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Wheeler, Raymond M.

Publications and source records attributed to Wheeler, Raymond M..

At least 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
NASA NTRS2012

NASA Advanced Life Support Technology Testing and Development

Prior to 2010, NASA's advanced life support research and development was carried out primarily under the Exploration Life Support Project of NASA's Exploration Systems Mission Directorate. In 2011, the Exploration Life Support Project was merged with other projects covering Fire Prevention/Suppression, Radiation Protection, Advanced Environmental Monitoring and Control, and Thermal Control Systems. This consolidated project was called Life Support and Habitation Systems, which was managed under the Exploration Systems Mission Directorate. In 2012, NASA re-organized major directorates within the agency, which eliminated the Exploration Systems Mission Directorate and created the Office of the Chief Technologist (OCT). Life support research and development is currently conducted within the Office of the Chief Technologist, under the Next Generation Life Support Project, and within the Human Exploration Operation Missions Directorate under several Advanced Exploration System projects. These Advanced Exploration Systems projects include various themes of life support technology testing, including atmospheric management, water management, logistics and waste management, and habitation systems. Food crop testing is currently conducted as part of the Deep Space Habitation (DSH) project within the Advanced Exploration Systems Program. This testing is focused on growing salad crops that could supplement the crew's diet during near term missions.

Wheeler, Raymond M.↗
NASA NTRS2012

Plant Atrium System for Food Production in NASA's Deep Space Habitat Tests

In preparation for future human exploration missions to space, human habitat designs and concepts need to be tested to assess integration issues, power requirements, crew operations, and technology I subsystem performance. One potential subsystem for early habitats is supplemental food production. Fresh foods, such as vegetables and small fruits, could be harvested on a continuous basis to improve the diet and quality of life. The system would need to fit conveniently into the habitat and not interfere with other components or operations. To test this concept, a plant growing "atrium" was designed to surround the lift between the lower and upper modules of the Deep Space Habitat and deployed at NASA DRA TS test site in 2011 and at NASA's JSC in 20I2. With this approach, un-utilized volume provided an area for vegetable growth. For the 20 II test, mizuna, lettuce, basil, radish and sweetpotato plants were grown in trays using commercially available red I blue LED light fixtures. Seedlings were transplanted into the atrium and cared for by the crew. Plants were then harvested two weeks later following completion of the test. In 20I2, mizuna, lettuce, and radish plants were grown similarly but under flat panel banks of white LEDs. In 20 I2, the crew went through plant harvesting, including sanitizing the leafy greens and radishes, which were then consumed. Each test demonstrated successful production of vegetables within a functional hab module. The round red I blue LEDs for the 20Il test lighting cast a purple light in the hab, and were less uniformly distributed over the plant trays. The white LED panels provided broad spectrum light with more uniform distribution. Post-test questionnaires showed that the crew enjoyed tending and consuming the plants, and that the white LED light in 2012 provided welcome extra light for the main hab area.

Massa, Gioia↗
NASA NTRS2012

Microbial Characterization Space Solid Wastes Treated with a Heat Melt Compactor

The on going purpose of the project efforts was to characterize and determine the fate of microorganisms in space-generated solid wastes before and after processing by candidate solid waste processing. For FY 11, the candidate technology that was assessed was the Heat Melt Compactor (HMC). The scope included five HMC. product disks produced at ARC from either simulated space-generated trash or from actual space trash, Volume F compartment wet waste, returned on STS 130. This project used conventional microbiological methods to detect and enumerate microorganisms in heat melt compaction (HMC) product disks as well as surface swab samples of the HMC hardware before and after operation. In addition, biological indicators were added to the STS trash prior to compaction in order to determine if these spore-forming bacteria could survive the HMC processing conditions, i.e., high temperature (160 C) over a long duration (3 hrs). To ensure that surface dwelling microbes did not contaminate HMC product disk interiors, the disk surfaces were sanitized with 70% alcohol. Microbiological assays were run before and after sanitization and found that sanitization greatly reduced the number of identified isolates but did not totally eliminate them. To characterize the interior of the disks, ten 1.25 cm diameter core samples were aseptically obtained for each disk. These were run through the microbial characterization analyses. Low counts of bacteria, on the order of 5 to 50 per core, were found, indicating that the HMC operating conditions might not be sufficient for waste sterilization. However, the direct counts were 6 to 8 orders of magnitude greater, indicating that the vast majority of microbes present in the wastes were dead or non-cultivable. An additional indication that the HMC was sterilizing the wastes was the results from the added commercial spore test strips to the wastes prior to HMC operation. Nearly all could be recovered from the HMC disks post-operation and all were showed negative growth when run through the manufacturer's protocol, meaning that the 106 or so spores impregnated into the strips were dead. Control test strips, i.e., not exposed to the HMC conditions were all strongly positive. One area of concern is that the identities of isolates from the cultivable counts included several human pathogens, namely Staphylococcus aureus. The project reported here provides microbial characterization support to the Waste Management Systems element of the Life Support and Habitation Systems program.

