it won't. If it works, we are on for humans on Mars by 2024.

Time is short but it was a short timespan from Saturn V design in 1962 to launch in 1967. Much less was known then about big rockets than is known now and Starship has effectively already been in development for 3 or 4 years already. The Mars Mission is of course much simpler than Apollo because the Starship flies direct as one ship to Mars after fuelling in LEO. The Falcon 9 Heavy was a wrong turning that Space X took. Returning to a single rocket, albeit two stage,  is  making everything more straightforward.

Yes, it's still a very complex and costly task but Space X seem to have the money and the talent. The fact that their rocket is so big and they propose a 6 Starship mission makes everything simpler when you get to Mars - you could call it throwing mass at the problem.

As for NASA, I've always said they are vital for launch, coms and surveillance for any Mars Mission. I disagree with their unfocussed approach to space exploration and science, that's all,  and the fact they are at the mercy of American Pork Barrel politics.

I'm not talking about any fancy Boston Dynamics Robots - just basic robots as used in the mining industry on Earth, but being adapted for Mars operations, and/or those being developed by NASA for Mars. We have cars that can park themselves, and pretty much drive themselves on motorways...we have robot lawn mowers and robot vacuum cleaners. These all work with near perfect efficiency.  I think under human supervision there is no doubt they can take on the task of drilling out or melting water ice on Mars.  The human passenger rover can lay down transponders so the robot rovers have a "map" to work from.

Let's not get overawed by the task. If we needed to mine 2000 tons that could equate to an ice wall 48 metres wide and 3 metres high (and 12 metres deep). Might be a lot less than that, dependent on the purity of the ice. It's probably the equivalent of demolishing a house.

We basically have a difference of opinion about how much we know and, knowing what we do, how easy it would be to deploy robot rovers under human supervision to mine ice. I think we know a lot (and I have given evidence for that) and we have the technology to undertake the task (I have given evidence for that as well).

Are you proposing that humans operate your ground drill through EVAs? One of my principles of a Mars Mission is that we should absolutely minimise the number of EVAs. No EVAs would be required for the rover ice mining mission, save for exceptional circumstances.
Whilst a robotic system to emplace a ground drill is not impossible it just sounds way more complex to me. We have seen from the InSight Lander that drilling down can present problems. If your drill does get stuck, the cause and solution is not immediately obvious, whereas a stuck rover on the surface can be towed out of trouble.

Are you proposing piping water back to the PP facility or carting it in rovers? If the latter, then your system is no different from mine. If the former, then have you done the calculations on the mass of the piping, and whether heating would be required?

I would not call a well drill a "simple tool" - all the diagrams of them I have seen make them look pretty complex. Rock drills and hammers are pretty simple.

[Regarding the diversion back to previous topics:

1. You'll see in the latest Starship illustrations that far from using a rope pulley system, they are using a kind of lift (the door turns into a lift platform). I specifically mentioned the possibility of a lift system, though I didn't foresee them turning a cargo door into a lift platform.

2. I have definitely mentioned the advantage of quick deployment of PV - specifically ATK-type fan systems. ]

kbd512 wrote:

Louis,

2024 is only 4 years away.  That's an incredibly short period of time for "We have this idea for a giant new rocket" (that continues to change as engineering reality begins to set in) to "We have a complete deep space transportation and habitation system that's been tested, at least once, in the environments it's expected to operate in".  It just is.  It doesn't matter what you believe about that.  I'm sure it's great for rallying the troops, but nobody with any good sense should ever expect that to happen.  If it does happen, then great.  I'd be ecstatic if it did.

I look at how long it took Falcon Heavy, something that "seemed" like a simple matter of bolting three Falcon 9 cores together in Elon Musk's own words, to first launch.  The amount of effort that actually required equated to designing a completely new vehicle core.  In the end, that's exactly what SpaceX had to do.  Elon had an idea in his head, but real engineering is what dictated what would actually be required to make it a reality.  It wasn't nearly as fast or as cheap as he thought it'd be, but yes, it was a monumental achievement and I was cheering it on as I watched it ascend to orbit.

