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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 19 records

Low Temperature Environment Operations of Turboengines (Design and User's Problems)

The author summarizes and links together a number of papers that were presented at the Propulsion and Energetics (PEP) symposium on low temperature environment operation of turbojet engines that was held October 8 to 12, 1990. Topics covered include operational experience of ice ingestion in the turboprop engine in the 2,000 hp class, icing on helicopter turbo engines, icing test facilities, ice relevant cloud physical parameters, and low temperature and fuel problems.

R Jacques↗

Spacecraft Charging in Low Temperature Environments

Spacecraft charging in plasma and radiation environments is a temperature dependent phenomenon due to the reduction of electrical conductivity in dielectric materials at low temperatures. Charging time constants are proportional to l/conductivity may become very large (on the order of days to years) at low temperatures and accumulation of charge densities in insulators in charging environments traditionally considered benign at ambient temperatures may be sufficient to produce charge densities and electric fields of concern in insulators at low temperatures. Low temperature charging is of interest because a number of spacecraft-primarily infrared astronomy and microwave cosmology observatories-are currently being design, built, and or operated at very cold temperatures on the order of 40K to 100K. This paper reviews the temperature dependence of spacecraft charging processes and material parameters important to charging as a function of temperature with an emphasis on low temperatures regimes.

Parker, Linda N.↗

Development of Electronics for Low-Temperature Space Missions

Electronic systems that are capable of operating at cryogenic temperatures will be needed for many future NASA space missions, including deep space probes and spacecraft for planetary surface exploration. In addition to being able to survive the harsh deep space environment, low-temperature electronics would help improve circuit performance, increase system efficiency, and reduce payload development and launch costs. Terrestrial applications where components and systems must operate in low-temperature environments include cryogenic instrumentation, superconducting magnetic energy storage, magnetic levitation transportation systems, and arctic exploration. An ongoing research and development project for the design, fabrication, and characterization of low-temperature electronics and supporting technologies at NASA Glenn Research Center focuses on efficient power systems capable of surviving in and exploiting the advantages of low-temperature environments. Supporting technologies include dielectric and insulating materials, semiconductor devices, passive power components, optoelectronic devices, and packaging and integration of the developed components into prototype flight hardware. An overview of the project is presented, including a description of the test facilities, a discussion of selected data from component testing, and a presentation of ongoing research activities being performed in collaboration with various organizations.

Patterson, Richard L.↗

Development of Electronics for Low Temperature Space Missions

The operation of electronic systems at cryogenic temperatures is anticipated for many future NASA space missions such as deep space probes and planetary surface exploration. For example, an unheated interplanetary probe launched to explore the rings of Saturn would reach an average temperature near Saturn of about -183 C. In addition to surviving the deep space harsh environment, electronics capable of low temperature operation would contribute to improving circuit performance, increasing system efficiency, and reducing payload development and launch costs. Terrestrial applications where components and systems must operate in low temperature environments include cryogenic instrumentation, superconducting magnetic energy storage, magnetic levitation transportation system, and arctic exploration. An on-going research and development program on low temperature electronics at the NASA Glenn Research Center focuses on the development of efficient power systems capable of surviving and exploiting the advantages of low temperature environments. Inhouse efforts include the design, fabrication, and characterization of low temperature power systems and the development of supporting technologies for low temperature operations, such as dielectric and insulating materials, semiconductor devices, passive power components, opto-electronic devices, as well as packaging and integration of the developed components into prototype flight hardware.

Patterson, Richard L.↗

Electronic Components and Systems for Cryogenic Space Applications

Electronic components and systems capable of operation at cryogenic temperatures are anticipated in many future NASA space missions such as deep space probes and planetary surface exploration. For example, an unheated interplanetary probe launched to explore the rings of Saturn would reach an average temperature near Saturn of about - 183 C. In addition to surviving the deep space harsh environment, electronics capable of low temperature operation would contribute to improving circuit performance, increasing system efficiency, and reducing payload development and launch costs. Terrestrial applications where components and systems must operate in low temperature environments include cryogenic instrumentation, superconducting magnetic energy storage, magnetic levitation transportation system, and arctic exploration. An on-going research and development program at the NASA Glenn Research Center focuses on the development of reliable electronic devices and efficient power systems capable of surviving in low temperature environments. An overview of the program will be presented in this paper. A description of the low temperature test facilities along with selected data obtained from in-house component testing will also be discussed. Ongoing research activities that are being performed in collaboration with various organizations will also be presented.

