Mars One

[JohnFornaro]

A well meaning and possibly somewhat funded individual has managed ... to scale a bit of a knowledge hill.

Carefully edited to summarize some of my own purposes, of course.  But still, a stellar example of yet another graduate of my fictitious online school of sarcasm.

This is brilliant:

The temperature of the conversation inside crucibles like here is conducted along various heat sinks or interfaces to the greater conversations in the public sphere.

I know plenty about sarcasm and praise.

Remember that on a spacecraft power is used much more efficiently than in a house. ...

If you want to have a completely self-contained system on Mars then yes, you would need much larger numbers.

I haven't been discussing the cruise phase at all.  I'm only focusing on living on the planet surface at the moment.  That should be very clear.

Also clear is my intent to discuss a completely self contained system, part and parcel of the Mars-One proposal, mentioned in the OP, BTW.  Particularly crucial in a one-way trip scenario.

Moving to Larson & Pranke for a moment.

Power per person per day = 24 kwh

P.997:  L&P suggest just under 60kWh/day for a crew of six on Mars, assuming that they're eating "store bought" food.  The system they're modeling is not closed life support nor completely self contained.

To me, this seems low.  So I guess I'll read up some more.

Before I forget:

Are you also asserting that there are no mistakes in your assumptions?

The numbers are from Larson and Pranke

Nice dodge.

[Dalhousie]

Remember that on a spacecraft power is used much more efficiently than in a house. ...

If you want to have a completely self-contained system on Mars then yes, you would need much larger numbers.

I haven't been discussing the cruise phase at all.  I'm only focusing on living on the planet surface at the moment.  That should be very clear.

It should be clear that I have been talking about surface operations as well.  Not that basic life support requirements are actually significantly different in either case.

Also clear is my intent to discuss a completely self contained system, part and parcel of the Mars-One proposal, mentioned in the OP, BTW.  Particularly crucial in a one-way trip scenario.

That is fine, is a calculation that needs to be done. I myself are more interested in early missions and Mars stations.  These are not mutually exclusive, early missions, whether one way or expeditions, will be very similar. Later missions will also be similar, with higher degrees of self sufficiency, and a gradual change from one to the other. 

What you need to define of course is the desired level of self sufficiency in all cases.  Even highly closed systems are not totally efficient, not even on a planetary scale.  There are always losses, so there will always need to be replenishment.  The advantage with being on Mars is that you can replenish from the local environment.  So for example 90% water recycling with an open O2 system is reasonable for an expedition.  Water recycling still makes sense, as waste water disposal on Mars is going to be tricky.

Moving to Larson & Pranke for a moment.

Power per person per day = 24 kwh

P.997:  L&P suggest just under 60kWh/day for a crew of six on Mars, assuming that they're eating "store bought" food.  The system they're modeling is not closed life support nor completely self contained.

To me, this seems low.  So I guess I'll read up some more.

It did to me at first too, but when you follow the numbers through it does work out, across checked against actual missions.  Note that the total power for past and present space stations is misleading as they must supply very power-hungry experiments such as smelting.  Actual life support power is much less.

Before I forget:

Are you also asserting that there are no mistakes in your assumptions?

The numbers are from Larson and Pranke

Nice dodge.

How is this a “dodge”?  It is the truth. I don’t have the book to hand, so I can’t double check. When I did this exercise six years ago with a colleague the numbers appear to work out.  According to my notes the information is from the chapter in Larson and Pranke by G.A Landis, B.I McKissock, and S.G Bailey, p 645 – p 648. 

[JohnFornaro]

Remember that on a spacecraft power is used much more efficiently than in a house. ...

If you want to have a completely self-contained system on Mars then yes, you would need much larger numbers.

I haven't been discussing the cruise phase at all.  I'm only focusing on living on the planet surface at the moment.  That should be very clear.

It should be clear that I have been talking about surface operations as well.  Not that basic life support requirements are actually significantly different in either case.

However, in that particular exchange, you were talking about "spacecraft power", which is only an issue during the cruise phase.  Perhaps you meant to say: "Remember that on a martian base, power is used much more efficiently than in a house."?

What you they need to define of course is the desired level of self sufficiency in all cases.

Fixed that for ya.  "They" meaning the Mars-One people.  I'm just reading and commenting, I'm not proposing.  Their ostensible goal is that the one way mission they send up there will be completely self sufficient over the natural lives of the colonists sent, which includes the thorny and difficut issue of geriatric care.  Their website asserts that they have considered all the attendant difficulties of realizing this mission, and offer the surprisingly low, low, price of $6B.  Six percent of the cost of the nearby ISS.  Were I to have suggested this, the humor index on this site would have undergone a huge spike upwards.

