SEARCH · Engineering Papers

Results for “capacity test”

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.

SourceResearch connectionFrom yearThrough year

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

At least 469 records · Page 26

All sources NASA NTRS DOE OSTI

NASA NTRSDate not supplied

Characterization Testing of a 20 Kelvin Cryocooler for Space Applications

Future NASA space exploration missions will require long-duration storage and liquefaction of cryogenic liquids, enabled by active cooling provided by cryocoolers. Recent gap analyses of Lunar and Mars transportation systems have identified 20 K-class cryocoolers as a critical enabling technology for chemical and nuclear thermal propulsion architectures using liquid hydrogen propellant. To address this technology gap, NASA has undergone the development of a high-efficiency, high-capacity 20 K cryocooler via an SBIR partnership with Creare. While the January 2025 testing demonstrated functionality and compliance with contractual requirements, the objective of the NASA-led characterization effort was to generate a dataset for supporting future mission designs across a broader operating envelope, including off-nominal conditions. The cryocooler demonstrated strong performance, achieving a peak coefficient of performance of 17.68% relative to Carnot efficiency and a maximum lift capacity of 24.4 W at 21 K. Overall, the results confirm that the 20 W 20 K cryocooler provides a flexible range of capabilities to enable zero boil-off storage of liquid hydrogen for future Lunar and Mars missions. The data collected provide a strong foundation for model validation and future system design efforts.

Cryocooler↗

NASA NTRSDate not supplied

Characterization Testing of a 20 Kelvin Cryocooler for Space Applications

Zero boil-off↗

NASA NTRS1983

Load deflection characteristics of inflated structures

A single, closed form relationship to relate load to the deformed dimensions of the horizontal torus was developed. Wall elasticity was included in the analysis, and special care was taken to predict the final footprint area of the loaded structure. The test fixture utilized is shown. The tori used for the bulk of the testing were rubber inner tubes for a 32 and 160 pneumatic tire. The inner tube being tested was plumbed, to a mercury-filled manometer, which had a 50 inch measurement capacity, by use of a special adapter. The adapter fit over the valve stem and allowed air to be added from a shop-air source and to be bled through the standard valve mechanism. In this fashion, tests requiring the maintenance of a constant indication of air pressure could be run with little difficulty.

Baumgarten, J. R.↗

NASA NTRS1978

Measurement of the time-temperature dependent dynamic mechanical properties of boron/aluminum composites

A relatively simple flexural vibration test is developed for accurate measurement of the low-strain dynamic modulus and damping capacity of B/Al composite bar specimens from -200 C to over 500 C. The specimens are prepared from 8-ply unidirectional panels containing 50 volume percent fibers composed of 203-micron commercial boron-on-tungsten fibers. The basic test technique consists of the forced flexural vibration of the composite bar specimens at their two lowest free-free symmetrical resonant modes in a high-vacuum cryostat furnace. Specimen damping is determined from oscilloscope photographs of the free decay obtained after simultaneously removing the resonant drive signal and grounding the vibration-drive electrode. The availability of time-temperature dynamic data coupled with the predictive accuracy of composite theory suggests a future potential for using such data in examining environmental effects on composite macrostructure and microstructure.

Dicarlo, J. A.↗

NASA NTRS1984

Long life nickel electrodes for a nickel-hydrogen cell. III - Results of an accelerated test and failure analyses

Nineteen different designs of nickel electrodes were tested in Ni/H2 boiler plate cells in an accelerated low earth orbit cycle regime to the end of their life. The failure analyses of these cells showed that the major performance changes due to the cycling was a severe reduction of their high rate discharge capability rather than an absolute capacity reduction. Many physical changes of the nickel electrodes were observed after the cycling test. These changes include dimensional expansion, sinter rupture, loose black powdering of the active material, morphology changes, active material migration, increase of pore volume, change of pore distribution, and increase of surface area. All of these were caused by active material expansion with cycling. Among these changes, the morphology change which involves migration of active material away from the current collecting nickel sinter appears to be that most responsible for the reduction of the rate capability.

