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  • Man/System Technology and Life Support  (387)
  • Aerospace Medicine  (156)
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  • 1
    Publication Date: 2018-06-11
    Description: The world's first extravehicular activity (EVA) was performed by A. A. Leonov on March 18, 1965 during the Russian Voskhod-2 mission. The first US EVA was executed by Gemini IV astronaut Ed White on June 3, 1965, with an umbilical tether that included communications and an oxygen supply. A hand-held maneuvering unit (HHMU) also was used to test maneuverability during the brief EVA; however the somewhat stiff umbilical limited controlled movement. That constraint, plus difficulty returning through the vehicle hatch, highlighted the need for increased thermal control and improved EVA ergonomics. Clearly, requirements for a useful EVA were interrelated with the vehicle design. The early Gemini EVAs generated requirements for suits providing micro-meteor protection, adequate visual field and eye protection from solar visual and infrared radiation, gloves optimized for dexterity while pressurized, and thermal systems capable of protecting the astronaut while rejecting metabolic heat during high workloads. Subsequent Gemini EVAs built upon this early experience and included development of a portable environmental control and life support systems (ECLSS) and an astronaut maneuvering unit. The ECLSS provided a pressure vessel and controller with functional control over suit pressure, oxygen flow, carbon dioxide removal, humidity, and temperature control. Gemini EVA experience also identified the usefulness of underwater neutral buoyancy and altitude chamber task training, and the importance of developing reliable task timelines. Improved thermal management and carbon dioxide control also were required for high workload tasks. With the Apollo project, EVA activity was primarily on the lunar surface; and suit durability, integrated liquid cooling garments, and low suit operating pressures (3.75 pounds per square inch absolute [psia] or 25.8 kilopascal [kPa],) were required to facilitate longer EVAs with ambulation and significant physical workloads with average metabolic rates of 1000 BTU/hr and peaks of up to 2200 BTU/hr. Mobility was further augmented with the Lunar Roving Vehicle. The Apollo extravehicular mobility unit (EMU) was made up of over 15 components, ranging from a biomedical belt for capturing and transmitting biomedical data, urine and fecal containment systems, a liquid cooling garment, communications cap, a modular portable life support system (PLSS), a boot system, thermal overgloves, and a bubble helmet with eye protection. Apollo lunar astronauts performed successful EVAs on the lunar surface from a 5 psia (34.4 kPa) 100% oxygen environment in the Lunar Lander. A maximum of three EVAs were performed on any mission. For Skylab a modified A7LB suit, used for Apollo 15, was selected. The Skylab astronaut life support assembly (ALSA) provided umbilical support through the life support umbilical (LSU) and used open loop oxygen flow, rather than closed-loop as in Apollo missions. Thermal control was provided by liquid water circulated by spacecraft pumps and electrical power also was provided from the spacecraft via the umbilical. The cabin atmosphere of 5 psia (34.4 kPa), 70% oxygen, provided a normoxic atmosphere and because of the very low nitrogen partial pressures, no special protocols were required to protect against decompression sickness (DCS) as was the case with the Apollo spacecraft with a 5 psi, 100% oxygen environment.
    Keywords: Man/System Technology and Life Support
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  • 2
    Publication Date: 2018-06-11
    Description: Numerous studies have indicated that dysregulation of the immune system occurs during or after spaceflight. Using 21 day -6 degrees head-down tilt bed rest as a spaceflight analog, this study describes the effects of artificial gravity (AG) as a daily countermeasure on immunity, stress and reactivation of clinically important latent herpes viruses. The specific aims were to evaluate psychological and physiological stress, to determine the status of the immune system, and to quantify reactivation of latent herpes viruses. Blood, saliva, and urine samples were collected from each participating subject at different times throughout the study. An immune assessment was performed on all treatment and control subjects that consisted of a comprehensive peripheral immunophenotype analysis, intracellular cytokine profiles and a measurement of T cell function. The treatment group displayed no differences throughout the course of the study with regards to peripheral leukocyte distribution, cytokine production or T cell function. Shedding of Epstein barr virus (EBV), Cytomegalovirus (CMV), and Varicella zoster virus (VZV) was quantified by real time PCR in saliva and urine samples, respectively. There was no significant difference in CMV DNA in the treatment group as compared to the control group. EBV and VZV on the other hand showed a mild reactivation during the study. There were no significant differences in cortisol between the control and treatment groups. In addition, no significant differences between antiviral antibody titers (EBV-VCA, -EA, -EBNA, CMV) or tetramer-positive (EBV, CMV) were found between the two groups. EBV DNA copies in blood were typically undetectable but never exceeded 1,500 copies per 106 PBMCs. Overall, these data indicate that the artificial gravity countermeasure and the 21 day head-down tilt bed rest regimen had no observable adverse effect on immune function.
    Keywords: Aerospace Medicine
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  • 3
    Publication Date: 2018-06-11
    Description: A growing number of studies show strong associations between stress and altered immune function. In vivo studies of chronic and acute stress have demonstrated that cognitive stressors are strongly correlated with high levels of catecholamines (CT) and corticosteroids (CS). Although both CS and CT individually can inhibit the production of T-helper 1 (TH1, type-1 like) cytokines and simultaneously promote the production of T-helper 2 (TH2, type-2 like) cytokines in antigen-specific and mitogen stimulated human leukocyte cultures in vitro, little attention has been focused on the effects of combination CT and CS in immune responses that may be more physiologically relevant. We therefore investigated the combined effects of in vitro CT and CS upon the type-1/type-2 cytokine balance of human peripheral blood mononuclear cells (PBMC) as a model to study the immunomodulatory effects of superimposed acute and chronic stress. Results demonstrated a significant decrease in type-1 cytokine production (IFN-gamma) and a significant increase in type-2 cytokine production (IL-4, IL-10) in our CS+CT incubated cultures when compared to either CT or CS agents alone. Furthermore, variable enhancement of type-1/type-2 immune deviation occurred depending upon when the CT was added. The data suggest that CS can increase the sensitivity of PBMC to the immunomodulatory effects of CT and establishes an in vitro model to study the combined effects of in vivo type-1/type-2 cytokine alterations observed in acute and chronic stress.
    Keywords: Aerospace Medicine
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  • 4
    Publication Date: 2018-06-11
    Description: A viewgraph presentation on the Decompression Sickness (DCS) Contingency Plan for manned spaceflight is shown. The topics include: 1) Approach; 2) DCS Contingency Plan Overview; 3) Extravehicular Activity (EVA) Cuff Classifications; 4) On-orbit Treatment Philosophy; 5) Long Form Malfunction Procedure (MAL); 6) Medical Checklist; 7) Flight Rules; 8) Crew Training; 9) Flight Surgeon / Biomedical Engineer (BME) Training; and 10) DCS Emergency Landing Site.
    Keywords: Aerospace Medicine
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  • 5
    Publication Date: 2018-06-11
    Description: Sonography is the only medical imaging modality aboard the ISS, and is likely to remain the leading imaging modality in future human space flight programs. While trauma sonography (TS) has been well recognized for terrestrial trauma settings, the technique had to be evaluated for suitability in space flight prior to adopting it as an operational capability. The authors found the following four-phased evaluative approach applicable to this task: 1) identifying standard or novel terrestrial techniques for potential use in space medicine; 2) developing and testing these techniques with suggested modifications on the ground (1g) either in clinical settings or in animal models, as appropriate; 3) evaluating and refining the techniques in parabolic flight (0g); and 4) validating and implementing for clinical use in space. In Phase I of the TS project, expert opinion and literature review suggested TS to be a potential screening tool for trauma in space. In Phase II, animal models were developed and tested in ground studies, and clinical studies were carried out in collaborating trauma centers. In Phase III, animal models were flight-tested in the NASA KC-135 Reduced Gravity Laboratory. Preliminary results of the first three phases demonstrated potential clinical utility of TS in microgravity. Phase IV studies have begun to address crew training issues, on-board imaging protocols, and data transfer procedures necessary to offer the modified TS technique for space use.
    Keywords: Aerospace Medicine
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  • 6
    Publication Date: 2018-06-11
    Description: The toxicological assessments of 2 grab sample canisters (GSCs) from the Shuttle are reported. Analytical methods have not changed from earlier reports. The Shuttle atmosphere was acceptable for human respiration.
    Keywords: Man/System Technology and Life Support
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  • 7
    Publication Date: 2018-06-11
    Description: A review of currently available data on in vivo induced chromosome damage in the blood lymphocytes of astronauts proves that, after protracted exposure of a few months or more to space radiation, cytogenetic biodosimetry analyses of blood collected within a week or two of return from space provides a reliable estimate of equivalent radiation dose and risk. Recent studies indicate that biodosimetry estimates from single spaceflights lie within the range expected from physical dosimetry and biophysical models, but very large uncertainties are associated with single individual measurements and the total sample population remains low. Retrospective doses may be more difficult to estimate because of the fairly rapid time-dependent loss of "stable" aberrations in blood lymphocytes. Also, biodosimetry estimates from individuals who participate in multiple missions, or very long (interplanetary) missions, may be complicated by an adaptive response to space radiation and/or changes in lymphocyte survival and repopulation. A discussion of published data is presented and specific issues related to space radiation biodosimetry protocols are discussed.
    Keywords: Aerospace Medicine
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  • 8
    Publication Date: 2018-06-11
    Description: Spacecraft maximum allowable concentrations (SMACs) for C3 to C8, straight-chain, aliphatic aldehydes have been previously assessed and have been documented in volume 4 of Spacecraft Maximum Allowable Concentrations for Selected Airborne Contaminants (James, 2000). These aldehydes as well as associated physical properties are shown in Table 1. The C3 to C8 aliphatic aldehydes can enter the habitable compartments and contaminate breathing air of spacecraft by several routes including incomplete oxidation of alcohols in the Environmental Control and Life Support System (ECLSS) air revitalization subsystem, as a byproduct of human metabolism, through materials off-gassing, or during food preparation. These aldehydes have been detected in the atmosphere of manned space vehicles in the past. Analysis performed by NASA of crew cabin air samples from the Russian Mir Space Station revealed the presence of C3 to C8 aldehydes at concentrations peaking at approximately 0.1 mg/cu m.
    Keywords: Man/System Technology and Life Support
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  • 9
    Publication Date: 2018-06-11
    Description: In this paper, we present a space invariant architecture to enable the Independent Component Analysis (ICA) to solve chemical detection from two unknown mixing chemical sources. The two sets of unknown paired mixture sources are collected via JPL 16-ENose sensor array in the unknown environment with, at most, 12 samples data collected. Our space invariant architecture along with the maximum entropy information technique by Bell and Sejnowski and natural gradient descent by Amari has demonstrated that it is effective to separate the two mixing unknown chemical sources with unknown mixing levels to the array of two original sources under insufficient sampled data. From separated sources, they can be identified by projecting them on the 11 known chemical sources to find the best match for detection. We also present the results of our simulations. These simulations have shown that 100% correct detection could be achieved under the two cases: a) under-completed case where the number of input (mixtures) is larger than number of original chemical sources; and b) regular case where the number of input is as the same as the number of sources while the time invariant architecture approach may face the obstacles: overcomplete case, insufficient data and cumbersome architecture.
    Keywords: Man/System Technology and Life Support
    Type: Journal of Advanced Computational Intelligence and Intelligent Informatics; Volume 11; No. 10; 1197-1203
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  • 10
    Publication Date: 2018-06-11
    Description: The candidate crops for planetary food systems include: wheat, white and sweet potatoes, soybean, peanut, strawberry, dry bean including le ntil and pinto, radish, rice, lettuce, carrot, green onion, tomato, p eppers, spinach, and cabbage. Crops such as wheat, potatoes, soybean, peanut, dry bean, and rice can only be utilized after processing, while others are classified as ready-to-eat. To process foods in space, the food processing subsystem must be capable of producing a variety of nutritious, acceptable, and safe edible ingredients and food produ cts from pre-packaged and resupply foods as well as salad crops grown on the transit vehicle or other crops grown on planetary surfaces. D esigning, building, developing, and maintaining such a subsystem is b ound to many constraints and restrictions. The limited power supply, storage locations, variety of crops, crew time, need to minimize waste , and other equivalent system mass (ESM) parameters must be considere d in the selection of processing equipment and techniques.
    Keywords: Man/System Technology and Life Support
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  • 11
    Publication Date: 2018-06-11
    Description: The NASA Study of Cataract in Astronauts (NASCA) is a five-year, multi-centered, investigation of lens opacification in populations of U.S. astronauts, military pilots, and ground-based (nonaviator) comparison participants. For astronauts, the explanatory variable of most interest is radiation exposure during space flight, however to properly evaluate its effect, the secondary effects of age, nutrition, general health, solar ocular exposure, and other confounding variables encountered in non-space flight must also be considered. NASCA contains an initial baseline, cross-sectional objective assessment of the severity of cortical (C), nuclear (N), and posterior subcapsular (PSC) lens opacification, and annual follow-on assessments of severity and progression of these opacities in the population of astronauts and in participants sampled from populations of military pilots and ground-based exposure controls. From these data, NASCA will estimate the degree to which space radiation affects lens opacification for astronauts and how the overall risks of each cataract type for astronauts compared with those of the other exposure control groups after adjusting for differences in age and other explanatory variables.
    Keywords: Aerospace Medicine
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  • 12
    Publication Date: 2018-06-11
    Description: Immune system dysregulation has been demonstrated to occur during spaceflight and has the potential to cause serious health risks to crewmembers participating in exploration-class missions. A comprehensive immune assessment was recently performed on 13 short duration Space Shuttle crewmembers and 8 long duration International Space Station (ISS) crewmembers. Statistically significant post-flight phenotype alterations (as compared to pre-flight baseline) for the Shuttle crewmembers included: granulocytosis, increased percentage of B cells, reduced percentage of NK cells, elevated CD4/CD8 ratio, elevated levels of memory CD4+ T cells, and a CD8+ T cell shift to a less differentiated state. For the Shuttle crewmembers, T cell function was surprisingly elevated post-flight, among both the CD4+ and CD8+ subsets. This is likely an acute stress response in less-deconditioned crewmembers. The percentage of CD4+/IL-2+, CD4+/IFNg+ and CD8+/IFNg+ T cells were all decreased at landing. Culture secreted IFNg production was significantly decreased at landing, whereas production of Th2 cytokines was largely unchanged. It was found that the IFNg:IL-10 ratio was obviously declined in the Shuttle crewmembers immediately post-flight. A similar pattern of alterations were observed for the long duration ISS crewmembers. In contrast to Shuttle crewmembers, the ISS crewmembers demonstrated a dramatic reduction in T cell function immediately post-flight. This may be related to the effect of acute landing stress in conjunction with prolonged deconditioning associated with extended flight. The reduction in IFNg:IL-10 ratio (Th2 shift) was also observed post-flight in the ISS crewmembers to a much higher degree. These data indicate consistent peripheral phenotype changes and altered cytokine production profiles occur following space travel of both short and long duration.
    Keywords: Aerospace Medicine
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  • 13
    Publication Date: 2018-06-11
    Description: Biologists typically define living organisms as carbon and water-based cellular forms with :self-replication" as the fundamental trait of the life process. However, this standard dictionary definition of life does not help scientists to categorize self-replicators like viruses, prions, proteons and artificial life. CNP also named nanobacteria were discovered in early 1990s as about 100 nanometer-sized bacteria-like particles with unique apatite mineral-shells around them, and found to be associated with pathological-calcification related diseases. Although CNP have been isolated and cultured from mammalian blood and diseased calcified tissues, and their biomineralizing properties well established, their biological nature and self-replicating capability have always been severely challenged. The terms "self-replication", "self-assembly" or "self-propagation" have been widely used for all systems including nanomachines, crystals, computer viruses and memes. In a simple taxonomy, all biological and non-biological "self replicators", have been classified into "living" or "nonliving" based on the properties of the systems and the amount of support they require to self-replicate. To enhance our understanding about self-replicating nature of CNP, we have investigated their growth in specific culture conditions using conventional inverted light microscope and BioStation IM, Nikon s latest time-lapse imaging system. Their morphological structure was examined using scanning (SEM) and transmission (TEM) electron microscopy. This present study, in conjunction with previous findings of metabolic activity, antibiotic sensitivity, antibody specificity, morphological aspects and infectivity, all concomitantly validate CNP as living self-replicators.
    Keywords: Aerospace Medicine
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  • 14
    Publication Date: 2018-06-11
    Description: Microgravity of spaceflight induces bone loss due in part to decreased bone formation by osteoblasts. We have previously examined the microgravity-induced changes in gene expression profiles in 2T3 preosteoblasts using the Random Positioning Machine (RPM) to simulate microgravity conditions. Here, we hypothesized that exposure of preosteoblasts to an independent microgravity simulator, the Rotating Wall Vessel (RWV), induces similar changes in differentiation and gene transcript profiles, resulting in a more confined list of gravi-sensitive genes that may play a role in bone formation. In comparison to static 1g controls, exposure of 2T3 cells to RWV for 3 days inhibited alkaline phosphatase activity, a marker of differentiation, and downregulated 61 genes and upregulated 45 genes by more than two-fold as shown by microarray analysis. The microarray results were confirmed with real time PCR for downregulated genes osteomodulin, bone morphogenic protein 4 (BMP4), runx2, and parathyroid hormone receptor 1. Western blot analysis validated the expression of three downregulated genes, BMP4, peroxiredoxin IV, and osteoglycin, and one upregulated gene peroxiredoxin I. Comparison of the microarrays from the RPM and the RWV studies identified 14 gravi-sensitive genes that changed in the same direction in both systems. Further comparison of our results to a published database showing gene transcript profiles of mechanically loaded mouse tibiae revealed 16 genes upregulated by the loading that were shown to be downregulated by RWV and RPM. These mechanosensitive genes identified by the comparative studies may provide novel insights into understanding the mechanisms regulating bone formation and potential targets of countermeasure against decreased bone formation both in astronauts and in general patients with musculoskeletal disorders.
    Keywords: Aerospace Medicine
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  • 15
    Publication Date: 2018-06-11
    Description: Cosmic rays were discovered in 1911 by the Austrian physicist, Victor Hess. The planet earth is continuously bathed in high-energy galactic cosmic ionizing radiation (GCR), emanating from outside the solar system, and sporadically exposed to bursts of energetic particles from the sun referred to as solar particle events (SPEs). The main source of GCR is believed to be supernovae (exploding stars), while occasionally a disturbance in the sun's atmosphere (solar flare or coronal mass ejection) leads to a surge of radiation particles with sufficient energy to penetrate the earth's magnetic field and enter the atmosphere. The inhabitants of planet earth gain protection from the effects of cosmic radiation from the earth s magnetic field and the atmosphere, as well as from the sun's magnetic field and solar wind. These protective effects extend to the occupants of aircraft flying within the earth s atmosphere, although the effects can be complex for aircraft flying at high altitudes and high latitudes. Travellers in space do not have the benefit of this protection and are exposed to an ionizing radiation field very different in magnitude and quality from the exposure of individuals flying in commercial airliners. The higher amounts and distinct types of radiation qualities in space lead to a large need for understanding the biological effects of space radiation. It is recognized that although there are many overlaps between the aviation and the space environments, there are large differences in radiation dosimetry, risks and protection for airline crew members, passengers and astronauts. These differences impact the application of radiation protection principles of risk justification, limitation, and the principle of as low as reasonably achievable (ALARA). This chapter accordingly is divided into three major sections, the first dealing with the basic physics and health risks, the second with the commercial airline experience, and the third with the aspects of cosmic radiation appertaining to space travel including future considerations.
