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Research Containing: Contamination

Conditions of formation of stable deposits of incomplete combustion products of liquid rocket fuels on the external elements of orbital stations

by on 9 June 2015in Technology Development & Demonstration No comment

The results of the Dvicon and Kromka-1 space experiments aimed at studying the state of contaminant deposits on control samples exposed for a long time in the zone of emission incomplete combustion products from the orientation engines of the Mir Orbital Station and International Space Station. An analysis of the data on the intensity of the action of incomplete combustion products on the control samples during the space experiments made it possible to formulate a critical condition of formation of stable dry deposits of toxic contaminants.

Related URLs:
http://dx.doi.org/10.1134/S1990793108050205

Methodology of studying the parameters of contaminant emissions from the orientation engines of orbital stations during and after the flight

by on 9 June 2015in Technology Development & Demonstration No comment

The methodology of space experiments aimed at studying the dynamics of the emission of contaminants from the nozzles of the orientation engines of orbital stations is described. It was demonstrated that the use of passive diagnostic means, such as plates with special coatings and porous absorbents exposed for a long time near the engines, makes it possible to determine the quantitative characteristics and spatial distribution of incomplete combustion products.

Related URLs:
http://dx.doi.org/10.1134/S1990793108050217

Prediction of Atomic Oxygen Erosion Yield for Spacecraft Polymers

by on 9 June 2015in Physical Sciences No comment

The ability to predict the atomic oxygen erosion yield of polymers based on their chemistry and physical properties has been only partially successful because of a lack of reliable low-Earth-orbit erosion yield data. The retrieval of the polymer erosion and contamination experiment after 3.95 years in low Earth orbit as part of the Materials International Space Station Experiment 2 provided accurate measurements of the erosion yields of 38 polymers and pyrolytic graphite. The resulting erosion yield data was used to develop a predictive tool with a correlation coefficient of 0.895 and uncertainty of ±6.3×10-25 cm3/atom. The predictive tool uses the chemical structures and physical properties of polymers to predict in-space atomic oxygen erosion yield. A technique which uses the erosion yields of two materials is presented to allow prediction of the erosion yield of a composite material.

Related URLs:
http://dx.doi.org/10.2514/1.48849

Microbial monitoring of crewed habitats in space-current status and future perspectives

by on 9 June 2015in Biology & Biotechnology No comment

Previous space research conducted during short-term flight experiments and long-term environmental monitoring on board orbiting space stations suggests that the relationship between humans and microbes is altered in the crewed habitat in space. Both human physiology and microbial communities adapt to spaceflight. Microbial monitoring is critical to crew safety in long-duration space habitation and the sustained operation of life support systems on space transit vehicles, space stations, and surface habitats. To address this critical need, space agencies including NASA (National Aeronautics and Space Administration), ESA (European Space Agency), and JAXA (Japan Aerospace Exploration Agency) are working together to develop and implement specific measures to monitor, control, and counteract biological contamination in closed-environment systems. In this review, the current status of microbial monitoring conducted in the International Space Station (ISS) as well as the results of recent microbial spaceflight experiments have been summarized and future perspectives are discussed.

Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/25130885

Microbial contamination monitoring and control during human space missions

by on 9 June 2015in Biology & Biotechnology No comment

The ubiquity and resilience of microorganisms makes them unavoidable in most environments including space habitats. The impaired immune system of astronauts in flight raises the level of concern about disease risk during human space missions and additionally these biological contaminants may affect life support systems and hardware. In this review, the microbial contamination observed in manned space stations and in particular the International Space Station ISS will be discussed, demonstrating that it is a microbiologically safe working and living habitat. Microbial contamination levels were in general below the implemented quality standards, although, occasional contamination hazard reports indicate that the current prevention and monitoring strategies are the strict minimum.

Related URLs:
http://www.sciencedirect.com/science/article/pii/S0032063311002765

 Root Cause Assessment of Pressure Drop Rise of a Packed Bed of Lithium Hydroxide in the International Space Station Trace Contaminant Control System

by on 9 June 2015in Biology & Biotechnology No comment

The trace contaminant control system (TCCS) located in the International Space Station's (ISS) U.S. laboratory module employs physical adsorption, thermal catalytic oxidation, and chemical adsorption to remove trace chemical contamination produced by equipment offgassing and anthropogenic sources from the cabin atmosphere. The chemical adsorption stage, consisting of a packed bed of granular lithium hydroxide (LiOH), is located after the thermal catalytic oxidation stage and is designed to remove acid gas byproducts that may be formed in the upstream oxidation stage. While in service on board the ISS, the LiOH bed exhibited a change in flow resistance that leading to flow control difficulties in the TCCS. Post flight evaluation revealed LiOH granule size attrition among other changes. An experimental program was employed to investigate mechanisms hypothesized to contribute to the change in the packed bed's flow resistance. Background on the problem is summarized, including a discussion of likely mechanisms. The experimental program is described, results are presented, and implications for the future are discussed.

