ERIC Educational Resources Information Center
Kallkvist, Marie; Gomez, Stephen; Andersson, Holger; Lush, David
2009-01-01
The purpose of this study was to create and evaluate personalised virtual learning spaces (PVLSs) in a course that was previously delivered face-to-face only. The study addressed three related questions: (1) Can a PVLS successfully be introduced into a course where IT has not previously featured? (2) Can the PVLSs be used to enhance the assessment…
STUDY CARRELS, DESIGNS FOR INDEPENDENT STUDY SPACE.
ERIC Educational Resources Information Center
BEYNON, JOHN
BECAUSE OF THE DEMAND FOR INDIVIDUALIZED INSTRUCTION, NEW SCHOOLS ARE BEING PLANNED WITH LESS CLASSROOM SPACE AND MORE LIBRARY AND INDIVIDUAL STUDY SPACES. THESE NEW SCHOOLS REQUIRE NEW KINDS OF FURNITURE DESIGNED PRIMARILY TO GIVE THE STUDENT A DEGREE OF PRIVACY RATHER THAN TO PROVIDE OPTIMUM CONTROL TO TEACHERS. THE CARREL, PREVIOUSLY USED…
Crewmember and mission control personnel interactions during International Space Station missions.
Kanas, Nick A; Salnitskiy, Vyacheslav P; Boyd, Jennifer E; Gushin, Vadim I; Weiss, Daniel S; Saylor, Stephanie A; Kozerenko, Olga P; Marmar, Charles R
2007-06-01
Reports from astronauts and cosmonauts, studies from space analogue environments on Earth, and our previous research on the Mir Space Station have identified a number of psychosocial issues that can lead to problems during long-duration space missions. Three of these issues (time effects, displacement, leader role) were studied during a series of long-duration missions to the International Space Station (ISS). As in our previous Mir study, mood and group climate questions from the Profile of Mood States or POMS, the Group Environment Scale or GES, and the Work Environment Scale or WES were completed weekly by 17 ISS crewmembers (15 men, 2 women) in space and 128 American and Russian personnel in mission control. The results did not support the presence of decrements in mood and group cohesion during the 2nd half of the missions or in any specific quarter. The results did support the predicted displacement of negative feelings to outside supervisors in both crew and mission control subjects on all six questionnaire subscales tested. Crewmembers related cohesion in their group to the support role of their commander. For mission control personnel, greater cohesion was linked to the support role as well as to the task role of their leader. The findings from our previous study on the Mir Space Station were essentially replicated on board the ISS. The findings suggest a number of countermeasures for future on-orbit missions, some of which may not be relevant for expeditionary missions (e.g., to Mars).
Calcium Kinetics During Long-Duration Space Flight
NASA Technical Reports Server (NTRS)
Smith, Scott M.; OBrien, K. O.; Wastney, M. E.; Morukov, B. V.; Larina, I.; Abrams, S. A.; Lane, H. W.; Nillen, J. L.; Davis-Street, J. E.; Oganov, V.;
2001-01-01
Bone loss represents one of the most significant effects of space flight on the human body. Understanding the mechanisms underlying this loss is critical for maintaining crew health and safety during and after flight. This investigation documents the changes in bone metabolism and calcium kinetics during and after space flight. We previously reported calcium studies on three subjects during and after a 115-d stay on the Russian space station Mir. We report here data on an additional three subjects, whose stays on Mir were approximately 4 (n=l) and 6 (n=2) mos. Previously published data are included for comparison.
NASA Technical Reports Server (NTRS)
Ehrhart, L. M.
1980-01-01
The status of marine turtle populations in the KSC area was studied using data from previous results from ground and aerial surveillance conducted from 1976 to April 1979. During ground surveillance, various data were recorded on emergent turtles such as: species, weight, tag number (if previously tagged), time discovered, activity at discovery and the location of discovery. Observations were also made on nesting and reproductive characteristics, population estimates, immigration and emigration and growth rate of the turtles. Mortality studies were additionally made and autopsies performed on dead turtles found in the area. It is concluded that further mortality documentation should be done just prior to and just after a future space launch operation in order to accurately assess the cause and effect relationship of such a launch on the turtle population.
NASA Technical Reports Server (NTRS)
Duyar, A.; Guo, T.-H.; Merrill, W.; Musgrave, J.
1992-01-01
In a previous study, Guo, Merrill and Duyar, 1990, reported a conceptual development of a fault detection and diagnosis system for actuation faults of the space shuttle main engine. This study, which is a continuation of the previous work, implements the developed fault detection and diagnosis scheme for the real time actuation fault diagnosis of the space shuttle main engine. The scheme will be used as an integral part of an intelligent control system demonstration experiment at NASA Lewis. The diagnosis system utilizes a model based method with real time identification and hypothesis testing for actuation, sensor, and performance degradation faults.
Behavioural Type Affects Space Use in a Wild Population of Crows (Corvus corone).
Deventer, Sarah A; Uhl, Florian; Bugnyar, Thomas; Miller, Rachael; Fitch, W Tecumseh; Schiestl, Martina; Ringler, Max; Schwab, Christine
2016-11-01
While personality-dependent dispersal is well studied, local space use has received surprisingly little attention in this context, despite the multiple consequences on survival and fitness. Regarding the coping style of individuals, recent studies on personality-dependent space use within a habitat indicate that 'proactive' individuals are wider ranging than 'reactive' ones. However, such studies are still scarce and cover limited taxonomic diversity, and thus, more research is needed to explore whether this pattern generalises across species. We examined the link between coping style and space use in a population of crows ( Corvus corone ) freely inhabiting the urban zoo of Vienna, Austria. We used a binary docility rating (struggle during handling vs. no struggle) and a tonic immobility test to quantify individual coping style. Individual space use was quantified as the number of different sites at which each crow was observed, and we controlled for different number of sightings per individual by creating a space use index. Only the binary docility rating showed repeatability over time, and significantly predicted space use. In contrast to previous studies, we found that reactive crows (no struggle during handling) showed wider ranging space use within the study site than proactive individuals (who struggled during handling). The discrepancy from previous results suggests that the relationship between behavioural type and space use may vary between species, potentially reflecting differences in socioecology.
Previous experience in manned space flight: A survey of human factors lessons learned
NASA Technical Reports Server (NTRS)
Chandlee, George O.; Woolford, Barbara
1993-01-01
Previous experience in manned space flight programs can be used to compile a data base of human factors lessons learned for the purpose of developing aids in the future design of inhabited spacecraft. The objectives are to gather information available from relevant sources, to develop a taxonomy of human factors data, and to produce a data base that can be used in the future for those people involved in the design of manned spacecraft operations. A study is currently underway at the Johnson Space Center with the objective of compiling, classifying, and summarizing relevant human factors data bearing on the lessons learned from previous manned space flights. The research reported defines sources of data, methods for collection, and proposes a classification for human factors data that may be a model for other human factors disciplines.
Regular Decompositions for H(div) Spaces
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kolev, Tzanio; Vassilevski, Panayot
We study regular decompositions for H(div) spaces. In particular, we show that such regular decompositions are closely related to a previously studied “inf-sup” condition for parameter-dependent Stokes problems, for which we provide an alternative, more direct, proof.
Symbolic, Nonsymbolic and Conceptual: An Across-Notation Study on the Space Mapping of Numerals.
Zhang, Yu; You, Xuqun; Zhu, Rongjuan
2016-07-01
Previous studies suggested that there are interconnections between two numeral modalities of symbolic notation and nonsymbolic notation (array of dots), differences and similarities of the processing, and representation of the two modalities have both been found in previous research. However, whether there are differences between the spatial representation and numeral-space mapping of the two numeral modalities of symbolic notation and nonsymbolic notation is still uninvestigated. The present study aims to examine whether there are differences between the spatial representation and numeral-space mapping of the two numeral modalities of symbolic notation and nonsymbolic notation; especially how zero, as both a symbolic magnitude numeral and a nonsymbolic conceptual numeral, mapping onto space; and if the mapping happens automatically at an early stage of the numeral information processing. Results of the two experiments demonstrate that the low-level processing of symbolic numerals including zero and nonsymbolic numerals except zero can mapping onto space, whereas the low-level processing of nonsymbolic zero as a semantic conceptual numeral cannot mapping onto space, which indicating the specialty of zero in the numeral domain. The present study indicates that the processing of non-semantic numerals can mapping onto space, whereas semantic conceptual numerals cannot mapping onto space. © The Author(s) 2016.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hoyer, Chad E.; Manni, Giovanni Li; Truhlar, Donald G., E-mail: truhlar@umn.edu, E-mail: gagliard@umn.edu
2014-11-28
The diatomic molecule Fe{sub 2} was investigated using restricted active space second-order perturbation theory (RASPT2). This molecule is very challenging to study computationally because predictions about the ground state and excited states depend sensitively on the choice of the quantum chemical method. For Fe{sub 2} we show that one needs to go beyond a full-valence active space in order to achieve even qualitative agreement with experiment for the dissociation energy, and we also obtain a smooth ground-state potential curve. In addition we report the first multireference study of Fe{sub 2}{sup +}, for which we predict an {sup 8}Σ{sub u}{sup −}more » ground state, which was not predicted by previous computational studies. By using an active space large enough to remove the most serious deficiencies of previous theoretical work and by explicitly investigating the interpretations of previous experimental results, this study elucidates previous difficulties and provides – for the first time – a qualitatively correct treatment of Fe{sub 2}, Fe{sub 2}{sup +}, and Fe{sub 2}{sup −}. Moreover, this study represents a record in terms of the number or active electrons and active orbitals in the active space, namely 16 electrons in 28 orbitals. Conventional CASPT2 calculations can be performed with at most 16 electrons in 16 orbitals. We were able to overcome this limit by using the RASPT2 formalism.« less
Consider the category: The effect of spacing depends on individual learning histories.
Slone, Lauren K; Sandhofer, Catherine M
2017-07-01
The spacing effect refers to increased retention following learning instances that are spaced out in time compared with massed together in time. By one account, the advantages of spaced learning should be independent of task particulars and previous learning experiences given that spacing effects have been demonstrated in a variety of tasks across the lifespan. However, by another account, spaced learning should be affected by previous learning because past learning affects the memory and attention processes that form the crux of the spacing effect. The current study investigated whether individuals' learning histories affect the role of spacing in category learning. We examined the effect of spacing on 24 2- to 3.5-year-old children's learning of categories organized by properties to which children's previous learning experiences have biased them to attend (i.e., shape) and properties to which children are less biased to attend (i.e., texture and color). Spaced presentations led to significantly better learning of shape categories, but not of texture or color categories, compared with massed presentations. In addition, generalized estimating equations analyses revealed positive relations between the size of children's "shape-side" productive vocabularies and their shape category learning and between the size of children's "against-the-system" productive vocabularies and their texture category learning. These results suggest that children's attention to and memory for novel object categories are strongly related to their individual word-learning histories. Moreover, children's learned attentional biases affected the types of categories for which spacing facilitated learning. These findings highlight the importance of considering how learners' previous experiences may influence future learning. Copyright © 2017 Elsevier Inc. All rights reserved.
The effect of spaceflight and microgravity on the human brain.
Van Ombergen, Angelique; Demertzi, Athena; Tomilovskaya, Elena; Jeurissen, Ben; Sijbers, Jan; Kozlovskaya, Inessa B; Parizel, Paul M; Van de Heyning, Paul H; Sunaert, Stefan; Laureys, Steven; Wuyts, Floris L
2017-10-01
Microgravity, confinement, isolation, and immobilization are just some of the features astronauts have to cope with during space missions. Consequently, long-duration space travel can have detrimental effects on human physiology. Although research has focused on the cardiovascular and musculoskeletal system in particular, the exact impact of spaceflight on the human central nervous system remains to be determined. Previous studies have reported psychological problems, cephalic fluid shifts, neurovestibular problems, and cognitive alterations, but there is paucity in the knowledge of the underlying neural substrates. Previous space analogue studies and preliminary spaceflight studies have shown an involvement of the cerebellum, cortical sensorimotor, and somatosensory areas and the vestibular pathways. Extending this knowledge is crucial, especially in view of long-duration interplanetary missions (e.g., Mars missions) and space tourism. In addition, the acquired insight could be relevant for vestibular patients, patients with neurodegenerative disorders, as well as the elderly population, coping with multisensory deficit syndromes, immobilization, and inactivity.
An Investigation of State-Space Model Fidelity for SSME Data
NASA Technical Reports Server (NTRS)
Martin, Rodney Alexander
2008-01-01
In previous studies, a variety of unsupervised anomaly detection techniques for anomaly detection were applied to SSME (Space Shuttle Main Engine) data. The observed results indicated that the identification of certain anomalies were specific to the algorithmic method under consideration. This is the reason why one of the follow-on goals of these previous investigations was to build an architecture to support the best capabilities of all algorithms. We appeal to that goal here by investigating a cascade, serial architecture for the best performing and most suitable candidates from previous studies. As a precursor to a formal ROC (Receiver Operating Characteristic) curve analysis for validation of resulting anomaly detection algorithms, our primary focus here is to investigate the model fidelity as measured by variants of the AIC (Akaike Information Criterion) for state-space based models. We show that placing constraints on a state-space model during or after the training of the model introduces a modest level of suboptimality. Furthermore, we compare the fidelity of all candidate models including those embodying the cascade, serial architecture. We make recommendations on the most suitable candidates for application to subsequent anomaly detection studies as measured by AIC-based criteria.
New Space Industries for the Next Millennium
NASA Technical Reports Server (NTRS)
Smitherman, D. V., Jr. (Compiler)
1998-01-01
New Space Industries For the Next Millennium is a final report of the findings from the New Space Industries Workshop held in Washington, DC, in February 1998. The primary purpose of this workshop was to identify what must be done to develop new markets, and to generate plans, milestones and new organizational relationships designed to facilitate the goal of space development. This document provides a summary report on the results of that workshop and is not intended as a statement of NASA or government policy. Previous studies had shown great potential for the development of new markets in space (e.g., travel and entertainment, space solar power, satellite and space transfer services, research and development in space, space manufacturing, and space resources), and a great need for coordination and formation of infrastructures (e.g., space transportation, space business parks, and space utilities), to facilitate the growth of new space businesses. The New Space Industries Workshop brought together government, academia, and industry participants from several previous studies and other professionals interested in the development of space for commercial purposes. Their participation provided input into the role of government and industry in space development as well as the technology needs that will enable space development. The opening of the frontier of space, not just to government missions but to private individuals and commercial business, is a challenge of overarching importance. It is our hope that the workshop and this final report continue in earnest the process of identifying and overcoming the barriers to large-scale public access and development of space in the early years of the next century.
Radiation Protection Studies of International Space Station Extravehicular Activity Space Suits
NASA Technical Reports Server (NTRS)
Cucinotta, Francis A. (Editor); Shavers, Mark R. (Editor); Saganti, Premkumar B. (Editor); Miller, Jack (Editor)
2003-01-01
This publication describes recent investigations that evaluate radiation shielding characteristics of NASA's and the Russian Space Agency's space suits. The introduction describes the suits and presents goals of several experiments performed with them. The first chapter provides background information about the dynamic radiation environment experienced at ISS and summarized radiation health and protection requirements for activities in low Earth orbit. Supporting studies report the development and application of a computer model of the EMU space suit and the difficulty of shielding EVA crewmembers from high-energy reentrant electrons, a previously unevaluated component of the space radiation environment. Chapters 2 through 6 describe experiments that evaluate the space suits' radiation shielding characteristics. Chapter 7 describes a study of the potential radiological health impact on EVA crewmembers of two virtually unexamined environmental sources of high-energy electrons-reentrant trapped electrons and atmospheric albedo or "splash" electrons. The radiological consequences of those sources have not been evaluated previously and, under closer scrutiny. A detailed computational model of the shielding distribution provided by components of the NASA astronauts' EMU is being developed for exposure evaluation studies. The model is introduced in Chapters 8 and 9 and used in Chapter 10 to investigate how trapped particle anisotropy impacts female organ doses during EVA. Chapter 11 presents a review of issues related to estimating skin cancer risk form space radiation. The final chapter contains conclusions about the protective qualities of the suit brought to light form these studies, as well as recommendations for future operational radiation protection.
NASA Astrophysics Data System (ADS)
Amaral, J. T.; Becker, V. M.
2018-05-01
We investigate ρ vector meson production in e p collisions at HERA with leading neutrons in the dipole formalism. The interaction of the dipole and the pion is described in a mixed-space approach, in which the dipole-pion scattering amplitude is given by the Marquet-Peschanski-Soyez saturation model, which is based on the traveling wave solutions of the nonlinear Balitsky-Kovchegov equation. We estimate the magnitude of the absorption effects and compare our results with a previous analysis of the same process in full coordinate space. In contrast with this approach, the present study leads to absorption K factors in the range of those predicted by previous theoretical studies on semi-inclusive processes.
NASA Technical Reports Server (NTRS)
Shearer, William T.; Lugg, Desmond J.; Ochs, H. D.; Pierson, Duane L.; Reuben, James M.; Rosenblatt, Howard M.; Sams, Clarence; Smith, C. Wayne; Smith, E. Obrian; Smolen, James E.
1999-01-01
The potential threat of immunosuppression and abnormal inflammatory responses in long-term space travel, leading to unusual predilection for opportunistic infections, malignancy, and death, is of ma or concern to the National Aeronautics and Space Administration (NASA) Program. This application has been devised to seek answers to questions of altered immunity in space travel raised by previous investigations spanning 30-plus years. We propose to do this with the help of knowledge gained by the discovery of the molecular basis of many primary and secondary immunodeficiency diseases and by application of molecular and genetic technology not previously available. Two areas of immunity that previously received little attention in space travel research will be emphasized: specific antibody responses and non-specific inflammation and adhesion. Both of these areas of research will not only add to the growing body of information on the potential effects of space travel on the immune system, but be able to delineate any functional alterations in systems important for antigen presentation, specific immune memory, and cell:cell and cell:endothelium interactions. By more precisely defining molecular dysfunction of components of the immune system, it is hoped that targeted methods of prevention of immune damage in space could be devised.
Space transfer concepts and analyses for exploration missions: Technical directive 10
NASA Technical Reports Server (NTRS)
Woodcock, Gordon R.
1992-01-01
The current technical effort is part of the third phase of a broad-scoped and systematic study of space transfer concepts for human lunar and Mars missions. The study addressed issues that were raised during the previous phases but specifically on launch vehicle size trades and MEV options.
The space-dependent model and output characteristics of intra-cavity pumped dual-wavelength lasers
NASA Astrophysics Data System (ADS)
He, Jin-Qi; Dong, Yuan; Zhang, Feng-Dong; Yu, Yong-Ji; Jin, Guang-Yong; Liu, Li-Da
2016-01-01
The intra-cavity pumping scheme which is used to simultaneously generate dual-wavelength lasers was proposed and published by us and the space-independent model of quasi-three-level and four-level intra-cavity pumped dual-wavelength lasers was constructed based on this scheme. In this paper, to make the previous study more rigorous, the space-dependent model is adopted. As an example, the output characteristics of 946 nm and 1064 nm dual-wavelength lasers under the conditions of different output mirror transmittances are numerically simulated by using the derived formula and the results are nearly identical to what was previously reported.
Job, Xavier E; de Fockert, Jan W; van Velzen, José
2016-08-01
Behavioural and electrophysiological evidence has demonstrated that preparation of goal-directed actions modulates sensory perception at the goal location before the action is executed. However, previous studies have focused on sensory perception in areas of peripersonal space. The present study investigated visual and tactile sensory processing at the goal location of upcoming movements towards the body, much of which is not visible, as well as visible peripersonal space. A motor task cued participants to prepare a reaching movement towards goals either in peripersonal space in front of them or personal space on the upper chest. In order to assess modulations of sensory perception during movement preparation, event-related potentials (ERPs) were recorded in response to task-irrelevant visual and tactile probe stimuli delivered randomly at one of the goal locations of the movements. In line with previous neurophysiological findings, movement preparation modulated visual processing at the goal of a movement in peripersonal space. Movement preparation also modulated somatosensory processing at the movement goal in personal space. The findings demonstrate that tactile perception in personal space is subject to similar top-down sensory modulation by motor preparation as observed for visual stimuli presented in peripersonal space. These findings show for the first time that the principles and mechanisms underlying adaptive modulation of sensory processing in the context of action extend to tactile perception in unseen personal space. Copyright © 2016 Elsevier Ltd. All rights reserved.
Effect of Space Flight on Adrenal Medullary Function
NASA Technical Reports Server (NTRS)
Lelkes, Peter I.
1999-01-01
We hypothesize that microgravity conditions during space flight alter the expression and specific activities of the adrenal medullary CA synthesizing enzymes (CASE). Previously, we examined adrenals from six rats flown for six days aboard STS 54 and reported that microgravity induced a decrease in the expression and specific activity of rat adrenal medullary tyrosine hydroxylase, the rate limiting enzyme of CA synthesis, without affecting the expression of other CASE. In the past, we analyzed some of the > 300 adrenals from two previous Space Shuttle missions (PARE 03 and SLS 2). The preliminary results (a) attest to the good state of tissue preservation, thus proving the feasibility of subsequent large-scale evaluation, and (b) confirm and extend our previous findings. With this grant we will be able to expeditiously analyze all our specimens and to complete our studies in a timely fashion.
Developing a Learning Progression for Number Sense Based on the Rule Space Model in China
ERIC Educational Resources Information Center
Chen, Fu; Yan, Yue; Xin, Tao
2017-01-01
The current study focuses on developing the learning progression of number sense for primary school students, and it applies a cognitive diagnostic model, the rule space model, to data analysis. The rule space model analysis firstly extracted nine cognitive attributes and their hierarchy model from the analysis of previous research and the…
Classrooms of Spatial Justice: Counter-Spaces and Young Men of Color in a GED Program
ERIC Educational Resources Information Center
Schwartz, Joni
2014-01-01
This article, based on an ethnographic study of an urban General Education Development (GED) program, suggests that for some marginalized young men of color, Adult education programs are counter-spaces of spatial justice in opposition to previous negative school spaces. Framed by critical race theory (CRT) and drawing on critical geography and…
Determination of Global Stability of the Slosh Motion in a Spacecraft via Num Erical Experiment
NASA Astrophysics Data System (ADS)
Kang, Ja-Young
2003-12-01
The global stability of the attitude motion of a spin-stabilized space vehicle is investigated by performing numerical experiment. In the previous study, a stationary solution and a particular resonant condition for a given model were found by using analytical method but failed to represent the system stability over parameter values near and off the stationary points. Accordingly, as an extension of the previous work, this study performs numerical experiment to investigate the stability of the system across the parameter space and determines stable and unstable regions of the design parameters of the system.
Centaur operations at the space station: Cost and transportation analysis
NASA Technical Reports Server (NTRS)
1988-01-01
A study was conducted to expand on the results of an initial study entitled Centaur Operations at the Space Station. The previous study developed technology demonstration missions (TDMs) that utilized the Centaur G-prime upper stage to advance OTV technologies required for accomodations and operations at the Space Station. An initial evaluation was performed of the cost to NASA for TDM implementation. Due to the potential for commercial communication satellite operation utilizing the TDM hardware, an evaluation of the Centaur's transportation potential was also performed.
Space Station and the life sciences
NASA Technical Reports Server (NTRS)
White, R. J.; Leonard, J. I.; Cramer, D. B.; Bishop, W. P.
1983-01-01
Previous fundamental research in space life sciences is examined, and consideration is devoted to studies relevant to Space Station activities. Microgravity causes weight loss, hemoconcentration, and orthostatic intolerance when astronauts returns to earth. Losses in bone density, bone calcium, and muscle nitrogen have also been observed, together with cardiovascular deconditioning, fluid-electrolyte metabolism alteration, and space sickness. Experiments have been performed with plants, bacteria, fungi, protozoa, tissue cultures, invertebrate species, and with nonhuman vertebrates, showing little effect on simple cell functions. The Spacelab first flight will feature seven life science experiments and the second flight, two. Further studies will be performed on later flights. Continued life science studies to optimize human performance in space are necessary for the efficient operation of a Space Station and the assembly of large space structures, particularly in interaction with automated machinery.
NASA Technical Reports Server (NTRS)
1975-01-01
User benefits resulting from the application of space systems to previously described application areas were identified, and methods to assign priorities to application areas and to quantify the benefits were described. The following areas were selected for in-depth review: communications, materials processing in space, weather and climate, and institutional arrangements for space applications. Recommendations concerning studies that should be undertaken to develop a more precise understanding of the source and magnitude of the realizable economic benefits were also presented.
Spacing and length of passing sidings and the incremental capacity of single track.
DOT National Transportation Integrated Search
2016-02-18
The objective of this study is to evaluate the effect of initial siding spacing and distribution of siding length on the incremental capacity of infrastructure investments on single-track railway lines. Previous research has shown a linear reduction ...
Analysis of a rotating advanced-technology space station for the year 2025
NASA Technical Reports Server (NTRS)
Queijo, M. J.; Butterfield, A. J.; Cuddihy, W. F.; King, C. B.; Stone, R. W.; Garn, P. A.
1988-01-01
An analysis is made of several aspects of an advanced-technology rotating space station configuration generated under a previous study. The analysis includes examination of several modifications of the configuration, interface with proposed launch systems, effects of low-gravity environment on human subjects, and the space station assembly sequence. Consideration was given also to some aspects of space station rotational dynamics, surface charging, and the possible application of tethers.
ERIC Educational Resources Information Center
Möhring, Wenke; Newcombe, Nora S.; Frick, Andrea
2014-01-01
Spatial scaling is an important prerequisite for many spatial tasks and involves an understanding of how distances in different-sized spaces correspond. Previous studies have found evidence for such an understanding in preschoolers; however, the mental processes involved remain unclear. In the present study, we investigated whether children and…
Potter, Timothy; Corneille, Olivier; Ruys, Kirsten I; Rhodes, Ginwan
2007-04-01
Findings on both attractiveness and memory for faces suggest that people should perceive more similarity among attractive than among unattractive faces. A multidimensional scaling approach was used to test this hypothesis in two studies. In Study 1, we derived a psychological face space from similarity ratings of attractive and unattractive Caucasian female faces. In Study 2, we derived a face space for attractive and unattractive male faces of Caucasians and non-Caucasians. Both studies confirm that attractive faces are indeed more tightly clustered than unattractive faces in people's psychological face spaces. These studies provide direct and original support for theoretical assumptions previously made in the face space and face memory literatures.
NASA Technical Reports Server (NTRS)
Newcombe, David; Stuecker, Tara; La Duc, Myron; Venkateswaran, Kasthuri
2005-01-01
Previous studies indicated evidence of opportunistic pathogens samples obtained during missions to the International Space Station (ISS). This study utilized TaqMan quantitative PCR to determine specific gene abundance in potable and non-potable ISS waters. Probe and primer sets specific to the small subunit rRNA genes were used to elucidate overall bacterial rRNA gene numbers. while those specific for Burkholderia cepacia and Stenotrophomonas maltophilia were optimized and used to probe for the presence of these two opportunistic pathogens. This research builds upon previous microbial diversity studies of ISS water and demonstrates the utility of Q-PCR tool to examine water quality.
NASA Technical Reports Server (NTRS)
Stapelfeldt, Karl R.; Brenner, Michael P.; Warfield, Keith R.; Dekens, Frank G.; Belikov, Ruslan; Brugarolas, Paul B.; Bryden, Geoffrey; Cahoy, Kerri L.; Chakrabarti, Supriya; Dubovitsky, Serge;
2014-01-01
"Exo-C" is NASA's first community study of a modest aperture space telescope designed for high contrast observations of exoplanetary systems. The mission will be capable of taking optical spectra of nearby exoplanets in reflected light, discover previously undetected planets, and imaging structure in a large sample of circumstellar disks. It will obtain unique science results on planets down to super-Earth sizes and serve as a technology pathfinder toward an eventual flagship-class mission to find and characterize habitable exoplanets. We present the mission/payload design and highlight steps to reduce mission cost/risk relative to previous mission concepts. At the study conclusion in 2015, NASA will evaluate it for potential development at the end of this decade. Keywords: Exoplanets, high contrast imaging, optical astronomy, space mission concepts
Immunological analyses of U.S. Space Shuttle crewmembers
NASA Technical Reports Server (NTRS)
Taylor, G. R.; Neale, L. S.; Dardano, J. R.
1986-01-01
Changes in the immunoresponsiveness of 'T' lymphocytes following space flight have been reported previously. Additional data collected before and after 11 Shuttle space flights show that absolute lymphocyte numbers, lymphocyte blastogenic capability, and eosinophil percent in the peripheral blood of crewmembers are generally depressed postflight. These responses resemble those associated with physical and emotional stress and may not be related to flight per se. Additional data from Space Shuttle flights 41B and 41D, involving 11 crewmembers, indicate a postflight decrease in cells reacting with 'B' lymphocyte and monocyte monoclonal antibody tags. Further, the loss of 'T' lymphocyte blast capability correlates with the decreased monocyte count (correlation coefficient = 0.697). This finding implies that the previously reported loss of blastogenic capability may be a function of decreased monocyte control, as noted in several nonspaceflight related studies.
Problem Space Matters: The Development of Creativity and Intelligence in Primary School Children
ERIC Educational Resources Information Center
Welter, Marisete Maria; Jaarsveld, Saskia; Lachmann, Thomas
2017-01-01
Previous research showed that in primary school, children's intelligence develops continually, but creativity develops more irregularly. In this study, the development of intelligence, measured traditionally, i.e., operating within well-defined problem spaces (Standard Progressive Matrices) was compared with the development of intelligence…
Cross-modal metaphorical mapping of spoken emotion words onto vertical space.
Montoro, Pedro R; Contreras, María José; Elosúa, María Rosa; Marmolejo-Ramos, Fernando
2015-01-01
From the field of embodied cognition, previous studies have reported evidence of metaphorical mapping of emotion concepts onto a vertical spatial axis. Most of the work on this topic has used visual words as the typical experimental stimuli. However, to our knowledge, no previous study has examined the association between affect and vertical space using a cross-modal procedure. The current research is a first step toward the study of the metaphorical mapping of emotions onto vertical space by means of an auditory to visual cross-modal paradigm. In the present study, we examined whether auditory words with an emotional valence can interact with the vertical visual space according to a 'positive-up/negative-down' embodied metaphor. The general method consisted in the presentation of a spoken word denoting a positive/negative emotion prior to the spatial localization of a visual target in an upper or lower position. In Experiment 1, the spoken words were passively heard by the participants and no reliable interaction between emotion concepts and bodily simulated space was found. In contrast, Experiment 2 required more active listening of the auditory stimuli. A metaphorical mapping of affect and space was evident but limited to the participants engaged in an emotion-focused task. Our results suggest that the association of affective valence and vertical space is not activated automatically during speech processing since an explicit semantic and/or emotional evaluation of the emotionally valenced stimuli was necessary to obtain an embodied effect. The results are discussed within the framework of the embodiment hypothesis.
Cross-modal metaphorical mapping of spoken emotion words onto vertical space
Montoro, Pedro R.; Contreras, María José; Elosúa, María Rosa; Marmolejo-Ramos, Fernando
2015-01-01
From the field of embodied cognition, previous studies have reported evidence of metaphorical mapping of emotion concepts onto a vertical spatial axis. Most of the work on this topic has used visual words as the typical experimental stimuli. However, to our knowledge, no previous study has examined the association between affect and vertical space using a cross-modal procedure. The current research is a first step toward the study of the metaphorical mapping of emotions onto vertical space by means of an auditory to visual cross-modal paradigm. In the present study, we examined whether auditory words with an emotional valence can interact with the vertical visual space according to a ‘positive-up/negative-down’ embodied metaphor. The general method consisted in the presentation of a spoken word denoting a positive/negative emotion prior to the spatial localization of a visual target in an upper or lower position. In Experiment 1, the spoken words were passively heard by the participants and no reliable interaction between emotion concepts and bodily simulated space was found. In contrast, Experiment 2 required more active listening of the auditory stimuli. A metaphorical mapping of affect and space was evident but limited to the participants engaged in an emotion-focused task. Our results suggest that the association of affective valence and vertical space is not activated automatically during speech processing since an explicit semantic and/or emotional evaluation of the emotionally valenced stimuli was necessary to obtain an embodied effect. The results are discussed within the framework of the embodiment hypothesis. PMID:26322007
NASA Technical Reports Server (NTRS)
Smitherman, David V., Jr.
2003-01-01
The steps required for space colonization are many to grow from our current 3-person International Space Station, now under construction, to an infrastructure that can support hundreds and eventually thousands of people in space. This paper will summarize the author's findings from numerous studies and workshops on related subjects and identify some of the critical next steps toward space colonization. Findings will be drawn from the author s previous work on space colony design, space infrastructure workshops, and various studies that addressed space policy. In conclusion, this paper will note that significant progress has been made on space facility construction through the International Space Station program, and that significant efforts are needed in the development of new reusable Earth to Orbit transportation systems. The next key steps will include reusable in space transportation systems supported by in space propellant depots, the continued development of inflatable habitat and space elevator technologies, and the resolution of policy issues that will establish a future vision for space development.
Approach to an Affordable and Productive Space Transportation System
NASA Technical Reports Server (NTRS)
McCleskey, Carey M.; Rhodes, Russel E.; Lepsch, Roger A.; Henderson, Edward M.; Robinson, John W.
2012-01-01
This paper describes an approach for creating space transportation architectures that are affordable, productive, and sustainable. The architectural scope includes both flight and ground system elements, and focuses on their compatibility to achieve a technical solution that is operationally productive, and also affordable throughout its life cycle. Previous papers by the authors and other members of the Space Propulsion Synergy Team (SPST) focused on space flight system engineering methods, along with operationally efficient propulsion system concepts and technologies. This paper follows up previous work by using a structured process to derive examples of conceptual architectures that integrate a number of advanced concepts and technologies. The examples are not intended to provide a near-term alternative architecture to displace current near-term design and development activity. Rather, the examples demonstrate an approach that promotes early investments in advanced system concept studies and trades (flight and ground), as well as in advanced technologies with the goal of enabling highly affordable, productive flight and ground space transportation systems.
Investigation of Secondary Neutron Production in Large Space Vehicles for Deep Space
NASA Technical Reports Server (NTRS)
Rojdev, Kristina; Koontz, Steve; Reddell, Brandon; Atwell, William; Boeder, Paul
2016-01-01
Future NASA missions will focus on deep space and Mars surface operations with large structures necessary for transportation of crew and cargo. In addition to the challenges of manufacturing these large structures, there are added challenges from the space radiation environment and its impacts on the crew, electronics, and vehicle materials. Primary radiation from the sun (solar particle events) and from outside the solar system (galactic cosmic rays) interact with materials of the vehicle and the elements inside the vehicle. These interactions lead to the primary radiation being absorbed or producing secondary radiation (primarily neutrons). With all vehicles, the high-energy primary radiation is of most concern. However, with larger vehicles, there is more opportunity for secondary radiation production, which can be significant enough to cause concern. In a previous paper, we embarked upon our first steps toward studying neutron production from large vehicles by validating our radiation transport codes for neutron environments against flight data. The following paper will extend the previous work to focus on the deep space environment and the resulting neutron flux from large vehicles in this deep space environment.
14 CFR 60.17 - Previously qualified FSTDs.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Previously qualified FSTDs. 60.17 Section 60.17 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRMEN FLIGHT SIMULATION TRAINING DEVICE INITIAL AND CONTINUING QUALIFICATION AND USE § 60.17 Previously...
14 CFR 60.17 - Previously qualified FSTDs.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Previously qualified FSTDs. 60.17 Section 60.17 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRMEN FLIGHT SIMULATION TRAINING DEVICE INITIAL AND CONTINUING QUALIFICATION AND USE § 60.17 Previously...
14 CFR 60.17 - Previously qualified FSTDs.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Previously qualified FSTDs. 60.17 Section 60.17 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRMEN FLIGHT SIMULATION TRAINING DEVICE INITIAL AND CONTINUING QUALIFICATION AND USE § 60.17 Previously...
14 CFR 60.17 - Previously qualified FSTDs.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Previously qualified FSTDs. 60.17 Section 60.17 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRMEN FLIGHT SIMULATION TRAINING DEVICE INITIAL AND CONTINUING QUALIFICATION AND USE § 60.17 Previously...
14 CFR 60.17 - Previously qualified FSTDs.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Previously qualified FSTDs. 60.17 Section 60.17 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRMEN FLIGHT SIMULATION TRAINING DEVICE INITIAL AND CONTINUING QUALIFICATION AND USE § 60.17 Previously...
NASA Technical Reports Server (NTRS)
Keller, Lindsay P.; Berger, Eve L.
2017-01-01
Limited samples are available for the study of space weathering effects on airless bodies. The grains returned by the Hayabusa mission to asteroid 25143 Itokawa provide the only samples currently available to study space weathering of ordinary chondrite regolith. We have previously studied olivine-rich Itokawa grains and documented their surface alteration and exposure ages based on the observed density of solar flare particle tracks. Here we focus on the rarer Itokawa plagioclase grains, in order to allow comparisons between Itokawa and lunar soil plagioclase grains for which an extensive data set exists.
NASA Technical Reports Server (NTRS)
Ray, Paul S.
1992-01-01
The safety and survival of the crewmembers has been the prime concern of NASA. Previous studies have been conducted mainly for emergencies occurring during the operating mode of the fully assembled Station. The present study was conducted to evaluate the emergency requirements for the caution and warning, logistics, maintenance, and assembly stage MB-6 of the Station in space. Effective caution and warning is essential to achieve safe egress in emergencies. In order to survive a long period in space, the safety and emergency requirements for maintenance, logistics, and extravehicular assembly operation in space must be met.
Environmental stressors during space flight: potential effects on body temperature
NASA Technical Reports Server (NTRS)
Jauchem, J. R.
1988-01-01
1. Organisms may be affected by many environmental factors during space flight, e.g., acceleration, weightlessness, decreased pressure, changes in oxygen tension, radiofrequency radiation and vibration. 2. Previous studies of change in body temperature--one response to these environmental factors--are reviewed. 3. Conditions leading to heat stress and hypothermia are discussed.
Reorientation in a Rhombic Environment: No Evidence for an Encapsulated Geometric Module
ERIC Educational Resources Information Center
Hupbach, A.; Nadel, L.
2005-01-01
Reorientation behavior of young children has been described as dependent upon a geometric module that is incapable of interacting with landmark information. Whereas previous studies typically used rectangular spaces that provided geometric information about distance, we used a rhombic space that allowed us to explore the way children use geometric…
Space charge effects on the third order coupled resonance
NASA Astrophysics Data System (ADS)
Franchetti, Giuliano; Gilardoni, Simone; Huschauer, Alexander; Schmidt, Frank; Wasef, Raymond
2017-08-01
The effect of space charge on bunched beams has been the subject of numerous numerical and experimental studies in the first decade of 2000. Experimental campaigns performed at the CERN Proton Synchrotron in 2002 and at the GSI SIS18 in 2008 confirmed the existence of an underlying mechanism in the beam dynamics of periodic resonance crossing induced by the synchrotron motion and space charge. In this article we present an extension of the previous studies to describe the effect of space charge on a controlled coupled (2D) third order resonance. The experimental and simulation results of this latest campaign shed a new light on the difficulties of the 2D particle dynamics. We find striking experimental evidence that space charge and the coupled resonance create an unusual coupling in the phase space, leading to the formation of an asymmetric halo. Moreover, this study demonstrates a clear link between halo formation and fixed-lines.
NASA Technical Reports Server (NTRS)
Hall, Michael L.; Doster, Joseph M.
1986-01-01
Many proposed space reactor designs employ heat pipes as a means of conveying heat. Previous researchers have been concerned with steady state operation, but the transient operation is of interest in space reactor applications due to the necessity of remote startup and shutdown. A model is being developed to study the dynamic behavior of high temperature heat pipes during startup, shutdown and normal operation under space environments. Model development and preliminary results for a hypothetical design of the system are presented.
Akiva-Kabiri, Lilach; Linkovski, Omer; Gertner, Limor; Henik, Avishai
2014-08-01
In musical-space synesthesia, musical pitches are perceived as having a spatially defined array. Previous studies showed that symbolic inducers (e.g., numbers, months) can modulate response according to the inducer's relative position on the synesthetic spatial form. In the current study we tested two musical-space synesthetes and a group of matched controls on three different tasks: musical-space mapping, spatial cue detection and a spatial Stroop-like task. In the free mapping task, both synesthetes exhibited a diagonal organization of musical pitch tones rising from bottom left to the top right. This organization was found to be consistent over time. In the subsequent tasks, synesthetes were asked to ignore an auditory or visually presented musical pitch (irrelevant information) and respond to a visual target (i.e., an asterisk) on the screen (relevant information). Compatibility between musical pitch and the target's spatial location was manipulated to be compatible or incompatible with the synesthetes' spatial representations. In the spatial cue detection task participants had to press the space key immediately upon detecting the target. In the Stroop-like task, they had to reach the target by using a mouse cursor. In both tasks, synesthetes' performance was modulated by the compatibility between irrelevant and relevant spatial information. Specifically, the target's spatial location conflicted with the spatial information triggered by the irrelevant musical stimulus. These results reveal that for musical-space synesthetes, musical information automatically orients attention according to their specific spatial musical-forms. The present study demonstrates the genuineness of musical-space synesthesia by revealing its two hallmarks-automaticity and consistency. In addition, our results challenge previous findings regarding an implicit vertical representation for pitch tones in non-synesthete musicians. Copyright © 2014 Elsevier Inc. All rights reserved.
Facebook and MySpace: complement or substitute for face-to-face interaction?
Kujath, Carlyne L
2011-01-01
Previous studies have claimed that social-networking sites are used as a substitute for face-to-face interaction, resulting in deteriorating relationship quality and decreased intimacy among its users. The present study hypothesized that this type of communication is not a substitute for face-to-face interaction; rather, that it is an extension of communication with face-to-face partners. A survey was administered to examine the use of Facebook and MySpace in this regard among 183 college students. The study confirmed that Facebook and MySpace do act as an extension of face-to-face interaction, but that some users do tend to rely on Facebook and MySpace for interpersonal communication more than face-to-face interaction.
Coherent lidar wind measurements from the Space Station base using 1.5 m all-reflective optics
NASA Technical Reports Server (NTRS)
Bilbro, J. W.; Beranek, R. G.
1987-01-01
This paper discusses the space-based measurement of atmospheric winds from the point of view of the requirements of the optical system of a coherent CO2 lidar. A brief description of the measurement technique is given and a discussion of previous study results provided. The telescope requirements for a Space Station based lidar are arrived at through discussions of the desired system sensitivity and the need for lag angle compensation.
NASA Technical Reports Server (NTRS)
1971-01-01
The baseline preliminary design developed for the Bioexplorer spacecraft under a previous contract was used, and further study effort devoted in areas of thermal control, attitude control, and power subsystem design. The use of the space shuttle vehicle as a potential launch and recovery vehicle for the Bioresearch module was also evaluated.
An Embodiment Perspective on Number-Space Mapping in 3.5-year-old Dutch Children
ERIC Educational Resources Information Center
Noordende, Jaccoline E.; Volman, M(Chiel). J. M.; Leseman, Paul P. M.; Kroesbergen, Evelyn H.
2017-01-01
Previous research suggests that block adding, subtracting and counting direction are early forms of number-space mapping. In this study, an embodiment perspective on these skills was taken. Embodiment theory assumes that cognition emerges through sensory-motor interaction with the environment. In line with this assumption, it was investigated if…
Satoh, Kazuo; Yamazaki, Takashi; Nakayama, Takako; Umeda, Yoshiko; Alshahni, Mohamed Mahdi; Makimura, Miho; Makimura, Koichi
2016-05-01
As a part of a series of studies regarding the microbial biota in manned space environments, fungi were isolated from six pieces of equipment recovered from the Japanese Experimental Module "KIBO" of the International Space Station and from a space shuttle. Thirty-seven strains of fungi were isolated, identified and investigated with regard to morphological phenotypes and antifungal susceptibilities. The variety of fungi isolated in this study was similar to that of several previous reports. The dominant species belonged to the genera Penicillium, Aspergillus and Cladosporium, which are potential causative agents of allergy and opportunistic infections. The morphological phenotypes and antifungal susceptibilities of the strains isolated from space environments were not significantly different from those of reference strains on Earth. © 2016 The Societies and John Wiley & Sons Australia, Ltd.
The Cauchy Problem in Local Spaces for the Complex Ginzburg-Landau EquationII. Contraction Methods
NASA Astrophysics Data System (ADS)
Ginibre, J.; Velo, G.
We continue the study of the initial value problem for the complex Ginzburg-Landau equation
The first meeting of the Advisory Committee on the Future of the US Space Program (C-FUSSP)
NASA Technical Reports Server (NTRS)
1990-01-01
These are minutes of the Advisory Committee on the Future of the U.S. Space Program (C-FUSSP). From September 13-15, 1990, presentations were made by the major leaders at NASA as well as industry leaders. The presentations draw on previous studies of the future of NASA space programs. Allowance was made for plenty of questions. The minutes reflect the views of governmental units such as the National Space Council, the NASA Administrators Office, Office of Space Science and Applications, Office of Space Flight, Office of Space Operations, Office of Aeronautics, Exploration, and Technology as well as other pertinent units and outside organizations. Members of the committee are listed at the conclusion of the minutes.
2003-06-21
KENNEDY SPACE CENTER, FLA. - At the KSC Visitor Complex, former astronaut James A. Lovell (standing left) greets former astronaut Story Musgrave (standing right) at his induction ceremony into the U.S. Astronaut Hall of Fame. Also seated on the dais are, from left, former astronaut and Senator John H. Glenn, astronaut and Associate Director (Technical) of the Johnson Space Center John W. Young, and former astronaut Buzz Aldrin, all previously inducted into the Hall of Fame. Being inducted with Musgrave are Space Shuttle astronauts Daniel Brandenstein, Robert "Hoot" Gibson, and Sally Ride. Conceived by six of the Mercury Program astronauts, the U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The four new inductees join 48 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
Safety and environmental constraints on space applications of fusion energy
NASA Technical Reports Server (NTRS)
Roth, J. Reece
1990-01-01
Some of the constraints are examined on fusion reactions, plasma confinement systems, and fusion reactors that are intended for such space related missions as manned or unmanned operations in near earth orbit, interplanetary missions, or requirements of the SDI program. Of the many constraints on space power and propulsion systems, those arising from safety and environmental considerations are emphasized since these considerations place severe constraints on some fusion systems and have not been adequately treated in previous studies.
Criteria for Public Open Space Enhancement to Achieve Social Interaction: a Review Paper
NASA Astrophysics Data System (ADS)
Salih, S. A.; Ismail, S.
2017-12-01
A This paper presents a various literatures, studies, transcripts and papers aiming to provide an overview of some theories and existing research on the significance of natural environments and green open spaces to achieve social interaction and outdoor recreation. The main objective of the paper is to identify the factors that affecting social interaction in green open spaces, through proving that an appropriate open spaces is important to enhance social interaction and community. This study employs (qualitative) summarizing content analysis method which mainly focused on collect and summarizing of documentation such as transcripts, articles, papers, and books from more than 25 source, regarding the importance of public open spaces for the community. The summarizing content analysis of this paper is the fundament for a qualitative oriented procedure of text interpretation used to analyse the information gathered. Results of this study confirms that sound social interaction need an appropriate physical space including criteria of: design, activities, access and linkage, administration and maintenance, place attachment and users’ characteristics, also previous studies in this area have a health perspective with measures of physical activity of open spaces in general.
Enhanced Text Spacing Improves Reading Performance in Individuals with Macular Disease
Blackmore-Wright, Sally; Georgeson, Mark A.; Anderson, Stephen J.
2013-01-01
The search by many investigators for a solution to the reading problems encountered by individuals with no central vision has been long and, to date, not very fruitful. Most textual manipulations, including font size, have led to only modest gains in reading speed. Previous work on spatial integrative properties of peripheral retina suggests that ‘visual crowding’ may be a major factor contributing to inefficient reading. Crowding refers to the fact that juxtaposed targets viewed eccentrically may be difficult to identify. The purpose of this study was to assess the combined effects of line spacing and word spacing on the ability of individuals with age-related macular degeneration (ARMD) to read short passages of text that were printed with either high (87.5%) or low contrast (17.5%) letters. Low contrast text was used to avoid potential ceiling effects and to mimic a possible reduction in letter contrast with light scatter from media opacities. For both low and high contrast text, the fastest reading speeds we measured were for passages of text with double line and double word spacing. In comparison with standard single spacing, double word/line spacing increased reading speed by approximately 26% with high contrast text (p < 0.001), and by 46% with low contrast text (p < 0.001). In addition, double line/word spacing more than halved the number of reading errors obtained with single spaced text. We compare our results with previous reading studies on ARMD patients, and conclude that crowding is detrimental to reading and that its effects can be reduced with enhanced text spacing. Spacing is particularly important when the contrast of the text is reduced, as may occur with intraocular light scatter or poor viewing conditions. We recommend that macular disease patients should employ double line spacing and double-character word spacing to maximize their reading efficiency. PMID:24244676
NASA Technical Reports Server (NTRS)
Badhwar, G. D.; Huff, H.; Wilkins, R.; Thibeault, Sheila
2002-01-01
Space radiation transport models clearly show that low atomic weight materials provide a better shielding protection for interplanetary human missions than high atomic weight materials. These model studies have concentrated on shielding properties against charged particles. A light-weight, inflatable habitat module called TransHab was built and shown to provide adequate protection against micrometeoroid impacts and good shielding properties against charged particle radiation in the International Space Station orbits. An experiment using a tissue equivalent proportional counter, to study the changes in dose and lineal energy spectra with graphite, aluminum, and a TransHab build-up as shielding, was carried out at the Los Alamos Nuclear Science Center neutron facility. It is a continuation of a previous study using regolith and doped polyethylene materials. This paper describes the results and their comparison with the previous study. Published by Elsevier Science Ltd.
Pilot Non-Conformance to Alerting System Commands During Closely Spaced Parallel Approaches
NASA Technical Reports Server (NTRS)
Pritchett, Amy R.; Hansman, R. John
1997-01-01
Pilot non-conformance to alerting system commands has been noted in general and to a TCAS-like collision avoidance system in a previous experiment. This paper details two experiments studying collision avoidance during closely-spaced parallel approaches in instrument meteorological conditions (IMC), and specifically examining possible causal factors of, and design solutions to, pilot non-conformance.
Cell culture experiments planned for the space bioreactor
NASA Technical Reports Server (NTRS)
Morrison, Dennis R.; Cross, John H.
1987-01-01
Culturing of cells in a pilot-scale bioreactor remains to be done in microgravity. An approach is presented based on several studies of cell culture systems. Previous and current cell culture research in microgravity which is specifically directed towards development of a space bioprocess is described. Cell culture experiments planned for a microgravity sciences mission are described in abstract form.
2003-06-21
KENNEDY SPACE CENTER, FLA. - At the KSC Visitor Complex, former astronaut James A. Lovell (standing left) applauds former astronaut Sally K. Ride at her induction ceremony into the U.S. Astronaut Hall of Fame. Seated on the dais, from left, are former astronauts Gordon Cooper, Scott Carpenter, and Buzz Aldrin, all previously inducted into the Hall of Fame. Being inducted with Ride are Space Shuttle astronauts Daniel Brandenstein, Robert "Hoot" Gibson, and Story Musgrave. Conceived by six of the Mercury Program astronauts, the U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The four new inductees join 48 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
Calcium and Bone Metabolism During Spaceflight
NASA Technical Reports Server (NTRS)
Smith, Scott M.
2002-01-01
The ability to understand and counteract weightlessness-induced bone loss will be critical for crew health and safety during and after space station or exploration missions lasting months or years, respectively. Until its deorbit in 2001 , the Mir Space Station provided a valuable platform for long-duration space missions and life sciences research. Long-duration flights are critical for studying bone loss, as the 2- to 3-week Space Shuttle flights are not long enough to detect changes in bone mass. This review will describe human spaceflight data, focusing on biochemical surrogates of bone and calcium metabolism. This subject has been reviewed previously. 1-
Design of the Space Station Freedom power system
NASA Technical Reports Server (NTRS)
Thomas, Ronald L.; Hallinan, George J.
1989-01-01
The design of Space Station Freedom's electric power system (EPS) is reviewed, highlighting the key design goals of performance, low cost, reliability and safety. Tradeoff study results that illustrate the competing factors responsible for many of the more important design decisions are discussed. When Freedom's EPS is compared with previous space power designs, two major differences stand out. The first is the size of the EPS, which is larger than any prior system. The second major difference between the EPS and other space power designs is the indefinite expected life of Freedom; 30 years has been used for life-cycle-cost calculations.
Psychological adaptation and salutogenesis in space: Lessons from a series of studies
NASA Astrophysics Data System (ADS)
Ritsher, J. B.; Kanas, N. A.; Ihle, E. C.; Saylor, S. A.
2007-02-01
Individuals who adapt positively to an inhospitable or extreme environment can derive benefit from their experiences. This positive effect may include an initial improvement in mental health as someone adjusts to the environment (adaptation) as well as more sustained personal growth during the mission (salutogenesis). We review relevant findings from our prior work, including two post-mission surveys of astronauts and cosmonauts, and three studies of crewmembers during missions in a space station simulator, the Mir space station, and the International Space Station (ISS). We also present new analyses showing evidence for adaptation to ISS missions. This finding replicates our previous results from the simulation study, but this effect was not found on the Mir. A better understanding of psychological adaptation and salutogenesis during space flight should help us develop strategies to enhance crewmembers' in-flight stress tolerance and post-flight adjustment.
A clinical study of space closure with nickel-titanium closed coil springs and an elastic module.
Samuels, R H; Rudge, S J; Mair, L H
1998-07-01
A previous study has shown that a 150-gram nickel-titanium closed coil spring (Sentalloy, GAC International Inc.) closed spaces more quickly and more consistently than an elastic module (Alastik, Unitec/3M). This study used the same friction sensitive sliding mechanics of pitting the six anterior teeth against the second bicuspid and first molars, to examine the rate of space closure of 100-gram and 200-gram nickel-titanium closed coil springs. The results for the three springs and elastic module were compared. The nickel-titanium closed coil springs produced a more consistent space closure than the elastic module. The 150- and 200-gram springs produced a faster rate of space closure than the elastic module or the 100-gram spring. No significant difference was noted between the rates of closure for the 150- and the 200-gram springs.
Symposium Conclusion: Women's cardiovascular health after bed rest or space flight
NASA Astrophysics Data System (ADS)
Hughson, Richard L.; Arbeille, Phillipe; Shoemaker, Kevin; Edgell, Heather
The Canadian Space Agency has recently funded research on two long-duration missions to study cardiovascular deconditioning associated with bed rest or space flight. The first, Women's International Space simulation for Exploration (WISE-2005) examined the responses during a 60-day head down bed rest (HDBR) of 24 women with or without a countermeasure that consisted of supine treadmill running within a lower body negative pressure (LBNP) device followed by 10-minutes resting LBNP and on different days high intensity resistance exercise on a flywheel device. The second study, Cardiovascular and cerebrovascular Control on return from the International Space Station (CCISS) is currently underway with two male astronauts tested and the first woman anticipated later this year. Women have been previously identified as being more susceptible to orthostatic intolerance than men after both bed rest and space flight studies. Thus, in the WISE-2005 study we examined responses of the cardiovascular system after HDBR in women and compared these to previously published data from men. We found that after HDBR women have a greater increase in heart rate with infusion of the drug isoproterenol and this was consistent with observations in men. However, during drug infusion the women had a reduction in leg vascular resistance while men had an increase. The exercise countermeasure group had preserved heart rate and leg vascular resistance responses to drug infusion. The ability to vasoconstrict the legs and splanchnic region is critical to maintenance of upright posture after HDBR and space flight. In the WISE-2005 study, subjects who were able to constrict the legs and/or splanchnic region after HDBR were much less likely to have a marked drop in blood pressure before the end of 10-minutes upright tilt, and subjects who performed the countermeasure were more likely to be in this group of tilt test finishers. These data provide new insight into mechanisms that might be responsible for fainting after bed rest or space flight, and they can be used to understand why specific populations such as the elderly might be more likely to faint during life on Earth. Supported by Canadian Space Agency.
Are two spaces better than one? The effect of spacing following periods and commas during reading.
Johnson, Rebecca L; Bui, Becky; Schmitt, Lindsay L
2018-04-24
The most recent edition of the American Psychological Association (APA) Manual states that two spaces should follow the punctuation at the end of a sentence. This is in contrast to the one-space requirement from previous editions. However, to date, there has been no empirical support for either convention. In the current study, participants performed (1) a typing task to assess spacing usage and (2) an eye-tracking experiment to assess the effect that punctuation spacing has on reading performance. Although comprehension was not affected by punctuation spacing, the eye movement record suggested that initial processing of the text was facilitated when periods were followed by two spaces, supporting the change made to the APA Manual. Individuals' typing usage also influenced these effects such that those who use two spaces following a period showed the greatest overall facilitation from reading with two spaces.
Space radiation and cardiovascular disease risk
Boerma, Marjan; Nelson, Gregory A; Sridharan, Vijayalakshmi; Mao, Xiao-Wen; Koturbash, Igor; Hauer-Jensen, Martin
2015-01-01
Future long-distance space missions will be associated with significant exposures to ionizing radiation, and the health risks of these radiation exposures during manned missions need to be assessed. Recent Earth-based epidemiological studies in survivors of atomic bombs and after occupational and medical low dose radiation exposures have indicated that the cardiovascular system may be more sensitive to ionizing radiation than was previously thought. This has raised the concern of a cardiovascular disease risk from exposure to space radiation during long-distance space travel. Ground-based studies with animal and cell culture models play an important role in estimating health risks from space radiation exposure. Charged particle space radiation has dense ionization characteristics and may induce unique biological responses, appropriate simulation of the space radiation environment and careful consideration of the choice of the experimental model are critical. Recent studies have addressed cardiovascular effects of space radiation using such models and provided first results that aid in estimating cardiovascular disease risk, and several other studies are ongoing. Moreover, astronauts could potentially be administered pharmacological countermeasures against adverse effects of space radiation, and research is focused on the development of such compounds. Because the cardiovascular response to space radiation has not yet been clearly defined, the identification of potential pharmacological countermeasures against cardiovascular effects is still in its infancy. PMID:26730293
Space radiation and cardiovascular disease risk.
