ognizant Communication Corporation


VOLUME 7, NUMBER 1 (Abs 63-121), 2000

Life Support & Biosphere Science, Vol. 7, pp. 84-141, 2000
1069-9422/00 $20.00 + .00
Copyright © 2000 Cognizant Comm. Corp.
Printed in the USA. All rights reserved.

Note: Volume 7, Number 1 is a special abstract issue from the 4th International Conference on Life Support and Biosphere Science held in Baltimore, Maryland, August 6-9, 2000. Abstracts were presented in the following areas:

FPS 63, Page 84

A Comparison of Peroxide Values and Sensory Evaluation (Aroma) of Seven Aqueous Extracted Peanut Oil and a Commercial Peanut Oil

C. Cathings and R. Pace

Tuskegee University.

Little information exists on the stability of aqueous extracted peanut oil (AEPO) and the effect of the peanut skin and heat treatment. The purpose of this study was to examine peroxide values (PV) and sensory values (aroma) of six AEPOs from peanuts extracted with and without skin and three levels of heat treatments. The treated AEPOs were evaluated and compared to Tuskegee University hydroponic peanut oil (TUH) extracted from hydroponic peanuts (blanch-roasted with skin) and commercial Sessions peanut oil (SPO). It is also important to mention the SPO had antioxidant addition for stability purposes. The oils were stored at 55(C during the evaluation period. The peroxide values (PV) were taken twice a day for five days and once on days 9 and 12. The PV of the TUH and SPO were not significantly different (P<0.05); however, there was a SD (P<0.05) between the raw without skin oil (RWO) and the BRTS on all but the first day. The SPO, TUH, BRTS and the raw with skin oils (RWS) was slightly rancid (SR) on day 12 and all other oils were moderately rancid (MR). The sensory evaluation was conducted once a day in tandem with the PV. A scale was developed to compare the values of sensory with those of PV analysis. The aroma values were not significantly different (P<0.05). The aroma values were MR for all oils on day 12. In conclusion, BRTS and TUH were comparable to SPO in both sensory and peroxide values.

FPS 64, Page 85

Development of a 'Gourmet' Menu Items for Long-Term Manned Space Missions in an ALSS Environment

Christopher M. Gregson and Tung-Ching Lee

Department of Food Science, the Center for Advanced Food Technology and NJ-NSCORT.
Rutgers University
63 Dudley Road
New Brunswick, New Jersey 08901, U.S.A.

The quality of food in an Advanced Life Support System (ALSS) environment, especially on long-term space missions, is of major importance. In this psychologically stressful environment food-fatigue and nutrition are important considerations. As the diet must be based almost entirely on a small number of food crops and processing methods, devising desirable diets is challenging. The objective of this work was to produce 'gourmet' menu items using as few ingredients that cannot be produced from the ALSS crops as possible.

A novel approach was used in this work by combining the techniques available from food science and approaches taken in the culinary arts. An initial study was made of the foods producible using the limited resources. Through nutritional tables, primary physical descriptors (color, texture etc.), professional culinary experience and knowledge of traditional food combination conventions, menu items were devised. These were assessed in terms of preparation time, level of skill required, practicality within the ALSS system and gastronomic quality.

Suitable menu items can be devised using only the available resources with a small number of additions, e.g. salt. Flavoring ingredients, sweeteners and a small number of processing aids that cannot be made from the ALSS crops are essential to improve variety but must be transported from earth. The problems faced in providing a quality diet and ways in which solutions can be implemented by the astronauts are discussed by focusing in on particular examples.

Whereas most previous studies have concentrated on the nutritional and practical aspects of food preparation within an ALSS environment, this study has shown that by combining knowledge from the culinary arts and food science, the quality of food provision can be significantly improved. The approach used in this study could be used to provide high-quality foods for diets from limited ingredients (e.g. vegetarian) on earth.

FPS 65, Page 86

Control of Food Safety Hazards During Food Processing and Storage in the Bio-Plex

Dawn L. Hentges

School of Family and Consumer Sciences
Bowling Green State University
Bowling Green, Ohio 43403

The food system, being designed for Advanced Life Support (ALS) on long duration space missions, is a plant-based diet which requires most of the food to be grown, processed, and prepared in the BIO-Plex (Bioregenerative Planetary Life Support Systems Test Complex). Conversion of crops to edible foods will require extensive food processing within the Interconnecting Transfer Tunnel of the closed environment of the habitat.

Since all consumables in the BIO-Plex will be recycled and reused, food safety is a primary concern. Biological, chemical, and physical hazards, which may occur in the proposed BIO-Plex food system, were identified.

Procedures for controlling these food safety hazards were suggested in consideration of the limitations and restraints of the closed system for facility design, food storage, use and location of multifunctional equipment, possible concentration of toxic volatiles, and sanitation during food processing to prevent cross-contamination and ensure safety. These recommendations were based on: a) observation of ALS crop production and

The BIO-Plex facility at the Johnson Space Center, b) review of proposed ALS food processing protocols, c) use of a Hazard Analysis Critical Control Point (HACCP) approach, d) NASA/JSC BIO-Plex Food System Level 2.5 Requirements, e) Consideration of ergonomics and work efficiency, f) Good Manufacturing Practices, and g) the 1999 FDA Food Code.

FPS 66, Page 87

Process Development for Single-Cell Oil Production from Inedible Biomass

Jean B. Hunter1, Cheryl J. Greenwalt2, and Michael Howeler3

1Agricultural and Biological Engineering Department, Cornell University
2Kraft Foods, Evanston, IL
3Agricultural and Biological Engineering Department, Cornell University

The relatively low productivity of oilseed crops relative to tubers and grains in hydroponic culture poses an economic barrier to production of refined higher plant oils in a bioregenerative life support system. Equivalent system-mass cost analysis indicates that soy and peanut oils will cost 6.5 - 12 times the trade cost of terrestrially produced oils; more if the defatted residue cannot be utilized in a crew diet already rich in protein and carbohydrates. A renewable alternative to higher plant lipids is single-cell oil (SCO), triglycerides accumulated as carbon storage products by certain yeasts and algae under nitrogen limitation. The oleaginous yeast Cryptococcus curvatus produces a 17% yield of SCO on sugars and 11% on ethanol in a 72-hour batch fermentation. The resulting oil has a fatty acid distribution similar to palm oil or lard and is rich in tocopherols.

This presentation will compare SCO biosynthesis on two substrates: mixed biomass hydrolysate sugars and ethanol from a Fischer-Tropsch process proposed for ISRU propellant production. Media optimization, scaleup to a 15-L bioreactor, and ESM cost analysis for both substrates will also be presented.

FPS 67, Page 88

Artificial Gut Bioassay System: Influence of Ascorbic Acid on the Bio-Availability of Iron from Hydroponic Spinach Using Human Caco-2 Cell Line

Corinne F. Johnson, Raymond P. Glahn, Gerald F. Combs, Ross M. Welch, Raymond M. Wheeler, and Robert W. Langhans

Controlled Environment Agriculture
Department of Floriculture and Ornamental Horticulture
Cornell University
Ithaca, New York 14853

Spinach, Spinacia oleracea, is among the NASA ALS crops selected to enhance variety in the diet for astronaut crews on the International Space Station, Lunar, and Martian bases. Astronaut crews have presented with reduced red blood cell counts after space flight, suggesting that dietary iron loads should be similarly reduced to avoid iron-overloading. Concerns regarding spinach as a source of excessive dietary iron may be unfounded, as spinach is actually a poor source of bio-available iron in ground studies. Hydroponic spinach (cv. Whitney) was produced using Controlled Environment Agriculture (CEA) techniques. Pre-harvest light quality treatments of cool white fluorescent, and fluorescent supplemented with light from either red or far-red light-emitting diodes were compared for influence on iron bioavailability to humans. Influence of addition of ascorbic acid during in vitro digestion was also examined. Freeze dried spinach was digested in vitro using pH conditions similar to peptic environment with pepsin enzyme. Digests with and without supplemental ascorbic acid were prepared. Alteration of pH to intestinal levels and addition of a pancreatin and bile solution further simulated peptic digestion. The spinach digests were pipetted onto sterile dialysis membrane inserts that allowed solubilized iron to pass through to the human Caco-2 cell culture below. Monolayers of human Caco-2 cells cultured on a nutrient media were exposed to the in vitro preparations of spinach digests for 24 hours. The iron-storage protein, ferritin, is produced in intestinal cells at levels proportional to iron availability. Cells were harvested and ferritin was assayed using standard radio-immuno assay techniques. Iron bioavailability was low in all treatments. Pre-harvest light quality had no influence on iron bioavailability however addition of ascorbic acid to the digests significantly increased iron bioavailability of the hydroponic spinach.

FPS 68, Page 89

Description of an Extruder for a Mars Mission

Jozef L Kokini and Muthukumar Dhanasekharan

Department of Food Science, Rutgers University
New Brunswick, NJ 08901

The needs for extrusion in space are very different than extruders on earth. Extruders in Mars must be small, flexible and built with light and tough materials. They must also be optimal in terms of energy consumption. We need the extruder to to be not only as a regular extruder, but also as, a grinder, a mixer, ice-cream maker and an oil expeller. We anticipate that the extruder will be modular in nature and would be able to operate at a temp range from -20° C to 200° C and will have a temperature control system which is accurate in all of these temps. We would like to be able to manufacture breakfast cereals, snacks, licorice, peanut butter, tomato paste, candy, thin-cut snacks like potato chips and meat and chicken analogs leading to products like beef jerky. We also want to manufacture oil from soy and peanuts. To accomplish these objectives we expect that the barrel and the screw elements will need to be modular in nature and we expect to have rotary dyes. It must be able to operate at a temperature range from -20° C to 200° C and will have a temperature control system, which is accurate in all of these temperatures. We also need the extruder to be interchangeably single screw extruder or a twin screw co-rotating/ counter-rotating extruder. A "clampshell" design will be useful in saving space requirements for dismantling the extruder. Different designs must also be considered for ease of automation such as the use of robotics technology to change screw configurations. We need the gear drive and motor to be manufactured from light materials and control system to be as low weight as possible. Another requirement would certainly be ease of operation because the astronauts are not expected to be food technologists. This can be accomplished by creating a database system with the different operating conditions and screw configurations for the various food products. Also an expert system could be used in troubleshooting extrusion problems.

FPS 69, Page 90

Acceptability of Near-Vegan ALS Foods in a 30-Day Diet Study

David Levitsky, Rupert Spies, Adriana P. Rovers, Ammar Olabi, and Jean B. Hunter

Division of Nutritional Sciences, Cornell University

In order to evaluate the quality and system mass costs of plant based diets intended for bioregenerative life support systems, 225 foods based on ALS crops have been developed and tested for acceptability by panels of omnivores aged 30-55 years. Nearly all scored above 6 on a 9-point hedonic scale and the average acceptability was 6.9. The foods included breakfast items, salads, entrees, side dishes, beverages, desserts, soups and snacks.

A subset of the above foods was re-tested in a short-term closed diet study . Sixteen free-living subjects, 9 women and 7 men from the earlier taste panel, consumed only foods provided by the study for a period of 30 days. The study was divided into three 10-day segments. In each segment the same foods were presented, but in different order. Subjects ate weekday breakfasts and lunches at the study site and carried away snacks and their weekend and evening meals, returning all leftovers to the study site.

An individual's satisfaction with a diet depends on the acceptability of the foods in the diet, the subject's degree of adaptation to the diet, the degree of personal food choice allowed, the variety of foods in the diet, and sensory fatigue or boredom with individual foods. Our hypothesis was that subjects dissatisfied with the diet would reduce their food intake, find individual foods less acceptable, experience more negative mood states, and feel tempted to cheat on the diet.

