ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Other Sources  (747)
  • LUNAR AND PLANETARY EXPLORATION  (552)
  • ELECTRONICS AND ELECTRICAL ENGINEERING  (195)
  • 1980-1984  (747)
  • 1925-1929
  • 1920-1924
  • 1983  (747)
  • 1928
Collection
  • Other Sources  (747)
Source
Keywords
Years
  • 1980-1984  (747)
  • 1925-1929
  • 1920-1924
Year
  • 1
    facet.materialart.
    Unknown
    Test methods and results of the 10-cell bipolar Ni-H2 battery (1983)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: Characterization tests were carried out at three charge levels and four discharge levels. The "c' or capacity of the battery is designated at 6.5 ampere-hours. The recharge ampere-hours was the same for all test conditions, 6.5 A-H, regardless of the discharge capacity removed for any particular discharge rate. Less capacity can be removed at higher discharge rates to the same termination voltage, which was 0.50 volts for the weakest (lowest voltage) cell. The general trend of efficiencies increases as the charge rate increases as noted in results of the table included in the handout package. The data also indicate the efficiency increases as the discharge rate decreases. This is true; however, efficiencies at the discharge rates of c and 2c are penalized because these cycles received more overcharge than necessary.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Goddard Space Flight Center The 1982 Goddard Space Flight Center Battery Workshop; p 496-500
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 2
    facet.materialart.
    Unknown
    Determination of the reliability of Ni-Cd batteries from survival data on cells fabricated 1964 - 1977 (1983)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: The probability of Ni-Cd battery survival was determined by researching survival data on cells fabricated from 1964-1977. A log of cell failure times were plotted against cumulative failure percentage and mean and standard deviation were determined.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Goddard Space Flight Center The 1982 Goddard Space Flight Center Battery Workshop; p 470-479
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 3
    facet.materialart.
    Unknown
    Experimental design (1983)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: The design of long life, low weight nickel cadmium cells is studied. The status of a program to optimize nickel electrodes for the best performance is discussed. The pore size of the plaque, the mechanical strength and active material loading are considered in depth.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Goddard Space Flight Center The 1982 Goddard Space Flight Center Battery Workshop; p 253-469
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 4
    facet.materialart.
    Unknown
    Advanced nickel hydrogen cell configuration study (1983)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: An evaluation of the current nickel hydrogen cell design is presented. The IPV, or the Individual Pressure Vessel, is the state of the art right now. The present design, 3 1/2 inch cell, has a current limit of 50 ampere-hours. The nickel hydrogen cell design is the state of the art. Its size is 3 1/2 inches which limits it to 50 hours. The probable limits of that are probably 160 amphere IPV cell remaining in the passive cooling mode. The IPV stacks is a parallel connection of electrodes. Positive electrodes are connected with leads to the top portion of the stack and negative electrodes are connected with leads and pulled down to the bottom. So it is a combination connection of paralleling series electrostacking--parallel inside each individual stack, and series connected from one stack to the next. It offers, in the analysis, improvements in packaging, cost, energy density, and specific energy.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Goddard Space Flight Center The 1982 Goddard Space Flight Center Battery Workshop; p 480-495
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 5
    facet.materialart.
    Unknown
    Nickel hydrogen/nickel cadmium battery trade studies (1983)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: Nickel Hydrogen cell and battery technology has matured to the point where a real choice exists between Nickel Hydrogen and Nickel Cadmium batteries for each new spacecraft application. During the past few years, a number of spacecraft programs have been evaluated at Hughes with respect to this choice, with the results being split about fifty-fifty. The following paragraphs contain criteria which were used in making the battery selection.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Goddard Space Flight Center The 1982 Goddard Space Flight Center Battery Workshop; p 430-438
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 6
    facet.materialart.
    Unknown
    Canadian experience with nickel cadmium systems (1983)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: The Defense Research Establishment Ottawa (DREO) has been studying the nickel-cadmium system, both vented and sealed, since the early 1950's. Reasonable success has been achieved in a wide variety of applications covering: military vehicle use under Arctic conditions; high performance military aircraft; manpacked communications sets; remote standby power and small portable instrumentation. Early studies on the vented system for high rate vehicle and aircraft cranking applications proved useful in later studies on the sealed NiCd system. This was especially true in the areas of plate loading and electrolyte composition. To achieve high rate cranking currents of 20C to 30C, it was necessary to have light to moderate plate loadings, a large reactive surface area, and electrolyte of optimum conductivity. DREO undertook some fundamental studies to understand the system from the inside out rather than test cells from the outside and then analyze their components. The conclusions of these studies were incorporated into the Procurement Specification for Ni-Cd cells ISISA Spec S615-P-2. A brief comment will be made on the choice of cell design and how some of the factors of cell manufacture could affect cell performance.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Goddard Space Flight Center The 1982 Goddard Space Flight Center Battery Workshop; p 439-451
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 7
    facet.materialart.
    Unknown
    Real and potential nickel hydrogen superiority (1983)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: Events from the development and orbital flight experience with a nickel hydrogen battery are described. The events highlight characteristics of nickel hydrogen which afford superior capability in overcharge, overdischarge and state of charge evaluation, when compared to the nickel cadmium electrochemical system. Some developments in nickel hydrogen technology that provide the potential of furthering nickel hydrogen superiority for satellite applications are also discussed.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Goddard Space Flight Center The 1982 Goddard Space Flight Center Battery Workshop; p 416-429
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 8
    facet.materialart.
    Unknown
    Ni-H2 batteries for communications satellites (1983)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: Ni-H2 batteries are just now being put into service. All of the remaining INTELSAT V satellites (approximately 10), starting with the next to be launched in early 1983, will use Ni-H2 batteries. In addition, the next generation of INTELSAT VI satellites, and probably INTELSAT VII and VIII, will use Ni-H2 batteries. This means that international telecommunications satellites will use Ni-H2 batteries through the 1990's. It is projected that the lifetime of these batteries will be greater than 10 years at deep depth-of-discharge (DOD), and that the battery subsystem will no longer limit satellite lifetime or communications capability during eclipse periods. This paper discusses the advantages of the Ni-H2 battery, as compared with the Ni-Cd battery, for telecommunications satellites.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Goddard Space Flight Center The 1982 Goddard Space Flight Center Battery Workshop; p 389-415
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 9
    facet.materialart.
    Unknown
    Status of SAFT silver hydrogen cell development (1983)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: Nickel-hydrogen cells appear to be an improvement over the nickel-cadmium in applications requiring longer lifetime and reduced weight. An even more efficient couple, the silver-hydrogen couple, is also considered. After a theoretical study first performed by the Battelle Institute of Geneva under ESA (European Space Agency) contract, SAFT has undertaken more detailed analyses of the silver-hydrogen degradation mechanisms. ESA and the French Department of Defense contracted with SAFT for a full-development program of the silver-hydrogen technology.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Goddard Space Flight Center The 1982 Goddard Space Flight Center Battery Workshop; p 347-371
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 10
    facet.materialart.
    Unknown
    Reconditioning and the nickel electrode (1983)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: This effects of reconditioning on the performance of NiCd batteries are reviewed. These effects are correlated with cell experiments and individual electrode investigations. The effects of reconditioning on the positive electrode performance are found to be significant. A mechanism is proposed that rationalizes the operation of the nickel electrode and suggests that reconditioning minimizes depth of discharge stress during use and maintains uniformity of the active material.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Goddard Space Flight Center The 1982 Goddard Space Flight Center Battery Workshop; p 324-345
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 11
    facet.materialart.
    Unknown
    Spacecraft battery reconditioning cost considerations (1983)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: Cost considerations for spacecraft battery reconditioning are studied. Results indicate that the cost of performing reconditioning is minuscule compared with spacecraft system investment. Results also indicate that spacecraft life extension of a few days justifies incorporation of reconditioning circuitry.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Goddard Space Flight Center The 1982 Goddard Space Flight Center Battery Workshop; p 303-310
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 12
    facet.materialart.
    Unknown
    Unique battery reconditioning cycle for RCA's geostationary satellites and its applicability for low Earth satellite (1983)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: Six (6) geostationary spacecraft, manufactured by RCA Astro, are presently operating in orbit. All of their batteries are performing well. They all contain unique battery reconditioning circuitry, permitting individual cell reconditioning to practically zero volts without the danger of cell reversal. This reconditioning is performed just prior to start of each eclipse season. This technique has maintained the battery's end-of-discharge voltage with mission life. The oldest operating RCA Astro geostationary spacecraft, Satcom F1 and F2, have now completed almost 7 and 6-3/4 years in orbit, respectively. Their battery performance, reported herein, show that a major milestone in the mission longevity of nickel-cadmium batteries has heen achieved. Low earth orbit test data show a long lasting effect of maintaining end-of-discharge voltages for nickel cadmium cells using periodic reconditioning. The unique RCA light-weight reconditioning circuitry can accomplish a quick reconditioning and prevent cell reversal. Reconditioning, thus, has the potential for extending mission life of geostationary as well as low earth orbit spacecraft, when two or more batteries are present.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Goddard Space Flight Center The 1982 Goddard Space Flight Center Battery Workshop; p 311-323
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 13
    facet.materialart.
    Unknown
    Deep discharge reconditioning: Pros and cons (1983)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: Deep-discharge reconditioning (DDR) can be of great benefit to battery performance, especially in geosynchronous orbit, if performed properly and regularly, and can be essential to operation of batteries at the high depths of discharge (DOD) required to minimize weight. The procedure should be tailored to fit the nature of the degradation occuring during regular cycling. DDR is not without its drawbacks, however, and these differ depending on the normal DOD to be sustained and/or whether the discharge is done at the battery or the cell level. Battery-level discharge carries the minimum weight penalty but raises questions of the effects of low-rate cell reversal that as yet have no firm answers. Cell level discharge avoids cell reversal but carries significant penalties of weight and complexity. Thus no universal procedure or method of implementation of deep-discharge reconditioning is now available and thus the various approaches must be evaluated for each application.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Goddard Space Flight Center The 1982 Goddard Space Flight Center Battery Workshop; p 297-302
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 14
    facet.materialart.
