Experimental measurements of electrical discharges caused by corona, glow discharges, and voltage breakdown were made under conditions encountered in aerospace vehicles operating within the 70,000 to 250,000 foot altitude range. All measurements were made in gases commonly used to pressurize spacecraft electrical and electronic compartments: nitrogen, nitrogenoxygen mixtures, and normal atmosphere at sea-level pressure. Test results show that: (1) the onset voltage at which the electrical discharge occurred is much lower for spaced wires than for bundled or twisted wires; (2) the onset voltage between wires increases as the insulation thickness and dielectric constant are increased and decreases as the wire diameter and wire spacing are increased; and (3) that the onset voltage of components depends on the type of component and its connection and installation.
{"title":"Electrical Discharges at Altitudes between 70,000 and 250,000 Feet","authors":"W. Dunbar","doi":"10.1109/TA.1965.4319807","DOIUrl":"https://doi.org/10.1109/TA.1965.4319807","url":null,"abstract":"Experimental measurements of electrical discharges caused by corona, glow discharges, and voltage breakdown were made under conditions encountered in aerospace vehicles operating within the 70,000 to 250,000 foot altitude range. All measurements were made in gases commonly used to pressurize spacecraft electrical and electronic compartments: nitrogen, nitrogenoxygen mixtures, and normal atmosphere at sea-level pressure. Test results show that: (1) the onset voltage at which the electrical discharge occurred is much lower for spaced wires than for bundled or twisted wires; (2) the onset voltage between wires increases as the insulation thickness and dielectric constant are increased and decreases as the wire diameter and wire spacing are increased; and (3) that the onset voltage of components depends on the type of component and its connection and installation.","PeriodicalId":13050,"journal":{"name":"IEEE Transactions on Aerospace","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1965-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74066632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A technique has been developed for the determination of heat-shield sublimation (char) and surface recession (ablation) during an atmospheric reentry. A radioactive "line" source embedded in the heat-shield material sublimes and ablates at the same rate as the heat shield. Decreases in source activity are monitored by miniaturized nuclear counters. Accuracies exceeding 90 percent are obtainable. The technique provides a continuous indication of char and ablation rates.
{"title":"Heat-Shield Ablation and Sublimation Determinations through Radioisotope Techniques","authors":"G. W. Brandon, W. G. Davis","doi":"10.1109/TA.1965.4319813","DOIUrl":"https://doi.org/10.1109/TA.1965.4319813","url":null,"abstract":"A technique has been developed for the determination of heat-shield sublimation (char) and surface recession (ablation) during an atmospheric reentry. A radioactive \"line\" source embedded in the heat-shield material sublimes and ablates at the same rate as the heat shield. Decreases in source activity are monitored by miniaturized nuclear counters. Accuracies exceeding 90 percent are obtainable. The technique provides a continuous indication of char and ablation rates.","PeriodicalId":13050,"journal":{"name":"IEEE Transactions on Aerospace","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1965-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73954850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Conductor materials for aerospace application should have low resistivity, low density, high strength, and ductility over the temperature range of application. Our work on the development of such materials has shown that the three most promising high-temperature conductors covering both oxidizing and nonoxidizing environments are zone-refined rhodium (< 1600°C), dispersion-hardened platinum (< 1500°C), and dispersion-hardened gold (< 900°C). Methods of producing and fabricating these high-temperature conductors are presented, together with their electrical and mechanical properties.
{"title":"High-Temperature Conductor Materials Development for Aerospace Applications","authors":"M. Gimpl, N. Fuschillo, K. Zwilsky","doi":"10.1109/TA.1965.4319815","DOIUrl":"https://doi.org/10.1109/TA.1965.4319815","url":null,"abstract":"Conductor materials for aerospace application should have low resistivity, low density, high strength, and ductility over the temperature range of application. Our work on the development of such materials has shown that the three most promising high-temperature conductors covering both oxidizing and nonoxidizing environments are zone-refined rhodium (< 1600°C), dispersion-hardened platinum (< 1500°C), and dispersion-hardened gold (< 900°C). Methods of producing and fabricating these high-temperature conductors are presented, together with their electrical and mechanical properties.","PeriodicalId":13050,"journal":{"name":"IEEE Transactions on Aerospace","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1965-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76462016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Conductive dendrites occur as a result of electrochemical reaction between metal conductors bridged by water and the voltage impressed between the conductors. Their formation is the initial step in a sequence that can result in an open circuit, short circuit or disabling change in circuit impedance. The dendrites of various metals were observed and photographed under the microscope. Growth rates were measured for voltage gradients and electrode spacings appropriate to electrical and electronic equipment.
