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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Spaceflight Induces Strength Decline in Caenorhabditis elegans

Soni, P., Edwards, H., Anupom, T., Rahman, M., Lesanpezeshki, L., Blawzdziewicz, J., Cope, H., Gharahdaghi, N., Scott, D., Toh, L.S., Williams, P.M., Etheridge, T., Szewczyk, N., Willis, Craig R.G., Vanapalli, S.A. 22 November 2023 (has links)
Yes / Background: Understanding and countering the well-established negative health consequences of spaceflight remains a primary challenge preventing safe deep space exploration. Targeted/personalized therapeutics are at the forefront of space medicine strategies, and cross-species molecular signatures now define the 'typical' spaceflight response. However, a lack of direct genotype-phenotype associations currently limits the robustness and, therefore, the therapeutic utility of putative mechanisms underpinning pathological changes in flight. Methods: We employed the worm Caenorhabditis elegans as a validated model of space biology, combined with 'NemaFlex-S' microfluidic devices for assessing animal strength production as one of the most reproducible physiological responses to spaceflight. Wild-type and dys-1 (BZ33) strains (a Duchenne muscular dystrophy (DMD) model for comparing predisposed muscle weak animals) were cultured on the International Space Station in chemically defined media before loading second-generation gravid adults into NemaFlex-S devices to assess individual animal strength. These same cultures were then frozen on orbit before returning to Earth for next-generation sequencing transcriptomic analysis. Results: Neuromuscular strength was lower in flight versus ground controls (16.6% decline, p
22

Le vol habité dans l’économie symbolique de la construction européenne / Crafting Europe from outer space : human spaceflight in the symbolic economy of the European building

Patarin-Jossec, Julie 19 December 2018 (has links)
Régis par une rhétorique opposant « science » et « politique », les programmes de stations spatiales civiles sont présentés comme projets diplomatiques censés adoucir des tensions géopolitiques, justifiés par les possibilités d’expérimentation en condition de micropesanteur qu’ils octroient à la communauté scientifique et industrielle internationale. Précédée par des collaborations officieuses entre laboratoires européens et soviétiques, l’Europe de l’Ouest entre dans l’exploration spatiale habitée en 1982. Depuis, l’entraînement et le transport des astronautes de l’Agence spatiale européenne (ESA) se partagent entre les États-Unis (NASA) et la Russie (Roscosmos), dont les programmes nationaux pourvoient leur gouvernement en autonomie de lancement et de transport spatial. Au fil des décennies, alors que les agences spatiales détenant un programme habité (à l’exception de la Chine) se rejoignent dans un projet commun à partir de la fin des années 1990 (l’International Space Station), et alors que la Russie devient détentrice d’un monopole d’accès à l’espace à partir de 2011, les mécanismes symboliques et politiques structurant le programme spatial habité européen évoluent en conséquence. L’entraînement des astronautes en Russie, relatif à ce monopole des lancements habités, entraine la reproduction de traditions et rituels qui, hérités du spatial soviétique, en viennent à constituer l’armature symbolique et axiologique d’un corps d’astronautes en charge de représenter « l’unité dans la diversité » propre à l’Europe. Nourrissant des relations plus ou moins institutionnalisées avec d’anciennes républiques socialistes du fait de son autonomie (de plus en plus relative) vis-à-vis de l’Union Européenne, l’ESA devient progressivement une plateforme via laquelle le procès de restructuration des États d’Europe de l’Est entamé à la fin des années 1980 peut être analysé à l’aune des réseaux industriels, des interdépendances techniques et des échanges scientifiques qui y transitent. Afin de saisir ces relations d’interdépendances, une approche par la théorie des champs semble pertinente à deux points de vue. Tout d’abord, s’intéresser à la genèse et à l’organisation du programme spatial habité européen suppose de considérer ce dernier comme le résultat d’une trajectoire institutionnelle empruntant à différents champs : autorité cognitive de la science moderne, rôle de la production industrielle dans la construction étatique, et rapport à la territorialisation dans l’exercice d’un pouvoir politique national contribuent à la morphologie actuelle des affaires spatiales en Europe. Ensuite, une analyse bourdieusienne permet de circonscrire les vols habités comme un espace social structuré, où se convertissent, se maintiennent et se confrontent des capitaux portés par des acteurs de champs de production autonomes. L’économie des relations entre science, industrie et État, esquissée au gré de ce pari théorique, permet d’envisager certaines des conditions sociales par lesquelles les manières de « faire État » en Europe occidentale et le développement de la bureaucratie ont pu être nourris par des développements scientifiques et techniques profondément ancrés dans le temps comme dans l’espace. Mettant particulièrement en lumière la formation des habitus des astronautes de l’ESA, l’esquisse d’une théorie d’un « champ de médiation » est appréhendée, de manière à saisir les conditions de ces relations structurelles entre champs scientifique, industriel et bureaucratique dans le cas d’un secteur spatial en mutation. / Ruled by a rhetoric which opposes “science” and “politics”, civil space stations programmes are often introduced as diplomatic projects supposed to soften geopolitical tensions, then justified by the possibilities of experimentation under microgravity that those stations grant to the international scientific and industrial community. Preceded by informal collaborations between European and Soviet laboratories, Western Europe starts its entry into human spaceflights in 1982. Since then, the training and transport of astronauts from the European Space Agency (ESA) have been shared between United States (NASA) and Russia (Roscosmos), whose national programmes provide autonomous launch and space transport capacities. Over the decades, while space agencies holding a human space programme (except China) join in a common project from late 1990 (the International Space Station), and as Russia becomes the holder of a monopoly regarding access to space from 2011, symbolic and political mechanisms structuring the European human space programme evolve accordingly. The training of astronauts in Russia, relating to this monopoly of crews’ transportation, entails the reproduction of traditions and rituals which, inherited from the Soviet space era, contributes to the symbolic and axiological building of an astronaut corps in charge of representing Europe’s “unity in diversity”. Nourishing more or less institutionalized relations with former Socialist republics because of its (increasingly relative) autonomy towards the European Union, ESA gradually becomes a platform through which the structuration of Eastern European States, started in the late 1980s, can be analyzed through industrial networks, technical interdependencies and scientific exchanges that pass through. In order to grasp these interdependencies, the fruitfulness of an approach by the field theory can be resumed in two arguments. First, taking an interest in the genesis and organization of the European inhabited space programme implies that the latter should be regarded as the result of an institutional trajectory borrowing from different fields: cognitive authority of the occidental modern science, role of industrial production in State construction, and territorialization in the exercise of a national political power contribute to the current morphology of space affairs in Europe. Secondly, a Bourdieusien analysis allows circumscribing human space flights as a structured social space, where are converted, maintained and confronted capitals which are carried by actors of autonomous fields of production. This, without a priori postulating the loss of autonomy of one of these fields. The economy of relations between science, industry and the State, sketched at the whim of this theoretical wager, then allows to envisage some of the social conditions by which scientific and technical developments, deeply rooted in time and space, could contribute to shaping the ways of “making State” and to the development of bureaucracy in western Europe. With particular emphasis on the training of ESA astronauts, the outline of a “mediation field” theory is apprehended, so as to understand conditions of these structural relations between scientific, industrial and bureaucratic fields in the case of a changing space sector. Based on multisite and multilevel ethnography (United Nations, ESA technical centres, control centres), interviews with scientists, space agency officials, operators and crew members of the agencies contributing to the ISS (N = 182), as well as archival work (EU, ESA and Soviet Academy of Sciences), this study shows how “Space Europe” (as the EU and ESA refer to it) “takes shape” and reproduces the symbolic conditions of its internal cohesion (i.e. values and identity binding its member-States) through the daily organization (procedural, mental and carnal) of its crewed space program.
23

