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SLS / Orion / Beyond-LEO HSF - Constellation => Missions To The Moon (HSF) => Topic started by: Warren Platts on 05/21/2016 06:06 pm

Title: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 05/21/2016 06:06 pm
The theory of a bone-dry Moon was a reasonable hypothesis after the Apollo missions. Arguably, it initially led to a confirmation bias that discounted early evidence of a wetter Moon--such as the discounting as contamination of trace amounts of phyllosilicates in certain Apollo samples (that should be reexamined IMHO).

The Giant Impact theory was proposed post-Apollo (Hartmann & Davis 1975) (http://adsabs.harvard.edu/abs/1975Icar...24..504H) to explain the apparent depletion in volatiles (and siderophiles). The idea was that the Theia impactor plus a big chunk of the Earth's mantle vaporized, and as the cloud condensed to form the Moon, most of the volatiles were lost to space. Thus, one might expect that the volatiles that remained, would be enriched in heavy isotopes. Lunar hydrogen isotopes do show a slight enrichment in deuterium, but it is very slight, and they are much less enriched than comets. (Saal et al. 2013) (http://geology.case.edu:16080/~vanorman/pdf/Saal_etal_Science_2013.pdf).

Given a common origin, composition, and concentration of H2O on both the Earth and the Moon, it could be that it would be a lot easier to obtain water sufficient to support an aggressive space exploration program by simply drilling for it a select Near Side, low latitude locations than it would be to mine water ice from the lunar poles. To draw an analogy with Earth's petroleum industry, getting water from the lunar poles would be as if our first petroleum had to be extracted from Alberta tar sands, rather than shallow Pennsylvania oil wells.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: the_other_Doug on 05/21/2016 06:24 pm
The myth of a bone-dry Moon was a reasonable hypothesis after the Apollo missions. Arguably, it initially led to a confirmation bias that discounted early evidence of a wetter Moon--such as the discounting as contamination of trace amounts of phyllosilicates in certain Apollo samples (that should be reexamined IMHO).

The Giant Impact theory was proposed post-Apollo (Hartmann & Davis 1975) (http://adsabs.harvard.edu/abs/1975Icar...24..504H) to explain the apparent depletion in volatiles (and siderophiles). The idea was that the Theia impactor plus a big chunk of the Earth's mantle vaporized, and as the cloud condensed to form the Moon, most of the volatiles were lost to space. Thus, one might expect that the volatiles that remained, would be enriched in heavy isotopes. Lunar hydrogen isotopes do show a slight enrichment in deuterium, but it is very slight, and they are much less enriched than comets. (Saal et al. 2013) (http://geology.case.edu:16080/~vanorman/pdf/Saal_etal_Science_2013.pdf).

Given a common origin, composition, and concentration of H2O on both the Earth and the Moon, it could be that it would be a lot easier to obtain water sufficient to support an aggressive space exploration program by simply drilling for it a select Near Side, low latitude locations than it would be to mine water ice from the lunar poles. To draw an analogy with Earth's petroleum industry, getting water from the lunar poles would be as if our first petroleum had to be extracted from Alberta tar sands, rather than shallow Pennsylvania oil wells.

You do realize that what you characterize as the "myth" of a bone-dry Moon is still the accepted model of the Moon amongst the planetary science community?

You may have a valid point -- but to start out by declaiming that the currently accepted models and theories are myths isn't exactly the best way to begin, IMHO.  It's sort of like going to the New Physics section and reading people's posts that start out with "the myth of Relativity has been accepted for far too long, you all need to discard it and accept my turtles-all-the-way-down theory in order to understand how we can get to other stars in days."

In other words, I'm not sure this forum is the best place to attack, or even insist that we re-think, the current models and theories of lunar creation and composition.  Which would strongly argue that you will never be able to find underground ice reservoirs as you describe on the Moon.

In summary, your post isn't about lunar exploration.  It's a "what-if everything we understand about the Moon is wrong?" post.  And I'm really not sure that's an appropriate topic for us to entertain.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 05/21/2016 08:03 pm
You do realize that what you characterize as the "myth" of a bone-dry Moon is still the accepted model of the Moon amongst the planetary science community?

All right, I changed it to "theory". That should satisfy you. However, you are wrong that the theory that the Moon is "bone-dry" is still the accepted model amongst the planetary science community. That tells me you are not an expert in the subject, and therefore, you may want to do a little research before making such pronoucements.

Quote
In summary, your post isn't about lunar exploration.

And this is a crock as well. What's got me motivated was a recent post by Dennis Wingo on his blog that reviews Paul Spudis's latest book, The Value of the Moon, where Dennis briefly summarized the infrastructural problems that mining water out of permanently shaded craters:

In order to mine water in hundred ton lots, you need a lot of infrastructure.  You need front end loaders, dump trucks, and a plethora of other surface vehicles, whether robotic or human operated.  You need lots of electrical power to provide the energy to these vehicles ... I would posit that these plans for massive water harvesting ... are to be set aside and removed from our thought toolbox, at least for a while.

Thus, rather than going directly for the water, Mr. Wingo would seem to suggest that we should build a manufacturing base first, in order to manufacture the dump trucks, etc. required to mine water in 100 tonne lots. I'm not sure how many hundred ton lots he thinks we should mine in a year, but to be game changing, it's going to have to more than one hundred mT per year:

1 tonne/yr ---> good demonstration project
10 tonne/yr ---> can launch a lander or two back into orbit
100 tonne/yr ---> will make a dent in the cost of a moon base
1000 tonne/yr ---> enough for a self-licking ice cream cone
10,000 tonne/yr ---> enough to support an aggressive, sustainable, abundant chemical Mars architecture

Dennis has a point: to ship all the mining infrastructure necessary for game-changing amounts of lunar fuel is going to be huge. You could probably send an Apollo-on-steroids crewed mission to Mars for the amount of upmass it would take to do 10,000 tonnes per year at a 30 K crater.

Thus, it is not surprising that the original VSE program never got any traction to get off the ground.

I say now that the old regime is about to give way, it's time to radically rethink our options. A lot has been learned since 2008. The evidence for a Moon's mantle/crust that is/was as "wet" as the Earth's can be partially summarized as follows:

1. The fire fountain volcanoes that produced Apollo 15 and 17 glasses contain up to 1 ppt of H2O in melt inclusions.
2. Trace amounts of apatite--a water containing mineral--are widespread and indicate similar concentrations.
3. GRAIL results that show the Moon is "fracked" down to 80 km, thus allowing a potentially huge source rock volume to provide water that could make it's way to the surface.
4. The Kola Superdeep Borehole on Earth found water described as "boiling" with H2 gas at a depth of 12 km down: that is roughly equivalent to 72 km down on the Moon.
4. LADEE results that show surprisingly high amounts of H2 gas in the lunar exosphere that is consistent with outgassing of juvenile volatiles.
5. The documented existence of geological structures that most closely resemble terrestrial maars that were formed as the result of phreatomagmatic eruptions.

The latter in particular show the way forward IMHO. In the early days of petroleum exploration, they didn't do massive seismographic and gravimetric surveys to find oil. They simply looked for natural oil seeps and drilled there.

The other thing is that I have been invited to discuss these ideas at the 7th annual joint Space Resources Roundtable/Space and Terrestrial Mining Sciences Symposium at the Colorado School of Mines in a few weeks, so I'd like the opportunity to bounce these ideas off the NSF community. I hope that's alright with you Doug!  :)
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: the_other_Doug on 05/21/2016 08:50 pm
I've read the same results you have, and while they indicate that there was some water in the materials that formed the Moon, they don't (at least to the reviewers I've read, anyway) indicate that there are reserves of water ice waiting to be mined.  With the kind of "big splat" dynamics that I've seen discussed in detail, while a lot of the volatiles were lost to space, a lot of interactions happened on the initial clump of matter that served as the gravitational focus that built up the mass of the current Moon.  Some water was trapped inside, and is seen in the various areas you mentioned.  This supposedly accounts for the minute traces of water found in the examples you mention.

But, heck, the appearance of some arguably chondritic materials in the inclusions you mention in the Apollo 15 and 17 fire-fountain glasses have spurred Jack Schmitt to claim that the "big splat" theory is fundamentally flawed, to the extent he doesn't believe in it.  And he's the only planetary scientist who ever actually visited another planet.

And yet, his point of view is a decided minority opinion out there.

That said, it's certainly not a bad thing to follow up on all sorts of varying theories that have some basis in the observed data.  And if there are ways to establish the truth of whether or not there is ice to be mined on the Moon (except for the comet-impact-emplaced water at the poles), yeah, go for it.  But I think you need to identify the truth of that theory, and locate the buried water, before you go about setting up the infrastructure required to mine it.  We know there is water at the poles; the location and accessibility of subsurface water ice deposits are both debatable at present.

But again, that said, there is nothing but good to come from initial planning for mining such water, should it be found.  My only concern, as I mentioned, is that your new lunar composition paradigm, while interesting to discuss, is not the majority opinion out there, at least from what I've read in the journals.  The old paradigm has to do a little fast footwork to account for the current anomalies, totally granted -- I just didn't think that discussion of the various current theories of lunar origin and composition was appropriate for this particular site.  Though, as you can tell, I'd love to get into such a good discussion -- I'm just not sure what forum would be appropriate for it.

Good luck with your presentation, by the way.  Even if it's not considered to be something appropriate for this forum in particular (which I sort of hope won't happen), I'd love to see your presentation materials at some point.  Maybe after you've given your presentation, you can post something about it here?

Again, I wasn't trying to say you're not doing good work.  Just that debates on lunar origin and composition theories might not be appropriate here... but if found to be what you're predicting, your mining thinking most certainly is!  :)
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 05/22/2016 02:40 am
With the kind of "big splat" dynamics that I've seen discussed in detail, while a lot of the volatiles were lost to space, a lot of interactions happened on the initial clump of matter that served as the gravitational focus that built up the mass of the current Moon.

A point of nomenclature: the Moon-forming event should be called "giant impact" IMHO; the impact of a secondary moon that allegedly caused the formation of the lunar highlands (Jutzi & Asphaug 2011) (http://www.nature.com/nature/journal/v476/n7358/abs/nature10289.html) should be called "big splat". Yes, some people call the giant impact "big splat", but really that's confusing, besides not being an apt description: the more recent simulations that have tried to explain the similar Earth/Moon mantle composition (e.g., Canup 2012) (http://science.sciencemag.org/content/early/2012/10/16/science.1226073) are not very splat-like: the two bodies completely fuse and become well mixed, with a halo of debris that becomes the Moon. Quite unlike carapace formed by Jutzi and Asphaug's big splat.

Quote from: Doug
I've read the same results you have, and while they indicate that there was some water in the materials that formed the Moon, they don't (at least to the reviewers I've read, anyway) indicate that there are reserves of water ice waiting to be mined.

That there are reserves of water ice "waiting to be mined" is not really debatable any more. Between the bistatic radar results (Spudis et al. 2013) (http://onlinelibrary.wiley.com/doi/10.1002/jgre.20156/abstract) and the LCROSS spectroscopy results (Colaprete et al. 2010) (http://science.sciencemag.org/content/330/6003/463), it's pretty clear that there's a lot of water up there. Indeed, the Spudis paper cited above underestimated the amount of ice in the anomalous craters by an order of magnitude (they report 600 million tonnes of ice: it should be 6 billion tonnes). In fact, there's so much ice, it's hard to explain all of it as coming from comets and meteors and solar wind: probably juvenile water provides a significant percentage of the polar ice deposits IMO.

But the purpose of this thread is not to discuss mining water ice, it's about drilling for economically valuable volatile resources at certain, rare, low-latitude, Near Side locations.

Quote from: Doug
But, heck, the appearance of some arguably chondritic materials in the inclusions you mention in the Apollo 15 and 17 fire-fountain glasses have spurred Jack Schmitt to claim that the "big splat" theory is fundamentally flawed, to the extent he doesn't believe in it.  And he's the only planetary scientist who ever actually visited another planet. And yet, his point of view is a decided minority opinion out there.

I never said the giant impact theory of the formation of the Moon is false. The beauty--and weakness--of that theory is that it can explain practically anything, and not just for the Earth-Moon system, but for the rest of the planets as well. Venus doesn't have a moon? No problem: the giant impactor merely got ejected. Uranus is tilted sideways? No problem: a giant impactor knocked it on its side. The Moon is bone-dry? No problem: the cloud caused by the giant impact caused it to lose all its volatiles. The Moon really has the same primordial concentration of water as the Earth? No problem: you can make a numerical simulation do anything you want.

So I have no problem with the giant impact hypothesis per se--it just has to be constrained by the empirical evidence of abundant juvenile water. And certainly, at least the upper layers of the Moon have been depleted in volatiles. But I believe this was a relatively gradual process that happened after the Moon formed.

The GRAIL results say the Moon is fracked to a high porosity on the order of 12% on average down to a depth of perhaps 70-80 km (Wieczorek et al. 2013) (http://science.sciencemag.org/content/339/6120/671?keytype=ref&siteid=sci&ijkey=Zr4YoyrsTuuqA). Beyond those depths, the mantle is too hot and plastic to maintain pores over geologically long periods. However, the pressure at 75 km down with a temperature of 200 C, it's hard (for me) to imagine that those pores could remain open if there was not a fluid within them pressurized to lithostatic pressures. That is what I want to talk about. I think the Kola Superdeep Borehole has much to say in this regard...

Quote from: Doug
I just didn't think that discussion of the various current theories of lunar origin and composition was appropriate for this particular site.  Though, as you can tell, I'd love to get into such a good discussion -- I'm just not sure what forum would be appropriate for it.

I've been posting on NSF since 2008; there must be a hundred threads here that get into the nitty gritty of lunar geology. Anyways, you can't discuss lunar resource exploration without discussing how those resources get formed. And you can't discuss how lunar resources get formed unless you discuss how the Moon itself was formed. Otherwise it would be like a petroleum or mining geologist on Earth who didn't believe in plate tectonics. I have heard of such characters, but they are rare birds.

Quote from: Doug
Good luck with your presentation ... I'd love to see your presentation materials at some point.  Maybe after you've given your presentation, you can post something about it here?

I'm planning on it, assuming I can raise the funds (https://www.gofundme.com/23y6y8k) to get there!  ;D
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: savuporo on 05/22/2016 05:11 am
Given a common origin, composition, and concentration of H2O on both the Earth and the Moon...

This isnt established, by far. One recent example:
http://www.nature.com/ngeo/journal/v7/n6/full/ngeo2173.html

Quote
The conventional wisdom that the Moon is virtually anhydrous has been overturned. Even with the uncertainties in interpreting the H2O contents of apatite, it is unambiguously clear that the mantle source regions for the volcanic glasses contain as much water as the terrestrial mantle sources for MORBs. However, the striking similarity in the water contents of MORBs and lunar volcanic glasses should not lead one to conclude that the Moon has Earth-like water abundances. The MORB mantle represents the driest region of the terrestrial mantle. The terrestrial oceans alone represent about 230 ppmw of the bulk Earth's water, more than double what has been estimated for the volcanic glass source regions1. In addition, the KREEP-related rock source regions seem to contain considerably less water than the mantle sources for the volcanic glasses, possibly only a few ppmw. Even if the Moon did have a bulk water content like those of the volcanic glass source regions, it would not raise questions about the validity of the giant impact model for the Moon's origin, as some have proposed.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: the_other_Doug on 05/22/2016 03:38 pm
Given a common origin, composition, and concentration of H2O on both the Earth and the Moon...

This isnt established, by far. One recent example:
http://www.nature.com/ngeo/journal/v7/n6/full/ngeo2173.html

Quote
The conventional wisdom that the Moon is virtually anhydrous has been overturned. Even with the uncertainties in interpreting the H2O contents of apatite, it is unambiguously clear that the mantle source regions for the volcanic glasses contain as much water as the terrestrial mantle sources for MORBs. However, the striking similarity in the water contents of MORBs and lunar volcanic glasses should not lead one to conclude that the Moon has Earth-like water abundances. The MORB mantle represents the driest region of the terrestrial mantle. The terrestrial oceans alone represent about 230 ppmw of the bulk Earth's water, more than double what has been estimated for the volcanic glass source regions1. In addition, the KREEP-related rock source regions seem to contain considerably less water than the mantle sources for the volcanic glasses, possibly only a few ppmw. Even if the Moon did have a bulk water content like those of the volcanic glass source regions, it would not raise questions about the validity of the giant impact model for the Moon's origin, as some have proposed.

Thanks!  I had become aware of new work on the fire-fountain glasses a while back; for some reason, I seem to recall reading about a variety of new work on the glasses longer ago than the Nature article states, in fact.  ISTR becoming aware of it more like 10 to 15 years ago, while the linked article seems to indicate I couldn't have heard about it until far more recently.  I particularly recall the comments that the apatite found in lunar samples has a similar hydration level to the MORBs, and that this is indicative of heterogeneous distribution of what Warren calls juvenile water in the early accretion of the Moon.

Heck, there was a lot of discussion even back in the 1970s and 1980s that a number of different volatiles, including water, were of necessity involved in the fire fountains.  That was the first point at which I became aware that volatiles had, by definition, been incorporated into the lunar lava melts -- else, what had powered the fire fountains?

So, as I say, I know I had been aware that volatiles had been detected in some of the fire fountain glasses, and I was aware of the apatite that had been found in the samples.  I was not aware that there had been any new papers that supported speculations on relatively large underground deposits of water ice located close enough to the surface, in non-polar locations, for utilization.

My understanding was that there was a certain amount of hydrated minerals from water included in the mare melts, and that all of the melts have since basically frozen out and expressed themselves in all of the lava flows and fire fountains, etc., that occurred between four and one billion years ago.  Basically, that the Moon had already vented most all of its "free" volatiles, leaving only some hydrated minerals -- not actual water ice deposits.  In other words, that in terms of accessible water resources, the polar deposits were pretty much it.  Leaving the majority of Moon "bone-dry" for practical purposes.

I'll be doing some more literature searches in the next few weeks to see if there is anything that changes the landscape since the linked Nature articles published two years ago.  But, I gotta say, I was certain I had read about all of this longer ago -- the moral of the story is that life becomes an adventure when your memory filing system starts to lose its date headers...  ???
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Bob Shaw on 05/22/2016 03:56 pm
I wonder if Lunar surface 'swirls' are in any way associated with volatiles? So far as I can see, there are several competing theories for their origin, none of which cover all the bases.

If swirls are dependent on a dwindling source of volatiles (as well as the other mechanisms) then they might be more readily explained - in particular, the business of some swirls being associated with magnetic anomalies and some not. Might we posit a magnetic field associated with charged H and O2 from water, interacting with the Solar Wind and the Earth's magnetotail? And, as volatiles are depleted, such a field might depart.

Just a thought, but potentially useful for some target sites...

https://en.wikipedia.org/wiki/Lunar_swirls
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 05/22/2016 07:51 pm
Given a common origin, composition, and concentration of H2O on both the Earth and the Moon...

This isnt established, by far. One recent example:
http://www.nature.com/ngeo/journal/v7/n6/full/ngeo2173.html

Quote
The conventional wisdom that the Moon is virtually anhydrous has been overturned. Even with the uncertainties in interpreting the H2O contents of apatite, it is unambiguously clear that the mantle source regions for the volcanic glasses contain as much water as the terrestrial mantle sources for MORBs. However, the striking similarity in the water contents of MORBs and lunar volcanic glasses should not lead one to conclude that the Moon has Earth-like water abundances. The MORB mantle represents the driest region of the terrestrial mantle. The terrestrial oceans alone represent about 230 ppmw of the bulk Earth's water, more than double what has been estimated for the volcanic glass source regions1. In addition, the KREEP-related rock source regions seem to contain considerably less water than the mantle sources for the volcanic glasses, possibly only a few ppmw. Even if the Moon did have a bulk water content like those of the volcanic glass source regions, it would not raise questions about the validity of the giant impact model for the Moon's origin, as some have proposed.

This reinforces what I've been saying. I don't deny a giant impact, as it's pretty much consistent with any conceivable suite of empirical evidence. The idea that a bunch of volatiles would be lost during such an impact was always an assumption rather an empirical fact. Alternatively, volatiles could have been lost during the giant impact, but must have then been restored through more impacts right after the Moon's formation.

As for heterogeneous distributions, that's also what I'm saying: you can't just drill anywhere and expect to hit water. The lunar glasses examined so far show water concentrations on the order of MORBs, that is around 0.2% (2,000 ppm). These may be the driest oceanic basalts; basalts associated with mantle plume hot spots tend to be significantly wetter. There is no evidence I'm aware of that the lunar samples so far examined have came from hotspot locations. Lunar hotspot plumes could have water contents on the order of 1% or more. These are the areas we should be looking at for exploration purposes IMO.

Thus it is probably not a coincidence that the canonical surface feature thought to be formed by an outgassing event(s) is the Ina D-caldera that happens to be perched atop a low shield volcano at the intersection of two major rille systems. Probably the water "source rocks" underlying Ina are much wetter than even the wettest glass samples measured so far. Since the Earth and Moon mantle are so similar, we are warranted in assuming a ~1% primordial water concentration for the rock underlying the Ina D-caldera.

I agree that a giant impact probably formed the Moon (although the fission hypothesis is still alive IMO), and that the water distribution is highly heterogeneous within the lunar interior.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: redliox on 05/22/2016 08:43 pm
Short answer: lunar water is only going to affect lunar architectures.  If NASA decides to go to Mars, the simplest way to get there is a straight line that bypasses Luna.  It'll be useful for lunar colonies and ascending from Luna, but not much beyond Cislunar space; it's more fuel conservative otherwise to avoid the lunar gravity well for missions beyond Earth.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 05/22/2016 09:52 pm
One big difference between the Earth and the Moon is that water in the Earth's mantle is recycled: subduction zones send water back down into the mantle that compensates for the water lost at mid-oceanic ridges and other volcanos. On the Moon, once water makes it to the surface, it is basically lost to the interior forever. (OTOH, since there is more mantle circulation on the Earth, water is lost at a faster rate, so it's somewhat a wash.)

But might there be other mechanisms that could move water into lunar crust beyond its primordial concentration? I propose a mechanism that I call impact pumping that is analogous to the action of seismic pumping on Earth (Sibson et al. 1975) (http://jgs.geoscienceworld.org/content/131/6/653).

The way seismic pumping works is that at a zone undergoing a lot of shear strain (as in a transform fault), the rock will want to stretch in the direction of least  compressive forces, causing fractures to propagate in the orthogonal direction. The fractures allow the rock to stretch without requiring plastic deformation. These fractures will then fill with fluids. Then, when the earthquake finally happens, the tensional strain is released, thus overpressuring the fluid-filled pore fractures. The fluid will then cause hydrofracturing in the direction of least compressive forces--straight up in this case. The main flow will go up the main fault line if it can, allowing large amounts of fluids to be moved large distances in short times.

Impact pumping would be rather similar. The Moon's mantle is technically a solid in that shear waves can propagate through it; thus it can be fractured. The depth of the fracture zone beneath an impact is very roughly equal to the crater's diameter. Since the permanently fracked zone extends down to about 80 km according to the GRAIL results, then impact craters wider than 80 km must have caused fractures below the permanently fracked zone. The resultant pore spaces could be expected to fill with fluids composed of volatiles dissolved in the rock. But since the rock will readily deform plastically, such fractures will be short lived: as the pores exceed lithostatic pressure, the relatively weak rock will readily give way, allowing the fluid to be squeezed upward into the lower permanently fracked zone. The pores will close up and heal as soon as the fluids are squeezed out.  In this manner, local zones could be radically enhanced in water above and beyond what's contained in their primordial bulk water content.

Empirical evidence, I think, may be found in the rather similar rimless hollows of Mercury. While they share an overall morphological similarity to the lunar hollows, there are some differences. Number one being that there are like 10 times as many of them on Mercury (400+) as there are on the Moon (40+). However, the vast majority (but not all) of the Mercury hollows are found within impact craters. It could be a similar impact pumping mechanism squeezed volatiles on Mercury upward, thus excavating the rimless pits.

However, even with impact pumping, it is hard to conceive a phreatic zone on the Moon that could extend all the way to near surface depths, because the lunar crust is so fracked, with an porosity of ~12%. As an example, consider a single cubic meter of primordial lunar rock. Assuming a 10% porosity, then are 100 L of pore space within the rock. If the rock has a density of 2800 kg/m3 and 1% water by weight, then if all water is taken out of the rock, then 25 L of water will be produced, thus filling up only 25% of the pore space.

Thus, if the fracked zone extends down to 80 km, then even if zero water was lost to space, the phreatic zone would only fill up the lower 20 km of the fracked zone. Impact pumping could increase this somewhat, and locally, intruding mantle plumes could bring in more, but still most of the fracked zone will not be filled with water. Furthermore, the vacuum of space will extend down into the fracked zone that is not filled with fluid, barring impermeable layers. If the entire fracked zone were connected by a system of cracks that led all the way to the surface, the entire fracked zone would be sucked dry, probably on the order of 107 years (cf. Stern 1999) (http://onlinelibrary.wiley.com/doi/10.1029/1999RG900005/abstract). This is all consistent with the fact that Apollo didn't find signs of hydrothermal veins, as well as the "quality factor" discussed in box 1 of the Robinson & Taylor paper that Savuporo linked to above, whereby seismic waves propagate more readily through rocks whose pore spaces are filled with vacuum.

On the other hand, the tiny channels that connect pore spaces in rocks tend to get clogged by minerals, and high pressures and temperatures cause cracks to heal, and there could be local places where intrusive sills form impermeable caps that trap water in the deepest layers of the fracked zone. So there very well could be hydrothermal deposits, it's just that they form very deep in the Moon, and the Moon lacks the uplift processes on Earth that lift up entire mountain chains only to have the tops eroded away, exposing deeply formed hydrothermal deposits. The place to look for these on the Moon would be in superdeep, giant craters floors where most or all of the crust has been excavated. But that's another story.

Then there are the rimless hollows themselves. The evidence is that they formed very recently in geological terms, so some volatiles must still be trapped in deeper layers. The hard part is coming up with a model that can allow such volatiles to migrate to near surface depths in large enough quantities to be involved in such violent excavations....
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Phil Stooke on 05/22/2016 10:08 pm
"The conventional wisdom that the Moon is virtually anhydrous has been overturned."

I would prefer to say it has been slightly adjusted.  A little bit of water, not a lot.

"the canonical surface feature thought to be formed by an outgassing event(s) is the Ina D-caldera that happens to be perched atop a low shield volcano at the intersection of two major rille systems."

It might be on a shield volcano, but that's only one interpretation of the topography.  It's not a caldera.  It certainly is not at the intersection of two major rille systems.  Also we now have lots of Ina-like objects, some which actually are associated with volcanic domes (near Cauchy) and an ancient caldera rim (west of Tobias Mayer) - so other Ina-like features make that case better than Ina does.  Lastly, the volatiles associated with Ina and its pals - if any - might be radiogenic argon rather than water. 

For more on Ina-like features, see:

Braden, S.E., Stopar, J.D., Robinson, M.S., Lawrence, S.J., Van Der Bogert, C.H. and Hiesinger, H., 2014. Evidence for basaltic volcanism on the Moon within the past 100 million years. Nature Geoscience, 7(11), pp.787-791.



Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 05/22/2016 10:11 pm
Short answer: lunar water is only going to affect lunar architectures.  If NASA decides to go to Mars, the simplest way to get there is a straight line that bypasses Luna.  It'll be useful for lunar colonies and ascending from Luna, but not much beyond Cislunar space; it's more fuel conservative otherwise to avoid the lunar gravity well for missions beyond Earth.

It depends on how much and on how cheaply rocket fuel could be delivered to L2 Lagrange point. The L2 point is an ideal place to top off fuel tanks for a journey to Mars. No one is proposing to launch a Mars mission from the surface of the Moon. Check out this MTV:

(http://i.imgur.com/KuMTJjw.png)

This is from one of the older ULA papers. It would take 847 tonnes of rocket propellant. It could carry 16 people with a single stage delta v of like 11 km/s. This could cut the transit time by half over a Hohmann transfer, all fully propulsively--no need for a fancy aerocapture system. Alternatively, it could do a round-trip on a single fill-up using Hohmann transfers if there was no refueling capability at Mars. Liquid hydrogen is the best radiation shielding we know of. What's not to love about it?

Well, number one I guess, is that it's inconceivable that that much propellant could be moved from Earth's surface to the L2 point. It'd take over 50 Falcon Heavy launches to get that much propellant up there. But it wouldn't be that big of a deal for a small fleet of single-stage, lunar tanker-landers to get that much propellant up there.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: savuporo on 05/22/2016 10:54 pm
As for heterogeneous distributions, that's also what I'm saying: you can't just drill anywhere and expect to hit water. The lunar glasses examined so far show water concentrations on the order of MORBs, that is around 0.2% (2,000 ppm). These may be the driest oceanic basalts; basalts associated with mantle plume hot spots tend to be significantly wetter. There is no evidence I'm aware of that the lunar samples so far examined have came from hotspot locations. Lunar hotspot plumes could have water contents on the order of 1% or more. These are the areas we should be looking at for exploration purposes IMO.
Meanwhile, PSRs are theorized to contain 1-10% wt water in surface layer regolith - in areas that are identifiable from a combination of orbital observations. In a region where constantly solar powered operations could be possible, because of permanently sunlit peaks - and the feasibility of utilizing any of the lunar resources depends primarily on the available energy source required for processing, anyway.

Although certainly valuable and interesting, I don't see why should this shift the primary focus away from polar volatile research  (http://lunarvolatiles.nasa.gov/past-workshops/).
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Lar on 05/22/2016 11:09 pm
This possibility that water can be found 20-80 km down with luck is fascinating, but I'm with savopuro... if we are trying to decide how to bootstrap up, using polar volatiles first seems like it would be less effort than drilling a long ways into the crust, especially if poor understanding will lead to dry holes. That sounds like it would be hard to do in early days.

So why not exploit polar ice first? Use the water to in part power industrialization and exploration of the moon.  Over time the moon will be well enough mapped and understood and there will be enough facilities and materiel present that doing drilling will be less risk, since if it is a dry hole, we haven't lost nearly as much time and effort (and used up as much landed mass) proportionately....
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: savuporo on 05/22/2016 11:26 pm
BTW, European Lunar Symposium just concluded couple days ago.

Plenty of interesting talks and papers:
http://els2016.arc.nasa.gov/downloads/ELS_2016_Program_1.9.pdf
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: the_other_Doug on 05/22/2016 11:39 pm
Short answer: lunar water is only going to affect lunar architectures.  If NASA decides to go to Mars, the simplest way to get there is a straight line that bypasses Luna.  It'll be useful for lunar colonies and ascending from Luna, but not much beyond Cislunar space; it's more fuel conservative otherwise to avoid the lunar gravity well for missions beyond Earth.

It depends on how much and on how cheaply rocket fuel could be delivered to L2 Lagrange point. The L2 point is an ideal place to top off fuel tanks for a journey to Mars. No one is proposing to launch a Mars mission from the surface of the Moon...

Yeah -- the current NASA DRA (Design Reference Architecture) for landing humans on Mars involves setting up a cislunar infrastructure and basically putting the stack for Mars transit together at EML-1 or EML-2.

It doesn't specifically call for refueling options from lunar resources, but a lot of the side-talk around this relatively recent update to the DRA includes talk (and some studies) around "encouraging" third parties to develop lunar resource fuel generation (basically, processing lunar water into LH2 and LOX) and providing these fuels to the cislunar infrastructure.

I think it might be interesting, and would definitely be possible, to see, for example, Orbital/ATK or SpaceX bid on a contract to provide lunar-resource fuels, and the next humans on the Moon could be industrial workers, not explorers or scientists, there simply to set up a refining plant.  If it turns out that such a plant can more easily be located at Ina-D rather than Shackleton, well, more power to y'all... :)
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: savuporo on 05/22/2016 11:56 pm
It doesn't specifically call for refueling options from lunar resources, but a lot of the side-talk around this relatively recent update to the DRA includes talk (and some studies) around "encouraging" third parties to develop lunar resource fuel generation (basically, processing lunar water into LH2 and LOX) and providing these fuels to the cislunar infrastructure.

There is a huge, enormous gap going from talking about 100-2000 ppm molecule concentrations in possible minerals to a refueling rockets from industrial scale refineries.

Notice how there is no design reference architecture for any kind of ISRU operation anywhere, apart from 1% scale model MOXIE that might fly four or six years from now.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 05/23/2016 12:13 am
"The conventional wisdom that the Moon is virtually anhydrous has been overturned."

1. I would prefer to say it has been slightly adjusted.  A little bit of water, not a lot.

"the canonical surface feature thought to be formed by an outgassing event(s) is the Ina D-caldera that happens to be perched atop a low shield volcano at the intersection of two major rille systems."

2. It might be on a shield volcano, but that's only one interpretation of the topography. 

3. It's not a caldera. 

4. It certainly is not at the intersection of two major rille systems. 

5. Also we now have lots of Ina-like objects, some which actually are associated with volcanic domes (near Cauchy) and an ancient caldera rim (west of Tobias Mayer) - so other Ina-like features make that case better than Ina does. 

6. Lastly, the volatiles associated with Ina and its pals - if any - might be radiogenic argon rather than water. 

7. For more on Ina-like features, see:

Braden, S.E., Stopar, J.D., Robinson, M.S., Lawrence, S.J., Van Der Bogert, C.H. and Hiesinger, H., 2014. Evidence for basaltic volcanism on the Moon within the past 100 million years. Nature Geoscience, 7(11), pp.787-791.

Phil! Great to hear from you! Thank you for taking the time to post here! :D

Taking your points in order:

1. It's all relative. 6 billion tonnes of water could launch a space shuttle every day for 200,000 years. We're not looking for Waterworld--we just want to launch some spacecraft.

2. Serpentinization of olivine can also form a dome... But whatever it is, it's gotta be something special because we don't see these things everywhere.

3. I agree it's not a true caldera. That's just the name that's been handed to us by history. Sort of like the Sea of Tranquility is not a true sea. (Also, compare google searches of "Ina" vs. "D-caldera" ;) )

4. I was basing that statement on Schultz et al.'s (2006) (http://www.nature.com/nature/journal/v444/n7116/full/nature05303.html) paper. I'll quote the relevant paragraph in full:

Quote from: Schultz et al.
Ina is just one of at least four similar endogenic features, most related to a system of west-northwest–east-southeast (WNW–ESE)-trending rilles around the Imbrium impact basin. Ina is at the intersection of northeast–southwest-trending structural elements (radial to Imbrium) and subtle WNW–ESE-trending regional structural elements crossing the Imbrium ejecta. The Hyginus depression is similarly situated at the intersection of the two rilles (Rima Hyginus): a northwest–southeast graben extending to the northwest, and an eastnortheast–west-southwest (ENE–WSW) graben to the southwest, which parallels an adjacent en echelon system of rilles (Rima Ariadaeus). Another small irregular depression in Mare Tranquilitatis near the crater Arago also occurs along an extension of the ENE–WSW (Rima Ariadaeus) system where it intersects a different set of rilles. These occurrences in similar structural settings indicate that volatiles (for example, juvenileCO2 and evenH2O) trapped deep within the Moon episodically escape along crustal weaknesses, thereby continually freshening the regolith.

You know more about the lunar geography than I do, Phil, so I'll happily defer to your statement. So it's at the intersection of two "structural elements" that are not true rilles. Still, Schultz's (and my) larger point is that these objects seem to be associated with "crustal weaknesses" that provide an avenue for volatile movements to near surface depths.

5. OK, the paper you linked to has 70 such features listed in the supplementary information section (uploaded below). A a while back you gave a list of 41 such features (also attached below if that's OK with you). It seems that while there is some overlap, there are ones you have listed that Braden et al. do not have. Is that right? Also, I would like to plot all of these features on a map of the Moon, but the only thing I've got is Google Moon, and it's pretty low res. Is there some other relatively accesible lunar GIS system that you would recommend to use instead?

6. As for argon, that's really hard to believe. I know Arlin Crotts wrote a bit about that, but Ar forms super-gradually. It's hard to see how the pressure could build up enough to cause a maar-like explosion. Alternatively, I guess pressure could build up in pore spaces at deep levels to close to lithostatic pressures. Once it was released, I guess you could get a prolonged jet that could blow off the regolith. However, even if it is argon, rather than H2O that is responsible for their formation, that would still be a valuable resource perhaps, since Ar would make a good fuel for ion-propulsion engines.

7. Thanks for the link. I have a few issues with the paper. (1) They say the smooth deposits "superpose" the rough ones, and while they are certainly higher elevation, just by looking at the color photos, the rough terrain is younger (at least defined in terms of exposure to space) than the smooth deposits. (2) they think the smooth deposits are lava flows, but if that were the case, the (a) they'd be fresher than the rough terrain, (b) there should be cracks and vents visible, (c) the edges of the lobes are too steep to have formed from a flowing liquid. (3) They cite the Schultz paper (2006) that argues for the outgassing theory, but do not criticize it or otherwise discuss outgassing.

When I look at profiles of the smooth lobes, what they remind me of are picnic tables that have received a fresh snowfall. The picture I see is of jets blowing regolith up, and regolith falling back into areas of the pit where the jets are not going. I see an initial explosion, followed by gas jets, or geyser-like episodic gas releases that could form the smooth lobes. Thus the rough terrain (where the jets emit from) would have a very fresh appearance, but the smooth lobes would have an intermediate aged appearance because it would be a mixture of regolith, some of which had been exposed to space weathering for a long time, other parts not so much.

Then there's the issue of nomenclature again. I agree they shouldn't be called "calderas". You, Phil, coined the term "meniscus hollows" because the smooth lobes look sort of like mercury menisci. I called them "rimless pits" above in a post to show a purported link to the rimless pits of Mercury that they at least superficially resemble. I kind of want to call them  "lunar maars" because I think that's the best Earth analog that they resemble. So what do you recommend Phil?

For more on Ina-like features, see:

Braden, S.E., Stopar, J.D., Robinson, M.S., Lawrence, S.J., Van Der Bogert, C.H. and Hiesinger, H., 2014. Evidence for basaltic volcanism on the Moon within the past 100 million years. Nature Geoscience, 7(11), pp.787-791.
[/quote]
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: nadreck on 05/23/2016 01:04 am


1. It's all relative. 6 billion tonnes of water could launch a space shuttle every day for 200,000 years. We're not looking for Waterworld--we just want to launch some spacecraft.



NO the arithmetic critic in my brain just hates the sound of fingernails on chalkboard:

Rough count:  6,000,000,000t water = 750,000,000t H2 / 106t = ~7,000,000 launches or ~20,000 years at one a day


Polar volatiles are the way to go for early bootstrapping - note that on Earth drilling to a practical limit for exploitive purposes (oil/natural gas) is 10,000 meters and that requires the most massive 3 stand drill rigs, thousands of tons of steel drill pipe and 6 months of elapsed time with a motor rated at thousands of horsepower (meaning you need more than a mega watt of solar power on the moon. And all that for a single test hole maybe 40cm in diameter.

As for the economics of shipping propellant made from lunar volatiles to LEO, if you assume two different designs of tanker craft: LEO to EM-L2 (which if designed to use Aerobraking might need only 300m/s of ΔV at full load and 3.5km/s to return the craft) and Lunar surface to EM-L2 (Full ΔV 2.5km/s, and maybe 2.6km/s to return). Then every kilo of propellant transferred to LEO might represent as little as 3kg of propellant  launched from the surface and about 4.5kg of water processed into propellant.


EDIT oops mixed units in the last sentence, they should all be the same mass units so the ratio of mass of water extracted to propellant mass destined for LEO is 4.5 to 1 and the ratio for propellant launched from the moon to arrived at LEO leaving enough for the craft to return is 3 to 1
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 05/23/2016 05:03 am
Delta-v is not economics.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: nadreck on 05/23/2016 05:12 am
Delta-v is not economics.

No but it is one of the inputs, I am pointing out that delivering the propellant to LEO only costs 2.8km/s of propulsive ΔV.  Now since the transports to EM-L2 from the lunar surface and LEO from EM-L2 need to return, it costs more than just the mass ratio implied by 2.8km/s, but definitely a lot less than the mass ratio needed for the full 11km/s round trip ΔV from lunar surface to LEO and back. So as I pointed out the economics are dictated by the ratio of water produced and propellant refined on the lunar surface to the amount supplied in LEO.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 05/23/2016 06:26 am
You need a reusable rocket to do lunar propellant at any kind of sensible value. You will likely have to have this on Earth as well. What's easier, a rocket base on the Moon or on Earth?
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 05/23/2016 06:33 am
We have very few data points for cost of a lunar rocket. The Apollo lunar lander was incredibly expensive, perhaps about as much as a Saturn V, even though the Saturn V had FAR more payload and delta-v. I don't think delta-v is a very good metric for cost. If you held everything else equal, sure, higher delta-v means less payload and higher cost, but everything is MOST CERTAINLY NOT equal!

Heck, on the Earth, the oxidizer is (chemically) free in the air and the fuel is (chemically) free in the ground.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Steven Pietrobon on 05/23/2016 08:06 am
We have very few data points for cost of a lunar rocket. The Apollo lunar lander was incredibly expensive, perhaps about as much as a Saturn V, even though the Saturn V had FAR more payload and delta-v.

In 2010 dollars, total Saturn V (including engines) cost was $42.3B. The total LM cost was $14.4B, about 34% of the cost of the Saturn V.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 05/23/2016 12:18 pm
We have very few data points for cost of a lunar rocket. The Apollo lunar lander was incredibly expensive, perhaps about as much as a Saturn V, even though the Saturn V had FAR more payload and delta-v.

In 2010 dollars, total Saturn V (including engines) cost was $42.3B. The total LM cost was $14.4B, about 34% of the cost of the Saturn V.

A better data point would be the DC-X. Other than the fact that it landed vertically, it's not unlike what an ACES-style tanker-lander would be like: merely tanks and a few RL-10 rocket engines with no other payload. It was also reusable. From beginning to end, the program lasted 21 months, and cost around $100M in today's $$$.

Meanwhile, PSRs are theorized to contain 1-10% wt water in surface layer regolith - in areas that are identifiable from a combination of orbital observations. In a region where constantly solar powered operations could be possible, because of permanently sunlit peaks - and the feasibility of utilizing any of the lunar resources depends primarily on the available energy source required for processing, anyway.

Although certainly valuable and interesting, I don't see why should this shift the primary focus away from polar volatile research  (http://lunarvolatiles.nasa.gov/past-workshops/).

This possibility that water can be found 20-80 km down with luck is fascinating, but I'm with savopuro... if we are trying to decide how to bootstrap up, using polar volatiles first seems like it would be less effort than drilling a long ways into the crust, especially if poor understanding will lead to dry holes. That sounds like it would be hard to do in early days.

So why not exploit polar ice first? Use the water to in part power industrialization and exploration of the moon.  Over time the moon will be well enough mapped and understood and there will be enough facilities and materiel present that doing drilling will be less risk, since if it is a dry hole, we haven't lost nearly as much time and effort (and used up as much landed mass) proportionately....

The idea that these meniscus hollows (MHs), rimless pits (RPs), irregular mare patches (IMPs), pseudo-calderas (PCs), lunar maars (LMs), whatever-you-want-to-call-them (although I have to admit that Braden's "irregular mare patches" makes for the best acronym) could be likely places to prospect for economically recoverable volatiles is not original to me (e.g., cf. the Shultz et al. 2006 paper linked to in my previous post). I'm not saying we must forget about the poles, but that we shouldn't forget about these structures either. Also, I'm not proposing that we drill 20-80 km down. Somehow--if the outgassing hypothesis is correct--volatiles were delivered right to the surface, so a very shallow well, say 10 to 100 m, might be able to yield usable quantities of volatiles.

