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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 307 records · Page 17

Antenna grout replacement system

An epoxy grout suitable for use in mounting and positioning bearing runner plates used in hydrostatic bearing assemblies for rotatably mounting large radio telescope structures to stationary support pedestals is described. The epoxy grout may be used in original mountings or may be used as part of a replacement system for repairing cavities in existing grout resulting from grout deterioration. The epoxy grout has a relatively short work life and cure time even in the presence of hydraulic oil. The epoxy grout cures without shrinking or sagging to form a grout which is sufficiently strong and durable to provide a grout especially well suited for use under the high pressure loading and close tolerance requirements of large hydrostatic bearing assemblies.

Mcclung, C. E.↗

Influence Of Holes On The In-Plane Tensile Strength And Fatigue Durability Of A NICALON(Trademark)/Si-N-C Ceramic Matrix Composite

Effects of different sizes of holes as well as different percentages of open areas on the in-plane tensile strength and fatigue durability of the SiC/Si-N-C composite were investigated in this study. Test specimens with no holes, four different diameters of holes (1.0 to 3.2 mm), and four different open areas (20 to 35%) were machined. All mechanical testing was performed in air at a temperature of 910 C. Fatigue tests were conducted with a load ratio, R = 0.05, and a frequency of 0.33 Hz. In general, both the in-plane tensile strength of the composite and its fatigue durability decreased with an increase in the size of the hole and percentage of the open area. Reductions in the in-plane tensile strength and cyclic fatigue life of the composite were described by empirical equations with the diameter of the hole and the percent open area as the independent variables. The validity of these two empirical equations was verified with additional tensile and fatigue test data generated on the composite specimens.

Kalluri, Sreeramesh↗

Photophysics of Laser Dye-Doped Polymer Membranes for Laser-Induced Fluorescence Photogrammetry

Laser-induced fluorescence target generation in dye-doped polymer films has recently been introduced as a promising alternative to more traditional photogrammetric targeting techniques for surface profiling of highly transparent or reflective membrane structures. We investigate the photophysics of these dye-doped polymers to help determine their long-term durability and suitability for laser-induced fluorescence photogrammetric targeting. These investigations included experimental analysis of the fluorescence emission pattern, spectral content, temporal lifetime, linearity, and half-life. Results are presented that reveal an emission pattern wider than normal Lambertian diffuse surface scatter, a fluorescence time constant of 6.6 ns, a pump saturation level of approximately 20 micro J/mm(exp 2), and a useful lifetime of more than 300,000 measurements. Furthermore, two demonstrations of photogrammetric measurements by laser-induced fluorescence targeting are presented, showing agreement between photogrammetric and physically measured dimensions within the measurement scatter of 100 micron.

Dorrington, Adrian A.↗

Battery passports for promoting electric vehicle resale and repurposing

Starting in 2026, most batteries sold in the European Union will require a battery passport. This initiative is part of a broader legislative framework, led by the European Commission, to improve sustainable battery materials sourcing practices and enable a circular economy. All batteries having a capacity of greater than 2 kilowatt-hours will be covered under the legislation, effectively encompassing all electric vehicle (EV) batteries and stationary grid storage batteries. At its core, a battery passport defines a minimum, standard set of information that must be reported for every battery made and sold (see Figure 1). Legislative actions have so far focused on labeling standards enabling raw material traceability and recycling, which has received ongoing support from the European Council and Parliament. Furthermore, work remains to finalize the electrochemical performance and durability minimum reporting requirements by 2024, which has been challenging since performance and durability are subject to many different interpretations.