Vesmírná turistika / Space Tourism

Ciba, Tomáš January 2010 (has links)
This diploma thesis analyzes the actual travelling possibilities into space for space tourists. Following a general clarification of key concepts in the area of cosmonautics, aeronautical technology and physics as well as definition of space tourism and space tourist, this thesis deals with travelling to the International Space Station by means of the Russian spaceship Sojuz TMA. A review for the significant initiative Ansari X Prize follows, which became the moving power for emergence of private companies in the field of manned cosmonautics. After that, a cross-sectional analysis of the most successful space project in the Ansari X Prize Competition by Virgin Galactic, being the leader on the nascent market of commercial suborbital flights, is performed. Virgin Galactic offers its clients so called suborbital jumps on the threshold of space for the fragment of high price in comparison with a several-day stay on the ISS. The thesis is concluded by author's questionnaire involving two groups of experts: technical experts as well as marketing and product development professionals in the field of tourism.
24

Improving Project Management With Simulation And Completion Distributi

Cates, Grant 01 January 2004 (has links)
Despite the critical importance of project completion timeliness, management practices in place today remain inadequate for addressing the persistent problem of project completion tardiness. Uncertainty has been identified as a contributing factor in late projects. This uncertainty resides in activity duration estimates, unplanned upsetting events, and the potential unavailability of critical resources. This research developed a comprehensive simulation based methodology for conducting quantitative project completion-time risk assessments. The methodology enables project stakeholders to visualize uncertainty or risk, i.e. the likelihood of their project completing late and the magnitude of the lateness, by providing them with a completion time distribution function of their projects. Discrete event simulation is used to determine a project's completion distribution function. The project simulation is populated with both deterministic and stochastic elements. Deterministic inputs include planned activities and resource requirements. Stochastic inputs include activity duration growth distributions, probabilities for unplanned upsetting events, and other dynamic constraints upon project activities. Stochastic inputs are based upon past data from similar projects. The time for an entity to complete the simulation network, subject to both the deterministic and stochastic factors, represents the time to complete the project. Multiple replications of the simulation are run to create the completion distribution function. The methodology was demonstrated to be effective for the on-going project to assemble the International Space Station. Approximately $500 million per month is being spent on this project, which is scheduled to complete by 2010. Project stakeholders participated in determining and managing completion distribution functions. The first result was improved project completion risk awareness. Secondly, mitigation options were analyzed to improve project completion performance and reduce total project cost.
25