    Unknown
    Control requirements for future battery systems (1983)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: It is argued that sophisticated battery control systems are required to support the high power, high energy spacecraft secondary battery systems of the post 1985 time period. Four categories of battery control system functions are defined and discussed: battery operational control, auxiliary system control, battery system status indication and fault detection fault isolation. A concept for implementation of such a control system is also presented and discussed.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Goddard Space Flight Center The 1982 Goddard Space Flight Center Battery Workshop; p 270-279
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 15
    facet.materialart.
    Unknown
    A comparison of voltage limit charge control for fixed array and sun oriented array missions (1983)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: A comparison of voltage limited control methods limit control methods for fixed array and oriented array missions is given. The LANDSAT D, Earth Radiation Budget Experiment and Solar maximum Mission techniques are compared.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: The 1982 Goddard Space Flight Center Battery Workshop; p 231-258
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 16
    facet.materialart.
    Unknown
    Battery charge control with temperature compensated voltage limit (1983)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: Battery charge control for orbiting spacecraft with mission durations from three to ten years, is a critical design feature that is discussed. Starting in 1974, the General Electric Space Systems Division designed, manufactured and tested battery systems for six different space programs. Three of these are geosynchronous missions, two are medium altitude missions and one is a near-earth mission. All six power subsystems contain nickel cadmium batteries which are charged using a temperature compensated voltage limit. This charging method was found to be successful in extending the life of nickel cadmium batteries in all three types of earth orbits. Test data and flight data are presented for each type of orbit.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Goddard Space Flight Center The 1982 Goddard Space Flight Center Battery Workshop; p 259-269
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 17
    facet.materialart.
    Unknown
    Computer modeling of batteries from non-linear circuit elements (1983)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: A simple non-linear circuit model for battery behavior is given. It is based on time-dependent features of the well-known PIN change storage diode, whose behavior is described by equations similar to those associated with electrochemical cells. The circuit simulation computer program ADVICE was used to predict non-linear response from a topological description of the battery analog built from advice components. By a reasonable choice of one set of parameters, the circuit accurately simulates a wide spectrum of measured non-linear battery responses to within a few millivolts.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Goddard Space Flight Center The 1982 Goddard Space Flight Center Battery Workshop; p 201-215
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 18
    facet.materialart.
    Unknown
    Modeling a Li/SOCl2 battery for design purposes (1983)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: A generalized code applicable to many different electrochemical systems and geometric designs is discussed. The code is to be set up so that physical property data such as thermal conductivity, viscosity, density, and configuration (e.g. physical dimensions) are the input data. Thus, by changing these parameters many different battery configurations can be handled. The outputs, as a function of time and space, are voltage, current, temperature, pressure, velocity, and species concentration.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Goddard Space Flight Center The 1982 Goddard Space Flight Center Battery Workshop; p 178-199
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 19
    facet.materialart.
    Unknown
    Fitting voltage curves with an electrochemically derived equation (1983)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: Previous work is refined and extended to describe the discharge curve of Ni-Cd cells. Several models are discussed which are based on chronopotentiometry theory and on a thermodynamic approach. Emphasis is placed on improvement of the fit for the initial portion of discharge. Equations are presented which improve the fit for all regions of the discharge curve.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Goddard Space Flight Center The 1982 Goddard Space Flight Center Battery Workshop; p 164-177
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 20
    facet.materialart.
    Unknown
    Battery model for electrical power system energy balance (1983)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: A model to simulate nickel-cadmium battery performance and response in a spacecraft electrical power system energy balance calculation was developed. The voltage of the battery is given as a function of temperature, operating depth-of-charge (DOD), and battery state-of-charge. Also accounted for is charge inefficiency. A battery is modeled by analysis of the results of a multiparameter battery cycling test at various temperatures and DOD's.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Goddard Space Flight Center The 1982 Goddard Space Flight Center Battery Workshop; p 117-124
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 21
    facet.materialart.
    Unknown
    Validating cell/battery safety (1983)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: Using the accelerating rate calorimeter, the hazards associated with exothermic reactions occurring in Li/SO2 cells under the conditions of discharge, forced overdischarge, resistive overdischarge, and forced overdischarge at low tempratures are quantitatively defined in terms of: rate of pressure generation, overall pressure rise, rate of temperature, and overall heat generation. Consistent with the findings of other investigators, it is believed that the major reactions contributing to Li/SO2 cell exothermicity are: the lithium/acetonitrile reaction, the thermal decomposition of lithium dithionite, and the lithium/sulfur reaction.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Goddard Space Flight Center The 1982 Goddard Space Flight Center Battery Workshop; p 85-99
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 22
    facet.materialart.
    Unknown
    Design of a safe cylindrical lithium/thionyl chloride cell (1983)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: Cell design criteria were established which can result in a safe lithium/thionyl chloride cell. A cell vent, a low area internal anode cell, cell balance and composition of the cathode-electrolyte solution were found to be important factors in the design of a safe cell. In addition to routine testing, both undischarged and discharged cells were subjected to electrical abuse, environmental abuse and mechanical abuse without disassembly.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Goddard Space Flight Center The 1982 Goddard Space Flight Center Battery Workshop; p 75-84
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 23
    facet.materialart.
    Unknown
    Controlling hazardous reactions during voltage reversal of high energy lithium cells (1983)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: The roll of general cell design characteristics in preventing hazardous reactions during voltage reversal of lithium cells is discussed. Anode limited versus cathode limited design and case positive versus case negative design are addressed.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Goddard Space Flight Center The 1982 Goddard Space Flight Center Battery Workshop; p 67-74
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 24
    facet.materialart.
    Unknown
    Safety tests (1983)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: The ovedischarge test program and results for double A and D lithium cells are discussed. Temperature increases and sparking responses are dressed.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Goddard Space Flight Center The 1982 Goddard Space Flight Center Battery Workshop; p 60-63
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 25
    facet.materialart.
    Unknown
    Low temperature performance tests (1983)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: Lithium cell performance at extremely low temperatures was tested and materials which could be used to make a cell completely electro-chemically inert for the purpose of deactivation were investigated. The effects of temperature and current density on polarization and performance loss are discussed along with discharge recovery behavior.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Goddard Space Flight Center The 1982 Goddard Space Flight Center Battery Workshop; p 64-66
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 26
    facet.materialart.
    Unknown
    Policies governing the use of lithium batteries in the Navy (1983)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: Lithium batteries offer many advantages for Navy systems but may also exhibit undesirable hazardous behavior. Safety problems have been traced to a variety of chemical and physical causes. The Navy has established a central safety office with responsibility for all lithium battery use. Before an item is approved for Navy use, it must pass both a design review and a set of end item tests. These reviews focus on complete systems which include a battery inside the end item. After system approval, specific regulations govern the transportation, storage, and disposal of the unit containing lithium batteries. Each of these areas is discussed in detail.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Goddard Space Flight Center The 1982 Goddard Space Flight Center Battery Workshop; p 23-34
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 27
    facet.materialart.
    Unknown
    The Galileo probe Li/SO2 battery: The safest battery on Jupiter (1983)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: The unique power requirement of NASA's Galileo Jupiter Probe are most readily met by a Li/SO2 battery; however, because this battery system is not space flight proven, extensive effort was required to qualify this device from the stand point of performance and safety. Due to the rather checkered safety record of the Li/SO2 system, safety has been foremost among the design considerations and has been addressed at the cell, battery and system level. The mission requirements which led to the choice of the Li/SO2 battery and the safety engineering which went into the battery and power system design are described.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Goddard Space Flight Center The 1982 Goddard Space Flight Center Battery Workshop; p 15-22
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 28
    facet.materialart.
    Unknown
    forced overdischarge related safety aspects of Li/SO2 and Li/SOCl2 cells (1983)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: Results of an experiment investigating overdischarge behavior of two types of Li/SO2 cells are presented. Forced overdischarges of the Li/LiBr, CH3CN/SO2 cell can result in unsafe behavior such as venting with fire and release of toxic gases. The hazards may be minimized or eliminated by careful cell design considerations and practice of high standards of quality contol in cell manufacture. Seemingly safe cells at 25 C when forced overdischarged at -25 C, even at low currents, exhibited incipient signs of hazards. Their cathodes indicated signs of shock sensitivity. Cathode limited Li/SOCl2 cells were safe during forced overdischarge for long periods of time. Lithium limited Li/SOCl2 cells in which practically all Li had been used up before cell reversal did not exhibit hazardous behavior. Anode limited Li/SOCl2 cells, but not Li limited, exhibited detonations, all during overdischarges at relatively low current densities of or = 1 mA/sq cm 2. Anode potentials 4v with large oscillations preceeded the events. The events were confined to the anode and the temperature rose high enough to melt Ni grids.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Goddard Space Flight Center The 1982 Goddard Space Flight Center Battery Workshop; p 47-59
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 29
    facet.materialart.
    Unknown
    Primary lithium batteries, some consumer considerations (1983)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: In order to determine whether larger size lithium batteries would be commercially marketable, the performance of several D size lithium batteries was compared with that of an equivalent alkaline manganese battery, and the relative costs of the different systems were compared. It is concluded that opportunities exist in the consumer market for the larger sizes of the low rate and moderate rate lithium batteries, and that the high rate lithium batteries need further improvements before they can be recommended for consumer applications.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Goddard Space Flight Center The 1982 Goddard Space Flight Center Battery Workshop; p 35-45
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 30
    facet.materialart.
    Unknown
    Hazardous behavior of lithium batteries. Case histories (1983)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: Case histories were described of hazardous behavior for three different cell sizes ranging in nominal capacity from 300 mAh to 12,000 Ah. Design characteristics and other facts believed to have been responsible for the cell explosions, are presented. Obvious facts are discussed as causes for hazardous behavior of lithium batteries in general and oxyhalide batteries in particular.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Goddard Space Flight Center The 1982 Goddard Space Flight Center Battery Workshop; p 3-14
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 31
    facet.materialart.
