Musk's plans for Mars

kbd512 · 2016-10-11 15:14:11

Bob,

Instead of throwing four $72M RS-25's in the Ocean after eight minutes of use, maybe we should use RS-25's in this proposed vehicle's upper stage. We have to figure out how to use ADEPT to retrieve the upper stage, or the RS-25's at a minimum. The payloads should be headed to ISS, so a RS-25 storage module and an ADEPT EDL hardware to return the RS-25's to Earth. The TMI stages can use RL-10's for humans or electric propulsion for cargo. That'd probably be the most efficient way to do it with current technology and it should please our vendors.

louis · 2016-10-11 18:11:39

Hi Bob -

I'm v. interested in your words (from your link) as follows:

"Elon in his IAC presentation says the ITS carrying its 100 member crew might be able to reach Mars in 80 days at a particular close Mars opposition. This is dependent on the departure delta-v however. In the blog post "Propellant depots for interplanetary flight". I noted that at a higher departure delta-v possible by using a smaller 6 metric ton habitat for only a crew of 3, the Ariane 5 used as the in space propulsion stage might be able to make it to Mars in only 35 days, when leaving at such a particularly close Mars opposition."

I suspected we might get a much faster transit time with a more modest payload.

I really favour a very different mission architecture (from the Musk and NASA approaches, it would seem) based on a series of (robotic) pre-landings ensuring we have all the necessary supplies there on the surface in a relatively small drop zone and then a small crew of humans (3) being transited in the smallest possible craft, and maybe making rendezvous with a Mars descent/ascender vehicle in LMO.

If it is the case we could get the transit time down to 35 or even 60 days, that would make a huge difference to the whole dynamic of the mission, cutting out so much of the challenging zero G conditions (and obviating the need for an artificial G system).

RGClark wrote:

RGClark wrote:
In his presentation at about the 54 minute mark Musk discusses that the second stage in its tanker form or in its spaceship form will be able to reach orbit when used as a single stage. He states though the tanker will not be able to land, presumably because of insufficient reserve fuel. Then it could still be an expendable SSTO.
However, he states it could be used as cargo ship for fast intercontinental deliveries. In this case it would need to land so presumably he means this would be at speeds just below orbital.
http://youtu.be/H7Uyfqi_TE8?t=3240
Also, notable is that the upper stage at about a third the size of the booster could instead be used as the booster for a smaller launch system. You would then develop also a smaller upper stage. This results in a system about 1/3rd the size so could transport 1/3rd the number of people, about 35 or so.
This is interesting because Elon said they may have a development upper stage within 4 years, which could then be used instead as the booster. It may even be possible to use an existing upper stage on an existing rocket for the smaller ITS upper stage we now need, such as the Delta IV upper stage or even the Ariane 5 core used as upper stage. This would clearly reduce the development cost if we could use an existing upper stage.
A quite high payload to LEO could be done using the Ariane 5 core as the upper stage in this scenario:
3820ln(1 + 2500 ÷ (90 + 170 +240)) + 4650ln(1 + 158 ÷ (12 +240)) = 9,100 m/s
So we could get 240 metric tons to LEO with this much smaller system.

By using the ITS upper stage tanker instead as a first stage, we can get a smaller implementation of a Mars transport system. This would be useful as a first flight exploratory mission crewed by professional astronauts, before colonization flights began. Moreover, since Elon says a demonstration upper stage could be ready in four years such an initial flight might even be ready then.
Curiously, according to the calculation, if using the Ariane 5 as the upper stage, this launcher could carry as payload to LEO more than enough to fully refuel the upper stage. Then the same upper stage could be used as the in-space propulsion stage to Mars, and just by a single launch, rather than using multiple launches to refuel according to the much larger SpaceX plan:
A smaller, faster version of the SpaceX Interplanetary Transport System to Mars.
http://exoscientist.blogspot.com/2016/1 … pacex.html

Bob Clark

SpaceNut · 2016-10-11 19:24:24

While the shorter times to mars helps the dibilitating effects of 0G its the jury for mars gravity that we know nothing about.

louis · 2016-10-12 03:38:24

That's true, but (a) no journey to Mars can be without any risk and (b) we do know the effects of zero gravity on people for extended periods.

