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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 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
NASA NTRS2019

Advanced Cryogenic Insulation Systems

New materials in recent decades have enabled advances in thermal insulation systems for storage and transfer of cryogens. To preserve the cold and achieve efficient cryogenic systems, a combination of materials, testing, and engineering is required. The total heat leak into any cryogenic assembly is comprised of three main parts: 1) heat leak through the insulation, 2) heat leak through the support structures, and 3) heat leak attributed to piping penetrations and feedthroughs (and their negative effects on the insulation). This "cold triangle" approach provides a basis for evaluating performance benefits of new materials and analyzing the cost effectiveness in overall system design. Provided are thermophysical data for aerogels, aerogel composites, novel multilayered composites, and glass bubbles for standard test conditions of 293 K and 78 K under conditions from high vacuum to ambient pressure. Examples of cryogenic storage tanks show the relative importance of both insulation and structural materials for achieving designs of highest energy efficiency.

Multilayer Insulation↗
NASA NTRS1993

Cryogenic optical systems and instruments V; Proceedings of the Meeting, San Diego, CA, July 23, 24, 1992

Topics discussed in this volume include cryogenic system design and optical technology; cryogenic instruments; cryogenic/IR mechanisms, testing, and performance; and space cryogenic dewars and coolers. Papers included are on the SIRTF cryooptics technology plan, the development of the SPIRIT III sensor, the design of a rapidly cooled cryogenic mirror, the cryogenic Michelson interferometer on the Space Shuttle, a reflective optical system for a hemispherical field radiometer, and infrared filters for cryogenic radiometers. Attention is also given to the development of a variable-profile scan mirror mechanism, a direct-drive digitally commutated filter wheel positioning system for cryogenic optical applications, a high-performance chopping secondary mirror for infrared astronomy, recent developments in compressor-based Joule-Thomson cooling, a radiative cryogenic cooler for the pressure modulator IR radiometer, and SIRTF thermal design modifications to increase lifetime.

Melugin, Ramsey K.↗
NASA NTRS1990

Cryogenic optical systems and instruments IV; Proceedings of the Meeting, San Diego, CA, July 10-12, 1990

Consideration is given to cryogenic system design and optical technology; cryogenic instruments, sensors, and detectors; space cryogenic dewars and coolers; and cryogenic mechanisms, testing, and structures. Particular attention is given to mission optimization of the Space Infrared Telescope Facility (SIRTF), alternative aperture stop position designs for SIRTF, scaling laws for lightweight optics, evaluation of a far-infrared Ge:Ga multiplexed detector array, cryogenic limb array etalon spectrometer calibration, reliability growth of coolers for advanced optical systems and instruments, flight-qualified solid argon cooler for the BBXRT instrument, precision mechanisms for optical alignments at cryogenic temperatures, versatile cryogenic rotary-positioning systems, and optical alignments of the Cosmic Background Explorer observatory.

Melugin, Ramsey K.↗
NASA NTRS1986

Cryogenic optical systems and instruments II; Proceedings of the Meeting, Los Angeles, CA, Jan. 23, 24, 1986

The topics of the present conference encompass cryogenic optical system design considerations, cryogenic instruments and their components, the design and performance of cryogenic dewars for space, and technologies supporting cryogenic systems and instruments. Attention is given to the Space IR Telescope Facility (SIRTF) observatory's design and on-orbit servicing, hardware development for the Gravity Probe-B program, the multiband imaging photometer aboard SIRTF, and the SIRTF wide field, diffraction-limited array camera. Also discussed are the cryogenic star-tracking telescope for Gravity Probe-B, a balloon-borne spectrometer for measurement of lower stratospheric trace constituents, the primary mirror support system design for a cryogenic space telescope, and the SQUID readout and ultralow magnetic fields of Gravity Probe-B.

Melugin, Ramsey K.↗
NASA NTRS1970

Low heat-gain cryogenic-liquid transfer system

Cryogenic-liquid transfer system, containing a ring structure with tensioned small diameter, high strength wires, provides adequate physical support for the piping, minimizes the conductive heat paths between the piping and jacket, and allows for thermal expansion and contraction of the piping.

Hows, G. E.↗
NASA NTRS2009

Gauging Systems Monitor Cryogenic Liquids

Rocket fuel needs to stay cool - super cool, in fact. The ability to store gas propellants like liquid hydrogen and oxygen at cryogenic temperatures (below -243 F) is crucial for space missions in order to reduce their volumes and allow their storage in smaller (and therefore, less costly) tanks. The Agency has used these cryogenic fluids for vehicle propellants, reactants, and life support systems since 1962 with the Centaur upper stage rocket, which was powered with liquid oxygen and liquid hydrogen. During proposed long-duration missions, super-cooled fluids will also be used in space power systems, spaceports, and lunar habitation systems. In the next generation of launch vehicles, gaseous propellants will be cooled to and stored for extended periods at even colder temperatures than currently employed via a process called densification. Densification sub-cools liquids to temperatures even closer to absolute zero (-459 F), increasing the fluid s density and shrinking its volume beyond common cryogenics. Sub-cooling cryogenic liquid hydrogen, for instance, from 20 K (-423 F) to 15 K (-432.4 F) reduces its mass by 10 percent. These densified liquid gases can provide more cost savings from reduced payload volume. In order to benefit from this cost savings, the Agency is working with private industry to prevent evaporation, leakage, and other inadvertent loss of liquids and gases in payloads - requiring new cryogenic systems to prevent 98 percent (or more) of boil-off loss. Boil-off occurs when cryogenic or densified liquids evaporate, and is a concern during launch pad holds. Accurate sensing of propellants aboard space vehicles is also critical for proper engine shutdown and re-ignition after launch, and zero boil-off fuel systems are also in development for the Altair lunar lander.