    Unknown
    Modeling battery life through changes in voltage fit coefficients (1983)
    In:  CASI
    Details
    Publication Date: 2006-10-01
    Description: A number of 12 ampere-hour cells, nickel cadmium, were cycled under various conditions of temperature and depth of discharge. Using this data, it was confirmed that a five parameter fit equation could be used to model the data within a few millivolts. Both charge and discharge curves can be fit with accuracies in the range of one or two millivolts. The fit coefficients when plotted versus cycles show definite trends and patterns which can be used in an operational sense to predict battery voltage as a function of temperature and depth of discharge.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: NASA. Goddard Space Flight Center The 1982 Goddard Space Flight Center Battery Workshop; p 125-163
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 32
    facet.materialart.
    Unknown
    New cryogenic P-channel metal-oxide-semiconductor field effect transistor (MOSFET) with optimized doping yielding performance superior to the G-118, W-164, and 3N165 at 77 K, 4 K, and 1.8 K (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 33
    facet.materialart.
    Unknown
    Modeling of single-event upset in bipolar integrated circuits (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The results of work done on the quantitative characterization of single-event upset (SEU) in bipolar random-access memories (RAMs) have been obtained through computer simulation of SEU in RAM cells that contain circuit models for bipolar transistors. The models include current generators that emulate the charge collected from ion tracks. The computer simulation results are compared with test data obtained from a RAM in a bipolar microprocessor chip. This methodology is applicable to other bipolar integrated circuit constructions in addition to RAM cells.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Nuclear Science (ISSN 0018-9499); NS-30; 4540-454
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 34
    facet.materialart.
    Unknown
    Solar system history as recorded in the Saturnian ring structure (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Holberg's analysis of the Voyager Saturn photographs in reflected and transparent light, and occultation data of stars seen through the rings are discussed. A hyperfine structure with 10,000 ringlets can be explained by the Baxter-Thompson negative diffusion. This gives the ringlets a stability which makes it possible to interpret them as fossils which originated at cosmogonic times. It is shown that the bulk structure can be explained by the combined cosmogonic shadows of the satellites Mimas and Janus and the Shepherd satellites. This structure originated at the transition from the plasma phase to the planetesimal phase. The shadows are not simple void regions but exhibit a characteristic signature. Parts of the fine structure, explained by Holberg as resonances with satellites, are interpreted as cosmogonic shadow effects. However, there are a number of ringlets which can neither be explained by cosmogonic nor by resonance effects. Analysis of ring data can reconstruct the plasma-planetesimal transition with an accuracy of a few percent. Previously announced in STAR as N84-12013
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Astrophysics and Space Science (ISSN 0004-640X); 97; 1, No; 79-94
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 35
    facet.materialart.
    Unknown
    The damage equivalence of electrons, protons, alphas and gamma rays in rad-hard MOS devices (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: This paper reports on a study of damage equivalence in rad-hard MOS devices with 100,000 rads (SiO2) capability. Damage sensitivities for electrons of 1, 2, 3, 5, and 7 MeV, protons of 1, 3, 7, 22, and 40 MeV, 3.4-MeV alphas, and Co-60 gammas were measured and compared. Results indicated that qualitatively the same charge recombination effects occurred in hard oxide devices for doses of 100,000 rads (SiO2) as in soft oxide parts for doses of 1 to 4 krads (SiO2). Consequently, damage equivalency or non-equivalency depended on radiation type and energy. However, recovery effects, both during and after irradiation, controlled relative damage sensitivity and its dependency on total dose, dose rate, supply bias, gate bias, radiation type, and energy. Correction factors can be derived from these data or from similar tests of other hard oxide type, so as to properly evaluate the combined effects of the total space environment.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Nuclear Science (ISSN 0018-9499); NS-30; 4363-436
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 36
    facet.materialart.
    Unknown
    Stability of streams and lakes on Mars (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The freezing of small Martian streams is modelled for a variety of climatic conditions, on the supposition that the Martian atmosphere may have been considerably thicker in the past, at the time of the formation of the valley networks. This model examines the energy balance at the upper and lower surfaces of ice on streams, in order to determine the rate at which ice thickens with time. Results indicate that freezing rates are not strongly dependent on atmospheric pressure, and, under windy conditions, dependence on atmospheric pressure is even weaker. It is noted that the main problem in valley formation is in initiating the flow. Groundwater seepage alone is inadequate, due to the difficulty of groundwater system replenishment.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Icarus (ISSN 0019-1035); 56; 476-495
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 37
    facet.materialart.
    Unknown
    Large amplitude MHD waves upstream of the Jovian bow shock (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Observations of large amplitude MHD waves upstream of Jupiter's bow shock are analyzed. The waves are found to be right circularly polarized in the solar wind frame, which suggests that they are propagating in the fast magnetosonic mode. A complete spectral and minimum variance eigenvalue analysis of the data was performed. The power spectrum of the magnetic fluctuations contains several peaks. The fluctuations at 2.3 MHz have a direction of minimum variance anti-parallel to the direction of the average magnetic field. Several harmonics at 6, 9, and 12 MHz are also present. The direction of minimum variance of these fluctuations lies at approximately 40 deg to the magnetic field. It is argued that these fluctuations are waves excited by protons reflected off the Jovian bow shock. The inferred speed of the reflected protons is about two times the solar wind speed in the solar wind frame. A linear instability analysis is presented that suggests an explanation for many of the observed features of the observations. The fluctuations apparently contain a significant fraction of magnetic energy that is linearly polarized and in the Alfven mode.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Journal of Geophysical Research (ISSN 0148-0227); 88; 9989-999
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 38
    facet.materialart.
    Unknown
    Light element geochemistry and spallogenesis in lunar rocks (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Abundance and isotopic compositions are measured for the very volatile elements carbon, nitrogen and sulfur in 11 lunar rocks representing a wide spectrum of textures and compositions. Samples were combusted sequentially at three temperatures in order to remove terrestrial contaminants before melting the lunar rock and liberating lunar volatiles. The combustion results indicate very little terrestrial sulfur contamination, with sulfur contents correlated with the TiO2 contents of the basalts analyzed. Sulfur isotopic compositions are remarkably uniform and similar to the Canon Diablo meteorite standard. Nitrogen levels are found to be no greater than those obtained with procedural blanks, corresponding to abundances less than 0.1 microg/g. Stable nitrogen isotope measurements indicate a spallogenic N-15 production rate of 4.1 x 10 to the -6th microg N-15/g sample/million years, in agreement with previous estimates. No indigenous carbon in excess of procedural blank levels of about 0.7 microg/g is found in lunar basalts. Levels of 1 to 5 microg/g found in highland rocks may derive from meteoritic or terrestrial sources. The average measured spallogenic C-13 production rate is 4.1 x 10 to the -6th microg C-13/g sample/million years.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Geochimica et Cosmochimica Acta (ISSN 0016-7037); 47; 1769-178
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 39
    facet.materialart.
    Unknown
    The flux and source of energetic protons in Saturn's inner magnetosphere (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The flux of energetic protons in Saturn's inner magnetosphere was observed in two channels from 48 to 63 and 63 to 160 MeV. Absorption features due to the G ring and the satellites Enceladus and Mimas were easily identifiable. The flux observed in the absorption slot of Mimas can be maintained by the decay of a cosmic ray albedo neutron flux of 0.007/sq cm/s/sr. This flux is entirely consistent with calculations of the neutron flux produced by galactic cosmic ray interactions with the rings of Saturn. The omnidirectional proton flux of 0.0082/sq cm/s at 2.734 R sub s requires a residence time of 30 years. Both the residence time and the energy spectrum are comparable to those found in the inner radiation belt of the Earth. The angular distribution is nearly isotropic in the Mimas slot and beyond 4R sub s. Otherwise the pitch angle distribution is pancake and is approximated by sin(n)theta with n in the range 2 to 7. This distribution is consistent with an isotropic neutron source in the ring plane. Previously announced in STAR as N83-22084
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Journal of Geophysical Research (ISSN 0148-0227); 88; 8923-893
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 40
    facet.materialart.
    Unknown
    Survey of low-energy plasma electrons in Saturn's magnetosphere - Voyagers 1 and 2 (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The low energy plasma electron environment within Saturn's magnetosphere was surveyed by the Plasma Science Experiment (PLS) during the Voyager encounters with Saturn. Over the full energy range of the PLS instrument (10 eV to 6 keV) the electron distribution functions are clearly non-Maxwellian in character; they are composed of a cold (thermal) component with Maxwellian shape and a hot (suprathermal) non-Maxwellian component. A large scale positive radial gradient in electron temperature is observed, increasing from less than 1 eV in the inner magnetosphere to as high as 800 eV in the outer magnetosphere. Three fundamentally different plasma regimes were identified from the measurements: (1) the hot outer magnetosphere, (2) the extended plasma sheet, and (3) the inner plasma torus. Previously announced in STAR as N83-34872
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Journal of Geophysical Research (ISSN 0148-0227); 88; 8847-887
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 41
    facet.materialart.
    Unknown
    The Z3 zonal harmonic model of Saturn's magnetic field Analyses and implications (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The planetary magnetic field of Saturn has been studied by the spacecraft Pioneer 11 in 1979, Voyager 1 in 1980, and Voyager 2 in 1981. The field is found to be primarily dipolar and axially coincident with the rotation axis, but with significant quadrupole and octupole moments. The harmonic terms are g1(0) = 21535 nT, g2(0) = 1642 nT, and g3(0) = 2743 nT. This model field, Z3, in conjunction with a model for an equatorial ring current, represents very precisely the in situ magnetic-field measurements and data on charged-particle absorption by satellites and rings within 8 Saturn radii of the planet. However, this axisymmetric model fails to explain the periodic modulation of Saturn's kilometric radiation or Saturn's electrostatic discharges. This enigma of Saturn's magnetosphere remains unsolved in spite of extensive reconsideration of all available data bearing on this issue.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Journal of Geophysical Research (ISSN 0148-0227); 88; 8771-877
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 42
    facet.materialart.
