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No one has ever beaten a 1% per-week boiloff because nobody has ever needed to.
There's much truth in what you say, but LH2 (or LD2) boiloff is and will remain a non-trivial problem nevertheless. Take a look at http://www.dunnspace.com/cryogen_space_ … torage.htm
The SEI "Battlestar Galactica" and the more recent NTR-powerd Boeing "Mega CEV" nor the MarsDirect liquid hydrogen-from-Earth operate ERV concept wouldn't even enter the realm of reason with that kind of 1%/wk boiloff rate.
Yup. Indeed so. They've all got this same problem, I'm afraid.
However I would point out that at least as far as MarsDirect is concerned, now that we are sure there's plenty H2O on Mars it's not actually necessary to bring all that LH2 from earth. It requires a redrafting of the plan, but I don't see why we shouldn't end up with a better mission profile than before.
I'm pleased we appear to agree that the Martian export market for D2 is basically non-existent. (Although I'll admit the idea of Airship Hindenburg-like re-entry vehicles has a certain comic appeal... could we make their landing ground Lakehurst NJ, do you suppose, just for old times sake?)
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I agree that in theory it would be possible to create a near fully-automated facility on Mars, the real question is how much it would weigh.
How many launches would it take to achieve such a complex facility? Over a hundred would be my guess
Theoretically possible but simply not practical given politics and economics
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I agree that in theory it would be possible to create a near fully-automated facility on Mars, the real question is how much it would weigh.
How many launches would it take to achieve such a complex facility? Over a hundred would be my guess
Theoretically possible but simply not practical given politics and economics
Aah what a coincidence I just posted to another thread about this.
See my post http://www.newmars.com/forums/viewtopic.php?t=1804]here
Well anyway in the post I mention a 1980 report from NASA that I found on the web called: Advanced Automation for Space Missions and it talks exactly about my ideas and they say its possible with 1980 technology. However they talk about sending a Space Manufacturing Facility (SMF) to the Moon.
They estimated that such a SMF would weigh about 100 tons or four Apollo missions. It should be about for 99% independent of Earth resources and supplies. Only problem building would be microchips. Not electronic components such as diodes, resistors or other but microchips. However you are able to do a lot with simple electronic components the only problem would be that your devices will be big and slow.
But all of the aspects are discussed in the report from processing lunar soil and extract the elements to building other automated machines.
Waht? Tehr's a preveiw buottn?
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(This is by way of a postscript)
This is written as a sort of postscript
I'm not interested in von Neumann…
... says smurf975.
I assume this is some sort of joke.
He says he's in IT, so I’m sure he must be well aware that all present day IT derives from theories first developed by von Neumann (and, to be fair, Alan Turing). Certainly, my university taught all this to the first year IT class when I attended.
For others who don’t already know, go look at http://en.wikipedia.org/wiki/Von_Neuman … nn_machine and find out something of what smurf and I have already learned:
QUOTE/
A von Neumann machine is either of two different machines(*) popularized by the famous mathematician John von Neumann.
General-purpose computer
A von Neumann machine is a model created by John von Neumann for a computing machine that uses a single storage structure to hold both the set of instructions on how to perform the computation and the data required or generated by the computation. Most modern computers use this von Neumann architecture.
Universal constructor
The term von Neumann machine also refers to the idea of a self-reproducing machine, which was first examined in a rigorous manner and popularized by John von Neumann who called it a "Universal Constructor". In principle, if a machine (for example an industrial robot) could be given enough capability, raw material and instructions then that robot could make an exact physical copy of itself. The copy would need to be programmed in order to do anything. If both robots were reprogrammable, then the original robot could be instructed to copy its program to the new robot. Both robots would now have the capability of building copies of themselves.
These machines could be used to explore—or conquer—the universe. The fact that we haven't seen any from other civilizations is a contributing element of the Fermi paradox. One of the predictions of some proponents of nanotechnology is very small Von Neumann machines which, should they become out of control, would advance over the planet as a "grey goo".
