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#51 2017-04-12 17:14:31

Dook
Banned
From: USA
Registered: 2004-01-09
Posts: 1,409

Re: DeGrasse Tyson's Mars challenge to Elon Musk

louis wrote:

I am consistently amazed at your lack of faith in the ability of humans to find solutions to the problems you come up with!  Are you really saying there is no way to capture the H2O vapour when mining ice? There will be ways of lifting solid chunks of ice bearing regolith out of the surface, of that I am sure. We can try out all these techniques in a Mars analogue facility on Earth and Mars analogue terrains on Earth before we get there. 

I am not ignoring the difficulties of ISRU, I like to hear about them - it's just I think most can be overcome.

You claim huge power requirements to create oxygen. I've shown how it can be done with the equivalent of 0.7 Kws constant per person , or 4.2 Kws for a six person mission. That is not huge.

A discussion on another thread shows how we can in fact get a Mars analogue air through compression and treatment of the Mars atmosphere. 

Whatever method is used, I doubt it is going to be a huge increase on that 0.7Kw per person figure and that is a very modest power requirement, remembering that MIT indicate ultra light weight PV would deliver 100 Kws for 100 x 100 metres of PV panelling. That probably delivers something like 60-70 kws constant for a six mission (MIT's proposal).  That will be more than enough for heating, lighting, water recycling and filtering, and air production. The surplus can be devoted to ISRU and agriculture.

By analogue air I mean something v. similar to Earth air - same pressure and same constituent parts, more or less.

We can certainly build air pumps using 3D printers.

The reason we need to build habitats on Mars is that the landers will also be the return craft.  Building cut and cover trenches is quick and convenient. I think the early colonists will be highly motivated and prepared to accept this sort of basic accommodation to begin with. The habs won't be cold!  They will be heated and highly insulated using locally produced rockwool equivalent from basalt or similar.

I'm not coming up with problems, they already exist.  You ignoring them doesn't mean they aren't there. 

Am I saying there is no way to capture water vapor when mining ice?  No, I'm saying you're not addressing all the details.  You think we can use 3D printers to make whatever we need when they will only make very few things, things we won't need. 

We can lift solid chunks of ice out of the surface?  So, you're going to dig through frozen regolith, with what?  Powered by what?

Most of the difficulties can be overcome?  They can be reduced, that doesn't make a certain process efficient or reasonable. 

You've shown that you can power a Moxie with .7 kws per person?  Provide a link. 

In a discussion in another thread you've shown that we can get Mars analogue air through compression and treatment of Mars atmosphere?  What is treatment of Mars atmosphere?

Ultra light PV would deliver 100 kw for 100 x 100 meters of paneling.  That's 300 feet by 300 feet!  That is insane!  That's 90,000 thousand panels! 

This is exactly the problem.  To you 6 and 100,000 are just about the same thing.  They're not.  They're not even close.  You don't understand how insanely ridiculous that is.  There's no way we're going to ship 90,000 solar panels to Mars.  There's no way we're going to manufacture 90,000 solar panels on Mars, well, not for another 500-1,000 years.

Analogue air is Earth air?  Earth air is 78% nitrogen, where are you going to get the nitrogen from on Mars? 

You can build air pumps with a 3D printer?  Where are you going to get the block aluminum alloy to cut out the rotor blade and the housing?  How are you going to make the rotor seals?  How are you going to make the electric motor?  How are you going to make the wires?

The Mars landers will be Earth Return Vehicles?  No, they won't.  The Mars lander's heat shield would be used up unless you want to have another heat shield underneath it.  The settlers would somehow climb up and remove the used one.  That would mean a lot of extra weight per tuna can sent to Mars and a lot of time and energy spent refueling the liquid oxygen and hydrogen tanks.  This idea of rocketing anything from Mars to the Earth is inefficient and wasteful of critical resources and time. 

Building cut and cover trenches is quick?  Not if you hit rock it's not.  You stop dead and can't go any farther.  And if you hit frozen regolith, which is a certainty, you're stuck too.  And if the sides of the trench collapse while you're digging you're dead.

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#52 2017-04-12 17:17:05

Oldfart1939
Member
Registered: 2016-11-26
Posts: 2,384

Re: DeGrasse Tyson's Mars challenge to Elon Musk

Louis-

In spite of our differences about PV versus nuclear, I'm sure that humans will fine the pragmatic answer to the problem. Dook, on the other hand is a total negativist. Nobody ever said it would be easy!

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#53 2017-04-12 17:36:11

louis
Member
From: UK
Registered: 2008-03-24
Posts: 7,208

Re: DeGrasse Tyson's Mars challenge to Elon Musk


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

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#54 2017-04-12 18:06:54

Dook
Banned
From: USA
Registered: 2004-01-09
Posts: 1,409

Re: DeGrasse Tyson's Mars challenge to Elon Musk

Oldfart1939 wrote:

Louis-

In spite of our differences about PV versus nuclear, I'm sure that humans will fine the pragmatic answer to the problem. Dook, on the other hand is a total negativist. Nobody ever said it would be easy!

No one said it would be easy? You two are trying to make it ten times harder by wasting launch vehicles to move unecessary equipment to Mars that won't be used, wasting time and risking lives by trying to dig a trench through frozen regolith, and wasting critical resources like oxygen and water just to send Mars rocks home so you can touch a piece of Mars.

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#55 2017-04-12 18:17:44

Dook
Banned
From: USA
Registered: 2004-01-09
Posts: 1,409

Re: DeGrasse Tyson's Mars challenge to Elon Musk

louis wrote:

Those projects are in the early stages and might allow a 3D printer to make parts for a battery.  And, since the 3D printer is so critical to colonizing Mars Elon Musk should wait until it's perfected before he attempts to send anyone there.

If and when this idea is perfected, where are you going to get the raw materials on Mars?  They're going to have to be shipped from the Earth.  So what is the point of having a 3D printer on Mars if we have to ship all the materials that it uses from the Earth?

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#56 2017-04-13 03:21:40

louis
Member
From: UK
Registered: 2008-03-24
Posts: 7,208

Re: DeGrasse Tyson's Mars challenge to Elon Musk

Researching this some more, it seems like there is already 3D printer technology that can print computer chips and electronic circuits. This clearly offers the prospect of the Mars colony making its own computers and electronic devices in small numbers.

So what do we need for 3D printing (apart from the 3D printers - which it now seems we may also be able to print...). Well it comes down to making metal and plastic powders that can be used in 3D printers as far as I can tell. 