    Unknown
    Photometry and polarimetry of Saturn at 2640 and 7500 A (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Voyager 2 photometric and polarimetric data are reduced and tabulated, with spatially resolved limb-to-terminator scans across Saturn's equatorial zone providing information on the altitude distribution of UV-absorbing hazes, together with the phase function and polarizing properties of stratospheric and tropospheric aerosols. It is found that the UV photometry and polarimetry are best fit by Rayleigh's phase matrix. A stratospheric haze of small particles is allowed as long as the optical depth is near unity or less, and the center of the haze layer is in the 30 to 70 mbar region. The altitudes presently derived for three latitudes agree with those obtained by ground-based methane band studies and analyses from Pioneer 11. A high altitude absorber is abundant in the polar regions.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Journal of Geophysical Research (ISSN 0148-0227); 88; 8679-869
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 43
    facet.materialart.
    Unknown
    Evaluation of the emission capabilities of Spindt-type field emitting cathodes (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The electron emitting capabilities of Spindt-type field emitting cathodes (FEC) are being studied at the Lewis Research Center, NASA. These cathodes, having 5000 emitting points in a 1 mm diameter, have been shown to be capable of emission current densities of 10 A/sq cm and higher. The purposes of this study are to (1) demonstrate that the cathodes can be processed and used in a tube-type configuration, (2) determine whether, at a sufficiently high current density, the cathode can operate in the space charge mode, and (3) evaluate failure mechanisms in this unique type of electron emitter. FEC's have been tested in a diode configuration, by the use of pulse techniques, up to current densities of 6 A/sq cm and anode potentials of 3000 V. Space charge effects have been observed in the range of 5 A/sq cm as an apparent linear increase of cathode current with anode voltage for a constant emitter-gate potential. Failed cathodes were studied by means of scanning electron microscopy and the major failure modes encountered are attributed to gas evolution, followed by arcing, which destroys either individual emitters or a large segment of the cathode area.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Applications of Surface Science (ISSN 0378-5963); 16; 277-291
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 44
    facet.materialart.
    Unknown
    Morphology and chemistry of projectile residue in small experimental impact craters (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Small-scale impact craters (5-7 mm in diameter) were produced with a light gas gun in high purity Au and Cu targets using soda lime glass (SL) and man-made basalt glass (BG) as projectiles. Maximum impact velocity was 6.4 km/s resulting in peak pressures of approximately 120-150 GPa. Copious amounts of projectile melts are preserved as thin glass liners draping the entire crater cavity; some of this liner may be lost by spallation, however. SEM investigations reveal complex surface textures including multistage flow phenomena and distinct temporal deposition sequences of small droplets. Inasmuch as some of the melts were generated at peak pressures greater than 120 GPa, these glasses represent the most severely shocked silicates recovered from laboratory experiments to date. Major element analyses reveal partial loss of alkalis; Na2O loss of 10-15 percent is observed, while K2O loss may be as high as 30-50 percent. Although the observed volatile loss in these projectile melts is significant, it still remains uncertain whether target melts produced on planetary surfaces are severely fractionated by selective volatilization processes.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Journal of Geophysical Research, Supplement (ISSN 0148-0227); 88; B353-B36
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 45
    facet.materialart.
    Unknown
    The production curve for agglutinates in planetary regoliths (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Models for the production of agglutinates are developed that can be applied to the lunar surface or to any planetary or asteroidal body lacking an atmosphere. Models are developed using rate equations for progressively more complex situations and range from Model 1, which is a simple linear increase of agglutinate content with time, to Model 4, which includes provision for recycling of existing agglutinates and replenishment and burial of exposed soil. Model 4 has some aspects of a steady state because, depending on the rate constants, agglutinate content may be limited to an intermediate value, even for long exposure times. In an extreme case, agglutinate content may be limited to a value near zero. These models predict that agglutinates should be low in abundance in areas of thin regolith, such as the Lunokhod-2 site on the moon, and on asteroids. The models may also help explain the apparent low agglutinate abundances of lunar regolith breccias and meteorite regolith breccias.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Journal of Geophysical Research, Supplement (ISSN 0148-0227); 88; B193-B19
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 46
    facet.materialart.
    Unknown
    Ancient crustal components in the Fra Mauro breccias (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Texturally pristine clasts preserve primary petrographic relationships and mineral compositions, yielding insights into igneous processes of the early lunar crust that cannot be gained from highly shocked and brecciated 'chemically pristine' samples. The use of texture as a prime criterion allows for expansion of the data base derived solely from chemical criteria, and provides complementary data. Texturally pristine clasts from the Apollo 14 site studied here include anorthosite, troctolites, gabbronorites, and basalts. Alkali anorthosites are plagioclase orthocumulates and may form by flotation in Mg-suite plutons. Ferroan anorthosite was cataclastically deformed and metamorphosed to granulite facies. Troctolites include both 01 + Plg and 01 + En + Plg cumulates. Major and trace element analyses of two troctolites reveal 'eastern' geochemical affinities that contrast other 'western' troctolites. Gabbronorites are Pig + Plg + or - Sp cumulates whose parent magmas may range from high-Al to intermediate-Ti mare basalt. At least three varieties of mare basalt are found at Apollo 14: high-Al, low-Ti; low-Al, intermediate-Ti; and low-Al, Ti VHK basalt. VHK (Very High Potassium) basalt is a new variety indigenous to Apollo 14.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Journal of Geophysical Research, Supplement (ISSN 0148-0227); 88; B177-B19
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 47
    facet.materialart.
    Unknown
    An upper bound on the radius of a highly electrically conducting lunar core (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Parker's (1980) nonlinear inverse theory for the electromagnetic sounding problem is converted to a form suitable for analysis of lunar day-side transfer function data by: (1) transforming the solution in plane geometry to that in spherical geometry; and (2) transforming the theoretical lunar transfer function in the dipole limit to an apparent resistivity function. The theory is applied to the revised lunar transfer function data set of Hood et al. (1982), which extends in frequency from 10 to the -5th to 10 to the -3rd Hz. On the assumption that an iron-rich lunar core, whether molten or solid, can be represented by a perfect conductor at the minimum sampled frequency, an upper bound of 435 km on the maximum radius of such a core is calculated. This bound is somewhat larger than values of 360-375 km previously estimated from the same data set via forward model calculations because the prior work did not consider all possible mantle conductivity functions.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Journal of Geophysical Research, Supplement (ISSN 0148-0227); 88; B97-B102
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 48
    facet.materialart.
    Unknown
    An improved push-pull voltage fed converter using a tapped output-filter inductor (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: A new concept of using a tapped output-filter inductor and an auxiliary commutating diode to reduce the likelihood of transformer core saturation in a push-pull, voltage-fed converter is presented. The linearized circuit model and transfer functions are derived with a hybrid approach using both state-space and circuit averaging. Operation of the new converter - including parasitic effects - is discussed, and a design equation for inductor tap ratio is established. It is predicted and experimentally confirmed that the new converter has more symmetrical transformer core operation, and the potential exits for lower transistor turnon current and reduced transistor voltage stress. These benefits reduce switching loss and enhance transistor reliability.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 49
    facet.materialart.
    Unknown
    Atmospheric tides on Venus. III - The planetary boundary layer (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Diurnal solar heating of Venus' surface produces variable temperatures, winds, and pressure gradients within a shallow layer at the bottom of the atmosphere. The corresponding asymmetric mass distribution experiences a tidal torque tending to maintain Venus' slow retrograde rotation. It is shown that including viscosity in the boundary layer does not materially affect the balance of torques. On the other hand, friction between the air and ground can reduce the predicted wind speeds from about 5 to about 1 m/sec in the lower atmosphere, more consistent with the observations from Venus landers and descent probes. Implications for aeolian activity on Venus' surface and for future missions are discussed.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Icarus (ISSN 0019-1035); 56; 165-175
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 50
    facet.materialart.
    Unknown
    Structure and dynamics of Saturn's outer magnetosphere and boundary regions (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: In 1979-1981, the three USA spacecraft Pioneer 11 and Voyagers 1 and 2 discovered and explored the magnetosphere of Saturn to the limited extent possible on flyby trajectories. Considerable variation in the locations of the bow shock (BS) and magnetopause (MP) surfaces were observed in association with variable solar wind conditions and, during the Voyager 2 encounter, possible immersion in Jupiter's distant magnetic tail. The limited number of BS and MP crossings were concentrated near the subsolar region and the dawn terminator, and that fact, together with the temporal variability, makes it difficult to assess the three dimensional shape of the sunward magnetospheric boundary. The combined BS and MP crossing positions from the three spacecraft yield an average BS-to-MP stagnation point distance ratio of 1.29 +/- 0.10. This is near the 1.33 value for the Earth's magnetosphere, implying a similar sunward shape at Saturn. Study of the structure and dynamical behavior of the outer magnetosphere, both in the sunward hemisphere and the magnetotail region using combined plasma and magnetic field data, suggest that Saturn's magnetosphere is more similar to that of Earth than that of Jupiter. Previously announced in STAR as N83-30346
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Journal of Geophysical Research (ISSN 0148-0227); 88; 8791-880
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 51
    facet.materialart.
    Unknown
    Channels and valleys on Mars (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Tentative conclusions about the origins of channels and valleys on Mars based on the consensus of investigators who have studied the problem are presented. The morphology of outflow channels is described in detail, and the morphology, distribution, and genesis of Martian valleys are addressed. Secondary modification of channels and valleys by mass-wasting phenomena, eolian processes, cratering, and mantling by lava flows is discussed. The physics of the flows needed to account for the immense volumes of Martian outflow channels is considered in detail, including the possible influence of debris flows and mudflows, glaciers, and ice sheets. It is concluded that Mars once probably possessed an atmosphere with higher temperatures and pressures than at present which played an essential role in an active hydrological cycle.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Geological Society of America, Bulletin (ISSN 0016-7606); 94; 1035-105
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 52
    facet.materialart.
