Author Topic: Water, Methane, and Oxygen ISRU on Mars  (Read 7814 times)

Offline redliox

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Water, Methane, and Oxygen ISRU on Mars
« on: 05/15/2016 05:35 PM »
This relatively fresh study sparked the need for a[nother][1] dedicated ISRU thread: http://mepag.jpl.nasa.gov/reports/Mars_Water_ISRU_Study.pdf
I'm honestly surprised there hasn't been a thread directly made for ISRU despite how prominently it is mentioned in numerous Mars threads here at Nasaspaceflight.com.  Do post commentary about the subject and especially new developments related to extracting and manufacturing resources on Mars, especially water and methane.

Regarding the M-WIP Study, they've begun to consider the importance extracting Martian water is to both life support and propellant for a Martian Ascent Vehicle.  On the side, I suspect somewhere Robert Zubrin of the Mars Society is laughing, although at least pleased some aspects of NASA are finally moving toward the water/lox/methane manufacture he championed over 20 years ago.  But seriously, the discovery of abundant water/hydrogen as both ice and minerals thanks to the Odyssey and MRO probes has probably eased the transition toward ISRU.  Now we have proof there are definite resources to use; both the hydrogen and carbon dioxide for the Sabatier reactions are on Mars.

The study identifies 4 areas to extract water from:
A) Glaciers
B) Poly-hydrated minerals
C) Phyllosilicate minerals
D) Regolith

While glaciers are the most obvious source of water, the disadvantage pointed out is they: 1) outside of the poles, they're buried under a lot of regolith, and 2) become unstable when exposed because the ice naturally sublimates.  It will take a lot of effort to dig it up, and after that you have to extract it asap before the ice evaporates.  In a worst case, a base built on a glacier might tilt or fall apart if the area around it is unearthed.  Methods are being considered for glacial extraction, but it considered a less mature option compared to the other 3 resource options.

Outside of resource discussion, there is some acknowledgement NASA is indeed considering at least partial resource utilization; LOX production seems to be already on the table, with MOXIE via the 2020 rover being a prelude.  So now it is coming down to deciding how the methane and water will be obtained.  This in turn warrants further missions to demonstrate both Sabatier reactors and robotics to harvest material.

As news develops for ISRU, do mention them here and inject the occasional opinion, so long as it relates to ISRU on Mars.

1 - Edit/Lar (thanks to A_M_Swallow)
Here are links to two previous ISRU threads.

Advanced Concepts / Making a Lunar Ascent rocket fuel on the Moon
http://forum.nasaspaceflight.com/index.php?topic=9434.msg176666#msg176666

Advanced Concepts / ISRU techniques and uses
http://forum.nasaspaceflight.com/index.php?topic=11824.msg241841#msg241841
« Last Edit: 05/16/2016 10:27 PM by Lar »
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Offline guckyfan

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Re: Water, Methane, and Oxygen ISRU on Mars
« Reply #1 on: 05/15/2016 06:30 PM »
The amount of water needed for a NASA base as planned may be extractable from all kinds of sources. However the amounts needed for a SpaceX architecture with MCT and a colony with many people is much higher. IMO it can only be effectively extracted from glaciers.

The regolith cover as determined by orbital radar is no more than 10m. That's not too much given there is a need for many thousands of tons of water. Removing a max amount of 10m of regolith may be a lot easier than mining the ice which is as hard as concrete at Mars temperatures. I don't see sublimation as a major problem as long as the ice is shaded from direct sunlight. Even sublimation needs the same energy as normal heating to liquid and then gaseous form. That's a lot of energy for much ice to sublimate and energy comes from sunlight.

Building the base directly on a glacier may not be a good idea. Though if the regolith cover is 10m that may become a problem only when the base becomes large, becomes a city.

I don't see

Offline nadreck

Re: Water, Methane, and Oxygen ISRU on Mars
« Reply #2 on: 05/15/2016 07:02 PM »
My understanding of the findings is that they would not have any information about glaciers that have more than 10 meters of regolith coverage. I think there may be deeper ones, and that they could be drilled into directionally or horizontally to be harvested.

However, there may also be boundaries between glacier and bedrock that could prove advantageous.
It is all well and good to quote those things that made it past your confirmation bias that other people wrote, but this is a discussion board damnit! Let us know what you think! And why!

Offline redliox

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Re: Water, Methane, and Oxygen ISRU on Mars
« Reply #3 on: 05/15/2016 07:18 PM »
The amount of water needed for a NASA base as planned may be extractable from all kinds of sources. However the amounts needed for a SpaceX architecture with MCT and a colony with many people is much higher. IMO it can only be effectively extracted from glaciers.

