
Water extraction on Mars for an expanding human colony - micaeloliveira
http://fermatslibrary.com/s/water-extraction-on-mars-for-an-expanding-human-colony
======
zeteo
Needs for net in-situ production, by section:

1) Drinking, hygiene, "everyday living": 0.07 kg/hr/person

2.1) Regolith processing: negligible.

2.2) Manufacturing: 0.04 kg/hr/person

2.3) Perchlorate remediation: negligible.

2.4) Plant growth: 0.003 kg/hr/person

2.5) Habitat maintenance: 0.01 kg/hr/person

Total: 0.123 kg/hr/person

=====

In-situ sources:

3) Atmospheric processing (MARRS): 0.02 kg/hr/person

4.1) Robotic extractor (MISWE): 0.2 kg/hr

4.1) Bore hole digging rover w/ microwave heating: 0.3 kg/hr

4.2) Hothouse: 2.08 kg/hr (implied from Table 3)

=====

Questions abound. Why are important quantities such as 2.2) and 3) estimated
per person when their link to population size is very unclear? Why is the
reserve in Fig. 1 an afterthought (sufficient for 6 months minimum consumption
at best) when mission frequency is stated to be two years? Etc.

~~~
abraham6464
> Why are important quantities such as 2.2) and 3) estimated per person when
> their link to population size is very unclear?

The answer for 2.2) seems to be that this water would be mostly related to
concrete production for habitat construction/maintenance. More people means
more construction/maintenance.

See: "Concrete production will most likely use the most water out of all the
manufactured materials because that water isn’t easily reclaimed. And,
although there may be more need for manufactured products towards the early
stages of the colony, the amount required will be normalized to the amount of
people in the colony."

The explanation for 3) appears to be that this water is a byproduct of oxygen
production, which occurs in proportion to oxygen consumption, which should be
proportional to population size.

See: "This amount relates to the water that would be extracted from the
atmosphere during the process of extracting the required oxygen for breathable
air (Wieland, 1998)."

~~~
zeteo
Yes, I've seen the explanations in the paper but it's still confusing.

2.2) New construction should depend on population _growth_ not population
levels. In table 1, the population growth rate varies between 20% and 100% per
mission, so it's hard to see the ratio (new construction)/population staying
constant.

3) This assumes that a) all oxygen is produced from the atmosphere, none from
the soil, plants etc. b) there will be no oxygen demand from manufacturing
etc. Both assumptions seem quite tenuous.

------
Tossrock
The .6 kg/hr/person figure for water is pretty generous - that works out to
3.8 gallons/day/person. As any burner could tell you, you only really need
about 1 gallon of water per day for survival. Spending 2.8 gallons per day on
hygiene is quite luxurious when you consider that you have to crack that water
out of regolith. Taking a 1-gallon sponge bath once a week and drinking the
rest would cut it to < .2 kg/hr/person - before reclamation!

~~~
delecti
That includes water used for growing food. I don't think they're being
generous at all. You don't grow your own food at Burning Man. :P

~~~
Tossrock
Incorrect - the 0.6 number is purely for personal survival. They cite the
number when including plant maintenance, regolith processing, etc, as 1.2. See
the article:

> "The amount of water needed for extended human survival is around 0.6
> kg/hr/person which includes water for consumption, hygiene, and everyday
> living in space (Bobe et al., 2007; Horneck et al., 2003, 2006). This
> estimate is based on space station living and, assuming water consumption is
> less in a micro-gravity environment, would increase up to 0.7 kg/hr/person
> to account for living with gravity. The amount required if demands from a
> growing colony (regolith processing, manufacturing, perchlorate remediation,
> plant growth, habitat maintenance, etc.) are added to human needs is
> estimated at 1.2 kg/hr/person."

------
Rhapso
It boggles my mind, with the understanding and technology we have, that we
have not leveraged our entire world economy to the single goal of establishing
human colonies off world and sending generation ships to nearby stars.

It is the single most beneficial act to the survival likelihood of the human
species that seems available to us.

~~~
base
It boggles my mind, with the understanding and technology we have, that we
have not leveraged our entire world economy to the single goal of eradicating
poverty of the world.

~~~
thescriptkiddie
There goes the "but we have so many problems down here" argument again.
Starting a Mars colony would require the efforts of a few thousand people and
cost a few percent of world GDP. Eradicating poverty would require the
cooperation of millions of people, many of whom would sooner murder each
other, and more than half of world GDP. So not only are the two projects not
mutually exclusive, a Mars colony is actually _much_ less difficult.

~~~
__jal
Depends on what the goal is.

If your Mars colony is just a PR^H^H national pride game - you've got a
handful of people, some high-school kids' plant experiment and the Little Box
with the Antenna some TLA agency asked you to leave behind - then sure, it
would be no more expensive than the SDI, the Libyan war or any other stupid
boondoggle we can apparently afford.

If you want an actual self-sufficient colony, you've got a much bigger
project. I don't think we know what is actually required to create a self-
sustaining technical culture in space, because we've only really done it by
accident and not in space. But this: [http://www.antipope.org/charlie/blog-
static/2010/07/insuffic...](http://www.antipope.org/charlie/blog-
static/2010/07/insufficient-data.html) is as decent a hand-wavey starting
point as any. And it is quite a bit more resource-intensive than a few
kilopeople/few percent of organized human output.