I think if we could get the transit time down to under 60 days each way we can take a calculated risk.

Interesting discussion here of gravity issue:

https://www.quora.com/What-is-the-longe … e-to-Earth

SpaceNut wrote:

While the shorter times to mars helps the dibilitating effects of 0G its the jury for mars gravity that we know nothing about.

Valeri Polyakov spent 437 days and was remarkably healthy. He suffered only 7% bone loss during that period. They note he was a highly motivated doctor who understood the health issues and wanted to prove people could survive a journey to Mars.

Perhaps all the crew for the first mission should be similarly highly motivated doctors?

Impaler · 2016-10-15 02:22:13

RobertDyck wrote:

MGS had a thermal emission spectrometer. It not only observed spectra, but also thermal momentum. That means how quickly minerals warmed up at dawn, and cooled after dusk. Geologists used this data to determine surface minerals. They found two predominant surface types. Type 2 included 9.2% Fe-smectite (probably nontronite), and 2.2% illite. Type 1 included 9.9% illite, and 2.4% kaolinite! These are types of clay. Kaolinite is white clay, used to make porcelain; it's the end product of a long series of weather steps. They are formed by moving water, cannot be formed at the bottom of a lake or sea or ocean. Kaolinite takes at least 10 million years to form on Earth. It's presence means there were flowing rivers and streams, not just "brief floods". For millions of years. The theory is Mars was warm and wet for a billion years.

That's a low grade iron ore by Earth standards, high grade ore is near 70 percent Iron, the absolute bottom of the economically viable range is 20 percent. So your basically confirming exactly what I said about Iron ore. Iron is the only metal I'd be confident in obtaining on Mars or any other rocky planet for that matter.

Some other sulfide and evaporite type minerals may exist in usable deposits that might be sources of Aluminum, Calcium and Magnesium

Kaolinite needs any water, not flowing water to form and are believed to form in place underground through groundwater action, also it is irrelevant to gold deposits as their would never have been any native gold to erode out into these streams to form a placer deposit.

louis · 2016-10-15 06:38:10

Couple of points:

1. There are definitely higher grade iron ores on Mars than 20%.

2. "Economically viable" is meaningless on Mars, at least in the context of the early colony. It is also economically unviable to drill out ice from glaciers, transport it in tracked vehicles for use in domestic premises - but that is what we will likely do on Mars.

3. You're not really saying Mars is made entirely of iron are you!? So we will find lot of other usable mineral deposits. Basalt is an obvious one.

Impaler wrote:

RobertDyck wrote:
MGS had a thermal emission spectrometer. It not only observed spectra, but also thermal momentum. That means how quickly minerals warmed up at dawn, and cooled after dusk. Geologists used this data to determine surface minerals. They found two predominant surface types. Type 2 included 9.2% Fe-smectite (probably nontronite), and 2.2% illite. Type 1 included 9.9% illite, and 2.4% kaolinite! These are types of clay. Kaolinite is white clay, used to make porcelain; it's the end product of a long series of weather steps. They are formed by moving water, cannot be formed at the bottom of a lake or sea or ocean. Kaolinite takes at least 10 million years to form on Earth. It's presence means there were flowing rivers and streams, not just "brief floods". For millions of years. The theory is Mars was warm and wet for a billion years.
That's a low grade iron ore by Earth standards, high grade ore is near 70 percent Iron, the absolute bottom of the economically viable range is 20 percent. So your basically confirming exactly what I said about Iron ore. Iron is the only metal I'd be confident in obtaining on Mars or any other rocky planet for that matter.
Some other sulfide and evaporite type minerals may exist in usable deposits that might be sources of Aluminum, Calcium and Magnesium
Kaolinite needs any water, not flowing water to form and are believed to form in place underground through groundwater action, also it is irrelevant to gold deposits as their would never have been any native gold to erode out into these streams to form a placer deposit.