So, any time someone says "I'm going to build a super heavy lift launch vehicle and have it land humans somewhere on another planet in 4 years", I simply look at past similar efforts and note that not a single one of them were pulled off that fast.  There's on a single example available for a point of comparison, but there it is.  It just so happens that it's a very complex and costly task.

Regarding what you're "with" or "not with" with NASA on, that seems to be entirely dependent on whether or not they tell you exactly what you want to hear.  Whenever they don't, you claim they're inept / corrupt / whatever other disparaging descriptors you attribute to the only group who simply presents actual data.  It's not done with the intent to agree or disagree with your assertions or beliefs.

You also have this way of ignoring established and proven ways to go about accomplishing a task in the simplest way possible, which also tends to be the most reliable way to do something.  Again, I can only surmise that that's because it disagrees with some part of your ideation about why we do things the way we do.

There are an endless number of more technologically sophisticated ways of screwing a bolt into a socket, but in the end the lowly wrench or socket set tends to be the simplest and most reliable way to do it, irrespective of circumstances.  Sure, we have robots that can do the same thing, provided the work piece is precisely positioned, the robot knows exactly where it is, and an entire list of other caveats.  With all of those pre-conditions met, the robot can likely do the job faster than a human.  However, when last I checked, motor vehicle service centers were still staffed with humans using hand tools, not robots in automated work cells.

Robots really shine when performing highly repetitive and simplistic tasks, such as drilling a hole in an engine block in the precise spot it should be located at, and doing that thousands of times per day.  Some of the most advanced robots, such as those created by Boston Dynamics, while being much more generally useful than a drill robot in a specialized work cell, also have a habit of simply falling on their faces from time to time when they're not otherwise moving or doing something else- because all that sophisticated software is real complexity, every bit as real as any mechanical complexity from greater parts count, whether you believe it or not.

I hope you can understand why someone who's interested in the general reliability of some set of equipment used to perform some specific task wouldn't want to rely on such technology functioning properly when lives are at stake.  It has nothing at all to do with trying to dash your dreams of a robot-enabled future.  At the very least, I hope you know you're not the only person who wished they could simply press the "easy button" and have the robot take care of something.  That's really a tacit admission that such tech is still experimental in nature and I don't want to perform a science experiment with the lives of the astronauts on their first mission to Mars.  I want them to prove that the fundamental ideas about what we can do are sound, that we've demonstrated we can apply those concepts to enable future missions, and that we have a reliable way to send people to and from Mars.  We can still go buck-wild with automation on the second mission.

Here are my favorite examples:

A rope an pulley is too complicated or takes too long, therefore we need to design an inflatable slide and air mattress to bounce sensitive power generation equipment off of that to get all of it to the ground faster because otherwise my ideation about whether or not it's faster to unload 100 fission reactors or 1,000's of solar panels and batteries isn't satisfied.  Well, yeah, of course it takes longer to unload 10 times as much equipment.  Why would we even need to argue about that?

If you had countered with, "Well, while that's true, I can also temporarily set some of them up near my Starship to start producing power immediately and I don't need to immediately transport a reactor a kilometer or two from my ship", then I would've thought to myself, okay, he's actually thought this through and he has reasonable and practical solutions to actual problems.  Instead, we veered off onto one of these tangents that any engineer I know would just scratch their head over.  Sometimes it just looks like argumentation for sake of arguing what would seldom, if ever, be argued over if we were trying to accomplish the same task here on Earth.

I don't accept that we will probably have to drill to obtain water, therefore I'm going to assert we need a team of autonomous excavating robots that are going to get at the ice faster with laser drills and then we're going to have other robots that scoop up the ice and possibly more robots that take it back to the ship, all while being overseen by a small team of humans in a rover that needs to provide for their every need while they're operating it.

Whereas, we could send a single exploration mission to one of these ice deposits to take samples of the water, find out what's in it, determine how much is in some specific area we want to land in, decide what extraction methods would work best, and then design / test equipment to do that.  Doesn't that seem like a more reasonable approach to using a natural resource that's also more likely to result in success?  That's exactly how we do it here on Earth.  The idea that the entire engineering rule book gets thrown out because we're operating on another planet seems a bit peculiar to me.