I try to think about it from the perspective of a petroleum geologist. To make a classic oil or gas reservoir, you need  three things: (1) a source rock; (2) a reservoir rock; (3) a cap rock.

Our source rock is the purported phreatic zone located at the bottom of the fracked zone. IMO, the fact that these structures are concentrated in the lunar maria region not because the maria basalts are somehow enriched in water, but because they provide impermeable stratigraphic traps that have prevented dewatering of ancient, juvenile water deposits. Note that Wieczorek et al.'s (2012) (http://science.sciencemag.org/content/early/2012/12/04/science.1231530) estimates of crustal porosity did not analyze the maria regions. I am not aware of any other GRAIL analysis of the maria, but I am guessing the porosity is lower than the surrounding highlands.

The reservoir rock is the megaregolith immediately underlying the main regolith blanket. This layer should be both highly porous and permeable. In addition, these structures seem to correlate with signs of local crustal weakness; such areas could provide faults that would allow movement of volatiles from deeper traps to surface traps.

Then there is the cap rock. I'm saying that the reason these structures tend to correlate with domes at least in some places is that the regolith itself provides the cap rock. How can unconsolidated regolith form an impermeable cap rock you ask? Whilst gas molecules can diffuse through the regolith, the diffusion is a slow process. As long as the pressure is low, H2O molecules can pass through in a vapor state; but if the pressure becomes too high, the H2O will start to freeze, forming a permafrost layer. Such a layer would have two main effects: (1) it would reduce permeability to about zero; (2) it would increase the tensile strength of the regolith allowing pressure buildups greater than the regolith overburden pressure (which is on the order of 1/2 an atmosphere). But if H2O is involved, and the pressure is at 1/2 atm, and the temperature is at 1 C, then the H2O will tend to condense into a liquid form. Since the basalt flows that form the maria cause a sort of horizontal stratigraphy, there could be layers that would collect such free water and keep it from sinking back down. 

@Nadrek: thanks for pointing my arithmetic error!  :D

Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 05/23/2016 03:53 pm
We have very few data points for cost of a lunar rocket. The Apollo lunar lander was incredibly expensive, perhaps about as much as a Saturn V, even though the Saturn V had FAR more payload and delta-v.

In 2010 dollars, total Saturn V (including engines) cost was $42.3B. The total LM cost was $14.4B, about 34% of the cost of the Saturn V.
Or $50m (then-costs) for the lander and $110m for the rocket. Same order of magnitude. My point still stands.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Lar on 05/23/2016 04:20 pm
You need a reusable rocket to do lunar propellant at any kind of sensible value. You will likely have to have this on Earth as well. What's easier, a rocket base on the Moon or on Earth?
When? Today? Or when you have a large population of loonies and robust lunar manufacturing base?

I think the history of the colonization/settlement [1] of the North American continent is instructive. Time and again, organizations did things that would have longer term payoffs, and in some cases, lost a lot of money while waiting. It may not make pure economic sense for lunar propellant on day 1, but it will eventually. The companies that do it initially may not survive, though (where is the Astor Fur Company? The Hudson's Bay Company?  the Rock Island? the Milwaukee Road? Or even the Central Pacific?). Some will survive, some merge with others, some will morph (Hudson's Bay Company, once the largest landowner in NA, and a defacto government in many areas, is a department store chain now) and some will disappear.

The idea that these meniscus hollows (MHs), rimless pits (RPs), irregular mare patches (IMPs), pseudo-calderas (PCs), lunar maars (LMs), whatever-you-want-to-call-them (although I have to admit that Braden's "irregular mare patches" makes for the best acronym) could be likely places to prospect for economically recoverable volatiles is not original to me (e.g., cf. the Shultz et al. 2006 paper linked to in my previous post). I'm not saying we must forget about the poles, but that we shouldn't forget about these structures either. Also, I'm not proposing that we drill 20-80 km down. Somehow--if the outgassing hypothesis is correct--volatiles were delivered right to the surface, so a very shallow well, say 10 to 100 m, might be able to yield usable quantities of volatiles.

Thanks for clarifying. I'm going to draw another analogy from settling the West... the Michigan Copper Rush[2].  The surface metallic copper was scooped up first because it was easy, but the ores in the region ultimately yielded fare more copper.  People made a lot of money from nugget copper before it panned out, and that money helped build infrastructure... that infrastructure made subsurface mining possible.

My argument is, go where the water is easy to get and known for sure to be there first. Once some infrastructure has grown and money is being made and the surface water is getting played out? Drill baby drill...

1 - by westerners... the indigenous people were already there
2 - c/Michigan/California/* * and c/Copper/Gold/* * as well and the same point holds.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: savuporo on 05/23/2016 04:38 pm
A better data point would be the DC-X. Other than the fact that it landed vertically, it's not unlike what an ACES-style tanker-lander would be like: merely tanks and a few RL-10 rocket engines with no other payload...
And yet again, technology testbeds, launch vehicles and spacecraft are all very different things.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Kansan52 on 05/23/2016 04:58 pm
Well, for a lay person, all this makes my head hurt but is very interesting.

Inferring from the discussion, would mining lunar ice makes thing better for BLEO? Some of the items not in the discussion, robotic equipment, strip mining for water, and mag lev launch rails.

NASA spent some Constellation money with Caterpillar for Lunar robotic equipment. So that is some of the work already done for this type of effort.

There were some papers based on resource recovery with strip mining, including H2O (if memory serves). The Caterpillars would help that type of operation.

The e-launch (mag lev launch rails) could launch containers of ice. The containers could be formed from the mined lunar materials. A recovery vehicle could rendezvous with the container for final precise delivery.

This is a very limited outline. It leaves out the most important item, a Big A$$ Budget. But a robotic operation could reduce costs by limiting or eliminating the highest cost item, people to run this.

I even saw a notion that results of the strip mining would produce gold. Since most people do not hold gold, what they own is in a depository, selling gold shares and water may make it profitable.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 05/23/2016 06:26 pm
A better data point would be the DC-X. Other than the fact that it landed vertically, it's not unlike what an ACES-style tanker-lander would be like: merely tanks and a few RL-10 rocket engines with no other payload...
And yet again, technology testbeds, launch vehicles and spacecraft are all very different things.

Good point, but most of the technology required for a true spacecraft tanker-lander has already been developed by ULA. They're at the point where they're saying they don't even need to do a technology demonstration in space for their reusable, refueable Centaur/ACES. They know it will work. All that would be required for surface operations is the landing kit. Not trivial, to be sure, but not measured in 10's of billions of USD either.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: savuporo on 05/23/2016 06:40 pm
..most so the technology required for a true spacecraft tanker-lander has already been developed by ULA. They're at the point where they're saying they don't even need to do a technology demonstration in space for their reusable, refueable Centaur/ACES...
If they keep saying this for another decade with stronger conviction, as they have been for the last, I'm sure the ghost of Gerard O'Neill will grant this wish
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: the_other_Doug on 05/23/2016 07:15 pm
..most so the technology required for a true spacecraft tanker-lander has already been developed by ULA. They're at the point where they're saying they don't even need to do a technology demonstration in space for their reusable, refueable Centaur/ACES...
If they keep saying this for another decade with stronger conviction, as they have been for the last, I'm sure the ghost of Gerard O'Neill will grant this wish

And I've got to say, ULA has been saying this about ACES since they announced it.  I'm really, really wary of people peddling paper spacecraft and insisting that they will be able to build them quickly, and are absolutely convinced there doesn't need to be any kind of testing program or any check-out flights.  That's not confidence -- it's arrogance.

And you know what they say, pride always cometh before the fall...   :-\
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: gbaikie on 05/24/2016 08:59 am
The best place to mine anything on the Moon is the polar regions.
One has the peaks of eternal light. Plus by connecting solar farms in different regions
one can get continuous electrical power. So with one area of peaks of eternal light one can get
80% or more of time with sunlight. Or 50% of time elsewhere on Moon has 2 weeks of darkness.

Plus one has areas where temperature is very cold, allowing low temperatures with passive cooling.
Such cooler areas are not limited to dark craters- with level ground the sun strikes at low angle. Though
a surface near vertical can warm up as much surfaces in equatorial regions.
A main problem in a vacuum in terms of any activity using energy, is getting rid of the heat- and so generally a cooler environment is more helpful rather than making it more difficult.
The lunar surface is covered with a layer of fine dust- which acts like insulation in terms of heat transfers.
Therefore a person is spacesuit in a cold crater will not get cold. Whereas things which are not generating heat, will eventually get cold. So polar regions is not like Earth's polar regions in terms of things getting colder
[or much colder] unless something isn't generating heat and/or heat can't distributed evenly.
Or a sealed can of water is not going to cold as fast as it would in Earth's cold arctic- but if given enough time eventually it will get much colder. Or in cold regions on Earth with vehicle if you turn it off and give enough time it gets to too cold to start it again. With polar region one leave the vehicle off for longer time to reach the same degree of it being cold.
But on the Moon, one can't afford parking vehicles- you want them running constantly- because of those vehicle are very expensive.
Now on the Moon one can control your immediate environment much easier than you can on Earth. One could heat with reflected light, a 10 by 10 foot area on flat ground to 1000 C and within 1 foot beyond it have it 0 C. Our atmosphere doesn't allow one to do this on Earth. Or roughly if a cold ground is somehow a problem, one warm can up- and that not as crazy as it would be on Earth.
So you do need to design things to operate within a vacuum and deal with the dust, but a "cold vacuum" doesn't add much- if any - complexity- and as I said has aspects which one take advantage of. 

The largest basic problems with mining lunar water is: lack of needed exploration, and two lack of demand of lunar water [or more water you "have to mine" the worst the problem of lack of demand becomes].
So we want to start out with a relatively low amount of water mined. Or the advantage of picking the Moon rather than asteroids, is one could start out "needing" the least amount of water mined per year.
The other main advantage of the Moon vs Space rock, is one has domestic consumption vs solely needing to export. So with Moon one starts with domestic consumption and expand the market by export. And you have a lock on the domestic consumption. Space rock require you to move the water [or whatever] to a marketplace- or it by itself doesn't have domestic marketplace. Or other people aren't going to your rock- whereas people who not doing water mining will be going to the Moon and need your water. One party can convert your water into rocket fuel, others may just want the water for another reason, such as shipped to be sold for Mars missions. You the water miner will want to buy rocket fuel at low lunar orbit [to expand and maintain your operation], you also want electrical power or chemical power for your operations. You also may want things made of iron/steel and that could made on the Moon. Etc.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 05/24/2016 01:27 pm
Heck, on the Earth, the oxidizer is (chemically) free in the air and the fuel is (chemically) free in the ground.

The same is true of the Moon. Nobody is talking about extracting water from apatite, if that's what you're implying the plan is. Indeed, there may be free H2 available at locations such as the Ina D-pseudo caldera.

Quote from: gbaike
One has the peaks of eternal light. Plus by connecting solar farms in different regions
one can get continuous electrical power. So with one area of peaks of eternal light one can get
80% or more of time with sunlight. Or 50% of time elsewhere on Moon has 2 weeks of darkness.

The only real advantage of the polar location per se (that is, other than its proximity to permanently shaded craters) is the relatively mild and constant temperature profile. The constant solar is nice, but the problem is it's coming in at 90 degrees, so you can't just lay your panels on the ground; you need to put them on masts, and then you'll have the problem of your panels shading each other. Also, most people vastly underestimate the power requirements of an industrial fuel production plant producing fuel in truly game-changing quantities. This is a long winded way of saying you'd probably want to use space-based solar power.

Drilling for volatiles trapped at  shallow levels would require VASTLY less infrastructure. A single 20 mT lander could deliver a drilling rig capable of drilling down 100 m or more.

Quote from: Doug
And I've got to say, ULA has been saying this about ACES since they announced it.  I'm really, really wary of people peddling paper spacecraft and insisting that they will be able to build them quickly, and are absolutely convinced there doesn't need to be any kind of testing program or any check-out flights.  That's not confidence -- it's arrogance.

Arrogance aside, the idea that a tanker-lander (about the simplest lunar lander imaginable) would cost in Apollo LM ballpark figures is total hyperbole.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 05/24/2016 07:30 pm
OK, I took the two databases (Stooke 2013; Braden 2014), and consolidated them into a single spreadsheet. Where there were obvious duplications, I consolidated the data into a single line. Also, although both papers use a "wraparound" method for longitude, I looked up the "selenological coordinate system in the Wikipedia. They say it's supposed to be just like Earth, and Google Earth doesn't recognize longitudes > 180°, so I converted all west longitudes to the ordinary form (so that 350° = 10°W = -10°).

I wound up with 98 total meniscus hollows, the largest single list I know of so far (although I suspect Phil is sitting a few more! ;) ). Haven't plotted them all yet, but an obvious pattern is they are confined to maria in a latitudinal band extending from 38°N to 25°S.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: gbaikie on 05/24/2016 07:44 pm
Heck, on the Earth, the oxidizer is (chemically) free in the air and the fuel is (chemically) free in the ground.

The same is true of the Moon. Nobody is talking about extracting water from apatite, if that's what you're implying the plan is. Indeed, there may be free H2 available at locations such as the Ina D-pseudo caldera.

Quote from: gbaike
One has the peaks of eternal light. Plus by connecting solar farms in different regions
one can get continuous electrical power. So with one area of peaks of eternal light one can get
80% or more of time with sunlight. Or 50% of time elsewhere on Moon has 2 weeks of darkness.

The only real advantage of the polar location per se (that is, other than its proximity to permanently shaded craters) is the relatively mild and constant temperature profile. The constant solar is nice, but the problem is it's coming in at 90 degrees, so you can't just lay your panels on the ground; you need to put them on masts, and then you'll have the problem of your panels shading each other. Also, most people vastly underestimate the power requirements of an industrial fuel production plant producing fuel in truly game-changing quantities. This is a long winded way of saying you'd probably want to use space-based solar power.

Drilling for volatiles trapped at  shallow levels would require VASTLY less infrastructure. A single 20 mT lander could deliver a drilling rig capable of drilling down 100 m or more.

The only reason we don't already have commercial lunar water mining is because the lunar poles [or moon generally] has not been explored to find minable sites.

It possible that there is water 100 meter below the surface of the Moon- somewhere at the surface, but this seems like a more difficult thing to explore in order to find. Plus, once you find it by drilling for it, you are mining it.

My idea is to do what Congress has already passed into law- explore the Moon and then explore Mars.
What I think would allow NASA to start this, is a cheap, quick and low cost lunar exploration which determines if and where there is sites which are potentially commercially minable.

So tomorrow or anytime in future, NASA could get approval for lunar exploration mission which will have it's
total program cost of 40 billion and to be finished within 10 year of the start of program.
The program includes:
Developing orbit depots to an operational status- a depot only capable of storing and delivering LOX, is adequate.
Lunar robotic exploration program which explores Moon.
Finish lunar exploration program by landing crews in regions previously robotically explored, to do a more thorough exploration of region, and returning lunar sample to Earth for further analysis.
And then, Start Mars program.
And to start the Mars program, NASA can't spending billions per year on ISS nor doing things costing billions on the Moon.
So Lunar exploration will occur at same time as ISS program- and ISS program has to do something with ISS
by the time of the start of Mars program- and I would not suggest NASA de-orbiting ISS, but find some other way.
So if NASA explores the Moon, and finds minable areas on the Moon, then commercial lunar water mining can occur while NASA explores Mars.
If NASA can't find minable lunar water on poles or even if they do, perhaps if [cost is low enough] NASA or some other party can search for water under the surface of the Moon. Or if commercial lunar were to begin it's possible one will have commercial lunar exploration of the Moon which could find minable water below the surface. Or most exploration for mining is done commercially on Earth- and commercial lunar mining is having success, this would help towards funding of further exploration which is not required to be done by NASA.

As for making masts for solar power, we were making sailing masts centuries ago, and on the Moon there is no wind and one has 1/6th gravity. Put panel high enough and one can operate under the bottom section panels- or you don't have to have long cables to bring power to split the water. So you focus on having a vertical solar panel array, which can be hundred or more feet high.
And ultimately one wants a widely space grid network which has constant power available for the network of solar arrays. And I suppose that at bottom of mast one can increase the voltage for transmission over longer distances.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 05/24/2016 08:11 pm
Heck, on the Earth, the oxidizer is (chemically) free in the air and the fuel is (chemically) free in the ground.

The same is true of the Moon. Nobody is talking about extracting water from apatite, if that's what you're implying the plan is. Indeed, there may be free H2 available at locations such as the Ina D-pseudo caldera.

No, it's not. There are not vast quantities of easily accessible oxygen and fuel (hydrogen or methane) on the Moon. I'm talking stuff that isn't in trace quantities and stuff that doesn't require electrolysis (or similar) to acquire.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: savuporo on 05/24/2016 08:48 pm
There are not vast quantities of easily accessible oxygen and fuel (hydrogen or methane) on the Moon...
Did I miss something? There is new data or interpretation of existing data that would have conclusively disproven the more extreme hypothesis of exposed water ice in PSRs?
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: savuporo on 05/24/2016 09:47 pm
And what is extreme about water ice being stable at 30 K?!?
Its extreme in the context of full range of current hypotheses to explain the existing data about composition of surface materials in PSRs. Ice rinks at the crater floors continue to be possible, but unlikely. The reality will likely be something more modest.

EDIT: the point of my post was, that we currently cant tell what exactly is there with high certainty, and we definitely cannot tell how easily accessible or usable any of the materials are. Further data needed.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: gbaikie on 05/25/2016 03:11 am

Suppose one picks what is regarded as best site out of 98. How many holes will you drill and how deep do you drill before deciding that water isn't available at the site one thought was the best one.
And many of the 98 do need to check, before deciding there isn't any minable water be found by using whatever methodology you thought was best.

Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 05/25/2016 11:19 am
Quote from: Warren
What is extreme about stable water ice at 30 K?

The point of my post was, that we currently can't tell what exactly is there with high certainty, and we definitely cannot tell how easily accessible or usable any of the materials are. Further data needed.

Yes of course. We've been through that all that before. But for the sake of the argument, let's assume that the polar craters really are 2 meter thick ice rinks. I think we'd both agree that would be about the most "easily accessible" frozen resource we could hope for. Thus, the point of this thread is that even if that were the case (which I agree is unlikely), it would still be easier to drill for volatiles if they can be found at shallow depths.

Think about it this way: I have a pond in front of my house. In winter, it is easier for me to simply turn on the faucet connected to the water well than it is for me to go out and cut and melt blocks of ice every time I need some water.

We know there are these geological features we call meniscus hollows or IMPs or whatever. We don't know for sure what caused them, but we do know for sure that they were formed very recently, on the order of 1-10 million years ago, maybe even sooner. And although there is a faction of researchers who cling to the old idea that these are lava flows, the most likely theory IMO is Schultz's outgassing hypothesis. But to excavate surface deposits via outgassing or a water explosion, that logically entails that such volatiles must have got to the surface somehow.

Thus, if (1) outgassing caused Ina and its ilk; and (2) it happened very recently, then (3) there very well could be near surface locations where significant quantities of volatiles could be obtained today.

However, there is a big theoretical knowledge gap that's been preventing taking seriously the above logical argument. Although outgassing is the most popular explanation, there has been next to no theoretical work done on exactly how that could be accomplished. Really, it's a petroleum geology problem with water and other volatiles substituting for oil and natural gas; but most lunar geologists have probably never set foot on an oil rig in their lives.

Also, it is a prediction of my model that significant quantities of H2 gas would be recovered from any successful wells.

We look for potential drilling sites by looking for geological signs of outgassing. I just gave you a list of 98 locations. We conduct volatile exploration on the Moon the same way we conduct oil exploration on the Earth--IOW, we don't go around randomly punching holes the way you make it sound.

Ok, but that sounds to me to be quite expensive.

Trivial. Everything in space is "quite expensive". The google X-prize is offering $30M to land a frackin beach ball on the Moon, and it can't be done for less than the prize. It's all relative, but, just like it is less expensive to produce oil from the Ghawar supergiant oil field than it is to produce it from Alberta tar sands, it would be less expensive to produce water and volatiles on the Moon by drilling for it rather than mining it.

Quote from: gbaike
Suppose one picks what is regarded as best site out of 98. How many holes will you drill and how deep do you drill before deciding that water isn't available at the site one thought was the best one.

You do it just like they do it in the industry. You go until you either run out of money or you strike it rich....

Quote
minable water

I can see how it could be possible to find the difference between mining and drilling to be confusing. Here is a link that explains the difference: http://bfy.tw/5wJs (http://bfy.tw/5wJs)
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: savuporo on 05/25/2016 01:00 pm
But for the sake of the argument, let's assume that the polar craters really are 2 meter thick ice rinks. I think we'd both agree that would be about the most "easily accessible" frozen resource we could hope for.
Not necessarily. Other forms of hydrogen concentration might be possibly better
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 05/25/2016 01:18 pm
There are not vast quantities of easily accessible oxygen and fuel (hydrogen or methane) on the Moon...
Did I miss something? There is new data or interpretation of existing data that would have conclusively disproven the more extreme hypothesis of exposed water ice in PSRs?
Both you and Warren may not be understanding this matter clearly. Water is not oxygen and hydrogen, it must be electrolyzed first. Which I clarified in the NEXT SENTENCE that you clipped out. On Earth, oxygen and fuel is already chemically available without electrolysis.

edit/Lar: Soften
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 05/25/2016 01:21 pm
::)

Quote from: gbaike
It possible that there is water 100 meter below the surface of the Moon- somewhere at the surface, but this seems like a more difficult thing to explore in order to find.

Dude, that's what this whole thread is about. We look for potential drilling sites by looking for geological signs of outgassing. I just gave you a list of 98 locations. We conduct volatile exploration on the Moon the same way we conduct oil exploration on the Earth--IOW, we don't go around randomly punching holes the way you make it sound.

Quote from: Robotbeat
There are not vast quantities of easily accessible oxygen and fuel (hydrogen or methane) on the Moon. I'm talking stuff that isn't in trace quantities and stuff that doesn't require electrolysis (or similar) to acquire.

This is pure disinformation. Sad.

Quote from: savuporo
the more extreme hypothesis of exposed water ice in PSRs?

And what is extreme about water ice being stable at 30 K?!?

edit/Lar: soften a bit.
Do not accuse me of "disinformation" because you lack reading comprehension!

Water must be electrolyzed.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Lar on 05/25/2016 01:53 pm
I've tried just passively softening words but that's not working.

Accusing people of not having reading comprehension is not exactly a good example of being excellent to each other.  Play the ball not the man.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: savuporo on 05/25/2016 02:21 pm
There are not vast quantities of easily accessible oxygen and fuel (hydrogen or methane) on the Moon...
Did I miss something? There is new data or interpretation of existing data that would have conclusively disproven the more extreme hypothesis of exposed water ice in PSRs?
Both you and Warren may not be understanding this matter clearly. Water is not oxygen and hydrogen, it must be electrolyzed first. Which I clarified in the NEXT SENTENCE that you clipped out. On Earth, oxygen and fuel is already chemically available without electrolysis.

edit/Lar: Soften

And again, because you missed the point, two important aspects that have been made over and over :

- First, we have no information what the chemical and mineral composition of the hypothesized resources are. In mining terms, it is speculative, undiscovered  portion of resources and by far not characterized reserves. The data we have fits various weaker and stronger hypotheses and is totally insufficient to turn this into even inferred or demonstrated reserves - any time soon.
Much more information is needed before we can make absolute claims like "There are not vast quantities of easily accessible oxygen and fuel (hydrogen or methane) on the Moon.". For all we know, there can be free hydrogen in PSRs. Whether its 'easily accessible' or not is all relative. Subjectively, nothing in space is 'easy'

- The exact chemical bonds of utilizing these theorized resources are just one input variable into total process engineering complexity. Given that we are talking about completely new process engineering disciplines, it might or might not end up significant variable.

Quote
oxygen and fuel is already chemically available without electrolysis.
There is no 'fuel' naturally available on earth ( or probably anywhere, where oxidizer is present nearby ) - even dry firewood has to be gathered and broken up. How easy that is depends on where you are at and a few other factors.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 05/25/2016 03:31 pm
There are not vast quantities of easily accessible oxygen and fuel (hydrogen or methane) on the Moon...
Did I miss something? There is new data or interpretation of existing data that would have conclusively disproven the more extreme hypothesis of exposed water ice in PSRs?
Both you and Warren may not be understanding this matter clearly. Water is not oxygen and hydrogen, it must be electrolyzed first. Which I clarified in the NEXT SENTENCE that you clipped out. On Earth, oxygen and fuel is already chemically available without electrolysis.

edit/Lar: Soften

And again, because you missed the point, two important aspects that have been made over and over
I didn't miss the point, I was making a simple one which you didn't understand, partly because you truncated what I wrote. Lunar resources like what Warren Platts (the most optimistic person in this regard) supposes all require electrolysis to turn into oxidizer and fuel. The free hydrogen, if it exists, is in fairly trace amounts and still lacks an oxidizer. I was taking all this into account when I wrote the above, you two just (selectively) misread what I actually wrote. You clipped it out of your quoted text and Warren just seems to have skipped reading what I wrote entirely.

Quote
Quote
oxygen and fuel is already chemically available without electrolysis.
There is no 'fuel' naturally available on earth ( or probably anywhere, where oxidizer is present nearby ) - even dry firewood has to be gathered and broken up. How easy that is depends on where you are at and a few other factors.
Yes, there is. That's why there are forest fires, coal seam fires, etc. There's free fuel available on Earth as well as free oxidizer. You stick a hole in the ground, and methane comes out. The energy required for fracking or sticking that hole in the ground is a good order of magnitude less than electrolysis.

Chop firewood takes kilojoules of energy to release megajoules. Electrolysis takes megajoules to release megajoules.

The argument for lunar resources being better is based on energy (or similarly, delta-v). I.e. you need more energy and propellant to launch from Earth than from the Moon. But if you actually look at the AVAILABILITY of the propellant, Earth is still far better. And that's why I brought up electrolysis. Even if the lunar resources were as easily available as is claimed, i.e. totally pure water (it's not, by the way... and I will eat my words if proven wrong, so hold me accountable when we land a vehicle near these ostensible water resources), you STILL have to input a whole lot of energy into them to get them into usable propellant.

The difference of availability of the actual propellant is almost ALWAYS ignored in these discussions. The energy required to extract and process propellant on the Moon is orders of magnitude higher than on Earth, which negates the gravitational potential energy difference (except for corner cases, like refueling a lunar lander). (Not to mention differences in cost.)
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: savuporo on 05/25/2016 05:03 pm
Lunar resources like what Warren Platts (the most optimistic person in this regard) supposes all require electrolysis to turn into oxidizer and fuel. The free hydrogen, if it exists, is in fairly trace amounts and still lacks an oxidizer.
What data do you base your assertions on ?

Quote
The difference of availability of the actual propellant is almost ALWAYS ignored in these discussions. The energy required to extract and process propellant on the Moon..
You seem to be equating chemical bond energy requirements with difficulty of turning completely hypothetical resources ( not characterized reserves, huge difference ) into usable materials, which is at the root of my disagreement.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 05/25/2016 05:07 pm
Lunar resources like what Warren Platts (the most optimistic person in this regard) supposes all require electrolysis to turn into oxidizer and fuel. The free hydrogen, if it exists, is in fairly trace amounts and still lacks an oxidizer.
What data do you base your assertions on ?
...
Middle school chemistry. Water won't magically turn into hydrogen and oxygen, it requires electrolysis, an input of energy. Minimum of 16MJ/kg, more like 30MJ/kg to split water into hydrogen and oxygen.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 05/25/2016 05:11 pm
...

Quote
The difference of availability of the actual propellant is almost ALWAYS ignored in these discussions. The energy required to extract and process propellant on the Moon..
You seem to be equating chemical bond energy requirements with difficulty of turning completely hypothetical resources ( not characterized reserves, huge difference ) into usable materials, which is at the root of my disagreement.
Yeah, electrolysis is simply the MINIMUM energy requirements to turn these supposed vast amounts of water into useful propellant. It is not a maximum. On Earth, the fuel is already chemically present in an oxidizable form. And on Earth, the oxidizer is already free in the atmosphere (and takes only a small amount of energy to concentrate).

Since we cannot easily quantify the actual difficulty of operating on the Moon, we have to at least look at the minimum difficulty.


...and I focus on propellants, because if we perfect reusable launch systems (which is also required for lunar propellant, by the way! No way to economically extract lunar resources using an expendable ascent vehicle/lander), the cost of the propellant becomes an important factor.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Kansan52 on 05/25/2016 05:21 pm
But the water does not need to be processed on the Moon with mag lev launch rail. Send the ice to a processing location/fuel depot.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: muomega0 on 05/25/2016 06:30 pm
....... Electrolysis takes megajoules to release megajoules.

  Even if the lunar resources were as easily available as is claimed, i.e. totally pure water (it's not, by the way... and I will eat my words if proven wrong, so hold me accountable when we land a vehicle near these ostensible water resources), you STILL have to input a whole lot of energy into them to get them into usable propellant.
Any links to other threads appreciated...   XEUS (http://forum.nasaspaceflight.com/index.php?topic=39126.msg1464471#msg1464471)    Marsdirect (http://forum.nasaspaceflight.com/index.php?topic=37733.msg1438945#msg1438945)  Cislunar1000 (http://forum.nasaspaceflight.com/index.php?topic=38938.msg1495059#msg1495059)

Updates/corrections welcome...

Electrolysis
100mT of propellant.   Assume you need a  5.7:1 ratio, so 15mT of hydrogen.  (H20 is 11% H by mass)
2.4 gal/kgH, so 35,821 gals of H20   40* kWhr/kg or 597000 kwhr of energy required at 100% efficiency.
12 hrs a day * 360 days is 4320 hrs (the ~lifetime of the lightest weight PEM fuel cell  )
At 75% efficiency and 4320 hrs,    its 184 kW

Liquid Hydrogen
451 KJ/kg heat of vaporization   x 15mT   or 6731343 kJ   over 4320 hrs is 1558 KJ/hr  or 432 Watts thermal.
Assume 100We/Wt   for the cooler, so that's another 40kW.

Liquid Oxygen....Power for Caterpillars....
214 KJ/kg                                 x 85mT     .......     1.2 MW   + coolers at 20W/W   =   122 kW

yikes!~

So now the weight of the power, mining equipment (plus power!), coolers, and heat rejection, needs to be determined, including lifetimes and maintenance and the costs tp develop and to send the equipment to the surface, including tanks, and back to orbit...not to mention boiloff.   Then scale this for Mars for a 1 year stay, so if its 400mT/yr, so pick both hydrogen or oxygen or one...

OTOH, way more interesting than capsules and expendable LVs :D

Why not mine the resources from asteroids (http://forum.nasaspaceflight.com/index.php?topic=38660.msg1438374#msg1438374), insitu, and avoid the gravity wells, and place the propellant near Mars, where its need for the crew return trip home to shorten the trip time?

But the water does not need to be processed on the Moon with mag lev launch rail. Send the ice to a processing location/fuel depot.
Asteroids avoid gravity wells...while the 3 depots (LEO, L2, Mars) are filled from earth, robots and crew can be explorin' for water and 'gold'.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: savuporo on 05/25/2016 06:55 pm
Lunar resources like what Warren Platts (the most optimistic person in this regard) supposes all require electrolysis to turn into oxidizer and fuel. The free hydrogen, if it exists, is in fairly trace amounts and still lacks an oxidizer.
What data do you base your assertions on ?
...
Middle school chemistry. Water won't magically turn into hydrogen and oxygen, it requires electrolysis, an input of energy. Minimum of 16MJ/kg, more like 30MJ/kg to split water into hydrogen and oxygen.
Not answering the question. What do you base your assertions of composition of volatiles in lunar polar regions on ? Specifically, mineralogical, elemental, molecular and isotopic make up of volatiles ?

Since we cannot easily quantify the actual difficulty of operating on the Moon, we have to at least look at the minimum difficulty.
You cant, without knowing whats there.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Lar on 05/25/2016 07:03 pm
Agree with the energy balance comments...  in general making propellant from raw materials (especially when those raw materials are the combustion reaction product, suchas water for Hydrolox and water/CO2 for methalox) means putting in as much energy as you get back out, plus some more to make up for losses

The difference is just that you are putting the energy in slowly (via electricity or electrical power to run heaters for endothermic reactions or whatever) and getting it out faster.

On the other hand if you are extracting methane from the ground you're not making it. So the energy you pay is less than it contains (or else why do it). If you are extracting O2 from the air, you're not making it (by dissassociating water or whatever) either.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 05/25/2016 07:33 pm
Lunar resources like what Warren Platts (the most optimistic person in this regard) supposes all require electrolysis to turn into oxidizer and fuel. The free hydrogen, if it exists, is in fairly trace amounts and still lacks an oxidizer.
What data do you base your assertions on ?
...
Middle school chemistry. Water won't magically turn into hydrogen and oxygen, it requires electrolysis, an input of energy. Minimum of 16MJ/kg, more like 30MJ/kg to split water into hydrogen and oxygen.
Not answering the question. What do you base your assertions of composition of volatiles in lunar polar regions on ? Specifically, mineralogical, elemental, molecular and isotopic make up of volatiles ?
I am answering the question. This whole infuriating conversation rests on the idea of pure water on the Moon, and my claim is that even if you had pure water, you would have to inject a lot of energy to make it into propellant. Understand?
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 05/25/2016 07:33 pm
...
Since we cannot easily quantify the actual difficulty of operating on the Moon, we have to at least look at the minimum difficulty.
You cant, without knowing whats there.
Yes, we frakking can. If we assume there's pure water in the best case scenario, we can know what the minimum energy is. Understand?
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: gbaikie on 05/25/2016 08:31 pm
Quote from: Warren
What is extreme about stable water ice at 30 K?

The point of my post was, that we currently can't tell what exactly is there with high certainty, and we definitely cannot tell how easily accessible or usable any of the materials are. Further data needed.

Yes of course. We've been through that all that before. But for the sake of the argument, let's assume that the polar craters really are 2 meter thick ice rinks. I think we'd both agree that would be about the most "easily accessible" frozen resource we could hope for. Thus, the point of this thread is that even if that were the case (which I agree is unlikely), it would still be easier to drill for volatiles if they can be found at shallow depths.
Right or in the case of Mars, where there there is a good chance of water underground, one could water
as cheap and one can get water on Earth.
Quote
Think about it this way: I have a pond in front of my house. In winter, it is easier for me to simply turn on the faucet connected to the water well than it is for me to go out and cut and melt blocks of ice every time I need some water.
Well everyone uses a lot of water, but on the moon one does not need much water. What one person uses
of water per year on Earth, is more that what is needed for lunar rocket fuel market on the Moon.

Think the purpose of NASA exploration of the moon is to find commercially minable lunar water which can be use to make rocket fuel. And NASA main purpose of exploring mars is to determine if one get cheap water on Mars- and drilling for water on Mars is a way to get cheap water. But such ground water would of the quantities of around a billion tonnes of water available from the drilled well. Drilling for 1/2 million tonnes of water [as total reserve available in particular location, would not be example of very cheap- cheap but not as cheap as could hoped for. Whereas if you could drill on Moon and get 1/2 million tonnes it far more than is needed, and makes water less $50 per lb. And I think if lunar were $500 per lb, it's minable on the Moon- of course $50 per lb is a lot better.
But were lunar water $50 or $500 it's not the only factor in terms of cost of rocket fuel, a significant portion of the cost particular with less expensive water is the cost of the energy needed to make it.
Another significant cost is transportation of water or the rocket fuel to a location you need it. Or if at poles
and wanted water or rocket fuel from the equator of the Moon. Or if had to take water from 1000 miles away
and needed say 100 tons of it in a season, it might be cheaper to get ice from a frozen pond. And one has trucks and roads available. Of course one might not care if water is more expensive if trucked as is not significant cost.

Anyhow having very cheap water is attractive if one is interested in settlements- and farming.
Quote
We know there are these geological features we call meniscus hollows or IMPs or whatever. We don't know for sure what caused them, but we do know for sure that they were formed very recently, on the order of 1-10 million years ago, maybe even sooner. And although there is a faction of researchers who cling to the old idea that these are lava flows, the most likely theory IMO is Schultz's outgassing hypothesis. But to excavate surface deposits via outgassing or a water explosion, that logically entails that such volatiles must have got to the surface somehow.

Thus, if (1) outgassing caused Ina and its ilk; and (2) it happened very recently, then (3) there very well could be near surface locations where significant quantities of volatiles could be obtained today.

Well, empty caves 100 meter down may be a significant value and almost any volatile could have value.
But having lunar water available at $500 per lb, is enough to add more markets in space and such markets
will lower the main cost of leaving Earth, which allows more markets in space to be developed- including commercial exploration.

We look for potential drilling sites by looking for geological signs of outgassing. I just gave you a list of 98 locations. We conduct volatile exploration on the Moon the same way we conduct oil exploration on the Earth--IOW, we don't go around randomly punching holes the way you make it sound.

Ok, but that sounds to me to be quite expensive.
Quote
Trivial. Everything in space is "quite expensive". The google X-prize is offering $30M to land a frackin beach ball on the Moon, and it can't be done for less than the prize. It's all relative, but, just like it is less expensive to produce oil from the Ghawar supergiant oil field than it is to produce it from Alberta tar sands, it would be less expensive to produce water and volatiles on the Moon by drilling for it rather than mining it.
Expensive compare to exploring a small area on the surface of polar regions.

Quote from: gbaike
Suppose one picks what is regarded as best site out of 98. How many holes will you drill and how deep do you drill before deciding that water isn't available at the site one thought was the best one.
Quote
You do it just like they do it in the industry. You go until you either run out of money or you strike it rich....
Exactly. And who going to pay for it. How many will go bankrupt
Or do you want NASA to be like an industry. You are big fan of socialism?
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Lar on 05/25/2016 08:36 pm
People who are "infuriated" maybe should set this thread aside for a while.

Lunar resources like what Warren Platts (the most optimistic person in this regard) supposes all require electrolysis to turn into oxidizer and fuel. The free hydrogen, if it exists, is in fairly trace amounts and still lacks an oxidizer.
What data do you base your assertions on ?
...
Middle school chemistry. Water won't magically turn into hydrogen and oxygen, it requires electrolysis, an input of energy. Minimum of 16MJ/kg, more like 30MJ/kg to split water into hydrogen and oxygen.
Not answering the question. What do you base your assertions of composition of volatiles in lunar polar regions on ? Specifically, mineralogical, elemental, molecular and isotopic make up of volatiles ?
I am answering the question. This whole infuriating conversation rests on the idea of pure water on the Moon, and my claim is that even if you had pure water, you would have to inject a lot of energy to make it into propellant. Understand?

I read savupuro as asking (you) about (sources for) the projected volatiles composition. Not as talking about electrolysis energy.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 05/25/2016 08:44 pm
People who are "infuriated" maybe should set this thread aside for a while.

Lunar resources like what Warren Platts (the most optimistic person in this regard) supposes all require electrolysis to turn into oxidizer and fuel. The free hydrogen, if it exists, is in fairly trace amounts and still lacks an oxidizer.
What data do you base your assertions on ?
...
Middle school chemistry. Water won't magically turn into hydrogen and oxygen, it requires electrolysis, an input of energy. Minimum of 16MJ/kg, more like 30MJ/kg to split water into hydrogen and oxygen.
Not answering the question. What do you base your assertions of composition of volatiles in lunar polar regions on ? Specifically, mineralogical, elemental, molecular and isotopic make up of volatiles ?
I am answering the question. This whole infuriating conversation rests on the idea of pure water on the Moon, and my claim is that even if you had pure water, you would have to inject a lot of energy to make it into propellant. Understand?

I read savupuro as asking (you) about (sources for) the projected volatiles composition. Not as talking about electrolysis energy.
I was just taking Warren's claim as it stands. I'm NOT making any claims about volatiles composition! The question is irrelevant to my point. This is why I'm infuriated. I make a claim, the guy doesn't understand it, then demands I answer an irrelevant question.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Lar on 05/25/2016 08:49 pm
Chill. People are wrong on the internet all the time.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: nadreck on 05/25/2016 09:17 pm
There is a product on the market HyStat type V specs on page 6 (http://www.hydrogenics.com/docs/default-source/pdf/2-1-1-industrial-brochure_english.pdf?sfvrsn=2) that produces about 47t a year (for the model 60-10 model) of hydrogen from electrolysis it takes about 5.2 kwh to produce each Nm3 (cubic meter at STP or 44.5 moles of H2). So one of these units needs 312kw of power, two would give you nearly 100t of hydrogen and 800t of oxygen, so if you presume that harvesting the water, and liquefying and storing the produce can be done with half the energy required for electrolysis then just under 1 megawatt of power gets you 700t a year of propellant (at the standard mixture ratio for Hydrolox rocket engines) and 200t of extra oxygen (feedstock for some other process?).


So at what scale does this sort of enterprise make sense? Or does it never? Well as I had noted much earlier in the thread that you could ship propellant to LEO at a ratio of 3 to 1, so the above system could put 233t of propellant in LEO each year and represents 32t of electrolysis equipment. Possibly 10,000m2 of solar panels (10t of thin film and their supports?) and of course everything (and everyone) you need to gather about 2.5 cubic meters (2.5t) of water a day.  So scale it up by a factor of 10 - 25 tones of water a day, enough propellant to LEO to launch move about 1000t from LEO to the moon each year. That reduces the launch cost of an item to the moon by 70%. At a cost of 420t of electrolysis and solar power equipment along with an as yet un-estimated mass of compression/liquefaction/storage and of course the water harvesting in the first place. It probably takes more than a year to break even, but it looks to me like it might be practical.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: savuporo on 05/26/2016 06:09 am
There are not vast quantities of easily accessible oxygen and fuel (hydrogen or methane) on the Moon. I'm talking stuff that isn't in trace quantities and stuff that doesn't require electrolysis (or similar) to acquire.
The free hydrogen, if it exists, is in fairly trace amounts and still lacks an oxidizer.
I'm NOT making any claims about volatiles composition! The question is irrelevant to my point. This is why I'm infuriated.
Respectfully, and i may indeed read this wrong, but i think you are making a few claims pertinent to volatiles on the moon - or lack thereof.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 05/26/2016 03:08 pm
There are not vast quantities of easily accessible oxygen and fuel (hydrogen or methane) on the Moon. I'm talking stuff that isn't in trace quantities and stuff that doesn't require electrolysis (or similar) to acquire.
The free hydrogen, if it exists, is in fairly trace amounts and still lacks an oxidizer.
I'm NOT making any claims about volatiles composition! The question is irrelevant to my point. This is why I'm infuriated.
Respectfully, and i may indeed read this wrong, but i think you are making a few claims pertinent to volatiles on the moon - or lack thereof.
I'm saying that Warren Platt's claim about water being freely available doesn't get you oxygen and hydrogen for free. He also made some claims about (I think?) chemical hydrogen, but as I said, that doesn't include any chemical oxygen.