Patterson, R. L.↗

Stable Isotope Composition of Carbonates Formed in Low-Temperature Terrestrial Environments as Martian Analogs

We examine the carbon and oxygen isotope composition of carbonate minerals that formed in two low-temperature terrestrial environments. Field locations were chosen to represent environments where microcrystalline carbonates (caliches) form. Samples include caliche crusts collected from the tsekel zone of N. Yucatan, Mexico, as well as carbonate mud from the edge of a near-by salt pan, representing both ancient and modern-precipitated carbonates. Additional field samples of surface-coating caliche were collected from two volcanic fields in Arizona. Preliminary results indicate that there is an overall depletion of 18O and 13C as a function of the extent of meteoric diagenesis. These data are used as terrestrial analogs to gauge whether carbonates that have been found within Martian meteorites could possibly have formed under these or similar conditions on Mars.

Socki, Richard A.↗

Low-Temperature Power Electronics Program

Many space and some terrestrial applications would benefit from the availability of low-temperature electronics. Exploration missions to the outer planets, Earth-orbiting and deep-space probes, and communications satellites are examples of space applications which operate in low-temperature environments. Space probes deployed near Pluto must operate in temperatures as low as -229 C. Figure 1 depicts the average temperature of a space probe warmed by the sun for various locations throughout the solar system. Terrestrial applications where components and systems must operate in low-temperature environments include cryogenic instrumentation, superconducting magnetic energy storage, magnetic levitation transportation system, and arctic exploration. The development of electrical power systems capable of extremely low-temperature operation represents a key element of some advanced space power systems. The Low-Temperature Power Electronics Program at NASA Lewis Research Center focuses on the design, fabrication, and characterization of low-temperature power systems and the development of supporting technologies for low-temperature operations such as dielectric and insulating materials, power components, optoelectronic components, and packaging and integration of devices, components, and systems.

Patterson, Richard L.↗

Low-Temperature Electronic Components Being Developed

In many future NASA missions, such as deep space planetary exploration and the Next Generation Space Telescope, electrical components and systems must operate reliably and efficiently in extremely low temperature environments. Most modern electronic components cannot operate below moderately low operating temperatures (-40 to -55 C). The low-temperature electronics program at the NASA Lewis Research Center is focusing on the development and characterization of low-temperature components and the integration of the developed devices into demonstrable very low-temperature (-200 C) power systems such as dc-dc converters. Such low-temperature electronics will not only tolerate hostile environments but also will reduce system size and weight by eliminating radioisotope heating units, thereby reducing launch cost, improving reliability and lifetime, and increasing energy densities. Low-temperature electronic components will also have a great influence on terrestrial applications such as medical instrumentation, magnetic levitation transportation systems, and arctic and antarctic exploration. Lewis researchers are now performing extensive evaluations of commercially available as well as custom-made devices. These include various types of energy storage and signal capacitors, power switching devices, magnetic and superconducting materials, and primary lithium batteries, to name a few.

Patterson, Richard L.↗

Potential Uses of Deep Space Cooling for Exploration Missions

Nearly all exploration missions envisioned by NASA provide the capability to view deep space and thus to reject heat to a very low temperature environment. Environmental sink temperatures approach as low as 4 Kelvin providing a natural capability to support separation and heat rejection processes that would otherwise be power and hardware intensive in terrestrial applications. For example, radiative heat transfer can be harnessed to cryogenically remove atmospheric contaminants such as carbon dioxide (CO2). Long duration differential temperatures on sunlit versus shadowed sides of the vehicle could be used to drive thermoelectric power generation. Rejection of heat from cryogenic propellant could avoid temperature increase thus avoiding the need to vent propellants. These potential uses of deep space cooling will be addressed in this paper with the benefits and practical considerations of such approaches.

