Plant Nursery In Space?

--- In spacesettlers@y..., Lucio de Souza Coelho
> While I tend to agree with you when you say that a good
biodiversity is
> probably enough to provide a "more-or-less stable" environment,
the problem
> is: I think that humans need a *very* stable environment to live
healthily
> and comfortably. Moreover, not *any* "very stable environment",
but one
> occupying a somewhat narrow band of O2 and CO2 concentration in the
> atmosphere, humidity, temperature, etc. So, I much doubt that
the "more or
> less stable" state where a closed ecosystem will converge into
will be
> comfortable (or even acceptable) for humans standards. Talking
about
> Biosphere II, I would hardly say that the bionauts
lived "comfortably" in
> there...

I couldn't agree with you more. Stable doesn't mean much. Look at
Mars, it has a stable environment. So does the Arctic and so does
the Amazon.

The achille's heel will be this new science of environmental
engineering. The habitat construction, even though more massive in
scale than anything ever constructed before, will be very well
understood and should pose few surprises. But how do we get
environmental stability when we seal it up?

>
> So, since we have plenty of energy and raw materials in space,
lets just
> forget about using ecosystems to recycle air and water and use
machines to
> do that. Space habitats don't have to be Earths in miniature, they
just have
> to be a place were people will like to live.

Sure. Maybe. But what machines? None have been built, nor designed.
Here on earth, the ecosystem is a functioning process that can be
studied, components isolated, interrelationships understood, a
engineering trade can be developed from this science. That
engineering can then be duplicated in the future environs of the
habitat.

How can you design machines for tasks that can't even be defined. If
we don't know the complex interrelationships of a biosphere, how can
we design mechanical processes to replace the biosphere?
>
> Lucio Coelho
>
> From: "Al Globus"
> To:
> Sent: Wednesday, August 28, 2002 4:57 PM
> Subject: Re: Fw: [spacesettlers] Plant Nursery In Space?
>
> (...)
> > While this may be true, it's not necessarily the case. Consider
> > Biosphere II. They designed this extremely complex system with
lots of
> > different organisms and it quickly evolved in all kinds of
unexpected
> > ways -- but it did work. It took over a year to require a
resupply of
> > oxygen (note that running out proves that they did get good
closure).
> > Perhaps all that thinking was unnecessary. Maybe you can just
throw a
> > very wide variety of plants and animals in the system and let it
evolve
> > to something more-or-less stable, and that will be good enough
most of
> > the time.
> >
> > To test this hypothesis I took random clumps of soil, including
some
> > plants and whatever small organisms happened to be there, out of
my
> > backyard and sealed them in a couple of 1-2 quart plastic,
transparent
> > containers. Over a year later, with no care what-so-ever, both
contains
> > still had living grasses in them. While this hardly constitutes
proof,
> > it is indicative, along with the Biosphere II experience, that
simply
> > providing a very wide range of organisms in a closed environment
will