Trying to avoid this from becoming clogged with SpaceX fandom, but I knew it would be brought up sooner or later.  My only statement for SpaceX along with Red Dragon, in regards to ISRU, is that it seems the obvious candidate for field testing ISRU; the trouble with standard probes is that you end up competing for payload space with scientists - MOXIE was lucky to get room on 2020.  I suggest holding off on MCT talk until SpaceX declares what's needed in September.

The regolith cover as determined by orbital radar is no more than 10m. That's not too much given there is a need for many thousands of tons of water. Removing a max amount of 10m of regolith may be a lot easier than mining the ice which is as hard as concrete at Mars temperatures. I don't see sublimation as a major problem as long as the ice is shaded from direct sunlight. Even sublimation needs the same energy as normal heating to liquid and then gaseous form. That's a lot of energy for much ice to sublimate and energy comes from sunlight.

10 meters is still over 32 feet deep...as in over five and a half times the height of an average man...as in hundreds and hundreds of pounds/kilos of material...some of which may also be as hard as concrete and in irregular chunks dropped by ancient Martian seas and glaciers.  Moving all of that will drain batteries hard, more so if nuclear power is limited if allowed at all.  That's no idle work, and it is more conservative of energy to draw on easy-to-access regolith heavy in hydrogen, be it ice or gypsum.

The best option for ice is akin to plans for exploring Europa; drill and use a crybot to melt the ice, essentially making a well with the vapor getting collected by the excavator above.  Glacial ice isn't exactly the first choice, but neither is it off the table.  Most likely if ice is considered it will have to be shallowly covered, as in 3 meters or less.  It is a juicy fruit for ISRU, but unless you're flying to the (Martian) north pole it isn't easy to pick at the moment.

My understanding of the findings is that they would not have any information about glaciers that have more than 10 meters of regolith coverage. I think there may be deeper ones, and that they could be drilled into directionally or horizontally to be harvested.

However, there may also be boundaries between glacier and bedrock that could prove advantageous.

There's still a lot they don't know about ice on Mars, obviously since we've only seen a direct hint of it via Phoenix (but no one's driven to the north pole yet).  There's better knowledge about chemically-bound water via Spirit, Opportunity, and Curiosity which is why there's a slight favor towards it for the moment.  I wouldn't be surprised if they opt for a little of both ideally, at least for something in mid-lattitudes; many of the sites for both the 2020 rover and human exploration state they're going for a mix of both kinds of water whenever possible.
« Last Edit: 05/15/2016 07:20 PM by redliox »
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Offline A_M_Swallow

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Re: Water, Methane, and Oxygen ISRU on Mars
« Reply #4 on: 05/15/2016 09:07 PM »
Here are links to two previous ISRU threads.

Advanced Concepts / Making a Lunar Ascent rocket fuel on the Moon
http://forum.nasaspaceflight.com/index.php?topic=9434.msg176666#msg176666


Advanced Concepts / ISRU techniques and uses
http://forum.nasaspaceflight.com/index.php?topic=11824.msg241841#msg241841

Offline guckyfan

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Re: Water, Methane, and Oxygen ISRU on Mars
« Reply #5 on: 05/16/2016 04:36 AM »
My understanding of the findings is that they would not have any information about glaciers that have more than 10 meters of regolith coverage. I think there may be deeper ones,

The argument for max 10m was that radar could see and measure regolith covers of more than 10m, not that they could not see water deeper than that. They do not have enough depth resolution to see covers less than 10m in radar reflections from orbit. So it seems there are no or no very large glaciers with regolith covers of more than 10m because they don't see regolith covers over glaciers.

Offline guckyfan

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Re: Water, Methane, and Oxygen ISRU on Mars
« Reply #6 on: 05/16/2016 04:47 AM »
Trying to avoid this from becoming clogged with SpaceX fandom, but I knew it would be brought up sooner or later.  My only statement for SpaceX along with Red Dragon, in regards to ISRU, is that it seems the obvious candidate for field testing ISRU; the trouble with standard probes is that you end up competing for payload space with scientists - MOXIE was lucky to get room on 2020.  I suggest holding off on MCT talk until SpaceX declares what's needed in September.

I understand this is not a SpaceX thread and acknowledged it by arguing both NASA and SpaceX situations. I don't think you can reasonably exclude the SpaceX situation from an ISRU thread.