Since such a machine is capable of reproduction, it could arguably qualify as a life-form.
/END QUOTE
For more details, go to http://en.wikipedia.org/wiki/Clanking_r … replicator (von Neumann machines are also sometimes called 'Clanking Replicators' it seems, although I had never heard of that name for them before now.)
Cleary, nanotechnology will not get too far without considerable steps towards von Neuman machines, and at the same time, the development of serious, full-strength von Neumann machines almost certainly depends on developments in nanotechnology.
The two technologies must go together, hand-in-hand.
I hope this has helped clear up any confusion.
(*) Here I am guilty of failing to make it clear that there are two things both called 'von Neumann machine'. This is because I'm used to calling the first kind 'von Neumann engine', 'von Neumann architecture', or 'von Neumann algorithm'. Of course being in IT, smurf will know all this already but for the rest of you, sorry for the confusion.
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Hi,
I'm sorry about my poor choosing of words in the post you are responding to. I did not intend to offend you or prove that I know more of anything, which I don’t, just a hobbyist.
What I mend with the IT and electronics remark is that robots that only do a certain number of steps don't need modern (fast) processing. Basically you could also use a punch card to do it. Only normally they use PLC's (I think it means something like Programmable Logic Control) which are just electronic punch cards that can be reprogrammed at anytime, be it locally, by network or wireless. I think you would find similar devices in programmable microwave ovens. So they are pretty common and cheap.
However yes you would need a fancy computer and AI to oversee that everything is working according to plan. But in my idea you would use humans in a control center to do this. Like you have now in power plants and refineries. So you have cameras and sensors installed and humans will interpret the data.
About von Neumann I was mistaken I thought he was only about nanomachines (which I think are still to far away) but after reading this http://sources.wikipedia.org/wiki/Advan … nts]report from nasa which is about automated factories in space. I see he is more about the theory behind robots building other robots and automated processes then only nanotech.
And no I'm not IT educated or work (now) in that sector. However I did study energy technology (but I didn't finish it). Energy technology is about electrical machines, electricity, automation and some electronics. No fancy education but perhaps I could have been one of those overseeing engineers.
I don't know much about IT but can program simple stuff and I am working to improve my skills.
---
Reading that NASA report it introduced me to http://sources.wikipedia.org/wiki/Advan … _5.6]three ways of realization. You have:
1. Top-Down Approach
2. Bottom-Up Approach
3. Middle-out Approach
You are basically going for the top-down approach when you say that we must wait for a breakthrough in science. (The report actually states it that way)
The bottom-up approach is like evolution, which is you start now and improve as needed.
The middle-out approach that is the best, states that you use what you have now but make sure everything works well.
If you want to translate it to the IT world of project development methodologies:
1. Top-Down Approach - Waterfall model
2. Bottom-Up Approach - Hacking
3. Middle-out Approach - Extreme programming / Agile programming
Waht? Tehr's a preveiw buottn?
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I agree that the deuterium export idea is a non-starter from the point of view of making a profit, but it has much more value than that if you look at the big picture. Other than media and advertising, deuterium is the only known resource on Mars. A mission that harvests some deuterium (even a token quantity), ships it back to Earth, and sells it to a Canadian, will open up people's minds to the possibility of commerce on other worlds. That is its true value.
Shipping deuterium to Earth most likely won't be profitable, but it will start a cash flow while Martians are prospecting for more valuable exports. It will also help develop the infrastructure for shipping to Earth. When gold and platinum are found, the stage will be set for profitable export to Earth.
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I was thinking about the solar system.
The four inner planets are made of rock and the others on the outside are gas giants. So the lighter elements are further from the sun. This makes sense due to gravity and all.
But doesn't this mean that Venus may have more heavier and valueable elements then Mars?
Waht? Tehr's a preveiw buottn?