Subjects' food intake was measured by weighing individual food dishes before and after meals. Energy intake was extrapolated from these measurements. Subjects rated each food for acceptability on a 9 point scale at each presentation. They were weighed 5x/week. The Profile of Mood Scores test was administered at intervals before, during and after the study. An exit interview with each subject covered dietary infractions and changes in physical activity, among other issues.

This presentation will cover preliminary results of the study, and their significance to the BIO-Plex food system. The study has not been completed as of the abstract deadline.

FPS 70, Page 91

Comparison of Nutrient Uptake in Raphanus sativus with Recommended Dietary Allowance

Sabrina Maxwell1 and Leah Holt Grange

1The Boeing Co.

The development of a bioregenerative diet may lower the costs of long duration space missions such as a Lunar or Mars base, and may provide an improved diet for the crew of International Space Station (ISS) missions. One of the challenges for developing a bioregenerative diet with a high degree of food closure (>50%) is the supply of nutrients required by both plants and humans. Some elements that are necessary to sustain crew health, are not required for plant health, and therefore may not be taken up by plants. Some of these elements can even be toxic to plants at high enough levels. It is the focus of this research to determine if plants will uptake elements not needed for plant nutrition. Further, to what extent that uptake will provide for the Recommended Dietary Allowance (RDA), as established by the United States Department of Agriculture (USDA) and as part of a bioregenerative diet as identified by the National Aeronautics and Space Administration (NASA) Advanced Life Support community.

This project is the first in a two part extended study. During this phase of the study, a hydroponic system was designed to provide a continuous feed of nutrient solution to the plants. Two nutrient solutions were prepared, one using an aqueous leaching technique of composted waste material, and a commercial nutrient as a control. Analysis of the nutrient uptake by radish was conducted by ICP-ES and Total Kjadahl Nitrogen (TKN) analysis for both the experimental nutrient solution, and the commercial nutrient solution. These results were analyzed to determine the degree to which the experimental solution provided for nutrient delivery as compared to the commercial solution, and the USDA values for radish. The resulting nutrient analysis was then used to calculate the percentage of the RDA this crop would provide as part of a bioregenerative diet.

FPS 71, Pages 92-93

Lycopene Retention in Tomato-Based Food Products Designed for Long-Term Space Missions

Catalin Moraru and Tung-Ching Lee

Department of Food Science, the Center for Advanced Food Technology and NJ-NSCORT
Rutgers University

JUSTIFICATION: Tomato is one of the main crops selected for growth and processing during the long-term space missions, due to the high acceptance and health benefits. Lycopene, the major carotenoid in tomato serves as an important antioxidant to protect against oxidative and photo-oxidative damage of foods as well as maintaining a good health status of humans. This is extremely valuable during the long-term space missions as antioxidant protection is essential. However, during the production of tomato-based foods, the lycopene losses due to breakdown and/or isomerization are not well documented.

OBJECTIVES: This study aimed to determine to what extent the lycopene would isomerize or breakdown in tomato based products (e.g., tomato sauce, paste, jam, pasta, or extruded foods) designed for space missions

METHODS: Hydroponically grown tomatoes were used to manufacture tomato sauce, paste and jam. The tomato paste was further used, together with rice flour, to manufacture pasta and expanded products in a lab-scale single screw extruder. Different lycopene concentrations and processing parameters were evaluated. HPLC quantification method for lycopene was used to discriminate and quantify between the natural lycopene (all-trans) and its cis isomers in tomato based products.

RESULTS: Various degrees of losses in the lycopene content were found in the processed tomato based products. Result confirmed that the losses were due to both the isomerization of the natural, all-trans lycopene into forms having one or several cis double bonds and by lycopene breakdown. Processing methods and their parameters played major roles in lycopene retention.

SIGNIFICANCE: This study confirmed that lycopene retention in tomato-based products is affected by both breakdown and isomerization. This is important since the cis isomers are less effective as an antioxidant. Our findings can be used to select the processing parameters for optimizing the preservative and health effects of lycopene in tomato-based products.

Tomato is one of the main crops selected for growth and processing during the long-term space missions, due to the high acceptance and health benefits. Lycopene, the major carotenoid in tomato serves as an important antioxidant to protect against oxidative and photo-oxidative damage of foods as well as maintaining a good health status of humans. This is extremely valuable during the long-term space missions as antioxidant protection is essential. However, during the production of tomato-based foods, the lycopene losses due to breakdown and/or isomerization are not well documented. This study aimed to determine to what extent the lycopene would isomerize or breakdown in tomato based products (e.g., tomato sauce, paste, jam, pasta, or extruded foods) designed for space missions Hydroponically grown tomatoes were used to manufacture tomato sauce, paste and jam. The tomato paste was further used, together with rice flour, to manufacture pasta and expanded products in a lab-scale single screw extruder. Different lycopene concentrations and processing parameters were evaluated. HPLC quantification method for lycopene was used to discriminate and quantify between the natural lycopene (all-trans) and its cis isomers in tomato based products. Various degrees of losses in the lycopene content were found in the processed tomato based products. Result confirmed that the losses were due to both the isomerization of the natural, all-trans lycopene into forms having one or several cis double bonds and by lycopene breakdown. Processing methods and their parameters played major roles in lycopene retention. This study confirmed that lycopene retention in tomato-based products is affected by both breakdown and isomerization. This is important since the cis isomers are less effective as an antioxidant. Our findings can be used to select the processing parameters for optimizing the preservative and health effects of lycopene in tomato-based products.

FPS 72, Page 94

Development of a Ten-Day Cycle Menu for Advanced Life Support

Katherine A. Ruminsky and Dawn L. Hentges

Bowling Green State University
School of Family and Consumer Sciences
Bowling Green, Ohio 43403

The Advanced Life Support (ALS) program at NASA-Johnson Space Center was initiated for use in long duration space missions. ALS is a human life support system, which will use physiochemical and biological processes to regenerate and recover oxygen, food, and water. With weight and volume restrictions and prolonged periods between resupply from earth, as much as 90 percent of the energy requirements must come from food grown, processed, and prepared in space. ALS involves the use of hydroponically grown crops to supply and regenerate air and food for the crew. The baseline crop list includes potato, sweet potato, brown rice, wheat, peanut, soybean, lettuce, tomato, carrot, chard, radish, spinach, green onion, and dry beans (pinto and lentil). Selected crops were considered based upon their ability to produce maximum edible biomass, to maximize space and light (artificial), as well as upon the nutrients that they can produce. A ten-day cycle menu has been developed consisting of items prepared from the baseline crop list. Of the recipes created for the menu, resupply items contributed only 4.54% by weight and 9.18% of the total calories. The menu has been analyzed to conform to the baseline crop list and Recommended Dietary Allowances (RDAs) of nutrients for long duration space missions.

FPS 73, Page 95

A Dynamic Menu Selection Model for The Optimization of Bioregenerative Diets

Carrie Vicens, Carolyn Wang, Ammar Olabi, Jean Hunter, and Peter Jackson

School of Operations Research and Industrial Engineering
Cornell University

Previous research on bioregenerative life-support space diets led to the development of a linear program that optimizes a cyclical menu for an astronaut crew. Although this minimum cost diet program meets basic nutritional and acceptability requirements, it lacks direct input from the astronauts relating to their meal preferences. This situation is contrary to shuttle mission policy where astronauts choose their preferred foods before the mission. The dynamic selection model described in this paper enhances the original model by allowing the astronauts to directly choose a portion of their menu. In addition, the new model improves upon the method of tracking the number of servings of each meal category.

In order to test the model's performance under extreme conditions, the model was run on a variety of specific sets of potential astronaut preferences. Four cases were adopted in the choice component of the diet: foods high in sodium, high acceptability foods, a large number of desserts, and random sets of foods. The results demonstrate that nearly all these preference sets will result in feasible solutions at varying, but mostly reasonable, costs. Therefore, the new dynamic menu selection model can realistically provide for increased flexibility in menu selection for astronaut crews.

FPS 74, Page 96

Sweet potato Bread for BIO-Plex: Effect of Crop Storage Time on Bread Functionality

Elena Vittadini and Yael Vodovotz

Conrad N. Hilton College of Hotel and Restaurant Management
University of Houston
Houston, TX 77204

Sweet potato has been designated a baseline crop for Advanced Life Support and specifically, to be grown in the BIO-Plex at NASA's Johnson Space Center. Due to the infrequent harvest of the sweet potatoes during an extended crewed test, the raw crops will need to be stored for various lengths of time prior to food processing. Sweet potatoes were grown hydroponically and harvested after days. The canner sweet potatoes were stored at 65 C and 80% relative humidity for 0-6 months. Moisture content of the raw sweet potato decreased with storage time. Sweet potato bread was baked in an automated bread machine and cooled for one hour prior to testing. Texture, water activity and sensory analysis were measured for each sample and compared. Results will be discussed taking into consideration the changes in sweet potatoes composition.

HF 76, Page 97

The Human System as a Primary Driver in Long-Duration Vehicle Architecture

Constance M. Adams and M.Arch., RA

Space Architect, Lockheed Martin Human Factors / TransHab Project;
NASA-Johnson Space Center
Mail Code EX-14
Houston TX 77058
Tel. 281.483.4137
E-mail: cmadams@ems.jsc.nasa.gov

Thus far, the history of design of human-rated space vehicles has been driven by the process of risk mitigation in the engineering of craft capable of sustaining life during launch, on-orbit and landing operations. In pursuing the relentless reduction of risk factors inherent in an undertaking of this scale and complexity, the field of spacecraft engineering has set new standards in research, analysis and quality control in all subsystems. As human occupation of space or off-planet environments lengthens, however, the reduction of mechanical or structural risk is no longer sufficient to ensure the safety and productivity of space missions.

Given the maturity of space vehicle engineering, the greatest risk remaining in long-duration spaceflight is in the human system. Crew health, well-being, productivity and safety-and mission success-now must contend with threats that are not only external but internal as well, as the ability of the human to continue performing well over an extended period of time becomes a major factor in the overall mission scenario. How can spacecraft be optimized for support of their human crew? This is the risk-reduction task which stands now on the critical path for space exploration. "Design-to" and "build-to" requirements for complex, in-depth human engineering in advanced vehicles are badly needed, and studies need to be initiated which can both drive those requirements and help set new standards for reduction of human-system risks in space. Our goal in this colloquium is to identify the primary targets for this effort.

HF 77, Page 98

Biomedical Aspects Of Early Mars Expeditions

John B. Charles, Ph.D.

NASA Johnson Space Center
Mail Code SF2
Houston, TX USA 77058
Phone: 281-483-7224
Fax:  281-483-6636
E-mail: John.b.charles1@jsc.nasa.gov

This paper will describe the current planning for exploration-class missions, emphasizing the medical and human factors aspects of such expeditions. The details of mission architecture are still under study, but a typical Mars design reference mission comprises a six-month transit from Earth to Mars, eighteen months in residence on Mars, and a six-month transit back to Earth. Physiological stressors will include environmental factors such as prolonged exposure to radiation, weightlessness in transit, and hypogravity and a toxic atmosphere while on Mars. Psychological stressors will include remoteness from Earth, confinement, and potential interpersonal conflicts, all complicated by circadian alterations. Medical risks including trauma must also be considered. Results of planning for assuring human health and performance will be presented.