    Keywords: Aerospace Medicine
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  • 16
    Publication Date: 2018-06-11
    Description: As logistical access for in-flight space research becomes more limited, the use of ground based spaceflight analogs for life science studies will increase. These studies are particularly important as NASA progresses towards the Lunar and eventually Mars missions outlined in the 2005 Vision for Space Exploration. Countermeasures must be developed to mitigate the clinical risks associated with exploration class space missions. In an effort to coordinate studies across multiple disciplines, NASA has selected 90-day bed rest as the analog of choice, and initiated the Flight Analogs Project to implement research studies with or without the evaluation of countermeasures. Although bed rest is not the analog of choice to evaluate spaceflight-associated immune dysfunction, a standard Immune Assessment was developed for subjects participating in the 90-day bed best studies. The Immune Assessment consists of: leukocyte subset distribution, T cell functional responses, intracellular cytokine production profiles, latent viral reactivation, virus specific T cell levels, virus specific T cell function, stress hormone levels and a behavioral assessment using stress questionnaires. The purpose of the assessment during the initial studies (without countermeasure) is to establish control data against which future studies (with countermeasure) will be evaluated. It is believed that some of the countermeasures planned to be evaluated in future studies, such as exercise, pharmacologic intervention or nutritional supplementation, have the ability to impact immune function. Therefore immunity will likely be monitored during those studies. The data generated during the first three control studies showed that the subjects in general did not display altered peripheral leukocyte subsets, constitutive immune activation, significant latent viral reactivation (EBV, VZV) or altered T cell function. Interestingly, for some subjects the level of constitutively activated T cells (CD8+/CD69+) and virus-specific T cells (CMV and EBV) both decreased during the studies. This likely reflects the isolation of the subjects (from an immunological perspective) and absence of everyday subclinical challenges to the immune system. Cortisol levels (plasma and saliva) did not vary significantly during the studies. This probably reflects a lack of physiological stress during the study and the stress of readaptation to the 1xG environment at R+1. These data demonstrate the absence of significant immune alteration during 90-day bed rest, and establish control data against which future studies (including countermeasures) may be compared.
    Keywords: Aerospace Medicine
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  • 17
    Publication Date: 2018-06-11
    Description: The purpose of this investigation was to determine if increasing body mass while maintaining bodyweight would affect ground reaction forces and joint kinetics during walking and running. It was hypothesized that performing gait with increased mass while maintaining body weight would result in greater ground reaction forces, and would affect the net joint torques and work at the ankle, knee and hip when compared to gait with normal mass and bodyweight. Vertical ground reaction force was measured for ten subjects (5M/5F) during walking (1.34 m/s) and running (3.13 m/s) on a treadmill. Subjects completed one minute of locomotion at normal mass and bodyweight and at four added mass (AM) conditions (10%, 20%, 30% and 40% of body mass) in random order. Three-dimensional joint position data were collected via videography. Walking and running were analyzed separately. The addition of mass resulted in several effects. Peak impact forces and loading rates increased during walking, but decreased during running. Peak propulsive forces decreased during walking and did not change during running. Stride time increased and hip extensor angular impulse and positive work increased as mass was added for both styles of locomotion. Work increased at a greater rate during running than walking. The adaptations to additional mass that occur during walking are different than during running. Increasing mass during exercise in microgravity may be beneficial to increasing ground reaction forces during walking and strengthening hip musculature during both walking and running. Future study in true microgravity is required to determine if the adaptations found would be similar in a weightless environment.
    Keywords: Aerospace Medicine
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  • 18
    Publication Date: 2018-06-11
    Description: Background: A previous study has shown that analysis of high-frequency QRS components (HF-QRS) is highly sensitive and reasonably specific for detecting reversible perfusion defects on myocardial perfusion imaging (MPI) scans during adenosine. The purpose of the present study was to try to reproduce those findings. Methods: 12-lead high-resolution electrocardiogram recordings were obtained from 100 patients before (baseline) and during adenosine Tc-99m-tetrofosmin MPI tests. HF-QRS were analyzed regarding morphology and changes in root mean square (RMS) voltages from before the adenosine infusion to peak infusion. Results: The best area under the curve (AUC) was found in supine patients (AUC=0.736) in a combination of morphology and RMS changes. None of the measurements, however, were statistically better than tossing a coin (AUC=0.5). Conclusion: Analysis of HF-QRS was not significantly better than tossing a coin for determining reversible perfusion defects on MPI scans.
    Keywords: Aerospace Medicine
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  • 19
    Publication Date: 2018-06-11
    Description: Over the past year, NASA's focus has turned to crewed long duration and exploration missions. On these journeys, crewmembers will be required to execute thousands of procedures to maintain life support systems, check out space suits, conduct science experiments, and perform medical exams. To support the many complex tasks crewmembers undertake in microgravity, NASA is interested in providing crewmembers a hands-free work environment to promote more efficient operations. The overarching objective is to allow crewmembers to use both of their hands for tasks related to their mission, versus holding a paper manual or interacting with a display. The use of advanced, hands-free tools will undoubtedly make the crewmembers task easier, but they can also add to overall task complexity if not properly designed. A leading candidate technology for supporting a hands-free environment is the Head-Mounted Display (HMD). A more recent technology (e-book reader) that could be easily temp-stowed near the work area is also a potential hands-free solution. Previous work at NASA involved the evaluation of several commercially available HMDs for visual quality, comfort, and fit, as well as suitability for use in microgravity. Based on results from this work, three HMDs were selected for further evaluation (along with an e-book reader), using International Space Station (ISS)-like maintenance procedures. Two evaluations were conducted in the Space Station Mockup and Trainer Facility (SSMTF) located at the NASA Johnson Space Center (building 9). The SSMTF is a full scale, medium fidelity replica of the pressurized portions of the ISS. It supports crew training such as ingress and egress, habitability, and emergency procedures. In each of the two evaluations, the participants performed two maintenance procedures. One maintenance procedure involved inspecting air filters in a life support system and replacing them with a clean filter if one were found to be contaminated. The second maintenance procedure focused on working in a confined space; specifically, pulling down a rack to inspect wiring configurations, and rewiring in a different pattern. The maintenance procedures were selected to assess mobility, tool use, and access to multiple document sources during task performance. That is, the participant had to move from rack to rack, use a wrench, a camera, etc., replace components, and refer to diagrams to complete tasks. A constraint was imposed that the ISS-like format of the procedures was to be retained, and not modified or optimized for the electronic device ("plug and play" approach). This was based on future plans to test with real procedures on ISS.
    Keywords: Man/System Technology and Life Support
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  • 20
    Publication Date: 2018-06-11
    Description: The Respiratory Support Pack (RSP) is a medical pack onboard the International Space Station (ISS) that contains much of the necessary equipment for providing aid to a conscious or unconscious crewmember in respiratory distress. Inside the RSP lid pocket is a 5.5 by 11 inch paper procedural cue card, which is used by a Crew Medical Officer (CMO) to set up the equipment and deliver oxygen to a crewmember. In training, crewmembers expressed concerns about the readability and usability of the cue card; consequently, updating the cue card was prioritized as an activity to be completed. The Usability Testing and Analysis Facility at the Johnson Space Center (JSC) evaluated the original layout of the cue card, and proposed several new cue card designs based on human factors principles. The approach taken for the assessment was an iterative process. First, in order to completely understand the issues with the RSP cue card, crewmember post training comments regarding the RSP cue card were taken into consideration. Over the course of the iterative process, the procedural information was reorganized into a linear flow after the removal of irrelevant (non-emergency) content. Pictures, color coding, and borders were added to highlight key components in the RSP to aid in quickly identifying those components. There were minimal changes to the actual text content. Three studies were conducted using non-medically trained JSC personnel (total of 34 participants). Non-medically trained personnel participated in order to approximate a scenario of limited CMO exposure to the RSP equipment and training (which can occur six months prior to the mission). In each study, participants were asked to perform two respiratory distress scenarios using one of the cue card designs to simulate resuscitation (using a mannequin along with the hardware). Procedure completion time, errors, and subjective ratings were recorded. The last iteration of the cue card featured a schematic of the RSP, colors, borders, and simplification of the flow of information. The time to complete the RSP procedure was reduced by approximately three minutes with the new design. In an emergency situation, three minutes significantly increases the probability of saving a life. In addition, participants showed the highest preference for this design. The results of the studies and the new design were presented to a focus group of astronauts, flight surgeons, medical trainers, and procedures personnel. The final cue card was presented to a medical control board and approved for flight. The revised RSP cue card is currently onboard ISS.
    Keywords: Aerospace Medicine
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  • 21
    Publication Date: 2018-06-05
    Description: A new class of strong, lightweight, porous materials has been invented as an outgrowth of an effort to develop reinforced silica aerogels. The new material, called X-Aerogel is less hygroscopic, but no less porous and of similar density to the corresponding unmodified aerogels. However, the property that sets X-Aerogels apart is their mechanical strength, which can be as much as two and a half orders of magnitude stronger that the unmodified aerogels. X-Aerogels are envisioned to be useful for making extremely lightweight, thermally insulating, structural components, but they may also have applications as electrical insulators, components of laminates, catalyst supports, templates for electrode materials, fuel-cell components, and filter membranes.
    Keywords: Man/System Technology and Life Support
    Type: NASA Tech Briefs, October 2007; 19
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  • 22
    Publication Date: 2018-06-02
    Description: A design has been proposed for a photodetector that would exhibit a high quantum efficiency (as much as 90 percent) over a wide wavelength band, which would typically be centered at a wavelength of 1.55 m. This and similar photodetectors would afford a capability for detecting single photons - a capability that is needed for research in quantum optics as well as for the practical development of secure optical communication systems for distribution of quantum cryptographic keys. The proposed photodetector would be of the hot-electron, phonon-cooled, thin-film superconductor type. The superconducting film in this device would be a meandering strip of niobium nitride. In the proposed photodetector, the quantum efficiency would be increased through incorporation of optiA design has been proposed for a photodetector that would exhibit a high quantum efficiency (as much as 90 percent) over a wide wavelength band, which would typically be centered at a wavelength of 1.55 m. This and similar photodetectors would afford a capability for detecting single photons - a capability that is needed for research in quantum optics as well as for the practical development of secure optical communication systems for distribution of quantum cryptographic keys. The proposed photodetector would be of the hot-electron, phonon-cooled, thin-film superconductor type. The superconducting film in this device would be a meandering strip of niobium nitride. In the proposed photodetector, the quantum efficiency would be increased through incorporation of opti-
    Keywords: Man/System Technology and Life Support
    Type: NASA Tech Briefs, May 2007; 31-32
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  • 23
    Publication Date: 2018-06-11
    Description: The Lunar Mars Life Support Test series successfully demonstrated integration and operation of advanced technologies for closed-loop life support systems, including physicochemical and biological subsystems. Increased closure was obtained when targeted technologies, such as brine dewatering subsystems, were added to further process life support system byproducts to recover resources. Physicochemical and biological systems can be integrated satisfactorily to achieve desired levels of closure. Imbalances between system components, such as differences in metabolic quotients between human crews and plants, must be addressed. Each subsystem or component that is added to increase closure will likely have added costs, ranging from initial launch mass, power, thermal, crew time, byproducts, etc., that must be factored into break even analysis. Achieving life support system closure while maintaining control of total mass and system complexity will be a challenge.
    Keywords: Man/System Technology and Life Support
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  • 24
    Publication Date: 2018-06-11
    Description: A case study of a medical emergency aboard the International Space Station is reviewed. The case involves a female crewmember who is experiencing acute abdominal pain. The interplay of the Crew Medical Officer (CMO) and the NASA Flight Surgeon is given. Possible diagnoses, and advised medical actions are reviewed. Along the case study questions are posed to the reader, and at the end answers are given.
    Keywords: Aerospace Medicine
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  • 25
    Publication Date: 2018-06-11
    Description: A comprehensive analysis of both the molecular genetic and phenotypic responses of any organism to the spaceflight environment has never been accomplished due to significant technological and logistical hurdles. Moreover, the effects of spaceflight on microbial pathogenicity and associated infectious disease risks have not been studied. The bacterial pathogen Salmonella typhimurium was grown aboard Space Shuttle mission STS-115 and compared to identical ground control cultures. Global microarray and proteomic analyses revealed 167 transcripts and 73 proteins changed expression with the conserved RNA-binding protein Hfq identified as a likely global regulator involved in the response to this environment. Hfq involvement was confirmed with a ground based microgravity culture model. Spaceflight samples exhibited enhanced virulence in a murine infection model and extracellular matrix accumulation consistent with a biofilm. Strategies to target Hfq and related regulators could potentially decrease infectious disease risks during spaceflight missions and provide novel therapeutic options on Earth.
    Keywords: Aerospace Medicine
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  • 26
    Publication Date: 2018-06-11
    Description: Malnutrition, either by insufficient supply of some nutrients or by overfeeding has a profound effect on the health of an organism. Therefore, optimal nutrition is mandatory on Earth (1 g), in microgravity and also when applying artificial gravity to the human system. Immobilization like in microgravity or bed rest also has a profound effect on different physiological systems, like body fluid regulation, the cardiovascular, the musculoskeletal, the immunological system and others. Up to now there is no countermeasure available which is effective to counteract cardiovascular deconditioning (rf. Chapter 5) together with maintenance of the musculoskeletal system in a rather short period of time. Gravity seems therefore to be one of the main stimuli to keep these systems and application of certain duration of artificial gravity per day by centrifugation has often been proposed as a very potential countermeasure against the weakening of the physiological systems. Up to now, neither optimal intensity nor optimal length of application of artificial gravity has been studied sufficiently to recommend a certain, effective and efficient protocol. However, as shown in chapter 5 on cardiovascular system, in chapter 6 on the neuromuscular system and chapter 7 (bone and connective system) artificial gravity has a very high potential to counteract any degradation caused by immobilization. But, nutrient supply -which ideally should match the actual needs- will interact with these changes and therefore has also to be taken into account. It is well known that astronauts beside the Skylab missions- were and are still not optimally nourished during their stay in space (Bourland et al. 2000;Heer et al. 1995;Heer et al. 2000b;Smith et al. 1997;Smith & Lane 1999;Smith et al. 2001;Smith et al. 2005). It has also been described anecdotally that astronauts have lower appetites. One possible explanation could be altered taste and smell sensations during space flight, although in some early space flights no significant changes were found (Heidelbaugh et al. 1968;Watt et al. 1985). However, data from a recent head-down bed rest study showed significant decrease in smell sensation (Enck et al. unpublished data) suggesting that fluid shifts might have an impact. If this holds true and which has to be validated in further studies, this seems to play an important role for lowered food intake causing insufficient energy intake and subsequently insufficient supply of most of the macro- and micronutrients. Other nutrients are taken in excess, for example sodium. As it is very well known from daily food consumption especially premanufactured food with high salt content seems to be more palatable than that with low salt content. Salt also functions as preservation which is very important taking into account the space food system limitations (i.e., lack of refrigerators and freezers). The preference for food with high salt intake by astronauts might therefore very likely be caused by altered smell and taste sensations in microgravity.
    Keywords: Aerospace Medicine
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  • 27
    Publication Date: 2018-06-05
    Description: On-the-Fly Reprocessing (OTFR) is a collection of data-processing routines that work within the context of the Hubble Space Telescope (HST) pipeline data-flow system. The purpose served by OTFR is to generate, on demand, scientifically useful data products from raw HST data stored in an archive. First, on the basis of the requested final data products, OTFR retrieves the corresponding sets of raw data from the archives. Next, OTFR processes the raw data sets to remove artifacts and to establish proper header and other template information. Finally, the calibration routines appropriate to the specific data sets are invoked to produce the requested data products, and the data products are released to an archive distribution system for transmission to the requesting party. OTFR offers two notable advantages: (1) Inasmuch as calibrated data occupy about 8 times as much storage space as do raw data, by obviating storage of calibrated data, OTFR reduces the storage capacity needed by the archive; and (2) the calibration routines can be updated to give requesters the benefit of the most recent calibrations.
    Keywords: Man/System Technology and Life Support
    Type: NASA Tech Briefs, March 2007; 6
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  • 28
    Publication Date: 2018-06-11
    Description: Toxicology dates to the very earliest history of humanity with various poisons and venom being recognized as a method of hunting or waging war with the earliest documentation in the Evers papyrus (circa 1500 BCE). The Greeks identified specific poisons such as hemlock, a method of state execution, and the Greek word toxos (arrow) became the root of our modern science. The first scientific approach to the understanding of poisons and toxicology was the work during the late middle ages of Paracelsus. He formulated what were then revolutionary views that a specific toxic agent or "toxicon" caused specific dose-related effects. His principles have established the basis of modern pharmacology and toxicology. In 1700, Bernardo Ramazzini published the book De Morbis Artificum Diatriba (The Diseases of Workers) describing specific illnesses associated with certain labor, particularly metal workers exposed to mercury, lead, arsenic, and rock dust. Modern toxicology dates from development of the modern industrial chemical processes, the earliest involving an analytical method for arsenic by Marsh in 1836. Industrial organic chemicals were synthesized in the late 1800 s along with anesthetics and disinfectants. In 1908, Hamilton began the long study of occupational toxicology issues, and by WW I the scientific use of toxicants saw Haber creating war gases and defining time-dosage relationships that are used even today.
    Keywords: Aerospace Medicine
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  • 29
    Publication Date: 2018-06-11
    Description: The addition of inertia to exercising astronauts could increase ground reaction forces and potentially provide a greater health benefit. However, conflicting results have been reported regarding the adaptations to additional mass (inertia) without additional net weight (gravitational force) during locomotion. We examined the effect of increasing inertia while maintaining net gravitational force on vertical ground reaction forces and kinematics during walking and running. Vertical ground reaction force was measured for ten healthy adults (5 male/5 female) during walking (1.34 m/s) and running (3.13 m/s) using a force-measuring treadmill. Subjects completed locomotion at normal weight and mass, and at 10, 20, 30, and 40% of added inertial force. The added gravitational force was relieved with overhead suspension, so that the net force between the subject and treadmill at rest remained equal to 100% body weight. Peak vertical impact forces and loading rates increased with increased inertia during walking, and decreased during running. As inertia increased, peak vertical propulsive forces decreased during walking and did not change during running. Stride time increased during walking and running, and contact time increased during running. Vertical ground reaction force production and adaptations in gait kinematics were different between walking and running. The increased inertial forces were utilized independently from gravitational forces by the motor control system when determining coordination strategies.
    Keywords: Aerospace Medicine
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  • 30
    Publication Date: 2018-06-11
    Description: Medical requirements for the future Crew Exploration Vehicle (CEV), Lunar Surface Access Module (LSAM), advanced Extravehicular Activity (EVA) suits and Lunar habitat are currently being developed. Crews returning to the lunar surface will construct the lunar habitat and conduct scientific research. Inherent in aggressive surface activities is the potential risk of injury to crewmembers. Physiological responses and the operational environment for short forays during the Apollo lunar missions were studied and documented. Little is known about the operational environment in which crews will live and work and the hardware will be used for long-duration lunar surface operations. Additional information is needed regarding productivity and the events that affect crew function such as a compressed timeline. The Space Medicine Division at the NASA Johnson Space Center (JSC) requested a study in December 2005 to identify Apollo mission issues relevant to medical operations that had impact to crew health and/or performance. The operationally oriented goals of this project were to develop or modify medical requirements for new exploration vehicles and habitats, create a centralized database for future access, and share relevant Apollo information with the multiple entities at NASA and abroad participating in the exploration effort.