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It appears to be so yes. In the article that John posted earlier, http://www.cns-snc.ca/Bulletin/A_Miller … .pdf]Heavy Water: A manufacturer's guide for the hydrogen century, it says that Venus contains a whopping 2.2% deuterium in it's water, whereas earth only has 0.0155%. The article says there is much less water, however, on Venus (which is why there is more deuterium) so it may be in fact harder to get to.
For clarity, Mars has 0.1% deuterium in its water.
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Shipping deuterium to Earth most likely won't be profitable, but it will start a cash flow...
It sure will. In the wrong direction.
(Manned space has already got one of these cash flows; it's called NASA.)
A mission that harvests some deuterium (even a token quantity), ships it back to Earth, and sells it to a Canadian, will open up people's minds to the possibility of commerce on other worlds.
Yup. It would open people's minds to the possibility of going broke on a seriously epic scale from commerce on other worlds.
Anyway, why a Canadian?
When gold and platinum are found, the stage will be set for profitable export to Earth.
Gold's worth about $380/ounce these days. That translates to about $13,400/kg. At that price, and considering the likely cost of mining, refining, and transportation from the surface of Mars to the surface of earth, I don't think gold would be anywhere near a profitable cargo. Platinum, at about $750/ounce, doesn't look like a sure-fire profitable cargo either.
And anyway, you've got to find commercial quantities to mine first. They just may not exist.
So, what's going to be profitable for Mars?
Well, really it's too soon to say, but here's some suggestions:
-- scientific knowledge
-- R&R for asteroid miners
-- supply base (especially of water) for asteroid miners
-- tourism
-- "I went to Mars & all I got was this lousy tee-shirt" tee-shirts.
-- Movie locations
I am a strong believer in making space profitable, as no other way can it be made self-sustaining and thus secure for the long term. What concerns me about Mars is that I really can't see any obvious way to make it self-financing. The parallel that keeps coming to mind is Antarctica. We've been visiting the South Pole for over a century and had a permanent base there for 50 years-- but not one immigrant, or one profitable export. And getting to and from, and living at, the South Pole is a dawdle compared with Mars.
Practical, realistic suggestion for Martian profitability, please!
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If you want a good resource that mars could provide here is one, its food.
Mars with its almost terrestial day and atmosphere will be an easier place to use domes than say the moon, and a lot cheaper to operate than say the use of spinning colonies. The materials that plants need are readily available on mars
The markets
1) Earth orbit, It will i think be cheaper to deliver to the higher earth orbits than for it to be launched up thye heavier gravity well of the earth.
2) Asteroid miners, it is true that it will be cheaper and more profitable to mine the asteroids than to get materials from mars. But it is the exact opposite if you need food/medical supplies delivery from mars would be cheaper and easier to facilitate no large O'Neill type colonies solely devoted to growing food, just for providing people with a decent gravity enviroment
3) Luna, there will be food grown on the moon even if under artificial light(but more likely simply using mirrors to focus the light from somewhere else). but it will be hard to do and mars will grow the luxury items that people will want.
Im sorry to say when fusion does come pure deutrium reactors will hopefully be outmoded by ones that use helium3 as there is a lot less waste to deal with and there is a power gain. Initially the main source will be the moon but as soon as is possible the better sources of the gas giants will be used. there delivery by mass driver from mars may be a godsend
Chan eil mi aig a bheil ùidh ann an gleidheadh an status quo; Tha mi airson cur às e.
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Mars with its almost terrestial day and atmosphere will be an easier place to use domes than say the moon, and a lot cheaper to operate than say the use of spinning colonies. The materials that plants need are readily available on mars
I fear the solar and cosmic radiation flux on both the moon and Mars will rule out such domes. Not just human inhabitants but animal and vegetable ones would receive unaccepatable doses of radiation.
Any such farms on Mars (and the moon) will have to be buried underground and use artificial light or mirrors as you say
O'Neill-type space colonies would be easier to design to avoid these issues and already being outside a planetary gravity well, would be in a better position to make cheap deliveries.
I don't think Mars is going to attract many colonists until we've got von Neumann machines and other processes working there long enough to have terraformed the planet enough to make the environment acceptable enough for human habitation. That must surely take hundreds of years.