Me:Are you also asserting that there are no mistakes in your assumptions?

You: The numbers are from Larson and Pranke.

Me: Nice dodge.

You, all innocent like: "How is this a 'dodge'?  It is the truth."

Of course it is true that you're quoting your recollection of L&P.  The dodge, obviously, is that you have not answered the question.  You have accepted your recollection of L&P's numbers as your own.  Are these assumptions completely free of mistakes?

I suspect that the answer is "no".  Were I to describe a successful mission planner, I would say that she would answer questions directly, not insist upon scoring debate points.

If the answer is an unambiguous "yes", then the hard work is finished already, and we can use the data in L&P without further consideration or verification. 

Checking out p.645 of L&P for a moment, we find a lengthy discussion of how to figure power requirements, but it summarizes a Mars mission, and doesn't break it down completely.

NASA's studies for a MArs mission project baseline power to be 30kW-50kW for transfer vehicles, 25kW-100kW for initial surface habitats (growing ot 160kW for resource processing), and 10kW for surface rovers.

Per table 18.4, on p.583, this would be for a six man crew.  For a first order estimate, OK, I guess.  I simply don't know enough to analyze this figure completely at this time.  I'd go with the larger numbers.  Note that they assume "store bought" food.

[Dalhousie]

Fixed that for ya.  "They" meaning the Mars-One people.  I'm just reading and commenting, I'm not proposing.  Their ostensible goal is that the one way mission they send up there will be completely self sufficient over the natural lives of the colonists sent, which includes the thorny and difficut issue of geriatric care.  Their website asserts that they have considered all the attendant difficulties of realizing this mission, and offer the surprisingly low, low, price of $6B.  Six percent of the cost of the nearby ISS.  Were I to have suggested this, the humor index on this site would have undergone a huge spike upwards.

No argument from me.  I have many issues with the Mars one idea, not least there isn’t enough detail to sensibly evaluate it.

You, all innocent like: "How is this a 'dodge'?  It is the truth."

Of course it is true that you're quoting your recollection of L&P.  The dodge, obviously, is that you have not answered the question.  You have accepted your recollection of L&P's numbers as your own.  Are these assumptions completely free of mistakes?

I suspect that the answer is "no".  Were I to describe a successful mission planner, I would say that she would answer questions directly, not insist upon scoring debate points. [/quote]

You are the one trying to score points here, not me. I don’t play games. I do not currently have a copy of Larson and Pranke to hand to cross check. I have given you the page numbers I got the numbers from, if you wish.  This is not dodging the issue, this is stating facts.

If the answer is an unambiguous "yes", then the hard work is finished already, and we can use the data in L&P without further consideration or verification. 

Checking out p.645 of L&P for a moment, we find a lengthy discussion of how to figure power requirements, but it summarizes a Mars mission, and doesn't break it down completely.

NASA's studies for a MArs mission project baseline power to be 30kW-50kW for transfer vehicles, 25kW-100kW for initial surface habitats (growing ot 160kW for resource processing), and 10kW for surface rovers.

Per table 18.4, on p.583, this would be for a six man crew.  For a first order estimate, OK, I guess.  I simply don't know enough to analyze this figure completely at this time.  I'd go with the larger numbers.  Note that they assume "store bought" food.

Are these kw or kwh?

[Dalhousie]

Why is it considered necessary to specify construction of a nuclear reactor to power lights during dust storms instead of overscaling the greenhouses to produce a stored surplus, which may then be consumed during and immediately after dust storms? This seems to me to be rather lower-tech and therefore much more robust, given that a large number of people in the past did just that and survived fine. It also avoids the inevitable political and public opinion complications which attend nuclear power and takes advantage of the relatively sterile and cold conditions of Mars' surface, which should aid in food preservation and storage.

EDIT: By "did just that," I mean that many people in the past, eg. Scandinavians, have confronted issues, eg. winter, which prevented them from growing foods for long periods of time and which were not, at the time, amenable to solution by technological means. Therefore, they grew a surplus and stored it to survive during winter and before the next harvest. Similarly, the practice of storing food against famines, referred to in the Biblical story of Joseph.

Sorry for the slow response, I have been caught up with the Shenzhou mission.

