How to create the ISRU and the Energy for the process...

[Tywin]

Marspedia is very interesting...


https://marspedia.org/Home


I think so, the energy and the robots to create the ISRU are decades away...

[Robotbeat]

Marspedia is very interesting...


https://marspedia.org/Home


I think so, the energy and the robots to create the ISRU are decades away...

We already did ISRU on Mars. Perseverence demonstrated making oxygen (and fuel, CO) using nuclear power.

[Slarty1080]

The whole chemical processing set up to turn H₂O and CO₂ into O₂ and CH₄ is relatively trivial chemical engineering (gas light era technology). It does need to be built (and then tested in situ), but it's not rocket science even if it is unfamiliar to many people.

CO₂ is available in abundance from the atmosphere after filtration and compression via multiple technologies. The two most difficult challenges are in providing sufficient power and accessing sufficient pure water. Power at least initially will probably come from a mixture of smaller nuclear units Like Kilopower:
https://cen.acs.org/energy/nuclear-power/NASA-thinks-nuclear-reactors-supply/98/i19
Together with a vast quantity of solar power.

Water is present in abundance on Mars but the most easily accessible deposits are in the more difficult to reach higher latitudes. A lot of water is also present at lower latitudes where it could be accessed, but tends to be more obscured by overburden. So the most likely way of accessing it would be a robotic drill and or rodwell. It should be doable but would be more difficult with a robot. Drilling is not fundamentally difficult but has posed a challenge for some recent missions. One of the biggest issues is the unknowns around the water extraction such as the trafficability of the areas where the ice is located, the extent, depth and variability of the overburden and the ice deposit as well as the purity of the ice and the quantity and nature both physical and chemical of the impurities all of which will impact the extraction and purification methods. 

This probably needs a precursor robotic Starship mission with a number of different technologies that can be experimented with like simple rodwells with a heaters, Pressure swing adsorption kit with pumps, different drilling techniques, simple bulldozing, use of explosives and covering the ground with a low greenhouse and circulating warm CO₂ etc. Once they have gone to town on the surface to see what works we will know where we stand on a proper demonstration mission. 

[LMT]

"Electrochemical Methane Production from CO2 for Orbital and Interplanetary Refueling"

Going forward, as more robust and efficient CO2 electrolysis systems are engineered, their lower operational temperatures and pressures provide an opportunity to decrease system weight as compared with the Sabatier system. This potentially substantial reduction in payload mass could compensate for their lower productivity...

Refs.

Sheehan, S.W., 2021. Electrochemical methane production from CO2 for orbital and interplanetary refueling. IScience, 24(3), p.102230.

[high road]

The '13000 m² of solar panels' seems to be the hardest part.

[JohnFornaro]

Marspedia is very interesting...


https://marspedia.org/Home


I think so, the energy and the robots to create the ISRU are decades away...

We already did ISRU on Mars. Perseverence demonstrated making oxygen (and fuel, CO) using nuclear power.

How large a human tended base could Perseverance support?  You're deliberately talking past his point about the scale of the operation to no larger purpose.  Do better.

[JohnFornaro]

The whole chemical processing set up to turn H₂O and CO₂ into O₂ and CH₄ is relatively trivial chemical engineering (gas light era technology). It does need to be built (and then tested in situ), but it's not rocket science even if it is unfamiliar to many people.

Right.  And Peseverance falling towards the surface of Mars under the attraction of gravity isn't rocket science either.   The issue is not about the relative complexity of the task at hand, but rather the difficulty in performing that task reliably, and at scale on the surface of Mars.  Do better.

[JohnFornaro]

Marspedia is very interesting...


https://marspedia.org/Home


I think so, the energy and the robots to create the ISRU are decades away...

A quibble, if I may:  They forgot to put the power requirements of the H2 recycling compressor.

[lamontagne]

Marspedia is very interesting...


https://marspedia.org/Home


I think so, the energy and the robots to create the ISRU are decades away...

A quibble, if I may:  They forgot to put the power requirements of the H2 recycling compressor.

Damn, back to the drawing board!
I'll try to find the power in the Areva documents.  There were two versions of this, one low and one high pressure so my excuse would be that it got lost in the choice between the two.
This was mostly developed on a thread on NASASpaceflight.com by the way.
https://forum.nasaspaceflight.com/index.php?topic=39785.1860

If you see any other problems let me know!

[lamontagne]

Marspedia is very interesting...


https://marspedia.org/Home


I think so, the energy and the robots to create the ISRU are decades away...

Glad you like it!  This was developed on a thread here. Can't remember which one though.  So that is why once I finish a project here, if it's any good, in goes into Marspedia, where I am an editor.

edit   https://forum.nasaspaceflight.com/index.php?topic=39785.1860

[lamontagne]

The '13000 m² of solar panels' seems to be the hardest part.

Getting clean water is the hardest part and the most uncertain and with the most technological uncertainties.
roll out solar panels, discussed in threads here multiple times, are fairly simple, and already exist on Earth.