I just want to know what problems you're trying to solve with these solutions that are so highly dependent on complex autonomous or semi-autonomous systems.  Do you understand that software complexity is just as real as any mechanical complexity and the results can be every bit as deleterious to accomplishing a task?  When we watch those Boston Dynamics robots fall on their faces while sitting / standing in place, do you understand what just happened (complete failure of the computer control systems that cause them to remain upright)?

So, I'll ask again.

If we could send a small team of humans to operate a small drilling rig to drill a well that we could either pump liquid water out of the ground after drilling down to the water table, or even drilling a small hole in a block of surface ice and then melting the surrounding ice with steam so we can pump out liquid water, then why would we resort to using a team of laser-drill-equipped semi-autonomous excavation machines and more robots that break up the ice and cart it back to the ship, while still requiring human oversight?

Are we more likely to be successful using a simple plan executed with simple tools, specifically selected with foreknowledge of the problems we'll face, or a comparatively more complicated plan using more complex tools and only cursory knowledge of the problems we'll encounter?


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

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#15 2019-11-03 17:16:32

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 17,360

Re: Practical Water Extraction Methods for Starship Missions

So far with what has been indicated for capability the Starship has no human long term life support and the modified dragon for crew is still waiting to fly.

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#16 2019-11-03 17:18:32

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 3,755
Website

Re: Practical Water Extraction Methods for Starship Missions

Louis,  you quite obviously know little or nothing about drilling into the Earth.  We in Texas do,  we have done it for oil for over a century,  and for water longer than that.  Drilling like that looks NOTHING AT ALL like what JPL came up with for Insight.  Scientists are NOT engineers!  I AM an engineer!

Drilling on Mars will be very much like drilling into the Earth.  It takes a real bit (and,  yes,  you replace them quite often),  a real drill string,  a real turntable,  and a real human crew.  This is experientially more art than science.  Robots simply cannot do it effectively,  PRECISELY BECAUSE it is more art than science.

You also seem to know next to nothing about how to extract liquids from the pores in the subsurface strata.  We in Texas do.  We have also done this for over a century in oil field and water well work.  Steam injection is in fact a primary extraction method,  as well as part of secondary methods.  Fracking is a tertiary method,  and it works too,  as long as you do not overstep the already-known bounds for frack fluid disposal (which some do for no more than corporate greed). 

On Mars,  my best guess is that "subsurface strata" are less important than meteor impact-driven mixing of regolith particles.  What that really means is there is some proportion of a formation that is ice, and some proportion that is sand,  gravel,  rocks,  and boulders.  Drilling with a real rig takes care of that;  that NASA JPL self-hammering nonsense does not. 

It is easier to deal with the volume and mass of well drill-hole detritus removal than any sort of mining.  You are talking about half a meter diameter a few thousand meters long (~600 cubic meters) vs removal of hundreds to thousands of square meters  of regolith AT THE VERY LEAST many dozens of meters deep (~10^4 cubic meters).  What is going to be easier to deal with,  <1000 cu.m or 10,000+ cu.m?

Your trust in robotics is very misplaced.  The older vehicles that did not rely on robotics are actually far more reliable than the newer ones that do.  Applies to cars,  to airplanes,  to anything you think you can automate.  If you delete the robotics,  performance is slightly reduced,  but the number of possible failure modes is DRASTICALLY reduced.  That is my personal field observation fixing cars and airplanes,  and designing flying weapon systems. 

You would be quite idiotic to ignore those observed facts.

GW

Last edited by GW Johnson (2019-11-03 17:24:18)


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#17 2019-11-03 17:42:37

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 17,360

Re: Practical Water Extraction Methods for Starship Missions

Finally getting through the
https://www.nasa.gov/sites/default/file … elease.pdf
Which had quite a few TBD indicators throughout the paper...Nasa is still trying to develope a system for mars whie running tests in Antartica which is no mars...
First is the low gravity which will allow vapor to transistion from ice with only a slight bit of heat from the drilling and then as it rises its going to refreeze binding the drill. So we will need to place a dome to seal the drilling and pressurize to keep the water in liquid form.