Sorry. O'Neill-type space colonies could be ready and in use much sooner and cost less.
And talking of terraforming, I wonder if terraforming Venus might just be possible more quickly than Mars? How? Put a nice big sunshade at the Lagrange point between Venus and the sun? Work on its atmosphere with microbes to cause its CO2 to break up into O2 and soot? Just a thought...
(Incidentally, a sunshade at earth-sun Lagrange point is one technological fix for global warming, but that doesn't fit in with the new environmentalist religion that requires us to suffer if we are to be saved.)
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Frankly the cost of terraforming venus or mars and the time it will take will make it the work of generations.
The problem with making O'neill colonies are that they are tremendous structural, engineering and physical tasks.
We will need a large well trained space construction crew and a way to protect them from radiation and low g hazards. These people need food and a place to stay and the materials to make these colonies.
These items cannot come from Earth
If these items cannot come from earth they must be made elsewhere. The moon using O'neills plan to use mass drivers will provide the materials and the tools.
But food will be a problem and mars is the only place that will allow the agriculture (even if under domes) that can provide.
The averadge rem count on mars is high. But materials can be made that will reduce to a fraction this problem. Or if we find this too much of a problem well we redirect light, mirrors are very easy to make (this will work on the moon too). In fact O'neill was going to use THIS same method to get around some of the problems on his colonies.
O'neills colonies will come but they will be after we have functioning LARGE colonies on the moon and mars. The making of these colonies will give us the trained personel to build in space, the tools to operate in space, and what we lack most of all the experience to operate in space.
Chan eil mi aig a bheil ùidh ann an gleidheadh an status quo; Tha mi airson cur às e.
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The problem with making O'neill colonies are that they are tremendous structural, engineering and physical tasks.
As so are any major projects on Mars or the moon.
Question: Is a mass driver feasable to launch cargo from Mars to orbit? Does anyone know if the Martian atmosphere is too dense for this? (I personally don't see why it should be, but just don't know. But whatever, the moon has a lower escape velocity and no significant atmosphere.)
We will need a large well trained space construction crew and a way to protect them from radiation and low g hazards. These people need food and a place to stay and the materials to make these colonies
Wouldn't Phobos and Deimos be ideal space construction bases? They could provide accommodation (in tunnels) that also protects from radiation, and a supply of raw materials. Meanwhile, Mars is on their doorstep with food, etc.
The delta-V from Mars to either moon (surface to surface) would be trivial compared with Earth to anywhere, and if the Martian atmosphere can be used for re-entry aerobraking,the round trip delta-V is probably less than using the moon, which lacks two handy little natural satellites of its own.
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Wouldn't Phobos and Deimos be ideal space construction bases? They could provide accommodation (in tunnels) that also protects from radiation, and a supply of raw materials. Meanwhile, Mars is on their doorstep with food, etc.
Yeah but they have almost no gravity so if people are living on it they will become boneless blobs, that can't go anywhere except space.
I think there these options:
1. Von Neumann machines
2. Cheap access to space (similair cost of sending something by slow boat from Japan to the US)
3. Spend trillions of dollars.
Waht? Tehr's a preveiw buottn?
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Shipping deuterium to Earth most likely won't be profitable, but it will start a cash flow...
It sure will. In the wrong direction.
Let's see...sending missions to Mars is a negative cash flow of billions. Returning deuterium to Earth and selling it is a POSITIVE cash flow of millions. It's not much, but it is in the right direction.
Anyway, why a Canadian?
Ok kids, let's say it all together now, "C-A-N-D-U."
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Ah yeah the Canadian heavy water reactor... Iiii don't see them as being the source of be-all/end-all demand for D2/D2O, especially as a cookie-cutter Westinghouse 600MW or 1100MW light water reactors will be getting cheaper daily after the PRC (Peoples' Republic of California) & co wise up that nuclear energy is a nessesitty.