The metals are mostly within easy reach on the surface of Mars, the most obvious being iron ore. But it seems that others like zinc, manganese and aluminium will be available. I think initially we will be focussed on iron... So we need to take to Mars machines that can
analyse ores, heat and dissociate elements or compounds within them, produce pure forms of materials and if necessary powderise them. All of that is doable.  And it seems with 3D printers,we will be able to make a lot if not all of those machines on Mars eventually.

We could also cast basalt v. easily. That's very useful.

After a few years we can grow bamboo, also a v. versatile material.

For simpler plastic moulding there is no doubt we could make small scale injection moulding machines on Mars (given talented individuals can do it in their homes):

http://makezine.com/projects/make-41-ti … n-molding/


As for Musk, well he's planning to solve this with brute force in effect - by using the ITS/MCT to transport huge tonnages of cargo to Mars...hundreds, maybe thousands of tonnes, before people arrive in numbers. This will enable the first colonists to put in place what amounts to a very mature industrial infrastructure, albeit on a relatively small scale.


Dook wrote:
louis wrote:

Those projects are in the early stages and might allow a 3D printer to make parts for a battery.  And, since the 3D printer is so critical to colonizing Mars Elon Musk should wait until it's perfected before he attempts to send anyone there.

If and when this idea is perfected, where are you going to get the raw materials on Mars?  They're going to have to be shipped from the Earth.  So what is the point of having a 3D printer on Mars if we have to ship all the materials that it uses from the Earth?


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

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#57 2017-04-13 03:23:04

louis
Member
From: UK
Registered: 2008-03-24
Posts: 7,208

Re: DeGrasse Tyson's Mars challenge to Elon Musk

This is the link for 3D printing of electronic devices.

http://www.voxel8.com/


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

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#58 2017-04-13 09:24:01

Dook
Banned
From: USA
Registered: 2004-01-09
Posts: 1,409

Re: DeGrasse Tyson's Mars challenge to Elon Musk

I looked at your link, it shows a normal chip manufacturing machine, not a 3D printer making chips.  So, you want to ship a 3D printer so you can make brackets on Mars and now you want to ship a chip manufacturing machine so they can make chips too? 

So, we're going to have to sacrifice shipping some food or water to Mars so you can send a 3D printer to make brackets, a chip manufacturing machine to make chips, and then they will need a battery making machine, a hard drive making machine, a wire making machine, a solar panel making machine, a glass making machine, and another machine to separate elements.   That's a whole lot of extra rockets launched and it won't do a thing because they're not going to need brackets, they're going to need food and water.

Metals are on the surface of Mars?  Yeah, as dust particles mixed with other elements.  Iron ore and silicon are everywhere, easy to get, the alloy elements necessary to make steel and aluminum alloy are more rare. 

A 3D printer can make the machines?  So, you want to use the 3D printer to make the machine that separates the elements?  But you have to separate the elements first then melt the ore so it becomes a solid chunk of iron, then put the solid block of iron in the 3D printer for it to cut it into a shape.  A 3D printer can't make a machine, it can make a few parts, not nearly enough for the whole thing. 

We can grow bamboo?  So, instead of growing fruit trees or grains or vegetables you want to grow bamboo that we can use to make a chair? 

An injection molding machine can make stuff on Mars?  It can, just not the stuff you would need.

None of this makes any sense.  You think having a machine that can make brackets and bamboo chairs is going to accelerate the settlement of Mars when it actually does the opposite. 

Okay, do this, list all the things that your 3D printer can make?  And all the things you can make with bamboo.  That way we can see if any of them are more necessary than food and water. 

Elon Musk is going to solve this with his big rocket?  Well, I'll believe it when I see it but let's say he does get that thing to fly, what's more important: food, water, greenhouse panels, solar panels, rovers, and RTG's, OR machinery that can make only one or two parts of complicated manufacturing machines?

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#59 2017-04-13 10:24:37

Oldfart1939
Member
Registered: 2016-11-26
Posts: 2,384

Re: DeGrasse Tyson's Mars challenge to Elon Musk

Dook-

I hate to respond this way, but you are pushing the boundaries of normal civil discourse here by falsely attributing statements to me that I didn't make. I at no time pushed for return of tons of rocks and regolith to Earth, and in fact commented that having a laboratory on Mars makes a lot more sense--then send the data back electronically.

Moving forward, the major reason for having 3-D printing available is for manufacture of repair parts of mechanism. It make a lot more sense to me to have the electronic parts available to be printed at need than bringing 100% of the mechanical parts of--say--a rover. Bring the necessary metallic printer powders and make the needed parts in situ. SpaceX is manufacturing most of the turbopump parts for their Merlin D-1 rocket motors by metal 3-D printing.

Link to additive manufacturing of rocket motor parts:  http://www.spaceflightinsider.com/organ … se-engine/

You also earlier confused CNC milling processes with 3-D printing, but have conveniently ignored that error in subsequent posts. Your knowledge of how minerals are extracted is underwhelming. Coal, for example, isn't chipped or scratched from the deposits, but skillful application of blasting explosives fragments huge chunks which are conveniently moved to crushers. I envision something similar could be done in the mining of water-rich regolith. Yeah, that will require some of the heavy equipment specifically designed for Mars be transported there in the Musk Brute Force Heavy Lifters. One ice deposit recently discovered on Mars contains roughly the water of Lake Superior., conveniently underground in a region the size of New Mexico. Refer to SpaceflightInsider.com for this information; also on Space.com. What will be one of the first industrial facilities on Mars? A water processing facility, where huge chunks of water-rich frozen regolith are simply thawed out in a dome structure and after water extraction, the still damp soil be processed
for agricultural purposes. And on one thing I'll agree with you: bamboo, initially, is a waste of resources compared to food production. Louis and I are also in disagreement in regards to power generation; I'm a big supporter of Thorium-based nuclear energy, which is far less hazardous than Uranium/Plutonium systems, especially in spent fuel disposal. The massive Solar farms aren't really manageable in the early stages of Mars development, since weight and lifetime limitations of batteries play an enormous role. I don't care to place my faith on the storage and subsequent oxidation of elemental Iron as a backup energy source, either.

In no particular order, since all are essential, we'll need the following resource utilization: Oxygen, Water, energy, and food production. Coupled with adequate shelter, we can exist there. Maybe not comfortably at first, but survive.

Last edited by Oldfart1939 (2017-04-13 10:45:31)

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#60 2017-04-13 11:59:27

Dook
Banned
From: USA
Registered: 2004-01-09
Posts: 1,409

Re: DeGrasse Tyson's Mars challenge to Elon Musk

Oldfart1939 wrote:

Dook-

I hate to respond this way, but you are pushing the boundaries of normal civil discourse here by falsely attributing statements to me that I didn't make. I at no time pushed for return of tons of rocks and regolith to Earth, and in fact commented that having a laboratory on Mars makes a lot more sense--then send the data back electronically.