Boerma, Marjan; Nelson, Gregory A; Sridharan, Vijayalakshmi; Mao, Xiao-Wen; Koturbash, Igor; Hauer-Jensen, Martin
2015-12-26
Future long-distance space missions will be associated with significant exposures to ionizing radiation, and the health risks of these radiation exposures during manned missions need to be assessed. Recent Earth-based epidemiological studies in survivors of atomic bombs and after occupational and medical low dose radiation exposures have indicated that the cardiovascular system may be more sensitive to ionizing radiation than was previously thought. This has raised the concern of a cardiovascular disease risk from exposure to space radiation during long-distance space travel. Ground-based studies with animal and cell culture models play an important role in estimating health risks from space radiation exposure. Charged particle space radiation has dense ionization characteristics and may induce unique biological responses, appropriate simulation of the space radiation environment and careful consideration of the choice of the experimental model are critical. Recent studies have addressed cardiovascular effects of space radiation using such models and provided first results that aid in estimating cardiovascular disease risk, and several other studies are ongoing. Moreover, astronauts could potentially be administered pharmacological countermeasures against adverse effects of space radiation, and research is focused on the development of such compounds. Because the cardiovascular response to space radiation has not yet been clearly defined, the identification of potential pharmacological countermeasures against cardiovascular effects is still in its infancy.
NASA Technical Reports Server (NTRS)
Moeller, Robert C.; Borden, Chester; Spilker, Thomas; Smythe, William; Lock, Robert
2011-01-01
The JPL Rapid Mission Architecture (RMA) capability is a novel collaborative team-based approach to generate new mission architectures, explore broad trade space options, and conduct architecture-level analyses. RMA studies address feasibility and identify best candidates to proceed to further detailed design studies. Development of RMA first began at JPL in 2007 and has evolved to address the need for rapid, effective early mission architectural development and trade space exploration as a precursor to traditional point design evaluations. The RMA approach integrates a small team of architecture-level experts (typically 6-10 people) to generate and explore a wide-ranging trade space of mission architectures driven by the mission science (or technology) objectives. Group brainstorming and trade space analyses are conducted at a higher level of assessment across multiple mission architectures and systems to enable rapid assessment of a set of diverse, innovative concepts. This paper describes the overall JPL RMA team, process, and high-level approach. Some illustrative results from previous JPL RMA studies are discussed.
Li, Fangzheng; Zhang, Fen; Li, Xiong; Wang, Peng; Liang, Junhui; Mei, Yuting; Cheng, Wenwen; Qian, Yun
2017-01-01
Urban green spaces encourage outdoor activity and social communication that contribute to the health of local residents. Examining the relationship between the use of urban green spaces and factors influencing their utilization can provide essential references for green space site selection in urban planning. In contrast to previous studies that focused on internal factors, this study highlights the external factors (traffic convenience, population density and commercial facilities) contributing to the use of urban green spaces. We conducted a spatiotemporal analysis of the distribution of visitors in 208 selected green spaces in central Beijing. We examined the relationship between the spatial pattern of visitor distribution within urban green spaces and external factors, using the Gini coefficient, kernel density estimation, and geographical detectors. The results of the study were as follows. The spatial distribution of visitors within central Beijing’s green spaces was concentrated, forming different agglomerations. The three examined external factors are all associated with the use of green spaces. Among them, commercial facilities are the important external factor associated with the use of green spaces. For the selection of sites for urban green spaces, we recommend consideration of external factors in order to balance urban green space utilization. PMID:28264451
Li, Fangzheng; Zhang, Fen; Li, Xiong; Wang, Peng; Liang, Junhui; Mei, Yuting; Cheng, Wenwen; Qian, Yun
2017-02-27
Urban green spaces encourage outdoor activity and social communication that contribute to the health of local residents. Examining the relationship between the use of urban green spaces and factors influencing their utilization can provide essential references for green space site selection in urban planning. In contrast to previous studies that focused on internal factors, this study highlights the external factors (traffic convenience, population density and commercial facilities) contributing to the use of urban green spaces. We conducted a spatiotemporal analysis of the distribution of visitors in 208 selected green spaces in central Beijing. We examined the relationship between the spatial pattern of visitor distribution within urban green spaces and external factors, using the Gini coefficient, kernel density estimation, and geographical detectors. The results of the study were as follows. The spatial distribution of visitors within central Beijing's green spaces was concentrated, forming different agglomerations. The three examined external factors are all associated with the use of green spaces. Among them, commercial facilities are the important external factor associated with the use of green spaces. For the selection of sites for urban green spaces, we recommend consideration of external factors in order to balance urban green space utilization.
Studying the unfolding process of protein G and protein L under physical property space
Zhao, Liling; Wang, Jihua; Dou, Xianghua; Cao, Zanxia
2009-01-01
Background The studies on protein folding/unfolding indicate that the native state topology is an important determinant of protein folding mechanism. The folding/unfolding behaviors of proteins which have similar topologies have been studied under Cartesian space and the results indicate that some proteins share the similar folding/unfolding characters. Results We construct physical property space with twelve different physical properties. By studying the unfolding process of the protein G and protein L under the property space, we find that the two proteins have the similar unfolding pathways that can be divided into three types and the one which with the umbrella-shape represents the preferred pathway. Moreover, the unfolding simulation time of the two proteins is different and protein L unfolding faster than protein G. Additionally, the distributing area of unfolded state ensemble of protein L is larger than that of protein G. Conclusion Under the physical property space, the protein G and protein L have the similar folding/unfolding behaviors, which agree with the previous results obtained from the studies under Cartesian coordinate space. At the same time, some different unfolding properties can be detected easily, which can not be analyzed under Cartesian coordinate space. PMID:19208146
A Study of Defense Applications of Space Solar Power
NASA Astrophysics Data System (ADS)
Jaffe, Paul
2010-01-01
Space solar power (SSP) is generally considered to be the collection in space of energy from the sun and its wireless transmission from space for use on earth. It has been observed that the implementation of such a system could offer energy security, environmental, and technological advantages to those who would undertake its development. A study conducted by the Naval Research Laboratory (NRL) sought to determine if unique, cost effective, and efficient approaches exist for supplying significant power on demand for Navy, Marine Corps, or other Department of Defense applications by employing a space-based solar power system. The study was initiated by and prepared for top NRL management in part as a result of the publication of the National Security Space Office's (NSSO) report "Space-Based Solar Power as an Opportunity for Strategic Security." The NSSO report's recommendations included statements calling for the U.S. Government to conduct analyses, retire technical risk, and become an early demonstrator for SBSP. It should be noted that the principal objective of the NRL study differed significantly from that of the multitude of previous studies performed in reference to SBSP in that it focused on defense rather than utility grid applications.
Chen, Yiyong; Liu, Tao; Xie, Xiaohuan; Marušić, Barbara Goličnik
2016-01-01
A well-designed open space that encourages outdoor activity and social communication is a community asset that could potentially contribute to the health of local residents and social harmony of the community. Numerous factors may influence the use of each single space and may result in a variety of visitors. Compared with previous studies that focused on accessibility, this study highlights the relationship between the utilization and characteristics of community open spaces in China. The Overseas Chinese Town community in Shenzhen is regarded as an example. The association between the number of visitors and space characteristics is examined with multivariate regression models. Results show that large areas with accessible lawns, well-maintained footpaths, seats, commercial facilities, and water landscapes are important characteristics that could increase the use of community open spaces. However, adding green vegetation, sculptures, and landscape accessories in open spaces has limited effects on increasing the outdoor activities of residents. Thus, to increase the use of community open spaces, landscape designers should focus more on creating user-oriented spaces with facilities that encourage active use than on improving ornamental vegetation and accessories. PMID:27367713
ERIC Educational Resources Information Center
de Guzman, Allan B.; Lagdaan, Lovely France M.; Lagoy, Marie Lauren V.
2015-01-01
Subjective memory complaints are one of the major concerns of the elderly and remain a challenging area in gerontology. There are previous studies that identify different factors affecting subjective memory complaints. However, an extended model that correlates life-space on subjective memory complaints remains a blank spot. The objective of this…
Effects of Space Weathering on Reflectance Spectra of Ureilites: First Studies
NASA Technical Reports Server (NTRS)
Goodrich, C. A.; Gillis-Davis, J.; Cloutis, E.; Applin, D.; Takir, D.; Hibbitts, C.; Christoffersen, R.; Fries, M.; Klima, R.; Decker, S.
2018-01-01
Ureilites are differentiated meteorites (ultramafic rocks interpreted to be mantle residues) that contain as much carbon as the most carbon-rich carbonaceous chondrites (CCs). Reflectance spectra of ureilites are similar to those of some CCs. Hence, ureilitic asteroids may accidentally be categorized as primitive because their spectra could resemble those of C-complex asteroids, which are thought to be CC-like. We began spectral studies of progressively laser-weathered ureilites with the goals of predicting UV-VIS-IR spectra of ureilitic asteroids, and identifying features that could distinguish differentiated from primitive dark asteroids. Space weathering has not previously been studied for ureilites, and, based on space weathering studies of CCs and other C-rich materials, it could significantly alter their reflectance spectra.
2003-06-21
KENNEDY SPACE CENTER, FLA. - At the KSC Visitor Complex, former astronaut Daniel Brandenstein (standing right) is presented to the audience at his induction ceremony into the U.S. Astronaut Hall of Fame. Also standing is former astronaut James A. Lovell. Seated on the dais, from left, are former astronauts John H. Glenn and Gordon Cooper, both previously inducted into the Hall of Fame. Being inducted with Brandenstein are Space Shuttle astronauts Robert "Hoot" Gibson, Story Musgrave, and Sally K. Ride. Conceived by six of the Mercury Program astronauts, the U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The four new inductees join 48 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
2003-06-21
KENNEDY SPACE CENTER, FLA. - At the KSC Visitor Complex, former astronaut Frederick H. (Rick) Hauck (standing right) congratulates former astronaut Daniel Brandenstein (standing center) at his induction ceremony into the U.S. Astronaut Hall of Fame. Also standing is former astronaut James A. Lovell. Seated on the dais, from left, are former astronauts John H. Glenn and Gordon Cooper, both previously inducted into the Hall of Fame. Being inducted with Brandenstein are Space Shuttle astronauts Robert "Hoot" Gibson, Story Musgrave, and Sally K. Ride. Conceived by six of the Mercury Program astronauts, the U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The four new inductees join 48 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
2003-06-21
KENNEDY SPACE CENTER, FLA. - At the KSC Visitor Complex, former astronaut Robert L. Crippen (right) presents former astronaut Sally K. Ride (standing center) at her induction ceremony into the U.S. Astronaut Hall of Fame. Also standing is former astronaut James A. Lovell. Seated on the dais are, from left, former astronauts John H. Glenn, Gordon Cooper, Buzz Aldrin, and Walter Cunningham, all previously inducted into the Hall of Fame. Being inducted with Ride are Space Shuttle astronauts Daniel Brandenstein, Robert "Hoot" Gibson, and Story Musgrave. Conceived by six of the Mercury Program astronauts, the U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The four new inductees join 48 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
2003-06-21
KENNEDY SPACE CENTER, FLA. - At the KSC Visitor Complex, former astronaut Robert L. Crippen (standing right) congratulates former astronaut Sally K. Ride at her induction ceremony into the U.S. Astronaut Hall of Fame. Also standing is former astronaut James A. Lovell. Seated on the dais, from left, are former astronauts Gordon Cooper, Scott Carpenter, Buzz Aldrin, Walter Cunningham, Edgar B. Mitchell, and Fred W. Haise, all previously inducted into the Hall of Fame. Being inducted with Ride are Space Shuttle astronauts Daniel Brandenstein, Robert "Hoot" Gibson, and Story Musgrave. Conceived by six of the Mercury Program astronauts, the U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The four new inductees join 48 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
The spatial comfort study of shophouse at Kampung Madras
NASA Astrophysics Data System (ADS)
Ginting, Y. U. U.; Ginting, N.; Zahrah, W.
2018-03-01
This Research comes from the increasing quantity of shophouse in downtown Medan and the suburban area. The condition of shophouse tend to have narrowly spaced rooms, the middle area of the house are poorly lighted, and lots of space left unused. This research is supported by many spatial issues from previous studies. This study is conducted to determine the level of comfort of shophouse as a function of living space and focused on the spatial aspect namely anthropometry, indoor space circulation, space requirement and function, spatial design and indoor visual. This study uses the descriptive method with the qualitative and quantitative approach. Data collection technique is done by field observation, questionnaire method is also used to get the respondent perception of the spatial comfort of a shophouse. The result indicates that the level of spatial comfort of the shophouse is an uncomfort. So the improvements in the circulation of access to the building, spatial design, lighting, and aeration are needed to improve the spatial comfort of a shophouse.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nishioka, S., E-mail: nishioka@ppl.appi.keio.ac.jp; Goto, I.; Hatayama, A.
2014-02-15
Our previous study by two dimension in real space and three dimension in velocity space-particle in cell model shows that the curvature of the plasma meniscus causes the beam halo in the negative ion sources. The negative ions extracted from the periphery of the meniscus are over-focused in the extractor due to the electrostatic lens effect, and consequently become the beam halo. The purpose of this study is to verify this mechanism with the full 3D model. It is shown that the above mechanism is essentially unchanged even in the 3D model, while the fraction of the beam halo ismore » significantly reduced to 6%. This value reasonably agrees with the experimental result.« less
Kalijodo transformation in establishment of healthy environment in Jakarta
NASA Astrophysics Data System (ADS)
Sutanto, Erik; Junadi, Purnawan
2018-03-01
A good city setting can create a healthy environment. One of the structuring of cities that can create a healthy environment is the development of public space like Green Open Space (RTH) and Child-Friendly Integrated Public Space (RPTRA) such as in Kalijodo, Jakarta, Indonesia. The objective of building a public space in Kalijodo is to restore the functioning of the green zone in the area that previously used for housing residents and prostitution businesses to increase public space in Jakarta. The purpose of this study is to describe the formation of a healthy environment and the impact felt by users of this public space. The research method used in this research is descriptive qualitative with a phenomenological approach through interview, observation and documentation. There are three types of community activities in the public sphere, such as sports, children’s playground, and relaxation. The results show that the decline in crime rates and the presence of facilities and infrastructure in time to establish a healthy environment. The construction of facilities in the public spaces changes the image of Kalijodo from the previous place that has a negative image then turned into a positive image because the environment of Kalijodo became healthy. We also find that this changing image creates a positive spirit of the surrounding community and people are generally healthier and happier.
Free-floating Failed Star Artist Concept
2013-09-05
This artist concept portrays a free-floating brown dwarf, or failed star. A new study using data from NASA Spitzer Space Telescope shows that several of these objects are warmer than previously thought.
Calcium and Bone Homeostasis During 4-6 Months Space Flight
NASA Technical Reports Server (NTRS)
Smith, Scott M.; OBrien, K.; Wastney, M.; Morukov, B.; Larina, I.; Abrams, S.; Lane, H.; Nillen, J.; Davis-Street, J.; Paloski, W. H. (Technical Monitor)
2000-01-01
Bone and calcium homeostasis are altered by weightlessness. We previously reported calcium studies on three subjects from the first joint US/Russian mission to Mir. We report here data on an additional three male subjects, whose stays on Mir were 4 (n= 1) and 6 (n=2) mos. Data were collected before, during, and after the missions. Inflight studies were conducted at 2-3 mos. Endocrine and biochemical indices were measured, along with 3-wk calcium tracer studies. Percent differences are reported compared to preflight. Ionized calcium was unchanged (2.8 +/-2.1 %) during flight. Calcium absorption was variable inflight, but was decreased after landing. Vitamin D stores were decreased 35 +/-24% inflight, similar to previous reports. Serum PTH was decreased 59 +/-9% during flight (greater than we previously reported), while 1,25(OH)(sub 2)-Vitamin D was decreased in 2 of 3 subjects. Markers of bone resorption (e.g., crosslinks) were increased in all subjects. Bone-specific alkaline phosphatase was decreased (n=1) or unchanged (n=2), while osteocalcin was decreased 34 +/-23%. Previously presented data showed that inflight bone loss is associated with increased resorption and unchanged/decreased formation. The data reported here support these earlier findings. These studies will help to extend our understanding of space flight-induced bone loss, and of bone loss associated with diseases such as osteoporosis or paralysis.
Wigner functions from the two-dimensional wavelet group.
Ali, S T; Krasowska, A E; Murenzi, R
2000-12-01
Following a general procedure developed previously [Ann. Henri Poincaré 1, 685 (2000)], here we construct Wigner functions on a phase space related to the similitude group in two dimensions. Since the group space in this case is topologically homeomorphic to the phase space in question, the Wigner functions so constructed may also be considered as being functions on the group space itself. Previously the similitude group was used to construct wavelets for two-dimensional image analysis; we discuss here the connection between the wavelet transform and the Wigner function.
Revolutionary Concepts of Radiation Shielding for Human Exploration of Space
NASA Technical Reports Server (NTRS)
Adams, J. H., Jr.; Hathaway, D. H.; Grugel, R. N.; Watts, J. W.; Parnell, T. A.; Gregory, J. C.; Winglee, R. M.
2005-01-01
This Technical Memorandum covers revolutionary ideas for space radiation shielding that would mitigate mission costs while limiting human exposure, as studied in a workshop held at Marshall Space Flight Center at the request of NASA Headquarters. None of the revolutionary new ideas examined for the .rst time in this workshop showed clear promise. The workshop attendees felt that some previously examined concepts were de.nitely useful and should be pursued. The workshop attendees also concluded that several of the new concepts warranted further investigation to clarify their value.
Removal of Thelazia callipaeda from the subconjunctival space.
Yagi, T; Sasoh, M; Kawano, T; Ito, K; Uji, Y; Ando, K
2007-01-01
To report the finding of Thelazia callipaeda within the human subconjunctival space. An 81-year-old man with a history of traumatic conjunctival laceration that occurred 2 years previously had white worms in the subconjunctival space of his right eye. Five worms were removed from the subconjunctival space via a local peritomy, since there was no conjunctival laceration noted during the examination. These worms were identified as T callipaeda. T callipaeda cannot dig holes in the ocular wall due to the lack of hooks or sharp spines within the mouth. Therefore, the authors speculate that these worms entered the subconjunctival space through a conjunctival laceration that had occurred 2 years previously.
A Phenomenological Study of the Office Environments of Clinical Social Workers.
Jones, Jamie K
2018-01-01
The purpose of this study was to explore the meaning and uses of the office space among licensed clinical social workers in private practice. Previous research suggests the importance of the office space in clinical practice in regard to therapeutic alliance, client behavior, and the well-being of the therapist. However, therapist offices contain much variation in design. This study looked further into specifically how the therapy room is important through the perspective of the licensed clinical social workers in order to identify common themes. Seven licensed clinical social workers in private psychotherapy practice were interviewed in their offices. Phenomenological research methods were used to explore and analyze their experiences. While the offices contained many physical differences, the intentions behind the designs were similar. Three themes emerged regarding how participants used and designed their spaces. First, participants used their offices to provide care for clients and themselves. Second, participants used their spaces to communicate therapeutic messages and to reveal and/or conceal aspects of themselves. Third, participants also used their space in direct practice. This phenomenological study provided insight into the importance and use of the psychotherapy office space. These findings may be helpful for therapists designing or redesigning their own practice spaces.
Exploring Tactile Perceptual Dimensions Using Materials Associated with Sensory Vocabulary.
Sakamoto, Maki; Watanabe, Junji
2017-01-01
Considering tactile sensation when designing products is important because the decision to purchase often depends on how products feel. Numerous psychophysical studies have attempted to identify important factors that describe tactile perceptions. However, the numbers and types of major tactile dimensions reported in previous studies have varied because of differences in materials used across experiments. To obtain a more complete picture of perceptual space with regard to touch, our study focuses on using vocabulary that expresses tactile sensations as a guiding principle for collecting material samples because these types of words are expected to cover all the basic categories within tactile perceptual space. We collected 120 materials based on a variety of Japanese sound-symbolic words for tactile sensations, and used the materials to examine tactile perceptual dimensions and their associations with affective evaluations. Analysis revealed six major dimensions: "Affective evaluation and Friction," "Compliance," "Surface," "Volume," "Temperature," and "Naturalness." These dimensions include four factors that previous studies have regarded as fundamental, as well as two new factors: "Volume" and "Naturalness." Additionally, we showed that "Affective evaluation" is more closely related to the "Friction" component (slipperiness and dryness) than to other tactile perceptual features. Our study demonstrates that using vocabulary could be an effective method for selecting material samples to explore tactile perceptual space.
Lexical integration of novel words without sleep.
Lindsay, Shane; Gaskell, M Gareth
2013-03-01
Learning a new word involves integration with existing lexical knowledge. Previous work has shown that sleep-associated memory consolidation processes are important for the engagement of novel items in lexical competition. In 3 experiments we used spaced exposure regimes to investigate memory for novel words and whether lexical integration can occur within a single day. The degree to which a new spoken word (e.g., cathedruke) engaged in lexical competition with established phonological neighbors (e.g., cathedral) was employed as a marker for lexical integration. We found evidence for improvements in recognition and cued recall following a time period including sleep, but we also found lexical competition effects emerging within a single day. Spaced exposure to novel words on its own did not bring about this within-day lexical competition effect (Experiment 2), which instead occurred with either spaced or massed exposure to novel words, provided that there was also spaced exposure to the phonological neighbors (Experiments 1 and 3). Although previous studies have indicated that sleep-dependent memory consolidation may be sufficient for lexical integration, our results show it is not a necessary precondition. (c) 2013 APA, all rights reserved.
Individual Differences in the Flexibility of Peripersonal Space.
Hunley, Samuel B; Marker, Arwen M; Lourenco, Stella F
2017-01-01
The current study investigated individual differences in the flexibility of peripersonal space (i.e., representational space near the body), specifically in relation to trait claustrophobic fear (i.e., fear of suffocating or being physically restricted). Participants completed a line bisection task with either a laser pointer (Laser condition), allowing for a baseline measure of the size of one's peripersonal space, or a stick (Stick condition), which produces expansion of one's peripersonal space. Our results revealed that individuals high in claustrophobic fear had larger peripersonal spaces than those lower in claustrophobic fear, replicating previous research. We also found that, whereas individuals low in claustrophobic fear demonstrated the expected expansion of peripersonal space in the Stick condition, individuals high in claustrophobic fear showed less expansion, suggesting decreased flexibility. We discuss these findings in relation to the defensive function of peripersonal space and reduced attentional flexibility associated with trait anxieties.
Advanced Space Transportation Concepts and Propulsion Technologies for a New Delivery Paradigm
NASA Technical Reports Server (NTRS)
Robinson, John W.; McCleskey, Carey M.; Rhodes, Russel E.; Lepsch, Roger A.; Henderson, Edward M.; Joyner, Claude R., III; Levack, Daniel J. H.
2013-01-01
This paper describes Advanced Space Transportation Concepts and Propulsion Technologies for a New Delivery Paradigm. It builds on the work of the previous paper "Approach to an Affordable and Productive Space Transportation System". The scope includes both flight and ground system elements, and focuses on their compatibility and capability to achieve a technical solution that is operationally productive and also affordable. A clear and revolutionary approach, including advanced propulsion systems (advanced LOX rich booster engine concept having independent LOX and fuel cooling systems, thrust augmentation with LOX rich boost and fuel rich operation at altitude), improved vehicle concepts (autogeneous pressurization, turbo alternator for electric power during ascent, hot gases to purge system and keep moisture out), and ground delivery systems, was examined. Previous papers by the authors and other members of the Space Propulsion Synergy Team (SPST) focused on space flight system engineering methods, along with operationally efficient propulsion system concepts and technologies. This paper continues the previous work by exploring the propulsion technology aspects in more depth and how they may enable the vehicle designs from the previous paper. Subsequent papers will explore the vehicle design, the ground support system, and the operations aspects of the new delivery paradigm in greater detail.
Block 2 SRM conceptual design studies. Volume 1, Book 1: Conceptual design package
NASA Technical Reports Server (NTRS)
Smith, Brad; Williams, Neal; Miller, John; Ralston, Joe; Richardson, Jennifer; Moore, Walt; Doll, Dan; Maughan, Jeff; Hayes, Fred
1986-01-01
The conceptual design studies of a Block 2 Solid Rocket Motor (SRM) require the elimination of asbestos-filled insulation and was open to alternate designs, such as case changes, different propellants, modified burn rate - to improve reliability and performance. Limitations were placed on SRM changes such that the outside geometry should not impact the physical interfaces with other Space Shuttle elements and should have minimum changes to the aerodynamic and dynamic characteristics of the Space Shuttle vehicle. Previous Space Shuttle SRM experience was assessed and new design concepts combined to define a valid approach to assured flight success and economic operation of the STS. Trade studies, preliminary designs, analyses, plans, and cost estimates are documented.
Online Behavior in Virtual Space: An Empirical Study on Helping
ERIC Educational Resources Information Center
Hsu, Jung-Lung; Hwang, Wu-Yuin; Huang, Yueh-Min; Liu, Jui-Jung
2011-01-01
Although previous studies have acknowledged that helping behavior has many potential benefits, little research has aimed at understanding which factors would possibly enhance helping behaviors among team members in CSCL environment. Accordingly, this study was intended to identify underlying factors leading learners to collaborate in virtual CSCL…
Brownian motion with adaptive drift for remaining useful life prediction: Revisited
NASA Astrophysics Data System (ADS)
Wang, Dong; Tsui, Kwok-Leung
2018-01-01
Linear Brownian motion with constant drift is widely used in remaining useful life predictions because its first hitting time follows the inverse Gaussian distribution. State space modelling of linear Brownian motion was proposed to make the drift coefficient adaptive and incorporate on-line measurements into the first hitting time distribution. Here, the drift coefficient followed the Gaussian distribution, and it was iteratively estimated by using Kalman filtering once a new measurement was available. Then, to model nonlinear degradation, linear Brownian motion with adaptive drift was extended to nonlinear Brownian motion with adaptive drift. However, in previous studies, an underlying assumption used in the state space modelling was that in the update phase of Kalman filtering, the predicted drift coefficient at the current time exactly equalled the posterior drift coefficient estimated at the previous time, which caused a contradiction with the predicted drift coefficient evolution driven by an additive Gaussian process noise. In this paper, to alleviate such an underlying assumption, a new state space model is constructed. As a result, in the update phase of Kalman filtering, the predicted drift coefficient at the current time evolves from the posterior drift coefficient at the previous time. Moreover, the optimal Kalman filtering gain for iteratively estimating the posterior drift coefficient at any time is mathematically derived. A discussion that theoretically explains the main reasons why the constructed state space model can result in high remaining useful life prediction accuracies is provided. Finally, the proposed state space model and its associated Kalman filtering gain are applied to battery prognostics.
14 CFR 302.413 - Evidence of previous violations.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Evidence of previous violations. 302.413 Section 302.413 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION... proceeding or criminal or civil action may, if relevant and material, be admitted in any enforcement...
14 CFR 302.413 - Evidence of previous violations.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Evidence of previous violations. 302.413 Section 302.413 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION... proceeding or criminal or civil action may, if relevant and material, be admitted in any enforcement...
14 CFR 302.413 - Evidence of previous violations.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Evidence of previous violations. 302.413 Section 302.413 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION... proceeding or criminal or civil action may, if relevant and material, be admitted in any enforcement...
14 CFR 302.413 - Evidence of previous violations.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Evidence of previous violations. 302.413 Section 302.413 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION... proceeding or criminal or civil action may, if relevant and material, be admitted in any enforcement...
14 CFR 302.413 - Evidence of previous violations.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Evidence of previous violations. 302.413 Section 302.413 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION... proceeding or criminal or civil action may, if relevant and material, be admitted in any enforcement...
Gupta, Prachi; Thombare, Ram; Pakhan, A. J.; Singhal, Sameer
2011-01-01
Role of complete dentures in reducing apnea-hypoapnea index in edentulous obstructive sleep apnea patient has shown promising results in previous studies. This study was undertaken to ascertain the role of complete denture and complete denture with slight increase in vertical dimension using custom made occlussal jig, on retropharyngeal space, posterior airway space, pharyngeal depth, and spirometric readings in comparison with those in edentulous group. Significant changes were observed in both intervention groups and thus, paving the way for doing further research for the consideration of using complete denture with modifications as an oral appliance in edentulous obstructive sleep apnea patient. PMID:21991477
Støverud, Karen-Helene; Langtangen, Hans Petter; Ringstad, Geir Andre; Eide, Per Kristian; Mardal, Kent-Andre
2016-01-01
Previous computational fluid dynamics (CFD) studies have demonstrated that the Chiari malformation is associated with abnormal cerebrospinal fluid (CSF) flow in the cervical part of the subarachnoid space (SAS), but the flow in the SAS of the posterior cranial fossa has received little attention. This study extends previous modelling efforts by including the cerebellomedullary cistern, pontine cistern, and 4th ventricle in addition to the cervical subarachnoid space. The study included one healthy control, Con1, and two patients with Chiari I malformation, P1 and P2. Meshes were constructed by segmenting images obtained from T2-weighted turbo spin-echo sequences. CFD simulations were performed with a previously verified and validated code. Patient-specific flow conditions in the aqueduct and the cervical SAS were used. Two patients with the Chiari malformation and one control were modelled. The results demonstrated increased maximal flow velocities in the Chiari patients, ranging from factor 5 in P1 to 14.8 in P2, when compared to Con1 at the level of Foramen Magnum (FM). Maximal velocities in the cervical SAS varied by a factor 2.3, while the maximal flow in the aqueduct varied by a factor 3.5. The pressure drop from the pontine cistern to the cervical SAS was similar in Con1 and P1, but a factor two higher in P2. The pressure drop between the aqueduct and the cervical SAS varied by a factor 9.4 where P1 was the one with the lowest pressure jump and P2 and Con1 differed only by a factor 1.6. This pilot study demonstrates that including the posterior cranial fossa is feasible and suggests that previously found flow differences between Chiari I patients and healthy individuals in the cervical SAS may be present also in the SAS of the posterior cranial fossa.
Vowel Space Characteristics of Speech Directed to Children With and Without Hearing Loss
Wieland, Elizabeth A.; Burnham, Evamarie B.; Kondaurova, Maria; Bergeson, Tonya R.
2015-01-01
Purpose This study examined vowel characteristics in adult-directed (AD) and infant-directed (ID) speech to children with hearing impairment who received cochlear implants or hearing aids compared with speech to children with normal hearing. Method Mothers' AD and ID speech to children with cochlear implants (Study 1, n = 20) or hearing aids (Study 2, n = 11) was compared with mothers' speech to controls matched on age and hearing experience. The first and second formants of vowels /i/, /ɑ/, and /u/ were measured, and vowel space area and dispersion were calculated. Results In both studies, vowel space was modified in ID compared with AD speech to children with and without hearing loss. Study 1 showed larger vowel space area and dispersion in ID compared with AD speech regardless of infant hearing status. The pattern of effects of ID and AD speech on vowel space characteristics in Study 2 was similar to that in Study 1, but depended partly on children's hearing status. Conclusion Given previously demonstrated associations between expanded vowel space in ID compared with AD speech and enhanced speech perception skills, this research supports a focus on vowel pronunciation in developing intervention strategies for improving speech-language skills in children with hearing impairment. PMID:25658071
NASA Technical Reports Server (NTRS)
1993-01-01
Based on Johnson Space Flight Center's development of a rotating bioreactor cell culture apparatus for Space Shuttle medical research, Johnson Space Flight Center engineers who worked on the original project formed a company called Synthecon, with the intention of commercializing the bioreactor technology. Synthecon grows three dimensional tissues in the bioreactor. These are superior to previous two-dimensional tissue samples in the study of human cell growth. A refined version of the Johnson Space Center technology, Synthecon's Rotary Cell Culture System includes a cell culture chamber that rotates around a horizontal axis. The cells establish an orbit that approximates free fall through the liquid medium in the chamber. The technology has significant applications for cancer research and treatment as well as AIDS research.
Reduction in wick drain effectiveness with spacing for Utah silts and clays.
DOT National Transportation Integrated Search
2012-04-01
Although decreasing the spacing of vertical drains usually decreases the time for consolidation, previous field tests have shown that there is a critical drain spacing for which tighter spacing does not decrease the time for consolidation. This...
Studies of the Coherent Half-Integer Resonance
NASA Astrophysics Data System (ADS)
Cousineau, Sarah; Holmes, Jeff; Galambos, John; Macek, Robert; Fedotov, Alexei; Wei, Jie
2002-12-01
We present studies of space-charge-induced beam profile broadening at high intensities in the Proton Storage Ring (PSR) at Los Alamos National Laboratory. Previous work has associated the observed broadening in the vertical direction with the coherent half integer resonance [1]. Here, we study the effect of the space charge environment on this resonance; specifically, we investigate the strength of the resonance versus beam intensity, longitudinal bunching factor, transverse lattice tune, and two different beam injection scenarios. For each case, detailed particle-in-cell simulations are combined with experimental results to elucidate the behavior and sensitivity of the beam resonance response.
Personal miniature electrophysiological tape recorder
NASA Astrophysics Data System (ADS)
Green, H.
1981-11-01
The use of a personal miniature electrophysiological tape recorder to measure the physiological reactions of space flight personnel to space flight stress and weightlessness is described. The Oxford Instruments Medilog recorder, a battery-powered, four-channel cassette tape recorder with 24 hour endurance is carried on the person and will record EKG, EOG, EEG, and timing and event markers. The data will give information about heart rate and morphology changes, and document adaptation to zero gravity on the part of subjects who, unlike highly trained astronauts, are more representative of the normal population than were the subjects of previous space flight studies.
Genetic changes induced by space flight factors in barley seeds on Soyuz-5 and Soyuz-9 craft
NASA Technical Reports Server (NTRS)
Nuzhdin, N. I.; Dozortseva, R. L.
1980-01-01
Air-dry seeds of the barley Zimujuschij moscowskyi of the 1969 harvest were taken into space onboard the spaceships Soyuz-5 and Soyuz-9. A cytological study of the mitoses in meristemic cells in rootlet terminals revealed that space flight factors (SFF) in nonirradiated seeds induced about 3% of aberrant cells. After irradiation the effect of SFF increased over two-fold. Although the radio protectors ensured the seeds against from the SFF-induced damage either in irradiated or nonirradiated seed cells which is inconsistent with the previously obtained data.
Astronautics and Aeronautics, 1991-1995: A Chronology
NASA Technical Reports Server (NTRS)
Gawdiak, Ihor Y. (Compiler); Shetland, Charles (Compiler)
2000-01-01
This chronology of events in aeronautics, aviation, space science, and space exploration was prepared by the Federal Research Division of the Library of Congress and RSIS for the History Division of the National Aeronautics and Space Administration (NASA). It covers the years 1991-1995 and continues the series of annual chronologies published by NASA. The present volume uses the format of the previous edition of this series, Astronautics and Aeronautics, 1986-1990: A Chronology. It also integrates, in the appendices, information presented in previous publication
Accuracy of saccades to remembered targets as a function of body orientation in space
NASA Technical Reports Server (NTRS)
Vogelstein, Joshua T.; Snyder, Lawrence H.; Angelaki, Dora E.
2003-01-01
A vertical asymmetry in memory-guided saccadic eye movements has been previously demonstrated in humans and in rhesus monkeys. In the upright orientation, saccades generally land several degrees above the target. The origin of this asymmetry has remained unknown. In this study, we investigated whether the asymmetry in memory saccades is dependent on body orientation in space. Thus animals performed memory saccades in four different body orientations: upright, left-side-down (LSD), right-side-down (RSD), and supine. Data in all three rhesus monkeys confirm previous observations regarding a significant upward vertical asymmetry. Saccade errors made from LSD and RSD postures were partitioned into components made along the axis of gravity and along the vertical body axis. Up/down asymmetry persisted only in body coordinates but not in gravity coordinates. However, this asymmetry was generally reduced in tilted positions. Therefore the upward bias seen in memory saccades is egocentric although orientation in space might play a modulatory role.
NASA Technical Reports Server (NTRS)
Markson, R.; Anderson, B.; Govaert, J.; Fairall, C. W.
1989-01-01
A novel coronal current-determining instrument is being used at NASA-KSC which overcomes previous difficulties with wind sensitivity and a voltage-threshold 'deadband'. The mounting of the corona needle at an elevated location reduces coronal and electrode layer space-charge influences on electric fields, rendering the measurement of space charge density possible. In conjunction with a space-charge compensation model, these features allow a more realistic estimation of cloud base electric fields and the potential for lightning strike than has previously been possible with ground-based sensors.
Purpose: Previous studies have positively correlated human nature exposures with health promoting outcomes such as increased physical activity, improved cognitive function, increased social engagement, and reduced ambient air pollution. When using remotely-sensed data to investig...
Observations of School Culture: From Theorists to Curriculum Issues
ERIC Educational Resources Information Center
Tavares-Silva, Fabiany de C.; Pessanha, Eurize C.
2012-01-01
In recent years, we have developed research studies to analyze the relationships between the fields of history and sociology of curriculum, school, and culture. Using previously conducted studies, we investigate topics such as school culture and education management, which broaden our understanding of education, school days and spaces, classes and…
Flexible Packaging Concept for a Space Suit Portable Life Support Subsystem
NASA Technical Reports Server (NTRS)
Thomas, Gretchen; Dillon, Paul; Oliver, Joe; Zapata, Felipe
2009-01-01
Neither the Shuttle Extravehicular Mobility Unit (EMU), the space suit currently used for space shuttle and International Space Station (ISS) missions, nor the Apollo EMU, the space suit successfully used on previous lunar missions, will satisfy the requirements for the next generation Constellation Program (CxP) lunar suit. The CxP system or Constellation Space Suit Element (CSSE) must be able to tolerate more severe environmental and use conditions than any previous system. These conditions include missions to the severely cold lunar poles and up to 100 Extravehicular Activity (EVA) excursions without ground maintenance. Much effort is focused on decreasing the mass and volume of the Portable Life Support Subsystem (PLSS) over previous suit designs in order to accommodate the required increase in functionality. This paper documents the progress of a conceptual packaging effort of a flexible backpack for the CSSE PLSS. The flexible backpack concept relies on a foam protection system to absorb, distribute, and dissipate the energy from falls on the lunar surface. Testing and analysis of the foam protection system concept that was conducted during this effort indicates that this method of system packaging is a viable solution.
Neale, Chris; Aspinall, Peter; Roe, Jenny; Tilley, Sara; Mavros, Panagiotis; Cinderby, Steve; Coyne, Richard; Thin, Neil; Bennett, Gary; Thompson, Catharine Ward
2017-12-01
This research directly assesses older people's neural activation in response to a changing urban environment while walking, as measured by electroencephalography (EEG). The study builds on previous research that shows changes in cortical activity while moving through different urban settings. The current study extends this methodology to explore previously unstudied outcomes in older people aged 65 years or more (n = 95). Participants were recruited to walk one of six scenarios pairing urban busy (a commercial street with traffic), urban quiet (a residential street) and urban green (a public park) spaces in a counterbalanced design, wearing a mobile Emotiv EEG headset to record real-time neural responses to place. Each walk lasted around 15 min and was undertaken at the pace of the participant. We report on the outputs for these responses derived from the Emotiv Affectiv Suite software, which creates emotional parameters ('excitement', 'frustration', 'engagement' and 'meditation') with a real-time value assigned to them. The six walking scenarios were compared using a form of high dimensional correlated component regression (CCR) on difference data, capturing the change between one setting and another. The results showed that levels of 'engagement' were higher in the urban green space compared to those of the urban busy and urban quiet spaces, whereas levels of 'excitement' were higher in the urban busy environment compared with those of the urban green space and quiet urban space. In both cases, this effect is shown regardless of the order of exposure to these different environments. These results suggest that there are neural signatures associated with the experience of different urban spaces which may reflect the older age of the sample as well as the condition of the spaces themselves. The urban green space appears to have a restorative effect on this group of older adults.
Liquid belt radiator design study
NASA Technical Reports Server (NTRS)
Teagan, W. P.; Fitzgerald, K. F.
1986-01-01
The Liquid Belt Radiator (LBR) is an advanced concept developed to meet the needs of anticipated future space missions. A previous study documented the advantages of this concept as a lightweight, easily deployable alternative to present day space heat rejection systems. The technical efforts associated with this study concentrate on refining the concept of the LBR as well as examining the issues of belt dynamics and potential application of the LBR to intermediate and high temperature heat rejection applications. A low temperature point design developed in previous work is updated assuming the use of diffusion pump oil, Santovac-6, as the heat transfer media. Additional analytical and design effort is directed toward determining the impact of interface heat exchanger, fluid bath sealing, and belt drive mechanism designs on system performance and mass. The updated design supports the earlier result by indicating a significant reduction in system specific system mass as compared to heat pipe or pumped fluid radiator concepts currently under consideration (1.3 kg/sq m versus 5 kg/sq m).
Stereotype locally convex spaces
NASA Astrophysics Data System (ADS)
Akbarov, S. S.
2000-08-01
We give complete proofs of some previously announced results in the theory of stereotype (that is, reflexive in the sense of Pontryagin duality) locally convex spaces. These spaces have important applications in topological algebra and functional analysis.
Tree growth and soil relations at the 1925 Wind River spacing test in coast Douglas-fir.
Richard E. Miller; Donald L. Reukema; Harry W. Anderson
2004-01-01
The 1925 Wind River spacing test is the earliest field trial seeking to determine the most appropriate spacing for planting Douglas-fir. Spacing treatments were not replicated, although individual spacings were subsampled by two to four tree-measurement plots. Previously, greater growth occurred at the wider spacings (10 and 12 ft) than at the closer spacings (4, 5, 6...
2004-05-01
KENNEDY SPACE CENTER, FLA. -- Before the induction ceremony of five space program heroes into the U.S. Astronaut Hall of Fame, former astronaut Gene Cernan waves to guests as he is introduced as a previous inductee. He walked in space on Gemini 9, orbited the Moon on Apollo 10 and walked on the Moon as commander of Apollo 17. The ceremony was held at the Apollo/Saturn V Center at KSC. New inductees are Richard O. Covey, commander of the Hubble Space Telescope repair mission; Norman E. Thagard, the first American to occupy Russia’s Mir space station; the late Francis R. "Dick" Scobee, commander of the ill-fated 1986 Challenger mission; Kathryn D. Sullivan, the first American woman to walk in space; and Frederick D. Gregory, the first African-American to command a space mission and the current NASA deputy administrator. The U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The five inductees join 52 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
2004-05-01
KENNEDY SPACE CENTER, FLA. -- Before the induction ceremony of five space program heroes into the U.S. Astronaut Hall of Fame, former astronaut Gordon Cooper is introduced as a previous inductee. One of America’s original Mercury Seven astronauts, Cooper flew the last and longest Project Mercury orbital mission and spent eight days in space aboard Gemini 5. The ceremony was held at the Apollo/Saturn V Center at KSC. New inductees are Richard O. Covey, commander of the Hubble Space Telescope repair mission; Norman E. Thagard, the first American to occupy Russia’s Mir space station; the late Francis R. "Dick" Scobee, commander of the ill-fated 1986 Challenger mission; Kathryn D. Sullivan, the first American woman to walk in space; and Frederick D. Gregory, the first African-American to command a space mission and the current NASA deputy administrator. The U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The five inductees join 52 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
NASA Astrophysics Data System (ADS)
Miyajima, Hiroyuki; Yuhara, Naohiro
Regenerative Life Support Systems (RLSS), which maintain human lives by recycling substances essential for living, are comprised of humans, plants, and material circulation systems. The plants supply food to the humans or reproduce water and gases by photosynthesis, while the material circulation systems recycle physicochemically and circulate substances disposed by humans and plants. RLSS attracts attention since manned space activities have been shifted from previous short trips to long-term stay activities as such base as a space station, a lunar base, and a Mars base. The present typical space base is the International Space Station (ISS), a manned experimental base for prolonged stays, where RLSS recycles only water and air. In order to accommodate prolonged and extended manned activity in future space bases, developing RLSS that implements food production and regeneration of resources at once using plants is expected. The configuration of RLSS should be designed to suit its own duty, for which design requirements for RLSS with an unprecedented configuration may arise. Accordingly, it is necessary to establish a conceptual design method for generalized RLSS. It is difficult, however, to systematize the design process by analyzing previous design because there are only a few ground-experimental facilities, namely CEEF (Closed Ecology Experiment Facilities) of Japan, BIO-Plex (Bioregenerative Planetary Life Support Systems Test Complex) of the U.S., and BIOS3 of Russia. Thus a conceptual design method which doesn’t rely on previous design examples is required for generalized RLSS from the above reasons. This study formalizes a conceptual design process, and develops a conceptual design support tool for RLSS based on this design process.
Kuznets, E I; Bobrov, A F; Bekreneva, L N; Mikhailova, L I; Utekhin, B A; Pruzhinina, T I; Iakovleva, E V; Chadov, V I
1996-01-01
The problem of evaluating and predicting the thermal status of a cosmonaut in the long-term space mission is a pressing one and remains to be solved. The previous studies indicated that the best plan to be followed is to evaluate the thermal status of a cosmonaut during his egress into outer space with the use of the procedure of parotid thermometry of the mean body temperature.
Rates of Space Weathering in Lunar Regolith Grains
NASA Technical Reports Server (NTRS)
Zhang, S.; Keller, L. P.
2012-01-01
While the processes and products of lunar space weathering are reasonably well-studied, their accumulation rates in lunar soils are poorly constrained. Previously, we showed that the thickness of solar wind irradiated rims on soil grains is a smooth function of their solar flare particle track density, whereas the thickness of vapor-deposited rims was largely independent of track density [1]. Here, we have extended these preliminary results with data on additional grains from other mature soils.
Topological materials discovery using electron filling constraints
NASA Astrophysics Data System (ADS)
Chen, Ru; Po, Hoi Chun; Neaton, Jeffrey B.; Vishwanath, Ashvin
2018-01-01
Nodal semimetals are classes of topological materials that have nodal-point or nodal-line Fermi surfaces, which give them novel transport and topological properties. Despite being highly sought after, there are currently very few experimental realizations, and identifying new materials candidates has mainly relied on exhaustive database searches. Here we show how recent studies on the interplay between electron filling and nonsymmorphic space-group symmetries can guide the search for filling-enforced nodal semimetals. We recast the previously derived constraints on the allowed band-insulator fillings in any space group into a new form, which enables effective screening of materials candidates based solely on their space group, electron count in the formula unit, and multiplicity of the formula unit. This criterion greatly reduces the computation load for discovering topological materials in a database of previously synthesized compounds. As a demonstration, we focus on a few selected nonsymmorphic space groups which are predicted to host filling-enforced Dirac semimetals. Of the more than 30,000 entires listed, our filling criterion alone eliminates 96% of the entries before they are passed on for further analysis. We discover a handful of candidates from this guided search; among them, the monoclinic crystal Ca2Pt2Ga is particularly promising.
McClain, Zachary; Hawkins, Linda A; Yehia, Baligh R
2016-01-01
Health outcomes are affected by patient, provider, and environmental factors. Previous studies have evaluated patient-level factors; few focusing on environment. Safe clinical spaces are important for lesbian, gay, bisexual, and transgender (LGBT) communities. This study evaluates current models of LGBT health care delivery, identifies strengths and weaknesses, and makes recommendations for LGBT spaces. Models are divided into LGBT-specific and LGBT-embedded care delivery. Advantages to both models exist, and they provide LGBT patients different options of healthcare. Yet certain commonalities must be met: a clean and confidential system. Once met, LGBT-competent environments and providers can advocate for appropriate care for LGBT communities, creating environments where they would want to seek care.
How Prevalent Is Object-Based Attention?
Pilz, Karin S.; Roggeveen, Alexa B.; Creighton, Sarah E.; Bennett, Patrick J.; Sekuler, Allison B.
2012-01-01
Previous research suggests that visual attention can be allocated to locations in space (space-based attention) and to objects (object-based attention). The cueing effects associated with space-based attention tend to be large and are found consistently across experiments. Object-based attention effects, however, are small and found less consistently across experiments. In three experiments we address the possibility that variability in object-based attention effects across studies reflects low incidence of such effects at the level of individual subjects. Experiment 1 measured space-based and object-based cueing effects for horizontal and vertical rectangles in 60 subjects comparing commonly used target detection and discrimination tasks. In Experiment 2 we ran another 120 subjects in a target discrimination task in which rectangle orientation varied between subjects. Using parametric statistical methods, we found object-based effects only for horizontal rectangles. Bootstrapping methods were used to measure effects in individual subjects. Significant space-based cueing effects were found in nearly all subjects in both experiments, across tasks and rectangle orientations. However, only a small number of subjects exhibited significant object-based cueing effects. Experiment 3 measured only object-based attention effects using another common paradigm and again, using bootstrapping, we found only a small number of subjects that exhibited significant object-based cueing effects. Our results show that object-based effects are more prevalent for horizontal rectangles, which is in accordance with the theory that attention may be allocated more easily along the horizontal meridian. The fact that so few individuals exhibit a significant object-based cueing effect presumably is why previous studies of this effect might have yielded inconsistent results. The results from the current study highlight the importance of considering individual subject data in addition to commonly used statistical methods. PMID:22348018
NASA Astrophysics Data System (ADS)
Tsuda, Shin-Ichi; Nakano, Yuta; Watanabe, Satoshi
2017-11-01
Recently, several studies using Molecular Dynamics (MD) simulation have been conducted for investigation of Ostwald ripening of cavitation bubbles in a finite space. The previous studies focused a characteristic length of bubbles as one of the spatially-averaged quantities, but each bubble behavior was not been investigated in detail. The objective of this study is clarification of the characteristics of each bubble behavior in Ostwald ripening, and we conducted MD simulation of a Lennard-Jones fluid in a semi-confined space. As a result, the time dependency of the characteristic length of bubbles as a spatially-averaged quantity suggested that the driving force of the Ostwald ripening is Evaporation/Condensation (EC) across liquid-vapor surface, which is the same result as the previous works. The radius change of the relatively larger bubbles also showed the same tendency to a classical EC model. However, the sufficiently smaller bubbles than the critical size, e.g., the bubbles just before collapsing, showed a different characteristic from the classical EC model. Those smaller bubbles has a tendency to be limited by mechanical non-equilibrium in which viscosity of liquid is dominant rather than by EC across liquid-vapor surface. This work was supported by JSPS KAKENHI Grant Number JP16K06085.
Rocket experiment METS - Microwave Energy Transmission in Space
NASA Astrophysics Data System (ADS)
Kaya, N.; Matsumoto, H.; Akiba, R.
A Microwave Energy Transmission in Space (METS) rocket experiment is being planned by the Solar Power Satellite Working Group at the Institute of Space and Astronautical Science in Japan for the forthcoming International Space Year, 1992. The METS experiment is an advanced version of the previous MINIX rocket experiment (Matsumoto et al., 1990). This paper describes a conceptual design of the METS rocket experiment. It aims at verifying a newly developed microwave energy transmission system for space use and to study nonlinear effects of the microwave energy beam in the space plasma environment. A high power microwave of 936 W will be transmitted by the new phased-array antenna from a mother rocket to a separated target (daughter rocket) through the ionospheric plasma. The active phased-array system has a capability of focusing the microwave energy around any spatial point by controlling the digital phase shifters individually.
1992-01-01
The IML-1 mission was the first in a series of Shuttle flights dedicated to fundamental materials and life sciences research with the international partners. The participating space agencies included: NASA, the 14-nation European Space Agency (ESA), the Canadian Space Agency (CSA), the French National Center of Space Studies (CNES), the German Space Agency and the German Aerospace Research Establishment (DAR/DLR), and the National Space Development Agency of Japan (NASDA). Dedicated to the study of life and materials sciences in microgravity, the IML missions explored how life forms adapt to weightlessness and investigated how materials behave when processed in space. Both life and materials sciences benefited from the extended periods of microgravity available inside the Spacelab science module in the cargo bay of the Space Shuttle Orbiter. In this photograph, Commander Ronald J. Grabe works with the Mental Workload and Performance Evaluation Experiment (MWPE) in the IML-1 module. This experiment was designed as a result of difficulty experienced by crewmembers working at a computer station on a previous Space Shuttle mission. The problem was due to the workstation's design being based on Earthbound conditions with the operator in a typical one-G standing position. Information gained from this experiment was used to design workstations for future Spacelab missions and the International Space Station. Managed by the Marshall Space Flight Center, IML-1 was launched on January 22, 1992 aboard the Space Shuttle Orbiter Discovery (STS-42 mission).
Costs and benefits of tool-use on the perception of reachable space.
Bourgeois, Jérémy; Farnè, Alessandro; Coello, Yann
2014-05-01
Previous studies have shown that using a tool modifies in a short time-scale both near-body space perception and arm-length representation in the body schema. However, to date no research has specifically investigated the effect of tool-use on an action-related perceptual task. We report here a study assessing the effect of tool-use on the perception of reachable space for perceptual estimates made in reference to either the tool or the hand. Using the tool on distal objects resulted in an extension of perceived reachable space with the tool and reduced the variability of reachability estimates. Tool use also extended perceived reachable space with the hand, but with a concomitant increase of the variability of reachability estimates. These findings suggest that tool incorporation into the represented arm following tool-use improves the anticipation of action possibilities with the tool, while hand representation becomes less accurate. Copyright © 2014 Elsevier B.V. All rights reserved.
Duggal, K L
2016-01-01
A new technique is used to study a family of time-dependent null horizons, called " Evolving Null Horizons " (ENHs), of generalized Robertson-Walker (GRW) space-time [Formula: see text] such that the metric [Formula: see text] satisfies a kinematic condition. This work is different from our early papers on the same issue where we used (1 + n )-splitting space-time but only some special subcases of GRW space-time have this formalism. Also, in contrast to previous work, we have proved that each member of ENHs is totally umbilical in [Formula: see text]. Finally, we show that there exists an ENH which is always a null horizon evolving into a black hole event horizon and suggest some open problems.
NASA Astrophysics Data System (ADS)
Sartori, G.; Valente, G.
2003-02-01
Functions which are equivariant or invariant under the transformations of a compact linear group G acting in a Euclidean space Bbb Rn, can profitably be studied as functions defined in the orbit space of the group. The orbit space is the union of a finite set of strata, which are semialgebraic manifolds formed by the G-orbits with the same orbit-type. In this paper, we provide a simple recipe to obtain rational parametrizations of the strata. Our results can be easily exploited, in many physical contexts where the study of equivariant or invariant functions is important, for instance in the determination of patterns of spontaneous symmetry breaking, in the analysis of phase spaces and structural phase transitions (Landau theory), in equivariant bifurcation theory, in crystal field theory and in most areas where use is made of symmetry-adapted functions. A physically significant example of utilization of the recipe is given, related to spontaneous polarization in chiral biaxial liquid crystals, where the advantages with respect to previous heuristic approaches are shown.
Autogenic-Feedback Training for the Control of Space Motion Sickness
NASA Technical Reports Server (NTRS)
Cowings, Patricia S.; Toscano, W. B.
1994-01-01
This paper presents case-studies of 9 shuttle crewmembers (prime and alternates) and one U.S. Navy F-18 pilot, as they participated in all preflight training and testing activities in support of a life sciences flight experiment aboard Spacelab-J, and Spacelab-3. The primary objective of the flight experiment was to determine if Autogenic-feedback training (AFT), a physiological self-regulation training technique would be an effective treatment for motion sickness and space motion sickness in these crewmembers. Additional objectives of this study involved the examining human physiological responses to motion sickness on Earth and in space, as well as developing predictive criteria for susceptibility to space motion sickness based on ground-based data. Comparisons of these crewmembers are made to a larger set of subjects from previous experiments (treatment and "test-only" controls subjects). This paper describes all preflight methods, results and proposed changes for future tests.
Caswell, Joseph M; Singh, Manraj; Persinger, Michael A
2016-08-01
Previous research investigating the potential influence of geomagnetic factors on human cardiovascular state has tended to converge upon similar inferences although the results remain relatively controversial. Furthermore, previous findings have remained essentially correlational without accompanying experimental verification. An exception to this was noted for human brain activity in a previous study employing experimental simulation of sudden geomagnetic impulses in order to assess correlational results that had demonstrated a relationship between geomagnetic perturbations and neuroelectrical parameters. The present study employed the same equipment in a similar procedure in order to validate previous findings of a geomagnetic-cardiovascular dynamic with electrocardiography and heart rate variability measures. Results indicated that potential magnetic field effects on frequency components of heart rate variability tended to overlap with previous correlational studies where low frequency power and the ratio between low and high frequency components of heart rate variability appeared affected. In the present study, a significant increase in these particular parameters was noted during geomagnetic simulation compared to baseline recordings. Copyright © 2016 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.
Reducing Mission Costs by Leveraging Previous Investments in Space
NASA Technical Reports Server (NTRS)
Miller, Ron; Adams, W. James
1999-01-01
The Rapid Spacecraft Development Office (RSDO) at NASA's Goddard Space Flight Center has been charged with the responsibility to reduce mission cost by allowing access to previous developments on government and commercial space missions. RSDO accomplishes this responsibility by implementing two revolutionary contract vehicles, the Rapid Spacecraft Acquisition (RSA) and Quick Ride. This paper will describe the concept behind these contracts, the current capabilities available to missions, analysis of pricing trends to date using the RSDO processes, and future plans to increase flexibility and capabilities available to mission planners.