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#18 2019-11-03 17:53:01

louis
Member
From: UK
Registered: 2008-03-24
Posts: 5,329

Re: Practical Water Extraction Methods for Starship Missions

This has no implicatinos for my favoured approach. I posted a video here a few days ago showing how slowly ice sublimates in a vacuum  even with application of heat...the point in any case is that you would be dislodging ice chunks...so if some ice sublimates where heat is applied via mechanical action, that is of no consequence. There will absolutely be no need for a dome for the rovers to operate on an ice face!

SpaceNut wrote:

Finally getting through the
https://www.nasa.gov/sites/default/file … elease.pdf
Which had quite a few TBD indicators throughout the paper...Nasa is still trying to develope a system for mars whie running tests in Antartica which is no mars...
First is the low gravity which will allow vapor to transistion from ice with only a slight bit of heat from the drilling and then as it rises its going to refreeze binding the drill. So we will need to place a dome to seal the drilling and pressurize to keep the water in liquid form.


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

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#19 2019-11-03 18:09:37

louis
Member
From: UK
Registered: 2008-03-24
Posts: 5,329

Re: Practical Water Extraction Methods for Starship Missions

The InSight lander is of no relevance to what I propose. It is drilling DOWN - as kbd proposes doing - and it is a puny thing weighing in at 350 kgs or thereabouts.

So it sounds like you are going to have people conducting regular EVAs to undertake a ground drilling mission. That is madness. That isn't understanding the demands of Mars. Getting people to don spacesuits every day or at regular intervals will be demoralising, time-consuming and inefficient.

I've no interest in ways to "extract liquids from the pores in the subsurface strata" for Mission One on Mars (I have a general interesting in wells which I have looked into before now, not least because exhausted wells can be used as a form of energy storage if you pump water back in, but leave that aside). It will be an ineffiicient and potentially dangerous method of acquiring water.

I don't accept my proposal for Mission One involves "removal of hundreds to thousands of square meters  of regolith".  You probably need to remove something like 100-500 tons of regolith to get at the buried glacier or ice lake.  The ice will be very pure. So we don't need to mine huge, huge amounts of mixed ice and regolith.

GW Johnson wrote:

Louis,  you quite obviously know little or nothing about drilling into the Earth.  We in Texas do,  we have done it for oil for over a century,  and for water longer than that.  Drilling like that looks NOTHING AT ALL like what JPL came up with for Insight.  Scientists are NOT engineers!  I AM an engineer!

Drilling on Mars will be very much like drilling into the Earth.  It takes a real bit (and,  yes,  you replace them quite often),  a real drill string,  a real turntable,  and a real human crew.  This is experientially more art than science.  Robots simply cannot do it effectively,  PRECISELY BECAUSE it is more art than science.

You also seem to know next to nothing about how to extract liquids from the pores in the subsurface strata.  We in Texas do.  We have also done this for over a century in oil field and water well work.  Steam injection is in fact a primary extraction method,  as well as part of secondary methods.  Fracking is a tertiary method,  and it works too,  as long as you do not overstep the already-known bounds for frack fluid disposal (which some do for no more than corporate greed). 

On Mars,  my best guess is that "subsurface strata" are less important than meteor impact-driven mixing of regolith particles.  What that really means is there is some proportion of a formation that is ice, and some proportion that is sand,  gravel,  rocks,  and boulders.  Drilling with a real rig takes care of that;  that NASA JPL self-hammering nonsense does not. 

It is easier to deal with the volume and mass of well drill-hole detritus removal than any sort of mining.  You are talking about half a meter diameter a few thousand meters long (~600 cubic meters) vs removal of hundreds to thousands of square meters  of regolith AT THE VERY LEAST many dozens of meters deep (~10^4 cubic meters).  What is going to be easier to deal with,  <1000 cu.m or 10,000+ cu.m?