Routine omics collection is a golden opportunity for European human research in space and analog environments

Cope, H., Willis, Craig R.G., MacKay, M.J., Rutter, L.A., Toh, L.S., Williams, P.M., Herranz, R., Borg, J., Bezdan, D., Giacomello, S., Muratani, M., Mason, C.E., Etheridge, T., Szewczyk, N.J. 06 October 2022 (has links)
Yes / Widespread generation and analysis of omics data have revolutionized molecular medicine on Earth, yet its power to yield new mechanistic insights and improve occupational health during spaceflight is still to be fully realized in humans. Nevertheless, rapid technological advancements and ever-regular spaceflight programs mean that longitudinal, standardized, and cost-effective collection of human space omics data are firmly within reach. Here, we consider the practicality and scientific return of different sampling methods and omic types in the context of human spaceflight. We also appraise ethical and legal considerations pertinent to omics data derived from European astronauts and spaceflight participants (SFPs). Ultimately, we propose that a routine omics collection program in spaceflight and analog environments presents a golden opportunity. Unlocking this bright future of artificial intelligence (AI)-driven analyses and personalized medicine approaches will require further investigation into best practices, including policy design and standardization of omics data, metadata, and sampling methods. / H.C., R.H., J.B., D.B., S.G., T.E., and N.J.S. are members of the ESA Space Omics Topical Team, funded by the ESA grant/contract 4000131202/20/NL/PG/pt “Space Omics: Towards an integrated ESA/NASA –omics database for spaceflight and ground facilities experiments” awarded to R.H., which was the main funding source for this work. H.C. is also supported by the Horizon Center for Doctoral Training at the University of Nottingham (UKRI grant no. EP/S023305/1). S.G. is supported by the Swedish Research Council VR grant 2020-04864. L.A.R. and M.M. represent the Omics Subgroup of the Japan Society for the Promotion of Science KAKENHI funding group “Living in Space” and are supported by JP15K21745, JP20H03234, and 20F20382. L.A.R. is also supported by the JSPS postdoctoral fellowship P20382. We thank Dr. Sarah Castro-Wallace, the NASA GeneLab Animal AWG, ISSOP, ESA Space Omics Topical Team, ESA Personalized Medicine Topical Team, and Global Alliance for Genomic Health (GA4GH) for useful discussions.
26

Hypervelocity impact analysis of International Space Station Whipple and Enhanced Stuffed Whipple Shields

Kalinski, Michael E. 12 1900 (has links)
Approved for public release; distribution in unlimited. / The International Space Station (ISS) must be able to withstand the hypervelocity impacts of micrometeoroids and orbital debris that strike its many surfaces. In order to design and implement shielding which will prevent hull penetration or other operational losses, NASA must first model the orbital debris and micrometeoroid environment. Based upon this environment, special multi-stage shields called Whipple and Enhanced Stuffed Whipple Shields are developed and implemented to protect ISS surfaces. Ballistic limit curves that establish shield failure criteria are determined via ground testing. These curves are functions of material strength, shield spacing, projectile size, shape and density, as well as a number of other variables. The combination of debris model and ballistic limit equations allows NASA to model risk to ISS using a hydro-code called BUMPER. This thesis modifies and refines existing ballistic limit equations for U.S. Laboratory Module shields to account for the effects of projectile (debris/ micro-meteoroid) densities. Using these refined ballistic limit equations this thesis also examines alternative shielding materials and configurations to optimize shield design for minimum mass and maximum stopping potential, proposing alternate shield designs for future NASA ground testing. A final goal of this thesis is to provide the Department of Defense a background in satellite shield theory and design in order to improve protection against micrometeoroid and orbital debris impacts on future spacebased national systems. / Lieutenant, United States Navy
27