HF 78, Page 99

A Fatigue Management System for Long Duration Space Flight

Jon French, Kelly Neville and Douglas Eddy

Air Force Research Laboratory
Brooks AFB, TX 78235

NASA has need of a rapid, reliable and non-invasive means to objectively evaluate the physical and cognitive capability of astronauts about to perform demanding missions, particularly during extended duration space flight. Once such means under consideration by JSC is the Space flight-Cognitive Assessment Tool (S-CAT), which is designed to assess cognitive performance following a wide variety of neurological stressors using a set of five cognitive performance tests. The current study evaluated the sensitivity of S-CAT to one of the pre-dominant stressors facing astronauts, fatigue induced by sleep deprivation and circadian disruption. The recuperative effects of short (2 or 4 hour) naps on performance also were examined. Two groups of eight US military pilots (ages 30-40) participated in this study of the performance effects of 46 hrs of sleep deprivation - a period that extended over two circadian performance nadirs. In addition to S-CAT, four performance tests typically used in fatigue research were performed repetitively during the sleep deprivation period. The S-CAT battery of tasks was performed every six hours up to the 36th hour of sleep deprivation. For all tests, the greatest effects were seen on response time data. One of the five S-CAT tests, the Math Reasoning test, exhibited significant fatigue-related decrements on the last 3 of the 6 trials, following 23 hrs of wakefulness. Two other tests, Continuous Processing and Matching to Sample, showed significant decrements on 2 of the trials, after 23 and 29 hours awake. It is likely that S-CAT will identify astronauts too fatigued to optimally perform sensitive missions. Future studies plan to evaluate S-CAT sensitivity to other stressors that could impair performance. A fatigue management system for long duration space flight is described that considers actigraphically monitored sleep quality and quantity, S-CAT performance and attenuated, strategic naps prior to mission critical events.

HF 79, Page 100

Human Considerations in the Design of Closed Environmental Systems

Ephimia Morphew1, Jennifer Novak2, Danielle Balmer1, Terry Ballard1, Kieran Smart1, and Jason Kring1

1Johnson Engineering/Johnson Space Center, Houston, TX 77058, emorphew@ems.jsc.nasa.gov
2National Space Biomedical Research Institute, NASA Johnson Space Center, 2101 NASA Road 1, SF, Houston, TX 77058-3696

While advances in physical, chemical, and bioregenerative life support systems have brought us closer to achieving fully-closed/self-contained environments, operational experience with the Mir, Skylab, Biosphere I & II, and the International Space Station (ISS) programs has furthered our understanding of the complex effects of human-environmental interactions in these systems. Data from Skylab, Mir, and ISS reveal some of the greatest human-in-the-loop challenges facing operations on ISS including habitable volume, stowage, and accommodation of on-orbit useable and non-useable items (trash). Examples of challenges related to these factors include organizing, locating, and identifying stowage items, and the effect of non-standard stowage on the habitable/functional volume of the station (Skylab & Mir). For Instance, experiential data showed that crewmembers demonstrated a natural reluctance to occupy or to pass through a space that is not normally used for such purposes on earth. In other words, they utilized the volume the way humans would in similar compartments on the Earth. Additionally, a lack of sufficient, dedicated and organized attention to stowage volume lead to increased time and effort on behalf of the crew. Such effects demonstrate the ability of habitability factors to affect performance and behavior of space flight crews. These and other data will be reviewed, in addition to corresponding concepts and principles that should be considered in the design of all closed, self-contained, human-supporting environments. The goal is to provide life support scientists, engineers, and designers with an understanding of several design-remediating factors that impact human functioning and performance in these systems.

HF 80, Page 101

Telemedicine in Support of the Remote Operational Environment

Christian Otto, MD

Queen's University Department Family/Emergency Medicine
10 Beagle Court, Kingston, Ontario K7M 6V7, Canada
Home: 613-389-4543
Fax: 613-544-9899
E-mail: caotto@msn.com

Introduction: The remote operational environment may be characterized by isolation, hazardous environmental conditions, and a stressful work routine: factors which increase the likelihood of a medical event. Telemedicine technology offers medical assistance to the remote operational environment without sacrificing infrastructure and manpower restrictions. Several terrestrial models provide insight into the development of space based telemedicine platforms.

Studies like the Baffinnet Telemedicine Project which serves isolated Inuit communities in the Canadian High Arctic provide a clinical benchmark for remote telemedicine services. This project demonstrates the feasibility and effectiveness of delivering health care to sizeable populations in a remote area. A successful transfer of this technology to the Antarctic, a region of even greater isolation and inaccessibility, has occurred. The American, British and Australian Antarctic programs have developed telemedicine services to assist their medical officers in offering extensive medical care including surgical services in an environment where autonomous onsite care is required. Remote telemedicine systems that have been validated in these environments may be further refined in expeditionary settings involving similar isolated or hazardous terrain but with fewer personnel, and defined mission objectives. The Mount McKinley and Mount Logan High Altitude Telemedicine Projects are two studies that have examined weight, volume, power, durability and portability issues in an expeditionary setting, factors that are critical to medical systems designed for space flight.

Telemedicine services will be a future component of the International Space Station's (ISS) Crew Health Care System. This technology will be essential in the successful management of an acute medical emergency which is expected to occur over the lifetime of the ISS. The ISS will also serve as a testing ground for new telemedicine technologies and protocols destined for use in long duration missions to the Moon and Mars.

Conclusion: Telemedicine technology is capable of delivering enhanced health care to the remote operational environment. This technology is being developed in several terrestrial models which represent space analogues and will therefore play a critical role in the transfer of telemedicine technology to the space environment.

HF 81, Page 102

Medical Aspects of Antarctic Experience

Michele E. Raney, M.D.

223 Grand Canal, Balboa Island, CA 92662
Phone/ Fax: (949) 675-7880
E-mail: raney@inetworld.net

Even though the United States has maintained a permanent presence at antarctic research stations for over 40 years, provision of medical care at these remote sites remains challenging. Today, medical care in Antarctica is increasingly divergent from what is readily available in the United States. Resources are constrained; on-site diagnostic and therapeutic modalities and trained medical support staff are frequently limited or non-existent, and consultants, if accessible, may be unfamiliar with the environment and unrealistic in their advice. Thus, the practice of medicine may seem inappropriate or even antiquated, compared to that in a modern medical center, adding to an already frustrating situation. Environmental constraints add to the psychological stresses of confinement and isolation, and regardless of whom is ill or injured, the entire station is affected.

A successful antarctic mission must address a number of health issues. Forty years of international antarctic experience underscore that proper physical and psychological screening of personnel selected for isolated duty is essential. Appropriate physician selection and directed training of all medical personnel is required, and effective means for consultation, evacuation (when permissible), and international cooperation must be outlined. There is a constant need for cross-training of non-medical personnel, and modalities for off-site support through consultation and telemedicine must be continually updated. Finally, the impact of injury, illness, or death on a station's ability to fulfill its research, exploration, and operational goals must be addressed.

In such a harsh physical and psychological environment, medical research has been directed along a number of lines including small group interactions in isolation, psychological well-being, circadian alterations, and hormonal effects. Immunologic changes with isolation have been the focus of several studies, as have the transmission (or prevention of transmission) of infectious diseases. There has been cardiovascular research, primarily related to diet, as well as some limited nutritional studies. Cross cultural studies are in preliminary stages, and retrospective analyses of long term health effects of isolation have been or are being conducted.

In conclusion, the study of human factors during isolation at remote antarctic research stations encompasses numerous operational, interpersonal, and physiological issues.

HF 83, Page 103

Bionomic Design & Biospheres: Quantifying the Human Factors of Habitability

James A. Wise, Ph.D1 and Sheryl Bishop, Ph.D.2

1CEO, Eco*Integrations, Inc., Richland, Washington, & College of Architecture & Landscape Architecture, The University of Minnesota
2University of Texas Medical Branch, Department of Preventive Medicine and Community Health

A growing body of theory and convergent research from evolutionary psychology and externalized cognition suggests connections between sensed structural patterns of the physical work and living environment and the work performance and quality of life experienced by it's occupants. There is a central 'Bionomic-design hypothesis' which proposes that the general spatial and (particularly) fractal structures of benign ancestral human environments still act as a template for perceptual and cognitive processes which share controls of our perception, memory, and emotional management with the physical environment.

In considerable disparate research, positive effects on cognitive performance, group dynamics, workstress, employee job satisfaction, employee productivity, recovery from surgery, and even reduced criminal recidivism have been linked to design elements that analogously or literally recreate environmental features and qualities of savanna environments where the human species evolved. These are proposed to provide the bases for many 'green building benefits' that have been widely reported in workplaces, and for genuine habitability improvements across different isolated and confined environments (ICEs). Occupant exposure to the structure and pattern of preferred natural environments occurs as a common consequence of different design strategies that proceed from both ecological and restorative design philosophies, and prior Human Factors studies.

This paper presentation will: link the research from several specialty fields into a coherent examination of the Bionomic design hypothesis; exam the structural and metric properties of natural landscapes and their fractal patterns; and show how analogous habitability enhancing design can be done in high technology ICEs which often operate under severe engineering constraints. We conclude with the informed speculation that there is a 'general theory of habitability' appropriate to guide ICEs design, and that it derives from our bodies' ancient wisdom retained from adaptation in our species' ancestral environments.

MA 84, Page 104

Conceptual Gas Exchange Model for Use of Hypobaric Atmospheres in Plant Growth Habitats on Mars

Kenneth A. Corey

Department of Plant & Soil Sciences
French Hall
University of Massachusetts
Amherst, MA 01003
Tel: (413) 545-5220
Fax: (413 545-3075
E-mail: kcorey@pssci.umnass.edu

In-situ resource utilization, provision of human life support requirements by bioregenerative methods, and engineering constraints for construction and deployment of plant growth structures on the surface of Mars all suggest the need for plant growth studies at hypobaric pressures. Past work demonstrated that plants will likely tolerate and grow at pressures at or below 10 kPa. Based upon this premise, a conceptual gas exchange model for the use of lightweight, inflatable structures for plaot growth was developed for lettuce and rice. The model is based upon assumptions involving limits of total atmospheric pressure in the range of 5 to 15 kPa with a combination of passive and active modification of partial pressures of oxygen, carbon dioxide, water vapor, and diluent gases. Various modification and control scenarios were developed to illustrate the dynamics of crop gas exchange with the goals of maximizing design simplicity and the use of local resources. The model provides input for defining minimal values for atmospheric parameters for plant growth and will aid in the development of engineering designs for extraterrestrial plant growth structures that employ rarefied atmospheres

MA 85, Page 105

System Design Techniques for Reducing the Power Requirements of Advanced Life Support Systems

Cory Finn
NASA Ames Research Center, Moffett Field, California

Julie Levri
Orbital Sciences Corporation, Moffett Field, California and Stevens Institute of Technology, Hoboken, New Jersey

Chris Pawlowski and Sekou Crawford
Orbital Sciences Corporation, Moffett Field, California

The high power requirement associated with overall operation of regenerative life support systems is a critical technological challenge. Optimization of individual processors alone will not be sufficient to produce an optimized system. System studies must be used in order to improve the overall efficiency of life support systems.

Current research efforts at NASA Ames Research Center are aimed at developing approaches for reducing system power and energy usage in advanced life support systems. System energy integration and energy reuse techniques are being applied to advanced life support, in addition to advanced control methods for efficient distribution of power and thermal resources. An overview of current results of this work will be presented.

The development of integrated system designs that reuse waste heat from sources such as crop lighting and solid waste processing systems will reduce overall power and cooling requirements. Using an energy integration technique known as Pinch analysis, system heat exchange designs are being developed that match hot and cold streams according to specific design principles. For various designs, the potential savings for power, heating and cooling are being identified and quantified.

The use of state-of-the-art control methods for distribution of resources, such as system cooling water or electrical power, will also reduce overall power and cooling requirements. Control algorithms are being developed which dynamically adjust the use of system resources by the various subsystems and components in order to achieve an overall goal, such as smoothing of power usage and/or heat rejection profiles, while maintaining adequate reserves of food, water, oxygen, and other consumables, and preventing excessive build-up of waste materials. Reductions in the peak loading of the power and thermal systems will lead to lower overall requirements. Computer simulation models are being used to test various control system designs.

