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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS2012

Characterization of Tantalum Polymer Capacitors

Overview Reviewed data Caution must be taken when accelerating test conditions Data not useful to establish an acceleration model Introduction of new failure mechanism skewing results Evidence of Anti-Wear-Out De-doping of polymer Decreased capacitance Increased ESR Not dielectric breakdown Needs further investigation Further investigation into tantalum polymer capacitor technology Promising acceleration model for Manufacturer A Possibility for use in high-reliability space applications with suitable voltage derating.

Voltage Acceleration↗
NASA NTRS2016

Robots for Astrobiology!

The search for life and its study is known as astrobiology. Conducting that search on other planets in our Solar System is a major goal of NASA and other space agencies, and a driving passion of the community of scientists and engineers around the world. We practice for that search in many ways, from exploring and studying extreme environments on Earth, to developing robots to go to other planets and help us look for any possible life that may be there or may have been there in the past. The unique challenges of space exploration make collaborations between robots and humans essential. The products of those collaborations will be novel and driven by the features of wholly new environments. For space and planetary environments that are intolerable for humans or where humans present an unacceptable risk to possible biologically sensitive sites, autonomous robots or telepresence offer excellent choices. The search for life signs on Mars fits within this category, especially in advance of human landed missions there, but also as assistants and tools once humans reach the Red Planet. For planetary destinations where we do not envision humans ever going in person, like bitterly cold icy moons, or ocean worlds with thick ice roofs that essentially make them planetary-sized ice caves, we will rely on robots alone to visit those environments for us and enable us to explore and understand any life that we may find there. Current generation robots are not quite ready for some of the tasks that we need them to do, so there are many opportunities for roboticists of the future to advance novel types of mobility, autonomy, and bio-inspired robotic designs to help us accomplish our astrobiological goals. We see an exciting partnership between robotics and astrobiology continually strengthening as we jointly pursue the quest to find extraterrestrial life.

Robotics↗
NASA NTRS2016

The Astrobiology of the Subsurface: Exploring Cave Habitats on Earth, Mars and Beyond

We are using the spectacular underground landscapes of Earth caves as models for the subsurfaces of other planets. Caves have been detected on the Moon and Mars and are strongly suspected for other bodies in the Solar System including some of the ice covered Ocean Worlds that orbit gas giant planets. The caves we explore and study include many extreme conditions of relevance to planetary astrobiology exploration including high and low temperatures, gas atmospheres poisonous to humans but where exotic microbes can flourish, highly acidic or salty fluids, heavy metals, and high background radiation levels. Some cave microorganisms eat their way through bedrock, some live in battery acid conditions, some produce unusual biominerals and rare cave formations, and many produce compounds of potential pharmaceutical and industrial significance. We study these unique lifeforms and the physical and chemical biosignatures that they leave behind. Such traces can be used to provide a "Field Guide to Unknown Organisms" for developing life detection space missions.

caves↗
NASA NTRS2014

Report of the Workshop for Life Detection in Samples from Mars

The question of whether there is or was life on Mars has been one of the most pivotal since Schiaparellis' telescopic observations of the red planet. With the advent of the space age, this question can be addressed directly by exploring the surface of Mars and by bringing samples to Earth for analysis. The latter, however, is not free of problems. Life can be found virtually everywhere on Earth. Hence the potential for contaminating the Mars samples and compromising their scientific integrity is not negligible. Conversely, if life is present in samples from Mars, this may represent a potential source of extraterrestrial biological contamination for Earth. A range of measures and policies, collectively termed 'planetary protection', are employed to minimise risks and thereby prevent undesirable consequences for the terrestrial biosphere. This report documents discussions and conclusions from a workshop held in 2012, which followed a public conference focused on current capabilities for performing life-detection studies on Mars samples. The workshop focused on the evaluation of Mars samples that would maximise scientific productivity and inform decision making in the context of planetary protection. Workshop participants developed a strong consensus that the same measurements could be employed to effectively inform both science and planetary protection, when applied in the context of two competing hypotheses: 1) that there is no detectable life in the samples; or 2) that there is martian life in the samples. Participants then outlined a sequence for sample processing and defined analytical methods that would test these hypotheses. They also identified critical developments to enable the analysis of samples from Mars.

