Monday, March 17, 2008

Habitats

I was recognized as quite the knurd when I was still quite young, though no one used that word where I grew up. The word for us back then was “brain” or “smart aleck” (later “smart ass”). It was generally assumed that I was interested in space, the space program, and rockets.

As nearly as I can tell, I may be the only person in my cohort who was never interested in blowing things up, and that included rocketry in general. Even in my interest in nuclear physics (which I later learned was actually nuclear chemistry and nuclear engineering), I was more interested in reactors than bombs. As for rocketry, I picked it up the way I learned country music. When it’s what everyone around you talks about, you learn some of it.

I was interested in astronomy, however, and I have always liked the deep space probe findings. I just was not that interested in how to get the probes to where they were going. Similarly, I did have an interest in some of the things that would go along with space colonization. To that end, one of the earliest things I ever tried to do with my trusty chemistry set was to grow some plants hydroponically. My effort met with dismal failure; I found out very quickly about root rot and the perils of constant immersion on several kinds of plants, including potatoes. To this day, the only plants I’ve ever grown have been in soil.

Nevertheless, I persisted in my interests; one of the attractions of the field of environmental modeling, in fact, was the notion that it would be possible to use such engineering tools to analyze and perhaps design, self-contained ecologies. It was in all the space novels, right?

But the whole thing seemed to be moving so slowly. A guy I lived with for a year after I first moved to Berkeley, Steve Ellner, is now a professor of biomathematics at Cornell, and one of his ongoing projects is a system of connected pools with water flowing through the system. His research team uses the setup to examine some basic ideas about ecosystem stability. And I mean really basic things like the onset of chaotic behavior and limit cycles, things that should have been studied thirty years ago.

There was a NASA program called CELSS, Contained Environment Life Support Systems. It was supposed to address the question of long term life support environments for manned deep space missions, like a Mars mission, or a Moon base. They gave up on doing something like it for the Space Station, because it turns out to be a lot easier and cheaper just to supply things from Earth, but the farther out you get, the more the economics change. But, as nearly as I can tell, the CELSS program was cancelled a few years ago. I say “as nearly as I can tell” because there doesn’t seem to be a lot of information about the program cancellation, just a cessation of work. It’s as if it just died a lingering death through disinterest.

Then there is the case of Biosphere II. On the inevitable convention panel, I once heard a supposedly knowledgeable person explain that it failed because “as any engineer can tell you” concrete oxidizes as it hardens, and that sucked oxygen out of the air. So the Biosphere II designers were just stupid, you see. Anyone with any sense (like the speaker, I daresay) could have gotten it to work.

In fact, concrete does not “oxidize.” It does absorb carbon dioxide, however, and that was actually beneficial to the folks in Biosphere II. Because they’d put in a lot of soils that were high in organic matter, and the soil bacteria oxidized the organic matter to CO2. If there had been no concrete, they’d have had to put in CO2 scrubbers, because there was no way the plants in BII could have absorbed all the CO2, and CO2 is a toxic gas, lethal at above 5% concentration.

The real problem with Biosphere II is that it had never been done before. Things that have never been done before don’t always turn out to be easy; sometimes they’re downright difficult, and occasionally they are outright impossible.

I don’t think that self-contained habitats are impossible. After all, we live in one such habitat; it just happens to be really, really big. What we don’t know is how small one can make a habitat, and how much control you have to put on it to make it small. And when I say we don’t know, I mean that no one has any idea. None. Because, as I just said, no one has ever done it.

In my experience, people who want to colonize space are of the belief that habitats are the easy part; they spend all their imagination on new and spiffy ways to get into space and none on how anyone is going to live there. But if we could make self-contained habitats, they would have enormous benefits for living here on Earth. We could put people into deserts, rain forests, glaciers, swamps, under the ocean, anywhere, without running the risk of destroying the local ecology. Such a technology could be of enormous benefit. And once we have it perfected, then moving people into space becomes a much easier task, if they really want to move into space, as opposed to just leaving the Earth because we’ve made such a mess of it.

2 comments:

Anonymous said...

uh-maz-ing

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