To clarify, not the technology to purify the water, reverse osmosis can purify almost anything, but rather to dig the stuff out, melt it and do whatever gross filtration is required with entirely automated systems.

[lamontagne]

Sadly, the H2Gen e120 electrolyser no longer seems to be available. 

Areva sold the technology to a larger company, GTT.  It is now rebranded as Elogen :

https://elogenh2.com/en/our-products/electrolyseurs-containerises/
https://elogenh2.com/wp-content/uploads/2021/04/Elogen_Product_sheet-Elyte50.pdf

The Sabatier reactor program may have been a collateral victim of COVID?  Need to investigate.

[JohnFornaro]

Sadly, the H2Gen e120 electrolyser no longer seems to be available. 

Areva sold the technology to a larger company, GTT.  It is now rebranded as Elogen :

https://elogenh2.com/en/our-products/electrolyseurs-containerises/
https://elogenh2.com/wp-content/uploads/2021/04/Elogen_Product_sheet-Elyte50.pdf

The Sabatier reactor program may have been a collateral victim of COVID?  Need to investigate.

To the PDF, where they mention "bargs" of gas.  Finally, I understand this classic panel from Calvin & Hobbes:

[lamontagne]

Sadly, the H2Gen e120 electrolyser no longer seems to be available. 

Areva sold the technology to a larger company, GTT.  It is now rebranded as Elogen :

https://elogenh2.com/en/our-products/electrolyseurs-containerises/
https://elogenh2.com/wp-content/uploads/2021/04/Elogen_Product_sheet-Elyte50.pdf

The Sabatier reactor program may have been a collateral victim of COVID?  Need to investigate.

To the PDF, where they mention "bargs" of gas.  Finally, I understand this classic panel from Calvin & Hobbes:

  Bar gage, of course.  Who new that Calvin's dad worked in HVAC?  I am very impressed by your profound knowledge of C&H.

[JohnFornaro]

I am very impressed by your profound knowledge of C&H.

I try.

[Tywin]

Another problem is the robotics, for building all this...

This is very complex and expensive...

[lamontagne]

Another problem is the robotics, for building all this...

This is very complex and expensive...

The complete logistics of setting up process containers, tanks, piping and power systems seems daunting.   Connecting up containers on the ground can be surprisingly difficult, as real ground refuses to be perfectly flat, for example.

That is why an ideal solution might remain almost entirely on a Starship.  Unfortunately, Mars air is not quite humid enough to provide the required water.  So the real difficulty, I think, is digging out the water and getting it to an installation on a Starship.
Large scale storage also seems difficult, since it probably requires insulated tanks, i.e. Another modified Starship.  Perhaps if there is a fuel depot developed for Low Earth Orbit, the technology could be used on Mars as well?

[Hamish.Student]

In regards to the general build out of an ISRU plant, could you not containerise (think shipping) the equipment with a series of "basic" connectors on the outside in a standardised location/format. Then you are talking about moving a standard sized object, easy enough to solve (Look to autonomous ports). For connecting the units together, look at something like Boston Dynamics Spot and its Arm. Have hoses for connecting the units be in retractable housings like garden hose for ease of use.

[lamontagne]

In regards to the general build out of an ISRU plant, could you not containerise (think shipping) the equipment with a series of "basic" connectors on the outside in a standardised location/format. Then you are talking about moving a standard sized object, easy enough to solve (Look to autonomous ports). For connecting the units together, look at something like Boston Dynamics Spot and its Arm. Have hoses for connecting the units be in retractable housings like garden hose for ease of use.

Would love to see a contest or a test done on this subject here on Earth, on a non prepared surface:

-Offload containers remotely, perhaps provide them with self leveling systems.
-Place them at the required distance from one another.
-Unpack the connectors.
-Attach the connectors from one shipping container to the next.
-Force a time limit of 15 minutes between each command from 'Earth'.

-Unpack solar power systems
-Connect-up and start-up power.
-Test power and controls

It would be necessary to check all of this anyway, before hand. 

Perhaps Spacex will issue out a tender and let us watch the tests?  Or DARPA might make a equivalent field test for military equipment?

[Twark_Main]

The '13000 m² of solar panels' seems to be the hardest part.

Getting clean water is the hardest part and the most uncertain and with the most technological uncertainties.
roll out solar panels, discussed in threads here multiple times, are fairly simple, and already exist on Earth.

To clarify, not the technology to purify the water, reverse osmosis can purify almost anything, but rather to dig the stuff out, melt it and do whatever gross filtration is required with entirely automated systems.

The problem with a Rodwell is that on Mars it requires internal pressure to keep the "pool" liquid.

It seems like a more planet-appropriate strategy would instead operate at atmospheric pressure, sublimate the water directly to vapor, and recapture it via condensation. Conveniently this also purifies the water by distillation.

A good idea, I think, is to efficiently recycle the latent heat back into the ice. In theory this should greatly reduce the energy requirements.

Another good idea, I think, is to use simple solar thermal. Even just a black bag filled with ice and connected to the atmospheric condenser could yield a big increase in throughput.

