|ognizant Communication Corporation|
International Journal for Human Support Research
(Formerly Life Support and Biosphere Science)
VOLUME 11, NUMBERS 1/2
Habitation, Vol. 11, pp. 5-14
1542-9660/06 $60.00 + .00
Copyright © 2006 Cognizant Comm. Corp.
Printed in the USA. All rights reserved.
A Flexible Microsensor Array for Root Zone Monitoring of a Porous Tube Plant Growth System for Microgravity
Sandeep Sathyan,1 Chang-Soo Kim,2 H. Troy Nagle,3 Christopher S. Brown,4 and D. Marshall Porterfield5
1Department of Electrical and Computer Engineering, University
of Missouri-Rolla, Rolla, MO 65409, USA
2Departments of Electrical & Computer Engineering and Biological Sciences, University of Missouri-Rolla, Rolla, MO 65409, USA
3 Biomedical MicroSensors Laboratory, Department of Electrical and Computer Engineering, North Carolina State University, Raleigh, NC 27695-7911, USA
4Kenan Institute for Engineering, Technology, & Science, North Carolina State University, Raleigh, NC 27695-7911, USA
5Department of Agricultural & Biological Engineering, and Department of Horticulture & Landscape Architecture, Purdue University, W. Lafayette, IN 47907, USA
Control of oxygen and water in the root zone is vital to support plant growth in the microgravity environment. The ability to control these sometimes opposing parameters in the root zone is dependent upon the availability of sensors to detect these components and provide feedback for control systems. The objective of this work was to design and build advanced sensor technology that could be adapted to future hardware systems and monitor the balance between water and oxygen availability. Here we demonstrate the feasibility of using microsensor arrays on a flexible substrate for dissolved oxygen detection, and a four-electrode impedance microprobe for surface wetness detection on the surface of a porous tube (PT) nutrient delivery system. The Flexible Dissolved Oxygen Microsensor (FDOM) reported surface oxygen concentrations that correlated with the oxygen concentrations of the solution inside the PT when operated at positive pressures. But it showed convergence to zero oxygen values at negative pressures due to inadequate water film formation on the porous tube surface. The four-electrode microprobe (FEM) is useful as a basic wetness detector as it provides a clear differentiation between dry and wet surfaces. This is important as the output of the FDOM is dramatically affected by the differences in oxygen concentrations in gas and aqueous phases. The unique features of the FDOM array and FEM include small size, simple structure, mechanical flexibility, and multipoint sensing. The demonstrated technology is anticipated to provide reliable sensor feedback monitoring specialized plant nutrient delivery systems in both terrestrial and microgravity environments.
Key words: Dissolved oxygen microsensor; Conductivity microprobe; Porous tube; Plant nutrient delivery system; Polyimide
Address correspondence to D. Marshall Porterfield, Department of Agricultural & Biological Engineering, and Department of Horticulture & Landscape Architecture, Purdue University, W. Lafayette, IN 47907, USA. Tel: 765-494-1190; Fax: 765-496-1115; E-mail: email@example.com
Physiological Design of a Space Suit Cooling/Warming Garment and Thermal Control as Keys to Improve Astronaut Comfort, Performance, and Safety
Victor S. Koscheyev,1 Gloria R. Leon,2 Aitor Coca,1 and Robert C. Treviño3
1Department of Kinesiology, University of Minnesota, Cooke
Hall, 1900 University Ave., S.E., Minneapolis, MN 55455, USA
2Department of Psychology, University of Minnesota, Elliott Hall, 75 E. River Rd., Minneapolis, MN 55455, USA
3EC5/Advanced EVA Technology, NASA Johnston Space Center, 2101 NASA Road One, Houston, TX 77058, USA
We describe our past and current program of research focused on the application of physiological principles of heat transfer to advance the effectiveness of space suits currently used by astronauts and for future lunar or Mars missions. The output of these investigations is as follows: 1) a physiologically based more lightweight shortened liquid cooling/warming garment (SLCWG) designed to increase effectiveness while minimizing circulating water volume, flow rate, and energy consumption; 2) physiologically designed warming gloves with tubing bypass to mitigate hand/finger discomfort and augment heat delivery by blood flow; 3) augmentation of heat delivery by blood flow to improve lower limb blood circulation and sustain comfort; 4) an adequate index of thermal balance/imbalance and comfort with potential to initiate automatic thermal feedback to an advanced spacesuit portable life support system.
Key words: Space thermal comfort; Physiologically designed EVA garment; Physiologically designed EVA gloves; Thermal monitoring indices
Address correspondence to Victor S. Koscheyev, M.D., Ph.D., Department of Kinesiology, University of Minnesota, Cooke Hall, 1900 University Ave., S.E., Minneapolis, MN 55455, USA. Tel: (612) 625-8827; Fax: (612) 625-1061; E-mail: firstname.lastname@example.org
Participant Observation of a Mars Surface Habitat Mission Simulation
William J. Clancey
NASA-Ames Research Center, Intelligent Systems Division MS269-3, Moffett
Field, CA 94035, USA
Florida Institute for Human and Machine Cognition, Pensacola, FL, USA
For 12 days in April 2002 we performed a closed simulation in the Mars Desert Research Station in Utah, isolated from other people, while exploring the area and sharing daily chores. Email provided our only means of contact; all mission-related messages were mediated by a remote mission support team. This protocol enabled a systematic and controlled study of crew activities, scheduling, and use of space. The study was primarily a methodological experiment in participant observation and work practice analysis, gathering quantitative data as part of an ethnographic study. The work practice analysis focused on two questions: Where did the time go--why did the crew feel rushed and unable to complete their work? How can we measure productivity, to compare habitat designs, schedules, roles, and tools? Analysis suggests that a simple scheduling change--having lunch and dinner earlier, plus eliminating afternoon meetings--increased the available productive time by 41%. Furthermore, observation of work practices suggested how to eliminate direct use of GPS devices by the crew, illustrating how an ethnographic study can help produce dramatically new operations concepts.