Moving forward, the major reason for having 3-D printing available is for manufacture of repair parts of mechanism. It make a lot more sense to me to have the electronic parts available to be printed at need than bringing 100% of the mechanical parts of--say--a rover. Bring the necessary metallic printer powders and make the needed parts in situ. SpaceX is manufacturing most of the turbopump parts for their Merlin D-1 rocket motors by metal 3-D printing.

Link to additive manufacturing of rocket motor parts:  http://www.spaceflightinsider.com/organ … se-engine/

You also earlier confused CNC milling processes with 3-D printing, but have conveniently ignored that error in subsequent posts. Your knowledge of how minerals are extracted is underwhelming. Coal, for example, isn't chipped or scratched from the deposits, but skillful application of blasting explosives fragments huge chunks which are conveniently moved to crushers. I envision something similar could be done in the mining of water-rich regolith. Yeah, that will require some of the heavy equipment specifically designed for Mars be transported there in the Musk Brute Force Heavy Lifters. One ice deposit recently discovered on Mars contains roughly the water of Lake Superior., conveniently underground in a region the size of New Mexico. Refer to SpaceflightInsider.com for this information; also on Space.com. What will be one of the first industrial facilities on Mars? A water processing facility, where huge chunks of water-rich frozen regolith are simply thawed out in a dome structure and after water extraction, the still damp soil be processed
for agricultural purposes. And on one thing I'll agree with you: bamboo, initially, is a waste of resources compared to food production. Louis and I are also in disagreement in regards to power generation; I'm a big supporter of Thorium-based nuclear energy, which is far less hazardous than Uranium/Plutonium systems, especially in spent fuel disposal. The massive Solar farms aren't really manageable in the early stages of Mars development, since weight and lifetime limitations of batteries play an enormous role. I don't care to place my faith on the storage and subsequent oxidation of elemental Iron as a backup energy source, either.

In no particular order, since all are essential, we'll need the following resource utilization: Oxygen, Water, energy, and food production. Coupled with adequate shelter, we can exist there. Maybe not comfortably at first, but survive.

You don't want to send Mars rocks back to the Earth?  Okay, fine.

Please list all the Mars settlement components that your 3D printer can make? 

Where are you going to get the raw materials that your 3D printer needs?

You don't need to bring 100% of the parts for a rover.  You need a composite repair kit, extra electric motors, and a wire repair kit.  These things will already be included because they can be used to repair not only the rovers but the habitat and Moxie as well.

I confused CNC milling process with 3D printing?  Perhaps you can explain to me how it works then?  How does a machine spray a metal and have it bond together? 

Did you happen to notice the size of the machine in your Aerojet link?  Just from the picture it looks to be about 20 feet wide. 

My knowledge of how minerals are extracted is underwhelming?  Wow, you are sooo smart.  Please inform me how it's done. 

Coal isn't chipped or scratched, they use explosives and then move the material to crushers?  So, you want to put explosives on rocket ships to Mars?  And some kind of coal crushing machine to process frozen regolith as well?  Explosives on spacecraft?  Huh?  That's crazy, but hey, there's all kinds of crazy in the world, what do I know, you are soooo much smarter than I am.

As for harvesting Mars ice and melting it in a dome then processing the moist regolith.  You don't have to process it, the dome is warm in the day so the water evaporates and condenses on the insides of the dome, then it runs down and collects in trays all along the bottom inside of the dome.  The trays could connect to small buried water tanks or have irrigation tubes that send the water back to the trees/vegetables. 

The first Mars settlement will need, oxygen, water, shelter, and energy?  Finally we agree on something.  Too many people on here have skipped ahead to a point a thousand years in the future.

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#61 2017-04-13 12:47:53

Oldfart1939
Member
Registered: 2016-11-26
Posts: 2,384

Re: DeGrasse Tyson's Mars challenge to Elon Musk

OK, here are answers to a few questions in your response to my statements:

Additive manufacturing, a.k.a. 3-D printing. The machines make repeated passes and deposit powdered metal on the growing surface of the object printed; high energy lasers subsequently fuse the metal to the growing solid object--no longer powder but solid. If you read some of the previous links I provided, we wouldn't need this explanation.

What parts can be made? Gears, driveshafts, wheel hubs, small mechanical parts. Valves, pipe junctions, etc. Mundane everyday stuff. It's certainly a lot more efficient to send the Additive manufacturing printers and a supply of various metal powders than, say, a set of transmission parts possibly never used?

Worried about sending explosives on a spaceship? Bwahahaha! The entire enterprise is RIDING on a huge amount of potentially explosive fuel. Personally, I'd suggest taking along a huge amount of Ammonium Nitrate fertilizer, which in prilled form is sold by Dynamit Nobel as the blasting agent used in strip mining coal here in Wyoming. Oh--did I mention fertilizer? Yeah, it's also the #1 fertilizer component for adding nitrogen to soil. Two birds--one stone. If you still object; explosives for blasting can be improvised using some LOX plus sugar.

Water processing is another gap in your knowledge base. The icy regolith is still an unknown, and we don't know how much actual soil , or regolith, is in the ice--or vice versa. So--if just allowed to melt, we may wind up with a huge pile of very wet mud--from which water will take a loooong time to evaporate. It would be much faster to utilize a standard sewage treatment centrifuge to separate the solids from the desired water, then use the internal plow system to periodically scrape out the solids into a container on it's way to the greenhouses.

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#62 2017-04-13 13:39:08

Dook
Banned
From: USA
Registered: 2004-01-09
Posts: 1,409

Re: DeGrasse Tyson's Mars challenge to Elon Musk

Oldfart1939 wrote:

OK, here are answers to a few questions in your response to my statements:

Additive manufacturing, a.k.a. 3-D printing. The machines make repeated passes and deposit powdered metal on the growing surface of the object printed; high energy lasers subsequently fuse the metal to the growing solid object--no longer powder but solid. If you read some of the previous links I provided, we wouldn't need this explanation.

What parts can be made? Gears, driveshafts, wheel hubs, small mechanical parts. Valves, pipe junctions, etc. Mundane everyday stuff. It's certainly a lot more efficient to send the Additive manufacturing printers and a supply of various metal powders than, say, a set of transmission parts possibly never used?