    Unknown
    Three Mars years - Viking Lander 1 imaging observations (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The Mutch Memorial Station (Viking Lander 1) on Mars acquired imaging and meteorological data over a period of 2245 martian days (3.3 martian years). This article discusses the deposition and erosion of thin deposits (ten to hundreds of micrometers) of bright red dust associated with global dust storms, and the removal of centimeter amounts of material in selected areas during a dust storm late in the third winter. Atmospheric pressure data acquired during the period of intense erosion imply that baroclinic disturbances and strong diurnal solar tidal heating combined to produce strong winds. Erosion occurred principally in areas where soil cohesion was reduced by earlier surface sampler activities. Except for redistribution of thin layers of materials, the surface appears to be remarkably stable, perhaps because of cohension of the undisturbed surface material.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Science (ISSN 0036-8075); 222; 463-468
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 53
    facet.materialart.
    Unknown
    Low-noise 115-GHz receiver using superconducting tunnel junctions (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: A 110-118-GHz receiver based on a superconducting quasiparticle tunnel junction mixer is described. The single-sideband noise temperature is as low as 68 + or - 3 K. This is nearly twice the sensitivity of any other receiver at this frequency. The receiver was designed using a low-frequency scale model in conjunction with the quantum mixer theory. A scaled version of the receiver for operation at 46 GHz has a single-sideband noise temperature of 55 K. The factors leading to the success of this design are discussed.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Applied Physics Letters (ISSN 0003-6951); 43; 786-788
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 54
    facet.materialart.
    Unknown
    Stability and capture of asteroids (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The problem of stability of asteroids is treated from the point of view of Hill's stability-concept and using Lyapunov's Characteristic Numbers. The quantitative measure of stability (S) introduced earlier is evaluated for over 300 asteroids and a surprisingly simple relation is established between the semi-major axes of some of the asteroids' orbits and S. A detailed analysis is presented of the Lyapunov Characteristic Numbers for two minor planets and the time-variation of these numbers is discussed. The technology of capture of asteroids is vitally dependent on their orbital stability, therefore, these two problems, i.e., capture and stability, are closely related. In fact, some predictable instabilities may be properly utilized to capture and/or change asteroidal orbits to accomplish collisions with the Earth.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Sao Paulo Univ. The Motion of Planets and Nat. and Artificial Satellites, Volume 2; p 39-46
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 55
    facet.materialart.
    Unknown
    A Sr and Nd isotopic study of five Yamato polymict eucrites and a comparison to other Antarctic and ordinary eucrites (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Description: Sr and Nd isotopic analysis of five Yamato polymict eucrites indicate that these samples formed at about 4.6 Ga ago with initial Sr and Nd ratios essentially the same as the analyzed non-Antarctic eucrites. The Yamato eucrites have Sr, Sm, and Nd concentrations that consistently lie among the highest found in eucritic samples. This characteristic identifies these Yamato samples as a closely related group. Comparisons between these Yamato samples and other Antarctic polymict eucrites clearly estabishes that they all share some characteristic trace element features. Comparisons of Antarctic polymict eucrites with non-Antarctic ordinary eucrites reveal consistent differences. The most obvious is an enrichment of Rb in the polymict eucrites. These comparisons suggest that the Antarctic polymict eucrites belong to a single large family of material that is itself fairly diverse and distinct from the non-Antarctic eucrites.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: National Institute of Polar Research, Memoirs, Special Issue (ISSN 0386-0744); 30, D
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 56
    facet.materialart.
    Unknown
    Condensation of chondrules (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Description: Analysis of current experimental results concerned with the kinetic constraints on chondrule formation showed that the major physical properties of chondrules could have been produced by direct condensation of metastable liquid silicates droplets from a hot gas in the primordial nebula. It is argued that such a condensation process would have to be followed by crystallization, accretion, and partial comminution of the droplets. The chemical mechanisms driving this process are described, including: nucleation constraints on comminution and crystallization; slow transformations and chemical reactions in chain silicates; and the slow diffusion of ions. It is shown that the physical mechanisms for chondrule condensation are applicable to a broad spectrum of chondrule sources.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 57
    facet.materialart.
    Unknown
    External control of planetary radio emission (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Description: Recent studies using data from Voyagers 1 and 2 to correlate variations in the Saturn kilometric radiation (SKR) with changes in solar-wind properties are summarized and illustrated with graphs. Best SKR correlations have been obtained with the solar-wind ram pressure and the related kinetic energy flux. It is pointed out that the related phenomenon on earth, the auroral kilometric radiation, occurs mainly in the nightside auroral region (as opposed to the dayside cleft region for SKR) and is best correlated with solar-wind velocity and inverted-V electron-precipitation events, implying a different stimulation process. The evidence for solar-wind control of the non-Io-related decametric radiation of Jupiter is also reviewed.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Oesterreichische Akademie der Wissenschaften, mathematisch-naturwissenschaftliche Klasse, Sitzungsberichte, Abteilung 2 (ISSN 0723-9319); 192; 8-10,
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 58
    facet.materialart.
    Unknown
    New propulsion components for electric vehicles (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Improved component technology is described. This includes electronically commutated permanent magnet motors of both drum and disk configurations, an unconventional brush commutated motor, ac induction motors, various controllers, transmissions and complete systems. One or more of these approaches to electric vehicle propulsion may eventually displace presently used controllers and brush commutated dc motors. Previously announced in STAR as N83-25982
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 59
    facet.materialart.
    Unknown
    Annual Conference on Nuclear and Space Radiation Effects, Gatlinburg, TN, July 18-21, 1983, Proceedings (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Topics discussed include radiation effects in devices; the basic mechanisms of radiation effects in structures and materials; radiation effects in integrated circuits; spacecraft charging and space radiation effects; hardness assurance for devices and systems; and radiation transport, energy deposition and charge collection. Papers are presented on the mechanisms of small instabilities in irradiated MOS transistors, on the radiation effects on oxynitride gate dielectrics, on the discharge characteristics of a simulated solar cell array, and on latchup in CMOS devices from heavy ions. Attention is also given to proton upsets in orbit, to the modeling of single-event upset in bipolar integrated circuits, to high-resolution studies of the electrical breakdown of soil, and to a finite-difference solution of Maxwell's equations in generalized nonorthogonal coordinates.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: (ISSN 0018-9499)
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 60
    facet.materialart.
    Unknown
    Bibliography (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: A bibliography of articles entered into the data base at the Lunar and Planetary Institute Library from November 1982 through January 1983 is presented. An abstract of each article is given. The subjects covered by the articles include: the motion of the moon and dynamics of the earth-moon system: shape and gravity field of the moon; the physical structure of the moon, its thermal and stress history; the morphology of the lunar surface, the origin and stratigraphy of lunar formations, and mapping of the moon; the chemical composition of the moon, lunar petrology, mineralogy, and crystallography; electromagnetic properties of the moon; the planets; and other objects, including asteroids, comets, meteorites, and cosmic dust.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Moon and the Planets (ISSN 0165-0807); 29; 237-327
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 61
    facet.materialart.
    Unknown
    Single event upset (SEU) of semiconductor devices - A summary of JPL test data (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The data summarized describe single event upset (bit-flips) for 60 device types having data storage elements. The data are from 15 acceleration tests with both protons and heavier ions. Tables are included summarizing the upset threshold data and listing the devices tested for heavy ion induced bit-flip and the devices tested with protons. With regard to the proton data, it is noted that the data are often limited to one proton energy, since the tests were usually motivated by the engineering requirement of comparing similar candidate devices for a system. It is noted that many of the devices exhibited no upset for the given test conditions (the maximum fluence and the maximum proton energy Ep are given for these cases). It is believed, however, that some possibility of upset usually exists because there is a slight chance that the recoil atom may receive up to 10 to 20 MeV of recoil energy (with more energy at higher Ep).
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Nuclear Science (ISSN 0018-9499); NS-30; 4520-452
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 62
    facet.materialart.
    Unknown
    Recovery of damage in rad-hard MOS devices during and after irradiation by electrons, protons, alphas, and gamma rays (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: This paper reports on the recovery properties of rad-hard MOS devices during and after irradiation by electrons, protons, alphas, and gamma rays. The results indicated that complex recovery properties controlled the damage sensitivities of the tested parts. The results also indicated that damage sensitivities depended on dose rate, total dose, supply bias, gate bias, transistor type, radiation source, and particle energy. The complex nature of these dependencies make interpretation of LSI device performance in space (exposure to entire electron and proton spectra) difficult, if not impossible, without respective ground tests and analyses. Complete recovery of n-channel shifts was observed, in some cases within hours after irradiation, with equilibrium values of threshold voltages greater than their pre-irradiation values. This effect depended on total dose, radiation source, and gate bias during exposure. In contrast, the p-channel shifts recovered only 20 percent within 30 days after irradiation.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Nuclear Science (ISSN 0018-9499); NS-30; 4157-416
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 63
    facet.materialart.
    Unknown
    Distributed control of large space antennas (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: A systematic way to choose control design parameters and to evaluate performance for large space antennas is presented. The structural dynamics and control properties for a Hoop and Column Antenna and a Wrap-Rib Antenna are characterized. Some results of the effects of model parameter uncertainties to the stability, surface accuracy, and pointing errors are presented. Critical dynamics and control problems for these antenna configurations are identified and potential solutions are discussed. It was concluded that structural uncertainties and model error can cause serious performance deterioration and can even destabilize the controllers. For the hoop and column antenna, large hoop and long meat and the lack of stiffness between the two substructures result in low structural frequencies. Performance can be improved if this design can be strengthened. The two-site control system is more robust than either single-site control systems for the hoop and column antenna.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Proc. of the Workshop on Appl. of Distributed System Theory to the Control of Large Space Struct.; p 225-247
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 64
    facet.materialart.