Strayer, Richard F.↗
NASA NTRS2011

The Effect of Plant Cultivar, Growth Media, Harvest Method and Post Harvest Treatment on the Microbiology of Edible Crops

Systems for the growth of crops in closed environments are being developed and tested for potential use in space applications to provide a source of fresh food. Plant growth conditions, growth media composition and harvest methods can have an effect on the microbial population of the plant, and therefore should be considered along with the optimization of plant growth and harvest yields to ensure a safe and palatable food crop. This work examines the effect of plant cultivar, growth media, and harvest method on plant microbial populations. Twelve varieties of leafy greens and herbs were grown on a mixture of Fafard #2 and Arcillite in the pillow root containment system currently being considered for the VEGGIE plant growth unit developed by Orbitec. In addition, ,Sierra and Outredgeous lettuce varieties were grown in three different mixtures (Fafard #2, Ardllite, and Perlite/Vermiculite). The plants were analyzed for microbial density. Two harvest methods, "cut and come again" (CACA) and terminal harvest were also compared. In one set ofexpe'riments red leaf lettuce and mizuna were grown in pots in a Biomass Production System for education. Plants were harvested every two weeks by either method. Another set of experiments was performed using the rooting pillows to grow 5 varieties of leafy greens and cut harvesting at different intervals. Radishes were harvested and replanted at two-week intervals. Results indicate up to a 3 IOglO difference in microbial counts between some varieties of plants. Rooting medium resulted in an approximately 2 IOglO lower count in the lettuce grown in arscillite then those grown in the other mixtures. Harvest method and frequency had less impact on microbial counts only showing a significant increase in one variety of plant. Post harvest methods to decrease the bacterial counts on edible crops were investigated in these and other experiments. The effectiveness of PRO-SAN and UV-C radiation is compared.

Hummerick, Mary P.↗
NASA NTRS2011

VEGGIE Pillow Testing: Microbial Analysis of Cut-and-Come-Again Species Testing

With NASA focused on researching and developing technology for deep space missions, the need for a reliable supplementary food source must also be considered. For the ISS, resupplying the food source is more practical and cost effect since the facility is in low Earth orbit. However, as NASA attempts to push the frontier in space, the costs and distance for resupply will surely increase. Plants would contribute to the proportion of food and reduce the dependency on food from Earth. In addition, plants would provide oxygen production, carbon dioxide removal, and psychological benefits. As a result, a vegetable production system, VEGGIE, was developed for NASA to produce salad crops with minimal resources and study the beneficial effects. The VEGGIE pillow is a single use bag for growing crops that is used with the VEGGIE hardware. The VEGGIE pillow was tested with four different species of plants with the cut-and-come-again harvest method to determine the greatest yield. Instead of harvesting the entire plant, the harvest consisted of cutting leaves to allow the plant to regrow leaves. The harvest methods included cutting the plants weekly, bi-weekly, and monthly. A fifth plant species, radishes, was also harvested and replanted. Microbial load analysis and an ANOVA significance test were utilized. The data suggest that the two Brassica plants have the greatest yields; however, the microbial load is also greatest for the two plants per gram of fresh weight. Furthermore, the results support the reuse of pillows for multiple harvests as shown by the replanted radishes.