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Comparison of antibiotic resistance, biofilm formation and conjugative transfer of Staphylococcus and Enterococcus isolates from International Space Station and Antarctic Research Station Concordia

by on 9 June 2015in Biology & Biotechnology No comment

The International Space Station (ISS) and the Antarctic Research Station Concordia are confined and isolated habitats in extreme and hostile environments. The human and habitat microflora can alter due to the special environmental conditions resulting in microbial contamination and health risk for the crew. In this study, 29 isolates from the ISS and 55 from the Antarctic Research Station Concordia belonging to the genera Staphylococcus and Enterococcus were investigated. Resistance to one or more antibiotics was detected in 75.8 % of the ISS and in 43.6 % of the Concordia strains. The corresponding resistance genes were identified by polymerase chain reaction in 86 % of the resistant ISS strains and in 18.2 % of the resistant Concordia strains. Plasmids are present in 86.2 % of the ISS and in 78.2 % of the Concordia strains. Eight Enterococcus faecalis strains (ISS) harbor plasmids of about 130 kb. Relaxase and/or transfer genes encoded on plasmids from gram-positive bacteria like pIP501, pRE25, pSK41, pGO1 and pT181 were detected in 86.2 % of the ISS and in 52.7 % of the Concordia strains. Most pSK41-homologous transfer genes were detected in ISS isolates belonging to coagulase-negative staphylococci. We demonstrated through mating experiments that Staphylococcus haemolyticus F2 (ISS) and the Concordia strain Staphylococcus hominis subsp. hominis G2 can transfer resistance genes to E. faecalis and Staphylococcus aureus, respectively. Biofilm formation was observed in 83 % of the ISS and in 92.7 % of the Concordia strains. In conclusion, the ISS isolates were shown to encode more resistance genes and possess a higher gene transfer capacity due to the presence of three vir signature genes, virB1, virB4 and virD4 than the Concordia isolates.

Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/23411852

Space habitation and microbiology: status and roadmap of space agencies

by on 9 June 2015in Biology & Biotechnology No comment

The ubiquitous nature of microbiology is reflected in the diversity of microbiological research and operational efforts at NASA. For example, the impact of microorganisms on other planets and the protection of Earth from the potential of microbial life elsewhere is the responsibility of the Office of Planetary Protection (http://planetaryprotection.nasa.gov/about). While the Office of Planetary Protection does not include forward or back contamination to or from a low Earth orbit, research platforms, such as the ISS, are being used to better understand the survival of microorganisms and corresponding contamination control in the extreme conditions of space (2, 4, 10). Another example is the NASA Center for Astrobiology, which focuses on the origin, evolution, distribution, and future of life in the universe (https://astrobiology.nasa.gov/). The large focus on microbiology is within its human exploration operations. NASA has historically set microbiological requirements, including stringent monitoring regimes, to mitigate risks to the health and performance of astronauts. Microorganisms can have both positive and negative impacts on many aspects of human spaceflight, including the risk and prevention of infectious diseases, performance of Environmental Control and Life Support Systems (ECLSS), spaceflight foods, and vehicle design and integrity. Even though a great amount of information has been obtained (1, 5, 7, 8), several key questions regarding the impact of microorganisms on human spaceflight still remain. Research into the uncertainties of risks that may affect crew health are the responsibility of the NASA Human Research Program (http://www.nasa.gov/exploration/humanresearch/). The research that addresses our fundamental understanding of space life science and its translation for benefits to the general public on Earth is the responsibility of NASA Space Biology.

Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/25130884

Survey of environmental biocontamination on board the International Space Station

by on 9 June 2015in Biology & Biotechnology No comment

The International Space Station (ISS) is an orbital living and working environment extending from the original Zarya control module built in 1998. The expected life span of the completed station is around 10 years and during this period it will be constantly manned. It is inevitable that the ISS will also be home to an unknown number of microorganisms. This survey reports on microbiological contamination in potable water, air, and on surfaces inside the ISS. The viable counts in potable water did not exceed 1.0 × 10 2   CFU / ml . Sphingomonas sp. and Methylobacterium sp. were identified as the dominant genera. Molecular analysis demonstrated the presence of nucleic acids belonging to various pathogens, but no viable pathogens were recovered. More than 500 samples were collected at different locations over a period of 6 years to characterize air and surface contamination in the ISS. Concentrations of airborne bacteria and fungi were lower than 7.1 × 10 2 and 4.4 × 10 1   CFU / m 3 , respectively. Staphylococcus sp. was by far the most dominant airborne bacterial genus, whereas Aspergillus sp. and Penicillium sp. dominated the fungal population. The bacterial concentrations in surface samples fluctuated from 2.5 × 10 1 to 4.3 × 10 4   CFU / 100   cm 2 . Staphylococcus sp. dominated in all of these samples. The number of fungi varied between 2.5 × 10 1 and 3.0 × 10 5   CFU / 100   cm 2 , with Aspergillus sp. and Cladosporium sp. as the most dominant genera. Furthermore, the investigations identified the presence of several (opportunistic) pathogens and strains involved in the biodegradation of structural materials.

Related URLs:
http://www.sciencedirect.com/science/article/pii/S0923250805002627

The effect of spaceflight on growth of Ulocladium chartarum colonies on the international space station

by on 9 June 2015in Biology & Biotechnology No comment

The objectives of this 14 days experiment were to investigate the effect of spaceflight on the growth of Ulocladium chartarum, to study the viability of the aerial and submerged mycelium and to put in evidence changes at the cellular level. U. chartarum was chosen for the spaceflight experiment because it is well known to be involved in biodeterioration of organic and inorganic substrates covered with organic deposits and expected to be a possible contaminant in Spaceships. Colonies grown on the International Space Station (ISS) and on Earth were analysed post-flight. This study clearly indicates that U. chartarum is able to grow under spaceflight conditions developing, as a response, a complex colony morphotype never mentioned previously. We observed that spaceflight reduced the rate of growth of aerial mycelium, but stimulated the growth of submerged mycelium and of new microcolonies. In Spaceships and Space Stations U. chartarum and other fungal species could find a favourable environment to grow invasively unnoticed in the depth of surfaces containing very small amount of substrate, posing a risk factor for biodegradation of structural components, as well as a direct threat for crew health. The colony growth cycle of U. chartarum provides a useful eukaryotic system for the study of fungal growth under spaceflight conditions.

Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/23637980