Your trust in robotics is very misplaced.  The older vehicles that did not rely on robotics are actually far more reliable than the newer ones that do.  Applies to cars,  to airplanes,  to anything you think you can automate.  If you delete the robotics,  performance is slightly reduced,  but the number of possible failure modes is DRASTICALLY reduced.  That is my personal field observation fixing cars and airplanes,  and designing flying weapon systems. 

You would be quite idiotic to ignore those observed facts.

GW

Last edited by louis (2019-11-03 18:10:00)


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#20 2019-11-03 19:15:03

kbd512
Moderator
Registered: 2015-01-02
Posts: 3,106

Re: Practical Water Extraction Methods for Starship Missions

Louis,

The giant rocket is merely the first component in a lengthy chain of components that all have to function flawlessly.  Your assertion that the Starship rocket is simpler than the Saturn V is patently false and any engineer worth their salt knows that.  Falcon 9 Heavy actually flies, which is a major selling point.  Whether or not you believe that to be a "wrong turn" is an entirely different matter.  That said, the ability to throw more mass at a logistics problem typically makes the problem easier to solve.

Most of us aren't fond of politics being mixed with space exploration, either.  However, we tolerate it on account of the results.

Regarding my proposed solution, YES, I'm absolutely dictating that humans perform the work.  There is no point at all in going to Mars to stare at it from a distance and take pictures.  We can already do that from the comfort of our own homes for far less cost and no possibility of killing anyone.  We don't need to risk lives to gawk at machines operating from a few feet away.  We could most certainly do everything you described from orbit without ever setting foot on the planet.  Someone needs to go there and get their hands dirty building out the infrastructure that will be required to live there on a permanent basis.  Those people will need simple, functional, reliable tools that get the job done with minimal cost and complexity by executing a simple plan that's based on prior knowledge of what's required.  I am not risking the lives of our astronauts to babysit glorified farming equipment.  We already have a small army of people to do that back here on Earth.  Sometimes you just gotta man up, or woman up, and get things done.

I have a feature on my Cadillac that does indeed allow it to park itself.  I've used that silly feature a grand total of 1 time in a demonstration at the dealership.  However, if the software ever screws that up, I'm still responsible for the damage the software causes.  As such, I have spent the time and money and acquired the experience required to know how to drive and park a car, meaning any passenger vehicle, no matter how large or small or sophisticated.  It doesn't matter if the car was built in 1910 or 2010, I still know how to operate it, with or without any stupid computers.  Self-parking and self-driving cars don't have any practical utility, apart from giving thieves yet another way to steal your car that doesn't actually require walking up to the car to steal it.  You still have to get in and out of the car to go anywhere.  I really don't understand the fascination with this sort of stuff.

GUI's weren't invented to make computers more functional.  They were invented to allow people who really don't know how to operate a computer to do something moderately useful with one.  There are certain times when visualization is still very helpful, but punching in simple and repetitive commands isn't one of them.  Nothing about the complexity of the GUI should be construed as a simplification of how the computer actually operates, because the addition of the GUI drastically increases the computing power and complexity of the software required to do what it does.

So, if you can't perform an EVA on Mars, there's very little point in going there.  Not being able to play through a few holes on Mars isn't helping humanity "get the big picture"- meaning, gain a greater appreciation for the vastness and complexity and variety of the universe we live in.  You absolutely have to get your hands dirty to do that.

I could talk to you all day about the pure joy of flying.  Apart from putting you to sleep, you still wouldn't understand why I do it.

Alternatively, we could run our hands over and jostle everything that's keeping us from plummeting back to Earth like a meteor, execute some minor gymnastics to enter the cockpit, have a quick chat with someone who actually cares about us living to fly another day to tell them what were up to, smell the gas as our sleek little machine coughs and sputters to life, be deafened by the bone rattling roar of our engine as it strains to keep that slender finely crafted chunk of metal out front knifing through the air as it's pulling us down the runway, and as our bird leaps off the ground...  Then and only then will you truly understand why I'd willingly risk my life to do this as many times as I can before I die.  Thereafter, you will be treated to a view of the world around you that not so many of us are privileged to experience.  There are an infinite number of ways to die and none of us are leaving this place alive, but this particular one seems infinitely more preferable to a hospital bed in a nursing home.

