Search NASA⌕ Search

SEARCH · Search NASA

Results for “long life”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 361 records · Page 20

Long term life support for space exploration

A general strategy for the development of life-support systems is discussed in terms of present and future requirements for NASA exploration missions. A general life-support strategy is delineated for both intravehicular activity (IVA) and extravehicular activity (EVA) for lunar and Mars transfer vehicles, Mars habitats, and pressurized rovers. The baseline capability presented corresponds to the systems needs for the Space Station Freedom permanently manned capability and the Shuttle Extended Duration Orbiter. Design guidelines and system design goals are given for IVA life support with an emphasis on closed-loop systems, and the design prerogatives for EVA include a minimum time to transition between IVA and EVA, and minimum resitriction for human activity.

Rummel, John D.↗

Long-term life testing of Geostationary Operational Environmental Satellite (GOES) encoder lamps

The aging characteristics and lifetimes of tungsten filament encoder lamps were determined as a function of operating voltage and filament material. For pure tungsten and thoria doped (1 pct.) filament lamps, crystal grain growth over the center portion of the filament leads to the ultimate failure of the lamp. The development of notches associated with this grain growth is the cause of lamp burn out. Eventually, one of the notches will 'etch' through the filament, causing it to fail open. For rhenium doped (3 pct.) filament lamps, distortion of the filament leads to the ultimate failure of the lamp. The lifetime of these lamps is about 1 year at an operating voltage of 5.0 volts. The pure tungsten filament lamps have the longest average lifetime, and the thoria doped filament lamps have the shortest at 5.0 volts. The lifetimes of these lamps is about 7 years at an operating voltage of 3.5 volts. Data suggest that the rhenium doped lamps will have the longest average lifetime at 3.5 volts, and the thoria doped will have the shortest. These lifetimes are comparable to the desired lifetimes of 7 years.

Powers, Charles E.↗

Long cycle life rechargeable lithium batteries

Cycle life and safety of delta-LiAl/TiS2 cells were evaluated using laboratory and AA-size cells. Analysis of the alloys (which contained 60, 70, 80, or 85 wt-pct. lithium and are designated 60 LiAl etc.) showed them to contain a mixture of elemental Li and Al4Li9. Cycling efficiencies correlated with the amount of free lithium in the anode. Using an electrolyte with the composition 48 v/o THF:48 v/o 2-MeTHF:4 v/o 2-MeF/LiAsF6(1.5M), a 70 LiAl/TiS2 laboratory cell yielded a cycling efficiency of 96.4 pct. when cycled at a 100 pct. discharge depth which compares well with Li anode cycling efficiencies of 96 to 97.5 pct. obtained previously in this electrolyte. The highest cycling efficiency of any delta-LiAl/TiS2 laboratory cell was 96.7 pct. when the 60 LiAl alloy was used with the 35 v/o PC:35 v/o EC:30 v/o triglyme/LiAsF6(1.0M) electrolyte. The 70 LiAl alloy was selected for further testing in AA cells since it was malleable for the fabrication of spirally wound electrodes, and its overall cycling performance was sufficiently good. AA-size 70 LiAl/TiS2 cells appear to have capacity/rate properties similar to those for identical Li/TiS2 cells. The use of the delta-LiAl alloy anodes does not appear to offer any safety advantage when cycled cells are shorted or heated.

Pasquariello, D. M.↗

Modified, Packaged Tortillas Have Long Shelf Life

Tortillas made from modified recipe and sealed in low-pressure nitrogen in foil pouches in effort to increase their shelf life at room temperature. Preliminary tests show that shelf life of these tortillas at least five months; in contrast, commercial tortillas last only few days. Part of water in recipe replaced with glycerin. Particularly necessary to avoid Clostridium botulinum, which grows in anaerobic environments and produces deadly toxin that causes botulism.

