Automatic checkout and control
Automatic checkout and control of launch vehicles during prelaunch phase, and utilization of techniques in electric power industry
Sivo, J. N.↗
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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Weld beveling of large-diameter pipes
Technique employs electric drill and newly developed special jig to J-bevel, in the field, ends of pipes measuring between 15.24 cm and 45.72 cm in diameter in preparation for welding. Jig's construction and operation are described.
Liebenstein, R.↗
Spacecraft Charge Buildup Analysis
Design and characteristics of spacecraft propulsion system using charge buildup and electric propulsion techniques
Bilsky, H. W.↗
Development of a space qualified high reliability rotary actuator. Volume 1: Technical report
A space-qualified, high reliability, 150 ft-lb rated torque rotary acutator based on the Bendix Dynavector drive concept was developed. This drive is an integrated variable reluctance orbit motor-epicyclic transmission actuator. The performance goals were based on future control moment gyro torquer applications and represent a significant advancement in the torque-to-weight ratio, backlash, inertia and response characteristics of electric rotary drives. The program accomplishments have been in two areas: (1) the development of two high ratio (818:1) actuator configurations (breadboard and flightweight), and (2) the invention of a reliable proximity switch sensor system for self-commutation without use of optical or electrical brush techniques.
Presley, R. W.↗
Development of a space qualified high reliability rotary actuator for spaceflight use. Volume 2: Appendices to technical report
A space-qualified, high reliability, 150 ft-lb rated torque rotary actuator is described. This drive is an integrated variable reluctance orbit motor-epicyclic transmission actuator. The performance goals were based on future control moment gyrotorquer applications and represent an advancement in the torque-to-weight ratio, backlash, inertia and response characteristics of electric rotary drives. The program accomplishments have been in two areas (1) the development of two high ratio (818:1) actuator configurations (breadboard and flightweight) and (2) the invention of a reliable proximity switch sensor system for self-commutation without use of optical or electrical brush techniques.
Presley, R. W.↗
Ultrasonic calibration device
Device is an instrument for producing known changes in both acoustic absorption and phase velocity. Calibration signal arises from actual change of acoustic parameters, not from electrical simulation. Instrument is able to simulate changes in sensitivity enhancement achieved by use of ultrasonic resonators, which cannot be achieved using electrical calibration techniques.
Heyman, J. S.↗
Lithium-doped solar cell pilot line fabrication and test programs
An investigation was conducted to determine the technology readiness of lithium-doped silicon solar cells with respect to use in space programs. A pilot line fabrication program was established, in which the pilot line cells were evaluated after being exposed to environments ordinarily imposed on nonlithium-doped silicon solar cells. Results indicate that further process improvements are required, particularly with respect to the P/N junction diffusion and the electrical contacting technique (including solder coating). It is concluded that lithium-doped cells can be fabricated to exhibit (1) high efficiencies, (2) uniform cell-to-cell recovery characteristics after exposure to 1-MeV electrons; and (3) good stability in most environments investigated (the only exception being the thermal shock environment).
Berman, P. A.↗
Fatigue crack growth at elevated temperature 316 stainless steel and H-13 steel
Crack growths were measured at elevated temperatures under four types of loading: pp, pc, cp, and cc. In H-13 steel, all these four types of loading gave nearly the same crack growth rates, and the length of hold time had negligible effects. In AISI 316 stainless steel, the hold time effects on crack growth rate were negligible if the loading was tension-tension type; however, these effects were significant in reversed bending load, and the crack growth rates under these four types of loading varied considerably. Both tensile and compressive hold times caused increased crack growth rate, but the compressive hold period was more deleterious than the tensile one. Metallographic examination showed that all the crack paths under different types of loading were largely transgranular for both CTS tension-tension specimens and SEN reversed cantilever bending specimens. In addition, an electric potential technique was used to monitor crack growth at elevated temperature.
Chen, W. C.↗
Separating biological cells
Technique utilizing electric field to promote biological cell separation from suspending medium in zero gravity increases speed, reduces sedimentation, and improves efficiency of separation in normal gravity.
Brooks, D. E.↗
Hybrid holographic non-destructive test system
An automatic hybrid holographic non-destructive testing (HNDT) method and system capable of detecting flaws or debonds contained within certain materials are described. This system incorporates the techniques of optical holography, acoustical/optical holography and holographic correlation in determining the structural integrity of a test object. An automatic processing system including a detector and automatic data processor is used in conjunction with the three holographic techniques for correlating and interpreting the information supplied by the non-destructive systems. The automatic system also includes a sensor which directly translates an optical data format produced by the holographic techniques into electrical signals and then transmits this information to a digital computer for indicating the structural properties of the test object. The computer interprets the data gathered and determines whether further testing is necessary as well as the format of this new testing procedure.
Kurtz, R. L.↗
Development and test fuel cell powered on-site integrated total energy systems. Phase 3: Full-scale power plant development
The on-site system application analysis is summarized. Preparations were completed for the first test of a full-sized single cell. Emphasis of the methanol fuel processor development program shifted toward the use of commercial shell-and-tube heat exchangers. An improved method for predicting the carbon-monoxide tolerance of anode catalysts is described. Other stack support areas reported include improved ABA bipolar plate bonding technology, improved electrical measurement techniques for specification-testing of stack components, and anodic corrosion behavior of carbon materials.