Notionally, a subsurface ice deposit might be broken up and "gardened" by conventional blasting techniques, then covered with a selective solar blanket. A vacuum pump negatively pressurizes below the blanket (similar to vacuum soil surcharging on Earth), and the blanket acts as a greenhouse to trap solar radiation and reduce heat loss.  At night the sublimation drops off, and the same vacuum pump can evacuate an interstitial MLI layer, further reducing nighttime heat loss.

If you can somehow pipe your colony's waste heat under the blanket, that helps too.

[LMT]

The problem with a Rodwell is that on Mars it requires internal pressure to keep the "pool" liquid.

No, any base site has sufficient pressure; Rodwell proposals are common.  E.g., the Colorado School of Mines' "Resource Assessment of Phlegra Montes, Mars", noted previously.

[Twark_Main]

The problem with a Rodwell is that on Mars it requires internal pressure to keep the "pool" liquid.

No, any base site has sufficient pressure; Rodwell proposals are common.  E.g., the Colorado School of Mines' "Resource Assessment of Phlegra Montes, Mars", noted previously.

Peak pressure on Mars is 1.16 kPa, so the liquid phase of water has either a non-existent or a very narrow liquid temperature range. Salinity will have some benefit, but at low pressures you're still greatly narrowing the stable operating regime of a Rodwell where it resists operational "collapse" (already a non-trivial concern, even on Earth).

[Robotbeat]

I think the Rodwell approach is overrated on Mars because often the ice will be mixed with regolith, so it’ll fill up with debris.

[LMT]

The problem with a Rodwell is that on Mars it requires internal pressure to keep the "pool" liquid.

No, any base site has sufficient pressure; Rodwell proposals are common.  E.g., the Colorado School of Mines' "Resource Assessment of Phlegra Montes, Mars", noted previously.

Peak pressure on Mars is 1.16 kPa, so the liquid phase of water has either a non-existent or a very narrow liquid temperature range. Salinity will have some benefit, but at low pressures you're still greatly narrowing the stable operating regime...

Repeated hand-waving.

Martian Rodwell conditions do work, as demonstrated at JSC.

[Slarty1080]

The big problem is we still don't know enough about the Martian ice deposits, the depth of their debris over burden, the nature of the overburden, the depth and purity of the ice and the nature and extent of contaminants both in their chemistry and physically (dust, sand, gravel, boulders etc). And how these contaminants vary with depth.

It will be much easier to design a suitable method for extraction and purification when this information becomes available. It would be wise to attempt multiple methods of extraction and purification on the first robotic mission to see what works and gain a more detailed understanding.

[high road]

The '13000 m² of solar panels' seems to be the hardest part.

Getting clean water is the hardest part and the most uncertain and with the most technological uncertainties.
roll out solar panels, discussed in threads here multiple times, are fairly simple, and already exist on Earth.

To clarify, not the technology to purify the water, reverse osmosis can purify almost anything, but rather to dig the stuff out, melt it and do whatever gross filtration is required with entirely automated systems.

Which can easily be solved by bringing the H2 along, Mars Direct style. H2 is only 5% of the propellant mass, you're not sending, operating and maintaining water extraction equipment on that small a mass budget. At least not until there are people there to fix hundreds of little unforeseen issues that can be easily fixed if only you had someone on location, but are otherwise complete blockers.

[Barley]

The big problem is we still don't know enough about the Martian ice deposits, the depth of their debris over burden, the nature of the overburden, the depth and purity of the ice and the nature and extent of contaminants both in their chemistry and physically (dust, sand, gravel, boulders etc). And how these contaminants vary with depth.

It will be much easier to design a suitable method for extraction and purification when this information becomes available.  It would be wise to attempt multiple methods of extraction and purification on the first robotic mission to see what works and gain a more detailed understanding.

I agree up to the bold bit.  To me that means trying something, with some chance of success, as soon as possible.  If you have a robot that can try multiple things by all means send it, but don't wait for it.  As soon as you have a robot that can try one thing try that one thing.  Even a failed attempt will learn far more than theorizing in the lab trying to perfect an all purpose robot.  Perhaps if you just put missions in the plural.

[Slarty1080]

The big problem is we still don't know enough about the Martian ice deposits, the depth of their debris over burden, the nature of the overburden, the depth and purity of the ice and the nature and extent of contaminants both in their chemistry and physically (dust, sand, gravel, boulders etc). And how these contaminants vary with depth.

It will be much easier to design a suitable method for extraction and purification when this information becomes available.  It would be wise to attempt multiple methods of extraction and purification on the first robotic mission to see what works and gain a more detailed understanding.

I agree up to the bold bit.  To me that means trying something, with some chance of success, as soon as possible.  If you have a robot that can try multiple things by all means send it, but don't wait for it.  As soon as you have a robot that can try one thing try that one thing.  Even a failed attempt will learn far more than theorizing in the lab trying to perfect an all purpose robot.  Perhaps if you just put missions in the plural.

I agree no point in waiting, ideally try as much as you can, but if it has to be just a one shot experiment then do that. My concern is who is planning the Starship robot lander experiments? Is there even a one shot being planned?