Bourland, Charles↗

Acoustic Emission Health Monitoring of Fill Purge COPV's Used in Aerospace and Automotive Applications and Designed for Long Cycle Life

Cumulative composite damage in composite pressure vessels (CPVs) currently is not monitored on-orbit. Consequently, hazards due to catastrophic burst before leak (BBL) or compromised CPV reliability cannot be ascertained or mitigated, posing a risk to crew and mission assurance. The energy associated with CPV rupture can be significant, especially with high pressure gases are under containment, and the energy releases can be severe enough to cause injury, death, loss of assets or mission. Dual-Use Rationale: CPVs similar to those used by NASA on ISS, for example, are finding increasing use in automotive and transportation industry applications. These CPVs generally have a nonload sharing liner and are repeatedly filled over their service lifetime, typically with hydrogen or compressed natural gas (CNG). The same structural health monitoring equipment and software developed by NASA WSTF for evaluating, in real-time, the health of NASA CPVs on ISS will be used to evaluate the health of automotive CPVs, the only differences being the type and design of the CPV, and the in-service lifetime pressure histories. HSF Need(s)/Performance Characteristic(s) Supported: 1) Enable on-board vehicle systems management for mission critical functions at destinations with > 3 second time delay 2) Enable autonomous nominal operations and FDIR for crewed and un-crewed systems 3) Reduce on-board crew time to sustain and manage vehicle by factor of 2x at destinations with > 6 second time delay (see Crew Autonomy sheet) 4) Reduce earth-based mission ops "back room engineering" requirements for distant mission support delay (see Mission Autonomy sheet)

Waller, Jess↗

High energy, long cycle life electrode for lithium-ion batteries

Anodes for electrochemical cells and batteries are described herein. In particular, and anode comprises silicon oxide particles on a transition metal current collector (e.g., copper, nickel, copper alloy, and the like), wherein the particles comprise nanocrystalline domains of silicon dispersed within a silicon oxide matrix. The particles do not include a metal oxide coating, and are produced by heating a silicon monoxide powder at a temperature in the range of about 400 to about 1100° C. under an inert atmosphere for about 2 to about 20 hours. In some embodiments, the particles are free from a metal oxide coating and have an average diameter of about 20 to 10000 nm; the nanocrystalline domains of silicon comprise about 10 to about 90 mole percent of the particles; and the nanocrystalline domains have dimensions of about 0.2 to about 50 nm in average diameter.

25 ENERGY STORAGE↗

Electrodes with silicon oxide active materials for lithium ion cells achieving high capacity, high energy density and long cycle life performance

Improved negative electrodes can comprise a silicon based active material blended with graphite to provide more stable cycling at high energy densities. In some embodiments, the negative electrodes comprise a blend of polyimide binder mixed with a more elastic polymer binder with a nanoscale carbon conductive additive. The silicon-based blended graphite negative electrodes can be matched with positive electrodes comprising nickel rich lithium nickel manganese cobalt oxides to form high energy density cells with good cycling properties.

Venkatachalam, Subramanian↗

Electrodes with silicon oxide active materials for lithium ion cells achieving high capacity, high energy density and long cycle life performance

Improved negative electrodes can comprise a silicon based active material blended with graphite to provide more stable cycling at high energy densities. In some embodiments, the negative electrodes comprise a blend of polyimide binder mixed with a more elastic polymer binder with a nanoscale carbon conductive additive. The silicon-based blended graphite negative electrodes can be matched with positive electrodes comprising nickel rich lithium nickel manganese cobalt oxides to form high energy density cells with good cycling properties.

Venkatachalam, Subramanian↗

Lithium ion cells with high performance electrolyte and silicon oxide active materials achieving very long cycle life performance

Improved negative electrodes can comprise a silicon based active material blended with graphite to provide more stable cycling at high energy densities. In some embodiments, the negative electrodes comprise a blend of polyimide binder mixed with a more elastic polymer binder with a nanoscale carbon conductive additive. Electrolytes have been formulated that provide for extended cycling of cells incorporating a mixture of a silicon-oxide based active material with graphite active material in negative electrodes that can be matched with positive electrodes comprising nickel rich lithium nickel manganese cobalt oxides to cells with unprecedented cycling properties for large capacity cell based on a silicon negative electrode active material.