I'm simply taking his claims as they are and analyzing them, I am not making any new claims about volatiles composition other than analyzing what he's saying.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: jongoff on 05/26/2016 03:49 pm
There are not vast quantities of easily accessible oxygen and fuel (hydrogen or methane) on the Moon. I'm talking stuff that isn't in trace quantities and stuff that doesn't require electrolysis (or similar) to acquire.
The free hydrogen, if it exists, is in fairly trace amounts and still lacks an oxidizer.
I'm NOT making any claims about volatiles composition! The question is irrelevant to my point. This is why I'm infuriated.
Respectfully, and i may indeed read this wrong, but i think you are making a few claims pertinent to volatiles on the moon - or lack thereof.
I'm saying that Warren Platt's claim about water being freely available doesn't get you oxygen and hydrogen for free. He also made some claims about (I think?) chemical hydrogen, but as I said, that doesn't include any chemical oxygen.

I'm simply taking his claims as they are and analyzing them, I am not making any new claims about volatiles composition other than analyzing what he's saying.

I do agree that even if the precursors are there, that a big part of ISRU hardware is actually going to be the power generation overhead for running electrolysis. (Note: this also applies on Mars/Venus, elsewhere, for the points you made previously--creating chemical propellants from what are effectively their combustion products is always going to be power intensive).

~Jon
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: guckyfan on 05/26/2016 04:27 pm
I do agree that even if the precursors are there, that a big part of ISRU hardware is actually going to be the power generation overhead for running electrolysis. (Note: this also applies on Mars/Venus, elsewhere, for the points you made previously--creating chemical propellants from what are effectively their combustion products is always going to be power intensive).

~Jon

I fully agree. It applies everywhere. However the moon is near earth. Moon ressources have to compete more with potentially cheap products launched from earth. Products from Mars are in a completely different situation. I have argued before, how will fuel from the moon compete with fuel from earth in LEO?
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: guckyfan on 05/26/2016 04:30 pm
A completely different point. Is the isotope ratio of lunar water known? Water on Mars has more heavy water than on earth. Some have argued that may cause problems. Assuming that water in cold traps in lunar craters comes from comet impacts, deuterium may be even a lot more concentrated there.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 05/26/2016 07:12 pm
But the power requirements are old news. This is the first time I've heard that they are a showstopper. Which is ironic, since Chris is the one who's always talking up the latest developments in solar cell technology, how cheap it is, how efficient it is, how light-weight it is, how you can just roll it out on the ground and get all the power you want, cosign losses be damned.

But we can put some numbers to it. To be truly game-changing we want 10,000 mT of H2O per year. That'd support a low-cost, abundant chemical Mars architecture with a very aggressive launch schedule.

Thus, 16e6 J/kg * 1e7 kg = 160e12 J. Thus 160e12 J/yr / piX1e7 s/yr = 5 MW average rocket fuel burning rate. Assume 50% electrolysis efficiency = 10 MW. Double the capacity so we can only run half the time = 20 MW. Add 25% margin = 25MW. Assume 250 W of sunlight per m^2 of solar panels is converted to electricity = 25 MW / 250 W/m^2 = 100,000 m^2 = 10 hectares = 0.1 km^2. Assume 1250 W/kg, 25 MW / 1.25 kW/kg = 20,000 kg = 20 mT. Doesn't seem particularly undoable, especially if the array was stationed at the L1 point, instead of trying to set it up on the surface. Probably a single Falcon Heavy could do it.

To be honest, that seems rather like I'm low-balling the estimate. I feel like I dropped a zero in there somewhere, but even if I underestimated the mass by an order of magnitude, that wouldn't be a showstopper, considering the benefit that could be achieved.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 05/26/2016 07:17 pm
A completely different point. Is the isotope ratio of lunar water known? Water on Mars has more heavy water than on earth. Some have argued that may cause problems. Assuming that water in cold traps in lunar craters comes from comet impacts, deuterium may be even a lot more concentrated there.

Nobody's measured the isotope ratio in from polar craters. However, if it comes mostly from comets, it should be enriched in deuterium. Still, it's hard to see how that could be a problem for something, as the percentages involved are going to be tiny in any case.

But if isotope ratios are a problem, then what I am proposing--drilling for lunar juvenile water--that problem would be obviated, since we know that the Moon's juvenile water isotope ratio is pretty close to the Earth's.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: nadreck on 05/26/2016 07:30 pm
16e6 J/kg * 1e7 kg = 160e12 J. Thus 160e12 J/yr / piX1e7 s/yr = 5 MW average rocket fuel burning rate

Note given the numbers on the HiStat V I posted above I get less than 10MW for the amount of hydrolox propellant you want BUT your formula makes not sense to me how is pi in there? What does "average rocket fuel burning rate" mean?
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 05/26/2016 07:38 pm
Average annual rocket fuel burning rate is simply the energy content of all your rocket burns in Joules, divided by one year's worth of time in seconds, and you get an answer in Watts for your units. The "pi", that's just something I remember from my old astrophysics 101 professor, Michael S. Turner, back when he was still a hippie, as an approximate shorthand for the number of seconds in a year: 3.14 X 107 ≈ 3.16 X 107.  ;D
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: nadreck on 05/26/2016 07:45 pm
Average annual rocket fuel burning rate is simply the energy content of all your rocket burns in Joules, divided by one year's worth of time in seconds, and you get an answer in Watts for your units. The "pi", that's just something I remember from my old astrophysics 101 professor, Michael S. Turner, back when he was still a hippie, as an approximate shorthand for the number of seconds in a year: 3.14 X 107 ≈ 3.16 X 107.  ;D

Oh, I simply do 3600X24X365 (31,536,000). Ok, but I thought you wanted 10,000t of propellant a year? that is equal to the product of electrolizing 12,857t of water ( 9t of water electrolized produces 1t of H2 and 8t of O2 which is equal to 7t of propellant and an extra 2t of O2).
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 05/26/2016 07:56 pm
Re: power requirements I get 10 MW as total electrolysis power requirement--IF you assume your system is running at full capacity 365 days a year. If you can only run half the time (e.g., because it's night time), then you have to double the capacity to make up for the lost time.

Sure you could have a storage system, but I'm guessing it'd take less mass to just double the size of your solar array. Of course if you have a SBSP system beaming energy from L1, you could run all the time, but you'd still need the extra big array for efficiency losses due to the beaming process. Not sure what that would be, the efficiency of beaming. But at least you could use lasers rather than microwaves.

You are correct, I was simply assuming stoichiometric. I've heard of mass ratios as low as 5:1. But again, if we're drilling for primordial (i.e., juvenile) water, there's a good chance it'd be supersaturated with H2 gas, so you could maybe achieve some efficiencies there.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: gbaikie on 05/26/2016 08:52 pm
So at what scale does this sort of enterprise make sense? Or does it never?

I think the reason, the moon should be explored, is because the Moon required the least amount of
rocket fuel to be made in terms of being viable or profitable.
Or if you splitting water and making 47 tonnes of H2 [376 tons of LOX] this about the level of production
I would guess you want after about 3 years of mining lunar water. Or mining about 400 ton of water per
year, but first year one could target 50 to 100 tons of water and have plan of about 400 ton in 3 to 4 years
and be over 1000 tons within a decade from the start of operation.

The more water mined and made into rocket fuel the cheaper it is to get to the Moon- and one is making impact on Earth launch costs, and making it more likely for any type investment money to go to space markets like lunar water mining.
And you are not in hurry to increase production in order supply a unlimited demand, but rather one doing everything you can to increase demand for rocket fuel.
Or you at stage of market where trying to convince people they should buy personal computer when a few year ago, personal computer, didn't really exist.

One could sell rocket fuel at lunar surface for quite an expensive price, because if rocket fuel were on the surface at price of about $20,000 per kg, this lower the cost of sending tourist to the Moon where the rocket fuel is available. You don't need a Apollo LEM which carries the return rocket fuel in addition to crew to lunar surface. So need half the vehicle and reduce payload launch mass from Earth, instead once crew arrive one pays 50 million or less for the rocket fuel to return them. So instead costing 1/2 billion per trip, it might cost less than 400 + 50 million for lunar rocket fuel- it could even work out to less if one paid 40 K per kg for return rocket fuel.

But what trying to do is increase the demand for the lunar water one mines. Or people aren't sending tourist to the Moon at the present, because it too high of a price. But even if lower lunar rocket fuel to $10,000 per kg this lower price is not doing much to increase demand- whether it's 25, 50, or 100 million added to mission
cost it's not much of driver.
Also you want to lower your cost of getting to the Moon, so land a less in beginning make some rocket fuel, and lower your cost to land more and increase your production level.

What lunar water miner needs to lower your cost of getting to the Moon, is rocket fuel available at low lunar orbit. For LEO use up rocket fuel to get to Low lunar or launch it empty to Low lunar orbit, refuel at low lunar
and land with largest payload.
So earth launch rocket fuel could delivered to Low Lunar and sell it to Lunar water miner- that would lower cost of getting infrastructure need at the lunar surface.
But as lunar water miner one wants to supply Low Lunar with lunar rocket fuel- or provide rocket fuel at same
cost as shipping it from Earth. And you could start by just sell excess LOX, rather than H2.
So you want to sell lunar rocket fuel at surface and expand your market to Low lunar. And later expand to EML-1 or 2. Or Lunar orbit and high earth orbit are second highest price for rocket fuel at the moment.
And you want to flip it, to having lunar surface rocket fuel being much cheaper than High Earth orbit, even cheaper than LEO. And once it is considerable cheaper than LEO, one spend the extra amount of money need to ship lunar rocket fuel to LEO.
So you start of with lowest capital cost and make least amount of rocket fuel- and going to want to use it. Or one probably want to send some crew to the Moon to establish and fix problem. So you going to be a buyer of the lunar return rocket fuel, and continue to be one of "customers" of lunar rocket fuel at lunar surface.
And what you doing is building a business- people who know how to make lunar rocket fuel. Or investors want to invest in a company that knows what it is doing, and you need capital to expand as fast as you can to prevent other companies taking away your business.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: jongoff on 05/26/2016 11:00 pm
I fully agree. It applies everywhere. However the moon is near earth. Moon ressources have to compete more with potentially cheap products launched from earth. Products from Mars are in a completely different situation. I have argued before, how will fuel from the moon compete with fuel from earth in LEO?

I think it *might* be able to compete, even in LEO, with Earth-launched propellants, but only if they go in with an emphasis on making their $/kg in LEO price as competitive as possible. In my book that includes: a) propellantless launch for the ISRU prop, b) aerocapture and reuse of tankers in LEO (ACES/Distributed Launch), c) using the lowest cost launch from Earth for emplacing the original infrastructure, and d) possibly propellantless landing of at least some materials on the Moon. Also, if ESA or any other group ends up doing a human tended lunar base, a commercial lunar ISRU company could theoretically leverage that infrastructure in ways to make them more competitive.

It's still a toss-up if a lunar ISRU system can keep competitive with evolving launch vehicle capabilities in LEO or not, but as soon as you start getting further from earth and closer to the Moon (say a staging base in NRO or EML-1 or 2), and the case becomes that much easier to close.

~Jon
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 05/27/2016 12:07 am
I fully agree. It applies everywhere. However the moon is near earth. Moon ressources have to compete more with potentially cheap products launched from earth. Products from Mars are in a completely different situation. I have argued before, how will fuel from the moon compete with fuel from earth in LEO?

I think it *might* be able to compete, even in LEO, with Earth-launched propellants, but only if they go in with an emphasis on making their $/kg in LEO price as competitive as possible. In my book that includes: a) propellantless launch for the ISRU prop, b) aerocapture and reuse of tankers in LEO (ACES/Distributed Launch), c) using the lowest cost launch from Earth for emplacing the original infrastructure, and d) possibly propellantless landing of at least some materials on the Moon. Also, if ESA or any other group ends up doing a human tended lunar base, a commercial lunar ISRU company could theoretically leverage that infrastructure in ways to make them more competitive.

It's still a toss-up if a lunar ISRU system can keep competitive with evolving launch vehicle capabilities in LEO or not, but as soon as you start getting further from earth and closer to the Moon (say a staging base in NRO or EML-1 or 2), and the case becomes that much easier to close.

~Jon

I would add e) pluck the lowest hanging fruit first. If 10,000 mT/yr of H2O could be obtained by through one or a few relatively shallow wells at lower latitude, near-side locations, that would no doubt be a lot less expensive compared to mining and processing frozen regolith in PSRs.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Lar on 05/27/2016 01:48 am
I would add e) pluck the lowest hanging fruit first. If 10,000 mT/yr of H2O could be obtained by through one or a few relatively shallow wells at lower latitude, near-side locations, that would no doubt be a lot less expensive compared to mining and processing frozen regolith in PSRs.
This is where I think the crux of the difference of opinion lies. Given what you said up thread about possible dry holes and the need to keep trying until you run out of money, the PSRs seem like more of a sure thing... the grade of water might not be as good but you know it's there and you know where to go. Once you have it up and running you can fuel lunar hoppers to go prospecting elsewhere.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 05/27/2016 02:01 am
But the power requirements are old news. This is the first time I've heard that they are a showstopper....
Excuse me, but where did I say it was a showstopper?

I'm merely saying that if we're going to base our arguments about why lunar propellants are better based on potential energy (being out of Earth's gravity well), then we need to talk about how it takes much less cost/energy to extract Earth propellants in the first place.


I don't even think that lunar propellants have no place whatsoever, I just don't think it's at ALL a slam-dunk as it's often portrayed. Good reusable tech (also required for lunar props) will make launching stuff from Earth MUCH cheaper, and this point is rarely acknowledged by proponents of lunar propellant.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Lar on 05/27/2016 02:19 am
I don't even think that lunar propellants have no place whatsoever, I just don't think it's at ALL a slam-dunk as it's often portrayed. Good reusable tech (also required for lunar props) will make launching stuff from Earth MUCH cheaper, and this point is rarely acknowledged by proponents of lunar propellant.

Agreed about needing to do the total energy balance when doing the trades.

But I think some things are worth doing to do them, because they are a forcing function for other things, even if they don't quite make perfect economic sense. Lunar propellant may be one of those. (as discussed on the settlement rationale thread, Mars settlement may be another, writ very large, thing that doesn't make straight up economic sense yet is worth doing)
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 05/27/2016 02:33 am
I don't even think that lunar propellants have no place whatsoever, I just don't think it's at ALL a slam-dunk as it's often portrayed. Good reusable tech (also required for lunar props) will make launching stuff from Earth MUCH cheaper, and this point is rarely acknowledged by proponents of lunar propellant.

Agreed about needing to do the total energy balance when doing the trades.

But I think some things are worth doing to do them, because they are a forcing function for other things, even if they don't quite make perfect economic sense. Lunar propellant may be one of those. (as discussed on the settlement rationale thread, Mars settlement may be another, writ very large, thing that doesn't make straight up economic sense yet is worth doing)
I'm not sure that's a good analogy. Mars settlement isn't about economic payback or efficiency, whereas lunar propellant is.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Lar on 05/27/2016 02:39 am
I'm not sure that's a good analogy. Mars settlement isn't about economic payback or efficiency, whereas lunar propellant is.
When I think about "the Big Picture"[1] I think there's an aspect of forcing present in any industrialization or exploitation or settlement operation we might contemplate. So, maybe.

1 - 12 credits...
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: KelvinZero on 05/27/2016 11:27 am
I'm not sure that's a good analogy. Mars settlement isn't about economic payback or efficiency, whereas lunar propellant is.
I have never understood this focus on lunar propellants to get to Mars. The attraction of Mars is all those volatiles.  But rockets require HUGE amounts of volatiles. If you can extract that level of volatiles from the moon, you clearly don't need to go to mars to find a glut of volatiles for moderate uses such as hydroponics.

Long before we exhaust the resources at the lunar poles we would have the experience to hop to various asteroids, that may in fact require less delta-v than the lunar surface but need confidence in equipment to run for months without hope of rescue from earth.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 05/27/2016 03:55 pm
The attraction of Mars is that it can be at least partially terraformed, ultimately.

We could, within a century or less, raise the pressure on Mars to a level where survival without a pressuresuit is possible in some locations. A significant variety of plant life (perhaps carefully bred or engineered) could live there once the pressure and temperature increases high enough. Over millennia, it's even possible to generate on oxygen-rich atmosphere (although this will take a ridiculously long time). Same can not be said of the Moon.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: jongoff on 05/27/2016 04:32 pm
I'm not sure that's a good analogy. Mars settlement isn't about economic payback or efficiency, whereas lunar propellant is.

I disagree. You're never going to get Mars settlement affordable enough for large numbers of people to do it if you're doing it inefficiently. Doing Mars settlement efficiently will open it up to a much wider range of colonists. And quite frankly I don't think Elon's going to get to the number of colonists he wants and the ticket prices he wants without almost everything working: RLVs, Mars ISRU for propellants and construction materials/housing, aerocapture/aerobraking, depots, solar electric power, lunar ISRU for propellants, etc.

~Jon
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 05/27/2016 05:17 pm
I'm not sure that's a good analogy. Mars settlement isn't about economic payback or efficiency, whereas lunar propellant is.

I disagree. You're never going to get Mars settlement affordable enough for large numbers of people to do it if you're doing it inefficiently. ...
Of course. Context is important here, Jon. But the end goal for Mars is a garden Mars. For Moon, it's mining, etc. Resource extraction, i.e. economics and efficiency.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: TrevorMonty on 05/27/2016 06:20 pm
But the power requirements are old news. This is the first time I've heard that they are a showstopper. Which is ironic, since Chris is the one who's always talking up the latest developments in solar cell technology, how cheap it is, how efficient it is, how light-weight it is, how you can just roll it out on the ground and get all the power you want, cosign losses be damned.

But we can put some numbers to it. To be truly game-changing we want 10,000 mT of H2O per year. That'd support a low-cost, abundant chemical Mars architecture with a very aggressive launch schedule.

Thus, 16e6 J/kg * 1e7 kg = 160e12 J. Thus 160e12 J/yr / piX1e7 s/yr = 5 MW average rocket fuel burning rate. Assume 50% electrolysis efficiency = 10 MW. Double the capacity so we can only run half the time = 20 MW. Add 25% margin = 25MW. Assume 250 W of sunlight per m^2 of solar panels is converted to electricity = 25 MW / 250 W/m^2 = 100,000 m^2 = 10 hectares = 0.1 km^2. Assume 1250 W/kg, 25 MW / 1.25 kW/kg = 20,000 kg = 20 mT. Doesn't seem particularly undoable, especially if the array was stationed at the L1 point, instead of trying to set it up on the surface. Probably a single Falcon Heavy could do it.

To be honest, that seems rather like I'm low-balling the estimate. I feel like I dropped a zero in there somewhere, but even if I underestimated the mass by an order of magnitude, that wouldn't be a showstopper, considering the benefit that could be achieved.
It is cheaper to split water in space at depot, as large space solar array is considerably cheaper to build and maintain. Plus it has access to sun 24/7. Still need to produce fuel on surface to provide tanker's surface to orbit/depot fuel.

Splitting in space results in surplus oxygen, which could be used with earth supplied LH.
If there is methane on lunar poles then this could be used with surplus oxygen.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: jongoff on 05/27/2016 07:02 pm
It is cheaper to split water in space at depot, as large space solar array is considerably cheaper to build and maintain. Plus it has access to sun 24/7. Still need to produce fuel on surface to provide tanker's surface to orbit/depot fuel.

I'm not sure I'm convinced this is true. Large arrays in space are hard from a deployment/stiffness/dynamics standpoint. Large arrays on the ground could theoretically use support structures made locally. It's not obvious to me which would win-out in practice.

~Jon
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 05/27/2016 07:14 pm
It is cheaper to split water in space at depot, as large space solar array is considerably cheaper to build and maintain. Plus it has access to sun 24/7. Still need to produce fuel on surface to provide tanker's surface to orbit/depot fuel.

I'm not sure I'm convinced this is true. Large arrays in space are hard from a deployment/stiffness/dynamics standpoint. Large arrays on the ground could theoretically use support structures made locally. It's not obvious to me which would win-out in practice.

~Jon
I'd say in-space arrays. You could make a VERY large array that doesn't need to have actuators to follow the Sun. On the Moon, you'd need those or you'd be throwing even more of the Sun away. And because of the long lunar night, you'd need to over-size your electrolysis equipment as well (to get the same average production) since you wouldn't store the energy. Even for the "peak of (near-)eternal light" on the Moon, it'd be kind of awkward to build a huge, rotating array and you'd be ultimately more limited.


I was thinking about this for Mars, as well. It's better to electrolyze on-orbit what you can. Even for ISS, we send up water and electrolyze on-orbit.

Stiffness requirements are DRAMATICALLY relaxed, too, if you're not under thrust. You could use a heliogyro-type arrangement, even, to save even more structure (although I think it's better not to in this case).
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Space Ghost 1962 on 05/27/2016 07:26 pm
It is cheaper to split water in space at depot, as large space solar array is considerably cheaper to build and maintain. Plus it has access to sun 24/7. Still need to produce fuel on surface to provide tanker's surface to orbit/depot fuel.

I'm not sure I'm convinced this is true. Large arrays in space are hard from a deployment/stiffness/dynamics standpoint. Large arrays on the ground could theoretically use support structures made locally. It's not obvious to me which would win-out in practice.

~Jon
I'd say in-space arrays.
Agree.

You may be able to deal with an incredibly lightweight film as an alternative, that might be manipulated back into place using an external means of various kinds.

We just tend to think in ground metaphors.

Solar panels/concentrators are basically 2d structures, and intrinsically low mass. In fact, getting away from substrate can allow you more optimal absorption (multilayer) / reflection (multilayer) / dissipation (space filling) mechanisms that we can't use in a high gradient environment because of need for substrate.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: jongoff on 05/27/2016 08:12 pm
It is cheaper to split water in space at depot, as large space solar array is considerably cheaper to build and maintain. Plus it has access to sun 24/7. Still need to produce fuel on surface to provide tanker's surface to orbit/depot fuel.

I'm not sure I'm convinced this is true. Large arrays in space are hard from a deployment/stiffness/dynamics standpoint. Large arrays on the ground could theoretically use support structures made locally. It's not obvious to me which would win-out in practice.

~Jon
I'd say in-space arrays.
Agree.

You may be able to deal with an incredibly lightweight film as an alternative, that might be manipulated back into place using an external means of various kinds.

We just tend to think in ground metaphors.

Solar panels/concentrators are basically 2d structures, and intrinsically low mass. In fact, getting away from substrate can allow you more optimal absorption (multilayer) / reflection (multilayer) / dissipation (space filling) mechanisms that we can't use in a high gradient environment because of need for substrate.

I'm just skeptical of having multi-hundred MW arrays work well in an environment where you're having to do frequent rendezvous/docking/propellant transfer, etc. And an in-space system is still likely going to need to have some sort of actuation on the arrays, because most orbits have the sun moving relative to them. Ultimately, I'm not sure in-space arrays will win out. Though to be honest, I don't know if lunar arrays will work out better either. I think most people with strong opinions on this haven't thought through the complexities enough to justify the strength of their opinions...

~Jon
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 05/27/2016 08:23 pm
I'd vote for in-space array, with beamed power down to lunar surface. Not sure how practicable that would be, but if ever there was a case for SBSP, it would be to power a lunar propellant refinery. Transporting water to space is problematic for a number of reasons: (a) you have no gravity, so that complicates plumbing etc.; (b) a mass ratio of 5 means you're going to have to vent off something like 20% of your cargo, so why send it up in the first place? (c) it'd be redundant, because you're going to have to have a refinery on the ground in order to launch the water in the first place, barring a mass-less mass driver; (d) it's going to balloon your development costs because you have to design two entire different refineries to do one job.

I agree with Jon, however; our crystal balls are not now transparent enough to see the future.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 05/27/2016 08:41 pm
The attraction of Mars is that it can be at least partially terraformed, ultimately.... Same can not be said of the Moon.

I'll not call this disinformation, and simply chalk it up to lack of reading the literature. But it is possible to terraform the Moon as well, and for it to be stable at human civilizational time scales, at least as far as we have survived so far.

A meteor that is only ~20 m in diameter is sufficient to produce a transient atmosphere on the moon that is collisional. These events happen on  the order of every ~100 years. The Tycho impact probably caused a transient atmosphere that was measured in millibars--about what it is at Hellas Planatia. Such impacts are probably why there is no dust on lunar boulders.

S. Alan Stern (1999) "The lunar atmosphere: History, status, current problems, and context" (http://onlinelibrary.wiley.com/doi/10.1029/1999RG900005/full)


Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Space Ghost 1962 on 05/27/2016 08:50 pm
It is cheaper to split water in space at depot, as large space solar array is considerably cheaper to build and maintain. Plus it has access to sun 24/7. Still need to produce fuel on surface to provide tanker's surface to orbit/depot fuel.

I'm not sure I'm convinced this is true. Large arrays in space are hard from a deployment/stiffness/dynamics standpoint. Large arrays on the ground could theoretically use support structures made locally. It's not obvious to me which would win-out in practice.

~Jon
I'd say in-space arrays.
Agree.

You may be able to deal with an incredibly lightweight film as an alternative, that might be manipulated back into place using an external means of various kinds.

We just tend to think in ground metaphors.

Solar panels/concentrators are basically 2d structures, and intrinsically low mass. In fact, getting away from substrate can allow you more optimal absorption (multilayer) / reflection (multilayer) / dissipation (space filling) mechanisms that we can't use in a high gradient environment because of need for substrate.

I'm just skeptical of having multi-hundred MW arrays work well in an environment where you're having to do frequent rendezvous/docking/propellant transfer, etc. And an in-space system is still likely going to need to have some sort of actuation on the arrays, because most orbits have the sun moving relative to them. Ultimately, I'm not sure in-space arrays will win out. Though to be honest, I don't know if lunar arrays will work out better either. I think most people with strong opinions on this haven't thought through the complexities enough to justify the strength of their opinions...

~Jon

Depends on the economics and the qualification of power systems, given near term or longer term systems.

To the point - current systems for either are undesirable. Suggest that the question is "when/how/what do/happens to make systems desirable?"

Things I think about here:
  * Did you know that you can spin stabilize air/fluid systems with membranes in zero g using non mechanical systems? Likely scales to hundreds of meters
  * On orbit systems can be segregate in plane (or halo) such that operations can be deconflicted?
  * Station keeping at L points can be managed with coordinated CoM for extremely low props cost?
  * Short distance (kilometers) uncoupled energy transfer (soliton) can be safe, < 80 % efficient, and low mass?
  * Non rigid e.g. elastic systems can be made to function with acceptable control authority with better efficiency as they scale then rigid systems?

None of this "real" yet in terms of TRL. Individually nothing desirable on its own merit to warrant flight at this point. All "doable" as test/proposals. Reminds me of unfoldable antennas of past decades, flexible habs (e.g. BEAM) currently being attempted.

The promise of >1000:1 weight to power advantage though means a) lifetime on orbit power test (cubesat?), b) manageable scaleable film deployment/steerable (smallsat secondary payload), and formation flying power generation array (medium launch primary payload) progression might deliver on such to improve TRL.

Now, to justify for IRND/grant ... how  do these generate independent advantages of existing systems? Oops.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 05/27/2016 09:30 pm
The attraction of Mars is that it can be at least partially terraformed, ultimately.... Same can not be said of the Moon.

I'll not call this disinformation, and simply chalk it up to lack of reading the literature. But it is possible to terraform the Moon as well, and for it to be stable at human civilizational time scales, at least as far as we have survived so far.

A meteor that is only ~20 m in diameter is sufficient to produce a transient atmosphere on the moon that is collisional. These events happen on  the order of every ~100 years. The Tycho impact probably caused a transient atmosphere that was measured in millibars--about what it is at Hellas Planatia. Such impacts are probably why there is no dust on lunar boulders.

S. Alan Stern (1999) "The lunar atmosphere: History, status, current problems, and context" (http://onlinelibrary.wiley.com/doi/10.1029/1999RG900005/full)
I was aware. Too temporary and wasteful to ever be worth it. You'd never do it, it'd be better to make large habitats.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 05/27/2016 09:38 pm
What is too temporary about 10,000 years?
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 05/27/2016 10:19 pm
What is too temporary about 10,000 years?
...the fact that it'd take about that long to evolve a breathable atmosphere.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: RonM on 05/27/2016 10:30 pm
The attraction of Mars is that it can be at least partially terraformed, ultimately.... Same can not be said of the Moon.

I'll not call this disinformation, and simply chalk it up to lack of reading the literature. But it is possible to terraform the Moon as well, and for it to be stable at human civilizational time scales, at least as far as we have survived so far.

A meteor that is only ~20 m in diameter is sufficient to produce a transient atmosphere on the moon that is collisional. These events happen on  the order of every ~100 years. The Tycho impact probably caused a transient atmosphere that was measured in millibars--about what it is at Hellas Planatia. Such impacts are probably why there is no dust on lunar boulders.

S. Alan Stern (1999) "The lunar atmosphere: History, status, current problems, and context" (http://onlinelibrary.wiley.com/doi/10.1029/1999RG900005/full)
I was aware. Too temporary and wasteful to ever be worth it. You'd never do it, it'd be better to make large habitats.

Even on Mars it wouldn't be worth the effort. Just make large habitats.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: jongoff on 05/27/2016 11:18 pm
  * Did you know that you can spin stabilize air/fluid systems with membranes in zero g using non mechanical systems? Likely scales to hundreds of meters

Yes, we're about to start an SBIR Phase I for a cubesat Heliogyro solar sail. It's potentially over 300m tip-to-tip. But it does have a really low fundamental frequency. I guess my concern is big gossamer structures attached to a transportation node. There are plenty of applications where centrifugally-stabilized solar arrays and radiators could be really interesting, but I'm having a hard time seeing how to do that with a space station that's doing regular rendezvous operations, in a way that wouldn't cause potential issues.

Maybe I'm making a big deal out of it, but something makes me a bit cautious about the idea of combining a high-traffic space facility with a super low first mode mega-array (something with 10MW+ capacity).

~Jon
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: TrevorMonty on 05/27/2016 11:52 pm
I'd vote for in-space array, with beamed power down to lunar surface. Not sure how practicable that would be, but if ever there was a case for SBSP, it would be to power a lunar propellant refinery. Transporting water to space is problematic for a number of reasons: (a) you have no gravity, so that complicates plumbing etc.; (b) a mass ratio of 5 means you're going to have to vent off something like 20% of your cargo, so why send it up in the first place? (c) it'd be redundant, because you're going to have to have a refinery on the ground in order to launch the water in the first place, barring a mass-less mass driver; (d) it's going to balloon your development costs because you have to design two entire different refineries to do one job.

I agree with Jon, however; our crystal balls are not now transparent enough to see the future.
The orbital refinery could beam power to lunar refinery to get though lunar night.
Surplus Oxygen (gas thrusters)can be used for station keeping and settling of fluids.

You can also use it with Earth LH, every 1kg of LH will give 5kg of propellant so it is not that expensive.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 05/28/2016 12:11 am
The attraction of Mars is that it can be at least partially terraformed, ultimately.... Same can not be said of the Moon.

I'll not call this disinformation, and simply chalk it up to lack of reading the literature. But it is possible to terraform the Moon as well, and for it to be stable at human civilizational time scales, at least as far as we have survived so far.

A meteor that is only ~20 m in diameter is sufficient to produce a transient atmosphere on the moon that is collisional. These events happen on  the order of every ~100 years. The Tycho impact probably caused a transient atmosphere that was measured in millibars--about what it is at Hellas Planatia. Such impacts are probably why there is no dust on lunar boulders.

S. Alan Stern (1999) "The lunar atmosphere: History, status, current problems, and context" (http://onlinelibrary.wiley.com/doi/10.1029/1999RG900005/full)
I was aware. Too temporary and wasteful to ever be worth it. You'd never do it, it'd be better to make large habitats.

Even on Mars it wouldn't be worth the effort. Just make large habitats.
On Mars, yes, you'd have to do that at first. But there are enough extant volatiles that some partial terraforming is feasible in a reasonable timescale.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: KelvinZero on 05/28/2016 01:06 am
The attraction of Mars is that it can be at least partially terraformed, ultimately.
Im not arguing there are not still reasons to go to Mars. Im just saying we would already be past that more critical hurdle of becoming an interplanetary species. A town that exports massive amounts of volatiles is way beyond a town that merely uses resources for self sufficiency. The rest is frills.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 05/28/2016 02:04 am
The attraction of Mars is that it can be at least partially terraformed, ultimately.
Im not arguing there are not still reasons to go to Mars. Im just saying we would already be past that more critical hurdle of becoming an interplanetary species. A town that exports massive amounts of volatiles is way beyond a town that merely uses resources for self sufficiency. The rest is frills.
Counterpoint: A town which is solely built on resource extraction will not likely become self-sufficient.

Mars is a continent, the Moon is (billed as) a mine site.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: gbaikie on 05/28/2016 04:01 am
But the power requirements are old news. This is the first time I've heard that they are a showstopper....
Excuse me, but where did I say it was a showstopper?

I'm merely saying that if we're going to base our arguments about why lunar propellants are better based on potential energy (being out of Earth's gravity well), then we need to talk about how it takes much less cost/energy to extract Earth propellants in the first place.


I don't even think that lunar propellants have no place whatsoever, I just don't think it's at ALL a slam-dunk as it's often portrayed. Good reusable tech (also required for lunar props) will make launching stuff from Earth MUCH cheaper, and this point is rarely acknowledged by proponents of lunar propellant.

I would say it this way, if earth launch costs are lowered, then NASA doesn't need to explore the Moon- because having lower launch cost [$100 to 500 per lb to LEO- or $200 to $1000 to high Earth] will lower the cost of commercial exploration and subsequent mining of lunar water. Or lunar water would still be worth about $100 per lb- and after a decade or so it could get to $10 per lb. And at current launch cost, it might take +2 decades to get to $10 per lb- and eventually get down to $1 per lb or less. And as marker of progress, when lunar water can be about $1 per lb, one can think about Earth SPS. And when lunar water at $10 per lb one can think of having lunar grid power available at about $1 [or less] per kw hour. Grid power being any amount of electrical one wants, one can get, and power available whenever you want it.
Now probably get this constant power by having solar power which encircles the small Lunar polar region- so grid power available if one is near the lunar poles. Of course if run transmission lines or beam the power one also have access to this grid power- anywhere lunar surface or with beamed power,  lunar orbit.

The long term purpose of NASA in terms of exploration of Moon and Mars should be getting to point where Earthlings can get solar energy from Space transmitted to anywhere on Earth surface and at a cost currently being paid for electrical power- and eventually much cheaper.

A reason for NASA to explore the Moon, is so NASA can explore Mars- and eventually so gets Earth SPS [within a century- maybe within 50 years].

NASA purpose for exploring Mars should be related to possibility of future human settlements on Mars.
If there are Mars settlements, one is pretty close to having Earth SPS. But Mars settlements aren't NASA exploration- rather Mars settlements are people moving to Mars- Ie, what Elon Musk wants.
You are not going to get Mars settlement without Lunar commercial water mining OR water mining in space other than on the Mars. Or using something like Nuclear Orions. If using Nuclear Orions you will also get Earth SPS. This assuming Nuclear Orion are not run like the Space shuttle program- or some sort of a government jobs program.
But returning to won't have Mars settlements without commercial lunar mining. You won't get Mars settlement without lowering  earth launch cost, significantly, and if lower launch cost, the moon will become a low enough cost, that don't need a government program to explore the Moon- it will be privately done. And once explored to find water deposits, it will then be commercially mined.

So what suggest is planning on getting to point of having lunar water commercially mined before Mars settlement.
Not necessary, before NASA exploration of Mars. Or while NASA is exploring Mars, after NASA has explored the Moon, commercial lunar water mining might occur.
And exploring the Moon to determine if and where there is commercially minable water, is a reason or reinforces idea of the need to explore Mars.
And if one has commercial lunar mining, the US government is not going to terminate addition Mars exploration. Or to explore Mars is going to require decades to do it properly, and so Mars exploration needs a long duration governmental commitment of funding.
And if one has commercial lunar mining- it seems politically improbable that Congress would cancel a Mars exploration program. Though if you already have Mars settlements- I can see it being logical to end the Mars exploration program- because it's completed it's purpose- NASA should explore some other place.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: gbaikie on 05/28/2016 04:16 am
The attraction of Mars is that it can be at least partially terraformed, ultimately.
Im not arguing there are not still reasons to go to Mars. Im just saying we would already be past that more critical hurdle of becoming an interplanetary species. A town that exports massive amounts of volatiles is way beyond a town that merely uses resources for self sufficiency. The rest is frills.
Counterpoint: A town which is solely built on resource extraction will not likely become self-sufficient.

Mars is a continent, the Moon is (billed as) a mine site.

The Moon starts with mining [water mining and other mining]. But the Moon can be a starport. But before this
the Moon can be observatory site. And can a place to build Earth satellites. Can be holiday resort. And an industrial base for space related projects. So sky cities in Venus- built on the Moon, as example of big projects. The lack of atmosphere allows things not to be required to be folded up- one can launch a city from the moon- as well as smaller things- aircraft carriers or smaller.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Retired Downrange on 05/31/2016 11:59 pm
A new, water-logged history of the Moon
May 31, 2016 by Marlowe Hood

http://phys.org/news/2016-05-water-logged-history-moon.html

"After the Apollo missions scooped up rocks from the Moon's surface and brought them home, scientists were convinced for decades that they had proof our nearest celestial neighbour was drier than a bone.

How wrong they were.
New technology detected water in those dusty samples"


Read more at: http://phys.org/news/2016-05-water-logged-history-moon.html#jCp

Title: Re: Impact of lunar free water on Exploration Architecture
Post by: KelvinZero on 06/02/2016 11:08 am
Counterpoint: A town which is solely built on resource extraction will not likely become self-sufficient.
Mars is a continent, the Moon is (billed as) a mine site.
My list of rebuttals got a bit long. To be clear, I blame you. :-)

A mine on earth is probably after specific metal, not the CHON elements.. because that would be silly. Of course it is not a great basis for self sufficiency.

Apart from that of course there is no reason to make a mine site self sufficient on earth. Firstly we are not putting much energy into that anywhere on earth, secondly it presumably has fairly cheap, regular transport.

Im not specifically arguing a volatile exporter has to be self sufficient any more than a mars base has to be self sufficient. But it has demonstrably more than everything you need to attempt this.

The moon being billed as just a mine site is exactly what I was complaining about. If it can export volatiles it  far exceeds the resources required for merely replacing losses of a self sufficient colony.

But more importantly, it is not just a location but a set of technologies. The delta-v and the technology required for such a base means you are right next door to a colonised asteroid civilisation. Not in travel time or kilometers, but in the thing that matters: delta-v and technology.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: guckyfan on 06/02/2016 03:04 pm
How wrong they were.
New technology detected water in those dusty samples"

Great. Just like the millions of tons of gold dissolved in sea water worldwide.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 06/02/2016 11:14 pm
A new, water-logged history of the Moon
May 31, 2016 by Marlowe Hood

http://phys.org/news/2016-05-water-logged-history-moon.html

"After the Apollo missions scooped up rocks from the Moon's surface and brought them home, scientists were convinced for decades that they had proof our nearest celestial neighbour was drier than a bone.

How wrong they were.
New technology detected water in those dusty samples"

Thanks for the link. Here's the link to the Nature article (open access). (http://www.nature.com/ncomms/2016/160531/ncomms11684/full/ncomms11684.html)

How wrong they were.
New technology detected water in those dusty samples"

Great. Just like the millions of tons of gold dissolved in sea water worldwide.

Not a good analogy: the bulk water content of the silica portion of the Moon (the mantle and crust) of >100 ppm is the average water content. Note the 100 ppm figure is conservative, some inclusions had 300 ppm, and there are a myriad of processes that can reduce the water content in a surface hand sample. In addition, the water content of hotspot mantle plumes (on Earth) is more on the order of 1% (10,000 ppm). I have one reference where they get 3%.

I don't know if anyone has ever attempted to calculate the bulk content of oil within the Earth's upper crust, but it is sure to be a miniscule amount. By your reasoning, it would never be economical to drill for oil. Yet we still have gushers (cf. Deepwater Horizon).

The question is: Have there ever been any gushers on the Moon? I say the very existence of the meniscus hollows or irregular mare patches (IMPs) is prima facie evidence for local concentrations of water and other volatiles that escaped in geologically recent times.

I did a calculation a few years ago, and to excavate the Ina D-caldera, the amount of water required would fill the pit with 10 feet of water. Since the pit has an area of ~1 square mile, that'd be enough water to produce 10,000 tonnes per year for a thousand years. More than enough for any conceivable lunar project for as long as we can realistically conceive.

Conservatively, the Moon's polar regions contain 10 billion mT of frozen H2O in various forms. Just going by the water phase diagram, frozen water is stable in a vacuum if it is cold enough. However, micrometeors, cosmic rays, and sputtering caused by deflected solar wind ions take their toll over long periods of time. Thus it is doubtful whether the current rate of meteoric water is enough to sustain the polar ice deposits. The only other source would be juvenile water, and the only area that shows any evidence of outgassing of juvenile water is the central mare basalt region.


Title: Re: Impact of lunar free water on Exploration Architecture
Post by: guckyfan on 06/03/2016 06:28 am
Not a good analogy: the bulk water content of the silica portion of the Moon (the mantle and crust) of >100 ppm is the average water content. Note the 100 ppm figure is conservative, some inclusions had 300 ppm, and there are a myriad of processes that can reduce the water content in a surface hand sample. In addition, the water content of hotspot mantle plumes (on Earth) is more on the order of 1% (10,000 ppm). I have one reference where they get 3%.

Actually a very good analogy IMO. There is no evidence of any usable concentration of that water. Bone dry is the word scientists have used and they are very likely right, no matter how much water that is over the total volume of the moon.

The only proven source of water that can be accessed with any half reasonable effort is the ice in the polar cold traps. And we really don't know how much that is. I am all for going there and finding out. Manned or with rovers.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Phil Stooke on 06/03/2016 06:55 am
" I say the very existence of the meniscus hollows or irregular mare patches (IMPs) is prima facie evidence for local concentrations of water and other volatiles that escaped in geologically recent times. "

It's nice to see my term meniscus hollows getting an airing.  However, they might have been created by radiogenic gases such as helium and argon puffing up through the regolith, no water required!  What's that you say? - no proof?  Of course not, but there's no proof of water in those locations either.  What you say is enticing but until we get a lander into one of them the evidence for water is missing.  Don't get me wrong, I would like to find that evidence.  But I don't want to count on it when it's not in hand.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Lar on 06/03/2016 11:49 am
That's my point too, we should go for the sure thing first, if it exists. Even if it's small, because we need to gain experience with ISRU and we need to bootstrap up.... hence polar ice first.  This will be huge if it's real. But it can wait.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 06/03/2016 06:43 pm
Not a good analogy: the bulk water content of the silica portion of the Moon (the mantle and crust) of >100 ppm is the average water content.
Actually a very good analogy IMO. There is no evidence of any usable concentration of that water.

Mere assertion. I have presented evidence here, both empirical and theoretical, that supports the hypothesis that usable amounts of water could be found in certain low latitude locations. You are certainly free to disagree with the argument presented here, but "scientists from the 1970's pronounced the Moon to be bone-dry" isn't much of a counterargument.

Quote from: guckyfan
The only proven source of water that can be accessed with any half reasonable effort is the ice in the polar cold traps. And we really don't know how much that is. I am all for going there and finding out. Manned or with rovers.

That's my point too, we should go for the sure thing first, if it exists. Even if it's small, because we need to gain experience with ISRU and we need to bootstrap up.... hence polar ice first.  [Drilling for free water?] will be huge if it's real. But it can wait.

The problem is not finding water on the Moon: it is being able to produce water economically. Given a choice between starting a small hard rock mine versus drilling a shallow well, it's not hard to see which one requires the least amount of initial capital.