    Unknown
    Semiconductor optoelectronic devices for free-space optical communications (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The properties of individual injection lasers are reviewed, and devices of greater complexity are described. These either include or are relevant to monolithic integration configurations of the lasers with their electronic driving circuitry, power combining methods of semiconductor lasers, and electronic methods of steering the radiation patterns of semiconductor lasers and laser arrays. The potential of AlGaAs laser technology for free-space optical communications systems is demonstrated. These solid-state components, which can generate and modulate light, combine the power of a number of sources and perform at least part of the beam pointing functions. Methods are proposed for overcoming the main drawback of semiconductor lasers, that is, their inability to emit the needed amount of optical power in a single-mode operation.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Communications Magazine (ISSN 0163-6804); 21; Sept
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 65
    facet.materialart.
    Unknown
    Atmospheric storm explanation of saturnian electrostatic discharges (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Saturn electrostatic discharges (SED) monitored by the Voyager 1 were investigated to determine the source of the phenomena. Consideration has been given to two sources: the atmosphere at equatorial latitudes, where the cloud-top wind velocities correspond to the Saturn 10 hr 10 min rotation period; and the rings at 1.8 Saturn radius. The data were analyzed in terms of time and frequency, revealing a time-varying frequency, few detectable discharges outside of a low threshold, and the appearances and disappearances of the SED with no correlation with frequency. The periodicity of the SED episodes indicated that the source was occulted between revolutions, which ruled out the ring source. The SED signals were only detected on the dayside, suggesting the signals propagated through the dayside ionosphere. Diurnal variations in the ion densities could prohibit the signals from escaping on the nightside, a factor supported by detection of low frequency SED only during close passage of the Voyager. Ray tracing experiments have demonstrated that storm sources have emissions observable with the storm on the limb at the observed 30-40 MHz interval.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Nature (ISSN 0028-0836); 303; May 5
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 66
    facet.materialart.
    Unknown
    Speculation on Martian north polar wind circulation and the resultant orientations of polar sand dunes (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: When seen at frost cap minimum, Martian north polar erg dunes north of 80 deg N record east winds, while those south of that latitude record west winds. Many of the transverse dunes are considered to be reversing dunes, and dunes in the two fields may have reversed at least once during the lifetime of the Viking Orbiters. It is proposed that the average polar winds are strong, off-pole northwest winds in the fall, moderate west winds in winter, latitude-dependent weak-to-strong off-pole northeast winds in spring, and weak west winds in summer, as has been largely confirmed by Viking images of near polar clouds. Over millenia, the combination of reversing west and east winds could produce the biomodal distributions of dune orientations observed at the north pole.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Icarus (ISSN 0019-1035); 55; Sept
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 67
    facet.materialart.
    Unknown
    Formation and photochemistry of methylamine in Jupiter's atmosphere (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: In the upper troposphere and lower stratosphere of Jupiter, translationally hot H atoms are produced in the photolysis of ammonia, phospine, and acetylene which react with methane to form methyl radicals. The latter combine with NH2 to form methylamine. It is presently shown that the combined production of methylamine and subsequent photolysis to HCN is unlikely to account for the HCN observed near Jupiter's tropopause. The recommendation of NH2 and C2H3 radicals to yield C2H5N, followed by photolysis to HCN, is the preferred path. An upper limit column density on CH3PH2 is estimated to be about 10 to the 13th/sq cm, as compared to 10 to the 15th/sq cm for CH3NH2.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Icarus (ISSN 0019-1035); 55; Sept
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 68
    facet.materialart.
    Unknown
    Modeling of the 10-micron natural laser emission from the mesospheres of Mars and Venus (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The NLTE radiative transfer problem is solved to obtain the 00 deg 1 vibrational state population. This model successfully reproduces the existing center-to-limb observations, although higher spatial resolution observations are needed for a definitive test. The model also predicts total fluxes which are close to the observed values. The strength of the emission is predicted to be closely related to the instantaneous near-IR solar heating rate.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Icarus (ISSN 0019-1035); 55; Sept
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 69
    facet.materialart.
    Unknown
    Observations of the 10-micron natural laser emission from the mesospheres of Mars and Venus (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Observations of the total flux and center to limb dependence of the nonthermal emission occurring in the cores of the 9.4 and 10.4 micrometers CO2 bands on Mars are compared to a theoretical model based on this mechanism. The model successfully reproduces the observed center to limb dependence of this emission, to within the limits imposed by the spatial resolution of the observations of Mars and Venus. The observed flux from Mars agrees closely with the prediction of the model; the flux observed from Venus is 74 percent of the flux predicted by the model. This emission is used to obtain the kinetic temperatures of the Martian and Venusian mesospheres. For Mars near 70 km altitude, a rotational temperature analysis using five lines gives T = 135 + or - 20 K. The frequency width of the emission is also analyzed to derive a temperature of 126 + or - 6 K. In the case of the Venusian mesosphere near 109 km, the frequency width of the emission gives T = 204 + or - 10 K.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Icarus (ISSN 0019-1035); 55; Sept
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 70
    facet.materialart.
    Unknown
    Some dynamical properties of vortex streets in Saturn's atmosphere from analyses of Voyager images (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The first observations of a vortex street in an atmosphere other than that of the earth are presented, made from a sequence of images of Saturn taken by Voyager 2 in August 1981. The analysis of these images shows that the feature sits at the maximum of the westward jet and suggests that it may be produced by material rising up from below the level of the visible clouds.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Geophysical Research Letters (ISSN 0094-8276); 10; Sept
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 71
    facet.materialart.
    Unknown
    Ferromagnetic resonance and magnetic properties of ALHA 81005 (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Seven chips of primarily matrix material from the Antarctic meteorite ALHA 81005 were analyzed by ferromagnetic resonance (FMR) and magnetic hysteresis techniques. The FMR spectra of two chips have a resonance at g of about 2.1 that resembles the g of about 2.1 resonance that is characteristic of lunar soils. Thus the FMR spectra are consistent with the lunar regolith being a progenitor for the matrix material. For the two chips, the FMR surface exposure (maturity) index was about 5 units, which is equivalent to a value for an immature lunar soil. The total concentration of metallic iron is on the order of 0.11 equivalent wt. pct, which is within the observed range for Apollo 16 rocks and soils.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Geophysical Research Letters (ISSN 0094-8276); 10; Sept
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 72
    facet.materialart.
    Unknown
    Recent cosmic ray exposure history of ALHA 81005 (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Measurements of the Be-10 and Al-26 contents of ALHA 81005 constrain the length and conditions of its exposure to cosmic rays. Calculations based on one-step irradition models imply that the time spent by this object in space is shorter than that spent by most 'asteroidal' meteorites. On the other hand the results are readily consistent with a lunar origin for ALHA 81005.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Geophysical Research Letters (ISSN 0094-8276); 10; Sept
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 73
    facet.materialart.
    Unknown
    Trapped noble gases indicate lunar origin for Antarctic meteorite (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The isotopic abundances of the noble gases (He, Ne, Ar, Kr, Xe) are reported for Antarctic ALHA 81005. It contains solar wind-implanted gases whose absolute and relative concentrations are quite similar to lunar regolith samples but not to other meteorites. ALHA 81005 also contains a large excess Ar-40 component which is identical to the component in lunar fines implanted from the lunar atmosphere. Large concentrations of cosmogenic Ne-21, Kr-82, and Xe-126 in ALHA 81005 indicate a total cosmic ray exposure age of at least 200 million years. The noble gas data alone are strong evidence for a lunar origin of this meteorite.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Geophysical Research Letters (ISSN 0094-8276); 10; Sept
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 74
    facet.materialart.
    Unknown
    The Tunguska event - No cometary signature in evidence (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: It is suggested that existing data on the 1908 Tunguska fall precludes an interpretation of the object as an either active or extinct comet fragment. Because a fireball of the Tunguska mass is not efficiently decelerated by the earth's atmosphere, it would at an entry velocity of about 30 km/sec have had to resist aerodynamic pressures greater than one billon dyn/sq cm before disintegrating. The inherently extremely fragile cometary material could not have survived a load of this magnitude. The data on Type II fireballs with prominent terminal flares are extrapolated, to estimate Tunguska's critical dynamic pressure at the same time of explosion as being of the order of 200 million dyn/sq cm, and its preexplosion velocity as about 10 km/sec, thereby ruling out a comet-like orbit. The Tunguska object is most consistently described as a small Apollo-type asteroid, 90-190 m across.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Astronomical Journal (ISSN 0004-6256); 88; Sept
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 75
    facet.materialart.
    Unknown
    Radio emission signature of Saturn immersions in Jupiter's magnetic tail (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: During the interval from about May through August 1981, when Voyager 2 was inbound to Saturn, the Planetary Radio Astronomy instrument measured repeated, dramatic decreases in the intensity of the Saturn Kilometric Radiation (SKR). The emission dropouts averaged two orders of magnitude below mean energy levels and varied from about 1 to 10 Saturn rotations in duration. Comparison with pre-Saturn encounter Voyager 1 observations (June to November, 1980) shows that the SKR dropouts were unique to the Voyager 2 observing interval, consistent with the closer proximity of Saturn to Jupiter's distant magnetotail in 1981. Further, the dropouts occurred on the average at times when Voyager 2 is known to have been within or near Jupiter's magnetic tail.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Journal of Geophysical Research (ISSN 0148-0227); 88; Sept. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 76
    facet.materialart.
    Unknown
    Solar related waves in the Venusian atmosphere from the cloud tops to 100 km (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: A quasi-linear diagnostic model using observed solar-related temperatures and a specified solar mean circulation and surface structure to find the solar-related circulation above the clouds of Venus is presented. Despite the greater dependence of model-derived, solar-related circulation on the mean flow than is the case for terrestrial tides, as well as the uncertainty concerning this mean flow, significant conclusions are drawn for the solar-related circulation and thermal structure of Venus. An anomalously large response is found in the polar regions, due to the model's requirement of a process such as dissipation which will act as a major sink for momentum. Dissipation is specified in the model as Rayleigh friction with an unknown free parameter coefficient. In view of this, dissipation is either very efficient by terrestrial standards and accompanied by small solar-related circulation, or similar to that of earth and possessed of a circulation large enough to have an impact on the mean circulation.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Journal of the Atmospheric Sciences (ISSN 0022-4928); 40; June 198
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 77
    facet.materialart.