Nguyen, Bao-Thang↗
NASA NTRS2011

Characterization of Volume F Trash from Four Recent STS Missions: Microbial Occurrence, Numbers, and Identifications

The fate of space-generated solid wastes, including trash, for future missions is under consideration by NASA. Several potential treatment options are under active technology development. Potential fates for space-generated solid wastes: Storage without treatment; storage after treatment(s) including volume reduction, water recovery, sterilization, and recovery plus recycling of waste materials. For this study, a microbial characterization was made on trash returned from four recent STS missions. The material analyzed were 'Volume F' trash and other bags of accompanying trash. This is the second of two submitted papers on these wastes. This first one covered trash content, weight and water content. Upon receipt, usually within 2 days of landing, trash contents were catalogued and placed into categories: drink containers, food waste, personal hygiene items, and packaging materials, i.e., plastic film and duct tape. Microbial counts were obtained with cultivatable counts on agar media and direct counts using Acridine Orange fluorescent stain (AODC). Trash bag surfaces, 25 square cm , were also sampled. Direct counts were approximately 1 x 10(exp 6) microbes/square cm and cultivatable counts ranged from 1 x 10 to 1 X 10(exp 4) microbes/ square cm-2. Aerobic microbes, aerobic sporeformers, and yeasts plus molds were common for all four missions. Waste items from each category were placed into sterile ziplock bags and 1.5 L sterile DI water added. These were then dispersed by hand shaking for 2 min. prior to inoculation of count media or determining AODC. In general, cultivatable microbes were found in drinks, food wastes, and personal hygiene items. Direct counts were usually higher than cultivatable counts. Some pathogens were found: Staphylococcus auerus, Escherichia coli (fecal wastes). Count ranges: drink pouches - AODC 2 x 10(exp 6) to 1 X 10(exp 8) g(sub fw) (exp -1); cultivatable counts variable between missions; food wastes: Direct counts were close to aerobic plate counts. Counts ranged from 10(exp 6) to 10(exp 9) per g(sub fw). Identities of isolates from cultivation media were obtained using a Biolog Microbial ID System or microSEQ molecular ID methodology using an ABI3130 gene analyzer.

Strayer, Richard F.↗
NASA NTRS2011

Characterization of Volume F Trash from Four Recent STS Missions: Weights, Categorization, Water Content

The fate of space-generated solid wastes, including trash, for future missions is under consideration by NASA. Several potential treatment options are under consideration and active technology development. Potential fates for space-generated solid wastes are: Storage without treatment; storage after treatment(s) including volume reduction, water recovery, sterilization, and recovery plus recycling of waste materials. Recycling might be important for partial or full closure scenarios because of the prohibitive costs associated with resupply of consumable materials. For this study, we determined the composition of trash returned from four recent STS missions. The trash material was 'Volume F' trash and other trash, in large zip-lock bags, that accompanied the Volume F trash. This is the first of two submitted papers on these wastes. This one will cover trash content, weight and water content. The other will report on the microbial Characterization of this trash. STS trash was usually made available within 2 days of landing at KSC. The Volume F bag was weighed, opened and the contents were catalogued and placed into one of the following categories: food waste (and containers), drink containers, personal hygiene items - including EVA maximum absorbent garments (MAGs)and Elbow packs (daily toilet wipes, etc), paper, and packaging materials - plastic firm and duct tape. Trash generation rates for the four STS missions: Total wet trash was 0.602 plus or minus 0.089 kg(sub wet) crew(sup -1) d(sup -1) containing about 25% water at 0.154 plus or minus 0.030 kg(sub water) crew(sup -1) d(sup -1) (avg plus or minus stdev). Cataloguing by category: personal hygiene wastes accounted for 50% of the total trash and 69% of the total water for the four missions; drink items were 16% of total weight and 16% water; food wastes were 22% of total weight and 15% of the water; office waste and plastic film were 2% and 11% of the total waste and did not contain any water. The results can be used by NASA to determine requirements and criteria for Waste Management Systems on future missions.

Strayer, Richard F.↗
NASA NTRS2011

Ammonia Offgassing from SA9T

NH3 is a degradation product of SA9T, a solid-amine sorbent developed by Hamilton Sundstrand, that is continually emitted into the gas stream being conditioned by this sorbent. NH3 offgassing rates were measured using FTIR spectroscopy using a packed bed at similar contact times as offgassing tests conducted at Hamilton Sundstrand and at the Ames Research Center. The bed was challenged with moist air at several flow rates and humidities and NH3 concentration of the effluent was measured for several hours. The NH3 offgassing rates in open-loop testing were calculated from the steady state outlet NH3 concentration and flow rate. NH3 offgassing rates from SA9T were found to be influenced by the contact time with the adsorbent (flow rate) and by the humidity of the inlet gas stream, which are consistent with previous studies. Closed-loop vacuum-swing adsorption cycling rates verified that NH3 offgassing continues when a constant source of water vapor is present.