Lim, H. S.↗

NASA NTRS1974

Vegetation density as deduced from ERTS-1 MSS response

Reflectance from vegetation increases with increasing vegetation density in the 0.75- to 1.35 micron wavelength interval. Therefore, ERTS-1 bands 6 (0.7 to 0.8 micron) and 7 (0.8 to 1.1 micron) contain information that should relate to the probable yield of crops and the animal carrying capacity of rangeland. The results of an experiment designed specifically to test the relations among leaf area index (LAI), plant population, plant cover and plant height, and the ERTS-1 MSS responses for 3 corn, 10 sorghum, and 10 cotton fields are given. Plant population was as useful as LAI for characterizing the sorghum and corn fields, and plant height was as good as LAI for characterizing cotton fields. These findings generally support the utility of ERTS-1 data for explaining variability in green biomass, harvestable forage and other indicators of productivity.

Wiegand, C. L.↗

NASA NTRS1978

Performance investigations of liquid-metal heat pipes for space and terrestrial applications

The high heat transfer capacity of liquid-metal heat pipes is demonstrated in performance tests with mercury, potassium, sodium, and lithium working fluids and wick structures which serve to minimize liquid pressure losses and vapor/liquid interactions. Appropriate wicks for horizontal and vertical operation are described. It is shown that heat-transfer with these wicks is limited by vapor flow effects. Examples are given of particular effects associated with a long adiabatic section between evaporator and condenser and with a heat source of uniform temperature as opposed to a source of uniform power.

Kemme, J. E.↗

NASA NTRS1984

A high voltage electrical power system for low Earth orbit applications

The results of testing a high voltage electrical power system (EPS) breadboard using high voltage power processing equipment developed at Marshall Space Flight Center and Ni-Cd batteries are discussed. These test results are used to extrapolate to an efficient, reliable, high capacity EPS for near term low Earth orbit, high power applications. EPS efficiencies, figures of merit, and battery reliability with a battery protection and reconditioning circuit are presented.

Lanier, J. R., Jr.↗

NASA NTRS1984

Sensitivity of thermal inertia calculations to variations in environmental factors

The sensitivity of thermal inertia (TI) calculations to errors in the measurement or parameterization of a number of environmental factors is considered here. The factors include effects of radiative transfer in the atmosphere, surface albedo and emissivity, variations in surface turbulent heat flux density, cloud cover, vegetative cover, and topography. The error analysis is based upon data from the Heat Capacity Mapping Mission (HCMM) satellite for July 1978 at three separate test sites in the deserts of the western United States. Results show that typical errors in atmospheric radiative transfer, cloud cover, and vegetative cover can individually cause root-mean-square (RMS) errors of about 10 percent (with atmospheric effects sometimes as large as 30-40 percent) in HCMM-derived thermal inertia images of 20,000-200,000 pixels.

Kahle, A. B.↗

NASA NTRS1986

Parametric and cycle tests of a 40-AH bipolar nickel-hydrogen battery

The performance of a 12 V, 40 ampere-hour bipolar battery during various charge current, discharge current, temperature, and pressure operating conditions is investigated. The cell voltages, temperatures, ampere-hours, and watt-hours derived from the charge/discharge cycle tests are studied. Consideration is given to battery voltage and discharge capacity as a function of discharge current, the correlation between energy delivered on a discharge and battery temperature, battery voltage response to pulse discharges, and the voltage-temperature relationship. The data reveal that the bipolar Ni-H battery is applicable to high power systems.

Cataldo, R. L.↗

NASA NTRS1991

Performance characteristics of lithium primary cells after controlled storage

A program was initiated to investigate the effects of storage on the performance of lithium primary cells. Two types of liquid cathode cells were chosen to investigate these effects. The cell types included Li-SOCl2/BCX cells, Li-SO2 cells from two different manufacturers, and a small sample size of 8-year-old Li-SO2 cells. The following measurements are performed at each test interval: open circuit voltage, resistance and weight, microcalorimetry, ac impedance, capacity, and voltage delay. The authors examine the performance characteristics of these cells after one year of controlled storage at two temperatures (10 and 30 C). The Li-SO2 cells experienced little to no voltage and capacity degradation after one year storage. The Li-SOCl2/BCX cells exhibited significant voltage and capacity degradation after 30 C storage. Predischarging shortly prior to use appears to be an effective method of reducing the initial voltage drop. Studies are in progress to correlate ac impedance and microcalorimetry measurements with capacity losses and voltage delay.

