The Case Against Mars - Why Mars is not a good target!

John Creighton · 2004-06-11 09:40:32

Currently there are 32 CANDU type reactors in the world. I
don't know the specifics yet, but let's just speculate. If a
CANDU uses 10 tonnes of deuterium per year, that is $3.2 billion
worth of deuterium for the whole bunch. (10 tonnes X 32 reactors
X $10 million/tonne = $3.2 billion)
It's not a huge market but it's a start.

Hmmm...
http://www.abo.fi/~mlindroo/spacemarkets/sld007.htm]
around 20 million to get a metric tone to low earth orbit
and a tone of deuterium is worth 10 million dollars. I
think with current launch technology this just falls short.
I think for this to be really profitable the launch cost should
be 1 million dollars per ton. That would give a large market
for all the other costs which would include the development
of the technology and the construction of the infrastructure.

John Creighton · 2004-06-11 10:13:10

I wonder if reusables could bridge that gap. A 3.2 billion dollar a year market would be 32 billion over 10 years. If a reusable could be developed for say 10 billion that could deliver one metric to low earth orbit with a marginal cost of 1 million dollars and fly 3200 times before failing. Over 10 years we need to move 3200 tones to orbit. With this launch system it would cost 3.2 billion dollars. That leaves 17.8 billion dollars to construct the facilities, the launch vehicles and hall the stuff between mars and earth. It might work but I think it is very speculative.

Anyway is deuterium something that can be recycled?
What is gained by using deuterium in nuclear reactors and will it always be worth the cost of the deuterium?

clark · 2004-06-11 10:22:32

That works out to about 100 flights a year, which means two flights a week. With one vehichle? That might be optimistic.

John Creighton · 2004-06-11 10:35:26

That works out to about 100 flights a year, which means two flights a week. With one vehichle? That might be optimistic.

Yeah, I think I am being very optimistic. If such a vehicle could be developed for 10 billion it probably would already be developed. But then again technology is always progressing, and as time passes it should become easier to develop such a vehicle and hopefully the market for deuterium will grow. Maybe we should require the vehicle be able to haul at least 5 tones of deuterium to LEO. I know it will be easier to get to Low Martian orbit, but I want to leave some margins.

Bill White · 2004-06-11 10:35:28

I wonder if reusables could bridge that gap. A 3.2 billion dollar a year market would be 32 billion over 10 years. If a reusable could be developed for say 10 billion that could deliver one metric to low earth orbit with a marginal cost of 1 million dollars and fly 3200 times before failing. Over 10 years we need to move 3200 tones to orbit. With this launch system it would cost 3.2 billion dollars. That leaves 17.8 billion dollars to construct the facilities, the launch vehicles and hall the stuff between mars and earth. It might work but I think it is very speculative.
Anyway is deuterium something that can be recycled?
What is gained by using deuterium in nuclear reactors and will it always be worth the cost of the deuterium?

I am confused by this, John. Maybe I am missing the basic point.

Isn't the idea to ship deuterium from Mars to Earth?

Earth already has some deuterium and therefore Mars exports will lower the price by increasing supply however an increased supply might facilitate greater use of CANDU technology.

Lots of beans to count, here.

Anyway, isn't the mission critical technology a "made on Mars" means to ship deuterium to Earth?

IMHO, one possibility is magensium based solid fuel rockets to low Mars orbit then re-use solar ion tugs that brought cargo from Earth to Mars for a return trip from Mars to Earth.

= = =

Maybe we should require the vehicle be able to haul at least 5 tones of deuterium to LEO

Why would we carry deuterium to LEO? I thought Mars was deuterium rich and Earth deuterium poor, relatively speaking?

John Creighton · 2004-06-11 10:40:09

Maybe we should require the vehicle be able to haul at least 5 tones of deuterium to LEO
Why would we carry deuterium to LEO? I thought Mars was deuterium rich and Earth deuterium poor, relatively speaking?

It is just a way to measure the performance of the rocket. I mean to say if the rocket was on earth it could do this but the rocket is on mars. Therefore the rocket would be able to haul the stuff to a higher altitude or haul up more stuff in one shot.