RobS · 2016-10-15 07:03:00

Copper deposits are often associated with basalt, and Mars appears to have a lot of basalt. I grew up in Connecticut near a colonial era copper mine in sandstone, located right under a massive basalt sheet. Cyprus (from which the word copper comes) has copper in pillow lava.

Impaler · 2016-10-15 16:35:16

louis wrote:

Couple of points:
1. There are definitely higher grade iron ores on Mars than 20%.
2. "Economically viable" is meaningless on Mars, at least in the context of the early colony. It is also economically unviable to drill out ice from glaciers, transport it in tracked vehicles for use in domestic premises - but that is what we will likely do on Mars.
3. You're not really saying Mars is made entirely of iron are you!? So we will find lot of other usable mineral deposits. Basalt is an obvious one.

1 - Completely unsubstantiated, the existence of small nodules of higher purity is not what matters, it's macro rock fraction iron which matters and we have no indication of high grade ore, but we can be confident of low grade. The highest purity and first resource to exploit is likely to be iron meteorites scattered on the surface but we would not call that an ore.

2 - Economic viability always exists no matter when or where you are, it just varies based on your technology, the logistical difficulty in accessing the site, the scale of the mining operation and what your competitors are mining, a new technology or new deposit can render another deposit not economically viable anymore. Describing an iron ore deposit as low grade is not to say it can not be economically mined, it would be no grade in that case so I think you've misunderstood what grade means here. Obviously over time we would develop a benchmark for what constitutes economically viable on mars for any ore type and this is likely to depend on many factors beyond just the richness of the ore.

3 - I don't understand how you drew that meaning, I said I would be confident that Iron exists in at least earth standard low grade deposits on any terrestrial planet because iron is one of the most common elements in the universe and will always be a significant fraction of any rocky planetoid along with things like silicon, magnesium and aluminum. The fusion process of stars guarantees these elements are the most common heavy elements. But irons super abundance and it's low affinity to bond with silicon means it's basically guaranteed to be found enriched in some rocks up to the low grade level.

Last edited by Impaler (2016-10-15 16:42:53)

louis · 2016-10-15 21:00:45

You seemed to be talking down the prospects for mineral exploration on Mars.

The early colony on Mars will be incredibly energy rich - probably generating anything up to 100 Kws per person (averaged on a 24/7 basis) in the initial stages. Compensating for poor density of iron deposits will be of no concern.

I also didn't understand why you made no mention of ubiquitous basalt and silica on Mars - both very useful. You were making Mars sound like this resource-challenged planet when it is actually replete with resources: iron, silica, basalt, water, carbon and other great resources we will never need to fly there.

If you are saying I misunderstood you and you too think Mars is a huge bonanza of resources, all well and good.

Impaler wrote:

louis wrote:
Couple of points:
1. There are definitely higher grade iron ores on Mars than 20%.
2. "Economically viable" is meaningless on Mars, at least in the context of the early colony. It is also economically unviable to drill out ice from glaciers, transport it in tracked vehicles for use in domestic premises - but that is what we will likely do on Mars.
3. You're not really saying Mars is made entirely of iron are you!? So we will find lot of other usable mineral deposits. Basalt is an obvious one.
1 - Completely unsubstantiated, the existence of small nodules of higher purity is not what matters, it's macro rock fraction iron which matters and we have no indication of high grade ore, but we can be confident of low grade. The highest purity and first resource to exploit is likely to be iron meteorites scattered on the surface but we would not call that an ore.
2 - Economic viability always exists no matter when or where you are, it just varies based on your technology, the logistical difficulty in accessing the site, the scale of the mining operation and what your competitors are mining, a new technology or new deposit can render another deposit not economically viable anymore. Describing an iron ore deposit as low grade is not to say it can not be economically mined, it would be no grade in that case so I think you've misunderstood what grade means here. Obviously over time we would develop a benchmark for what constitutes economically viable on mars for any ore type and this is likely to depend on many factors beyond just the richness of the ore.
3 - I don't understand how you drew that meaning, I said I would be confident that Iron exists in at least earth standard low grade deposits on any terrestrial planet because iron is one of the most common elements in the universe and will always be a significant fraction of any rocky planetoid along with things like silicon, magnesium and aluminum. The fusion process of stars guarantees these elements are the most common heavy elements. But irons super abundance and it's low affinity to bond with silicon means it's basically guaranteed to be found enriched in some rocks up to the low grade level.