NASA Technical Reports Server (NTRS)
2003-01-01
KENNEDY SPACE CENTER, FLA. At the KSC Visitor Complex, former astronaut James A. Lovell (standing left) applauds former astronaut Sally K. Ride at her induction ceremony into the U.S. Astronaut Hall of Fame. Seated on the dais, from left, are former astronauts Gordon Cooper, Scott Carpenter, and Buzz Aldrin, all previously inducted into the Hall of Fame. Being inducted with Ride are Space Shuttle astronauts Daniel Brandenstein, Robert 'Hoot' Gibson, and Story Musgrave. Conceived by six of the Mercury Program astronauts, the U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The four new inductees join 48 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
2004-05-01
KENNEDY SPACE CENTER, FLA. - Former astronaut Scott Carpenter is introduced as a previous inductee into the U.S. Astronaut Hall of Fame. He and other Hall of Fame members were present for the induction of five new space program heroes into the U.S. Astronaut Hall of Fame: Richard O. Covey, commander of the Hubble Space Telescope repair mission; Norman E. Thagard, the first American to occupy Russia’s Mir space station; the late Francis R. "Dick" Scobee, commander of the ill-fated 1986 Challenger mission; Kathryn D. Sullivan, the first American woman to walk in space; and Frederick D. Gregory, the first African-American to command a space mission and the current NASA deputy administrator. The induction ceremony was held at the Apollo/Saturn V Center at KSC. The U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The five inductees join 52 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
2004-05-01
KENNEDY SPACE CENTER, FLA. -- Before the induction ceremony of five space program heroes into the U.S. Astronaut Hall of Fame, former astronaut Ed Mitchell is introduced as a previous inductee. Mitchell explored the Moon's hilly Fra Mauro region with Alan B. Shepard during the 1971 Apollo 14 mission. The ceremony was held at the Apollo/Saturn V Center at KSC. New inductees are Richard O. Covey, commander of the Hubble Space Telescope repair mission; Norman E. Thagard, the first American to occupy Russia’s Mir space station; the late Francis R. "Dick" Scobee, commander of the ill-fated 1986 Challenger mission; Kathryn D. Sullivan, the first American woman to walk in space; and Frederick D. Gregory, the first African-American to command a space mission and the current NASA deputy administrator. The U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The five inductees join 52 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
2004-05-01
KENNEDY SPACE CENTER, FLA. -- Before the induction ceremony of five space program heroes into the U.S. Astronaut Hall of Fame, former astronaut John Glenn Jr. is greeted with applause as he is introduced as a previous inductee. One of America's original Mercury Seven astronauts, in 1962 he became the first American to orbit the Earth. Twenty-six years later, at age 77, he spent nine days in space aboard Space Shuttle Discovery. The ceremony was held at the Apollo/Saturn V Center at KSC. New inductees are Richard O. Covey, commander of the Hubble Space Telescope repair mission; Norman E. Thagard, the first American to occupy Russia’s Mir space station; the late Francis R. "Dick" Scobee, commander of the ill-fated 1986 Challenger mission; Kathryn D. Sullivan, the first American woman to walk in space; and Frederick D. Gregory, the first African-American to command a space mission and the current NASA deputy administrator. The U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The five inductees join 52 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
Mural art as a media on making urban kampung's public space
NASA Astrophysics Data System (ADS)
Susanto, Dalhar; Widyarko, Widyarko; Nadia Ilmiani, Ajeng
2017-12-01
The lack of public space is one of the main problems in the big cities in Indonesia. Urban kampungas part of the city is also no exception. Rapid growth on population sparks uncontrollable physical development that erode open space inside urbankampung. Sometimes, what is left is just neglected space which don‟t „live‟ and far from the definition of public space. Mural art has been existed since the beginning of human civilization. Now, it has evolved into one of the popular urban art. The previous research has proven that the process of urban art making through participatory approach could trigger community interaction in a space. Interaction itself is a main factor that may trigger the establishmentof a public space. With the same method, this research attempts to build mural in a neglected space inside urbankampung named Palsigunung. After all of the process done, the space still haven‟t changed from the previous condition, which is still a neglected space. Together with facilitator, kampung‟s residents need to be involved identifying the problem and also the solution to the lack of public space in their kampung. Particularly for urban kampungPalsigunung, the needed solution might not be mural.
A preliminary study of the Soviet civil space program. Volume 1: Organization and Operations
NASA Technical Reports Server (NTRS)
Newton, Elizabeth K.
1990-01-01
The organization, planning, and personnel is focused of Soviet space, advantage is taken of glasnost and improved foreign relations to explore a hitherto obscure subject. The way in which the civil space program obtains approval and funding is altered. Missions must be approved before the Supreme Soviet, and public opinion is beginning to play a greater role in the legislature's budget decision. The Soviet civil space program remains a collection of disparate elements, not unified by any national, centralized space agency. An attempt was made to catalog and delineate the relationships between the components proves helpful. There is little or no coordination of independent associations' efforts, and the planning process relied on previously to set priorities and allocate resources appears to be currently inoperative or in a state of flux. The civil space program is moving in new directions: toward budget tautness, more international interactions, an emphasis on civilian over military applications, commercialization, and fiscal accountability. This study is a snapshot of a dynamic subject, but hopefully on which has highlighted the critical elements to track.
Psychosocial interactions during ISS missions
NASA Astrophysics Data System (ADS)
Kanas, N. A.; Salnitskiy, V. P.; Ritsher, J. B.; Gushin, V. I.; Weiss, D. S.; Saylor, S. A.; Kozerenko, O. P.; Marmar, C. R.
2007-02-01
Based on anecdotal reports from astronauts and cosmonauts, studies of space analog environments on Earth, and our previous research on the Mir Space Station, a number of psychosocial issues have been identified that can lead to problems during long-duration space expeditions. Several of these issues were studied during a series of missions to the International Space Station. Using a mood and group climate questionnaire that was completed weekly by crewmembers in space and personnel in mission control, we found no evidence to support the presence of predicted decrements in well-being during the second half or in any specific quarter of the missions. The results did support the predicted displacement of negative feelings to outside supervisors among both crew and ground subjects. There were several significant differences in mood and group perceptions between Americans and Russians and between crewmembers and mission control personnel. Crewmembers related cohesion to the support role of their leader, and mission control personnel related cohesion to both the task and support roles of their leader. These findings are discussed with reference to future space missions.
How category learning affects object representations: Not all morphspaces stretch alike
Folstein, Jonathan R.; Gauthier, Isabel; Palmeri, Thomas J.
2012-01-01
How does learning to categorize objects affect how we visually perceive them? Behavioral, neurophysiological, and neuroimaging studies have tested the degree to which category learning influences object representations, with conflicting results. Some studies find that objects become more visually discriminable along dimensions relevant to previously learned categories, while others find no such effect. One critical factor we explore here lies in the structure of the morphspaces used in different studies. Studies finding no increase in discriminability often use “blended” morphspaces, with morphparents lying at corners of the space. By contrast, studies finding increases in discriminability use “factorial” morphspaces, defined by separate morphlines forming axes of the space. Using the same four morphparents, we created both factorial and blended morphspaces matched in pairwise discriminability. Category learning caused a selective increase in discriminability along the relevant dimension of the factorial space, but not in the blended space, and led to the creation of functional dimensions in the factorial space, but not in the blended space. These findings demonstrate that not all morphspaces stretch alike: Only some morphspaces support enhanced discriminability to relevant object dimensions following category learning. Our results have important implications for interpreting neuroimaging studies reporting little or no effect of category learning on object representations in the visual system: Those studies may have been limited by their use of blended morphspaces. PMID:22746950
NASA Astrophysics Data System (ADS)
Chishti, Arif Ali; Baumstark-Khan, Christa; Hellweg, Christine; Reitz, Guenther
Astronauts in space are exposed to a potentially harmful radiation field, which does not exist in its quality and quantity on earth. Radiation exposure in space can lead to delayed or acute health effects. A successful long-term space mission requires better risk estimation and development of appropriate countermeasures, therefore study of the cellular radiation response is necessary. Ionizing radiation can provoke active cellular responses (cell cycle arrest, DNA repair, apoptosis or other forms of cell type). Exposure to ionizing radiation also activates various signaling pathways in human cells. In the cellular radiation-response, two pivotal signal transduction pathways have to be comprehensively studied i.e. the p53-pathway and NF-κB-pathway. Discovery of fluorescent proteins has revolutionized biological research by making it possible to carry out functional studies in living cells and understanding complex signaling pathways. Previously the green fluorescent proteins EGFP and d2EGFP were used for signaling pathway studies. In this work the new red fluorescent protein tdTomato will be used for comprehensive investigation of NF-κB and other transcription factor activation after exposure of human cells to ionizing radiation (X-rays, heavy ions; space conditions). tdTomato has many advantages over EGFP because of its high fluorescence signals and a better signal/noise ratio in human cells. The previously constructed reporter system with d2EGFP was used to evaluate NF-kB activation after exposure to heavy ion particles of different biological effectiveness. The sensitivity threshold of this system was determined to be 2 particle traversals per cell nucleus. In the current study a more sensitive reporter assay will be constructed using a GAL4-VP16 turbo system that comprises a receptor plasmid and a reporter plasmid. This reporter assay will be designed and constructed with tdTomato and evaluation will be done with different molecular techniques.
Effect of Within-Category Spacing on Free Recall
ERIC Educational Resources Information Center
Borges, Marilyn A.; Mandler, George
1972-01-01
Contrary to previous experiments which found recall with blocked spacing always superior to recall with random" spacings, these experiments found that total recall was a function of two independent factors: (a) category representation, and (b) items per category represented (IPC). Both factors are dependent upon within-category spacing.…
[Assessment of the Space Station Program
NASA Technical Reports Server (NTRS)
Kerrebrock, Jack L.
1994-01-01
This letter report by the National Research Council's (NRC's) Aeronautics and Space Engineering Board addresses comments on NASA's response to the Board's 1993 letter report, NASA's response to technical and management recommendations from previous NRC technical reports on the Space Station, and an assessment of the current International Space Station Alpha (ISSA) program.
Walker, Esther J; Bergen, Benjamin K; Núñez, Rafael
2017-04-01
People use space in a variety of ways to structure their thoughts about time. The present report focuses on the different ways that space is employed when reasoning about deictic (past/future relationships) and sequence (earlier/later relationships) time. In the first study, we show that deictic and sequence time are aligned along the lateral axis in a manner consistent with previous work, with past and earlier events associated with left space and future and later events associated with right space. However, the alignment of time with space is different along the sagittal axis. Participants associated future events and earlier events-not later events-with the space in front of their body and past and later events with the space behind, consistent with the sagittal spatial terms (e.g., ahead, in front of) that we use to talk about deictic and sequence time. In the second study, we show that these associations between sequence time and sagittal space are sensitive to person-perspective. This suggests that the particular space-time associations observed in English speakers are influenced by a variety of different spatial properties, including spatial location and perspective. Copyright © 2016. Published by Elsevier B.V.
Popp, Erik; Hüttlin, Petra; Weilbacher, Frank; Münzberg, Matthias; Schneider, Niko; Kreinest, Michael
2017-01-01
Introduction Emergency management of upper cervical spine injuries often requires cervical spine immobilisation and some critical patients also require airway management. The movement of cervical spine created by tracheal intubation and cervical spine immobilisation can potentially exacerbate cervical spinal cord injury. However, the evidence that previous studies have provided remains unclear, due to lack of a direct measurement technique for dural sac's space during dynamic processes. Our study will use myelography method and a wireless human motion tracker to characterise and compare the change of dural sac's space during tracheal intubations and cervical spine immobilisation in the presence of unstable upper cervical spine injury such as atlanto-occipital dislocation or type II odontoid fracture. Methods and analysis Perform laryngoscopy and intubation, video laryngoscope intubation, laryngeal tube insertion, fiberoptic intubation and cervical collar application on cadaveric models of unstable upper cervical spine injury such as atlanto-occipital dislocation or type II odontoid fracture. The change of dural sac's space and the motion of unstable cervical segment are recorded by video fluoroscopy with previously performing myelography, which enables us to directly measure dural sac's space. Simultaneously, the whole cervical spine motion is recorded at a wireless human motion tracker. The maximum dural sac compression and the maximum angulation and distraction of the injured segment are measured by reviewing fluoroscopic and myelography images. Ethics and dissemination This study protocol has been approved by the Ethics Committee of the State Medical Association Rhineland-Palatinate, Mainz, Germany. The results will be published in relevant emergency journals and presented at relevant conferences. Trial registration number DRKS00010499. PMID:28864483
A DTN-Based Multiple Access Fast Forward Service for the NASA Space Network
NASA Technical Reports Server (NTRS)
Israel, David; Davis, Faith; Marquart. Jane
2011-01-01
The NASA Space Network provides a demand access return link service capable of providing users a space link "on demand". An equivalent service in the forward link direction is not possible due to Tracking and Data Relay Spacecraft (TDRS) constraints. A Disruption Tolerant Networking (DTN)-based Multiple Access Fast Forward (MAFF) service has been proposed to provide a forward link to a user as soon as possible. Previous concept studies have identified a basic architecture and implementation approach. This paper reviews the user scenarios and benefits of an MAFF service and proposes an implementation approach based on the use of DTN protocols.
Mars Science Laboratory Press Conference
2011-07-22
John Grant, geologist, Smithsonian National Air and Space Museum in Washington, speaks at a Mars Science Laboratory (MSL) press conference at the Smithsonian's National Air and Space Museum on Friday, July 22, 2011 in Washington. The Mars Science Laboratory (MSL), or Curiosity, is scheduled to launch late this year from NASA's Kennedy Space Center in Florida and land in August 2012. Curiosity is twice as long and more than five times as heavy as previous Mars rovers. The rover will study whether the landing region at Gale crater had favorable environmental conditions for supporting microbial life and for preserving clues about whether life ever existed. Photo Credit: (NASA/Carla Cioffi)
Kinematics and age of 15 stars-photometric solar analogs
NASA Astrophysics Data System (ADS)
Galeev, A. I.; Shimansky, V. V.
2008-03-01
The radial and space velocities are inferred for 15 stars that are photometric analogs of the Sun. The space velocity components (U, V, W) of most of these stars lie within the 10-60 km/s interval. The star HD 225239, which in our previous papers we classified as a subgiant, has a space velocity exceeding 100 km/s, and belongs to the thick disk. The inferred fundamental parameters of the atmospheres of solar analogs are combined with published evolutionary tracks to estimate the masses and ages of the stars studied. The kinematics of photometric analogs is compared to the data for a large group of solar-type stars.
User interfaces in space science instrumentation
NASA Astrophysics Data System (ADS)
McCalden, Alec John
This thesis examines user interaction with instrumentation in the specific context of space science. It gathers together existing practice in machine interfaces with a look at potential future usage and recommends a new approach to space science projects with the intention of maximising their science return. It first takes a historical perspective on user interfaces and ways of defining and measuring the science return of a space instrument. Choices of research methodology are considered. Implementation details such as the concepts of usability, mental models, affordance and presentation of information are described, and examples of existing interfaces in space science are given. A set of parameters for use in analysing and synthesizing a user interface is derived by using a set of case studies of diverse failures and from previous work. A general space science user analysis is made by looking at typical practice, and an interview plus persona technique is used to group users with interface designs. An examination is made of designs in the field of astronomical instrumentation interfaces, showing the evolution of current concepts and including ideas capable of sustaining progress in the future. The parameters developed earlier are then tested against several established interfaces in the space science context to give a degree of confidence in their use. The concept of a simulator that is used to guide the development of an instrument over the whole lifecycle is described, and the idea is proposed that better instrumentation would result from more efficient use of the resources available. The previous ideas in this thesis are then brought together to describe a proposed new approach to a typical development programme, with an emphasis on user interaction. The conclusion shows that there is significant room for improvement in the science return from space instrumentation by attention to the user interface.
Vlot, John; Wijnen, René; Stolker, Robert Jan; Bax, Klaas N
2014-03-01
Determinants of working space in minimal access surgery have not been well studied. Using computed tomography (CT) to measure volumes and linear dimensions, we are studying the effect of a number of determinants of CO2 working space in a porcine laparoscopy model. Here we report the effects of pre-stretching of the abdominal wall. Earlier we had noted an increase in CO2 pneumoperitoneum volume at repeat insufflation with an intra-abdominal pressure (IAP) of 5 mmHg after previous stepwise insufflation up to an IAP of 15 mmHg. We reviewed the data of this serendipity group; data of 16 pigs were available. In a new group of eight pigs, we also explored this effect at repeat IAPs of 10 and 15 mmHg. Volumes and linear dimensions of the CO2 pneumoperitoneum were measured on reconstructed CT images and compared between the initial and repeat insufflation runs. Previous stepwise insufflation of the abdomen with CO2 up to 15 mmHg significantly (p < 0.01) increased subsequent working-space volume at a repeat IAP of 5 mmHg by 21 %, 7 % at a repeat IAP of 10 mmHg and 3 % at a repeat IAP of 15 mmHg. The external anteroposterior diameter significantly (p < 0.01) increased by 0.5 cm (14 %) at repeat 5 mmHg. Other linear dimensions showed a much smaller change. There was no statistically significant correlation between the duration of the insufflation run and the volume increase after pre-stretching at all IAP levels. Pre-stretching of the abdominal wall allows for the same surgical-field exposure at lower IAPs, reducing the negative effects of prolonged high-pressure CO2 pneumoperitoneum on the cardiorespiratory system and microcirculation. Pre-stretching has important scientific consequences in studies addressing ways of increasing working space in that its effect may confound the possible effects of other interventions aimed at increasing working space.
NASA Technical Reports Server (NTRS)
Greenisen, M. C.; Bishop, P. A.; Sothmann, M.
2008-01-01
The purpose of this study was to determine the consequences of extended periods of weightlessness during space missions on astronauts f ability to perform a simulated contingency egress while wearing either of the Launch and Entry suits immediately after space flight. In our previous lab-based study of simulated contingency egress, we found only 4 of 12 non-astronauts wearing the Launch and Entry Suit (LES) successfully completed the simulated egress. However, 4 of 4 of the previous failures (when tested wearing the LES), were then successful in completing the test wearing the Advanced Crew Escape Suit (ACES). Therefore, this study tested 21 Astronaut Volunteers wearing either the LES or ACES while performing a simulated egress on a treadmill (TM) onboard the Crew Transportation Vehicle immediately after space flight at either the Kennedy Space Center or Edwards AFB. Astronauts walked for 400 meters at 1.6m/sec with g-suit inflation level set to preflight testing levels, visor down, breathing from the suit emergency O2 supply. Metabolic, heartrate, and perceived exertion data were collected during these post-flight tests. Exactly the same preflight simulated egress tests on a TM were performed in the lab at NASA/JSC by each crewmember at L-60. Preflight testing found 2 of the 21 crewmembers were unable to complete the simulated contingency egress. Postflight, 9 crew (8 ACES, 1 LES) completed the simulated contingency egress of 400 meters at 1.6m/sec. and 12 failed to meet that standard (7 ACES, 5 LES). Preflight physiological response tests failed to identify crew capable of performing the egress vs. those who failed. However, 18 of the 21 crew did make at least 2.67 minutes into the postflight egress testing. At that point in time, heartrate was higher (P <=.20) for the failures compared to the finishers. These findings indicate that NASA fs switch to the ACES for space flight crews should be expedited.
The French Space Operation Act: Technical Regulations
NASA Astrophysics Data System (ADS)
Trinchero, J. P.; Lazare, B.
2010-09-01
The French Space Operation Act(FSOA) stipulates that a prime objective of the National technical regulations is to protect people, property, public health and the environment. Compliance with these technical regulations is mandatory as of 10 December 2010 for space operations by French space operators and for space operations from French territory. The space safety requirements and regulations governing procedures are based on national and international best practices and experience. A critical design review of the space system and procedures shall be carried out by the applicant, in order to verify compliance with the Technical Regulations. An independent technical assessment of the operation is delegated to CNES. The principles applied when drafting technical regulations are as follows: requirements must as far as possible establish the rules according to the objective to be obtained, rather than how it is to be achieved; requirements must give preference to international standards recognised as being the state of the art; requirements must take previous experience into account. Technical regulations are divided into three sections covering common requirements for the launch, control and return of a space object. A dedicated section will cover specific rules to be applied at the Guiana Space Centre. The main topics addressed by the technical regulations are: operator safety management system; study of risks to people, property, public health and the Earth’s environment; impact study on the outer space environment: space debris generated by the operation; planetary protection.
Effect of science laboratory centrifuge of space station environment
NASA Technical Reports Server (NTRS)
Searby, Nancy
1990-01-01
It is argued that it is essential to have a centrifuge operating during manned space station operations. Background information and a rationale for the research centrifuge are given. It is argued that we must provide a controlled acceleration environment for comparison with microgravity studies. The lack of control groups in previous studies throws into question whether the obseved effects were the result of microgravity or not. The centrifuge could be used to provide a 1-g environment to supply specimens free of launch effects for long-term studies. With the centrifuge, the specimens could be immediately transferred to microgravity without undergoing gradual acclimation. Also, the effects of artificial gravity on humans could be investigated. It is also argued that the presence of the centrifuge on the space station will not cause undo vibrations or other disturbing effects.
ACES: An Enabling Technology for Next Generation Space Transportation
NASA Astrophysics Data System (ADS)
Crocker, Andrew M.; Wuerl, Adam M.; Andrews, Jason E.; Andrews, Dana G.
2004-02-01
Andrews Space has developed the ``Alchemist'' Air Collection and Enrichment System (ACES), a dual-mode propulsion system that enables safe, economical launch systems that take off and land horizontally. Alchemist generates liquid oxygen through separation of atmospheric air using the refrigeration capacity of liquid hydrogen. The key benefit of Alchemist is that it minimizes vehicle takeoff weight. All internal and NASA-funded activities have shown that ACES, previously proposed for hypersonic combined cycle RLVs, is a higher payoff, lower-risk technology if LOX generation is performed while the vehicle cruises subsonically. Andrews Space has developed the Alchemist concept from a small system study to viable Next Generation launch system technology, conducting not only feasibility studies but also related hardware tests, and it has planned a detailed risk reduction program which employs an experienced, proven contractor team. Andrews also has participated in preliminary studies of an evolvable Next Generation vehicle architecture-enabled by Alchemist ACES-which could meet civil, military, and commercial space requirements within two decades.
Regeneratively cooled rocket engine for space storable propellants
NASA Technical Reports Server (NTRS)
Wagner, W. R.
1973-01-01
Analysis, design, fabrication, and test efforts were performed for the existing OF2/B2H6 regeneratively cooled lK (4448 N) thrust chamber to illustrate simultaneous B2H6 fuel and OF2 oxidizer cooling and to provide results for a gaseous propellant condition injected into the combustion chamber. Data derived from performance, thermal and flow measurements confirmed predictions derived from previous test work and from concurrent analytical study. Development data derived from the experimental study were indicated to be sufficient to develop a preflight thrust chamber demonstrator prototype for future space mission objectives.
Operational Implementation of Space Debris Mitigation Procedures
NASA Astrophysics Data System (ADS)
Gicquel, Anne-Helene; Bonaventure, Francois
2013-08-01
During the spacecraft lifetime, Astrium supports its customers to manage collision risks alerts from the Joint Space Operations Center (JSpOC). This was previously done with hot-line support and a manual operational procedure. Today, it is automated and integrated in QUARTZ, the Astrium Flight Dynamics operational tool. The algorithms and process details for this new 5- step functionality are provided in this paper. To improve this functionality, some R&D activities such as the study of dilution phenomenon and low relative velocity encounters are going on. Regarding end of life disposal, recent operational experiences as well as studies results are presented.
Investigation of periodontal tissue during a long space flights
NASA Astrophysics Data System (ADS)
Solovyeva, Zoya; Viacheslav, Ilyin; Skedina, Marina
Previous studies conducted on the International Space Station found that upon completion of the space flight there are significant changes in the local immunity and periodontal microflora of astronauts. Also research in ground-based experiments that simulate space flight factors showed that prolonged hypokinesia antiorthostatic leads to impaired functional indicators of the periodontal vascular system, an unidirectional change from the microbiota and the immune system. That results in the appearance and progressive increase of the parodontial pathogenic bacteria and increase of the content of immunoglobulins in the oral fluid. All these changes are classified as risk factors for the development of inflammatory periodontal diseases in astronauts. However, the studies were unable to determine whether the changes result from a long space flight and the peculiarities of formation the local immunity and periodontal microbiota during the space flight, or they are one of the specific manifestations of the readaptationary post-flight condition of the body. In this regard, the planned research in a long space flight suggests: to use the means of microbial control, which can retain of the anaerobes periodontal microbiota sampling directly in the space flight; to assess the specificity of changes of the periodontal immune status under the influence of the space flight factors, and to assess the state of microcirculation of periodontal tissue in astronauts. A comprehensive study of the reaction of dentition during the space flight will make it possible to study the pathogenesis of changes for developing an adequate prevention aimed at optimizing the state of dentition of the astronauts.
Casimir force in the Gödel space-time and its possible induced cosmological inhomogeneity
NASA Astrophysics Data System (ADS)
Khodabakhshi, Sh.; Shojai, A.
2017-07-01
The Casimir force between two parallel plates in the Gödel universe is computed for a scalar field at finite temperature. It is observed that when the plates' separation is comparable with the scale given by the rotation of the space-time, the force becomes repulsive and then approaches zero. Since it has been shown previously that the universe may experience a Gödel phase for a small period of time, the induced inhomogeneities from the Casimir force are also studied.
Shuttle Orbiter-like Cargo Carrier on Crew Launch Vehicle
NASA Technical Reports Server (NTRS)
Martinovic, Zoran
2009-01-01
The following document summarizes the results of a conceptual design study for which the goal was to investigate the possibility of using a crew launch vehicle to deliver the remaining International Space Station elements should the Space Shuttle orbiter not be available to complete that task. Conceptual designs and structural weight estimates for two designs are presented. A previously developed systematic approach that was based on finite-element analysis and structural sizing was used to estimate growth of structural weight from analytical to "as built" conditions.
NASA Astrophysics Data System (ADS)
Schulte, Wolfgang; Hofer, Stefan; Hofmann, Peter; Thiele, Hans; von Heise-Rotenburg, Ralf; Toporski, Jan; Rettberg, Petra
2007-06-01
For more than a decade Kayser-Threde, a medium-sized enterprise of the German space industry, has been involved in astrobiology research in partnership with a variety of scientific institutes from all over Europe. Previous projects include exobiology research platforms in low Earth orbit on retrievable carriers and onboard the Space Station. More recently, exobiology payloads for in situ experimentation on Mars have been studied by Kayser-Threde under ESA contracts, specifically the ExoMars Pasteur Payload. These studies included work on a sample preparation and distribution systems for Martian rock/regolith samples, instrument concepts such as Raman spectroscopy and a Life Marker Chip, advanced microscope systems as well as robotic tools for astrobiology missions. The status of the funded technical studies and major results are presented. The reported industrial work was funded by ESA and the German Aerospace Center (DLR).
Shuttle - Mir Program Insignia
1994-09-20
The rising sun signifies the dawn of a new era of human Spaceflight, the first phase of the United States/Russian space partnership, Shuttle-Mir. Mir is shown in its proposed final on orbit configuration. The Shuttle is shown in a generic tunnel/Spacehab configuration. The Shuttle/Mir combination, docked to acknowledge the union of the two space programs, orbits over an Earth devoid of any definable features or political borders to emphasize Earth as the home planet for all humanity. The individual stars near the Space Shuttle and the Russian Mir Space Station represent the previous individual accomplishments of Russia's space program and that of the United States. The binary star is a tribute to the previous United States-Russian joint human Spaceflight program, the Apollo-Soyuz Test Project (ASTP). The flags of the two nations are symbolized by flowing ribbons of the national colors interwoven in space to represent the two nations joint exploration of space. NASA SHUTTLE and PKA MNP are shown in the stylized logo fonts of the two agencies that are conducting this program.
Enabling CSPA Operations Through Pilot Involvement in Longitudinal Approach Spacing
NASA Technical Reports Server (NTRS)
Battiste, Vernol (Technical Monitor); Pritchett, Amy
2003-01-01
Several major airports around the United States have, or plan to have, closely-spaced parallel runways. This project complemented current and previous research by examining the pilots ability to control their position longitudinally within their approach stream.This project s results considered spacing for separation from potential positions of wake vortices from the parallel approach. This preventive function could enable CSPA operations to very closely spaced runways. This work also considered how pilot involvement in longitudinal spacing could allow for more efficient traffic flow, by allowing pilots to keep their aircraft within tighter arrival slots then air traffic control (ATC) might be able to establish, and by maintaining space within the arrival stream for corresponding departure slots. To this end, this project conducted several research studies providing an analytic and computational basis for calculating appropriate aircraft spacings, experimental results from a piloted flight simulator test, and an experimental testbed for future simulator tests. The following sections summarize the results of these three efforts.
Scofield, David C; Rytlewski, Jeffrey D; Childress, Paul; Shah, Kishan; Tucker, Aamir; Khan, Faisal; Peveler, Jessica; Li, Ding; McKinley, Todd O; Chu, Tien-Min G; Hickman, Debra L; Kacena, Melissa A
2018-05-01
This study was initiated as a component of a larger undertaking designed to study bone healing in microgravity aboard the International Space Station (ISS). Spaceflight experimentation introduces multiple challenges not seen in ground studies, especially with regard to physical space, limited resources, and inability to easily reproduce results. Together, these can lead to diminished statistical power and increased risk of failure. It is because of the limited space, and need for improved statistical power by increasing sample size over historical numbers, NASA studies involving mice require housing mice at densities higher than recommended in the Guide for the Care and Use of Laboratory Animals (National Research Council, 2011). All previous NASA missions in which mice were co-housed, involved female mice; however, in our spaceflight studies examining bone healing, male mice are required for optimal experimentation. Additionally, the logistics associated with spaceflight hardware and our study design necessitated variation of density and cohort make up during the experiment. This required the development of a new method to successfully co-house male mice while varying mouse density and hierarchical structure. For this experiment, male mice in an experimental housing schematic of variable density (Spaceflight Correlate) analogous to previously established NASA spaceflight studies was compared to a standard ground based housing schematic (Normal Density Controls) throughout the experimental timeline. We hypothesized that mice in the Spaceflight Correlate group would show no significant difference in activity, aggression, or stress when compared to Normal Density Controls. Activity and aggression were assessed using a novel activity scoring system (based on prior literature, validated in-house) and stress was assessed via body weights, organ weights, and veterinary assessment. No significant differences were detected between the Spaceflight Correlate group and the Normal Density Controls in activity, aggression, body weight, or organ weight, which was confirmed by veterinary assessments. Completion of this study allowed for clearance by NASA of our bone healing experiments aboard the ISS, and our experiment was successfully launched February 19, 2017 on SpaceX CRS-10. Copyright © 2018 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.
NASA Technical Reports Server (NTRS)
2004-01-01
KENNEDY SPACE CENTER, FLA. -- Former astronaut Frederick (Rick) Hauck acknowledges the warm response to his introduction as a previous inductee into the U.S. Astronaut Hall of Fame. He and other Hall of Fame members were present for the induction of five new space program heroes into the U.S. Astronaut Hall of Fame: Richard O. Covey, commander of the Hubble Space Telescope repair mission; Norman E. Thagard, the first American to occupy Russias Mir space station; the late Francis R. 'Dick' Scobee, commander of the ill-fated 1986 Challenger mission; Kathryn D. Sullivan, the first American woman to walk in space; and Frederick D. Gregory, the first African-American to command a space mission and the current NASA deputy administrator. Hauck flew on three Space Shuttle missions, including command of the redesigned spaceship on its critical first flight after the explosion of Challenger. The induction ceremony was held at the Apollo/Saturn V Center at KSC. The U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The five inductees join 52 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
2004-05-01
KENNEDY SPACE CENTER, FLA. -- Former astronaut Frederick (Rick) Hauck acknowledges the warm response to his introduction as a previous inductee into the U.S. Astronaut Hall of Fame. He and other Hall of Fame members were present for the induction of five new space program heroes into the U.S. Astronaut Hall of Fame: Richard O. Covey, commander of the Hubble Space Telescope repair mission; Norman E. Thagard, the first American to occupy Russia’s Mir space station; the late Francis R. "Dick" Scobee, commander of the ill-fated 1986 Challenger mission; Kathryn D. Sullivan, the first American woman to walk in space; and Frederick D. Gregory, the first African-American to command a space mission and the current NASA deputy administrator. Hauck flew on three Space Shuttle missions, including command of the redesigned spaceship on its critical first flight after the explosion of Challenger. The induction ceremony was held at the Apollo/Saturn V Center at KSC. The U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The five inductees join 52 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
2004-05-01
KENNEDY SPACE CENTER, FLA. -- Former astronaut Ed Gibson acknowledges the warm response to his introduction as a previous inductee into the U.S. Astronaut Hall of Fame. He and other Hall of Fame members were present for the induction of five new space program heroes into the U.S. Astronaut Hall of Fame: Richard O. Covey, commander of the Hubble Space Telescope repair mission; Norman E. Thagard, the first American to occupy Russia’s Mir space station; the late Francis R. "Dick" Scobee, commander of the ill-fated 1986 Challenger mission; Kathryn D. Sullivan, the first American woman to walk in space; and Frederick D. Gregory, the first African-American to command a space mission and the current NASA deputy administrator. Gibson orbited the Earth for 84 days during the final manned flight of the Skylab Space Station in 1973 and 1974. The induction ceremony was held at the Apollo/Saturn V Center at KSC. The U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The five inductees join 52 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
2004-05-01
KENNEDY SPACE CENTER, FLA. -- Before the induction ceremony of five space program heroes into the U.S. Astronaut Hall of Fame, former astronaut Wally Schirra is greeted with applause as he is introduced as a previous inductee. One of America's original Mercury Seven astronauts, Schirra is the only one who flew in all three of the nation's pioneering space programs, Mercury, Gemini, and Apollo. The ceremony was held at the Apollo/Saturn V Center at KSC. New inductees are Richard O. Covey, commander of the Hubble Space Telescope repair mission; Norman E. Thagard, the first American to occupy Russia’s Mir space station; the late Francis R. "Dick" Scobee, commander of the ill-fated 1986 Challenger mission; Kathryn D. Sullivan, the first American woman to walk in space; and Frederick D. Gregory, the first African-American to command a space mission and the current NASA deputy administrator. The U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The five inductees join 52 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
Hesterberg, Stephen G; Duckett, C Cole; Salewski, Elizabeth A; Bell, Susan S
2017-04-01
Identifying and quantifying the relevant properties of habitat structure that mediate predator-prey interactions remains a persistent challenge. Most previous studies investigate effects of structural density on trophic interactions and typically quantify refuge quality using one or two-dimensional metrics. Few consider spatial arrangement of components (i.e., orientation and shape) and often neglect to measure the total three-dimensional (3D) space available as refuge. This study tests whether the three-dimensionality of interstitial space, an attribute produced by the spatial arrangement of oyster (Crassostrea virginica) shells, impacts the foraging success of nektonic predators (primary blue crab, Callinectes sapidus) on mud crab prey (Eurypanopeus depressus) in field and mesocosm experiments. Interstices of 3D-printed shell mimics were manipulated by changing either their orientation (angle) or internal shape (crevice or channel). In both field and mesocosm experiments, under conditions of constant structural density, predator foraging success was influenced by 3D aspects of interstitial space. Proportional survivorship of tethered mud crabs differed significantly as 3D interstitial space varied by orientation, displaying decreasing prey survivorship as angle of orientation increased (0° = 0.76, 22.5° = 0.13, 45° = 0.0). Tethered prey survivorship was high when 3D interstitial space of mimics was modified by internal shape (crevice survivorship = 0.89, channel survivorship = 0.96) and these values did not differ significantly. In mesocosms, foraging success of blue crabs varied with 3D interstitial space as mean proportional survivorship (± SE) of mud crabs was significantly lower in 45° (0.27 ± 0.06) vs. 0° (0.86 ± 0.04) orientations and for crevice (0.52 ± 0.11) vs. channel shapes (0.95 ± 0.02). These results suggest that 3D aspects of interstitial space, which have direct relevance to refuge quality, can strongly influence foraging success in our oyster reef habitat. Our findings highlight the importance of spatial arrangement in mediating consumptive pathways in hard-structured habitats and demonstrate how quantifying the three-dimensionality of living space captures aspects of habitat structure that have been missing from previous empirical studies of trophic interactions and structural complexity. © 2017 by the Ecological Society of America.
2004-05-01
KENNEDY SPACE CENTER, FLA. -- Before the induction ceremony of five space program heroes into the U.S. Astronaut Hall of Fame, astronaut John Young is warmly greeted as he is introduced as a previous inductee. Co-holder of a record for the most space flights, six, he flew on Gemini 3 and 10, orbited the Moon on Apollo 10, walked on the Moon on Apollo 16, and commanded two space shuttle missions, STS-1 and STS-9. Young currently serves as associate director, technical, at Johnson Space Center. The induction ceremony was held at the Apollo/Saturn V Center at KSC. New inductees are Richard O. Covey, commander of the Hubble Space Telescope repair mission; Norman E. Thagard, the first American to occupy Russia’s Mir space station; the late Francis R. "Dick" Scobee, commander of the ill-fated 1986 Challenger mission; Kathryn D. Sullivan, the first American woman to walk in space; and Frederick D. Gregory, the first African-American to command a space mission and the current NASA deputy administrator. The U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The five inductees join 52 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
NASA Technical Reports Server (NTRS)
Mcallister, J. G.
1984-01-01
Space based servicing of an orbit transfer vehicle (OTV) was previously outlined in sufficient detail to arrive at OTV and support system servicing requirements. Needed space station facilities and their functional requirements were identified. The impact of logistics and space serviceable design on the OTV design is detailed herein. RL10 derivative rocket engine inspection task times are enumerated.
Descriptions of Space Processing Applications Rocket (SPAR) experiments
NASA Technical Reports Server (NTRS)
Naumann, R. J. (Editor)
1979-01-01
The experiments for all the Space Processing Applications Rocket experiments, including those flown on previous Space Processing flights as well as those under development for future flights are described. The experiment objective, rationale, approach, and results or anticipated results are summarized.
The Space Infrared Interferometric Telescope (SPIRIT): Recent Study Results and Plans
NASA Astrophysics Data System (ADS)
Leisawitz, David; SPIRIT Mission Study Team
2007-12-01
SPIRIT was recommended in the 2002 "Community Plan for Far-IR/Submillimeter Space Astronomy.” A structurally connected interferometer, SPIRIT provides sensitive sub-arcsecond angular resolution images and integral field spectroscopy in the 25 to 400 micron wavelength range. SPIRIT was designed to revolutionize our understanding of planetary system formation, reveal otherwise-undetectable planets through the disk perturbations they induce, spectroscopically probe the atmospheres of extrasolar giant planets in orbits typical of most of the planets in our solar system, and yield significant new insight into the processes associated with galaxy formation and development. This paper updates previously presented study results and describes future study plans. Our SPIRIT mission concept study proposal was peer reviewed and selected by NASA for support under the Origins Probe Mission Concept Study program. NASA's Goddard Space Flight Center and four industry partners - Ball Aerospace, Boeing, Lockheed-Martin, and Northrop-Grumman - contributed generously the study. The Origins Probe study results were reviewed by an Advisory Review Panel.
Hattori, Hiroshi; Akasaka, Kiyokazu; Otsudo, Takahiro; Takei, Keiichi; Yamamoto, Mitsuru
2017-01-01
Background: Throwing athletes risk medial elbow injury from extreme valgus stress generated across the medial elbow during throwing. Braces have been developed to protect the elbow joint; however, no previous study has investigated the effects of elbow bracing on medial elbow joint space gapping associated with repetitive throwing. Hypothesis/Purpose: The purpose of this study was to investigate the effects of elbow bracing on medial elbow joint space gapping during repetitive throwing. Our hypothesis was that an elbow brace may reduce mechanical stress on the elbow by reducing medial elbow joint space gapping. Study Design: Controlled laboratory study. Methods: Twenty-five high school baseball players participated in this study. Each subject pitched 100 times under 2 conditions: control (without elbow brace) and elbow brace. The ulnohumeral joint space was measured ultrasonically before pitching and after every block of 20 pitches. Measurement of the ulnohumeral joint space was carried out using ultrasound with the forearm hanging by the side. Two-way repeated-measures analysis of variance and post hoc tests were used to compare ulnohumeral joint space with repeated pitching and between the elbow brace and control conditions. Results: In the control condition, ulnohumeral joint space after 60 pitches was significantly greater than that before pitching (P < .01). In contrast, in the elbow brace condition, ulnohumeral joint space was not significantly different after repeated pitching. When comparing these 2 conditions, ulnohumeral joint space in the control condition was significantly greater than that in the elbow brace condition after 60 pitches (P < .01). Conclusion: An elbow brace has the effect of preventing medial elbow joint space gapping with repeated throwing when determined ultrasonically by measuring the ulnohumeral joint space under gravity load. Clinical Relevance: An elbow brace worn during baseball pitching practice may help reduce mechanical stress on the elbow by reducing medial elbow joint space gapping. PMID:28451622
Airglow studies using observations made with the GLO instrument on the Space Shuttle
NASA Astrophysics Data System (ADS)
Alfaro Suzan, Ana Luisa
2009-12-01
Our understanding of Earth's upper atmosphere has advanced tremendously over the last few decades due to our enhanced capacity for making remote observations from space. Space based observations of Earth's daytime and nighttime airglow emissions are very good examples of such enhancements to our knowledge. The terrestrial nighttime airglow, or nightglow, is barely discernible to the naked eye as viewed from Earth's surface. However, it is clearly visible from space - as most astronauts have been amazed to report. The nightglow consists of emissions of ultraviolet, visible and near-infrared radiation from electronically excited oxygen molecules and atoms and vibrationally excited OH molecules. It mostly emanates from a 10 km thick layer located about 100 km above Earth's surface. Various photochemical models have been proposed to explain the production of the emitting species. In this study some unique observations of Earth's nightglow made with the GLO instrument on NASA's Space Shuttle, are analyzed to assess the proposed excitation models. Previous analyses of these observations by Broadfoot and Gardner (2001), performed using a 1-D inversion technique, have indicated significant spatial structures and have raised serious questions about the proposed nightglow excitation models. However, the observation of such strong spatial structures calls into serious question the appropriateness of the adopted 1-D inversion technique and, therefore, the validity of the conclusions. In this study a more rigorous 2-D tomographic inversion technique is developed and applied to the available GLO data to determine if some of the apparent discrepancies can be explained by the limitations of the previously applied 1-D inversion approach. The results of this study still reveal some potentially serious inadequacies in the proposed photochemical models. However, alternative explanations for the discrepancies between the GLO observations and the model expectations are suggested. These include upper atmospheric tidal effects and possible errors in the pointing of the GLO instrument.
NASA Technical Reports Server (NTRS)
Coleman, E. A.
1980-01-01
Scientific information from previous space flights, space medicine, exercise physiology, and sports medicine was used to prepare a physical fitness manual suitable for use by members of the NASA astronaut population. A variety of scientifically valid exercise programs and activities suitable for the development of physical fitness are provided. Programs, activities, and supportive scientific data are presented in a concise, easy to read format so as to permit the user to select his or her mode of training with confidence and devote time previously spent experimenting with training routines to preparation for space flight. The programs and activities included were tested and shown to be effective and enjoyable.
Approach to an Affordable and Sustainable Space Transportation System
NASA Technical Reports Server (NTRS)
McCleskey, Caey M.; Rhodes, R. E.; Robinson, J. W.; Henderson, E. M.
2012-01-01
This paper describes an approach and a general procedure for creating space transportation architectural concepts that are at once affordable and sustainable. Previous papers by the authors and other members of the Space Propulsion Synergy Team (SPST) focused on a functional system breakdown structure for an architecture and definition of high-payoff design techniques with a technology integration strategy. This paper follows up by using a structured process that derives architectural solutions focused on achieving life cycle affordability and sustainability. Further, the paper includes an example concept that integrates key design techniques discussed in previous papers. !
Space station WP-04 power system preliminary analysis and design document, volume 3
NASA Technical Reports Server (NTRS)
1986-01-01
Rocketdyne plans to generate a system level specification for the Space Station Electric Power System (EPS) in order to facilitate the usage, accountability, and tracking of overall system level requirements. The origins and status of the verification planning effort are traced and an overview of the Space Station program interactions are provided. The work package level interfaces between the EPS and the other Space Station work packages are outlined. A trade study was performed to determine the peaking split between PV and SD, and specifically to compare the inherent total peaking capability with proportionally shared peaking. In order to determine EPS cost drivers for the previous submittal of DRO2, the life cycle cost (LCC) model was run to identify the more significant costs and the factors contributing to them.
2016-01-01
A new technique is used to study a family of time-dependent null horizons, called “Evolving Null Horizons” (ENHs), of generalized Robertson-Walker (GRW) space-time (M¯,g¯) such that the metric g¯ satisfies a kinematic condition. This work is different from our early papers on the same issue where we used (1 + n)-splitting space-time but only some special subcases of GRW space-time have this formalism. Also, in contrast to previous work, we have proved that each member of ENHs is totally umbilical in (M¯,g¯). Finally, we show that there exists an ENH which is always a null horizon evolving into a black hole event horizon and suggest some open problems. PMID:27722202
NASA Astrophysics Data System (ADS)
Daugherty, James F.
2005-09-01
The tuning accuracy and intonation tendencies of a high school mixed choir (N=46) were measured from digital recordings obtained as the ensemble performed an a cappella motet under concert conditions in N=3 singer spacing configurations (close, lateral, circumambient) and N=2 choir formations (sectional and mixed). Methods of analysis were modeled on Howard's (2004) pitch-based measurements of the tuning accuracy of crowds of football fans. Results were discussed in terms of (a) previous studies on choir spacing (Daugherty, 1999, 2003) and self-to-other singer ratios (Ternstrm, 1995, 1999); (b) contributions of choir spacing to vocal/choral pedagogy; and (c) potential ramifications for the design and use of auditoria and portable standing risers for choral performances.
Asymptotic symmetries and electromagnetic memory
NASA Astrophysics Data System (ADS)
Pasterski, Sabrina
2017-09-01
Recent investigations into asymptotic symmetries of gauge theory and gravity have illuminated connections between gauge field zero-mode sectors, the corresponding soft factors, and their classically observable counterparts — so called "memories". Namely, low frequency emissions in momentum space correspond to long time integrations of the corre-sponding radiation in position space. Memory effect observables constructed in this manner are non-vanishing in typical scattering processes, which has implications for the asymptotic symmetry group. Here we complete this triad for the case of large U(1) gauge symmetries at null infinity. In particular, we show that the previously studied electromagnetic memory effect, whereby the passage of electromagnetic radiation produces a net velocity kick for test charges in a distant detector, is the position space observable corresponding to th Weinberg soft photon pole in momentum space scattering amplitudes.
Immunology presentation at the 1990 NASA/NSF Antarctica Biomedical Science Working Group
NASA Technical Reports Server (NTRS)
Meehan, Richard T.
1990-01-01
An overview of methodology used for determining human in vitro lymphocyte activation, proliferation and effector cell function was presented and results of previous manned space flight immunology studies from Apollo through Shuttle were reviewed. Until the Shuttle era, lymphocyte assays were not very sensitive and had such large variations among normal subjects that it was difficult to define a consistent effect of space flight. More sensitive assay, however, even with Shuttle missions as brief as 6 days indicate depressed T-cell proliferative responses are routinely observed following space flight. Using a slight modification of the Shuttle assay, five different human stress-immunology models have been studied over the last 6 years in our lab. These have included: academic examinations of medical students having blood drawn during major test periods on three separate groups of first year students and two hypoxia studies (at 25,000 feet in a 6 week chamber ascent to the equivalent of Mount Everest and twice on Pikes Peak at 14,000 feet). These studies are particularly pertinent to Antarctica, since the altitude equivalent of 11,000 feet at the South Pole may affect some of the variables that are being measured in immunology, physiology or cognitive studies. An extravehicular study was performed drawing blood from 35 individuals before and immediately following a chamber exposure study. Preliminary results from 30 Shuttle astronauts investigated immunophenotype analysis and the role of a novel monocyte population in modulating the previously observed suppressed in vitro immune function. The results of the Air Force Academy cadet stress study were also presented.
Effects of Long Duration Spaceflight on Venous and Arterial Compliance
NASA Technical Reports Server (NTRS)
Ribeiro, L. C.; Lee, S. M. C.; Martin, D. S.; Ploutz-Snyder, R.; Stenger, M. B.; Westby, C. M.; Platts, S. H.
2014-01-01
The visual impairment and intracranial pressure syndrome (VIIP) is a newly described space flight-associated medical condition made up of a constellation of symptoms affecting at least 34% of American astronauts who have flown International Space Station (ISS) missions. VIIP is defined primarily by visual acuity deficits and anatomical changes to eye structures, and is thought to be related to elevated intracranial pressure secondary to space flightinduced cephalad fluid shifts. Loss of visual acuity could be a significant threat to crew health and performance and may be suggestive of other adaptations with implications for years post-flight. Our primary objective is to determine whether vascular compliance is altered by space flight and whether such adaptations are related to the incidence of VIIP. In particular, we will measure ocular parameters and vascular compliance in vessels of the head and neck in astronauts who have no space flight experience, in astronauts before, during, and after space flight, and in bed rest subjects with conditions similar to space flight. Additionally, we will analyze astronaut data from the Lifetime Surveillance of Astronaut Health (LSAH) archive to determine which factors might be predictive of the development of VIIP. The project will be conducted in four separate but related parts. To understand the baseline condition of astronauts without any prior space flight experience, we will study 10 astronauts who have never flown in space by performing a comprehensive evaluation of the vasculature of the head, neck and eyes. Hemodynamic data (stroke volume and blood pressure), ocular (tonometry and ocular ultrasound), venous and arterial parameters will be acquired across a range of tilt angles (20, 10, 0, -10, -20 degrees). Vessels to be studied include the temporal, jugular, and vertebral veins and the cerebral, carotid and vertebral arteries. Ophthalmic data from the annual physical will be obtained through data sharing. To examine the relation between vascular compliance in the head and neck and the development of VIIP after a long duration space flight, we will study 10 astronauts before, during, and after long-duration ISS missions. Pre- and post-flight testing will be identical to that described above. During flight, images of the same vessels of interest will be obtained for later analysis. Ophthalmic data including VIIP scores will be obtained through data sharing from medically-required tests. To investigate the effects of age and elevated sodium intake, two potential contributors to VIIP, we will study 24 men (in two age groups: 25-35 and 45-55) during a 14 day 6deg head-down bed rest, a well-accepted analog of space flight. Standard NASA bed rest conditions will be maintained except for dietary sodium. Sodium intake will be similar to that of ISS astronauts, which is higher than consumed in previous bed rest studies. Pre- and post-bed rest testing procedures will be identical to the testing protocol described above for astronauts. Ophthalmic testing (optical coherence tomography, fundoscopy, and tonometry) will be conducted on the same day that vascular compliance measures are obtained. To identify parameters that may relate to an increase in an astronaut's susceptibility to developing VIIP, we will use data mining techniques to evaluate astronaut data obtained from the LSAH. Medical history, family history, space flight history and its related exposures, and history of high performance jet aircraft exposure will be examined for their potential relationship to ocular data. We hypothesize that the cephalad fluid shift induced by space flight will result in structural and functional adaptations in head and neck vessels leading to decreased vascular compliance and related to the development of VIIP symptoms. Further, although VIIP has not been observed in previous bed rest studies, we hypothesize that an elevated sodium intake will increase the incidence of VIIP symptoms in this space flight analog. Finally, we hypothesize that data mining analyses will reveal relationships between health history, previous exposures (including space flight and high performance aircraft), and the development of VIIP in the astronaut population.
Current Fluctuations in Stochastic Lattice Gases
NASA Astrophysics Data System (ADS)
Bertini, L.; de Sole, A.; Gabrielli, D.; Jona-Lasinio, G.; Landim, C.
2005-01-01
We study current fluctuations in lattice gases in the macroscopic limit extending the dynamic approach for density fluctuations developed in previous articles. More precisely, we establish a large deviation theory for the space-time fluctuations of the empirical current which include the previous results. We then estimate the probability of a fluctuation of the average current over a large time interval. It turns out that recent results by Bodineau and Derrida [Phys. Rev. Lett.922004180601] in certain cases underestimate this probability due to the occurrence of dynamical phase transitions.
2004-05-01
KENNEDY SPACE CENTER, FLA. -- Former astronaut Owen Garriott acknowledges the applause as he is introduced as a previous inductee into the U.S. Astronaut Hall of Fame. He and other Hall of Fame members were present for the induction of five new space program heroes into the U.S. Astronaut Hall of Fame: Richard O. Covey, commander of the Hubble Space Telescope repair mission; Norman E. Thagard, the first American to occupy Russia’s Mir space station; the late Francis R. "Dick" Scobee, commander of the ill-fated 1986 Challenger mission; Kathryn D. Sullivan, the first American woman to walk in space; and Frederick D. Gregory, the first African-American to command a space mission and the current NASA deputy administrator. Garriott exercised his expertise as a solar physicist on two space missions, the 59-day Skylab 3 flight in 1973, and an 11-day trip aboard the Space Shuttle Columbia a decade later. The induction ceremony was held at the Apollo/Saturn V Center at KSC. The U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The five inductees join 52 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
2004-05-01
KENNEDY SPACE CENTER, FLA. -- Former astronaut Robert Crippen smiles at the warm greeting he is receiving when introduced as a previous inductee into the U.S. Astronaut Hall of Fame. He and other Hall of Fame members were present for the induction of five new space program heroes into the U.S. Astronaut Hall of Fame: Richard O. Covey, commander of the Hubble Space Telescope repair mission; Norman E. Thagard, the first American to occupy Russia’s Mir space station; the late Francis R. "Dick" Scobee, commander of the ill-fated 1986 Challenger mission; Kathryn D. Sullivan, the first American woman to walk in space; and Frederick D. Gregory, the first African-American to command a space mission and the current NASA deputy administrator. Crippen piloted the first Space Shuttle flight in 1981 and commanded three other Shuttle missions in the next 3-1/2 years. In the early 1990s he served as director of NASA’s Kennedy Space Center. The induction ceremony was held at the Apollo/Saturn V Center at KSC. The U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The five inductees join 52 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
ERIC Educational Resources Information Center
Sapiie, Stephanie
2012-01-01
Whereas previous studies of the Indonesian student movement have been limited to studies of single episodes of activism of student protests, this work focuses on the narratives, and repertoires that, together with crucial external events of political and economic realignments created both pressures and opportunities that produced contentious…
Metacognitive Control over the Distribution of Practice: When Is Spacing Preferred?
ERIC Educational Resources Information Center
Toppino, Thomas C.; Cohen, Michael S.; Davis, Meghan L.; Moors, Amy C.
2009-01-01
The authors clarify the source of a conflict between previous findings related to metacognitive control over the distribution of practice. In a study by L. Son (2004), learners were initially presented pairs of Graduate Record Examination (GRE) vocabulary words and their common synonyms for 1 s, after which they chose to study the pair again…
Non-Targeted Effects and the Dose Response for Heavy Ion Tumorigenesis
NASA Technical Reports Server (NTRS)
Chappell, Lori J.; Cucinotta, Francis A.
2010-01-01
There is no human epidemiology data available to estimate the heavy ion cancer risks experienced by astronauts in space. Studies of tumor induction in mice are a necessary step to estimate risks to astronauts. Previous experimental data can be better utilized to model dose response for heavy ion tumorigenesis and plan future low dose studies.
NASA Technical Reports Server (NTRS)
2004-01-01
KENNEDY SPACE CENTER, FLA. -- Former astronaut Charles Duke receives a warm welcome as he is introduced as a previous inductee into the U.S. Astronaut Hall of Fame. He and other Hall of Fame members were present for the induction of five new space program heroes into the U.S. Astronaut Hall of Fame: Richard O. Covey, commander of the Hubble Space Telescope repair mission; Norman E. Thagard, the first American to occupy Russias Mir space station; the late Francis R. 'Dick' Scobee, commander of the ill- fated 1986 Challenger mission; Kathryn D. Sullivan, the first American woman to walk in space; and Frederick D. Gregory, the first African-American to command a space mission and the current NASA deputy administrator. Duke explored the rugged highlands of the Moons Descartes region with John Young during the Apollo 16 mission in April 1972. The induction ceremony was held at the Apollo/Saturn V Center at KSC. The U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The five inductees join 52 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo- Soyuz, and Space Shuttle programs.
2004-05-01
KENNEDY SPACE CENTER, FLA. -- Former astronaut Charles Duke receives a warm welcome as he is introduced as a previous inductee into the U.S. Astronaut Hall of Fame. He and other Hall of Fame members were present for the induction of five new space program heroes into the U.S. Astronaut Hall of Fame: Richard O. Covey, commander of the Hubble Space Telescope repair mission; Norman E. Thagard, the first American to occupy Russia’s Mir space station; the late Francis R. "Dick" Scobee, commander of the ill-fated 1986 Challenger mission; Kathryn D. Sullivan, the first American woman to walk in space; and Frederick D. Gregory, the first African-American to command a space mission and the current NASA deputy administrator. Duke explored the rugged highlands of the Moon’s Descartes region with John Young during the Apollo 16 mission in April 1972. The induction ceremony was held at the Apollo/Saturn V Center at KSC. The U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The five inductees join 52 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
2004-05-01
KENNEDY SPACE CENTER, FLA. -- Former astronaut Jim Lovell acknowledges the applause as he is introduced as a previous inductee into the U.S. Astronaut Hall of Fame. He and other Hall of Fame members were present for the induction of five new space program heroes into the U.S. Astronaut Hall of Fame: Richard O. Covey, commander of the Hubble Space Telescope repair mission; Norman E. Thagard, the first American to occupy Russia’s Mir space station; the late Francis R. "Dick" Scobee, commander of the ill-fated 1986 Challenger mission; Kathryn D. Sullivan, the first American woman to walk in space; and Frederick D. Gregory, the first African-American to command a space mission and the current NASA deputy administrator. Lovell piloted Gemini 7, commanded Gemini 12, orbited the Moon on Apollo 8 and commanded the aborted Apollo 13 moon flight. The induction ceremony was held at the Apollo/Saturn V Center at KSC. The U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The five inductees join 52 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
Space 2100: A Shared Visioning Exercise for the Future Space Economy
NASA Astrophysics Data System (ADS)
Ferguson, C. K.; Nall, M. E.; Scott, D. W.; Tinker, M. L.; Oneil, D.; Sivak, A. D.; Wright, G. M.; Eberly, E. A.; Ramdall, C.