The Kentucky Re-entry Universal Payload System (KRUPS): Sub-orbital Flights

Sparks, James Devin 01 January 2018 (has links)
The Kentucky Re-entry Universal Payload System (KRUPS) is an adaptable testbed for atmosphere entry science experiments, with an initial application to thermal protection systems (TPS). Because of the uniqueness of atmospheric entry conditions that ground testing is unable to replicate, scientists principally rely on numerical models for predicting entry conditions. The KRUPS spacecraft, developed at the University of Kentucky, provides an inexpensive means of obtaining validation data to verify and improve these models. To increase the technology readiness level (TRL) of the spacecraft, two sub-orbital missions were developed. The first mission, KUDOS, launched August 13th, 2017 on a Terrier-Improved Malamute rocket to an altitude of ~150 km. The second mission, KOREVET, launched on March 25th, 2018 on the same type of rocket to an altitude of ~170 km. The chief purpose of both missions was to validate the spacecraft design, ejection mechanism, on-board power, data transmission, and data collection. After both missions, the overall TRL improved from 4 to 5 by validating most subsystems in a relevant environment. Both of these missions were invaluable preparation for the project's ultimate goal of releasing multiple experimental testbeds from the ISS.
28

Characterizing the Impact of Low Shear Modeled Microgravity on Population Dynamics, Biofilm Formation and Silver Susceptibility of Microbial Consortia Isolated from International Space Station Potable Water

January 2019 (has links)
abstract: Understanding how microorganisms adapt and respond to the microgravity environment of spaceflight is important for the function and integrity of onboard life support systems, astronaut health and mission success. Microbial contamination of spacecraft Environmental Life Support Systems (ECLSS), including the potable water system, are well documented and have caused major disruption to spaceflight missions. The potable water system on the International Space Station (ISS) uses recycled wastewater purified by multiple processes so it is safe for astronaut consumption and personal hygiene. However, despite stringent antimicrobial treatments, multiple bacterial species and biofilms have been recovered from this potable water system. This finding raises concern for crew health risks, vehicle operations and ECLSS system integrity during exploration missions. These concerns are further heightened given that 1) potential pathogens have been isolated from the ISS potable water system, 2) the immune response of astronauts is blunted during spaceflight, 3) spaceflight induces unexpected alterations in microbial responses, including growth and biofilm formation, antimicrobial resistance, stress responses, and virulence, and 4) different microbial phenotypes are often observed between reductionistic pure cultures as compared to more complex multispecies co-cultures, the latter of which are more representative of natural environmental conditions. To advance the understanding of the impact of microgravity on microbial responses that could negatively impact spacecraft ECLSS systems and crew health, this study characterized a range of phenotypic profiles in both pure and co-cultures of bacterial isolates collected from the ISS potable water system between 2009 and 2014. Microbial responses profiled included population dynamics, resistance to silver, biofilm formation, and in vitro colonization of intestinal epithelial cells. Growth characteristics and antibiotic sensitivities for bacterial strains were evaluated to develop selective and/or differential media that allow for isolation of a pure culture from co-cultures, which was critical for the success of this study. Bacterial co-culture experiments were performed using dynamic Rotating Wall Vessel (RWV) bioreactors under spaceflight analogue (Low Shear Modeled Microgravity/LSMMG) and control conditions. These experiments indicated changes in fluid shear have minimal impact on strain recovery. The antimicrobial efficacy of silver on both sessile co-cultures, grown on 316L stainless steel coupons, and planktonic co-cultures showed that silver did not uniformly reduce the recovery of all strains; however, it had a stronger antimicrobial effect on biofilm cultures than planktonic cultures. The impact of silver on the ability of RWV cultured planktonic and biofilm bacterial co-cultures to colonize human intestinal epithelial cells showed that, those strains which were impacted by silver treatment, often increased adherence to the monolayer. Results from these studies provide insight into the dynamics of polymicrobial community interactions, biofilm formation and survival mechanisms of ISS potable water isolates, with potential application for future design of ECLSS systems for sustainable human space exploration. / Dissertation/Thesis / Masters Thesis Molecular and Cellular Biology 2019
29

International Space Station Remote Sensing Pointing Analysis

Jacobson, Craig 01 January 2005 (has links)
This paper analyzes the geometric and disturbance aspects of utilizing the International Space Station for remote sensing of earth targets. The proposed instrument is SHORE (Station High-Sensitivity Ocean Research Experiment), a multi-band optical spectrometer with 15 m pixel resolution. The analysis investigates the contribution of the error effects to the quality of data collected by the instrument. The analysis begins with the discussion of the coordinate systems involved and then conversion from the target coordinate system to the instrument coordinate system. Next the geometry of remote observations from the Space Station is investigated including the effects of the instrument location in Space Station and the effects of the line of sight to the target. The disturbance and error environment on Space Station is discussed covering factors contributing to drift and jitter, accuracy of pointing data and target and instrument accuracies. Finally, there is a brief discussion of image processing to address any post error correction options.
30

A study of International Space Station ground/crew communication methods with applications to human Moon and Mars missions

Esper, Jennifer Eileen. January 2007 (has links)
Thesis (M.S.)--Mississippi State University. Department of Aerospace Engineering. / Title from title screen. Includes bibliographical references.

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