{"title":"Wet Electric Faults, Part I Dendrites","authors":"D. K. Elliot","doi":"10.1109/TA.1965.4319808","DOIUrl":"https://doi.org/10.1109/TA.1965.4319808","url":null,"abstract":"Conductive dendrites occur as a result of electrochemical reaction between metal conductors bridged by water and the voltage impressed between the conductors. Their formation is the initial step in a sequence that can result in an open circuit, short circuit or disabling change in circuit impedance. The dendrites of various metals were observed and photographed under the microscope. Growth rates were measured for voltage gradients and electrode spacings appropriate to electrical and electronic equipment.","PeriodicalId":13050,"journal":{"name":"IEEE Transactions on Aerospace","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1965-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79811305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The experimental portion of the Aerospace program for the determination of RFI at orbital altitudes is described. The need for this effort is shown, and potential sources of RFI are outlined. The methods planned are described in detail and actual hardware for use on the first experimental flight is discussed briefly. Hardware includes antennas, preselectors, and crystal video logarithmic receivers. It is expected that results of the first experiment will be available late in 1965.
{"title":"Radio Frequency Interference at Orbital Altitudes","authors":"L. A. Hoffman","doi":"10.1109/TA.1965.4319847","DOIUrl":"https://doi.org/10.1109/TA.1965.4319847","url":null,"abstract":"The experimental portion of the Aerospace program for the determination of RFI at orbital altitudes is described. The need for this effort is shown, and potential sources of RFI are outlined. The methods planned are described in detail and actual hardware for use on the first experimental flight is discussed briefly. Hardware includes antennas, preselectors, and crystal video logarithmic receivers. It is expected that results of the first experiment will be available late in 1965.","PeriodicalId":13050,"journal":{"name":"IEEE Transactions on Aerospace","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1965-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81892095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nuclear radiation effects on semiconductor devices and circuits are modelled using flowgraph techniques. The usefulness and applicability of a model adequate for both transient and permanent radiation effects in devices and circuits is based on several recent developments in modelling techniques: · the lumped-parameter semiconductor diffusion-controlled model. · the systematic formulation of equivalent circuits with independent and controlled sources. · the development of the closed system approach to assess variation in terms of sensitivity for systems with large number of variables. · the utilization of a computer routine which provides circuit response to given excitations or due to given parameter changes. The lumped semiconductor device model proposed by Linvill is modified to include effects of both neutron and pulse radiation sources. The network-like nature of the lumped device model provides insight into the physical processes involved as well as into circuit changes produced by irradiation. Examples of circuit applications illustrate the use of the lumped model with radiation induced generators of carriers. To account for variations for circuit response due to parameter changes, a technique of evaluating sensitivities for models of any complexity are developed. Criteria for optimization of circuits under parameter changes are established. Emphasis is not on experimental data but on methods and criteria for establishing and evaluating models of circuits in a radiation environment.
{"title":"Modelling of Radiation Effects in Semiconductor Devices and Circuits","authors":"J. B. Compton, W. Happ","doi":"10.1109/TA.1965.4319825","DOIUrl":"https://doi.org/10.1109/TA.1965.4319825","url":null,"abstract":"Nuclear radiation effects on semiconductor devices and circuits are modelled using flowgraph techniques. The usefulness and applicability of a model adequate for both transient and permanent radiation effects in devices and circuits is based on several recent developments in modelling techniques: · the lumped-parameter semiconductor diffusion-controlled model. · the systematic formulation of equivalent circuits with independent and controlled sources. · the development of the closed system approach to assess variation in terms of sensitivity for systems with large number of variables. · the utilization of a computer routine which provides circuit response to given excitations or due to given parameter changes. The lumped semiconductor device model proposed by Linvill is modified to include effects of both neutron and pulse radiation sources. The network-like nature of the lumped device model provides insight into the physical processes involved as well as into circuit changes produced by irradiation. Examples of circuit applications illustrate the use of the lumped model with radiation induced generators of carriers. To account for variations for circuit response due to parameter changes, a technique of evaluating sensitivities for models of any complexity are developed. Criteria for optimization of circuits under parameter changes are established. Emphasis is not on experimental data but on methods and criteria for establishing and evaluating models of circuits in a radiation environment.","PeriodicalId":13050,"journal":{"name":"IEEE Transactions on Aerospace","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1965-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73158468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Performance characteristics of electrical contacts lubricated with niobium diselenide were found to be superior to similar materials lubricated with molybdenum disulfide while transferring power to a slow speed silver slip ring for a period of 1000 hours. Lower and more stable contact voltage was the main improvement shown while operating in a vacuum chamber near 2.0 × 10-8 torr.