    Keywords: Aerospace Medicine
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  • 31
    Publication Date: 2018-06-11
    Description: Thermoregulation in the space environment is critical for survival, especially in off- nominal operations. In such cases, mathematical models of thermoregulation are frequently employed to evaluate safety-of-flight issues in various human mission scenarious. In this study, the 225-node Wissler model and the 41-Node Metabolic Man model are employed to evaluate the effects of such a scenario. Metabolic loads on astronauts wearing the advanced crew escape suit (ACES) and liquid cooled ventilation garment (LCVG) are imposed on astronauts exposed to elevated cabin temperatures resulting from a systems failure. The study indicates that the performance of the ACES/LCVG cooling system is marginal. Increases in workload and or cabin temperature above nominal will increase rectal temperature, stored heat load, heart rate, and sweating, which could lead to deficits in the performance of cognitive and motor tasks. This is of concern as the ACES/LCVG is employed during Shuttle decent when the likelihood of a safe landing may be compromised. The study indicates that the most effective mitigation strategy would be to decrease the LCVG inlet temperature.
    Keywords: Aerospace Medicine
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  • 32
    Publication Date: 2018-06-11
    Description: Aerobic deconditioning occurs during long duration space flight despite the use of exercise countermeasures (Convertino, 1996). As a part of International Space Station (ISS) medical operations, periodic tests designed to estimate aerobic capacity are performed to track changes in aerobic fitness and to determine the effectiveness of exercise countermeasures. These tests are performed prior to, during, and after missions of greater than 30 days in duration. Crewmembers selected for missions aboard the ISS perform a graded exercise test on a cycle ergometer approximately 270 days prior to their scheduled launch date in order to measure peak oxygen consumption (VO2PK) and peak heart rate (HRpk). Approximately 30 to 45 days prior to launch, crewmembers perform a submaximal cycle ergometer test at work rates set to elicit 25, 50 and 75% of their pre-flight VO2PK. This test, known as the Periodic Fitness Evaluation (PFE), serves as a baseline measure to which subsequent in-and post-flight exercise tests are compared. While onboard the ISS, crewmembers are normally scheduled to perform the PFE beginning with flight day (FD) 14 and every 30 days thereafter. The PFE is also conducted 5 and 30 days following flight. Using PFE data, aerobic fitness is estimated by quantifying the VO2 vs. HR relationship using linear regression and calculating the VO2 that would occur at the crewmember s previously measured HRpk. Currently, for data collected during flight, this technique assumes that the pre- vs. in-flight oxygen consumption per given cycle workload is similar. However, the validity of this assumption is based upon a sparse amount of data collected during the Skylab era (Michel, et al. 1977). The method of using heart rate and cycle ergometer work rates has been used to estimate aerobic fitness in normal gravity (Astrand and Ryhming, 1954; Lee, 1993). Due to spaceflight induced physiological alterations, such as shifts in extracellular fluid (e.g. plasma) volume, this method may not be valid during space flight. In addition, the ergometer onboard ISS is vibration-isolated and moves with the astronaut s application of force into the pedals. The effect of this movement on the VO2 of cycle exercise on ISS has not been quantified.
    Keywords: Aerospace Medicine
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  • 33
    Publication Date: 2019-07-27
    Description: This viewgraph presentation reviews issues of health care in space. Some of the issues reviewed are: (1) Physiological adaptation to microgravity, partial gravity, (2) Medical events during spaceflight, (3) Space Vehicle and Environmental and Surface Health Risks, (4) Medical Concept of Operations (CONOPS), (4a) Current CONOPS & Medical Hardware for Shuttle (STS) and ISS, (4b) Planned Exploration Medical CONOPS & Hardware needs, (5) Exploration Plans for Lunar Return Mission & Mars, and (6) Developing Medical Support Systems.
    Keywords: Aerospace Medicine
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  • 34
    Publication Date: 2019-07-13
    Description: The Cumulative Trauma Disorder (CTD) risks for three different tasks using McCauley-Bell and Badiru's (1993) formula based on task, personal, and organizational factors were examined. For the Multi-Layer Insulation (MLI) blanket task, the results showed that the task, personal, and organizational risks were at about the same level. The personal risk factors for this task were evaluated using a hypothetical female employee age 52. For the pizza dough task, it was shown that the organizational risk was particularly high, with task related factors also at quite dangerous levels. On the other hand, there was a very low level of personal risk factors, based on a female age 17. The flow cytometer task was assessed with three different participants, a11 of whom had quite disparate levels of personal risk, which slightly affected the overall CTD risk. This reveals how individual difference variables certainly need to be considered. The task and organizational risks for this task were rated at about the same moderate level. The overall CTD risk averaged across the three participants was .335, indicating some risk. Compruing across the tasks revealed that the pizza dough task created the greatest overall CTD risk by far (.568), with the MLI (.325) and flow cytometer task (.335) having some risk associated with them. Future research should look into different tasks for more of a comparison
    Keywords: Aerospace Medicine
    Type: KSC-2007-031 , 13th International Conference on Industry, Engineering, and Management Systems; Mar 12, 2007 - Mar 14, 2007; Cocoa Beach, FL; United States
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  • 35
    Publication Date: 2019-07-12
    Description: The Air Commerce Act of 1926 set the beginning for standards in aviation maintenance. Even after deregulation in the late l970s, maintenance standards and requirements still have not changed far from their initial criteria. After a potential candidate completes Federal Aviation Administration training prerequisites, they may test for their Airframe and Powerplant (A&P) certificate. Performing maintenance in the aviation industry for a minimum of three years, the technician may then test for their Inspection Authorization (IA). After receiving their Airframe and Powerplant certificate, a technician is said to have a license to perform. At no time within the three years to eligibility for Inspection Authorization are they required to attend higher-level inspection training. What a technician learns in the aviation maintenance industry is handed down from a seasoned technician to the new hire or is developed from lessons learned on the job. Only in Europe has the Joint Aviation Authorities (JAA) required higher-level training for their aviation maintenance technicians in order to control maintenance related accidents (Lu, 2005). Throughout the 1990s both the General Accounting Office (GAO) and the National Transportation Safety Board (NTSB) made public that the FAA is historically understaffed (GAO, 1996). In a safety recommendation the NTSB stated "The Safety Board continues to lack confidence in the FAA's commitment to provide effective quality assurance and safety oversight of the ATC system (NTSB, 1990)." The Federal Aviation Administration (FAA) has been known to be proactive in creating safer skies. With such reports you would suspect the FAA to also be proactive in developing more stringent inspection training for aviation maintenance technicians. The purpose of this study is to estimate the effectiveness of higher-level inspection training, such as Visual Testing (VT) for aviation maintenance technicians, to improve the safety of aircraft and to make recommendations to management with regard to the value of such training.
    Keywords: Man/System Technology and Life Support
    Type: KSC-2007-047
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  • 36
    Publication Date: 2019-07-12
    Description: An essential requirement for making space travel and long term missions more efficient and affordable to NASA includes finding innovative ways to supply oxygen for life support and propulsion. In this experiment, carrier gas hot extraction was investigated as a possible method for measuring the oxygen from samples of lunar soil simulants before and after oxygen extraction. The determination of oxygen using the R0600 Oxygen Determinator is usually limited to oxides with low oxygen concentrations, but after the manipulation of certain furnace operating parameters such as analysis time and ramp rate, the R0600 was used to determine the oxygen content of high concentration oxides such as Fe 2O3 , Al2O3 , and SiO2.
    Keywords: Man/System Technology and Life Support
    Type: KSC-2007-161
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  • 37
    Publication Date: 2019-07-19
    Description: During an ExtraVehicular Activity (EVA), both the heat generated by the astronaut's metabolism and that produced by the Portable Life Support System (PLSS) must be rejected to space. The heat sources include the heat of adsorption of metabolic CO2, the heat of condensation of water, the heat removed from the body by the liquid cooling garment and the load from the electrical components. Although the sublimator hardware to reject this load weighs only 3.48 lbs, an additional eight pounds of water are loaded into the unit of which about six to eight are sublimated and lost; this is the single largest expendable during an eight-hour EVA. Using a radiator to reject heat from the Astronaut during an EVA, we can significantly reduce the amount of expendable water consumed by the sublimator. Last year we reported on the design and initial operational assessment tests of our novel radiator designated the Radiator And Freeze Tolerant heat eXchanger (RAFT-X). Herein, we report on tests conducted in the NASA Johnson Space Center Chamber E Thermal Vacuum Test Facility. Up to 800 Btu/h of heat were rejected in lunar and Mars environments with temperatures as cold as 150 F. Tilting the radiator did not cause an observable loss in performance. The RAFT-X endured freeze/thaw cycles and in fact, the heat exchanger was completely frozen three times without any apparent damage to the unit. We were also able to operate the heat exchanger in a partially frozen configuration to throttle the heat rejection rate from 530 Btu/h at low water flow rate down to 300 Btu/h. Finally, the deliberate loss of a single loop heat pipe only degraded the heat rejection performance by about 2 to 5%.
    Keywords: Man/System Technology and Life Support
    Type: 37th International Conference on Environmental Systems; Jul 09, 2007 - Jul 12, 2007; Chicago, IL; United States
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  • 38
    Publication Date: 2019-07-19
    Description: Ocular counter-rolling (OCR) induced by whole body tilt in roll has been explored after spaceflight as an indicator of the adaptation of the otolith function to microgravity. It has been claimed that the overall pattern of OCR responses during static body tilt after spaceflight is indicative of a decreased role of the otolith function, but the results of these studies have not been consistent, mostly due to large variations in the OCR within and across individuals. By contrast with static head tilt, off-vertical axis rotation (OVAR) presents the advantage of generating a sinusoidal modulation of OCR, allowing averaged measurements over several cycles, thus improving measurement accuracy. Accordingly, OCR and the sense of roll tilt were evaluated in seven astronauts before and after spaceflight during OVAR at 45 /s in darkness at two angles of tilt (10 and 20 ). There was no significant difference in OCR during OVAR immediately after landing compared to preflight. However, the amplitude of the perceived roll tilt during OVAR was significantly larger immediately postflight, and then returned to control values in the following days. Since the OCR response is predominantly attributed to the shearing force exerted on the utricular macula, the absence of change in OCR postflight suggests that the peripheral otolith organs function normally after short-term spaceflight. However, the increased sense of roll tilt indicates an adaptation in the central processing of gravitational input, presumably related to a re-weigthing of the internal representation of gravitational vertical as a result of adaptation to microgravity.
    Keywords: Aerospace Medicine
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  • 39
    Publication Date: 2019-07-19
    Description: Microbial monitoring of spacecraft environments provides key information in the assessment of infectious disease risk to the crew. Monitoring aboard the Mir space station and International Space Station (ISS) has provided a tremendous informational baseline to aid in determining the types and concentrations of microorganisms during a mission. Still, current microbial monitoring hardware utilizes culture-based methodology which may not detect many medically significant organisms, such as Legionella pneumophila. We hypothesize that evaluation of the ISS environment using non-culture-based technologies would reveal microorganisms not previously reported in spacecraft, allowing for a more complete health assessment. To achieve this goal, a spaceflight experiment, operationally designated as SWAB, was designed to evaluate the DNA from environmental samples collected from ISS and vehicles destined for ISS. Results from initial samples indicate that the sample collection and return procedures were successful. Analysis of these samples using denaturing gradient gel electrophoresis and targeted PCR primers for fungal contaminants is underway. The current results of SWAB and their implication for in-flight molecular analysis of environmental samples will be discussed.
    Keywords: Aerospace Medicine
    Type: 5th Space Microbiology Workshop; Sep 17, 2007 - Sep 21, 2007; Tokyo; Japan
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  • 40
    Publication Date: 2019-07-19
    Description: For nearly 3.5 years, the Volatile Organic Analyzer (VOA) has routinely analyzed the International Space Station (ISS) atmosphere for a target list of approximately 20 volatile organic compounds (VOCs). Additionally, an early prototype of the VOA collected data aboard submarines in two separate trials. Comparison of the data collected on ISS and submarines showed a surprising similarity in the atmospheres of the two environments. Furthermore, in both cases it was demonstrated that the VOA data can detect hardware issues unrelated to crew health. Finally, it was also clear in both operations that the VOA s size and resource consumption were major disadvantages that would restrict its use in the future. The VOA showed the value of measuring VOCs in closed environments, but it had to be shrunk if it was to be considered for future operations in these environments that are characterized by cramped spaces and limited resources. The Sionex Microanalyzer is a fraction of the VOA s size and this instrument seems capable of maintaining or improving upon the analytical performance of the VOA. The two design improvements that led to a smaller, less complex instrument are the Microanalyzer s use of recirculated air as the gas chromatograph s carrier gas and a micromachined detector. Although the VOA s ion mobility spectrometer and the Microanalyzer s differential mobility spectrometer (DMS) are related detector technologies, the DMS was more amenable to micromachining. This paper will present data from the initial assessment of the Microanalyzer. The instrument was challenged with mixtures that simulated the VOCs typically detected in closed-environment atmospheres.
    Keywords: Aerospace Medicine
    Type: Amsterdam
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  • 41
    Publication Date: 2019-07-19
    Description: When cells are exposed to radiation, cellular lesions are induced in the DNA including double strand breaks (DSBs), single strand breaks and clustered DNA damage, which if not repaired with high fidelity may lead to detrimental biological consequences. Complex DSBs are induced by ionizing radiation and characterized by the presence of base lesions close to the break termini. They are believed to be one of the major causes of the biological effects of IR. The complexity of DSBs increases with the ionization density of the radiation and these complex DSBs are distinct from the damage induced by sparsely ionizing gamma-radiation. It has been hypothesized that complex DSBs produced by heavy ions in space pose problems to the DNA repair machinery. We have used imm uno-cyto-chemical staining of phosphorylated histone H2AX (gamma-H2AX) foci, as a marker of DSBs. We have investigated the formation and loss of gamma-H2AX foci and RAD51 foci (a protein involved in the homologous recombination pathway) in mammalian cells induced by low fluences of low-LET gamma-radiation and high-LET Fe-56 ions (1GeV/n, 151 keV/micron LET). M059J and M059K cells, which are deficient and proficient in DNA-PK(sub cs) activity respectively, were used to examine the role of DNA-PK(sub cs), a key protein in the non-homologous end joining (NHEJ) pathway of DSB repair, along with HF19 human fibroblasts. Followi ng irradiation with Fe-56 ions the rate of repair was slower in M059J cells compared with that in M059K, indicating a role for DNA-PK(sub cs) in the repair of DSB induced by Fe-56 ions. However a small percentage of DSBs induced are rejoined within 5 h although many DSBs still persist up to 24 h. When RAD51 was examined in M059J/K cells, RAD51 foci are visible 24 hours after irradiation in approximately 40% of M059J cells compared with 〈5% of M059K cells indicating that persistent DSBs or those formed at stalled replication forks recruit RAD51 in DNA-PK(sub cs) deficient cells. Following 1 Gy gamma-radiation the induction of gamma-H2AX foci is similar in M059J and M059K cells. However, the repair rate of DSBs is slower in M059J cells than in M059K as shown previously but faster than seen with DSB induced by 56Fe ions. Vanillin, an inhibitor of DNA-PK(sub cs), reduces significantly the rate of DSB repair in HF19 cells following 1 Gy gamma-radiation but at 0.25 Gy gamma-irradiation the rate of DSB repair is similar in the presence or absence vanillin, thus suggesting the repair of a sub-set of DSBs induced by low dose, low-LET radiation does not require DNA-PK(sub cs). This sub-set of DSBs is formed in lower yield with high LET radiation. T he complexity of DNA DSBs induced by HZE radiation will be discussed in terms of reduced repair efficiency and provide scope to model different sub-classes of DSBs as precursors that may lead to the detrimental health effects of HZE radiation.
    Keywords: Aerospace Medicine
    Type: 18th Annual NASA Space Radiation Investigators Conference; Jul 13, 2007 - Jul 15, 2007; Rohnert Park, CA; United States
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  • 42
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    Publication Date: 2019-07-19
    Description: During space travel, astronauts are exposed to energetic particles of a complex composition and energy distribution. For the same amount of absorbed dose, these particles can be much more effective than X- or gamma rays in the induction of biological effects, including cell inactivation, genetic mutations, cataracts, and cancer induction. Several of the biological consequences of space radiation exposure have already been observed in astronauts. This presentation will introduce the space radiation environment and discuss its associated health risks. Accurate assessment of the radiation risks and development of respective countermeasures are essential for the success of future exploration missions to the Moon and Mars.
    Keywords: Aerospace Medicine
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  • 43
    Publication Date: 2019-07-19
    Description: The Space Flight Cognitive Assessment Tool for Windows (WinSCAT) is a medical requirement on the International Space Station, and its purpose is to evaluate cognitive functioning after physical insult (e.g., head trauma, decompression sickness, exposure to toxic gases, medication side effects). The current objective is to assess cognitive functioning in a long duration space mission analog environment where Artificial Gravity is being applied as a countermeasure in a Bed Rest study. Methods: Fifteen male subjects (8 treatment and 7 control) who participated in 21 days of -6 degree head-down bed rest were assessed. Three practice and three baseline WinSCAT test sessions were administered during the pre-bed rest phase of study participation. During the bed rest phase, the WinSCAT test was scheduled every other day, following the centrifuge, for a total of 10 test sessions. (The treatment group received 60 minutes of centrifugation each day during the 21 days of bed rest. The control subjects were strapped to the centrifuge for the same length of time as the treatment group but were not spun.) During the post-bed rest (reconditioning) phase, the test was administered 4 times. Results: Individual differences were found both within and between the treatment and control groups. After controlling for the number of subjects in each group, the treatment group accounted for more off-nominal WinSCAT scores than the control group. Conclusions:There is some preliminary evidence that centrifuge spinning might negatively impact cognitive functioning. However, due to sample size limitations, it cannot be ascertained whether there were significant differences in cognitive performance between the treatment and control groups. If centrifugation had a negative effect on cognitive functioning, consistent decrements would be expected to be found with all treatment subjects across time. Individual differences in underlying cognitive ability and motivation level are other possible explanations for the results found in this study.
    Keywords: Aerospace Medicine
    Type: 28th Annual International Gravitational Physiology Meeting; Apr 08, 2007 - Apr 13, 2007; San Antonio, TX; United States
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  • 44
    Publication Date: 2019-07-19
    Description: We have previously detected VZV in healthy astronauts both during spaceflight and shortly after landing. Herein, we show that VZV shed in seropositive astronauts is infectious. A total of 40 saliva samples were obtained from each of the 3 astronauts. From each astronaut, 14 samples were taken 109 to 133 days before liftoff, 1 sample was taken every day during 12 days in space, and one sample was taken for 14 consecutive days beginning the second day after landing. Quantitative PCR was used to detect VZV DNA in saliva. None of 42 preflight saliva samples contained VZV DNA. VZV DNA was detected in saliva from 2 of 3 astronauts. In 1 astronaut, 6 of 12 samples obtained during space flight contained 120 to 2,500 copies of VZV DNA per ml; after landing, 1250 copies of VZV DNA were present on day 2, 45 copies on day 3, and 110 copies on day 5. All samples taken 6 to 15 days after touchdown were negative for VZV DNA. In the second astronaut, 5 of 12 samples obtained during space flight contained 18 to 650 copies of VZV DNA per ml; after landing, 560 copies of VZV DNA were present in saliva on day 2, 340 copies on day 4, 45 copies on day 5, and 23 copes on day 6. All samples taken 7 to 15 days after touchdown were negative for VZV DNA. Saliva taken 2 to 6 days after landing from all 3 astronauts was cultured on human fetal lung cells. After one subcultivation, a cytopathic effect developed in cultures inoculated with saliva from the two astronauts whose saliva contained VZV DNA. Both PCR and immunostaining identified the isolates to be VZV and not HSV-1. Importantly, the astronaut in whom no VZV was detected had a history of zoster 9 years earlier. It is possible that a boost in cell-mediated immunity to VZV which is known to develop after zoster protected him from subclinical reactivation. The genotype of the two VZV isolates was determined by VZV ORF22-based PCR/sequencing along with FRET-based PCR assays that target specific nucleotide polymorphisms. Both VZV isolates were found to be the European genotype which also contained a rare MspI restriction enodnuclease site in VZV ORF62 at position 107,252. These findings extend our previous demonstration of VZV DNA in saliva of astronauts by showing that infectious VZV is also present. Thus, like HSV-1 and HSV-2, VZV can reactivate and shed infectious virus in the absence of clinical disease.