25 ENERGY STORAGE↗

Space Wear Vision -Development of a Wardrobe for Life in Space Vehicles and Habitats

A new vision is needed for the development of a wardrobe for NASA's journey to Mars in the 2030s. All human space missions require significant logistical mass and volume that add an unprecedented burden on long-duration missions beyond low-Earth orbit. The logistical burden is at least twice as great for prolonged exploration and settlements on planetary surfaces compared to missions in low-Earth orbit. The space wear vision is to design apparel that uniquely meets criteria and constraints for sustaining human presence in space. For long duration missions without landing on planetary surface, humans can use only what they carry in their spacecraft, while for settlements, additional resources may be available. The immediate space wear goal is to develop those elements needed for prolonged manned exploration beyond low Earth orbit. Three major objectives have been identified for achieving this goal: satisfying crew preferences, logistics reduction and repurposing, and systems integration. Garments must be comfortable, durable, safe to wear, and aesthetically pleasing. In addition, with limited cleaning resources, garments must be developed to reduce the logistical burden by reducing clothing mass and extending clothing wear. Furthermore, garments must have minimal impact on the life support systems of spacecraft. The approach to achieving the immediate space wear goal is to conduct multiple studies on Earth and on the International Space Station (ISS), thus laying out the path for finding materials and designing garments that meet the three objectives of prolonged manned exploration. Several studies have been undertaken recently for the first time, namely, to ascertain garment length of wear and to assess the acceptance of such extended wear. Most garments in these studies have been exercise T-shirts and shorts, and routine-wear T-shirts. Eleven studies have been completed: five studies of exercise T-shirts, three of exercise shorts, two of routine wear T-shirts, and one of shirts used as sleep-wear. The IVA (Intra Vehicular Activity) Clothing Study has been the first study with Roscosmos under the "Utilization Sharing Plan On-Board ISS," while the other studies have been conducted at the Johnson Space Center in a controlled environment similar to the ISS. For exercise clothing, study participants wore garments during aerobic exercise. For routine wear clothing, study participants wore the T-shirts daily in an office or laboratory. Daily questionnaires collected data on ordinal preferences of nine sensory elements and on reasons for retiring a used garment. More studies have been initiated on Earth, and some should be planned to engage more astronauts and cosmonauts in the design of the new space wear. Future studies will extend to other types of garments in the wardrobe; another will address microbial growth on textiles. Others will address cleaning and sanitation of clothing in space vehicles. Efforts will be made for additional ISS studies with NASA's international partners.

Orndorff, Evelyne↗

A self-healing plastic ceramic electrolyte by an aprotic dynamic polymer network for lithium metal batteries

Abstract Oxide ceramic electrolytes (OCEs) have great potential for solid-state lithium metal (Li 0 ) battery applications because, in theory, their high elastic modulus provides better resistance to Li 0 dendrite growth. However, in practice, OCEs can hardly survive critical current densities higher than 1 mA/cm 2 . Key issues that contribute to the breakdown of OCEs include Li 0 penetration promoted by grain boundaries (GBs), uncontrolled side reactions at electrode-OCE interfaces, and, equally importantly, defects evolution (e.g., void growth and crack propagation) that leads to local current concentration and mechanical failure inside and on OCEs. Here, taking advantage of a dynamically crosslinked aprotic polymer with non-covalent –CH 3 ⋯CF 3 bonds, we developed a plastic ceramic electrolyte (PCE) by hybridizing the polymer framework with ionically conductive ceramics. Using in-situ synchrotron X-ray technique and Cryogenic transmission electron microscopy (Cryo-TEM), we uncover that the PCE exhibits self-healing/repairing capability through a two-step dynamic defects removal mechanism. This significantly suppresses the generation of hotspots for Li 0 penetration and chemomechanical degradations, resulting in durability beyond 2000 hours in Li 0 -Li 0 cells at 1 mA/cm 2 . Furthermore, by introducing a polyacrylate buffer layer between PCE and Li 0 -anode, long cycle life >3600 cycles was achieved when paired with a 4.2 V zero-strain cathode, all under near-zero stack pressure.