RGClark · 2016-10-16 06:26:35

RGClark wrote:

By using the ITS upper stage tanker instead as a first stage, we can get a smaller implementation of a Mars transport system. This would be useful as a first flight exploratory mission crewed by professional astronauts, before colonization flights began. Moreover, since Elon says a demonstration upper stage could be ready in four years such an initial flight might even be ready then.
Curiously, according to the calculation, if using the Ariane 5 as the upper stage, this launcher could carry as payload to LEO more than enough to fully refuel the upper stage. Then the same upper stage could be used as the in-space propulsion stage to Mars, and just by a single launch, rather than using multiple launches to refuel according to the much larger SpaceX plan:
A smaller, faster version of the SpaceX Interplanetary Transport System to Mars.
http://exoscientist.blogspot.com/2016/1 … pacex.html

Update. Dr. John Schilling's launcher performance calculator allows a more accurate estimate of payload to LEO. Using it, I got 178 metric tons to LEO, still enough payload to send a fully refueled Ariane 5 to Mars with a single launch architecture.

A smaller, faster version of the SpaceX Interplanetary Transport System to Mars, UPDATED, 10/15/2016.
http://exoscientist.blogspot.com/2016/1 … pacex.html

Bob Clark

RobS · 2016-10-16 08:03:11

Thanks, Bob, for your work. I think we all agree Musk's approach is surprisingly big; "too" big by our way of thinking. It's interesting, though, looking back on all his earlier hints about the system, that it was inevitable that it had to be this big! He said all along he wanted to land 100 people on Mars at once. I do wonder whether he'll pull it off. It's an approach that NASA won't want to take, too; it's too big.

Tom Kalbfus · 2016-10-16 08:58:39

We are living in the 21st century, I expected bigger! After all, when I lived in the 20th century, what did I have to compare it to but the 19th century, that was an era of horses and buggies and steam locomotives, and now we fly in airplanes and can travel anywhere in the world in a matter of hours. The Wright Brothers thought big. One hundred years ago we were fighting the First World War, and there was tremendous development in aviation technology at that time, and it continued through the Great Depression and World War II to land us in the Jet Age, from the point of view of a child growing up in the 1970s, I expected that to continue, I expected that we would be living in space by now. From the 1970s looking backwards I see tremendous progress in aviation, and I expected that to continue right into space. There were people in the 1970s that were thinking even bigger than Elon Musk today, everyone was hitching their wagon to that supposed miracle shuttle that NASA was trying to develop. It looked like an airliner to us, and we couldn't wait to buy tickets into space. A funny thing happened on the way to the 21st century however, something called "The Great Stall" occurred, we got frozen in those airplanes, the technological developments started emphasizing how to pack as many seats in those airliners as possible to reduce ticket prices! There used to be supersonic concords, but the Arabs put a stop to those! They wanted us facing to Mecca and praying instead of going into space, so we could live the lives of Lawrence of Arabia and Ally Babba and the Forty Thieves instead of colonizing space! seems the Arabs got their way at least in their own region, they get to pretend they are living in the 7th century except with bombs and guns and oil wells to pay for them.

RobertDyck · 2016-10-16 12:36:23

After crushing and sifting to concentrate ore, hematite concretions are greater than 99% iron oxide. They don't have sulphur or other contaminants, so don't need to be smelted with limestone. They can be smelted by the direct iron method.

Bytownite is a mineral and part of basalt. Anorthite and bytownite will dissolve in acid, so can be processed to produce aluminum. One byproduct of this is silica gel, which can be calcinated to completion to produce silica. The only silica sand found so far is a tiny deposit just inches long, but one of the rovers did discover that one. However, if there isn't enough silica sand to produce glass, then you can use the silica gel that's a byproduct of producing aluminum.