In 2013, NASA's Marshall Space Flight Center chartered a diverse team for a six-week "sprint" to envision how Earth, space, and public/private entities might be operating in the year 2100. This sprint intended to inspire innovation, creativity and improved teamwork between all levels of employees, in addition to pulling diverse ideas about exploration from organizations that are not traditionally included in technology development at NASA. The team was named Space 2100. In 2014, the team ran a sprint based on the previous outcomes to a) develop detailed estimates of operations and challenges of space activities in the vicinity of the Earth and Moon in the year 2050, b) identify evolutionary steps to make this vision a reality, and c) recommend actions to enable those steps. In 2015, the team continued building on previous years by identifying technologies and approaches to reduce and ultimately eliminate the need for resupply from Earth, enabling self-sufficient exploration throughout the solar system. This exercise identified 30 technologies as potential critical paths to Earth independency. Space 2100's conclusions and recommendations are not part of NASA's strategic planning or policy. This paper explores the three Space 2100 sprints and their implications for the future of space exploration.
Perin, Jamie; Walker, Neff
2015-01-01
Background Recent steep declines in child mortality have been attributed in part to increased use of contraceptives and the resulting change in fertility behaviour, including an increase in the time between births. Previous observational studies have documented strong associations between short birth spacing and an increase in the risk of neonatal, infant, and under-five mortality, compared to births with longer preceding birth intervals. In this analysis, we compare two methods to estimate the association between short birth intervals and mortality risk to better inform modelling efforts linking family planning and mortality in children. Objectives Our goal was to estimate the mortality risk for neonates, infants, and young children by preceding birth space using household survey data, controlling for mother-level factors and to compare the results to those from previous analyses with survey data. Design We assessed the potential for confounding when estimating the relative mortality risk by preceding birth interval and estimated mortality risk by birth interval in four categories: less than 18 months, 18–23 months, 24–35 months, and 36 months or longer. We estimated the relative risks among women who were 35 and older at the time of the survey with two methods: in a Cox proportional hazards regression adjusting for potential confounders and also by stratifying Cox regression by mother, to control for all factors that remain constant over a woman's childbearing years. We estimated the overall effects for birth spacing in a meta-analysis with random survey effects. Results We identified several factors known for their associations with neonatal, infant, and child mortality that are also associated with preceding birth interval. When estimating the effect of birth spacing on mortality, we found that regression adjustment for these factors does not substantially change the risk ratio for short birth intervals compared to an unadjusted mortality ratio. For birth intervals less than 18 months, standard regression adjustment for confounding factors estimated a risk ratio for neonatal mortality of 2.28 (95% confidence interval: 2.18–2.37). This same effect estimated within mother is 1.57 (95% confidence interval: 1.52–1.63), a decline of almost one-third in the effect on neonatal mortality. Conclusions Neonatal, infant, and child mortality are strongly and significantly related to preceding birth interval, where births within a short interval of time after the previous birth have increased mortality. Previous analyses have demonstrated this relationship on average across all births; however, women who have short spaces between births are different from women with long spaces. Among women 35 years and older where a comparison of birth spaces within mother is possible, we find a much reduced although still significant effect of short birth spaces on child mortality. PMID:26562139
Perin, Jamie; Walker, Neff
2015-01-01
Recent steep declines in child mortality have been attributed in part to increased use of contraceptives and the resulting change in fertility behaviour, including an increase in the time between births. Previous observational studies have documented strong associations between short birth spacing and an increase in the risk of neonatal, infant, and under-five mortality, compared to births with longer preceding birth intervals. In this analysis, we compare two methods to estimate the association between short birth intervals and mortality risk to better inform modelling efforts linking family planning and mortality in children. Our goal was to estimate the mortality risk for neonates, infants, and young children by preceding birth space using household survey data, controlling for mother-level factors and to compare the results to those from previous analyses with survey data. We assessed the potential for confounding when estimating the relative mortality risk by preceding birth interval and estimated mortality risk by birth interval in four categories: less than 18 months, 18-23 months, 24-35 months, and 36 months or longer. We estimated the relative risks among women who were 35 and older at the time of the survey with two methods: in a Cox proportional hazards regression adjusting for potential confounders and also by stratifying Cox regression by mother, to control for all factors that remain constant over a woman's childbearing years. We estimated the overall effects for birth spacing in a meta-analysis with random survey effects. We identified several factors known for their associations with neonatal, infant, and child mortality that are also associated with preceding birth interval. When estimating the effect of birth spacing on mortality, we found that regression adjustment for these factors does not substantially change the risk ratio for short birth intervals compared to an unadjusted mortality ratio. For birth intervals less than 18 months, standard regression adjustment for confounding factors estimated a risk ratio for neonatal mortality of 2.28 (95% confidence interval: 2.18-2.37). This same effect estimated within mother is 1.57 (95% confidence interval: 1.52-1.63), a decline of almost one-third in the effect on neonatal mortality. Neonatal, infant, and child mortality are strongly and significantly related to preceding birth interval, where births within a short interval of time after the previous birth have increased mortality. Previous analyses have demonstrated this relationship on average across all births; however, women who have short spaces between births are different from women with long spaces. Among women 35 years and older where a comparison of birth spaces within mother is possible, we find a much reduced although still significant effect of short birth spaces on child mortality.
Galvin, John J; Oba, Sandra I; Başkent, Deniz; Chatterjee, Monita; Fu, Qian-Jie
2015-01-01
Previous cochlear implant (CI) studies have shown that single-channel amplitude modulation frequency discrimination (AMFD) can be improved when coherent modulation is delivered to additional channels. It is unclear whether the multi-channel advantage is due to increased loudness, multiple envelope representations, or to component channels with better temporal processing. Measuring envelope interference may shed light on how modulated channels can be combined. In this study, multi-channel AMFD was measured in CI subjects using a 3-alternative forced-choice, non-adaptive procedure ("which interval is different?"). For the reference stimulus, the reference AM (100 Hz) was delivered to all 3 channels. For the probe stimulus, the target AM (101, 102, 104, 108, 116, 132, 164, 228, or 256 Hz) was delivered to 1 of 3 channels, and the reference AM (100 Hz) delivered to the other 2 channels. The spacing between electrodes was varied to be wide or narrow to test different degrees of channel interaction. Results showed that CI subjects were highly sensitive to interactions between the reference and target envelopes. However, performance was non-monotonic as a function of target AM frequency. For the wide spacing, there was significantly less envelope interaction when the target AM was delivered to the basal channel. For the narrow spacing, there was no effect of target AM channel. The present data were also compared to a related previous study in which the target AM was delivered to a single channel or to all 3 channels. AMFD was much better with multiple than with single channels whether the target AM was delivered to 1 of 3 or to all 3 channels. For very small differences between the reference and target AM frequencies (2-4 Hz), there was often greater sensitivity when the target AM was delivered to 1 of 3 channels versus all 3 channels, especially for narrowly spaced electrodes. Besides the increased loudness, the present results also suggest that multiple envelope representations may contribute to the multi-channel advantage observed in previous AMFD studies. The different patterns of results for the wide and narrow spacing suggest a peripheral contribution to multi-channel temporal processing. Because the effect of target AM frequency was non-monotonic in this study, adaptive procedures may not be suitable to measure AMFD thresholds with interfering envelopes. Envelope interactions among multiple channels may be quite complex, depending on the envelope information presented to each channel and the relative independence of the stimulated channels.
2015-01-01
Rationale Previous cochlear implant (CI) studies have shown that single-channel amplitude modulation frequency discrimination (AMFD) can be improved when coherent modulation is delivered to additional channels. It is unclear whether the multi-channel advantage is due to increased loudness, multiple envelope representations, or to component channels with better temporal processing. Measuring envelope interference may shed light on how modulated channels can be combined. Methods In this study, multi-channel AMFD was measured in CI subjects using a 3-alternative forced-choice, non-adaptive procedure (“which interval is different?”). For the reference stimulus, the reference AM (100 Hz) was delivered to all 3 channels. For the probe stimulus, the target AM (101, 102, 104, 108, 116, 132, 164, 228, or 256 Hz) was delivered to 1 of 3 channels, and the reference AM (100 Hz) delivered to the other 2 channels. The spacing between electrodes was varied to be wide or narrow to test different degrees of channel interaction. Results Results showed that CI subjects were highly sensitive to interactions between the reference and target envelopes. However, performance was non-monotonic as a function of target AM frequency. For the wide spacing, there was significantly less envelope interaction when the target AM was delivered to the basal channel. For the narrow spacing, there was no effect of target AM channel. The present data were also compared to a related previous study in which the target AM was delivered to a single channel or to all 3 channels. AMFD was much better with multiple than with single channels whether the target AM was delivered to 1 of 3 or to all 3 channels. For very small differences between the reference and target AM frequencies (2–4 Hz), there was often greater sensitivity when the target AM was delivered to 1 of 3 channels versus all 3 channels, especially for narrowly spaced electrodes. Conclusions Besides the increased loudness, the present results also suggest that multiple envelope representations may contribute to the multi-channel advantage observed in previous AMFD studies. The different patterns of results for the wide and narrow spacing suggest a peripheral contribution to multi-channel temporal processing. Because the effect of target AM frequency was non-monotonic in this study, adaptive procedures may not be suitable to measure AMFD thresholds with interfering envelopes. Envelope interactions among multiple channels may be quite complex, depending on the envelope information presented to each channel and the relative independence of the stimulated channels. PMID:26431043
Orbital stability of compact three-planets systems.
NASA Astrophysics Data System (ADS)
Gavino, Sacha; Lissauer, Jack
2018-04-01
Recent discoveries unveiled a significant number of compact multi-planetary systems, where the adjacent planets orbits are much closer to those found in the Solar System. Studying the orbital stability of such compact systems provides information on how they form and how long they survive. We performed a general study of three Earth-like planets orbiting a Sun-mass star in circular and coplanar prograde orbits. The simulations were performed over a wide range of mutual Hill radii and were conducted for virtual times reaching at most 10 billion years. Both equally-spaced and unequally spaced planet systems are investigated. We recover the results of previous studies done for systems of planets spaced uniformly in mutual Hill radius and we investigate mean motion resonances and test chaos. We also study systems with different initial spacing between the adjacent inner pair of planets and the outer pair of planets and we displayed their lifetime on a grid at different resolution. Over 45000 simulations have been done. We then characterize isochrones for lifetime of systems of equivalent spacing. We find that the stability time increases significantly for values of mutual Hill radii beyond 8. We also study the affects of mean motion resonances, the degree of symmetry in the grid and test chaos.
Ab initio conformational analysis of N-formyl ?-alanine amide including electron correlation
NASA Astrophysics Data System (ADS)
Yu, Ching-Hsing; Norman, Mya A.; Schäfer, Lothar; Ramek, Michael; Peeters, Anik; van Alsenoy, Christian
2001-06-01
The conformational properties of N-formyl L-alanine amide (ALA) were investigated using RMP2/6-311G∗∗ ab initio gradient geometry optimization. One hundred forty four structures of ALA were optimized at 30° grid points in its φ(N-C(α)), ψ(C(α)-C‧) conformational space. Using cubic spline functions, the grid structures were then used to construct analytical representations of complete surfaces, in φ,ψ-space, of bond lengths, bond angles, torsional sensitivity and electrostatic atomic charges. Analyses show that, in agreement with previous studies, the right-handed helical conformation, αR, is not a local energy minimum of the potential energy surface of ALA. Comparisons with protein crystallographic data show that the characteristic differences between geometrical trends in dipeptides and proteins, previously found for ab initio dipeptide structures obtained without electron correlation, are also found in the electron-correlated geometries. In contrast to generally accepted features of force fields used in empirical molecular modeling, partial atomic charges obtained by the CHELPG method are found to be not constant, but to vary significantly throughout the φ,ψ-space. By comparing RHF and MP2 structures, the effects of dispersion forces on ALA were studied, revealing molecular contractions for those conformations, in which small adjustments of torsional angles entail large changes in non-bonded distances.
Probing the Depths of Space Weathering: A Cross-sectional View of Lunar Rock 76015
NASA Technical Reports Server (NTRS)
Noble, Sarah K.; Keller, L. P.; Stroud, Rhonda
2007-01-01
The term "space weathering" refers to the cumulative effects of several processes operating at the surface of any solar system body not protected by a thick atmosphere. These processes include cosmic and solar ray irradiation, solar wind implantation and sputtering, as well as melting and vaporization due to micrometeorite bombardment. Space weathering discussions have generally centered around soils but exposed rocks will also incur the effects of weathering. Rocks have much longer surface lifetimes than an individual soil grain and thus record a longer history of exposure. By studying the weathering products which have built up on a rock surface, we can gain a deeper perspective on the weathering process and better assess the relative importance of various weathering components. The weathered coating, or patina, of the lunar rock 76015 has been previously studied using SEM and TEM. It is a noritic breccia with both "glazed" (smooth glassy) and "classic" (microcratered and pancake-bearing) patina coatings. Previous TEM work on 76015 relied on ultramicrotomy to prepare cross sections of the patina coating, but these sections were limited by the "chatter" and loss of material in these brittle samples. Here we have used a focused ion beam (FIB) instrument to prepare cross sections in which the delicate stratigraphy of the patina coating is beautifully preserved.
On the kinematic detection of accreted streams in the Gaia era: a cautionary tale
NASA Astrophysics Data System (ADS)
Jean-Baptiste, I.; Di Matteo, P.; Haywood, M.; Gómez, A.; Montuori, M.; Combes, F.; Semelin, B.
2017-08-01
The ΛCDM cosmological scenario predicts that our Galaxy should contain hundreds of stellar streams in the solar vicinity, fossil relics of the merging history of the Milky Way and more generally of the hierarchical growth of galaxies. Because of the mixing time scales in the inner Galaxy, it has been claimed that these streams should be difficult to detect in configuration space but can still be identifiable in kinematic-related spaces like the energy/angular momenta spaces, E - Lz and L⊥ - Lz, or spaces of orbital/velocity parameters. By means of high-resolution, dissipationless N-body simulations containing between 25 × 106 and 35 × 106 particles, we model the accretion of a series of up to four 1:10 mass ratio satellites then up to eight 1:100 satellites and search systematically for the signature of accretions in these spaces. The novelty of this work with respect to the majority of those already published is our analysis of fully consistent models, where both the satellite(s) and the Milky Way galaxy are "live" systems, which can react to the interaction and experience kinematical heating, tidal effects and dynamical friction (the latter, a process often neglected in previous studies). We find that, in agreement with previous works, all spaces are rich in substructures, but that, contrary to previous works, the origin of these substructures - accreted or in-situ - cannot be determined for the following reasons. In all spaces considered (1) each satellite provides the origin of several independent over-densities; (2) over-densities of multiple satellites overlap; (3) satellites of different masses can produce similar substructures; (4) the overlap between the in-situ and the accreted population is considerable everywhere; and (5) in-situ stars also form substructures in response to the satellite(s') accretion. These points are valid even if the search is restricted to kinematically-selected halo stars only. As we are now entering the "Gaia era", our results warn that extreme caution must be employed before interpreting over-densities in any of those spaces as evidence of relics of accreted satellites. Reconstructing the accretion history of our Galaxy will require a substantial amount of accurate spectroscopic data, that, complemented by the kinematic information, will possibly allow us to (chemically) identify accreted streams and measure their orbital properties.
Preliminary Multivariable Cost Model for Space Telescopes
NASA Technical Reports Server (NTRS)
Stahl, H. Philip
2010-01-01
Parametric cost models are routinely used to plan missions, compare concepts and justify technology investments. Previously, the authors published two single variable cost models based on 19 flight missions. The current paper presents the development of a multi-variable space telescopes cost model. The validity of previously published models are tested. Cost estimating relationships which are and are not significant cost drivers are identified. And, interrelationships between variables are explored
NASA Astrophysics Data System (ADS)
Jee, M. J.; Dawson, K. S.; Hoekstra, H.; Perlmutter, S.; Rosati, P.; Brodwin, M.; Suzuki, N.; Koester, B.; Postman, M.; Lubin, L.; Meyers, J.; Stanford, S. A.; Barbary, K.; Barrientos, F.; Eisenhardt, P.; Ford, H. C.; Gilbank, D. G.; Gladders, M. D.; Gonzalez, A.; Harris, D. W.; Huang, X.; Lidman, C.; Rykoff, E. S.; Rubin, D.; Spadafora, A. L.
2011-08-01
We present weak gravitational lensing analysis of 22 high-redshift (z >~ 1) clusters based on Hubble Space Telescope images. Most clusters in our sample provide significant lensing signals and are well detected in their reconstructed two-dimensional mass maps. Combining the current results and our previous weak-lensing studies of five other high-z clusters, we compare gravitational lensing masses of these clusters with other observables. We revisit the question whether the presence of the most massive clusters in our sample is in tension with the current ΛCDM structure formation paradigm. We find that the lensing masses are tightly correlated with the gas temperatures and establish, for the first time, the lensing mass-temperature relation at z >~ 1. For the power-law slope of the M-TX relation (MvpropT α), we obtain α = 1.54 ± 0.23. This is consistent with the theoretical self-similar prediction α = 3/2 and with the results previously reported in the literature for much lower redshift samples. However, our normalization is lower than the previous results by 20%-30%, indicating that the normalization in the M-TX relation might evolve. After correcting for Eddington bias and updating the discovery area with a more conservative choice, we find that the existence of the most massive clusters in our sample still provides a tension with the current ΛCDM model. The combined probability of finding the four most massive clusters in this sample after the marginalization over cosmological parameters is less than 1%. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555, under program 9290, 9919, and 10496.
On the coplanar eccentric non-restricted co-orbital dynamics
NASA Astrophysics Data System (ADS)
Leleu, A.; Robutel, P.; Correia, A. C. M.
2018-03-01
We study the phase space of eccentric coplanar co-orbitals in the non-restricted case. Departing from the quasi-circular case, we describe the evolution of the phase space as the eccentricities increase. We find that over a given value of the eccentricity, around 0.5 for equal mass co-orbitals, important topological changes occur in the phase space. These changes lead to the emergence of new co-orbital configurations and open a continuous path between the previously distinct trojan domains near the L_4 and L_5 eccentric Lagrangian equilibria. These topological changes are shown to be linked with the reconnection of families of quasi-periodic orbits of non-maximal dimension.
Development of High-Resolution UV-VIS Diagnostics for Space Plasma Simulation
NASA Astrophysics Data System (ADS)
Taylor, Andrew; Batishchev, Oleg
2012-10-01
Non-invasive far-UV-VIS plasma emission allows remote diagnostics of plasma, which is particularly important for space application. Accurate vacuum tank space plasma simulations require monochromators with high spectral resolution (better than 0.01A) to capture important details of atomic and ionic lines, such as Ly-alpha, etc. We are building a new system based on the previous work [1], and will discuss the development of a spectrometry system that combines a single-pass vacuum far-UV-NIR spectrometer and a tunable Fabry-Perot etalon. [4pt] [1] O. Batishchev and J.L. Cambier, Experimental Study of the Mini-Helicon Thruster, Air Force Research Laboratory Report, AFRL-RZ-ED-TR-2009-0020, 2009.
NASA Technical Reports Server (NTRS)
Conway, Edmund J.
1992-01-01
An overview of previous studies related to laser power transmission is presented. Particular attention is given to the use of solar pumped lasers for space power applications. Three general laser mechanisms are addressed: photodissociation lasing driven by sunlight, photoexcitation lasing driven directly by sunlight, and photoexcitation lasing driven by thermal radiation.
Association of park access with usual stress of adolescents
USDA-ARS?s Scientific Manuscript database
Chronic usual stress is associated with obesity, weight gain, disorders of growth, development, and metabolism, and is also a risk factor for chronic diseases, such as cardiovascular disease. Previous studies have found that the presence of subjective measures of green space in adolescents’ built e...
Negative space charge effects in photon-enhanced thermionic emission solar converters
DOE Office of Scientific and Technical Information (OSTI.GOV)
Segev, G.; Weisman, D.; Rosenwaks, Y.
2015-07-06
In thermionic energy converters, electrons in the gap between electrodes form a negative space charge and inhibit the emission of additional electrons, causing a significant reduction in conversion efficiency. However, in Photon Enhanced Thermionic Emission (PETE) solar energy converters, electrons that are reflected by the electric field in the gap return to the cathode with energy above the conduction band minimum. These electrons first occupy the conduction band from which they can be reemitted. This form of electron recycling makes PETE converters less susceptible to negative space charge loss. While the negative space charge effect was studied extensively in thermionicmore » converters, modeling its effect in PETE converters does not account for important issues such as this form of electron recycling, nor the cathode thermal energy balance. Here, we investigate the space charge effect in PETE solar converters accounting for electron recycling, with full coupling of the cathode and gap models, and addressing conservation of both electric and thermal energy. The analysis shows that the negative space charge loss is lower than previously reported, allowing somewhat larger gaps compared to previous predictions. For a converter with a specific gap, there is an optimal solar flux concentration. The optimal solar flux concentration, the cathode temperature, and the efficiency all increase with smaller gaps. For example, for a gap of 3 μm the maximum efficiency is 38% and the optimal flux concentration is 628, while for a gap of 5 μm the maximum efficiency is 31% and optimal flux concentration is 163.« less
O-space with high resolution readouts outperforms radial imaging.
Wang, Haifeng; Tam, Leo; Kopanoglu, Emre; Peters, Dana C; Constable, R Todd; Galiana, Gigi
2017-04-01
While O-Space imaging is well known to accelerate image acquisition beyond traditional Cartesian sampling, its advantages compared to undersampled radial imaging, the linear trajectory most akin to O-Space imaging, have not been detailed. In addition, previous studies have focused on ultrafast imaging with very high acceleration factors and relatively low resolution. The purpose of this work is to directly compare O-Space and radial imaging in their potential to deliver highly undersampled images of high resolution and minimal artifacts, as needed for diagnostic applications. We report that the greatest advantages to O-Space imaging are observed with extended data acquisition readouts. A sampling strategy that uses high resolution readouts is presented and applied to compare the potential of radial and O-Space sequences to generate high resolution images at high undersampling factors. Simulations and phantom studies were performed to investigate whether use of extended readout windows in O-Space imaging would increase k-space sampling and improve image quality, compared to radial imaging. Experimental O-Space images acquired with high resolution readouts show fewer artifacts and greater sharpness than radial imaging with equivalent scan parameters. Radial images taken with longer readouts show stronger undersampling artifacts, which can cause small or subtle image features to disappear. These features are preserved in a comparable O-Space image. High resolution O-Space imaging yields highly undersampled images of high resolution and minimal artifacts. The additional nonlinear gradient field improves image quality beyond conventional radial imaging. Copyright © 2016 Elsevier Inc. All rights reserved.
NASA Technical Reports Server (NTRS)
Woodcock, Gordon
1997-01-01
This study is an extension of a previous effort by the Principal Investigator to develop baseline data to support comparative analysis of Highly Reusable Space Transportation (HRST) concepts. The analyses presented herin develop baseline data bases for two two-stage-to-orbit (TSTO) concepts: (1) Assisted horizontal take-off all rocket (assisted HTOHL); and (2) Assisted vertical take-off rocket based combined cycle (RBCC). The study objectives were to: (1) Provide configuration definitions and illustrations for assisted HTOHL and assisted RBCC; (2) Develop a rationalization approach and compare these concepts with the HRST reference; and (3) Analyze TSTO configurations which try to maintain SSTO benefits while reducing inert weight sensitivity.
Chen, Xueli; Gao, Xinbo; Qu, Xiaochao; Chen, Duofang; Ma, Xiaopeng; Liang, Jimin; Tian, Jie
2010-10-10
The camera lens diaphragm is an important component in a noncontact optical imaging system and has a crucial influence on the images registered on the CCD camera. However, this influence has not been taken into account in the existing free-space photon transport models. To model the photon transport process more accurately, a generalized free-space photon transport model is proposed. It combines Lambertian source theory with analysis of the influence of the camera lens diaphragm to simulate photon transport process in free space. In addition, the radiance theorem is also adopted to establish the energy relationship between the virtual detector and the CCD camera. The accuracy and feasibility of the proposed model is validated with a Monte-Carlo-based free-space photon transport model and physical phantom experiment. A comparison study with our previous hybrid radiosity-radiance theorem based model demonstrates the improvement performance and potential of the proposed model for simulating photon transport process in free space.
Main medical results of extended flights on space station Mir in 1986-1990
NASA Astrophysics Data System (ADS)
Grigoriev, A. I.; Bugrov, S. A.; Bogomolov, V. V.; Egorov, A. D.; Polyakov, V. V.; Tarasov, I. K.; Shulzhenko, E. B.
During 1986-1990 seven prime spacecrews (16 cosmonauts) have flow on-board the Mir orbital complex. The longest space mission duration was 366 days. The principal objectives of the medical tasks were the maintenance of good health and performance of the spacecrews and conducting medical research programs which included study of the cardiovascular, motor, endocrine, blood, immune, and metabolic systems. Results obtained point to the ability of humans to readily adapt to a year-long stay in space and maintain good health and performance. Readaptation had a similar course as after other previous long-term space flights of up to 8 months in duration. Primary body system changes were not qualitatively different from findings after flights aboard the Salyut 6 and 7 space stations. In this case, during and after an 11-12 month flight, body system alterations were even less severe which was a result of adequate countermeasure use, their systematic and creative employment and maintenance of required environments to support life and work in space.
Hiley, Michael J; Yeadon, Maurice R
2014-08-01
The upstart is a fundamental skill in gymnastics, requiring whole body coordination to transfer the gymnast from a swing beneath the bar to a support position above the bar. The aim of this study was to determine the solution space within which a gymnast could successfully perform an upstart. A previous study had shown that the underlying control strategy for the upstart could be accounted for by maximizing the likelihood of success while operating in a noisy environment. In the current study, data were collected on a senior gymnast and a computer simulation model of a gymnast and bar was used to determine the solution space for maximizing success while operating in a noisy environment. The effects of timing important actions, gymnast strength, and movement execution noise on the success of the upstart were then systematically determined. The solution space for the senior gymnast was relatively large. Decreasing strength and increasing movement execution noise reduced the size of the solution space. A weaker gymnast would have to use a different technique than that used by the senior gymnast to produce an acceptable success rate.
A bootstrap based space-time surveillance model with an application to crime occurrences
NASA Astrophysics Data System (ADS)
Kim, Youngho; O'Kelly, Morton
2008-06-01
This study proposes a bootstrap-based space-time surveillance model. Designed to find emerging hotspots in near-real time, the bootstrap based model is characterized by its use of past occurrence information and bootstrap permutations. Many existing space-time surveillance methods, using population at risk data to generate expected values, have resulting hotspots bounded by administrative area units and are of limited use for near-real time applications because of the population data needed. However, this study generates expected values for local hotspots from past occurrences rather than population at risk. Also, bootstrap permutations of previous occurrences are used for significant tests. Consequently, the bootstrap-based model, without the requirement of population at risk data, (1) is free from administrative area restriction, (2) enables more frequent surveillance for continuously updated registry database, and (3) is readily applicable to criminology and epidemiology surveillance. The bootstrap-based model performs better for space-time surveillance than the space-time scan statistic. This is shown by means of simulations and an application to residential crime occurrences in Columbus, OH, year 2000.
Solar concentrators for advanced solar-dynamic power systems in space
NASA Technical Reports Server (NTRS)
Rockwell, Richard
1993-01-01
This report summarizes the results of a study performed by Hughes Danbury Optical Systems, HDOS, (formerly Perkin-Elmer) to design, fabricate, and test a lightweight (2 kg/sq M), self supporting, and highly reflective sub-scale concentrating mirror panel suitable for use in space. The HDOS panel design utilizes Corning's 'micro sheet' glass as the top layer of a composite honeycomb sandwich. This approach, whose manufacturability was previously demonstrated under an earlier NASA contract, provides a smooth (specular) reflective surface without the weight of a conventional glass panel. The primary result of this study is a point design and it's performance assessment.
REVIEWS OF TOPICAL PROBLEMS: Sky surveys and deep fields of ground-based and space telescopes
NASA Astrophysics Data System (ADS)
Reshetnikov, Vladimir P.
2005-11-01
Selected results obtained in major observational sky surveys (DSS, 2MASS, 2dF, SDSS) and deep field observations (HDF, GOODS, UHDF, etc.) are reviewed. Modern surveys provide information on the characteristics and space distribution of millions of galaxies. Deep fields allow one to study galaxies at the stage of formation and to trace their evolution over billions of years. The wealth of observational data is altering the face of modern astronomy: the formulation of problems and their solutions are changing and all the previous knowledge, from planetary studies in the solar system to the most distant galaxies and quasars, is being revised.
2003-06-20
KENNEDY SPACE CENTER, FLA. - Hundreds of guests attend a ribbon cutting ceremony officially opening the U.S. Astronaut Hall of Fame as part of the Kennedy Space Center Visitor Complex. The ceremony was held in conjunction with the induction of four Space Shuttle astronauts into the Hall of Fame including Daniel Brandenstein, Robert "Hoot" Gibson, Story Musgrave, and Sally Ride. Conceived by six of the Mercury Program astronauts, the U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The four new inductees join 48 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
The Space Homestead and Creation of Real Estate and Industry beyond Earth
NASA Astrophysics Data System (ADS)
Detweiler, Michael K.; Curreri, Peter A.
2008-01-01
During the 1970s large habitats were proposed by G. K. O'Neill and studied by NASA that could house 10,000 to 4 million people in Earth/Moon space. These people would be employed in building space solar satellites and more habitats for new settlers. Such a program, the NASA studies concluded, could reach financial break even in 38 years with peak Apollo level expenditures. It was suggested in a previous paper that human settlement of space could begin not by building city size structures but with a minimum technology habitat that could provide subsistence for a more minimal number of people and be capable of producing new habitats with extraterrestrial materials and energy. These habitats would be mostly independent from Earth. The approach could provide a quicker return on investment and lower start-up costs, and could be of a scale that could be developed and tested within the planned NASA transportation and lunar base architecture. This paper examines the population growth kinetics of humans in space, and the development of space solar power industry using small bolo shaped habitats in comparison to using larger habitat designs as considered in the 1970s.
NASA Technical Reports Server (NTRS)
2004-01-01
KENNEDY SPACE CENTER, FLA. -- Former astronaut Vance Brand is introduced as a previous inductee into the U.S. Astronaut Hall of Fame. He and other Hall of Fame members were present for the induction of five new space program heroes into the U.S. Astronaut Hall of Fame: Richard O. Covey, commander of the Hubble Space Telescope repair mission; Norman E. Thagard, the first American to occupy Russias Mir space station; the late Francis R. 'Dick' Scobee, commander of the ill-fated 1986 Challenger mission; Kathryn D. Sullivan, the first American woman to walk in space; and Frederick D. Gregory, the first African-American to command a space mission and the current NASA deputy administrator. Brand was Command Module Pilot on the 1975 Apollo- Soyuz Test Project, the first linkup in orbit between spaceships of the United States and Soviet Union, and he later commanded three Space Shuttle missions. The induction ceremony was held at the Apollo/Saturn V Center at KSC. The U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The five inductees join 52 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
Ng, Mee Kam; Tang, Wing Shing; Lee, Joanna; Leung, Darwin
2010-01-01
By applying the Lefebvrian lens, this paper tries to understand why unlike previous similar cases, the latest removal of the Star Ferry and Queen's Pier was so controversial. To Lefebvre, embedded in "spatial practices" that "secrete" a place are two contradicting spaces: "conceived spaces" produced by planners to create exchange values and "lived spaces" appropriated by citizens for use values. Applying Lefebvre's framework to examine the "Piers saga", it is found that the pre-Second World War (WWII) piers were "conceived" by spatial practices of a colonial and racially segregated trading enclave. The public space in the commercial heart that housed the previous generations of piers was not accessible to the Chinese community, thus denying them opportunities to appropriate them and turn them into "lived" spaces. It was only after WWII when the Government carried out further reclamation to meet the needs of an industrializing economy that inclusive public spaces were conceived in the commercial heart, enabling the general public to "appropriate" them as "lived" space. When the Government planned to remove this very first "lived" space in the political and economic heart of the city to conceive further reclamation for the restructuring economy, the more enlightened citizens were determined to defend it.
2004-05-01
KENNEDY SPACE CENTER, FLA. -- Former astronaut Dan Brandenstein acknowledges the applause as he is introduced as a previous inductee into the U.S. Astronaut Hall of Fame. He and other Hall of Fame members were present for the induction of five new space program heroes into the U.S. Astronaut Hall of Fame: Richard O. Covey, commander of the Hubble Space Telescope repair mission; Norman E. Thagard, the first American to occupy Russia’s Mir space station; the late Francis R. "Dick" Scobee, commander of the ill-fated 1986 Challenger mission; Kathryn D. Sullivan, the first American woman to walk in space; and Frederick D. Gregory, the first African-American to command a space mission and the current NASA deputy administrator. Brandenstein piloted one Space Shuttle mission and commanded three others, including the maiden flight of Endeavour, and later served as chief of the Astronaut Office. The induction ceremony was held at the Apollo/Saturn V Center at KSC. The U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The five inductees join 52 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
2004-05-01
KENNEDY SPACE CENTER, FLA. -- Former astronaut Vance Brand is introduced as a previous inductee into the U.S. Astronaut Hall of Fame. He and other Hall of Fame members were present for the induction of five new space program heroes into the U.S. Astronaut Hall of Fame: Richard O. Covey, commander of the Hubble Space Telescope repair mission; Norman E. Thagard, the first American to occupy Russia’s Mir space station; the late Francis R. "Dick" Scobee, commander of the ill-fated 1986 Challenger mission; Kathryn D. Sullivan, the first American woman to walk in space; and Frederick D. Gregory, the first African-American to command a space mission and the current NASA deputy administrator. Brand was Command Module Pilot on the 1975 Apollo-Soyuz Test Project, the first linkup in orbit between spaceships of the United States and Soviet Union, and he later commanded three Space Shuttle missions. The induction ceremony was held at the Apollo/Saturn V Center at KSC. The U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The five inductees join 52 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
2004-05-01
KENNEDY SPACE CENTER, FLA. -- Former astronaut Al Worden acknowledges the applause as he is introduced as a previous inductee into the U.S. Astronaut Hall of Fame. He and other Hall of Fame members were present for the induction of five new space program heroes into the U.S. Astronaut Hall of Fame: Richard O. Covey, commander of the Hubble Space Telescope repair mission; Norman E. Thagard, the first American to occupy Russia’s Mir space station; the late Francis R. "Dick" Scobee, commander of the ill-fated 1986 Challenger mission; Kathryn D. Sullivan, the first American woman to walk in space; and Frederick D. Gregory, the first African-American to command a space mission and the current NASA deputy administrator. Worden served as Command Module pilot on the 1971 Apollo 15 moon mission, during which he orbited the Moon and took a space walk 200,000 miles from Earth. The induction ceremony was held at the Apollo/Saturn V Center at KSC. The U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The five inductees join 52 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
2003-06-21
KENNEDY SPACE CENTER, FLA. - At the KSC Visitor Complex, former astronaut James Lovell makes the opening remarks at the induction ceremony of four Space Shuttle astronauts into the U.S. Astronaut Hall of Fame. Being inducted are Daniel Brandenstein, Robert "Hoot" Gibson, Story Musgrave, and Sally Ride. Conceived by six of the Mercury Program astronauts, the U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The four new inductees join 48 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
The role of small satellites in the development of the South African space programme
NASA Astrophysics Data System (ADS)
Martinez, Peter
In the 1990s a team of scientists and engineers at Stellenbosch University built the first South African satellite to fly in space, the 64-kg Sunsat. This university-based satellite programme took advantage of the skills and facilities developed in the previous South African space programme of the 1980s and early 1990s, which had developed a much larger satellite (Greensat), but was cancelled in the mid-1990s prior to launch. Sunsat incorporated a number of novel capabilities for a microsatellite platform, and interest was shown in these technologies by other groups developing similar satellites. As the University was not the ideal environment to develop the commercial potential of these microsatellite technologies, a company called Sunspace was later established, thus creating industrial capacity in South Africa in a niche area of space technology. This new industrial capability, together with the infrastructure from the previous space programme, have created a foundation upon which to build the new South African space programme. This paper discusses the historical, current and possible future roles of small satellites in the development of the South African space programme.
Hattori, Hiroshi; Akasaka, Kiyokazu; Otsudo, Takahiro; Takei, Keiichi; Yamamoto, Mitsuru
2017-04-01
Throwing athletes risk medial elbow injury from extreme valgus stress generated across the medial elbow during throwing. Braces have been developed to protect the elbow joint; however, no previous study has investigated the effects of elbow bracing on medial elbow joint space gapping associated with repetitive throwing. The purpose of this study was to investigate the effects of elbow bracing on medial elbow joint space gapping during repetitive throwing. Our hypothesis was that an elbow brace may reduce mechanical stress on the elbow by reducing medial elbow joint space gapping. Controlled laboratory study. Twenty-five high school baseball players participated in this study. Each subject pitched 100 times under 2 conditions: control (without elbow brace) and elbow brace. The ulnohumeral joint space was measured ultrasonically before pitching and after every block of 20 pitches. Measurement of the ulnohumeral joint space was carried out using ultrasound with the forearm hanging by the side. Two-way repeated-measures analysis of variance and post hoc tests were used to compare ulnohumeral joint space with repeated pitching and between the elbow brace and control conditions. In the control condition, ulnohumeral joint space after 60 pitches was significantly greater than that before pitching ( P < .01). In contrast, in the elbow brace condition, ulnohumeral joint space was not significantly different after repeated pitching. When comparing these 2 conditions, ulnohumeral joint space in the control condition was significantly greater than that in the elbow brace condition after 60 pitches ( P < .01). An elbow brace has the effect of preventing medial elbow joint space gapping with repeated throwing when determined ultrasonically by measuring the ulnohumeral joint space under gravity load. An elbow brace worn during baseball pitching practice may help reduce mechanical stress on the elbow by reducing medial elbow joint space gapping.
Advancement of the Wide-angle JEM-EUSO Optical System with Holographic and Fresnel Lenses
NASA Technical Reports Server (NTRS)
Takizawa, Y.; Adams, J.H.
2007-01-01
JEM-EUSO is a space mission to observe extremely high-energy cosmic rays, evolved from the previous design studies of EUSO. It is adjusted for the Japan Experiment Module (JEM) of the International Space Station (ISS). JEM-EUSO uses a wide-angle refractive telescope in near-ultraviolet wavelength region to observe from ISS the time-and-space-resolved atmospheric fluorescence images of the extensive air showers. The JEM-EUSO optics is re-designed after the ESA-Phase A studies to upgrade the light-collecting-power by using a new material CYTOP, and its overall light-collecting power is about 1.5 times higher than the ESA-Phase A baseline optics. We describe in this paper an optimized optics design that maximizes the sensitivity of JEM-EUSO, and the results of the optics manufacturing tests.
NASA Technical Reports Server (NTRS)
1986-01-01
The second task of a study with the overall objective of providing a conceptual definition of the Technology Development Mission Experiments proposed by LaRC on space station is discussed. During this task, the information (goals, objectives, and experiment functional description) assembled on a previous task was translated into the actual experiment definition. Although still of a preliminary nature, aspects such as: environment, sensors, data acquisition, communications, handling, control telemetry requirements, crew activities, etc., were addressed. Sketches, diagrams, block diagrams, and timeline analyses of crew activities are included where appropriate.
Temperature Effects of Ultraviolet Irradiation on Material Degradation
NASA Astrophysics Data System (ADS)
Mori, Kazuyuki; Ishizawa, Junichiro
Ultraviolet rays (UV) cause organic materials to deteriorate. UV irradiation ground testing is therefore important to understand the “adequate lifetime assessment” and the “end-of-life (EOL) characteristic” of materials used in space. In previous experiments, high temperatures were found to accelerate the UV degradation of cross-linked ethylene tetrafluoroethylene (X-ETFE). This causes concern of potentially similar effects in other materials. In this study, we evaluated UV degradation at high temperatures and subsequently determined materials usable in space that had shown accelerated degradation due to UV irradiation at high temperatures.
Advanced-technology space station study: Summary of systems and pacing technologies
NASA Technical Reports Server (NTRS)
Butterfield, A. J.; Garn, P. A.; King, C. B.; Queijo, M. J.
1990-01-01
The principal system features defined for the Advanced Technology Space Station are summarized and the 21 pacing technologies identified during the course of the study are described. The descriptions of system configurations were extracted from four previous study reports. The technological areas focus on those systems particular to all large spacecraft which generate artificial gravity by rotation. The summary includes a listing of the functions, crew requirements and electrical power demand that led to the studied configuration. The pacing technologies include the benefits of advanced materials, in-orbit assembly requirements, stationkeeping, evaluations of electrical power generation alternates, and life support systems. The descriptions of systems show the potential for synergies and identifies the beneficial interactions that can result from technological advances.
NASA GeneLab Project: Bridging Space Radiation Omics with Ground Studies
NASA Technical Reports Server (NTRS)
Beheshti, Afshin; Miller, Jack; Kidane, Yared H.; Berrios, Daniel; Gebre, Samrawit G.; Costes, Sylvain V.
2018-01-01
Accurate assessment of risk factors for long-term space missions is critical for human space exploration: therefore it is essential to have a detailed understanding of the biological effects on humans living and working in deep space. Ionizing radiation from Galactic Cosmic Rays (GCR) is one of the major risk factors factor that will impact health of astronauts on extended missions outside the protective effects of the Earth's magnetic field. Currently there are gaps in our knowledge of the health risks associated with chronic low dose, low dose rate ionizing radiation, specifically ions associated with high (H) atomic number (Z) and energy (E). The GeneLab project (genelab.nasa.gov) aims to provide a detailed library of Omics datasets associated with biological samples exposed to HZE. The GeneLab Data System (GLDS) currently includes datasets from both spaceflight and ground-based studies, a majority of which involve exposure to ionizing radiation. In addition to detailed information for ground-based studies, we are in the process of adding detailed, curated dosimetry information for spaceflight missions. GeneLab is the first comprehensive Omics database for space related research from which an investigator can generate hypotheses to direct future experiments utilizing both ground and space biological radiation data. In addition to previously acquired data, the GLDS is continually expanding as Omics related data are generated by the space life sciences community. Here we provide a brief summary of space radiation related data available at GeneLab.
Overview of the Center for Space Construction
NASA Technical Reports Server (NTRS)
Hearth, Donald P.
1990-01-01
The purpose of this overview is to summarize the objectives and structure of the Center. The center is a major element of the University's initiative to upgrade space-related research and education on the Boulder campus. With the support of NASA's University Space Engineering Research Centers Program, we provide a mechanism for interdisciplinary and system-level space engineering research and training. Twenty faculty members and 56 students from seven academic units are associated with the Center and are interacting with each other and with the CSC Associates. As a result of feedback from the 1989 symposium, we have focused the efforts of the Center during the past several months on Lunar Base construction. This included a system level study of a Lunar Base in an Independent Study Project by a group of students from across the Center during the spring semester. This project is being continued this fall. During the two-year history of the Center, 13 students previously affiliated with the Center have graduated and there have been 55 publications from the Center.
NASA Technical Reports Server (NTRS)
Papadopoulos, Michael; Tolson, Robert H.
1993-01-01
The Modal Identification Experiment (MIE) is a proposed experiment to define the dynamic characteristics of Space Station Freedom. Previous studies emphasized free-decay modal identification. The feasibility of using a forced response method (Observer/Kalman Filter Identification (OKID)) is addressed. The interest in using OKID is to determine the input mode shape matrix which can be used for controller design or control-structure interaction analysis, and investigate if forced response methods may aid in separating closely spaced modes. A model of the SC-7 configuration of Space Station Freedom was excited using simulated control system thrusters to obtain acceleration output. It is shown that an 'optimum' number of outputs exists for OKID. To recover global mode shapes, a modified method called Global-Local OKID was developed. This study shows that using data from a long forced response followed by free-decay leads to the 'best' modal identification. Twelve out of the thirteen target modes were identified for such an output.
Space environment and lunar surface processes
NASA Technical Reports Server (NTRS)
Comstock, G. M.
1979-01-01
The development of a general rock/soil model capable of simulating in a self consistent manner the mechanical and exposure history of an assemblage of solid and loose material from submicron to planetary size scales, applicable to lunar and other space exposed planetary surfaces is discussed. The model was incorporated into a computer code called MESS.2 (model for the evolution of space exposed surfaces). MESS.2, which represents a considerable increase in sophistication and scope over previous soil and rock surface models, is described. The capabilities of previous models for near surface soil and rock surfaces are compared with the rock/soil model, MESS.2.
14 CFR 47.37 - Aircraft last previously registered in a foreign country.
Code of Federal Regulations, 2013 CFR
2013-01-01
... TRANSPORTATION AIRCRAFT AIRCRAFT REGISTRATION Certificates of Aircraft Registration § 47.37 Aircraft last previously registered in a foreign country. (a) A person who is the owner of an aircraft last previously... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Aircraft last previously registered in a...
14 CFR 47.37 - Aircraft last previously registered in a foreign country.
Code of Federal Regulations, 2014 CFR
2014-01-01
... TRANSPORTATION AIRCRAFT AIRCRAFT REGISTRATION Certificates of Aircraft Registration § 47.37 Aircraft last previously registered in a foreign country. (a) A person who is the owner of an aircraft last previously... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Aircraft last previously registered in a...
Abstract Background: Greater exposure to urban green spaces has been linked to reduced risks of depression, cardiovascular disease, diabetes and premature death. Alleviation of chronic stress is a hypothesized pathway to improved health. Previous studies linked chronic stress wit...
Back to the future: the role of the ISS and future space stations in planetary exploration.
NASA Astrophysics Data System (ADS)
Muller, Christian; Moreau, Didier
2010-05-01
Space stations as stepping stones to planets appear already in the1954 Disney-von Braun anticipation TV show but the first study with a specific planetary scientific objective was the ANTEUS project of 1978. This station was an evolution of SPACELAB hardware and was designed to analyse Mars samples with better equipment than the laboratory of the VIKING landers. It would have played the role of the reception facility present in the current studies of Mars sample return, after analysis, the "safe" samples would have been returned to earth by the space shuttle. This study was followed by the flights of SPACELAB and MIR. Finally after 35 years of development, the International Space Station reaches its final configuration in 2010. Recent developments of the international agreement between the space agencies indicate a life extending to 2025, it is already part of the exploration programme as its crews prepare the long cruise flights and missions to the exploration targets. It is now time to envisage also the use of this stable 350 tons spacecraft for planetary and space sciences. Planetary telescopes are an obvious application; the present SOLAR payload on COLUMBUS is an opportunity to use the target pointing capabilities from the ISS. The current exposure facilities are also preparing future planetary protection procedures. Other applications have already been previously considered as experimental collision and impact studies in both space vacuum and microgravity. Future space stations at the Lagrange points could simultaneously combine unique observation platforms with an actual intermediate stepping stone to Mars.
2004-02-13
KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, workers confirm the Multi-Purpose Logistics Module Donatello is safely in place on a work stand. Previously housed in the Operations and Checkout Building, Donatello was brought into the SSPF for routine testing. This is the first time all three MPLMs (Donatello, Raffaello and Leonardo) are in the SSPF. The MPLMs were built by the Italian Space Agency, to serve as reusable logistics carriers and the primary delivery system to resupply and return station cargo requiring a pressurized environment. The third MPLM, Raffaello, is scheduled to fly on Space Shuttle Atlantis on mission STS-114.
2004-02-13
KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, the Multi-Purpose Logistics Module Donatello is slowly lowered toward a work stand. Previously housed in the Operations and Checkout Building, Donatello was brought into the SSPF for routine testing. This is the first time all three MPLMs (Donatello, Raffaello and Leonardo) are in the SSPF. The MPLMs were built by the Italian Space Agency, to serve as reusable logistics carriers and the primary delivery system to resupply and return station cargo requiring a pressurized environment. The third MPLM, Raffaello is scheduled to fly on Space Shuttle Atlantis on mission STS-114.
2004-02-13
KENNEDY SPACE CENTER, FLA. - The Multi-Purpose Logistics Module Donatello is moved away from the payload canister in the Space Station Processing Facility. Previously housed in the Operations and Checkout Building, Donatello was brought into the SSPF for routine testing. This is the first time all three MPLMs (Donatello, Raffaello and Leonardo) are in the SSPF. The MPLMs were built by the Italian Space Agency, to serve as reusable logistics carriers and the primary delivery system to resupply and return station cargo requiring a pressurized environment. The third MPLM, Raffaello is scheduled to fly on Space Shuttle Atlantis on mission STS-114.
2004-02-13
KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, workers help the Multi-Purpose Logistics Module Donatello settle onto a work stand. Previously housed in the Operations and Checkout Building, Donatello was brought into the SSPF for routine testing. This is the first time all three MPLMs (Donatello, Raffaello and Leonardo) are in the SSPF. The MPLMs were built by the Italian Space Agency, to serve as reusable logistics carriers and the primary delivery system to resupply and return station cargo requiring a pressurized environment. The third MPLM, Raffaello, is scheduled to fly on Space Shuttle Atlantis on mission STS-114.
2004-02-13
KENNEDY SPACE CENTER, FLA. - The Multi-Purpose Logistics Module Donatello is suspended by cables over the payload canister in the Space Station Processing Facility. Previously housed in the Operations and Checkout Building, Donatello was brought into the SSPF for routine testing. This is the first time all three MPLMs (Donatello, Raffaello and Leonardo) are in the SSPF. The MPLMs were built by the Italian Space Agency, to serve as reusable logistics carriers and the primary delivery system to resupply and return station cargo requiring a pressurized environment. The third MPLM, Raffaello is scheduled to fly on Space Shuttle Atlantis on mission STS-114.
NASA Astrophysics Data System (ADS)
Vidanović, Ivana; Bogojević, Aleksandar; Balaž, Antun; Belić, Aleksandar
2009-12-01
In this paper, building on a previous analysis [I. Vidanović, A. Bogojević, and A. Belić, preceding paper, Phys. Rev. E 80, 066705 (2009)] of exact diagonalization of the space-discretized evolution operator for the study of properties of nonrelativistic quantum systems, we present a substantial improvement to this method. We apply recently introduced effective action approach for obtaining short-time expansion of the propagator up to very high orders to calculate matrix elements of space-discretized evolution operator. This improves by many orders of magnitude previously used approximations for discretized matrix elements and allows us to numerically obtain large numbers of accurate energy eigenvalues and eigenstates using numerical diagonalization. We illustrate this approach on several one- and two-dimensional models. The quality of numerically calculated higher-order eigenstates is assessed by comparison with semiclassical cumulative density of states.
Wide Field and Planetary Camera for Space Telescope
NASA Technical Reports Server (NTRS)
Lockhart, R. F.
1982-01-01
The Space Telescope's Wide Field and Planetary Camera instrument, presently under construction, will be used to map the observable universe and to study the outer planets. It will be able to see 1000 times farther than any previously employed instrument. The Wide Field system will be located in a radial bay, receiving its signals via a pick-off mirror centered on the optical axis of the telescope assembly. The external thermal radiator employed by the instrument for cooling will be part of the exterior surface of the Space Telescope. In addition to having a larger (1200-12,000 A) wavelength range than any of the other Space Telescope instruments, its data rate, at 1 Mb/sec, exceeds that of the other instruments. Attention is given to the operating modes and projected performance levels of the Wide Field Camera and Planetary Camera.
1999-08-01
Designed by the crew members, the STS-103 emblem depicts the Space Shuttle Discovery approaching the Hubble Space Telescope (HST) prior to its capture and berthing. The purpose of the mission was to remove and replace some of the Telescope's older and out-of-date systems with newer, more reliable and more capable ones, and to make repairs to HST's exterior thermal insulation that had been damaged by more than nine years of exposure to the space environment. The horizontal and vertical lines centered on the Telescope symbolize the ability to reach and maintain a desired attitude in space, essential to the instrument's scientific operation. The preservation of this ability was one of the primary objectives of the mission. After the flight, the Telescope resumed its successful exploration of deep space and will continue to be used to study solar system objects, stars in the making, late phases of stellar evolution, galaxies and the early history of the universe. HST, as represented on this emblem was inspired by views from previous servicing missions, with its solar arrays illuminated by the Sun, providing a striking contrast with the blackness of space and the night side of Earth.
Levelling the Reading Gap: A Socio-spatial Study of School Libraries and Reading in Singapore
ERIC Educational Resources Information Center
Loh, Chin Ee
2016-01-01
This article takes a comparative socio-spatial approach at the intersection of social class and reading politics to provide a fresh way of examining school reading policies and practices, unearthing previously hidden spaces of inequity for reading intervention. The juxtaposition of two nested case studies in Singapore, one of an elite all-boys'…
NASA Astrophysics Data System (ADS)
Tchvialeva, Lioudmila; Lee, Tim K.; Markhvida, Igor; Zeng, Haishan; Doronin, Alexander; Meglinski, Igor
2014-03-01
The incidence of the skin melanoma, the most commonly fatal form of skin cancer, is increasing faster than any other potentially preventable cancer. Clinical practice is currently hampered by the lack of the ability to rapidly screen the functional and morphological properties of tissues. In our previous study we show that the quantification of scattered laser light polarization provides a useful metrics for diagnostics of the malignant melanoma. In this study we exploit whether the image speckle could improve skin cancer diagnostic in comparison with the previously used free-space speckle. The study includes skin phantom measurements and computer modeling. To characterize the depolarization of light we measure the spatial distribution of speckle patterns and analyse their depolarization ratio taken into account radial symmetry. We examine the dependences of depolarization ratio vs. roughness for phantoms which optical properties are of the order of skin lesions. We demonstrate that the variation in bulk optical properties initiates the assessable changes in the depolarization ratio. We show that image speckle differentiates phantoms significantly better than free-space speckle. The results of experimental measurements are compared with the results of Monte Carlo simulation.
NASA Astrophysics Data System (ADS)
Hozumi, Y.; Saito, A.; Sakanoi, T.; Yamazaki, A.; Hosokawa, K.
2017-12-01
Mesospheric bores were observed by Visible and near Infrared Spectral Imager (VISI) of the ISS-IMAP mission (Ionosphere, Mesosphere, upper Atmosphere and Plasmasphere mapping mission from the International Space Station) in O2 airglow at 762 nm wavelength. The mesospheric bore is moving front of sharp jump followed by undulations or turbulence in the mesopause region. Since previous studies of mesospheric bore were mainly based on ground-based airglow imaging that is limited in field-of-view and observing site, little is known about its horizontal extent and global behavior. Space-borne imaging by ISS-IMAP/VISI provides an opportunity to study the mesospheric bore with a wide field-of-view and global coverage. A mesospheric bore was captured by VISI in two consecutive paths on 9 July 2015 over the south of African continent (48ºS - 54ºS and 15ºE). The wave front aligned with south-north direction and propagated to west. The phase velocity and wave length of the following undulation were estimated to 100 m/s and 30 km, respectively. Those parameters are similar to those reported by previous studies. 30º anti-clockwise rotation of the wave front was recognized in 100 min. Another mesospheric bore was captured on 9 May 2013 over the south Atlantic ocean (35ºS - 43ºS and 24ºW - 1ºE) with more than 2,200 km horizontal extent of wave front. The wave front aligned with southeast-northwest direction. Because the following undulation is recognized in the southwest side of the wave front, it is estimated to propagate to northeast direction. The wave front was modulated with 1,000 km wave length. This modulation implies inhomogeneity of the phase velocity.
Wu, Jian Sheng; Si, Meng Lin; Li, Wei Feng
2016-09-01
Urban green space is an important ecological landscape, whose spatial distribution plays a significant role in improving the eco-environment and people's living quality. This study was initia-ted from the perspective of supply and demand balance to evaluate the equity of distribution of urban parks, drawing on previous research, and introduced an integrated framework for evaluating the equity of urban public facilities using spatial multi-analysis. A method concerning gravity model to assess the equity of urban green space was introduced, taking the effect of boundary into account. The case study area was the Futian District of Shenzhen and its 2000 m buffer area. Then, some optimizations were suggested for better allocation of the green space. The results showed that the equity of Futian District was low. The equity of community parks was lowest, followed by that of regional parks, while the countryside ecological parks owned the highest equity. About 50% of the Futian district area was in a state of balance between supply and demand and the rest were in a state of insufficient supply. Greening rate and space allocation of parks and road traffic systems should be improved to better plan the green space in Futian District. For urban green space planning, the parks of small area should be paid more attention to meet the needs of residents for daily recreation. By taking the effect of boundary into account, we observed that the residential area on the edge of the study area could enjoy the park green space, and the green space in the boundary area outside the region would be also shared by residents on both sides of the administrative boundary.
Fiber-Optic Sensing for In-Space Inspection
NASA Technical Reports Server (NTRS)
Pena, Francisco; Richards, W. Lance; Piazza, Anthony; Parker, Allen R.; Hudson, Larry D.
2014-01-01
This presentation provides examples of fiber optic sensing technology development activities performed at NASA Armstrong. Examples of current and previous work that support in-space inspection techniques and methodologies are highlighted.
Vice President Mike Pence Visits Kennedy Space Center - Tour of
2018-02-21
Vice President Mike Pence, pointing, tours the SpaceX hangar at Launch Complex 39A, at NASA's Kennedy Space Center in Florida, on Feb. 21, 2018. The group is getting a close-up look at a previously flown Falcon 9 rocket. During his visit, Pence chaired a meeting of the National Space Council in the high bay of the center's Space Station Processing Facility. The council's role is to advise the president regarding national space policy and strategy, and review the nation's long-range goals for space activities.