Author contact information:
Cory K. Finn, Ph.D.
NASA Ames Research Center, Mail Stop 239-8, Moffett Field, California 94035
Tel: (650) 604-1027; Email: cfinn@mail.arc.nasa.gov

MA 86, Page 106

A Biomass Production Model for Sweetpotato Grown in Controlled Environments

J. H. Hill*, A. H. B. M. Wijte, D. Z. Douglas, and D. G. Mortley

Center for Food and Environmental Systems for the Human Exploration of Space, GWCAES, Tuskegee University, Tuskegee, AL 36088 and California State University Long Beach, Long Beach, CA 90840.

Crop growth models are active repositories of the information known and assumptions made about a crop within the scope of parameters being considered. These models are particularly useful in highlighting critical information gaps, directing future research and optimizing research resources. Once developed, crop growth models can serve crop producers by providing information which improves crop yield from inputs typically reflecting environmental conditions, proposed nutrient applications and cultivar characteristics. Plant growth models have been developed for field grown crops such as maize, rice, wheat, sorghum, soybeans and potatoes. There has been limited work on model development for sweetpotatoes grown hydroponically in closed chambers. This model simulates biomass accumulation of sweetpotatoes grown in controlled environments using nutrient film technique. Because the environment is controlled, variability of the environmental parameters is reduced. The processes modeled are carbohydrate production and growth through carbohydrate allocation. Among its inputs the model requires photosynthetic photon flux and photoperiod, temperature, humidity, N sources and applications, critical N concentration levels in the plant parts, and photosynthetic rates. Principal outputs from the model are fresh and dry biomass weights of the different plant parts over time as well as the weights of senesced plant parts. The model was developed in Stella II, Version 3.0 on the Apple Macintosh. Current work includes collecting data for model validation and moving the model to a PC platform.

MA 87, Page 107

A Simulation Study Comparing Incineration and Composting in a Mars-based Advanced Life Support System

John Hogan, Sukwon Kang, and Jim Cavazzoni
Department of Environmental Sciences
Rutgers, The State University of New Jersey
New Brunswick, New Jersey

Julie Levri
Department of CEOE
Stevens Institute of Technology
Hoboken, New Jersey

Cory Finn
NASA Ames Research Center
Moffett Field, California

The objective of this study is to compare incineration and composting in a Mars-based advanced life support (ALS) system. The variables explored include waste pre-processing requirements, reactor sizing and buffer capacities. The study incorporates detailed mathematical models of biomass production and waste processing into an existing dynamic ALS system model. The ALS system and incineration models (written in MATLAB/SIMULINK©) were developed at the NASA Ames Research Center. The composting process is modeled using first order kinetics, with different degradation rates for individual waste components (carbohydrates, proteins, fats, cellulose and lignin). The biomass waste streams are generated using modified "Energy Cascade" crop models, which use light- and dark-cycle temperatures, irradiance, photoperiod, [CO2], planting density, and relative humidity as model inputs. The study also includes an evaluation of equivalent system mass (ESM).

Author contact information:
John Hogan, Ph.D., Post-Doctoral Associate
Department of Environmental Sciences, Rutgers, The State University of New Jersey
14 College Farm Rd., New Brunswick, New Jersey 08901
Tel: (732) 932-6684; Email: hogan@aesop.rutgers.edu

MA 88, Page 108

A Scalable Predictive Model of Food Preparation Labor

Ammar Olabi
Food Science Department

Jean Hunter
Agricultural and Biological Engineering Department

Peter Jackson
School of Operations Research and Industrial Engineering
Cornell University
Ithaca, New York

Lighting energy has long been considered the limiting resource in food production for bioregenerative life support systems, but crew labor is of comparable importance, especially for long mission. A power plant, once emplaced on a planetary surface, can be amortized over missions of indeterminate length, while crew labor costs increase in proportion to mission duration.

Trade studies on food in an advanced life support system must consider three basic food sources: terrestrially produced ready-to-serve foods needing minimal preparation, terrestrially produced bulk ingredients, and crops produced in-situ. Bulk ingredients and fresh crops can support a more varied and appealing diet, but at the price of crew labor invested in food preparation. Hence the cost of preparation labor should be estimated for each particular scenario considered in a trade study or optimization - insofar as possible, for individual dishes and ingredients.

Preparation of ALS-compatible foods was videotaped and analyzed to determine the specific tasks of making up each recipe and the time associated with each task. Tasks, times and ingredient quantities were entered in a custom database. Database queries were used to build linear regression models of each task as a function of the quantity of ingredient processed, or to estimate the average task time for quantity-independent tasks. Labor predictions were generated by summing the estimated task time over all tasks in a recipe. The model's predictions were initially validated on the input data and then on new recipes and previously studied recipes produced at different batch sizes. The validated model is appropriate for use in optimizations and trade studies though some refinements are still needed.

Author contact information:
Jean Hunter, Ph.D.
Department of Agricultural and Biological Engineering, Cornell University
218 Riley Robb Hall, Wing Drive, Ithaca, New York 14853
Tel: (607) 255-2297; Email: jbh5@cornell.edu

MA 89, Page 109

Optimization of Ingredient Processing in a Bioregenerative Diet

Randy Rivera and Grace Fung
School of Operations Research and Industrial Engineering

Ammar Olabi
Food Science Department

Jean Hunter
Agricultural and Biological Engineering Department

Peter Jackson
School of Operations Research and Industrial Engineering
Cornell University
Ithaca, New York

Food production in a high closure bioregenerative life support system is essential for long-duration planetary exploration missions. In the long run it is more cost effective to produce crops and prepare foods on the planetary surface than to transport meals from Earth. To date, crew labor cost is the least well defined of the resource costs for a bioregenerative food system, but our estimates indicate that it rivals biomass production costs in importance. Crew time is valuable and its use for life support activities should be limited; on the other hand, crop production resources are also limited by cost and space constraints at the mission design level. Harvesting and processing small quantities of crops is labor-intensive; on the other hand, large inventories indicate inefficient use of crop production resources, and stored foods can spoil.

In a high closure scenario, it is necessary to schedule crop production plans and food processing operations together in order to allocate an efficient planting area and to minimize the inventory level. A model is needed to optimize the batch size and processing schedule of each food ingredient and the amount of each ingredient in inventory, subject to constraints on crop and labor availability. By varying the model's constraint on crew labor hours devoted to processing, the optimal (low-cost) inventory of each ingredient can be estimated. The successful optimization of ingredient processing activities will aid in efficient use of system resources in space life support.

Author contact information:
Jean Hunter, Ph.D.
Department of Agricultural and Biological Engineering, Cornell University
218 Riley Robb Hall, Wing Drive, Ithaca, New York 14853
Tel: (607) 255-2297; Email: jbh5@cornell.edu

MA 90, Page 110

Applying Technology Ranking and Systems Engineering in Advanced Life Support

Harry Jones

NASA Ames Research Center
Moffett Field, California

According to the Advanced Life Support (ALS) Program Plan, the Systems Modeling and Analysis Project (SMAP) has two important tasks: 1) prioritizing investments in ALS Research and Technology Development (R&TD), and 2) guiding the evolution of ALS systems. Investments could be prioritized simply by independently ranking different technologies, but we should also consider a technology's impact on system design. Guiding future ALS systems will require SMAP to consider many aspects of systems engineering.

R&TD investments can be prioritized using familiar methods for ranking technology. The first step is gathering data on technology performance, safety, readiness level, and cost. Then the technologies are ranked using metrics or by decision analysis using net present economic value. The R&TD portfolio can be optimized to provide the maximum expected payoff in the face of uncertain future events.

But more is needed. The optimum ALS system can not be designed simply by selecting the best technology for each predefined subsystem. Incorporating a new technology, such as food plants, can change the specifications of other subsystems, such as air regeneration. Systems must be designed top-down starting from system objectives, not bottom-up from selected technologies.

The familiar top-down systems engineering process includes defining mission objectives, mission design, system specification, technology analysis, preliminary design, and detail design. Technology selection is only one part of systems analysis and engineering, and it is strongly related to the subsystem definitions.

ALS systems should be designed using top-down systems engineering. R&TD technology selection should consider how the technology affects ALS system design. Technology ranking is useful but it is only a small part of systems engineering.

Author contact information:
Harry Jones, Ph.D.
NASA Ames Research Center, Mail Stop 239-8, Moffett Field, California 94035-1000
Tel: (650) 604-5518; Email: hjones@mail.arc.nasa.gov

MA 91, Page 111

Modeling of Composting for Waste Processing and Resource Recovery in Advanced Life Support Systems

S. Kang
Department of Bioresource Engineering

J. A. Hogan
Department of Environmental Sciences

K. C. Ting
Department of Bioresource Engineering
Rutgers, The State University of New Jersey
New Brunswick, New Jersey

Using MATLAB/SIMULINK© , a steady-state composting simulation model has been constructed and coupled with the wastes generated from the biomass production, food processing, and crew components from a pre-existing Advanced Life Support (ALS) system model developed at NASA's Ames Research Center. The composting model provides a mass accounting of oxygen utilized, and the carbon dioxide, water, ammonia, nitrate and solid residue produced. Using first order kinetics, the model is able to individually account for the stoichiometry of a variety of waste constituents (carbohydrates, proteins, fats, cellulose, lignin), which undergo different rates of biodegradation. Composting reactor sizes and masses were calculated based on various input scenarios, including various levels of food production (i.e. inedible biomass formation) and specific waste production (e.g. paper trash). This work is part of a larger effort aimed at developing the numerous subsystem models required to allow the "swapping" of different physicochemical (P/C) and biological regenerative technologies to investigate integrated scenario development.

Author contact information:
Sukwon Kang, Ph.D., Post Doctoral Associate
Department of Bioresource Engineering, Rutgers, The State University of New Jersey
Cook College, 20 Ag Extension Way, New Brunswick, New Jersey 08901-8500
Tel: (732) 932-9753; Email: kang@bioresource.rutgers.edu

MA 92, Page 112

Application of Energy Integration Techniques to the Design of Advanced Life Support Systems

Julie Levri
Orbital Sciences Corporation, Moffett Field, California
and Stevens Institute of Technology, Hoboken, New Jersey

Cory Finn
NASA Ames Research Center
Moffett Field, California

Exchanging heat between hot and cold streams within an advanced life support system can save energy. This savings will reduce the equivalent system mass (ESM) of the system. Different system configurations are examined under steady-state conditions for various percentages of food growth and waste treatment. The scenarios investigated represent possible design options for a Mars reference mission. Reference mission definitions are drawn from the ALSS Modeling and Analysis Reference Missions Document, which includes definitions for space station evolution, Mars landers, and a Mars base.

For each scenario, streams requiring heating or cooling are identified and characterized by mass flow, supply and target temperatures and heat capacities. The Pinch Technique is applied to identify good matches for energy exchange between the hot and cold streams and to calculate the minimum external heating and cooling requirements for the system. For each pair of hot and cold streams that are matched, there will be a reduction in the amount of external heating and cooling required, and the original heating and cooling equipment will be replaced with a heat exchanger. The net cost savings can be either positive or negative for each stream pairing, and the priority for implementing each pairing can be ranked according to its potential cost savings.

Using the Pinch technique, a complete system heat exchange network is developed and heat exchangers are sized to allow for calculation of ESM. The energy-integrated design typically has a lower total ESM than the original design with no energy integration. A comparison of ESM savings in each of the scenarios is made to direct future Pinch Analysis efforts.

Author contact information:
Julie A. Levri
Department of CEOE, Stevens Institute of Technology
Hoboken, New Jersey 07030
Tel: (201) 216-5337; Email: jlevri@stevens-tech.edu

MA 93, Page 113

Total Mission Wastes and Resource Management

Sabrina Maxwell

The Boeing Company
Kennedy Space Center, Florida

Waste processing and resource recovery is a critical issue for any long duration mission. Resources necessary to sustain the crew have an associated mass penalty for storage of the resource and the waste produced by its use. The launch and onboard storage costs of life support commodities and their wastes are significant impacts. These factors drive the need to minimize the amount of materials to be launched into space and maximize the conversion of waste products into usable products.