10 meters is still over 32 feet deep...as in over five and a half times the height of an average man...as in hundreds and hundreds of pounds/kilos of material...some of which may also be as hard as concrete and in irregular chunks dropped by ancient Martian seas and glaciers.  Moving all of that will drain batteries hard, more so if nuclear power is limited if allowed at all. 

I already argued that removing a regolith cover that thick is only worth it if you need a lot of water. There is also the chance that they find areas where the cover is only 1m deep as is the lower boundary of cover determined by the fact that less cover would cause long term sublimation of the ice below.

That's no idle work, and it is more conservative of energy to draw on easy-to-access regolith heavy in hydrogen, be it ice or gypsum.

That's only true as long as the amount of water needed is low. Extracting water from regolith requires a lot more energy than melting water from glacier ice.

Edit: fixed quotes
« Last Edit: 05/16/2016 04:49 AM by guckyfan »

Offline Rei

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Re: Water, Methane, and Oxygen ISRU on Mars
« Reply #7 on: 05/16/2016 09:14 AM »
A basic summary of my reading of that document: "high importance, low TRL"

I think we all here already knew that  ;)  The differences in system mass between a with-ISRU and without-ISRU mission are tremendous, making ISRU tremendously important.  But our experience with "low maintenance low mass Martian bobcats and water isolation systems" is, let's just say, "lacking" - as is our quantification of the scale, homogeneity of mechanical and chemical properties, etc of the various potential resources.  We've got plenty of broad orbital data and tons of spread-out individual surface analyses.  But that does not a reserves characterization make.

It's good to see the reality check, particularly on the "glacial ice" concept (the overburden problem, the sublimation problem, the rocks-and-sand-and-who-knows-what mixed in problem, the hardness problem, etc).  Even though they're still being generous on a lot of cases, for example assuming that weathering has already basically mined the minerals for you in B, C and D.  Maybe if you let purely ISRU factors determine the landing site, but scientists prefer sites where the strata haven't been weathered into a homogenous mess.    But, who knows.  :)

Also, it appears that they're assuming nothing more than simple distillation, which is quite the assumption - they just leave it open with their "not addressed" remark on page 60.  Distillation only removes non-volatile chemicals - to pick an example example, it won't remove the HCl from decomposing perchlorates.  And even paired with RO, the best RO membranes tend to be attacked by chlorine, and the non-chlorine sensitive ones tend to be pH-sensitive.

That is to say, there's some very significant engineering work and an awful lot of testing ahead.  But also, the importance of the task means it'll probably get done sooner or later.

Nice excavator design for loose soils on P.38.  :)  I worry about rocks jamming it up, though.  Apparently they do too.

Good presentation  :)
« Last Edit: 05/16/2016 12:43 PM by Rei »

Offline guckyfan

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Re: Water, Methane, and Oxygen ISRU on Mars
« Reply #8 on: 05/16/2016 09:52 AM »
That was a funny part of the NASA workshop about selecting landing sites. A glacier expert said, glacial ice is always very clean. Get a block of that ice into the habitat, let it melt and drink it.

An expert on ECLSS was shocked. She said, get us a sample of that ice, give us 15 to 20 years development time and we will give you a space rated device that can make it drinkable.

I guess the truth will be somewhere inbetween.

Offline redliox

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Re: Water, Methane, and Oxygen ISRU on Mars
« Reply #9 on: 05/16/2016 10:32 AM »
That was a funny part of the NASA workshop about selecting landing sites. A glacier expert said, glacial ice is always very clean. Get a block of that ice into the habitat, let it melt and drink it.

An expert on ECLSS was shocked. She said, get us a sample of that ice, give us 15 to 20 years development time and we will give you a space rated device that can make it drinkable.

I guess the truth will be somewhere inbetween.

...and that beautifully illustrates how not all rocket scientists are experts.  8)

Of course, regarding ice, I'd hope for some testing before drinking it, but it sounds consistent with how I've heard frozen water can be surprisingly pure.  The real limitation with glaciers on Mars is how to access them, hence why I stressed that particular resource; it's big and obvious but good luck rigging a solar-powered rover to dig it out.  Yet, especially for mid and high lattitudes, the abundance is enough to keep them on the list.