Check out this little drilling rig here. (http://www.lifewaterdrillingtechnology.com/features--performance.html) It weighs less than 3 tonnes, and two of them can fit into a standard shipping container. It can drill to 500 feet easily. It can be towed behind a pickup truck. A single, relatively small lander could deliver one to a Near Side, low-latitude, line-of-sight location.

Now consider mining for frozen ice. Water at such temperatures has the hardness of quartz. So you'll need a drill anyway, so you drill holes for your blasting explosives. Then a loader/backhoe, if not a full on excavator, will be required, to dig it out, and load up some sort of haulage truck or extensive conveyor belt system or cable car system. Then you've got to process it somehow, and deal with nasty stuff like lots of mercury. Not to mention you'll need communication relays and greater delta v requirements.

These are probably the reasons that NASA is not all over this, and why private companies cannot get any traction. Thus  Dennis Wingo is proposing a whole new approach: go for iron first, and then manufacturing most of your mining equipment on the Moon. Whether or not the latter mode is a more practicable approach, it illustrates graphically the problems associated with mining the polar craters.

We're sort of like where the oil industry was in the 19th century. If you're a 19th century producer wannabe, and you're cash, mass, transportation, and infrastructurally starved, do you go for boondock Alberta tar sands first, or shallow Pennsylvania oil wells with much better lines of communication?

Quote from: Warren Platts
" I say the very existence of the meniscus hollows or irregular mare patches (IMPs) is prima facie evidence for local concentrations of water and other volatiles that escaped in geologically recent times. "

It's nice to see my term meniscus hollows getting an airing.  However, they might have been created by radiogenic gases such as helium and argon puffing up through the regolith, no water required!  What's that you say? - no proof?  Of course not, but there's no proof of water in those locations either.  What you say is enticing but until we get a lander into one of them the evidence for water is missing.  Don't get me wrong, I would like to find that evidence.  But I don't want to count on it when it's not in hand.

Hey Phil, do you have a reference for the Ar/He hypothesis? I agree there is no proof one way or the other until an on-the-ground survey has been done. Thus, appeal to the best explanation is the best we can work with for now. We can compare Ar versus H2O to see which better explains the facts:

We do have a few facts:

1. The meniscus hollows are found pretty much exclusively in certain mare basalt regions on the Near Side. Meanwhile, Ar is being continuously produced all over the Moon. Therefore, the basalt mares are probably required to provide stratigraphic traps where Ar can pool up and be released in quantities big enough to excavate big pits such as the Ina feature. But if there are stratigraphic traps that can trap Ar, then such traps can also trap H2O and other volatiles. It can't be the case that stratigraphic traps only work for Ar.

2. There are, to my knowledge, no nearly pure Ar fumaroles on Earth. It can be found in some natural gas deposits, but it's a minor component. Meanwhile, we know that water is the main ingredient used in excavating terrestrial maars, that are probably the closest terrestrial analogs to meniscus hollows IMO.

3. A big problem with gas-only explanations for meniscus hollows is the storage volume required, and the available mass flux at which it could be delivered to the surface. Thus it's hard to get a violent explosion capable of doing the main excavation of a meniscus hollow. However, if you can suddenly turn a liquid into a gas, you have the potential for very violent explosions.

4. Ar doesn't freeze at the temperatures found at the meniscus hollows, so it can freely diffuse through the regolith, dissipating any pressure buildup. Water, on the other hand, if the pressure gets anywhere above like 100 Pascals, it will start to freeze. This will have two main effects: (1) it will form an impermeable permafrost that will prevent further seepage, thus allowing pressures to gradually build up; (2) it will increase the tensile strength of the regolith to ensure that when the pressure is finally released, its going to be extra violent. (The largest maars on Earth are found in northern permafrost regions).

Thus, while I agree that the Ar hypothesis is conceivable, it's mere existence qua theory shouldn't dissuade us from exploring meniscus hollows IMHO. A simple rover should be able to go there and exclude the other main hypothesis, that these are purely volcanic features not involving outgassing. Being able to tell the difference between Ar vs. H2O mediated outgassing might require a sample return mission.

The main problem with the H2O hypothesis, as evidenced by many of the comments above,  is that it can't get past the giggle-factor/smell-test for a lot of people, despite the fact that these locations have been considered to be possibly valuable locations for ISRU by several lunar scientists  for decades now.

But it is a matter of logic, really, that at the temperature and pressure regime that should exist immediately below meniscus hollows, then the H2O should condense, entailing that if it is there at all in the first place, then such water should be relatively much less difficult to access compared to polar craters.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 06/03/2016 07:38 pm
Yesterday, I compiled a .kmz file that has the 98 meniscus hollows that I am aware of. It's easily loaded into Google Moon. If you want to play around with it, there's a layer with old geological maps of the Moon that makes it a lot more interesting, as the Google Moon satellite photos aren't very high res.

(http://i.imgur.com/8jtKPfj.png)
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Lar on 06/03/2016 09:03 pm
That's my point too, we should go for the sure thing first, if it exists. Even if it's small, because we need to gain experience with ISRU and we need to bootstrap up.... hence polar ice first.  [Drilling for free water?] will be huge if it's real. But it can wait.

The problem is not finding water on the Moon: it is being able to produce water economically. Given a choice between starting a small hard rock mine versus drilling a shallow well, it's not hard to see which one requires the least amount of initial capital.

Check out this little drilling rig here. (http://www.lifewaterdrillingtechnology.com/features--performance.html) It weighs less than 3 tonnes, and two of them can fit into a standard shipping container. It can drill to 500 feet easily. It can be towed behind a pickup truck. A single, relatively small lander could deliver one to a Near Side, low-latitude, line-of-sight location.

Now consider mining for frozen ice. Water at such temperatures has the hardness of quartz. So you'll need a drill anyway, so you drill holes for your blasting explosives. Then a loader/backhoe, if not a full on excavator, will be required, to dig it out, and load up some sort of haulage truck or extensive conveyor belt system or cable car system. Then you've got to process it somehow, and deal with nasty stuff like lots of mercury. Not to mention you'll need communication relays and greater delta v requirements.

These are probably the reasons that NASA is not all over this, and why private companies cannot get any traction. Thus  Dennis Wingo is proposing a whole new approach: go for iron first, and then manufacturing most of your mining equipment on the Moon. Whether or not the latter mode is a more practicable approach, it illustrates graphically the problems associated with mining the polar craters.

We're sort of like where the oil industry was in the 19th century. If you're a 19th century producer wannabe, and you're cash, mass, transportation, and infrastructurally starved, do you go for boondock Alberta tar sands first, or shallow Pennsylvania oil wells with much better lines of communication?

While I agree that we should go for easy vs. hard, clearly we have a difference of opinion on which is easier. You seem to assume that polar ice has to be mined for. Proposals I've seen use drilling and heat rather than hardrock mining. So your drilling rig and processing equipment make the argument for me!  Polar first, then as we grow capability, expand.

I'd rather not have any dry holes. Not at first when we can ill afford them.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 06/03/2016 10:17 pm
While I agree that we should go for easy vs. hard, clearly we have a difference of opinion on which is easier. You seem to assume that polar ice has to be mined for. Proposals I've seen use drilling and heat rather than hardrock mining. So your drilling rig and processing equipment make the argument for me!  Polar first, then as we grow capability, expand.

I'd rather not have any dry holes. Not at first when we can ill afford them.

You misunderstand me. It does not make sense to go whole hog for either mining or drilling until proper prospecting has been done. This has not been done for the polar regions or anywhere else.

As for concrete designs for mining polar ice deposits, I have seen the same designs. Similar strategies are used to extract oil from tar sands. However, of tar sand deposits, they find it more economical to surface mine it when the overburden is less than 75 meters thick. The same will hold for polar ice deposits: these will be shallow, surface deposits; it will be more economical to surface mine them.

I am not proposing that NASA's exploration program be radically restructured to go all out for developing the meniscus hollows. What I am proposing in the short term is that these meniscus hollows be slated as exploration targets. They are scientifically interesting in addition to their ISRU potential.

No matter how you slice it, meniscus hollows will be easier--defined as cheaper--to explore than polar, permanently shaded craters. Moreover, it is possible to do both. The options are not mutually exclusive.

That is, unless you have enough capability to get to Ina or Hygenus, but not enough capability to get to Whipple or Shackleton. In that case, the options ARE mutually exclusive, and it's a choice between exploring a meniscus hollow or doing nothing but power points.

Really, my proposal is aimed at commercial companies like DSI or Shackleton. Right now, neither has enough $$$ to explore anything. But before they have enough $$$ to explore a polar crater, they will necessarily have enough to investigate a meniscus hollow. Thus, it's ironic that you bring up the need for waiting and avoiding dry holes. By your logic, when a company has enough resources to investigate a meniscus hollow, it should wait until it has saved up enough capital to go for a polar crater, that may not prove economical in any case (it's a dry hole for practical purposes), and only then backtrack and do what it could have done in the first place.

Not a good business model.

Better to go as soon as possible. Even if the meniscus hollows were shown to be not formed due to outgassing, at least you would have a chance to test out your equipment at low-latitude, line-of-sight locations. Which is probably what they would do anyway. So given that you are going to test out equipment at low latitude locations before sending them to polar locations, should one throw a dart, or should one go revisit an Apollo landing site, or should one go for a location that actually has massive ISRU potential?

Also, these meniscus hollows sometimes form dense clusters, so it would be possible for a single, solar-powered rover to investigate several in one mission. E.g., the Gruithuisen (GEM) group below. There's about half a dozen of them in a line 7 kilometers long. (Each of the tick marks on the left are 5 km each).

(http://i.imgur.com/JeQSRXm.png)
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Lar on 06/04/2016 08:02 pm
I had the impression that we had far better prospecting done for the polar regions than we had for meniscus regions. Insofar as one can say that without having visited either with a surface probe.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 06/05/2016 04:16 am
I had the impression that we had far better prospecting done for the polar regions than we had for meniscus regions. Insofar as one can say that without having visited either with a surface probe.

The same probes have looked at meniscus hollows, with the exception of the LCROSS. The Moon Mineralogy Mapper (M3) has taken a close look at the Ina feature. But there's only so much that can be done with remote sensing. There has been no more ardent advocate of mining the polar craters than Paul Spudis, but he will be the first to tell you we need to do more prospecting before we commit to any major mining projects.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Lar on 06/05/2016 04:20 am
Sounds like we need to send a Silver Dragon full of prospecting equipment to both places...
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 06/09/2016 12:20 am
Well, I presented the paper today. Actually fairly well received. Robert Zubrin and Nantel Suzuki, Program Executive HEOMD at NASA HQ sat down next to me at lunch to pick my brain. Interesting day. George Sowers, VP of Advanced Operations at ULA basically bid $500,000 per tonne at lunar surface. They will take delivery. I took his figures and was able to calculate a wellhead price for lunar water of $3.45/liter. Better than Perrier--and it's even carbonated! :D Jerry Sanders says RPM still a funded activity, albeit stuck in Phase A purgatory.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: the_other_Doug on 06/09/2016 12:56 am
Well, I presented the paper today. Actually fairly well received. Robert Zubrin and Nantel Suzuki, Program Executive HEOMD at NASA HQ sat down next to me at lunch to pick my brain. Interesting day. George Sowers, VP of Advanced Operations at ULA basically bid $500,000 per tonne at lunar surface. They will take delivery. I took his figures and was able to calculate a wellhead price for lunar water of $3.45/liter. Better than Perrier--and it's even carbonated! :D Jerry Sanders says RPM still a funded activity, albeit stuck in Phase A purgatory.

From your proposals to the gods' ears, Warren.  Anything that would let us do the kind of legitimate prospecting to establish the presence and potential accessibility of low-latitude water deposits is to be highly encouraged.

I can see the development of a relatively low-cost set of unmanned landers, to be sent to a variety of meniscus hollows and other likely sites, there to perform a number of in-situ measurements to try and establish if there might be good water drilling prospects at any of them.  I could speculate on the best instrument suites to send -- I'm thinking of focused seismic measurements, ground-penetrating radar measurements, and sensitive spectrometers that can see very tiny enrichments of the local lunar atmosphere in volatiles, to name a few -- but I'd definitely get some of those going ASAP.

You're gonna need that kind of proof of the deposits actually existing where you think they exist, before you get the money you need to start up drilling operations, I think.  But, hey -- it's well worth the expense of the initial surveys, even if there is only a one-in-a-hundred chance of finding and verifying a good bet for a "wet hole" site that can be exploited in the relatively near future...
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 06/09/2016 02:13 am
Robert was wracking his brain trying to think of some kind of orbital sensing could determine the truth of the matter, and Mr. Suzuki was hinting that it might be possible to redirect existing orbital assets to take a closer look at these meniscus hollows. So the question I would put to you all is what existing instruments on current orbital assets (e.g., LRO) could be used to shed light on the question?

PS I was accosted by George Sowers and Bernard Kutter and was told the bid price had gone down to $50/kg! Talk about volatility...
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: jongoff on 06/09/2016 04:53 am
Well, I presented the paper today. Actually fairly well received. Robert Zubrin and Nantel Suzuki, Program Executive HEOMD at NASA HQ sat down next to me at lunch to pick my brain. Interesting day. George Sowers, VP of Advanced Operations at ULA basically bid $500,000 per tonne at lunar surface. They will take delivery. I took his figures and was able to calculate a wellhead price for lunar water of $3.45/liter. Better than Perrier--and it's even carbonated! :D Jerry Sanders says RPM still a funded activity, albeit stuck in Phase A purgatory.

Warren,
Interesting paper! It'll be interesting if you can find a way to validate or invalidate this from orbit (as per your other post). Powerwise a near-side location isn't anywhere near as convenient as the poles, but if you have liquid water available, that's intriguing enough to be worth the hassle of having to deal with the less favorable power situation. I'm skeptical, just because it sounds too good to be true, but will be interested to hear where your research takes you. If you wanted to experimental drilling, how small of a rig do you think you could get to? 3mT is heavy enough to be a challenge, but if you could somehow get it under 1mT, it seems like there would be more options available.

~Jon
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: guckyfan on 06/09/2016 12:41 pm
How wrong they were.
New technology detected water in those dusty samples"

Great. Just like the millions of tons of gold dissolved in sea water worldwide.

I read the whole thread carefully now. I should have done that before. Seems I have to retract my statement and apologize.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: jongoff on 06/09/2016 05:45 pm
How wrong they were.
New technology detected water in those dusty samples"

Great. Just like the millions of tons of gold dissolved in sea water worldwide.

I read the whole thread carefully now. I should have done that before. Seems I have to retract my statement and apologize.


That's a level of class you don't often see on an online forum.

~Jon
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Steven Pietrobon on 06/10/2016 06:43 am
Jon, thanks for your posts on this. What do you think are the prospects of other light elements being able to be sourced from these miniscus hollows? For example carbon and nitrogen, which would be needed to produce food and expand life on/in the Moon.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 06/10/2016 06:49 am
Warren, I'm super skeptical this is a real find and that water/volatiles are really so easy to acquire as that.

But I'll be very glad to be proven wrong. The Moon would be a lot more interesting to utilize if it's true. Having such abundant water would make steam rockets attractive and thus would significantly reduce the cost of launching stuff from the Moon.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: the_other_Doug on 06/10/2016 04:10 pm
The only problem I can see in terms of verifying that meniscus hollows are indeed indicative of underground water/ice reservoirs, is that I can't come up with a way to find and verify such things from orbit.

The two main things I can think of that you'll need to do will be:

- shallow sampling in and around such features, with detailed spectroscopy of the samples to find volatiles (which means special handling to keep surface conditions from driving off said volatiles before you can look for them), and

- seismic profiling of these regions at far greater detail than Apollo ever managed.  This means emplacing a lot of seismometers and geophones all around a given area and then setting off either explosive charges or arranging well-targeted impacts.  The process is now quite mature on Earth, used every day in the petroleum industry.  It's more difficult to do remotely, and certainly more expensive to do on the Moon.  But I think it's really the only way we're going to be able to identify places where you might find volatiles reservoirs that would justify mining/drilling operations.

So, unfortunately, I can't think of any way to prove the theory without putting a lot of surface assets in place around one or more of the hollows.  Which means we're talking a higher initial investment than you'd like to verify the presence of the reservoirs, and then to identify potential drilling sites.

I wish I could think of orbital sensors that could positively locate volatiles reservoirs, but I just can't.  I'd suggest that it might be easier to go prospecting for them after you have some kind of infrastructure set up either on or around the Moon, so it might end up making more sense to start out using the polar ices, and once you've driven access prices down somewhat with your surface and/or cislunar infrastructure, then go off in search of juvenile water, when it will be far cheaper and easier to do the prospecting...
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: TrevorMonty on 06/10/2016 05:38 pm
Doug had good point. Given costs of doing anything on moon it is better to target known water sources ice polar craters.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: gbaikie on 06/11/2016 02:35 am
Doug had good point. Given costs of doing anything on moon it is better to target known water sources ice polar craters.

I think one also has similar approach to Mars exploration.
Or I would say one of the ultimate purpose of a NASA Mars Exploration is to find drill-able sources of water [or some other kind of cheap water for human settlement use]. But for exploration purposes you don't need such vast amounts of water. So, one might start by taking Mars water from the atmosphere. Main advantage being works anywhere, and could be robotic [so, mine Martian water before first crew arrive]. This similar to bringing Hydrogen and using the CO2 of Mars atmosphere- and one could do both or neither.
And next step of exploration might focus to surface sources of water, and finally finding best location to drill for martian water which would be cheap per unit amount [of clean/fresh water] and also has large reservoirs of available water [which makes it very cheap if there is need/demand of billions of tons of water per year or per decade]. Of course if early on you come across a source of very cheap water, you, of course, celebrate- and Mars settlements should be encouraged significantly from such a discovery.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: jongoff on 06/11/2016 03:43 am
Warren, I'm super skeptical this is a real find and that water/volatiles are really so easy to acquire as that.

I'm cautiously skeptical too. It would be epic if true, but seems a little too good to be true so far.

Quote
But I'll be very glad to be proven wrong. The Moon would be a lot more interesting to utilize if it's true. Having such abundant water would make steam rockets attractive and thus would significantly reduce the cost of launching stuff from the Moon.

You won't give up on the idea of wasting 1/2 of your ISRU production capacity using rockets to launch payloads off of the Moon (instead of perfectly realistic propellantless launch methods that work just fine on the Moon), will you? You're going to get me to stay up stupid late writing my next "Slings and Arrows" post, aren't you. :-)

~Jon
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: jongoff on 06/11/2016 03:53 am
The only problem I can see in terms of verifying that meniscus hollows are indeed indicative of underground water/ice reservoirs, is that I can't come up with a way to find and verify such things from orbit.

The two main things I can think of that you'll need to do will be:

- shallow sampling in and around such features, with detailed spectroscopy of the samples to find volatiles (which means special handling to keep surface conditions from driving off said volatiles before you can look for them), and

- seismic profiling of these regions at far greater detail than Apollo ever managed.  This means emplacing a lot of seismometers and geophones all around a given area and then setting off either explosive charges or arranging well-targeted impacts.  The process is now quite mature on Earth, used every day in the petroleum industry.  It's more difficult to do remotely, and certainly more expensive to do on the Moon.  But I think it's really the only way we're going to be able to identify places where you might find volatiles reservoirs that would justify mining/drilling operations.

So, unfortunately, I can't think of any way to prove the theory without putting a lot of surface assets in place around one or more of the hollows.  Which means we're talking a higher initial investment than you'd like to verify the presence of the reservoirs, and then to identify potential drilling sites.

I wish I could think of orbital sensors that could positively locate volatiles reservoirs, but I just can't.  I'd suggest that it might be easier to go prospecting for them after you have some kind of infrastructure set up either on or around the Moon, so it might end up making more sense to start out using the polar ices, and once you've driven access prices down somewhat with your surface and/or cislunar infrastructure, then go off in search of juvenile water, when it will be far cheaper and easier to do the prospecting...

I agree that I'm also not sure if there's a way to do this via remote sensing from orbit (which would be far simpler). Is this something that ground penetrating radar could help with?

On the lander side, the way you describe things makes it sound like it might be a good idea to have a big lander with a whole bunch of mini hopper vehicles that could spread sensors or charges around. If you're not trying to have the mini hoppers do the full deorbit burn from LLO, you might be able to use something cubesat scale that had enough delta-V to launch from the mothership lander, and then move over and land at a remote site a few km away. There might actually be a way to do this with a single mission if you're clever about it. But still not particularly cheap.

~Jon
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: A_M_Swallow on 06/11/2016 04:19 am

I agree that I'm also not sure if there's a way to do this via remote sensing from orbit (which would be far simpler). Is this something that ground penetrating radar could help with?

On the lander side, the way you describe things makes it sound like it might be a good idea to have a big lander with a whole bunch of mini hopper vehicles that could spread sensors or charges around. If you're not trying to have the mini hoppers do the full deorbit burn from LLO, you might be able to use something cubesat scale that had enough delta-V to launch from the mothership lander, and then move over and land at a remote site a few km away. There might actually be a way to do this with a single mission if you're clever about it. But still not particularly cheap.

~Jon

A mini-lander. Possibly a variant on Mighty Eagle?
https://en.wikipedia.org/wiki/Mighty_Eagle (https://en.wikipedia.org/wiki/Mighty_Eagle)
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: jongoff on 06/11/2016 05:14 am

I agree that I'm also not sure if there's a way to do this via remote sensing from orbit (which would be far simpler). Is this something that ground penetrating radar could help with?

On the lander side, the way you describe things makes it sound like it might be a good idea to have a big lander with a whole bunch of mini hopper vehicles that could spread sensors or charges around. If you're not trying to have the mini hoppers do the full deorbit burn from LLO, you might be able to use something cubesat scale that had enough delta-V to launch from the mothership lander, and then move over and land at a remote site a few km away. There might actually be a way to do this with a single mission if you're clever about it. But still not particularly cheap.

~Jon

A mini-lander. Possibly a variant on Mighty Eagle?
https://en.wikipedia.org/wiki/Mighty_Eagle (https://en.wikipedia.org/wiki/Mighty_Eagle)

No, I'm talking a lot smaller than that.

~Jon
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Proponent on 06/11/2016 10:35 am
Is this something that ground penetrating radar could help with?

Off-hand, I would think so.  Moon dust is a lousy conductor, and that helps in two ways.  Firstly, it means that diurnal temperature variations damp out quickly with depth, so the meniscus should come pretty close to the surface (like a meter).  Secondly, a poor conductor, i.e., good dielectric (at least on centimetric scales) should allow microwaves to penetrate better.

[Addendum]  In fact, S-band observations from LRO and Chanrayaan-1 were used to rule out thick layers of ice down to depths of several meters at the lunar poles (see the attachment).  I'm not up on all of the radar data from these spacecraft, but presumably they scanned the whole moon.  I wonder what constraints, if any, that puts on water menisci.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: the_other_Doug on 06/11/2016 04:49 pm
Ground-penetrating radar has been deployed more than once from lunar orbit.  The problem has historically been that such orbital deployments lack the spatial resolution needed to easily interpret the results.

It does occur to me that, while I really like Jon's idea of a main lander bus that deploys sensors like geophones and seismometers, I wonder if you have to actually land all that mass and then have more mass there to hop the sensors into place, along a kilometers-wide grid.

What about penetrators?  Referring back to the petroleum industry, when they are trying to set up a geophone grid out in "difficult terrain," they'll drop penetrators out of airplanes or helicopters.  The sensor packages are latched in and proof against very hard impacts of up to 100 m/s or more, with battery-fed power systems and radio antennae that pop up through the hole in the ground left by the impact.

The Mars penetrators attached to MPL were designed after these, and while they failed, a percentage of those deployed in petroleum prospecting fail, too.  The idea on the Moon would be to deploy a bunch of relatively cheap, dumb penetrators, establish a good geophone grid that would be tolerant of missing up to, say, 10% of the planned grid, and then proceed to fire big dumb impactors into pre-selected locations.  The whole geophone grid only has to operate for the time it takes to set off your impacts (or, for more deluxe deployments, explosive charges gently placed at pre-selected locations by soft landers) for you to get your basic seismic profiling of that area.

This plan wouldn't require a lot of expensive surface work, and could actually be done by orbital assets -- though these orbital assets would be there to shoot things down onto/into the surface, not so much to just take measurements from above.

By using penetrators, you could set up a seismic profiling mission for a given area, put together a bus containing the penetrators and a system that deploys them into the desired surface grid, then either land a rover that deposits explosive charges at selected locations, or use impacts (or perhaps impacts-plus-explosive-charges?) to generate the seismic signals.  Do your profiling in one big shot, then take your data and go off to reduce it and see if you spot telltale seismic indicators of frozen water deposits.

I'd prefer to do it all with more controllable surface operations, but those would obviously be much more expensive.  At least the penetrator option could be done relatively cheaply, and could be repeated at different target sites to get comparisons in ground truth between various sites that appear similar from above...
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 06/11/2016 08:11 pm
Speaking of radars, I don't think anything like the SHARAD system on MRO has been tried on the Moon. The S-band stuff is only ~15 cm wavelength, whereas SHARAD has 15 m wavelength. The problem is the resolution isn't all that great: on order of ~1 km horizontally, 10 m vertically. Meanwhile, the size of these lunar maars is about the same, so only a single pixel would show up.

However, there are some rather dense clusters that would seem to stem from the same underground source. These zones might be big enough to get an unambiguous return.

(http://i.imgur.com/OB0N3gT.png)

One thing at that conference: the M-WIP study was trying to say that SHARAD disproved any reasonably accessible groundwater. Zubrin thought that was baloney. I have to agree with him. We don't care about average conditions. We want to find the exceptional conditions.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: jongoff on 06/11/2016 08:51 pm
We don't care about average conditions. We want to find the exceptional conditions.

This.

The challenge is that with surface access being so hard/expensive, it makes finding those exceptional conditions a lot more difficult. But I agree, so many people look at average material concentrations, when on Earth, we typically mine ore-bodies and other not-average locations, where some phenomenon or other has concentrated resources a lot higher than the average concentration.

I just wish we could get the cost of lunar prospecting down to a level that we could afford to do more of it.

~Jon
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: gbaikie on 06/11/2016 09:51 pm

I agree that I'm also not sure if there's a way to do this via remote sensing from orbit (which would be far simpler). Is this something that ground penetrating radar could help with?

On the lander side, the way you describe things makes it sound like it might be a good idea to have a big lander with a whole bunch of mini hopper vehicles that could spread sensors or charges around. If you're not trying to have the mini hoppers do the full deorbit burn from LLO, you might be able to use something cubesat scale that had enough delta-V to launch from the mothership lander, and then move over and land at a remote site a few km away. There might actually be a way to do this with a single mission if you're clever about it. But still not particularly cheap.

~Jon

A mini-lander. Possibly a variant on Mighty Eagle?
https://en.wikipedia.org/wiki/Mighty_Eagle (https://en.wikipedia.org/wiki/Mighty_Eagle)

No, I'm talking a lot smaller than that.

~Jon

Have mothership "lander" at elliptical orbit [EML-1 to 50 km lunar surface or would impact lunar surface at 2 km/sec]. When near moon decelerate by 1 km/sec. Launch mini hoppers at different times and would impact at varied locations along the trajectory path at about 1 km/sec [if without any delta-v added- oh, if no delta-v added they impact in about same area- though mothership has separate burns which add up to 1 km/sec they could land/crash in different areas]. Then mothership accelerate by 1 km/sec and returns to it's orbit [maybe refuel and gets more mini hoppers]. Or it isn't a lander.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: gbaikie on 06/11/2016 10:27 pm
We don't care about average conditions. We want to find the exceptional conditions.

This.

The challenge is that with surface access being so hard/expensive, it makes finding those exceptional conditions a lot more difficult. But I agree, so many people look at average material concentrations, when on Earth, we typically mine ore-bodies and other not-average locations, where some phenomenon or other has concentrated resources a lot higher than the average concentration.

I just wish we could get the cost of lunar prospecting down to a level that we could afford to do more of it.

~Jon
By having lunar program one can lower cost.
And terms NASA program have it be relativity brief program.
So less than 10 years, 3 billion per year on robotic, thereafter robotic switches focus to Mars robotic program.
So one doing assemble line type robotic missions- FBC type stuff. Or it's the robotic not launch cost which major factor of costs, one also mission operation costs, one get more mission operations done per year per operator. Yeah, lunar exploration could add up to 40 billion [20 billion robotic/20 billion crewed] but one should be getting things done for money spent. And by gear up the robotic, one should be able lower Mars robotic costs- or any other robotic exploration
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Proponent on 06/11/2016 11:38 pm
The Mars penetrators attached to MPL were designed after these, and while they failed, a percentage of those deployed in petroleum prospecting fail, too.  The idea on the Moon would be to deploy a bunch of relatively cheap, dumb penetrators, establish a good geophone grid that would be tolerant of missing up to, say, 10% of the planned grid, and then proceed to fire big dumb impactors into pre-selected locations.

The has been a lunar penetrator as well, the Japanese Lunar-A (https://en.wikipedia.org/wiki/Lunar-A).  Like Deep Space 2 at Mars, it failed.  (I jest: it "failed" for administrative reasons long before launch, i.e., it got canceled.)
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: A_M_Swallow on 06/12/2016 01:55 am

I agree that I'm also not sure if there's a way to do this via remote sensing from orbit (which would be far simpler). Is this something that ground penetrating radar could help with?

On the lander side, the way you describe things makes it sound like it might be a good idea to have a big lander with a whole bunch of mini hopper vehicles that could spread sensors or charges around. If you're not trying to have the mini hoppers do the full deorbit burn from LLO, you might be able to use something cubesat scale that had enough delta-V to launch from the mothership lander, and then move over and land at a remote site a few km away. There might actually be a way to do this with a single mission if you're clever about it. But still not particularly cheap.

~Jon

A mini-lander. Possibly a variant on Mighty Eagle?
https://en.wikipedia.org/wiki/Mighty_Eagle (https://en.wikipedia.org/wiki/Mighty_Eagle)

No, I'm talking a lot smaller than that.

~Jon

There are RCS rocket motors in the 5-10 lbf that could be used for the micro-landers main engine.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: georgesowers on 06/22/2016 04:52 pm
I really enjoyed Warren's presentation at the Space Resources Workshop.  After having issued what I thought was a very challenging price point of $500k/ton, Warren gets up and claims to be able to deliver for an order of magnitude less!!  I was very encouraged :D (Though, to be completely fair, my price was for propellant and Warren was quoting water.)

Understand the idea is speculative, but the upside is enormous.  My charts from the same conference are now online:
http://www.ulalaunch.com/uploads/docs/Published_Papers/Commercial_Space/TransportationEnablingRobustCislunarEconomy_June16.pdf

The problem I'm trying to solve is how to bootstrap the cislunar economy.  As shown in presentation, there is a (albeit tenuous) business case IF propellant can be purchased on the surface of the moon for $500k/ton.  Or for you asteroid guys, $1000k/ton at L1.  Bootstrapping comes about from the fact that once such a supply is established, the cost to launch anything from earth to the moon is reduced by more than a factor of 3 through refueling with lunar (or asteroid) propellant.  At Warren's prices the factor is more like 6.  In other words launch cost to the moon (or other BLEO location) become almost as low as launch costs to LEO.

How many new business cases are then enabled?
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 06/22/2016 06:08 pm
I really enjoyed Warren's presentation at the Space Resources Workshop.  After having issued what I thought was a very challenging price point of $500k/ton, Warren gets up and claims to be able to deliver for an order of magnitude less!!  I was very encouraged :D (Though, to be completely fair, my price was for propellant and Warren was quoting water.)

Understand the idea is speculative, but the upside is enormous.  My charts from the same conference are now online:
http://www.ulalaunch.com/uploads/docs/Published_Papers/Commercial_Space/TransportationEnablingRobustCislunarEconomy_June16.pdf

The problem I'm trying to solve is how to bootstrap the cislunar economy.  As shown in presentation, there is a (albeit tenuous) business case IF propellant can be purchased on the surface of the moon for $500k/ton.  Or for you asteroid guys, $1000k/ton at L1.  Bootstrapping comes about from the fact that once such a supply is established, the cost to launch anything from earth to the moon is reduced by more than a factor of 3 through refueling with lunar (or asteroid) propellant.  At Warren's prices the factor is more like 6.  In other words launch cost to the moon (or other BLEO location) become almost as low as launch costs to LEO.

How many new business cases are then enabled?

The idea of purchasing propellant in orbit is super powerful, and something that NASA should really pursue for exploration (you have like ONE big ship to refuel vs a bunch of satellite boosters).


And as you mentioned with "you asteroid guys," it can be fairly agnostic as to HOW, exactly, the propellant gets there.

It's like the perfect market almost. Propellant in orbit, like the "money" of space.

You could allow EVERYONE to try their hands at their favorite cheap space idea, whether that be:

1) Lunar isru (of various types)
2) asteroid isru
3) Mars isru?
4) Earth exospheric ISRU (i.e. orbital atmospheric scooping)
4) Earth surface ISRU, i.e.:
   -RLV launch (big RLV or small RLV, air-breathing first stage or rocket, NTR or chemical, VTVL or HTHL)
   -big dumb booster
   -small dumb booster (OTRAG)
   -alt-launch, ala space elevators, rotovator-assisted launch, gun launch, rail launch, etc.
5) solar wind ISRU?
6) other?

It allows the opportunity for all kinds of launch and space resource utilization ideas to be tested with a demonstrated customer that only cares about the propellant and not how you got it there.

So, I applaud this idea heartily.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 06/28/2016 08:09 pm
I really enjoyed Warren's presentation at the Space Resources Workshop.  After having issued what I thought was a very challenging price point of $500k/ton, Warren gets up and claims to be able to deliver for an order of magnitude less!!  I was very encouraged :D (Though, to be completely fair, my price was for propellant and Warren was quoting water.)

Understand the idea is speculative, but the upside is enormous.  My charts from the same conference are now online:
http://www.ulalaunch.com/uploads/docs/Published_Papers/Commercial_Space/TransportationEnablingRobustCislunarEconomy_June16.pdf

Wow! Thanks for the kind words George! :) Actually, using the figures from your presentation, and assuming a 3 mT drilling rig constructed a well in the right spot that put out 5 gallons per minute (a typical household water flow in Colorado), it works out as follows:

3,000 kg mass of drilling rig
50,000 $/kg construction cost on Earth
35,000 $/kg transportation cost to lunar surface
$255M total cost of drilling unit
$25.5M total cost per year amortized for 10 years
3,000 $/kg annual operating costs/kg
$9M   total annual operating cost
$34.5 total annual operating cost plus amortized plant costs
10,000 mT = total water production

3,450 $/mT wellhead price of water (= $3.45/Liter)

Of course the ULA isn't going to go for steampunk solar-powered water steam engines. They want clean LO2/LH2, and it's gotta be mass ratio 5! So converting that much water into rocket propellant on the Moon would be a major undertaking.

Using George's figure for plant efficiency of 25.5 kg/yr /kg of propellant production plant mass--and assuming a mass ratio of 5 rather than stoichiometric mass ratio of 8--then 10,000 mT of water would produce 6,667 mT of mass ratio 5 propellant--then producing that much rocket fuel would take a production plant massing 261.438 mT.

Thus, working that figure out:

261,438 kg * $50,000/kg = $13,071,895,425 total construction cost
261,438 kg * $35,000/kg = $ 9,150,326,797 total transportation cost
------------------------------------------------
$22,222,222,222 total unit cost (that's bizarre how that number worked out...)

261,438 kg * $3,000/kg = $784,313,725  annual operating cost

$2,222,222,222 annual amortized plant cost
$  784,313,725 annual operating cost
---------------------------------------
$3,006,535,948 total annual costs propellant plant
$   34,500,000 total water feedstock cost
---------------------------------------
$3,041,035,948 total annual costs
6,666.67 mT total annual production propellant
---------------------------------------
$456,155 / mT cost of propellant production
$500,000 / mT bid price of lunar propellant
---------------------------------------
$3,333,333,333 total revenues
(3,041,035,948) total annual costs
---------------------------------------
$292,297,386 total annual profit
$3,041,035,948 annual cost of investment
---------------------------------------
9.6% ROI

So not the greatest ROI one can hope for, but we can see a couple of things from this exercise:

(1) the importance of keeping your feedstock costs low--that's why we've got to do drilling if it's at all possible--this point holds for Mars as well IMHO;

(2) when producing so much propellant at the thousands of tonnes scale, it might be possible to achieve some sort of economy of scale, and bring down that 25.5 kg/yr of rocket propellant per kg of propellant plant mass--e.g., the fuel tanks of the initial landers could form the basis for the needed tank farm;

(3) some sort of propellantless launch capability a la Jon Goff's ideas would really bring down the FOB cost to L1 (since the bid price there is $1M/mT), thus increasing room for profit. Because to convince investors to buy into a lunar propellant scheme, they are probably going to want a high ROI (unless they are Elon Musk types willing to do it for the good of humanity! ;) ).


Title: Re: Impact of lunar free water on Exploration Architecture
Post by: TrevorMonty on 06/28/2016 09:46 pm
The $500/kg is price required if you trying to deliver this fuel to LEO and compete with earth supplied fuel in LEO.

For EML1 fuel the price can be considerably higher.  As a rough estimate lunar surface price only needs to match LEO fuel price. Both transport systems would use about same amount of fuel to deliver a kg fuel to EML1.

For Lunar surface fuel demand eg refueling a lander supplying a lunar base.  The price can be what ever it costs to deliver a kg LEO fuel to surface.

Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 06/29/2016 02:26 am
The $500/kg is price required if you trying to deliver this fuel to LEO and compete with earth supplied fuel in LEO.
...
Maybe. That's not competing against fully reusable RLVs.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: TrevorMonty on 06/29/2016 04:51 am
The $500/kg is price required if you trying to deliver this fuel to LEO and compete with earth supplied fuel in LEO.
...
Maybe. That's not competing against fully reusable RLVs.
Everything is linked to cost of earth supplied LEO fuel, cheaper it is, cheaper Lunar fuel needs to be. On plus side lower launch costs also reduce cost of establishing lunar facilities.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 06/29/2016 12:46 pm
The $500/kg is price required if you trying to deliver this fuel to LEO and compete with earth supplied fuel in LEO.
...
Maybe. That's not competing against fully reusable RLVs.
Everything is linked to cost of earth supplied LEO fuel, cheaper it is, cheaper Lunar fuel needs to be. On plus side lower launch costs also reduce cost of establishing lunar facilities.
Right. But I think it's important that lunar propellant systems be designed with the idea of competing with full RLVs from the start. $500/kg just isn't low enough, because that could easily be done with full RLVs. Full RLVs should be capable of around $100/kg in LEO. Getting better than that would be challenging (though not impossible) for RLVs, so that's a good price point.

Of course, lunar propellant doesn't have to compete in LEO. If you're sending stuff beyond Earth, then propellant in a higher orbit (ala EML1/2) is both more valuable to the customer AND would be cheaper to supply for lunar propellant. The only problem is it's easier to make a business case for propellant in LEO (where you could refuel ACES stages) than in EML1/2 where your only customers would be NASA and maybe Mars/Moon tourism/colonization (which is more speculative, obviously, and overall a smaller market than telecomm).
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 06/29/2016 03:05 pm
What do you mean by "full RLV"? (A) While SpaceX's landing of 1st-stages is certainly very impressive, making a reusable 2nd stage is going to be a much tougher nut to crack; (B) Skylon-style SSTO's may not ever be practical. Indeed, I would say that the presence of cheap lunar propellant in LEO would be the thing that would make a reusable 2nd stage practicable because you could refuel, and then propulsively burn off the 10 km/sec velocity that 1st stages don't have to deal with.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 06/29/2016 03:22 pm
What do you mean by "full RLV"? (A) While SpaceX's landing of 1st-stages is certainly very impressive, making a reusable 2nd stage is going to be a much tougher nut to crack; (B) Skylon-style SSTO's may not ever be practical. Indeed, I would say that the presence of cheap lunar propellant in LEO would be the thing that would make a reusable 2nd stage practicable because you could refuel, and then propulsively burn off the 10 km/sec velocity that 1st stages don't have to deal with.
Full RLVs meaning upper stage as well as first stage. Skylon is (perhaps) impractical for other reasons, and shouldn't be the model for what "full RLV" means.

Also, it's not 10km/s but 7km/s. That's a factor of 2 difference in energy.

But yeah, my point is that getting a heatshield to work effectively is not necessarily a harder problem than building an entire lunar propellant industry and will need to be solved eventually even if you do have lunar propellant. Shuttle actually did a pretty good job with a reusable heatshield considering it was an order of magnitude larger than needed, used 70s technology (we have WAY better low-maintenance heatshield tech that could be deployed if someone wanted to), and had a host of other conflicting requirements (being manrated, hooked to the side of a tank that shed foam instead of on top, large cross-range requirements leading to huge wings, etc) beside the huge overhead of effectively being a jobs program for the South.

You shouldn't be comparing to just Falcon 9, but to BFR and to Blue Origin's eventual fully reusable orbital launch vehicle. Both companies are going in that direction and will in all likelihood be building/testing their vehicles (including reusable upper stages) around 2020.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 06/29/2016 03:23 pm
If you're right about the ease of access of water on the Moon, then you should still be able to compete just fine with full RLVs. But don't sandbag/underestimate the competition by only comparing to expendable vehicles or partial (and slow turnaround) RLVs.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: TrevorMonty on 06/29/2016 05:50 pm
Lower launch costs will increase demand for lunar travel, which will require more landers to be refueled
on the moon with lunar fuel.

Ideally a lander would go directly between LEO and lunar surface, refuelling at each end. If there is a significant price difference between LEO and lunar fuel prices then it becomes worth while refueling at EML1 with cheaper LEO supplied fuel.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 06/29/2016 05:55 pm
Lower launch costs will increase demand for lunar travel, which will require more landers to be refueled
on the moon with lunar fuel. ...
An RLV would enable a lander that doesn't /have/ to refuel on the Moon with lunar propellant, although that will definitely be the easiest possible business case for lunar propellant.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: A_M_Swallow on 06/29/2016 06:28 pm
Lower launch costs will increase demand for lunar travel, which will require more landers to be refueled
on the moon with lunar fuel. ...
An RLV would enable a lander that doesn't /have/ to refuel on the Moon with lunar propellant, although that will definitely be the easiest possible business case for lunar propellant.

Lunar refuelling does not have to wait for a manned lander. It can be tested with a small reusable cargo lander.

Cargo to LEO.
Fuel and LOX to propellant depot in LEO.
Refuel lander.
Load cargo.
Fly to lunar orbit.

Possible refuelling in lunar orbit.
Land lander.
Unload lander.
Refuel fuel and/or LOX.

Fly to lunar orbit.
Possible refuelling in lunar orbit.
Fly to depot at LEO.

Machines needed to mine Moon for LOX and fuel.
Refine LOX.
Refine fuel.
Store propellant until needed, protecting against high and low temperatures.
Refuel landers.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 06/30/2016 05:03 pm
The $500/kg is price required if you trying to deliver this fuel to LEO and compete with earth supplied fuel in LEO. For EML1 fuel the price can be considerably higher.

As a rough estimate lunar surface price only needs to match LEO fuel price. Both transport systems would use about same amount of fuel to deliver a kg fuel to EML1.