This is a good question.  The issue for me is that, on Mars is that, unlike terrestrial winters, which are predictable, and unlike Joseph, who had advance notice, dust storms are not predictable enough to fit into a growing cycle.  If you were to rely purely on natural sunlight you could loose your crop at any time and then need to grow a new one.  Maybe on average you could produce enough storable food (and not all food is storable without extensive preservation to tide you over the storms, maybe not.  You would of course be restricted to crops with fast growth cycles.  No perennial crops for instance.

If you were replying on plant growths for water and oxygen recycling then I suspect that some kind of artificial light supplement on demand is essential.

The issue with nculerar power alos is, other than the management of the reactors, the fact that you need to important the fuel from Earth.  Useful uranium and thorium deposits are not likely on Mars.

[QuantumG]

http://www.bbc.co.uk/news/world-europe-18506033

[JohnFornaro]

Are these assumptions completely free of mistakes?

I suspect that the answer is "no".

Yer so modest.  I'm less so.  L&P's assumptions are not completely free of mistakes.  The book, by acknowledgement from the authors is a primer, and not a substitute for mission analysis and design.  If I knew better than they, I'd have written the book before they did.

Are these kw or kwh?

I just checked again.  KW.

The assumptions on power requirements for a six person martian base, as reported in L&P, are dependent on verification, and are not discussed in extensive detail.

There is a conflict in the daily power requirements of a six person martian base, between  the numbers on page 645 and 997, as reported in L&P.  I don't know which is correct, and am working this problem from a lunar standpoint.

If anyone wants to score points with me, I'd certainly apprecieate independently verifiable facts or assumptions about power usage in these two contexts, Mars and Luna.

What you they need to define of course is the desired level of self sufficiency in all cases. 

I keep having to fix this for ya.

They have stated quite clearly that their goal is for the one way manned Mars mission to be completely self sufficient, while seeming to acknowledge that resupply from Earth will be crucial for the survival of the colony/base, possibly for natural lifetimes of the original crew members.

"If you look at the team involved in Mars One, none of us would do this as a hoax," says Mr Lansdorp.

I'm certain that they are not a hoax and I am certain that the mission so far desribed would fail.

We're chatting over glasses of steaming mint tea at a road side cafe in The Hague.

Helpful background information.  I find myself believing that the mission as described is more likely now to succeed!  As they say in Burn Before (or was it After?) Reading, "tea can do many things darling, but it can't bring back the dead".

However, at the moment, the focus appears to be more on the monetisation [British for monetization (ahem)] of the concept in an expectation that the income will assure the solution of the problems by others.

Which is what everyone's trying to do.  No blame.

Even ignoring the potential mismatch between the project income and its costs and questions about its longer-term viability, the Mars One proposal does not demonstrate a sufficiently deep understanding of the problems to give real confidence that the project would be able to meet its very ambitious schedule.

Don't believe me, believe him!  [Points thumb over shoulder.]

They have already lined up the potential suppliers ...

So have I, incidentally.  Ask for a proposal; get a proposal.  How am I going to pay these guys?  It's a mystery.  But enough about me...

[truth is life]

This is a good question.  The issue for me is that, on Mars is that, unlike terrestrial winters, which are predictable, and unlike Joseph, who had advance notice, dust storms are not predictable enough to fit into a growing cycle.  If you were to rely purely on natural sunlight you could loose your crop at any time and then need to grow a new one.  Maybe on average you could produce enough storable food (and not all food is storable without extensive preservation) to tide you over the storms, maybe not.  You would of course be restricted to crops with fast growth cycles.  No perennial crops for instance.

I suspect that you could produce enough storable foods based on the observed high productivity of farms in Western nations. Although those do depend on extensive material and non-material inputs, any Martian farm would be quite intensive and probably have high per-acre outputs...maybe enough to match, say, the US on a per-capita productivity level, especially if optimized foods are chosen. Mars could be a foodie's paradise--everything is local and seasonal, after all

(How many commercially important perennial crops are there, BTW? I know that at least some very important crops, like rice and wheat, are annuals, by and large)

Could be the basis for an interesting trade study, although I suspect any actual colonization is far enough away that it would be entirely pointless except as a mental exercise. After all, some people have semi-seriously proposed that we could all be robots by the time any of this could possibly be relevant, which would make "life-support" entirely pointless, no?

If you were replying on plant growths for water and oxygen recycling then I suspect that some kind of artificial light supplement on demand is essential.

Well, yes, stockpiling a year or two's worth of food won't do you much good if you all suffocate from CO2 buildup or dehydrate (is there some relatively short, convenient term for that like "starve", anyone?) to death because your air/water filtration system died. And physical-chemical means might take enough extra power that you would be better off having a nuclear plant in the first place...hm...