Dong, Yingnan↗

Chemical bonding technology for terrestrial photovoltaic modules

Encapsulated photovoltaic modules must hold together for 20 years, reliably resisting delamination and separation of any of the component materials. Delamination of encapsulation materials from each other, or from solar cells and interconnects, can create voids for accumulation of water, promoting corrosive failure. Delamination of silicone elastomers from unprimed surfaces was a common occurrence with early modules, but the incidences of silicone delamination with later modules decreased when adhesion promoters recommended by silicone manufacturers were used. An investigation of silicone delamination from unprimed surfaces successfully identified the mechanism, which was related to atmospheric oxygen and moisture. This early finding indicated that reliance on physical bonding of encapsulation interfaces for long life in an outdoor environment would be risky. For long outdoor life, the material components of a module must therefore be held together by weather-stable adhesion promoters that desirably form strong, interfacial chemical bonds.

Coulter, D. R.↗

A Self‐Healing Chemistry‐Enabled Organic Cathode for Sustainable and Stable Sodium‐Ion Batteries

Sodium‐on batteries (SIBs) are promising alternatives to lithium‐ion batteries (LIBs) because of the low cost, abundance, and high sustainability of sodium resources. Analogous to LIBs, the high‐capacity electrodes in SIBs always suffer from rapid capacity decay upon long‐term cycling due to the particle pulverization induced by a large volume change. Circumventing particle pulverization plays a critical role in developing high‐energy and long‐life SIBs. Herein, tetrahydroxy‐1,4‐benzoquinone disodium salt (TBDS) that can self‐heal the cracks by hydrogen bonding between hydroxyl group and carbonyl group is employed as a cathode for sustainable and stable SIBs. The self‐healing TBDS exhibits long cycle life of 1000 cycles with a high rate capability up to 2 A g −1 due to the fast Na‐ion diffusion reaction in the TBDS cathode. The intermolecular hydrogen bonding has been comprehensively characterized to understand the self‐healing mechanism. The hydrogen bonding‐enabled self‐healing organic materials are promising for developing high‐energy and long‐cycle‐life SIBs.

25 ENERGY STORAGE↗

Capillary priming characteristics of a dual passage heat pipe in zero-g

Technical improvements of a long life heat rejection system, suitable for long duration high power missions, that can be constructed and deployed in orbit is discussed. A mathematical model is formulated and a computer program developed which describes the transient priming characteristics of a dual passage heat pipe. An experimental test package is described for flight in the KC-135 Zero-g Aircraft, to be used to verify the modeling predictions.

Peterson, G. P.↗

High Efficiency, 100 mJ per pulse, Nd:YAG Oscillator Optimized for Space-Based Earth and Planetary Remote Sensing

We report on a newly solid state laser transmitter, designed and packaged for Earth and planetary space-based remote sensing applications for high efficiency, low part count, high pulse energy scalability/stability, and long life. Finally, we have completed a long term operational test which surpassed 2 Billion pulses with no measured decay in pulse energy.

Remote Sensing↗

A Potential Venera-D Element: SAEVe (Seismic and Atmospheric Exploration of Venus)

The Seismic and Atmospheric Exploration of Venus (SAEVe) mission concept study developed a long duration Venus lander concept that addressed high priority Venus science that includes seismology as well and long duration atmospheric measurements. SAEVe is a compact lander concept based on LLISSE (Long-Life In-situ Solar System Explorer) developments and capability.

Venus↗

High Reliability, High Mix, Ultralow Volume Surface Mount Technology for Space Applications

For the past two years, JPL has been working to introduce surface mount technology (SMT) for high reliability space applications. The thrust has centered around four research and development projects, the aim of which is to facilitate the use of SMT for designing, producing, inspecting, and quantifying surface mount printed wiring assemblies for ultralow volume, long life space applications. This paper explores the current approach being pursued at JPL and some of the problems peculiar to applying SMT to spacecraft applications.

volume long life↗