Going to Mars needs to be a human experience.  If you really can't understand that, then you need to pay whatever 75 bucks amounts to in the Queen's money and go take a ride in a real airplane.  If you're the same afterwards, then nobody can help you.

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#21 2019-11-03 19:39:15

louis
Member
From: UK
Registered: 2008-03-24
Posts: 5,329

Re: Practical Water Extraction Methods for Starship Missions

Kbd -

The whole purpose of going to Mars is to allow humans to experience it and transform it. So I have nothing in principle against  getting up close and personal with the planet. But here we are focussed on Mission One...well, at least I am (because I have no problem with drilling water wells down into the ground on later missions).

For Mission One I think we should be minimising EVAs and focussing on the job in hand: which is essentially propellant production. EVAs bring danger and waste time.  I have seen estimates for getting in a spacesuit ranging from 40 mins to 90 mins...and then pretty much the same in reverse - that's an hour and half possibly out of your working sol. It's not a trivial thing. And every time you do an EVA you have to have a dust suppression system. Doing an EVA on the Moon back in the 70s in a Rover knowing you were being watched back on Earth by billions was a fun thing to do. But you will be asking the pioneers on Mars to engage in these laborious EVA activities to undertake essentially menial and repetitive tasks that nobody will be watching. The potential for health and safety issues to arise is obvious in such circumstances where you constrain high achievers in that way - their minds will be elsewhere after a few sols.

Flying sounds like a good buzz! Personally, I rather like riding my bicycle...which probably carries a similar risk of injury per hour of use!

I am definitely not proposing a risk-free approach (but you seem to have changed tack from risk aversion to risk embracing!).  I am looking at this purely as what is the most secure route to establishing a permanent human settlement on Mars. Once we have the settlement secure I want us to be adventurous and bold in exploring the planet. Sounds like you would probably enjoy piloting a rocket-hopper over Mars surveying the landscape!

kbd512 wrote:

Louis,

The giant rocket is merely the first component in a lengthy chain of components that all have to function flawlessly.  Your assertion that the Starship rocket is simpler than the Saturn V is patently false and any engineer worth their salt knows that.  Falcon 9 Heavy actually flies, which is a major selling point.  Whether or not you believe that to be a "wrong turn" is an entirely different matter.  That said, the ability to throw more mass at a logistics problem typically makes the problem easier to solve.

Most of us aren't fond of politics being mixed with space exploration, either.  However, we tolerate it on account of the results.

Regarding my proposed solution, YES, I'm absolutely dictating that humans perform the work.  There is no point at all in going to Mars to stare at it from a distance and take pictures.  We can already do that from the comfort of our own homes for far less cost and no possibility of killing anyone.  We don't need to risk lives to gawk at machines operating from a few feet away.  We could most certainly do everything you described from orbit without ever setting foot on the planet.  Someone needs to go there and get their hands dirty building out the infrastructure that will be required to live there on a permanent basis.  Those people will need simple, functional, reliable tools that get the job done with minimal cost and complexity by executing a simple plan that's based on prior knowledge of what's required.  I am not risking the lives of our astronauts to babysit glorified farming equipment.  We already have a small army of people to do that back here on Earth.  Sometimes you just gotta man up, or woman up, and get things done.

I have a feature on my Cadillac that does indeed allow it to park itself.  I've used that silly feature a grand total of 1 time in a demonstration at the dealership.  However, if the software ever screws that up, I'm still responsible for the damage the software causes.  As such, I have spent the time and money and acquired the experience required to know how to drive and park a car, meaning any passenger vehicle, no matter how large or small or sophisticated.  It doesn't matter if the car was built in 1910 or 2010, I still know how to operate it, with or without any stupid computers.  Self-parking and self-driving cars don't have any practical utility, apart from giving thieves yet another way to steal your car that doesn't actually require walking up to the car to steal it.  You still have to get in and out of the car to go anywhere.  I really don't understand the fascination with this sort of stuff.