Carefully look over Dr. Sowers' presentation. The price in LEO in order to close a business case for lunar propellant is not $500/kg--it's $3,000/kg. ULA will pay $500/kg on the lunar surface, if they have to go and pick it up themselves. If the producers (or asteroid miners) can get it to L1, they'll pay $1,000/kg. If the producers can get it to LEO, ULA would be willing to pay $3,000/kg for it. $3,000/kg is in about the current, right ballpark; if SpaceX's advertising is to be believed, they could maybe deliver propellant for close to $3K/kg; Air & Space magazine (http://www.airspacemag.com/space/is-spacex-changing-the-rocket-equation-132285884/?no-ist) says the cost is more like $5,000/kg; probably the true price is somewhere in between.

As for $100/kg from Earth's surface to LEO, I'll believe that the day I see it; probably that'll be the day they inaugurate transcontinental flights on battery powered jumbo jets! ;)

Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 06/30/2016 05:17 pm
To get back on the thread topic of actually drilling for water on the Moon, Dr. Zubrin and I were wracking our brains trying to figure out a possible means locating potential drilling sites using existing orbital assets. Probably the best sensing technology would be ground penetrating radar (GPR). I compiled this list of some radars that have been pointed at the Moon and Mars:

8.00E+06   37.5   arecibo
4.70E+07   6.4   arecibo
2.38E+09   0.13   arecibo
4.30E+08   0.70   arecibo
5.00E+06   60.0   Kaguya
1.90E+06   158  MARSIS
2.80E+06   108  MARSIS
3.80E+06   78.9   MARSIS
4.80E+06   62.5   MARSIS
1.50E+07   20.0   SHARAD
2.50E+07   12.0   SHARAD
1.58E+08   1.9   ALSE
1.58E+07   19.0   ALSE
5.27E+06   57.0   ALSE
6.00E+07   5.0   Chang'e-3
5.00E+08   0.6   Chang'e-3

First column is frequency, followed by the calculated wavelength. Range resolution is going to be on the order of 1 wavelength (meaning you're going to have trouble detecting layers thinner than one wavelength); depth of penetration is going to be on the order of 10 or so wavelengths.

Of existing orbital assets, there is only LRO, and its transmitter is defunct; also, its wavelength was in the S-band (around 13 cm). However, maybe it could be possible to beam Arecibo radar at 6 meters, and run LRO in passive, bistatic mode. I suspect that the antenna is too small to register echos at 6 meters, but maybe there's a clever way to do it.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 06/30/2016 08:22 pm
One of the predictions in my presentation is that the lava flows where these meniscus hollow/lunar maars are found would be a lot like the Columbia River Basalt Group, a huge area in eastern Washington and Oregon, including parts of Idaho and Nevada, where a series basaltic lava floods occurred during the Miocene (about 10 to 15 mybp).

(https://upload.wikimedia.org/wikipedia/commons/4/40/Columbia_River_Flood-Basalt_Province.jpg)
(source: Wikipedia article on CRBG)

The main practical prediction is that the individual flows would form layers on the order of 100 m thick. The tops and bottoms of these would be somewhat porous, allowing some water flow and storage. These "interflow zones" would be on the order of perhaps 10 m or so, with a porosity on the order of 10%. Such interflow zones would be separated by the main, dense, interior portion of each flow, thus providing the requisite stratigraphic structure to form a confined aquifer.

(http://i.imgur.com/XA5WOpX.png)
(source: Reidel et al. 2002 Natural Gas Storage in Basalt Aquifers)

Of the lunar GPR attempts, the Chang'e-3 and Kaguya results confirm that the lunar mare basalts tend to have this structure...
 
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: jongoff on 07/01/2016 07:42 pm
The $500/kg is price required if you trying to deliver this fuel to LEO and compete with earth supplied fuel in LEO.

For EML1 fuel the price can be considerably higher.  As a rough estimate lunar surface price only needs to match LEO fuel price. Both transport systems would use about same amount of fuel to deliver a kg fuel to EML1.

For Lunar surface fuel demand eg refueling a lander supplying a lunar base.  The price can be what ever it costs to deliver a kg LEO fuel to surface.

A couple of points:

1- The $500/kg on the lunar surface number to be competitive for LEO assumes propulsive breaking in LEO and rocket launch from the lunar surface. With aerocapture, your lunar propellant can be 2-3x as expensive and still be competitive. With propellantless launch from lunar *and* aerobraking, it can be 3-4x as expensive on the lunar surface ($1500-2000/kg) and still hit their required $/kg in LEO target.

2- While they can charge different rates at different destinations, the biggest market is going to be LEO, so it's worth trying to find ways to be competitive for LEO propellant delivery.

3- I think that being competitive in LEO with Earth-launched sources is going to require good water sources *and* using low-cost launch to get your stuff there in the first place *and* aerobraking *and (probably)* propellantless launch.

Just a few quick thoughts.

~Jon
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: jongoff on 07/01/2016 07:48 pm
The $500/kg is price required if you trying to deliver this fuel to LEO and compete with earth supplied fuel in LEO.
...
Maybe. That's not competing against fully reusable RLVs.
Everything is linked to cost of earth supplied LEO fuel, cheaper it is, cheaper Lunar fuel needs to be. On plus side lower launch costs also reduce cost of establishing lunar facilities.
Right. But I think it's important that lunar propellant systems be designed with the idea of competing with full RLVs from the start. $500/kg just isn't low enough, because that could easily be done with full RLVs. Full RLVs should be capable of around $100/kg in LEO. Getting better than that would be challenging (though not impossible) for RLVs, so that's a good price point.

Like with humor, timing matters in this situation. Sure, full RLVs of sufficient sophistication could eventually get to $500/kg, but that's several generations down the road from what is being worked on today by the SpaceX's and Blue Origins of the world. A big question is how will RLV prices progress over time, and when will the buildup of lunar capabilities happen.

Quote
Of course, lunar propellant doesn't have to compete in LEO. If you're sending stuff beyond Earth, then propellant in a higher orbit (ala EML1/2) is both more valuable to the customer AND would be cheaper to supply for lunar propellant. The only problem is it's easier to make a business case for propellant in LEO (where you could refuel ACES stages) than in EML1/2 where your only customers would be NASA and maybe Mars/Moon tourism/colonization (which is more speculative, obviously, and overall a smaller market than telecomm).

Exactly--finding a way to be competitive in LEO seems like the safest bet if you want to make this happen.

~Jon
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: jongoff on 07/01/2016 08:11 pm
To get back on the thread topic of actually drilling for water on the Moon, Dr. Zubrin and I were wracking our brains trying to figure out a possible means locating potential drilling sites using existing orbital assets. Probably the best sensing technology would be ground penetrating radar (GPR). I compiled this list of some radars that have been pointed at the Moon and Mars:

snip

First column is frequency, followed by the calculated wavelength. Range resolution is going to be on the order of 1 wavelength (meaning you're going to have trouble detecting layers thinner than one wavelength); depth of penetration is going to be on the order of 10 or so wavelengths.

Of existing orbital assets, there is only LRO, and its transmitter is defunct; also, its wavelength was in the S-band (around 13 cm). However, maybe it could be possible to beam Arecibo radar at 6 meters, and run LRO in passive, bistatic mode. I suspect that the antenna is too small to register echos at 6 meters, but maybe there's a clever way to do it.

If you wanted to do a spacecraft with a bistatic receiver antenna for 6m wavelength radio waves sent from Arecibo, how big would that antenna/processor need to be? I'm curious, because even if LRO can't do it, maybe this is something that could be done by a dedicated smallsat?

~Jon
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Steven Pietrobon on 07/02/2016 06:51 am
Of course the ULA isn't going to go for steampunk solar-powered water steam engines. They want clean LO2/LH2, and it's gotta be mass ratio 5! So converting that much water into rocket propellant on the Moon would be a major undertaking.

Have you looked at using an MR of 6:1? The Isp decrease is pretty small compared to 5:1, only 0.25%, while density increases by 11.4%. This means that production losses will be decreased as well as requiring smaller tanks for the same delta-V.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 07/02/2016 02:34 pm
ISP decrease may be small, but the chamber temp will be higher, putting more wear and tear on your engines, perhaps melting some parts.

That as much as anything is why engines run fuel rich instead of stoichiometric.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: jongoff on 07/02/2016 05:50 pm
ISP decrease may be small, but the chamber temp will be higher, putting more wear and tear on your engines, perhaps melting some parts.

That as much as anything is why engines run fuel rich instead of stoichiometric.

I've always wondered about doing upper-stage LOX-rich TAN for ISRU applications. Start the burn with the TAN running a bit lean of stoich, and the core running normal, and then shut the TAN off once the excess LOX has been used. So the stage MR can be 8:1, you use the LOX-rich part first to minimize gravity losses on whatever burn you're doing, and keep the main chamber operating at normal mixture ratios.

I haven't even tried to make a SWAG model of the performance of such a beast, but I wonder if it would buy you anything over just leaving the excess LOX behind.

~Jon
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: yokem55 on 07/04/2016 04:28 am
The $500/kg is price required if you trying to deliver this fuel to LEO and compete with earth supplied fuel in LEO.
...
Maybe. That's not competing against fully reusable RLVs.
Everything is linked to cost of earth supplied LEO fuel, cheaper it is, cheaper Lunar fuel needs to be. On plus side lower launch costs also reduce cost of establishing lunar facilities.
Right. But I think it's important that lunar propellant systems be designed with the idea of competing with full RLVs from the start. $500/kg just isn't low enough, because that could easily be done with full RLVs. Full RLVs should be capable of around $100/kg in LEO. Getting better than that would be challenging (though not impossible) for RLVs, so that's a good price point.

Like with humor, timing matters in this situation. Sure, full RLVs of sufficient sophistication could eventually get to $500/kg, but that's several generations down the road from what is being worked on today by the SpaceX's and Blue Origins of the world. A big question is how will RLV prices progress over time, and when will the buildup of lunar capabilities happen.

Quote
Of course, lunar propellant doesn't have to compete in LEO. If you're sending stuff beyond Earth, then propellant in a higher orbit (ala EML1/2) is both more valuable to the customer AND would be cheaper to supply for lunar propellant. The only problem is it's easier to make a business case for propellant in LEO (where you could refuel ACES stages) than in EML1/2 where your only customers would be NASA and maybe Mars/Moon tourism/colonization (which is more speculative, obviously, and overall a smaller market than telecomm).

Exactly--finding a way to be competitive in LEO seems like the safest bet if you want to make this happen.

~Jon
It isn't that hard to imagine a fully reused SpaceX BFR with a tanker upper stage delivering to LEO in the neighborhood of $200/kilo. Let's say they build 10 vehicles for $300 million each, and fly each one 5 times per year for five years (50 total flights per year). That puts the per flight depreciation at $12 million per flight. Refurbishment costs of 10% of the original vehicle cost at $30 million per flight, $3 million in launch ops expenses, and you have ~250 metric tons in LEO for 45 million. Figure 90% of that is fuel, and you're at $200/kilo. If the refurb costs come down, or the vehicles can be flown more than 25 times, and it gets even better.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Proponent on 07/04/2016 01:32 pm
Of course the ULA isn't going to go for steampunk solar-powered water steam engines. They want clean LO2/LH2, and it's gotta be mass ratio 5! So converting that much water into rocket propellant on the Moon would be a major undertaking.

Have you looked at using an MR of 6:1? The Isp decrease is pretty small compared to 5:1, only 0.25%, while density increases by 11.4%. This means that production losses will be decreased as well as requiring smaller tanks for the same delta-V.

Using the same assumptions as in this post (https://forum.nasaspaceflight.com/index.php?topic=31040.msg1518743#msg1518743), except that lunar gravity is substituted for terrestrial gravity (which decreases the mass of the engine needed to maintain a minimum thrust-to-weight ratio of 1.3), I've looked at a single-stage, lox-hydrogen vehicle with a delta-V of 5 km/s (approximately lunar surface to an L-point and back).

The upper plot shows the "available" mass fraction1: that's the fraction of the burn-out mass not accounted for by engines, tanks and residual fluids, as a function of the mixture ratio.  O/F ranges from that corresponding to maximum Isp to stoichiometric.  The lower plot shows the chamber temperature.

The "available" mass is not pure payload: it includes landing gear, avionics, inter-tank structures, insulation, and so on.  It does look, though, like there is probably a modest payload gain by running just slightly richer than stoichiometric.  If the available mass fraction were smaller, as it would be for an Earth-to-orbit SSTO, then the margin left over for payload would be smaller too and the payload fraction would benefit more from higher O/F than is the case here.

Another thing to consider is varying the O/F during flight, optimizing the O/F at each moment to maximize the available mass fraction.  The progression of O/F and chamber temperature is shown in the second pair of plots, assuming 30 unequally-spaced O/F settings are used.  You can see a little numerical noise in these plots, so the result is not fully converged, but the ultimate answer will not differ greatly from what's shown here.

The O/F starts out a maximum impulse density (as it should: the first cubic centimeter of propellant burned need not be lifted off the pad, hence its mass is irrelevant and performance is maximized by maximizing the impulse delivered).  Subsequent tranches of propellant, which must be accelerated before being burned, tend toward higher exhaust velocities.

There are a few other quirks to be explained here, but I won't bother, as the benefit of even a large O/F range seems pretty small in this case: the available mass fraction rises to 0.922, beating the optimal fixed-O/F case by just 0.01.  And that's assuming there is no performance or mass penalty on the engine, despite its large O/F range.  Incidentally, the overall O/F in the variable-O/F case winds up being slightly lean: 8.19.

By the way, If anyone has a suggestion for a better mass model, I'd like to hear about it.



1. If anyone can think of a better term than "available," I'm all ears.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 07/04/2016 02:19 pm
Of course the ULA isn't going to go for steampunk solar-powered water steam engines. They want clean LO2/LH2, and it's gotta be mass ratio 5! So converting that much water into rocket propellant on the Moon would be a major undertaking.

Have you looked at using an MR of 6:1? The Isp decrease is pretty small compared to 5:1, only 0.25%, while density increases by 11.4%. This means that production losses will be decreased as well as requiring smaller tanks for the same delta-V.

Nope. Bernard Kutter himself told me to my face, probably for the reasons stated by Proponent and Chris (Robotbeat) above, that it's got to be mass ratio 5. That's the deal! :D
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 07/04/2016 02:49 pm
Of existing orbital assets [with radar reception capability], there is only LRO, and its transmitter is defunct; also, its wavelength was in the S-band (around 13 cm). However, maybe it could be possible to beam Arecibo radar at 6 meters, and run LRO in passive, bistatic mode. I suspect that the antenna is too small to register echos at 6 meters, but maybe there's a clever way to do it.

If you wanted to do a spacecraft with a bistatic receiver antenna for 6m wavelength radio waves sent from Arecibo, how big would that antenna/processor need to be? I'm curious, because even if LRO can't do it, maybe this is something that could be done by a dedicated smallsat?

~Jon

I asked a question on Paul Spudis's latest blog post (http://www.spudislunarresources.com/blog/china-continues-its-long-march-to-the-moon/#comment-5512) about using LRO in bistatic mode for long-wave radar. He said it can't be done. Kaguya had something like a 13 meter long antenna. But with some creative origami folding, probably a relatively small and cheap satellite could be launched with only passive radar reception capability. This would save a lot of cash, because you wouldn't need the transmitter with major power requirements. Also, we'd be only interested in the Near Side anyways, so no need for the Dark Side measurement capability.

The Spudis blog is interesting as he points out that the upcoming Chang'E 5 sample return mission is headed for the vicinity of the Chang'E 3 lander. Paul points out that this is not the best place from a scientific perspective; but what if somehow the Chinese are aware of the ISRU possibilities of volatiles in the mare basalt regions? Note that Chang'E 3 was supposed to land in Sinus Iridum originally, but, unannounced, it landed in the north Imbrium basin instead--which just so happens to be near one of Kaguya's published GPR tracks. In effect, Chang'E 3, with its own GPR, was in position to groundtruth Kaguya, which it did by apparently finding the same major reflector at about 360 meters down. Note also that the Gruithuisen group of meniscus hollows are not too far away.

So perhaps the Chang'E 5 mission's real purpose is to find geochemicall evidence of free water within the mare basalts, perhaps by finding trace amounts of phyllosilicates that wouldn't be apparent to orbiting platforms. Note that trace amounts of phyllosilicates were in fact identified in samples collected by Apollo 11--which landed in the Mare Tranquilitatus--but were chalked up to contamination by the humid atmosphere at the Houston sample receiving facility. Hopefully the Chang'E 5 samples will be collected and received in such a way that the possibility of contamination by terrestrial atmospheric water vapor will be ruled out.

(http://i.imgur.com/Al7s5pS.png)
(for scale, the Kaguya track spans 12 degrees of latitude, which is almost exactly 360 km) 
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 07/06/2016 01:29 pm
The way GPR works is that the speed of radar waves depends on the relative dielectric permittivity έr:

v = c / sqrt(έr) where c is the speed of light in a vacuum

When the radar wave speed changes because of going from one layer to another due to differing έr, then part of the energy is reflected and refracted.

Thus if έr is 1 (the relative dielectric permittivity of air or vacuum), then v is just c. For solid basalt with no porosity then έr ≈ 8; for water, έr ≈ 80

If an interflow zone between two basalt flows was saturated with water, this would have the effect of markedly raising the bulk, relative dielectric permittivity έr. This would also have the effect of enhancing the range resolution (i.e., so thinner layers would be detected. OTOH, if a porous interflow zone's pore spaces were filled with gases or vacuum, this would have the effect of lowering έr (increasing EM speed v), while degrading the range resolution (thinner layers will not be detected).

Now, one of the predictions of free water model is that the water distribution will be extremely patchy. Even within the mare basalt region (MBR), faulting and fracturing by meteor impacts would not allow traps to form everywhere. However, due to the high έr of water, saturated zones should be visible to GPR. In addition, if there is free water down there, we should expect it to pool up in dish-shaped formations (concave down, "synclinal aquifers").

Thus the Kaguya results are interesting. They did not find major subsurface reflectors all over the Moon. They were only found in a few places within the MBR. Also the reflectors do seem to correlate with synclinally shaped formations.

(http://i.imgur.com/OPp8vSO.png)
(http://i.imgur.com/KoxoIfe.png)
(http://i.imgur.com/8t1Xh4h.png)
(Source: Ono et al. 2009 Science Vol. 323, p. 909)

Red arrows in original. I added the red lines that show the trend of the formation.

It could be possible, perhaps even likely, that these radargrams produced  by Kaguya represent actual detections of lunar free water....

You saw it here first! :D

IMHO YMMV
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: jongoff on 07/06/2016 03:41 pm
Warren,
I'm neck deep in a proposal right now, but I'll chat with some local friends to figure out if there's some way to do a bistatic radar receiver on a cubesat-scale platform. A lot depends on what the radar receiver needs to look like, but it might be doable.

~Jon
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 07/06/2016 05:55 pm
Warren,
I'm neck deep in a proposal right now, but I'll chat with some local friends to figure out if there's some way to do a bistatic radar receiver on a cubesat-scale platform. A lot depends on what the radar receiver needs to look like, but it might be doable.

~Jon

I would guess that it should be doable. Kaguya's LRS antenna was just an array of 4 dipole antennas (which are simply metal rods--no dish needed) in a cross-shaped pattern with a "(two sets of dipole antennas with a tip-to-tip length of 30 m) (https://directory.eoportal.org/web/eoportal/satellite-missions/s/selene)".

The wavelength λ = 60 m, thus the antenna diameter is λ/2. Arecibo can transmit at two wavelengths that would be interest: 37.5 m (8 MHz) and 6.4 m (47 MHz). So opting for a similar design, a tip-to-tip length of 18.75 m (9 3/8 m each) would capture the 8 MHz reflections. And while I'm no antenna geek, isn't it the case that ideally you want the length of your dipole antenna to be even multiples of the wavelength? Thus, 18.75 m is about ~3 X 6.4 m, and so such an antenna could probably also register the 47 MHz echos, without active modification.

(As a science bonus, it would be able to capture radio waves from other planets without Earth interference when on the Far Side of the Moon.)
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: jongoff on 07/06/2016 06:43 pm
Warren,
I'm neck deep in a proposal right now, but I'll chat with some local friends to figure out if there's some way to do a bistatic radar receiver on a cubesat-scale platform. A lot depends on what the radar receiver needs to look like, but it might be doable.

~Jon

I would guess that it should be doable. Kaguya's LRS antenna was just an array of 4 dipole antennas (which are simply metal rods--no dish needed) in a cross-shaped pattern with a "(two sets of dipole antennas with a tip-to-tip length of 30 m) (https://directory.eoportal.org/web/eoportal/satellite-missions/s/selene)".

The wavelength λ = 60 m, thus the antenna diameter is λ/2. Arecibo can transmit at two wavelengths that would be interest: 37.5 m (8 MHz) and 6.4 m (47 MHz). So opting for a similar design, a tip-to-tip length of 18.75 m (9 3/8 m each) would capture the 8 MHz reflections. And while I'm no antenna geek, isn't it the case that ideally you want the length of your dipole antenna to be even multiples of the wavelength? Thus, 18.75 m is about ~3 X 6.4 m, and so such an antenna could probably also register the 47 MHz echos, without active modification.

(As a science bonus, it would be able to capture radio waves from other planets without Earth interference when on the Far Side of the Moon.)

Warren,

Interesting. We do happen to do a lot of work with deployable booms... Most of them are composite, but it might be possible to get them with an embedded conductor to function as an antenna...

~Jon
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Phil Stooke on 07/06/2016 06:52 pm
Off topic but a necessary correction:

"Note that Chang'E 3 was supposed to land in Sinus Iridum originally, but, unannounced, it landed in the north Imbrium basin instead--"

Not true.  The Sinus Iridum landing area included Sinus Iridum but was much larger.  Chang'E 3 landed at the east end of it so that any delay in landing could be accommodated by a later landing which would still be within the landing area - land near the centre of Sinus Iridum and a day's delay has moved the orbit ground track outside the landing area. 

http://meetingorganizer.copernicus.org/EPSC2012/EPSC2012-151-1.pdf (http://meetingorganizer.copernicus.org/EPSC2012/EPSC2012-151-1.pdf)
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 07/06/2016 07:52 pm
Warren,
I'm neck deep in a proposal right now, but I'll chat with some local friends to figure out if there's some way to do a bistatic radar receiver on a cubesat-scale platform. A lot depends on what the radar receiver needs to look like, but it might be doable.

~Jon

I would guess that it should be doable. Kaguya's LRS antenna was just an array of 4 dipole antennas (which are simply metal rods--no dish needed) in a cross-shaped pattern with a "(two sets of dipole antennas with a tip-to-tip length of 30 m) (https://directory.eoportal.org/web/eoportal/satellite-missions/s/selene)".

The wavelength λ = 60 m, thus the antenna diameter is λ/2. Arecibo can transmit at two wavelengths that would be interest: 37.5 m (8 MHz) and 6.4 m (47 MHz). So opting for a similar design, a tip-to-tip length of 18.75 m (9 3/8 m each) would capture the 8 MHz reflections. And while I'm no antenna geek, isn't it the case that ideally you want the length of your dipole antenna to be even multiples of the wavelength? Thus, 18.75 m is about ~3 X 6.4 m, and so such an antenna could probably also register the 47 MHz echos, without active modification.

(As a science bonus, it would be able to capture radio waves from other planets without Earth interference when on the Far Side of the Moon.)

Warren,

Interesting. We do happen to do a lot of work with deployable booms... Most of them are composite, but it might be possible to get them with an embedded conductor to function as an antenna...

~Jon
CNT yarns can be made into composites with good mechanical properties and also have good conductivity. (You have to find the right format of CNTs for this to work... a lot of the earlier formats were terrible and gave CNTs a bad name.)
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: high road on 07/06/2016 08:07 pm
This thread, and it's many predecessors, seem to be skipping a vital point. Everybody's talking about digging up water, but what about just getting to the oxygen? That's still 88.89% of the mass of LOX/LH2 propellant, and 80% of methalox propellant. Why not take LH2 up from Earth and add LOX from the moon?

To me, it seems logical to keep the experimental fuel station as low-tech as possible. No near-absolute-zero temperatures, no harder to reach polar locations, the needed 'paydirt' is easier to extract than ice at those temperatures, oxygen is easier to store than hydrogen, etc. Power requirements might be higher for the extraction process itself, but I doubt that's the major cost driver. And while ramping up production, the lunar infrastructure gets larger, and there's more experience with the local environment. (using waste dirt to build stuff). LH2 would only come long after. Probably even after that non-rocket launch capability (and IMO, even after somebody successfully tested non-rocket landing capibility).

The fact that this is apparantly not obvious, means that I'm missing something. So educate me, and explain why a LOX/LH2 production plant on the moon makes more sense than a LOX production plant, even though it is far more complex and only delivers 11.11% more fuel mass? (or 20%, if it's a methalox plant, and that means 15% of the fuel mass comes from a human source)
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 07/06/2016 09:28 pm
Stripping oxygen from solid oxides certainly is possible and has been done, but it sucks compared to water and CO2 electrolysis. Lots of chemistry and annoying solid byproducts (which, sure, could be industrially useful, but are a big pain). Practically speaking, if you have a choice, you're going to use volatiles.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: high road on 07/06/2016 09:52 pm
Didn't SCARAB, PILOT, Roxygen and RESOLVE show that it could be done in principle? 'Two scoops a day is enough' IIRC. Looking these up, I do see RESOLVE uses a hydrogen reduction technique, but one could in theory reclaim the hydrogen instead of mining for more.

I can imagine it would be quite a hassle. But so is designing mining equipment that can work in near-absolute-zero temperatures.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 07/07/2016 12:35 am
Oh yes, it definitely can be done. If water were not found on the Moon, we'd just go the solid oxides route.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: jongoff on 07/07/2016 03:17 am
Warren,
I'm neck deep in a proposal right now, but I'll chat with some local friends to figure out if there's some way to do a bistatic radar receiver on a cubesat-scale platform. A lot depends on what the radar receiver needs to look like, but it might be doable.

~Jon

I would guess that it should be doable. Kaguya's LRS antenna was just an array of 4 dipole antennas (which are simply metal rods--no dish needed) in a cross-shaped pattern with a "(two sets of dipole antennas with a tip-to-tip length of 30 m) (https://directory.eoportal.org/web/eoportal/satellite-missions/s/selene)".

The wavelength λ = 60 m, thus the antenna diameter is λ/2. Arecibo can transmit at two wavelengths that would be interest: 37.5 m (8 MHz) and 6.4 m (47 MHz). So opting for a similar design, a tip-to-tip length of 18.75 m (9 3/8 m each) would capture the 8 MHz reflections. And while I'm no antenna geek, isn't it the case that ideally you want the length of your dipole antenna to be even multiples of the wavelength? Thus, 18.75 m is about ~3 X 6.4 m, and so such an antenna could probably also register the 47 MHz echos, without active modification.

(As a science bonus, it would be able to capture radio waves from other planets without Earth interference when on the Far Side of the Moon.)

Warren,

Interesting. We do happen to do a lot of work with deployable booms... Most of them are composite, but it might be possible to get them with an embedded conductor to function as an antenna...

~Jon
CNT yarns can be made into composites with good mechanical properties and also have good conductivity. (You have to find the right format of CNTs for this to work... a lot of the earlier formats were terrible and gave CNTs a bad name.)

But for a 9m boom, you really don't need anything that exotic. If you were trying to reduplicate Explore 49 that had four 230m long booms forming its dipole antenna, some cleverness might be worthwhile.

~Jon
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Impaler on 07/07/2016 05:56 am
Lunar cold traps will likely have large amounts of dry ice which will be co-produced with any water.  Creating a hydrocarbon propellant is thus more likely to efficiently utilize ISRU mass0.  The lunar gravity well is not deep enough for ISP advantages of hydrogen to be attractive, while lower tank mass of hydrocarbon benefits a reusable surface to orbit tanker.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: high road on 07/07/2016 06:54 am
Oh yes, it definitely can be done. If water were not found on the Moon, we'd just go the solid oxides route.

So for clarity, in order of complexity, this is the correct order:

1) subsurface ice pockets --> can be extracted under 'normal' lunar environmental conditions. Best of both known alternatives.
2) solid oxides --> require complex treatment plant.
3) polar ice caps --> require 0K mining equipment, and it's not an ideal location to launch from.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Proponent on 07/07/2016 07:20 am
I would guess that it should be doable. Kaguya's LRS antenna was just an array of 4 dipole antennas (which are simply metal rods--no dish needed) in a cross-shaped pattern with a "(two sets of dipole antennas with a tip-to-tip length of 30 m) (https://directory.eoportal.org/web/eoportal/satellite-missions/s/selene)".

The wavelength λ = 60 m, thus the antenna diameter is λ/2. Arecibo can transmit at two wavelengths that would be interest: 37.5 m (8 MHz) and 6.4 m (47 MHz). So opting for a similar design, a tip-to-tip length of 18.75 m (9 3/8 m each) would capture the 8 MHz reflections. And while I'm no antenna geek, isn't it the case that ideally you want the length of your dipole antenna to be even multiples of the wavelength? Thus, 18.75 m is about ~3 X 6.4 m, and so such an antenna could probably also register the 47 MHz echos, without active modification.

A dipole is ideally an odd multiple of half the wavelength.  I would think, though, that bistatic radar with an Earthbound transmitter would be tough at frequencies below about 50 MHz, because of the ionosphere.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: jongoff on 07/07/2016 08:50 am
Lunar cold traps will likely have large amounts of dry ice which will be co-produced with any water.  Creating a hydrocarbon propellant is thus more likely to efficiently utilize ISRU mass0.  The lunar gravity well is not deep enough for ISP advantages of hydrogen to be attractive, while lower tank mass of hydrocarbon benefits a reusable surface to orbit tanker.

I'm not convinced at all. We really don't know what the chemical composition of the lunar cold traps is. We have theories, and some evidence of water, but no real ground truth. This just seems like wishful thinking by those who think Hydrogen is Satan's own cocktail drink.

~Jon
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: KelvinZero on 07/07/2016 11:37 am
I have heard there was evidence of more Carbon Monoxide than water.

universetoday article (http://www.universetoday.com/76329/water-on-the-moon-and-much-much-more-latest-lcross-results/)

Of course we have to send a rover. It is so frustrating that it has been about 6 years. There still isn't a commitment to a specific mission is there?
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: A_M_Swallow on 07/07/2016 04:26 pm
I have heard there was evidence of more Carbon Monoxide than water.

universetoday article (http://www.universetoday.com/76329/water-on-the-moon-and-much-much-more-latest-lcross-results/)

Of course we have to send a rover. It is so frustrating that it has been about 6 years. There still isn't a commitment to a specific mission is there?

Do any of the challengers NASA runs involve putting a spectrum analyser or ground piecing radar on a rover whose payload is under 110 kg?

The prize money could be under two million dollars. The specifications of the rover chassis can be suspiciously similar to one of the commercial space rated lunar rovers. The two winners could receive sponsorship for the flight to the Moon from NASA and/or a mining company. Operational costs would be a different but related line item.

Alternatively various awards and grants could be used.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 07/07/2016 07:01 pm
Off topic but a necessary correction:

"Note that Chang'E 3 was supposed to land in Sinus Iridum originally, but, unannounced, it landed in the north Imbrium basin instead--"

Not true.  The Sinus Iridum landing area included Sinus Iridum but was much larger.  Chang'E 3 landed at the east end of it so that any delay in landing could be accommodated by a later landing which would still be within the landing area - land near the centre of Sinus Iridum and a day's delay has moved the orbit ground track outside the landing area. 

That's interesting and makes sense. I was thinking of Paul Spudis's article on it the day after it landed.
 (http://www.airspacemag.com/daily-planet/a-new-site-to-explore-on-the-moon-180948756/?no-ist) He does point out that the lander did in fact land at the eastern edge of its designated landing box, but left open the possibility about whether it happened "by design or fortuitous accident". So really, where it landed was their first choice, and Sinus Iridum was the backup landing spot. Which reinforces my earlier point that there seems to have been an intent to ground-truth the Kaguya GPR results.

I'm glad you're still paying attention to this thread Phil, since you know as much about the meniscus hollows as anybody. So my question to you is: How would you recommend remote sensing these features, either using existing assets (which means LRO I guess) or a cubesat? E.g., I wonder if anything useful could be gleaned using the LRO LAMP instrument...
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 07/07/2016 07:22 pm
Lunar cold traps will likely have large amounts of dry ice which will be co-produced with any water.  Creating a hydrocarbon propellant is thus more likely to efficiently utilize ISRU mass0.  The lunar gravity well is not deep enough for ISP advantages of hydrogen to be attractive, while lower tank mass of hydrocarbon benefits a reusable surface to orbit tanker.

We don't want to turn the Moon into a self-licking ice-cream cone like Mars. The goal is to produce a useful product for the people of Planet Earth. Right now there is plenty of business boosting satellites from LEO to GEO, but those boosters want to use LH2/LO2.

Anyways, I see little point in making hydrocarbon rocket fuel--even on Mars--given that you're going to be cracking water in any case. There is really nothing worthwhile to be gained for the added layer of complexity IMHO. Sure, LH2 must be cooled to very cold temperatures compared to LCH4 and LOX, but (a) we know how to do it--it's not a showstopper; and (b) the specific heat of vaporization of LH2 is much higher, meaning it takes a lot more Joules of heat to vaporize a kilogram of LH2 versus LCH4. Thus absent active cooling, methane rockets are going to have a higher boiloff rate. Meanwhile, the boiloff from LH2 can provide active cooling for the LO2 for free.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 07/07/2016 07:25 pm
Earth is a self-licking ice cream cone, so I'm fine with Mars also being one, if it really can be self-licking. ;)

But it's a good distinction. The Moon is supposed to be primarily industrially/economically useful, not primarily a goal in and of itself.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Impaler on 07/07/2016 11:45 pm
The ultimate 'purpose' of the body is irrelevant here, in both cases your producing propellant from ISRU and put it into a large rocket which blasts off the surface is a necessary step.  If hydrocarbon propellant dose the job better then hydrogen then that's all that matters.


I have heard there was evidence of more Carbon Monoxide than water.

universetoday article (http://www.universetoday.com/76329/water-on-the-moon-and-much-much-more-latest-lcross-results/)

I was well aware of this and was surprised other were not, they seem to be imagining just a slab of pure water ice.  Our theories of how these cold traps forms leads inevitably to a cocktail of volatiles, so co-production of Carbon compounds is inevitable and a process for separation is thus also necessary.  Now the question is do you simply dump all that carbon, or do you use it and save half the water mass that would otherwise be needed to make a hydro-Lox propellant mix.  Even if the customer is only buying hydro-Lox (which will not be the case if SpaceX becomes a buyer) the hydrocarbon propellant would still be ideal for propelling the delivery tanker vehicles because your going to burn more propellant then you deliver.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 07/07/2016 11:55 pm
Earth is a self-licking ice cream cone, so I'm fine with Mars also being one, if it really can be self-licking. ;)

I never really thought about that, but yeah, you're right, the Earth is a sort of self-licking ice-cream cone. The question is whether Mars can also be made into an autarky.

Quote
But it's a good distinction. The Moon is supposed to be primarily industrially/economically useful, not primarily a goal in and of itself.

I agree that it is a good distinction. However, I disagree that it has to be an either-or thing in the soup-or-salad sense. You can have both in the cream-or-sugar sense. The Moon is no doubt instrumentally valuable to the people of Planet Earth, but it is also intrinsically valuable in itself; and any lunar colony would also be intrinsically valuable in itself.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: gbaikie on 07/08/2016 03:22 am
This thread, and it's many predecessors, seem to be skipping a vital point. Everybody's talking about digging up water, but what about just getting to the oxygen? That's still 88.89% of the mass of LOX/LH2 propellant, and 80% of methalox propellant. Why not take LH2 up from Earth and add LOX from the moon?
What is important is the cheapest method of getting Oxygen on the Moon.

Quote
To me, it seems logical to keep the experimental fuel station as low-tech as possible. No near-absolute-zero temperatures, no harder to reach polar locations, the needed 'paydirt' is easier to extract than ice at those temperatures, oxygen is easier to store than hydrogen, etc. Power requirements might be higher for the extraction process itself, but I doubt that's the major cost driver. And while ramping up production, the lunar infrastructure gets larger, and there's more experience with the local environment. (using waste dirt to build stuff). LH2 would only come long after. Probably even after that non-rocket launch capability (and IMO, even after somebody successfully tested non-rocket landing capability).

As far as low tech, it's pretty easy to get oxygen and hydrogen from Water.
And the "near-abolute-zero" temperatures are not a significant problem, nor is it particularly difficult to get or leave the polar regions of the Moon. So for instance without much modification a person in spacesuit could stand on lunar surface which was 50K and in total dark [save the stars above you] and operate as easily as if at equator of the Moon with blazing sun overhead. Or someone in a spacesuit will become too warm unless one is refrigerating the spacesuit. With Apollo they used a block of ice to keep crew cool. And can one make a block of ice easily from water in vacuum. As water freezes in vacuum rapidly and will continue to evaporate and cool until it's about -150 C.
The lunar polar region in general [rather in dark crater] is considered to be a more benign environment as compared the non polar region of the Moon. And it's possible one mine lunar water which not in a crater- though generally it's considered that most water would be found in permanently shadowed craters.
I think if mining in permanent crater, one warm a sector of the ground to relatively high temperature- say 274 K and at same time provide this smaller region with light. Or reflected sunlight which about 400 watts per square meter would do this. Take 1 square meter of sunlight and have reflect on the ground so it's 3 times the area [3 square meters] 1360 divide by 3 is 453 watts. One could also reflect sunlight to bottom of a crater and harvest solar energy from it- and doing this one get "waste heat" from doing this [and "waste" visible light] and that could be "used" to warm a small area. Though depends on situation. But if operating machinery it's going making waste heat and will tend retain heat for a fair amount of time.
Or if put a 55 gallon drum of water at say 20 C on lunar surface which is 50 K, the barrel will warm the 50 K ground and not cool the water by much, or not freeze for hours. Or on Earth if put same barrel on the ground in -20 C weather, it also will take a long time to cool. And would cool quicker as compared to being in the dark crater of the Moon. This because a barrel of water has a lot of thermal mass. And the Moon in general
is like putting something in a thermos- sealed hot coffee, stays hot for quite a while. And lunar surface has low thermal mass and it's acts like very good insulation.
Also aluminum gains strength if at cryogenic conditions, and things handling a lot of cold material will get  cold pretty quickly [particularly any kind of metal which conducts heat quickly]. So say front end loader's bucket could get cold fairly quickly. But one could design it so bucket gets cold and rest of machine, does not get cold [one could heat the bucket also, but it doesn't seem to make much sense to do so.].
As for : "Power requirements might be higher for the extraction process itself, but I doubt that's the major cost driver. "
Power requirement are significant factor just in terms of splitting water.
On earth splitting aluminum ore [Al2O3 ] into aluminum  and oxygen requires about 3 times more energy
per kg oxygen gotten as compared to splitting H20 and getting the Oxygen.
Splitting Al2O3 get about 1/2 mass being oxygen and other half Aluminum, splitting water gets 8 of O2 vs 1 of Hydrogen. Splitting Al2O3 gives a lot of aluminum and splitting water give a little bit of Hydrogen in terms of
mass- but in terms of volume, when splitting water one gets a large amount of Hydrogen gas vs Oxygen gas [or in liquid or solid form in both].
Also another factor re power requirement:
Say you had 10 ton pile of Al2O3 and 10 ton pile of snow on lunar surface.
How much would either or both be worth? I would say essentially nothing at this point in time or a one ton
pile of lunar dirt is worth more. Or problem is there is not enough of it- or whatever send there to make into oxygen will cost more than simply shipping the same amount of LOX from Earth. But you should lose less money with picking the pile of snow.
Though if piles were 100 tons instead, then you have chance of making a profit, but 1000 tons would be better. And terms of making money, it depend on how long after shipping the stuff to do it, that one has processed it into O2.
But there is not a pile of Al2O3 or snow on the Moon, and question is how much stuff do you have to send
to the Moon before you get 100 tons of Al2O3 or H20. Both Al2O3 and H20 mixed into with other lunar material.
With lunar water one could heat all the mixed together stuff to +200 K and get some water gas- heat to 400 K and get more of it. So how do get the Al2O3 separated from everything else [assuming there is lunar ore resembling or mostly Al2O3- or what ore do you want to get the Oxygen from?
To answer my own question, one could mine lunar iron ore. It's magnetic, so can be separated using a magnet. And lunar iron is both pure Fe and FeO [both magnetic].
So I know two ways of getting the oxygen from Iron oxide. One is way humans have doing it for tens of centuries, heat iron ore and add CO, which become CO2. So then can use hydrogen to make methane and O2.
Another way is again heat ore, use Hydrogen and make water.
So I figure lunar water miner can also mine iron ore. They could remove the iron with magnets before heating material to get the water, and later sell iron ore to anyone wanting to make iron or steel. Or a water miner could also get into iron business.
   
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: high road on 07/08/2016 10:30 am
Gbaikie, getting hydrogen from water is easy. Getting pure water ice on the moon is the part that I think is hard. Or at least, that is getting handwaved away in comparison to extracting oxygen from Lunar regolith.

Permanent shadowed craters do not require more robust space suits? I'll take your word for it. And like aluminum, water ice becomes harder at lower temperatures. Which one is harder at which temperatures, is beyond me.

Heating up the soil would indeed make things easier. But, like the ice in those space suits, water ice in the soil will sublimate and escape into space. Unless you want to throw away a lot of paydirt, it would require a considerable effort to cover an industrial-size extraction site with an airtight canopy or other structure. Not impossible, but it adds to the cost, which is indeed the vital point.

You're going for aluminum and iron ore. But why not stick to regolith? Long before we would like to make steel in situ, we would like to make Lunarcrete. Added benefit: it does not require purity to be useful, so less complexity.

The cost of power on the lunar surface, at least until there is a company on the moon that supplies the power, is not measured as a running cost as it is here, but in the initial launch cost to get the infrastructure over there to produce said power, and the maintenance cost to keep it running. Both will be quite small in comparison to hauling industrial equipment (to produce industrial amounts of fuel), oxygen/hydrogen storage and handling equipment, transportation, a launcher and whatever complex structures you might need to the moon, and maintaining all of that.

Intuitively, having half the storage and handling facilities (one for oxygen, none for hydrogen), and not having to build an airtight a hydrogentight canopy over the extraction site, and being able to 'simply' pile up waste rock out in the open, until it can be used to expand the base, would cut a lot of required mass. Plus: only one tank on the launch vehicle increases useful payload mass. (could also be solved by having dedicated oxygen/hydrogen launches, but that pushes your break-even point further out).

Edit: I know you guys prefer engineering over accounting and finance, but the problem is in attributing costs to the finished good. When you produce hydrogen + oxygen, 89% of your revenue is coming from oxygen. If hydrogen-related costs are more than 11% of the production cost, you'd be better off (financially) by dumping it, rather than shipping it.

