New Mars Forums

Now, I'm a little ignorant of current cutting edge robotics, but I was under the impression that we're a long way from building machines which possess the dexterity and adaptability of even a heavily encumbered human being.

This discussion is quite fascinating, and I feel bad for interupting it even slightly, but I think it should be kept in mind that by the time we're capable of the autonomous alchemy which you folks are talking about, we should be able to do quite a lot of things, even building a better space suit.   

Sir, why does youth imply foolishness? 

I beg you to explain how my ideas are  any more simplistic than those accepted by the adult generations.  But please do not write with such self-righteous discourtesy, as if I am a buffoon by default, whether it be because I am young or critical of the affluence and jingoism of modern American culture.

I worry about the usefullness of such discussion: a good idea is a good idea, regardless of the characteristics of the person mentions it.  The purpose of this forum, at least, is to talk about Mars, and not to fish for compliments.

Does anybody know what plant species are most efficient at such energy storage while at the same time being fairly ideal as a food source for Astronauts and growing rapidly?  I would think that traditional cereal plants are quite out of the question, but legumes?  Seems like we would really need a superplant...

Behold! The Product of Boredom:

Think this'd work?

Well, BGD, you just had to go and ruin our fun, didn't you?  :;):

Seriously though, you make some very good points: without a supply of oxygen, even this anaerobic waste treatment system is next to useless.  I feel your list of potential Martian oxygen sources is incomplete in that it disregards the hydrolysis of water obtained from the ice caps and any potential permafrost.  True, that is also a power intensive operation, but energy input is not really the issue.

Please allow me to attempt to explain:

A good life support system should have an extremely high degree of closure in the oxygen and water regeneration loops, and some degree of closure in the food loop.  Provided we build a mechanically sound ecological vessel, then we should prevail in water/oxygen retention; oxygen chemically bound up in the waste water I have described before can freed eventually by the biological processes occurring in the greenhouse stage.

I got a C in chemistry, so correct me if I'm wrong in saying that

  CH4 + O2 --> C  + 2H2O

So, if we oxidize the biogas produced by the digester and condense the water, we end up with complete closure of the water/oxygen loops.

However, I'm not certain how the carbon we produce can be used, but I'd bet the Martian metallurgists could find something fun to do with it.

Yet, on Mars, with as much CO2 as we could ever ask for, there is no risk of carbon loss in the system, thanks to the yummy photoautotrophs we'll be bringing along.

So, I think that's one way this technology could be employed as (at least a component of) a CELSS. 

Sure, it'll could get a little energy intensive, but that's why the Mars Direct plan (wisely) calls for the use of nuclear power... it's the only way to fly in the near term.

(A thousand apologies for the rambling nature of this post... it's late)

I realize this is a bit of dead topic, but I have a few points to make that cannot be suppressed.  I'm quite ignorant in this field, so please correct my concerns:

1.) I've never heard of humans eating microbes before: it's not exactly what we're evolved for, and any critters on the menu would likely have to be specially modified in order to be edible to us.
2.) It doesn't seem like a diet of microbes could be quite complete (yes, I know whales manage on it, but they're rather different from us, and are eating mostly zooplankton).  They don't produce many complex carbohydrates, dietary fibers, or protein, to name a few.  We'd be far better off growing broccoli and beans.

Definitely!

I'm involved in an extensive research project at Washington State University dealing with this very technology.  Though the general technique has been around for more than a hundred years, recent engineering has been advancing efficiency and utility by leaps and bounds.

Here on Earth, the method is more useful for pollution-control than energy generation, though that is due more to the competitive price of fossil fuels rather than any limitation of its own. 

Yet it is ideally suited for integration into controlled ecological life support systems.... here's what I've been considering as of late:

The essential unit transforms human solid waste into biogas (70% methane, 30% Carbon Dioxide) and a slurry of waste water, undigestible organic material(cellulose, hemicellulose, lignin, etc.), and inorganic particles/solutes (minerals, etc.).  This process requires no oxygen or  supplementary heat (35 C is more than sufficient) and removes at least up to 90% of the polluting capacity of the raw sewage.

The large quantity of methane produced, albeit of a smaller volume than what could be produced from the Martian atmosphere via hydrogen feed-stock, can well supplement the in situ propellant generation techniques that are the focal point of the Mars Direct and Semi Direct plans.

With the nutrient rich waste water and CO2 (added to an amount obtained from the Martian atmosphere), appropriate-spectrum light is all that is needed for a greenhouse system which recycles both water and carbon.

What I have described above is certainly not the most efficient process imaginable, but with a bit of fancy biochemical footwork, I'm confident it could be made quite competitive, as far as CELSS go.

Again, I'm just a student/intern, so let me know what you folks think!