RobS · 2016-10-16 12:45:12

I wonder whether a robotic digger with a magnet to separate out nickel-iron fragments might be the best way to go. No doubt there are lag deposits in some of the channel deposits and they will be enriched in nickel-iron because of its high density. Why reduce iron oxide to iron when we already have iron laying around? It can then be purified using hot carbon monoxide to form carbonyls, just like asteroidal materials.

SpaceNut · 2016-10-16 15:57:38

So if we build it based on the current rovers with only what we need to add to make it collect the materials then we have an experiment that we can do right here on earth. This would allow for energy comsumption rates and telerobotic collection to be proven.

So once we have the ore and its processed, then what are we going to do with it as we need the means to shape it in order to fabricate living and other stuff with it. What would that amass for energy needs and total mass to the surface to land and would it be portable.

GW Johnson · 2016-10-16 16:14:44

What I am seeing here is an angels-on-the-head-of-a-pin argument regarding extractable resources. We will know NOTHING until we actually go there.

Considering the historical ground truth versus remote sensing differences, my conclusion is inevitable, notwithstanding the local rover results. Their instruments are very limited, and none of them have ever been able to dig more than a single-digit number of cm below the surface.

The point of establishing some sort of permanent presence on Mars (robot or human) is to resolve some of this. That IS the point of Musk's Mars plan: to establish that some-sort-of-permanent presence on Mars.

You don't successfully do that, self-restricting to min-thrown-mass concepts, like Mars Direct. Or by restricting yourself to no-risk-of-losing-a-crew, the way NASA now does.

It just takes a lot more stuff landed on Mars to answer questions like that. THAT is why Musk's ship design is so big. It's a best-guess, and not so out-of-line with what I proposed, over at "exrocketman" for my 2016 version.

What any sort of base or colony might be able to do, depends very fundamentally on this amount of stuff you land. And on what assumptions you make. That is inherent.

Best to focus on that get-something-on-Mars objective; the rest is mere speculation. Speculation might be fun, but it is not very realistic or helpful.

GW

Last edited by GW Johnson (2016-10-16 16:23:41)

RobertDyck · 2016-10-16 17:43:26

GW, now you're exaggerating. We know next to nothing about Proxima b; all we know is orbital period and mass relative to its star. However, we know quite a bit about Mars. Mars Global Surveyor found hematite at multiple locations, the highest concentration was Meridiani Planum. "Ground truth" from Opportunity has shown us reality vs remote sensing data. There is hematite. Spirit also found hematite, although not quite as large a deposit, and not as exposed on the surface.

I have quoted a paper published in Science, with an appendix only available online and a note that this appendix would be published in a later paper to be submitted to the Journal of Geophysical Research. That paper was published in Science in year 2000. Here is one from 2010, actually published in Journal of Geophysical Research: Distribution and variation of plagioclase compositions on Mars

3.3. Plagioclase Feldspar Mapping
...
six plagioclase compositional maps were constructed that correspond to the compositional subdivisions for this solid solution mineral: albite (An0–10), oligoclase (An10–30), andesine (An30–50), labradorite (An50–70), bytownite (An70–90), and anorthite (An90–100).
...
4.1. Range of Plagioclase Compositions
Compositional maps reveal an apparent wide range of plagioclase compositions distributed randomly across Mars (Figure 3). Plagioclase compositions ranging from albite (An1–10) to anorthite (up to An92) were modeled as the average compositions for individual spectra. Visual comparisons revealed that in spite of the wide range of modeled compositions, most (81%) TES spectra selected in this study model as calcic plagioclase. Labradorite, An50–70 (49% of TES observations studied), and bytownite, An70–90 (25%), are the dominant plagioclase compositions (Table 2 and Figures 3d–3e) in the Martian crust, with lesser amounts of other plagioclase.

Satellite data is used on Earth to identify resources. So this is just the latest state-of-the-art prospecting technology.

GW Johnson · 2016-10-17 09:49:37

I'm not saying there's not usable iron ore all over Mars, because there is. For purposes of life support and propellant manufacture, water-as-ice is the more important resource, at least initially.