Worried about sending explosives on a spaceship? Bwahahaha! The entire enterprise is RIDING on a huge amount of potentially explosive fuel. Personally, I'd suggest taking along a huge amount of Ammonium Nitrate fertilizer, which in prilled form is sold by Dynamit Nobel as the blasting agent used in strip mining coal here in Wyoming. Oh--did I mention fertilizer? Yeah, it's also the #1 fertilizer component for adding nitrogen to soil. Two birds--one stone. If you still object; explosives for blasting can be improvised using some LOX plus sugar.

Water processing is another gap in your knowledge base. The icy regolith is still an unknown, and we don't know how much actual soil , or regolith, is in the ice--or vice versa. So--if just allowed to melt, we may wind up with a huge pile of very wet mud--from which water will take a loooong time to evaporate. It would be much faster to utilize a standard sewage treatment centrifuge to separate the solids from the desired water, then use the internal plow system to periodically scrape out the solids into a container on it's way to the greenhouses.

You can make wheels?  Driveshafts?  Are those things likely to break?  They could.  I think it's doubtful.  Wheels can be bent but you can take a hammer and bend them back. 

You can make small mechanical parts?  For what?  For the Moxie?  Okay, let's see, can it make the intake fan?  Not really because you need a bearing.  Can it make any of the electronics that control the Moxie operations?  No.  Can it make the catalyst screens?  Nope.  So, it can't make any of the things that are likely to break or need replacing.   

The 3D printer can make certain valves?  Okay, I'm sure the Moxie has valves that allow the oxygen to go into a tank.  The valves will probably be operated by an electrical component, a solenoid.  It's always the solenoid that goes out, the hard components of an air valve almost never break.  Your 3D printer won't make a solenoid.   

A 3D printer can make pipe junctions?  Uhh, for what?  You're going to collect, process, and attempt to manufacture metal to make pipes, for what?  The pipes would only be as long as the 3D printer so you're talking about very short pipes to be used for what?

Pipe manufacturing is not something the first or second, or third, or fourth settlements will do.  That's probably 500 years in the future. 

What reason would they want to make pipes when the next settlement will need a habitat, greenhouse, food, water, another Moxie, and nuclear power plant?  The habitat water pipes will be extremely lightweight plastic tubing and each settlement will have extra sent with them.  They won't be metal.   

That potentially explosive rocket fuel in the spacecraft has to be mixed and ignited to explode/burn.  Your dynamite just needs a static electric spark to explode. 

You think we can use LOX, something critical for life, and sugar, which is food, just to blow up Martian ice?  So you think they are going to have so much oxygen and so much food that they can use it to blow up the Martian ground?

And you want a sewage treatment plant just to separate water from regolith?  How about this, you drop the ice chunks into a bucket and let it melt, the regolith will settle to the bottom.  Then use the water on the plants or, if you want to drink it, you filter it.  That's just too simple, too easy, right?   
   
You keep bouncing back and forth, from the first settlement needs and essentials to 500 years in the future.  This is just like the 90 day report all over again, trying to make it way, way harder and complicated than it already is.

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#63 2017-04-13 14:17:34

Oldfart1939
Member
Registered: 2016-11-26
Posts: 2,384

Re: DeGrasse Tyson's Mars challenge to Elon Musk

Hey Dook!

There you go again, trying to put words into my mouth. Not once did I mention dynamite.

On one of the other threads you have not read prior to becoming Mr. Know-it-all here, one of the most important items needed for an early settlement is a Bobcat type front loader and attached auger. That type of equipment needs spare parts--usually LOTS of spare parts--in order to be kept functional. This is absolutely necessary for moving sufficient regolith into greenhouses and doing high heavy lifting for their construction. In general, metal parts BREAK, and not simply bend. Pumps for water will undoubtedly be metallic, and parts needed for them. I don't know what part of the universe you live, but certainly have never been on a farm or in an industrial chemical plant as I have. Your water bucket description is ridiculous. A single bucket of water accomplishes NOTHING. On the other hand, a centrifuge is capable of processing thousands of gallons of water hourly. Small units can do hundreds of gallons daily. That's agricultural scale water processing, and that's what's needed almost immediately--not in 500 years.

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#64 2017-04-13 14:56:36

Dook
Banned
From: USA
Registered: 2004-01-09
Posts: 1,409

Re: DeGrasse Tyson's Mars challenge to Elon Musk

Oldfart1939 wrote:

Hey Dook!

There you go again, trying to put words into my mouth. Not once did I mention dynamite.

On one of the other threads you have not read prior to becoming Mr. Know-it-all here, one of the most important items needed for an early settlement is a Bobcat type front loader and attached auger. That type of equipment needs spare parts--usually LOTS of spare parts--in order to be kept functional. This is absolutely necessary for moving sufficient regolith into greenhouses and doing high heavy lifting for their construction. In general, metal parts BREAK, and not simply bend. Pumps for water will undoubtedly be metallic, and parts needed for them. I don't know what part of the universe you live, but certainly have never been on a farm or in an industrial chemical plant as I have. Your water bucket description is ridiculous. A single bucket of water accomplishes NOTHING. On the other hand, a centrifuge is capable of processing thousands of gallons of water hourly. Small units can do hundreds of gallons daily. That's agricultural scale water processing, and that's what's needed almost immediately--not in 500 years.

You didn't mention dynamite?  Sure you did, you just had a typo and left off the "e". 

What does it take to explode ammonium nitrate?  A spark. 

Your not addressing the criticisms and instead responding with personal attacks.  You know that means you're losing the argument, right?

One of the most important early settlement items will be a bobcat?  No, it won't.  They will land in a habitat.  They will put together the solar panels.  They will move the RTG outside.  They will recharge the rover and use it and a cart to go and get other things.  Then they will assemble the greenhouse.  No bobcat needed. 

You don't move regolith into a greenhouse.  You build a greenhouse over regolith.  If you're talking about using an inflatable greenhouse, it's lifespan is a few years.  What are you going to do when it fails and your trees are exposed to Martian temperatures and die?  How are you going to replace the inflatable greenhouse every two years?   

In general metal parts break, they don't simply bend?  No.  Only brittle metals break.  Steel bends.  Aluminum bends unless it's been heat treated.  Ever bent a piece of steel back and forth, back and forth, over and over until it breaks?  You probably haven't. 

Pumps for water will be metallic?  The only water pump the settlers will need is the water pump in the habitat shower.  It's just like ones in RV campers.  They're driven by a DC motor.  It's always the motor that goes out.  You can water plants with a bucket, the same bucket that you use to melt the Mars ice. 

You're trying to build in complexity.  Why?