36 MATERIALS SCIENCE↗

Eight-cm mercury ion thruster system technology

The technology status of 8 cm diameter electron bombardment ion thrusters is presented. Much of the technology resulting from the 5 cm diameter thruster has been adapted and improved upon to increase the reliability, durability, and efficiency of the 8 cm thruster. Technology discussed includes: dependence of neutralizer tip erosion upon neutralizer flow rate; impregnated and rolled-foil insert cathode performance and life testing; neutralizer position studies; thruster ion beam profile measurements; high voltage pulse ignition; high utilization ion machined accelerator grids; deposition internal and external to the thruster; thruster vectoring systems; thruster cycling life testing and thruster system weights for typical mission applications.

Source record↗

8-cm mercury ion thruster system technology

The technology status of 8-cm diameter electron bombardment ion thrusters is presented. Much of the technology resulting from the 5-cm diameter thruster has been adapted and improved upon to increase the reliability, durability, and efficiency of the 8-cm thruster. Technology discussed includes: dependence of neutralizer tip erosion upon neutralizer flow rate; impregnated and rolled-foil insert cathode performance and life testing; neutralizer position studies; thruster ion beam profile measurements; high voltage pulse ignition; high utilization ion machined accelerator grids; deposition internal and external to the thruster; thruster vectoring systems; thruster cycling life testing and thruster system weights for typical mission applications.

Source record↗

Study of methods for applying and enhancing transfer film coatings of polytetrafluoroethylene (PTEE) to Space Shuttle Main Engine (SSME) High Pressure Oxygen Turbo Pump (HPOTP) bearings

Machines were constructed and evaluated for burnishing polytetrafluoroethylene on balls for use in the high pressure oxygen turbopump (HPOTP). The most positive performance was obtained with single-ball burnishing, but one technique for burnishing three balls simultaneously holds promise. Evaluations of the coatings in a HPOTP bearing of earlier design (employed smaller diameter balls) showed very little life enhancement before high torque and ball and race wear initiated. Other coating techniques, such as molybdenum disulfide combined with PTFE transfer films, hold promise for providing the more durable quantities of solid lubricant needed for the bearings.

Kannel, J. W.↗

Performance and Durability of Hybrid Fuel Cell Systems for Class-8 Long Haul Trucks

Hybrid fuel cell-battery configurations are investigated that overcome thermal management issues in fuel cell powertrains for heavy-duty Class 8 trucks. The battery is sized so that it has sufficient capacity to provide supplemental power and energy on a hill climb transient at end-of-life. A dynamic load sharing strategy is developed to distribute the power demand between the fuel cell system (FCS) and the energy storage system in a manner that optimizes their lifetimes. The FCS end-of-life is identified as the terminal point beyond which the stack cannot generate the rated power with target power density at 0.7 V and 40 °C ambient temperature. Reaching the target lifetime with a-Pt/C cathode catalyst in one hybrid configuration requires voltage clipping to 813 mV, idle power limited to 50 kW, catalyst overloading to 0.45 mg cm -2 total Pt in anode and cathode, and 44% active membrane area oversizing. The stack and FCS drive cycle efficiencies decrease by 4.2% and 5.4%, respectively, during the electrode lifetime. Further, the FCS performance, durability and cost are compared with the targets of 68% peak efficiency, 0.30 mg cm -2 total Pt loading, 2.5 kW/g PGM Pt group metal (PGM) loading, 750 mW cm -2 power density, 25,000-h lifetime and $80/kW cost.