IMO, reading the M-WIP gave me the impression gypsum should be pursued.  Aside from the mineral being water heavy, there is a very solid scientific motivation to seek it out: gypsum forms in seawater and hot springs.  Wherever you find the stuff, odds are you will find many things related to the deep history of Mars prior to the dry Amazonian Era, with or without fossils.  However, in fairness this could also be said of the other various minerals; gypsum just stands out as the least intensive to harvest, including the fact it's a soft chalk less abrasive to equipment.
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Offline Rei

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Re: Water, Methane, and Oxygen ISRU on Mars
« Reply #10 on: 05/16/2016 11:44 AM »
Of course, regarding ice, I'd hope for some testing before drinking it, but it sounds consistent with how I've heard frozen water can be surprisingly pure.

On a planet full of ubiquitous toxic dust, IMHO that's beyond optimism.  You'll be drinking perchlorates, hexavalent chromium and arsenic just from dust contamination alone.

Quote
IMO, reading the M-WIP gave me the impression gypsum should be pursued.  Aside from the mineral being water heavy, there is a very solid scientific motivation to seek it out: gypsum forms in seawater and hot springs.  Wherever you find the stuff, odds are you will find many things related to the deep history of Mars prior to the dry Amazonian Era

Indeed - but as you'll note in the article, they're looking for gypsum that's already been weathered to fine sediment - they don't even consider (apart from relatively quickly to dismiss it) hard rock mining.  By contrast, geologists generally want their layers intact.

But hey, you might get lucky and find a place with both highly weathered and bare, unweathered gypsum  :)  That's certainly possible. 

Hmm, just thinking here, are there any good routes to sulfuric acid production from gypsum applicable to a Mars environment?  Sulfuric acid usually tops the list of most widely consumed important industrial chemicals on Earth, and I'm just thinking about future local production here.
« Last Edit: 05/16/2016 11:45 AM by Rei »

Offline Rei

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Re: Water, Methane, and Oxygen ISRU on Mars
« Reply #11 on: 05/16/2016 11:51 AM »
A glacier expert said, glacial ice is always very clean.
What sort of glacier expert would make a statement like that?  Here's what glacial ice looks like around where I live:

http://i.telegraph.co.uk/multimedia/archive/02167/dark-blue-impact_2167404k.jpg

I wouldn't even dream of calling that "very clean".  And we're not constantly blanketed in a cloud of fine dust - that just comes from dusting events once every couple dozen years for a given location (which is why it forms stripes).  Glaciers ability to trap dust is not only well known, but a very important part of glaciology - it's used to study past climates.

Here's what shallow subsurface water ice looks like on Mars:

https://en.wikipedia.org/wiki/Phoenix_%28spacecraft%29#/media/File:Phoenix_mission_horizon_stitched_high_definition.jpg

There's no way that that is in any way pure and clean.  Leading contention from Phoenix seems to be "frozen dusty brine".

As per Wikipedia, which cites five references on the topic:

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

Quote
Like glaciers on Earth, glaciers on Mars are not pure water ice. Many are thought to contain substantial proportions of debris, and a substantial number are probably better described as rock glaciers

https://en.wikipedia.org/wiki/Rock_glacier
« Last Edit: 05/17/2016 08:38 AM by Rei »

Offline guckyfan

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Re: Water, Methane, and Oxygen ISRU on Mars
« Reply #12 on: 05/16/2016 01:11 PM »
Glaciers can contain rocks, true. The water is still very clean.

It was said the glaciers on Mars they were talking about contain very little rocky material. It would show up as scatter in the signal. From lack of scatter they can safely assume very clean water.

Online RonM

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Re: Water, Methane, and Oxygen ISRU on Mars
« Reply #13 on: 05/16/2016 01:49 PM »
Glaciers can contain rocks, true. The water is still very clean.

It was said the glaciers on Mars they were talking about contain very little rocky material. It would show up as scatter in the signal. From lack of scatter they can safely assume very clean water.

The question is how did the glaciers form?

If the glaciers formed by the accumulation of snow, then the ice can be clean. Then again, with thin layers of a light coat of dust mixed in and then melted, dangerous chemicals can dissolve in the water and contaminate it. Sublimating the ice could avoid contamination from non volatiles in the dust, but removing volatiles would be more complex.

If the glaciers formed by ground water freezing, the water can be heavily contaminated.

Considering what we know about Mars surface chemistry, water extracted from glacial ice will require testing and purification.

When scouting base or colony locations, drilling into the ice and chemical analysis will be needed to determine which location has the ice requiring the least purification.

Offline guckyfan

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Re: Water, Methane, and Oxygen ISRU on Mars
« Reply #14 on: 05/16/2016 02:13 PM »

The question is how did the glaciers form?