    Unknown
    Vertical distribution of scattering hazes in Titan's upper atmosphere (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Radial intensity scans of a Voyager 2 high phase angle image of Titan have been inverted to yield vertical extinction profiles at 1 deg intervals around the limb. A detached haze layer with peak particle number densities of about 0.2 cu/cm exists at all latitudes south of about 45 N, and at an altitude of 300-350 km. The optical depth 0.01 level lies at a radius of 2932 + or - 5 km at the equator and at a radius of 2915 + or - 10 km over the poles (altitudes of 357 + or - 5 and 340 + or - 10 km, respectively). In addition to the haze layer at 300-350 km, there is a small enhancement in the extinction at about 450 km which exists at all latitudes between 75 deg S and about 60 deg N.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Icarus (ISSN 0019-1035); 55; July 198
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 78
    facet.materialart.
    Unknown
    Saturn meteorology - A diagnostic assessment of thin-layer configurations for the zonal flow (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Voyager imaging, infrared, and radio observations for Saturn have been recently interpreted by Smith et al. (1982) as an indication that the jet streams observed at the cloud tops extend to depths greater than the 10,000-bar level. This analysis assumes a maximum latitudinal temperature contrast of a few percent, a mean atmospheric rotation rate at depth given by Saturn's ratio period, and no variation with latitude of the bottom pressure level for the zonal flow system. These assumptions are not, however, firmly constrained by observation. The diagnostic analysis of plausible alternative configurations for Saturn's atmospheric structure demonstrates that a thin weather layer system (confined at mid to high latitudes to levels above 200 bar) cannot be excluded by any of the available observations. A quantitative estimate of the effects of moisture condensation (including the differentiation of mean molecular weight) suggests that these might provide the buoyancy contrasts necessary to support a thin-layer flow provided that Saturn's outer envelope is enriched approximately 10 times in water abundance relative to a solar composition atmosphere and strongly differentiated with latitude at the condensation level.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: (ISSN 0019-1035)
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 79
    facet.materialart.
    Unknown
    The atmosphere of Titan - An analysis of the Voyager 1 radio occultation measurements (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The equatorial atmosphere of Titan was probed by means of two coherently related radio signals transmitted from Voyager 1 at 13.0 and 3.6 cm wavelengths during the November 12, 1980 occultation of the spacecraft by the Saturn satellite. An analysis of the differential dispersive frequency measurements did not reveal any ionization layers in the upper atmosphere of Titan. The gas refractivity data, which extend from the surface to about 200 km altitude, were interpreted in two different ways. In the first, it is assumed that N2 makes up virtually all of the atmosphere, with small amounts of CH4 and other hydrocarbons present. In the second interpretation of the refractivity data, it is assumed that the 3.5 km altitude level corresponds to the bottom of a CH4 cloud layer and that N2 and CH4 were perfectly mixed below this level.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 80
    facet.materialart.
    Unknown
    The role of dissipation in shepherding of ring particles (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: A discussion is presented on the gravitational interaction between ring systems and nearby satellites. A shepherd satellite lacking damping mechanisms will force oscillations in the motion of a ring particle that are symmetrical with respect to the encounter geometry. If such damping mechanisms as density wave propagation or a dissipative medium are present, a lag in particle response provides the asymmetry that exerts a net torque on the rings. While the torque on a given particle depends on the degree of damping, that dependence disappears when the torque is averaged over a range of orbits spanning resonances if the degree of damping is within a certain range. A torque that is much lower than the standard formula results from excessively weak or strong damping.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 81
    facet.materialart.
    Unknown
    High-energy particles (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: It is pointed out that the magnetosphere of Jupiter is in many respects quite different from that of the earth. The energy required to drive the Jovian magnetosphere is apparently extracted from Jupiter's rotational energy rather than from the solar wind. Jupiter is a strong source of energetic charged particles which can be detected as far away as the orbit of Mercury. The structure and dynamics of the energetic particle distribution in the inner magnetosphere is discussed, taking into account observations, transport and losses in the inner magnetosphere, satellite interactions, and electron synchrotron radiation. The subsolar hemisphere is considered, giving attention to particle fluxes in the subsolar magnetosphere, conditions in the middle magnetosphere, and the characteristics of the outer magnetosphere. A description of the predawn magnetosphere is also provided.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 82
    facet.materialart.
    Unknown
    Ionosphere (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The original interest in an ionosphere on Jupiter was generated by the discovery of strong radio-frequency emissions at approximately 20 MHz which were thought to be plasma frequencies associated with Jupiter's ionosphere. The ionosphere of Jupiter provides a means to couple the magnetosphere to the atmosphere by virtue of its high conductivity and collisional interaction with the neutral atmosphere. The Pioneer and Voyager have provided direct measurements of profiles of electron concentration at selected locations on Jupiter. Attention is given to basic principles regarding the characteristics of the Jovian ionosphere, the ionization sources, aspects of ion recombination, ion chemistry, observations of Jupiter's ionosphere, the structure of Jupiter's upper atmosphere, and questions of ionospheric modeling. On the basis of the Pioneer and Voyager observations it appears that Jupiter's ionosphere and thermosphere undergo significant solar cycle changes.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 83
    facet.materialart.
    Unknown
    Venus -Mesospheric hazes of ice, dust, and acid aerosols (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Four distinct types of particles are suggested to be present in the upper atmosphere of Venus. The lowest and densest haze may consist of a submicron sulfuric acid aerosol which extends above the cloud tops, up to about 80 km, representing an extension of the upper cloud deck. Temperature structure measurements in the 70-120 km altitude range indicate the occasional appearance of two independent water ice layers, of which the lower may form between 80 and 100 km and is probably the detached haze layer noted in high contrast limb photography. A nucleation of this ice layer on sulfuric acid aerosols is hypothesized. Temperatures of the Venus mesopause, near 120 km altitude, are frequently cold enough to allow ice nucleation on meteoric dust or ambient ions, yielding a haze (analogous to noctilucent clouds on earth) which is expected to be tenuous to the point of optical invisibility.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 84
    facet.materialart.
    Unknown
    A 20-GHz IMPATT transmitter, summary (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: A three stage IMPATT diode amplifier capable of a 16 W CW output and a 2 dB bandwidth of 117 MHz was developed. On the component side, high performance circulators with a 0.2 dB insertion loss and bandwidth of 5 GHz were fabricated. State of the art GaAs IMPATT diodes incorporating diamond heat sink and double Read doping profile were also developed. The diodes are capable of a 2.5 W CW output. A few diodes achieved power outputs as high as 3 W. On the circuit side, high gain (up to 12 dB per stage) single diode, multituned circuits capable of 2 GHz and 930 MHx bandwidth were developed as the first and second stages, respectively, of the amplifier. A 12 diode waveguide cavity combiner was developed as the output stage. The output stage utilized commercially available single drift GaAs IMPATT diodes.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: A 20-GHz IMPATT Tansmitter 1; 126 p
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 85
    facet.materialart.
    Unknown
    Phosphine photochemistry in Saturn's atmosphere (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The phosphine photochemistry on Saturn is studied with a 1D photochemical model. The PH3 concentration is rapidly depleted with height (scale height 3.5 km) in the upper troposphere. Formation of P, a probable precursor of P4, (a potential red chromophore in the atmosphere), is highly improbable unless the rate constant for the recombination reaction PH + H2 + M yields PH3 + M is less than 10 to the -41st cm exp 6/molecule-squared sec. Coupling of PH3 and hydrocarbon photochemistry, specifically the C2H2 catalyzed photodissociation of CH, is important. Column production rates of the organophosphorus compounds CH3PH2 and HCP of 3 x 10 to the 8th/sq cm sec are predicted, with potentially observable column densities of greater than 1 x 10 to the 17th/sq cm.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Geophysical Research Letters (ISSN 0094-8276); 10; Oct. 198
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 86
    facet.materialart.
    Unknown
    The inner edge of Saturn's B ring (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The sharp, 90-km wide transition from an optical depth of 0.2 in the C ring to 1 in the B ring begins at 91,970 km from Saturn's center. This radius is found to be almost exactly at the inward stability limit of charged particles launched in the ring plane at the local Kepler velocity, provided these particles have large charge to mass ratio. The zonal harmonic models of Saturn's magnetic field from the Voyager data and the gravitational field model from Pioneer data are essential to get the very close agreement between theory and observation. The theoretical stability limits are 91,973 + or - 145 km from Voyager 1 magnetic field data and 91,991 + or 145 km from Voyager 2 magnetic data. The zonal harmonic magnetic field lines are not perpendicular to the ring plane. Therefore, in addition to the magnetic mirror, gravitational, and centrifugal forces, an unknown force must be postulated to produce equilibrium in the ring plane and make the stability calculation meaningful.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Journal of Geophysical Research (ISSN 0148-0227); 88; Aug. 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 87
    facet.materialart.
    Unknown
    Martian gases in an Antarctic meteorite? (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Significant abundances of trapped argon, krypton, and xenon have been measured in shock-altered phases of the achondritic meteorite Elephant Moraine 79001 from Antarctica. The relative elemental abundances, the high ratios of argon-40 to argon-36 (equal to or greater than 2000), and the high ratios of xenon-129 to xenon-132 (equal to or greater than 2.0) of the trapped gas more closely resemble Viking data for the Martian atmosphere than data for noble gas components typically found in meteorites. These findings support earlier suggestions, made on the basis of geochemical evidence, that shergottites and related rare meteorites may have originated from the planet Mars.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Science (ISSN 0036-8075); 221; Aug. 12
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 88
    facet.materialart.