    Keywords: Aerospace Medicine
    Type: International Herpesvirus Workshop; Jul 07, 2007 - Jul 12, 2007; Asheville, NC; United States
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  • 45
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    Publication Date: 2019-07-19
    Description: Dr. Davis' presentation includes a brief overview of space flight and the lessons learned for health care in microgravity. He will describe the development of policy for health care for international crews. He will conclude his remarks with a discussion of an integrated health care system.
    Keywords: Aerospace Medicine
    Type: Digital Health Conference: Integrated Health Care; Oct 10, 2006 - Oct 11, 2006; Baltimore, MD; United States
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  • 46
    Publication Date: 2019-07-19
    Description: The NASA Chief Health and Medical Officer (CHMO) recently directed that the agency establish crew health standards to aid in the development of requirements for future vehicles and habitats. Response to this direction includes development of a new NASA habitability and human factors standard and an accompanying design handbook. The new standard contains high-level, over-arching principles to assure its applicability and usability across all NASA development programs. The handbook will provide detailed design requirements and suggestions that will meet the standards. The information contained in NASA-STD-3000 will be updated and included in the new design handbook. In this approach, each new program will derive detailed program-specific requirements from the new standard using the handbook as a design guide and resource. With the completion of the standard, the focus of this year s effort is the development of the new handbook: Human Integration Design Handbook (HIDH). This is an opportunity for the space flight human factors and habitability community to consolidate up-to-date data for use by NASA programs and designers as well as outside researchers and policy makers looking for the next research focus. The goal of the handbook is to help NASA design and build human space flight systems which accommodate the capabilities and limitations of the crew so as to provide an environment where the crew can live and work effectively, safely, and comfortably. Handbook contents will address that primary goal, addressing unique aspects of space flight and habitation, including reduced gravity conditions, time lags, EVA systems and day/night cycles, not addressed in other standards or handbooks. The handbook will be divided into topics similar to NASA-STD-3000 (anthropometrics, architecture, workstations, etc.) and each topic area will contain elements for designers, human factors practitioners, program managers, operators, and researchers. The handbook will include the following elements: (1) Design considerations include a clear and concise summary of what is important to designers in space vehicle / habitat design, design information to translate Earth-base knowledge to the space environment, space issues and the data necessary to address those issues, and a consistent set of terminology. (2) Updates to Lessons Learned and example solutions from Shuttle and Station program experience will provide historical examples to help prevent repeating mistakes or reinvention of the wheel. (3) Requirements will aid in the translation of standards into program specific requirements. The scope of included requirements will define the pool that each program needs to consider and tailor for their specific program. (4) Requirements rationale will help understanding of the importance of these considerations. The HIDH development team at JSC is finalizing the format of the new handbook, prioritizing topic areas for expansion and update, and contacting subject matter experts within the scientific community to assist with this effort. Plans are also being made to continue handbook expansion and maintenance to assure it remains a valuable resource for human factors and human space flight programs.
    Keywords: Man/System Technology and Life Support
    Type: NASA Human Research Program Investigators Workshop; Feb 12, 2007 - Feb 14, 2007; League City, TX; United States
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  • 47
    Publication Date: 2019-07-19
    Description: The goal of this project was to examine the effects of artificial gravity (2.5 g) on skeletal muscle strength and key anabolic/catabolic markers known to regulate muscle mass. Two groups of subjects were selected for study: 1) a 21 day-bed rest (BR) control (C) group (N=7); and 2) an AG group (N=8), which was exposed to 21 days of bed-rest plus daily 1 hr exposures to AG (2.5 g). This particular experiment was part of an integrated AG Pilot Project sponsored by NASA/Johnson Space Center. The in vivo torque-velocity relationships of the knee extensors and plantar flexors of the ankle were determined pre and post treatment. Also, pre- and post treatment biopsy samples were obtained from both the vastus lateralis and soleus muscles and were used, in part, for a series of analyses on gene expression (mRNA abundance) of key factors implicated in the anabolic versus catabolic state of the muscle. Post/Pre toque-velocity determinations revealed greater decrements in knee extensor performance in the C versus AG group (P less than 0.04). The plantar flexor muscle group of the AG subjects actually demonstrated a net gain in torque-velocity relationship; whereas, in the C group the overall post/pre responses declined (AG vs C; P less than 0.001). Measurements of muscle fiber cross-sectional area (for both muscles) demonstrated a loss of approx. 20% in the C group while no losses were evident in the AG group. RT-PCR analyses of muscle biopsy specimens demonstrated that markers of growth and cytoskeletal integrity (IGF-1, IGF-1 BP4, mechano growth factor, total RNA, and pro-collagen 3a) were higher in the AG group, whereas catabolic markers (myostatin and atrogen) were elevated in the C group. Importantly, these patterns were seen in both muscles. Based on these observations we conclude that paradigms of AG have the potential to maintain the functional, biochemical, and structural homeostasis of skeletal muscle in the face of chronic unloading states. These findings also warrant further studies since it is likely that other robust paradigms of AG that employ various exercise strategies may be more effective in counteracting long duration unloading states as anticipated on the platforms of the Moon and Mars.
    Keywords: Aerospace Medicine
    Type: 28th Annual International Gravitational Physiology Meeting; Apr 08, 2007 - Apr 13, 2007; San Antonio, TX; United States
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  • 48
    Publication Date: 2019-07-19
    Description: The purpose is to assess physical and chemical degradation of select pharmaceutical formulations from the Shuttle and ISS medical kits. Eleven pharmaceuticals dispensed as different dosage forms were selected based on their physical / chemical characteristics and susceptibility to environmental factors such as, temperature, humidity and light sensitivity. When available, ground-controls of the study medications with matching brand and lot numbers were used for comparison. Samples retrieved from flight were stored along with their matching controls in a temperature and humidity controlled environmental chamber. Temperature, humidity, and radiation data from the Shuttle and ISS were retrieved from onboard HOBO U12 Temp/RH Data Loggers, and from passive dosimeters. Physical and chemical analyses of the pharmaceuticals were conducted using validated United States Pharmacopeia (USP) methods. Results indicated degradation of 6 of the 11 formulations returned from space flights. Four formulations, Amoxicillin / Clavulanate, promethazine, sulfamethoxazole / trimethoprim, and ciprofloxacin tablets depicted discoloration after flight. Chemical content analyses using High or Ultra Performance Liquid Chromatography (HPLC / UPLC) methods revealed that dosage forms of Amoxicillin / Clavulanate, promethazine, sulfamethoxazole / trimethoprim, lidocaine, ciprofloxacin and mupirocin contained less than 95% of manufacturer s labeled claim of active drug compound. Shuttle and ISS environments affect stability and shelf life of certain mediations flown on these missions. Data analysis is in progress to examine the effect of specific space flight environmental factors on pharmaceutical stability. The degradation profiles generated from ground studies in analog environments will be useful in establishing predictive shelf-life profiles for medications intended for use during long-term space exploration missions.
    Keywords: Aerospace Medicine
    Type: 2007 ACCP Annual Meeting; Oct 14, 2007 - Oct 17, 2007; Denver, CO; United States
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  • 49
    Publication Date: 2019-07-19
    Description: In space, astronauts are constantly bombarded with energetic particles. The goal of the National Aeronautics and Space Agency and the NASA Space Radiation Project is to ensure that astronauts can safely live and work in the space radiation environment. The space radiation environment poses both acute and chronic risks to crew health and safety, but unlike some other aspects of space travel, space radiation exposure has clinically relevant implications for the lifetime of the crew. Among the identified radiation risks are cancer, acute and late CNS damage, chronic and degenerative tissue decease, and acute radiation syndrome. The term "safely" means that risks are sufficiently understood such that acceptable limits on mission, post-mission and multi-mission consequences can be defined. The NASA Space Radiation Project strategy has several elements. The first element is to use a peer-reviewed research program to increase our mechanistic knowledge and genetic capabilities to develop tools for individual risk projection, thereby reducing our dependency on epidemiological data and population-based risk assessment. The second element is to use the NASA Space Radiation Laboratory to provide a ground-based facility to study the health effects/mechanisms of damage from space radiation exposure and the development and validation of biological models of risk, as well as methods for extrapolation to human risk. The third element is a risk modeling effort that integrates the results from research efforts into models of human risk to reduce uncertainties in predicting the identified radiation risks. To understand the biological basis for risk, we must also understand the physical aspects of the crew environment. Thus, the fourth element develops computer algorithms to predict radiation transport properties, evaluate integrated shielding technologies and provide design optimization recommendations for the design of human space systems. Understanding the risks and determining methods to mitigate the risks are keys to a successful radiation protection strategy.
    Keywords: Aerospace Medicine
    Type: 16th Humans in Space Symposium of the IAA; May 20, 2007 - May 24, 2007; Paris; France
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  • 50
    Publication Date: 2019-07-19
    Description: High-energy secondary neutrons, produced by the interaction of galactic cosmic rays (GCR) with the atmosphere, spacecraft structure and planetary surfaces, contribute a significant fraction to the dose equivalent radiation measurement in crew members and passengers of commercial aviation travel as well as astronauts in space missions. The Los Alamos Nuclear Science Center (LANSCE) neutron facility's 30L beam line (4FP30L-A/ICE House) is known to generate neutrons that simulate the secondary neutron spectrum of the Earth's atmosphere at high altitude. The neutron spectrum is also similar to that measured onboard spacecrafts like the MIR and the International Space Station (ISS). To evaluate the biological damage, we exposed human epithelial cells in vitro to the LANSCE neutron beams with an entrance dose rate of 2.5 cGy/hr, and studied the induction of chromosome aberrations that were identified with multicolor-banding in situ hybridization (mBAND) technique. With this technique, individually painted chromosomal bands on one chromosome allowed the identification of inter-chromosomal aberrations (translocation to unpainted chromosomes) and intra-chromosomal aberrations (inversions and deletions within a single painted chromosome). Compared to our previous results with gamma-rays and 600 MeV/nucleon Fe ions of high dose rate at NSRL (NASA Space Radiation Laboratory at Brookhaven National Laboratory), the neutron data from the LANSCE experiments showed significantly higher frequency of chromosome aberrations. However, detailed analysis of the inversion type revealed that all of the three radiation types in the study induced a low incidence of simple inversions. Most of the inversions in gamma-ray irradiated samples were accompanied by other types of intrachromosomal aberrations but few inversions were accompanied by interchromosomal aberrations. In contrast, neutrons and Fe ions induced a significant fraction of inversions that involved complex rearrangements of both inter- and intrachromosome exchanges. The distribution of damage sites on chromosome 3 was also compared for different radiation types. The breakpoints were randomly localized on chromosome 3 with neutrons and Fe ions exposure, whereas non-random distribution with clustering breakpoints was observed with gamma-rays exposure. The specific fingerprint of neutron radiations on chromosomal aberrations will be discussed.
    Keywords: Aerospace Medicine
    Type: 8th LANSCE User Group Meeting; Jun 10, 2007 - Jun 12, 2007; Los Alamos, NM; United States
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  • 51
    Publication Date: 2019-07-19
    Description: Purpose: Scopolamine is the preferred treatment for motion sickness during space flight because of its quick onset of action, short half-life and favorable side-effect profile. The dose administered depends on the mode of administration and usually ranges between 0.1 and 0.8 mg. Such small doses make it difficult to detect concentrations of scopolamine in biological fluids by using conventional HPLC methods. To measure scopolamine in saliva and thereby to evaluate the pharmacokinetics of scopolamine, we developed an LC/MS/MS method using off-line solid phase extraction. Method: Samples (0.5mL) were loaded onto Waters Oasis HLB co-polymer cartridges (10 mg, 1 mL) and eluted with 0.5 mL methanol without evaporation and reconstitution. HPLC separation of the eluted sample was performed using an Agilent Zorbax SB-CN column (50 x 2.1 mm) at a flow rate of 0.2 mL/min for 4 minutes. The mobile phase for separation was 90:10 (v/v) methanol: ammonium acetate (2 mM) in water, pH 5.0 +/- 0.1. Concentrations of scopolamine were determined using a Micromass Quattro Micro(TM) mass spectrometer with electrospray ionization (ESI). ESI mass spectra were acquired in positive ion mode with multiple reaction monitoring for the determination of scopolamine m/z = 304.2 yields 138.1 and internal standard (IS) hyoscyamine m/z = 290.2 yields 124.1. Results: The method is rapid, reproducible, specific and has the following parameters: scopolamine and the IS are eluted at 1.7 and 3.2 min respectively. The linear range is 50-5000 pg/mL for scopolamine in saliva with correlation coefficients 〉 0.99 with a CV 〈 0.5 %. The intra-day and inter-day CVs are 〈 15 % for quality control samples with concentrations of 75, 300, 750 and 3000 pg/mL of scopolamine in human saliva. Conclusion: Solid phase extraction allows more rapid sample preparation and greater precision than liquid extraction. Furthermore, we increased the sensitivity and specificity by adjusting the LC mobile phase and using an MS/MS detector.
    Keywords: Aerospace Medicine
    Type: 2007 AAPS Annual Meeting and Exposition; Nov 11, 2007 - Nov 15, 2007; San Diego, CA; United States
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  • 52
    Publication Date: 2019-07-19
    Description: The vestibular function and tracking eye movements were investigated in 12 Russian crew members of ISS missions on days 1(2), 4(5-6), and 8(9-10) after prolonged exposure to microgravity (126 to 195 days). The spontaneous oculomotor activity, static torsional otolith-cervico-ocular reflex, dynamic vestibulo-cervico-ocular responses, vestibular reactivity, tracking eye movements, and gaze-holding were studied using videooculography (VOG) and electrooculography (EOG) for parallel eye movement recording. On post-flight days 1-2 (R+1-2) some cosmonauts demonstrated: - an increased spontaneous oculomotor activity (floating eye movements, spontaneous nystagmus of the typical and atypical form, square wave jerks, gaze nystagmus) with the head held in the vertical position; - suppressed otolith function (absent or reduced by one half amplitude of torsional compensatory eye counter-rolling) with the head inclined statically right- or leftward by 300; - increased vestibular reactivity (lowered threshold and increased intensity of the vestibular nystagmus) during head turns around the longitudinal body axis at 0.125 Hz; - a significant change in the accuracy, velocity, and temporal characteristics of the eye tracking. The pattern, depth, dynamics, and velocity of the vestibular function and tracking eye movements recovery varied with individual participants in the investigation. However, there were also regular responses during readaptation to the normal gravity: - suppression of the otolith function was typically accompanied by an exaggerated vestibular reactivity; - the structure of visual tracking (the accuracy of fixational eye rotations, smooth tracking, and gaze-holding) was disturbed (the appearance of correcting saccades, the transition of smooth tracking to saccadic tracking) only in those cosmonauts who, in parallel to an increased reactivity of the vestibular input, also had central changes in the oculomotor system (spontaneous nystagmus, gaze nystagmus).
    Keywords: Aerospace Medicine
    Type: 16th IAA Humans in Space Symposium; May 20, 2007 - May 24, 2007; Beijing; China
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  • 53
    Publication Date: 2019-07-19
    Description: Extravehicular Activities (EVAs) for manned spacecraft vehicles have been performed for contingencies and nominal operations numerous times throughout history. This paper will investigate how previous U.S. manned spacecraft vehicles provided life support to crewmembers performing the EVA. Specifically defined are umbilical interfaces with respect to crewmember cooling, drinking water, air (or oxygen), humidity control, and carbon dioxide removal. As historical data is available, the need for planned versus contingency EVAs in previous vehicles as well as details for a nominal EVA day versus a contingency EVA day will be discussed. The hardware used to provide the cooling, drinking water, air (or oxygen), humidity control, and carbon dioxide removal, and the general functions of that hardware, will also be detailed, as information is available. The Crew Exploration Vehicle (CEV or Orion) EVA interfaces will be generically discussed to provide a glimpse of how similar they are to the EVA interfaces in previous vehicles. Conclusions on strategies that should be used for CEV based on previous spacecraft EVA interfaces will be made in the form of questions and recommendations.
    Keywords: Man/System Technology and Life Support
    Type: International Conference on Environmental Systems; Jul 09, 2007 - Jul 12, 2007; Chicago, IL; United States
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  • 54
    Publication Date: 2019-07-19
    Description: One could argue that NASA has never developed a true habitat for a planetary surface, with only the Lunar Module from the 1960's-era Apollo Program providing for a sparse 2 person, 3 day capability. An integral part of NASA's current National Vision for Space Exploration is missions back to the moon and eventually to Mars. One of the largest leaps i11 lunar surface exploration beyond the Apollo lunar missions will be the conduct of these extended duration human missions. These missions could range from 30 to 90 days in length initially and may eventually range up to 500 days in length. To enable these extended duration human missions, probably the single-most important lunar surface element is the Surface Habitat. The requirements that must be met by the Surface Habitat will go far beyond the safety, performance and operational requirements of the Lunar Module, and NASA needs to develop a basis for making intelligent, technically correct habitat design decisions. This paper will discuss the possibilities of the definition and development of a Habitation Readiness Level (HRL) scale that might be mapped to current Technology Readiness Levels (TRLs) for technology development. HRLs could help measure how well a particular technology thrust is advanced by a proposed planetary habitat concept. The readiness level would have to be measured differently than TRLs, and may include such milestones as habitat design performance under simulated mission operations and constraints (including relevant field testing), functional allocation demonstrations, crew interface evaluation and post-occupancy evaluation. With many concepts for planetary habitats proposed over the past 20 years, there are many strategic technical challenges facing designers of planetary habitats that will support NASA's exploration of the moon and Mars. The systematic assessment of a variety of planetary habitat options will be an important approach and will influence the associated requirements for human design, volumetrics, functionality, systems hardware and operations.
    Keywords: Man/System Technology and Life Support
    Type: 1st Exploration Conference; Jan 30, 2005 - Feb 01, 2005; Orlando, FL; United States
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  • 55
    Publication Date: 2019-07-19
    Description: NASA is developing a systems biology approach to improve the assessment of health risks associated with space radiation. The primary toxic and mutagenic lesion following radiation exposure is the DNA double strand break (DSB), thus a model incorporating proteins and pathways important in response and repair of this lesion is critical. One key protein heterodimer for systems models of radiation effects is the Ku(sub 70/80) complex. The Ku70/80 complex is important in the initial binding of DSB ends following DNA damage, and is a component of nonhomologous end joining repair, the primary pathway for DSB repair in mammalian cells. The C-terminal domain of Ku70 (Ku70c, residues 559-609), contains an helix-extended strand-helix motif and similar motifs have been found in other nucleic acid-binding proteins critical for DNA repair. However, the exact mechanism of damage recognition and substrate specificity for the Ku heterodimer remains unclear in part due to the absence of a high-resolution structure of the Ku70c/DNA complex. We performed a series of molecular dynamics (MD) simulations on a system with the subunit Ku70c and a 14 base pairs DNA duplex, whose starting structures are designed to be variable so as to mimic their different binding modes. By analyzing conformational changes and energetic properties of the complex during MD simulations, we found that interactions are preferred at DNA ends, and within the major groove, which is consistent with previous experimental investigations. In addition, the results indicate that cooperation of Ku70c with other subunits of Ku(sub 70/80) is necessary to explain the high affinity of binding as observed in experiments.