Monje, Oscar↗
NASA NTRS2011

Operational Evaluation of VEGGIE Food Production System in the Habitat Demonstration Unit

The 2010 Desert Research and Technology Studies (DRATS) of the VEGGIE Food Production System in the Habitat Demonstration Unit (HDU) Pressurized Excursion Module (PEM) was the first operational evaluation of salad crop production technology in a NASA analog test. A systematic evaluation of rooting media and nutrient delivery systems were evaluated for three lettuce cultivars that have shown promise as candidates for a surface based food production system. The VEGGIE nutrient delivery system worked well, was able to be maintained by multiple operators with a minimum of training, and supported excellent lettuce growth for the duration of the test. A Hazard Analysis and Critical Control Point (HACCP) evaluation was performed using ProSan(tm) as sanitation agent prior to consumption was approved, and the crew was allowed to consume the lettuce grown using the VEGGIE light cap and gravity based nutrient delivery system at the completion of the 14-day DRAT field test. The DRAT field test validated the crew operations; Growth of all lettuce cultivars was excellent. The operational DRAT field testing in the HDU identified light quality issues related to morphology and pigment development that will need to be addressed through additional testing. Feedback from the crew, ground support personnel, and human factors leads was uniformly positive on the psychological value of having the crop production system in the excursion module. A number of areas have been identified for future work, to minimize the "footprint" of the Food Production system through creative use of unused wall and floor space in the unit.

Stutte, Gary W.↗
NASA NTRS2011

Operation Evaluation of the VEGGIE Food Production System in the Habitat Demonstration Unit

The 2010 Desert Research and Technology Studies (DRATS) of the VEGGIE Food Production System in the Habitat Demonstration Unit (HDU) Pressurized Excursion Module (PEM) was the first operational evaluation of salad crop production technology in a NASA analog test. A systematic evaluation of rooting media and nutrient delivery systems were evaluated for three lettuce cultivars that have shown promise as candidates for a surface based food production system. The VEGGIE nutrient delivery system worked well, was able to be maintained by multiple operators with a minimum of training, and supported excellent lettuce growth for the duration of the test. A Hazard Analysis and Critical Control Point (HACCP) evaluation was performed using ProSantm as sanitation agent prior to consumption was approved, and the crew was allowed to consume the lettuce grown using the VEGGIE light cap and gravity based nutrient delivery system at the completion of the 14-day DRAT field test. The DRAT field test validated the crew operations; Growth of all lettuce cultivars was excellent. The operational DRAT field testing in the HDU identified light quality issues related to morphology and pigment development that will need to be addressed through additional testing. Feedback from the crew, ground support personnel, and human factors leads was uniformly positive on the psychological value of having the crop production system in the excursion module. A number of areas have been identified for future work, to minimize the "footprint" of the Food Production system through creative use of unused wall and floor space in the unit.

Stutte, Gary W.↗
NASA NTRS2011

Feasibility of Ultraviolet Light Emitting Diodes as an Alternative Light Source for Photocatalysis

The objective of this study was to determine whether ultraviolet light emitting diodes (UV-LEDs) could serve as an alternative photon source efficiently for heterogeneous photocatalytic oxidation (PCO). An LED module consisting of 12 high-power UV-A LEDs was designed to be interchangeable with a UV-A fluorescent black light blue (BLB) lamp in a Silica-Titania Composite (STC) packed bed annular reactor. Lighting and thermal properties were characterized to assess the uniformity and total irradiant output. A forward current of (I(sub F)) 100 mA delivered an average irradiance of 4.0 m W cm(exp -2), which is equivalent to the maximum output of the BLB, but the irradiance of the LED module was less uniform than that of the BLB. The LED- and BLB-reactors were tested for the oxidization of 50 ppmv ethanol in a continuous flow-through mode with 0.94 sec space time. At the same irradiance, the UV-A LED reactor resulted in a lower PCO rate constant than the UV-A BLB reactor (19.8 vs. 28.6 nM CO2 sec-I), and consequently lower ethanol removal (80% vs. 91%) and mineralization efficiency (28% vs. 44%). Ethanol mineralization increased in direct proportion to the irradiance at the catalyst surface. This result suggests that reduced ethanol mineralization in the LED- reactor could be traced to uneven irradiance over the photocatalyst, leaving a portion of the catalyst was under-irradiated. The potential of UV-A LEDs may be fully realized by optimizing the light distribution over the catalyst and utilizing their instantaneous "on" and "off' feature for periodic irradiation. Nevertheless, the current UV-A LED module had the same wall plug efficiency (WPE) of 13% as that of the UV-A BLB. These results demonstrated that UV-A LEDs are a viable photon source both in terms of WPE and PCO efficiency.