I thought I saw the poles as not being ideal to launch somewhere upthread, but I can't find it at the moment. And if you guys tell me zero K equipment requires no more maintenance than lunar night/day equipment, then I'll take your word for it and have the running cost at least be comparable. See, I'm being reasonable here. :-)
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: gbaikie on 07/08/2016 08:30 pm
Gbaikie, getting hydrogen from water is easy. Getting pure water ice on the moon is the part that I think is hard. Or at least, that is getting handwaved away in comparison to extracting oxygen from Lunar regolith.
I don't know if the moon has minable water. But I think NASA should explore the lunar polar region to determine whether the Moon has minable water. How hard it is to mine lunar water is a part of what could be determined by exploration.
And I believe another obstacle to commercially mining lunar water is the uncertainty related to operating a depot in the space environment [any orbit]. So I think NASA should start it's lunar exploration by establishing a depot in LEO which can store and transfer LOX. The idea is NASA would not make a profit operating such a depot, but it might demonstrate the way for future depots which could be profitable. Or basically I expect NASA to make various mistakes in terms of getting a LOX depot operational, and one can learn from mistakes.
As general note, I think it is unwise to think of NASA doing anything in order to be profitable, rather NASA should explore and experiment with usable technologies. Or NASA goal should enable commercial lunar water mining and future human settlements on Mars- or NASA does not do the mining or the settling, but there things which need to be known before these can be done {despite Elon Musk's claim, which seems to be otherwise}.
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Permanent shadowed craters do not require more robust space suits? I'll take your word for it. And like aluminum, water ice becomes harder at lower temperatures. Which one is harder at which temperatures, is beyond me.

I expect it's possible to mine lunar water without digging more than a meter below the surface, but again I don't know this. How lunar water will be mine can be determined by exploration and there a number ways to might be done. Or two commercial water companies may use different ways of doing it- and it's possible both could work.
Quote

Heating up the soil would indeed make things easier. But, like the ice in those space suits, water ice in the soil will sublimate and escape into space. Unless you want to throw away a lot of paydirt, it would require a considerable effort to cover an industrial-size extraction site with an airtight canopy or other structure. Not impossible, but it adds to the cost, which is indeed the vital point.
I expect a lunar mining site could limited to 1 km square area which have enough water for 10 years of operation and getting over 1000 tons of water. Or 1 square km to one meter depth with 10% water concentration, has 100,000 tons of water. And I would quite shocked if 100,000 tons of water could mined within 20 years. Main problem is the lack of demand for such amounts of lunar water in such a short period of time. Or if water is worth 1/2 million per ton, that is 50 billion dollar of water. And rocket fuel would gross about 100 billion, and lunar market would be somewhere around 100 billion per year- and our current  global satellite market totals about 200 billion per year- which is earth market related all things connected satellites. I mean 100 billion lunar market- not earth market related to all thing other than earth satellites in orbit. Though do think it possible within 3 decades, but then again I tend to be optimistic.
Or in terms of entire space related market I don't expect it to be trillions of dollars per year within 2 decade from the start of commercial lunar water, but it could close to 1 trillion dollar per year, maybe. Or basically one looking at something like significant or robust Mars settlements if over 1 trillion per year
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You're going for aluminum and iron ore. But why not stick to regolith? Long before we would like to make steel in situ, we would like to make Lunarcrete. Added benefit: it does not require purity to be useful, so less complexity.
Well there is a lot a available iron on the Moon, and within several decades it could cheaper to make steel on
the Moon as compared to making steel on Earth. Or at beginning I guess price of LOX is over $500 per kg and iron about $100 per kg or less, if there is demand of more than 100 tons of iron per year [which is not hard to imagine] it could become $50 or less per kg of iron [$50,000 per ton vs Earth $500 per ton- world steel production is 1599.5 million tons- wiki. The Moon could exceed this amount if there was a enough demand, but if doing less than 1 million, if doing tens thousands of tons per year, one would approaching Earth prices of iron/steel- because it's easier to do on the Moon AND it makes oxygen. Though at moment there appears to be shortage of carbon to make steel on the Moon. But due to Moon's low gravity, structurally speaking iron is better on the Moon than steel is on Earth. And Iron because it doesn't rust in lunar environment will be similar to stainless steel on Earth- or no need to paint it on Moon.
But what seems like the Moon will exceed Earth in production the soonest could the production of silicon metal- because oxygen has value on the Moon and heating things can be easier:
"Silicon is produced by heating sand (SiO2) with carbon to temperatures
around 2200°C. At room temperatures, silicon exists in two forms,
amorphous and crystalline. Amorphous appears as a brown powder while
crystalline silicon has a metallic luster and a grayish color.
http://www.mine-engineer.com/mining/mineral/silicon.htm
So makes CO2, and then you make Methane with hydrogen. Again problem is getting enough carbon if making vast of amounts of Silicon metal, but earth only makes ten thousand of tons of it per, vs a thousand million tons of steel.
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The cost of power on the lunar surface, at least until there is a company on the moon that supplies the power, is not measured as a running cost as it is here, but in the initial launch cost to get the infrastructure over there to produce said power, and the maintenance cost to keep it running. Both will be quite small in comparison to hauling industrial equipment (to produce industrial amounts of fuel), oxygen/hydrogen storage and handling equipment, transportation, a launcher and whatever complex structures you might need to the moon, and maintaining all of that.
Well the most significant part of mining water on the moon as far as everyone on Earth is concerned, is to establish companies making electrical energy on the Moon. Making rocket fuel from water requires a lot of electrical energy.
The Moon is good place for nuclear energy and solar energy.
On earth one gets solar energy from about 6 hours per day- or a quarter of the time. With Moon one gets
solar energy for 1/2 of the time [and more per square meter]. Or good place on Earth to get solar energy [below 40 degree latitude and less clouds] gets about 8 kW hour per average day. Anywhere on the Moon it's 16 kW per hour on average, constant sunlight is 1360 watts times 24 hours= 32.6 kW per day.
And places on lunar poles which exceed 50% of time having sunlight [1360 watts per square meter] or 80% or more- 32.6 times .8 is 26 Kw hours per average day. And more important than that, is one can circle to small lunar polar region with grid and get 100% of the time having electrical energy from the Sun. Can't do this on Earth or polar regions on Earth are very lousy places to get solar energy and Earth has 23 tilt on it's axis.

On Moon one could have this before one could have something like Space Power satellites for Earth, but first having it on the Moon would then eventually lead to having SPS for people on Earth. So give it 10 or 20 years after it's on the Moon, so at that time Earthling will get SPS from GEO providing majority of electrical needs on Earth. Ie Earth would never have a energy shortage.
Or if NASA gets going with Lunar exploration we could  have SPS for Earth within a century of NASA doing this lunar program [in meantime NASA after 10 years or less of lunar exploration, goes on to explore Mars to determine if and where Mars settlements would be viable].
 
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 07/08/2016 10:21 pm
@gbaike and highroad: Dudes, you are in the wrong thread. We're trying to discuss the possibility of NOT mining for water. Please actually read the previous parts of the thread... ::)
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: gbaikie on 07/08/2016 11:11 pm
<snip>

Intuitively, having half the storage and handling facilities (one for oxygen, none for hydrogen), and not having to build an airtight a hydrogentight canopy over the extraction site, and being able to 'simply' pile up waste rock out in the open, until it can be used to expand the base, would cut a lot of required mass. Plus: only one tank on the launch vehicle increases useful payload mass. (could also be solved by having dedicated oxygen/hydrogen launches, but that pushes your break-even point further out).
Not sure understand what technique is being employed, but if put something like Mylar over lunar surface- say something like 20 square meter area [400 square meters]. Pile sand bags around perimeter, then heat the area within, the volatiles will inflate the sheet of Mylar and they can be draw off at low pressure- say at Mars pressure or at about .1 psi or less. And then volatiles can collected in cold box [they will add heat to container so container should function as heat sink and as more volatiles condense they become part of heat sink's thermal mass. So, roughly a cold empty 55 gallon drum could be this cold box.
I imagine it will easier to make more water than can be split- and water or ice is easy to store in large quantities [tens or hundreds of tons] but generally speaking you don't want to store much rocket fuel- or it's money sitting there, costing you money. So the amount you store is amount used by one lander, so depends upon how big the landers are. Say there was a need of shipment of 200 tons of LOX. That doesn't sound like any vehicle leaving the Moon- or needed in lunar orbit or some other orbit. So I would store in orbit, and deliver to it in say 20 tons shipments. So in that case need lander [or something] which lift 20 tons off Moon [pretty big lunar lander] So it's gross mass is somewhere over 40 tons, and needs 3 tons or less of Hydrogen. Or this is plan, need to store at most 3 tons of hydrogen, probably frozen Hydrogen. Or 2 tons frozen and 1 ton liquid. So density liquid is 70.8 kg/m- 3000 / 70.8 is 43 cubic meters. say 3 meter cylinder is
7 cubic meter per 1 meter in length, 6 meters is 42- say two which bit more than 3 meter tall. Or for frozen 4 meter tall and liquid being 2 meter diameter and about 4 meter tall Or start with liquid and add frozen hydrogen storage if and when need such storage capacity.
Quote

Edit: I know you guys prefer engineering over accounting and finance, but the problem is in attributing costs to the finished good. When you produce hydrogen + oxygen, 89% of your revenue is coming from oxygen. If hydrogen-related costs are more than 11% of the production cost, you'd be better off (financially) by dumping it, rather than shipping it.

Edit: oh, yes you don't start out exporting Hydrogen from the Moon. You export LOX and/or lunar water from the Moon. Assuming someone wants water in High earth orbit [like crew going to Mars- shielding, drinking etc].

I think hydrogen per kg is worth more the 1 kg of LOX.
Or on the Moon if LOX is priced at $1000 per kg, than Hydrogen should be about $4000 per kg.
Or roughly the same if one were selling LOX in LEO, but if selling LOX for 1000 per kg, then Hydrogen
should be about $2000 per kg. Because Hydrogen is more bulky. Or per kg of LOX is cheaper to ship
than 1 kg of hydrogen. Now if you deliver a ton of liquid Hydrogen to the Moon one is delivering it's container also which has value as something which can store hydrogen. Or if going to deliver a big shortage tank for Hydrogen [or storing LOX or whatever] to the Moon, you might as well fill it with liquid hydrogen. So shipping hydrogen to lunar orbit or lunar surface is about 30% sending shortage tanks to Lunar orbit and lunar surface.
Also another reason hydrogen should be more expense, is hydrogen has more uses than to be used as rocket fuel- you can process iron oxide from Hydrogen for example.
With rocket fuel one uses 6 kg LOX per 1 kg Hydrogen and have 2 LOX left over- surplus. And if using fuel cells [to power lunar surface vehicles] using 8 LOX to 1 Hydrogen- returning the water to be split again.
Anyhow if flying about the Moon or going into orbit, one will create a shortage of Hydrogen and using hydrogen for process material creates shortage of Hydrogen. Or said differently a surplus of oxygen- making LOX cheaper. Anyways if 1000 and 4000, it's 1000 times 6 + 4000 divided by 7. Making LH&LOX
10,000 divided by 7 = $1428.57 per kg of rocket fuel.
And LOX from water is $8000 vs 4000 for 1 kg of Hydrogen or LOX is twice value from 1 kg of water [or 9 kg of water]. This assuming one not shipping Hydrogen from Earth, which today value is 20,000 per kg and with some lunar water mining could reduce to about $10,000 per kg. Or 1000 times 6 + 10,000 is
16000 divide by 7 is $2285.71 per kg of  LH&LOX rocket fuel.

Quote
I thought I saw the poles as not being ideal to launch somewhere upthread, but I can't find it at the moment. And if you guys tell me zero K equipment requires no more maintenance than lunar night/day equipment, then I'll take your word for it and have the running cost at least be comparable. See, I'm being reasonable here. :-)
Well in general one approaches the Moon at a equatorial inclination from Earth and it cost delta-v to change the inclination. Let's say one start at equatorial low lunar orbit, to change inclination would it done by increasing the apogee of the orbit, and at apogee one has least cost to change the inclination.
But one enter lunar orbit so you have a high apogee orbit. Or there ways of approaching the Moon at high inclination relative to the Moon. One cheapest spacecraft ever launched was Lunar prospector and did it's science of the moon from lunar polar orbit.
{Edit: plus LRO, European Lunar Express and the Indian lunar spacecraft}
In terms of Earth, it cost enormous amount of delta-v to change from Equatorial orbit to polar orbit. This related to puting stuff in GEO, if launch from 28 inclination [KSC] one does a GTO  and at apogee one changes the inclination to equatorial inclination [GEO}. I believe it costs somewhere about 1.5 km/sec of delta-v. If launching from Russia [51 inclination] the same trajectory is much higher. If launch European launch site at 6 degree inclination, doesn't cost much to change inclination to GEO [it's why Europe put the launch site near equator]. But if Russia wanted to send something to GEO, they could send satellite via to a moon trajectory, having change inclination cost essentially nothing and end up in GEO for less delta- but takes a long time to do this- and satellite birds are expense if spending time not doing what suppose to be doing.

Title: Re: Impact of lunar free water on Exploration Architecture
Post by: gbaikie on 07/08/2016 11:49 pm
@gbaike and highroad: Dudes, you are in the wrong thread. We're trying to discuss the possibility of NOT mining for water. Please actually read the previous parts of the thread... ::)
Drilling for oil is mining oil. I address my issues about this earlier in the thread.
I will sum it up here. I want NASA to do a cheap lunar exploration program, and then go to Mars.
I think it's possible that water may be found by drilling for it on the moon.
And it would be wonderful if drilling for water could result in large quantities of water.
Though I believe there is better chance of finding sites on Mars which could result in getting large amount of water by drilling water wells.
I don't think NASA in beginning of Mars exploration should spend much effort in such exploration, yet I think
it would make very significant discovery in terms of future Mars settlements. Or I think that within 10 years of having crew on Mars doing this would become an increasingly higher priority, since I believe the purpose of NASA Mars exploration should be to determine if Mars settlement can be viable- and having drill-able Mars water near the surface fits into part of my definition of Mars settlements being viable.

It possible NASA does not explore the Moon and it might be up to the private sector to explore the Moon, under such situation the idea looking for mother lodes of water on the Moon may favor [in terms of a bet] as compared to exploring the lunar poles. Though this also should weighed against the advantage of locating operations in lunar poles- as pointed to in most recent posts [and in lots of other posts]. Of course if find location to drill for water in or near lunar polar regions, then this would also have those advantages in addition.

Or if there a mad billionaire who wanted to spend 5 billion, I might suggest the drilling for water as a plan to consider, and in particular if sites were near lunar polar regions- AND for all we know, the Chinese might already doing this. As in there are mad billionaires in China, they are doing lunar mission involving ground radar which are vaguely close to poles.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 07/09/2016 12:37 am
@gbaike and highroad: Dudes, you are in the wrong thread. We're trying to discuss the possibility of NOT mining for water. Please actually read the previous parts of the thread... ::)
THIS.

Also, a little terseness is a very good thing to learn.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: high road on 07/09/2016 08:06 am
@gbaike and highroad: Dudes, you are in the wrong thread. We're trying to discuss the possibility of NOT mining for water. Please actually read the previous parts of the thread... ::)
THIS.

Also, a little terseness is a very good thing to learn.

Point taken. Avoiding sidetracking for now on. Starting with the semantical interpretation of the word 'mining'.

My point is: the easier it is to get water on the moon, the less it makes sense to store and sell the hydrogen part. That's a response to the thread title.

To illustrate this: if the moon was a solid ice cube, the hydrogen handling related costs would approach 50% of the total costs, while only accounting for 11% of the revenue. Either that cost is above what it costs to bring hydrogen from earth, either by the customer or by dedicated fuel launches, or there's a 39+% profit margin, which means competitors will be swarming to the moon, and dumping the hydrogen to undercut your price.

This means hydrogen would be dumped, like gasoline before there were engines that could use it. The hydrogen half of the fuel would not become cheaper or more readily available. No amount of freely accessible ice can change that. The only way it can have an impact on exploration architecture, is if there is a big enough demand for oxygen, so likely from a commercial, orbital market, that would indeed become a lot cheaper, I think. This is not a catch 22.

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I think hydrogen per kg is worth more the 1 kg of LOX.
That phrase is the only part of your post that I think is relevant to this thread, because it illustrates an important thinking error. What you are selling is fuel, at a certain location (LEO, GTO, wherever there is an existing market big enough to start the venture), and the value of what you're selling is the cost of getting that fuel there by any other means. Your competitors are bringing it from Earth, either with the payload or by a dedicated fuel station infrastructure. Hydrogen might be a little bulkier to handle, but not 16 times more bulky than oxygen. So the mass of the fuel itself is going to account for the biggest difference in market price between the two.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: TakeOff on 07/09/2016 03:54 pm
The first next human missions to the Moon will hardly launch anything from there but the crew (and samples). And they will need to land in a fully fueled ascent vehicle to be able to abort at any time during landing. So I think that ISRU (of water) on the Moon will not help humans returning to it to begin with. It will get useful only after major investments have been made in Lunar surface activities such as a permanently crewed base.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: gbaikie on 07/09/2016 06:50 pm
@gbaike and highroad: Dudes, you are in the wrong thread. We're trying to discuss the possibility of NOT mining for water. Please actually read the previous parts of the thread... ::)
THIS.

Also, a little terseness is a very good thing to learn.

Quote
I think hydrogen per kg is worth more the 1 kg of LOX.
That phrase is the only part of your post that I think is relevant to this thread, because it illustrates an important thinking error. What you are selling is fuel, at a certain location (LEO, GTO, wherever there is an existing market big enough to start the venture), and the value of what you're selling is the cost of getting that fuel there by any other means. Your competitors are bringing it from Earth, either with the payload or by a dedicated fuel station infrastructure. Hydrogen might be a little bulkier to handle, but not 16 times more bulky than oxygen. So the mass of the fuel itself is going to account for the biggest difference in market price between the two.
LH2 is 16 times more bulky.
LOX is 1141 kg per cubic meter. LH2 is 70.8 kg per cubic meter

From water one gets 1 kg of Hydrogen and 8 kg of Oxygen from 9 kg of water.
So in terms of volume one gets twice as much volume of hydrogen as oxygen when you split water.
But in terms of price per kg, hydrogen is 16 times more bulky.
100 tons of liquid hydrogen require volume of 1269 cubic meter: 5 meter diameter cylinder by 64.63 meter
tall.
And 100 tons of LOX would be the length divided by 16: 5 meter diameter by 4.04 meter tall

Or the Shuttle external tank carried 106,261 kg of LH2- [106 tons] and 629,340 kg of LOX
Volume of ET Hydrogen tank: 1,497,440 liter [1497.44 cubic meters] LOX tank: 553,358 liters
https://en.wikipedia.org/wiki/Space_Shuttle_external_tank
In is mixture of 1 kg hydrogen to 6 kg of LOX. About 2/3rd of volume being LH2

And empty mass of ET was "approximately 30,000 kg"
If have same diameter and not counting ends of cylinder 100 ton of LOX requires 1/16th the mass
of the tank. Let's call it 1/15th. So if 100 ton of hydrogen could require 20 tons of tank mass
and LOX would require 20 K / 15 = 1340 kg [say 1.5 tons] of tank mass.

If need to use the tank then the extra mass of tankage of shipping Hydrogen, does not matter much. If you want LH2 and the LH2 tank one could consider the LH2 tank as valuable per kg as compared to the LH2.
But if going to throw away the tank or "recycle" the material, then you consider the tank's mass in terms of scrap value {whatever that is}.
Another aspect related to boil off of a cryogenic rocket fuel.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: high road on 07/10/2016 06:28 pm
LH2 is 16 times more bulky.
LOX is 1141 kg per cubic meter. LH2 is 70.8 kg per cubic meter

I meant bulky in the sense of 'massive', as that is the basis we're going for here. I never even realized the wordt could also mean 'voluminous' until you brought it up.

Quote
Or the Shuttle external tank carried 106,261 kg of LH2- [106 tons] and 629,340 kg of LOX
Volume of ET Hydrogen tank: 1,497,440 liter [1497.44 cubic meters] LOX tank: 553,358 liters
https://en.wikipedia.org/wiki/Space_Shuttle_external_tank
In is mixture of 1 kg hydrogen to 6 kg of LOX. About 2/3rd of volume being LH2

And empty mass of ET was "approximately 30,000 kg"
If have same diameter and not counting ends of cylinder 100 ton of LOX requires 1/16th the mass
of the tank. Let's call it 1/15th. So if 100 ton of hydrogen could require 20 tons of tank mass
and LOX would require 20 K / 15 = 1340 kg [say 1.5 tons] of tank mass.

Let's take it even further: hydrogen requires more cooling, so for simplicity's sake let's attribute the entire 30 tons to the hydrogen-related launch mass, which makes 136kg of H2 for every 629kg of O2 for apparently H2-rich reactions like STS and 136kg of H2 for every 848kg of O2 for stoichiometric systems. That's what it takes to get the propellant up from Earth, so that's the market price in my previous explanation.

For the stoichometric burns, that means 86% of the revenue is coming from oxygen, and 14% from hydrogen, instead of 89% and 11%. Not enough to change my point.

For the hydrogen-rich scenario, you're dumping (alternative uses are not to be discussed in this thread) the excess O2. You need to produce the same amount of propellant, but you're selling 22% less of it in terms of mass. So your total profit margin drops by 22%. That's more than the extra revenue from selling hydrogen. (which, for easily accessible water on the moon at least, which is the focus of this thread, is already lower than the added cost of handling the hydrogen).

Be sure to make the difference between 'cost' and 'value' (the economic term for 'worth'). An increase in the production costs does not increase the market value.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Lar on 07/10/2016 07:03 pm
The first next human missions to the Moon will hardly launch anything from there but the crew (and samples). And they will need to land in a fully fueled ascent vehicle to be able to abort at any time during landing. So I think that ISRU (of water) on the Moon will not help humans returning to it to begin with. It will get useful only after major investments have been made in Lunar surface activities such as a permanently crewed base.
This seems like flags and footprints thinking... it doesn't admit of the possibility of teleoperated equipment that does mining (er, drilling) and refining to get the fuel.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: turbopumpfeedback2 on 07/10/2016 07:27 pm
The first next human missions to the Moon will hardly launch anything from there but the crew (and samples). And they will need to land in a fully fueled ascent vehicle to be able to abort at any time during landing. So I think that ISRU (of water) on the Moon will not help humans returning to it to begin with. It will get useful only after major investments have been made in Lunar surface activities such as a permanently crewed base.
This seems like flags and footprints thinking... it doesn't admit of the possibility of teleoperated equipment that does mining (er, drilling) and refining to get the fuel.

I agree that teleoperated mining (TOM) is an important option.

Actually, I think that TOM should be tried before any local human presence. The great thing about TOM is that it can be scaled: from a system producing kilograms to tons of H2 and O2.

If humans are involved on the surface the threshold is immediately very very high.

What worries me about TOM is the occurrence of two things
1) Dusty environment
2) Airtight seals

Somehow I have a feeling that TOM equipment will quickly succumb without direct human maintenance (note: all I know about mining equipment is from the TV). But I hope I am wrong.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Space Ghost 1962 on 07/10/2016 08:46 pm
The first next human missions to the Moon will hardly launch anything from there but the crew (and samples). And they will need to land in a fully fueled ascent vehicle to be able to abort at any time during landing. So I think that ISRU (of water) on the Moon will not help humans returning to it to begin with. It will get useful only after major investments have been made in Lunar surface activities such as a permanently crewed base.
This seems like flags and footprints thinking... it doesn't admit of the possibility of teleoperated equipment that does mining (er, drilling) and refining to get the fuel.

I agree that teleoperated mining (TOM) is an important option.

Actually, I think that TOM should be tried before any local human presence. The great thing about TOM is that it can be scaled: from a system producing kilograms to tons of H2 and O2.

Now, think for a minute. If you start out teleoperated (which allows you less risk, much more reduced footprint equipment/scope/operations requirement to begin), what's the reason for doing human presence?

Quote
If humans are involved on the surface the threshold is immediately very very high.

Carefully defend this assumption, for it is very naive.

Quote
What worries me about TOM is the occurrence of two things
1) Dusty environment
2) Airtight seals

Somehow I have a feeling that TOM equipment will quickly succumb without direct human maintenance (note: all I know about mining equipment is from the TV). But I hope I am wrong.

Without humans, not much needed for seals/dust. Equipment can be qualified/test for operation over a certain interval w/o human maintenance. This more certain than any human involvement on the surface.

So, having been in mines, having worked with mining equipment, and having seen how mining equipment is used for decades w/o change, can tell you that there are many issues here to this.

First, the mining interests at the moment don't have enough interest in teleoperated equipment, mostly because they have little experience with it, and rely on human resources instead, like a vast number of labor intensive industries that could also benefit.

The few "space mining" ones I've run into, carry this bias as well, driving the same issue as well - "people first because they are cheaper and more adaptable to situations". They really want to ennoble mining by translating it into a new, high risk environment, for high pay.

Humans in space are extremely expensive and might be adaptable given the right tools. Robotic/teleoperated equipment will be relied upon to do any mass movement or mining operations. Yet on earth where we need to make the equipment/experience work as standard practice, we don't yet, because, it's easier to use the old equipment/experience/practice, and not innovate. Because, we contrive to keep mining dependent on cheap, unskilled labor with low tech equipment- none of which could ever be used in space.

On the moon, you'd likely pioneer with precursor work to establish where/how/why/when equipment/process would function to discover/derive a practice. Mostly this would be robotic/teleoperated. Human involvement with onsite evaluation, prospecting/analysis, equipment "debugging"/redesign, process re-envisioning and the like make sense, but this kind of thing can be handled on an as needed basis with sorties.

As operations would scale, certainly they're be more sorties and economics to support them, but it's likely that robotic operation would fully displace humans from heavy equipment operation. No need for a "moon base".

And, a likely side effect of this is that the same equipment and practice would come back to earth use, and economically eliminate any remaining human miners over less than a decade.

It'll never eliminate the need for humans in mining. But it will greatly reduce the numbers of them needed, and those that will be left will be highly trained and specialized.

So traditional mining interests lose interest in space, for it is a "death sentence" for their industry as they know it.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: turbopumpfeedback2 on 07/10/2016 11:45 pm
The first next human missions to the Moon will hardly launch anything from there but the crew (and samples). And they will need to land in a fully fueled ascent vehicle to be able to abort at any time during landing. So I think that ISRU (of water) on the Moon will not help humans returning to it to begin with. It will get useful only after major investments have been made in Lunar surface activities such as a permanently crewed base.
This seems like flags and footprints thinking... it doesn't admit of the possibility of teleoperated equipment that does mining (er, drilling) and refining to get the fuel.

I agree that teleoperated mining (TOM) is an important option.

Actually, I think that TOM should be tried before any local human presence. The great thing about TOM is that it can be scaled: from a system producing kilograms to tons of H2 and O2.

Now, think for a minute. If you start out teleoperated (which allows you less risk, much more reduced footprint equipment/scope/operations requirement to begin), what's the reason for doing human presence?


I thought for a while, and I am not sure what to answer. But I did notice that the title of this thread is kind of circular: how can lunar water impact exploration architecture if the aim of exploration is to find lunar water? 

Quote
Quote
If humans are involved on the surface the threshold is immediately very very high.

Carefully defend this assumption, for it is very naive.


It could be that I am missing a point here. I simply stated that if program involves landing humans on the Moon it will be hugely expensive. By hugely expensive I mean that NASA's budget needs to grow to accommodate such a program.   


Quote


Quote
What worries me about TOM is the occurrence of two things
1) Dusty environment
2) Airtight seals

Somehow I have a feeling that TOM equipment will quickly succumb without direct human maintenance (note: all I know about mining equipment is from the TV). But I hope I am wrong.

Without humans, not much needed for seals/dust. Equipment can be qualified/test for operation over a certain interval w/o human maintenance. This more certain than any human involvement on the surface.

So, having been in mines, having worked with mining equipment, and having seen how mining equipment is used for decades w/o change, can tell you that there are many issues here to this.

Thanks for sharing the knowledge!
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: KelvinZero on 07/11/2016 11:10 am
Now, think for a minute. If you start out teleoperated (which allows you less risk, much more reduced footprint equipment/scope/operations requirement to begin), what's the reason for doing human presence?
To repair the robots!

Seriously, robots would create the best justification to send people. And I would prefer to land wearing my spacesuit atop the same tiny one ton lander that had flown many times before, instead of an Altair too expensive to test.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Space Ghost 1962 on 07/11/2016 08:36 pm
The first next human missions to the Moon will hardly launch anything from there but the crew (and samples). And they will need to land in a fully fueled ascent vehicle to be able to abort at any time during landing. So I think that ISRU (of water) on the Moon will not help humans returning to it to begin with. It will get useful only after major investments have been made in Lunar surface activities such as a permanently crewed base.
This seems like flags and footprints thinking... it doesn't admit of the possibility of teleoperated equipment that does mining (er, drilling) and refining to get the fuel.

I agree that teleoperated mining (TOM) is an important option.

Actually, I think that TOM should be tried before any local human presence. The great thing about TOM is that it can be scaled: from a system producing kilograms to tons of H2 and O2.

Now, think for a minute. If you start out teleoperated (which allows you less risk, much more reduced footprint equipment/scope/operations requirement to begin), what's the reason for doing human presence?


I thought for a while, and I am not sure what to answer.

Which is why it's important to think about posts. If you don't know, don't post until you do.

Quote
But I did notice that the title of this thread is kind of circular: how can lunar water impact exploration architecture if the aim of exploration is to find lunar water? 

Which was there before I posted. This "chicken and egg" thing affects a lot of space architectures. Like depots.

In short, props vended outside of gravity wells is a commercial activity, only supported by sustained exploration need. Unlikely in the near future. Howe you might "bootstrap" such might be a govt prize for, say, 1T of desireable/usable props (one of qualified hydrolox, kerolox, hypers) on "useful" orbit. But even if that were done, someone would make the argument that it wasn't "useful enough", so let it bankrupt and go away as not really being yet a marketplace but a stunt. Which is all a prize in the end is.

Quote
Quote
Quote
If humans are involved on the surface the threshold is immediately very very high.

Carefully defend this assumption, for it is very naive.


It could be that I am missing a point here. I simply stated that if program involves landing humans on the Moon it will be hugely expensive. By hugely expensive I mean that NASA's budget needs to grow to accommodate such a program.

Water for props, or humans on the moon? The first no, the second "depends" on a) what they are doing, b) how long they are going to be there, and c) how frequently they visit.   

NASA's scope of exploration is narrow and deterministic. Its budget is always very specific. It doesn't grow for nonspecific reasons.
Now, think for a minute. If you start out teleoperated (which allows you less risk, much more reduced footprint equipment/scope/operations requirement to begin), what's the reason for doing human presence?
To repair the robots!

In the fullness of time, perhaps.

Quote
Seriously, robots would create the best justification to send people.

People can far exceed robot precursors. But only when the robots prove insufficient. Robots will fix/build robots before that. However, robots are likely never to be good at subjective judgement and intuition. Because then they wouldn't be ... robots.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: high road on 07/12/2016 01:38 pm
Which was there before I posted. This "chicken and egg" thing affects a lot of space architectures. Like depots.

In short, props vended outside of gravity wells is a commercial activity, only supported by sustained exploration need. Unlikely in the near future. Howe you might "bootstrap" such might be a govt prize for, say, 1T of desireable/usable props (one of qualified hydrolox, kerolox, hypers) on "useful" orbit. But even if that were done, someone would make the argument that it wasn't "useful enough", so let it bankrupt and go away as not really being yet a marketplace but a stunt. Which is all a prize in the end is.

The lunar propellant is not a chicken and egg problem. The propellant depots and demand for fuel in earth orbit (where there is indeed a chicken and egg problem) need to be there before the lunar propellant production facilities can even sell their products. Once there's a market in low orbit, the question whether it would be cheaper to get those fuels on the moon rather than on earth, will be quantifyable.

Whether easily accessible water ice will have an impact at that point depends on what fuel is being used by that preexisting infrastructure:

- an SEP-tug infrastructure takes noble gas as fuel. No point in getting that from the moon
- an infrastructure where satellites themselves are refueled, requires easily storable propellants. Little point in getting that from the moon.
- an infrastructure that uses a reusable chemical tug (for faster transport, easier aerobraking and faster transits through the Van Allen belts) could use LH2/LOX, or methalox. Wether that means it would be cheaper to get from the moon, depends on how expensive launching from earth is at that time. Still, a high demand for LOX in earth orbit is a prerequisite for a lunar fuel station having an impact on the cost of sending stuff beyond Earth orbit.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Space Ghost 1962 on 07/12/2016 06:09 pm
Totally missed the point. Any propellant to anywhere to be used as any "add-on" is "chicken and egg" right now.

You'd source from moon/asteroid to even LEO to avoid the gravity well trap, and to allow "gas stations" anywhere needed, cost driven by access to "adjacent enough" resources to deploy from. Heart of a logistical network. Rest is trivial.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: gbaikie on 07/12/2016 11:50 pm
@gbaike and highroad: Dudes, you are in the wrong thread. We're trying to discuss the possibility of NOT mining for water. Please actually read the previous parts of the thread... ::)
THIS.

Also, a little terseness is a very good thing to learn.

Point taken. Avoiding sidetracking for now on. Starting with the semantical interpretation of the word 'mining'.

My point is: the easier it is to get water on the moon, the less it makes sense to store and sell the hydrogen part. That's a response to the thread title.

To illustrate this: if the moon was a solid ice cube, the hydrogen handling related costs would approach 50% of the total costs, while only accounting for 11% of the revenue. Either that cost is above what it costs to bring hydrogen from earth, either by the customer or by dedicated fuel launches, or there's a 39+% profit margin, which means competitors will be swarming to the moon, and dumping the hydrogen to undercut your price.

This means hydrogen would be dumped, like gasoline before there were engines that could use it. The hydrogen half of the fuel would not become cheaper or more readily available. No amount of freely accessible ice can change that. The only way it can have an impact on exploration architecture, is if there is a big enough demand for oxygen, so likely from a commercial, orbital market, that would indeed become a lot cheaper, I think. This is not a catch 22.

I think your analysis is faulty for number of reasons. One aspect is you think you have sell lunar rocket fuel to  LEO. In beginning of Lunar water mining, I sell rocket fuel to lunar surface and get as quickly as possible to the point selling it to Low lunar orbit.
If water was abundant and cheap, I probably would start selling rocket fuel to both lunar surface and low lunar orbit. There are number of reasons to sell rocket fuel to low lunar orbit.
One reason is one will have surplus of LOX if using split water for rocket fuel. And because LOX is fairly easy to store, one could afford to save the surplus if water is not as cheap and abundant. But in situation having a lot of water and making a lot of LH&LOX one have go more quickly to exporting it to Low Lunar orbit.
Now the rocket fuel one exports is LOX to Low lunar orbit, with the assumption that LH2 or other fuel will be brought from Earth.
But if Hydrogen is too expensive the store and you are dumping, one make H2O2 if you have O2 and H2 gas and water.:
"The most widely used synthesis method of hydrogen peroxide is the anthraquinone process. There, anthraquinone is first hydrogenated to anthrahydroquinone. This reduced compound is oxidized with molecular oxygen, regenerating anthraquinone and releasing hydrogen peroxide"
https://en.wikipedia.org/wiki/Peroxide
So the anthraquinone is reused or is not consumed, so addition to this you need to make a vacuum to concentrate it- easy to do on the Moon.
With Peroxide one use as mono-propellant or as oxidizer with other fuel. With LH2 and 95% Peroxide
the mixture is 11 parts Peroxide to 1 Hydrogen, and ISP is 312:
http://www.thespacerace.com/forum/index.php?topic=2583.0
So with Peroxide with every 10 tons of rocket fuel used, one needs even less H2 as compared to LH2&LOX- need to store less LH2. And peroxide in space is easier to store and denser than LOX.
As far as exporting rocket fuel from the Moon to Earth Low orbit, what is needed is for electrical power on the Moon to become cheaper. And price of electrical on Moon will become cheaper once one has rocket fuel at lunar Low orbit and one has reusable rockets going from Lunar surface to Low lunar orbit. And basically time for market to become more mature.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: jongoff on 07/13/2016 12:32 am
Totally missed the point. Any propellant to anywhere to be used as any "add-on" is "chicken and egg" right now.

You'd source from moon/asteroid to even LEO to avoid the gravity well trap, and to allow "gas stations" anywhere needed, cost driven by access to "adjacent enough" resources to deploy from. Heart of a logistical network. Rest is trivial.

With ULA expressing their willingness to buy a significant amount of propellant in LEO for Vulcan/ACES, it seems slightly less chicken-and-eggy. They still have to make Vulcan and ACES work obviously, but the fact that they think they can use propellant in LEO (presumable for enabling direct to GSO insertion missions) suggest there's at least some potential non-exploration demand for propellant in LEO.

~Jon
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Space Ghost 1962 on 07/13/2016 01:27 am
Totally missed the point. Any propellant to anywhere to be used as any "add-on" is "chicken and egg" right now.

You'd source from moon/asteroid to even LEO to avoid the gravity well trap, and to allow "gas stations" anywhere needed, cost driven by access to "adjacent enough" resources to deploy from. Heart of a logistical network. Rest is trivial.

With ULA expressing their willingness to buy a significant amount of propellant in LEO for Vulcan/ACES, it seems slightly less chicken-and-eggy.

Nothing would please me more, but from my understanding of ULA priorities, CAPEX, and working funds, ... wouldn't hold my breath waiting for it.

Its a opportunity consistent with long life hydrolox US expertise that ULA is globally dominant in.

But really though, how long has IVF been begging for dimes? C'mon.

Quote
They still have to make Vulcan and ACES work obviously, but the fact that they think they can use propellant in LEO (presumable for enabling direct to GSO insertion missions) suggest there's at least some potential non-exploration demand for propellant in LEO.

Someone should be pushing for it as well as certain other high visibility start-up related projects and programs, twisting two very sizable arms to get the $100M more to establish a more powerful future for ULA to mean something against its rival. And we haven't even talked about the pacing of Vulcan/Centaur "investment", let alone considered what/when with ACES, the oft indefinitely scheduled "second half".

Shall we say "crowded agenda"?  Too much "tactical pain" already?

ULA doesn't need vision or PR or circus acts. It needs a present (Tory) and a future (not just a new LV). And the future needs to happen as well as the present ... good luck getting that through BA/LMT, even in the $100K amounts.

So much for the inside baseball.

Back to lunar water (BTW there's helium and other noble gases on the Moon too, FYI). Likely you can surface/strip mine enough with robotic heavy machinery to feed ISRU robotic plant to provide hydrolox props to feed RL10's. And not just from the Moon. Hard work to fill tons into dewars and actively manage them.

But even with that done, not so easy to deliver to on orbit. Affording a station attendant would make it even worse. Quite a pipe dream. I can see it now - a line of automated DTAL landers as successive tankers, filling, departing, landing ... four billion and about a decade, give or take ...
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: high road on 07/13/2016 07:41 am
Totally missed the point. Any propellant to anywhere to be used as any "add-on" is "chicken and egg" right now.

You'd source from moon/asteroid to even LEO to avoid the gravity well trap, and to allow "gas stations" anywhere needed, cost driven by access to "adjacent enough" resources to deploy from. Heart of a logistical network. Rest is trivial.

Chicken and egg means you have to create both the demand and the supply side at the same time. The bare minimum supply side is a fuel station + refuelable spacecraft/satellite. Adding a new extraction and processing plant in space from the get-go multiplies your start up cost for the supply side,  but it does not change your potential demand, so the profit margin for the total investment would be lower, even if the running costs per kg of fuel produced are lower. So fuel production on the moon is not chicken and egg, rather a potential alternative once certain prerequisits (a functioning fuel market infrastructure in space) are met.

Adding a new demand side is even worse: You need to create a demand high enough for your fuel station to run, while launch costs are only a comparatively small percentage of the total cost of any space activity. You would have to increase the startup capital by orders of magnitude. No chicken and egg there, but a prerequisite to a prerequisite to a prerequisite. Unless human interest in space increases magically for no reason at all, that is, so economic sense (of the market that is the demand side to what you're selling) is no longer required.

Back to lunar water (BTW there's helium and other noble gases on the Moon too, FYI). Likely you can surface/strip mine enough with robotic heavy machinery to feed ISRU robotic plant to provide hydrolox props to feed RL10's. And not just from the Moon. Hard work to fill tons into dewars and actively manage them.

Yes, there are noble gasses on the moon. And SEP has an ISP that is one or two orders of magnitude higher than chemical fuel, depending on the design. Thus, the amount of fuel required by a SEP infrastructure is one or two orders of magnitude lower than the amount of fuel required by a chemical fuel infrastructure, for the same activity in orbit (which is the demand side for the space fuel infrastructure). Considering the initial investment is the big problem to overcome, it makes one or two orders of magnitude less sense to get those from the moon than chemical fuel.

1) If water was abundant and cheap, I probably would start selling rocket fuel to both lunar surface and low lunar orbit.

2) One reason is one will have surplus of LOX if using split water for rocket fuel.

1bis) But in situation having a lot of water and making a lot of LH&LOX one have go more quickly to exporting it to Low Lunar orbit.

3) But if Hydrogen is too expensive the store and you are dumping, one make H2O2 if you have O2 and H2 gas and water.:

Prerequisits, prerequisits, prerequisits:

1) In order for it to make sense to sell fuel to low lunar orbit, you need demand in low lunar orbit. In order to sell to earth orbit, you need demand in earth orbit. The difference is that in earth orbit, there is a big potential market already in business. If you want to use a fuel depot in low lunar orbit to supply that potential market of existing commercial activities, you need to either build a new, competitive fuel station, or haul the fuel station (that is needed to get the earth orbit market from potential to existing) from LEO to the now better located Lunar Orbit. I'm assuming any sensible fuel station architect will have that possibility in their design, to go along with the changing market conditions. Either way, the end user market remains the same.

2) In order to have a surplus of O2, selling H2 needs to be more profitable, not more expensive. You're having things in reverse. People don't buy H2 from the moon simply because it's there, but because it's cheaper than bringing it from earth. And it can only become cheaper if it does not have to compete with LOX from the moon, so when the added hydrogen handling cost is less than 14% of the total activity. Which might be the case if it is hard to extract water on the moon, not easy.

3) H2O2 is easier to store? Then by all means, that can be a clear winner.

edit: mixup of different levels of potentialness.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: gbaikie on 07/14/2016 10:21 pm

1) If water was abundant and cheap, I probably would start selling rocket fuel to both lunar surface and low lunar orbit.

2) One reason is one will have surplus of LOX if using split water for rocket fuel.

1bis) But in situation having a lot of water and making a lot of LH&LOX one have go more quickly to exporting it to Low Lunar orbit.

3) But if Hydrogen is too expensive the store and you are dumping, one make H2O2 if you have O2 and H2 gas and water.:

Prerequisits, prerequisits, prerequisits:

1) In order for it to make sense to sell fuel to low lunar orbit, you need demand in low lunar orbit. In order to sell to earth orbit, you need demand in earth orbit. The difference is that in earth orbit, there is a big potential market already in business.
Earth orbit is existing market, and potentially it could market for rocket fuel. But earth orbit isn't a big market and nor is the potential market for rocket fuel of Earth orbit a big market.

Or only reason I see for NASA to explore the Moon and then explore Mars is to add markets in space, and eventually make Earth orbit and beyond a big market. And once we have large market in space we can get SPS for Earthling on Earth surface. And SPS market would be about 1 trillion dollar market in space.
We current have a 200 billion dollar global space market. That market is an earth market related to activities done in Earth orbit. The 1 trillion SPS market would actually be GEO market and provide power to a 100 trillion dollar global Earth market - or earth activity using the power from space would "empowered" to do stuff costing [or spending] 100 trillion dollar. Or currently the global electrical market is more then 1 trillion dollar spent each year for the electrical, and that electrical power to use to "power"  the entire market of Earth.
Or all things related to using electrical power is the world's market. Or International Monetary Bank knows that if poor country can access to cheap electrical power, that is the way to make a poor country become rich. Or China is richer because resident pay on average about 13 cents per Kw hour, which cheaper power than what can got in poorer countries. And it cheaper than US and much cheaper than in Europe on average, or Germans are paying about 30 cent per kW hour. Or their high price of electrical power predictably will make Germans poorer.
So if we had a big space market then we make a huge space market which is providing electrical power to the global earth surface [and solve world poverty- make future global energy shortages, a memory].