This study identifies the waste stream of current Space Transport System (STS) missions, and assumes certain waste streams for International Space Station (ISS), and Mars missions. An analysis of current waste streams is critical for future mission planning in identifying technologies that may reduce the mission costs. These costs are incurred for the waste management elements in an environmental control and life support system (ECLSS). Wastes associated with STS missions will be quantified, technologies for processing assessed, and options for reduction suggested. The technologies selected for waste system processing are anticipated to require extensive development over the next few years as current technology readiness levels (TRL) indicate low system maturity for some. This makes the documentation of analysis techniques and supporting information that lead to the selection of waste processing technologies critical to provide traceability of information upon which to build a model for future missions.

Author contact information:
Sabrina Maxwell
The Boeing Company
PO Box 21233, Mail Stop KA91-F530, Kennedy Space Center, Florida 32815
Tel: (321) 383-2838; Email: Sabrina.Maxwell@Boeing.com

MA 94, Page 114

Modeling Nutrient Availability From Composting Inedible Sweetpotato Biomass

A.A. Trotman, H. Walton and J. Vaughn.

Tuskegee University Center for Food and Environmental Systems for Human Exploration of Space, Tuskegee Institute, AL 36088

The sweetpotato (Ipomea batatas (l.) Walp.) is one of several crops being studied by the National Aeronautics and Space Administration (NASA), as a source of food for astronauts while on planetary habitations. The need to provide a feasible method of waste management and resource recovery is essential to insure a self-sufficient environment with reduced dependence on resources from earth. The resulting compost was leached to recover nutrients, which was analyzed to determine the nutrient potential to support hydroponically grown crops. The material that was composted consisted of shredded sweetpotato stems and leaves (sweetpotato biomass) combined with ground, dehydrated sweetpotato storage roots (sweetpotato meal). A comparison of nutrient concentration in compost leachate from Days 21 and 42 with that in Hoagland nutrient solution showed that levels of P,K, Mg, Fe, B, Zn, Cu and Mn measured in compost leachate met or exceeded those in Hoagland solution and only NO3- and Ca would need to be supplemented. The concentrations of NO3- and Ca in leachates, though lower than those in Hoagland solution, were more than 9% of the concentration contained in Hoagland solution. The concentration of nitrate for leachate samples taken on Days 0, 21, and 42 were comparable to 17.3, 58.5 and 69.8%, respectively, of the nitrate level in Hoagland. In addition, Ca concentrations were comparable to 10.0, 32.2, and 30.9% for the same sampling period. Gross weight loss was 33.7% and 53% after 21 and 42 days, respectively. Dry weight loss was highly correlated (R2 = 1) with composting time. This study indicates from nutrient analysis and the high recovery of water-soluble minerals in compost leachate, that compost and compost leachate have the potential to be used as sources of nutrients for hydroponically grown crops. In addition, composting was effective in reducing the overall mass of solid waste material that may be produced in a closed environment. The present work provides preliminary information, which will contribute to NASA's ongoing effort to establish an effective method of waste management, in addition to providing a usable product while on extended space missions. The data can be used to model the nutrients that can be expected to accrue from composting sweetpotato and that will be available from this source for incorporation into the crop growth subsystem.

MA 95, Page 115

A Simulation Study of Using Solar Insolation for a Mars Greenhouse

Jim Cavazzoni

Department of Bioresource Engineering
Rutgers, The State University of New Jersey
New Brunswick, New Jersey

The purpose of this simulation study is to evaluate the feasibility of growing crops on Mars under natural lighting, and under a combination of natural plus supplemental lighting. The study uses detailed crop models for soybean, wheat and white potato. These crops are chosen to represent legumes, cereals and tubers, respectively. Data obtained from experiments at Kennedy Space Center, Florida, and Utah State University are used to establish baseline model simulations. Diurnal and seasonal changes in PAR (photosynthetically active radiation) are input to the crop models for a given latitude. To obtain the PAR values, the total insolation at the top of the Martian atmosphere is first calculated using standard equations. Next, the ratio of PAR to total insolation at the top of the Earth's atmosphere is used to calculate PAR at the top of the Martian atmosphere. The amount of PAR reaching the Martian surface is then reduced due to atmospheric scattering by dust particles. As a result of this scattering, a considerable fraction of the PAR reaching the surface is diffuse. This study, therefore, also accounts for the effects of diffuse light on canopy photosynthesis. A simple scattering model is used to calculate the total, direct and diffuse PAR at the surface as dependent on optical depth. Parametric studies include the amount of supplemental light, the optical depth for the background dust haze, and the transmission coefficient for the greenhouse.

Author contact information:
Jim Cavazzoni, Ph.D., Post-Doctoral Associate
Department of Bioresource Engineering, Rutgers, The State University of New Jersey
20 Ag Extension Way, New Brunswick, New Jersey 08901-8500
Tel: (732) 932-9753; Email: cavazzon@bioresource.rutgers.edu

MA 96, Page 116

Top-level Crop Models for Advanced Life Support System Studies

Jim Cavazzoni

Department of Bioresource Engineering
Rutgers, The State University of New Jersey
New Brunswick, New Jersey

The "Energy Cascade" model, which was originally developed for wheat (Volk, T., Bugbee, B., and Wheeler, R. M., "An Approach to Crop Modeling with the Energy Cascade," Life Support and Biosphere Science, Vol. 1, pp. 119-127, 1995), has been modified for several advanced life support (ALS) candidate crops for use in ALS system studies. The original model calculates daily crop growth rates using the following trends: a linear increase in canopy light absorption from emergence through canopy closure (occurring at time tA); a constant (maximum) light absorption after tA; a constant canopy quantum yield (CQYMAX) through the onset of senescence (occurring at time tQ), then decreasing linearly thereafter until crop maturity (occurring at time tM); a constant carbon use efficiency. The parameters tA, tQ and tM are model inputs. The original model was modified to include the plant growth and developmental components needed to calculate tA, tQ and tM from input environmental conditions. Detailed crop models were used to produce equations for CQYMAX as dependent on irradiance and [CO2], which were incorporated into the modified models. The models include a simple canopy transpiration component, and it is assumed that water and nutrients do not limit crop productivity. The resulting models thus use light- and dark-cycle temperatures, irradiance, photoperiod, [CO2], planting density, and relative humidity as model inputs. The model outputs include daily values of edible and total biomass, canopy CO2 assimilation and transpiration. Models were developed for wheat, soybean, white potato, lettuce, peanut, rice, sweet potato, dry bean and tomato. The crop models should be useful in estimating the direction and magnitude of changes in canopy gas-exchange, harvest index and production scheduling due to off-nominal conditions for ALS system studies.

Author contact information:
Jim Cavazzoni, Ph.D., Post-Doctoral Associate
Department of Bioresource Engineering, Rutgers, The State University of New Jersey
20 Ag Extension Way, New Brunswick, New Jersey 08901-8500
Tel: (732) 932-9753; Email: cavazzon@bioresource.rutgers.edu

MA 97, Page 117

Non-Parametric Approaches to Modeling Plant Canopy Gas Exchange Dynamics in Closed Environments

Geoffrey Cloutier and Mike Dixon

Department of Plant Agriculture
Division of Horticultural Science
University of Guelph
Guelph, Ontario, Canada

Deterministic modeling of plant canopy gas exchange is a valuable tool in the design of Advanced Life Support systems. Applications of such models include system sizing, the assessment and detection of aberrant system development, and the development of management scenarios aimed at the stabilization of mass fluxes (e.g., CO2 and nutrient dynamics).

Full canopy experiments which quantify full canopy gas exchange dynamics yield data which are i) difficult to replicate due to the costs associated with such large scale empirical trials and which ii) exhibit complex profiles in relation to crop age. While deterministic models can be developed by utilizing functions developed in traditional growth analysis, the data analyst is often forced to choose among particular parametric forms which may result in over-fitting of the data. This can result in a high-degree of collinearity among predictor variables, especially if a high order polynomial of a single predictor variable (i.e., time, crop age) is used.

This paper will review non-parametric procedures which are applicable to modeling full canopy gas exchange. These methods generate predicted values in complex profiles without having to assume any particular functional relationship with independent variables. Further, it is shown that these techniques can yield predictions with greater stability than their parametric counterparts. A bootstrap technique is also introduced in the context of form-free regression to estimate gas exchange variability in cases where true replication is difficult or impossible.

Author Contact Information:
Geoffrey Cloutier, Ph.D. Student
Space and Advanced Life Support Agriculture Lab, Department of Horticultural Science
University of Guelph, Guelph, Ontario, Canada N1G 2W1
Tel: (519) 824-4120 ext 2616; Email: cloutier@evbhort.uoguelph.ca

MA 98, Page 118

Modeling Nutrient Dynamics in Advanced Life Support Systems Using the Concept of Steady-State Nutrition

Geoffrey Cloutier
Department of Plant Agriculture
Horticultural Science
University of Guelph
Guelph, Ontario, Canada

Chistophe Lasseur
Thermal Control and Life Support Division

Mike Dixon
Department of Plant Agriculture
Horticultural Science
University of Guelph
Guelph, Ontario, Canada

Advanced Life Support Systems which incorporate higher plants necessitate the development of environment control algorithms which achieve an optimization of plant aerial and root zone variables. Traditional sensor-actuator based control strategies (e.g. pH EC) suffer from a lack of sensitivity to individual ion concentrations in achieving static root-zone conditions and fail to predict root zone nutrient dynamics. Deterministic models of nutrient (e.g. NO3-, K+, Ca2+, PO43-, Mg2+, etc. ) uptake can serve

A practical approach to modeling nutrient uptake dynamics makes use of the concept of steady state nutrition proposed by Ingestad and Agren (1988). This assumes constant nutrient concentrations in plant tissue regardless of their physiological stage which provides an interesting basis for the modeling of nutrient dynamics based on gas exchange dynamics in the aerial environment.

This paper will outline the theoretical and physiological basis for modeling nutrient uptake based on Net Carbon Dioxide Exchange Rate and assuming steady state nutrition. Some recently acquired data will be discussed in the context of the dynamic modeling of Higher Plant / MELiSSA systems. The parallel application of these models to hydroponic solution management is also discussed.

Author Contact Information:
Geoffrey Cloutier, Ph.D. Student
Space and Advanced Life Support Agriculture Lab, Department of Horticultural Science
University of Guelph, Guelph, Ontario, Canada N1G 2W1
Tel: (519) 824-4120 ext 2616; Email: cloutier@evbhort.uoguelph.ca

MA 99, Page 119

Crop Modeling for Multiple Crop Production for ALSS

David H. Fleisher, Jim Cavazzoni, Gene Giacomeli, and K. C. Ting

Bioresource Engineering Department
Rutgers, The State University of New Jersey
New Brunswick, New Jersey

Modifications and calibrations for controlled environment hydroponic production of white potato (cv. Norland) under elevated CO2 have been made to a detailed open-field crop growth and development model, SUBSTOR. Experiments, designed to provide the necessary growth and phenological data required for model calibrations, were conducted within a walk-in growth chamber retrofitted with hydroponic ebb and flood irrigation. Modifications to model growth and developmental parameters, including calibrated genetic coefficients, and source code changes to modeling subroutines will be discussed with respect to modeling efforts for controlled environment production of ALS crops. Application of modified-SUBSTOR for systems studies analysis will be examined. In particular, the use of detailed crop models for prediction of multiple crop scheduling in identical and separate growth facilities will be examined.

