Re: SPACE: How hard IS it to get off Earth?

Eric Watt Forste (
Mon, 15 Nov 1999 11:39:07 -0800

Billy Brown writes:
> Agricultural production requires only that we successfully grow a
> few dozen plant species in an environment where temperature, light
> levels and atmosphere composition are all subject to direct external
> control. This will, of course, require that we support a small
> variety of insects and microorganisms that are essential to the
> survival of said plants, but you don't need a complete ecosystem.
> As long as you can maintain the system in a stable state with a
> reasonable amount of human intervention you're in good shape.

Again, if it's going to be functioning in space, with a closed boundary, with living organisms in it, then it *is* a complete ecosystem. The question is not whether or not you need a complete ecosystem, the question is whether the ecosystem you construct will flourish or die.

The system you describe, a closed system with just a few species, has actually been attempted in early closure experiments. It proved, empirically, unstable. So I don't know why you feel that we already know how to do this when past attempts to do so have failed.

> The "Biosphere" approach, in contrast, requires that you create a
> completely self-sustaining ecology. You end up with at least an
> order of magnitude increase in the number of species involved, lots
> of extra biomass, and an unmanageable mess of interlocking feedback
> loops that are almost impossible to manage. Making it work at all
> will be far more difficult than in the agriculture approach, and
> making it produce food with any reasonable efficiency will be nearly
> impossible.

Perhaps you should familiarize yourself with the history of the research. The early closures all *failed* at some point and had to be opened. The current complex approach which you dismiss developed in response to an exploration of those failures and successful attempts to remedy them.

You are welcome to go into space with just a few species and die after six months or so, but I have other plans.