    Keywords: Aerospace Medicine
    Type: International Congress of Radiation Research; Jul 08, 2007 - Jul 12, 2007; San Francisco, CA; United States
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  • 56
    Publication Date: 2019-07-19
    Description: The Habitability & Environmental Factors and Space Medicine Divisions have developed the Space Flight Human System Standard (SFHSS) (NASA-STD-3001) to replace NASA-STD-3000 as a new NASA standard for all human spaceflight programs. The SFHSS is composed of 2 volumes. Volume 1, Crew Health, contains medical levels of care, permissible exposure limits, and fitness for duty criteria, and permissible outcome limits as a means of defining successful operating criteria for the human system. Volume 2, Habitability and Environmental Health, contains environmental, habitability and human factors standards. Development of the Human Integration Design Handbook (HIDH), a companion to the standard, is currently under construction and entails the update and revision of NASA-STD-3000 data. This new handbook will, in the fashion of NASA STD-3000, assist engineers and designers in appropriately applying habitability, environmental and human factors principles to spacecraft design. Organized in a chapter-module-element structure, the HIDH will provide the guidance for the development of requirements, design considerations, lessons learned, example solutions, background research, and assist in the identification of gaps and research needs in the disciplines. Subject matter experts have been and continue to be solicited to participate in the update of the chapters. The purpose is to build the HIDH with the best and latest data, and provide a broad representation from experts in industry, academia, the military and the space program. The handbook and the two standards volumes work together in a unique way to achieve the required level of human-system interface. All new NASA programs will be required to meet Volumes 1 and 2. Volume 2 presents human interface goals in broad, non-verifiable standards. Volume 2 also requires that each new development program prepare a set of program-specific human factors requirements. These program-specific human and environmental factors requirements must be verifiable and tailored to assure the new system meets the Volume 2 standards. Programs will use the HIDH to write their verifiable program-specific requirements.
    Keywords: Aerospace Medicine
    Type: Department of Defense Human Factors Engineering meeting; May 14, 2007 - May 17, 2007; Portsmouth, VA; United States
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  • 57
    Publication Date: 2019-07-19
    Description: The artificial gravity pilot project was designed to investigate the efficacy of daily exposure to a Gz acceleration gradient for counteracting the physiologic decrements induced by prolonged bed rest. A short radius centrifuge was used to produce a Gz gradient such that 1 g was applied at the level of the subject s heart and 2.5 g at the feet. For inclusion in the study, subjects were required to complete a 75-minute screening spin on the centrifuge. During the study, each active treatment subject was scheduled for a 60-minute spin each day for 20 consecutive days. During centrifugation, subjects were continuously monitored by a physician for signs and symptoms of pre-syncope, motion sickness, arrhythmias, joint/muscle pain and any other unanticipated problems. The physician was also present to provide emergency care in the case of a medical emergency. Cameras mounted on the centrifuge were used to provide a means of observing the subject s face and torso. Audio communication was continuously maintained. Other monitoring tools included two-lead EKG tracings, pulse oximetry, intermittent sphygmomanometer readings, lights in the peripheral visual field, and continuous blood pressure readout from a tonometry device. Thirty screening runs were attempted using twenty-seven subjects. Seven of these runs were terminated early for symptoms of pre-syncope, motion sickness, or GI distress. A total of eight subjects completed the active treatment arm of the study. Of the 160 centrifuge runs that were scheduled for these eight treatment subjects, 152 were completed, seven were terminated early, and one was not attempted. Of the seven early terminations, four were related to symptoms of pre-syncope, one to leg pain, one to GI discomfort, and one to equipment failure. Three terminations for adverse symptoms occurred on the first treatment day. Three terminations occurred on day nineteen of treatment and within 24 hours after scheduled soleus and quadriceps muscle biopsies. We have summarized the relative usefulness of the information obtained by the various monitoring modalities in making a decision to terminate a centrifuge run. The video and audio communication information was essential to the decision-making process. Heart rate and EKG tracings are considered valuable, even though no spins were terminated due to significant arrhythmias. The tonometer device was generally not reliable in this application. Our observations suggest that subjects may be less tolerant of centrifugation just after starting bed rest and after invasive procedures.
    Keywords: Aerospace Medicine
    Type: 28th Annual International Gravitational Physiology; Apr 08, 2007 - Apr 13, 2007; San Antonio, TX; United States
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  • 58
    Publication Date: 2019-07-19
    Description: The IMAG Pilot Study, recently completed at the University of Texas Medical Branch, filled in the second major gap in knowledge standing in the way of development of a practical Short Radius Centrifuge (SRC) and the use of Artificial Gravity (AG) as a multi-system countermeasure to combat the deconditioning associated with extended weightlessness. (The first challenge, to adapt rapidly rotating subjects to permit unlimited head movements without excessive motion sickness, was achieved in a series of studies at MIT involving incremental increases in head and centrifuge velocity.) It remained to be demonstrated that intermittent exposure to AG, at only one hour per day for 21 days, would have any positive effect on slowing or eliminating of deconditioning. Bed-rested normal subjects were used as a ground analog for astronauts in weightlessness. The results are clearly positive for the key physiological systems of interest: cardiovascular, muscle, and bone. No functionally relevant changes were observed in immune, cognitive, or sensory-motor function. Furthermore, we found that our initial concerns about the inability of deconditioned subjects to withstand daily centrifugation without syncope were misplaced. These encouraging initial results clearly support the further development of AG protocols. We recommend, as the next steps, the integration of a controlled exercise device on the SRC to determine the synergy between AG and exercise. Coupled with appropriate exercise device(s) the AG protocol will be tuned to-ward an optimal prescription for minimum exposure duration and frequency, maximum AG level and SRC speed.. Performance of these next steps will require extensive use of bed-rest/centrifuge facilities and eventually validation using an SRC in space. A space SRC could be placed in the ISS or on a planetary surface.
    Keywords: Aerospace Medicine
    Type: 28th Annual International Gravitational Physiology; Apr 08, 2007 - Apr 13, 2007; San Antonio, TX; United States
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  • 59
    Publication Date: 2019-07-19
    Description: Astronauts often use promethazine (PMZ) to counteract space motion sickness; however PMZ may cause drowsiness, which might impair cognitive function. In a NASA ground study, subjects received PMZ and their cognitive performance was then monitored over time. Subjects also reported sleepiness using the Karolinska Sleepiness Score (KSS), which ranges from 1 - 9. A problem arises when using KSS to establish an association between true sleepiness and performance because KSS scores tend to overly concentrate on the values 3 (fairly awake) and 7 (moderately tired). Therefore, we defined a latent sleepiness measure as a continuous random variable describing a subject s actual, but unobserved true state of sleepiness through time. The latent sleepiness and observed KSS are associated through a conditional probability model, which when coupled with demographic factors, predicts performance.
    Keywords: Aerospace Medicine
    Type: Joint Statistical Meetings; Jul 29, 2007 - Aug 02, 2007; Sal Lake City, UT; United States
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  • 60
    Publication Date: 2019-07-19
    Description: The most ambitious goal of the Vision of Space Exploration is to extend human presence across the solar system. Today, however, missions would have to bring all of the propellant, air, food, water, habitable volumes and shielding needed to sustain settlers beyond Earth. That is why resources for propellants, life support and construction of support systems and habitats must be found in space and utilized if humans hope to ever explore and colonize the solar system. The life support, fuel production and material processing systems currently proposed for spaceflight are essentially disconnected. Only traditional crop production has been proposed as a segment for bioregenerative life support systems, although the efficiency of higher plants for air regeneration is generally low. Thus, the investigation of air bioregeneration techniques based on the activity of photosynthetic organisms with higher rates of CO2 scrubbing and O2 release is very timely and important. Future systems for organic waste utilization in space may also benefit from the use of specific microorganisms. This janitorial job is efficiently carried out by microbes on Earth, which drive and connect different elemental cycles. It is likely that environmental control and life support systems based on bioregeneration will be capable of converting both organic and inorganic components of the waste at lunar settlements into edible biomass. The most challenging technologies for future lunar settlements are the extraction of elements (e.g. Fe, O, Si, etc) from local rocks for industrial feedstocks and the production of propellants. While such extraction can be accomplished by purely inorganic processes, the high energy requirements of such processes motivates the search for alternative technologies with lower energy requirements and appropriate efficiency. Well-developed terrestrial industrial biotechnologies for metals extraction and conversion could therefore be the prototypes for extraterrestrial biometallurgy.
    Keywords: Man/System Technology and Life Support
    Type: Rutgers SYmposium on Lunar Settlements; Jun 05, 2007 - Jun 07, 2007; Rutgers, NJ; United States
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  • 61
    Publication Date: 2019-07-18
    Description: Decompression sickness (DCS) is multivariable. But we hypothesize an aerobically fit person is less likely to experience hypobaric DCS than an unfit person given that fitness is exploited as part of the denitrogenation (prebreathe, PB) process prior to an altitude exposure. Aerobic fitness is peak oxygen uptake (VO2pk, ml/kg/min). METHODS: Treadmill or cycle protocols were used over 15 years to determine VO2pks. We evaluated dichotomous DCS outcome and venous gas emboli (VGE) outcome detected in the pulmonary artery with Doppler ultrasound associated with VO2pk for two classes of experiments: 1) those with no PB or PB under resting conditions prior to ascent in an altitude chamber, and 2) PB that included exercise for some part of the PB. There were 165 exposures (mean VO2pk 40.5 +/- 7.6 SD) with 25 cases of DCS in the first protocol class and 172 exposures (mean VO2pk 41.4 +/- 7.2 SD) with 25 cases of DCS in the second. Similar incidence of the DCS (15.2% vs. 14.5%) and VGE (45.5% vs. 44.8%) between the two classes indicates that decompression stress was similar. The strength of association between outcome and VO2pk was evaluated using univariate logistic regression. RESULTS: An inverse relationship between the DCS outcome and VO2pk was evident, but the relationship was strongest when exercise was done as part of the PB (exercise PB, coef. = -0.058, p = 0.07; rest or no PB, coef. = -0.005, p = 0.86). There was no relationship between VGE outcome and VO2pk (exercise PB, coef. = -0.003, p = 0.89; rest or no PB, coef. = 0.014, p = 0.50). CONCLUSIONS: A significant change in probability of DCS was associated with fitness only when exercise was included in the denitrogenation process. We believe a fit person that exercises during PB efficiently eliminates dissolved nitrogen from tissues.
    Keywords: Aerospace Medicine
    Type: Undersea and Hyperbaric Medical Society Annual Meeting; Jun 14, 2007 - Jun 16, 2007; United States
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  • 62
    Publication Date: 2019-07-19
    Description: From dealing with the inherent uncertainties in outcomes of scientific research to the lack of applicability of current NASA Procedural Requirements guidance documentation, research-based projects present challenges that require unique application of classical project management techniques. If additionally challenged by the creation of a new program transitioning from basic to applied research in a technical environment often unfamiliar with the cost and schedule constraints addressed by project management practices, such projects can find themselves struggling throughout their life cycles. Finally, supplying deliverables to a prime vehicle customer, also in the formative stage, adds further complexity to the development and management of research-based projects. The Biomedical Research and Countermeasures Projects Branch at NASA Johnson Space Center encompasses several diverse applied research-based or research-enabling projects within the newly-formed Human Research Program. This presentation will provide a brief overview of the organizational structure and environment in which these projects operate and how the projects coordinate to address and manage technical requirements. We will identify several of the challenges (cost, technical, schedule, and personnel) encountered by projects across the Branch, present case reports of actions taken and techniques implemented to deal with these challenges, and then close the session with an open forum discussion of remaining challenges and potential mitigations.
    Keywords: Aerospace Medicine
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  • 63
    Publication Date: 2019-07-19
    Description: Efficient, effective, multi-system countermeasures will likely be required to protect the health, safety, and performance of crews aboard planned exploration-class space flight missions to Mars and beyond. To that end, NASA, DLR, and IMBP initiated a multi-center international project to begin systematically exploring the utility of artificial gravity (AG) as a multi-system countermeasure in ground based venues using test subjects deconditioned by bed rest. The goal of this project is to explore the efficacy of short-radius, intermittent AG as a countermeasure to bone, muscle, cardiovascular, and sensory-motor adaptations to hypogravity. This session reports the results from a pilot study commissioned to validate a standardized protocol to be used by all centers involved in the project. Subject selection criteria, medical monitoring requirements, medical care procedures, experiment control procedures, and standardized dependent measures were established jointly. Testing was performed on 15 rigorously screened male volunteers subjected to 21 days of 6deg HDT bed rest. (All provided written consent to volunteer after the nature of the study and its hazards were clearly explained to them.) Eight were treated with daily 1hr AG exposures (2.5g at the feet decreasing to 1.0g at the heart) aboard a short radius (3m) centrifuge, while the other seven served as controls. Multiple tests of multiple dependent measures were made in each of the primary physiological systems of interest during a 10 day acclimatization period prior to HDT bed rest and again during an 8 day recovery period after the bed rest period was complete. Analyses of these data (presented in other papers in this session) suggest the AG prescription had salutary effects on aspects of the bone, muscle, and cardiovascular systems, with no untoward effects on the vestibular system, the immune system, or cognitive function. Furthermore, treatment subjects were able to tolerate 153/160 centrifuge sessions over the 21 day deconditioning protocol, suggesting that tolerance was unaffected by deconditioning. These positive results set the stage for full implementation of the planned multi-center international AG project. Future work will be devoted to developing optimization techniques for AG prescriptions (likely supplemented by exercise) to provide maximum physiological protection across all systems subject to space flight deconditioning in both men and women with minimum time and/or side effects. While a continuous AG solution (rotating vehicle) would likely be more efficient, this study suggests that intermittent AG could be an effective multi-system countermeasure.
    Keywords: Aerospace Medicine
    Type: 28th International Gravitational Physiology Meeting; Apr 08, 2007 - Apr 13, 2007; San Antonio, TX; United States
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  • 64
    Publication Date: 2019-07-19
    Description: In preparation for the NASA Artificial Gravity (AG) pilot study, the tolerability of the proposed AG parameters was tested in 11 ambulatory human subjects (6m, 5w) by exposing each to a short arm centrifuge trial. Subjects were oriented in the supine position (but inclined 6deg head down) on one arm of the centrifuge, and the rotation rate (30.6-33.4 rpm) and radial position of the feet were set to produce 2.5G of equivalent gravitational load at the force plate directly beneath the feet, 1G at the level of the mediastinum, and approximately 0.55G at the labyrinth. Amongst the 6 men participating in this preliminary study, 5 completed at least 60 minutes of the trial successfully with no adverse sequelae. However, amongst the female cohort the test was stopped by the medical monitor before 60 min in all but one case, with pre-syncope listed as the reason for termination in all cases. Mean time before abort of the centrifuge run amongst the women was 33.2 +/- 20.97 min. It is known that women have a greater predisposition to syncope during orthostatic stress, under normal tilt table conditions, during LBNP, and following space flight. The reasons for this difference are the subject of some debate, but anthropometric factors, the vasoactive effects of sex hormones, gender differences in susceptibility to motion sickness, catecholamine levels, ability to augment total peripheral resistance in response to orthostatic stress, and structural differences in cardiac anatomy and physiology have all been suggested. This finding led to the exclusion of women from the AG pilot study. Clearly if AG is to be employed as a multi-system countermeasure it must provide physiological protection at rotation rates within the tolerance limits of all potential astronauts. Further investigation of the responses of women to centrifugation will be necessary to determine how to adjust AG parameters for tolerance by female subjects before a more detailed investigation of the appropriate dose in terms of G load, rotation rate, exposure duration and frequency can be performed.
    Keywords: Aerospace Medicine
    Type: 28th Annual International Gravitational Physiology; Apr 08, 2007 - Apr 13, 2007; San Antonio, TX; United States
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  • 65
    Publication Date: 2019-07-19
    Description: To study the effects of 21 days of head-down bed rest (HDBR), with versus without an artificial gravity (AG) countermeasure, on cardiac autonomic and advanced electrocardiographic function. Fourteen healthy men participated in the study: seven experienced 21 days of HDBR alone ("HDBR controls") and seven the same degree and duration of HDBR but with approximately 1hr daily short-arm centrifugation as an AG countermeasure ("AG-treated"). Five minute supine high-fidelity 12-lead ECGs were obtained in all subjects: 1) 4 days before HDBR; 2) on the last day of HDBR; and 3) 7 days after HDBR. Besides conventional 12-lead ECG intervals and voltages, all of the following advanced ECG parameters were studied: 1) both stochastic (time and frequency domain) and deterministic heart rate variability (HRV); 2) beat-to-beat QT interval variability (QTV); 3) T-wave morphology, including signal-averaged T-wave residua (TWR) and principal component analysis ratios; 4) other SAECG-related parameters including high frequency QRS ECG and late potentials; and 5) several advanced ECG estimates of left ventricular (LV) mass. The most important results by repeated measures ANOVA were that: 1) Heart rates, Bazett-corrected QTc intervals, TWR, LF/HF power and the alpha 1 of HRV were significantly increased in both groups (i.e., by HDBR), but with no relevant HDBR*group differences; 2) All purely "vagally-mediated" parameters of HRV (e.g., RMSSD, HF power, Poincare SD1, etc.), PR intervals, and also several parameters of LV mass (Cornell and Sokolow-Lyon voltages, spatial ventricular activation times, ventricular gradients) were all significantly decreased in both groups (i.e., by HDBR), but again with no relevant HDBR*group differences); 3) All "generalized" or "vagal plus sympathetic" parameters of stochastic HRV (i.e., SDNN, total power, LF power) were significantly more decreased in the AG-treated group than in the HDBR-only group (i.e., here there was a relevant HDBR*group difference); and 4) QTV index was also significantly more changed (increased) in the AG-treated group than in the HDBR-only group, although this was clearly due to a greater decrease in generalized HRV and not to a greater increase in QTV proper because there was no relevant HDBR*group effect for either the SDNN or the RMSSD of QTV. Brief daily AG treatment by short-arm centrifuge during each of 21 days of HDBR does not appear to protect against HDBR-related losses of cardiac autonomic function or of LV mass as estimated by ECG.
    Keywords: Aerospace Medicine
    Type: International Gravitational Physiology Meeting; Apr 08, 2007 - Apr 13, 2007; San Antonio, TX; United States
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  • 66
    Publication Date: 2019-07-19
    Description: Cardiovascular effects of an artificial gravity (AG) countermeasure on deconditioned male volunteers were studied. In two groups of men we measured cardiovascular parameters at rest and in response to 30 minutes of 80 deg. head up tilt (HUT) before, at the end of, and four days following 21 days of 6 deg. head down bed rest (HDBR). One group (N=7) underwent no countermeasure while the other (N=8) received a daily, one hour, dose (2.5 gz at the foot, decreasing to 1.0 gz at the heart) of AG training on the Johnson Space Center short radius centrifuge. Cardiovascular parameters measured included heart rate, blood pressure, stroke volume, cardiac output, peripheral vascular resistance, plasma volume shifts, and vasoactive hormones. Untrained subjects exhibited shorter tilt survival (on average 8 minutes shorter) compared to trained subjects. By the end of bed rest, mean heart rate (MHR) was elevated in both groups (both supine and during tilt). In addition, treated subjects demonstrated lower, tilt-induced, increases in MHR four days following HDBR, indicating a more rapid return to pre bed rest conditions. Results from an index of autonomic balance (percentage of MHR spectral power in the respiratory frequency range) in control of heart rate are consistent with the interpretation that parasympathetic nervous system withdrawal was responsible for both tilt- and bed rest-induced increases in MHR. Our data support our pre-study hypothesis that AG treatment would lessen cardiovascular effects of deconditioning in bed rested men and suggest that AG should be further pursued as a space flight countermeasure.