Title: Re: Impact of lunar free water on Exploration Architecture
Post by: gbaikie on 07/15/2016 08:12 am
In next 6 month 45 launches are planned [some may not be launched]
9 are going to ISS, 10 to LEO, 26 beyond LEO.
So if double it, it's 90 launches per year and 52 beyond LEO.
the 26 in 6 months has most going to GEO, one is going to an asteroid
called, Bennu and with return sample. See:
http://spaceflightnow.com/launch-schedule/

So in terms of rocket fuel, 52 would be about 5 tons each or less.
A problem is the best way to GEO is from near 0 inclination. So if
going from European launch at 5.2 degrees or Indian's 13.8 degrees
you probably would not launch into 28 degree inclination to reach a depot
in 28 degree orbital inclination, and if launching from say 35 degrees or
higher one wouldn't want to go to 28 degree orbit. But from China and Japan
one can go to 28 degrees inclination orbit to get rocket fuel from
depot in 28 degrees.
Anyhow it could be as much as around 250 tons per year or about 1 billion
dollar gross worth in terms rocket sold at depot per year if one could capture
entire business.

In terms of low lunar orbit. The quantity of rocket fuel could equal to
amount of total payload deliver to lunar surface per year.
In addition less that 1/2 of total payload from Moon to Earth- people,
PGM, and "lunar samples". And additional rocket fuel used for payload from Lunar
surface to GEO, Earth L-points, and Mars orbits [and Mars surface]. Plus
anything going beyond Earth- other planets and asteroids.

So to mine lunar water and make rocket fuel how much mass is needed from
earth to lunar surface?
It seems if you want to mine a lot of water per year- say 1000 tons per year
then probably about 100 tons. Or to mine 1000 tons per year and do this
for 10 year - 10,000 tons, over the 10 year one need about 150 tons in terms
of all mass needed to establish and maintain this operation for 10 years.
But it seems one needs other lunar activity other than just the water
mining and making rocket fuel. Or with water mining a lunar base should quite cheap-
so over 10 years one have about 200 tons shipped to lunar surface- as far as cargo
rather the people crewing base. One could have 30 to 100 people going to
base over 10 year period- ISS has had about 100 people per 10 years.
In addition different space agencies may want separate lunar bases. Large
corporation may want separate lunar bases for research and lunar
exploration- find places to drill lunar water, as one example.
One could have hotels for lunar tourists. One could want telescopes
based on lunar surface. Other mining such as lunar iron, aluminum, calcium,
silicon [including glass], PGM, gold, etc.
So one could need to land about 100 tons per year on lunar surface,
requiring 100 tons of rocket fuel at low lunar orbit to land it and tens
to hundred tons to ship things off the moon.
And it's about twice the price of rocket fuel in LEO.

After 10 years the focus could shift to Mars exploration and Mars
settlements, this could shift from couple hundred tons to around
1000 tons of fuel per year at low lunar orbit and have ever increasing
amount from the Lunar surface, and eventually with lower cost, one is sending
rocket fuel to LEO orbit.

Though I should note that I think the amount lunar water mined would start
at about 50 tons the first year and build up to 100 tons per year, and perhaps
reach as much as 1000 tons per year in about 5 years.
Of course the topic of thread seems to be the idea of starting with more than 1000 tons per year of rocket fuel- and one would initially need to land much more than 100 tons to lunar surface to begin such larger scale
operations.

Edit: so NASA begins lunar exploration by making a LOX depot at 28 inclination. NASA might get to point of using 10 tons of LOX on average year. The point is not for NASA to be profitable in the depot business, but rather to get a depot to an operational status, and use depot for robotic missions to the Moon that are exploring the moon to find minable lunar water. NASA can also use depot for everything it's sending beyond LEO, including sending crew to lunar surface at the last couple years of Lunar exploration.
NASA should not sell rocket fuel at LEO to commercial satellite- except in terms of "experimental" purpose for satellite makers which are considering their future use of future commercial depots.
NASA might continue to operate depot in LEO, or latter improvements of depot, into the period it starts it's Mars exploration- 10 years after NASA launches the LOX depot and has finished it's Lunar exploration program.
Or at point of beginning of Mars program it may decide to privatize the depot. It should noted the depot at launch site inclination can considered as part of the infrastructure of the spaceport- or it should increase launches from the launch site- it makes launching from that inclination more attractive.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: gbaikie on 07/21/2016 03:45 am
Abundant lunar water at Lunar equator Vs more expense to mine water at lunar poles.

Generally if 1 cubic meter of lunar surface regolith has enough water to get 100 kg of water
extracted from it by heating regolith by less than 500 C, it should be in ballpark of being
commercially minable.
Likewise if one can drill less than 500 meters and get about 10,000 tons of water from this drilled
water well at somewhere on the Moon, then roughly, it should be minable.

Minable lunar water is something like 10,000 tons of water at $500 per kg. $1/2 million per ton
times 10,000 is 5 billion dollars gross.
For this to be the case there has be the assumption that one will in future mine more than
10,000 tons, but within a decade it's not likely one can sell much more than 10,000 tons.
Or said differently were company to mine say 10,000 tons of water within a decade, one would
a business capable in later years to mine more and a business which could be worth more than the
water [the 10,000 tons of water at 5 billion]. It for instance it could be worth more than SpaceX or
Facebook because you are establishing business with future earnings potential in high growth environment.
Or course if there is better competition or it's being poorly run, it could have little value as a business.

The lunar water price will be established by demand, and lunar water in first year could exceed $1000
per kg, and within 5 year be less than $250 per kg. The price point of $500 per kg is based upon idea that
one needs to export lunar rocket fuel to low lunar orbit and sell LOX at lunar orbit at about $4000
per kg or less. And currently LOX at low lunar orbit is worth about 8000 per kg. As currently, rocket fuel at lunar surface is worth about $20,000 per kg.
And general idea is one going to lower price rocket fuel at lunar surface to about $2000 per kg or less.
Or if lunar water is available at 500 per kg, one should able to make rocket fuel for 2000 per kg or less.
Rocket fuel being 6 kg of LOX and 1 Kg of Hydrogen.
And LOX being worth about $1000 per kg and LH2 being worth about $4000 per kg at lunar surface:
6 kg of LOX $6000, 1 kg of LH2 $4000. 10,000 divided by 7 is $1428 per kg of rocket fuel.
And rocket fuel like lunar water could be more expensive in first few years.
And cheaper than this within a decade. And could be cheaper in the beginning if Earth launch cost were
to lower significantly- say down to $500 per kg to LEO. And obviously were earth launch cost to increase
to $5000 per kg to LEO, lunar rocket fuel could higher than $2000 per kg at lunar surface.
Over the decades, Earth launch costs have lowered, the expectation is that this will continue, and
$500 kg for water allows for some decrease in earth launch costs, but not allowing for launch cost in
future time period to decrease to Earth to LEO to be less than $500 per kg.

But does expect that years of lunar water mining will result in lower Earth launch costs, but as much as
less than $500 per kg to LEO within a decade of starting lunar water mining.

All that said, abunadant lunar equatorial water vs expensive ice mining at lunar poles. So abundant
water gotten from water well can increasely become cheaper depending about how much water is
bought.
A lot of water could be bought if thousands of people are living in settlements on the Moon and one needs water for living and making food. Or US uses about 1/2 trillion tons of water per year [as does India and China]. Say, for thousands of people one could imagine as much as 1 billion tons per year being needed-
this considers one has population growth which could double every every 5 to 10 years. Or with up 1000 people it's doubling every year to 1000 and doubles in longer time periods thereafter- with thousands
doubling every decade. A billion tons of water a year is a lot if one has a stagnant population.
But I am not allowing for lunar settlement and imagine it's less than 1 million tons of water needed in
less than 3 decades from beginning lunar rocket fuel production. And beyond such time is increasingly unpredictable in terms market demand for lunar water, but I think I say that beyond 3 decades lunar water probably will be less than $100 per kg.
And I would say if start with abundant cheap lunar water it will not likely to much less than 100 per kg
within 2 decades- or less than $100,000 per ton. And we assume drilled lunar water at begin would be
about $100 per kg [or more]. Or 100,000 tons lunar water grossing 10 billion dollars.

So, if one had Equatorial lunar water at $100 per kg does this drive growth demand of future lunar water demand. Or does this low price cause more demand as compared lunar polar water at 500 per kg.
And I think answer that question would depend on price of lunar rocket fuel.
Or if lunar rocket fuel were 5 times cheaper, the answer would be, yes.
But price will not be 5 times cheaper.

To make LH2&LOX from water, requires splitting the water and this requires electrical power. If getting electrical power from nuclear energy the price of electrical power will be about the same whether at
Equator or Lunar polar region. Or the electrical power would not also be 5 times cheaper.
But if getting electrical power from solar energy, lunar polar region will have about a cost of electrical
power of about 50% less than lunar equator region.

According to wiki:
"Efficiency of modern hydrogen generators is measured by energy consumed per standard volume
of hydrogen (MJ/m3), assuming standard temperature and pressure of the H2. The lower the energy
used by a generator, the higher would be its efficiency; a 100%-efficient electrolyser would consume
39.4 kilowatt-hours per kilogram (142 MJ/kg) of hydrogen, 12,749 joules per litre (12.75 MJ/m3).
Practical electrolysis (using a rotating electrolyser at 15 bar pressure) may consume 50 kilowatt-hours
per kilogram (180 MJ/kg), and a further 15 kilowatt-hours (54 MJ) if the hydrogen is compressed for use in hydrogen cars"
https://en.wikipedia.org/wiki/Electrolysis_of_water
On the Moon it will cost about 50 Kw hours to split a 1 kg of H2 and 8 kg of oxygen, but on the Moon it
could cost less to make 1 kg of H2 compressed "for use in hydrogen cars"- or 350 bars [+5000 psi]. Compressor are same on the Moon, but pressurizing gases is different. Because, pressurizing gases
involves the temperature of the gases.

Earth provides 1 atm [14.7 psi] of air pressure, and Moon zero psi. Generally if you want to pressurize
the split H2 and O2, you split warm water and at pressure.
Earth has average temperature of 15 C [warm] and has 1 atm- advantage, to Earth.
So if want to split water at 20 C and at 1 atm, Earth is the place to be. But the Moon gains more
advantage if you want higher temperatures, costs less energy to keep something at 100 C- moon's
vacuum is good insulation. If want high pressure and warmer temperature the Earth and Moon "about
the same".

But from warm and high pressure gas, the advantage goes to the moon to pressurize it.
Or Moon has available cold stuff. On Earth one has very cheap water, and that is very
useful to cool something. So pressurize O2 and run pressurized hot gas at high pressure thru
water or bucket of water with ice cubes, and you can make LOX. Can't make LOX without
something to cool the pressurized gas.
At the equator of the Moon the average temperature of lunar soil a meter below the surface
in about -30 C. So lunar regolith could cool something. But if mining cheap water at the equator, you
got something a lot better than this cold lunar dirt, you use the water. Liquid water on the Moon
become very cold if expose to Lunar vacuum.
You have instant ice if you have liquid water on the Moon- so other than loss of evaporated
water, one has no cost to make unlimited ice on the Moon.
So one do same thing of ice cubes in water on the Moon- unlimited cooling to O C. One needs
a small amount of pressure to stop water from being ice [Mars pressure].
But you can do much better than this. Water evaporates in Moon vacuum to about -150 C.
So if coat pipes with water ice, one get unlimited -100 C of cold. Which is unavailable
on Earth- or costs electrical power to make it, on Earth.

So if have "free" or [water at 100 kg] -100 C, it costs less electrical power to make
LOX and LH2.
But lunar poles have billions of tonnes of lunar dirt at about 50 K [-223 K].
Lunar dirt is not as good as water, but 50 K dirt is better than -100 C water- if you
want to make LOX and LH2. 50 K dirt is particularly valuable if you want to make LH2
or frozen H2.
So if just want to make LOX, lunar equator is better place to make LOX from water than
Earth, and maybe better than lunar poles, but if want of make LH2 or frozen Hydrogen
lunar poles are better than Equator of Moon.

Should go over the details of specific heat of lunar dirt.If got lunar ice at 50 K in lunar dirt, amounting to 100 kg in cubic meter. At -100 C it's 1.389 KJ/K/Kg:
www.engineeringtoolbox.com/ice-thermal-properties-d_576.html

So at 50 K as guess it's say 1.2 KJ/K/Kg, to warm 1 kg from 50 K to 100 K [-173 C] is 60 KJ per kg,
100 kg: 6000 KJ and supposing cubic meter of lunar regolith is 1500 kg, and is .8 KJ/K/Kg- or to warm
to 100 K is 60,000 KJ. So to cool by 66,000 KJ it cost more than 66,000 K watts second of electrical
power [if somehow had 100% efficiency it would be the same] 66,000 / 1 hour [3600 seconds] is
18.3 kW hour. So if had 1 kg of H2 warm a cubic meter of lunar regolith, it like using 18.3 kW hours to compress it. Or heat pumps heat by compression of gases. Or cool by compression of gases. Or it's like
you get use electric power to split water and can get electrical power by chemically combining H2 and O2 [with conversion losses of waste heat] by using a fuel cell.

And other factor is solar energy is cheaper at lunar poles. Because one can get solar energy, 80% of
the time. Because at peak of eternal light one can get 80% of the time sunlight. And at Equator one
can get 50% of the time. So split 1.6 times more water per year if have 80% of time vs 50% of time.
And solar panels get less energy per year, and if selling electrical power from them, one has charge
more money per Kw hour as compared to solar panels with 80% of sunlight. So one would pay more
per kw hours and get less kw hours per year to do production with the power.

So at equator, one uses the same electrical power to split the water, as polar region, but to liquefy
the gases you use more electrical power to compress it, and cost more for electrical power if using
solar energy.

Now if not paying much for electrical power on the Moon, it's now much of  difference, but I think
electrical power on the Moon is worth 50 to 100 per Kw hour, in the beginning of lunar water mining.
I think having capability if having electrical power on the Moon, all the time and whenever you want
however much you need is worth $100 per Kw hour.
Or getting electrical power like you get it on Earth- you pay for the electrical power you use and one
get use as much as you need at any time. If instead one gets electrical power only 80% of the time,
and you will charged for it, even if don't use it. So get 100 Kw and must use or lose the 100 Kw.
It's like having 100 amp main, and can use 100 amp [not more] but if don't use 100 amp, you still get
charged for using 100 amps.
In comparison 80% of time and use allotted power, is worth about 1/2 of $100 per kw- or worth $50 per
Kw hour. And if only get 50% of the time, it's worth less than $50 per Kw hour.
This is one argument for nuclear energy- which is also %100 of time, but not metered, which I would
count as worth $90 per Kw hour.
And other thing is with lunar polar region one could get to point of getting 100% of the
time, AND eventually metered. With many customers one can balance the electrical load as it's done on Earth. Of course this also applies with Nuclear power-  anywhere on the Moon.

At $50 per kW hour. Splitting 1 Kg of Hydrogen cost $2500. Also you get 8 kg of O2 also. If
only count O2: $2500 / 8 = 312.5 per kg of O2. Or if H2 and O2 : 277.78 per kg.
Or if water is $500 per kg: rocket fuel cost 277.78 for electrical power at $50 per kw hour.
277.78 + 500 = 777.78.

If use wiki earth price to compress H2 to 350 bars, cooling to 0 C might make it into LH2 [not sure-
but quite certain if much colder] but 15 time $50 is $750. So 777.78 + 750 is $1527.78 per kg of LH2.
But with cooling to 0 C, in regard to O2 one  doesn't need 350 bars of pressure. Guy does it with:
"The RIX Oil-free compressor seemed a good choice. The SA-3E model could deliver 3 scfm at
a pressure of 3500 psi."
http://homemadeliquidnitrogen.com/compressor.html
To make 8 Kg LOX cost somewhere around 2 kw hour of electrical power.
277.78 + 500 + 10 = 927.78.

As compared to equator and water at 100 per kg:
If just using o2: 100 + 312.5 + 100 = 512.50 per kg

But this is just water and power [and not charging more per Kw hour for it at equator- say,
one is using a nuclear reactor- or advantage of colder temperature].

To shorten this, I think if have choice of water at poles or equator and equator
is $100 per kg, and poles is $500 per kg, the better deal/bet is paying $500 per kg at the poles.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Hop_David on 08/03/2016 07:34 pm
Now, think for a minute. If you start out teleoperated (which allows you less risk, much more reduced footprint equipment/scope/operations requirement to begin), what's the reason for doing human presence?

1) Light lag latency. About 3 seconds from earth's surface. Virtually zero for on site robot operators.
2) Bandwidth. Signal strength scales with inverse square. Or onsite operators may even use a fiber optic cable. For telerobot dexterity and telepresence, lots of bandwidth is desirable.
3) Maintenance.

I see robots alone initially. But as soon as we get our foot in the door, send humans. Humans and robots are a more effective team than either alone.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Hop_David on 08/03/2016 07:55 pm
I have heard there was evidence of more Carbon Monoxide than water.

universetoday article (http://www.universetoday.com/76329/water-on-the-moon-and-much-much-more-latest-lcross-results/)

Of course we have to send a rover. It is so frustrating that it has been about 6 years. There still isn't a commitment to a specific mission is there?

In the October 2010 issue of Science the LCROSS team reported 5.5% water. The were other volatiles -- hydrogen, oxygen, nitrogen and carbon compounds in the ejecta.

But in the September 2011 issue they published a correction. Volatile abundance was exaggerated by a factor of 5.5.

Is 1% water enough? I don't know. Likewise the other CHON compound abundances were downgraded.

From elevated CPR of mini-sar radar Spudis had said there's likely sheets of ice at least 2 meters thick on the cold trap floors. But the LRO's LEND data doesn't support Spudis' optimistic predictions.

Are there rich lunar deposits of volatile ices? Who knows? It will remain an open question until we send prospector rovers to these locations. Until then it's not a good idea to count our chickens before they're hatched.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Hop_David on 08/03/2016 08:03 pm
Earth is a self-licking ice cream cone, so I'm fine with Mars also being one, if it really can be self-licking. ;)

Sure, self licking ice cream cones are great once they're established. But to establish them you need to get past phase 2. (see attached graphic)


But it's a good distinction. The Moon is supposed to be primarily industrially/economically useful, not primarily a goal in and of itself.

If the moon has rich volatile deposits it will be a goal in and of itself as well as useful.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: gbaikie on 08/15/2016 07:57 am
Earth is a self-licking ice cream cone, so I'm fine with Mars also being one, if it really can be self-licking. ;)

Sure, self licking ice cream cones are great once they're established. But to establish them you need to get past phase 2. (see attached graphic)
Phase 1 [collect underpants] is explore and we have do this, before can begin phase 2

Quote
If the moon has rich volatile deposits it will be a goal in and of itself as well as useful.
And the same applies with Mars.
A rich volatile deposits on the Moon are any mud puddles, found, and on Mars it's a lake [underground lake or liquid water table] found. Of course if one found lakes on the Moon, and oceans on Mars, that would be better.
Moon needs water in quantities of range of 10,000 tons being $500 per kg [5 billion dollar] and Mars needs
water in quantities of range of 1 million tons at $10 per kg [10 billion dollars].
And once over 200,000 tons of lunar water is mined, lunar water should be about $100 per kg [20 billion dollars] and once 500 million tons of water is recovered on Mars it should be about $1 per kg [1/2 trillion dollars- and at this price, water would only be about 500 times more than cost of water on Earth]
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: lamontagne on 08/15/2016 04:43 pm
Any chance of finding significant quantities of Argon on the Moon?

I'm thinking about SEP cargo transfer missions using argon as a propellant.
For a cargo transfer to Mars, Moon argon could be cheaper than Earth argon.  For the return leg, argon production might be a possible using almost the same equipment as what is required for chemical propulsion, and there is plenty of argon on Mars.

With a high ISP SEP drive, we might be able to move with 1000 tonnes of argon what otherwise would require 10 000 tonnes of electrolysed water?

I'm thinking of argon but any propellant that works well with ion drives would be equivalent, so if anything else is available its fine with me.  At 20% efficiency though (as far as I have found out) oxygen is out of the running.

The Hydrogen in water might be ok, if the electrolysis costs are not too high? It seems intuitively advantageous to not have to bring the oxygen up to orbit.  Then that would make this post on topic ;-) 

The architecture would then be the following: use hydrogen and oxygen engines for chemical rockets that shuttle up and down from the moon.  The main cargo is hydrogen extracted from water on the moon(or argon), to be used as propellant for SEP vehicles for cargo transfer.  Trips to Mars would use Martian Hydrogen (or argon) for the return leg.  Not recommended for crewed vehicles.





Title: Re: Impact of lunar free water on Exploration Architecture
Post by: gbaikie on 08/15/2016 05:48 pm
Any chance of finding significant quantities of Argon on the Moon?
Argon gas comes from radioactive decay- or anything more than 1 billion years could have argon.
Mars atmopshere has 1.6% argon:
"Major      : Carbon Dioxide (CO2) - 95.32% ; Nitrogen (N2) - 2.7%
                 Argon (Ar) - 1.6%; Oxygen (O2) - 0.13%; Carbon Monoxide (CO) - 0.08% "
http://nssdc.gsfc.nasa.gov/planetary/factsheet/marsfact.html
And compressing Mars atmosphere so it's 5 to 10 psi is fairly easy.
Mars atmosphere is thin, but there is 25 trillion tons of it. And 1.6% of 25 is .4, so
there is about 400 billion tons of argon gas in Mars atmosphere.
For early exploration purpose one might extract water from Mars atmosphere. There is not much water
in the Mars atmosphere and one need to compress a lot of atmosphere, and by product of doing that
to make tens of tons of water could result in tons of Argon gas- or mostly nitrogen and argon gas with some oxygen gas in it.
This is expensive way to get water on Mars, but it could done robotically, or one could mine 10 tons of water
from Mars atmosphere before first crew lands on Mars. Or considering it cost about $10,000 per kg to land anything on Mars, making this water could cheaper than landing water needed by the crew. One also could have very large quantity of CO2 or CO2 ice, which also could useful. And such compression creates heat- it's
using electrical power- but one would not need other ways of keeping crew warm. Or the landed infrastructure- gives water, heat, and a lot CO2 which one might use for various purposes.
Or CO2 with hydrogen gas makes Oxygen and Methane- rocket fuel. But there also could other things done with the compressed CO2.


Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Impaler on 08/15/2016 06:26 pm
Noble gasses are not the only usable SEP propellants, they are simply the most efficient,

If your producing propellant locally their is a high likelihood that your going to use something sub-optimal in exchange for lower cost per unit.  I would bet on LOX as a likely propellant.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: lamontagne on 08/15/2016 07:39 pm
Noble gasses are not the only usable SEP propellants, they are simply the most efficient,

If your producing propellant locally their is a high likelihood that your going to use something sub-optimal in exchange for lower cost per unit.  I would bet on LOX as a likely propellant.

LOX is pretty much unavoidable as a propellant for taking off from the moon's surface.  My question was more about the mid term, in the sense of what might be a valuable cargo. I thought SEP might quickly become competitive, since it requires much less mass overall, even when taking the solar arrays and their low efficiency at Mars into account.  There probably is a breakeven point between SEP propellant and LOX fuel, and this again probably varies with the SEP propellant.  The very low density of hydrogen is a problem compared to argon, for high volume of SEP transportation, IMHO.


Title: Re: Impact of lunar free water on Exploration Architecture
Post by: high road on 08/15/2016 08:58 pm
Noble gasses are not the only usable SEP propellants, they are simply the most efficient,

If your producing propellant locally their is a high likelihood that your going to use something sub-optimal in exchange for lower cost per unit.  I would bet on LOX as a likely propellant.

LOX is pretty much unavoidable as a propellant for taking off from the moon's surface.  My question was more about the mid term, in the sense of what might be a valuable cargo. I thought SEP might quickly become competitive, since it requires much less mass overall, even when taking the solar arrays and their low efficiency at Mars into account.  There probably is a breakeven point between SEP propellant and LOX fuel, and this again probably varies with the SEP propellant.  The very low density of hydrogen is a problem compared to argon, for high volume of SEP transportation, IMHO.

I think he means using oxygen as SEP propellant. It's far more abundant on the moon than any noble gasses, so should cost far less to extract.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: gbaikie on 08/15/2016 09:54 pm
Noble gasses are not the only usable SEP propellants, they are simply the most efficient,

If your producing propellant locally their is a high likelihood that your going to use something sub-optimal in exchange for lower cost per unit.  I would bet on LOX as a likely propellant.

LOX is pretty much unavoidable as a propellant for taking off from the moon's surface.  My question was more about the mid term, in the sense of what might be a valuable cargo. I thought SEP might quickly become competitive, since it requires much less mass overall, even when taking the solar arrays and their low efficiency at Mars into account.  There probably is a breakeven point between SEP propellant and LOX fuel, and this again probably varies with the SEP propellant.  The very low density of hydrogen is a problem compared to argon, for high volume of SEP transportation, IMHO.

Argon gas is cheap on Earth, because there is market for liquid oxygen and Nitrogen- and argon gas is used for welding.
Extracting water from Mars atmosphere is expensive, and question on Mars is would there be a big market for
liquid CO2 or frozen CO2. There would be market for nitrogen- as it's needed to grow plants.
So if getting nitrogen from the air of Mars to make plant food- same reason mostly done on Earth- the abundant of CO2 liquid or frozen [and cheapness of it] could add to demand to get CO2 from Atmosphere.
But suppose there was a different way to get nitrogen [as there is on Earth- mining from the ground] then it depends how expensive it is to get from the ground as compared to cost to get it from the sky.

So if there is large market for nitrogen taken from Mars atmosphere, then argon on Mars will be cheap.
Argon would be cheap to ship from Earth- or certainly cheaper than shipping LH2. And I don't think argon would be cheap on the Moon- available perhaps but not a surplus [tons of it to ship].
Therefore one could have cheap argon at Earth surface and cheap argon on Mars surface.
And with ion engine- the whole point of them is using less rocket propellant. So ion rocket can get it's fuel
at high earth orbit and could do round trip and return to high earth for it's rocket fuel, but taking ion rocket into low orbit of Mars or Earth, one going to use a lot of ion rocket propellent. Or Mars low orbit makes more sense than Earth low orbit, because it requires less delta-v [less lost from spiraling of the orbit- which inefficient compared to hohmann transfers]. Anyways, if using Ion rockets to get to Mars low orbit- one probably want ion rocket fuel available in Low Mars orbit. But it will depend on cost of LOX in low mars orbit- which can exported from the moon to Mars low orbit [but maybe ion engines will used to to bring the Lunar LOX to Mars low orbit- anyhow, maybe]. Or Mars at some point is going to have high demand to export Mars food- which means a launch system [non rocket] which could make cost to from Mars surface to Mars orbit quite cheap [like $1 per kg- likewise with the Moon though maybe $.50 per kg].

Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 08/16/2016 01:29 am
Argon is going to be pretty cheap on Mars because you need nitrogen for a buffer gas, and also Argon is very plentiful in the Martian atmosphere.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: lamontagne on 08/16/2016 11:29 am
Noble gasses are not the only usable SEP propellants, they are simply the most efficient,

If your producing propellant locally their is a high likelihood that your going to use something sub-optimal in exchange for lower cost per unit.  I would bet on LOX as a likely propellant.

LOX is pretty much unavoidable as a propellant for taking off from the moon's surface.  My question was more about the mid term, in the sense of what might be a valuable cargo. I thought SEP might quickly become competitive, since it requires much less mass overall, even when taking the solar arrays and their low efficiency at Mars into account.  There probably is a breakeven point between SEP propellant and LOX fuel, and this again probably varies with the SEP propellant.  The very low density of hydrogen is a problem compared to argon, for high volume of SEP transportation, IMHO.

I think he means using oxygen as SEP propellant. It's far more abundant on the moon than any noble gasses, so should cost far less to extract.

I think oxygen for SEP is problematic.  I've read one study that puts the maximum attainable efficiency with oxygen at 20%.  Combining this with the higher ISP requirements of low thrust trajectories, SEP loses most of its edge, and we might just as well stick to chemical. 
The cost of developing a class of vehicles is so large, compared to the fuel costs, that I expect we need very clear advantages for a propulsion system to have an incentive to develop it.
Oxygen is chemically bonded to everything, as it is to water.  Deoxydizing aluminium or iron all require large amounts of energy to produce the oxygen.  It also produce useful by products, of course ;-)
On Earth, thee processes can be done relatively cheaply because we have large amounts of mostly pure carbon available, but I don't believe this is the case on the moon.
Of course there may be more loosely binded oxides out there. 





Title: Re: Impact of lunar free water on Exploration Architecture
Post by: lamontagne on 08/16/2016 11:35 am
Argon is going to be pretty cheap on Mars because you need nitrogen for a buffer gas, and also Argon is very plentiful in the Martian atmosphere.

Indeed, perhaps a possible product for our nascent colony to sell?  Returning MCTs might carry a few tonnes of argon, and leave this in orbit at a fuel depot?  Probably more profitable uses for that tonnage...
But one of the sad facts about the shuttle is that it delivered only a fraction of its payload capability over its decades of operation because there was no market for that extra capacity.  Perhaps depots could be the market needed?

Does Martian Methalox/argon out compete moon H2/LOX?


Title: Re: Impact of lunar free water on Exploration Architecture
Post by: jongoff on 08/16/2016 06:01 pm
Noble gasses are not the only usable SEP propellants, they are simply the most efficient,

If your producing propellant locally their is a high likelihood that your going to use something sub-optimal in exchange for lower cost per unit.  I would bet on LOX as a likely propellant.

LOX is pretty much unavoidable as a propellant for taking off from the moon's surface.  My question was more about the mid term, in the sense of what might be a valuable cargo. I thought SEP might quickly become competitive, since it requires much less mass overall, even when taking the solar arrays and their low efficiency at Mars into account.  There probably is a breakeven point between SEP propellant and LOX fuel, and this again probably varies with the SEP propellant.  The very low density of hydrogen is a problem compared to argon, for high volume of SEP transportation, IMHO.

I think he means using oxygen as SEP propellant. It's far more abundant on the moon than any noble gasses, so should cost far less to extract.

I think oxygen for SEP is problematic.  I've read one study that puts the maximum attainable efficiency with oxygen at 20%.  Combining this with the higher ISP requirements of low thrust trajectories, SEP loses most of its edge, and we might just as well stick to chemical. 

While this is true for traditional SEPs, due to the ionization losses for oxygen (being a molecule it has a lot more places to absorb energy before it ionizes, and it has lower mass per ionization event than say Argon or Xenon), there are some approaches that could solve this. Specifically, MSNW has a FRC thrust concept they've been developing that allows you to inject additional neutrals downstream of the ionization and first acceleration section, that uses charge exchange collisions to ionize the neutrals while neutralizing the fast-moving ions. Basically if done well, you can get multiple ions per initial ionization events, diluting that inefficiency term dramatically. IIRC, I think they were saying that they could get almost any cleanly vaporizable chemical (water, O2, CO2, N2, Nitrous, Hydrazine, etc) to function at an overall efficiency level comparable to Xenon in a Hall Effect Thruster. I can't remember how far along the process they go with this, but I think they did enough work to prove the concept can work, but haven't yet had a chance to fly a demo.

~Jon
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Robotbeat on 08/16/2016 07:37 pm
Ionization losses (even with "traditional" ion thrusters) are much less important at higher Isps.

So 20% efficiency limit for oxygen would only be valid at low Isp. (Although if you have a lot of propellant, you WANT a low Isp.)
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: jongoff on 08/16/2016 10:25 pm
Ionization losses (even with "traditional" ion thrusters) are much less important at higher Isps.

So 20% efficiency limit for oxygen would only be valid at low Isp. (Although if you have a lot of propellant, you WANT a low Isp.)

You also end up wanting a lower Isp if you're power limited (which in practice you almost always are), but yeah, if you run your ion engine at 10000s of Isp, ionization losses won't matter as much...

~Jon
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Oli on 08/17/2016 03:47 am
Argon is going to be pretty cheap on Mars because you need nitrogen for a buffer gas, and also Argon is very plentiful in the Martian atmosphere.

Indeed, perhaps a possible product for our nascent colony to sell?  Returning MCTs might carry a few tonnes of argon, and leave this in orbit at a fuel depot?  Probably more profitable uses for that tonnage...
But one of the sad facts about the shuttle is that it delivered only a fraction of its payload capability over its decades of operation because there was no market for that extra capacity.  Perhaps depots could be the market needed?

Does Martian Methalox/argon out compete moon H2/LOX?

Refueling at the destination isn't that important with EP. You can easily go to Mars and back on a single tank. Unless you're aiming for very fast transits.

I cannot see lunar propellant ever being important for exploration beyond lunar descent/ascent. Not in the "near term", when launching a few tons of crew capsule to lunar orbit is all that is needed/affordable, and not in the far future when transit will be done with multi-MW EP vehicles.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: sdsds on 08/17/2016 03:54 am
I cannot see lunar propellant every being important for exploration beyond lunar descent/ascent. Not in the "near term", when launching a few tons of crew capsule to lunar orbit is all that is needed/affordable, and not in the far future when transit will be done with multi-MW EP vehicles.

You do see that your line of thinking just begs for the reader to respond, "But what about the medium-distant future?" That's where all the schemes built around plentiful propellant being available on the lunar surface really shine!

For a massive, all-chemical propulsion campaign of Mars exploration and habitation, exporting at least one propellant from a lunar source looks really good.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Oli on 08/17/2016 04:18 am
I cannot see lunar propellant every being important for exploration beyond lunar descent/ascent. Not in the "near term", when launching a few tons of crew capsule to lunar orbit is all that is needed/affordable, and not in the far future when transit will be done with multi-MW EP vehicles.

You do see that your line of thinking just begs for the reader to respond, "But what about the medium-distant future?" That's where all the schemes built around plentiful propellant being available on the lunar surface really shine!

For a massive, all-chemical propulsion campaign of Mars exploration and habitation, exporting at least one propellant from a lunar source looks really good.

The cost of developing MW-class EP will be peanuts compared to setting up the infrastructure on the Moon for supplying 100s of tons of propellant to L1/L2.

Title: Re: Impact of lunar free water on Exploration Architecture
Post by: high road on 08/17/2016 07:21 am
Does Martian Methalox/argon out compete moon H2/LOX?

The cost of developing MW-class EP will be peanuts compared to setting up the infrastructure on the Moon for supplying 100s of tons of propellant to L1/L2.

Both for Mars and the moon, setting up shop only to get fuel is ridiculous. However, there are plenty of other reasons to go to either location. Once the infrastructure to maintain complex activities and launch heavy payloads off the surface is there (required to send people back), making the necessary adjustments to produce and launch fuel will require far less investements. On either location, there will be much more stuff going down than up for a long time to come, so reusable spacecraft will be launching 'empty'. So you're taking the 'free ride home' rather than paying for a launch.

And this assumes a demand for fuel in the hundreds of tons, meaning there's a location in deep space that's worth sending this much payload towards it, meaning costs of building things in deep space/the moon/Mars will have plumeted by this time.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: gbaikie on 08/17/2016 08:09 am
Argon is going to be pretty cheap on Mars because you need nitrogen for a buffer gas, and also Argon is very plentiful in the Martian atmosphere.

Indeed, perhaps a possible product for our nascent colony to sell?  Returning MCTs might carry a few tonnes of argon, and leave this in orbit at a fuel depot?  Probably more profitable uses for that tonnage...
But one of the sad facts about the shuttle is that it delivered only a fraction of its payload capability over its decades of operation because there was no market for that extra capacity.  Perhaps depots could be the market needed?

Does Martian Methalox/argon out compete moon H2/LOX?

Refueling at the destination isn't that important with EP. You can easily go to Mars and back on a single tank. Unless you're aiming for very fast transits.
I think NASA should aim for less than 3 months to Mars- and could done with chemical rockets
Quote
I cannot see lunar propellant ever being important for exploration beyond lunar descent/ascent. Not in the "near term", when launching a few tons of crew capsule to lunar orbit is all that is needed/affordable, and not in the far future when transit will be done with multi-MW EP vehicles.

NASA should explore the Moon using depot at LEO. And NASA should not mine lunar water, nor subsidize lunar water mining. And rocket fuel made on the Moon, might not be used for NASA Mars exploration. And probably will not used for NASA Mars exploration in beginning of the program. Or NASA should quickly explore the Lunar poles to determine if and where there is minable lunar water, end NASA lunar exploration and immediately begin Mars exploration program. Or if before NASA finished Lunar exploration, commercial lunar water mining began it will take a few years before Lunar rocket fuel can be used in connection to NASA Mars exploration.
NASA should not be dependent on Lunar water mining in connection to NASA Mars exploration.
The reason NASA explore the Moon is to determine if lunar water is minable- and were some party start mining lunar water next month [somehow] then NASA should not explore the Moon.
Also the purpose of NASA exploring Mars, should be to determine if settlements on Mars are viable- or if in two year there is a viable mars settlement- again, there is no reason NASA should explore Mars.
Or NASA should plan Lunar and Mars exploration programs, but if purpose of program has already been achieved, then that is reason not to continue the program.
Or I think it's rather silly to wait for Lunar and/or Mars settlements, instead NASA job should be to enable such things.
So to have commercial lunar rocket fuel, one will need customers for lunar rocket fuel. If you have lunar rocket fuel at lunar surface, one has halved the cost of sending people to the Lunar surface. Lunar tourists
only is probably too small a market. If have lunar rocket fuel at the surface one will significantly lower the cost of transporting lunar material back to Earth. So you could sell tens of tonnes of lunar material at about $100 per gram- about twice price of gold per gram. Also lunar tourist probably want to bring back lunar samples. So you have passengers and also some kind robotic return lunar samples. Or it's not either/or it's both.

By having rocket fuel at lunar surface, you make the Moon a destination for variety of activity- or "lunar tourists" may doing a working holiday related to stuff done on the Moon. Which could include lunar bases or research lab. Lunar telescopes. Iron mining. PGM mining. Private and public lunar exploration uses the site of lunar rocket as base camp to explore other location- say within 100 km radius of it.
But probably all the above is still not enough market for lunar rocket fuel, and the short term goal should be that within 5 years [or within 2 years] one plans on exporting lunar rocket fuel to Low lunar orbit.
The default assumption could be you use lunar rocket fuel to lift lunar rocket fuel to low lunar orbit, but there could other ways to getting lunar rocket fuel to lunar orbit. Ie use a cannon. And who ever wants the business of getting something to lunar orbit without using a rocket- is just one more customer, assuming they need some people on lunar surface- it possible it's exclusively done with teleoperation or something.
Regardless of how lunar rocket fuel is gotten to lunar orbit- by doing this one is increasing the market for Lunar rocket fuel and once that is done, one might have enough market demand for lunar water and rocket fuel.
So NASA does not focus on doing all things one can do on the Moon. Or all these thing are dependent on having lunar rocket fuel at lunar surface, and one first needs to explore the Moon, first before one start planning those kinds of things. So NASA explores the Moon and then explore Mars, it can plan all that and execute those programs. Or doesn't make any sense to plan a lunar base without first exploring the Moon.
And while NASA explores the Moon and than Mars, other space agencies will continue to their lunar exploration programs. Or if NASA explores the moon to find minable water, it probably will accelerate those other space agencies plans regarding the Moon- China, Europe, etc.
These other space agencies might want to subsidy some kind of lunar water mining, based upon what NASA discovers, that's fine, or one can't try to stop them. It doesn't matter who mines to Moon- but it's not something NASA has to try do in the near term.
And it possible that the results of NASA lunar exploration indicates that mining lunar water is not viable in the near term. Perhaps earth launch cost would have lower further. Perhaps there just needs to be enough billionaires who will to invest the money to do it. Maybe it's luck or chance. Perhaps other space agencies budgets will be slashed for whatever reasons. Or  commercial lunar water mining might start immediately or might require 10 years or more
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Oli on 08/17/2016 08:22 am
Does Martian Methalox/argon out compete moon H2/LOX?

The cost of developing MW-class EP will be peanuts compared to setting up the infrastructure on the Moon for supplying 100s of tons of propellant to L1/L2.

Both for Mars and the moon, setting up shop only to get fuel is ridiculous. However, there are plenty of other reasons to go to either location. Once the infrastructure to maintain complex activities and launch heavy payloads off the surface is there (required to send people back), making the necessary adjustments to produce and launch fuel will require far less investements. On either location, there will be much more stuff going down than up for a long time to come, so reusable spacecraft will be launching 'empty'. So you're taking the 'free ride home' rather than paying for a launch.

And this assumes a demand for fuel in the hundreds of tons, meaning there's a location in deep space that's worth sending this much payload towards it, meaning costs of building things in deep space/the moon/Mars will have plumeted by this time.

I understand that shipping fuel from the Moon to L1 is potentially a lot cheaper than shipping fuel from Earth to L1. So if you already have a sizable "Moon village" it might be worth considering.

Still, you must ask yourself how those settlements on Moon and Mars are being built in the first place, and the answer to that is probably efficient in-space propulsion. The alternative would be chemical + aerocapture + ISRU (the SpaceX way). In such a case there's need for lunar propellant at L1 either, at least not for Mars.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: gbaikie on 08/17/2016 08:39 am
Does Martian Methalox/argon out compete moon H2/LOX?

The cost of developing MW-class EP will be peanuts compared to setting up the infrastructure on the Moon for supplying 100s of tons of propellant to L1/L2.

Both for Mars and the moon, setting up shop only to get fuel is ridiculous. However, there are plenty of other reasons to go to either location. Once the infrastructure to maintain complex activities and launch heavy payloads off the surface is there (required to send people back), making the necessary adjustments to produce and launch fuel will require far less investements. On either location, there will be much more stuff going down than up for a long time to come, so reusable spacecraft will be launching 'empty'. So you're taking the 'free ride home' rather than paying for a launch.

And this assumes a demand for fuel in the hundreds of tons, meaning there's a location in deep space that's worth sending this much payload towards it, meaning costs of building things in deep space/the moon/Mars will have plumeted by this time.

I understand that shipping fuel from the Moon to L1 is potentially a lot cheaper than shipping fuel from Earth to L1. So if you already have a sizable "Moon village" it might be worth considering.

Still, you must ask yourself how those settlements on Moon and Mars are being built in the first place, and the answer to that is probably efficient in-space propulsion. The alternative would be chemical + aerocapture + ISRU (the SpaceX way). In such a case there's need for lunar propellant at L1 either (one could make a stop at L1 during transit from LEO to the lunar surface, doesn't seem worth it though when you can refuel on the lunar surface).
Lunar rocket fuel and/or lunar water at L-1 would be for Mars or other planet destinations.
But for the lunar activity, need rocket fuel at lunar orbit.
SEP could be used to transport from Low lunar orbit to L-1. And one could get lunar rocket fuel and water from Low lunar orbit and then go directly to Mars orbits [probably high mars orbit- Mars L-1 or 2].
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Oli on 08/17/2016 09:24 am
Ok, some additional thoughts.

Efficient in-space propulsion is pretty much a given for transporting fuel, since fuel doesn't have to go fast and can easily be divided into smaller packages. I assume efficient in-space propulsion is a minor cost factor compared to launch from the surface of planetary bodies.