Author contact information:
David H. Fleisher, Ph.D. Candidate / Graduate Fellow
Bioresource Engineering Department, Rutgers, The State University of New Jersey
20 Ag Extension Way, New Brunswick, New Jersey 08901 - 8500
Tel: (732) 932-9753; Email: fleisher@bioresource.rutgers.edu

MA 100, Page 120

Modeling Separate and Combined Atmospheres in BIO-Plex

Harry Jones and Cory Finn
NASA Ames Research Center
Moffett Field, California

Xianmin Kwauk
Sverdrup Technology
Moffett Field, California

Charles Blackwell
Lockheed Martin Engineering and Sciences
Moffett Field, California

We modeled BIO-Plex designs with separate or combined atmospheres and then simulated controlling the atmosphere composition. The BIO-Plex is the Bioregenerative Planetary Life Support Systems Test Complex, a large regenerative life support test facility under development at NASA Johnson Space Center.

Although plants grow better at above-normal carbon dioxide levels, humans can tolerate even higher carbon dioxide levels. Incinerator exhaust has very high levels of carbon dioxide. An elaborate BIO-Plex design would maintain different atmospheres in the crew and plant chambers and isolate the incinerator exhaust in the airlock. This design easily controls the crew and plant carbon dioxide levels but it uses many gas processors, buffers, and controllers.

If all the crew's food is grown inside BIO-Plex, all the carbon dioxide required by the plants is supplied by crew respiration and the incineration of plant and food waste. Because the oxygen mass flow must balance in a closed loop, the plants supply all the oxygen required by the crew and the incinerator. Using plants for air revitalization allows using fewer gas processors, buffers, and controllers.

In the simplest design, a single combined atmosphere was used for the crew, the plant chamber, and the incinerator. All gas processors, buffers, and controllers were eliminated. The carbon dioxide levels were necessarily similar for the crew and plants. If most of the food is grown, carbon dioxide can be controlled at the desired level by scheduling incineration.

An intermediate design uses one atmosphere for the crew and incinerator chambers and a second for the plant chamber. This allows different carbon dioxide levels for the crew and plants. Better control of the atmosphere is obtained by varying the incineration rate. Less gas processing, storage, and control is needed if more food is grown.

Author contact information:
Harry Jones, Ph.D.
NASA Ames Research Center, Mail Stop 239-8, Moffett Field, California 94035-1000
Tel: (650) 604-5518; Email: hjones@mail.arc.nasa.gov

MA 101, Page 121

Modeling Food Processing within Advanced Life Support Systems (ALSS)

Sukwon Kang, Hsienhsing Hsiang, and Kuan-Chong Ting

Bioresource Engineering Department
Rutgers, The State University of New Jersey
New Brunswick, New Jersey

A top-level model for food processing within advanced life support systems (ALSS) has been developed to analyze the processes that transform raw materials into palatable and acceptable menu items for crew members during long-duration space missions. The menu items are required to satisfy crew nutritional requirements and taste preferences. Daily diets are chosen according to the required levels of daily nutrition. The corresponding diet menu determines the amount of resources needed for food preparation including food ingredients, food processing equipment, energy consumption, and crew time. Waste generated during food preparation is also estimated. The food processing model was developed based on the outcome of an object-oriented analysis and implemented using Java programming language. Therefore, the model is modular and can be executed via the Internet.

Author contact information:
Sukwon Kang, Ph.D., Post Doctoral Associate
Department of Bioresource Engineering, Rutgers, The State University of New Jersey
Cook College, 20 Ag Extension Way, New Brunswick, New Jersey 08901-8500
Tel: (732) 932-9753; Email: kang@bioresource.rutgers.edu

MA 102, Page 122

Requirements for Mechanization, Automation, and Robotics System (MARS) within Biomass Production Systems (BPS) of an Advanced Life Support System (ALSS)

Sukwon Kang, Yuriko Ozaki, and Kuan-Chong Ting

Bioresource Engineering Department
Rutgers, The State University of New Jersey
New Brunswick, New Jersey

Mechanization, automation and robotics system (MARS) is expected to reduce crew labor requirement in the Biomass Production Systems (BPS) of an Advanced Life Support System (ALSS) for long-term human space mission. The cost of implementing MARS is the added mass and other resources for its operation. A concept of equivalent system mass has been used by NASA as a metric to evaluate this cost factor. This study has been conducted by modifying an existing object-oriented BPS model developed by the New Jersey NASA Specialized Center Of Research and Training (NJ-NSCORT). The modified model incorporates various types of mechanized equipment, automated machines, and/or robots with updated biomass production data. The model is used to simulate different combinations of crop mix/scheduling, cultural tasks, production space layout/material flow, labor/resource requirement and crew/machine interactions to investigate the effects of MARS on crew time requirements and other costs estimated in equivalent system mass. This simulation result will lead to the recommendation of level of automation needed for biomass production.

Author contact information:
Sukwon Kang, Ph.D., Post Doctoral Associate
Department of Bioresource Engineering, Rutgers, The State University of New Jersey
Cook College, 20 Ag Extension Way, New Brunswick, New Jersey 08901-8500
Tel: (732) 932-9753; Email: kang@bioresource.rutgers.edu

MA 103, Page 123

Impact of Carbon Dioxide Reduction and Oxygen Supply Options on Air Revitalization Systems for Long Duration Missions

Sabrina Maxwell and Alan Drysdale

The Boeing Company
Kennedy Space Center, Florida

Carbon dioxide reduction can increase closure of the air loop. However, closure alone is not a good indication of mission cost-effectiveness or desirability. Technology options for air revitalization systems with and without a carbon dioxide reduction system are considered as they affect the overall ECLSS mission cost as reflected by the equivalent system mass (ESM). Only nominal requirements are considered here. Contingency requirements could be significant but are not well enough defined for evaluation.

The impact of carbon dioxide reduction on overall mission cost and ESM is dependent on the mission scenario. For the post assembly-complete ISS, no savings in ESM are expected for carbon dioxide reduction. While the water savings resulting from any of the CRS technologies considered would reduce annual water requirements for the ARS by at least 50% over no carbon dioxide reduction, adequate water is available in items currently baselined for the ISS to provide for all crew activities including EVA.

For any of the Mars surface missions carbon dioxide reduction is expected to provide a reduction in ESM, and either carbon dioxide reduction or an in situ source of make-up oxygen should be included as a part of the ECLSS ARS. Future studies are needed to evaluate the impact of bioregeneration and in situ resource utilization (ISRU) on the ARS. While we believe that plants will have a significant effect on mission ESM, particularly with regards to air regeneration, the number of ECLSS systems with which they interface complicates the issue, and are beyond the scope of this study. Also, ISRU may provide cheaper oxygen than reducing ECLSS carbon dioxide.

Author contact information:
Sabrina Maxwell
The Boeing Company
PO Box 21233, Mail Stop KA91-F530, Kennedy Space Center, Florida 32815
Tel: (321) 383-2838; E-mail: Sabrina.Maxwell@Boeing.com

MA 104, Page 124

Review of Uncertain Data Handling Methods for Systems Analysis and Modeling

L. F. Rodriguez and K. C. Ting

Bioresource Engineering Department
Rutgers, The State University of New Jersey
New Brunswick, New Jersey

Effective modeling of Advanced Life Support (ALS) Systems is challenged by uncertain and unreliable data. Unfortunately, this type of data is inevitable in the ALS community as new technologies with the potential for inclusion in an ALS System are presently being developed. Often, it is useful to incorporate data from these developmental technologies into modeling and systems analysis. However, when this occurs, model output and systems analysis results are inherently compromised due to the uncertain and unreliable data. Therefore, it would be useful to have a measure of the uncertainty of results produced when uncertain data has been utilized during modeling and analysis. Several methods with this capability are reviewed here. These methods include Fuzzy Logic, Bayesian Analysis, Probabilistic Risk Analysis, Decision Analysis, Certainty Factors, and Multi-valued Logic. Special consideration will be given to methods that translate readily to the modeling of complex systems utilizing time stepping methods and methods that can be implemented under an object-oriented paradigm.

Author contact information:
Luis F. Rodriguez, Interdisciplinary Doctoral Program
Bioresource Engineering Department, Rutgers, The State University of New Jersey
20 Ag Extension Way, New Brunswick, New Jersey 08901-8500
Tel: (732) 932-9753; Email: lrodrigu@bioresource.rutgers.edu

PC 105, Page 125

Application of Sublimation Purification Technology to Long Duration Space Flight

N. V. Coppa,1 G. J. Maffia,2 and R. W. Schaeffer3

1NanoMaterials Company, Malvern, Pennsylvania
2Widener University, Chester Pennsylvania
3Franklin & Marshall College, Lancaster, Pennsylvania

 Sublimation-based purification technology (SPT) applied to spacecraft water recovery, purification, and recycle exhibits important features: the lack of expendable materials, exceptionally high purification factors (initial/final concentration), and the recovery of 100% of the water from liquid and solids while reducing the residues to a dry friable solid. We have studied the application of (SPT) to salt solutions, simulated brine and grey water, and ammonium solutions of varying pH and anion type. As of the writing of his abstract, our preliminary result indicated that a 1 M sodium nitrate ([Na+] = 8500 ppm ) solution was purified to a [Na+] = 4.7 parts per billion, and very preliminary results on brine solutions indicate that a brine containing [NH3+] = 590 ppm was purified to [NH3+] < 1.7 parts per million (the discrimination limit for ammonium ion). The residues from both solutions were a dry friable salt(s). We will present the results from the completed program on the study of purification of bring and grey water solutions as a function of processing conditions and energy consumption.

Our program of study also included an analysis of several features needed to adapt SPT to the spacecraft (limited energy) and zero g environment. Those studies included an analysis of the use of space resources vacuum and emissivity, a means of controlling dry solids, and the method of filling and emptying the SPT system in zero g. The results from these presently (1/12/00) ongoing studies will be presented.

Speaker: Nicholas V. Coppa, NanoMaterials Company, 7 Line Road, Malvern, PA 19355
Phone: 610 695 0081, Facsimile: 610 695 0081, ncoppa@bellatlantic.net

PC 106, Page 126

Methanol Production on Mars

Hal Couch & Joe Genovese, Hamilton Sundstrand
Joe Trevathan, NASA - JSC

Corresponding author:
Joseph Genovese
Chief, Advanced Technology
Hamilton Sundstrand
One Hamilton Rd. M.S. 1A-2-W66
Windsor Locks, CT 06096
Tel: (860) 654 5304
Fax: (860) 654 2673
E-mail: joseph.genovese@hs.utc.com

 In-Situ Resource Utilization (ISRU) is an enabling technology for the human exploration of Mars. Recent programs have been directed at the use of atmospheric carbon dioxide for production of oxygen (Mars 2001 Lander) and for the production of methane and oxygen (Mars 2003 Lander). The ability to produce other chemicals for use as fuels or as feed stocks for further processing could simplify and/or enhance future missions. NASA-JSC is developing various breadboard level systems to demonstrate production of rocket propellants and fuel cell reactants from the predominantly carbon dioxide Martian atmosphere. These systems are being used to identify technologies suitable for further development. One such process involves directly electrolyzing the CO2 in the Martian atmosphere to generate oxygen. The waste gas stream from this electrolyzer is a mixture of CO and CO2 in roughly 50/50 proportion. This waste gas stream, with the addition of hydrogen, can be utilized to form methanol, a storable liquid, which would be available for fueling return rockets or surface rovers. There are several approaches that can be used for the methanol synthesis, low and high pressure catalytic processes, electrochemical synthesis and even indirect synthesis by partial oxidation of methane. This study will present the various options in schematic form, present the predicted performance, and estimate the technical readiness level and system mass and energy requirement for a 0.15 kg of methanol per hour production rate.