GUI's weren't invented to make computers more functional.  They were invented to allow people who really don't know how to operate a computer to do something moderately useful with one.  There are certain times when visualization is still very helpful, but punching in simple and repetitive commands isn't one of them.  Nothing about the complexity of the GUI should be construed as a simplification of how the computer actually operates, because the addition of the GUI drastically increases the computing power and complexity of the software required to do what it does.

So, if you can't perform an EVA on Mars, there's very little point in going there.  Not being able to play through a few holes on Mars isn't helping humanity "get the big picture"- meaning, gain a greater appreciation for the vastness and complexity and variety of the universe we live in.  You absolutely have to get your hands dirty to do that.

I could talk to you all day about the pure joy of flying.  Apart from putting you to sleep, you still wouldn't understand why I do it.

Alternatively, we could run our hands over and jostle everything that's keeping us from plummeting back to Earth like a meteor, execute some minor gymnastics to enter the cockpit, have a quick chat with someone who actually cares about us living to fly another day to tell them what were up to, smell the gas as our sleek little machine coughs and sputters to life, be deafened by the bone rattling roar of our engine as it strains to keep that slender finely crafted chunk of metal out front knifing through the air as it's pulling us down the runway, and as our bird leaps off the ground...  Then and only then will you truly understand why I'd willingly risk my life to do this as many times as I can before I die.  Thereafter, you will be treated to a view of the world around you that not so many of us are privileged to experience.  There are an infinite number of ways to die and none of us are leaving this place alive, but this particular one seems infinitely more preferable to a hospital bed in a nursing home.

Going to Mars needs to be a human experience.  If you really can't understand that, then you need to pay whatever 75 bucks amounts to in the Queen's money and go take a ride in a real airplane.  If you're the same afterwards, then nobody can help you.

Last edited by louis (2019-11-03 19:39:44)


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#22 2019-11-03 20:50:51

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 17,360

Re: Practical Water Extraction Methods for Starship Missions

adding to post #2
A cubic foot of soil weighs between 74 and 110 pounds, depending on the type of soil and how moist it is. Which is also the same for mars as to water contnent. Dry, loose dirt weighs about 76 pounds per cubic foot, while moist, loose dirt weighs 78 pounds per cubic foot. As this is what I would expect with the loose sand areas in many of the pictures sent back by the rovers. A cubic foot of top soil weighs about 96 pounds, for a greenhouse after adding in human waste to make it fertile for planting and a cubic foot of dry, screened top soil weighs 44 to 48 pounds before.

1 lb is 2.2 kg
2,000 kg is 2 tons
One acre is 43,560 cubic ft
dry 44 to 48 pounds = 96.8 kg to 105.6 kg
wet 74 and 110 pounds = 162.8 to 242 kg

You probably need to remove something like 100-500 tons of regolith to get at the buried glacier or ice lake.

Whether dry or wet we are only interested in moving the soil covering the ice. so how much do you think the dirt over the ice is for thickness and then how many sq ft will need to be moved?

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#23 2019-11-03 23:38:50

kbd512
Moderator
Registered: 2015-01-02
Posts: 3,106

Re: Practical Water Extraction Methods for Starship Missions

Louis,

The technology IS the risk.  The more of it that you start betting your life on, the more things there are that can and will go wrong- typically in ways nobody ever expected, which would be why it wasn't discovered through testing.  I'm not for or against taking risks, I just want to know what benefit taking a particular risk provides.  If you're relying on complex robots to perform complex tasks, the number of ways that can go wrong only runs in one direction.

Whenever mechanization or automation fails, someone has to have the knowledge / skills / tools / parts to repair the machine or a replacement machine.  That's a lot easier to do with a population ranging into the billions and all the technology of humanity backing it than it is with 6 people in a tin can 40 million miles from home, no matter how intelligent and capable they are- which typically only applies within a very narrow context.

Here's how I could get behind this idea you have:

1. Skip the use of robots.  If they were truly mission enablers, then they would simply be sent out ahead of human landings to do everything required to prepare water for use before any humans arrived.  Since we don't seem to trust that they can do that on their own, we don't need them.  We've already sent plenty or robots to Mars and they've told us what they can tell us and done as much as they can do.  There's a limit to everything and we're already running into current technological limitations.