~~~
thescriptkiddie
The comparison to those stupid boondoggles doesn't really do the scale we're
talking about justice. A few percent of gross world product is 4 trillion
dollars per year. That's more expensive than the entire Second World War.
That's enough money to fund NASA for two centuries. That's enough money to
launch the mass of the empire state building into LEO _twice_ using current
disposable rockets.

------
cynical_sheet
I really don't get it! Could someone please explain this to me:

\- Why do humans today work so hard so that some other members of homo sapiens
species can inhabit another planet? Those creatures, you, everyone you know
and the entire species will be gone. Why bother to do that or anything at all?
What is the end game?

\- Is the decision to care about humans going to Mars made by careful &
rational consideration which resulted in conclusion that members of homo
sapiens species should be on Mars and that there is an objective moral duty to
do so? Why pick homo sapiens species instead of some other animal species? Is
it objectively true that a bio-chemical process known as a homo sapiens has
intrinsic value and that everyone should work to sustain it?

~~~
pc86
The human race is a race of explorers, and always has been. We will go to Mars
because it is there.

And if you really feel that mankind is on the same level as every other animal
on the planet, despite no other species having built skyscrapers, gone to the
moon, or printed their language, then that's not even really a conversation
worth having.

~~~
cynical_sheet
You are only saying that certain bio-chemical structures reshuffle atoms in a
different way, which in most cases suits their survival. You're judging a fish
by its ability to climb a tree. Also, you make it seem that there is an
objective scale which measures 'levels' [of greatness, I assume]. But, there
is no evidence that such a scale exists. You pick these arbitrary shuffling of
molecules, like building skyscrapers or going to another rock[Mars], as great
or progressive. That is the result of having an unjustified bias towards your
own species. Many animals can do things humans can't do and vice versa. But,
that is just a difference, not an objective superiority or inferiority.

~~~
thescriptkiddie
Why do these discussions always end up turning into pseudo-philosophical
nihilist pity parties?

We can define greatness however the fuck we want, because as far as we can
tell we're the only self-replicating assemblage of molecules that knows or
cares what greatness even means. So if, during whatever time we're not
spending making more copies of ourselves, we decide we enjoy shuffling
molecules into a particular arbitrary pattern, who the fuck is going to tell
us that isn't greatness? When you ask why we should bother making copies of
ourselves on a _different_ pile of dirt than the one we're currently on, you
might as well be asking why we should go on making copies of ourselves at all.
There is no endgame. There is only doing interesting shit, doing boring shit,
and death. I choose interesting shit.

~~~
cynical_sheet
I don't even know why people then write papers, do research or discuss things
when they could call someone dummy or label what they are talking about as
'pseudo-X'. What is 'pseudo-philosophical' about the questions asked? It is
your reply that is a diatribe devoid of any substance.

    
    
      'We can define greatness however the fuck we want, because as far as we can tell we're the only self-replicating assemblage of molecules that knows or cares what greatness even means.'
    

Hmm, this is not cool. I sense emotional rage from the beginning. 'Greatness'
or 'great' is actually well-defined. What you're writing is that many humans
can use language. That's obvious. Fish can swim, birds can fly, some fungi
inhabit radioactive space. It's all shuffling of particles.

    
    
      'So if, during whatever time we're not spending making more copies of ourselves, we decide we enjoy shuffling molecules into a particular arbitrary pattern, who the fuck is going to tell us that isn't greatness?'
    

It's not greatness, because greatness cannot apply to almost everything.
Imagine that every email you ever get is labeled as 'important'. Well, if
every is important, then labeling it as such become useless and just clutters
you subject line. Same with the word 'special'. If everyone is special, the no
one is. These words, like greatness apply to minority of things or otherwise
they become useless. So, since shuffling atoms is done all the time
everywhere, labeling that as greatness makes no sense.

    
    
      'When you ask why we should bother making copies of ourselves on a different pile of dirt than the one we're currently on, you might as well be asking why we should go on making copies of ourselves at all.'
    

Yes... and?

    
    
      'There is no endgame. There is only doing interesting shit, doing boring shit, and death. I choose interesting shit.'
    

These 3 activities and events are also shuffling of particles. So,
fundamentally, there is no distinction between them in the end. Since death
requires the least amount of effort, it would be the best choice for creatures
looking for an easy way out.

~~~
thescriptkiddie
Sorry about that aggressive comment, it was intended to be humourous.

------
ck2
Can you just imagine 128 people on Mars?

Definitely not within my lifetime.

Probably not within the lifetime of anyone alive today.

Politicians would rather spend money on wars.

------
nickdima
Good, now once we extract water here are the next steps to take:
[https://teespring.com/mars-colonization](https://teespring.com/mars-
colonization)

~~~
MuEta
Nothing against you, but why are link shorteners still allowed on HN? I feel
like they are an easy attack vector for malware, and don't make life any
easier for us as readers - in fact, they make it significantly harder because
I have no idea what I'm clicking.

~~~
nickdima
You're right, sorry, I edited the comment.