PC 107, Page 127

A Smart Toilet: Astronaut Health Monitoring by Real-Time Chemical Analysis of Urine

Stuart Farquharson,1 Yuan-Hsiang Lee,1 and Petrie Rainey2

1Advanced Fuel Research, Inc., 87 Church Street, East Hartford, CT, 06108
2Yale School of Medicine, Yale University, New Haven, CT, 06520

The adaptation of human physiology to the near-zero gravity of space causes several debilitating effects, such as loss of bone and muscle mass. The ability to monitor and assess these effects is extremely important to design countermeasures, such that a human presence can be established and space exploration can occur. To address this need, we have been investigating the ability of surface-enhanced Raman (SER) spectroscopy to monitor astronaut health through chemical analysis of urine. We have developed a new SER medium that allows real-time, quantitative analyses in flowing systems. This medium consists of silver particles incorporated into a sol-gel matrix. High quality SER spectra have been obtained for a number of biochemicals in actual urine specimens (e.g. creatinine, lactic acid, 3-methylhistidine, uric acid). These preliminary measurements strongly suggest that a SER based sensor could be integrated into the liquid waste stream of the International Space Station and future space vehicles as part of a "Smart Toilet". Initial urinalysis studies and a preliminary Smart Toilet design will be presented.

PC 108, Page 128

Evaluation of Incinerating Toilet as a Solid Waste Processor for a Closed Ecological Life Support System

John E. Feighery

NASA Lyndon B. Johnson Space Center
2101 Nasa Road 1
Houston, Texas 77058
Phone: 281-483-7873 Fax: 281-483-2508
Email: Jfeighery@ems.jsc.nasa.gov

The incinerating toilet contains a chamber that completely incinerates feces, urine, and waste paper by exposure to intense electric heat. Oxidation and cooling are both provided by forced air convection through the chamber and the surrounding enclosure. The NASA Johnson Space Center purchased a commercially available incinerating toilet with the objective of evaluating and possibly modifying the unit for use in the BIO-Plex, a human-rated test bed for integrated closed ecological life support system testing. Modifications include: separation of the oxidation and cooling airstreams by installing separate fans and ductwork; addition of temperature, pressure, and velocity sensors; and installation of an independent computer control system. Initial testing with human waste begins in February 2000, and shall be completed by May 2000. Test data will permit evaluation of the incinerating toilet for BIO-Plex use and optimization or redesign to reduce power consumption, exhaust gas production, and waste heat production.

At a minimum, a new or modified design for the toilet will be presented to address power and exhaust concerns. The potential role of the unit in the BIO-Plex Solids Processing System will be examined, as a primary processing system or as a supplemental or reduced mode capability. Any terrestrial or commercial applications for the improved unit will be explored. Finally, the suitability of the incinerating toilet will be evaluated for use in the various NASA Advanced Life Support mission scenarios.

PC 109, Page 129

A New Photocatalytic Reactor for Trace Contaminant Control-A Water Polishing System

A. Gonzalez-Martin, J. Kim, R. Sidik, J. Van Hyfte, L. A. Rutherford, C. Andrews, and M. Flusche

Lynntech, Inc.
7610 Eastmark Dr., Suite 202
College Station, TX 77840
Tel: (409) 693-0017
Fax: (409) 764-7479
E-mail: lynntech@tca.net

The aim of this project was to develop a new photocatalytic system for the destruction of organic contaminants as a post-processing subsystem (i.e., water polishing system) for the life support group at NASA/JSC. In the photocatalytic process, organic contaminants are degraded to benign end products on semiconductor surfaces, usually TiO2. We have successfully addressed some challenging issues related to the use of TiO2 in efficient photoreactors for the degradation of organic contaminants: (i) efficient and stable catalytic material; (ii) immobilization of the catalyst to produce a material that can be used in packed-bed reactors and that has high surface area per reactor volume, (iii) effective light penetration, (iv) effective, microgravity compatible, oxidant delivery; (v) reduced pressure drop, and (vi) minimum retention time. The result is a microgravity compatible system that operates at room temperature, and whose requirements are only the use of oxygen gas (or air) and low electrical power for the low energy UV-A lamps. Several samples simulating actual conditions have been tested, including solutions containing multiple organic compounds and inorganic ions. As deliverable, Lynntech designed and fabricated a water polishing prototype system. The system was mostly automated by the use of microchips. The prototype consisted on a set of planar reactors combined in a parallel/series configuration. Oxygen (pure or from air) is dissolved in the flowing water through the use of special gas modules. Water flow rate is control in the external panel. The system was tested with simulants containing organic and inorganic contaminants. In most conditions, TOC levels below 0.5 ppm were easily achieved. Depending on the composition of the simulant and flow rates, TOC levels below 0.25 ppm were also achieved.

PC 110, Page 130

The Study of Magnetically Assisted Fluidization in Microgravity and Variable Gravity: Simulation and Experiment

Goran N. Jovanovic,1 Thana Sornchamni,1 Joaquin Pinto Espinoza,1 James E. Atwater,2 and James R. Akse2

1Oregon State University
Department of Chemical Engineering
Gleeson Hall 307
Corvallis, Oregon 97331
Office: (541) 737 3614
Fax: (541) 737 4600
E-mail: goran@che.orst.edu
2UMPQUA Research Company, Myrtle Creek, OR

Fluidized bed reactors provide an ideal solution for mass transfer limited chemical reactions such as oxidation of solid wastes. Conventional fluidized beds require a constant gravitational restoring force to counterbalance fluid dynamic forces. In the Magnetically Assisted Gasification (MAG) process currently under development, the use of magnetic fields and susceptible media provide the basis for fluidized bed combustion and gasification reactions under a variety of gravitational environments, including microgravity. Magnetic forces are created in the interaction between a magnetic field and fluidization particles containing ferromagnetic material. The fields are conveniently oriented in the direction of or in opposition to other major forces acting on fluidization particles, including: buoyancy, gravity and drag. By manipulation of the intensity of the magnetic field, a simulated gravitational restoring force can be provided under a range of gravity conditions. In this paper we present a complex theoretical fluid-dynamic model describing behavior of the Magnetically Assisted Fluidized Bed (MAFB) in non-homogenous magnetic and fluid flow fields. Fluid (water) and particulate phases (custom made ferromagnetic beads) are represented as two interacting continua. The numerical solution of the model is fitted to the experimental laboratory data obtained at 1g. Currently we are preparing a demonstration experiment to be performed on-board the KC135A at gravity conditions ranging from 0g to 2g. The results of these tests will also be discussed.

PC 111, Page 131

Electrochemical Removal of Ammonium Ions from Bioreactor Effluent

J. Kim, C. Salinas, L. A. Rutherford, and A. Gonzalez-Martin

Lynntech, Inc.
7610 Eastmark Dr., Suite 202
College Station, TX 77840
Tel: (409) 693-0017
Fax: (409) 764-7479
E-mail: jkim@mail.tca.net

Ammonium ions are a byproduct of the oxidation of nitrogen-containing substances occurring in the initial treatment steps of water recovery systems. Removal of ammonium ions from the effluent stream from 1000 ppm to less than 0.25 ppm is an imperative need as a part of the space life support infrastructure. Drawbacks associated with processes proposed in the past include the generation of a secondary waste, cost, size, and/or the use of consumables that need to be stored or supplied. Lynntech is developing a technology that is based on an innovative, environmentally friendly electrochemical process for the effective removal of ammonium ions. The process does not use consumables but oxygen gas from air, readily available. In addition, the process does not generate a secondary waste. By controlling operational conditions, the ammonium ions may be transformed to nitrogen gas, which can be removed from the liquid phase in microgravity conditions by the use of a gas separation module. As an alternative, the ammonium ions may be transformed to nitrate ions that can be removed by an ion-exchange system, already in place in the life support infrastructure. Other advantages of the process include: it is energy efficient, operates at room temperature, and is microgravity compatible. Results showing the performance of the system using a bioreactor effluent simulant will be discussed.

PC 112, Page 132

Toward a Reverse Osmosis Membrane System for Recycling Space Mission Wastewater

Dr. Sangho Lee
Department of Mechanical Engineering, Northwestern University, Evanston IL 60208
Tel: 847-491-4180; Fax: 847-491-3915; E-mail: s-lee10@nwu.edu

Prof. Richard M. Lueptow
Department of Mechanical Engineering, Northwestern University, Evanston IL 60208
Tel: 847-491-4265; Fax: 847-491-3915; E-mail: r-lueptow@nwu.edu

Essential to extended human exploration and utilization of space is providing a clean supply of potable water as well as water for washing. Although recycling of wastewater is necessary for long-term space missions due to the limited capacity of water storage, it is challenging to produce stable and healthy water from the wastewater stream of hygiene water (hand, body, clothes, and dish washing), condensate water, and urine. In this study, initial measurements toward a wastewater reclamation system that provides a clean water supply using reverse osmosis (RO) membranes have been made using stirred cell filtration experiments. Low Pressure Reverse Osmosis (LPRO) membranes were used to obtain high flux of permeate as well as high rejection. Bench-top laboratory results have demonstrated that LPRO membranes are practical for wastewater recovery. Detergent removal was above 99%, and dissolved salt removal was above 90% in single pass treatment, while Total Organic Carbon (TOC) was nearly 80%. Most problematic is nitrogen rejection, which was 74% at best. Comparison of feed water before and after urea hydrolysis shows that the rejection of nitrogen compounds can be increased to 95% by allowing urea hydrolysis to occur. The removal efficiency for nitrogen compounds was also improved by increasing the shear rate near membrane surface. As a result, the product water in two passes could meet the hygiene water requirements for human space missions, and the product water in three passes could meet potable water regulations with an overall recovery of 77%. This study also suggests that that dynamic rotating membrane filtration, which can produce a high shear rate, will be useful to increase the system recovery as well as pollutant rejection. [Supported by NASA grant NAG9-1053]

PC 113, Page 133

A Water Reuse System for Pikes Peak, Colorado

Leslie Parker
Project Engineer, Camp Dresser & McKee, Charlotte, NC; formerly a Graduate Research Assistant , Colorado State University

Dr. Tom Sanders
Associate Professor, Colorado State University

Marybeth Edeen
Technical Advisor, Johnson Space Center

Camp Dresser & McKee
301 S. McDowell St. Suite 512
Charlotte, NC 28210
Tel: 704-342-4546
Fax: 704-342-2296
E-mail: lescsu@yahoo.com

As populations continue to increase and new water sources become scarcer, the need for water reuse is realized. This technology is needed not only for growing urban centers but also for remote locations such as the summit of Pike's Peak, Colorado or future Martian habitats. A graywater reuse system is being developed for the new Summit House on top of Pike's Peak using some of the same unit processes NASA is testing for a closed-loop space habitat. This system will help reduce traffic and labor at Pike's Peak by producing potable water, treating graywater and reusing it on site. The current system consists of hauling potable water to the Summit House in tanker trucks and hauling the graywater back down the nineteen-mile road to the Colorado Springs wastewater treatment plant. NASA wants a long-term test of the reuse design at the Summit because of the harsh conditions faced at an elevation of 14,110 feet, such as low temperatures, low oxygen content and low pressures. The graywater reuse system will consist of fuel cells, an immobilized cell bioreactor, reverse osmosis membranes and disinfection. This project will provide a working water reuse design that will be beneficial for use in future human space exploration and also in arid regions and remote sites here on Earth.

PC 114, Page 134

E-BEAM Water Treatment System for Removal of Organic Contamination

Piotr Lubicki and Friedemann Freund

Phytron Instruments, Inc.
986 Leonello Ave.
Los Altos, CA 94024
Tel: (650) 604-5183
Fax: (650) 969-0380
E-mail: pdrlub@ibm.net

Electron beam (E-BEAM) water treatment is an advanced oxidation technology. It causes decomposition of organic contaminants in water. The process is pure (no catalysts), simple (ambient temperature and pressure), energy-efficient.