    Keywords: Aerospace Medicine
    Type: 28th Annual International Gravitational Physiology Meeting; Apr 08, 2007 - Apr 13, 2007; San Antonio, TX; United States
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  • 67
    Publication Date: 2019-07-19
    Description: The impact of microgravity on the human body is a significant concern for space travelers. We report here initial results from a pilot study designed to explore the utility of artificial gravity (AG) as a countermeasure to the effects of microgravity, specifically to bone loss. After an initial phase of adaptation and testing, 15 male subjects underwent 21 days of 6 head-down bed rest to simulate the deconditioning associated with space flight. Eight of the subjects underwent 1 h of centrifugation (AG, 1 gz at the heart, 2.5 gz at the feet) each day for 21 days, while 7 of the subjects served as untreated controls (CN). Blood and urine were collected before, during, and after bed rest for bone marker determinations. At this point, preliminary data are available on the first 8 subjects (6 AG, and 2 CN). Comparing the last week of bed rest to before bed rest, urinary excretion of the bone resorption marker n-telopeptide increased 95 plus or minus 59% (mean plus or minus SD) in CN but only 32 plus or minus 26% in the AG group. Similar results were found for another resorption marker, helical peptide (increased 57 plus or minus 0% and 35 plus or minus 13% in CN and AG respectively). Bone-specific alkaline phosphatase, a bone formation marker, did not change during bed rest. At this point, sample analyses are continuing, including calcium tracer kinetic studies. These initial data demonstrate the potential effectiveness of short-radius, intermittent AG as a countermeasure to the bone deconditioning that occurs during bed rest.
    Keywords: Man/System Technology and Life Support
    Type: 28th Annual International Gravitational Physiology Meeting; Apr 08, 2007 - Apr 13, 2007; San Antonio, TX; United States
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  • 68
    Publication Date: 2019-07-19
    Description: While the vestibular system should be well-adapted to bed rest (a condition it experiences approximately 8/24 hrs each day), questions remain regarding the degree to which repeated exposures to the unusual gravito-inertial force environment of a short-radius centrifuge might affect central processing of vestibular information used in spatial orientation and balance control. Should these functions be impaired by intermittent AG, its feasibility as a counter-measure would be diminished. We, therefore, examined the effects of AG on spatial orientation and balance control in 15 male volunteers before and after 21 days of 6 HDT bed rest (BR). Eight of the subjects were treated with daily 1hr AG exposures (2.5g at the feet; 1.0g at the heart) aboard a short radius (3m) centrifuge, while the other seven served as controls (C). Spatial orientation was assessed by measures of ocular counter-rolling (OCR; rotation of the eye about the line of sight, an otolith-mediated reflex) and subjective visual vertical (SVV; perception of the spatial upright). Both OCR and SVV measurements were made with the subject upright, lying on their left sides, and lying on their right sides. OCR was measured from binocular eye orientation recordings made while the subjects fixated for 10s on a point target directly in front of the face at a distance of 1 m. SVV was assessed by asking subjects (in the dark) to adjust to upright (using a handheld controller) the orientation of a luminous bar randomly perturbed (15) to either side of the vertical meridian. Balance control performance was assessed using a computerized dynamic posturography (CDP) protocol similar to that currently required for all returning crew members. During each session, the subjects completed a combination of trials of sensory organization test (SOT) 2 (eyes closed, fixed platform) and SOT 5 (eyes closed, sway-referenced platform) with and without static and dynamic pitch plane head movements (plus or minus 20 deg., dynamic paced by an audible tone at 0.33Hz). OCR and CDP performance were unaffected by BR and BR+AG; post-BR measures were unchanged from baseline for both AG and C groups. Similarly, BR did not affect SVV in the C group. However, BR+AG disrupted one measure of spatial orientation: SVV error was significantly increased on R+0 and R+1 following BR in the AG group. These results suggest a transient untoward effect on central vestibular processing may accompany repeated exposure to intermittent AG, a potential side-effect that should be studied more closely in future studies.
    Keywords: Man/System Technology and Life Support
    Type: 28th Annual International Gravitational Physiology Meeting; Apr 08, 2007 - Apr 13, 2007; San Antonio, TX; United States
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  • 69
    Publication Date: 2019-07-19
    Description: Conventional saturation decompression protocols use linear decompression rates that become progressively slower at shallower depths, consistent with free gas phase control vs. dissolved gas elimination kinetics. If decompression is limited by control of free gas phase, linear decompression is an inefficient strategy. The NASA prebreathe reduction program demonstrated that exercise during O2 prebreathe resulted in a 50% reduction (2 h vs. 4 h) in the saturation decompression time from 14.7 to 4.3 psi and a significant reduction in decompression sickness (DCS: 0 vs. 23.7%). Combining exercise with intermittent recompression, which controls gas phase growth and eliminates supersaturation before exercising, may enable more efficient saturation decompression schedules. A tissue bubble dynamics model (TBDM) was used in conjunction with a NASA exercise prebreathe model (NEPM) that relates tissue inert gas exchange rate constants to exercise (ml O2/kg-min), to develop a schedule for decompression from helium saturation at 400 fsw. The models provide significant prediction (p 〈 0.001) and goodness of fit with 430 cases of DCS in 6437 laboratory dives for TBDM (p = 0.77) and with 22 cases of DCS in 159 altitude exposures for NEPM (p = 0.70). The models have also been used operationally in over 25,000 dives (TBDM) and 40 spacewalks (NEPM). The standard U.S. Navy (USN) linear saturation decompression schedule from saturation at 400 fsw required 114.5 h with a maximum Bubble Growth Index (BGI(sub max)) of 17.5. Decompression using intermittent recompression combined with two 10 min exercise periods (75% VO2 (sub peak)) per day required 54.25 h (BGI(sub max): 14.7). Combined intermittent recompression and exercise resulted in a theoretical 53% (2.5 day) reduction in decompression time and theoretically lower DCS risk compared to the standard USN decompression schedule. These results warrant future decompression trials to evaluate the efficacy of this approach.
    Keywords: Aerospace Medicine
    Type: 2007 Undersea and Hyperabaric Medical Society; Jun 14, 2007 - Jun 16, 2007; Dunkirk, MD; United States
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  • 70
    Publication Date: 2019-07-19
    Description: Human presence in space, whether permanent or temporary, is accompanied by the presence of microbes. However, the extent of microbial changes in response to spaceflight conditions and the corresponding changes to infectious disease risk is unclear. Previous studies have indicated that spaceflight weakens the immune system in humans and animals. In addition, preflight and in-flight monitoring of the International Space Station (ISS) and other spacecraft indicates the presence of opportunistic pathogens and the potential of obligate pathogens. Altered antibiotic resistance of microbes in flight has also been shown. As astronauts and cosmonauts live for longer periods in a closed environment, especially one using recycled water and air, there is an increased risk to crewmembers of infectious disease events occurring in-flight. Therefore, understanding how the space environment affects microorganisms and their disease potential is critically important for spaceflight missions and requires further study. The goal of this flight experiment, operationally called MICROBE, is to utilize three model microbial pathogens, Salmonella typhimurium, Pseudomonas aeruginosa, and Candida albicans to examine the global effects of spaceflight on microbial gene expression and virulence attributes. Specifically, the aims are (1) to perform microarray-mediated gene expression profiling of S. typhimurium, P. aeruginosa, and C. albicans, in response to spaceflight in comparison to ground controls and (2) to determine the effect of spaceflight on the virulence potential of these microorganisms immediately following their return from spaceflight using murine models. The model microorganisms were selected as they have been isolated from preflight or in-flight monitoring, represent different degrees of pathogenic behavior, are well characterized, and have sequenced genomes with available microarrays. In particular, extensive studies of S. typhimurium by the Principal Investigator, Dr. Nickerson, using ground-based analog systems demonstrate important changes in the genotypic, phenotypic, and virulence characteristics of this pathogen resulting from exposure to a flight-like environment (i.e. modeled microgravity).
    Keywords: Aerospace Medicine
    Type: NASA HRP Investigators'' Workshop; Feb 12, 2007 - Feb 14, 2007; United States
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  • 71
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    Publication Date: 2019-07-19
    Description: Computerized dynamic posturography (CDP) has become a standard technique for objectively quantifying balance control performance, diagnosing the nature of functional impairments underlying balance disorders, and monitoring clinical treatment outcomes. We have long used CDP protocols to assess recovery of sensory-motor function in astronauts following space flight. The most reliable indicators of post-flight crew performance are the sensory organization tests (SOTs), particularly SOTs 5 and 6, which are sensitive to changes in availability and/or utilization of vestibular cues. We have noted, however, that some astronauts exhibiting obvious signs of balance impairment after flight are able to score within clinical norms on these tests, perhaps as a result of adopting competitive strategies or by their natural skills at substituting alternate sensory information sources. This insensitivity of the CDP protocol could underestimate of the degree of impairment and, perhaps, lead to premature release of those crewmembers to normal duties. To improve the sensitivity of the CDP protocol we have introduced static and dynamic head tilt SOT trials into our protocol. The pattern of postflight recovery quantified by the enhanced CDP protocol appears to more aptly track the re-integration of sensory-motor function, with recovery time increasing as the complexity of sensory-motor/biomechanical task increases. The new CDP protocol therefore seems more suitable for monitoring post-flight sensory-motor recovery and for indicating to crewmembers and flight surgeons fitness for return to duty and/or activities of daily living. There may be classes of patients (e.g., athletes, pilots) having motivation and/or performance characteristics similar to astronauts whose sensory-motor treatment outcomes would also be more accurately monitored using the enhanced CDP protocol. Furthermore, the enhanced protocol may be useful in early detection of age-related balance disorders.
    Keywords: Aerospace Medicine
    Type: 78th Annual Scientific Meeting; May 13, 2007 - May 17, 2007; New Orleans, LA; United States
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  • 72
    Publication Date: 2019-07-19
    Description: Virtual environments (VE) offer unique training opportunities, particularly for training astronauts and preadapting them to the novel sensory conditions of microgravity. Sensorimotor aftereffects of VEs are often quite similar to adaptive sensorimotor responses observed in astronauts during and/or following space flight. The purpose of this research was to compare disturbances in sensorimotor coordination produced by dome virtual environment display and to examine the effects of exposure duration, and repeated exposures to VR systems. The current study examined disturbances in eye-head-hand (EHH) and eye-head coordination. Preliminary results will be presented. Eleven subjects have participated in the study to date. One training session was completed in order to achieve stable performance on the EHH coordination and VE tasks. Three experimental sessions were performed each separated by one day. Subjects performed a navigation and pick and place task in a dome immersive display VE for 30 or 60 min. The subjects were asked to move objects from one set of 15 pedestals to the other set across a virtual square room through a random pathway as quickly and accurately as possible. EHH coordination was measured before, immediately after, and at 1 hr, 2 hr, 4 hr and 6 hr following exposure to VR. EHH coordination was measured as position errors and reaction time in a pointing task that included multiple horizontal and vertical LED targets. Repeated measures ANOVAs were used to analyze the data. In general, we observed significant increases in position errors for both horizontal and vertical targets. The largest decrements were observed immediately following exposure to VR and showed a fairly rapid recovery across test sessions, but not across days. Subjects generally showed faster RTs across days. Individuals recovered from the detrimental effects of exposure to the VE on position errors within 1-2 hours. The fact that subjects did not significantly improve across days suggests that in order to achieve dual adaptation of EHH coordination may require more than three training sessions. These findings provide some direction for developing training schedules for VE users that facilitate adaptation, support the idea that preflight training of astronauts may serve as useful countermeasure for the sensorimotor effects of space flight, and support the idea that VEs may serve as an analog for sensorimotor effects of spaceflight.
    Keywords: Aerospace Medicine
    Type: 28th Annual International Gravitational Physiology Conference; Apr 08, 2006 - Apr 13, 2006; San Antonio, TX; United States
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  • 73
    Publication Date: 2019-07-19
    Description: Any non-robotic mission to the Mars surface will need to rely on various life support technologies. The large metabolic generation rate and low tolerance to elevated levels of carbon dioxide (CO2) in the Mars atmosphere make CO2 removal one of the preeminent tasks in this domain. In addition, these same features provide a strong impetus for using regenerable CO2 removal technologies. In the past, many of these regenerable technologies have relied on the low partial pressure CO2 surrounding the vehicle to provide an ultimate sink for removing this gas contaminant, however any Mars mission will have to overcome the presence of the Mars atmosphere. This paper describes the investigation of methods to capture the exhaled CO2 from a suited crewmember before it becomes diluted with the high volumetric air flow present within the space suit. Typical expired air contains CO2 partial pressures in the range of 20-35 mm Hg. This research investigated methods to capture this high partial pressure CO2 prior to its dilution with the low partial pressure CO2 ventilation flow. Specifically the research looked at potential designs for a collection cup for use inside the space suit helmet. This collection cup should not be considered the same as a breathing mask typical of that worn by firefighters, etc. Instead, the collection cup is a non-contact device that makes use of detailed analyses of the ventilation flow environment within the helmet. The research used a detailed Computational Fluid Dynamic (CFD) code called Fluent to provide modeling of the various gas species (CO2, water vapor, O2) as they pass through a helmet. This same model was used to numerically evaluate several different collection cup designs for this same CO2 segregation effort.
    Keywords: Man/System Technology and Life Support
    Type: 34th International Conference on Environmental Systems; Jul 09, 2007 - Jul 12, 2007; Chicago, IL; United States
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  • 74
    Publication Date: 2019-07-19
    Description: During an ExtraVehicular Activity (EVA), both the heat generated by the astronaut's metabolism and that produced by the Portable Life Support System (PLSS) must be rejected to space. The heat sources include the heat of adsorption of metabolic CO2, the heat of condensation of water, the heat removed from the body by the liquid cooling garment and the load from the electrical components. Although the sublimator hardware to reject this load weighs only 3.48 lbs, an additional eight pounds of water are loaded into the unit of which about six to eight are sublimated and lost; this is the single largest expendable during an eight-hour EVA. Using a radiator to reject heat from the Astronaut during an EVA, we can significantly reduce the amount of expendable water consumed by the sublimator. Last year we reported on the design and initial operational assessment tests of our novel radiator designated the Radiator And Freeze Tolerant heat eXchanger (RAFT-X). Herein, we report on tests conducted in the NASA Johnson Space Center Chamber E Thermal Vacuum Test Facility. Up to 800 Btu/h of heat were rejected in lunar and Mars environments with temperatures as cold as -150 F. Tilting the radiator did not cause an observable loss in performance. The RAFT-X endured freeze / thaw cycles and in fact, the heat exchanger was completely frozen three times without any apparent damage to the unit. We were also able to operate the heat exchanger in a partially frozen configuration to throttle the heat rejection rate from 530 Btu/h at low water flow rate down to 300 Btu/h. Finally, the deliberate loss of a single loop heat pipe only degraded the heat rejection performance by about 2 to 5%.
    Keywords: Man/System Technology and Life Support
    Type: 37th International Conference on Environmental Systems; Jul 09, 2007 - Jul 12, 2007; Chicago, IL; United States
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  • 75
    Publication Date: 2019-07-19
    Description: Two of the fundamental problems facing the development of a Portable Life Support System (PLSS) for use on Mars, are (i) heat rejection (because traditional technologies use sublimation of water, which wastes a scarce resource and contaminates the premises), and (ii) rejection of CO2 in an environment with a ppCO2 of 0.4-0.9 kPa. Patent-pending Metabolic heat regenerated Temperature Swing Adsorption (MTSA) technology is being developed to address both these challenges. The technology utilizes an adsorbent that when cooled with liquid CO2 to near sublimation temperatures (~195K) removes metabolically-produced CO2 in the vent loop. Once fully loaded, the adsorbent is then warmed externally by the vent loop (approx. 300K), rejecting the captured CO2 to Mars ambient. Two beds are used to effect a continuous cycle of CO2 removal/rejection as well as facilitate heat exchange out of the vent loop. Any cryogenic fluid can be used in the application; however, since CO2 is readily available at Mars and can be easily produced and stored on the Martian surface, the solution is rather elegant and less complicated when employing liquid CO2. As some metabolic heat will need to be rejected anyway, finding a practical use for metabolic heat is also an overall benefit to the PLSS. To investigate the feasibility of the technology, a series of experiments was conducted which lead to the selection and partial characterization of an appropriate adsorbent. The adsorbent NaX successfully removed CO2 from a simulated vent loop at the prescribed temperature swing anticipated during PLSS operating conditions on Mars using a cryogenic fluid. Thermal conductivity of the adsorbent was also measured to eventually aid in a demonstrator design of the technology. These results provide no show stoppers to the development of MTSA technology and allow its development to focus on other design challenges as listed in the conclusions.
    Keywords: Man/System Technology and Life Support
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  • 76
    Publication Date: 2019-07-19
    Description: With NASA's new Vision for Exploration to send humans beyond Earth orbit, it is critical to consider the human as a system that demands early and continuous user involvement, and an iterative prototype/test/redesign process. Addressing human-system interface issues early on can be very cost effective even cost reducing when performed early in the design and development cycle. To achieve this goal within Crew Exploration Vehicle (CEV) Project Office, human engineering (HE) team is formed. Key tasks are to apply HE requirements and guidelines to hardware/software, and provide HE design, analysis and evaluation of crew interfaces. Initial activities included many practice-orientated evaluations using low-fidelity CEV mock-ups. What follows is a description of such evaluations that focused on a HE requirement regarding Net Habitable Volume (NHV). NHV is defined as the total remaining pressurized volume available to on-orbit crew after accounting for the loss of volume due to deployed hardware and structural inefficiencies which decrease functional volume. The goal of the NHV evaluations was to develop requirements providing sufficient CEV NHV for crewmembers to live and perform tasks in support of mission goals. Efforts included development of a standard NHV calculation method using computer models and physical mockups, and crew/ stakeholder evaluations. Nine stakeholders and ten crewmembers participated in the unsuited evaluations. Six crewmembers also participated in a suited evaluation. The mock-up was outfitted with volumetric representation of sub-systems such as seats, and stowage bags. Thirteen scenarios were developed to represent mission/crew tasks and considered to be primary volume drivers (e.g., suit donning) for the CEV. Unsuited evaluations included a structured walkthrough of these tasks. Suited evaluations included timed donning of the existing launch and entry suit to simulate a contingency scenario followed by doffing/ stowing of the suits. All mockup evaluations were videotaped. Structured questionnaires were used to document user interface issues and volume impacts of layout configuration. Computer model and physical measures of the NHV agreed within 1 percent. This included measurement of the gross habitable volume, subtraction of intrusive volumes, and other non-habitable spaces. Calculation method developed was validated as a standard means of measuring NHV, and was recommended as a verification method for the NHV requirements. Evaluations confirmed that there was adequate volume for unsuited scenarios and suit donning/ doffing activity. Seats, suit design stowage and waste hygiene system noted to be critical volume drivers. The low-fidelity mock-up evaluations along with human modeling analysis generated discussions that will lead to high-level systems requirements and human-centered design decisions. This approach allowed HE requirements and operational concepts to evolve in parallel with engineering system concepts and design requirements. As the CEV design matures, these evaluations will continue and help with design decisions, and assessment, verification and validation of HE requirements.
    Keywords: Man/System Technology and Life Support
    Type: 16th IAA Humans in Space Symposium; May 20, 2007 - May 24, 2007; Beijing; China
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  • 77
    Publication Date: 2019-07-19
    Description: Orthostatic hypotension is a recognized risk for crewmembers returning from space. Numerous cardiovascular mechanisms have been proposed to account for this problem including vascular and cardiac dysfunction. We studied arterial and cardiac function in 6-degree head-down tilt bed rest, which is the most widely accepted ground-based analog of spaceflight. Eleven subjects are included in this study (8 men and 3 women). Data analysis was limited to the first 49 days, and compared to pre-bed rest baseline data. Using ultrasound, data was collected on arterial diameters and flows at baseline and during reactive hyperemia and following administration of nitroglycerin. Echocardiography was used to acquire information regarding systolic and diastolic function as well as ventricular mass and diameter. Plasma volumes were significantly decreased by 7 days of bed rest and stayed down through 49 days. There were no differences in reactive hyperemic response in the arm at any time point. However, the hyperemic response in the leg was significantly increased at day 49. Arterial responses to nitroglycerin did not change over the duration of bed rest (day effect) in either the arm or leg, but there was a significant difference between the arm and the leg responses. There was a marked decrease in anterior tibial intimal-medial thickness at days 21, 35 and 49. Several cardiac functional parameters including IVRT, Mitral e-wave, ejection time, velocity of circumferential shortening and myocardial performance index were significantly changed following 49 days of bed rest. These data show that some cardiovascular measures change during bed rest, while others do not. Further study is needed to determine if these measures can provide any insight into the effects of bed rest, or spaceflight, on human cardiovascular performance.