Life Detection↗
NASA NTRS2017

The Astrobiology of the Subsurface: Caves and Rock Fracture Habitats on Earth, Mars and Beyond

The Astrobiology of the Subsurface: Exploring Cave Habitats on Earth, Mars and Beyond. We are using the spectacular underground landscapes of Earth caves as models for the subsurfaces of other planets. Caves have been detected on the Moon and Mars and are strongly suspected for other bodies in the Solar System including some of the ice covered Ocean Worlds that orbit gas giant planets. The caves we explore and study include many extreme conditions of relevance to planetary astrobiology exploration including high and low temperatures, gas atmospheres poisonous to humans but where exotic microbes can fluorish, highly acidic or salty fluids, heavy metals, and high background radiation levels. Some cave microorganisms eat their way through bedrock, some live in battery acid conditions, some produce unusual biominerals and rare cave formations, and many produce compounds of potential pharmaceutical and industrial significance. We study these unique lifeforms and the physical and chemical biosignatures that they leave behind. Such traces can be used to provide a Field Guide to Unknown Organisms for developing life detection space missions.

Caves↗
NASA NTRS2016

Space Biology Meets Astrobiology: Critical Synergies and Concerns

The broad fields of space biology and astrobiology share much in common in terms of science questions, approaches, and goals. However, historical circumstances and funding agency practices have frequently resulted in a wide separation between the two related areas. Is this a good thing? We believe that it is not, and that much is to be gained in each field from sharing ideas, resources, and perhaps projects between investigators traditionally working in one discipline or the other. Some of the strengths that the Space Biology community offers include sophistication and experience in flying experiments on space missions. In turn, Astrobiology has focused heavily on ground-based and field research. Challenging physical and chemical conditions experienced in space and on other planets partially overlap, and much can be gleaned from the body of work of each community along these topical lines. A combination of these areas of expertise and experience could result in major advances to all involved. When possible, avoiding having to reinvent methods or approaches already used by a sister community can result in greater efficiencies of resource use. We will discuss some case studies where we believe there are significant overlaps including adaptation to a variety of environmental stresses, extremophiles as potential flight organisms, microfluidics as applied to planetary environment simulations, and others.

Extremophiles↗
NASA NTRS2018

Soil Water Content Effects on Net Ecosystem CO2 Exchange and Actual Evapotranspiration in a Mediterranean Semiarid Savanna of Central Chile

Biosphere-atmosphere water and carbon fluxes depend on ecosystem structure, and their magnitudes and seasonal behavior are driven by environmental and biological factors. We studied the seasonal behavior of net ecosystem CO2 exchange (NEE), Gross Primary Productivity (GPP), Ecosystem Respiration (RE), and actual evapotranspiration (ETa) obtained by eddy covariance measurements during two years in a Mediterranean Acacia savanna ecosystem (Acacia caven) in Central Chile. The annual carbon balance was −53 g C/sq. m in 2011 and −111 g C/sq. m in 2012, showing that the ecosystem acts as a net sink of CO2, notwithstanding water limitations on photosynthesis observed in this particularly dry period. Total annual ETa was of 128 mm in 2011 and 139 mm in 2012. Both NEE and ETa exhibited strong seasonality with peak values recorded in the winter season (July to September), as a result of ecosystem phenology, soil water content and rainfall occurrence. Consequently, the maximum carbon assimilation rate occurred in wintertime. Results show that soil water content is a major driver of GPP and RE, defining their seasonal patterns and the annual carbon assimilation capacity of the ecosystem, and also modulating the effect that solar radiation and air temperature have on NEE components at shorter time scales.