Vice President Mike Pence Visits Kennedy Space Center - Tour of
2018-02-21
Vice President Mike Pence tours the SpaceX hangar at Launch Complex 39A, at NASA's Kennedy Space Center in Florida, on Feb. 21, 2018. The group is getting a close-up look at a previously flown Falcon 9 rocket. During his visit, Pence chaired a meeting of the National Space Council in the high bay of the center's Space Station Processing Facility. The council's role is to advise the president regarding national space policy and strategy, and review the nation's long-range goals for space activities.
NASA Technical Reports Server (NTRS)
Leonard, Daniel; Parsons, Jeremy W.; Cates, Grant
2014-01-01
In May 2013, NASA's GSDO Program requested a study to develop a discrete event simulation (DES) model that analyzes the launch campaign process of the Space Launch System (SLS) from an integrated commodities perspective. The scope of the study includes launch countdown and scrub turnaround and focuses on four core launch commodities: hydrogen, oxygen, nitrogen, and helium. Previously, the commodities were only analyzed individually and deterministically for their launch support capability, but this study was the first to integrate them to examine the impact of their interactions on a launch campaign as well as the effects of process variability on commodity availability. The study produced a validated DES model with Rockwell Arena that showed that Kennedy Space Center's ground systems were capable of supporting a 48-hour scrub turnaround for the SLS. The model will be maintained and updated to provide commodity consumption analysis of future ground system and SLS configurations.
Microbiological analysis of debris from Space Transportation System (STS)-55 Spacelab D-2
NASA Technical Reports Server (NTRS)
Huff, T. L.
1994-01-01
Filter debris from the Spacelab module D-2 of STS-55 was analyzed for microbial contamination. Debris from cabin and avionics filters was collected by Kennedy Space Center personnel on May 8, 1993, 2 days postflight. Debris weights were similar to those of previous Spacelab missions. Approximately 5.1E+5 colony forming units per gram of debris were enumerated from the cabin and avionics filter debris, respectively. these numbers were similar in previous missions for which the entire contents were analyzed without sorting of the material. Bacterial diversity was small compared to previous missions, with no gram negative bacteria isolated. Only one bacterial species, Corynebacterium pseudodiphtheriticum, was not isolated previously by the laboratory from Spacelab debris. This organism is a normal inhabitant of the pharynx. A table listing all species of bacteria isolated by the laboratory from previous Spacelab air filters debris collection is provided.
Implications of previous space commercialization experiences for the reusable launch vehicle
NASA Astrophysics Data System (ADS)
Obermann, Richard M.; Williamson, Ray A.
2003-07-01
The United States' 1994 National Space Transportation Policy directed the National Aeronautics and Space Administration (NASA) to work with industry on the development of technologies required for a reusable launch vehicle (RLV). In the partnership that has evolved from that directive, NASA envisions its role as providing support for technological risk reduction and for developing space transportation to serve government needs. NASA officials assume that the development of an operational, commercial RLV will be carried out by the private sector without use of government funds. Under that scenario, the Federal government will simply become a customer for commercial RLV services. In evaluating the prospects for the development of a commercially viable RLV, it may be useful to examine "lessons learned" from previous space commercialization efforts—both those that succeeded and those that did not. It can be argued that several distinct streams of market and technological development may have to converge for successful commercialization of space systems to occur. Potential factors influencing the prospects for commercialization include the size and growth rate of the potential customer base, the extent to which a governmental customer exists to underpin the market, the development of associated "value-added" markets, the stability of governmental policies, the levels of technological and business risk, and the degree to which competitive markets exist. This paper examines two previous space commercialization experiences, evaluates the relative importance of the various factors that influence the prospects for success of commercialization efforts, and assesses the implications of those factors for the commercial viability of the proposed RLV.
Bentz, Erika N; Pomilio, Alicia B; Lobayan, Rosana M
2014-12-01
The extension of the study of the conformational space of the structure of (+)-catechin at the B3LYP/6-31G(d,p) level of theory is presented in this paper. (+)-Catechin belongs to the family of the flavan-3-ols, which is one of the five largest phenolic groups widely distributed in nature, and whose biological activity and pharmaceutical utility are related to the antioxidant activity due to their ability to scavenge free radicals. The effects of free rotation around all C-O bonds of the OH substituents at different rings are taken into account, obtaining as the most stable conformer, one that had not been previously reported. One hundred seven structures, and a study of the effects of charge delocalization and stereoelectronic effects at the B3LYP/6-311++G(d,p) level are reported by natural bond orbital analysis, streamlining the order of these structures. For further analysis of the structural and molecular properties of this compound in a biological environment, the calculation of polarizabilities, and the study of the electric dipole moment are performed considering the whole conformational space described. The results are analyzed in terms of accumulated knowledge for (4α → 6″, 2α → O → 1″)-phenylflavans and (+)-catechin in previous works, enriching the study of both types of structures, and taking into account the importance of considering the whole conformational space in modeling both the polarizability and the electric dipole moment, also proposing to define a descriptive subspace of only 16 conformers.
Just how hot are the ω Centauri extreme horizontal branch pulsators?
NASA Astrophysics Data System (ADS)
Latour, M.; Randall, S. K.; Chayer, P.; Fontaine, G.; Calamida, A.; Ely, J.; Brown, T. M.; Landsman, W.
2017-04-01
Context. Past studies based on optical spectroscopy suggest that the five ω Cen pulsators form a rather homogeneous group of hydrogen-rich subdwarf O stars with effective temperatures of around 50 000 K. This places the stars below the red edge of the theoretical instability strip in the log g-Teff diagram, where no pulsation modes are predicted to be excited. Aims: Our goal is to determine whether this temperature discrepancy is real, or whether the stars' effective temperatures were simply underestimated. Methods: We present a spectral analysis of two rapidly pulsating extreme horizontal branch (EHB) stars found in ω Cen. We obtained Hubble Space Telescope/COS UV spectra of two ω Cen pulsators, V1 and V5, and used the ionisation equilibrium of UV metallic lines to better constrain their effective temperatures. As a by-product we also obtained FUV lightcurves of the two pulsators. Results: Using the relative strength of the N iv and N v lines as a temperature indicator yields Teff values close to 60 000 K, significantly hotter than the temperatures previously derived. From the FUV light curves we were able to confirm the main pulsation periods known from optical data. Conclusions: With the UV spectra indicating higher effective temperatures than previously assumed, the sdO stars would now be found within the predicted instability strip. Such higher temperatures also provide consistent spectroscopic masses for both the cool and hot EHB stars of our previously studied sample. Based on observations (proposal GO-13707) with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26666.
Reading Speed Does Not Benefit from Increased Line Spacing in AMD Patients
CHUNG, SUSANA T. L.; JARVIS, SAMUEL H.; WOO, STANLEY Y.; HANSON, KARA; JOSE, RANDALL T.
2009-01-01
Purpose Crowding, the adverse spatial interaction due to the proximity of adjacent targets, has been suggested as an explanation for slow reading in peripheral vision. Previously, we showed that increased line spacing, which presumably reduces crowding between adjacent lines of text, improved reading speed in the normal periphery (Chung, Optom Vis Sci 2004;81:525–35). The purpose of this study was to examine whether or not individuals with age-related macular degeneration (AMD) would benefit from increased line spacing for reading. Methods Experiment 1: Eight subjects with AMD read aloud 100-word passages rendered at five line spacings: the standard single spacing, 1.5×, 2×, 3×, and 4× the standard spacing. Print sizes were 1× and 2× of the critical print size. Reading time and number of reading errors for each passage were measured to compute the reading speed. Experiment 2: Four subjects with AMD read aloud sequences of six 4-letter words, presented on a computer monitor using the rapid serial visual presentation (RSVP) paradigm. Target words were presented singly, or flanked above and below by two other words that changed in synchrony with the target word, at various vertical word separations. Print size was 2× the critical print size. Reading speed was calculated based on the RSVP exposure duration that yielded 80% of the words read correctly. Results Averaged across subjects, reading speeds for passages were virtually constant for the range of line spacings tested. For sequences of unrelated words, reading speeds were also virtually constant for the range of vertical word separations tested, except at the smallest (standard) separation at which reading speed was lower. Conclusions Contrary to the previous finding that reading speed improved in normal peripheral vision, increased line spacing in passages, or increased vertical separation between words in RSVP, did not lead to improved reading speed in people with AMD. PMID:18772718
Results of the First US Manned Orbital Space Flight
NASA Technical Reports Server (NTRS)
1962-01-01
The results of the first United States manned orbital space flight conducted on February 20, 1962 are presented. The prelaunch activities, spacecraft description, flight operations, flight data, and postflight analyses presented form a continuation of the information previously published for the two United States manned suborbital space flights conducted on May 5, 1961, and July 21, 1961, respectively, by the National Aeronautics and Space Administration.
2016-05-01
is very likely that they may develop a solution for planetary defense. 8 United States is leading in space private investments. SpaceX , for...technology, with the ultimate goal of enabling people to live on other planets.5 SpaceX is the only private company ever to return a spacecraft from low...a technically challenging feat previously accomplished only by governments.6 Contracted by NASA and commercial companies, SpaceX already did 50
Magnetic Resonance Characterization of Axonal Response to Spinal Cord Injury
2011-10-01
Outcomes 6 Conclusions 6 References 6-29 Appendices Introduction During the first year we pursued studies of Magnetic Resonance q-space imaging...QSI) of the spinal cord and myelin imaging. The QSI studies extended our previous work establishing our ability to define the distribution of axon...Conventional MR imaging of the central nervous systems studies water protons exclusively. Although other compounds, such a lipid and proteins, have
jsc2018m000314_Spinning_Science_Multi-use_Variable-g_Platform_Arrives_at_the_Space_Station-MP4
2018-05-09
Spinning Science: Multi-use Variable-g Platform Arrives at the Space Station --- The Multi-use Variable-gravity Platform (MVP) Validation mission will install and test the MVP, a new hardware platform developed and owned by Techshot Inc., on the International Space Station (ISS). Though the MVP is designed for research with many different kinds of organisms and cell types, this validation mission will focus on Drosophila melanogaster, more commonly known as the fruit fly. This platform will be especially important for fruit fly research, as it will allow researchers to study larger sample sizes of Drosophila melanogaster than in other previous hardware utilizing centrifuges and it will be able to support fly colonies for multiple generations.
Low-g fluid mixing - Further results from the Tank Pressure Control Experiment
NASA Technical Reports Server (NTRS)
Bentz, M. D.; Knoll, R. H.; Hasan, M. M.; Lin, C. S.
1993-01-01
The Tank Pressure Control Experiment (TPCE) made its first space flight on STS-43 in 1991. Its objective was to test the effectiveness of low-energy axial jet mixing at controlling pressures in low gravity. The experiment used refrigerant 113 at near-saturation conditions, at an 83 percent fill level, to simulate the fluid dynamics and thermodynamics of cryogenic fluids in future space applications. Results from this flight were reported previously. TPCE was again flown in space on STS-52 in 1992, this time primarily to study boiling and related thermal phenomena which will be reported elsewhere. However additional mixing and pressure control data were obtained from the reflight that supplement the data from the first flight.
2003-06-20
KENNEDY SPACE CENTER, FLA. - Former astronaut James Lovell addresses the audience at a ribbon cutting ceremony officially opening the U.S. Astronaut Hall of Fame as part of the Kennedy Space Center Visitor Complex. The ceremony was held in conjunction with the induction of four Space Shuttle astronauts into the Hall of Fame including Daniel Brandenstein, Robert "Hoot" Gibson, Story Musgrave, and Sally Ride. Conceived by six of the Mercury Program astronauts, the U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The four new inductees join 48 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
NASA Astrophysics Data System (ADS)
Ciufolini, Ignazio; Pavlis, Erricos C.; Sindoni, Giampiero; Ries, John C.; Paolozzi, Antonio; Matzner, Richard; Koenig, Rolf; Paris, Claudio
2017-08-01
In the previous paper we have introduced the LARES 2 space experiment. The LARES 2 laser-ranged satellite is planned for a launch in 2019 with the new VEGA C launch vehicle of the Italian Space Agency (ASI), ESA and ELV. The main objectives of the LARES 2 experiment are accurate measurements of General Relativity, gravitational and fundamental physics and accurate determinations in space geodesy and geodynamics. In particular LARES 2 is aimed to achieve a very accurate test of frame-dragging, an intriguing phenomenon predicted by General Relativity. Here we report the results of Monte Carlo simulations and covariance analyses fully confirming an error budget of a few parts in one thousand in the measurement of frame-dragging with LARES 2 as calculated in our previous paper.
Mazars, Christian; Brière, Christian; Grat, Sabine; Pichereaux, Carole; Rossignol, Michel; Pereda-Loth, Veronica; Eche, Brigitte; Boucheron-Dubuisson, Elodie; Le Disquet, Isabel; Medina, Francisco-Javier; Graziana, Annick; Carnero-Diaz, Eugénie
2014-01-01
Growing plants in space for using them in bioregenerative life support systems during long-term human spaceflights needs improvement of our knowledge in how plants can adapt to space growth conditions. In a previous study performed on board the International Space Station (GENARA A experiment STS-132) we evaluate the global changes that microgravity can exert on the membrane proteome of Arabidopsis seedlings. Here we report additional data from this space experiment, taking advantage of the availability in the EMCS of a centrifuge to evaluate the effects of cues other than microgravity on the relative distribution of membrane proteins. Among the 1484 membrane proteins quantified, 227 proteins displayed no abundance differences between µ g and 1 g in space, while their abundances significantly differed between 1 g in space and 1 g on ground. A majority of these proteins (176) were over-represented in space samples and mainly belong to families corresponding to protein synthesis, degradation, transport, lipid metabolism, or ribosomal proteins. In the remaining set of 51 proteins that were under-represented in membranes, aquaporins and chloroplastic proteins are majority. These sets of proteins clearly appear as indicators of plant physiological processes affected in space by stressful factors others than microgravity.
Mazars, Christian; Brière, Christian; Grat, Sabine; Pichereaux, Carole; Rossignol, Michel; Pereda-Loth, Veronica; Eche, Brigitte; Boucheron-Dubuisson, Elodie; Le Disquet, Isabel; Medina, Francisco-Javier; Graziana, Annick; Carnero-Diaz, Eugénie
2014-07-16
Growing plants in space for using them in bioregenerative life support systems during long-term human spaceflights needs improvement of our knowledge in how plants can adapt to space growth conditions. In a previous study performed on board the International Space Station (GENARA A experiment STS-132) we evaluate the global changes that microgravity can exert on the membrane proteome of Arabidopsis seedlings. Here we report additional data from this space experiment, taking advantage of the availability in the EMCS of a centrifuge to evaluate the effects of cues other than microgravity on the relative distribution of membrane proteins. Among the 1484 membrane proteins quantified, 227 proteins displayed no abundance differences between µ g and 1 g in space, while their abundances significantly differed between 1 g in space and 1 g on ground. A majority of these proteins (176) were over-represented in space samples and mainly belong to families corresponding to protein synthesis, degradation, transport, lipid metabolism, or ribosomal proteins. In the remaining set of 51 proteins that were under-represented in membranes, aquaporins and chloroplastic proteins are majority. These sets of proteins clearly appear as indicators of plant physiological processes affected in space by stressful factors others than microgravity.
Oversampling the Minority Class in the Feature Space.
Perez-Ortiz, Maria; Gutierrez, Pedro Antonio; Tino, Peter; Hervas-Martinez, Cesar
2016-09-01
The imbalanced nature of some real-world data is one of the current challenges for machine learning researchers. One common approach oversamples the minority class through convex combination of its patterns. We explore the general idea of synthetic oversampling in the feature space induced by a kernel function (as opposed to input space). If the kernel function matches the underlying problem, the classes will be linearly separable and synthetically generated patterns will lie on the minority class region. Since the feature space is not directly accessible, we use the empirical feature space (EFS) (a Euclidean space isomorphic to the feature space) for oversampling purposes. The proposed method is framed in the context of support vector machines, where the imbalanced data sets can pose a serious hindrance. The idea is investigated in three scenarios: 1) oversampling in the full and reduced-rank EFSs; 2) a kernel learning technique maximizing the data class separation to study the influence of the feature space structure (implicitly defined by the kernel function); and 3) a unified framework for preferential oversampling that spans some of the previous approaches in the literature. We support our investigation with extensive experiments over 50 imbalanced data sets.
Global Survey on Future Trends in Human Spaceflight: the Implications for Space Tourism
NASA Astrophysics Data System (ADS)
Gurtuna, O.; Garneau, S.
2002-01-01
With the much-publicized first ever space tourist flight, of Dennis Tito, and the announcement of the second space tourist flight to take place in April 2002, it is clear that an alternative motivation for human spaceflight has emerged. Human spaceflight is no longer only about meeting the priorities of national governments and space agencies, but is also about the tangible possibility of ordinary people seeing the Earth from a previously exclusive vantage point. It is imperative that major space players look beyond the existing human spaceflight rationale to identify some of the major driving forces behind space tourism, including the evolving market potential and developments in enabling technologies. In order to determine the influence of these forces on the future of commercial human spaceflight, the responses of a Futuraspace survey on future trends in human spaceflight are analyzed and presented. The motivation of this study is to identify sought-after space destinations, explore the expected trends in enabling technologies, and understand the future role of emerging space players. The survey will reflect the opinions of respondents from around the world including North America, Europe (including Russia) and Asia. The profiles of targeted respondents from space industry, government and academia are high-level executives/managers, senior researchers, as well as former and current astronauts. The survey instrument is a questionnaire which is validated by a pilot study. The sampling method is non-probabilistic, targeting as many space experts as possible who fit our intended respondent profile. Descriptive and comparative statistical analysis methods are implemented to investigate both global and regional perceptions of future commercial trends in human spaceflight. This study is not intended to be a formal market study of the potential viability of the space tourism market. Instead, the focus is on the future trends of human spaceflight, by drawing on the knowledge and vision of a pool of space experts from many countries, representing the multidisciplinary and international nature of human spaceflight. A comprehensive look into the future can be achieved which surpasses our individual perceptions of future trends and which will complement existing and future space tourism market studies.
Djernaes, Julie D; Nielsen, Jon V; Berg, Lise C
2017-03-01
The widths of spaces between the thoracolumbar processi spinosi (interspinous spaces) are frequently assessed using radiography in sports horses; however effects of varying X-ray beam angles and geometric distortion have not been previously described. The aim of this prospective, observational study was to determine whether X-ray beam angle has an effect on apparent widths of interspinous spaces. Thoracolumbar spine specimens were collected from six equine cadavers and left-right lateral radiographs and sagittal and dorsal reconstructed computed tomographic (CT) images were acquired. Sequential radiographs were acquired with each interspinous space in focus. Measurements were performed for each interspinous space in the focus position and up to eight angled positions as the interspinous space moved away from focus (±). Focus position measurements were compared to matching sagittal CT measurements. Effect of geometric distortion was evaluated by comparing the interspinous space in radiographs with sagittal and dorsal reconstructed CT images. A total of 49 interspinous spaces were sampled, yielding 274 measurements. X-ray beam angle significantly affected measured width of interspinous spaces in position +3 (P = 0.038). Changes in width did not follow a consistent pattern. Interspinous space widths in focus position were significantly smaller in radiographs compared to matching reconstructed CT images for backs diagnosed with kissing spine syndrome (P < 0.001). Geometric distortion markedly affected appearance of interspinous space width between planes. In conclusion, X-ray beam angle and geometric distortion influence radiographically measured widths of interspinous spaces in the equine thoracolumbar spine, and this should be taken into consideration when evaluating sport horses. © 2016 American College of Veterinary Radiology.
Spaceflight and ageing: reflecting on Caenorhabditis elegans in space.
Honda, Yoko; Honda, Shuji; Narici, Marco; Szewczyk, Nathaniel J
2014-01-01
The prospect of space travel continues to capture the imagination. Several competing companies are now promising flights for the general population. Previously, it was recognized that many of the physiological changes that occur with spaceflight are similar to those seen with normal ageing. This led to the notion that spaceflight can be used as a model of accelerated ageing and raised concerns about the safety of individuals engaging in space travel. Paradoxically, however, space travel has been recently shown to be beneficial to some aspects of muscle health in the tiny worm Caenorhabditis elegans. C. elegans is a commonly used laboratory animal for studying ageing. C. elegans displays age-related decline of some biological processes observed in ageing humans, and about 35% of C. elegans' genes have human homologs. Space flown worms were found to have decreased expression of a number of genes that increase lifespan when expressed at lower levels. These changes were accompanied by decreased accumulation of toxic protein aggregates in ageing worms' muscles. Thus, in addition to spaceflight producing physiological changes that are similar to accelerated ageing, it also appears to produce some changes similar to delayed ageing. Here, we put forward the hypothesis that in addition to the previously well-appreciated mechanotransduction changes, neural and endocrine signals are altered in response to spaceflight and that these may have both negative (e.g. less muscle protein) and some positive consequences (e.g. healthier muscles), at least for invertebrates, with respect to health in space. Given that changes in circulating hormones are well documented with age and in astronauts, our view is that further research into the relationship between metabolic control, ageing, and adaptation to the environment should be productive in advancing our understanding of the physiology of both spaceflight and ageing.
Study of the space environmental effects on spacecraft engineering materials
NASA Technical Reports Server (NTRS)
Obrien, Susan K.; Workman, Gary L.; Smith, Guy A.
1995-01-01
The issue of the effects of the space environment on spacecraft needs to be understood for the long term exposure of structures in space. In order to better understand the effect of these hostile phenomena on spacecraft, several types of studies are worth performing in order to simulate at some level the effect of the environment. For example the effect of protons and electrons impacting structural materials are easily simulated through experiments using the Van de Graff and Pelletron accelerators currently housed at MSFC. Proton fluxes with energies of 700 KeV - 2.5 MeV can be generated and used to impinge on sample targets to determine the effects of the particles. Also the Environmental Effects Facility at MSFC has the capability to generate electron beams with energies from 700 KeV to 2.5 MeV. These facilities will be used in this research to simulate space environmental effects from energetic particles. Ultraviolet radiation, particularly less than 400 nm wavelength, is less well characterized at this time. The Environmental Effects Facility has a vacuum system dedicated to studying the effects of ultraviolet radiation on specific surface materials. This particular system was assembled in a previous study in order to perform a variety of experiments on materials proposed for the Space Station. That system has continued to function as planned and has been used in carrying out portions of the proposed study.
14 CFR Appendix L to Part 121 - Type Certification Regulations Made Previously Effective
Code of Federal Regulations, 2010 CFR
2010-01-01
... Previously Effective L Appendix L to Part 121 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... AND OPERATIONS OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Pt. 121, App. L Appendix L to Part 121—Type Certification Regulations Made Previously Effective Appendix L lists...
Federal Register 2010, 2011, 2012, 2013, 2014
2012-02-10
... Space Telescope. A principal advantage of TDRSS is providing communications services, which previously... instead be placed on the Space Communications and Navigation Program (SCaN) Web site and updated... satellites and ground stations used by NASA for space communications near the Earth. The system was designed...
Home Air Purifiers Eradicate Harmful Pathogens
NASA Technical Reports Server (NTRS)
2014-01-01
Marshall Space Flight Center funded the University of Madison-Wisconsin to develop ethylene scrubbers to keep produce fresh in space. Akida Holdings of Jacksonville, Florida, licensed the technology and developed Airocide, an air purifier that can kill airborne pathogens. Previously designed for industrial spaces, there is now a specially designed unit for home use.
Taste of Super-Dwarf Rice Cultured in Space
NASA Astrophysics Data System (ADS)
Hirai, Hiroaki; Kitaya, Yoshiaki
2016-07-01
The interest of food production for lunar base and manned Mars mission has increased recently. So far, plants cultured long duration in space were leafy vegetables, arabidopsis, wheat, barley and so on. Although rice is a staple food for most of the world, research on rice cultivation in space has not been done much. Rice grains are nutrient-rich with carbohydrate, protein and dietary fiber. Moreover, rice is a high yield crop and harvested grains have a long shelf life. Rice symbolizes the rice-eating culture of Japan, is extremely useful as a specific cultured plant candidate of Japan in space. In the previous report, 'Kozo-no-sumika' found from seedlings in raising of seedling was introduced as a super-dwarf rice to culture in space. Considering this rice as food in space, we investigate the taste characteristics of this rice. At present, waxy 'Kozo-no-sumika' and nonwaxy 'Hosetsu dwarf' of super-dwarf rice and 'Nipponbare' of previous standard rice for sensory test are cultured in paddy field. Hereafter, we will harvest rice, investigate yield, evaluate taste.
Effects of Autonomic Conditioning on Motion Sickness Tolerance
NASA Technical Reports Server (NTRS)
Cowings, P. S.; Toscano, W. B.
1994-01-01
This paper presents case-studies of 9 shuttle crewmembers (prime and alternates) and one U.S. Navy F-18 pilot, as they participated in all preflight training and testing activities in support of a life sciences flight experiment aboard Spacelab-J, and Spacelab-3. The primary objective of the flight experiment was to determine if Autogenic-feedback training (AFT), a physiological self-regulation training technique would be an effective treatment for motion sickness and space motion sickness in these crewmembers. Additional objectives of this study involved the examining human Physiological- responses to motion sickness on Earth and in space, as well as developing predictive criteria for susceptibility to space motion sickness based on ground-based data. Comparisons of these crewmembers are made to a larger set of subjects from previous experiments (treatment and test-only controls subjects). This paper describes all preflight methods, results and proposed changes for future tests.
Peaks in Phase Space Density: A Survey of the Van Allen Probes Era
NASA Astrophysics Data System (ADS)
Boyd, A. J.; Turner, D. L.; Reeves, G. D.; Spence, H. E.
2017-12-01
One of the challenges of radiation belt studies is the differentiation between acceleration mechanisms, particularly local acceleration and radial diffusion. This is often done through careful examination of phase space density profiles in terms of adiabatic coordinates. In particular, local acceleration processes produce growing peaks in phase space density. Many previous studies have shown clear observations of these features for individual events. However, it remains unclear how often and where these growing peaks are observed over a long time period. With the availability of several years of high quality observations from multiple spacecraft, we now have an opportunity to quantify phase space density profiles not only for multiple events, but also across a wide range of energies. In this study, we examine phase space density from more than four years of data from the Van Allen Probes and THEMIS to determine the statistical properties of the observed peaks in phase space density. First, we determine how often growing peaks are observed. Second, we examine where the peaks are located in terms of the adiabatic invariants mu, K and L* and how these locations relate to geomagnetic indices, solar wind conditions and the plasmapause location. Third, we explore how these peaks evolve in time. Together, these results will reveal the relative importance of different acceleration processes and how these affect the various electron populations within the radiation belt.
Two-stage earth-to-orbit vehicles with dual-fuel propulsion in the Orbiter
NASA Technical Reports Server (NTRS)
Martin, J. A.
1982-01-01
Earth-to-orbit vehicle studies of future replacements for the Space Shuttle are needed to guide technology development. Previous studies that have examined single-stage vehicles have shown advantages for dual-fuel propulsion. Previous two-stage system studies have assumed all-hydrogen fuel for the Orbiters. The present study examined dual-fuel Orbiters and found that the system dry mass could be reduced with this concept. The possibility of staging the booster at a staging velocity low enough to allow coast-back to the launch site is shown to be beneficial, particularly in combination with a dual-fuel Orbiter. An engine evaluation indicated the same ranking of engines as did a previous single-stage study. Propane and RP-1 fuels result in lower vehicle dry mass than methane, and staged-combustion engines are preferred over gas-generator engines. The sensitivity to the engine selection is less for two-stage systems than for single-stage systems.
Morbidity is related to a green living environment.
Maas, J; Verheij, R A; de Vries, S; Spreeuwenberg, P; Schellevis, F G; Groenewegen, P P
2009-12-01
As a result of increasing urbanisation, people face the prospect of living in environments with few green spaces. There is increasing evidence for a positive relation between green space in people's living environment and self-reported indicators of physical and mental health. This study investigates whether physician-assessed morbidity is also related to green space in people's living environment. Morbidity data were derived from electronic medical records of 195 general practitioners in 96 Dutch practices, serving a population of 345,143 people. Morbidity was classified by the general practitioners according to the International Classification of Primary Care. The percentage of green space within a 1 km and 3 km radius around the postal code coordinates was derived from an existing database and was calculated for each household. Multilevel logistic regression analyses were performed, controlling for demographic and socioeconomic characteristics. The annual prevalence rate of 15 of the 24 disease clusters was lower in living environments with more green space in a 1 km radius. The relation was strongest for anxiety disorder and depression. The relation was stronger for children and people with a lower socioeconomic status. Furthermore, the relation was strongest in slightly urban areas and not apparent in very strongly urban areas. This study indicates that the previously established relation between green space and a number of self-reported general indicators of physical and mental health can also be found for clusters of specific physician-assessed morbidity. The study stresses the importance of green space close to home for children and lower socioeconomic groups.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Calva-tildeo, M.O.; Reboucas, M.J.; Teixeira, A.F.F.
The breakdown of causality in homogeneous Goedel-type space-time manifolds is examined. An extension of Reboucas--Tiomno (RT) and Accioly--Goncalves studies is made. The existence of noncausal curves is also investigated under two different conditions on the energy-momentum tensor. An integral representation of the infinitesimal generators of isometries is obtained, extending previous works on the RT geometry.
DOT National Transportation Integrated Search
2012-05-01
Vehicle re-identification methods can be used to anonymously match vehicles crossing two different locations based on vehicle attribute data. : This research builds upon a previous study and investigates different methods for solving the re-identific...
Increasing Learning: Classroom Assessment Techniques in the Online Classroom
ERIC Educational Resources Information Center
Cross, Ted; Palese, Kelly
2015-01-01
Five full-time online mathematics instructors participated in a study to test the impact of using discussion forums as a space for formative assessments. Mean student posting activity and student quiz scores for sections in which the instructors used formative assessments were compared with previous sections in which formative assessments were not…
Effects of Free Molecular Heating on the Space Shuttle Active Thermal Control System
NASA Technical Reports Server (NTRS)
McCloud, Peter L.; Wobick, Craig A.
2007-01-01
During Space Transportation System (STS) flight 121, higher than predicted radiator outlet temperatures were experienced from post insertion and up until nominal correction (NC) burn two. Effects from the higher than predicted heat loads on the radiator panels led to an additional 50 lbm of supply water consumed by the Flash Evaporator System (FES). Post-flight analysis and research revealed that the additional heat loads were due to Free Molecular Heating (FMH) on the radiator panels, which previously had not been considered as a significant environmental factor for the Space Shuttle radiators. The current Orbiter radiator heat flux models were adapted to incorporate the effects of FMH in addition to solar, earth infrared and albedo sources. Previous STS flights were also examined to find additional flight data on the FMH environment. Results of the model were compared to flight data and verified against results generated by the National Aeronautics and Space Administration (NASA), Johnson Space Center (JSC) Aero-sciences group to verify the accuracy of the model.
Asymptotic Analysis of the Ponzano-Regge Model with Non-Commutative Metric Boundary Data
NASA Astrophysics Data System (ADS)
Oriti, Daniele; Raasakka, Matti
2014-06-01
We apply the non-commutative Fourier transform for Lie groups to formulate the non-commutative metric representation of the Ponzano-Regge spin foam model for 3d quantum gravity. The non-commutative representation allows to express the amplitudes of the model as a first order phase space path integral, whose properties we consider. In particular, we study the asymptotic behavior of the path integral in the semi-classical limit. First, we compare the stationary phase equations in the classical limit for three different non-commutative structures corresponding to the symmetric, Duflo and Freidel-Livine-Majid quantization maps. We find that in order to unambiguously recover discrete geometric constraints for non-commutative metric boundary data through the stationary phase method, the deformation structure of the phase space must be accounted for in the variational calculus. When this is understood, our results demonstrate that the non-commutative metric representation facilitates a convenient semi-classical analysis of the Ponzano-Regge model, which yields as the dominant contribution to the amplitude the cosine of the Regge action in agreement with previous studies. We also consider the asymptotics of the SU(2) 6j-symbol using the non-commutative phase space path integral for the Ponzano-Regge model, and explain the connection of our results to the previous asymptotic results in terms of coherent states.
Genomewide Linkage Disequilibrium Mapping of Severe Bipolar Disorder in a Population Isolate
Ophoff, Roel A.; Escamilla, Michael A.; Service, Susan K.; Spesny, Mitzi; Meshi, Dar B.; Poon, Wingman; Molina, Julio; Fournier, Eduardo; Gallegos, Alvaro; Mathews, Carol; Neylan, Thomas; Batki, Steven L.; Roche, Erin; Ramirez, Margarita; Silva, Sandra; De Mille, Melissa C.; Dong, Penny; Leon, Pedro E.; Reus, Victor I.; Sandkuijl, Lodewijk A.; Freimer, Nelson B.
2002-01-01
Genomewide association studies may offer the best promise for genetic mapping of complex traits. Such studies in outbred populations require very densely spaced single-nucleotide polymorphisms. In recently founded population isolates, however, extensive linkage disequilibrium (LD) may make these studies feasible with currently available sets of short tandem repeat markers, spaced at intervals as large as a few centimorgans. We report the results of a genomewide association study of severe bipolar disorder (BP-I), using patients from the isolated population of the central valley of Costa Rica. We observed LD with BP-I on several chromosomes; the most striking results were in proximal 8p, a region that has previously shown linkage to schizophrenia. This region could be important for severe psychiatric disorders, rather than for a specific phenotype. PMID:12119601
Asteroid Redirect Crewed Mission Space Suit and EVA System Architecture Trade Study
NASA Technical Reports Server (NTRS)
Bowie, Jonathan T.; Blanco, Raul A.; Watson, Richard D.; Kelly, Cody; Buffington, Jesse; Sipila, Stephanie A.
2014-01-01
This paper discusses the Asteroid Redirect Crewed Mission (ARCM) space suit and Extravehicular Activity (EVA) architecture trade study and the current state of the work to mature the requirements and products to the mission concept review level. The mission requirements and the resulting concept of operations will be discussed. A historical context will be presented as to present the similarities and differences from previous NASA missions. That will set the stage for the trade study where all options for both pressure garment and life support were considered. The rationale for the architecture decisions will then be presented. Since the trade study did identity risks, the subsequent tests and analyses that mitigated the risks will be discussed. Lastly, the current state of the effort will be provided.
ISS Local Environment Spectrometers (ISLES)
NASA Technical Reports Server (NTRS)
Krause, Linda Habash; Gilchrist, Brian E.
2014-01-01
In order to study the complex interactions between the space environment surrounding the ISS and the ISS surface materials, we propose to use lowcost, high-TRL plasma sensors on the ISS robotic arm to probe the ISS space environment. During many years of ISS operation, we have been able to condut effective (but not perfect) extravehicular activities (both human and robotic) within the perturbed local ISS space environment. Because of the complexity of the interaction between the ISS and the LEO space environment, there remain important questions, such as differential charging at solar panel junctions (the so-called "triple point" between conductor, dielectric, and space plasma), increased chemical contamination due to ISS surface charging and/or thruster activation, water dumps, etc, and "bootstrap" charging of insulating surfaces. Some compelling questions could synergistically draw upon a common sensor suite, which also leverages previous and current MSFC investments. Specific questions address ISS surface charging, plasma contactor plume expansion in a magnetized drifting plasma, and possible localized contamination effects across the ISS.
A unified framework for mesh refinement in random and physical space
DOE Office of Scientific and Technical Information (OSTI.GOV)
Li, Jing; Stinis, Panos
In recent work we have shown how an accurate reduced model can be utilized to perform mesh renement in random space. That work relied on the explicit knowledge of an accurate reduced model which is used to monitor the transfer of activity from the large to the small scales of the solution. Since this is not always available, we present in the current work a framework which shares the merits and basic idea of the previous approach but does not require an explicit knowledge of a reduced model. Moreover, the current framework can be applied for renement in both randommore » and physical space. In this manuscript we focus on the application to random space mesh renement. We study examples of increasing difficulty (from ordinary to partial differential equations) which demonstrate the effciency and versatility of our approach. We also provide some results from the application of the new framework to physical space mesh refinement.« less
NASA Astrophysics Data System (ADS)
Kanas, Nick; Ritsher, Jennifer
2005-05-01
In isolated and confined environments, two important leadership roles have been identified: the task/instrumental role (which focuses on work goals and operational needs), and the supportive/expressive role (which focuses on morale goals and emotional needs). On the International Space Station, the mission commander should be familiar with both of these aspects of leadership. In previous research involving a 135-day Mir space station simulation in Moscow and a series of on-orbit Mir space station missions during the Shuttle/Mir program, both these leadership roles were studied. In new analyses of the Shuttle/Mir data, we found that for crewmembers, the supportive role of the commander (but not the task role) related positively with crew cohesion. For mission control personnel on the ground, both the task and supportive roles of their leader were related positively to mission control cohesion. The implications of these findings are discussed in terms of leadership on board the International Space Station.
Kanas, Nick; Ritsher, Jennifer
2005-01-01
In isolated and confined environments, two important leadership roles have been identified: the task/instrumental role (which focuses on work goals and operational needs), and the supportive/expressive role (which focuses on morale goals and emotional needs). On the International Space Station, the mission commander should be familiar with both of these aspects of leadership. In previous research involving a 135-day Mir space station simulation in Moscow and a series of on-orbit Mir space station missions during the Shuttle/Mir program, both these leadership roles were studied. In new analyses of the Shuttle/Mir data, we found that for crewmembers, the supportive role of the commander (but not the task role) related positively with crew cohesion. For mission control personnel on the ground, both the task and supportive roles of their leader were related positively to mission control cohesion. The implications of these findings are discussed in terms of leadership on board the International Space Station. c2005 Elsevier Ltd. All rights reserved.
Singh, Puneet; Jana, Sumitash; Ghosal, Ashitava; Murthy, Aditya
2016-12-13
The number of joints and muscles in a human arm is more than what is required for reaching to a desired point in 3D space. Although previous studies have emphasized how such redundancy and the associated flexibility may play an important role in path planning, control of noise, and optimization of motion, whether and how redundancy might promote motor learning has not been investigated. In this work, we quantify redundancy space and investigate its significance and effect on motor learning. We propose that a larger redundancy space leads to faster learning across subjects. We observed this pattern in subjects learning novel kinematics (visuomotor adaptation) and dynamics (force-field adaptation). Interestingly, we also observed differences in the redundancy space between the dominant hand and nondominant hand that explained differences in the learning of dynamics. Taken together, these results provide support for the hypothesis that redundancy aids in motor learning and that the redundant component of motor variability is not noise.
Exploration of joint redundancy but not task space variability facilitates supervised motor learning
Singh, Puneet; Jana, Sumitash; Ghosal, Ashitava; Murthy, Aditya
2016-01-01
The number of joints and muscles in a human arm is more than what is required for reaching to a desired point in 3D space. Although previous studies have emphasized how such redundancy and the associated flexibility may play an important role in path planning, control of noise, and optimization of motion, whether and how redundancy might promote motor learning has not been investigated. In this work, we quantify redundancy space and investigate its significance and effect on motor learning. We propose that a larger redundancy space leads to faster learning across subjects. We observed this pattern in subjects learning novel kinematics (visuomotor adaptation) and dynamics (force-field adaptation). Interestingly, we also observed differences in the redundancy space between the dominant hand and nondominant hand that explained differences in the learning of dynamics. Taken together, these results provide support for the hypothesis that redundancy aids in motor learning and that the redundant component of motor variability is not noise. PMID:27911808
Growing quality of life: urban trees, birth weight, and crime
John Kirkland; Geoffrey Donovan
2011-01-01
City dwellers can find many reasons to value neighborhood trees. The urban greenery provides relief from the built environment that many find appealing. In fact, a previous study found that a tree in front of a home increased that home's sales price by more than $7,000. Two new studies explore the measurable effects that urban trees and green spaces have a human...
Effects of thinning on development of southern pine beetle infestations in old growth stands
Peter Turchin; James Davidson; Jane Leslie. Hayes
1999-01-01
A study was conducted to quantify the relationship between southern pine beetle infestation growth and the intertree spacing in old growth pine stands. The problem with extrapolating the results of previous studies to old growths tands is that it is unclear whether the same mechanism will operate in stands of older trees characterized by double the diameter (20-25 cm...
Sixty years from discovery to solution: crystal structure of bovine liver catalase form III
DOE Office of Scientific and Technical Information (OSTI.GOV)
Foroughi, Leila M.; Kang, You-Na; Matzger, Adam J.
2012-03-27
The crystallization and structural characterization of bovine liver catalase (BLC) has been intensively studied for decades. Forms I and II of BLC have previously been fully characterized using single-crystal X-ray diffraction. Form III has previously been analyzed by electron microscopy, but owing to the thinness of this crystal form an X-ray crystal structure had not been determined. Here, the crystal structure of form III of BLC is presented in space group P212121, with unit-cell parameters a = 68.7, b = 173.7, c = 186.3 {angstrom}. The asymmetric unit is composed of the biological tetramer, which is packed in a tetrahedronmore » motif with three other BLC tetramers. This higher resolution structure has allowed an assessment of the previously published electron-microscopy studies.« less
About the coordinate time for photons in Lifshitz space-times
NASA Astrophysics Data System (ADS)
Villanueva, J. R.; Vásquez, Yerko
2013-10-01
In this paper we studied the behavior of radial photons from the point of view of the coordinate time in (asymptotically) Lifshitz space-times, and we found a generalization to the result reported in previous works by Cruz et al. (Eur. Phys. J. C 73:7, 2013), Olivares et al. (Astrophys. Space Sci. 347:83-89, 2013), and Olivares et al. (arXiv:1306.5285). We demonstrate that all asymptotically Lifshitz space-times characterized by a lapse function f( r) which tends to one when r→∞, present the same behavior, in the sense that an external observer will see that photons arrive at spatial infinity in a finite coordinate time. Also, we show that radial photons in the proper system cannot determine the presence of the black hole in the region r +< r<∞, because the proper time as a result is independent of the lapse function f( r).
Dependence of hydrogen arcjet operation on electrode geometry
NASA Technical Reports Server (NTRS)
Pencil, Eric J.; Sankovic, John M.; Sarmiento, Charles J.; Hamley, John A.
1992-01-01
The dependence of 2 kW hydrogen arcjet performance on cathode to anode electrode spacing was evaluated at specific impulses of 900 and 1000 s. Less than 2 absolute percent change in efficiency was measured for the spacings tested which did not repeat the 14 absolute percent variation reported in earlier work with similar electrode designs. A different nozzle configuration was used to quantify the variation in hydrogen arcjet performance over an extended range of electrode spacing. Electrode gap variation resulted in less than 3 absolute percent change in efficiency. These null results suggested that electrode spacing is decoupled from hydrogen arcjet performance considerations over the ranges tested. Initial studies were conducted on hydrogen arcjet ignition. The dependence of breakdown voltage on mass flow rate and hydrogen arcjet ignition on rates of pulse repetition and pulse voltage rise were also included for comparison with previous results obtained using simulated hydrazine.
Solar energy concentrator system for crystal growth and zone refining in space
NASA Technical Reports Server (NTRS)
Mcdermit, J. H.
1975-01-01
The technological feasibility of using solar concentrators for crystal growth and zone refining in space has been performed. Previous studies of space-deployed solar concentrators were reviewed for their applicability to materials processing and a new state-of-the-art concentrator-receiver radiation analysis was developed. The radiation analysis is in the form of a general purpose computer program. It was concluded from this effort that the technology for fabricating, orbiting and deploying large solar concentrators has been developed. It was also concluded that the technological feasibility of space processing materials in the focal region of a solar concentrator depends primarily on two factors: (1) the ability of a solar concentrator to provide sufficient thermal energy for the process and (2) the ability of a solar concentrator to provide a thermal environment that is conductive to the processes of interest. The analysis indicate that solar concentrators can satisfactorily provide both of these factors.
The history of space exploration
NASA Technical Reports Server (NTRS)
Collins, Martin J.; Kraemer, Sylvia K.
1994-01-01
Presented are the acknowledgements and introduction sections of the book 'Space: Discovery and Exploration.' The goal of the book is to address some basic questions of American space history, including how this history compares with previous eras of exploration, why the space program was initiated when it was, and how the U.S. space program developed. In pursuing these questions, the intention is not to provide exhaustive answers, but to point the reader toward a more varied picture of how our venture in space has intersected with American government, politics, business, and science.
Blood and clonogenic hemopoietic cells of newts after the space flight
NASA Astrophysics Data System (ADS)
Michurina, T. V.; Domaratskaya, E. I.; Nikonova, T. M.; Khrushchov, N. G.
Ribbed newts were used for studying the effect of space flight on board of the biosatellite (Cosmos-2229) on blood and clonogenic hemopoietic cells. In blood of newts of the flight group, the relative proportion of neutrophils increased, whereas that of lymphocytes and eosinophils decreased. Space flight did not result in loss of the ability of newt blood cells to incorporate H^3-thymidine. Analysis of clonogenic hemopoietic cells was performed using the method of hemopoietic colony formation on cellulose acetate membranes implanted into the peritoneal cavity of irradiated newts. To analyze reconstitution of hemopoiesis after irradiation donor hemopoietic cells from flight or control newts were transplanted into irradiated newts whose hemopoietic organs were investigated. The newt can be considered an adequate model for studying hemopoiesis under the conditions of the space flight. Previous studies on rats subjected to 5- to 19-day space flights revealed a decrease in the number of clonogenic cells in their hemopoietic organs accompanied by specific changes in the precursor cell compartment and in blood /1,2/. Hence, it was interesting to analyze blood and hemopoietic tissue of lower vertebrates after a space flight and to compare the response to it of animals belonging to different taxonomic groups. We analyzed blood and clonogenic hemopoietic cells of ribbed newts, Pleurodeles waltl (age one year, weight 20-28 g) subjected to a 12-day space flight on board of a Cosmos-2229 biosatellite. The same animals were used in studies on limb and lens regeneration. The results were compared with those obtained with control groups of newts: (1) basic control, operated newts sacrificed on the day of biosatellite launching (BC); (2) synchronous control, operated newts kept in the laboratory under simulated space flight conditions (SC); and (3) intact newts (IC).
2012-05-21
CAPE CANAVERAL, Fla. – At the NASA Railroad yard at Kennedy Space Center in Florida, helium tank cars are lifted from their trucks onto flat cars in preparation for a journey to the Florida East Coast Railway interchange in Titusville, Fla., where the train’s tank cars will be transferred for delivery to the SpaceX engine test complex outside McGregor, Texas. The railroad cars were needed in support of the Space Shuttle Program but currently are not in use by NASA following the completion of the program in 2011. Originally, the tankers belonged to the U.S. Bureau of Mines. At the peak of the shuttle program, there were approximately 30 cars in the fleet. About half the cars were returned to the bureau as launch activity diminished. Five tank cars are being loaned to SpaceX and repurposed to support their engine tests in Texas. Eight cars previously were shipped to California on loan to support the SpaceX Falcon 9 rocket launches from Space Launch Complex-4 on Vandenberg Air Force Base. SpaceX already has three helium tank cars previously used for the shuttle program at Space Launch Complex-40 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/spacex. Photo credit: NASA/Jim Grossmann
2012-05-21
CAPE CANAVERAL, Fla. – At the NASA Railroad yard at Kennedy Space Center in Florida, helium tank cars have been removed from their trucks and loaded onto flat cars in preparation for a journey to the Florida East Coast Railway interchange in Titusville, Fla., where the train’s tank cars will be transferred for delivery to the SpaceX engine test complex outside McGregor, Texas. The railroad cars were needed in support of the Space Shuttle Program but currently are not in use by NASA following the completion of the program in 2011. Originally, the tankers belonged to the U.S. Bureau of Mines. At the peak of the shuttle program, there were approximately 30 cars in the fleet. About half the cars were returned to the bureau as launch activity diminished. Five tank cars are being loaned to SpaceX and repurposed to support their engine tests in Texas. Eight cars previously were shipped to California on loan to support the SpaceX Falcon 9 rocket launches from Space Launch Complex-4 on Vandenberg Air Force Base. SpaceX already has three helium tank cars previously used for the shuttle program at Space Launch Complex-40 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/spacex. Photo credit: NASA/Jim Grossmann
2004-02-13
KENNEDY SPACE CENTER, FLA. - Overhead cables carry the Multi-Purpose Logistics Module Donatello from the payload canister (lower right) to a work stand in the Space Station Processing Facility. Previously housed in the Operations and Checkout Building, Donatello was brought into the SSPF for routine testing. This is the first time all three MPLMs (Donatello, Raffaello and Leonardo) are in the SSPF. The MPLMs were built by the Italian Space Agency, to serve as reusable logistics carriers and the primary delivery system to resupply and return station cargo requiring a pressurized environment. The third MPLM, Raffaello is scheduled to fly on Space Shuttle Atlantis on mission STS-114.
2004-02-13
KENNEDY SPACE CENTER, FLA. - Workers on the floor of the Space Station Processing Facility watch as overhead cables carry the Multi-Purpose Logistics Module Donatello to a work stand. Previously housed in the Operations and Checkout Building, Donatello was brought into the SSPF for routine testing. This is the first time all three MPLMs (Donatello, Raffaello and Leonardo) are in the SSPF. The MPLMs were built by the Italian Space Agency, to serve as reusable logistics carriers and the primary delivery system to resupply and return station cargo requiring a pressurized environment. The third MPLM, Raffaello is scheduled to fly on Space Shuttle Atlantis on mission STS-114.
2004-05-01
KENNEDY SPACE CENTER, FLA. -- Former astronaut Joe Engle acknowledges the applause as he is introduced as a previous inductee into the U.S. Astronaut Hall of Fame. He and other Hall of Fame members were present for the induction of five new space program heroes into the U.S. Astronaut Hall of Fame: Richard O. Covey, commander of the Hubble Space Telescope repair mission; Norman E. Thagard, the first American to occupy Russia’s Mir space station; the late Francis R. "Dick" Scobee, commander of the ill-fated 1986 Challenger mission; Kathryn D. Sullivan, the first American woman to walk in space; and Frederick D. Gregory, the first African-American to command a space mission and the current NASA deputy administrator. Engle made 16 flights in the X-15 rocket plane before he became a NASA astronaut and flew two Space Shuttle missions. In 1981, he commanded the second flight of Columbia, the first manned spacecraft to be reflown in space, and in 1985 he commanded a five-man crew on the 20th shuttle flight, a satellite-deploy and repair mission. The induction ceremony was held at the Apollo/Saturn V Center at KSC. The U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The five inductees join 52 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
TANK SPACE ALTERNATIVES ANALYSIS REPORT
DOE Office of Scientific and Technical Information (OSTI.GOV)
TURNER DA; KIRCH NW; WASHENFELDER DJ
2010-04-27
This report addresses the projected shortfall of double-shell tank (DST) space starting in 2018. Using a multi-variant methodology, a total of eight new-term options and 17 long-term options for recovering DST space were evaluated. These include 11 options that were previously evaluated in RPP-7702, Tank Space Options Report (Rev. 1). Based on the results of this evaluation, two near-term and three long-term options have been identified as being sufficient to overcome the shortfall of DST space projected to occur between 2018 and 2025.
NASA Astrophysics Data System (ADS)
Scofield, David C.; Rytlewski, Jeffrey D.; Childress, Paul; Shah, Kishan; Tucker, Aamir; Khan, Faisal; Peveler, Jessica; Li, Ding; McKinley, Todd O.; Chu, Tien-Min G.; Hickman, Debra L.; Kacena, Melissa A.
2018-05-01
This study was initiated as a component of a larger undertaking designed to study bone healing in microgravity aboard the International Space Station (ISS). Spaceflight experimentation introduces multiple challenges not seen in ground studies, especially with regard to physical space, limited resources, and inability to easily reproduce results. Together, these can lead to diminished statistical power and increased risk of failure. It is because of the limited space, and need for improved statistical power by increasing sample size over historical numbers, NASA studies involving mice require housing mice at densities higher than recommended in the Guide for the Care and Use of Laboratory Animals (National Research Council, 2011). All previous NASA missions in which mice were co-housed, involved female mice; however, in our spaceflight studies examining bone healing, male mice are required for optimal experimentation. Additionally, the logistics associated with spaceflight hardware and our study design necessitated variation of density and cohort make up during the experiment. This required the development of a new method to successfully co-house male mice while varying mouse density and hierarchical structure. For this experiment, male mice in an experimental housing schematic of variable density (Spaceflight Correlate) analogous to previously established NASA spaceflight studies was compared to a standard ground based housing schematic (Normal Density Controls) throughout the experimental timeline. We hypothesized that mice in the Spaceflight Correlate group would show no significant difference in activity, aggression, or stress when compared to Normal Density Controls. Activity and aggression were assessed using a novel activity scoring system (based on prior literature, validated in-house) and stress was assessed via body weights, organ weights, and veterinary assessment. No significant differences were detected between the Spaceflight Correlate group and the Normal Density Controls in activity, aggression, body weight, or organ weight, which was confirmed by veterinary assessments. Completion of this study allowed for clearance by NASA of our bone healing experiments aboard the ISS, and our experiment was successfully launched February 19, 2017 on SpaceX CRS-10.
Mars Science Laboratory Press Conference
2011-07-22
Dawn Sumner, geologist, University of California, Davis speaks at a Mars Science Laboratory (MSL) press conference at the Smithsonian's National Air and Space Museum on Friday, July 22, 2011 in Washington. The Mars Science Laboratory (MSL), or Curiosity, is scheduled to launch late this year from NASA's Kennedy Space Center in Florida and land in August 2012. Curiosity is twice as long and more than five times as heavy as previous Mars rovers. The rover will study whether the landing region at Gale crater had favorable environmental conditions for supporting microbial life and for preserving clues about whether life ever existed. Photo Credit: (NASA/Carla Cioffi)
Mars Science Laboratory Press Conference
2011-07-22
NASA chief scientist, Dr. Waleed Abdalati, speaks at a Mars Science Laboratory (MSL) press conference at the Smithsonian's National Air and Space Museum on Friday, July 22, 2011 in Washington. The Mars Science Laboratory (MSL), or Curiosity, is scheduled to launch late this year from NASA's Kennedy Space Center in Florida and land in August 2012. Curiosity is twice as long and more than five times as heavy as previous Mars rovers. The rover will study whether the landing region at Gale crater had favorable environmental conditions for supporting microbial life and for preserving clues about whether life ever existed. Photo Credit: (NASA/Carla Cioffi)
Materials science on parabolic aircraft: The FY 1987-1989 KC-135 microgravity test program
NASA Technical Reports Server (NTRS)
Curreri, Peter A. (Editor)
1993-01-01
This document covers research results from the KC-135 Materials Science Program managed by MSFC for the period FY87 through FY89. It follows the previous NASA Technical Memorandum for FY84-86 published in August 1988. This volume contains over 30 reports grouped into eight subject areas covering acceleration levels, space flight hardware, transport and interfacial studies, thermodynamics, containerless processing, welding, melt/crucible interactions, and directional solidification. The KC-135 materials science experiments during FY87-89 accomplished direct science, preparation for space flight experiments, and justification for new experiments in orbit.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Moriarty, M.P.
1993-01-15
The heat transport subsystem for a liquid metal cooled thermionic space nuclear power system was modelled using algorithms developed in support of previous nuclear power system study programs, which date back to the SNAP-10A flight system. The model was used to define the optimum dimensions of the various components in the heat transport subsystem subjected to the constraints of minimizing mass and achieving a launchable package that did not require radiator deployment. The resulting design provides for the safe and reliable cooling of the nuclear reactor in a proven lightweight design.
NASA Astrophysics Data System (ADS)
Moriarty, Michael P.
1993-01-01
The heat transport subsystem for a liquid metal cooled thermionic space nuclear power system was modelled using algorithms developed in support of previous nuclear power system study programs, which date back to the SNAP-10A flight system. The model was used to define the optimum dimensions of the various components in the heat transport subsystem subjected to the constraints of minimizing mass and achieving a launchable package that did not require radiator deployment. The resulting design provides for the safe and reliable cooling of the nuclear reactor in a proven lightweight design.
Conditions for extinction events in chemical reaction networks with discrete state spaces.
Johnston, Matthew D; Anderson, David F; Craciun, Gheorghe; Brijder, Robert
2018-05-01
We study chemical reaction networks with discrete state spaces and present sufficient conditions on the structure of the network that guarantee the system exhibits an extinction event. The conditions we derive involve creating a modified chemical reaction network called a domination-expanded reaction network and then checking properties of this network. Unlike previous results, our analysis allows algorithmic implementation via systems of equalities and inequalities and suggests sequences of reactions which may lead to extinction events. We apply the results to several networks including an EnvZ-OmpR signaling pathway in Escherichia coli.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gu, A.G.; Miller, M.S.
1991-01-01
All space missions require a reliable, compact source of energy. This paper describes preliminary neutronics studies of pocket'' reactor concepts employing PuF{sub 6} and transplutonic materials as fuels for space high power/energy Nuclear Pumped Lasers (NPLs). Previous research has studied NPL reactor concepts with thin fuel layers, aerosol fuels and gaseous UF{sub 6}. The total reactor volumes for compact reactors with these types of fuels typically range from 3 m{sup 3} to 50 m{sup 3}. By employing PuF{sub 6} and transplutonic fuels at the same low densities, a calculated value for Keff of 1.2 has been achieved for conditions ofmore » 900 K and 5 atm, with total reactor volumes of 1.5 m{sup 3} for PuF{sub 6}, 0.51 m{sup 3} for Am-242m, 0.58 m{sup 3} for Cm-245 and 0.63 m{sup 3} for Cf-249.« less
Feasibility of flywheel energy storage systems for applications in future space missions
NASA Technical Reports Server (NTRS)
Santo, G. Espiritu; Gill, S. P.; Kotas, J. F.; Paschall, R.