Deligiannis, F.↗

NASA NTRS1991

Performance of low resistance microchannel plate stacks

Results are presented from an evaluation of three sets of low resistance microchannel plate (MCP) stacks; the tests encompassed gain, pulse-height distribution, background rate, event rate capacity as a function of illuminated area, and performance changes due to high temperature bakeout and high flux UV scrub. The MCPs are found to heat up, requiring from minutes to hours to reach stabilization. The event rate is strongly dependent on the size of the area being illuminated, with larger areas experiencing a gain drop onset at lower rates than smaller areas.

Siegmund, O. H. W.↗

NASA NTRS1993

A lunar/Martian anchor emplacement system

On the Moon or Mars, it is necessary to have an anchor, or a stable, fixed point able to support the forces necessary to rescue a stuck vehicle, act as a stake for a tent in a Martian gale, act as a fulcrum in the erection of general construction poles, or support tent-like regolith shields. The anchor emplacement system must be highly autonomous. It must supply the energy and stability for anchor deployment. The goal of the anchor emplacement system project is to design and build a prototype anchor and to design a conceptual anchor emplacement system. Various anchors were tested in a 1.3 cubic meter test bed containing decomposed granite. A simulated lunar soil was created by adjusting the moisture and compaction characteristics of the soil. We conducted tests on emplacement torque, amount of force the anchor could withstand before failure, anchor pull out force at various angles, and soil disturbances caused by placing the anchor. A single helix auger anchor performed best in this test bed based on energy to emplace, and the ultimate holding capacity. The anchor was optimized for ultimate holding capacity, minimum emplacement torque, and minimum soil disturbance in sandy soils yielding the following dimensions: helix diameter (4.45 cm), pitch (1.27 cm), blade thickness (0.15 cm), total length (35.56 cm), shaft diameter (0.78 cm), and a weight of 212.62 g. The experimental results showed that smaller diameter, single-helix augers held more force than larger diameter augers for a given depth. The emplacement system consists of a flywheel and a motor for power, sealed in a protective box supported by four legs. The flywheel system was chosen over a gear system based on its increased reliability in the lunar environment.

Clinton, Dustin↗

NASA NTRS1997

Behavior of 2-Cell CPV Ni-H2 Battery During Pulse Discharge

A study was carried out to determine the transient voltage behavior of the 2-cell CPV nickel-hydrogen battery with the objective of using the results as a basis for mathematical modeling. The 2-cell CPV battery which is manufactured by Eagle Picher, Inc. for the GOES program yields 18.5 Ah at C/2 rate of discharge at 10 C with a mid-discharge voltage of 2.514 V. The capacity increased with decrease of temperature and a maximum capacity of 22 Ah was obtained at -5 C. The pulse tests consisted of obtaining the voltage profile in the first 20 milliseconds of the one minute pulse discharge at 37 A and pulse discharge was repeated as a function of state- of- charge. The pulse test at 10 C and 20 C provided voltage profiles with the expected decrease in voltage as the pulse was applied. The end of pulse voltage decreased with the state-of-charge. The battery voltage was above 2V at the end of the one-minute pulse at 8 % state-of-charge at 10 C. The voltage profile during the 37 A pulse discharge consists of an initial drop in voltage which was independent of the state of charge. The invariability in the value for the initial drop in voltage with state of charge is a very important observation. The results show that towards the end of discharge the dominant resistance is not ohmic in nature. It could be hypothesized from the nature of the voltage transients that the dominant mechanism towards the end of discharge is proton diffusion. The study also shows that the dominant resistance in the voltage plateau during discharge is activation polarization.

