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Article #6505Biosphere 2 update
From: Taber MacCallum
Date: Sun, 27 Dec 1992 21:18
Date: Sun, 27 Dec 1992 21:18
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10881 bytes
Biosphere update: December 27, 1992 First I need to put a disclaimer in here, my posts are entirely comprised of my biased opinions and do not reflect in any way Space Biospheres Venture (SBV) policies, officials or other crew members. Also nobody else at SBV reads the posts, I write them in my personal free time and they are written for no other reason. I have received many more questions than I can adequately address in the time I have, but the response is great, thanks, sometimes it is a little rough in here. The question of why run Biosphere 2 on ambient light is good and approaches the fundamental question of what does Bio 2 have to do with space colony designs. The decision to make Bio 2 open to direct sunlight or opaque with light pipes or electric light was a big one early in design and centered on economics, science, safety, operation and esthetics. (SBV is a totally private, tax paying company.) Making an opaque structure is cheaper and required no technology development to make air tight. But the operating cost of electric lights plus the tremendous added heat load was far to much. Remember that heat removal in a vacuum or near vacuum is already a big problem and energy generation in the amounts required to grow plants using grow lights is problematic. As it is, heat removal is our biggest energy demand and the largest single operating cost. The heating/cooling/dehumidification and filtering system for the air handles a volume equivalent to the biosphere every 1.5 minutes. A disadvantage of glass is that if the cooling system failed during a summers day, the biosphere would over heat in under 20 minutes. Light pipes depend on the sun as well and cost too much. Science comes to the rescue, one of the biggest questions was what are the stability characteristics of a closed ecological system and how are they effected by changes in the systems energy flux, so lets tackle this problem right off the bat. Biosphere would be MUCH easier to operate if the light input was high and constant, it was a trade off. As it is, we are operating on greatly reduced light because the structure blocks out 60% of the photo-active energy. The diurnal and seasonal oscillations in light provide one of the most interesting opportunities to study the system. Also visitors currently provide our main means of attempting to pay for operating Bio 2 and if it was not possible to see in from all around, it would stifle tourism. Now people can go right up to the glass and wave at us. And yes, as needed, a team of window cleaners go around the outside, dirty glass can reduce the light transmission by 10 to 20 % very quickly. Inside we only need to do the bottom two or three sections of glass in specific areas. It is probably worth giving some perspective to Biosphere 2 and why it is designed the way it is. Bio 2 is in a way analogous to the Delta Clipper - X, it needs to fly after it is built or we don't learn nearly as much and it is hard to get the money back on a total flop. When we started the project in '85, I always had to spell "Biosphere" to people on the phone and people said "what's that?" now it is a very common word. No closed ecological systems or even partially-closed ecological systems that included humans had ever even been seriously paper studied in the west, much less attempted. The BIOS projects in Siberia were mostly roomers and no hard data was available. The projects culminating with BIOS 3, were comparatively simple, only partially-closed and had some serious nutrient cycling problems. Our approach was to take functioning ecosystems as analogs and use them as the building blocks of a total system. Thus the seven biomes, an atmosphere, a lithosphere, a water system or hydrosphere, an information/data and control system and an energy source are the very basic components of Biosphere 2, analogous to the Earth. The name Biosphere 2 comes from the idea that it is based on the Earth or Biosphere 1. The agriculture is operated to maximize food production which dictates how it is operated, allowing very little flexibility to make adjustments for changing atmospheric or energy conditions. The wilderness biomes have different seasonallity, life strategies, dominant metabolic pathways etc. which give us allot of flexibility in managing Bio 2. The desert and Savannah are especially flexible because dormancy can be controlled by temperature, humidity and rainfall, allowing us to bring them into production as needed. We are trying to learn by doing, we are going to come out at the end of the first test flight with allot of questions and a few answers to problems created by the things we did wrong. In a way it is a proof-of-concept, that complex systems can be scaled down dramatically and still work. This top down approach to stability is in contrast to the idea that stability is found in simple systems constructed from the bottom up, individual species by species which is closer to the NASA approach. Both ways of looking at system designs are very valid, even though unfortunately sometimes people fall into separate camps and look askance at each other. There is allot of cross