Getting it from Mars is still not a viable option as opposed to simply refining it here on Earth from our seawater (which we happen to have quite a bit of) economicly speaking, and if you DID have alot of the stuff, then it wouldn't be worth so much...
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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Yeah but they have almost no gravity so if people are living on it they will become boneless blobs, that can't go anywhere except space.
Well, Mars is real handy for R&R&G (G is gravity) And anyway, there could be a rotating habitation up there alongsides Phobos.
I think there these options:
1. Von Neumann machines
2. Cheap access to space (similair cost of sending something by slow boat from Japan to the US)
3. Spend trillions of dollars.
Or all of the above (although don't hold your breath for number 2 as stated. 'Cheap' is a relative term, and what you seek here is, well, just a tad overhopeful.)
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Returning deuterium to Earth and selling it is a POSITIVE cash flow of millions.
Not if nobody'll buy it because it's basically already free to the people who want it (nuke reactor people) here on earth.
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Well its not exactly free I would say, but if there is a huge demand for it, then i'm sure that we can find a way to produce the stuff more cheaply here on Earth than hauling it from Mars.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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Well its not exactly free I would say, but if there is a huge demand for it, then i'm sure that we can find a way to produce the stuff more cheaply here on Earth than hauling it from Mars.
Thats also that I think, that is that at this moment there is no commercial need for a space, moon and mars bases.
Waht? Tehr's a preveiw buottn?
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thats also that i think, that is that at this moment there is no commercial need for space, moon and mars bases,
Using history there was no commercial need for England to create colonies in the americas. But they did. It was only when they discovered tobbacco could be grown that these colonies really took off. It will need the bases to be made first so that research will be done and, only then will products be discovered that make financial returns. At the moment space makes very little money. Research makes little money. But the results of that research do.
What space does offer is unlimited resources to a world that is beginning to starve for them. We need those resources to allow our civilisation to go on. We need those resources so we can tackle our planets problems.
In the end it is a matter of will, it is will that allows mankind to make the step as they say a journey starts with a single footstep.
Chan eil mi aig a bheil ùidh ann an gleidheadh an status quo; Tha mi airson cur às e.
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What space does offer is unlimited resources to a world that is beginning to starve for them. We need those resources to allow our civilisation to go on. We need those resources so we can tackle our planets problems.
Unfortunatly, that isn't entirely accurate... no, we don't really need the wealth of space for Earth. The population of the Earth will probably plateu at around 10Bn people, with genetic engineering feeding them all will be pretty easy, and there are 100's of years of coal, thousands of years of uranium/thorium, and tens of thousands of years of deuterium for fusion in our oceans... As for other reasources, water, metals, polymer feedstocks, etc I think we could get by just fine with extensive recycling.
The notion that we have to go to space because we're going to "run out" of things will easily get torpedoed in congress or somthing... The only thing in space we NEED is the one you can't put a pricetag on (yet)... it is the next land over horizon that has drawn us since the beginning.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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...that is that at this moment there is no commercial need for a space, moon and mars bases.
This is unfortunately true today. The ISS is living proof of it, I suppose.
That's why I've said before that I'm a believer in SSPSs as the way forward in space; I think they can be commercially viable in the near future given cheap enough access to space (please go away Shuttle--and NASA too?) rising oil prices and at least a degree of von Neumann machinery...
This should automatically lead, as SSPS construction and operating activity grows, to an increasing number of people in space... a true space base, if you like. And as raw material is mined on the moon and sent into orbit by mass driver, we have our moon base too.
With a growing population off-earth and traffic between earth, space and moon causing the cost of access to space fall farther, it would soon mean that a Mars expedition would be something that was cheap enough to be undertaken by a non-government agency or society; the National Geographical Society, maybe?
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Using history there was no commercial need for England to create colonies in the americas. But they did.
None of the English colonies were paid for or controlled by the government; all of them were started by people who either went to make their fortune (Virginia, for example) or to have freedom to practice their own kind of religion (Massachusetts, for example)
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