    Keywords: Aerospace Medicine
    Type: NASA Human Research Project Investigators Meeting; Feb 12, 2007 - Feb 14, 2007; League City, TX; United States
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  • 78
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2019-07-19
    Description: Space radiation presents major challenges to astronauts on the International Space Station and for future missions to the Earth s moon or Mars. Methods used to project risks on Earth need to be modified because of the large uncertainties in projecting cancer risks from space radiation, and thus impact safety factors. We describe NASA s unique approach to radiation safety that applies uncertainty based criteria within the occupational health program for astronauts: The two terrestrial criteria of a point estimate of maximum acceptable level of risk and application of the principle of As Low As Reasonably Achievable (ALARA) are supplemented by a third requirement that protects against risk projection uncertainties using the upper 95% confidence level (CL) in the radiation cancer projection model. NASA s acceptable level of risk for ISS and their new lunar program have been set at the point-estimate of a 3-percent risk of exposure induced death (REID). Tissue-averaged organ dose-equivalents are combined with age at exposure and gender-dependent risk coefficients to project the cumulative occupational radiation risks incurred by astronauts. The 95% CL criteria in practice is a stronger criterion than ALARA, but not an absolute cut-off as is applied to a point projection of a 3% REID. We describe the most recent astronaut dose limits, and present a historical review of astronaut organ doses estimates from the Mercury through the current ISS program, and future projections for lunar and Mars missions. NASA s 95% CL criteria is linked to a vibrant ground based radiobiology program investigating the radiobiology of high-energy protons and heavy ions. The near-term goal of research is new knowledge leading to the reduction of uncertainties in projection models. Risk projections involve a product of many biological and physical factors, each of which has a differential range of uncertainty due to lack of data and knowledge. The current model for projecting space radiation cancer risk relies on the three assumptions of linearity, additivity, and scaling along with the use of population averages. We describe uncertainty estimates for this model, and new experimental data that sheds light on the accuracy of the underlying assumptions. These methods make it possible to express risk management objectives in terms of quantitative metrics, i.e., the number of days in space without exceeding a given risk level within well defined confidence limits. The resulting methodology is applied to several human space exploration mission scenarios including lunar station, deep space outpost, and a Mars mission. Factors that dominate risk projection uncertainties and application of this approach to assess candidate mitigation approaches are described.
    Keywords: Aerospace Medicine
    Type: Space Safety in a Global World; May 14, 2007 - May 16, 2007; Chicago, IL; United States
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  • 79
    Publication Date: 2019-07-19
    Description: Energetic primary and secondary particles pose a health risk to astronauts in extended ISS and future Lunar and Mars missions. High-LET radiation is much more effective than low-LET radiation in the induction of various biological effects, including cell inactivation, genetic mutations, cataracts and cancer. Most of these biological endpoints are closely correlated to chromosomal damage, which can be utilized as a biomarker for radiation insult. In this study, human epithelial cells were exposed in vitro to gamma rays, 1 GeV/nucleon Fe ions and secondary neutrons whose spectrum is similar to that measured inside the Space Station. Chromosomes were condensed using a premature chromosome condensation technique and chromosome aberrations were analyzed with the multi-color banding (mBAND) technique. With this technique, individually painted chromosomal bands on one chromosome allowed the identification of both interchromosomal (translocation to unpainted chromosomes) and intrachromosomal aberrations (inversions and deletions within a single painted chromosome). Results of the study confirmed the observation of higher incidence of inversions for high-LET irradiation. However, detailed analysis of the inversion type revealed that all of the three radiation types in the study induced a low incidence of simple inversions. Half of the inversions observed in the low-LET irradiated samples were accompanied by other types of intrachromosome aberrations, but few inversions were accompanied by interchromosome aberrations. In contrast, Fe ions induced a significant fraction of inversions that involved complex rearrangements of both the inter- and intrachromosome exchanges.
    Keywords: Aerospace Medicine
    Type: NASA Human Research Program Investigators'' Workshop; Feb 12, 2007 - Feb 14, 2007; League City, TX; United States
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  • 80
    Publication Date: 2019-07-19
    Description: Protecting crew from ionizing radiation is a key life sciences problem for long-duration space missions. The three major sources/types of radiation are found in space: galactic cosmic rays, trapped Van Allen belt radiation, and solar particle events. All present varying degrees of hazard to crews; however, exposure to high doses of any of these types of radiation ultimately induce both acute and long-term biological effects. High doses of space radiation can lead to the development of toxicity associated with the acute radiation syndrome (ARS) which could have significant mission impact, and even render the crew incapable of performing flight duties. The creation of efficient radiation protection technologies is considered an important target in space radiobiology, immunology, biochemistry and pharmacology. Two major mechanisms of cellular, organelle, and molecular destruction as a result of radiation exposure have been identified: 1) damage induced directly by incident radiation on the macromolecules they encounter and 2) radiolysis of water and generation of secondary free radicals and reactive oxygen species (ROS), which induce chemical bond breakage, molecular substitutions, and damage to biological molecules and membranes. Free-radical scavengers and antioxidants, which neutralize the damaging activities of ROS, are effective in reducing the impact of small to moderate doses of radiation. In the case of high doses of radiation, antioxidants alone may be inadequate as a radioprotective therapy. However, it remains a valuable component of a more holistic strategy of prophylaxis and therapy. High doses of radiation directly damage biological molecules and modify chemical bond, resulting in the main pathological processes that drive the development of acute radiation syndromes (ARS). Which of two types of radiation-induced cellular lethality that ultimately develops, apoptosis or necrosis, depends on the spectrum of incident radiation, dose, dose rate, and functional conditions of impacted cells/organisms. The administration of an experimental anti-radiation vaccine may provide an immunologically based, adjunct method of prevention or prophylaxis against clinical ARS. The administration of experimental anti-radiation serum (ARS) and the use of the blood dialysis methods, such as immune plasma-sorption, may assist in the clearance of radiation-specific toxins and may enhance established strategies for the mitigation of the biological effects leading to ARS, and should be evaluated for use on exploration-class space missions.
    Keywords: Aerospace Medicine
    Type: 3rd International Symposium, Problems in Space Biology; Jan 24, 2007 - Jan 27, 2007; Moscow; Russia
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  • 81
    Publication Date: 2019-07-18
    Description: Introduction: Achieving NASA's Space Exploration Vision scientific objectives will require human access into cratered and uneven terrain for the purpose of sample acquisition to assess geological, and perhaps even biological features and experiments. Operational risk management is critical to safely conduct the anticipated tasks. This strategy, along with associated contingency plans, will be a driver of EVA system requirements. Therefore, a medical contingency EVA scenario was performed with the Haughton-Mars Project/NASA to develop belay and medical evacuation techniques for exploration and rescue respectively. Methods: A rescue system to allow two rescuer astronauts to evacuate one in incapacitated astronaut was evaluated. The systems main components were a hard-bottomed rescue litter, hand-operated winch, rope, ground picket anchors, and a rover-winch attachment adapter. Evaluation was performed on 15-25deg slopes of dirt with embedded rock. The winch was anchored either by adapter to the rover or by pickets hammered into the ground. The litter was pulled over the surface by rope attached to the winch. Results: The rescue system was utilized effectively to extract the injured astronaut up a slope and to a waiting rover for transport to a simulated habitat for advanced medical care, although several challenges to implementation were identified and overcome. Rotational stabilization of the winch was found to be important to get maximize mechanical advantage from the extraction system. Discussion: Further research and testing needs to be performed to be able to fully consider synergies with the other Exploration surface systems, in conducting contingency operations. Structural attachment points on the surface EVA suits may be critical to assist in incapacitated evacuation. Such attach points could be helpful in microgravity incapacitated crewmember transport as well. Wheeled utility carts or wheels that may be attachable to a litter may also aid in extraction and transport. Utilizing parts of the rover (e.g. seats) to deploy as a litter may be considered. Testing in simulated 1/6-g to determine feasibility of winch operation and anchor establishment will further reduce implementation uncertainties.
    Keywords: Aerospace Medicine
    Type: AsMA Annual Conference; May 06, 2007 - May 10, 2007; New Orleans, LA; United States
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  • 82
    Publication Date: 2019-08-26
    Description: A universal-joint assembly has been devised for transferring axial tension or compression to a load cell. To maximize measurement accuracy, the assembly is required to minimize any moments and non-axial forces on the load cell and to exhibit little or no hysteresis. The requirement to minimize hysteresis translates to a requirement to maximize axial stiffness (including minimizing backlash) and a simultaneous requirement to minimize friction. In practice, these are competing requirements, encountered repeatedly in efforts to design universal joints. Often, universal-joint designs represent compromises between these requirements. The improved universal-joint assembly contains two universal joints, each containing two adjustable pairs of angular-contact ball bearings. One might be tempted to ask why one could not use simple ball-and-socket joints rather than something as complex as universal joints containing adjustable pairs of angularcontact ball bearings. The answer is that ball-and-socket joints do not offer sufficient latitude to trade stiffness versus friction: the inevitable result of an attempt to make such a trade in a ball-and-socket joint is either too much backlash or too much friction. The universal joints are located at opposite ends of an axial subassembly that contains the load cell. The axial subassembly includes an axial shaft, an axial housing, and a fifth adjustable pair of angular-contact ball bearings that allows rotation of the axial housing relative to the shaft. The preload on each pair of angular-contact ball bearings can be adjusted to obtain the required stiffness with minimal friction, tailored for a specific application. The universal joint at each end affords two degrees of freedom, allowing only axial force to reach the load cell regardless of application of moments and non-axial forces. The rotational joint on the axial subassembly affords a fifth degree of freedom, preventing application of a torsion load to the load cell.
    Keywords: Man/System Technology and Life Support
    Type: MSC-23876 , NASA Tech Briefs, March 2007; 13
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  • 83
    Publication Date: 2019-08-26
    Description: The Pointing History Engine (PHE) is a computer program that provides mathematical transformations needed to reconstruct, from downlinked telemetry data, the attitude of the Spitzer Space Telescope (formerly known as the Space Infrared Telescope Facility) as a function of time. The PHE also serves as an example for development of similar pointing reconstruction software for future space telescopes. The transformations implemented in the PHE take account of the unique geometry of the Spitzer telescope-pointing chain, including all data on relative alignments of components, and all information available from attitude-determination instruments. The PHE makes it possible to coordinate attitude data with observational data acquired at the same time, so that any observed astronomical object can be located for future reference and re-observation. The PHE is implemented as a subroutine used in conjunction with telemetry-formatting services of the Mission Image Processing Laboratory of NASA s Jet Propulsion Laboratory to generate the Boresight Pointing History File (BPHF). The BPHF is an archival database designed to serve as Spitzer s primary astronomical reference documenting where the telescope was pointed at any time during its mission.
    Keywords: Man/System Technology and Life Support
    Type: NPO-43374 , NASA Tech Briefs, March 2007; 12
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  • 84
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2019-07-12
    Description: The International Space Station is a closed and complex environment, so some contamination of its internal atmosphere and water system is expected. To protect space crews from contaminants in potable and hygiene water, the National Aeronautics and Space Administration (NASA) requested that the National Research Council (NRC) provide guidance on how to develop water exposure guidelines and review NASA s development of the exposure guidelines for specific chemicals. NASA selects water contaminants for which spacecraft water exposure guidelines (SWEGs) will be established; this involves identifying toxicity effects relevant to astronauts and calculating exposure concentrations on the basis of those end points. SWEGs are established for exposures of 1, 10, 100, and 1,000 days. This report is the second volume in the series, Spacecraft Water Exposure Guidelines for Selected Chemicals. SWEG reports for acetone, alkylamines, ammonia, barium, cadmium, caprolactam, formate, formaldehyde, manganese, total organic carbon, and zinc are included in this report. The committee concludes that the SWEGs developed for these chemicals are scientifically valid based on the data reviewed by NASA and are consistent with the NRC (2000) report, Methods for Developing Spacecraft Water Exposure Guidelines. SWEG reports for additional chemicals will be presented in a subsequent volume.
    Keywords: Man/System Technology and Life Support
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  • 85
    Publication Date: 2019-07-12
    Description: Improved, solid-state photoelectrochemical cells for converting solar radiation to electricity have been proposed. (In general, photoelectrochemical cells convert incident light to electricity through electrochemical reactions.) It is predicted that in comparison with state-of-the-art photoelectrochemical cells, these cells will be found to operate with greater solar-to-electric energy-conversion efficiencies.
    Keywords: Man/System Technology and Life Support
    Type: NPO-40539 , NASA Tech Briefs, August 2007; 9
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  • 86
    Publication Date: 2019-07-12
    Description: A method of fabricating channels having widths of tens of nanometers in silicon substrates and burying the channels under overlying layers of dielectric materials has been demonstrated. With further refinement, the method might be useful for fabricating nanochannels for manipulation and analysis of large biomolecules at single-molecule resolution. Unlike in prior methods, burying the channels does not involve bonding of flat wafers to the silicon substrates to cover exposed channels in the substrates. Instead, the formation and burying of the channels are accomplished in a more sophisticated process that is less vulnerable to defects in the substrates and less likely to result in clogging of, or leakage from, the channels. In this method, the first step is to establish the channel pattern by forming an array of sacrificial metal nanowires on an SiO2-on-Si substrate. In particular, the wire pattern is made by use of focused-ion-beam (FIB) lithography and a subsequent metallization/lift-off process. The pattern of metal nanowires is then transferred onto the SiO2 layer by reactive-ion etching, which yields sacrificial SiO2 nanowires covered by metal. After removal of the metal covering the SiO2 nanowires, what remains are SiO2 nanowires on an Si substrate. Plasma-enhanced chemical vapor deposition (PECVD) is used to form a layer of a dielectric material over the Si substrate and over the SiO2 wires on the surface of the substrate. FIB milling is then performed to form trenches at both ends of each SiO2 wire. The trenches serve as openings for the entry of chemicals that etch SiO2 much faster than they etch Si. Provided that the nanowires are not so long that the diffusion of the etching chemicals is blocked, the sacrificial SiO2 nanowires become etched out from between the dielectric material and the Si substrate, leaving buried channels. At the time of reporting the information for this article, channels 3 m long, 20 nm deep, and 80 nm wide (see figure) had been fabricated by this method.
    Keywords: Man/System Technology and Life Support
    Type: NPO-30839 , NASA Tech Briefs, July 2007; 17
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  • 87
    Publication Date: 2019-07-12
    Description: An all-solid-state diffusion bonding process that exploits the eutectoid reaction between molybdenum and titanium has been developed for use in fabricating thermoelectric devices based on skutterudite compounds. In essence, the process is one of heating a flat piece of pure titanium in contact with a flat piece of pure molybdenum to a temperature of about 700 C while pushing the pieces together with a slight pressure [a few psi (of the order of 10 kPa)]. The process exploits the energy of mixing of these two metals to form a strong bond between them. These two metals were selected partly because the bonds formed between them are free of brittle intermetallic phases and are mechanically and chemically stable at high temperatures. The process is a solution of the problem of bonding hot-side metallic interconnections (denoted hot shoes in thermoelectric jargon) to titanium-terminated skutterudite n and p legs during the course of fabrication of a unicouple, which is the basic unit cell of a thermoelectric device (see figure). The hot-side operating temperature required for a skutterudite thermoelectric device is 700 C. This temperature precludes the use of brazing to attach the hot shoe; because brazing compounds melt at lower temperatures, the hot shoe would become detached during operation. Moreover, the decomposition temperature of one of the skutterudite compounds is 762 C; this places an upper limit on the temperature used in bonding the hot shoe. Molybdenum was selected as the interconnection metal because the eutectoid reaction between it and the titanium at the ends of the p and n legs has characteristics that are well suited for this application. In addition to being suitable for use in the present bonding process, molybdenum has high electrical and thermal conductivity and excellent thermal stability - characteristics that are desired for hot shoes of thermoelectric devices. The process takes advantage of the chemical potential energy of mixing between molybdenum and titanium. These metals have a strong affinity for each other. They are almost completely soluble in each other and remain in the solid state at temperatures above the eutectoid temperature of 695 C. As a result, bonds formed by interdiffusion of molybdenum and titanium are mechanically stable at and well above the original bonding temperature of about 700 C. Inasmuch as the bonds are made at approximately the operating temperature, thermomechanical stresses associated with differences in thermal expansion are minimized.
    Keywords: Man/System Technology and Life Support
    Type: NPO-40883 , NASA Tech Briefs, July 2007; 13
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  • 88
    facet.materialart.
    Unknown
    In:  CASI
    Publication Date: 2019-07-12
    Description: A new type of lens design features broadband achromatic performance as well as telecentricity, using a minimum number of spherical elements. With appropriate modifications, the lens design form can be tailored to cover the range of response of the focal-plane array, from Si (400-1,000 nm) to InGaAs (400-1,700 or 2,100 nm) or InSb/HgCdTe reaching to 2,500 nm. For reference, lenses typically are achromatized over the visible wavelength range of 480-650 nm. In remote sensing applications, there is a need for broadband achromatic telescopes, normally satisfied with mirror-based systems. However, mirror systems are not always feasible due to size or geometry restrictions. They also require expensive aspheric surfaces. Non-obscured mirror systems can be difficult to align and have a limited (essentially one-dimensional) field of view. Centrally obscured types have a two-dimensional but very limited field in addition to the obscuration. Telecentricity is a highly desirable property for matching typical spectrometer types, as well as for reducing the variation of the angle of incidence and cross-talk on the detector for simple camera types. This rotationally symmetric telescope with no obscuration and using spherical surfaces and selected glass types fills a need in the range of short focal lengths. It can be used as a compact front unit for a matched spectrometer, as an ultra-broadband camera objective lens, or as the optics of an integrated camera/spectrometer in which the wavelength information is obtained by the use of strip or linear variable filters on the focal plane array. This kind of camera and spectrometer system can find applications in remote sensing, as well as in-situ applications for geological mapping and characterization of minerals, ecological studies, and target detection and identification through spectral signatures. Commercially, the lens can be used in quality-control applications via spectral analysis. The lens design is based on the rear landscape lens with the aperture stop in front of all elements. This allows sufficient room for telecentricity in addition to making the stop easily accessible. The crucial design features are the use of a doublet with an ultra-low dispersion glass (fluorite or S-FPL53), and the use of a strong negative element, which enables flat field and telecentricity in conjunction with the last (field lens) element. The field lens also can be designed to be in contact with the array, a feature that is desirable in some applications. The lens has a 20deg field of view, for a 50-mm focal length, and is corrected over the range of wavelengths of 450-2,300 nm. Transverse color, which is the most pernicious aberration for spectroscopic work, is controlled at the level of 1 m or below at 0.7 m field and 5 m at full field. The maximum chief ray angle is less than 1.7 , providing good telecentricity. An additional feature of this lens is that it is made exclusively with glasses that provide good transmission up to 2,300 nm and even some transmission to 2,500 nm; thus, the lens can be used in applications that cover the entire solar-reflected spectrum. Alternative realizations are possible that provide enhanced resolution and even less transverse color over a narrower wavelength range.