We've talked before about remote sensing versus ground truth, especially regarding buried (!!!) resources, which the ice must be in order not to sublime. Stuff on the surface can be remotely catalogued and mapped and characterized fairly well. Buried stuff still cannot. Sorry, but that's just the truth of it.

Some of the discussions above, and in other threads, focus on mineral extraction as the basis of some sort of economy. What would be the point of shipping Martian hematite (or even finished steel products) to Earth at incredible expense? We pretty much recycle steel scrap these days, anyway. Not so much need for iron ore mining here at home these days.

Resources on Mars like that hematite are far more important for building things locally on Mars, instead of shipping steel stock and parts from Earth at incredible expense. So ore-refining and steel-making are very important to the long-term future of any Mars colony. Just like they are any industrialized country here on Earth. Those processes (whatever they end up being) will be different from those used here, precisely because the environment is so different there.

I'm pretty sure that same picture obtains for most of the minerals we could extract on Mars (or most anywhere else), even the so-called precious ones. Start landing lots of, say, platinum, from asteroids, and it is no longer rare, and its value drops. So what is the point of that? How can you base an economic model on something that will lose value over time?

What you want to import from off-Earth is stuff that you cannot get on Earth at all. There are some rare metals that might qualify. But not gold.

My real point is that it is far too early to speculate on the economy to be established with a permanent colony on Mars. Whatever that economic commodity basis is, it will be something we haven't yet seen, and which also is unavailable on Earth. That's the only sort of thing that justifies the transportation expense. One example from history is tobacco grown in the New World. Another was spices from the far east.

One such item does not make an economy, though, and neither does one foreign colony or entity to trade with. The tobacco example from 400 years ago was part of a multi-location/multi-commodity trade among Europe, the Caribbean, Africa, and North America. The other two "products" in that network were rum/sugar cane, and slaves. They stumbled into it. It was not pre-planned.

What we don't want to emulate from that old example today is having only money be the objective function, without any ethical constraints. That's where the slavery came from. There's a strong tendency to do exactly that in many countries today, though. Capitalism is indeed the greatest engine of creation ever devised by man. But capitalism without rules and ethical constraints always devolves to piracy and slavery. We've already seen it multiple times throughout history. We're seeing it again today.

Back to topic: first priority for Mars is going there to find out what all is really there, and where exactly it is. It takes human adaptability in-situ to accomplish that task effectively. A piece of this will be learning to live off the land, which will be harder than any previous such experiences, precisely because the environment is so unremittingly lethal.

That's more than enough to keep an outpost occupied for some decades after getting established. Somewhere in those decades, we will likely find whatever it is (hopefully multiple things) that qualifies as an export that people back home will want, and can get no where else.

At least, that's what history says. You just have to have faith that it will happen again. But, it won't be anything we already have seen(!!!!) on Mars. All those things we already have here at home.

GW

Last edited by GW Johnson (2016-10-17 10:10:01)

clark · 2016-10-17 17:23:34

Been a while, but I recall the economic equation starts to make sense when you have a cis-lunar environment. Not before.

Moon serves Leo/geo, mars serves moon and a potential automated asteroid mining environment. Earth consumes energy and services.

All highly speculative

RobertDyck · 2016-10-17 18:21:00

The "Canadian Space Summit" is being held November 13-15. They bring together "Canadian Space Leaders". I got on the list, as I'm the only remaining founder/president of a Mars Society chapter in Canada. The Canadian Space Society is hosting the meeting in Winnipeg this year. They want to form a chapter in Winnipeg; former members of the Mars Society Canada in Toronto/Ottawa/Montreal joined the Canadian Space Society. Someone from the Planetary Society is organizing. I used to be a member of the Planetary Society. Anyway, the point is the Canadian federal government is starting consultation for next year's budget, the point of this meeting is to organize/lobby space stuff in the budget. When I registered, I said my goal is to promote a Canadian rover to Mars. The same one that former Canadian Space Agency president Marc Garneau wanted. He's now a Member of Parliament, in the party that currently forms government. He wanted a rover about the size of Spirit or Opportunity, with a multi-segment drill, 10 segments each 1 metre long so it could drill up to 10 metres deep. And I said I want to send it to the frozen pack ice at Elysium Planetia.

