Message: 11
Date: Thu, 30 Aug 2001 19:46:57 -0000

>
> Why tie yourself down to using composting?

CEC -- Cation Exchange Capacity

Lunar regolith is not soil, and Martian soil is about
the worst kind.
What both of these lack is the ability to hold onto
nutrients such as
K+ and Ca++. This ability is called Cation Exchange
Capacity or CEC.
The soil materials with the highest CEC are clay and
humus. Clay is
heavy to transport and difficult to make. Humus,
OTOH, are the
complex organic molecules which are very difficult for

bacteria to
break down, so they are what's left after a thorough
composting process.

If you use a pure hydroponic setup, CEC is not
necessary, but it does
add a great deal of stability to the system by acting
as a buffer for
nutrients.
I fully agree with the above. The question is: Will
humus added to regolith make a suitable soil? - TK
>[snip] I don't know which one will ultimately be
"better", and it may
be that one is better in one situation (e.g.,
composting on the
energy-poor surface of Mars) and another in another
situation (e.g.,
wet oxidation in an energy-rich orbital habitat).<

I'm sure that some combination will work better than
either
exclusively. I favor an approach of fast oxidation
for potentially
infectious materials and composting for other organic
wastes.

> I also have a request. Could you please say
"**CONTROLLED**
Ecological Life Support Systems instead of "Closed
Ecological...",
and moderate the "100% recycling and resource
reclamation" goal?<

By the time we start sending ships to other stars, I
expect getting as
close to 100% as possible will payback greatly in fuel

saved. Also,
Biosphere2 had a goal of exchanging the inside air
only once every 100
years but actually only managed to keep it to once a
day. I think it
behooves us to set the ultimate goals for research
high with the
understanding that intermediate goals will need to be
reached first.
Thus, the "closed ecology" is the goal which we strive

for with our
"controlled environments".

++JohnWheeler
I agree with the above as well. Te Green CELSS Task
FORCE is going for complete closure so that we have a
baseline from which to work. After achieving complete
closure, anything less than that is relatively easy. -
TK
P.S. I seriously doubt Terry is actually reading this

message, as he
posted AFAICT the exact same messages on at least one

=====
Terry Ryan Kok - scientist, ecotechnician, wizard
Elf Lore Family ELDER - Sanctuary Rock facilitator
Green CELSS Task Force focalizer
Starlight Technology: (812) 275-0694
biostar_a@...

"I agree with the above as well. Te Green CELSS Task FORCE is going for
complete closure so that we have a baseline from which to work. After
achieving complete closure, anything less than that is relatively easy. -
TK "

One of the core concepts of SSI is that the utilization of extraterrestrial
resources will make living off Earth much easier than would otherwise be
the case, and that we should take advantage of these resources to speed the
breakout of our civilization into space.

If I have a habitat on the Moon, then it doesn't need to be 100% closed
with respect to oxygen, because 40% of lunar regolith is oxygen and oxygen
is something we'll definitely be producing from regolith for other
applications. (It probably will need to be closed with respect to
nitrogen and carbon, however.)

If we have a habitat on Mars, then it certainly doesn't need to be 100%
closed with respect to carbon dioxide --- just compress outside air and
bring it inside!! The eternal hope of the Mars Society advocates,
furthermore, is that there may be easily reachable subsurface water. If
so, then 100% closure with respect to water would not be needed either.
And if there's water, then oxygen can be electrolyzed from water. Mars is
very resource rich. (Energy poor, however.)

If we have a habitat near a C-type NEO, then it doesn't need to be 100%
closed with respect to carbon, and may not need to be 100% closed with
respect to water and a bunch of other useful materials as well.

Full closure might be very expensive or difficult to achieve. By contrast,
having a sufficient degree of closure to adequately support a Moon or Mars
or NEO base might be much easier and less expensive.

Insistence on full closure just makes it seem harder to live in space than
needs to be. For what are you designing if you have as your goal full
closure?

Ron Menich