My idea of melting Mars ice in a bucket idea is ridiculous?  I got you figured out now.  You're one of those obsessive/compulsive/autistic guys.  You can't do things the easy way.  They have to be complex to satisfy your urges.  How many times do you lock the door when you leave the house?

I didn't say it would be a single bucket or even a small bucket.  I'm sure your sewage treatment plant idea, just to melt ice, is much, much better, hehe...

The ability to handle thousands of gallons of water hourly is what's needed immediately on Mars?  Thousands of gallons hourly?  There isn't even an ounce of reality in any of your ideas.  There isn't going to be any water processing other than in the habitat recycled shower, the water will be filtered.

Last edited by Dook (2017-04-13 15:06:40)

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#65 2017-04-13 15:16:20

Dook
Banned
From: USA
Registered: 2004-01-09
Posts: 1,409

Re: DeGrasse Tyson's Mars challenge to Elon Musk

The mini Moxie unit has a case, tanks, a condenser, sensors, a cryocooler, an accumulator, electronics, an imager, wires, and an exhaust pipe. 

Your 3D printer can make only the exhaust pipe, other than the case it's the one thing that is least likely to ever break.

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#66 2017-04-13 15:50:08

louis
Member
From: UK
Registered: 2008-03-24
Posts: 7,208

Re: DeGrasse Tyson's Mars challenge to Elon Musk

I think Dook is also making a fundamental error in assessing the requirements of an early Mars colony.

We can see various stages with population numbers...somewhat arbitrarily  -

10 - Gets you started. Puts some infrastructure in place including crucially a substantial energy source.

100 - You can be operating a wide range of industrial processes and 3D printers.

1000 - By this stage you have a full industrial infrastructure that can maintain itself.

100,000 - You are now beginning to replicate in full Earth society: reproduction, education, culture, industry and so on.

No doubt Dook thinks a population of 1000 is a ridiculously high total to aim for in the next few decades even though it's only ten trips in Musk's planned ITS (aka Mars Colonial Transporter), so we could quite easily be at that figure by 2040.

But Dook probably also thinks 1000 is way too small to support a wide ranging industrial infrastructure. A few years ago I would have doubted that myself but I think the advances in 3D printer machines and robots are proving decisive, together with Musk's rocket revolution, and are changing the whole scene.  Allied with CNC machines, it means that we can build machines - even 3D printers - that will provide for all our basic industrial needs: energy generation, cabling, life support equipment, batteries, computers, construction materials, clothing, hygiene, farming equipment,  household goods, transport and so on.

Let's put it the other way round: what exactly would we NOT be able to produce with 1000 highly trained colonists who have access to an abundance of energy, say 100 3D printers, several robot assembly lines, and numerous CNC machines?


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

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#67 2017-04-13 16:17:31

Oldfart1939
Member
Registered: 2016-11-26
Posts: 2,384

Re: DeGrasse Tyson's Mars challenge to Elon Musk

Dynamit Nobel is the correctly spelled name of the company manufacturing Ammonium Nitrate for blasting purposes. And no, it doesn't detonate very easily at all, one of the reasons you'll see special belly-dump trucks hauling it on the highways. It's used by the ton by the open-pit coal mines. A spark will NOT come close to detonating it. Until Oklahoma City, anyone could go down to the local garden store and buy it in 50 pound sacks.Me losing the argument? Nope.
The Bobcat front loader is also perceived as necessary for piling regolith onto the hab structures for shielding against solar flare radiation storms. The inflatable greenhouses will by necessity have floors, and regolith will be hauled inside. Otherwise, pressurization will simply blow them away.

An industrial basket type centrifuge doesn't weigh that much in the smaller sizes, especially when scaled to initial usage. That's what I envision initially, if we're "mining water" for agricultural use. If we don't get enough water--no agriculture. Why piping? Water distribution systems. We're not going to growing a philodendron for it's attractiveness. Any functional scale of agriculture requires LOTS of water. I irrigated 60 acres of hay for 21 years, and that is a huge amount of water to apply, and that isn't done by the bucketful, but in acre-feet. That calculates to roughly 43,500  cubic feet of water per hay season per acre. That's a lot of water to process. Hay is a relatively water-intensive crop. I also don't think the greenhouses will be an acre in size, either. An acre, by the way measures 208.71 feet x 208.71 feet. Gardening in an enclosed environment will probably need about 25 % that amount of water, since all that transpires out will re-condense on the structure and get recycled. The point is, we don't go out and actively develop the water saturated regolith, we bring ALL the food from Earth. Another point; the centrifuge will only operate when sufficient "mud" is available. A pretty BIG centrifuge weighs about a ton. Smaller units capable of processing 10,000 cubic feet of water over several days to weeks would mass around 500 kg, well within load limits for even a Red Dragon capsule. So--there will definitely be a requirement of a fair amount of pipe and a pumping system to adequately water/irrigate the growing crops.

Re: greenhouses. I envision the inflatables to last only a few years, with replacement by ISRU manufactured rigid Lexan (polycarbonate) structures. Trees? not right away, but lots and lots of root crops; turnips, potatoes, radishes, carrots, parsnips, sweet potatoes, and peanuts. The gardening will be intensive plantings by necessity; every square meter covered with something growing, and replanting occurs immediately after harvest. Fertilizer will be at a premium, so lots of Ammonium Nitrate needed there, too.

Regarding the metals in various implements; the malleability of steel isn't uniform, since there are myriads of steels produced. Just picking the correct steel for a given application can drive an engineer to distraction.  High carbon steels such as that used in knife blades, are brittle. The scraper edge in a front loader is usually a high Manganese steel, which is also very brittle. If you're talking 1080 machining grade steel, yeah, it bends. It's pretty soft. So--yeah, I've seen steel fail due to metal fatigue, which is what your analogy about bending it back and forth was attempting to illustrate. I've seen all this crap in my ranch machine shop. Had all the stuff to repair anything on the ranch: Bridgeport milling machine, TOS-Trencin 20" x 60" bed  precision lathe, plus 3 welders, etc. That's how I know PARTS BREAK, and sometimes cannot be "bent back or beaten back" into a usable condition. I had to keep 2 tractors with front loaders running, along with a roll-type hay baler, and a swather-windrower, and that was in my spare time after operating my industrial chemical manufacturing plant full time.

Speaking of chemical plant operations, my observations about centrifugation are entirely based on first hand experience of 50 years in the chemical industry. I specialized in scale-up of processes from laboratory bench scale to pilot plant and plant scale. I'm looking at what would normally be called pilot plant scale for water purification for the small Mars colony. This is all on a relatively crude complexity level that we're discussing here.