Meza, Francisco J.↗
NASA NTRS2018

Bayesian Geostatistical Modelling of PM10 and PM2.5 Surface Level Concentrations in Europe Using High-Resolution Satellite-Derived Products

Air quality monitoring across Europe is mainly based on in situ ground stations which are too sparse to accurately assess the exposure effects of air pollution for the entire continent. The demand for precise predictive modelsthat estimate gridded geophysical parameters of ambient air at high spatial resolution has rapidly grown. Here, we investigate the potential of satellite derived products to improve particulate matter (PM) estimates. Bayesiangeostatistical models addressing confounding between the spatial distribution of pollutants and remotely sensed predictors were developed to estimate yearly averages of both, fine (PM2.5) and coarse (PM10) surface PM concentrations at 1 sq.km spatial resolution over 46 European countries and were compared to geostatistical, geographically weighted and land-use regression formulations. Rigorous model selection identified the Earth observation data which contribute most to pollutants' estimation. Geostatistical models outperformed the predictive ability of the frequently employed land-use regression. The resulting estimates of PM10 and PM2.5, which represent the main air quality indicators for the urban Sustainable Development Goal, indicate that in 2016, 66.2% of the European population was breathing air above the WHO Air Quality Guidelines thresholds. Our estimates are readily available to policy makers and scientists assessing the effects of long-term exposure to pollution on human and ecosystem health.

Beloconi, Anton↗
NASA NTRS2014

Gale Crater and Impact Processes - Curiosity's First 364 Sols on Mars

Impact processes at all scales have been involved in the formation and subsequent evolution of Gale crater. Small impact craters in the vicinity of the Curiosity MSL landing site and rover traverse during the 364 Sols after landing have been studied both from orbit and the surface. Evidence for the effect of impacts on basement outcrops may include loose blocks of sandstone and conglomerate, and disrupted (fractured) sedimentary layers, which are not obviously displaced by erosion. Impact ejecta blankets are likely to be present, but in the absence of distinct glass or impact melt phases are difficult to distinguish from sedimentary/volcaniclastic breccia and conglomerate deposits. The occurrence of individual blocks with diverse petrological characteristics, including igneous textures, have been identified across the surface of Bradbury Rise, and some of these blocks may represent distal ejecta from larger craters in the vicinity of Gale. Distal ejecta may also occur in the form of impact spherules identified in the sediments and drift material. Possible examples of impactites in the form of shatter cones, shocked rocks, and ropy textured fragments of materials that may have been molten have been observed, but cannot be uniquely confirmed. Modification by aeolian processes of craters smaller than 40 m in diameter observed in this study, are indicated by erosion of crater rims, and infill of craters with aeolian and airfall dust deposits. Estimates for resurfacing suggest that craters less than 15 m in diameter may represent steady state between production and destruction. The smallest candidate impact crater observed is ∼0.6 m in diameter. The observed crater record and other data are consistent with a resurfacing rate of the order of 10 mm/Myr; considerably greater than the rate from impact cratering alone, but remarkably lower than terrestrial erosion rates.

Curiosity↗
NASA NTRS2018

Chapter 6: Sulfur on Mars from the Atmosphere to the Core

Observations of the martian surface from orbiting spacecraft and in situ landers and rovers, as well as analyses of martian meteorites in terrestrial laboratories, have consistently indicated that Mars is a sulfur-rich planet. The global inventory of sulfur, from the atmosphere to the core, carries widespread implications of potential geophysical, geochemical, climatological, and astrobiological significance. For example, the sulfur content of the core carries implications for core density; the speciation of igneous sulfur minerals reflects the oxidation state of the magma from which they formed; sulfur-bearing gases may have exerted control on the temperatures at the surface of early Mars; and the widespread availability of sulfur on Mars would have provided an abundant source for energy and nutrients to fuel sulfur-metabolizing microbes, such as those that arose during the emergence of primitive life on Earth. Here we provide an overview of martian sulfur and its relevance to these areas of interest, including a discussion of analytical techniques and results acquired by space missions and meteorite analyses to date. We review current studies modeling the potential effects of sulfur-bearing gases on the past martian climate and possible constraints on atmospheric composition implied by sulfur isotopic data. We also explore the importance of sulfur to the search for extinct or extant life on Mars. Finally, we summarize a few areas of interest to future work, including advances in space exploration technology and preparation for Mars sample return.

