From: utzoo!decvax!cca!REM@MIT-MC@sri-unix
Newsgroups: net.space
Title: closed ecosystems
Article-I.D.: sri-unix.1621
Posted: Thu Jun  3 08:04:43 1982
Received: Fri Jun  4 05:03:31 1982

From: Robert Elton Maas 
After the reported round-1 closed-ecosystem experiment,
I suggest the following plan:

Divide each of the round-1 successful systems in half, resealing one
and conducting a detailed analysis on the other. The main thing to
find out is whether any materials toxic to human life are abundant in
the successful closed ecosystems. Throw out those which are toxic.

For round-2, attempt to construct a large ecosystem containing exactly
what was determined to be in each of the non-toxic successful
ecosystems. Of course some tiny but necessary lifeform will be
omitted, but if the first round-2 experiment with pure materials fails
we can try again with a small amount of natural crud thrown in (i.e.
throw in a small amount of what started the original experiment). With
the system dominated by the analyzed result of the round-1 experment,
but with crud thrown in to supply a seed crop of anything else needed,
I expect each round-2 experiment will stabilize to exactly what the
corresponding round-1 experiment did, rather than jumping to some
other stable mix. This should be verifiable by comparing analysis of
the round-2 results with the correspond round-1 analyses.

Next, I guess we need to perform perturbation tests on the successful
round-2 mixtures. See if we can add a foreign substance and have the
mixture return to its original state after a while. We may find there
are a finite number of stable mixtures, that adding foreign substances
either returns to the same mixture or jumps to another, and we may
find a recipe for jumping a mixture from any existing state to any
desired state.

Hopefully there's at least one stable mixture that has a high ambient
level of oxygen (sufficient for human breathing) and is stable against
moderate amounts of oxygen-removal algae-removal and
human-waste-return. If so, we've solved the space-station problem.

I hope they have funding for additional research!