Vaidyanathan, Hari↗

NASA NTRS1998

Behavior of 2-Cell CPV Ni-H2 Battery During Pulse Discharge

A study was carried out to determine the transient voltage behavior of the 2-cell CPV nickel-hydrogen battery with the objective of using the results as a basis for mathematical modeling. The 2-cell CPV battery which is manufactured by Eagle Picher, Inc. for the GOES program yields 18.5 Ah at C/2 rate of discharge at 10 C with a mid-discharge voltage of 2.514 V. The capacity increased with decrease of temperature and a maximum capacity of 22 Ah was obtained at -5 C. The pulse tests consisted of obtaining the voltage profile in the first 20 milliseconds of the one minute pulse discharge at 37 A and pulse discharge was repeated as a function of state-of-charge. The pulse test at 10 C and 20 C provided voltage profiles with the expected decrease in voltage as the pulse was applied. The end of pulse voltage decreased with the state-of-charge. The battery voltage was above 2V at the end of the one-minute pulse at 8 % state-of-charge at 10 C. The voltage profile during the 37 A pulse discharge consists of an initial drop in voltage which was independent of the state of charge. The invariability in the value for the initial drop in voltage with state of charge is a very important observation. The results show that towards the end of discharge the dominant resistance is not ohmic in nature. It could be hypothesized from the nature of the voltage transients that the dominant mechanism towards the end of discharge is proton diffusion. The study also shows that the dominant resistance in the voltage plateau during discharge is activation polarization.

Vaidyanathan, Hari↗

NASA NTRS1999

International Ultraviolet Explorer (IUE) Battery History and Performance

The "International Ultraviolet Explorer (IUE) Battery History and Performance" report provides the information on the cell/battery design, battery performance during the thirty eight (38) solar eclipse seasons and the end-of-life test data. It is noteworthy that IUE spacecraft was an in-house project and that the batteries were designed, fabricated and tested (Qualification and Acceptance) at the Goddard Space Flight Center. A detailed information is given on the cell and battery design criteria and the designs, on the Qualification and the Acceptance tests, and on the cell life cycling tests. The environmental, thermal, and vibration tests were performed on the batteries at the battery level as well as with the interface on the spacecraft. The telemetry data were acquired, analyzed, and trended for various parameters over the mission life. Rigorous and diligent battery management programs were developed and implemented from time to time to extend the mission life over eighteen plus years. Prior to the termination of spacecraft operation, special tests were conducted to check the battery switching operation, battery residual capacity, third electrode performance and battery impedance.

Rao, Gopalskrishna M.↗

NASA NTRS1997

Behavior of 2 Cell CPV NI-H2 Battery During Pulse Discharge

A study was carried out to determine the transient voltage behavior of the 2-cell CPV nickel-hydrogen battery with the objective of using the results as a basis for mathematical modeling. The 2-cell CPV battery which is manufactured by Eagle Picher, Inc. for the GOES program yields 18.5 Ah at C/2 rate of discharge at 10 C with a mid-discharge voltage of 2.514 V. The capacity increased with decrease of temperature and a maximum capacity of 22 Ah was obtained at - 5 C. The pulse test consisted of obtaining the voltage profile in the first 20 milliseconds of the one minute pulse discharge at 37 A and pulse discharge was repeated as a function of state-of-charge. The pulse test at 10 C and 20 C provided voltage profiles with the expected decrease in voltage as the pulse was applied. The end of pulse voltage decreased with the state-of-charge. The battery voltage was above 2V at the end of the one-minute pulse at 12% state-of-charge at 10 C. The voltage profile during the 37 A pulse discharge consists of an initial drop in voltage which was independent of the state of charge. The invariability in the value for the initial drop in voltage with state of charge is a very important observation and indicates that towards the end of discharge the dominant resistance is not ohmic in nature. It could be hypothesized from the nature of the voltage transients that the dominant mechanism towards the end of discharge is proton diffusion. The study also shows that the dominant resistance in the voltage plateau during discharge is activation polarization.

Gopalakrishna, M. Rao↗

NASA NTRS2000

Performance Characteristics of Lithium Ion Prototype Cells for 2003 Mars Sample Return Athena Rover

A viewgraph presentation outlines the mission objectives and power subsystem for the Mars Sample Return (MSR) Athena Rover. The NASA-DOD (depth of discharge) Interagency Li Ion program objectives are discussed. Evaluation tests performed at JPL are listed, and test results are shown for the Li-Ion cell initial capacity, charge/discharge capacity, voltage and ratio, specific energy, watt-hour efficiency, and cell voltage at various temperatures.

Ratnakumar, B. V.↗