It is just a way of leaving some margins. We aim for the technology to do this and if it doesn’t meet those specks it will still work. I was considering ion tugs for the flight between mars and earth but I left this out as an extraneous detail. I think the bigger question is what size of facility do we need to produce the deuterium and how much could such a facility produce annually?

John Creighton · 2004-06-11 10:48:11

IMHO, one possibility is magensium based solid fuel rockets to low Mars orbit then re-use solar ion tugs that brought cargo from Earth to Mars for a return trip from Mars to Earth.

I understand that my LEO comparisons my not be good because some technologies may reach LMO but will be unable to reach LEO. I don’t know if magnesium based solid fuels is one of these. But can solid fuel rockets be reusable? Aren’t solid fuel rockets more complex to deal with? With liquid fuel you just need to fill up the tank so to speak. With solid fuel the fuel must be bonded to the tank etched to the shape to give the right thrust profile and kept away from all heat sources. Remember solid fuel must contain the oxidizer too. Of course there are hybrid fuells that use a solid fuell and a liquid oxidizer. For some reason these fuells arn't used much.

Bill White · 2004-06-11 10:52:45

Maybe we should require the vehicle be able to haul at least 5 tones of deuterium to LEO
Why would we carry deuterium to LEO? I thought Mars was deuterium rich and Earth deuterium poor, relatively speaking?
It is just a way to measure the performance of the rocket. I mean to say if the rocket was on earth it could do this but the rocket is on mars. Therefore the rocket would be able to haul the stuff to a higher altitude or haul up more stuff in one shot.
It is just a way of leaving some margins. We aim for the technology to do this and if it doesn’t meet those specks it will still work. I was considering ion tugs for the flight between mars and earth but I left this out as an extraneous detail. I think the bigger question is what size of facility do we need to produce the deuterium and how much could such a facility produce annually?

It seems to me that if any deuterium could be exported using only "made on Mars" equipment all revenue received can be used to offset the cost of settlement. In essence, the value or cost of materials mined on Mars and used to construct Mars to LMO lift is not relevant, if the settlers can construct such lift in "spare time."

If you need to ship rocket motors from Earth, the cost of shipping those rocket motors must be subtracted from the gross revenue from selling deuterium. If you build solid fuel rockets from Marsian rust microwaved into steel and using magnesium as propellant, then the market value of deuterium delivered to Earth can all be used to offset settlement costs.

= = =

Edit: IMHO, we can never justify a Mars settlement based on revenue generated from deuterium export, however deuterium export may very well greatly mitigate the cost of maintaining a settlement founded for other reasons.

= = =

Research into burning magnesium with CO2 as the oxidant would seem sensible since both are abundant on Mars.

http://microgravity.grc.nasa.gov/fcarch … ...ium.htm

John Creighton · 2004-06-11 11:01:10

Of course a colonization effort will probably cost much more 32 billion every ten years. If the government is doing this in tandem great. Then maybe your solid fuel rockets are the best way to go. But if this is a purely private endeavourer, more would be needed to justify the settlement. We also must ask what is the upper limit private enterprise is will to spend on such speculative efforts. To get an idea of this maybe we should add up the total amount spent annually in the private sector between research and development, and mineral and oil exploration.

John Creighton · 2004-06-11 11:04:10

Research into burning magnesium with CO2 as the oxidant would seem sensible since both are abundant on Mars.
http://microgravity.grc.nasa.gov/fcarch … ...ium.htm

Hmmm… I wonder if you could have an air breathing engine on mars?

Bill White · 2004-06-11 11:07:15

Of course a colonization effort will probably cost much more 32 billion every ten years. If the government is doing this in tandem great. Then maybe your solid fuel rockets are the best way to go. But if this is a purely private endeavourer, more would be needed to justify the settlement. We also must ask what is the upper limit private enterprise is will to spend on such speculative efforts. To get an idea of this maybe we should add up the total amount spent annually in the private sector between research and development, and mineral and oil exploration.