1995-01-01
The objective of this study was to examine the overall feasibility of deploying electromechanical flywheel systems in space used for excess energy storage. Results of previous Rocketdyne studies have shown that the flywheel concept has a number of advantages over the NiH2 battery, including higher specific energy, longer life and high roundtrip efficiency. Based on this prior work, this current study was broken into four subtasks. The first subtask investigated the feasibility of replacing the NiH2 battery orbital replacement unit (ORU) on the international space station (ISSA) with a flywheel ORU. In addition, a conceptual design of a generic flywheel demonstrator experiment implemented on the ISSA was completed. An assessment of the life cycle cost benefits of replacing the station battery energy storage ORU's with flywheel ORU's was performed. A fourth task generated a top-level development plan for critical flywheel technologies, the flywheel demonstrator experiments and its evolution into the production unit flywheel replacement ORU.
A study of radar cross section measurement techniques
NASA Technical Reports Server (NTRS)
Mcdonald, Malcolm W.
1986-01-01
Past, present, and proposed future technologies for the measurement of radar cross section were studied. The purpose was to determine which method(s) could most advantageously be implemented in the large microwave anechoic chamber facility which is operated at the antenna test range site. The progression toward performing radar cross section measurements of space vehicles with which the Orbital Maneuvering Vehicle will be called upon to rendezvous and dock is a natural outgrowth of previous work conducted in recent years of developing a high accuracy range and velocity sensing radar system. The radar system was designed to support the rendezvous and docking of the Orbital Maneuvering Vehicle with various other space vehicles. The measurement of radar cross sections of space vehicles will be necessary in order to plan properly for Orbital Maneuvering Vehicle rendezvous and docking assignments. The methods which were studied include: standard far-field measurements; reflector-type compact range measurements; lens-type compact range measurement; near field/far field transformations; and computer predictive modeling. The feasibility of each approach is examined.
Space Station Freedom assembly and operation at a 51.6 degree inclination orbit
NASA Technical Reports Server (NTRS)
Troutman, Patrick A.; Brewer, Laura M.; Heck, Michael L.; Kumar, Renjith R.
1993-01-01
This study examines the implications of assembling and operating Space Station Freedom at a 51.6 degree inclination orbit utilizing an enhanced lift Space Shuttle. Freedom assembly is currently baselined at a 220 nautical mile high, 28.5 degree inclination orbit. Some of the reasons for increasing the orbital inclination are (1) increased ground coverage for Earth observations, (2) greater accessibility from Russian and other international launch sites, and (3) increased number of Assured Crew Return Vehicle (ACRV) landing sites. Previous studies have looked at assembling Freedom at a higher inclination using both medium and heavy lift expendable launch vehicles (such as Shuttle-C and Energia). The study assumes that the shuttle is used exclusively for delivering the station to orbit and that it can gain additional payload capability from design changes such as a lighter external tank that somewhat offsets the performance decrease that occurs when the shuttle is launched to a 51.6 degree inclination orbit.
Dynamic modeling and Super-Twisting Sliding Mode Control for Tethered Space Robot
NASA Astrophysics Data System (ADS)
Zhao, Yakun; Huang, Panfeng; Zhang, Fan
2018-02-01
Recent years, tethered space capturing systems have been considered as one of the most promising solutions for active space debris removal due to the increasing threat of space debris to spacecraft and astronauts. In this paper, one of the tethered space capturing systems, Tethered Space Robot (TSR), is investigated. TSR includes a space platform, a space tether, and a gripper as the terminal device. Based on the assumptions that the platform and the gripper are point masses and the tether is rigid, inextensible and remaining straight, the dynamic model of TSR is presented, in which the disturbances from space environment is considered. According to the previous study, the in-plane and out-of-plane angles of the tether oscillate periodically although the tether is released to the desired length. A super-twisting adaptive sliding mode control scheme is designed for TSR to eliminate the vibration of the tether to assure a successful capture in station-keeping phase. Both uncontrolled and controlled situations are simulated. The simulation results show that the proposed controller is effective. Additionally, after comparing with normal sliding mode control algorithm, it is verified that the proposed control scheme can avoid the chattering of normal sliding mode control and is robust for unknown boundary perturbations.
Regan, C E; Pilkington, J G; Bérénos, C; Pemberton, J M; Smiseth, P T; Wilson, A J
2017-01-01
When estimating heritability in free-living populations, it is common practice to account for common environment effects, because of their potential to generate phenotypic covariance among relatives thereby biasing heritability estimates. In quantitative genetic studies of natural populations, however, philopatry, which results in relatives being clustered in space, is rarely accounted for. The two studies that have been carried out so far suggest absolute declines in heritability estimates of up to 43% when accounting for space sharing by relatives. However, due to methodological limitations these estimates may not be representative. We used data from the St. Kilda Soay sheep population to estimate heritabilities with and without accounting for space sharing for five traits for which there is evidence for additive genetic variance (birthweight, birth date, lamb August weight, and female post-mortem jaw and metacarpal length). We accounted for space sharing by related females by separately incorporating spatial autocorrelation, and a home range similarity matrix. Although these terms accounted for up to 18% of the variance in these traits, heritability estimates were only reduced by up to 7%. Our results suggest that the bias caused by not accounting for space sharing may be lower than previously thought. This suggests that philopatry does not inevitably lead to a large bias if space sharing by relatives is not accounted for. We hope our work stimulates researchers to model shared space when relatives in their study population share space, as doing so will enable us to better understand when bias may be of particular concern. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.
Advanced designs for non-imaging submillimeter-wave Winston cone concentrators
NASA Astrophysics Data System (ADS)
Nelson, A. O.; Grossman, E. N.
2014-05-01
We describe the design and simulation of several non-imaging concentrators designed to couple submillimeter wavelength radiation from free space into highly overmoded, rectangular, WR-10 waveguide. Previous designs are altered to improve the uniformity of efficiency rather than the efficiency itself. The concentrators are intended for use as adapters between instruments using overmoded WR-10 waveguide as input or output and sources propagating through free space. Previous simulation and measurement have shown that the angular response is primarily determined by the Winston cone and is well predicted by geometric optics theory while the efficiencies are primarily determined by the transition section. Additionally, previous work has shown insensitivity to polarization, orientation and beam size. Several separate concentrator designs are studied, all of which use a Winston cone (also known as a compound parabolic concentrator) with an input diameter ranging from 4 mm to 16 mm, and "throat" diameters of less than 0.5 mm to 4 mm as the initial interface. The use of various length adiabatic circular-to-rectangular transition sections is investigated, along with the effect of an additional, 25 mm waveguide section designed to model the internal waveguide of the power meter. Adapters without a transition section and a rectangular Winston cone throat aperture and double cone configurations are also studied. Adapters are analyzed in simulation for consistent efficiency across the opening aperture.
Pexa, Brett S; Ryan, Eric D; Myers, Joseph B
2018-04-01
Previous research indicates that the amount of valgus torque placed on the elbow joint during overhead throwing is higher than the medial ulnar collateral ligament (UCL) can tolerate. Wrist and finger flexor muscle activity is hypothesized to make up for this difference, and in vitro studies that simulated activity of upper extremity musculature, specifically the flexor digitorum superficialis and flexor carpi ulnaris, support this hypothesis. To assess the medial elbow joint space at rest, under valgus stress, and under valgus stress with finger and forearm flexor contraction by use of ultrasonography in vivo. Controlled laboratory study. Participants were 22 healthy males with no history of elbow dislocation or UCL injury (age, 21.25 ± 1.58 years; height, 1.80 ± 0.08 m; weight, 79.43 ± 18.50 kg). Medial elbow joint space was measured by use of ultrasonography during 3 separate conditions: at rest (unloaded), under valgus load (loaded), and with a maximal grip contraction under a valgus load (loaded-contracted) in both limbs. Participants lay supine with their arm abducted 90° and elbow flexed 30° with the forearm in full supination. A handgrip dynamometer was placed in the participants' hand to grip against during the contracted condition. Images were reduced in ImageJ to assess medial elbow joint space. A 2-way (condition × limb) repeated-measures analysis of variance and Cohen's d effect sizes were used to assess changes in medial elbow joint space. Post hoc testing was performed with a Bonferroni adjustment to assess changes within limb and condition. The medial elbow joint space was significantly larger in the loaded condition (4.91 ± 1.16 mm) compared with the unloaded condition (4.26 ± 1.23 mm, P < .001, d = 0.712) and the loaded-contracted condition (3.88 ± 0.94 mm, P < .001, d = 1.149). No significant change was found between the unloaded and loaded-contracted conditions ( P = .137). Medial elbow joint space increases under a valgus load and then decreases when a maximal grip contraction is performed. This indicates that wrist and finger flexor muscle contraction may assist in limiting medial elbow joint space, a result similar to findings of previous research in vitro. Muscle activation of the upper extremity limits the medial elbow joint space, suggesting that injury prevention programs for throwing athletes should incorporate exercises for the elbow, wrist, and hand to limit excessive medial elbow joint space gapping during activities that create high valgus load.
Use of Hawaii Analog Sites for Lunar Science and In-Situ Resource Utilization
NASA Astrophysics Data System (ADS)
Sanders, G. B.; Larson, W. E.; Picard, M.; Hamilton, J. C.
2011-10-01
In-Situ Resource Utilization (ISRU) and lunar science share similar objectives with respect to analyzing and characterizing the physical, mineral, and volatile materials and resources at sites of robotic and human exploration. To help mature and stress instruments, technologies, and hardware and to evaluate operations and procedures, space agencies have utilized demonstrations at analog sites on Earth before use in future missions. The US National Aeronautics and Space Administration (NASA), the Canadian Space Agency (CSA), and the German Space Agency (DLR) have utilized an analog site on the slope of Mauna Kea on the Big Island of Hawaii to test ISRU and lunar science hardware and operations in two previously held analog field tests. NASA and CSA are currently planning on a 3rd analog field test to be held in June, 2012 in Hawaii that will expand upon the successes from the previous two field tests.
Use of Hawaii Analog Sites for Lunar Science and In-Situ Resource Utilization
NASA Technical Reports Server (NTRS)
Sanders, G. B.; Larson, W. E.; Picard, M.; Hamilton, J. C.
2011-01-01
In-Situ Resource Utilization (ISRU) and lunar science share similar objectives with respect to analyzing and characterizing the physical, mineral, and volatile materials and resources at sites of robotic and human exploration. To help mature and stress instruments, technologies, and hardware and to evaluate operations and procedures, space agencies have utilized demonstrations at analog sites on Earth before use in future missions. The US National Aeronautics and Space Administration (NASA), the Canadian Space Agency (CSA), and the German Space Agency (DLR) have utilized an analog site on the slope of Mauna Kea on the Big Island of Hawaii to test ISRU and lunar science hardware and operations in two previously held analog field tests. NASA and CSA are currently planning on a 3rd analog field test to be held in June, 2012 in Hawaii that will expand upon the successes from the previous two field tests.
Holographic representation of space-variant systems: system theory.
Marks Ii, R J; Krile, T F
1976-09-01
System theory for holographic representation of linear space-variant systems is derived. The utility of the resulting piecewise isoplanatic approximation (PIA) is illustrated by example application to the invariant system, ideal magnifier, and Fourier transformer. A method previously employed to holographically represent a space-variant system, the discrete approximation, is shown to be a special case of the PIA.
46 CFR 34.10-10 - Fire station hydrants, hose and nozzles-T/ALL.
Code of Federal Regulations, 2014 CFR
2014-10-01
... Weather deck 4 10 or 12 Machinery space 2 4 (f) Each combination firehose nozzle previously approved under... be of sufficient number and so located that any part of living quarters, storerooms, working spaces... water, one of which shall be from a single 50-foot length of hose. In main machinery spaces all portions...
46 CFR 34.10-10 - Fire station hydrants, hose and nozzles-T/ALL.
Code of Federal Regulations, 2011 CFR
2011-10-01
... Weather deck 4 10 or 12 Machinery space 2 4 (f) Each combination firehose nozzle previously approved under... be of sufficient number and so located that any part of living quarters, storerooms, working spaces... water, one of which shall be from a single 50-foot length of hose. In main machinery spaces all portions...
46 CFR 34.10-10 - Fire station hydrants, hose and nozzles-T/ALL.
Code of Federal Regulations, 2013 CFR
2013-10-01
... Weather deck 4 10 or 12 Machinery space 2 4 (f) Each combination firehose nozzle previously approved under... be of sufficient number and so located that any part of living quarters, storerooms, working spaces... water, one of which shall be from a single 50-foot length of hose. In main machinery spaces all portions...
46 CFR 34.10-10 - Fire station hydrants, hose and nozzles-T/ALL.
Code of Federal Regulations, 2012 CFR
2012-10-01
... Weather deck 4 10 or 12 Machinery space 2 4 (f) Each combination firehose nozzle previously approved under... be of sufficient number and so located that any part of living quarters, storerooms, working spaces... water, one of which shall be from a single 50-foot length of hose. In main machinery spaces all portions...
Teaching Reciprocal Space to Undergraduates via Theory and Code Components of an IPython Notebook
ERIC Educational Resources Information Center
Srnec, Matthew N.; Upadhyay, Shiv; Madura, Jeffrey D.
2016-01-01
In this technology report, a tool is provided for teaching reciprocal space to undergraduates in physical chemistry and materials science courses. Reciprocal space plays a vital role in understanding a material's electronic structure and physical properties. Here, we provide an example based on previous work in the "Journal of Chemical…
Chylack, Leo T; Peterson, Leif E; Feiveson, Alan H; Wear, Mary L; Manuel, F Keith; Tung, William H; Hardy, Dale S; Marak, Lisa J; Cucinotta, Francis A
2009-07-01
The NASA Study of Cataract in Astronauts (NASCA) is a 5-year longitudinal study of the effect of space radiation exposure on the severity/progression of nuclear, cortical and posterior subcapsular (PSC) lens opacities. Here we report on baseline data that will be used over the course of the longitudinal study. Participants include 171 consenting astronauts who flew at least one mission in space and a comparison group made up of three components: (a) 53 astronauts who had not flown in space, (b) 95 military aircrew personnel, and (c) 99 non-aircrew ground-based comparison subjects. Continuous measures of nuclear, cortical and PSC lens opacities were derived from Nidek EAS 1000 digitized images. Age, demographics, general health, nutritional intake and solar ocular exposure were measured at baseline. Astronauts who flew at least one mission were matched to comparison subjects using propensity scores based on demographic characteristics and medical history stratified by gender and smoking (ever/never). The cross-sectional data for matched subjects were analyzed by fitting customized non-normal regression models to examine the effect of space radiation on each measure of opacity. The variability and median of cortical cataracts were significantly higher for exposed astronauts than for nonexposed astronauts and comparison subjects with similar ages (P=0.015). Galactic cosmic space radiation (GCR) may be linked to increased PSC area (P=0.056) and the number of PSC centers (P=0.095). Within the astronaut group, PSC size was greater in subjects with higher space radiation doses (P=0.016). No association was found between space radiation and nuclear cataracts. Cross-sectional data analysis revealed a small deleterious effect of space radiation for cortical cataracts and possibly for PSC cataracts. These results suggest increased cataract risks at smaller radiation doses than have been reported previously.
NASA Technical Reports Server (NTRS)
Barbre', Robert E., Jr.; Deker, Ryan K.; Leahy, Frank B.; Huddleston, Lisa
2016-01-01
We present here the methodology and results of the Operational Acceptance Test (OAT) performed on the new Kennedy Space Center (KSC) 50-MHz Doppler Radar Wind Profiler (DRWP). On day-of-launch (DOL), space launch vehicle operators have used data from the DRWP to invalidate winds in prelaunch loads and trajectory assessments due to the DRWP's capability to quickly identify changes in the wind profile within a rapidly-changing wind environment. The previous DRWP has been replaced with a completely new system, which needs to undergo certification testing before being accepted for use in range operations. The new DRWP replaces the previous three-beam system made of coaxial cables and a copper wire ground plane with a four-beam system that uses Yagi antennae with enhanced beam steering capability. In addition, the new system contains updated user interface software while maintaining the same general capability as the previous system. The new DRWP continues to use the Median Filter First Guess (MFFG) algorithm to generate a wind profile from Doppler spectra at each range gate. DeTect (2015) contains further details on the upgrade. The OAT is a short-term test designed so that end users can utilize the new DRWP in a similar manner to the previous DRWP during mission operations at the Eastern Range in the midst of a long-term certification process. This paper describes the Marshall Space Flight Center Natural Environments Branch's (MSFC NE's) analyses to verify the quality and accuracy of the DRWP's meteorological data output as compared to the previous DRWP. Ultimately, each launch vehicle program has the responsibility to certify the system for their own use.
Effects of coloured lighting on the perception of interior spaces.
Odabaşioğlu, Seden; Olguntürk, Nіlgün
2015-02-01
Use of coloured lighting in interior spaces has become prevalent in recent years. Considerable importance is ascribed to coloured lighting in interior and lighting design. The effects of colour on the perception of interior spaces have been studied as surface colour; but here, the effects of three different types of chromatic light were investigated. The lighting differed in colour (red, green and white) and perceptions of interior space were assessed. 97 participants (59 women, 38 men; M age = 21.4 yr.) evaluated the experiment room on a questionnaire assessing eight evaluative factors: Pleasantness, Arousal, Aesthetics, Usefulness, Comfort, Spaciousness, Colour, and Lighting quality. Perceptions of the room differed by colour of lighting for some of the evaluative factors, but there was no sex difference in perceptions. Interior spaces may be perceived as equally pleasant under white, green and red lighting. Under white lighting a space is perceived as more useful, spacious, clear, and luminous. Green lighting would make the same effect. Green and white lighting were perceived equally comfortable in an interior space. Chromatic coloured lighting was perceived to be more aesthetic than white lighting. The results support previous findings for some evaluative factors, but differed for others.
Space Psychology and Psychiatry
NASA Astrophysics Data System (ADS)
Kanas, N.; Manzey, D.
2003-09-01
This book deals with psychological, psychiatric, and psychosocial issues that affect people who live and work in space. Unlike other books that focus on anecdotal reports and ground-based simulation studies, this book emphasizes the findings from psychological research conducted during actual space missions. Both authors have been active in such research. What is presented in this readable text has previously been found only in scientific journal articles. Topics that are discussed include: behavioral adaptation to space; human performance and cognitive effects; crewmember interactions; psychiatric responses; psychological counter-measures related to habitability factors, work-design, selection, training, and in-flight monitoring and support; and the impact of expeditionary missions to Mars and beyond. People finding this book of interest will include: psychology and social science students and professors in universities; medical students and residents in psychiatry and aerospace medicine; human factors workers in space and aviation professions; individuals involved with isolated environments on Earth (e.g., the Antarctic, submarines); aerospace workers in businesses and space agencies such as NASA and ESA; and anyone who is interested in learning the facts about the human side of long-duration space missions. Link: http://www.wkap.nl/prod/b/1-4020-1341-8
NASA Astrophysics Data System (ADS)
Xiao, Lu; Lang, Yichao; Christakos, George
2018-01-01
With rapid economic development, industrialization and urbanization, the ambient air PM2.5 has become a major pollutant linked to respiratory, heart and lung diseases. In China, PM2.5 pollution constitutes an extreme environmental and social problem of widespread public concern. In this work we estimate ground-level PM2.5 from satellite-derived aerosol optical depth (AOD), topography data, meteorological data, and pollutant emission using an integrative technique. In particular, Geographically Weighted Regression (GWR) analysis was combined with Bayesian Maximum Entropy (BME) theory to assess the spatiotemporal characteristics of PM2.5 exposure in a large region of China and generate informative PM2.5 space-time predictions (estimates). It was found that, due to its integrative character, the combined BME-GWR method offers certain improvements in the space-time prediction of PM2.5 concentrations over China compared to previous techniques. The combined BME-GWR technique generated realistic maps of space-time PM2.5 distribution, and its performance was superior to that of seven previous studies of satellite-derived PM2.5 concentrations in China in terms of prediction accuracy. The purely spatial GWR model can only be used at a fixed time, whereas the integrative BME-GWR approach accounts for cross space-time dependencies and can predict PM2.5 concentrations in the composite space-time domain. The 10-fold results of BME-GWR modeling (R2 = 0.883, RMSE = 11.39 μg /m3) demonstrated a high level of space-time PM2.5 prediction (estimation) accuracy over China, revealing a definite trend of severe PM2.5 levels from the northern coast toward inland China (Nov 2015-Feb 2016). Future work should focus on the addition of higher resolution AOD data, developing better satellite-based prediction models, and related air pollutants for space-time PM2.5 prediction purposes.
2003-06-21
KENNEDY SPACE CENTER, FLA. - At the KSC Visitor Complex, actor and Master of Ceremonies Lance Henriksen (at podium) introduces four newly inducted Space Shuttle astronauts to the audience at their induction ceremony into the U.S. Astronaut Hall of Fame. From left center, they are Story Musgrave, Sally K. Ride, Daniel Brandenstein, and Robert "Hoot" Gibson. Also standing, left, is former astronaut James A. Lovell. Conceived by six of the Mercury Program astronauts, the U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The four new inductees join 48 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
Abrasion Testing of Candidate Outer Layer Fabrics for Lunar EVA Space Suits
NASA Technical Reports Server (NTRS)
Mitchell, Kathryn
2009-01-01
During the Apollo program, the space suit outer layer fabrics were severely abraded after just a few Extravehicular Activities (EVAs). For example, the Apollo 12 commander reported abrasive wear on the boots, which penetrated the outer layer fabric into the thermal protection layers after less than eight hours of surface operations. Current plans for the Constellation Space Suit Element require the space suits to support hundreds of hours of EVA on the Lunar surface, creating a challenge for space suit designers to utilize materials advances made over the last forty years and improve upon the space suit fabrics used in the Apollo program. A test methodology has been developed by the NASA Johnson Space Center Crew and Thermal Systems Division for establishing comparative abrasion wear characteristics between various candidate space suit outer layer fabrics. The abrasion test method incorporates a large rotary drum tumbler with rocks and loose lunar simulant material to induce abrasion in fabric test cylinder elements, representative of what might occur during long term planetary surface EVAs. Preliminary materials screening activities were conducted to determine the degree of wear on representative space suit outer layer materials and the corresponding dust permeation encountered between subsequent sub-layers of thermal protective materials when exposed to a simulated worst case eight hour EVA. The test method was used to provide a preliminary evaluation of four candidate outer layer fabrics for future planetary surface space suit applications. This paper provides a review of previous abrasion studies on space suit fabrics, details the methodologies used for abrasion testing in this particular study, shares the results of the testing, and provides recommendations for future work.
Abrasion Testing of Candidate Outer Layer Fabrics for Lunar EVA Space Suits
NASA Technical Reports Server (NTRS)
Mitchell, Kathryn C.
2010-01-01
During the Apollo program, the space suit outer layer fabrics were badly abraded after just a few Extravehicular Activities (EVAs). For example, the Apollo 12 commander reported abrasive wear on the boots, which penetrated the outer layer fabric into the thermal protection layers after less than eight hours of surface operations. Current plans for the Constellation Space Suit Element require the space suits to support hundreds of hours of EVA on the Lunar surface, creating a challenge for space suit designers to utilize materials advances made over the last forty years and improve upon the space suit fabrics used in the Apollo program. A test methodology has been developed by the NASA Johnson Space Center Crew and Thermal Systems Division for establishing comparative abrasion wear characteristics between various candidate space suit outer layer fabrics. The abrasion test method incorporates a large rotary drum tumbler with rocks and loose lunar simulant material to induce abrasion in fabric test cylinder elements, representative of what might occur during long term planetary surface EVAs. Preliminary materials screening activities were conducted to determine the degree of wear on representative space suit outer layer materials and the corresponding dust permeation encountered between subsequent sub -layers of thermal protective materials when exposed to a simulated worst case eight hour EVA. The test method was used to provide a preliminary evaluation of four candidate outer layer fabrics for future planetary surface space suit applications. This Paper provides a review of previous abrasion studies on space suit fabrics, details the methodologies used for abrasion testing in this particular study, and shares the results and conclusions of the testing.
Nuclear safety for the space exploration initiative
NASA Technical Reports Server (NTRS)
Dix, Terry E.
1991-01-01
The results of a study to identify potential hazards arising from nuclear reactor power systems for use on the lunar and Martian surfaces, related safety issues, and resolutions of such issues by system design changes, operating procedures, and other means are presented. All safety aspects of nuclear reactor power systems from prelaunch ground handling to eventual disposal were examined consistent with the level of detail for SP-100 reactor design at the 1988 System Design Review and for launch vehicle and space transport vehicle designs and mission descriptions as defined in the 90-day Space Exploration Initiative (SEI) study. Information from previous aerospace nuclear safety studies was used where appropriate. Safety requirements for the SP-100 space nuclear reactor system were compiled. Mission profiles were defined with emphasis on activities after low earth orbit insertion. Accident scenarios were then qualitatively defined for each mission phase. Safety issues were identified for all mission phases with the aid of simplified event trees. Safety issue resolution approaches of the SP-100 program were compiled. Resolution approaches for those safety issues not covered by the SP-100 program were identified. Additionally, the resolution approaches of the SP-100 program were examined in light of the moon and Mars missions.
NASA Technical Reports Server (NTRS)
Kennedy, J. R.; Fitzpatrick, W. S.
1971-01-01
The computer executive functional system design concepts derived from study of the Space Station/Base are presented. Information Management System hardware configuration as directly influencing the executive design is reviewed. The hardware configuration and generic executive design requirements are considered in detail in a previous report (System Configuration and Executive Requirements Specifications for Reusable Shuttle and Space Station/Base, 9/25/70). This report defines basic system primitives and delineates processes and process control. Supervisor states are considered for describing basic multiprogramming and multiprocessing systems. A high-level computer executive including control of scheduling, allocation of resources, system interactions, and real-time supervisory functions is defined. The description is oriented to provide a baseline for a functional simulation of the computer executive system.
Adinkra (in)equivalence from Coxeter group representations: A case study
NASA Astrophysics Data System (ADS)
Chappell, Isaac; Gates, S. James; Hübsch, T.
2014-02-01
Using a MathematicaTM code, we present a straightforward numerical analysis of the 384-dimensional solution space of signed permutation 4×4 matrices, which in sets of four, provide representations of the 𝒢ℛ(4, 4) algebra, closely related to the 𝒩 = 1 (simple) supersymmetry algebra in four-dimensional space-time. Following after ideas discussed in previous papers about automorphisms and classification of adinkras and corresponding supermultiplets, we make a new and alternative proposal to use equivalence classes of the (unsigned) permutation group S4 to define distinct representations of higher-dimensional spin bundles within the context of adinkras. For this purpose, the definition of a dual operator akin to the well-known Hodge star is found to partition the space of these 𝒢ℛ(4, 4) representations into three suggestive classes.
The Unknown Hydrogen Exosphere: Space Weather Implications
NASA Astrophysics Data System (ADS)
Krall, J.; Glocer, A.; Fok, M.-C.; Nossal, S. M.; Huba, J. D.
2018-03-01
Recent studies suggest that the hydrogen (H) density in the exosphere and geocorona might differ from previously assumed values by factors as large as 2. We use the SAMI3 (Sami3 is Also a Model of the Ionosphere) and Comprehensive Inner Magnetosphere-Ionosphere models to evaluate scenarios where the hydrogen density is reduced or enhanced, by a factor of 2, relative to values given by commonly used empirical models. We show that the rate of plasmasphere refilling following a geomagnetic storm varies nearly linearly with the hydrogen density. We also show that the ring current associated with a geomagnetic storm decays more rapidly when H is increased. With respect to these two space weather effects, increased exosphere hydrogen density is associated with reduced threats to space assets during and following a geomagnetic storm.
Corrected Mean-Field Model for Random Sequential Adsorption on Random Geometric Graphs
NASA Astrophysics Data System (ADS)
Dhara, Souvik; van Leeuwaarden, Johan S. H.; Mukherjee, Debankur
2018-03-01
A notorious problem in mathematics and physics is to create a solvable model for random sequential adsorption of non-overlapping congruent spheres in the d-dimensional Euclidean space with d≥ 2 . Spheres arrive sequentially at uniformly chosen locations in space and are accepted only when there is no overlap with previously deposited spheres. Due to spatial correlations, characterizing the fraction of accepted spheres remains largely intractable. We study this fraction by taking a novel approach that compares random sequential adsorption in Euclidean space to the nearest-neighbor blocking on a sequence of clustered random graphs. This random network model can be thought of as a corrected mean-field model for the interaction graph between the attempted spheres. Using functional limit theorems, we characterize the fraction of accepted spheres and its fluctuations.
NASA Technical Reports Server (NTRS)
Sandor, Aniko; Moses, Haifa
2016-01-01
Speech alarms have been used extensively in aviation and included in International Building Codes (IBC) and National Fire Protection Association's (NFPA) Life Safety Code. However, they have not been implemented on space vehicles. Previous studies conducted at NASA JSC showed that speech alarms lead to faster identification and higher accuracy. This research evaluated updated speech and tone alerts in a laboratory environment and in the Human Exploration Research Analog (HERA) in a realistic setup.
ERIC Educational Resources Information Center
Sokhadze, Estate M.; El-Baz, Ayman; Baruth, Joshua; Mathai, Grace; Sears, Lonnie; Casanova, Manuel F.
2009-01-01
Previous studies by our group suggest that the neuropathology of autism is characterized by a disturbance of cortical modularity. In this model a decrease in the peripheral neuropil space of affected minicolumns provides for an inhibitory deficit and a readjustment in their signal to noise bias during information processing. In this study we…
A Comparison of Tandem Walk Performance Between Bed Rest Subjects and Astronauts
NASA Technical Reports Server (NTRS)
Miller, Chris; Peters, Brian; Kofman, Igor; Philips, Tiffany; Batson, Crystal; Cerisano, Jody; Fisher, Elizabeth; Mulavara, Ajitkumar; Feiveson, Alan; Reschke, Millard;
2015-01-01
Astronauts experience a microgravity environment during spaceflight, which results in a central reinterpretation of both vestibular and body axial-loading information by the sensorimotor system. Subjects in bed rest studies lie at 6deg head-down in strict bed rest to simulate the fluid shift and gravity-unloading of the microgravity environment. However, bed rest subjects still sense gravity in the vestibular organs. Therefore, bed rest isolates the axial-unloading component, thus allowing for the direct study of its effects. The Tandem Walk is a standard sensorimotor test of dynamic postural stability. In a previous abstract, we compared performance on a Tandem Walk test between bed rest control subjects, and short- and long-duration astronauts both before and after flight/bed rest using a composite index of performance, called the Tandem Walk Parameter (TWP), that takes into account speed, accuracy, and balance control. This new study extends the previous data set to include bed rest subjects who performed exercise countermeasures. The purpose of this study was to compare performance during the Tandem Walk test between bed rest subjects (with and without exercise), short-duration (Space Shuttle) crewmembers, and long-duration International Space Station (ISS) crewmembers at various time points during their recovery from bed rest or spaceflight.
Feathering instability of spiral arms. II. Parameter study
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lee, Wing-Kit, E-mail: wklee@asiaa.sinica.edu.tw; Institute of Astronomy and Astrophysics, Academia Sinica, Taipei 115, Taiwan
2014-09-10
We report the results of a parameter study of the feathering stability in the galactic spiral arms. A two-dimensional, razor-thin magnetized self-gravitating gas disk with an imposed two-armed stellar spiral structure is considered. Using the formulation developed previously by Lee and Shu, a linear stability analysis of the spiral shock is performed in a localized Cartesian geometry. Results of the parameter study of the base state with a spiral shock are also presented. The single-mode feathering instability that leads to growing perturbations may explain the feathering phenomenon found in nearby spiral galaxies. The self-gravity of the gas, characterized by itsmore » average surface density, is an important parameter that (1) shifts the spiral shock farther downstream and (2) increases the growth rate and decreases the characteristic spacing of the feathering structure due to the instability. On the other hand, while the magnetic field suppresses the velocity fluctuation associated with the feathers, it does not strongly affect their growth rate. Using a set of typical parameters of the grand-design spiral galaxy M51 at 2 kpc from the center, the spacing of the feathers with the maximum growth rate is found to be 530 pc, which agrees with the previous observational studies.« less
Utilizing Participatory Mapping and GIS to Examine the Activity Spaces of Homeless Youth.
Townley, Greg; Pearson, L; Lehrwyn, Josephine M; Prophet, Nicole T; Trauernicht, Mareike
2016-06-01
Although previous studies have informed our understanding of certain aspects of youth homelessness, few studies have critically examined the spatial and social environments utilized by youth as they navigate life on the streets. This study employed participatory mapping and Geographic Information Systems (GIS) to examine the activity spaces of homeless youth as they relate to sense of community and psychological well-being. Participants were 28 youth experiencing homelessness in Portland, Oregon, USA. Results suggest that youth engage most frequently in service-related activities, and their activity participation is significantly associated with sense of community and psychological well-being. The utility of innovative participatory methods for better understanding the diverse experiences of homeless youth is discussed alongside examination of their practical implications. © Society for Community Research and Action 2016.
Analysis of GMO Plum Plant Culture in System Operations Failure
NASA Technical Reports Server (NTRS)
Mercado, Dianne
2017-01-01
GMO plum trees are being evaluated at the Kennedy Space Center as a possible candidate for future space crops. Previously conducted horticultural testing compared the performance of several plum genotypes in controlled environment chambers, resulting in a down-selection to the NASA-11 genotype. Precursory studies determined the water use requirements to sustain the plants as well as the feasibility of grafting non-GMO plum scions onto GMO plum rootstocks of NASA-5, NASA-10, and NASA-11 genotypes. This study follows the growth and horticultural progress of plum trees and in-vitro cultures from August 2017 to November 2017, and provides supplemental support for future GMO plum studies. The presence of Hurricane Irma in early September 2017 resulted in the plants undergoing material deterioration from major changes to their overall horticultural progress.
Variation in developmental time affects mating success and Allee effects
Christelle Robinet; Andrew Liebhold; David Gray
2007-01-01
A fundamental question in biological conservation and invasion biology is why do some populations go extinct? Allee effects, notably those caused by mate location failure, are potentially key factors leading to the extinction of sparse populations. Several previous studies have focused on the inability of males and females to locate each other in space when populations...
ERIC Educational Resources Information Center
Reid, Hazel; West, Linden
2016-01-01
This paper explores the constraints to innovative, creative and reflexive careers counselling in an uncertain neo-liberal world. We draw on previously reported research into practitioners' use of a narrative model for career counselling interviews in England and a Europe-wide auto/biographical narrative study of non-traditional learners in…
ERIC Educational Resources Information Center
Cohen, Arie; Fiorello, Catherine A.; Farley, Frank H.
2006-01-01
A previous study on the underlying structure of the Wechsler intelligence test (WISC-R; [Wechsler, D. (1974). Manual WISC-R: Wechsler intelligence scale for children-Revised. New York: Psychological Corporation]), using smallest space analysis (SSA) [Guttman, L., and Levy, S. (1991). Two structural laws for intelligence tests.…
ERIC Educational Resources Information Center
Chen, Xiangming; Wei, Ge; Jiang, Shuling
2017-01-01
Previous research concerning teacher practical knowledge has revealed its epistemological foundations, content structure and research methodology, but little research examines its ethical dimension. Based on a four-year project in China, this study probes the ethical dimension of an experienced teacher's practical knowledge, explicated in a…
A parametric study of the drift-tearing mode using an extended-magnetohydrodynamic model
King, Jacob R.; Kruger, S. E.
2014-10-24
The linear, collisional, constant-ψ drift-tearing mode is analyzed for different regimes of the plasma-β, ion-skin-depth parameter space with an unreduced, extended-magnetohydrodynamic model. Here, new dispersion relations are found at moderate plasma β and previous drift-tearing results are classified as applicable at small plasma β.
USDA-ARS?s Scientific Manuscript database
A multidisciplinary, molecular and conventional epidemiological approach was applied to an investigation of endemic foot-and-mouth disease in Vietnam. Within the study space, it was found that 22.3 percent of sampled ruminants had previously been infected with FMD virus (FMDV) and that 2.4 percent w...
Heat transfer measurements for Stirling machine cylinders
NASA Technical Reports Server (NTRS)
Kornhauser, Alan A.; Kafka, B. C.; Finkbeiner, D. L.; Cantelmi, F. C.
1994-01-01
The primary purpose of this study was to measure the effects of inflow-produced heat turbulence on heat transfer in Stirling machine cylinders. A secondary purpose was to provide new experimental information on heat transfer in gas springs without inflow. The apparatus for the experiment consisted of a varying-volume piston-cylinder space connected to a fixed volume space by an orifice. The orifice size could be varied to adjust the level of inflow-produced turbulence, or the orifice plate could be removed completely so as to merge the two spaces into a single gas spring space. Speed, cycle mean pressure, overall volume ratio, and varying volume space clearance ratio could also be adjusted. Volume, pressure in both spaces, and local heat flux at two locations were measured. The pressure and volume measurements were used to calculate area averaged heat flux, heat transfer hysteresis loss, and other heat transfer-related effects. Experiments in the one space arrangement extended the range of previous gas spring tests to lower volume ratio and higher nondimensional speed. The tests corroborated previous results and showed that analytic models for heat transfer and loss based on volume ratio approaching 1 were valid for volume ratios ranging from 1 to 2, a range covering most gas springs in Stirling machines. Data from experiments in the two space arrangement were first analyzed based on lumping the two spaces together and examining total loss and averaged heat transfer as a function of overall nondimensional parameter. Heat transfer and loss were found to be significantly increased by inflow-produced turbulence. These increases could be modeled by appropriate adjustment of empirical coefficients in an existing semi-analytic model. An attempt was made to use an inverse, parameter optimization procedure to find the heat transfer in each of the two spaces. This procedure was successful in retrieving this information from simulated pressure-volume data with artificially generated noise, but it failed with the actual experimental data. This is evidence that the models used in the parameter optimization procedure (and to generate the simulated data) were not correct. Data from the surface heat flux sensors indicated that the primary shortcoming of these models was that they assumed turbulence levels to be constant over the cycle. Sensor data in the varying volume space showed a large increase in heat flux, probably due to turbulence, during the expansion stroke.
NASA Technical Reports Server (NTRS)
Pyle, Barry; Vasques, Marilyn; Aquilina, Rudy (Technical Monitor)
2002-01-01
Since the first human flights outside of Earth's gravity, crew health and well-being have been major concerns. Exposure to microgravity during spaceflight is known to affect the human immune response, possibly making the crew members more vulnerable to infectious disease. In addition, biological experiments previously flown in space have shown that bacteria grow faster in microgravity than they do on Earth. The ability of certain antibiotics to control bacterial infections may also differ greatly in microgravity. It is therefore critical to understand how spaceflight and microgravity affect bacterial virulence, which is their ability to cause disease. By utilizing spaceflight hardware provided by the European Space Agency (ESA), Dr. Barry Pyle and his team at Montana State University, Bozeman, will be performing an experiment to study the effects of microgravity on the virulence of a common soil and water bacterium, Pseudomonas aeruginosa. Importantly, these bacteria have been detected in the water supplies of previous Space Shuttle flights. The experiment will examine the effects of microgravity exposure on bacterial growth and on the bacterium's ability to form a toxin called Exotoxin A. Another goal is to evaluate the effects of microgravity on the physiology of the bacteria by analyzing their ability to respire (produce energy), by studying the condition of the plasma membrane surrounding the cell, and by determining if specific enzymes remain active. Proteins produced by the bacteria will also be assayed to see if the normal functions of the bacteria are affected. In the context of human life support in spaceflight, the results of this experiment will offer guidance in providing the highest possible water quality for the Shuttle in order to limit the risk of infection to human occupants and to minimize water system and spacecraft deterioration.
The phase-space structure of nearby dark matter as constrained by the SDSS
DOE Office of Scientific and Technical Information (OSTI.GOV)
Leclercq, Florent; Percival, Will; Jasche, Jens
Previous studies using numerical simulations have demonstrated that the shape of the cosmic web can be described by studying the Lagrangian displacement field. We extend these analyses, showing that it is now possible to perform a Lagrangian description of cosmic structure in the nearby Universe based on large-scale structure observations. Building upon recent Bayesian large-scale inference of initial conditions, we present a cosmographic analysis of the dark matter distribution and its evolution, referred to as the dark matter phase-space sheet, in the nearby universe as probed by the Sloan Digital Sky Survey main galaxy sample. We consider its stretchings andmore » foldings using a tetrahedral tessellation of the Lagrangian lattice. The method provides extremely accurate estimates of nearby density and velocity fields, even in regions of low galaxy density. It also measures the number of matter streams, and the deformation and parity reversals of fluid elements, which were previously thought inaccessible using observations. We illustrate the approach by showing the phase-space structure of known objects of the nearby Universe such as the Sloan Great Wall, the Coma cluster and the Boötes void. We dissect cosmic structures into four distinct components (voids, sheets, filaments, and clusters), using the Lagrangian classifiers DIVA, ORIGAMI, and a new scheme which we introduce and call LICH. Because these classifiers use information other than the sheer local density, identified structures explicitly carry physical information about their formation history. Accessing the phase-space structure of dark matter in galaxy surveys opens the way for new confrontations of observational data and theoretical models. We have made our data products publicly available.« less
The phase-space structure of nearby dark matter as constrained by the SDSS
NASA Astrophysics Data System (ADS)
Leclercq, Florent; Jasche, Jens; Lavaux, Guilhem; Wandelt, Benjamin; Percival, Will
2017-06-01
Previous studies using numerical simulations have demonstrated that the shape of the cosmic web can be described by studying the Lagrangian displacement field. We extend these analyses, showing that it is now possible to perform a Lagrangian description of cosmic structure in the nearby Universe based on large-scale structure observations. Building upon recent Bayesian large-scale inference of initial conditions, we present a cosmographic analysis of the dark matter distribution and its evolution, referred to as the dark matter phase-space sheet, in the nearby universe as probed by the Sloan Digital Sky Survey main galaxy sample. We consider its stretchings and foldings using a tetrahedral tessellation of the Lagrangian lattice. The method provides extremely accurate estimates of nearby density and velocity fields, even in regions of low galaxy density. It also measures the number of matter streams, and the deformation and parity reversals of fluid elements, which were previously thought inaccessible using observations. We illustrate the approach by showing the phase-space structure of known objects of the nearby Universe such as the Sloan Great Wall, the Coma cluster and the Boötes void. We dissect cosmic structures into four distinct components (voids, sheets, filaments, and clusters), using the Lagrangian classifiers DIVA, ORIGAMI, and a new scheme which we introduce and call LICH. Because these classifiers use information other than the sheer local density, identified structures explicitly carry physical information about their formation history. Accessing the phase-space structure of dark matter in galaxy surveys opens the way for new confrontations of observational data and theoretical models. We have made our data products publicly available.
Task-discriminative space-by-time factorization of muscle activity
Delis, Ioannis; Panzeri, Stefano; Pozzo, Thierry; Berret, Bastien
2015-01-01
Movement generation has been hypothesized to rely on a modular organization of muscle activity. Crucial to this hypothesis is the ability to perform reliably a variety of motor tasks by recruiting a limited set of modules and combining them in a task-dependent manner. Thus far, existing algorithms that extract putative modules of muscle activations, such as Non-negative Matrix Factorization (NMF), identify modular decompositions that maximize the reconstruction of the recorded EMG data. Typically, the functional role of the decompositions, i.e., task accomplishment, is only assessed a posteriori. However, as motor actions are defined in task space, we suggest that motor modules should be computed in task space too. In this study, we propose a new module extraction algorithm, named DsNM3F, that uses task information during the module identification process. DsNM3F extends our previous space-by-time decomposition method (the so-called sNM3F algorithm, which could assess task performance only after having computed modules) to identify modules gauging between two complementary objectives: reconstruction of the original data and reliable discrimination of the performed tasks. We show that DsNM3F recovers the task dependence of module activations more accurately than sNM3F. We also apply it to electromyographic signals recorded during performance of a variety of arm pointing tasks and identify spatial and temporal modules of muscle activity that are highly consistent with previous studies. DsNM3F achieves perfect task categorization without significant loss in data approximation when task information is available and generalizes as well as sNM3F when applied to new data. These findings suggest that the space-by-time decomposition of muscle activity finds robust task-discriminating modular representations of muscle activity and that the insertion of task discrimination objectives is useful for describing the task modulation of module recruitment. PMID:26217213
Task-discriminative space-by-time factorization of muscle activity.
Delis, Ioannis; Panzeri, Stefano; Pozzo, Thierry; Berret, Bastien
2015-01-01
Movement generation has been hypothesized to rely on a modular organization of muscle activity. Crucial to this hypothesis is the ability to perform reliably a variety of motor tasks by recruiting a limited set of modules and combining them in a task-dependent manner. Thus far, existing algorithms that extract putative modules of muscle activations, such as Non-negative Matrix Factorization (NMF), identify modular decompositions that maximize the reconstruction of the recorded EMG data. Typically, the functional role of the decompositions, i.e., task accomplishment, is only assessed a posteriori. However, as motor actions are defined in task space, we suggest that motor modules should be computed in task space too. In this study, we propose a new module extraction algorithm, named DsNM3F, that uses task information during the module identification process. DsNM3F extends our previous space-by-time decomposition method (the so-called sNM3F algorithm, which could assess task performance only after having computed modules) to identify modules gauging between two complementary objectives: reconstruction of the original data and reliable discrimination of the performed tasks. We show that DsNM3F recovers the task dependence of module activations more accurately than sNM3F. We also apply it to electromyographic signals recorded during performance of a variety of arm pointing tasks and identify spatial and temporal modules of muscle activity that are highly consistent with previous studies. DsNM3F achieves perfect task categorization without significant loss in data approximation when task information is available and generalizes as well as sNM3F when applied to new data. These findings suggest that the space-by-time decomposition of muscle activity finds robust task-discriminating modular representations of muscle activity and that the insertion of task discrimination objectives is useful for describing the task modulation of module recruitment.
2012-05-23
CAPE CANAVERAL, Fla. – The drawbridge span of the NASA Railroad’s Jay Jay Railroad Bridge over the Indian River north of Launch Complex 39 at NASA’s Kennedy Space Center in Florida is reopened following the passage of a NASA Railroad train. The permanent configuration of the bridge is open the span is lowered only for a train to cross. The railroad cars were needed in support of the Space Shuttle Program but currently are not in use by NASA following the completion of the program in 2011. Originally, the tankers belonged to the U.S. Bureau of Mines. At the peak of the shuttle program, there were approximately 30 cars in the fleet. About half the cars were returned to the bureau as launch activity diminished. Five tank cars are being loaned to SpaceX and repurposed to support their engine tests in Texas. Eight cars previously were shipped to California on loan to support the SpaceX Falcon 9 rocket launches from Space Launch Complex-4 on Vandenberg Air Force Base. SpaceX already has three helium tank cars previously used for the shuttle program at Space Launch Complex-40 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/spacex. Photo credit: NASA/Jim Grossmann
NASA Technical Reports Server (NTRS)
Lee, Mona D.; Tuttle, Ronald; Girten, Beverly
1995-01-01
There are limited data regarding changes in oxidative and antioxidant enzymes induced by simulated or actual weightlessness, and any additional information would provide insight into potential mechanisms involving other changes observed in muscles from animals previously flown in space. Thus, the NASA Biospecimen Sharing Program was an opportunity to collect valuable information. Oxidative and antioxidant enzyme levels, as well as lipid peroxidation, were measured in respiratory muscles from rates flown on board Space Shuttle mission STS-54. The results indicated that there was an increasing trend in citrate synthase activity in the flight diaphragm when compared to ground based controls, and there were no significant changes observed in the intercostal muscles for any of the parameters. However, the lipid peroxidation was significantly (p less than 0.05) decreased in the flight diaphragm. These results indicate that 6 day exposure to microgravity may have a different effect on oxidative and antioxidant activity in rat respiratory muscles when compared to data from previous 14 day hindlimb suspension studies.
Space program payload costs and their possible reduction
NASA Technical Reports Server (NTRS)
Vanvleck, E. M.; Deerwester, J. M.; Norman, S. M.; Alton, L. R.
1973-01-01
The possible ways by which NASA payload costs might be reduced in the future were studied. The major historical reasons for payload costs being as they were, and if there are technologies (hard and soft), or criteria for technology advances, that could significantly reduce total costs of payloads were examined. Payload costs are placed in historical context. Some historical cost breakdowns for unmanned NASA payloads are presented to suggest where future cost reductions could be most significant. Space programs of NOAA, DoD and COMSAT are then examined to ascertain if payload reductions have been brought about by the operational (as opposed to developmental) nature of such programs, economies of scale, the ability to rely on previously developed technology, or by differing management structures and attitudes. The potential impact was investigated of NASA aircraft-type management on spacecraft program costs, and some examples relating previous costs associated with aircraft costs on the one hand and manned and unmanned costs on the other are included.
Hydrodynamic aspects of shark scales
NASA Technical Reports Server (NTRS)
Raschi, W. G.; Musick, J. A.
1986-01-01
Ridge morphometrices on placoid scales from 12 galeoid shark species were examined in order to evaluate their potential value for frictional drag reduction. The geometry of the shark scales is similar to longitudinal grooved surfaces (riblets) that have been previously shown to give 8 percent skin-friction reduction for turbulent boundary layers. The present study of the shark scales was undertaken to determine if the physical dimensions of the ridges on the shark scales are of the right magnitude to be used by the sharks for drag reduction based on previous riblet work. The results indicate that the ridge heights and spacings are normally maintained between the predicted optimal values proposed for voluntary and burst swimming speeds throughout the individual's ontogeny. Moreover, the species which might be considered to be the faster posses smaller and more closely spaced ridges that based on the riblet work would suggest a greater frictional drag reduction value at the high swimming speeds, as compared to their more sluggish counterparts.
2003-03-06
KENNEDY SPACE CENTER, FLA. - The Astronaut Memorial Space Mirror at the KSC Visitor Complex has had added attention since the loss of the Columbia crew Feb. 1, 2003, when they died in an explosion as they were returning to Earth from mission STS-107. The memorial is a national tribute to 17 American astronauts who previously gave their lives to the quest to explore space.
NASA Technical Reports Server (NTRS)
Zerlaut, Gene A.; Gilligan, J. E.; Harada, Y.
1965-01-01
In a previous research program for the Jet Propulsion- Laboratory, extensive studies led to the development and specifications of three zinc oxide-pigmented thermal-control coatings. The principal objectives of this program are: improvement of the three paints (as engineering materials), determination of the validity of our accelerated space-simulation testing, and continuation of the zinc oxide photolysis studies begun in the preceding program. Specific tasks that are discussed include: improvement of potassium silicate coatings as engineering materials and elucidation of their storage and handling problems; improvement of methyl silicone coatings as engineering materials; studies of zinc oxide photolysis to establish reasons for the observed stability of zinc oxide; and determination of space-simulation parameters such as long-term stability (to 8000 ESH), effect of coating surface temperature on the rate of degradation, and validity of accelerated testing (by reciprocity and wavelength dependency studies).
The Federated Satellite Systems paradigm: Concept and business case evaluation
NASA Astrophysics Data System (ADS)
Golkar, Alessandro; Lluch i Cruz, Ignasi
2015-06-01
This paper defines the paradigm of Federated Satellite Systems (FSS) as a novel distributed space systems architecture. FSS are networks of spacecraft trading previously inefficiently allocated and unused resources such as downlink bandwidth, storage, processing power, and instrument time. FSS holds the promise to enhance cost-effectiveness, performance and reliability of existing and future space missions, by networking different missions and effectively creating a pool of resources to exchange between participants in the federation. This paper introduces and describes the FSS paradigm, and develops an approach integrating mission analysis and economic assessments to evaluate the feasibility of the business case of FSS. The approach is demonstrated on a case study on opportunities enabled by FSS to enhance space exploration programs, with particular reference to the International Space Station. The application of the proposed methodology shows that the FSS concept is potentially able to create large commercial markets of in-space resources, by providing the technical platform to offer the opportunity for spacecraft to share or make use of unused resources within their orbital neighborhood. It is shown how the concept is beneficial to satellite operators, space agencies, and other stakeholders of the space industry to more flexibly interoperate space systems as a portfolio of assets, allowing unprecedented collaboration among heterogeneous types of missions.
Local endwall heat/mass-transfer distributions in pin fin channels
NASA Astrophysics Data System (ADS)
Lau, S. C.; Kim, Y. S.; Han, J. C.
1987-10-01
Naphthalene sublimination experiments were conducted to study the effects of the pin configuration, the pin length-to-diameter ratio, and the entrance length on local endwall heat/mass transfer in a channel with short pin fins (pin length-to-diameter ratios of 0.5 and 1.0). The detailed distributions of the local endwall heat/mass-transfer coefficient were obtained for staggered and aligned arrays of pin fins, for the spanwise pin spacing-to-diameter ratio of 2.5, and for streamwise pin spacing-to-diameter ratios of 1.25 and 2.5. The Reynolds numbers were kept at about 33,000. Overall- and row-averaged Nusselt numbers compared very well with those from previous heat-transfer studies.
NASA Astrophysics Data System (ADS)
Del Seppia, C.; Mezzasalma, L.; Messerotti, M.; Cordelli, A.; Ghione, S.
2009-01-01
We have previously reported that the exposure to an abnormal magnetic field simulating the one encountered by the International Space Station (ISS) orbiting around the Earth may enhance autonomic response to emotional stimuli. Here we report the results of the second part of that study which tested whether this field also affects cognitive functions. Twenty-four volunteers participated in the study, 12 exposed to the natural geomagnetic field and 12 to the magnetic field encountered by ISS. The test protocol consisted of a set of eight tests chosen from a computerized test battery for the assessment of attentional performance. The duration of exposure was 90 min. No effect of exposure to ISS magnetic field was observed on attentional performance.
Investigation of low-cost ablative heat shield fabrication for space shuttles
NASA Technical Reports Server (NTRS)
Chandler, H. H.
1972-01-01
Improvements in the processes and design to reduce the manufacturing costs for low density ablative panels for the space shuttle are discussed. The areas that were studied included methods of loading honeycomb core, alternative reinforcement concepts, and the use of reusable subpanels. A review of previous studies on the fabrication of low-cost ablative panels and on permissible defects that do not affect thermal performance was conducted. Considerable differences in the quoted prices for ablative panels, even though the various contractors had reported similar fabrication times were discovered. How these cost differences arise from different estimating criteria and which estimating assumptions and other costs must be included in order to arrive at a realistic price are discussed.
Mars habitat modules: launch, scaling and functional design considerations.
Bell, Larry; Hines, Gerald D
2005-07-01
The Sasakawa International Center for Space Architecture (SICSA) is undertaking a multi-year research, planning and design study that is exploring near- and long-term commercial space development opportunities. The central goal of this activity is to conceptualize a scenario of sequential, integrated private enterprise initiatives that can carry humankind forward to Mars. Each development stage is planned as a building block to provide the economic foundation, technology advancements and operational infrastructure to support others that follow. This report presents fundamental issues and requirements associated with planning human Mars initiatives that can transfer crews, habitats and equipment from Earth to Mars orbit, deliver them to the planet's surface, and return people and samples safely back to Earth. The study builds in part upon previous studies which are summarized in SICSA's: Commercial Space Development Plan and the Artificial Gravity Science and Excursion Vehicle reports. Information and conclusions produced in this study provide assumptions and a conceptual foundation for a subsequent report titled The First Mars Outpost: Planning and Concepts. c2005 Elsevier Ltd. All rights reserved.
Computation of the soft anomalous dimension matrix in coordinate space
NASA Astrophysics Data System (ADS)
Mitov, Alexander; Sterman, George; Sung, Ilmo
2010-08-01
We complete the coordinate space calculation of the three-parton correlation in the two-loop massive soft anomalous dimension matrix. The full answer agrees with the result found previously by a different approach. The coordinate space treatment of renormalized two-loop gluon exchange diagrams exhibits their color symmetries in a transparent fashion. We compare coordinate space calculations of the soft anomalous dimension matrix with massive and massless eikonal lines and examine its nonuniform limit at absolute threshold.
MS Linnehan watches EVA 2 from aft flight deck
2002-03-05
STS109-E-5621 (5 March 2002) --- Astronaut Richard M. Linnehan, mission specialist, monitors the STS-109 mission's second space walk from the aft flight deck of the Space Shuttle Columbia. Astronauts James H. Newman and Michael J. Massimino were working on the Hubble Space Telescope (HST), temporarily captured in the shuttle's cargo bay. Linnehan had participated in the mission's first space walk on the previous day. This image was recorded with a digital still camera.