    Keywords: Man/System Technology and Life Support
    Type: NPO-44059 , NASA Tech Briefs, July 2007; 23-24
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  • 89
    Publication Date: 2019-07-12
    Description: A device that includes a rectangular-waveguide/slot-antenna structure and permanent magnets has been devised as a means of generating a substantially uniform plasma over a relatively large area, using relatively low input power and a low gas flow rate. The device utilizes electron cyclotron resonance (ECR) excited by microwave power to efficiently generate plasma in a manner that is completely electrodeless in the sense that, in principle, there is no electrical contact between the plasma and the antenna. Plasmas generated by devices like this one are suitable for use as sources of ions and/or electrons for diverse material-processing applications (e.g., etching or deposition) and for ion thrusters. The absence of plasma/electrode contact essentially prevents plasma-induced erosion of the antenna, thereby also helping to minimize contamination of the plasma and of objects exposed to the plasma. Consequently, the operational lifetime of the rectangular-waveguide/ slot-antenna structure is long and the lifetime of the plasma source is limited by the lifetime of the associated charged-particle-extraction grid (if used) or the lifetime of the microwave power source. The device includes a series of matched radiating slot pairs that are distributed along the length of a plasma-source discharge chamber (see figure). This arrangement enables the production of plasma in a distributed fashion, thereby giving rise to a uniform plasma profile. A uniform plasma profile is necessary for uniformity in any electron- or ion-extraction electrostatic optics. The slotted configuration of the waveguide/ antenna structure makes the device scalable to larger areas and higher powers. All that is needed for scaling up is the attachment of additional matched radiating slots along the length of the discharge chamber. If it is desired to make the power per slot remain constant in scaling up, then the input microwave power must be increased accordingly. Unlike in prior ECR microwave plasma-generating devices, there is no need for an insulating window on the antenna. Such windows are sources of contamination and gradually become ineffective as they become coated with erosion products over time. These characteristics relegate prior ECR microwave plasma-generating devices to non-ion beam, non-deposition plasma applications. In contrast, the lack of need for an insulating window in the present device makes it possible to use the device in both ion-beam (including deposition) and electron-beam applications. The device is designed so that ECR takes place above each slot and the gradient of the magnetic field at each slot is enough to prevent backflow of plasma.
    Keywords: Man/System Technology and Life Support
    Type: LEW-17589-1 , NASA Tech Briefs, July 2007; 22-23
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  • 90
    Publication Date: 2019-07-12
    Description: The High Altitude/Re-Entry Vehicle Infrared Imaging (HARVII) system is a portable instrumentation system for tracking and thermal imaging of a possibly distant and moving object. The HARVII is designed specifically for measuring the changing temperature distribution on a space shuttle as it reenters the atmosphere. The HARVII system or other systems based on the design of the HARVII system could also be used for such purposes as determining temperature distributions in fires, on volcanoes, and on surfaces of hot models in wind tunnels. In yet another potential application, the HARVII or a similar system would be used to infer atmospheric pollution levels from images of the Sun acquired at multiple wavelengths over regions of interest. The HARVII system includes the Ratio Intensity Thermography System (RITS) and a tracking subsystem that keeps the RITS aimed at the moving object of interest. The subsystem of primary interest here is the RITS (see figure), which acquires and digitizes images of the same scene at different wavelengths in rapid succession. Assuming that the time interval between successive measurements is short enough that temperatures do not change appreciably, the digitized image data at the different wavelengths are processed to extract temperatures according to the principle of ratio-intensity thermography: The temperature at a given location in a scene is inferred from the ratios between or among intensities of infrared radiation from that location at two or more wavelengths. This principle, based on the Stefan-Boltzmann equation for the intensity of electromagnetic radiation as a function of wavelength and temperature, is valid as long as the observed body is a gray or black body and there is minimal atmospheric absorption of radiation.
    Keywords: Man/System Technology and Life Support
    Type: LAR-16385-1 , NASA Tech Briefs, November 2007; 24
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  • 91
    Publication Date: 2019-07-12
    Description: A method of electrophoretic deposition (EPD) on substrates that are porous and electrically non-conductive has been invented. Heretofore, in order to perform an EPD, it has been necessary to either (1) use a substrate material that is inherently electrically conductive or (2) subject a non-conductive substrate to a thermal and/or chemical treatment to render it conductive. In the present method, instead of relying on the electrical conductivity of the substrate, one ensures that the substrate is porous enough that when it is immersed in an EPD bath, the solvent penetrates throughout the thickness, thereby forming quasi-conductive paths through the substrate. By making it unnecessary to use a conductive substrate, this method simplifies the overall EPD process and makes new applications possible. The method is expected to be especially beneficial in enabling deposition of layers of ceramic and/or metal for chemical and electrochemical devices, notably including solid oxide fuel cells.
    Keywords: Man/System Technology and Life Support
    Type: LEW-18009-1 , NASA Tech Briefs, November 2007; 18-19
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  • 92
    Publication Date: 2019-07-12
    Description: A free-to-roll (FTR) test technique and test rig make it possible to evaluate both the transonic performance and the wingdrop/ rock behavior of a high-strength airplane model in a single wind-tunnel entry. The free-to-roll test technique is a single degree-of-motion method in which the model is free to roll about the longitudinal axis. The rolling motion is observed, recorded, and analyzed to gain insight into wing-drop/rock behavior. Wing-drop/rock is one of several phenomena symptomatic of abrupt wing stall. FTR testing was developed as part of the NASA/Navy Abrupt Wing Stall Program, which was established for the purposes of understanding and preventing significant unexpected and uncommanded (thus, highly undesirable) lateral-directional motions associated with wing-drop/rock, which have been observed mostly in fighter airplanes under high-subsonic and transonic maneuvering conditions. Before FTR testing became available, wingrock/ drop behavior of high-performance airplanes undergoing development was not recognized until flight testing. FTR testing is a reliable means of detecting, and evaluating design modifications for reducing or preventing, very complex abrupt wing stall phenomena in a ground facility prior to flight testing. The FTR test rig was designed to replace an older sting attachment butt, such that a model with its force balance and support sting could freely rotate about the longitudinal axis. The rig (see figure) includes a rotary head supported in a stationary head with a forward spherical roller bearing and an aft needle bearing. Rotation is amplified by a set of gears and measured by a shaft-angle resolver; the roll angle can be resolved to within 0.067 degrees at a rotational speed up to 1,000 degrees/s. An assembly of electrically actuated brakes between the rotary and stationary heads can be used to hold the model against a rolling torque at a commanded roll angle. When static testing is required, a locking bar is used to fix the rotating head rigidly to the stationary head. Switching between the static and FTR test modes takes only about 30 minutes. The FTR test rig was originally mounted in a 16-ft (approximately 4.0-m) transonic wind tunnel, but could just as well be adapted to use in any large wind tunnel. In one series of tests on the FTR rig, static and dynamic characteristics of models of four different fighter airplanes were measured. Two of the models exhibited uncommanded lateral motions; the other two did not. A figure of merit was developed to discern the severity of lateral motions. Using this figure of merit, it was shown that the FTR test technique enabled identification of conditions under which the uncommanded lateral motions occurred. The wind-tunnel conditions thus identified were found to be correlated with flight conditions under which the corresponding full-size airplanes exhibited uncommanded lateral motions.
    Keywords: Man/System Technology and Life Support
    Type: LAR-17153-1 , NASA Tech Briefs, November 2007; 7
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  • 93
    Publication Date: 2019-07-12
    Description: Strategic Assessment of Risk and Technology (START) is a user-friendly computer program that assists human managers in making decisions regarding research-and-development investment portfolios in the presence of uncertainties and of non-technological constraints that include budgetary and time limits, restrictions related to infrastructure, and programmatic and institutional priorities. START facilitates quantitative analysis of technologies, capabilities, missions, scenarios and programs, and thereby enables the selection and scheduling of value-optimal development efforts. START incorporates features that, variously, perform or support a unique combination of functions, most of which are not systematically performed or supported by prior decision- support software. These functions include the following: Optimal portfolio selection using an expected-utility-based assessment of capabilities and technologies; Temporal investment recommendations; Distinctions between enhancing and enabling capabilities; Analysis of partial funding for enhancing capabilities; and Sensitivity and uncertainty analysis. START can run on almost any computing hardware, within Linux and related operating systems that include Mac OS X versions 10.3 and later, and can run in Windows under the Cygwin environment. START can be distributed in binary code form. START calls, as external libraries, several open-source software packages. Output is in Excel (.xls) file format.
    Keywords: Man/System Technology and Life Support
    Type: NPO-44800 , NASA Tech Briefs, November 2007; 13
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  • 94
    Publication Date: 2019-07-12
    Description: A computer program builds application programming interfaces (APIs) and related software components for installing and uninstalling application programs in any of a variety of computers and operating systems that support the Java programming language in its binary form. This program is partly similar in function to commercial (e.g., Install-Shield) software. This program is intended to enable satisfaction of a quasi-industry-standard set of requirements for a set of APIs that would enable such installation and uninstallation and that would avoid the pitfalls that are commonly encountered during installation of software. The requirements include the following: 1) Properly detecting prerequisites to an application program before performing the installation; 2) Properly registering component requirements; 3) Correctly measuring the required hard-disk space, including accounting for prerequisite components that have already been installed; and 4) Correctly uninstalling an application program. Correct uninstallation includes (1) detecting whether any component of the program to be removed is required by another program, (2) not removing that component, and (3) deleting references to requirements of the to-be-removed program for components of other programs so that those components can be properly removed at a later time.
    Keywords: Man/System Technology and Life Support
    Type: NPO-30778 , NASA Tech Briefs, December 2007; 21
    Format: application/pdf
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  • 95
    Publication Date: 2019-07-12
    Description: Output coupling of light from a whispering- gallery-mode (WGM) optical resonator directly to a photodetector has recently been demonstrated. By directly is meant that the coupling is effected without use of intervening optical components. Heretofore, coupling of light into and out of WGM resonators has been a complex affair involving the use of such optical components as diamond or glass prisms, optical fibers, coated collimators, and/or fiber tapers. Alignment of these components is time-consuming and expensive. To effect direct coupling, one simply mounts a photodetector in direct mechanical contact with a spacer that is, in turn, in direct mechanical contact with a WGM resonator disk. The spacer must have a specified thickness (typically of the order of a wavelength) and an index of refraction lower, by an adequate margin, than the indices of refraction of the photodetector and the WGM resonator disk. This mechanically simple approach makes it possible to obtain an optimum compromise between maximizing optical coupling and maximizing the resonance quality factor (Q).
    Keywords: Man/System Technology and Life Support
    Type: NPO-43178 , NASA Tech Briefs, December 2007; 29
    Format: application/pdf
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  • 96
    Publication Date: 2019-07-12
    Description: A compact, high-resolution, two-dimensional excitation-emission matrix fluorometer (EEMF) has been designed and built specifically for use in identifying and measuring the concentrations of organic compounds, including polluting hydrocarbons, in natural underwater settings. Heretofore, most EEMFs have been designed and built for installation in laboratories, where they are used to analyze the contents of samples collected in the field and brought to the laboratories. Because the present EEMF can be operated in the field, it is better suited to measurement of spatially and temporally varying concentrations of substances of interest. In excitation-emission matrix (EEM) fluorometry, fluorescence is excited by irradiating a sample at one or more wavelengths, and the fluorescent emission from the sample is measured at multiple wavelengths. When excitation is provided at only one wavelength, the technique is termed one-dimensional (1D) EEM fluorometry because the resulting matrix of fluorescence emission data (the EEM) contains only one row or column. When excitation is provided at multiple wavelengths, the technique is termed two-dimensional (2D) EEM fluorometry because the resulting EEM contains multiple rows and columns. EEM fluorometry - especially the 2D variety - is well established as a means of simultaneously detecting numerous dissolved and particulate compounds in water. Each compound or pool of compounds has a unique spectral fluorescence signature, and each EEM is rich in information content, in that it can contain multiple fluorescence signatures. By use of deconvolution and/or other mixture-analyses techniques, it is often possible to isolate the spectral signature of compounds of interest, even when their fluorescence spectra overlap. What distinguishes the present 2D EEMF over prior laboratory-type 2D EEMFs are several improvements in packaging (including a sealed housing) and other aspects of design that render it suitable for use in natural underwater settings. In addition, the design of the present 2D EEMF incorporates improvements over the one prior commercial underwater 2D EEMF, developed in 1994 by the same company that developed the present one. Notable advanced features of the present EEMF include the following: 1) High sensitivity and spectral resolution are achieved by use of an off-the-shelf grating spectrometer equipped with a sensor in the form of a commercial astronomical- grade 256 532-pixel charge-coupled-device (CCD) array. 2) All of the power supply, timing, control, and readout circuits for the illumination source and the CCD, ancillary environmental monitoring sensors, and circuitry for controlling a shutter or filter motor are custom-designed and mounted compactly on three circuit boards below a fourth circuit board that holds the CCD (see figure). 3) The compactness of the grating spectrometer, CCD, and circuit assembly makes it possible to fit the entire instrument into a compact package that is intended to be maneuverable underwater by one person. 4) In mass production, the cost of the complete instrument would be relatively low - estimated at approximately $30,000 at 2005 prices.
    Keywords: Man/System Technology and Life Support
    Type: SSC-00235 , NASA Tech Briefs, December 2007; 14-15
    Format: application/pdf
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  • 97
    Publication Date: 2019-07-12
    Description: A calibrator, referred to as the spider design, can be used to calibrate probes incorporating multiple acoustic sensing elements. The application is an acoustic energy density probe, although the calibrator can be used for other types of acoustic probes. The calibrator relies on the use of acoustic waveguide technology to produce the same acoustic field at each of the sensing elements. As a result, the sensing elements can be separated from each other, but still calibrated through use of the acoustic waveguides. Standard calibration techniques involve placement of an individual microphone into a small cavity with a known, uniform pressure to perform the calibration. If a cavity is manufactured with sufficient size to insert the energy density probe, it has been found that a uniform pressure field can only be created at very low frequencies, due to the size of the probe. The size of the energy density probe prevents one from having the same pressure at each microphone in a cavity, due to the wave effects. The "spider" design probe is effective in calibrating multiple microphones separated from each other. The spider design ensures that the same wave effects exist for each microphone, each with an indivdual sound path. The calibrator s speaker is mounted at one end of a 14-cm-long and 4.1-cm diameter small plane-wave tube. This length was chosen so that the first evanescent cross mode of the plane-wave tube would be attenuated by about 90 dB, thus leaving just the plane wave at the termination plane of the tube. The tube terminates with a small, acrylic plate with five holes placed symmetrically about the axis of the speaker. Four ports are included for the four microphones on the probe. The fifth port is included for the pre-calibrated reference microphone. The ports in the acrylic plate are in turn connected to the probe sensing elements via flexible PVC tubes. These five tubes are the same length, so the acoustic wave effects are the same in each tube. The flexible nature of the tubes allows them to be positioned so that each tube terminates at one of the microphones of the energy density probe, which is mounted in the acrylic structure, or the calibrated reference microphone. Tests performed verify that the pressure did not vary due to bends in the tubes. The results of these tests indicate that the average sound pressure level in the tubes varied by only 0.03 dB as the tubes were bent to various angles. The current calibrator design is effective up to a frequency of approximately 4.5 kHz. This upper design frequency is largely due to the diameter of the plane-wave tubes.
    Keywords: Man/System Technology and Life Support
    Type: SSC-00248 , NASA Tech Briefs, December 2007; 12-13
    Format: application/pdf
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  • 98
    Publication Date: 2019-07-12
    Description: The Design and Data Management System (DDMS) was developed to automate the NASA Engineering Order (EO) and Engineering Change Request (ECR) processes at the Propulsion Test Facilities at Stennis Space Center for efficient and effective Configuration Management (CM). Prior to the development of DDMS, the CM system was a manual, paper-based system that required an EO or ECR submitter to walk the changes through the acceptance process to obtain necessary approval signatures. This approval process could take up to two weeks, and was subject to a variety of human errors. The process also requires that the CM office make copies and distribute them to the Configuration Control Board members for review prior to meetings. At any point, there was a potential for an error or loss of the change records, meaning the configuration of record was not accurate. The new Web-based DDMS eliminates unnecessary copies, reduces the time needed to distribute the paperwork, reduces time to gain the necessary signatures, and prevents the variety of errors inherent in the previous manual system. After implementation of the DDMS, all EOs and ECRs can be automatically checked prior to submittal to ensure that the documentation is complete and accurate. Much of the configuration information can be documented in the DDMS through pull-down forms to ensure consistent entries by the engineers and technicians in the field. The software also can electronically route the documents through the signature process to obtain the necessary approvals needed for work authorization. The workflow of the system allows for backups and timestamps that determine the correct routing and completion of all required authorizations in a more timely manner, as well as assuring the quality and accuracy of the configuration documents.
    Keywords: Man/System Technology and Life Support
    Type: SSC-00208-1 , NASA Tech Briefs, December 2007; 21-22
    Format: application/pdf
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  • 99
    Publication Date: 2019-07-12
    Description: A document proposes self-deploying storage tanks, based on the cold elastic hibernated memory (CHEM) concept, to be used on remote planets. The CHEM concept, described in previous NASA Tech Briefs articles, involves the use of open-cell shape-memory-polymer (SMP) foam sandwich structures to make lightweight, space-deployable structures that can be compressed for storage and can later be expanded, then rigidified for use. A tank according to the proposal would be made of multiple SMP layers (of which at least one could be an SMP foam). The tank would be fabricated at full size in the rigid, deployed condition at ambient temperature, the SMP material(s) having been chosen so that ambient temperature would be below the SMP glass-transition temperature (T(sub g)). The tank would then be warmed to a temperature above T(sub g), where it would be compacted and packaged, then cooled to below T(sub g) and kept there during launch and transport to a distant planet. At the assigned position on the planet, the compacted tank would be heated above T(sub g) by the solar radiation making it rebound to its original size and shape. Finally, the tank would be rigidified through natural cooling to below T(sub g) in the planetary ambient environment.
    Keywords: Man/System Technology and Life Support
    Type: NPO-43479 , NASA Tech Briefs, December 2007; 19
    Format: application/pdf
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  • 100
    Publication Date: 2019-07-12
    Description: SmaggIce Version 2.0 is a software toolkit for geometric modeling and grid generation for two-dimensional, singleand multi-element, clean and iced airfoils. A previous version of SmaggIce was described in Preparing and Analyzing Iced Airfoils, NASA Tech Briefs, Vol. 28, No. 8 (August 2004), page 32. To recapitulate: Ice shapes make it difficult to generate quality grids around airfoils, yet these grids are essential for predicting ice-induced complex flow. This software efficiently creates high-quality structured grids with tools that are uniquely tailored for various ice shapes. SmaggIce Version 2.0 significantly enhances the previous version primarily by adding the capability to generate grids for multi-element airfoils. This version of the software is an important step in streamlining the aeronautical analysis of ice airfoils using computational fluid dynamics (CFD) tools. The user may prepare the ice shape, define the flow domain, decompose it into blocks, generate grids, modify/divide/merge blocks, and control grid density and smoothness. All these steps may be performed efficiently even for the difficult glaze and rime ice shapes. Providing the means to generate highly controlled grids near rough ice, the software includes the creation of a wrap-around block (called the "viscous sublayer block"), which is a thin, C-type block around the wake line and iced airfoil. For multi-element airfoils, the software makes use of grids that wrap around and fill in the areas between the viscous sub-layer blocks for all elements that make up the airfoil. A scripting feature records the history of interactive steps, which can be edited and replayed later to produce other grids. Using this version of SmaggIce, ice shape handling and grid generation can become a practical engineering process, rather than a laborious research effort.
    Keywords: Man/System Technology and Life Support
    Type: LEW-18187-1 , NASA Tech Briefs, December 2007; 23-24
    Format: application/pdf
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