How's that for getting involved? And how's that for "ground truth"?

clark · 2016-10-17 18:58:49

Mines bigger than yours.

RobertDyck · 2016-10-17 19:42:55

clark wrote:

Mines bigger than yours.

GW keeps saying we need ground truth for ice. Ok, I'm working on that. So how is yours bigger?

SpaceNut · 2016-10-17 22:08:09

The insitu water is for life support and crew return, its not for export and even the initial use of anyother insitu materials for a very long time as we will want to use them to increase the ability to stay longer and to have more room to work with in any habital space that we can create from these insitu elements.

clark · 2016-10-20 07:22:49

"Ground truth" requires a more robust and extensive incursion; missions based and driven on confirming the industrial scale location of and availability of minerals necessary for "production", whatever that means.

Rovers are and will always be science vehicles. Interesting in their own right, but mostly useless for what this board really wants.

GW Johnson · 2016-10-20 14:43:10

Well, for water, there's the effort-intensive and massive-volumes cooking (for small yield volumes) of moisture out of regolith pretty much anywhere on Mars, and there's very simple slant-well drilling and steam extraction from very massive buried deposits of ice. Those are the endpoints of the spectrum.

The problem is, you don't know whether the buried deposits are massive enough for drilling, or whether they are just thin layers and lenses of ice that will require strip mining. The strip mining alternative is just about as effort-intensive as regolith cooking, and probably requires even larger machinery. I still think even strip mining will yield more water for the effort expended, though. But I cannot say for sure. As far as I can tell, no one knows.

What you need is around a 1000 feet or more of ice vertically, that is is more ice-than-regolith, so that you have the room to drill down from one wellhead, turn and slant across the deposit horizontally. You can do those in a variety of compass directions from the one wellhead. The bigger the deposit geographically, the longer these horizontal legs can be, and longer you can do steam extraction and get enormous yields.

You cannot determine how deep a buried deposit goes, or what its quality is, with remote sensing. The only truth about that is "ground truth", obtained in situ by drilling "very deep". Perhaps I am over-conservative, but I have my doubts about inferring water from the hydrogen we actually can detect remotely. There are just too many other hydrogen-bearing compounds.

Digging few cm is utter nonsense for this purpose. 1 meter exploration drill depth is nowhere close. Drilling down 10 meters ain't "deep". Even 100 m ain't deep enough, you simply cannot turn a drill string that sharply. I'm talking half a km or more deep. Likely way more.

No robot probe or rover is ever going to be able to do anything like that. Not until the rest of "Star Trek" technology finally comes true. I don't know about the rest of you, but I'm not holding my breath for that.

If you do find a place like that (massive mostly-ice 0.5 km or more thick), it becomes very attractive to produce huge excesses of water there, and then truck it, or (later on) send it by pipeline, anywhere else you want on Mars. THAT'S how you build more than one settlement there.

That's not to say we cannot start our settlements somewhere else, but sooner or later, real humans on the surface of Mars must find that massive-ice place and exploit it. THAT is the fundamental enabler for permanent settlements.

I just do not see any way around that need. Maybe that's just the hardcore realist in me talking, but I'm not often wrong.

GW

Last edited by GW Johnson (2016-10-20 14:51:28)

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Re: Musk's plans for Mars

#217 2016-10-16 17:43:26

Re: Musk's plans for Mars

#218 2016-10-17 09:49:37

Re: Musk's plans for Mars

#219 2016-10-17 17:23:34

Re: Musk's plans for Mars

#220 2016-10-17 18:21:00

Re: Musk's plans for Mars

#221 2016-10-17 18:58:49

Re: Musk's plans for Mars

#222 2016-10-17 19:42:55

Re: Musk's plans for Mars

#223 2016-10-17 22:08:09

Re: Musk's plans for Mars

#224 2016-10-20 07:22:49

Re: Musk's plans for Mars

#225 2016-10-20 14:43:10

Re: Musk's plans for Mars

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