33 ADVANCED PROPULSION SYSTEMS↗

Bridging the Gap: Use of Spaceflight Technologies for Earth-Based Problems

Spaceflight is colloquially deemed, the final frontier, or the last area which humans have not yet explored in great depth. While this is true, there are still many regions on Earth that remain isolated from the urban, socially and electronically connected world. Because travelling to space requires a great deal of foresight, engineers are required to think creatively in order to invent technologies that are durable enough to withstand the rigors of the unique and often treacherous environment of outer space. The innovations that are a result of spaceflight designs can often be applied to life on Earth, particularly in the rural, isolated communities found throughout the world. The NASA Human Health and Performance Center (NHHPC) is a collaborative, virtual forum that connects businesses, non-profit organizations, academia, and government agencies to allow for better distribution of ideas and technology between these entities (http://www.nasa.gov/offices/NHHPC). There are many technologies that have been developed for spaceflight that can be readily applied to rural communities on Earth. For example, water filtration systems designed for spaceflight must be robust and easily repaired; therefore, a system with these qualifications may be used in rural areas on Earth. This particular initiative seeks to connect established, non-profit organizations working in isolated communities throughout the world with NASA technologies devised for spaceflight. These technologies could include water purification systems, solar power generators, or telemedicine techniques. Applying innovative, spaceflight technologies to isolated communities on Earth provides greater benefits from the same research dollars, thus fulfilling the Space Life Science motto at Johnson Space Center: Exploring Space and Enhancing Life. This paper will discuss this NHHPC global outreach initiative and give examples based on the recent work of the organization.

Brinley, Alaina↗

Space Shuttle Transportation (Roll-Out) Loads Diagnostics

The Space Transportation System (STS) consists of three primary components; an Orbiter Vehicle, an External Fuel Tank, and two Solid Rocket Boosters. The Orbiter Vehicle and Solid Rocket Boosters are reusable components, and as such, they are susceptible to durability issues. Recently, the fatigue load spectra for these components have been updated to include load histories acquired during the rollout phase of the STS processing for flight. Using traditional program life assessment techniques, the incorporation of these "rollout" loads produced unacceptable life estimates for certain Orbiter structural members. As a result, the Space Shuttle System Engineering and Integration Office has initiated a program to re-assess the method used for developing the "rollout" loads and performing the life assessments. In the fall of 2003 a set of tests were preformed to provide information to either validate existing load spectra estimation techniques or generate new load spectra estimation methods. Acceleration and strain data were collected from two rollouts of a partial-stack configuration of the Space Shuttle. The partial stack configuration consists of two Solid Rocket Boosters tied together at the upper External Tank attachment locations mounted on the Mobile Launch Platform carried by a Crawler Transporter (CT). In the current analysis, the data collected from this test is examined for consistency in speed, surface condition effects, and the characterization of the forcing function. It is observed that the speed of the CT is relatively stable. The dynamic response acceleration of the partial-stack is slightly sensitive to the surface condition of the road used for transport, and the dynamic response acceleration of the partial-stack generally increases as the transport speed increases. However, the speed sensitivity is dependent on the measurement location. Finally, the character of the forcing function is narrow-banded with the primary drivers being harmonics of two CT speed dependent excitations. One source is an excitation due to the CT treads striking the road surface, and the second is unknown.

Elliott, Kenny B.↗

Ceramic–Metal (Cermet) Composites: A Review of Key Properties and Synthesis Methods Focused on Nuclear Waste Immobilization

Here this paper reviews key properties, applications, and examples of ceramic-metal composites (cermets), and metal matrix composites (MMC) with emphasis on their applicability as waste forms for immobilizing nuclear waste. While the literature is mature for vitrified and cementitious radioactive waste forms, cermet materials have not received adequate attention as potential candidates for immobilizing nuclear waste. To promulgate this effort, this review connects cermet and MMC design, such as hardened tools, with the chemistry of radioactive waste streams. A discussion on certification and qualification standards for cermet waste forms, literature gaps, and “how-to” sections on cermet processing techniques. Key parameters discussed include thermal conductivity, chemical durability, and waste loading, as well as examples for metal-containing waste forms. As cermet waste forms gain momentum within the community, this review paper aims ensure the end-of-life nuclear fuel cycle is addressed from a materials and waste disposition perspective.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Toward improved durability in advanced combustors and turbines - Progress in prediction of thermomechanical loads

NASA is sponsoring the Turbine Engine Hot Section Technology (HOST) Project to address the need for improved durability in advanced combustors and turbines. Analytical and experimental activities aimed at more accurate prediction of the aerothermal environment, the thermomechanical loads, the material behavior and structural responses to such loading, and life predictions for high temperature cyclic operation have been underway for several years and are showing promising results. Progress is reported in the development of advanced instrumentation and in the improvement of combustor aerothermal and turbine heat transfer models that will lead to more accurate prediction of themomechanical loads.