The issue with nculerar power alos is, other than the management of the reactors, the fact that you need to important the fuel from Earth.  Useful uranium and thorium deposits are not likely on Mars.

And why is that, I wonder (genuine question: don't know much about Martian geology)? I wonder how incorporating the need to import fuel and spares might impact the relative masses for nuclear and solar systems.

[Dalhousie]

I suspect that you could produce enough storable foods based on the observed high productivity of farms in Western nations. Although those do depend on extensive material and non-material inputs, any Martian farm would be quite intensive and probably have high per-acre outputs...maybe enough to match, say, the US on a per-capita productivity level, especially if optimized foods are chosen. Mars could be a foodie's paradise--everything is local and seasonal, after all

(How many commercially important perennial crops are there, BTW? I know that at least some very important crops, like rice and wheat, are annuals, by and large)

Most fruits and nuts, and bamboo spring to mind, although bamboo can be harvested at almost any stage.  They are not essential, but are useful for dietary diversity and bamboo is a useful raw material.

Could be the basis for an interesting trade study, although I suspect any actual colonization is far enough away that it would be entirely pointless except as a mental exercise. After all, some people have semi-seriously proposed that we could all be robots by the time any of this could possibly be relevant, which would make "life-support" entirely pointless, no?

Certainly would make an interesting trade study.  I don't know enough about horticulture to do it though!

The issue with nculerar power alos is, other than the management of the reactors, the fact that you need to important the fuel from Earth.  Useful uranium and thorium deposits are not likely on Mars.

And why is that, I wonder (genuine question: don't know much about Martian geology)? I wonder how incorporating the need to import fuel and spares might impact the relative masses for nuclear and solar systems.

Uranium (and thorium) are what are called lithophile elements, they are concentrated in highly fractionated rocks like granite.  The martian crust is generally poorly fractionated (mostly basaltic as far as we know) and has very little granite (a few highly differeniated plugs asscoaietd with the older eroded vlocanoes and probably equivalent to terrestrial hawaiites or icelandites).  The probability of uranium and thorium deposits is therefore low.  You can always invoke unknown processes operating on Mars, but that is special pleading and should not be relied upon.

Hope this helps!

[docmordrid]

http://adsabs.harvard.edu/abs/1981Geokh.......10B

....In the first case, it is found that the thorium and uranium  contents of the volcanic Martian rocks (5 + or - 2.5 and 1.1 + or - 0.8 ppm,  respectively) are similar to those of many typical terrestrial and lunar basalts...

[Dalhousie]

http://adsabs.harvard.edu/abs/1981Geokh.......10B

....In the first case, it is found that the thorium and uranium  contents of the volcanic Martian rocks (5 + or - 2.5 and 1.1 + or - 0.8 ppm,  respectively) are similar to those of many typical terrestrial and lunar basalts...

Which illustrates my point.  Basaltic rocks generally not highly fractionated (with a few exceptions).

[Crispy]

Slashdot are doing a Q&A with the company's founder, Bas Lansdorp:

http://interviews.slashdot.org/story/12/06/26/140241/ask-bas-lansdorp-about-going-to-mars-one-way

One question per post. The ones with the most upvotes gets passed on and he'll reply in a few days.

[Atlan]

I dont quite understand why it has to be Mars. If they were doing the same thing on the Moon...i would say that more people, including me, would see this project as realistic. And it still would be challenging and interesting.

[Robotbeat]

I dont quite understand why it has to be Mars. If they were doing the same thing on the Moon...i would say that more people, including me, would see this project as realistic. And it still would be challenging and interesting.

The Moon has its own challenges, like much greater temperature swings, micrometeorites pelting every exposed surface, more abrasive dust, longer nights, more difficult to access volatiles (Mars has an atmosphere that provides most of what you'd need, with easy access on much of the Martian surface to buried ice). Also, the risk of acute radiation from solar particle events is higher, as is the overall radiation level (because of lack of atmosphere). Plus, the totally unshielded vacuum UV light from the sun limits what you can use for materials. Also, we know Mars has tons of essentially pre-refined iron-nickel alloy easily within walking distance from any point. And lots of salts and even some clay-like deposits.

I love the Moon, and if you think Mars is the wrong place for such an effort, go ahead and start an effort to do this on the Moon!

[JohnFornaro]

I dont quite understand why it has to be Mars. If they were doing the same thing on the Moon...i would say that more people, including me, would see this project as realistic. And it still would be challenging and interesting.

It's easy to understand why it has to be Mars.  That's where they want to go!  But I agree, a lunar expedition would be far more realistic, and more quickly implemented.