My understanding is that glaciers form by precipitation. So if they did not form from precipitation they are not glaciers. Given the discussion I assume they are glaciers and have been formed by precipitation. That would make it likely that they do include dust.

Glaciers that contain rocky material have gathered it while flowing.

Quite possible that my line of thought is too simplistic and wrong.

Offline redliox

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Re: Water, Methane, and Oxygen ISRU on Mars
« Reply #15 on: 05/16/2016 09:07 PM »
My understanding is that glaciers form by precipitation. So if they did not form from precipitation they are not glaciers. Given the discussion I assume they are glaciers and have been formed by precipitation. That would make it likely that they do include dust.

Glaciers that contain rocky material have gathered it while flowing.

Quite possible that my line of thought is too simplistic and wrong.

Not necessarily; we simply don't know what the Martian climate was like eons ago.  The current one is full of dust storms littered with polluting fines (i.e. very powdery dust), but in a wetter era that would have been confined as silt and less of an issue.  My educated guess would be that the more ancient the glacier, the more pure it will be, with layers formed in the Amazonian Era will have dust embedded.

Ironically, the same fines would be perfect mining material as it doesn't need to be ground up, just shoved into a vat for processing.
« Last Edit: 05/17/2016 05:21 PM by redliox »
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Offline guckyfan

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Re: Water, Methane, and Oxygen ISRU on Mars
« Reply #16 on: 05/17/2016 04:53 AM »
BTW, whenever there would be significant fuel production on Mars, there would be an excess of oxygen because rocket engines run fuel rich. CO2 extraction from the atmosphere would produce nitrogen, or rather a mix of nitrogen and argon, which is breathable. So a breathable atmosphere would be a welcome byproduct. Only CO2 removal should be necessary.

Offline the_other_Doug

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Re: Water, Methane, and Oxygen ISRU on Mars
« Reply #17 on: 05/17/2016 02:18 PM »
BTW, whenever there would be significant fuel production on Mars, there would be an excess of oxygen because rocket engines run fuel rich. CO2 extraction from the atmosphere would produce nitrogen, or rather a mix of nitrogen and argon, which is breathable. So a breathable atmosphere would be a welcome byproduct. Only CO2 removal should be necessary.

Hmm... this is a semantics note, but I have a bit of a hiccup seeing the concept floated of just removing the CO2 from Mars' atmosphere and you have a useful atmosphere left.

That's sort of like saying if you're looking to produce salt, all you need to do is remove the water from salt water, and you have useful salts.  I would look at it a lot more as removing the salt from the water, not vice-versa.

So, yeah -- what you describe, I would think of as purifying the CO2 in Mars' atmosphere by removing the less than 4% of trace gasses, which are almost entirely composed of nitrogen and argon.  That tracks logically a lot better than looking at it as a "CO2 removal" operation... ;)
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Offline guckyfan

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Re: Water, Methane, and Oxygen ISRU on Mars
« Reply #18 on: 05/17/2016 03:02 PM »
I think that's a misunderstanding. What I mean by CO2 removal is remove the rising CO2 from the breathable atmosphere inside the habitat. Otherwise it can be maintained by adding surplus oxygen from propellant production. No need for a closed loop ECLSS early on. Can wait with a closed loop system until it is a biological system, not similar to attempting closed loop on the ISS or in a spacecraft.

Offline A_M_Swallow

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Re: Water, Methane, and Oxygen ISRU on Mars
« Reply #19 on: 05/17/2016 03:33 PM »
BTW, whenever there would be significant fuel production on Mars, there would be an excess of oxygen because rocket engines run fuel rich. CO2 extraction from the atmosphere would produce nitrogen, or rather a mix of nitrogen and argon, which is breathable. So a breathable atmosphere would be a welcome byproduct. Only CO2 removal should be necessary.

Hmm... this is a semantics note, but I have a bit of a hiccup seeing the concept floated of just removing the CO2 from Mars' atmosphere and you have a useful atmosphere left.

That's sort of like saying if you're looking to produce salt, all you need to do is remove the water from salt water, and you have useful salts.  I would look at it a lot more as removing the salt from the water, not vice-versa.

So, yeah -- what you describe, I would think of as purifying the CO2 in Mars' atmosphere by removing the less than 4% of trace gasses, which are almost entirely composed of nitrogen and argon.  That tracks logically a lot better than looking at it as a "CO2 removal" operation... ;)

Removing the CO2 is easy, just cool to -78.5 C; −109.2 F; 194.7 K at 1 atmosphere.

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