    Unknown
    Radiation effects on MOS devices - dosimetry, annealing, irradiation sequence, and sources (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: This paper reports on some investigations of dosimetry, annealing, irradiation sequences, and radioactive sources, involved in the determination of radiation effects on MOS devices. Results show that agreement in the experimental and theoretical surface to average doses support the use of thermo-luminescent dosimeters (manganese activated calcium fluoride) in specifying the surface dose delivered to thin gate insulators of MOS devices. Annealing measurements indicate the existence of at least two energy levels,,s or a activation energies, for recovery of soft oxide MOS devices after irradiation by electrons, protons, and gammas. Damage sensitivities of MOS devices were found to be independent of combinations and sequences of radiation type or energies. Comparison of various gamma sources indicated a small dependence of damage sensitivity on the Cobalt facility, but a more significant dependence in the case of the Cesium source. These results were attributed to differences in the spectral content of the several sources.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: IEEE Transactions on Nuclear Science (ISSN 0018-9499); NS-30; June 198
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 89
    facet.materialart.
    Unknown
    Io's 4-micron band and the role of adsorbed SO2 (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The role of adsorbed SO2 on Io's surface particles in producing the observed spectral absorption band near 4 microns in Io's reflectance spectrum is explored. Calculations show that a modest 50 percent monolayer coating of adsorbed So2 molecules on submicron grains of sulfur or alkali sulfide, assumed to make up Io's uppermost optical surface ('radialith'), will result in a nu 1 + nu 3 absorption band near 4 microns with depth about 30 percent below the adjacent continuum, consistent with the observed strength of the Io band. The precise wavelength position of the nu 1 + nu 3 band of SO2 in different phase states such as frost, ice, adsorbate, and gas are summarized from the experimental literature and compared with the available telescopic measurements of the Io band position. The results suggest that the 4-micron band in Io's full disk spectrum can best be explained by the presence on Io's surface of widespread SO2 in the form of adsorbate rather than ice or frost.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Icarus (ISSN 0019-1035); 54; June 198
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 90
    facet.materialart.
    Unknown
    HCN formation on Jupiter - The coupled photochemistry of ammonia and Acetylene (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: HCN formation in the upper troposphere and lower stratosphere of Jupiter is presently modeled in terms of UV pyrolysis of the C2H5N isomer aziridine, which is a product of the NH2 and C2H3 radicals that originate from ammonia photolysis and the addition of H atoms to acetylene, respectively. The sensitivity of the HCN column density to the individual rate constants and the eddy diffusion coefficient profile is considered, along with the possibility that additional HCN-yielding pathways may exist. Both ammonia and phosphine are strongly depleted by photolysis.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Icarus (ISSN 0019-1035); 54; June 198
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 91
    facet.materialart.
    Unknown
    Does Venus breathe? (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: It is speculated that the periodic absorption and desorption of CO2 by the soil of Venus may buffer daily temperature, pressure and wind variations in the lower atmosphere, effectively eliminating the net tidal torque on the atmosphere. The redistribution of mass would still generate a sizable torque, however, which may serve as a balance for that which is caused by the gravitationally induced tide. This novel tidal mechanism represents a somewhat weaker competitor to the atmospheric tides which have previously been studied.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Icarus (ISSN 0019-1035); 54; June 198
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 92
    facet.materialart.
    Unknown
    Tubes in space - Very much alive (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Some advantages of TWTs over SSDs are discussed. Wideband TWTs have been developed which can produce 20 W of RF power at 20 GHz with 40 percent efficiency, a figure three or four times that available from SSDs such as FETs. The basic performance of TWTs exceeds that of SSDs for any given bandwidth and frequency. SSDs are transit time limited, and their performance deteriorates fundamentally as the reciprocal of the square of the operating frequency. Power limits for SSDs have been reached or are quickly being approached. Free electron devices such as tubes have an efficiency advantage because electrons in the vacuum travel faster than bulk charges in SSDs. Combined SSD devices are prone to burnout and incur penalties due to the need to dissipate heat. TWTs have a 6.7:1 advantage in radiator area ratio. Recent progress in TWT technology has produced a tenfold increase in CW output power, doubled to quadrupled the efficiency, and pushed frequency ranges into the terahertz region, orders of magnitude beyond the SSD cutoff.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Microwaves & RF; 22; Mar. 198
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 93
    facet.materialart.
    Unknown
    Thermal structure of Saturn from Voyager infrared measurements - Implications for atmospheric dynamics (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 94
    facet.materialart.
    Unknown
    Theories of radio emissions and plasma waves (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The complex region of Jupiter's radio emissions at decameter wavelengths, the so-called DAM, is considered, taking into account the basic theoretical ideas which underly both the older and newer theories and models. Linear theories are examined, giving attention to direct emission mechanisms, parallel propagation, perpendicular propagation, and indirect emission mechanisms. An investigation of nonlinear theories is also conducted. Three-wave interactions are discussed along with decay instabilities, and three-wave up-conversio. Aspects of the Io and plasma torus interaction are studied, and a mechanism by which Io can accelerate electrons is reviewed.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 95
    facet.materialart.
    Unknown
    Jupiter's magnetic field and magnetosphere (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Among the planets of the solar system, Jupiter is unique in connection with its size and its large magnetic moment, second only to the sun's. The Jovian magnetic field was first detected indirectly by radio astronomers who postulated its existence to explain observations of nonthermal radio emissions from Jupiter at decimetric and decametric wavelengths. Since the early radio astronomical studies of the Jovian magnetosphere, four spacecraft have flown by the planet at close distances and have provided in situ information about the geometry of the magnetic field and its strength. The Jovian magnetosphere is described in terms of three principal regions. The inner magnetosphere is the region where the magnetic field created by sources internal to the planet dominates. The region in which the equatorial currents flow is denoted as the middle magnetosphere. In the outer magnetosphere, the field has a large southward component and exhibits large temporal and/or spatial variations in magnitude and direction in response to changes in solar wind pressure.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 96
    facet.materialart.
    Unknown
    Nutritional characteristics of moon dust for soil microorganisms (1983)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: Approximately 46% of the lunar sample (10084,151), 125.42 mg, was solubilized in 680 ml 0.01 M salicylic acid. Atomic absorption spectroscopic analysis of the solubilized lunar sample showed the following amount of metal ions: Ca, 3.1; Mg, 4.0; K, 0.09; Na, 0.67; Fe, 7.3; Mn, 1.6; Cu, Ni, Cr, less than 0.1 each. All are in ppm. Salicylic acid used to solubilize the lunar sample was highly inhibitory to the growth of mixed soil microbes. However, the mineral part of the lunar extract stimulated the growth. For optimal growth of the soil microbes the following nutrients must be added to the moon extract; sources of carbon, nitrogen, sulfur, phosphorus, and magnesium in addition to water.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: NASA. Johnson (Lyndon B.) Space Center The 1983 NASA/ASEE Summer Faculty Fellowship Research Program Research Reports; NASA. Johnson (Lynd
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 97
    facet.materialart.
    Unknown
    Receivers (1983)
    In:  CASI
    Details
    Publication Date: 2014-09-11
    Description: Before discussing Deep Space Network receivers, a brief description of the functions of receivers and how they interface with other elements of the Network is presented. Different types of receivers are used in the Network for various purposes. The principal receiver type is used for telemetry and tracking. This receiver provides the capability, with other elements of the Network, to track the space probe utilizing Doppler and range measurements, and to receive telemetry, including both scientific data from the onboard experiments and engineering data pertaining to the health of the probe. Another type of receiver is used for radio science applications. This receiver measures phase perturbations on the carrier signal to obtain information on the composition of solar and planetary atmospheres and interplanetary space. A third type of receiver utilizes very long baseline interferometry (VLBI) techniques for both radio science and spacecraft navigation data. Only the telemetry receiver is described in detail in this document. The integration of the Receiver-Exciter subsystem with other portions of the Deep Space Network is described.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: The Deep Space Network: A Radio Commun. Instr. for Deep Space Exploration; 26 p
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 98
    facet.materialart.
    Unknown
    Low Noise Amplifiers (1983)
    In:  CASI
    Details
    Publication Date: 2014-09-11
    Description: One of the great technical challenges facing the Deep Space Network is receiving signals from a severely weight limited spacecraft hundreds of thousands to billions of kilometers from Earth. This weight limitation has always imposed strict limitations on the size of the spacecraft antenna and the amount of transmitter power radiated. The communication burden is placed upon the ground systems of the Deep Space Network which must recover an extremely weak signal in the presence of nearly overwhelming amounts of noise. Two key parameters that determine the signal to noise ratio of a received signal using a deep space station are the collecting area and efficiency of the antenna, and the amount of noise which is generated in, as well as allowed to enter in, the antenna-mounted receiver. These parameters are used to describe the relative ability of a deep space station to receive weak signals. As spacecraft to Earth communication distances have increased, the Deep Space Network engages in a relentless effort to increase the figure of merit through larger and more efficient antennas, higher frequencies, and lower system noise temperature.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: The Deep Space Network: A Radio Commun. Instr. for Deep Space Exploration; 32 p
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 99
    facet.materialart.
    Unknown
    SAR Speckle Noise Reduction Using Wiener Filter (1983)
    In:  CASI
    Details
    Publication Date: 2014-09-10
    Description: Synthetic aperture radar (SAR) images are degraded by speckle. A multiplicative speckle noise model for SAR images is presented. Using this model, a Wiener filter is derived by minimizing the mean-squared error using the known speckle statistics. Implementation of the Wiener filter is discussed and experimental results are presented. Finally, possible improvements to this method are explored.
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: Texas A and M Univ. Proc. of the NASA Symp. on Math. Pattern Recognition and Image Analysis; p 295-310
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 100
    facet.materialart.
    Unknown
    Approximation to the Probability Density at the Output of a Photmultiplier Tube (1983)
    In:  CASI
    Details
    Publication Date: 2014-09-10
    Description: The probability density of the integrated output of a photomultiplier tube (PMT) is approximated by the Gaussian, Rayleigh, and Gamma probability densities. The accuracy of the approximations depends on the signal energy alpha: the Gamma distribution is accurate for all alpha, the Raleigh distribution is accurate for small alpha (approximate or less than 1 photon) and the Gaussian distribution is accurate for large alpha (approximate or greater than 10 photons).
    Keywords: ELECTRONICS AND ELECTRICAL ENGINEERING
    Type: The Telecommun. and Data Acquisition Rept.; p 36-39
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...