{"title":"Electrical Sliding Contacts for Application in Space Environments","authors":"L. E. Moberly, J. Johnson","doi":"10.1109/TA.1965.4319809","DOIUrl":"https://doi.org/10.1109/TA.1965.4319809","url":null,"abstract":"Performance characteristics of electrical contacts lubricated with niobium diselenide were found to be superior to similar materials lubricated with molybdenum disulfide while transferring power to a slow speed silver slip ring for a period of 1000 hours. Lower and more stable contact voltage was the main improvement shown while operating in a vacuum chamber near 2.0 × 10-8 torr.","PeriodicalId":13050,"journal":{"name":"IEEE Transactions on Aerospace","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1965-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82681159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Temperature compensation of transducers using semiconductor strain gages involves an understanding of the interrelationships between basic sensor performance, transducer design and compensation techniques. This paper describes some of these interrelationships and gives specific information regarding conventional temperature compensation approaches used on production hardware.
{"title":"Temperature Compensation of Transducers Using Semiconductor Strain Gages","authors":"C. Shearer","doi":"10.1109/TA.1965.4319781","DOIUrl":"https://doi.org/10.1109/TA.1965.4319781","url":null,"abstract":"Temperature compensation of transducers using semiconductor strain gages involves an understanding of the interrelationships between basic sensor performance, transducer design and compensation techniques. This paper describes some of these interrelationships and gives specific information regarding conventional temperature compensation approaches used on production hardware.","PeriodicalId":13050,"journal":{"name":"IEEE Transactions on Aerospace","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1965-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83810648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Texas Instruments is presently engaged in design and development of the communication and data-handling subsystem (CDHS) and the associated aerospace ground equipment (AGE) for the Advanced Orbiting Solar Observatory (AOSO). This paper describes the AGE which will be used to test, monitor, exercise, and troubleshoot the CDHS. The observatory-class satellites are very complex and have sophisticated communications and data-handling equipment. The increase in complexity of satellite equipment has resulted in increased demands on the test capability of the checkout equipment. A computer-controlled checkout system has been selected as a result of an analysis of the satellite test requirements. By utilizing a general-purpose computer which controls special equipment designed for the AOSO, the requirement for a rapid, versatile checkout system has been met. This system is described in the following paragraphs.
{"title":"Computer-Controlled Aerospace Ground Equipment for the AOSO Communications and Data-Handling Subsystem","authors":"A. Reeves, M. K. Meredith","doi":"10.1109/TA.1965.4319832","DOIUrl":"https://doi.org/10.1109/TA.1965.4319832","url":null,"abstract":"Texas Instruments is presently engaged in design and development of the communication and data-handling subsystem (CDHS) and the associated aerospace ground equipment (AGE) for the Advanced Orbiting Solar Observatory (AOSO). This paper describes the AGE which will be used to test, monitor, exercise, and troubleshoot the CDHS. The observatory-class satellites are very complex and have sophisticated communications and data-handling equipment. The increase in complexity of satellite equipment has resulted in increased demands on the test capability of the checkout equipment. A computer-controlled checkout system has been selected as a result of an analysis of the satellite test requirements. By utilizing a general-purpose computer which controls special equipment designed for the AOSO, the requirement for a rapid, versatile checkout system has been met. This system is described in the following paragraphs.","PeriodicalId":13050,"journal":{"name":"IEEE Transactions on Aerospace","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1965-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88668337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Accurate estimates of aerospace electro-explosive device reliability can be made only by properly employed techniques of sensitivity testing. Improperly applied, sensitivity testing can produce misleading data which may compromise mission success or result in rejection of reliable units. This paper analyzes techniques used to estimate the reliability of "one shot" electro-explosive devices, discusses current practices which can produce suspect data, and suggests remedial action which will lead to accurate and dependable methods of reliability estimation.
{"title":"Problems in Sensitivity Testing of \"One Shot\" Electro-Explosive Devices","authors":"Herbert D. Peckham","doi":"10.1109/TA.1965.4319861","DOIUrl":"https://doi.org/10.1109/TA.1965.4319861","url":null,"abstract":"Accurate estimates of aerospace electro-explosive device reliability can be made only by properly employed techniques of sensitivity testing. Improperly applied, sensitivity testing can produce misleading data which may compromise mission success or result in rejection of reliable units. This paper analyzes techniques used to estimate the reliability of \"one shot\" electro-explosive devices, discusses current practices which can produce suspect data, and suggests remedial action which will lead to accurate and dependable methods of reliability estimation.","PeriodicalId":13050,"journal":{"name":"IEEE Transactions on Aerospace","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1965-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84799568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：