So--yeah, I get a little ticked off when I hear someone spouting off and pontificating, under the assumption the audience is naiive.

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#68 2017-04-13 17:06:26

louis
Member
From: UK
Registered: 2008-03-24
Posts: 7,208

Re: DeGrasse Tyson's Mars challenge to Elon Musk

If we are concerned about water utilisation in agriculture, it's notable that water usage for some crops is over 90% less with hydroponics, compared with conventional agriculture (or perhaps 60% less with a closed greenhouse system). One of the advantages of energy intensive indoor, artificially lit agriculture.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4483736/


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

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#69 2017-04-13 17:18:14

louis
Member
From: UK
Registered: 2008-03-24
Posts: 7,208

Re: DeGrasse Tyson's Mars challenge to Elon Musk

I query whether we need a "Moxie" to produce oxygen. Why can't we simply heat up iron oxide in a solar concentrator to 570 degrees celsius. Won't that do the trick? And won't it be possible to do that in large quantities?

For a community of 1000 we would need about 2200 kgs of oxygen per sol (for human breathing, that is).  I can envision a central oxygen plant, processing 7.3 tonnes of iron oxide every sol which would be  brought in by tracked robot rovers that collect the ore from the rich surrounding iron ore deposits a few kms outside the base. 200 Kg loads - 9 robust robot rovers making 4 round trips every sol, guided to the oxygen production facility by roadside transponders. In the iron ore fields they robotically scoop up the ore and deposit it automatically  in a rear hopper until the weight sensors indicate enough has been collected.


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

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#70 2017-04-13 17:22:24

Dook
Banned
From: USA
Registered: 2004-01-09
Posts: 1,409

Re: DeGrasse Tyson's Mars challenge to Elon Musk

Oldfart1939 wrote:

Dynamit Nobel is the correctly spelled name of the company manufacturing Ammonium Nitrate for blasting purposes. And no, it doesn't detonate very easily at all, one of the reasons you'll see special belly-dump trucks hauling it on the highways. It's used by the ton by the open-pit coal mines. A spark will NOT come close to detonating it. Until Oklahoma City, anyone could go down to the local garden store and buy it in 50 pound sacks.Me losing the argument? Nope.
The Bobcat front loader is also perceived as necessary for piling regolith onto the hab structures for shielding against solar flare radiation storms. The inflatable greenhouses will by necessity have floors, and regolith will be hauled inside. Otherwise, pressurization will simply blow them away.

An industrial basket type centrifuge doesn't weigh that much in the smaller sizes, especially when scaled to initial usage. That's what I envision initially, if we're "mining water" for agricultural use. If we don't get enough water--no agriculture. Why piping? Water distribution systems. We're not going to growing a philodendron for it's attractiveness. Any functional scale of agriculture requires LOTS of water. I irrigated 60 acres of hay for 21 years, and that is a huge amount of water to apply, and that isn't done by the bucketful, but in acre-feet. That calculates to roughly 43,500  cubic feet of water per hay season per acre. That's a lot of water to process. Hay is a relatively water-intensive crop. I also don't think the greenhouses will be an acre in size, either. An acre, by the way measures 208.71 feet x 208.71 feet. Gardening in an enclosed environment will probably need about 25 % that amount of water, since all that transpires out will re-condense on the structure and get recycled. The point is, we don't go out and actively develop the water saturated regolith, we bring ALL the food from Earth. Another point; the centrifuge will only operate when sufficient "mud" is available. A pretty BIG centrifuge weighs about a ton. Smaller units capable of processing 10,000 cubic feet of water over several days to weeks would mass around 500 kg, well within load limits for even a Red Dragon capsule. So--there will definitely be a requirement of a fair amount of pipe and a pumping system to adequately water/irrigate the growing crops.

Re: greenhouses. I envision the inflatables to last only a few years, with replacement by ISRU manufactured rigid Lexan (polycarbonate) structures. Trees? not right away, but lots and lots of root crops; turnips, potatoes, radishes, carrots, parsnips, sweet potatoes, and peanuts. The gardening will be intensive plantings by necessity; every square meter covered with something growing, and replanting occurs immediately after harvest. Fertilizer will be at a premium, so lots of Ammonium Nitrate needed there, too.

Regarding the metals in various implements; the malleability of steel isn't uniform, since there are myriads of steels produced. Just picking the correct steel for a given application can drive an engineer to distraction.  High carbon steels such as that used in knife blades, are brittle. The scraper edge in a front loader is usually a high Manganese steel, which is also very brittle. If you're talking 1080 machining grade steel, yeah, it bends. It's pretty soft. So--yeah, I've seen steel fail due to metal fatigue, which is what your analogy about bending it back and forth was attempting to illustrate. I've seen all this crap in my ranch machine shop. Had all the stuff to repair anything on the ranch: Bridgeport milling machine, TOS-Trencin 20" x 60" bed  precision lathe, plus 3 welders, etc. That's how I know PARTS BREAK, and sometimes cannot be "bent back or beaten back" into a usable condition. I had to keep 2 tractors with front loaders running, along with a roll-type hay baler, and a swather-windrower, and that was in my spare time after operating my industrial chemical manufacturing plant full time.

Speaking of chemical plant operations, my observations about centrifugation are entirely based on first hand experience of 50 years in the chemical industry. I specialized in scale-up of processes from laboratory bench scale to pilot plant and plant scale. I'm looking at what would normally be called pilot plant scale for water purification for the small Mars colony. This is all on a relatively crude complexity level that we're discussing here.

So--yeah, I get a little ticked off when I hear someone spouting off and pontificating, under the assumption the audience is naiive.

A bobcat is necessary to pile regolith on top of the habitat for shielding?  They land in a habitat.  How are you going to get the bobcat up there?

The inflatable greenhouses will have floors with regolith inside?  For light to pass through the inflatable would need thin plastic.  I don't see thin plastic able to have floors with regolith piled inside.  Also, what's the expected life span of the inflatable greenhouse?  How is a bobcat going to drive on top of or inside an inflatable?

A Bigelow inflatable is made with thicker cloth type material.  They are inflatable habitats, not greenhouses.  I suppose you could put some clear panels in the top of one but I would rather have a sturdy greenhouse built with thick plastic panels. 

Any functional scale of agriculture needs lots of water?  I don't think hay will be grown until we get some cows up there.

Ever hear of drip irrigation?

The centrifuge will only operate when sufficient mud is available?  It will never operate.  Water rarely exists on Mars because of the low atmospheric pressure.  On Mars, liquid water exists when the temperature hits 33 degrees F to somewhere around 35 degrees F.  Over about 35 degrees the water turns to vapor.  So, you're going to see water only during a very short time mid-day near the equator. 