Levine, Langanf H.↗
NASA NTRS2011

Concept for Sustained Plant Production on ISS Using VEGGIE Capillary Mat Rooting System

Plant growth in microgravity presents unique challenges associated with maintaining appropriate conditions for seed germination, seedling establishment, maturation and harvest. They include maintaining appropriate soil moisture content, nutrient balance, atmospheric mixing and containment. Sustained production imposes additional challenges of harvesting, replanting, and safety. The VEGGIE is a deployable (collapsible) plant growth chamber developed as part of a NASA SBIR Phase II by Orbitec, Madison, WI. The intent of VEGGIE is to provide a low-resource system to produce fresh vegetables for the crew on long duration missions. The VEGGIE uses and LED array for lighting, an expandable bellows for containment, and a capillary matting system for nutrient and water delivery. The project evaluated a number of approaches to achieve sustained production, and repeated plantings, using the capillary rooting system. A number of different root media, seed containment, and nutrient delivery systems were evaluated and effects on seed germination and growth were evaluated. A number of issues limiting sustained production, such as accumulation of nutrients, uniform water, elevated vapor pressure deficit, and media containment were identified. A concept using pre-planted rooting packs shown to effectively address a number of those issues and is a promising approach for future development as a planting system for microgravity conditions.

Stutte, Gary W.↗
NASA NTRS2011

Microbial Characterization of Solid-Wastes Treated with Heat Melt Compaction Technology

The research purpose of the project was to determine the fate of microorganisms in space-generated solid wastes after processing by a Heat Melt Compactor (HMC), which is a candidate solid waste treatment technology. Five HMC product disks were generated at Ames Research Center (ARC), Waste Management Systems element. The feed for two was simulated space-generated trash and feed for three was Volume F compartment wet waste returned on STS 130. Conventional microbiological methods were used to detect and enumerate microorganisms in HMC disks and in surface swab samples of HMC hardware before and after operation. Also, biological indicator test strips were added to the STS trash prior to compaction to test if HMC processing conditions, 150 C for approx 3 hr and dehydration, were sufficient to eliminate the test bacteria on the strips. During sample acquisition at KSC, the HMC disk surfaces were sanitized with 70% alcohol to prevent contamination of disk interiors. Results from microbiological assays indicated that numbers of microbes were greatly reduced but not eliminated by the 70% alcohol. Ten 1.25 cm diameter cores were aseptically cut from each disk to sample the disk interior. The core material was run through the microbial characterization analyses after dispersal in sterile diluent. Low counts of viable bacteria (5 to 50 per core) were found but total direct counts were 6 to 8 orders of magnitude greater. These results indicate that the HMC operating conditions might not be sufficient for complete waste sterilization, but the vast majority of microbes present in the wastes were dead or non-cultivable after HMC treatment. The results obtained from analyses of the commercial spore test strips that had been added fo the wastes prior to HMC operation further indicated that the HMC was sterilizing the wastes. Nearly all strips were recovered from the HMC disks and all of these were negative for spore growth when run through the manufacturer's protocol. The 10(exp 6) or so spores impregnated into the strips were no longer viable. Control test strips, i.e., not exposed to the HMC conditions, were all strongly positive. All isolates from the cultivable counts were identified, leading to one concern: several were identified as Staphylococcus aureus, a human pathogen. The project reported here provides microbial characterization support to the Waste Management Systems element of the Life Support and Habitation Systems program.

Strayer, Richard F.↗
NASA NTRS2010

Physiological Disorders in Closed, Controlled Environment Crops

This slide presentation reviews some of the physiological disorders that affect crops grown in closed controlled environments. A physiological disorder is understood to be a problem resulting from the influence of environmental and horticultural factors on plan development other than a problem caused by a pathogen or some other abiotic cause. The topics that are addressed are: (1) Calcium-Related Disorders (2) Oedema (Intumescence) (3) Long-Photoperiod Injury (4) Light Spectral Quality Effects (5) Super-Elevated CO2 Injuries (6) Ethylene (7) Other Disorders (8) Considerations for Closed Space Environments. Views of plant with the disorders are shown.

Wheeler, Raymond M.↗