Chambliss, Joseph↗

Potential Uses of Deep Space Cooling for Exploration Missions

Nearly all exploration missions envisioned by NASA provide the capability to view deep space and thus to reject heat to a very low temperature environment. Environmental sink temperatures approach as low as 4 Kelvin providing a natural capability to support separation and heat rejection processes that would otherwise be power and hardware intensive in terrestrial applications. For example, radiative heat transfer can be harnessed to cryogenically remove atmospheric contaminants such as carbon dioxide (CO2). Long duration differential temperatures on sunlit versus shadowed sides of the vehicle could be used to drive thermoelectric power generation. Rejection of heat from cryogenic propellant could counter temperature increases thus avoiding the need to vent propellants. These potential uses of deep space cooling will be addressed in this paper with the benefits and practical considerations of such approaches.

Chambliss, Joe↗

Evaluation of a low-density polyimide foam in a dynamic, high temperature environment

A low density polyimide foam material was tested in an arc tunnel to determine its potential for heat shield application on aerospace vehicles. The results show that the material has some reuse potential at surface temperatures as high as 750 K. When a black refractory paint was applied to the surface of the material, the surface recession was negligible at 750 K. An analytical thermal conductivity was derived for this material which, combined with measured thermal property values, can be used to make preliminary design thickness calculations for heat shield applications.

Pittman, C. M.↗

Electronic Components and Circuits for Extreme Temperature Environments

Planetary exploration missions and deep space probes require electrical power management and control systems that are capable of efficient and reliable operation in very low temperature environments. Presently, spacecraft operating in the cold environment of deep space carry a large number of radioisotope heating units in order to maintain the surrounding temperature of the on-board electronics at approximately 20 C. Electronics capable of operation at cryogenic temperatures will not only tolerate the hostile environment of deep space but also reduce system size and weight by eliminating or reducing the radioisotope heating units and their associate structures; thereby reducing system development as well as launch costs. In addition, power electronic circuits designed for operation at low temperatures are expected to result in more efficient systems than those at room temperature. This improvement results from better behavior and tolerance in the electrical and thermal properties of semiconductor and dielectric materials at low temperatures. The Low Temperature Electronics Program at the NASA Glenn Research Center focuses on research and development of electrical components, circuits, and systems suitable for applications in the aerospace environment and deep space exploration missions. Research is being conducted on devices and systems for reliable use down to cryogenic temperatures. Some of the commercial-off-the-shelf as well as developed components that are being characterized include switching devices, resistors, magnetics, and capacitors. Semiconductor devices and integrated circuits including digital-to-analog and analog-to-digital converters, DC/DC converters, operational amplifiers, and oscillators are also being investigated for potential use in low temperature applications. An overview of the NASA Glenn Research Center Low Temperature Electronic Program will be presented in this paper. A description of the low temperature test facilities along with selected data obtained through in-house component and circuit testing will also be discussed. Ongoing research activities that are being performed in collaboration with various organizations will also be presented.

Patterson, Richard L.↗

Electrical Devices and Circuits for Low Temperature Space Applications

The environmental temperature in many NASA missions, such as deep space probes and outer planetary exploration, is significantly below the range for which conventional commercial-off-the-shelf electronics is designed. Presently, spacecraft operating in the cold environment of such deep space missions carry a large number of radioisotope or other heating units in order to maintain the surrounding temperature of the on-board electronics at approximately 20 C. Electronic devices and circuits capable of operation at cryogenic temperatures will not only tolerate the harsh environment of deep space but also will reduce system size and weight by eliminating or reducing the heating units and their associate structures; thereby reducing system development cost as well as launch costs. In addition, power electronic circuits designed for operation at low temperatures are expected to result in more efficient systems than those at room temperature. This improvement results from better behavior in the electrical and thermal properties of some semiconductor and dielectric materials at low temperatures. An on-going research and development program on low temperature electronics at the NASA Glenn Research Center focuses on the development of efficient electrical systems and circuits capable of surviving and exploiting the advantages of low temperature environments. An overview of the program will be presented in this paper. A description of the low temperature test facilities along with selected data obtained from in-house component testing will also be discussed. On-going research activities that are being performed in collaboration with various organizations will also be presented.