Climate↗
NASA NTRS2020

Spitzer Microlensing Parallax Reveals Two Isolated Stars in the Galactic Bulge

We report the mass and distance measurements of two single-lens events from the 2017 Spitzer microlensing campaign. The ground-based observations yield the detection of finite-source effects, and the microlens parallaxes are derived from the joint analysis of ground-based observations and Spitzer observations. We find that the lens of OGLE-2017-BLG-1254 is a 0.60 ± 0.03 M⊙ star with D(LS) = 0.53 ± 0.11 kpc, where D(LS) is the distance between the lens and the source. The second event, OGLE-2017-BLG-1161, is subject to the known satellite parallax degeneracy, and thus is either a 0.51(sup +0.12, sub 3-0.10)M⊙ star with D(LS) = 0.40 ± 0.12 kpc or a 0.38(sup +0.13, sub -0.12) M⊙ star with D(LS) = 0.53 ± 0.19 kpc. Both of the lenses are therefore isolated stars in the Galactic bulge. By comparing the mass and distance distributions of the eight published Spitzer finite-source events with the expectations from a Galactic model, we find that the Spitzer sample is in agreement with the probability of finite-source effects occurring in single-lens events.

Weicheng Zang↗
NASA NTRS2020

The Integration of Life Sciences in Space: Astrobiology and Space Biology Virtual Workshops Report

A series of virtual workshops was held during June 2020 to seek ways to integrate the efforts of the astrobiology and space biology research communities under a broad umbrella of space life sciences. The overall goal was to help inspire creativity that will guide us towards new synergistic ideas complementing these existing disciplines that are of such importance to NASA. Workshop participants aspired to: (1) Exploit synergies across the biological sciences at NASA, (2) Foster research, enabling technology, and mission concepts that support commonalities in space biology, astrobiology, synthetic biology, planetary protection, and relevant human health, performance, and habitation concerns, (3) Envision the development of an “Arc of Biology in Space” to encompass this multi-faceted joint research community. The focused objective of the workshop series was to explore and demonstrate how the integration of astrobiology and space biology could be achieved, identify strengths and weaknesses in the current state of the art, and recognize where our greatest challenges lay. Specifically, we seek to: (1) Establish a scientific framework for an integrated life sciences effort, (2) Pioneer discovery by creating unique opportunities in the fundamental biological sciences, (3) Explore novel combinations of existing technologies across the relevant disciplines, (4) Invent new technologies and applications in space life sciences, and (5) Creatively increase access to spaceflight, emerging and novel technologies, Earth analogs, and simulated natural and spaceflight environments. The community aims for a broad arc of biological competence in the context of space and planetary science, spaceflight, and habitation. We will present dominant themes and innovative ideas that resulted from this interchange of relevant communities.

astrobiology↗
NASA NTRSDate not supplied

Common Scientific and Technological Interests Between Astrobiology and Space Biology

The disciplines of astrobiology (AB) and space biology (SB) clearly have common interests, however they have not been pursued jointly. SB and AB are inextricably linked, both intellectually and technologically. They can now be effectively linked operationally. Cross-cutting joint collaborations will enhance innovation and increase cost effectiveness. Session topics include joint science questions, technologies, instrumentation, and missions. Examples include life detection, overlapping planetary protection concerns, biofilms, radiation, hyper- and hypogravity, applications of artificial intelligence and machine learning, interoperable databases, facilities (i.e., spacecraft, lunar surface efforts, simulation chambers, analog sites, etc.), training opportunities, and other topics relevant to AB and SB joint ventures. We welcome contributions on this very broad topical area to facilitate cross-fertilization of these disciplines that are of great importance to NASA.

astrobiology↗
NASA NTRSDate not supplied

The Integration of Life Sciences in Space: Astrobiology and Space Biology Virtual Workshops Report