A Red Dragon could transport a 500 kg centrifuge?  Why?  You don't have to centrifuge water to separate dirt, you just let it settle.  Every unneeded thing you want to send means less food, water, and critical spare parts sent. 

Pipe will be needed to irrigate growing crops?  Plastic irrigation pipe, extremely lightweight and easy to send along with the settlers.  We can send three times what they will need and it will all weigh about 50 lbs.  No need for manufacturing.
You think the inflatable greenhouses will last a few years and be replaced by Mars made plastic panel greenhouses?  No way.  Your 3D printer won't make a plastic panel.  Neither will your centrifuge.  Neither will your sewage treatment plant.  Neither will your bobcat.  How are you going to make the plastic panels?

You have experience fixing farm equipment so you know that tractors need to be fixed?  You're thinking that the first settlers are going to have massive greenhouses with large growing areas and tractors and bailers and whatever.  They're not.  They're going to have, maybe, 100 foot wide domes per settlement.  And, each settlement will have 4-6 people.  We're talking first settlement here, not 500 years in the future. 

The audience is inefficient minded.  You and Louis think more stuff is better when it's the unneeded stuff and unneeded complexity of things that gets the colonists killed.

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#71 2017-04-13 17:40:16

Dook
Banned
From: USA
Registered: 2004-01-09
Posts: 1,409

Re: DeGrasse Tyson's Mars challenge to Elon Musk

louis wrote:

I query whether we need a "Moxie" to produce oxygen. Why can't we simply heat up iron oxide in a solar concentrator to 570 degrees celsius. Won't that do the trick? And won't it be possible to do that in large quantities?

For a community of 1000 we would need about 2200 kgs of oxygen per sol (for human breathing, that is).  I can envision a central oxygen plant, processing 7.3 tonnes of iron oxide every sol which would be  brought in by tracked robot rovers that collect the ore from the rich surrounding iron ore deposits a few kms outside the base. 200 Kg loads - 9 robust robot rovers making 4 round trips every sol, guided to the oxygen production facility by roadside transponders. In the iron ore fields they robotically scoop up the ore and deposit it automatically  in a rear hopper until the weight sensors indicate enough has been collected.

As for heating the iron oxide to 570 degrees C to release oxygen.  One, you have to go out and get the iron oxide, then separate the silicon and other elements somehow, then put the iron oxide into some container, glass I assume, then heat it with a thousand or more mirrors, and the oxygen would gas out.

I guess you could have a building with a worker inside that takes in raw regolith, uses centrifuges to separate the iron ore from the silicon and other, then pours the iron ore into a glass capsule, raises the capsule to some point where a thousand mirrors melts the iron, I guess the oxygen gasses out and would go into a tube that takes it into some kind of cooling/condenser and then sends the oxygen into a tank.

I don't like it. 

I think the centrifuges would use more electricity than a Moxie.  I don't like having to depend on a rover to drive around and scoop up regolith.  If that rover breaks down, you die.  And, after a while you have to keep going farther and farther from your base to scoop regolith.  Also, if there is a long dust storm, like a month or year long one that Mars gets, you lose your sunlight and can't make oxygen and everyone dies. 

The Moxie is better.  You don't have to do anything except connect it to your power supply and then take a bottle with compressed CO2 and spray out the dust on the dust filters once every two weeks.

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#72 2017-04-13 23:24:19

kbd512
Administrator
Registered: 2015-01-02
Posts: 7,431

Re: DeGrasse Tyson's Mars challenge to Elon Musk

Apis Cor has a very compact (4m x 1.6m x 1.5m) 3D printer that weighs 1,815kg.  It printed a small house in 24 hours.  To obtain the temperatures required for concrete to set in the Russian winter, a tent was built around the house during construction.  That same technique could be used on Mars.  The printer uses a variety of available construction materials as feedstock to supply material to the print head.  A pulverized Martian Sulfacrete (sulfur concrete made using Martian sulfur and regolith, stronger than Earth concrete and uses sulfur and heat instead of water to solidify the aggregate mix) could obviously be fed into the print head.

The finished prototype house cost ~$10K USD to construct and a cost breakdown is provided in the link below.  Obviously wiring, piping, and an air lock must be added for use on Mars, but surely another robot could print regolith piping with a plastic liner to supply water or steam.  The maximum size of the printed structure is 3.1m in height and 5m in diameter, for a maximum area of 132m^2.  That could be increased with a larger printer arm.

The first on-site house has been printed in Russia

There is no possibility that any structure we could affordably transport from Earth to Mars would ever provide as much radiation protection or protection from meteoroids.  The walls could literally be a meter thick using the 3D printer and easily hold 14.7psi.  More importantly, if water and breathing gases are locally sourced, then the only things we need to send to Mars are finished goods for power production, tanks for water / LOX / LN2 storage, computers, and aerospace vehicles.

The total tonnage required to create and support colonies becomes much more reasonable when the building materials come from Mars.  Mr. Musk's Mars colonization plan then falls within the realm of economic feasibility.  Landers can be simple Cygnus-derived tuna cans since habitation requirements have been taken care of before prospective Martians ever set foot on the planet.  If textiles were fabricated from Martian grown cotton and hemp, then the colonists would have locally sourced sheets, towels, and clothing.  The machinery to process cotton or hemp and to fabricate textiles weighs a lot less than the rocket fuel required to send clothing, sheets, and towels to Mars for any significant number of people.  If locally grown fruits and vegetables are added to the economics equation, then shipping people and electronics seems imminently reasonable.

The point is, we're not stuck with 20th century construction and growing methods.  If we limited ourselves to 20th century construction and growing methods, then a Mars colony is probably infeasible as a function of construction costs alone.

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#73 2017-04-14 02:53:28

louis
Member
From: UK
Registered: 2008-03-24
Posts: 7,208

Re: DeGrasse Tyson's Mars challenge to Elon Musk

Brilliant link, kbd.

I couldn't agree more about the need to develop Mars construction techniques in order to provide hab space on Mars without mass imports.

This machine does indeed look like a perfect solution. Would we need to build a larger slightly pressurised "tent" to enclose the construction site (so that temperature can be maintained during construction)?