Sokolowski, D. E.↗

Toward improved durability in advanced combustors and turbines: Progress in the prediction of thermomechanical loads

NASA is sponsoring the Turbine Engine Hot Section Technology (HOST) Project to address the need for improved durability in advanced combustors and turbines. Analytical and experimental activities aimed at more accurate prediction of the aerothermal environment, the thermomechanical loads, the material behavior and structural responses to such loading, and life predictions for high temperature cyclic operation have been underway for several years and are showing promising results. Progress is reported in the development of advanced instrumentation and in the improvement of combustor aerothermal and turbine heat transfer models that will lead to more accurate prediction of thermomechanical loads.

Sokolowski, Daniel E.↗

Optical Property Evaluation of Next Generation Thermal Control Coatings

Next generation white thermal control coatings were developed via the Small Business Innovative Research program utilizing lithium silicate chemistry as a binder. Doping of the binder with additives yielded a powder that was plasma spray capable and that could be applied to light weight polymers and carbon-carbon composite surfaces. The plasma sprayed coating had acceptable beginning-of-life and end-of-live optical properties, as indicated by a successful 1.5 year exposure to the space environment in low Earth orbit. Recent studies also showed the coating to be durable to simulated space environments consisting of 1 keV and 10 keV electrons, 4.5 MeV electrons, and thermal cycling. Large scale deposition was demonstrated on a polymer matrix composite radiator panel, leading to the selection of the coating for use on the Gravity Recovery And Interior Laboratory (GRAIL) mission.

Jaworske, Donald A.↗

Conversion of Wet Waste to Sustainable Aviation Fuel and Chemical Intermediates via Catalytic Upgrading

Wet waste is a low-cost, abundant feedstock capable of displacing significant amounts of domestic petrofuel and petrochemical consumption. We present a sequential biochemical-thermochemical pathway to upgrade wet waste into hydrocarbon sustainable aviation fuel blendstock and chemical intermediates with near-zero or net-negative life-cycle CO2 emissions. Waste is initially upgraded to carboxylic acids via arrested anaerobic digestion, then catalytically converted to hydrocarbons via sequential heterogeneous catalytic ketonization, cyclization, and hydrodeoxygenation. We will discuss kinetics, durability, and reactor design of key catalytic processes, as well as applicability of final products to targeted applications.

BIOMASS FUELS,INORGANIC, ORGANIC, PHYSICAL, AND AN↗

Reviving the rock-salt phases in Ni-rich layered cathodes by mechano-electrochemistry in all-solid-state batteries

The rock-salt phase (RSP) formed on the surface of Ni-rich layered cathodes in liquid-electrolyte lithium-ion batteries is conceived to be electrochemically "dead". Here we show massive RSP forms in the interior of LiNi x Mn y Co (1–x-y) O 2 (NMC) crystals in sulfide based all solid state batteries (ASSBs), but the RSP remains electrochemically active even after long cycles. The RSP and the layered structure constitute a two-phase mixture, a material architecture that is distinctly different from the RSP in liquid electrolytes. The tensioned layered phase affords an effective percolation channel into which lithium is squeezed out of the RSPs by compressive stress, rendering the RSPs electrochemically active. Consequently, the ASSBs with predominant RSP in the NMC cathode deliver remarkable long cycle life of 4000 cycles at high areal capacity of 4.3 mAh/cm 2 . Our study unveils distinct mechano-electrochemistry of RSPs in ASSBs that can be harnessed to enable high energy density and durable ASSBs.

25 ENERGY STORAGE↗