A series of virtual workshops was held during June 2020 to seek ways to integrate the efforts of the astrobiology and space biology research communities under a broad umbrella of space life sciences. The overall goal was to help inspire creativity that will guide us towards new synergistic ideas complementing these existing disciplines that are of such importance to NASA. Workshop participants aspired to: (1) Exploit synergies across the biological sciences at NASA, (2) Foster research, enabling technology, and mission concepts that support commonalities in space biology, astrobiology, synthetic biology, planetary protection, and relevant human health, performance, and habitation concerns, (3) Envision the development of an “Arc of Biology in Space” to encompass this multi-faceted joint research community. The focused objective of the workshop series was to explore and demonstrate how the integration of astrobiology and space biology could be achieved, identify strengths and weaknesses in the current state of the art, and recognize where our greatest challenges lay. Specifically, we seek to: (1) Establish a scientific framework for an integrated life sciences effort, (2) Pioneer discovery by creating unique opportunities in the fundamental biological sciences, (3) Explore novel combinations of existing technologies across the relevant disciplines, (4) Invent new technologies and applications in space life sciences, and (5) Creatively increase access to spaceflight, emerging and novel technologies, Earth analogs, and simulated natural and spaceflight environments. The community aims for a broad arc of biological competence in the context of space and planetary science, spaceflight, and habitation. We will present dominant themes and innovative ideas that resulted from this interchange of relevant communities.

astrobiology↗
NASA NTRS2021

Chemical Reactivity of In-Situ Lunar Dust for Biotoxicity Assessment

How does the chemical reactivity of in-situ lunar dust compare to Apollo samples currently stored in curation facilities here on Earth? Essential investigations of this question will help us to further mitigate exploration risks for future human explorers on the Moon and will also provide critical information for astrobiologists and space biologists using the Moon for scientific inquiry. Apollo 14 dust biotoxicity studies, carried out by the NASA Lunar Airborne Dust Toxicity Assessment Group (LADTAG), included numerous cellular and animal experiments. Intratracheal instillation and inhalation studies in rats both showed Apollo 14 dust to be intermediate in toxicity compared to low-tox titanium dusts and high-tox quartz dusts of similar particle sizes. The collective results were used in models to establish a safe exposure limit for astronauts. Although LADTAG took extensive steps to preserve what chemical reactivity may still have existed in the samples, it is simply unknown if they possessed true in-situ chemical reactivity or if that reactivity has decayed. Initial gas loss on collection and other alterations, and even intermittent exposure to Earth-normal conditions during subsequent decades of handling, obscure a forensic reconstruction of the initial state. Because a mineral dust’s chemical reactivity influences its biotoxicity, researchers have developed methods to “activate” lunar dust and simulants. Past studies that modeled impact processes and radiation in the lunar environment suggest that in-situ lunar dust is likely to be more chemically reactive than Earth-exposed samples. Because of these results, in-situ measurements are warranted. Since the lunar surface is heterogeneous, dust biotoxicity is expected to vary from site to site due to particle size, mineralogy, physical characteristics, degree of space weathering, and chemical reactivity. This circumstance dictates dust assessments at a suite of lunar sites enabled by CLPS opportunities. Dose, location, and duration of particle exposure will also affect biological responses. In-situ chemical reactivity measurements can inform cross-cutting collaborative research campaigns such as astrobiology studies examining regolith interactions with organisms and its ability to preserve chemical and structural biomarkers, as well as space biology investigations that examine regolith-microbe interactions relating to life support systems, plant growth, biomining, and development of regolith biocomposites.

Jon C Rask↗
NASA NTRS2008

Effects of hand soldering MIL-PRF 55365 tantalum capacitors

Different values of MIL-PRF-55365 tantalum capacitors were subjected to three different types of soldering conditions— Convection Reflow, JPL Standard Hand Soldering, and Optimized Hand Soldering. The electrical parameters for a large number of capacitors of each value were measured before and after thermal soldering stress. The results indicate that tantalum capacitors subjected to convection reflow conditions experience detectable changes in electrical parameters; capacitors subjected to hand solder conditions show reduced changes in electrical parameters when compared to the reflow samples. Optimized hand solder conditions are shown to have a minimal effect on electrical parameters.

Sheldon, Douglas↗