We definitely need to free up cargo space for 3D printers, CNC machines, micro-nutrients not readily available on Mars, communication technology etc.



kbd512 wrote:

Apis Cor has a very compact (4m x 1.6m x 1.5m) 3D printer that weighs 1,815kg.  It printed a small house in 24 hours.  To obtain the temperatures required for concrete to set in the Russian winter, a tent was built around the house during construction.  That same technique could be used on Mars.  The printer uses a variety of available construction materials as feedstock to supply material to the print head.  A pulverized Martian Sulfacrete (sulfur concrete made using Martian sulfur and regolith, stronger than Earth concrete and uses sulfur and heat instead of water to solidify the aggregate mix) could obviously be fed into the print head.

The finished prototype house cost ~$10K USD to construct and a cost breakdown is provided in the link below.  Obviously wiring, piping, and an air lock must be added for use on Mars, but surely another robot could print regolith piping with a plastic liner to supply water or steam.  The maximum size of the printed structure is 3.1m in height and 5m in diameter, for a maximum area of 132m^2.  That could be increased with a larger printer arm.

The first on-site house has been printed in Russia

There is no possibility that any structure we could affordably transport from Earth to Mars would ever provide as much radiation protection or protection from meteoroids.  The walls could literally be a meter thick using the 3D printer and easily hold 14.7psi.  More importantly, if water and breathing gases are locally sourced, then the only things we need to send to Mars are finished goods for power production, tanks for water / LOX / LN2 storage, computers, and aerospace vehicles.

The total tonnage required to create and support colonies becomes much more reasonable when the building materials come from Mars.  Mr. Musk's Mars colonization plan then falls within the realm of economic feasibility.  Landers can be simple Cygnus-derived tuna cans since habitation requirements have been taken care of before prospective Martians ever set foot on the planet.  If textiles were fabricated from Martian grown cotton and hemp, then the colonists would have locally sourced sheets, towels, and clothing.  The machinery to process cotton or hemp and to fabricate textiles weighs a lot less than the rocket fuel required to send clothing, sheets, and towels to Mars for any significant number of people.  If locally grown fruits and vegetables are added to the economics equation, then shipping people and electronics seems imminently reasonable.

The point is, we're not stuck with 20th century construction and growing methods.  If we limited ourselves to 20th century construction and growing methods, then a Mars colony is probably infeasible as a function of construction costs alone.


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

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#74 2017-04-14 03:44:56

louis
Member
From: UK
Registered: 2008-03-24
Posts: 7,208

Re: DeGrasse Tyson's Mars challenge to Elon Musk

I don't think collecting, delivering or feeding the iron ore would be difficult. Have your solar concentrator on a hillside. Robots can scoop up and deliver the iron ore. A chute or conveyor belt can deliver the iron ore to the collector. Robots, operated remotely by humans, would clear out waste material following melting of the ore.

Is there a requirement to separate out any silicon?  Why?

A community of 1000 would only be using about 2000 tonnes of iron ore per Earth annum.  A cubic metre of iron ore is about 5 tonnes. So you'd only be using 400 cubic metres, which I think is 7 x 7 metres at the surface. Even if that is spread out a lot more,  I don't think we are talking about a huge area of operation - certainly not more than a sq. km..

If there are 9 working rovers, one broken down rover doesn't signal death! lol  You'd maybe have 20 and a bigger concentrator so you produced an oxygen surplus and/or always had back up in the even of break down. 

Incidentally solar mirrors required for the concentrator can be 3D printed.

Dook wrote:
louis wrote:

I query whether we need a "Moxie" to produce oxygen. Why can't we simply heat up iron oxide in a solar concentrator to 570 degrees celsius. Won't that do the trick? And won't it be possible to do that in large quantities?

For a community of 1000 we would need about 2200 kgs of oxygen per sol (for human breathing, that is).  I can envision a central oxygen plant, processing 7.3 tonnes of iron oxide every sol which would be  brought in by tracked robot rovers that collect the ore from the rich surrounding iron ore deposits a few kms outside the base. 200 Kg loads - 9 robust robot rovers making 4 round trips every sol, guided to the oxygen production facility by roadside transponders. In the iron ore fields they robotically scoop up the ore and deposit it automatically  in a rear hopper until the weight sensors indicate enough has been collected.

As for heating the iron oxide to 570 degrees C to release oxygen.  One, you have to go out and get the iron oxide, then separate the silicon and other elements somehow, then put the iron oxide into some container, glass I assume, then heat it with a thousand or more mirrors, and the oxygen would gas out.

I guess you could have a building with a worker inside that takes in raw regolith, uses centrifuges to separate the iron ore from the silicon and other, then pours the iron ore into a glass capsule, raises the capsule to some point where a thousand mirrors melts the iron, I guess the oxygen gasses out and would go into a tube that takes it into some kind of cooling/condenser and then sends the oxygen into a tank.

I don't like it. 

I think the centrifuges would use more electricity than a Moxie.  I don't like having to depend on a rover to drive around and scoop up regolith.  If that rover breaks down, you die.  And, after a while you have to keep going farther and farther from your base to scoop regolith.  Also, if there is a long dust storm, like a month or year long one that Mars gets, you lose your sunlight and can't make oxygen and everyone dies. 

The Moxie is better.  You don't have to do anything except connect it to your power supply and then take a bottle with compressed CO2 and spray out the dust on the dust filters once every two weeks.


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

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#75 2017-04-14 08:55:07

Oldfart1939
Member
Registered: 2016-11-26
Posts: 2,384

Re: DeGrasse Tyson's Mars challenge to Elon Musk

kbd512-

THX for the excellent information regards the 3-D printed house.

Louis-

I hate to rain on your parade, but the one thing you haven't accounted for in your Iron redox energy production scheme, is how much energy input is required to get your inefficient system running. In order to build and run this monster system (which is FAR too complicated for a pioneering colony!), it's going to take a tremendous amount of energy as an input--energy which could be better utilized in construction of habitats and greenhouses. This is a simple thermodynamics issue; does the system you're building produce more energy than it consumes? From all the mining, transportation of regolith, energy expended in reducing Iron Oxides to elemental Iron, construction of all the processing facilities, etc., etc., etc., I really don't think this will come out being anything other than a black hole. Also, the concept of using artificial lighting for plant growth is another energy losing concept. Direct solar energy accumulation by plants is very efficient and requires very little assistance in greenhouses; only some heating during the Martian nights and energy to nominally pressurize them, and supply with water. Dr. Zubrin discusses the use of artificial illumination in his book: Entering Space. This is a MUST READ for all on this forum.

There's usually a major gap between concepts "on paper," and those capable of being executed in the real world. On paper, solar always looks great; real world applications---not as much. The chemistry that Louis has proposed sounds good conceptually, but the thermodynamics simply kill it dead in its tracks. Realistically: we'll use Nukes.

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