John, I agree with where you are coming from. I also do not think we will find one "killer export" suffiicent by itself to provide sufficient economic justification for a fully private mission.

But if we cobble together a variety of funding sources, including a billion per year (for example) from deuterium export maybe the gap can be bridged.

Anyway, I find this quote instructive:

You can’t beat the cost per pound of shipping back video footage. Until the price of space access drops significantly, video broadcast is likely to be one of the biggest exports from space.

From http://www.thespacereview.com/article/144/1]here.

= = =

Edit: I propose we start thinking a funding "kludge" - - mix and match whatever revenue sources can be cobbled together.

John Creighton · 2004-06-11 12:19:03

John, I agree with where you are coming from. I also do not think we will find one "killer export" suffiicent by itself to provide sufficient economic justification for a fully private mission.
But if we cobble together a variety of funding sources, including a billion per year (for example) from deuterium export maybe the gap can be bridged.

Maybe before that day we will have figured out how to extract it so cheaply from earth the we don’t need. But maybe that same day we will have figured out how to build a city up from the sand without ever going there.

quasar777 · 2004-06-11 14:01:48

concerning The Moon. consider where Mars colonists could go after being atrophied there. i`m not fully convinced they could return to Earth.

Ian Flint · 2004-06-11 17:24:45

Hmmm… I wonder if you could have an air breathing engine on mars?

You can. I don't know much about magnesium but silane (SiH4) is great. It is a liquid that burns in CO2. It has some solid exhaust, so it won't be good in an internal combustion engine or a jet engine, but it will work fine in rockets and ramjets -- or even steam engines!

Check it out in "The Case for Mars" pages 202-204.

Silane will be easy to obtain once solar panels are being made on Mars. It is produced as part of the process to purify silicon. It is liquid at -112 degrees C -- not much colder than night time temperatures on Mars.

Gennaro · 2004-06-11 18:40:26

If you need to ship rocket motors from Earth, the cost of shipping those rocket motors must be subtracted from the gross revenue from selling deuterium.

The only alternative to simple solid fuel rockets manufactured on Mars are SSTO from surface to LEO at both Mars and Earth and cyclers in between, each ship in the chain capable of a couple of hundred flights. It means you need to be able to ship SSTO's to Mars (or at least parts of them), whole or in easily assembled kits and run 'em till they break. We had an interesting discussion about this a couple of months ago.
In the long run, this is no doubt the way it's going to turn out, in my opinion.

Above the most primitive level of tiny and infrequent cargo volumes, expendables have no place in the Mars-Terra transport system.

geo_flux · 2004-06-12 18:04:19

OK assuming deuterium mining is profitable on Mars wouldn't it be safer and more cost effective to do it robotically? I know I'm not making myself popular by being the devil's advocate here but I cant see how any government or corporation would risk sending humans when its cheaper and easier to use robots.

MarsDog · 2004-06-12 20:09:24

Latest timetable for humans, Moon by 2020 and Mars not mentioned but assumed 2030 at earliest.
-
The robots are already running around Mars, and there won't be many a tear shed for the occasional dead robot. For safety and cost effectiveness the glory will go to the robots.
-
I would like to see at least one safe habitat built by robots, before human takeoff, ready to welcome people to Mars.

GCNRevenger · 2004-06-12 20:55:44

If we are far enough along to do the colony thing to the extent of actually mining materials to offset the cost of the mission, then I don't think it would be too big of a deal to build an RLV that runs on liquid methane and LOX, since we'd definatly be harvesting surface water by then. Solid fueled rockets are a big headache to build, and the Martian atmosphere is awfully thin to use a Silane/CO2 engine. In any event, I don't think a Martian colony will be making enough off any sort of export to break even this century. Its much easier to simply take deuterium from Earth's seawater than it is to haul it from Mars.

And about robots... there is alot that robots can do, particularly by direct remote control, but there are plenty of other things that they cannot. It realy only takes a few mechanical failures or unplanned issues to torpedo the whole operation, and it would be pretty darn inefficent to have to wait on signal delay if you had to intervene manually. Humans really do give you a better return on your investment if you are doing anything except poking rocks with tiny spectrometers.