2012-05-23
CAPE CANAVERAL, Fla. – A NASA Railroad train crosses the railroad’s Jay Jay Railroad Bridge north of Launch Complex 39 at NASA’s Kennedy Space Center in Florida. The train is on its way to the Florida East Coast Railway interchange in Titusville, Fla., where the train’s helium tank cars, a liquid oxygen tank car, and a liquid hydrogen dewar or tank car will be transferred for delivery to the SpaceX engine test complex outside McGregor, Texas. The railroad cars were needed in support of the Space Shuttle Program but currently are not in use by NASA following the completion of the program in 2011. Originally, the tankers belonged to the U.S. Bureau of Mines. At the peak of the shuttle program, there were approximately 30 cars in the fleet. About half the cars were returned to the bureau as launch activity diminished. Five tank cars are being loaned to SpaceX and repurposed to support their engine tests in Texas. Eight cars previously were shipped to California on loan to support the SpaceX Falcon 9 rocket launches from Space Launch Complex-4 on Vandenberg Air Force Base. SpaceX already has three helium tank cars previously used for the shuttle program at Space Launch Complex-40 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/spacex. Photo credit: NASA/Jim Grossmann
2012-05-23
CAPE CANAVERAL, Fla. – A NASA Railroad train crosses the railroad’s Jay Jay Railroad Bridge north of Launch Complex 39 at NASA’s Kennedy Space Center in Florida. The train is on its way to the Florida East Coast Railway interchange in Titusville, Fla., where the train’s helium tank cars, a liquid oxygen tank car, and a liquid hydrogen dewar or tank car will be transferred for delivery to the SpaceX engine test complex outside McGregor, Texas. The railroad cars were needed in support of the Space Shuttle Program but currently are not in use by NASA following the completion of the program in 2011. Originally, the tankers belonged to the U.S. Bureau of Mines. At the peak of the shuttle program, there were approximately 30 cars in the fleet. About half the cars were returned to the bureau as launch activity diminished. Five tank cars are being loaned to SpaceX and repurposed to support their engine tests in Texas. Eight cars previously were shipped to California on loan to support the SpaceX Falcon 9 rocket launches from Space Launch Complex-4 on Vandenberg Air Force Base. SpaceX already has three helium tank cars previously used for the shuttle program at Space Launch Complex-40 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/spacex. Photo credit: NASA/Jim Grossmann
2012-05-23
CAPE CANAVERAL, Fla. – Engineers board a NASA Railroad train in preparation for its departure from the NASA Railroad Yard at NASA’s Kennedy Space Center in Florida. The train is headed for the Florida East Coast Railway interchange in Titusville, Fla., where the train’s helium tank cars, a liquid oxygen tank car, and a liquid hydrogen dewar or tank car will be transferred for delivery to the SpaceX engine test complex outside McGregor, Texas. The railroad cars were needed in support of the Space Shuttle Program but currently are not in use by NASA following the completion of the program in 2011. Originally, the tankers belonged to the U.S. Bureau of Mines. At the peak of the shuttle program, there were approximately 30 cars in the fleet. About half the cars were returned to the bureau as launch activity diminished. Five tank cars are being loaned to SpaceX and repurposed to support their engine tests in Texas. Eight cars previously were shipped to California on loan to support the SpaceX Falcon 9 rocket launches from Space Launch Complex-4 on Vandenberg Air Force Base. SpaceX already has three helium tank cars previously used for the shuttle program at Space Launch Complex-40 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/spacex. Photo credit: NASA/Jim Grossmann
2012-05-23
CAPE CANAVERAL, Fla. – A NASA Railroad train passes in front of the 525-foot-tall Vehicle Assembly Building at NASA’s Kennedy Space Center in Florida. At the far right is the Orbiter Processing Facility. The train is on its way to the Florida East Coast Railway interchange in Titusville, Fla., where the train’s helium tank cars, a liquid oxygen tank car, and a liquid hydrogen dewar or tank car will be transferred for delivery to the SpaceX engine test complex outside McGregor, Texas. The railroad cars were needed in support of the Space Shuttle Program but currently are not in use by NASA following the completion of the program in 2011. Originally, the tankers belonged to the U.S. Bureau of Mines. At the peak of the shuttle program, there were approximately 30 cars in the fleet. About half the cars were returned to the bureau as launch activity diminished. Five tank cars are being loaned to SpaceX and repurposed to support their engine tests in Texas. Eight cars previously were shipped to California on loan to support the SpaceX Falcon 9 rocket launches from Space Launch Complex-4 on Vandenberg Air Force Base. SpaceX already has three helium tank cars previously used for the shuttle program at Space Launch Complex-40 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/spacex. Photo credit: NASA/Jim Grossmann
2012-05-21
CAPE CANAVERAL, Fla. – At the NASA Railroad yard at Kennedy Space Center in Florida, cranes are enlisted to lift helium tank cars from their trucks onto flat cars in preparation for a journey to the Florida East Coast Railway interchange in Titusville, Fla., where the train’s tank cars will be transferred for delivery to the SpaceX engine test complex outside McGregor, Texas. The yard is located in Kennedy’s Launch Complex 39 near the 525-foot-tall Vehicle Assembly Building, in the background. The railroad cars were needed in support of the Space Shuttle Program but currently are not in use by NASA following the completion of the program in 2011. Originally, the tankers belonged to the U.S. Bureau of Mines. At the peak of the shuttle program, there were approximately 30 cars in the fleet. About half the cars were returned to the bureau as launch activity diminished. Five tank cars are being loaned to SpaceX and repurposed to support their engine tests in Texas. Eight cars previously were shipped to California on loan to support the SpaceX Falcon 9 rocket launches from Space Launch Complex-4 on Vandenberg Air Force Base. SpaceX already has three helium tank cars previously used for the shuttle program at Space Launch Complex-40 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/spacex. Photo credit: NASA/Jim Grossmann
2012-05-23
CAPE CANAVERAL, Fla. – A NASA Railroad train passes in front of the twin bays of the Orbiter Processing Facility at NASA’s Kennedy Space Center in Florida. The train is on its way to the Florida East Coast Railway interchange in Titusville, Fla., where the train’s helium tank cars, a liquid oxygen tank car, and a liquid hydrogen dewar or tank car will be transferred for delivery to the SpaceX engine test complex outside McGregor, Texas. The railroad cars were needed in support of the Space Shuttle Program but currently are not in use by NASA following the completion of the program in 2011. Originally, the tankers belonged to the U.S. Bureau of Mines. At the peak of the shuttle program, there were approximately 30 cars in the fleet. About half the cars were returned to the bureau as launch activity diminished. Five tank cars are being loaned to SpaceX and repurposed to support their engine tests in Texas. Eight cars previously were shipped to California on loan to support the SpaceX Falcon 9 rocket launches from Space Launch Complex-4 on Vandenberg Air Force Base. SpaceX already has three helium tank cars previously used for the shuttle program at Space Launch Complex-40 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/spacex. Photo credit: NASA/Jim Grossmann
2012-05-23
CAPE CANAVERAL, Fla. – A NASA Railroad train passes in front of the twin bays of the Orbiter Processing Facility at NASA’s Kennedy Space Center in Florida. The train is on its way to the Florida East Coast Railway interchange in Titusville, Fla., where the train’s helium tank cars, a liquid oxygen tank car, and a liquid hydrogen dewar or tank car will be transferred for delivery to the SpaceX engine test complex outside McGregor, Texas. The railroad cars were needed in support of the Space Shuttle Program but currently are not in use by NASA following the completion of the program in 2011. Originally, the tankers belonged to the U.S. Bureau of Mines. At the peak of the shuttle program, there were approximately 30 cars in the fleet. About half the cars were returned to the bureau as launch activity diminished. Five tank cars are being loaned to SpaceX and repurposed to support their engine tests in Texas. Eight cars previously were shipped to California on loan to support the SpaceX Falcon 9 rocket launches from Space Launch Complex-4 on Vandenberg Air Force Base. SpaceX already has three helium tank cars previously used for the shuttle program at Space Launch Complex-40 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/spacex. Photo credit: NASA/Jim Grossmann
2012-05-23
CAPE CANAVERAL, Fla. – A NASA Railroad train has crossed the Indian River on the railroad’s Jay Jay Railroad Bridge north of Launch Complex 39 at NASA’s Kennedy Space Center in Florida. The train is on its way to the Florida East Coast Railway interchange in Titusville, Fla., where the train’s helium tank cars, a liquid oxygen tank car, and a liquid hydrogen dewar or tank car will be transferred for delivery to the SpaceX engine test complex outside McGregor, Texas. The railroad cars were needed in support of the Space Shuttle Program but currently are not in use by NASA following the completion of the program in 2011. Originally, the tankers belonged to the U.S. Bureau of Mines. At the peak of the shuttle program, there were approximately 30 cars in the fleet. About half the cars were returned to the bureau as launch activity diminished. Five tank cars are being loaned to SpaceX and repurposed to support their engine tests in Texas. Eight cars previously were shipped to California on loan to support the SpaceX Falcon 9 rocket launches from Space Launch Complex-4 on Vandenberg Air Force Base. SpaceX already has three helium tank cars previously used for the shuttle program at Space Launch Complex-40 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/spacex. Photo credit: NASA/Jim Grossmann
2012-05-23
CAPE CANAVERAL, Fla. – A NASA Railroad train crosses the railroad’s Jay Jay Railroad Bridge north of Launch Complex 39 at NASA’s Kennedy Space Center in Florida. The train is on its way to the Florida East Coast Railway interchange in Titusville, Fla., where the train’s helium tank cars, a liquid oxygen tank car, and a liquid hydrogen dewar or tank car will be transferred for delivery to the SpaceX engine test complex outside McGregor, Texas. The railroad cars were needed in support of the Space Shuttle Program but currently are not in use by NASA following the completion of the program in 2011. Originally, the tankers belonged to the U.S. Bureau of Mines. At the peak of the shuttle program, there were approximately 30 cars in the fleet. About half the cars were returned to the bureau as launch activity diminished. Five tank cars are being loaned to SpaceX and repurposed to support their engine tests in Texas. Eight cars previously were shipped to California on loan to support the SpaceX Falcon 9 rocket launches from Space Launch Complex-4 on Vandenberg Air Force Base. SpaceX already has three helium tank cars previously used for the shuttle program at Space Launch Complex-40 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/spacex. Photo credit: NASA/Jim Grossmann
2012-05-23
CAPE CANAVERAL, Fla. – A NASA Railroad train crosses the railroad’s Jay Jay Railroad Bridge north of Launch Complex 39 at NASA’s Kennedy Space Center in Florida. The train is on its way to the Florida East Coast Railway interchange in Titusville, Fla., where the train’s helium tank cars, a liquid oxygen tank car, and a liquid hydrogen dewar or tank car will be transferred for delivery to the SpaceX engine test complex outside McGregor, Texas. The railroad cars were needed in support of the Space Shuttle Program but currently are not in use by NASA following the completion of the program in 2011. Originally, the tankers belonged to the U.S. Bureau of Mines. At the peak of the shuttle program, there were approximately 30 cars in the fleet. About half the cars were returned to the bureau as launch activity diminished. Five tank cars are being loaned to SpaceX and repurposed to support their engine tests in Texas. Eight cars previously were shipped to California on loan to support the SpaceX Falcon 9 rocket launches from Space Launch Complex-4 on Vandenberg Air Force Base. SpaceX already has three helium tank cars previously used for the shuttle program at Space Launch Complex-40 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/spacex. Photo credit: NASA/Jim Grossmann
Orihuela, A; Averós, X; Solano, J; Clemente, N; Estevez, I
2016-03-01
Reproduction in tropical sheep is not affected by season, whereas the reproductive cycle of temperate-climate breeds such as Suffolk depends on the photoperiod. Close contact with tropical ewes during the anestrous period might induce Suffolk ewes to cycle, making the use of artificial light or hormonal treatments unnecessary. However, the integration of both breeds within the social group would be necessary to trigger this effect, and so the aim of the experiment was to determine the speed of integration of 2 groups of Saint Croix and Suffolk ewes into a single flock, according to space allowance and previous experience. For this, 6 groups of 10 ewes (half from each breed) from both breeds, housed at 2 or 4 m/ewe (3 groups/treatment) and with or without previous contact with the other breed, were monitored for 3 d. Each observation day, the behavior, movement, and use of space of ewes were collected during 10 min at 1-h intervals between 0900 and 1400 h. Generalized linear mixed models were used to test the effects of breed, space allowance, and previous experience on behavior, movement, and use of space. Net distances, interbreed farthest neighbor distance, mean interbreed distance, and walking frequencies were greater at 4 m/ewe ( < 0.05). Intrabreed nearest neighbor, mean intrabreed neighbor, and interbreed nearest neighbor distances and minimum convex polygons at 4 m/ewe were greatest for Saint Croix ewes, whereas the opposite was found for lying down ( < 0.05). Experienced ewes showed larger intrabreed nearest neighbor distances, minimum convex polygons, and home range overlapping ( < 0.05). Experienced ewes at 4 m/ewe showed longest total distances and step lengths and greatest movement activity ( < 0.05). Experienced ewes walked longer total distances during Day 1 and 2 ( < 0.05). Lying down frequency was greater for Day 3 than Day 1 ( < 0.05), and Suffolk ewes kept longer interindividual distances during Day 1 ( < 0.05). After 3 d of cohabitation, Suffolk and Saint Croix ewes did not fully integrate into a cohesive flock, with each breed displaying specific behavioral patterns. Decreasing space allowance and previous experience resulted in limited benefits for the successful group cohesion. Longer cohabitation periods might result in complete integration, although practical implementation might be difficult.
Feasibility Study of Space Based Solar Power to Tethered Aerostat Systems
NASA Technical Reports Server (NTRS)
Blank, Stephen J.; Leete, Stephen J.; Jaffe, Paul
2013-01-01
The feasibility of two-stage Space-Based Solar Power to Tethered Aerostat to Earth (SSP-TA) system architectures that offer significant advantages over conventional single stage space-to-earth architectures is being studied. There have been many proposals for the transmission of solar power collected in space to the surface of the earth so that solar energy could provide a major part of the electric power requirements on earth. There are, however, serious difficulties in implementing the single stage space-based solar power systems that have been previously studied. These difficulties arise due to: i) the cost of transporting the components needed for the extremely large microwave transmit beaming aperture into space orbit, ii) the even larger collection apertures required on earth, iii) the potential radiation hazard to personnel and equipment on earth, and iv) a lack of flexibility in location of the collection station on the earth. Two candidate system architectures are described here to overcome these difficulties. In both cases a two-stage space to tethered aerostat to earth transmission system (SSP-TA) is proposed. The use of high altitude tethered aerostats (or powered airships) avoids the effects of attenuation of EM energy propagating through the earth s lower atmosphere. This allows the use of beaming frequencies to be chosen from the range of high millimeter (THz) to near-infra-red (NIR) to the visible. This has the potential for: i) greatly reduced transportation costs to space, ii) much smaller receiver collection apertures and ground stations, iii) elimination of the potential radiation hazard to personnel and equipment on earth, and iv) ease in transportation and flexibility in location of the collection station on the earth. A preliminary comparison of system performance and efficiencies is presented.
Audio Motor Training at the Foot Level Improves Space Representation.
Aggius-Vella, Elena; Campus, Claudio; Finocchietti, Sara; Gori, Monica
2017-01-01
Spatial representation is developed thanks to the integration of visual signals with the other senses. It has been shown that the lack of vision compromises the development of some spatial representations. In this study we tested the effect of a new rehabilitation device called ABBI (Audio Bracelet for Blind Interaction) to improve space representation. ABBI produces an audio feedback linked to body movement. Previous studies from our group showed that this device improves the spatial representation of space in early blind adults around the upper part of the body. Here we evaluate whether the audio motor feedback produced by ABBI can also improve audio spatial representation of sighted individuals in the space around the legs. Forty five blindfolded sighted subjects participated in the study, subdivided into three experimental groups. An audio space localization (front-back discrimination) task was performed twice by all groups of subjects before and after different kind of training conditions. A group (experimental) performed an audio-motor training with the ABBI device placed on their foot. Another group (control) performed a free motor activity without audio feedback associated with body movement. The other group (control) passively listened to the ABBI sound moved at foot level by the experimenter without producing any body movement. Results showed that only the experimental group, which performed the training with the audio-motor feedback, showed an improvement in accuracy for sound discrimination. No improvement was observed for the two control groups. These findings suggest that the audio-motor training with ABBI improves audio space perception also in the space around the legs in sighted individuals. This result provides important inputs for the rehabilitation of the space representations in the lower part of the body.
Audio Motor Training at the Foot Level Improves Space Representation
Aggius-Vella, Elena; Campus, Claudio; Finocchietti, Sara; Gori, Monica
2017-01-01
Spatial representation is developed thanks to the integration of visual signals with the other senses. It has been shown that the lack of vision compromises the development of some spatial representations. In this study we tested the effect of a new rehabilitation device called ABBI (Audio Bracelet for Blind Interaction) to improve space representation. ABBI produces an audio feedback linked to body movement. Previous studies from our group showed that this device improves the spatial representation of space in early blind adults around the upper part of the body. Here we evaluate whether the audio motor feedback produced by ABBI can also improve audio spatial representation of sighted individuals in the space around the legs. Forty five blindfolded sighted subjects participated in the study, subdivided into three experimental groups. An audio space localization (front-back discrimination) task was performed twice by all groups of subjects before and after different kind of training conditions. A group (experimental) performed an audio-motor training with the ABBI device placed on their foot. Another group (control) performed a free motor activity without audio feedback associated with body movement. The other group (control) passively listened to the ABBI sound moved at foot level by the experimenter without producing any body movement. Results showed that only the experimental group, which performed the training with the audio-motor feedback, showed an improvement in accuracy for sound discrimination. No improvement was observed for the two control groups. These findings suggest that the audio-motor training with ABBI improves audio space perception also in the space around the legs in sighted individuals. This result provides important inputs for the rehabilitation of the space representations in the lower part of the body. PMID:29326564
Evolution of Space Dependent Growth in the Teleost Astyanax mexicanus
Gallo, Natalya D.; Jeffery, William R.
2012-01-01
The relationship between growth rate and environmental space is an unresolved issue in teleosts. While it is known from aquaculture studies that stocking density has a negative relationship to growth, the underlying mechanisms have not been elucidated, primarily because the growth rate of populations rather than individual fish were the subject of all previous studies. Here we investigate this problem in the teleost Astyanax mexicanus, which consists of a sighted surface-dwelling form (surface fish) and several blind cave-dwelling (cavefish) forms. Surface fish and cavefish are distinguished by living in spatially contrasting environments and therefore are excellent models to study the effects of environmental size on growth. Multiple controlled growth experiments with individual fish raised in confined or unconfined spaces showed that environmental size has a major impact on growth rate in surface fish, a trait we have termed space dependent growth (SDG). In contrast, SDG has regressed to different degrees in the Pachón and Tinaja populations of cavefish. Mating experiments between surface and Pachón cavefish show that SDG is inherited as a dominant trait and is controlled by multiple genetic factors. Despite its regression in blind cavefish, SDG is not affected when sighted surface fish are raised in darkness, indicating that vision is not required to perceive and react to environmental space. Analysis of plasma cortisol levels showed that an elevation above basal levels occurred soon after surface fish were exposed to confined space. This initial cortisol peak was absent in Pachón cavefish, suggesting that the effects of confined space on growth may be mediated partly through a stress response. We conclude that Astyanax reacts to confined spaces by exhibiting SDG, which has a genetic component and shows evolutionary regression during adaptation of cavefish to confined environments. PMID:22870223
Measurements of the Flowfield Interaction Between Tandem Cylinders
NASA Technical Reports Server (NTRS)
Neuhart, Dan H.; Jenkins, Luther N.; Choudhari, Meelan M.; Khorrami, Mehdi R.
2009-01-01
This paper presents the most recent measurements from an ongoing investigation of the unsteady wake interference between a pair of circular cylinders in tandem. The purpose of this investigation is to help build an in-depth experimental database for this canonical flow configuration that embodies the effects of component interaction in landing gear noise. This new set of measurements augments the previous database at the primary Reynolds number (based on tunnel speed and cylinder diameter) of 1.66 105 in four important respects. First, better circumferential resolution of surface pressure fluctuations is obtained via cylinder "clocking". Second, higher resolution particle image velocimetry measurements of the shear layer separating from the cylinders are achieved. Third, the effects of simultaneous boundary layer trips along both the front and rear cylinders, versus front cylinder alone in the previous measurements, are studied. Lastly, on-surface and off-surface characteristics of unsteady flow near the "critical" cylinder spacing, wherein the flow switches intermittently between two states that are characteristic of lower and higher spacings, are examined. This critical spacing occurs in the middle of a relatively sudden change in the drag of either cylinder and is characterized by a loud intermittent noise and a flow behavior that randomly transitions between shear layer attachment to the rear cylinder and constant shedding and rollup in front of it. Analysis of this bistable flow state reveals much larger spanwise correlation lengths of surface pressure fluctuations than those at larger and smaller values of the cylinder spacing.
A timely rationale for space exploration
NASA Technical Reports Server (NTRS)
Peterson, Douglas D.; Walters, Larry D.
1992-01-01
Space exploration is shown to be useful for enhancing a country's education, technology, and economic competitiveness. Technologies required for the Space Exploration Initiative are compared to emerging technologies identified by the U.S. Department of Commerce. The impact of previous space ventures on specific technologies are illustrated with examples such as miniaturized electronics, computers and software, and high-strength materials. The case for educational advancement as a by-product of space exploration is made by discussing the high-level requirements of the programs and describing the inspirational effect of space exploration on young students. Invigorating space exploration is argued to generate near- and long-term economic opportunities for key sectors of the national economy by means of technology transfer, space-resource utilization, and the commercialization of space.
Modeling Space Radiation with Radiomimetic Agent Bleomycin
NASA Technical Reports Server (NTRS)
Lu, Tao
2017-01-01
Space radiation consists of proton and helium from solar particle events (SPE) and high energy heavy ions from galactic cosmic ray (GCR). This mixture of radiation with particles at different energy levels has different effects on biological systems. Currently, majority studies of radiation effects on human were based on single-source radiation due to the limitation of available method to model effects of space radiation on living organisms. While NASA Space Radiation Laboratory is working on advanced switches to make it possible to have a mixed field radiation with particles of different energies, the radiation source will be limited. Development of an easily available experimental model for studying effects of mixed field radiation could greatly speed up our progress in our understanding the molecular mechanisms of damage and responses from exposure to space radiation, and facilitate the discovery of protection and countermeasures against space radiation, which is critical for the mission to Mars. Bleomycin, a radiomimetic agent, has been widely used to study radiation induced DNA damage and cellular responses. Previously, bleomycin was often compared to low low Linear Energy Transfer (LET) gamma radiation without defined characteristics. Our recent work demonstrated that bleomycin could induce complex clustered DNA damage in human fibroblasts that is similar to DNA damage induced by high LET radiation. These type of DNA damage is difficult to repair and can be visualized by gamma-H2Ax staining weeks after the initial insult. The survival ratio between early and late plating of human fibroblasts after bleomycin treatment is between low LET and high LET radiation. Our results suggest that bleomycin induces DNA damage and other cellular stresses resembling those resulted from mixed field radiation with both low and high LET particles. We hypothesize that bleomycin could be used to mimic space radiation in biological systems. Potential advantages and limitations of using bleomycin to treat biological specimen as an easily available model to study effects of space radiation on biological systems and to develop countermeasures for space radiation associated risks will be discussed.
Cell-wall architecture and lignin composition of wheat developed in a microgravity environment.
Levine, L H; Heyenga, A G; Levine, H G; Choi, J; Davin, L B; Krikorian, A D; Lewis, N G
2001-07-01
The microgravity environment encountered during space-flight has long been considered to affect plant growth and developmental processes, including cell wall biopolymer composition and content. As a prelude to studying how microgravity is perceived - and acted upon - by plants, it was first instructive to investigate what gross effects on plant growth and development occurred in microgravity. Thus, wheat seedlings were exposed to microgravity on board the space shuttle Discovery (STS-51) for a 10 day duration, and these specimens were compared with their counterparts grown on Earth under the same conditions (e.g. controls). First, the primary roots of the wheat that developed under both microgravity and 1 g on Earth were examined to assess the role of gravity on cellulose microfibril (CMF) organization and secondary wall thickening patterns. Using a quick freeze/deep etch technique, this revealed that the cell wall CMFs of the space-grown wheat maintained the same organization as their 1 g-grown counterparts. That is, in all instances, CMFs were randomly interwoven with each other in the outermost layers (farthest removed from the plasma membrane), and parallel to each other within the individual strata immediately adjacent to the plasma membranes. The CMF angle in the innermost stratum relative to the immediately adjacent stratum was ca 80 degrees in both the space and Earth-grown plants. Second, all plants grown in microgravity had roots that grew downwards into the agar; they did not display "wandering" and upward growth as previously reported by others. Third, the space-grown wheat also developed normal protoxylem and metaxylem vessel elements with secondary thickening patterns ranging from spiral to regular pit to reticulate thickenings. Fourthly, both the space- and Earth-grown plants were essentially of the same size and height, and their lignin analyses revealed no substantial differences in their amounts and composition regardless of the gravitational field experienced, i.e. for the purposes of this study, all plants were essentially identical. These results suggest that the microgravity environment itself at best only slightly affected either cell wall biopolymer synthesis or the deposition of CMFs, in contrast to previous assertions.
Cell-wall architecture and lignin composition of wheat developed in a microgravity environment
NASA Technical Reports Server (NTRS)
Levine, L. H.; Heyenga, A. G.; Levine, H. G.; Choi, J.; Davin, L. B.; Krikorian, A. D.; Lewis, N. G.; Sager, J. C. (Principal Investigator)
2001-01-01
The microgravity environment encountered during space-flight has long been considered to affect plant growth and developmental processes, including cell wall biopolymer composition and content. As a prelude to studying how microgravity is perceived - and acted upon - by plants, it was first instructive to investigate what gross effects on plant growth and development occurred in microgravity. Thus, wheat seedlings were exposed to microgravity on board the space shuttle Discovery (STS-51) for a 10 day duration, and these specimens were compared with their counterparts grown on Earth under the same conditions (e.g. controls). First, the primary roots of the wheat that developed under both microgravity and 1 g on Earth were examined to assess the role of gravity on cellulose microfibril (CMF) organization and secondary wall thickening patterns. Using a quick freeze/deep etch technique, this revealed that the cell wall CMFs of the space-grown wheat maintained the same organization as their 1 g-grown counterparts. That is, in all instances, CMFs were randomly interwoven with each other in the outermost layers (farthest removed from the plasma membrane), and parallel to each other within the individual strata immediately adjacent to the plasma membranes. The CMF angle in the innermost stratum relative to the immediately adjacent stratum was ca 80 degrees in both the space and Earth-grown plants. Second, all plants grown in microgravity had roots that grew downwards into the agar; they did not display "wandering" and upward growth as previously reported by others. Third, the space-grown wheat also developed normal protoxylem and metaxylem vessel elements with secondary thickening patterns ranging from spiral to regular pit to reticulate thickenings. Fourthly, both the space- and Earth-grown plants were essentially of the same size and height, and their lignin analyses revealed no substantial differences in their amounts and composition regardless of the gravitational field experienced, i.e. for the purposes of this study, all plants were essentially identical. These results suggest that the microgravity environment itself at best only slightly affected either cell wall biopolymer synthesis or the deposition of CMFs, in contrast to previous assertions.
NASA Astrophysics Data System (ADS)
Fast, Jerome D.; Osteen, B. Lance
In this study, a four-dimensional data assimilation technique based on Newtonian relaxation is incorporated into the Colorado State University (CSU) Regional Atmospheric Modeling System (RAMS) and evaluated using data taken from one experiment of the US Department of Energy's (DOE) 1991 Atmospheric Studies in COmplex Terrain (ASCOT) field study along the front range of the Rockies in Colorado. The main objective of this study is to determine the ability of the model to predict small-scale circulations influenced by terrain, such as drainage flows, and assess the impact of data assimilation on the numerical results. In contrast to previous studies in which the smallest horizontal grid spacing was 10 km and 8 km, data assimilation is applied in this study to domains with a horizontal grid spacing as small as 1 km. The prognostic forecasts made by RAMS are evaluated by comparing simulations that employ static initial conditions, with simulations that incorporate continuous data assimilation, and data assimilation for a fixed period of time (dynamic initialization). This paper will also elaborate on the application and limitation of the Newtonian relaxation technique in limited-area mesoscale models with a relatively small grid spacing.
1994-07-07
S94-36965 (20 Sept 1994) --- The rising sun signifies the dawn of a new era of human Spaceflight, the first phase of the U.S./Russian space partnership, Shuttle-Mir. Mir is shown in its proposed final on orbit configuration. The Shuttle is shown in a generic tunnel/Spacehab configuration. The Shuttle-Mir combination, docked to acknowledge the union of the two space programs, orbits over an Earth devoid of any definable features or political borders to emphasize Earth as the home planet for all humanity. The individual stars near the Shuttle and the Mir station represent the previous individual accomplishments of Russia's space program and that of the U.S. The binary star is a tribute to the previous U.S.-Russian joint human Spaceflight program, the Apollo-Soyuz Test Project. The flags of the two nations are symbolized by flowing ribbons of the national colors interwoven in space to represent the two nations joint exploration of space. NASA SHUTTLE and PKA MNP are shown in the stylized logo fonts of the two agencies that are conducting this program.
Long-term perceptions of outdoor thermal environments in an elementary school in a hot-humid climate
NASA Astrophysics Data System (ADS)
Shih, Wen-Mei; Lin, Tzu-Ping; Tan, Ning-Xin; Liu, Mu-Hsien
2017-09-01
Previous studies on thermal comfort in school environments have focused more on indoor thermal environments than outdoor ones, thus providing a limited understanding of occupants' long-term thermal perceptions. Taiwan is located in a subtropical region, where it can be stiflingly hot outside in summer. This highlights the need to ensure proper thermal comfort on campus. In the present study, thermal environment parameters were measured and collected in several outdoor spaces of an elementary school in southern Taiwan. In addition, a questionnaire was used to explore occupants' long-term thermal perceptions of these spaces. During summer months, the physiological equivalent temperature (PET) of these outdoor spaces in over 60% of the daytime in summer between 10 a.m. and 4 p.m. was higher than 38 °C PET, indicating high heat stress. The results of occupants' long-term perceptions of the thermal comfort of these spaces suggested that dissatisfaction with thermal comfort was associated more with solar radiation than with wind speed. Finally, this study simulated a campus environment where more trees are planted and compared the thermal comfort indices before and after the simulation. The results indicated that this solution contributed to a decrease in the PET of these environments, thereby alleviating high heat stress. This study can inform the improvement of microclimates and thermal comfort during campus layout planning. Planting trees judiciously across a campus increases outdoor shades and creates outdoor spaces that are more comfortable and adaptable to hot weather conditions, thereby ensuring frequent use of these spaces.
Dietary and Urinary Sulfur can Predict Changes in Bone Metabolism During Space Flight
NASA Technical Reports Server (NTRS)
Zwart, Sara R.; Heer, Martina; Shackelford, Linda; Smith, Scott M.
2015-01-01
Mitigating space flight-induced bone loss is critical for space exploration, and diet can play a major role in this effort. Previous ground-based studies provide evidence that dietary composition can influence bone resorption during bed rest. In this study we examined the role of dietary intake patterns as one factor that can influence bone mineral loss in astronauts during space flight. Crew members were asked to consume, for 4 days at a time, prescribed menus with either a low (0.3-0.6 g/mEq) or high (1.0-1.3 g/mEq) ratio of animal protein to potassium (APro:K). Menus were developed for each crewmember, and were designed to meet both crew preferences and study constraints. Intakes of energy, total protein, calcium, and sodium were held relatively constant between the two diets. The order of the menus was randomized, and crews completed each set (low and high) once before and twice during space flight, for a total of 6 controlled diet sessions. One inflight session and three postflight sessions (R+30, R+180, R+365) monitored typical dietary intake. As of this writing, data are available from 14 crew members. The final three subjects' inflight samples are awaiting return from the International Space Station via Space-X. On the last day of each of the 4-d controlled diet sessions, 24-h urine samples were collected, along with a fasting blood sample on the morning of the 5th day. Preliminary analyses show that urinary excretion of sulfate (normalized to lean body mass) is a significant predictor of urinary n-telopeptide (NTX). Dietary sulfate (normalized to lean body mass) is also a significant predictor of urinary NTX. The results from this study, will be important to better understand diet and bone interrelationships during space flight as well as on Earth. This study was funded by the Human Health Countermeasures Element of the NASA Human Research Program.
2003-06-20
KENNEDY SPACE CENTER, FLA. - Daniel LeBlanc, chief operating officer of Delaware North Companies Parks and Resorts at KSC, makes the opening remarks to hundreds of guests and media representatives attending a ribbon cutting ceremony officially opening the U.S. Astronaut Hall of Fame as part of the Kennedy Space Center Visitor Complex. The ceremony was held in conjunction with the induction of four Space Shuttle astronauts into the Hall of Fame including Daniel Brandenstein, Robert "Hoot" Gibson, Story Musgrave, and Sally Ride. Conceived by six of the Mercury Program astronauts, the U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The four new inductees join 48 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
2003-06-20
KENNEDY SPACE CENTER, FLA. - Center Director and former astronaut Roy D. Bridges, Jr., (holding scissors) cuts the ribbon at a ceremony officially opening the U.S. Astronaut Hall of Fame as part of the Kennedy Space Center Visitor Complex. Invited guests and dignitaries look on, such as former astronauts Edgar D. Mitchell on Bridges' left and James Lovell on his right. The ceremony was held in conjunction with the induction of four Space Shuttle astronauts into the Hall of Fame including Daniel Brandenstein, Robert "Hoot" Gibson, Story Musgrave, and Sally Ride. Conceived by six of the Mercury Program astronauts, the U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The four new inductees join 48 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
14 CFR 121.406 - Credit for previous CRM/DRM training.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Credit for previous CRM/DRM training. 121... previous CRM/DRM training. (a) For flightcrew members, the Administrator may credit CRM training received before March 19, 1998 toward all or part of the initial ground CRM training required by § 121.419. (b...
14 CFR 121.406 - Credit for previous CRM/DRM training.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Credit for previous CRM/DRM training. 121... previous CRM/DRM training. (a) For flightcrew members, the Administrator may credit CRM training received before March 19, 1998 toward all or part of the initial ground CRM training required by § 121.419. (b...
A New Perspective in the Etiology, Treatment, Prevention and Prediction of Space Motion Sickness
1988-12-01
ulsint options: Dilanlin (First choice based previous ground based ef- ficacity’), Dextromethorphan \\Dilantin, Carbamnazcpine, Dextrornczhorpl.an\\Car...First choice based previous ground based er- ricacity), Dcxtromethorphan\\Dilantin, Carbamazepinc, Dextromethorphan \\Car- bamrazepine 137 EVALUATION OF...Anticonvulsant options: Dilantin (First choice bised previous ground based ef- * flicacioy), Dextromethorphan \\Dilantin, Carbamazepine, Dextromethorphan \\Car
A linear chromatic mechanism drives the pupillary response.
Tsujimura, S.; Wolffsohn, J. S.; Gilmartin, B.
2001-01-01
Previous studies have shown that a chromatic mechanism can drive pupil responses. The aim of this research was to clarify whether a linear or nonlinear chromatic mechanism drives pupillary responses by using test stimuli of various colours that are defined in cone contrast space. The pupil and accommodation responses evoked by these test stimuli were continuously and simultaneously objectively measured by photorefraction. The results with isochromatic and isoluminant stimuli showed that the accommodative level remained approximately constant (< 0.25 D change in mean level) even when the concurrent pupillary response was large (ca. 0.30 mm). The pupillary response to an isoluminant grating was sustained, delayed (by ca. 60 ms) and larger in amplitude than that for a isochromatic uniform stimulus, which supports previous work suggesting that the chromatic mechanism contributes to the pupillary response. In a second experiment, selected chromatic test gratings were used and isoresponse contours in cone contrast space were obtained. The results showed that the isoresponse contour in cone contrast space is well described (r(2) = 0.99) by a straight line with a positive slope. The results indicate that a /L - M/ linear chromatic mechanism, whereby a signal from the long wavelength cone is subtracted from that of the middle wavelength cone and vice versa, drives pupillary responses. PMID:11674867
NASA Astrophysics Data System (ADS)
Alfano, Candice A.; Bower, Joanne L.; Cowie, Jennifer; Lau, Simon; Simpson, Richard J.
2018-01-01
Spaceflight to Mars will by far exceed the duration of any previous mission. Although behavioral health risks are routinely highlighted among the most serious threats to crew safety, understanding of specific emotional responses most likely to occur and interfere with mission success has lagged in comparison to other risk domains. Even within the domain of behavioral health, emotional constructs remain to be 'unpacked' to the same extent as other factors such as attention and fatigue. The current paper provides a review of previous studies that have examined emotional responses in isolated, confined, extreme environments (ICE) toward informing a needed research agenda. We include research conducted during space flight, long-duration space simulation analogs, and polar environments and utilize a well-established model of emotion and emotion regulation to conceptualize specific findings. Lastly, we propose four specific directions for future research: (1) use of a guiding theoretical framework for evaluating emotion responses in ICE environments; (2) leveraging multi-method approaches to improve the reliability of subjective reports of emotional health; (3) a priori selection of precise emotional constructs to guide measure selection; and (4) focusing on positive in addition to negative emotion in order to provide a more complete understanding of individual risk and resilience.
Is the kinetic equation for turbulent gas-particle flows ill posed?
Reeks, M; Swailes, D C; Bragg, A D
2018-02-01
This paper is about the kinetic equation for gas-particle flows, in particular its well-posedness and realizability and its relationship to the generalized Langevin model (GLM) probability density function (PDF) equation. Previous analyses, e.g. [J.-P. Minier and C. Profeta, Phys. Rev. E 92, 053020 (2015)PLEEE81539-375510.1103/PhysRevE.92.053020], have concluded that this kinetic equation is ill posed, that in particular it has the properties of a backward heat equation, and as a consequence, its solution will in the course of time exhibit finite-time singularities. We show that this conclusion is fundamentally flawed because it ignores the coupling between the phase space variables in the kinetic equation and the time and particle inertia dependence of the phase space diffusion tensor. This contributes an extra positive diffusion that always outweighs the negative diffusion associated with the dispersion along one of the principal axes of the phase space diffusion tensor. This is confirmed by a numerical evaluation of analytic solutions of these positive and negative contributions to the particle diffusion coefficient along this principal axis. We also examine other erroneous claims and assumptions made in previous studies that demonstrate the apparent superiority of the GLM PDF approach over the kinetic approach. In so doing, we have drawn attention to the limitations of the GLM approach, which these studies have ignored or not properly considered, to give a more balanced appraisal of the benefits of both PDF approaches.
Investigation of Lithium Metal Hydride Materials for Mitigation of Deep Space Radiation
NASA Technical Reports Server (NTRS)
Rojdev, Kristina; Atwell, William
2016-01-01
Radiation exposure to crew, electronics, and non-metallic materials is one of many concerns with long-term, deep space travel. Mitigating this exposure is approached via a multi-faceted methodology focusing on multi-functional materials, vehicle configuration, and operational or mission constraints. In this set of research, we are focusing on new multi-functional materials that may have advantages over traditional shielding materials, such as polyethylene. Metal hydride materials are of particular interest for deep space radiation shielding due to their ability to store hydrogen, a low-Z material known to be an excellent radiation mitigator and a potential fuel source. We have previously investigated 41 different metal hydrides for their radiation mitigation potential. Of these metal hydrides, we found a set of lithium hydrides to be of particular interest due to their excellent shielding of galactic cosmic radiation. Given these results, we will continue our investigation of lithium hydrides by expanding our data set to include dose equivalent and to further understand why these materials outperformed polyethylene in a heavy ion environment. For this study, we used HZETRN 2010, a one-dimensional transport code developed by NASA Langley Research Center, to simulate radiation transport through the lithium hydrides. We focused on the 1977 solar minimum Galactic Cosmic Radiation environment and thicknesses of 1, 5, 10, 20, 30, 50, and 100 g/cm2 to stay consistent with our previous studies. The details of this work and the subsequent results will be discussed in this paper.
Bone Proteoglycan Changes During Skeletal Unloading
NASA Technical Reports Server (NTRS)
Yamauchi, M.; Uzawa, K.; Pornprasertsuk, S.; Arnaud, S.; Grindeland, R.; Grzesik, W.
1999-01-01
Skeletal adaptability to mechanical loads is well known since the last century. Disuse osteopenia due to the microgravity environment is one of the major concerns for space travelers. Several studies have indicated that a retardation of the mineralization process and a delay in matrix maturation occur during the space flight. Mineralizing fibrillar type I collagen possesses distinct cross-linking chemistries and their dynamic changes during mineralization correlate well with its function as a mineral organizer. Our previous studies suggested that a certain group of matrix proteoglycans in bone play an inhibitory role in the mineralization process through their interaction with collagen. Based on these studies, we hypothesized that the altered mineralization during spaceflight is due in part to changes in matrix components secreted by cells in response to microgravity. In this study, we employed hindlimb elevation (tail suspension) rat model to study the effects of skeletal unloading on matrix proteoglycans in bone.
Bisphosphonates as a Countermeasure to Space Flight Induced Bone Loss
NASA Technical Reports Server (NTRS)
LeBlanc, Adrian; Matsumoto, Toshio; Jones, Jeffrey A.; Shapiro, Jay; Lang, Thomas F.; Smith, Scott M.; Shackelford, Linda C.; Sibonga, Jean; Evans, Harlan; Spector, Elisabeth;
2009-01-01
Bisphosphonates as a Countermeasure to Space Flight Induced Bone Loss (Bisphosphonates) will determine whether antiresorptive agents, in conjunction with the routine inflight exercise program, will protect ISS crewmembers from the regional decreases in bone mineral density documented on previous ISS missions.
Performance analysis of a coherent free space optical communication system based on experiment.
Cao, Jingtai; Zhao, Xiaohui; Liu, Wei; Gu, Haijun
2017-06-26
Based on our previous study and designed experimental AO system with a 97-element continuous surface deformable mirror, we conduct the performance analysis of a coherent free space optical communication (FSOC) system for mixing efficiency (ME), bit error rate (BER) and outage probability under different Greenwood frequency and atmospheric coherent length. The results show that the influence of the atmospheric temporal characteristics on the performance is slightly stronger than that of the spatial characteristics when the receiving aperture and the number of sub-apertures are given. This analysis result provides a reference for the design of the coherent FSOC system.
Mars Science Laboratory Press Conference
2011-07-22
John Grotzinger, Mars Science Laboratory (MSL) project scientist, Jet Propulsion Lab (JPL), Pasadena, Calif., holds up a model of the MSL, or Curiosity, at a press conference at the Smithsonian's National Air and Space Museum on Friday, July 22, 2011 in Washington. The MSL is scheduled to launch late this year from NASA's Kennedy Space Center in Florida and land in August 2012. Curiosity is twice as long and more than five times as heavy as previous Mars rovers. The rover will study whether the landing region at Gale crater had favorable environmental conditions for supporting microbial life and for preserving clues about whether life ever existed. Photo Credit: (NASA/Carla Cioffi)
Mars Science Laboratory Press Conference
2011-07-22
John Grotzinger, Mars Science Laboratory (MSL) project scientist, Jet Propulsion Lab (JPL), Pasadena, Calif., answers a reporter's question at a press conference at the Smithsonian's National Air and Space Museum on Friday, July 22, 2011 in Washington. The MSL is scheduled to launch late this year from NASA's Kennedy Space Center in Florida and land in August 2012. Curiosity is twice as long and more than five times as heavy as previous Mars rovers. The rover will study whether the landing region at Gale crater had favorable environmental conditions for supporting microbial life and for preserving clues about whether life ever existed. Photo Credit: (NASA/Carla Cioffi)
Parylene-based active micro space radiator with thermal contact switch
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ueno, Ai; Suzuki, Yuji
2014-03-03
Thermal management is crucial for highly functional spacecrafts exposed to large fluctuations of internal heat dissipation and/or thermal boundary conditions. Since thermal radiation is the only means for heat removal, effective control of radiation is required for advanced space missions. In the present study, a MEMS (Micro Electro Mechanical Systems) active radiator using the contact resistance change has been proposed. Unlike previous bulky thermal louvers/shutters, higher fill factor can be accomplished with an array of electrostatically driven micro diaphragms suspended with polymer tethers. With an early prototype developed with parylene MEMS technologies, radiation heat flux enhancement up to 42% hasmore » been achieved.« less
NASA Astrophysics Data System (ADS)
Kirkpatrick, A. W.; Keaney, M. A.; Bentz, K.; Groleau, M.; Tyssen, M.; Keyte, J.; Ball, C. G.; Campbell, M. R.; Grenon, S. M.; McBeth, P.; Broderick, T. J.
2010-03-01
Emergency surgery will be needed to prevent death if humans are used to explore beyond low earth's orbit. Laparoscopic surgery (LS) is envisioned as a less invasive option for space, but will induce further stresses and complicate logistical requirements. Thus, further study into the technology and physiology of LS in weightlessness is required. We recently utilized the National Research Council of Canada's Flight Research Laboratory's Falcon 20 aircraft as a terrestrial analogue space environment (TASE) for space surgery research. The Falcon 20 had never been used for this purpose nor had the involved teams collaborated previously. There were many process challenges including the lack of antecedent surgical studies on this aircraft, a requirement for multiple disciplines who were unfamiliar and geographically distant from each other, flight performance limitations with the Falcon 20, complex animal care requirements, requirements for prototypical in-flight life-support surgical suites, financial limitations, and a need to use non-flight hardened technologies. Stepwise suggested solutions to these challenges are outlined as guidelines for future investigators intending similar research. Overall, the Falcon 20 TASE, backed by the flight resources, especially the design and fabrication capabilities of the NRC-FRL, provide investigators with a versatile and responsive opportunity to pursue research into advanced medical techniques that will be needed to save lives during space exploration.
The Relationship between Natural Park Usage and Happiness Does Not Hold in a Tropical City-State
Saw, Le E.; Lim, Felix K. S.; Carrasco, Luis R.
2015-01-01
Previous studies have shown that contact with urban green spaces can produce positive effects on people's stress, health and well-being levels. However, much of this research has been conducted in the temperate regions of Europe or North America. Additionally, most studies have only compared the effects of urban and natural areas on health and well-being, but not made a finer distinction between different types of urban green spaces. We tested the relationship between well-being and the access or use of different types of green spaces among young adults in Singapore, a tropical city-state. The results showed that extraversion and emotional stability increased subjective well-being, positive affect and life satisfaction and decreased stress and negative affect. In addition, we found that level of physical activity increased positive affect and health problems increased negative affect. Neither access to green spaces nor the use of green spaces in Singapore significantly affected the well-being metrics considered, contradicting findings in the temperate regions of the world. We hypothesize that the differences in temperature and humidity and the higher greenery and biodiversity levels outside parks in Singapore could explain this phenomenon. Our results thus question the universality of the relationship between well-being and park usage and highlight the need for more research into the multifaceted effects of green spaces on well-being in the tropics. PMID:26222280
Thrust imbalance of solid rocket motor pairs on Space Shuttle flights
NASA Technical Reports Server (NTRS)
Foster, W. A., Jr.; Shu, P. H.; Sforzini, R. H.
1986-01-01
This analysis extends the investigation presented at the 17th Joint Propulsion Conference in 1981 to include fifteen sets of Space Shuttle flight data. The previous report dealt only with static test data and the first flight pair. The objective is to compare the authors' previous theoretical analysis of thrust imbalance with actual Space Shuttle performance. The theoretical prediction method, which involves a Monte Carlo technique, is reviewed briefly as are salient features of the flight instrumentation system and the statistical analysis. A scheme for smoothing flight data is discussed. The effects of changes in design parameters are discussed with special emphasis on the filament wound motor case being developed to replace the steel case. Good agreement between the predictions and the flight data is demonstrated.
Legacies of precipitation fluctuations on primary production: theory and data synthesis.
Sala, Osvaldo E; Gherardi, Laureano A; Reichmann, Lara; Jobbágy, Esteban; Peters, Debra
2012-11-19
Variability of above-ground net primary production (ANPP) of arid to sub-humid ecosystems displays a closer association with precipitation when considered across space (based on multiyear averages for different locations) than through time (based on year-to-year change at single locations). Here, we propose a theory of controls of ANPP based on four hypotheses about legacies of wet and dry years that explains space versus time differences in ANPP-precipitation relationships. We tested the hypotheses using 16 long-term series of ANPP. We found that legacies revealed by the association of current- versus previous-year conditions through the temporal series occur across all ecosystem types from deserts to mesic grasslands. Therefore, previous-year precipitation and ANPP control a significant fraction of current-year production. We developed unified models for the controls of ANPP through space and time. The relative importance of current-versus previous-year precipitation changes along a gradient of mean annual precipitation with the importance of current-year PPT decreasing, whereas the importance of previous-year PPT remains constant as mean annual precipitation increases. Finally, our results suggest that ANPP will respond to climate-change-driven alterations in water availability and, more importantly, that the magnitude of the response will increase with time.
The discovery of silicon oxide nanoparticles in space-weathered of Apollo 15 lunar soil grains
NASA Astrophysics Data System (ADS)
Gu, Lixin; Zhang, Bin; Hu, Sen; Noguchi, Takaaki; Hidaka, Hiroshi; Lin, Yangting
2018-03-01
Space weathering is an important process on the Moon and other airless celestial bodies. The most common space weathering effects are amorphization of the top surface of soil grains and formation of nanophase iron particles (npFe) within the partially amorphous rims. Hence, space weathering significantly affects optical properties of the surface of the Moon and other airless celestial bodies. Transmission electron microscope (TEM) analysis of Apollo 15 soil grains displays npFe (≤5 nm in size) embedded in the space-weathered rim (∼60 nm in thickness) of a pyroxene grain, consistent with previous studies. In contrast, submicron-sized fragments that adhere to the pyroxene grain show distinct space weathering features. Silicon oxide nanoparticles (npSiOx) were observed with npFe in a submicron-sized Mg-Fe silicate fragment. This is the first discovery of npSiOx as a product of space weathering. The npSiOx and the coexisting npFe are ∼10-25 nm in size, significantly larger than the typical npFe in the space weathered rim of the pyroxene grain. The coexisting npSiOx and npFe were probably formed directly in micrometeorite shock-induced melt, instead of in a solar-wind generated vapor deposit or irradiated rim. This new observation will shed light on space weathering processes on the Moon and airless celestial bodies.
2003-06-21
KENNEDY SPACE CENTER, FLA. - At the KSC Visitor Complex, former astronaut Robert "Hoot" Gibson (at podium) addresses the audience at his induction ceremony into the U.S. Astronaut Hall of Fame. Also standing is former astronaut James A. Lovell. Seated on the dais, from left, are actor and Master of Ceremonies Lance Henriksen and former astronaut John H. Glenn. Also being inducted with Gibson are Space Shuttle astronauts Daniel Brandenstein, Story Musgrave, and Sally K. Ride. Conceived by six of the Mercury Program astronauts, the U.S. Astronaut Hall of Fame opened in 1990 to provide a place where space travelers could be remembered for their participation and accomplishments in the U.S. space program. The four new inductees join 48 previously honored astronauts from the ranks of the Gemini, Apollo, Skylab, Apollo-Soyuz, and Space Shuttle programs.
Design of Structurally Efficient Tapered Struts
NASA Technical Reports Server (NTRS)
Messinger, Ross
2010-01-01
This report describes the analytical study of two full-scale tapered composite struts. The analytical study resulted in the design of two structurally efficient carbon/epoxy struts in accordance with NASA-specified geometries and loading conditions. Detailed stress analysis was performed of the insert, end fitting, and strut body to obtain an optimized weight with positive margins. Two demonstration struts were fabricated based on a well-established design from a previous Space Shuttle strut development program.
High frequency data acquisition system for space shuttle main engine testing
NASA Technical Reports Server (NTRS)
Lewallen, Pat
1987-01-01
The high frequency data acquisition system developed for the Space Shuttle Main Engine (SSME) single engine test facility at the National Space Technology Laboratories is discussed. The real time system will provide engineering data for a complete set of SSME instrumentation (approx. 100 measurements) within 4 hours following engine cutoff, a decrease of over 48 hours from the previous analog tape based system.
2003-03-06
KENNEDY SPACE CENTER, FLA. - A view of the Astronaut Memorial Space Mirror at the KSC Visitor Complex. The memorial is a national tribute to 17 American astronauts who previously gave their lives to the quest to explore space. The memorial has had added attention since the loss of the Columbia crew Feb. 1, 2003, when they died in an explosion as they were returning to Earth from mission STS-107.
2003-03-06
KENNEDY SPACE CENTER, FLA. - A view of the Astronaut Memorial Space Mirror at the KSC Visitor Complex. The memorial is a national tribute to 17 American astronauts who previously gave their lives to the quest to explore space. The memorial has had added attention since the loss of the Columbia crew Feb. 1, 2003, when they died in an explosion as they were returning to Earth from mission STS-107.
2003-03-06
KENNEDY SPACE CENTER, FLA. -- A view of the Astronaut Memorial Space Mirror at the KSC Visitor Complex. The memorial is a national tribute to 17 American astronauts who previously gave their lives to the quest to explore space. The memorial has had added attention since the loss of the Columbia crew Feb. 1, 2003, when they died in an explosion as they were returning to Earth from mission STS-107.
Space flight nutrition research: platforms and analogs
NASA Technical Reports Server (NTRS)
Smith, Scott M.; Uchakin, Peter N.; Tobin, Brian W.
2002-01-01
Conducting research during actual or simulated weightlessness is a challenging endeavor, where even the simplest activities may present significant challenges. This article reviews some of the potential obstacles associated with performing research during space flight and offers brief descriptions of current and previous space research platforms and ground-based analogs, including those for human, animal, and cell-based research. This review is intended to highlight the main issues of space flight research analogs and leave the specifics for each physiologic system for the other papers in this section.
NASA Technical Reports Server (NTRS)
Burchard, E. C.
1975-01-01
The physiological and psychological factors of manned space flight had a particular significance in the Skylab missions during which astronauts were subjected to a life in a space environment for longer periods of time than on previous space missions. The Skylab missions demonstrated again the great adaptability of human physiology to the environment of man. The results of Skylab have indicated also approaches for enhancing the capability of man to tolerate the physiological and psychological stresses of space flight.
Analysis of microgravity space experiments Space Shuttle programmatic safety requirements
NASA Technical Reports Server (NTRS)
Terlep, Judith A.
1996-01-01
This report documents the results of an analysis of microgravity space experiments space shuttle programmatic safety requirements and recommends the creation of a Safety Compliance Data Package (SCDP) Template for both flight and ground processes. These templates detail the programmatic requirements necessary to produce a complete SCDP. The templates were developed from various NASA centers' requirement documents, previously written guidelines on safety data packages, and from personal experiences. The templates are included in the back as part of this report.
High Frontier, The Journal for Space & Missile Professionals. Volume 4, Number 2, February 2008
2008-02-01
off the “Space and the Joint Fight” segment of this issue, another prior USCENTAF DIRSPACEFOR, Col Jay Ray- mond, and previously deployed space...describe some of these other challenges. Space is a contested environment. It will only become more of a challenge as time goes on. The Chinese anti...cannot afford to build systems into every satellite to protect them from every threat, but we cannot ignore the message the Chinese delivered more than a
Determination of the space-charge field amplitude in polymeric photorefractive polymers.
Hwang, Ui-Jung; Choi, Chil-Sung; Vuong, Nguyen Quoc; Kim, Nakjoong
2005-12-22
The space-charge field built in a polymeric photorefractive polymer was calculated by a simple method based on the oriented gas model. When anisotropic chromophores in a photorefractive polymer were exposed to an external field, they oriented preferentially to exhibit a birefringence. Then, under illumination of two coherent beams and an external field, they reoriented to form a photorefractive grating. During the formation of the grating, the chromophores were reoriented by the space-charge field as well as by the external applied field. The birefringence induced in the material by an external electric field was determined by measuring the transmittance of the sample which is placed between crossed polarizers, where birefringence depicts the orientation of the chromophores. By measuring the diffraction efficiency with a modified degenerate four-wave mixing setup, the index amplitude of the grating was determined. Finally, the space-charge field was determined by comparing the diffraction efficiency with the birefringence with respect to the applied electric field. In our study, the space-charge field was about 20% of the external applied field, which coincided with previous results obtained from our laboratory.
A simple assay to study social behavior in Drosophila: measurement of social space within a group
Simon, Anne F.; Chou, Man-Ting; Salazar, Evelyn D.; Nicholson, Terriann; Saini, Navdeep; Metchev, Stanimir; Krantz, David E.
2011-01-01
We have established a new simple behavioral paradigm in Drosophila melanogaster to determine how genes and the environment influence the behavior of flies within a social group. Specifically, we measure social space as the distance between two flies. The majority of Canton-s flies, regardless of their gender, are within two-body lengths from each other. Their social experience affects this behavior, with social isolation reducing and mating enhancing social space respectively, in both males and females. Unlike several other social behaviors in the fly, including the formation of social groups themselves (a well described behavior - Bartelt et al., 1985, De Gee et al., 2008, Lof et al., 2008, Lof et al., 2009), social space does not require the perception of the previously identified aggregation pheromone cis-Vaccenyl Acetate (Bartelt et al., 1985). Conversely, performance of the assay in darkness or mutations in the eye pigmentation gene white increased social space. Our results establish a new assay for the genetic dissection of a fundamental mode of social interaction. PMID:22010812
Keeping you at arm's length: modifying peripersonal space influences interpersonal distance.
Quesque, F; Ruggiero, G; Mouta, S; Santos, J; Iachini, T; Coello, Y
2017-07-01
Peripersonal space represents the area around the body where objects are coded in motor terms for the purpose of voluntary goal-directed actions. Previous studies have suggested that peripersonal space is also a safe space linked with our private area, influencing interpersonal space in social contexts. However, whether these two spaces rely on similar embodied processes remains an open issue. In the present study, participants observed a point-light walker (PLW) approaching them from different directions and passing near them at different distances from their right or left shoulder. While approaching, the PLW disappeared at a distance of 2 m and the task for the participants was to estimate if the interpersonal distance, at the time the PLW would have reached their level, was comfortable or not. Between two sessions of comfort judgments, the participants manipulated a 70 cm tool entailing an extension of peripersonal space, or a 10 cm tool entailing no extension of peripersonal space. The results revealed that the comfortable interpersonal distance was larger when the PLW crossed the mid-sagittal plane of the participants than when it approached them laterally, with a concomitant increase of response time. After participants manipulated the long tool, comfortable interpersonal distance increased, but predominantly when the PLW trajectory implied crossing the participants' mid-sagittal plane. This effect was not observed when participants manipulated the short tool. Two control tasks showed that using the long tool modified the reachability (control 1), but not the time to passage (control 2) estimates of PLW stimuli, suggesting that tool use extended peripersonal space without changing perceived visual distances. Overall, the data show that comfortable interpersonal distance is linked to the representation of peripersonal space. As a consequence, increasing peripersonal space through tool use has the immediate consequence that comfortable interpersonal distance from another person also increases, suggesting that interpersonal-comfort space and peripersonal-reaching space share a common motor nature.
The Performance of Left-Handed Participants on a Preferential Reaching Test
ERIC Educational Resources Information Center
Mamolo, Carla M.; Roy, Eric A.; Bryden, Pamela J.; Rohr, Linda E.