fertilization and ultimately the best system will be dictated by the circumstances and probably be a mix of the two ideas. One of Biosphere 2's strongest and weakest points, like the space shuttle, is that it attempts to do many things and in the process does nothing as well as it could if it had only one task. Space is by no means the only reason for Biosphere 2 and in many peoples thoughts it is a very minor application. With regard to space I hope to come out with new perspectives on long term space travel and topics including soil nutrient cycles, atmospheric chemistry, mission control inside and outside, food production, human group dynamics, human medical requirements, data acquisition and control, maintenance and operation of associated technical systems and waste recycling. The many functions Biosphere 2 tries and needs to fulfill are often in conflict with each other, these functions include ecological research on a global and biome scale, medical research, profit, education, genetics of small populations, marine system research, restoration ecology, food web studies, agriculture, analytical chemistry and spin-offs from engineering, technology and computer system development especially in modeling. The Biosphere 2 project came under allot of pressure to do ecological research even before the first two year test had even began. Note that much research was done just to design Biosphere 2. This happened faster than I and many other people thought, we were still in design and construction when the media began asking about our scientific credibility. To facilitate the research our scientific review committee (which we had from the very beginning) recommend among many other things, in a report made after closure, that we hire a Director of Science. The report is on the whole very good. Candidates for the position are being interviewed now and hopefully a selection will be made by end of January. For background reading, two recent articles have come out in the popular literature that are good, The current issue of Whole Earth Review is excellent and a recent Buzzworm article is supposedly "more investigative" but they badly blunder many facts they could have easily checked, plus a biased slant was put on the article due to PR problems, as well as the article, Buzzworm carries a regular article by Linda Leigh, another crew member. Also papers were given at the last cospar meeting, the proceedings from which should be out soon. If we wanted to hide what we were doing, we would not have built Biosphere 2 out of glass and invited people to see. The computer data acquisition, control and communication systems are problematic especially due to software limitations. One of the main tools for modeling and control is the General Symbolic "G2" expert system. We use a distributed broad-band network of 9000 series Hewlett Packard computers and Sun systems running UX. Each of which control specific areas of the biosphere using HP 48K I/O systems and independent programmable controllers run by the computer system. These systems communicate with dedicated monitoring, data base and supervisory computers forming a multi level, distributed system. Reliability of the system is great because when problems occur the system falls back to the next lower level. A PC ether network is bridged to the UX system and fulfills functions like mail, fax, word processing, etc.. Communication and tele-conferencing is also facilitated with video in and out, picture-tell, video phones, voice mail, private phone lines and meetings at the glass with an intercom. I'll get to the questions on Medical, Hygiene, Insects, CO2 Recycler and Analytical Chemistry in future posts. A few tidbits, we are now relying heavily on stored animal fodder from the summer to maintain goat milk production because the low light has reduced plant growth. Egg production has stopped because the chickens are molting. Recent cloudy weather has forced us to put more CO2 into storage for release in the spring. High CO2 brings the pH of the ocean to dangerously low levels. Without the ocean we could go to much higher CO2 levels. The current average CO2 level is 3700 ppm, oxygen is now at 14.8%. Living at an equivalent pO2 of approximately 13,000 feet or 96 mmHg has a definite effect on crew performance, especially in limiting physical exertion and disrupting sleep patterns in some crew members. The drug Diamox and/or concentrated oxygen at low flow rates during sleep helps relieve the problems in some crew members. We have not yet seen any marked signs of adaptation to the lowered pO2 in the physical exams or blood tests. The holidays have brought more feasting and we have all put on 1 to 2 Kg of weight! Cheers and a Happy New Year from Biosphere 2! Taber MacCallum
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Newsgroups: sci.space Path: arc1-ca.pugleaf.net!sparky!uunet!zaphod.mps.ohio-state.edu!wupost!udel!rochester!cantaloupe.srv.cs.cmu.edu!crabapple.srv.cs.cmu.edu!tmaccallum@igc.apc.org From: tmaccallum@igc.apc.org (Taber MacCallum) Subject: Biosphere 2 update Message-ID: <BzxsJG.3rD.1@cs.cmu.edu> X-Added: Forwarded by Space Digest Sender: news+@cs.cmu.edu Organization: [via International Space University] Original-Sender: isu@VACATION.VENARI.CS.CMU.EDU Distribution: sci Date: Sun, 27 Dec 1992 21:18:09 GMT Approved: bboard-news_gateway Lines: 204