So the problem really boils down to where it is cheapest to launch from and where there's sufficient infrastructure to support fuel production and launch.

Near-Earth Asteroids and the Moon are candidates (beyond Earth). Without existing infrastructure on the Moon I'd say Asteroids are the only "realistic" choice.

Where and how much fuel is used depends on the architecture. Chemical will always be used for crew from LEO to the Moon. Chemical might be used for crew to Mars, from LEO or L1. Chemical might also be used for cargo to the Moon or Mars, e.g. MCT.

The more fuel an architecture needs the more it makes sense to produce fuel away from Earth. MCT which uses a lot of fuel in LEO might actually be a good customer.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: high road on 08/17/2016 10:03 am
Does Martian Methalox/argon out compete moon H2/LOX?

The cost of developing MW-class EP will be peanuts compared to setting up the infrastructure on the Moon for supplying 100s of tons of propellant to L1/L2.

Both for Mars and the moon, setting up shop only to get fuel is ridiculous. However, there are plenty of other reasons to go to either location. Once the infrastructure to maintain complex activities and launch heavy payloads off the surface is there (required to send people back), making the necessary adjustments to produce and launch fuel will require far less investements. On either location, there will be much more stuff going down than up for a long time to come, so reusable spacecraft will be launching 'empty'. So you're taking the 'free ride home' rather than paying for a launch.

And this assumes a demand for fuel in the hundreds of tons, meaning there's a location in deep space that's worth sending this much payload towards it, meaning costs of building things in deep space/the moon/Mars will have plumeted by this time.

I understand that shipping fuel from the Moon to L1 is potentially a lot cheaper than shipping fuel from Earth to L1. So if you already have a sizable "Moon village" it might be worth considering.

Still, you must ask yourself how those settlements on Moon and Mars are being built in the first place, and the answer to that is probably efficient in-space propulsion. The alternative would be chemical + aerocapture + ISRU (the SpaceX way). In such a case there's need for lunar propellant at L1 either, at least not for Mars.

I had understood your 'hundreds of tons' as regardless of how the fuel is used: SEP or chemical. Hundreds of tons of fuel is hundreds of tons of fuel, no matter how much payload is being transported with said fuel. So a demand for 'hundreds of tons of fuel' for SEP transportation of (massive amounts of) goods to Mars, would still benefit from having those hundreds of tons of fuel launched from the moon, assuming off course that this fuel can be produced on the moon.

In fact, if you're transporting goods that require SEP drives to consume hundreds of tons of fuel, I highly doubt the fuel will be the only thing produced/assembled on the moon. Especially bulky or sensitive items.

But if that is not what you meant, I misunderstood.

So the problem really boils down to where it is cheapest to launch from and where there's sufficient infrastructure to support fuel production and launch.

Near-Earth Asteroids and the Moon are candidates (beyond Earth). Without existing infrastructure on the Moon I'd say Asteroids are the only realistic choice.

There's no existing infrastructure on those asteroids either. And while transportation costs are lower, the difficulty of maintenance and potential downtime goes up enormously. There is zero experience operating industrial mining equipment in space. Sending a mission to solve an unforeseen problem takes about a week for the moon, but months or even years for NEO's.

Quote
The more fuel an architecture needs the more it makes sense to produce fuel away from Earth. MCT which uses a lot of fuel in LEO might actually be a good customer.

Quite right. And given their tendency to make their own parts if they don't find a good enough supplier, I even expect them to do more than just 'buy' the fuel, if MCT has enough paying customers.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: gbaikie on 08/17/2016 05:51 pm
Ok, some additional thoughts.

Efficient in-space propulsion is pretty much a given for transporting fuel, since fuel doesn't have to go fast and can easily be divided into smaller packages. I assume efficient in-space propulsion is a minor cost factor compared to launch from the surface of planetary bodies.

So the problem really boils down to where it is cheapest to launch from and where there's sufficient infrastructure to support fuel production and launch.

Near-Earth Asteroids and the Moon are candidates (beyond Earth). Without existing infrastructure on the Moon I'd say Asteroids are the only "realistic" choice.
I agree, but most important factor is the size of the rocket fuel market- which can't limited to NASA only needs.
NASA would help make rocket fuel market in space by using a depot- or someone operating a depot- anywhere in any orbit. NASA should make a depot and make operational a depot in LEO. Make it simple- start with LOX only depot.
NASA should do this now. The idea of NASA LEO LOX depot is not to be profitable, but rather to move the technology from experimental to operational.
Having depots in space will significantly lower the cost of a Mars exploration program- such depot don't need to owned or operated by NASA, instead NASA is merely interested in buying the rocket fuel it needs- whenever and whereever it needs it- but one needs a proven way to transfer the rocket fuel. So you need such transfers made dependable and have known ways of doing it- and LEO depot can establish this.

NASA should start exploring the Moon using robots, and these robotic missions can use NASA LEO depot. And Lunar exploration is finished with crew landing at lunar poles and sample returns. The manned lunar exploration can occur within a two year time frame, starting within within 8 years of starting the lunar robotic part of lunar exploration program. Start with robotic and depot, end with crew landing, and then start Mars exploration program [manned program]. The Mars program likewise use a lot of robotic missions and uses LEO depot. But having crew at Mars makes using robotic exploration better. And and having crew on Mars surface will address issues related to future Mars settlements.
NASA starts small market [sort of] of rocket fuel in space, and making rocket fuel the Moon can enlarge this market, and with larger market, one can mine asteroids for water to make rocket fuel.
It may be the water from asteroids is used in LEO rocket fuel market [be competitive with rocket fuel shipped from Earth]. Whereas Lunar rocket fuel starts at lunar surface and low lunar orbit, and as prices of lunar rocket fuel lowers, the lunar rocket fuel can shipped to High earth and Mars orbits.
The main advantage of lunar rocket fuel is one does not need as large of a market- less than 1000 tons of water mined per year is enough to begin [start with 50 tons and grow it to 1000 tons in less than 10 years].
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Impaler on 08/18/2016 07:36 am
Noble gasses are not the only usable SEP propellants, they are simply the most efficient,

If your producing propellant locally their is a high likelihood that your going to use something sub-optimal in exchange for lower cost per unit.  I would bet on LOX as a likely propellant.

LOX is pretty much unavoidable as a propellant for taking off from the moon's surface.  My question was more about the mid term, in the sense of what might be a valuable cargo. I thought SEP might quickly become competitive, since it requires much less mass overall, even when taking the solar arrays and their low efficiency at Mars into account.  There probably is a breakeven point between SEP propellant and LOX fuel, and this again probably varies with the SEP propellant.  The very low density of hydrogen is a problem compared to argon, for high volume of SEP transportation, IMHO.

I think he means using oxygen as SEP propellant. It's far more abundant on the moon than any noble gasses, so should cost far less to extract.

I think oxygen for SEP is problematic.  I've read one study that puts the maximum attainable efficiency with oxygen at 20%.  Combining this with the higher ISP requirements of low thrust trajectories, SEP loses most of its edge, and we might just as well stick to chemical. 
The cost of developing a class of vehicles is so large, compared to the fuel costs, that I expect we need very clear advantages for a propulsion system to have an incentive to develop it.
Oxygen is chemically bonded to everything, as it is to water.  Deoxydizing aluminium or iron all require large amounts of energy to produce the oxygen.  It also produce useful by products, of course ;-)
On Earth, thee processes can be done relatively cheaply because we have large amounts of mostly pure carbon available, but I don't believe this is the case on the moon.
Of course there may be more loosely binded oxides out there.

Efficiency in an electrical system means the portion of energy that goes into accelerating the propellant stream, it dose not cause a drop in ISP rather it means you need more solar arrays to achieve a desired thrust level.   Oxygen would indeed be less efficient due to higher ionization energy needs but it shouldn't be that low.

I agree that if your sourcing from Earth or Mars then Krypton and Argon make more sense, but the premise of the question was what byproduct of lunar ice could be a SEP propellant and as it looks like noble gasses are not present in the ice it looks like LOX is the next best choice as it is highly abundant not only in water but also CO2, CO, SO2 and likely other compounds, extraction of Oxygen from metals and minerals is another much older idea that irrelevant to the thread.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: jongoff on 08/19/2016 12:32 am
Ok, some additional thoughts.

Efficient in-space propulsion is pretty much a given for transporting fuel, since fuel doesn't have to go fast and can easily be divided into smaller packages. I assume efficient in-space propulsion is a minor cost factor compared to launch from the surface of planetary bodies.

So the problem really boils down to where it is cheapest to launch from and where there's sufficient infrastructure to support fuel production and launch.

Near-Earth Asteroids and the Moon are candidates (beyond Earth). Without existing infrastructure on the Moon I'd say Asteroids are the only "realistic" choice.

Oli, I'm not convinced it's that clear cut, especially if the hypothesis that started this thread pans out. If you're talking about scaling up to 10,000 tons/yr of water levels of exports, I think the infrastructure cost of setting up a propellantless launch/landing infrastructure on the moon is going to be in the noise. Asteroids may have an advantage near-term if a) there aren't better concentrated sources of water on the moon, and b) if the demand level is low enough to not justify the infrastructure needed to make the Moon transportation competitive with the asteroids. Asteroids are easier to get started, but I'm not convinced they have an insurmountable advantage over the moon, especially if interesting resource concentrations exist like what Warren has been proposing.

~Jon
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: gbaikie on 08/19/2016 02:43 am
Ok, some additional thoughts.

Efficient in-space propulsion is pretty much a given for transporting fuel, since fuel doesn't have to go fast and can easily be divided into smaller packages. I assume efficient in-space propulsion is a minor cost factor compared to launch from the surface of planetary bodies.

So the problem really boils down to where it is cheapest to launch from and where there's sufficient infrastructure to support fuel production and launch.

Near-Earth Asteroids and the Moon are candidates (beyond Earth). Without existing infrastructure on the Moon I'd say Asteroids are the only "realistic" choice.

Oli, I'm not convinced it's that clear cut, especially if the hypothesis that started this thread pans out. If you're talking about scaling up to 10,000 tons/yr of water levels of exports, I think the infrastructure cost of setting up a propellantless launch/landing infrastructure on the moon is going to be in the noise. Asteroids may have an advantage near-term if a) there aren't better concentrated sources of water on the moon, and b) if the demand level is low enough to not justify the infrastructure needed to make the Moon transportation competitive with the asteroids. Asteroids are easier to get started, but I'm not convinced they have an insurmountable advantage over the moon, especially if interesting resource concentrations exist like what Warren has been proposing.

~Jon

I tend to think asteroid mining is mostly related to Mars settlements. And/or it's a reason one is settling on Mars- some people may live on Mars because they are involved in asteroid mining.
Mars is good location in terms mining asteroids near Mars.
Or we have NEOs [near earth asteroids] and there are near Mars asteroids. There are more near Mars asteroids than there are NEOs. Or not necessarily talking about Main belt Asteroids or Jupiter trojans.
So there are more asteroids near Mars orbit and on average these will have lower delta-v to Mars, as compared to NEOs to Earth. Also this population of asteroids should have more rocks with minable water.

And perhaps a more significant factor is one can more easily be allowed to bring asteroids or asteroid material to Mars [Mars orbits and surface]. Or asteroid mining may be politically more important than risk of damage related to this mining. Or Earthling are going to freak out if you want to bring space rock which 1 km in diameter or larger into Earth orbit. They probably freak out about 50 meter diameter rock- which isn't really a significant threat.   
Also one could use Mars atmosphere for aerocapture.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: jongoff on 08/19/2016 03:14 am
Ok, some additional thoughts.

Efficient in-space propulsion is pretty much a given for transporting fuel, since fuel doesn't have to go fast and can easily be divided into smaller packages. I assume efficient in-space propulsion is a minor cost factor compared to launch from the surface of planetary bodies.

So the problem really boils down to where it is cheapest to launch from and where there's sufficient infrastructure to support fuel production and launch.

Near-Earth Asteroids and the Moon are candidates (beyond Earth). Without existing infrastructure on the Moon I'd say Asteroids are the only "realistic" choice.

Oli, I'm not convinced it's that clear cut, especially if the hypothesis that started this thread pans out. If you're talking about scaling up to 10,000 tons/yr of water levels of exports, I think the infrastructure cost of setting up a propellantless launch/landing infrastructure on the moon is going to be in the noise. Asteroids may have an advantage near-term if a) there aren't better concentrated sources of water on the moon, and b) if the demand level is low enough to not justify the infrastructure needed to make the Moon transportation competitive with the asteroids. Asteroids are easier to get started, but I'm not convinced they have an insurmountable advantage over the moon, especially if interesting resource concentrations exist like what Warren has been proposing.

~Jon

I tend to think asteroid mining is mostly related to Mars settlements. And/or it's a reason one is settling on Mars- some people may live on Mars because they are involved in asteroid mining.
Mars is good location in terms mining asteroids near Mars.
Or we have NEOs [near earth asteroids] and there are near Mars asteroids. There are more near Mars asteroids than there are NEOs. Or not necessarily talking about Main belt Asteroids or Jupiter trojans.
So there are more asteroids near Mars orbit and on average these will have lower delta-v to Mars, as compared to NEOs to Earth. Also this population of asteroids should have more rocks with minable water.

And perhaps a more significant factor is one can more easily be allowed to bring asteroids or asteroid material to Mars [Mars orbits and surface]. Or asteroid mining may be politically more important than risk of damage related to this mining. Or Earthling are going to freak out if you want to bring space rock which 1 km in diameter or larger into Earth orbit. They probably freak out about 50 meter diameter rock- which isn't really a significant threat.   
Also one could use Mars atmosphere for aerocapture.

I don't necessarily agree or disagree, but I think there are probably threads where general asteroid mining or Mars architecture discussions make sense. We should probably stick to discussing the original topic on this thread.

~Jon
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: sdsds on 08/19/2016 03:45 am
Is there a well-known way to do "prospecting" with an instrument on the surface of one of these lunar features? Or does it really take drilling down to determine what's there?
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: jongoff on 08/19/2016 07:10 am
Is there a well-known way to do "prospecting" with an instrument on the surface of one of these lunar features? Or does it really take drilling down to determine what's there?

Warren suggested that ground penetrating radar in the right frequency range (IIRC something like a 6m band) could do the trick. I think you might be able to do that with a cubesat using bistatic radar with a ground-based transmitter (think Arecibo).

~Jon
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Oli on 08/19/2016 09:29 am
Does Martian Methalox/argon out compete moon H2/LOX?

The cost of developing MW-class EP will be peanuts compared to setting up the infrastructure on the Moon for supplying 100s of tons of propellant to L1/L2.

Both for Mars and the moon, setting up shop only to get fuel is ridiculous. However, there are plenty of other reasons to go to either location. Once the infrastructure to maintain complex activities and launch heavy payloads off the surface is there (required to send people back), making the necessary adjustments to produce and launch fuel will require far less investements. On either location, there will be much more stuff going down than up for a long time to come, so reusable spacecraft will be launching 'empty'. So you're taking the 'free ride home' rather than paying for a launch.

And this assumes a demand for fuel in the hundreds of tons, meaning there's a location in deep space that's worth sending this much payload towards it, meaning costs of building things in deep space/the moon/Mars will have plumeted by this time.

I understand that shipping fuel from the Moon to L1 is potentially a lot cheaper than shipping fuel from Earth to L1. So if you already have a sizable "Moon village" it might be worth considering.

Still, you must ask yourself how those settlements on Moon and Mars are being built in the first place, and the answer to that is probably efficient in-space propulsion. The alternative would be chemical + aerocapture + ISRU (the SpaceX way). In such a case there's need for lunar propellant at L1 either, at least not for Mars.

I had understood your 'hundreds of tons' as regardless of how the fuel is used: SEP or chemical. Hundreds of tons of fuel is hundreds of tons of fuel, no matter how much payload is being transported with said fuel. So a demand for 'hundreds of tons of fuel' for SEP transportation of (massive amounts of) goods to Mars, would still benefit from having those hundreds of tons of fuel launched from the moon, assuming off course that this fuel can be produced on the moon.

In fact, if you're transporting goods that require SEP drives to consume hundreds of tons of fuel, I highly doubt the fuel will be the only thing produced/assembled on the moon. Especially bulky or sensitive items.

But if that is not what you meant, I misunderstood.

So the problem really boils down to where it is cheapest to launch from and where there's sufficient infrastructure to support fuel production and launch.

Near-Earth Asteroids and the Moon are candidates (beyond Earth). Without existing infrastructure on the Moon I'd say Asteroids are the only realistic choice.

There's no existing infrastructure on those asteroids either. And while transportation costs are lower, the difficulty of maintenance and potential downtime goes up enormously. There is zero experience operating industrial mining equipment in space. Sending a mission to solve an unforeseen problem takes about a week for the moon, but months or even years for NEO's.

Quote
The more fuel an architecture needs the more it makes sense to produce fuel away from Earth. MCT which uses a lot of fuel in LEO might actually be a good customer.

Quite right. And given their tendency to make their own parts if they don't find a good enough supplier, I even expect them to do more than just 'buy' the fuel, if MCT has enough paying customers.

First of all, I was under the impression that NEAs contain large amounts of water ice. Turns out that's total nonsense and extracting water from NEAs is a difficult process. There goes the NEA option.

Regarding mining EP propellants, to my knowledge they aren't available on the Moon or NEAs, at least not in large, mineable quantities. Unless you use oxygen, hydrogen which comes with efficiency losses and/or higher tank mass fractions.

Oli, I'm not convinced it's that clear cut, especially if the hypothesis that started this thread pans out. If you're talking about scaling up to 10,000 tons/yr of water levels of exports, I think the infrastructure cost of setting up a propellantless launch/landing infrastructure on the moon is going to be in the noise.

Yes I guess a lunar mass driver would be interesting.

But frankly I'm more interested in the near-term (decades), how the economics turn out in the long term is anyone's guess. I'm very "pro-Moon". It's the obvious place to go next.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: A_M_Swallow on 08/19/2016 03:44 pm
Is there a well-known way to do "prospecting" with an instrument on the surface of one of these lunar features? Or does it really take drilling down to determine what's there?

Warren suggested that ground penetrating radar in the right frequency range (IIRC something like a 6m band) could do the trick. I think you might be able to do that with a cubesat using bistatic radar with a ground-based transmitter (think Arecibo).

~Jon

We may be able to get a cubesat sized probe to the lunar surface within 3-4 years. Someone needs to produce the probe.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: gbaikie on 08/19/2016 10:30 pm
Does Martian Methalox/argon out compete moon H2/LOX?

The cost of developing MW-class EP will be peanuts compared to setting up the infrastructure on the Moon for supplying 100s of tons of propellant to L1/L2.

Both for Mars and the moon, setting up shop only to get fuel is ridiculous. However, there are plenty of other reasons to go to either location. Once the infrastructure to maintain complex activities and launch heavy payloads off the surface is there (required to send people back), making the necessary adjustments to produce and launch fuel will require far less investements. On either location, there will be much more stuff going down than up for a long time to come, so reusable spacecraft will be launching 'empty'. So you're taking the 'free ride home' rather than paying for a launch.

And this assumes a demand for fuel in the hundreds of tons, meaning there's a location in deep space that's worth sending this much payload towards it, meaning costs of building things in deep space/the moon/Mars will have plumeted by this time.

I understand that shipping fuel from the Moon to L1 is potentially a lot cheaper than shipping fuel from Earth to L1. So if you already have a sizable "Moon village" it might be worth considering.

Still, you must ask yourself how those settlements on Moon and Mars are being built in the first place, and the answer to that is probably efficient in-space propulsion. The alternative would be chemical + aerocapture + ISRU (the SpaceX way). In such a case there's need for lunar propellant at L1 either, at least not for Mars.

I had understood your 'hundreds of tons' as regardless of how the fuel is used: SEP or chemical. Hundreds of tons of fuel is hundreds of tons of fuel, no matter how much payload is being transported with said fuel. So a demand for 'hundreds of tons of fuel' for SEP transportation of (massive amounts of) goods to Mars, would still benefit from having those hundreds of tons of fuel launched from the moon, assuming off course that this fuel can be produced on the moon.

In fact, if you're transporting goods that require SEP drives to consume hundreds of tons of fuel, I highly doubt the fuel will be the only thing produced/assembled on the moon. Especially bulky or sensitive items.

But if that is not what you meant, I misunderstood.

So the problem really boils down to where it is cheapest to launch from and where there's sufficient infrastructure to support fuel production and launch.

Near-Earth Asteroids and the Moon are candidates (beyond Earth). Without existing infrastructure on the Moon I'd say Asteroids are the only realistic choice.

There's no existing infrastructure on those asteroids either. And while transportation costs are lower, the difficulty of maintenance and potential downtime goes up enormously. There is zero experience operating industrial mining equipment in space. Sending a mission to solve an unforeseen problem takes about a week for the moon, but months or even years for NEO's.

Quote
The more fuel an architecture needs the more it makes sense to produce fuel away from Earth. MCT which uses a lot of fuel in LEO might actually be a good customer.

Quite right. And given their tendency to make their own parts if they don't find a good enough supplier, I even expect them to do more than just 'buy' the fuel, if MCT has enough paying customers.

First of all, I was under the impression that NEAs contain large amounts of water ice. Turns out that's total nonsense and extracting water from NEAs is a difficult process. There goes the NEA option.
Comets have a lot if water ice [and CO2]. Comets roughly start evaporating their suface water and CO2 at frost line [which is between Mars and Jupiter].
All asteroids or objects between Jupiter and the Sun have not been there for billions of years- they have migrated from beyond Jupiter. 
Earth orbital eccentricity varies over periods of 100,000 of years. See: wiki, Milankovitch cycles.

Dead comets could have a lot water or recently deceased would have more water.
There are also a type of asteroids with hydrates. C-types:
 "The typical composition of an asteroid depends on its distance from the Sun. At the outer edges of the asteroid belt, that is between three and three and a half times further from the Sun than the Earth, over eighty percent of the asteroids are known as C-type. "
www.esa.int/Our_Activities/Space_Science/Asteroids_Structure_and_composition_of_asteroids
And:
"Asteroids of this class have spectra very similar to those of carbonaceous chondrite meteorites (types CI and CM). The latter are very close in chemical composition to the Sun and the primitive solar nebula, except for the absence of hydrogen, helium and other volatiles. Hydrated (water-containing) minerals are present"
https://en.wikipedia.org/wiki/C-type_asteroid
So getting water from Hydrated minerals is like getting water from concrete- requires higher temperatures.
But in terms of energy, I would say less energy to bake rock to get water, as compared to splitting water- but
water rather than hydrates in terms of cheap water seems to me what looking for.
Or if there was 10% water as water compared to 20% water in hydrates form- I would pick the lower concentration of water.
But in terms creating earth with it's oceans, I would guess it mostly done by asteroids with hydrates- or impact energy would liberate the the water from the rock.
So in terms of getting water from asteroids, I would look from dead comets which have water below it's surface- or has water which has not evaporated, yet. And these should be fairly rare among NEAs or NEOs.

Of course it's possible that water at Lunar poles are hydrates rather water ice- and that affects whether the
lunar poles are minable.
 
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: KelvinZero on 08/19/2016 10:45 pm
Of course it's possible that water at Lunar poles are hydrates rather water ice- and that affects whether the
lunar poles are minable.
I think the evidence is specifically of pure water ice. Don't ask me to explain it though :)

http://lcross.arc.nasa.gov/observation.htm
...Scientists also confirmed the water was in the form of mostly pure ice crystals in some places
...NASA has convincingly confirmed the presence of water ice
...After the impacts, grains of mostly pure water ice were lofted into the sunlight
...Seeing mostly pure water ice grains in the plume means water ice was somehow delivered to the moon in the past, or chemical processes have been causing ice to accumulate in large quantities
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: gbaikie on 08/20/2016 01:36 am
"...astronomers Joe Hora, Giovanni Fazio and Howard Smith and their colleagues reported two years ago on the discovery that the NEO Don Quixote is actually an extinct comet - they were able to find its faint cometary tail in infrared images. Now they and their colleagues have completed a statistical analysis of the full near infrared catalog of NEOs, searching for possible short-period comets by using a combination of their orbital parameters and their surface albedos as inferred from their near infrared properties. The scientists found that between about 0.3 and 3% of the moderately bright NEOs are actually likely to be dormant, short-term period comets. They identify twenty-three specific ones as dormant comets. They also conclude that about one hundred large NEOs, with diameters larger than a kilometer. are probably also dormant short-period comets."
https://www.cfa.harvard.edu/news/su201541

If in right orbit, and if has faint tail, then it might be a space rock to mine for water.
Anyhow if above is correct, then there is more dead comets than I thought. But as I said, probably more of them near Mars' orbit which are minable.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Oli on 08/22/2016 01:05 pm
Comets have a lot if water ice [and CO2]. Comets roughly start evaporating their suface water and CO2 at frost line [which is between Mars and Jupiter].
All asteroids or objects between Jupiter and the Sun have not been there for billions of years- they have migrated from beyond Jupiter.
Earth orbital eccentricity varies over periods of 100,000 of years. See: wiki, Milankovitch cycles.

There are also a type of asteroids with hydrates. C-types:
 "The typical composition of an asteroid depends on its distance from the Sun. At the outer edges of the asteroid belt, that is between three and three and a half times further from the Sun than the Earth, over eighty percent of the asteroids are known as C-type. "
www.esa.int/Our_Activities/Space_Science/Asteroids_Structure_and_composition_of_asteroids
And:
"Asteroids of this class have spectra very similar to those of carbonaceous chondrite meteorites (types CI and CM). The latter are very close in chemical composition to the Sun and the primitive solar nebula, except for the absence of hydrogen, helium and other volatiles. Hydrated (water-containing) minerals are present"
https://en.wikipedia.org/wiki/C-type_asteroid
So getting water from Hydrated minerals is like getting water from concrete- requires higher temperatures.
But in terms of energy, I would say less energy to bake rock to get water, as compared to splitting water- but
water rather than hydrates in terms of cheap water seems to me what looking for.
Or if there was 10% water as water compared to 20% water in hydrates form- I would pick the lower concentration of water.
But in terms creating earth with it's oceans, I would guess it mostly done by asteroids with hydrates- or impact energy would liberate the the water from the rock.
So in terms of getting water from asteroids, I would look from dead comets which have water below it's surface- or has water which has not evaporated, yet. And these should be fairly rare among NEAs or NEOs.

Of course it's possible that water at Lunar poles are hydrates rather water ice- and that affects whether the
lunar poles are minable.

Regarding C-type asteroids, the process is described here:

http://www.uapress.arizona.edu/onlinebks/ResourcesNearEarthSpace/resources21.pdf

Quote
Process 1: Water Production. The crushed ore is placed in a closed vessel and heated to 400°C (Hashimoto et al. 1979) with steam at 1 atm pressure. The vapor is removed, cooled to 10°c, and solids and gases are separated from the liquid water. The water (some of which is recycled to the first step) is outgassed briefly in vacuum to remove dissolved gases, and placed in storage.

The issue I see is that the entire asteroid has to be processed, although some proposals (e.g. planetary resources) put the asteroid in a bag and heat it up. I suspect it would a lot easier with water ice, lower pressure/temperature and higher yield.

C-type asteroids and carbonaceous meteorites typically have 5% to 20% water. On average 10%.

http://www.nss.org/settlement/asteroids/NearEarthAsteroidMining(Ross2001).pdf
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Hop_David on 08/22/2016 04:51 pm
Dead comets could have a lot water or recently deceased would have more water.
There are also a type of asteroids with hydrates. C-types:
 "The typical composition of an asteroid depends on its distance from the Sun. At the outer edges of the asteroid belt, that is between three and three and a half times further from the Sun than the Earth, over eighty percent of the asteroids are known as C-type. "
www.esa.int/Our_Activities/Space_Science/Asteroids_Structure_and_composition_of_asteroids
And:
"Asteroids of this class have spectra very similar to those of carbonaceous chondrite meteorites (types CI and CM). The latter are very close in chemical composition to the Sun and the primitive solar nebula, except for the absence of hydrogen, helium and other volatiles. Hydrated (water-containing) minerals are present"
https://en.wikipedia.org/wiki/C-type_asteroid
So getting water from Hydrated minerals is like getting water from concrete- requires higher temperatures.
But in terms of energy, I would say less energy to bake rock to get water, as compared to splitting water- but
water rather than hydrates in terms of cheap water seems to me what looking for.
Or if there was 10% water as water compared to 20% water in hydrates form- I would pick the lower concentration of water.
But in terms creating earth with it's oceans, I would guess it mostly done by asteroids with hydrates- or impact energy would liberate the the water from the rock.
So in terms of getting water from asteroids, I would look from dead comets which have water below it's surface- or has water which has not evaporated, yet. And these should be fairly rare among NEAs or NEOs.

Of course it's possible that water at Lunar poles are hydrates rather water ice- and that affects whether the
lunar poles are minable.

There are a lot of short period comets with ~5 A.U. aphelions. I suspect the Sun Jupiter Trojans feed this population. Or maybe some of the short period comets are Hildas that have drifted from the fold. These comets spend most their time in the neighborhood of aphelion at 1/25 insolation. So their average temperature is pretty cold in spite of their periodic quick zooms through earth's neighborhood. Internal temperature will be close to their average temperature. Many 1 x 5 A.U. bodies likely have volatile ices in their interiors.

However a 1x5 A.U. comet would be moving about 39 km/s with regard to the sun when in our neghborhood. Earth's moving about 30 km/s. So at a minimum this comet would be moving 9 km/s with regard to earth when in our neighborhood. In terms of delta V, these aren't very accessible.


Asteroids accessible in terms of delta V will be in near circular, ~1 A.U. orbits.  These guys receive lots of sunlight 7 days a week, 365 days a year. Average temperature will be around 300 K. And the average temp of their interiors will also tend to be 300 K. Water ice in a vacuum will start sublimating violently at around 90 K. So water ice interiors for the accessible rocks is highly unlikely.

NEO water within our reach is going to be in the form of hydrated clays.


Ordinary Hohmann launch windows occur each synodic period.
Synodic period = (Period A * Period B)/(Period A - Period B).
A 1 A.U. orbit has a period of 1 year. So as the semi-major axis goes to 1 A.U., earth/asteroid synodic period goes to infinity.

To make matters worse, the very low delta Vs given by the Shoemaker-Helin method assume rendezvous at the asteroid's aphelion. So launch windows are even rarer than synodic.

If a launch window to an asteroid mine only opens each 10 or 20 years, it is impractical to have a supply line to this mine. Opportunities to return commodities to markets in the earth moon neighborhood are also very rare.


A way to circumvent the problem of rare launch windows is to park a rock in lunar orbit. This can be done with little delta V. Establishing asteroid mining infrastructure in lunar orbit would make the lunar surface much more  accessible. Tethers extended from an asteroid in a polar lunar orbit (http://hopsblog-hop.blogspot.com/2016/08/lunar-sky-hook.html) would make the poles as well as lower lunar latitudes easier to reach and depart from.

In my opinion guys like Planetary Resources or Deep Space Industries should be natural allies with folks like Shackleton Energy or Spudis.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: jongoff on 08/22/2016 06:57 pm
Oli, I'm not convinced it's that clear cut, especially if the hypothesis that started this thread pans out. If you're talking about scaling up to 10,000 tons/yr of water levels of exports, I think the infrastructure cost of setting up a propellantless launch/landing infrastructure on the moon is going to be in the noise.

Yes I guess a lunar mass driver would be interesting.

But frankly I'm more interested in the near-term (decades), how the economics turn out in the long term is anyone's guess. I'm very "pro-Moon". It's the obvious place to go next.

I wasn't talking mass drivers for the propellantless launch, and definitely not something that's "decades" out. I think there are realistic options that could be done for propellantless lunar launch that could be done as soon or sooner than you could send a similar-sized mining setup to a NEO. You might not get up to 10,000 tons/yr of propellantlessly launched water from the Moon with a Gen 1 system, but I could see plausible ways of getting into the 250-1000tons/yr range with stuff that could be landed on less than a half-dozen Xeus stages.

~Jon
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: jongoff on 08/22/2016 06:58 pm
Is there a well-known way to do "prospecting" with an instrument on the surface of one of these lunar features? Or does it really take drilling down to determine what's there?

Warren suggested that ground penetrating radar in the right frequency range (IIRC something like a 6m band) could do the trick. I think you might be able to do that with a cubesat using bistatic radar with a ground-based transmitter (think Arecibo).

~Jon

We may be able to get a cubesat sized probe to the lunar surface within 3-4 years. Someone needs to produce the probe.

Cubesat scale lunar landers are... while not impossible, rather challenging. Cubesat scale lunar orbiters are a lot more feasible.

~Jon
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: A_M_Swallow on 08/22/2016 07:49 pm
Is there a well-known way to do "prospecting" with an instrument on the surface of one of these lunar features? Or does it really take drilling down to determine what's there?

Warren suggested that ground penetrating radar in the right frequency range (IIRC something like a 6m band) could do the trick. I think you might be able to do that with a cubesat using bistatic radar with a ground-based transmitter (think Arecibo).

~Jon

We may be able to get a cubesat sized probe to the lunar surface within 3-4 years. Someone needs to produce the probe.

Cubesat scale lunar landers are... while not impossible, rather challenging. Cubesat scale lunar orbiters are a lot more feasible.

~Jon

By cubesat sized I meant the payload (~1kg) rather than the entire lander.

There may be companies, laboratories and universities able to pay a few million to put a satellite in orbit around the Moon.

p.s. Moon Express'es software flew the Mighty Eagle VTVL hardware in November 2013, so things may advance faster than we expect.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Steven Pietrobon on 08/23/2016 08:43 am
However a 1x5 A.U. comet would be moving about 39 km/s with regard to the sun when in our neghborhood. Earth's moving about 30 km/s. So at a minimum this comet would be moving 9 km/s with regard to earth when in our neighborhood. In terms of delta V, these aren't very accessible.

The formula to work out delta-v is (If you are the same Hop David that wrote that orbital dynamics colouring in book, you should know this! :-)

Vhyp² = Vesc² + Vinf²

Vhyp = hyperbola velocity (the speed in LEO you need to reach)
Vinf = velocity at infinity (your final velocity) = 9 km/s
Vesc = Earth's escape velocity = 11.2 km/s

Vhyp = 14.4 km/s

As LEO is 7.8 km/s, the delta-V from LEO is 14.4-7.8 = 6.6 km/s. Still quite high, but not as high as 9 km/s and less then what you need to land on the Moon.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: gbaikie on 08/23/2016 06:52 pm
However a 1x5 A.U. comet would be moving about 39 km/s with regard to the sun when in our neghborhood. Earth's moving about 30 km/s. So at a minimum this comet would be moving 9 km/s with regard to earth when in our neighborhood. In terms of delta V, these aren't very accessible.

The formula to work out delta-v is (If you are the same Hop David that wrote that orbital dynamics colouring in book, you should know this! :-)

Vhyp² = Vesc² + Vinf²

Vhyp = hyperbola velocity (the speed in LEO you need to reach)
Vinf = velocity at infinity (your final velocity) = 9 km/s
Vesc = Earth's escape velocity = 11.2 km/s

Vhyp = 14.4 km/s

As LEO is 7.8 km/s, the delta-V from LEO is 14.4-7.8 = 6.6 km/s. Still quite high, but not as high as 9 km/s and less then what you need to land on the Moon.

If comet passed Earth at 1 million miles distance or further ["in our neighborhood"] it would going 9 km/sec faster than Earth orbital speed- though if entered Earth gravity well, it would be going faster.
This is ignoring things like inclination of the orbit. But roughly, number of 6.6 km/s from LEO is correct.
If coming from high earth orbits and traveling at about 10 km/sec at LEO distance instead of 7.8 km/sec, it's less.
[edit: And coming from comet to Earth, it's less to end up at high earth orbits- particularly when add in the Oberth effects, and/or particularly if using Ion rocket engines {though generally, you don't have much Oberth effect with the low thrust ion engines}.]
And  6.6 km/s is about the delta-v needed from LEO to lunar surface- though you get to the Moon in days, rather than years.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Hop_David on 08/25/2016 12:24 am
However a 1x5 A.U. comet would be moving about 39 km/s with regard to the sun when in our neghborhood. Earth's moving about 30 km/s. So at a minimum this comet would be moving 9 km/s with regard to earth when in our neighborhood. In terms of delta V, these aren't very accessible.

The formula to work out delta-v is (If you are the same Hop David that wrote that orbital dynamics colouring in book, you should know this! :-)


Yes, that's me. I remain indebted to you for your help and advice with that book. You improved it a great deal. I sell about one or two of those a month.

Vhyp² = Vesc² + Vinf²
Vhyp = hyperbola velocity (the speed in LEO you need to reach)
Vinf = velocity at infinity (your final velocity) = 9 km/s
Vesc = Earth's escape velocity = 11.2 km/s

Vhyp = 14.4 km/s

As LEO is 7.8 km/s, the delta-V from LEO is 14.4-7.8 = 6.6 km/s. Still quite high, but not as high as 9 km/s and less then what you need to land on the Moon.

Yes, the 9 km/s I mentioned is Vinf . And to achieve 9 km/s Vinf only takes a 6.6 km/s LEO burn as you say.

That is still quite a lot. One of the selling points for asteroid guys is low delta V. They sing the praises of NEAs you can reach with less delta V than a soft lunar landing.

I had thought LEO to a soft lunar landing was about 6 km/s. But I could be wrong. At any rate, I don't think a 6.6 km/s delta V budget from LEO enjoys a big advantage over the moon. And the moon has big advantages over a short period comet when it comes to frequency of launch windows, trip times and light lag latency.

The rocks I'm enthusiastic about can be parked in the lunar neighborhood for as little as .17 km/s. See the Keck report (http://www.nss.org/settlement/asteroids/Asteroid_Retrieval_Feasibility_Study_2012.pdf). Asteroid 2008 HU4 is one of the rocks I looked at (http://hopsblog-hop.blogspot.com/2013/04/catching-asteroid.html). The rocks a Keck style vehicle can park in Lunar orbit might have hydrated clays. But volatile ices are unlikely.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Steven Pietrobon on 08/25/2016 05:55 am
Yes, that's me. I remain indebted to you for your help and advice with that book. You improved it a great deal. I sell about one or two of those a month.


Thanks. Even I find it useful now and again!

Quote
I had thought LEO to a soft lunar landing was about 6 km/s. But I could be wrong.

No, you are correct. I was getting ahead of myself. TLI is 3185 m/s, LOI 940 m/s, PDI 25 m/s and Lunar descent 2042 m/s. Total 6192 m/s or about 6.2 km/s.

Quote
The rocks I'm enthusiastic about can be parked in the lunar neighborhood for as little as .17 km/s. See the Keck report. Asteroid 2008 HU4 is one of the rocks I looked at. The rocks a Keck style vehicle can park in Lunar orbit might have hydrated clays. But volatile ices are unlikely.

Yes, having a resource rich asteroid in fairly easy reach could be quite useful.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: savuporo on 07/28/2017 04:30 am
Bump.

Very much on topic:
http://www.airspacemag.com/daily-planet/ashes-and-water-180964225/

https://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2993.html

Quote
Abstract

Laboratory analyses of lunar samples provide a direct means to identify indigenous volatiles and have been used to argue for the presence of Earth-like water content in the lunar interior. Some volatile elements, however, have been interpreted as evidence for a bulk lunar mantle that is dry. Here we demonstrate that, for a number of lunar pyroclastic deposits, near-infrared reflectance spectra acquired by the Moon Mineralogy Mapper instrument onboard the Chandrayaan-1 orbiter exhibit absorptions consistent with enhanced OH- and/or H2O-bearing materials. These enhancements suggest a widespread occurrence of water in pyroclastic materials sourced from the deep lunar interior, and thus an indigenous origin. Water abundances of up to 150 ppm are estimated for large pyroclastic deposits, with localized values of about 300 to 400 ppm at potential vent areas. Enhanced water content associated with lunar pyroclastic deposits and the large areal extent, widespread distribution and variable chemistry of these deposits on the lunar surface are consistent with significant water in the bulk lunar mantle. We therefore suggest that water-bearing volcanic glasses from Apollo landing sites are not anomalous, and volatile loss during pyroclastic eruptions may represent a significant pathway for the transport of water to the lunar surface.
Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Warren Platts on 08/04/2017 10:15 pm
That was an interesting article by Milliken et al. I took the liberty of overlaying some of their maps on my own database. Here is the coolest one I think:

(http://i.imgur.com/z59wIAT.jpg)

As you can see there is a lot of stuff in relatively close proximity to each other. It definitely looks to me like something is going on! The yellow markers are locations of the IMPs (Irregular Maar-like Pits), the false color hotspots are the locations of the pyroclastic deposits identified by Milliken et al., and the region marked out in black represents a zone where the Kaguya Lunar Radar Sounder identified powerful radar reflections at a depth of a few hundred meters.

The significance of the Milliken results IMHO is what they say: that the glass beads found by 2 out of 6 Apollo missions are not extremely rare anomalies. No doubt if there was more time to do exploration at the other 4 sites, I'd bet you'd find some glass beads there as well.

But more than that, it's pretty convincing proof that the lunar mantle has Earth-like water contents, on the order of a ppt. Thus we have a source rock, that can provide water, the IMPs show where there are conduits from deep within the Moon that allow water to move up, and the Kaguya reflectors are, arguably, consistent with free water confined within interflow zone reservoirs sandwiched between hundred meter thick basalt flows.

All three elements in a single graphic...

Title: Re: Impact of lunar free water on Exploration Architecture
Post by: Lampyridae on 08/07/2017 11:03 am
That was an interesting article by Milliken et al. I took the liberty of overlaying some of their maps on my own database. Here is the coolest one I think:

(http://i.imgur.com/z59wIAT.jpg)

As you can see there is a lot of stuff in relatively close proximity to each other. It definitely looks to me like something is going on! The yellow markers are locations of the IMPs (Irregular Maar-like Pits), the false color hotspots are the locations of the pyroclastic deposits identified by Milliken et al., and the region marked out in black represents a zone where the Kaguya Lunar Radar Sounder identified powerful radar reflections at a depth of a few hundred meters.

The significance of the Milliken results IMHO is what they say: that the glass beads found by 2 out of 6 Apollo missions are not extremely rare anomalies. No doubt if there was more time to do exploration at the other 4 sites, I'd bet you'd find some glass beads there as well.

But more than that, it's pretty convincing proof that the lunar mantle has Earth-like water contents, on the order of a ppt. Thus we have a source rock, that can provide water, the IMPs show where there are conduits from deep within the Moon that allow water to move up, and the Kaguya reflectors are, arguably, consistent with free water confined within interflow zone reservoirs sandwiched between hundred meter thick basalt flows.

All three elements in a single graphic...



I've always been quite convinced of the "wet moon" hypothesis, myself.

One thing I considered was that water vapour outgassing would precipitate (not really the right word) onto lava channel surfaces. Fractured Floor Craters (FFCs) have vertical sheets of fractures which fill with magma (or not) but also seem to be ideal conduits for interior outgassing, especially when the impact melt reaches into the volatile-rich mantle. Lava tubes may have similar ice reserves. Well, frosty rock - not solid blocks of ice, but even then the North Polar ice seems to be metres thick and fairly pure.

The deep radar reflection events from Kaguya are intriguing... too bad there's no practical way to get to them, but we may have convenient access in the form of those lava tube pits. I wonder if there are the equivalent of kimberlite pipes* on the Moon. If those were drained instead of clogging up like on Earth, they would provide really deep access as well as making for extremely cool future habitats. :P

*ie diatremes