John Creighton · 2004-06-13 11:13:47

And about robots... there is alot that robots can do, particularly by direct remote control, but there are plenty of other things that they cannot. It realy only takes a few mechanical failures or unplanned issues to torpedo the whole operation, and it would be pretty darn inefficient to have to wait on signal delay if you had to intervene manually. Humans really do give you a better return on your investment if you are doing anything except poking rocks with tiny spectrometers.

I want to know what is required for deuterium mining. Where does it come from, the soil air or water. If it comes from the water how do you get the water? Do you get it from the soil, air, polar ice caps or frost? As for mining with robots. If you use remote control, they better be very big. Otherwise there simply would not be much output for each operator on earth. But not all remote resource extraction requires remote control. For instance a sabatar reactor just has to sit there. Moreover, with all the advances in imagine processing, pattern recognition and artificial intelligence I don’t see why robots couldn’t do a simple task by themselves. For instance operate a strip mine.

RobS · 2004-06-13 17:30:52

Deuterium is found in water; the heavy hydrogen replaces ordinary hydrogen. At the Martian polar caps water will be immensely abundant. At the equator, there appear to be many places a well will reach icy regolith; pump down Martian air heated by sunlight and it will come back up cooler and humid, and the water can then be condensed.

The problem is that even on Mars, deuterium is very rare. I don't have the Case for Mars with me here in Europe, but you'd have to evaporate a thousand or so tonnes of water to get a tonne of heavy water. If you want to export a billlion dollars of deuterium, you'd have to export 100 tonnes of it, and that would require processing an incredible volume of water. But theoretically it would be cheaper than deuterium production on Earth because deuterium is five times more common; unless, of course, electricity and labor are five times more expensive, which they might be!

-- RobS

GCNRevenger · 2004-06-13 19:04:53

So, Deuterium is only five times more abundant in water on Mars than it is in Earth's oceans? Then the cost of extracting water from above or underground ice, removing the deuterium from it, on another planet, millions of miles from Earth, with no breathable air, ultra-cold temperatures, planetary dust storms, and other such fun would obviously destroy the advantage of more abundance on Mars than on Earth.

In fact, it might be so much harder to get large amounts of it on Mars, that it might be cheaper to have it shipped in from Earth!

John Creighton · 2004-06-13 20:05:59

I think a lot might depend on how the deuterium is extracted from the water. Maybe if it is five times more abundant in the water that translates into it being much more then five times easier to extract. Probably not, but does anyone now the process?

John Creighton · 2004-06-13 20:10:28

http://www.cns-snc.ca/Bulletin/A_Miller_Heavy_Water.pdf Heavy Water: A Manufacturers’ Guide for the Hydrogen Century

Rxke · 2004-06-14 00:38:47

A (very) belated comment on the original post, on Drexler's article:

I think his reasoning makes sense if you take into account where he's coming from: he is, after all, the godfather of nanomanufacturing...

If you read some of his stuff, where he also describes spaceflight using nano-derived hardware, he predicts it will be *cheap*
You just design spacecraft, engines, habs... on a computer, and it gets built automatically by the nanofactories, for a trivial cost. Only costs will be the chemicals, the only stuff not in total abundancy on Earth. Energy (in his scenario) will be plentiful, by 'growing' efficient solar-arrays, again for a trivial cost. First on Earth, later of course, cheap SSPSes in orbit.
But you can't keep building stuff w/o chemicals, and so he proposes to reach out of the Earth's orbit, to mine asteroids etc. That way even stripmining etc. isn't needed on Earth anymore, the riches come from 'the sky'
And if spaceflight becomes all but for free, it makes sense to harvest initially the closer-by Moon, then the 'bite-sized' asteroids instead of Mars...
No need to stripmine another planet (wich would be terraformable, using nanomanufacturing) if you have 'scraps' laying around closer by...

GCNRevenger · 2004-06-14 08:18:34

Ah yes nanoscale assembly of macroscale objects... its a 50/50 tossup if quantum mechanics and physics and such permit it at all, and it will definatly be a long, long time before we get that far.

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