Energetic electrons that interact with water form reactive species, foremost the highly oxidizing hydroxyl radicals (OH.) and reducing hydrogen atoms (H.) plus hydrated electrons (eeq-). E-BEAM irradiation is the only water purification process that produces simultaneously and in high concentrations reducing and oxidizing species. Having different reactivities and diffusivities, the chemistry is complex. The radicals react fast with water contaminants such as trichloroethylene, chloroform, bromoform, benzene, phenols, and many others. With sufficiently high doses (approximately 8 kJ/kg), all contaminants are broken down into water, carbon dioxide and harmless organic acids such carboxylic acids and hydrochloric acid.

Commercial E-BEAM plants have been shown to be economically competitive with conventional water treatment technologies such as chlorination and ozonation. However, they run at very high energies (2 MeV) and are energy-inefficient (approx. 40%).

X-ray protection and high voltage insulation requirements make them stationary. A small E-BEAM water treatment system can be built with low to medium beam energies.

A portable E-BEAM system is under development, designed for space inhabitation and long term space travel. Portability is achieved by using medium beam energy of about 200 keV without sacrificing beam efficiency. This is done by using a very thin, electron-transparent window that minimizes energy losses. A unique design of the high voltage power supply allows for excellent beam energy conversion. These steps shall bring down the power requirement to a level acceptable by NASA standards.

PC 115, Page 135

Pre-processing Technologies for Application in Space Missions

George M. Savage and Luis F. Diaz

CalRecovery, Inc.
1850 Gateway Blvd., Suite 1060
Concord, CA  94520
Tel: 925-356-3700
Fax: 925-356-7956
E-mail: Gsavage@calrecovery.com

Efficient chemical, biological, and thermal processing of solid waste in space for resource recovery will require preparatory processing (i.e., pre-processing) of the waste. Several types of pre-processing unit operations are used in terrestrial waste recovery systems. The more prevalent operations, size reduction and screening, address key physical parameters relevant to the efficiency and reaction rates of chemical, biological, and thermal conversion processes - namely, maximum particle size and uniformity of particle size distribution. Other pre-processing unit operations of relevance are air classification, magnetic separation, and densification. Each of these unit operations may be applicable for the processing of solid waste in space environments if properly designed and operated. Before being feasible for conditions in space, commercially available pre-processing equipment may need to be modified in order to overcome some substantial disadvantages related to space missions, e.g., bulkiness and large mass, among other detracting features. On the other hand, perhaps altogether new equipment may have to be designed and tested. This presentation focuses on pre-processing operations, their fundamental principles, and their utility in space applications. Also discussed are the potential limitations of using the unit operations in space and potential improvements to increase the technical feasibility of pre-processing operations. A specific research program is also described for optimizing a size reduction technology for application in space.

PC 116, Page 136

Preliminary Design Guidelines for Rotating Taylor-Couette Filtration

John A. Schwille
Department of Mechanical Engineering, Northwestern University, Evanston IL 60208
Tel: 847-491-4180; Fax: 847-491-3915; E-mail: j-schwille@nwu.edu

Deepanjan Mitra
Department of Mechanical Engineering, Northwestern University, Evanston IL 60208
Tel: 847-491-4180; Fax: 847-491-3915; E-mail: drm715@hecky.acns.nwu.edu

Richard M. Lueptow
Department of Mechanical Engineering, Northwestern University, Evanston IL 60208
Tel: 847-491-4180; Fax: 847-491-3915; E-mail: r-lueptow@nwu.edu
Correspondence to: R. Lueptow r-lueptow@nwu.edu

As exploration into space continues, a reliable method of recycling wastewater is essential to avoiding unreasonable amounts of stored water. Current filtration processes suffer from membrane fouling. A potential solution for this is the use of a rotating filter. Rotating filters consisting of a rotating inner filter cylinder and a concentric outer cylinder are widely used for separating plasma from blood. The Taylor vortices formed in the annulus wash particles away from the filter surface. The rotating inner filter produces a centrifugal field and a high shear rate which, along with the vortices, reduce membrane plugging. These filters have potential in any application where filter replacement is an issue. In this work, we are developing guidelines for the optimal design of rotating filtration systems, particularly for long term space missions. The prototype rotating filter used for the experiments consists of an outer cylinder 2.75 inches in diameter and various inner filter cylinders. The inner cylinders can be changed as necessary to study the effects of the filter pore size, radius ratio, and gap width. In addition, the effect of particle size, particle density, feed concentration, transmembrane pressure, and rotational speed are being studied. A 32 run experimental design has been developed according to Taguchi's design of experiments in order to minimize experimental trials and to investigate interactions among the parameters. Initial results show rotating filtration reduces particle buildup on the filter surface. Correlation of the cake layer buildup with concentration is evident. Results will be used to develop a set of design guidelines for rotating filters. [Supported by NASA grant NAG9-1053.]

T 117, Page 137

Phase Separation by Passively Induced Centrifugal Forces

Mr. Cable Kurwitz

Interphase Transport Phenomena Laboratory
Texas A&M University
College Station, Texas 77843

 Many life support systems require separation of gas and liquid phases. Historically this has been achieved by motor driven or surface active devices. However, long duration missions and the drive for low power systems have made passive, centrifugal systems an area of increasing importance.

Several phase separators utilizing passively induced flow fields in stationary cylindrical geometries have been designed, fabricated and tested in the KC-135. One of these devices is part of the Immobilized Microbe Microgravity wastewater Processing System shuttle flight experiment. This separator uses gas/grey water flowing at 4 liters per minute to achieve a near 1-g radial acceleration in a cylinder 4.5 inches in diameter. The active axial length of 4.5 inches allows for an effective buffer volume. This buffer volume allows a residence time, which is sufficient to separate a gas stream, which may be flowing at 0.6 ml/min. The separator consumes 20 watts of equivalent power. Inventory is monitored by an acoustic sensor, which measures the gas/liquid interface in the cylinder. The separator has operated successfully for hundreds of KC-135 parabolas including adverse g-fields as high as several tenths of a "g."

T 118, Page 138

Heat Pump Technology Development for Space Station Thermal Management

V. C. Mei+, R. E. Domitrovic, and F. C. Chen
Oak Ridge National Laboratory
Oak Ridge, Tennessee 37831-6070

T. Chung and R. Sharp
H&R Technical Associates
Oak Ridge, Tennessee 37830

 A space station thermal management system is essential to the success of the space missions. Many thermal management systems can be used in space, but not all of them can meet the required technical and institutional constraints. High system efficiency, adequate capacity, and a high rate of heat dissipation are essential to their proper functioning. A system with high energy efficiency means less power needed for the system. A high rate of heat dissipation means less radiator area is needed. Thermoelectric cooling, for example, would be ideal for space applications because it can be operated under micro-gravity operating conditions, it is reliable, and it does not require any refrigerant. However, its energy efficiency is too low. Absorption systems have been mentioned for space applications, but they are usually very bulky. Vapor compression heat pumps may still be viable for spacecraft thermal management.

 There are two other major concerns regarding the design of a vapor compression heat pump for use in space missions. One is the problem of compressor oil return under micro-gravity operating conditions, and the other is the required high energy efficiency of the heat pump [the coefficient of performance (COP) should be 4.5 or higher]. In the present study, the former concern was addressed with a new compressor design that has an oil filtering and returning mechanism built in the compressor. The latter concern was resolved by incorporating more advanced design features, such as liquid over-feeding, passive charging optimization technology, proper selection of components, and a variable speed drive.

 Liquid overfeeding was developed by the Oak Ridge National Laboratory and was successfully tested on terrestrial air conditioners. The test results showed a 12% improvement in cooling capacity and a 7.5% increase in system COP as a result of using liquid overfeeding. Passive charging optimization technology could further improve the performance of the advanced heat pump at off-design conditions. A variable speed compressor could also improve the overall system energy efficiency if the thermal load of the station varies over a certain period of time. This paper reports on the progress in developing and potential means of improving an experimental heat pump for space thermal management applications.

Corresponding author:
V. C. Mei
Oak Ridge National Laboratory
P. O. Box 2008
Oak Ridge, TN 37831-6070
Tel: 865-576-4945; Fax: 865-574-9338; E-mail: meivc@ornl.gov

T 119, Page 139

Thermal Sensitivity with a Liquid Cooling Garment: Optimization of Automatic Thermal Control in a Space Suit

Karen L. Nyberg

Mail Code EC2
NASA Johnson Space Center
Tel: (281) 483-9237
Fax: (281) 483-9167
E-mail: knyberg@ems.jsc.nasa.gov

Optimization of space suit thermal control systems mandates the minimization of power and resource consumption while maintaining comfortable conditions for the astronaut. By understanding the range of inlet temperatures that will provide adequate comfort for the astronaut, the efficiency of an automatic thermal controller can be improved. A reduction in the number of valve changes required to achieve a desired temperature will necessarily decrease the power consumption while the knowledge of cooling requirements to avoid overcooling could greatly reduce the amount of resources used.

A series of tests were conducted at the Johnson Space Center in an effort to quantify the human thermoregulatory role in maintaining thermal neutrality while a liquid cooling garment (LCG) provides cooling at the skin surface. Eight test subjects participated in the study in which water temperature to the LCG was controlled according to one of two thermal profiles. Subjects provided discrete and continuous record of their subjective thermal comfort as they rested and walked on a treadmill at a steady pace. Measurements of energy transfer and body temperatures were also monitored and recorded throughout each test period.

The relationship between subjective thermal comfort ratings and quantitative body energy storage will be evaluated and discussed. Consideration will be given to the magnitude of thermal changes that are detectable to the human test subject over a range of temperatures and metabolic conditions. A comparison will also be made concerning the effects of temperature direction of movement on relative sensitivity. Test results will be correlated strongly with the performance of an automatic thermal controller for an advanced space suit.

T 120, Page 140

Theoretical Study of the Performance of A Heat Pipe Architecture for Extra-Vehicular Life Support in Cold Convective Environments

Rube B. Williams, Ph.D.

Visiting Assistant Professor, Texas A&M University.

A heat pipe thermal control concept is investigated in a paper study from the standpoint of extra-vehicular life support in cold convective environments. The Martian environment is considered. Performance limits for selected architectures of heat pipes and selected working fluids, in support of maintaining uniform surface temperatures for a human-like geometry, are investigated.

Rube B. Williams, Jr., Ph.D.
Visiting Assistant Professor
Nuclear Engineering,
Texas A&M University
College Station, Texas 77843-3133
Tel: (409) 845-4166
Fax: 409/845-6443

UW 121, Page 141

Supercritical Air as a Gas Supply and Coolant in Warm Water Diving

JR Clarke,1 D Doerr,2 B Shykoff,1 and D Warkander1

1Navy Experimental Diving Unit
2NASA, Kennedy Space Center

In studies of diver tolerance to warm water, Navy Experimental Diving Unit (NEDU) divers tolerated moderate work in 101° F water for no more than 30 min, and then with symptoms of exhaustion. We are thus looking for engineering solutions to the problems associated with warm water diving. To this end, we are partnering with NASA, KSC to test the Supercritical Air Mobility Pack (SCAMP), developed through a NASA sponsored SBIR with Aerospace Design and Development, Inc. Supercritical air is a cryogenic fluid at a temperature above -230° F (~77 K) and pressure greater than 550 psi. The US Navy has previously used liquid air SCUBA for experimental diving, and NEDU has tested a prototype liquid air unit designed for space applications. However, this is the first time NEDU has tested a cryogenic SCBA that simultaneously provides breathing gas at positive pressure and cools the user by exchanging heat between a diver worn tube suit and the cryogenic dewar. Aside from the unit's cooling ability, NEDU is interested in the supercritical air unit due to the single phase nature of the stored fluid, with resultant position independence of the gas supply, and the absence of oxygen enrichment. We also found that the tested SCAMP, rated for an hour duration with moderate work loads, had duration reduced to approximately 35 min in a 120° F environmental chamber. Nevertheless, after the exercise period, subjects were relatively cool and comfortable. NEDU and NASA/KSC are developing a computer model to describe the complex thermal behavior of this unit when used in warm water.