Source record↗
NASA NTRS2015

Real-Time Model-Based Leak-Through Detection within Cryogenic Flow Systems

The timely detection of leaks within cryogenic fuel replenishment systems is of significant importance to operators on account of the safety and economic impacts associated with material loss and operational inefficiencies. Associated loss in control of pressure also effects the stability and ability to control the phase of cryogenic fluids during replenishment operations. Current research dedicated to providing Prognostics and Health Management (PHM) coverage of such cryogenic replenishment systems has focused on the detection of leaks to atmosphere involving relatively simple model-based diagnostic approaches that, while effective, are unable to isolate the fault to specific piping system components. The authors have extended this research to focus on the detection of leaks through closed valves that are intended to isolate sections of the piping system from the flow and pressurization of cryogenic fluids. The described approach employs model-based detection of leak-through conditions based on correlations of pressure changes across isolation valves and attempts to isolate the faults to specific valves. Implementation of this capability is enabled by knowledge and information embedded in the domain model of the system. The approach has been used effectively to detect such leak-through faults during cryogenic operational testing at the Cryogenic Testbed at NASA's Kennedy Space Center.

Walker, M.↗
NASA NTRS1992

Large scale cryogenic fluid systems testing

NASA Lewis Research Center's Cryogenic Fluid Systems Branch (CFSB) within the Space Propulsion Technology Division (SPTD) has the ultimate goal of enabling the long term storage and in-space fueling/resupply operations for spacecraft and reusable vehicles in support of space exploration. Using analytical modeling, ground based testing, and on-orbit experimentation, the CFSB is studying three primary categories of fluid technology: storage, supply, and transfer. The CFSB is also investigating fluid handling, advanced instrumentation, and tank structures and materials. Ground based testing of large-scale systems is done using liquid hydrogen as a test fluid at the Cryogenic Propellant Tank Facility (K-site) at Lewis' Plum Brook Station in Sandusky, Ohio. A general overview of tests involving liquid transfer, thermal control, pressure control, and pressurization is given.

Source record↗
NASA NTRS1973

Shuttle cryogenic supply system optimization study. Volume 2: Technical report, sections 4 through 9

The design and development of cryogenic supply systems for space shuttle vehicles are discussed. The weights, component counts, and statements of advantages and disadvantages of the systems considered are presented. Performance characteristics of the systems are analyzed in the form of graphs. Block diagrams and engineering drawings of the candidate systems are provided. Special consideration is given to flow rates and thermodynamic properties of the cryogenic systems.

Source record↗
NASA NTRS1973

Shuttle cryogenic supply system optimization study. Volume 3: Technical report, section 10, 11 and 12

The evaluation of candidate cryogenic fuel systems for space shuttle vehicles is discussed. A set of guidelines was used to establish a matrix of possible combinations for the integration of potential cryogenic systems. The various concepts and combinations which resulted from the integration efforts are described. The parameters which were considered in developing the matrix are: (1) storage of cryogenic materials, (2) fuel lines, (3) tank pressure control, (4) thermal control, (5) fluid control, and (6) fluid conditioning. Block diagrams and drawings of the candidate systems are provided. Performance predictions for the systems are outlined in tables of data.

Source record↗
NASA NTRS1971

Shuttle cryogenic supply system optimization study

Technical information on different cryogenic supply systems is presented for selecting representative designs. Parametric data and sensitivity studies, and an evaluation of related technology status are included. An integrated mathematical model for hardware program support was developed. The life support system, power generation, and propellant supply are considered. The major study conclusions are the following: Optimum integrated systems tend towards maximizing liquid storage. Vacuum jacketing of tanks is a major effect on integrated systems. Subcritical storage advantages over supercritical storage decrease as the quantity of propellant or reactant decreases. Shuttle duty cycles are not severe. The operational mode has a significant effect on reliability. Components are available for most subsystem applications. Subsystems and components require a minimum amount of technology development.

Source record↗
NASA NTRS1999

Cryogenic Insulation System for Soft Vacuum

The development of a cryogenic insulation system for operation under soft vacuum is presented in this paper. Conventional insulation materials for cryogenic applications can be divided into three levels of thermal performance, in terms of apparent thermal conductivity [k-value in milliwatt per meter-kelvin (mW/m-K)]. System k-values below 0.1 can be achieved for multilayer insulation operating at a vacuum level below 1 x 10(exp -4) torr. For fiberglass or powder operating below 1 x 10(exp -3) torr, k-values of about 2 are obtained. For foam and other materials at ambient pressure, k-values around 30 are typical. New industry and aerospace applications require a versatile, robust, low-cost thermal insulation with performance in the intermediate range. The target for the new composite insulation system is a k-value below 4.8 mW/m-K (R-30) at a soft vacuum level (from 1 to 10 torr) and boundary temperatures of approximately 77 and 293 kelvin (K). Many combinations of radiation shields, spacers, and composite materials were tested from high vacuum to ambient pressure using cryostat boiloff methods. Significant improvement over conventional systems in the soft vacuum range was demonstrated. The new layered composite insulation system was also shown to provide key benefits for high vacuum applications as well.

Augustynowicz, S. D.↗