Key words: Closed simulation; Mars Desert Research Station; Productivity; Participant observation; Work practice; Ethnographic study
Address correspondence to William J. Clancey, NASA-Ames Research Center, Intelligent Systems Division MS269-3, Moffett Field, CA 94035, USA. E-mail: William.J.Clancey@nasa.gov
Hypobaric Conditions Affect Gas Exchange, Ethylene Evolution, and Growth of Lettuce for Advanced Life Support Systems (ALS)
Chuanjiu He,1 Fred T. Davies, Jr.,1 and Ronald E. Lacey2
1Department of Horticultural Sciences, Texas A&M University,
College Station, TX 77843-2133, USA
2Department of Biological & Agricultural Engineering, Texas A&M University, College Station, TX 77843-2117, USA
There are important engineering and crop production advantages in growing plants under hypobaric (reduced atmospheric pressure) conditions for extraterrestrial base or spaceflight environments. Advantages include reduced pay load, greater safety because of lower pressure gradients, and improved plant growth. Elevated levels of the plant hormone, ethylene, can occur in enclosed crop production systems and in spaceflight environments, leading to adverse plant growth and sterility. Objectives of this research were to characterize the influence of hypobaria on growth and ethylene evolution of lettuce (Lactuca sativa L. cv. Buttercrunch). Growth was comparable in lettuce grown under 50 and 101 kPa (ambient) total gas pressures in a series of short-term experiments lasting up to 6 days. However, tip burn occurred under ambient pressure, but not low pressure. Tip burn also increased under high light (600 compared to 300 mmol m-2 s-1) and high pCO2 (600 compared to 100 Pa). Under ambient pressure, there were higher CO2 assimilation rates and considerably greater dark respiration rates (higher night consumption of metabolites) compared to low pressure. This could lead to greater growth (biomass production) of plants grown in low pressure over longer crop production cycles. Ethylene evolution was lower under low than ambient pressure.
Key words: Advanced Life Support (ALS); CELSS; Closed systems; Controlled environment; Ethylene; Hypobaria; Hypoxia; Growth chambers; Low pressure; Low pressure plant growth system (LPPG); Partial pressure of oxygen (pO2) and carbon dioxide (pCO2); Space science
Address correspondence to Fred Davies, Department of Horticultural Sciences, Texas A&M University, College Station, TX 77843-2133, USA. Tel: (979) 845-4524; Fax: (979) 845-0627; E-mail: email@example.com
The Eva Evaluation Exoskeleton (E3): A Proposed Tool for Studying Human-System Interaction in the Space Environment
Todd J. Mosher,1 Megan Mitchell,2 and Kelly Packard3
1Lockheed Martin Space Systems Company, P.O. Box 179, Denver
CO, 80201, USA
2P.O. Box 140901, Anchorage, AK 99514, USA
31819 E. 1425 N., Layton, UT 84040, USA
The EVA Evaluation Exoskeleton (E3) is an innovative approach to improve the process of designing human-system interfaces. E3 represents a new tool in participatory ergonomics that would help designers without significant training in human factors engineering to better understand human factors requirements and best practices in design. It is a new tool to better understand human-system interaction in the space environment and thus addresses risks associated with this human-system interaction.
Key words: Spacesuit ergonomics; Human factors; Extravehicular activity (EVA)
Address correspondence to Dr. Todd J. Mosher, Lockheed Martin Space Systems Company, P.O. Box 179, Denver CO, 80201, USA. Tel: (303) 971-9183; Fax: (303) 971-3748; E-mail: firstname.lastname@example.org
Menu Optimization for an Earth-Based Advanced Life Support System (ALSS) Test Bed Considering Crop Cultivation Scheduling
Tsuyoshi Masuda, Yasuhiro Tako, and Masahiro Endo
Institute for Environmental Sciences, Department of Environmental Simulation, Japan
The Closed Ecology Experiment Facilities (CEEF) is an Earth-based Advanced Life Support System (ALSS) test bed in Japan. A diet optimization model for the CEEF was developed using mixed integer linear programming (MILP) to consider crop cultivation scheduling. The diet optimization model provided a feasible minimized cultivation area for the CEEF using input cultivation data from the CEEF and assumptions for the habitation experiment. A practical, utilizable cultivation schedule was generated using the decision variables of the result and then verified. The developed schedule could supply necessary ingredients for the optimized diet with appropriate timing, although there were some practical issues on cultivation including complexity of the planting and scheduling.
Key words: Menu optimization; Cultivation schedule; Mixed integer linear programming; Closed Ecology Experiment Facilities (CEEF); Advanced Life Support System (ALSS) test
Address correspondence to Tsuyoshi Masuda, 1-7 Ienomae, Obuchi, Rokkasho, Kamikita, Aomori, 039-3212 Japan. Tel: 175-71-0802; Fax: 175-71-0800; E-mail: email@example.com