The point of the first mission is proving that we deserve to be there.  We will prove that to ourselves by surviving on Mars and returning to Earth.  We do not need an endless series of technological hurdles to overcome and we certainly don't need to bet lives on untested equipment and operating procedures.  Nothing good will come of that.

2. The human driven rover that has to be there anyway just in case something goes wrong (a tacit admission that robots can and do fail often enough to require human supervision), should be the "tool" used to search for water and excavate whatever is covering it.  It has to be pretty heavy anyway to hold everything required to support two or more crew for several days at a time and negotiate rugged terrain, which means it can also push regolith out of the way faster than multiple smaller and lighter robots that would still have to be transported to / from the big dig, perhaps several times if the initial attempts don't turn up anything, and powered and kept warm at night and repaired as required.  If you need redundancy, then send two human driven rovers.  Since propellant production is required just to go home, we can afford to send 4 people to dig or drill for water and leave 2 people behind on the Starship.

The weight of these robotic machines would be much better "spent" in terms of extra solar panels and batteries and replacement parts for human operated vehicles.  That's far more likely to increase the chances of success than having a few more small robots.  If the vehicle is built like a miniature tank, then it'll also have the durability and dependability of a tank for off-road driving conditions, which reduces the probability of failure.  It'll also have serious torque, traction, low-CG, and hauling capability to carry water.  Besides, making daily water runs in your own personal tank is likely to be your only opportunity to be alone with your thoughts and enjoy the sights of Mars without having someone else breathing down your neck.  Magnificent desolation and all that.

3. Don't make any task more sophisticated or complicated than it has to be.  If you can get a piece of equipment off a ship with a few meters of rope with little to no risk and without requiring new technology development, then use the rope and call it day.  Sometimes a wheel just needs to do what a wheel does and "reinventing the wheel" is simply a waste of time and money.  If a human can as ably perform the same task or will end up performing the task when mechanization fails, well, that'd be one reason for sending them to Mars.

We don't require "deck swabbing robots" in the Navy.  We call the good people who do that "Able Seamen".  They're able to clean up, repair busted equipment, remove trash, tend to the injured, fight fires, and do anything else the Navy requires.  None of us have ever seen the end of the list of what the Navy requires, so we're pretty sure we can take care of it.  Also, maintaining your equipment is not a punishment, nor is it a menial task without consequence.  It's a sign of affection for and trust in something that will take care of you when the time comes, so long as you take care of it.

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#24 2019-11-04 09:16:31

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 3,755
Website

Re: Practical Water Extraction Methods for Starship Missions

Re Spacenut post 17:

You don't need a dome.  It would have to be huge to contain the pipe derrick tower above the turntable. 

Merely seal the operating deck under the turntable to the ground,  and use an oil-based labyrinthine seal between deck and the spinning drill pipe.  At Martian conditions, a silicone oil would not freeze. 

If you keep the "air" pressure in the drill hole moderately above local atmospheric,  the water stays liquid.  It won't do the friction-heating and refreezing thing when you are not actively drilling,  so depressurized pipe extraction operations present no real risk. 

Once you properly line the drill hole and cap it with the plumbing head,  you can run any pressure down the bore hole that you want.  Steam extraction,  or even just hot water extraction would be quite feasible. 

These techniques have been used in oil field work for over a century now.  The ONLY thing the movie "Armageddon" got right was that real drillers would know how to drill through real-world ugly rock.

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

Last edited by GW Johnson (2019-11-04 09:31:19)


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#25 2019-11-04 13:22:24

louis
Member
From: UK
Registered: 2008-03-24
Posts: 5,329

Re: Practical Water Extraction Methods for Starship Missions

I saw a smaller version of one of these with a hydraulic hammer in operation yesterday...

https://www.youtube.com/watch?v=dTMeRpyqDWY

I think a hydraulic hammer would probably do the job better than drills on reflection in breaking down a glacier face into ice chunks.


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