Kaufman, A.↗
Forecasting of high voltage insulation performance: Testing of recommended potting materials and of capacitors
Nondestructive high voltage test techniques (mostly electrical methods) are studied to prevent total or catastrophic breakdown of insulation systems under applied high voltage in space. Emphasis is on the phenomenon of partial breakdown or partial discharge (P.D.) as a symptom of insulation quality, notably partial discharge testing under D.C. applied voltage. Many of the electronic parts and high voltage instruments in space experience D.C. applied stress in service, and application of A.C. voltage to any portion thereof would be prohibited. Suggestions include: investigation of the ramp test method for D.C. partial discharge measurements; testing of actual flight-type insulation specimen; perfect plotting resin samples with controlled defects for test; several types of plotting resins and recommendations of the better ones from the electrical characteristics; thermal and elastic properties are also considered; testing of commercial capaciters; and approximate acceptance/rejection/rerating criteria for sample test elements for space use, based on D.C. partial discharge.
Bever, R. S.↗
On error sources during airborne measurements of the ambient electric field
The principal sources of errors during airborne measurements of the ambient electric field and charge are addressed. Results of their analysis are presented for critical survey. It is demonstrated that the volume electric charge has to be accounted for during such measurements, that charge being generated at the airframe and wing surface by droplets of clouds and precipitation colliding with the aircraft. The local effect of that space charge depends on the flight regime (air speed, altitude, particle size, and cloud elevation). Such a dependence is displayed in the relation between the collector conductivity of the aircraft discharging circuit - on one hand, and the sum of all the residual conductivities contributing to aircraft discharge - on the other. Arguments are given in favor of variability in the aircraft electric capacitance. Techniques are suggested for measuring from factors to describe the aircraft charge.
Evteev, B. F.↗
Solar photolysis of ozone to singlet D oxygen atoms
The ground-level photolysis frequency of ozone J(O3) to produce metastable singlet D oxygen atoms (O (D-1)) is measured using a novel instrumental technique involving electrical conductivity. The O(D-1) atoms produced react with nitrous oxide (N2O) carrier gas to form higher oxides of nitrogen (NO(x)). These oxides were detected by mixing with methanol and determining the increase in electrical conductivity with a continuous-flow dual conductivity cell. Over 70 days of data were collected under varying sky conditions. The effect of temperature on J(O3) was measured. The results agree with model predictions. The effects of atmospheric aerosols, changes in overhead ozone column, and local cloudiness are discussed.
Blackburn, Thomas E.↗
Application of enhanced modern structured analysis techniques to Space Station Freedom electric power system requirements
A team of Space Station Freedom (SSF) system engineers are in the process of extensive analysis of the SSF requirements, particularly those pertaining to the electrical power system (EPS). The objective of this analysis is the development of a comprehensive, computer-based requirements model, using an enhanced modern structured analysis methodology (EMSA). Such a model provides a detailed and consistent representation of the system's requirements. The process outlined in the EMSA methodology is unique in that it allows the graphical modeling of real-time system state transitions, as well as functional requirements and data relationships, to be implemented using modern computer-based tools. These tools permit flexible updating and continuous maintenance of the models. Initial findings resulting from the application of EMSA to the EPS have benefited the space station program by linking requirements to design, providing traceability of requirements, identifying discrepancies, and fostering an understanding of the EPS.
Biernacki, John↗
Counteracting Gravitation In Dielectric Liquids
Force of gravity in variety of dielectric liquids counteracted by imposing suitably contoured electric fields. Technique makes possible to perform, on Earth, variety of experiments previously performed only in outer space and at great cost. Also used similarly in outer space to generate sort of artificial gravitation.
Israelsson, Ulf E.↗
Optical Scattering Characterization for the Glennan Microsystems Microscale Particulate Classifier
Small sensors that are tolerant to mechanically and thermally harsh environments present the possibility for in-situ particle characterization in propulsion, industrial, and planetary science applications. Under a continuing grant from the Glennan Microsystems Initiative to the Microgravity Fluids Physics Branch of the NASA-Glenn Research Center, a Microscale Particle Classifier (MiPAC) instrument is being developed. The MiPAC instrument will be capable of determining the size distribution of airborne particles from about 1 nm to 30 micrometers, and will provide partial information as to the concentration, charge state, shape, and structure of the particles, while being an order of magnitude smaller in size and lighter in weight than presently commercially available instruments. The portion of the instrument that will characterize the nm-range particles will employ electrical mobility techniques and is being developed under a separate grant to Prof. David Pui of the University of Minnesota. The portion of the instrument that will characterize the micrometer-size particles such as dirt, pollens, spores, molds, soot, and combustion aerosols will use light scattering techniques. The development of data analysis techniques to be employed in the light scattering portion of the instrument is covered by this grant.
Lock, James A.↗
Ion Generators
"Kaufman thrusters," or electron bombardment thrusters, were developed for a spacecraft electric propulsion technique called ion propulsion. The technique, conceived by a Lewis Research Center engineer, is used by industry to etch microcircuits for electronic systems and deposition of thin films as coatings on gas atoms to create ions in a discharge chamber. The ions are ejected from the chamber as ion beams, then mixed with an equal number of electrons becoming a thrusting force. Commonwealth Scientific Corporation's product line derives largely from Dr. Kaufman's technology and includes ion sources for a number of applications.
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