Patterson, R. L.↗

A thin film strain transducer

A device has been developed for the purpose of measuring longitudinal strain in thin polyethylene films. This paper describes the design, development, calibration, and application of this unique transducer in a variety of low temperature environments. This thin, ring-shaped device has a low effective modulus so as not to interfere with the strain that would naturally occur in a thin film. It has a standard 350 ohm impedance which is compatible with most available bridge balance, amplification, and telemetry instrumentation. This transducer has been successfully used for viscoelastic material characterization experiments in the laboratory, as well as in flight measurements of strain on the surface of scientific balloons during inflation, launch, ascent, and float.

Rand, J. L.↗

Pressure measurement at low temperatures

The present discussion centers on the following topics: (1) what types of pressure transducers show good potential for cryogenic use; (2) what are the output characteristics (stability, sensitivity, etc.) of a transducer when subjected to low temperature environments; and (3) are methods or apparatus available to calibrate cryogenically pressure transducers under static and dynamic conditions. Some information is available on the low-temperature performance of relatively few pressure transducer types; however, the information is either in the form of manufacturing specifications or unpublished reports. The results of this study clearly indicate that individual transducers, even from the same manufacturer, can exhibit totally different characteristics when subjected to identical cryogenic test procedures. This indicates the necessity of calibrating each transducer for use at low temperature. Also included in the discussion is the description of a static/dynamic low-temperature pressure transducer calibration facility, which is currently being developed.

Arvidson, J. M.↗

Plant Adaptation to Cold. 1: Chlorophyll. 2: Minerals

A number of montane herbs in northern Utah typically form flower buds beneath the snow cover and flower either through it or immediately after its recession. Two of these species, one naturally occurring, Claytonia lanceolata, and one cultivated bulb, Galanthus nivalis, were investigated for their response to this stress environment. Snow depth patterns, chlorophyll content of tissues, and plants grown in light-tight boxes, suggest that light passing through the snow to reach plants growing underneath is not critically involved in the timing of their developmental cycles or in their ability to endure this low temperature environment. Ability to endure stress seems to be closely related in a number of ways to activity at the plant membranes. Plants were protected from low temperature damage by application of cytokinin or calcium, both of which probably acted at the membrane. Potassium calcium antagonisms were reflected in the internal distribution of the ions under natural stress conditions; and plants that differentiated at the meristem while growing through the snow accumulated calcium at the tip during this growth.

Rosen, P.↗

Advanced Avionics and Processor Systems for a Flexible Space Exploration Architecture

The Advanced Avionics and Processor Systems (AAPS) project, formerly known as the Radiation Hardened Electronics for Space Environments (RHESE) project, endeavors to develop advanced avionic and processor technologies anticipated to be used by NASA s currently evolving space exploration architectures. The AAPS project is a part of the Exploration Technology Development Program, which funds an entire suite of technologies that are aimed at enabling NASA s ability to explore beyond low earth orbit. NASA s Marshall Space Flight Center (MSFC) manages the AAPS project. AAPS uses a broad-scoped approach to developing avionic and processor systems. Investment areas include advanced electronic designs and technologies capable of providing environmental hardness, reconfigurable computing techniques, software tools for radiation effects assessment, and radiation environment modeling tools. Near-term emphasis within the multiple AAPS tasks focuses on developing prototype components using semiconductor processes and materials (such as Silicon-Germanium (SiGe)) to enhance a device s tolerance to radiation events and low temperature environments. As the SiGe technology will culminate in a delivered prototype this fiscal year, the project emphasis shifts its focus to developing low-power, high efficiency total processor hardening techniques. In addition to processor development, the project endeavors to demonstrate techniques applicable to reconfigurable computing and partially reconfigurable Field Programmable Gate Arrays (FPGAs). This capability enables avionic architectures the ability to develop FPGA-based, radiation tolerant processor boards that can serve in multiple physical locations throughout the spacecraft and perform multiple functions during the course of the mission. The individual tasks that comprise AAPS are diverse, yet united in the common endeavor to develop electronics capable of operating within the harsh environment of space. Specifically, the AAPS tasks for the Federal fiscal year of 2010 are: Silicon-Germanium (SiGe) Integrated Electronics for Extreme Environments, Modeling of Radiation Effects on Electronics, Radiation Hardened High Performance Processors (HPP), and and Reconfigurable Computing.

Keys, Andrew S.↗