2005-01-01
Previous research in our laboratory has examined the distribution of preferred hand (PH) reaches in working space with right-handed participants. In one study, we examined the effects of tool position and task demands on the frequency of PH reaches with right-handers (Mamolo, Roy, Bryden, & Rohr, 2004). We found that PH reaches were at a maximum…
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ricafort, Juliet
A model was developed to determine the forces exerted by several flexor and extensor muscles of the human knee under static conditions. The following muscles were studied: the gastrocnemius, biceps femoris, semitendinosus, semimembranosus, and the set of quadricep muscles. The tibia and fibula were each modeled as rigid bodies; muscles were modeled by their functional lines of action in space. Assumptions based on previous data were used to resolve the indeterminacy.
Branch morphology in young poplar clones on floodplain sites in Missouri
Stephen G. Pallardy; Daniel E. Gibbins
2003-01-01
Four Populus clones were grown in central Missouri for 2 years at 1 x 1 m spacing to study total biomass production on floodplain sites previously in forage grasses. Branch morphology (living, first-order proleptic, and sylleptic shoots) was assessed for 2-year-old plants. All 2-year-old plants had lateral branches, and clones varied significantly in certain branch...
USDA-ARS?s Scientific Manuscript database
Leafy spurge is an invasive perennial weed infesting range and recreational lands of North America. Previous research and omics projects with leafy spurge have helped develop it as a model for studying numerous aspects of perennial plant development and response to abiotic stress. However, the lack ...
Maddox, Geoffrey B.; Balota, David A.
2015-01-01
The present study examined how the function relating continued retrieval practice (e.g., 1, 3, or 5 tests) and long-term memory retention is modulated by desirable difficulty (Bjork, 1994). Of particular interest was how retrieval difficulty differed across young and older adults and across manipulations of lag (Experiment 1) and spacing (Experiment 2). To extend on previous studies, acquisition phase response latency was used as a proxy for retrieval difficulty, and analysis of final test performance was conditionalized on acquisition phase retrieval success to more directly examine the influence of desirable difficulty on retention. Results from Experiment 1 revealed that continued testing in the short lag condition led to consistent increases in retention, whereas continued testing in the long lag condition led to increasingly smaller benefits in retention for both age groups. Results from Experiment 2 revealed that repeated spaced testing enhanced retention relative to taking one spaced test for both age groups; however, repeated massed testing only enhanced retention over taking one test for young adults. Across both experiments, the response latency results were overall consistent with an influence of desirable difficulty on retention. Discussion focuses on the role of desirable difficulty during encoding in producing the benefits of lag, spacing, and testing. PMID:25616776
Ivan, J Solomon; Goswami, Kaumudibikash
2015-06-01
Two natural requirements on a measurable quantity possessed by a paraxially propagating light-field to be suitable for free space optical communication are invariance under free space propagation and invariance under transverse plane rotation. While the former invariance ensures that the measurable quantity is robust while signalling through free space, the latter invariance ensures that a detector measuring the quantity can be oriented at any angle in the transverse plane, and a measurement by the detector yields the same value for the quantity irrespective of the transverse angle, thus avoiding alignment issues. The variance matrix of a paraxially propagating light-field is analyzed from the perspective of the aforementioned invariances. That the "charge" of a paraxial light-field, which is contained in the variance matrix, and which has been previously well studied for its suitability toward free space optical communication, possesses these two invariance properties, emerges naturally in the analysis. Seven functionally independent quantities other than charge, which are derived from the variance matrix, and which share these invariances, are presented and studied for their suitability toward signalling through turbulent atmosphere using the low-order Hermite-Gaussian modes. It is found that the spot size of a Gaussian light-field can be effectively used as a switch, to communicate through short distances in a turbulent atmosphere.
Onofri, Silvano; Selbmann, Laura; Pacelli, Claudia; de Vera, Jean Pierre; Horneck, Gerda; Hallsworth, John E; Zucconi, Laura
2018-06-19
The black fungi Cryomyces antarcticus and Cryomyces minteri are highly melanized and are resilient to cold, ultra-violet, ionizing radiation and other extreme conditions. These microorganisms were isolated from cryptoendolithic microbial communities in the McMurdo Dry Valleys (Antarctica) and studied in Low Earth Orbit (LEO), using the EXPOSE-E facility on the International Space Station (ISS). Previously, it was demonstrated that C. antarcticus and C. minteri survive the hostile conditions of space (vacuum, temperature fluctuations, and the full spectrum of extraterrestrial solar electromagnetic radiation), as well as Mars conditions that were simulated in space for a 1.5-year period. Here, we qualitatively and quantitatively characterize damage to DNA and cellular ultrastructure in desiccated cells of these two species, within the frame of the same experiment. The DNA and cells of C. antarcticus exhibited a higher resistance than those of C. minteri . This is presumably attributable to the thicker (melanized) cell wall of the former. Generally, DNA was readily detected (by PCR) regardless of exposure conditions or fungal species, but the C. minteri DNA had been more-extensively mutated. We discuss the implications for using DNA, when properly shielded, as a biosignature of recently extinct or extant life.
Dual-Use system architecture for a space situational awareness system in Japan
NASA Astrophysics Data System (ADS)
Otani, Y.; Kohtake, N.; Ohkami, Y.
The use of outer space plays a vital role in both defense and civil fields. Since the separation of space activities between civil and defense applications is extremely inefficient, the Dual-Use concept has been considered fundamental for promoting the effective use of space. To the best of the authors' knowledge, most previous studies on Dual-Use focused on the technological aspects, and very few on a system engineering approach to Dual-Use. This left some important issues untouched such as the operational aspects of a system of systems, which need to be understood in a more generic context. This paper presents the results of a conceptual study, system design and management analysis of Dual-Use system architecture. First, an outline of the Dual-Use concept will be described and a definition of Dual-Use given. The effectiveness of applying the Dual-Use system concept to Space Situational Awareness (SSA) for both defense and civil users as a system of systems will then be discussed and investigated with a stakeholders analysis, context diagram and design structure matrix method. It has demonstrated that there is a need for a Dual-Use SSA Data Center which works as a binder between defense and civil systems as well as a data policy for constructing a Dual-Use SSA system.
Chin, Wei-Chien-Benny; Wen, Tzai-Hung; Sabel, Clive E; Wang, I-Hsiang
2017-10-03
A diffusion process can be considered as the movement of linked events through space and time. Therefore, space-time locations of events are key to identify any diffusion process. However, previous clustering analysis methods have focused only on space-time proximity characteristics, neglecting the temporal lag of the movement of events. We argue that the temporal lag between events is a key to understand the process of diffusion movement. Using the temporal lag could help to clarify the types of close relationships. This study aims to develop a data exploration algorithm, namely the TrAcking Progression In Time And Space (TaPiTaS) algorithm, for understanding diffusion processes. Based on the spatial distance and temporal interval between cases, TaPiTaS detects sub-clusters, a group of events that have high probability of having common sources, identifies progression links, the relationships between sub-clusters, and tracks progression chains, the connected components of sub-clusters. Dengue Fever cases data was used as an illustrative case study. The location and temporal range of sub-clusters are presented, along with the progression links. TaPiTaS algorithm contributes a more detailed and in-depth understanding of the development of progression chains, namely the geographic diffusion process.
Visual selective attention with virtual barriers.
Schneider, Darryl W
2017-07-01
Previous studies have shown that interference effects in the flanker task are reduced when physical barriers (e.g., hands) are placed around rather than below a target flanked by distractors. One explanation of this finding is the referential coding hypothesis, whereby the barriers serve as reference objects for allocating attention. In five experiments, the generality of the referential coding hypothesis was tested by investigating whether interference effects are modulated by the placement of virtual barriers (e.g., parentheses). Modulation of flanker interference was found only when target and distractors differed in size and the virtual barriers were beveled wood-grain objects. Under these conditions and those of previous studies, the author conjectures that an impression of depth was produced when the barriers were around the target, such that the target was perceived to be on a different depth plane than the distractors. Perception of depth in the stimulus display might have led to referential coding of the stimuli in three-dimensional (3-D) space, influencing the allocation of attention beyond the horizontal and vertical dimensions. This 3-D referential coding hypothesis is consistent with research on selective attention in 3-D space that shows flanker interference is reduced when target and distractors are separated in depth.
Exo-C: A Space Mission for Direct Imaging and Spectroscopy of Extrasolar Planetary Systems
NASA Technical Reports Server (NTRS)
Stapelfeldt, Karl; Belikov, Ruslan; Marley, Mark; Bryden, Geoff; Serabyn, Eugene; Trauger, John; Cahoy, Kerri; Chakrabarti, Supriya; McElwain, Michael; Meadows, Victoria;
2015-01-01
Exo-C is NASAs first community study of a modest aperture space telescope designed for high contrast observations of exoplanetary systems. The mission will be capable of taking optical spectra of nearby exoplanets in reflected light, discovering previously undetected planets, and imaging structure in a large sample of circumstellar disks. It will obtain unique science results on planets down to super-Earth sizes and serve as a technology pathfinder toward an eventual flagship-class mission to find and characterize habitable Earth-like exoplanets. We present the mission/payload design and highlight steps to reduce mission cost/risk relative to previous mission concepts. Key elements are an unobscured telescope aperture, an internal coronagraph with deformable mirrors for precise wavefront control, and an orbit and observatory design chosen for high thermal stability. Exo-C has a similar telescope aperture, orbit, lifetime, and spacecraft bus requirements to the highly successful Kepler mission (which is our cost reference). The needed technology development is on-course for a possible mission start in 2017. This paper summarizes the study final report completed in January 2015. During 2015 NASA will make a decision on its potential development.
NASA Astrophysics Data System (ADS)
Shen, Yu-Sheng; Lung, Shih-Chun Candice
2017-02-01
Previous studies have shown both health and environmental benefits of green spaces, especially in moderating temperature and reducing air pollution. However, the characteristics of green structures have been overlooked in previous investigations. In addition, the mediation effects of green structures on respiratory mortality have not been assessed. This study explores the potential mediation pathways and effects of green structure characteristics on respiratory mortality through temperature, primary and secondary air pollutants separately using partial least squares model with data from Taiwan. The measurable characteristics of green structure include the largest patch percentage, landscape proportion, aggregation, patch distance, and fragmentation. The results showed that mortality of pneumonia and chronic lower respiratory diseases could be reduced by minimizing fragmentation and increasing the largest patch percentage of green structure, and the mediation effects are mostly through reducing air pollutants rather than temperature. Moreover, a high proportion of but fragmented green spaces would increase secondary air pollutants and enhance health risks; demonstrating the deficiency of traditional greening policy with primary focus on coverage ratio. This is the first research focusing on mediation effects of green structure characteristics on respiratory mortality, revealing that appropriate green structure planning can be a useful complementary strategy in environmental health management.
Shen, Yu-Sheng; Lung, Shih-Chun Candice
2017-02-23
Previous studies have shown both health and environmental benefits of green spaces, especially in moderating temperature and reducing air pollution. However, the characteristics of green structures have been overlooked in previous investigations. In addition, the mediation effects of green structures on respiratory mortality have not been assessed. This study explores the potential mediation pathways and effects of green structure characteristics on respiratory mortality through temperature, primary and secondary air pollutants separately using partial least squares model with data from Taiwan. The measurable characteristics of green structure include the largest patch percentage, landscape proportion, aggregation, patch distance, and fragmentation. The results showed that mortality of pneumonia and chronic lower respiratory diseases could be reduced by minimizing fragmentation and increasing the largest patch percentage of green structure, and the mediation effects are mostly through reducing air pollutants rather than temperature. Moreover, a high proportion of but fragmented green spaces would increase secondary air pollutants and enhance health risks; demonstrating the deficiency of traditional greening policy with primary focus on coverage ratio. This is the first research focusing on mediation effects of green structure characteristics on respiratory mortality, revealing that appropriate green structure planning can be a useful complementary strategy in environmental health management.
Lapointe, Stephen L; Barros-Parada, Wilson; Fuentes-Contreras, Eduardo; Herrera, Heidy; Kinsho, Takeshi; Miyake, Yuki; Niedz, Randall P; Bergmann, Jan
2017-12-01
Field experiments were carried out to study responses of male moths of the carpenterworm, Chilecomadia valdiviana (Lepidoptera: Cossidae), a pest of tree and fruit crops in Chile, to five compounds previously identified from the pheromone glands of females. Previously, attraction of males to the major component, (7Z,10Z)-7,10-hexadecadienal, was clearly demonstrated while the role of the minor components was uncertain due to the use of an experimental design that left large portions of the design space unexplored. We used mixture designs to study the potential contributions to trap catch of the four minor pheromone components produced by C. valdiviana. After systematically exploring the design space described by the five pheromone components, we concluded that the major pheromone component alone is responsible for attraction of male moths in this species. The need for appropriate experimental designs to address the problem of assessing responses to mixtures of semiochemicals in chemical ecology is described. We present an analysis of mixture designs and response surface modeling and an explanation of why this approach is superior to commonly used, but statistically inappropriate, designs.
Changes in mineral metabolism with immobilization/space flight
NASA Technical Reports Server (NTRS)
Gallagher, J. C.
1989-01-01
Researchers are still unsure of the accuracy of previous bone density measurements of their significance following a period of weightlessness. Rapid technological advances in the measurement of bone density will enable us now to measure bone density accurately at multiple sites in the skeleton with doses of radiation less than that given by a spine x ray. It may not be possible to obtain this type of information before the next series of space flights take place, although the bed-rest model may provide supporting information. Extensive testing of bone density on every astronaut should be performed before and after the space flight. Prevention and treatment can only be undertaken after gathering sufficient baseline information. The use of exercise in preventing bone loss is still highly speculative, but represents a relatively easy approach to the problem in terms of study.
A Dynamic/Anisotropic Low Earth Orbit (LEO) Ionizing Radiation Model
NASA Technical Reports Server (NTRS)
Badavi, Francis F.; West, Katie J.; Nealy, John E.; Wilson, John W.; Abrahms, Briana L.; Luetke, Nathan J.
2006-01-01
The International Space Station (ISS) provides the proving ground for future long duration human activities in space. Ionizing radiation measurements in ISS form the ideal tool for the experimental validation of ionizing radiation environmental models, nuclear transport code algorithms, and nuclear reaction cross sections. Indeed, prior measurements on the Space Transportation System (STS; Shuttle) have provided vital information impacting both the environmental models and the nuclear transport code development by requiring dynamic models of the Low Earth Orbit (LEO) environment. Previous studies using Computer Aided Design (CAD) models of the evolving ISS configurations with Thermo Luminescent Detector (TLD) area monitors, demonstrated that computational dosimetry requires environmental models with accurate non-isotropic as well as dynamic behavior, detailed information on rack loading, and an accurate 6 degree of freedom (DOF) description of ISS trajectory and orientation.
Light scalars on cosmological backgrounds
NASA Astrophysics Data System (ADS)
Markkanen, Tommi
2018-01-01
We study the behaviour of a light quartically self-interacting scalar field ϕ on curved backgrounds that may be described with the cosmological equation state parameter w. At leading order in the non-perturbative 2PI expansion we find a general formula for the variance < {\\widehat{φ}}^2> and show for several previously unexplored cases, including matter domination and kination, that the curvature of space can induce a significant excitation of the field. We discuss how the generation of a non-zero variance for w ≠ -1 can be understood as a process of self-regulation of the infrared divergences very similarly to what is known to occur in de Sitter space. To conclude, the appearance of an effective mass due to self-interaction is generic for a light scalar in curved space and can have important implications for reheating, vacuum stability and dark matter generation.
NASA Technical Reports Server (NTRS)
Nelson, Emily S.; Kizito, John P.
2003-01-01
A tightly knit numerical/experimental collaboration among the NASA Ames Research Center, NASA Glenn Research Center, and Payload Systems, Inc., was formed to analyze cell culturing systems for the International Space Station. The Cell Culture Unit is a facility scheduled for deployment on the space station by the Cell Culture Unit team at Ames. The facility houses multiple cell specimen chambers (CSCs), all of which have inlets and outlets to allow for replenishment of nutrients and for waste removal. For improved uniformity of nutrient and waste concentrations, each chamber has a pair of counterrotating stir bars as well. Although the CSC can be used to grow a wide variety of organic cells, the current study uses yeast as a model cell. Previous work identified groundbased protocols for perfusion and stirring to achieve yeast growth within the CSC that is comparable to that for yeast cultures grown in a shaken Ehrlenmeyer flask.
1985-06-01
Spacelab-3 launched aboard STS-51B, with the major science objective being to perform engineering tests on two new facilities: the rodent animal holding facility and the primate animal holding facility. In addition, scientists observed the animals to obtain first hand knowledge of the effects of launch and reentry stresses and behavior. The need for suitable animal housing to support research in space led to the development of the Research Animal Holding Facility at the Ames Research Center. Scientists often study animals to find clues to human physiology and behavior. Rats, insects, and microorganisms had already been studied aboard the Shuttle on previous missions. On Spacelab-3, scientists had a chance to observe a large number of animals living in space in a specially designed and independently controlled housing facility. Marshall Space Flight Center (MSFC) had management responsibility for the Spacelab-3 mission. This photograph depicts activities during the mission at the Huntsville Operations Support Center (HOSC) Spacelab Payload Operations Control Center (SL POCC) at MSFC.
1985-05-01
Spacelab-3 launched aboard STS-51B, with the major science objective being to perform engineering tests on two new facilities: the rodent animal holding facility and the primate animal holding facility. In addition, scientists observed the animals to obtain first hand knowledge of the effects of launch and reentry stresses and behavior. The need for suitable animal housing to support research in space led to the development of the Research Animal Holding Facility at the Ames Research Center. Scientists often study animals to find clues to human physiology and behavior. Rats, insects, and microorganisms had already been studied aboard the Shuttle on previous missions. On Spacelab-3, scientists had a chance to observe a large number of animals living in space in a specially designed and independently controlled housing facility. Marshall Space Flight Center (MSFC) had management responsibility for the Spacelab 3 mission. This photograph depicts activities during the mission at the Huntsville Operations Support Center (HOSC) Spacelab Payload Operations Control Center (SL POCC) at MSFC.
1985-05-01
Spacelab-3 launched aboard STS-51B, with the major science objective being to perform engineering tests on two new facilities: the rodent animal holding facility and the primate animal holding facility. In addition, scientists observed the animals to obtain first hand knowledge of the effects of launch and reentry stresses and behavior. The need for suitable animal housing to support research in space led to the development of the Research Animal Holding Facility at the Ames Research Center. Scientists often study animals to find clues to human physiology and behavior. Rats, insects, and microorganisms had already been studied aboard the Shuttle on previous missions. On Spacelab-3, scientists had a chance to observe a large number of animals living in space in a specially designed and independently controlled housing facility. Marshall Space Flight Center (MSFC) had management responsibility for the Spacelab-3 mission. This photograph depicts activities during the mission at the Huntsville Operations Support Center (HOSC) Spacelab Payload Operations Control Center (SL POCC) at MSFC.
1985-06-01
Spacelab-3 launched aboard STS-51B, with the major science objective being to perform engineering tests on two new facilities: the rodent animal holding facility and the primate animal holding facility. In addition, scientists observed the animals to obtain first hand knowledge of the effects of launch and reentry stresses and behavior. The need for suitable animal housing to support research in space led to the development of the Research Animal Holding Facility at the Ames Research Center. Scientists often study animals to find clues to human physiology and behavior. Rats, insects, and microorganisms had already been studied aboard the Shuttle on previous missions. On Spacelab-3, scientists had a chance to observe a large number of animals living in space in a specially designed and independently controlled housing facility. Marshall Space Flight Center (MSFC) had management responsibility for the Spacelab-3 mission. This photograph depicts activities during the mission at the Huntsville Operations Support Center (HOSC) Spacelab Payload Operations Control Center (SL POCC) at MSFC.
Conceptual study of on orbit production of cryogenic propellants by water electrolysis
NASA Technical Reports Server (NTRS)
Moran, Matthew E.
1991-01-01
The feasibility is assessed of producing cryogenic propellants on orbit by water electrolysis in support of NASA's proposed Space Exploration Initiative (SEI) missions. Using this method, water launched into low earth orbit (LEO) would be split into gaseous hydrogen and oxygen by electrolysis in an orbiting propellant processor spacecraft. The resulting gases would then be liquified and stored in cryogenic tanks. Supplying liquid hydrogen and oxygen fuel to space vehicles by this technique has some possible advantages over conventional methods. The potential benefits are derived from the characteristics of water as a payload, and include reduced ground handling and launch risk, denser packaging, and reduced tankage and piping requirements. A conceptual design of a water processor was generated based on related previous studies, and contemporary or near term technologies required. Extensive development efforts would be required to adapt the various subsystems needed for the propellant processor for use in space. Based on the cumulative results, propellant production by on orbit water electrolysis for support of SEI missions is not recommended.
Transportation node space station conceptual design
NASA Technical Reports Server (NTRS)
1988-01-01
A number of recent studies have addressed the problem of a transportation node space station. How things would change or what addition facilities would be needed to support a major lunar or Mars initiative is a much often asked question. The support of a lunar base, requiring stacks on the order of 200 metric tons each to land 25 m tons on the lunar surface with reusable vehicles is addressed. The problem of maintaining and reusing large single stage Orbit Transfer Vehicles (OTVs) and single stage lander/launchers in space are examined. The required people and equipment needed, to maintain these vehicles are only vaguely known at present. The people and equipment needed depend on how well the OTV and lander/launcher can be designed for easy reuse. Since the OTV and lander/launcher are only conceptually defined at present, the real maintenance and refurbishment requirements are unobtainable. An estimate of what is needed, based on previous studies and obvious requirements was therefore made. An attempt was made to err on the conservative side.
The character and mechanism of glacial variation in the peripheral Tibetan Plateau
NASA Astrophysics Data System (ADS)
Yi, S.; Wang, Q.; Sun, W.
2016-12-01
Global warming has accelerated glacier retreat in the peripheral Tibetan Plateau. Our study demonstrates consistent glacier variation in time series constructed by laser altimetry and space gravimetry in these regions. It largely enhances reliability of glacier changes and narrows down significant inconsistent in previous studies. The glacial melt is roughly weakening from southeast to northwest: from Nyenchen Tanglha to Himalaya then to Pamir even a positive gain in the Western Kunlun. A sharp melt of glacier on Nyenchen Tanglha is primarily caused by high temperature and rapid rise rather than decreasing in annual precipitation as previously thought. Glaciers on Hindu Kush, Karakoram and Western Kun even Pamir are less affect by slow rise of local temperature.
Counteracting Gravitation In Dielectric Liquids
NASA Technical Reports Server (NTRS)
Israelsson, Ulf E.; Jackson, Henry W.; Strayer, Donald M.
1993-01-01
Force of gravity in variety of dielectric liquids counteracted by imposing suitably contoured electric fields. Technique makes possible to perform, on Earth, variety of experiments previously performed only in outer space and at great cost. Also used similarly in outer space to generate sort of artificial gravitation.
2014-01-01
Background Integrating and analyzing heterogeneous genome-scale data is a huge algorithmic challenge for modern systems biology. Bipartite graphs can be useful for representing relationships across pairs of disparate data types, with the interpretation of these relationships accomplished through an enumeration of maximal bicliques. Most previously-known techniques are generally ill-suited to this foundational task, because they are relatively inefficient and without effective scaling. In this paper, a powerful new algorithm is described that produces all maximal bicliques in a bipartite graph. Unlike most previous approaches, the new method neither places undue restrictions on its input nor inflates the problem size. Efficiency is achieved through an innovative exploitation of bipartite graph structure, and through computational reductions that rapidly eliminate non-maximal candidates from the search space. An iterative selection of vertices for consideration based on non-decreasing common neighborhood sizes boosts efficiency and leads to more balanced recursion trees. Results The new technique is implemented and compared to previously published approaches from graph theory and data mining. Formal time and space bounds are derived. Experiments are performed on both random graphs and graphs constructed from functional genomics data. It is shown that the new method substantially outperforms the best previous alternatives. Conclusions The new method is streamlined, efficient, and particularly well-suited to the study of huge and diverse biological data. A robust implementation has been incorporated into GeneWeaver, an online tool for integrating and analyzing functional genomics experiments, available at http://geneweaver.org. The enormous increase in scalability it provides empowers users to study complex and previously unassailable gene-set associations between genes and their biological functions in a hierarchical fashion and on a genome-wide scale. This practical computational resource is adaptable to almost any applications environment in which bipartite graphs can be used to model relationships between pairs of heterogeneous entities. PMID:24731198
Effect of weightlessness and centrifugation on red cell survival in rats subjected to space flight
NASA Technical Reports Server (NTRS)
Leon, H. A.; Serova, L. V.; Landaw, S. A.
1980-01-01
Rats were flown aboard the Soviet biosatellite Cosmos 936 for 18.5 d during August, 1977. Five rats were subjected to near-weightless space flight, as with Cosmos 782, and five rats were subjected to a 1-G force via an on-board centrifuge. These rats and three control groups were injected with 2-(C-14) glycine 19 d preflight. The flight rats were recovered from orbit after 18.5 d of space flight. Erythrocyte hemolysis and lifespan were evaluated in the five groups of rats by quantitation of radioactive carbon monoxide exhaled in the breath which arises from the breakdown of the previously labeled hemoglobin. The results support the previous findings wherein hemolysis was found to increase as a result of weightless space flight. A comparison to the centrifuged animals indicates that artificial gravity attenuates the effect of weightlessness on hemolysis and appears to normalize the hemolytic rate in the early postflight period.
Earth-atmosphere system and surface reflectivities in arid regions from Landsat MSS data
NASA Technical Reports Server (NTRS)
Otterman, J.; Fraser, R. S.
1976-01-01
Previously developed programs for computing atmospheric transmission and scattering of the solar radiation are used to compute the ratios of the earth-atmosphere system (space) directional reflectivities in the nadir direction to the surface Lambertian reflectivity, for the four bands of the Landsat multispectral scanner (MSS). These ratios are presented as graphs for two water vapor levels, as a function of the surface reflectivity, for various sun elevation angles. Space directional reflectivities in the vertical direction are reported for selected arid regions in Asia, Africa, and Central America from the spectral radiance levels measured by the Landsat MSS. From these space reflectivities, surface reflectivities are computed applying the pertinent graphs. These surface reflectivities are used to estimate the surface albedo for the entire solar spectrum. The estimated albedos are in the range 0.34-0.52, higher than the values reported by most previous researchers from space measurements, but are consistent with laboratory and in situ measurements.
Global Scale Observations of Ionospheric Instabilities from GPS in Low Earth Orbit
NASA Technical Reports Server (NTRS)
Kramer, Leonard; Goodman, John L.
2003-01-01
The GPS receiver used for navigation on the Space Shuttle exhibits range rate noise which appears to result from scintillation of the satellite signals by irregularities in ionospheric plasma. The noise events cluster in geographic regions previously identified as susceptible to instability and disturbed ionospheric conditions. These mechanisms are reviewed in the context of the GPS observations. Range rate data continuously monitored during the free orbiting phase of several space shuttle missions reveals global scale distribution of ionospheric irregularities. Equatorial events cluster +/- 20 degrees about the magnetic equator and polar events exhibit hemispheric asymmetry suggesting influence of off axis geomagnetic polar oval system. The diurnal, seasonal and geographic distribution is compared to previous work concerning equatorial spread F, Appleton anomaly and polar oval. The observations provide a succinct demonstration of the utility of space based ionospheric monitoring using GPS. The susceptability of GPS receivers to scintillation represents 'an unanticipated technical risk not factored into the selection of receivers for the United States space program.
NASA Technical Reports Server (NTRS)
Uhran, M. L.; Youngblood, W. W.; Georgekutty, T.; Fiske, M. R.; Wear, W. O.
1986-01-01
Taking advantage of the microgravity environment of space NASA has initiated the preliminary design of a permanently manned space station that will support technological advances in process science and stimulate the development of new and improved materials having applications across the commercial spectrum. Previous studies have been performed to define from the researcher's perspective, the requirements for laboratory equipment to accommodate microgravity experiments on the space station. Functional requirements for the identified experimental apparatus and support equipment were determined. From these hardware requirements, several items were selected for concept designs and subsequent formulation of development plans. This report documents the concept designs and development plans for two items of experiment apparatus - the Combustion Tunnel and the Advanced Modular Furnace, and two items of support equipment the Laser Diagnostic System and the Integrated Electronics Laboratory. For each concept design, key technology developments were identified that are required to enable or enhance the development of the respective hardware.
A note on dust grain charging in space plasmas
NASA Technical Reports Server (NTRS)
Rosenberg, M.; Mendis, D. A.
1992-01-01
Central to the study of dust-plasma interactions in the solar system is the electrostatic charging of dust grains. While previous calculations have generally assumed that the distributions of electrons and ions in the plasma are Maxwellian, most space plasmas are observed to have non-Maxwellian tails and can often be fit by a generalized Lorentzian (kappa) distribution. Here we use such a distribution to reevaluate the grain potential, under the condition that the dominant currents to the grain are due to electron and ion collection, as is the case in certain regions of space. The magnitude of the grain potential is found to be larger than that in a Maxwellian plasma as long as the electrons are described by a kappa distribution: this enhancement increased with ion mass and decreasing electron kappa. The modification of the grain potential in generalized Lorentzian plasmas has implications for both the physics (e.g., grain growth and disruption) and the dynamics of dust in space plasmas. These are also briefly discussed.
Redshift Space Distortion on the Small Scale Clustering of Structure
NASA Astrophysics Data System (ADS)
Park, Hyunbae; Sabiu, Cristiano; Li, Xiao-dong; Park, Changbom; Kim, Juhan
2018-01-01
The positions of galaxies in comoving Cartesian space varies under different cosmological parameter choices, inducing a redshift-dependent scaling in the galaxy distribution. The shape of the two-point correlation of galaxies exhibits a significant redshift evolution when the galaxy sample is analyzed under a cosmology differing from the true, simulated one. In our previous works, we can made use of this geometrical distortion to constrain the values of cosmological parameters governing the expansion history of the universe. This current work is a continuation of our previous works as a strategy to constrain cosmological parameters using redshift-invariant physical quantities. We now aim to understand the redshift evolution of the full shape of the small scale, anisotropic galaxy clustering and give a firmer theoretical footing to our previous works.
NASA Technical Reports Server (NTRS)
Plaza-Rosado, Heriberto
1991-01-01
Thermal neutron activation analyses were carried out for various space systems components to determine gamma radiation dose rates and food radiation contamination levels. The space systems components selected were those for which previous radiation studies existed. These include manned space vehicle radiation shielding, liquid hydrogen propellant tanks for a Mars mission, and a food supply used as space vehicle radiation shielding. The computational method used is based on the fast neutron distribution generated by the BRYNTRN and HZETRN transport codes for Galactic Cosmic Rays (GCR) at solar minimum conditions and intense solar flares in space systems components. The gamma dose rates for soft tissue are calculated for water and aluminum space vehicle slab shields considering volumetric source self-attenuation and exponential buildup factors. In the case of the lunar habitat with regolith shielding, a completely exposed spherical habitat was assumed for mathematical convenience and conservative calculations. Activation analysis of the food supply used as radiation shielding is presented for four selected nutrients: potassium, calcium, sodium, and phosphorus. Radioactive isotopes that could represent a health hazard if ingested are identified and their concentrations are identified. For nutrients soluble in water, it was found that all induced radioactivity was below the accepted maximum permissible concentrations.
NASA Astrophysics Data System (ADS)
Plaza-Rosado, Heriberto
1991-09-01
Thermal neutron activation analyses were carried out for various space systems components to determine gamma radiation dose rates and food radiation contamination levels. The space systems components selected were those for which previous radiation studies existed. These include manned space vehicle radiation shielding, liquid hydrogen propellant tanks for a Mars mission, and a food supply used as space vehicle radiation shielding. The computational method used is based on the fast neutron distribution generated by the BRYNTRN and HZETRN transport codes for Galactic Cosmic Rays (GCR) at solar minimum conditions and intense solar flares in space systems components. The gamma dose rates for soft tissue are calculated for water and aluminum space vehicle slab shields considering volumetric source self-attenuation and exponential buildup factors. In the case of the lunar habitat with regolith shielding, a completely exposed spherical habitat was assumed for mathematical convenience and conservative calculations. Activation analysis of the food supply used as radiation shielding is presented for four selected nutrients: potassium, calcium, sodium, and phosphorus. Radioactive isotopes that could represent a health hazard if ingested are identified and their concentrations are identified. For nutrients soluble in water, it was found that all induced radioactivity was below the accepted maximum permissible concentrations.
Calcium Balance in Mature Rats Exposed to a Space Flight Model
NASA Technical Reports Server (NTRS)
Wolinsky, Ira
1996-01-01
Negative calcium balances are seen in humans during spaceflight and bed rest, an analog of space flight. Due to the infrequency and costliness of space flight and the difficulties, cost, and restraints in using invasive procedures in bed rest studies, several ground based animal models of space flight have been employed. The most useful and well developed of these models is hind limb unloading in the rat. In this model the hind limbs are non-weight bearing (unloaded) but still mobile; there is a cephalad fluid shift similar to that seen in astronauts in flight; the animals are able to feed, groom and locomote using their front limbs; the procedure is reversible; and, importantly, the model has been validated by comparison to space flight. Several laboratories have studied calcium balance using rats in hind limb unweighting. Roer and Dillaman used young male rats to study calcium balance in this model for 25 days. They found no differences in dietary calcium intake, percent calcium absorption, urinary and fecal excretion, hence indicating no differences in calcium balance between control and unloaded rats. In another study, employing 120 day old females, rats' hind limbs were unloaded for 28 days. While negative calcium balances were observed during a 25 day recovery period no balance measurements were possible during unweighting since the researchers did not employ appropriate metabolic cages. In a recent study from this laboratory, using 200 g rats in the space flight model for two weeks, we found depressed intestinal calcium absorption and increased fecal calcium excretion (indicating less positive calcium balances) and lower circulating 1,25-dihydroxyvitamin D. The above studies indicate that there remains a dearth of information on calcium balance during the hind limb unloading rat space flight model, especially in mature rats, whose use is a better model for planned manned space flight than juvenile or growing animals. With the aid of a newly designed metabolic cage developed in our laboratory it is now possible to accurately measure urinary and fecal calcium excretions in this space flight model. The purpose of this study, then, was to extend and enlarge our previous findings viz: to measure calcium balances in mature rats exposed to a space flight model.
NASA Technical Reports Server (NTRS)
Bloomfield, Harvey S.; Heller, Jack A.
1987-01-01
A preliminary feasibility assessment of the integration of reactor power system concepts with a projected growth space station architecture was conducted to address a variety of installation, operational disposition, and safety issues. A previous NASA sponsored study, which showed the advantages of space station - attached concepts, served as the basis for this study. A study methodology was defined and implemented to assess compatible combinations of reactor power installation concepts, disposal destinations, and propulsion methods. Three installation concepts that met a set of integration criteria were characterized from a configuration and operational viewpoint, with end-of-life disposal mass identified. Disposal destinations that met current aerospace nuclear safety criteria were identified and characterized from an operational and energy requirements viewpoint, with delta-V energy requirement as a key parameter. Chemical propulsion methods that met current and near-term application criteria were identified and payload mass and delta-V capabilities were characterized. These capabilities were matched against concept disposal mass and destination delta-V requirements to provide the feasibility of each combination.
A feasibility assessment of nuclear reactor power system concepts for the NASA Growth Space Station
NASA Technical Reports Server (NTRS)
Bloomfield, H. S.; Heller, J. A.
1986-01-01
A preliminary feasibility assessment of the integration of reactor power system concepts with a projected growth Space Station architecture was conducted to address a variety of installation, operational, disposition and safety issues. A previous NASA sponsored study, which showed the advantages of Space Station - attached concepts, served as the basis for this study. A study methodology was defined and implemented to assess compatible combinations of reactor power installation concepts, disposal destinations, and propulsion methods. Three installation concepts that met a set of integration criteria were characterized from a configuration and operational viewpoint, with end-of-life disposal mass identified. Disposal destinations that met current aerospace nuclear safety criteria were identified and characterized from an operational and energy requirements viewpoint, with delta-V energy requirement as a key parameter. Chemical propulsion methods that met current and near-term application criteria were identified and payload mass and delta-V capabilities were characterized. These capabilities were matched against concept disposal mass and destination delta-V requirements to provide a feasibility of each combination.
NASA Astrophysics Data System (ADS)
Nevodovskyi, P. V.; Vidmachenko, A. P.; Geraimchuk, M. D.; Ivahiv, O. V.
2016-10-01
Remote polarization studies are a very powerful method of solving of astronomical tasks with the study of the physical properties of the planets and their atmospheres. It allows research of objects as in situ, so in vitro, and has many other advantages. To use this method has already been developed and are continuing the development of many various special instruments called polarimeters. The essence of the space experiment consists in the fact to using the polarimeter installed on board a micro satellite, systematically, during each of its revolutions around the Earth, to monitor a polarization components of a diffusely reflected by atmosphere solar radiation in different, previously stipulated wavelengths. There are a lot of the optical schemes, which are used in devices of measuring and monitoring of parameters of polarized radiation, including those into space experiments of probing of the Earth's atmosphere from orbit of satellites. In this paper we analyze the potential for use of filter-polarimeter to measure the Stokes vector components.
Hand controller commonality evaluation process
NASA Technical Reports Server (NTRS)
Stuart, Mark A.; Bierschwale, John M.; Wilmington, Robert P.; Adam, Susan C.; Diaz, Manuel F.; Jensen, Dean G.
1993-01-01
Hand controller selection for NASA's Orbiter and Space Station Freedom is an important area of human-telerobot interface design and evaluation. These input devices will control remotely operated systems that include large crane-like manipulators (e.g., Remote Manipulator System or RMS), smaller, more dexterous manipulators (e.g., Flight Telerobotic Servicer or FTS), and free flyers (e.g., Orbital Maneuvering Vehicle or OMV). Candidate hand controller configurations for these systems vary in many ways: shape, size, number of degrees-of-freedom (DOF), operating modes, provision of force reflection, range of movement, and 'naturalness' of use. Unresolved design implementation issues remain, including such topics as how the current Orbiter RMS rotational and translational rate hand controllers compare with the proposed Space Station Freedom hand controllers, the advantages that position hand controllers offer for these applications, and whether separate hand controller configurations are required for each application. Since previous studies contain little empirical hand controller task performance data, a controlled study is needed that tests Space Station Freedom candidate hand controllers during representative tasks. This study also needs to include anthropometric and biomechanical considerations.
Li, Heng; Cao, Yu
2017-06-01
What influences how people implicitly associate "past" and "future" with "front" and "back?" Whereas previous research has shown that cultural attitudes toward time play a role in modulating space-time mappings in people's mental models (de la Fuente, Santiago, Román, Dumitrache & Casasanto, 2014), we investigated real life experiences as potential additional influences on these implicit associations. Participants within the same single culture, who are engaged in different intermediate-term educational experiences (Study 1), long-term living experiences (Study 2), and short-term visiting experiences (Study 3), showed their distinct differences in temporal focus, thereby influencing their implicit spatializations of time. Results across samples suggest that personal attitudes toward time related to real life experiences may influence people's space-time mappings. The findings we report on shed further light on the high flexibility of human conceptualization system. While culture may exert an important influence on temporal focus, a person's conceptualization of time may be attributed to a culmination of factors. © 2017 Scandinavian Psychological Associations and John Wiley & Sons Ltd.
Cost Modeling for Space Optical Telescope Assemblies
NASA Technical Reports Server (NTRS)
Stahl, H. Philip; Henrichs, Todd; Luedtke, Alexander; West, Miranda
2011-01-01
Parametric cost models are used to plan missions, compare concepts and justify technology investments. This paper reviews an on-going effort to develop cost modes for space telescopes. This paper summarizes the methodology used to develop cost models and documents how changes to the database have changed previously published preliminary cost models. While the cost models are evolving, the previously published findings remain valid: it costs less per square meter of collecting aperture to build a large telescope than a small telescope; technology development as a function of time reduces cost; and lower areal density telescopes cost more than more massive telescopes.
2012-05-23
CAPE CANAVERAL, Fla. – A NASA Railroad train passes in front of the 525-foot-tall Vehicle Assembly Building, left, and the twin bays of the Orbiter Processing Facility, right, at NASA’s Kennedy Space Center in Florida. The train is on its way to the Florida East Coast Railway interchange in Titusville, Fla., where the train’s helium tank cars, a liquid oxygen tank car, and a liquid hydrogen dewar or tank car will be transferred for delivery to the SpaceX engine test complex outside McGregor, Texas. The railroad cars were needed in support of the Space Shuttle Program but currently are not in use by NASA following the completion of the program in 2011. Originally, the tankers belonged to the U.S. Bureau of Mines. At the peak of the shuttle program, there were approximately 30 cars in the fleet. About half the cars were returned to the bureau as launch activity diminished. Five tank cars are being loaned to SpaceX and repurposed to support their engine tests in Texas. Eight cars previously were shipped to California on loan to support the SpaceX Falcon 9 rocket launches from Space Launch Complex-4 on Vandenberg Air Force Base. SpaceX already has three helium tank cars previously used for the shuttle program at Space Launch Complex-40 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/spacex. Photo credit: NASA/Jim Grossmann
2012-05-23
CAPE CANAVERAL, Fla. – A manatee relaxes in the Indian River near the NASA Railroad’s Jay Jay Railroad Bridge north of Launch Complex 39 at NASA’s Kennedy Space Center in Florida. The manatee was spotted by a cameraman on hand to photograph a NASA Railroad train on its way to the Florida East Coast Railway interchange in Titusville, Fla., where the train’s helium tank cars, a liquid oxygen tank car, and a liquid hydrogen dewar or tank car will be transferred for delivery to the SpaceX engine test complex outside McGregor, Texas. The railroad cars were needed in support of the Space Shuttle Program but currently are not in use by NASA following the completion of the program in 2011. Originally, the tankers belonged to the U.S. Bureau of Mines. At the peak of the shuttle program, there were approximately 30 cars in the fleet. About half the cars were returned to the bureau as launch activity diminished. Five tank cars are being loaned to SpaceX and repurposed to support their engine tests in Texas. Eight cars previously were shipped to California on loan to support the SpaceX Falcon 9 rocket launches from Space Launch Complex-4 on Vandenberg Air Force Base. SpaceX already has three helium tank cars previously used for the shuttle program at Space Launch Complex-40 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/spacex. Photo credit: NASA/Jim Grossmann
2012-05-23
CAPE CANAVERAL, Fla. – A manatee relaxes in the Indian River near the NASA Railroad’s Jay Jay Railroad Bridge north of Launch Complex 39 at NASA’s Kennedy Space Center in Florida. The manatee was spotted by a cameraman on hand to photograph a NASA Railroad train on its way to the Florida East Coast Railway interchange in Titusville, Fla., where the train’s helium tank cars, a liquid oxygen tank car, and a liquid hydrogen dewar or tank car will be transferred for delivery to the SpaceX engine test complex outside McGregor, Texas. The railroad cars were needed in support of the Space Shuttle Program but currently are not in use by NASA following the completion of the program in 2011. Originally, the tankers belonged to the U.S. Bureau of Mines. At the peak of the shuttle program, there were approximately 30 cars in the fleet. About half the cars were returned to the bureau as launch activity diminished. Five tank cars are being loaned to SpaceX and repurposed to support their engine tests in Texas. Eight cars previously were shipped to California on loan to support the SpaceX Falcon 9 rocket launches from Space Launch Complex-4 on Vandenberg Air Force Base. SpaceX already has three helium tank cars previously used for the shuttle program at Space Launch Complex-40 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/spacex. Photo credit: NASA/Jim Grossmann
2012-05-23
CAPE CANAVERAL, Fla. – A NASA Railroad train passes in front of the 525-foot-tall Vehicle Assembly Building, left, and the twin bays of the Orbiter Processing Facility, right, at NASA’s Kennedy Space Center in Florida. The train is on its way to the Florida East Coast Railway interchange in Titusville, Fla., where the train’s helium tank cars, a liquid oxygen tank car, and a liquid hydrogen dewar or tank car will be transferred for delivery to the SpaceX engine test complex outside McGregor, Texas. The railroad cars were needed in support of the Space Shuttle Program but currently are not in use by NASA following the completion of the program in 2011. Originally, the tankers belonged to the U.S. Bureau of Mines. At the peak of the shuttle program, there were approximately 30 cars in the fleet. About half the cars were returned to the bureau as launch activity diminished. Five tank cars are being loaned to SpaceX and repurposed to support their engine tests in Texas. Eight cars previously were shipped to California on loan to support the SpaceX Falcon 9 rocket launches from Space Launch Complex-4 on Vandenberg Air Force Base. SpaceX already has three helium tank cars previously used for the shuttle program at Space Launch Complex-40 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/spacex. Photo credit: NASA/Jim Grossmann
2012-05-23
CAPE CANAVERAL, Fla. – A manatee swims in the Indian River near the NASA Railroad’s Jay Jay Railroad Bridge north of Launch Complex 39 at NASA’s Kennedy Space Center in Florida. The manatee was spotted by a cameraman on hand to photograph a NASA Railroad train on its way to the Florida East Coast Railway interchange in Titusville, Fla., where the train’s helium tank cars, a liquid oxygen tank car, and a liquid hydrogen dewar or tank car will be transferred for delivery to the SpaceX engine test complex outside McGregor, Texas. The railroad cars were needed in support of the Space Shuttle Program but currently are not in use by NASA following the completion of the program in 2011. Originally, the tankers belonged to the U.S. Bureau of Mines. At the peak of the shuttle program, there were approximately 30 cars in the fleet. About half the cars were returned to the bureau as launch activity diminished. Five tank cars are being loaned to SpaceX and repurposed to support their engine tests in Texas. Eight cars previously were shipped to California on loan to support the SpaceX Falcon 9 rocket launches from Space Launch Complex-4 on Vandenberg Air Force Base. SpaceX already has three helium tank cars previously used for the shuttle program at Space Launch Complex-40 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/spacex. Photo credit: NASA/Jim Grossmann
2012-05-23
CAPE CANAVERAL, Fla. – Manatees relax in the Indian River near the NASA Railroad’s Jay Jay Railroad Bridge north of Launch Complex 39 at NASA’s Kennedy Space Center in Florida. The manatees were spotted by a cameraman on hand to photograph a NASA Railroad train on its way to the Florida East Coast Railway interchange in Titusville, Fla., where the train’s helium tank cars, a liquid oxygen tank car, and a liquid hydrogen dewar or tank car will be transferred for delivery to the SpaceX engine test complex outside McGregor, Texas. The railroad cars were needed in support of the Space Shuttle Program but currently are not in use by NASA following the completion of the program in 2011. Originally, the tankers belonged to the U.S. Bureau of Mines. At the peak of the shuttle program, there were approximately 30 cars in the fleet. About half the cars were returned to the bureau as launch activity diminished. Five tank cars are being loaned to SpaceX and repurposed to support their engine tests in Texas. Eight cars previously were shipped to California on loan to support the SpaceX Falcon 9 rocket launches from Space Launch Complex-4 on Vandenberg Air Force Base. SpaceX already has three helium tank cars previously used for the shuttle program at Space Launch Complex-40 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/spacex. Photo credit: NASA/Jim Grossmann
2012-05-23
CAPE CANAVERAL, Fla. – Bubbles form around a dolphin splashing in the Indian River near the NASA Railroad’s Jay Jay Railroad Bridge north of Launch Complex 39 at NASA’s Kennedy Space Center in Florida. The dolphin was spotted by a cameraman on hand to photograph a NASA Railroad train on its way to the Florida East Coast Railway interchange in Titusville, Fla., where the train’s helium tank cars, a liquid oxygen tank car, and a liquid hydrogen dewar or tank car will be transferred for delivery to the SpaceX engine test complex outside McGregor, Texas. The railroad cars were needed in support of the Space Shuttle Program but currently are not in use by NASA following the completion of the program in 2011. Originally, the tankers belonged to the U.S. Bureau of Mines. At the peak of the shuttle program, there were approximately 30 cars in the fleet. About half the cars were returned to the bureau as launch activity diminished. Five tank cars are being loaned to SpaceX and repurposed to support their engine tests in Texas. Eight cars previously were shipped to California on loan to support the SpaceX Falcon 9 rocket launches from Space Launch Complex-4 on Vandenberg Air Force Base. SpaceX already has three helium tank cars previously used for the shuttle program at Space Launch Complex-40 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/spacex. Photo credit: NASA/Jim Grossmann
2012-05-23
CAPE CANAVERAL, Fla. – At the NASA Railroad Yard at NASA’s Kennedy Space Center in Florida, preparations are under way for the departure of a train made up of tank cars. The railroad’s track runs past Kennedy’s 525-foot-tall Vehicle Assembly Building in the background. The train is headed for the Florida East Coast Railway interchange in Titusville, Fla., where the train’s helium tank cars, a liquid oxygen tank car, and a liquid hydrogen dewar or tank car will be transferred for delivery to the SpaceX engine test complex outside McGregor, Texas. The railroad cars were needed in support of the Space Shuttle Program but currently are not in use by NASA following the completion of the program in 2011. Originally, the tankers belonged to the U.S. Bureau of Mines. At the peak of the shuttle program, there were approximately 30 cars in the fleet. About half the cars were returned to the bureau as launch activity diminished. Five tank cars are being loaned to SpaceX and repurposed to support their engine tests in Texas. Eight cars previously were shipped to California on loan to support the SpaceX Falcon 9 rocket launches from Space Launch Complex-4 on Vandenberg Air Force Base. SpaceX already has three helium tank cars previously used for the shuttle program at Space Launch Complex-40 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/spacex. Photo credit: NASA/Jim Grossmann
2012-05-23
CAPE CANAVERAL, Fla. – A dolphin plays in the Indian River near the NASA Railroad’s Jay Jay Railroad Bridge north of Launch Complex 39 at NASA’s Kennedy Space Center in Florida. The dolphin was spotted by a cameraman on hand to photograph a NASA Railroad train on its way to the Florida East Coast Railway interchange in Titusville, Fla., where the train’s helium tank cars, a liquid oxygen tank car, and a liquid hydrogen dewar or tank car will be transferred for delivery to the SpaceX engine test complex outside McGregor, Texas. The railroad cars were needed in support of the Space Shuttle Program but currently are not in use by NASA following the completion of the program in 2011. Originally, the tankers belonged to the U.S. Bureau of Mines. At the peak of the shuttle program, there were approximately 30 cars in the fleet. About half the cars were returned to the bureau as launch activity diminished. Five tank cars are being loaned to SpaceX and repurposed to support their engine tests in Texas. Eight cars previously were shipped to California on loan to support the SpaceX Falcon 9 rocket launches from Space Launch Complex-4 on Vandenberg Air Force Base. SpaceX already has three helium tank cars previously used for the shuttle program at Space Launch Complex-40 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/spacex. Photo credit: NASA/Jim Grossmann
2012-05-23
CAPE CANAVERAL, Fla. – At the NASA Railroad Yard at NASA’s Kennedy Space Center in Florida, preparations are under way for the departure of a train made up of tank cars. The train will pass by Kennedy’s 525-foot-tall Vehicle Assembly Building in the background. The train is headed for the Florida East Coast Railway interchange in Titusville, Fla., where the train’s helium tank cars, a liquid oxygen tank car, and a liquid hydrogen dewar or tank car will be transferred for delivery to the SpaceX engine test complex outside McGregor, Texas. The railroad cars were needed in support of the Space Shuttle Program but currently are not in use by NASA following the completion of the program in 2011. Originally, the tankers belonged to the U.S. Bureau of Mines. At the peak of the shuttle program, there were approximately 30 cars in the fleet. About half the cars were returned to the bureau as launch activity diminished. Five tank cars are being loaned to SpaceX and repurposed to support their engine tests in Texas. Eight cars previously were shipped to California on loan to support the SpaceX Falcon 9 rocket launches from Space Launch Complex-4 on Vandenberg Air Force Base. SpaceX already has three helium tank cars previously used for the shuttle program at Space Launch Complex-40 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/spacex. Photo credit: NASA/Jim Grossmann
2012-05-23
CAPE CANAVERAL, Fla. – A dolphin swims in the Indian River near the NASA Railroad’s Jay Jay Railroad Bridge north of Launch Complex 39 at NASA’s Kennedy Space Center in Florida. The dolphin was spotted by a cameraman on hand to photograph a NASA Railroad train on its way to the Florida East Coast Railway interchange in Titusville, Fla., where the train’s helium tank cars, a liquid oxygen tank car, and a liquid hydrogen dewar or tank car will be transferred for delivery to the SpaceX engine test complex outside McGregor, Texas. The railroad cars were needed in support of the Space Shuttle Program but currently are not in use by NASA following the completion of the program in 2011. Originally, the tankers belonged to the U.S. Bureau of Mines. At the peak of the shuttle program, there were approximately 30 cars in the fleet. About half the cars were returned to the bureau as launch activity diminished. Five tank cars are being loaned to SpaceX and repurposed to support their engine tests in Texas. Eight cars previously were shipped to California on loan to support the SpaceX Falcon 9 rocket launches from Space Launch Complex-4 on Vandenberg Air Force Base. SpaceX already has three helium tank cars previously used for the shuttle program at Space Launch Complex-40 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/spacex. Photo credit: NASA/Jim Grossmann
NASA Astrophysics Data System (ADS)
Koblick, D. C.; Shankar, P.; Xu, S.
Previously, there have been many commercial proposals and extensive academic studies regarding ground and space based sensors to assist a space surveillance network in obtaining metric observations of satellites and debris near Geosynchronous Earth Orbit (GEO). Most use physics based models for geometric constraints, lighting, and tasker/scheduler operations of sensor architectures. Under similar physics modeling assumptions, the space object catalog is often different due to proprietary standards and datasets. Lack of catalog commonality between studies creates barriers and difficulty comparing performance benefits of sensor trades. To solve this problem, we have constructed a future GEO space catalog from publicly available datasets and literature. The annual number of new payloads and rocket bodies is drawn from a Poisson distribution while the growth of the current GEO catalog is bootstrapped from the historical payload, upper stage, and debris data. We adopt a spherically symmetric explosion model and couple it with the NASA standard breakup model to simulate explosions of payloads and rocket bodies as they are the primary drivers of the debris population growth. The cumulative number of fragments follow a power-law distribution. Result from 1,000 random catalog growth simulations indicates that the GEO space object population in the year 2050 will include over 3,600 objects, nearly half of which are debris greater than 10 cm spherical diameter. The number of rocket bodies and dead payloads is projected to nearly double over the next 33 years. For comparison, the current Air Force Space Command catalog snapshot contains fewer than 50 pieces of debris and coarse Radar Cross Section (RCS) estimates which include: small, medium, and large. The current catalog may be sufficient for conjunction studies, but not for analyzing future sensor system performance. The 2050 GEO projected catalog will be available online for commercial/academic research and development.
Thorne, M; Salt, A N; DeMott, J E; Henson, M M; Henson, O W; Gewalt, S L
1999-10-01
To establish the dimensions and volumes of the cochlear fluid spaces. Fluid space volumes, lengths, and cross-sectional areas were derived for the cochleas from six species: human, guinea pig, bat, rat, mouse, and gerbil. Three-dimensional reconstructions of the fluid spaces were made from magnetic resonance microscopy (MRM) images. Consecutive serial slices composed of isotropic voxels (25 microm3) representing the entire volume of fixed, isolated cochleas were obtained. The boundaries delineating the fluid spaces, including Reissner's membrane, were resolved for all specimens, except for the human, in which Reissner's membrane was not consistently resolved. Three-dimensional reconstructions of the endolymphatic and perilymphatic fluid spaces were generated. Fluid space length and variation of cross-sectional area with distance were derived by an algorithm that followed the midpoint of the space along the length of the spiral. The total volume of each fluid space was derived from a voxel count for each specimen. Length, volume, and cross-sectional areas are provided for six species. In all cases, the length of the endolymphatic fluid space was consistently longer than that of either perilymphatic scala, primarily as a result of a greater radius of curvature. For guinea pig specimens, the measured volumes of the fluid spaces were considerably lower than those suggested by previous reports based on histological data. The quantification of cochlear fluid spaces provided by this study will enable the more accurate calculation of drug and other solute movements in fluids of the inner ear during experimental or clinical manipulations.
In-space assembly and servicing infrastructures for the Evolvable Space Telescope (EST)
NASA Astrophysics Data System (ADS)
Lillie, Charles F.; MacEwen, Howard A.
2016-07-01
The concept for EST presented in past SPIE forums will benefit significantly from the current efforts of DARPA, NASA and several commercial organizations to develop an in-space infrastructure that will enable on-orbit assembly, servicing, repair and repurposing of space vehicles. Two documents provide particularly relevant discussions: "NASA's Journey to Mars: Pioneering Next Steps in Space Exploration" provides a recent (2015) outline of NASA's thoughts on human deep space exploration and the tools that will enable it, while the "On-Orbit Satellite Servicing Study: Project Report" details a number of the concepts and technologies that must be developed. In this paper we examine the concepts in these and related documents to explore how systems such as EST will shape and support the infrastructure needed by future space vehicles. In so doing, we address previous examples of on-orbit assembly and servicing of space vehicles; the lessons learned from these efforts and the existing systems and facilities available to execute servicing missions; the EST concept for an LUVOIR telescope designed for in-orbit assembly and servicing and the resulting requirements for a servicing vehicle; the use of heavy lift launch vehicles, including the SLS and Exploration Upper Stage to co-manifest other large payloads along with a crewed Orion mission; Deep Space Habitats (DSHs) in cislunar space as a site for assembly and servicing spacecraft vehicles, and a base for Maneuverable Servicing Vehicles; and how space vehicles need to be designed for in-space assembly and servicing (i.e., commonality of parts, systems, modularity, accessibility, and stable maneuverability).
Cost Modeling for Space Telescope
NASA Technical Reports Server (NTRS)
Stahl, H. Philip
2011-01-01
Parametric cost models are an important tool for planning missions, compare concepts and justify technology investments. This paper presents on-going efforts to develop single variable and multi-variable cost models for space telescope optical telescope assembly (OTA). These models are based on data collected from historical space telescope missions. Standard statistical methods are used to derive CERs for OTA cost versus aperture diameter and mass. The results are compared with previously published models.