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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 487 records · Page 27

User services in the TDRS II era

The next generation Tracking and Data Relay Satellite System (TDRS II) will provide a new level of telemetry, tracking and command services to user spacecraft. In addition to the S-band and Ku-band services, which have made the Space Network concept a reality, a new multifrequency dual-polarization high data rate Ka-band service will also be provided. The S-band multiple-access system will have a larger number of phased array elements, on-board beam forming, and a receive capability equivalent to a single-access antenna. A multifunctional intersatellite link, capable of relaying between TDRS IIs and providing an additional single-access service, is also planned. Enhancements, which include an improved location capability for both the TDRS II and user satellite, a navigation beacon, and a real-time emergency command capability will also be part of the TDRS II. The TDRS II will be three-axis stabilized sufficiently to provide these services to users either on the ground, in low earth orbit, or out to geosynchronous orbit.

Comberiate, Anthony B.↗

Integrated optics for fiber optic sensors

Recent progress achieved in the field of fiber-optic sensor applications is discussed with emphasis placed on LiNbO3-based integrated optics (IO). Particular consideration is given to advanced electromagnetic-field sensors, an integrated laser vibrometer system, and a fiber-optic gyroscope system. It is shown that the multifunction IO chips have enabled high perforamance fiber-optic sensors (e.g., fiber-optic gyros), provided advanced and unique signal processing capabilities and advanced architectures, and have a potential of making fiber-optic sensors at low cost.

Minford, W. J.↗

Flight Testing

It is considered by the Flight Mechanics Panel of AGARD as vitally important that the NATO flight test community meet regularly so that new techniques for flight test, instrumentation and data analysis and lessons learned from past and on-going programs be disseminated to ensure that safe efficient cost-effective and timely testing is accomplished. There are many new systems being tested or planned for testing in the near future. These include programmable signal processor radars, integrated flight, fire and propulsion control systems, thrust vectoring, low observable technologies, multifunction pilot displays and multisensor integration. Acquisition and processing of large quantities of avionics multiplex data are challenges that must be met. There is a need for greater use of simulators and other hardware-in-the-loop ground test facilities.

Source record↗

LADAR vision technology for automated rendezvous and capture

LADAR Vision Technology at Autonomous Technologies Corporation consists of two sensor/processing technology elements: high performance long range multifunction coherent Doppler laser radar (LADAR) technology; and short range integrated CCD camera with direct detection laser ranging sensors. Algorithms and specific signal processing implementations have been simulated for both sensor/processing approaches to position and attitude tracking applicable to AR&C. Experimental data supporting certain sensor measurement accuracies have been generated.

Frey, Randy W.↗

Mars aqueous chemistry experiment

The Mars Aqueous Chemistry Experiment (MACE) is designed to conduct a variety of measurements on regolith samples, encompassing mineral phase analyses, chemical interactions with H2O, and physical properties determinations. From these data, much can be learned or inferred regarding the past weathering environment, the contemporaneous soil micro-environments, and the general chemical and physical state of the Martian regolith. By analyzing both soil and duricrust samples, the nature of the latter may become more apparent. Sites may be characterized for comparative purposes and criteria could be set for selection of high priority materials on future sample return missions. Progress for the first year MACE PIDDP is reported in two major areas of effort: (1) fluids handling concepts, definition, and breadboard fabrication and (2) aqueous chemistry ion sensing technology and test facility integration. A fluids handling breadboard was designed, fabricated, and tested at Mars ambient pressure. The breadboard allows fluid manipulation scenarios to be tested under the reduced pressure conditions expected in the Martian atmosphere in order to validate valve operations, orchestrate analysis sequences, investigate sealing integrity, and to demonstrate efficacy of the fluid handling concept. Additional fluid manipulation concepts have also been developed based on updated MESUR spacecraft definition. The Mars Aqueous Chemistry Experiment Ion Selective Electrode (ISE) facility was designed as a test bed to develop a multifunction interface for measurements of chemical ion concentrations in aqueous solution. The interface allows acquisition of real time data concerning the kinetics and heats of salt dissolution, and transient response to calibration and solubility events. An array of ion selective electrodes has been interfaced and preliminary calibration studies performed.

Clark, Benton C.↗

Preliminary experimental results for a cryogenic brush seal configuration

Preliminary fluid nitrogen flow data are reported for a five-brush, ceramic-coated-rub-runner brush seal system, where the brushes and the rub runner were placed at each end of a centrally pressurized multifunction tester ('back-to-back' set of brushes) and tested at rotor speeds of 0, 10, 18, and 22.5 krpm. After testing, both the brushes and the ceramic-coated rub runner appeared pristine. The coating withstood both the thermomechanical and dynamic loadings with minor wear track scarring. The bristle tips showed some indication of material shearing (smearing) wear. The Ergun porous flow equation was applied to the brush seal data. The Ergun relation, which required heuristic information to characterize the coefficients, fit the gaseous data but was in poor agreement with the fluid results. The brush seal exit conditions were two phase. Two-phase, choked-flow design charts were applied but required one data point at each rotor speed to define the (C(sub f)A x Constant) flow and area coefficients. Reasonable agreement between prediction and data was found, as expected, but such methods are not to be construed as two-phase-flow brush seal analyses.

Carlile, J. A.↗

The Optical Properties Monitor (OPM): a Multipurpose Optical Laboratory in Space

The Optical Properties Monitor (OPM) is a multifunction in-flight laboratory for in-situ optical studies of materials. Many independent and related studies can be carried out on EURECA with the OPM instruments to address the experiment objectives. Test samples will be selected to address the materials and issues of the greatest interest to NASA, ESA, DoD, and the aerospace community. The objective of the OPM program is to study the effects of the space environment, both natural and induced, on optical, thermal control, solar array, and other materials.

Wilkes, Donald R.↗

The NT digital micro tape recorder

The description of an audio recorder may at first glance seem out of place in a conference which has been dedicated to the discussion of the technology and requirements of mass data storage. However, there are several advanced features of the NT system which will be of interest to the mass storage technologist. Moreover, there are a sufficient number of data storage formats in current use which have evolved from their audio counterparts to recommend a close attention to major innovative introductions of audio storage formats. While the existing analog micro-cassette recorder has been (and will continue to be) adequate for various uses, there are significant benefits to be gained through the application of digital technology. The elimination of background tape hiss and the availability of two relatively wide band channels (for stereo recording), for example, would greatly enhance listenability and speech intelligibility. And with the use of advanced high-density recording and LSI circuit technologies, a digital micro recorder can realize unprecedented compactness with excellent energy efficiency. This is what was accomplished with the NT-1 Digital Micro Recorder. Its remarkably compact size contributes to its portability. The high-density NT format enables up to two hours of low-noise digital stereo recording on a cassette the size of a postage stamp. Its highly energy-efficient mechanical and electrical design results in low power consumption; the unit can be operated up to 7 hours (for continuous recording) on a single AA alkaline battery. Advanced user conveniences include a multifunction LCD readout. The unit's compactness and energy-efficiency, in particular, are attributes that cannot be matched by existing analog and digital audio formats. The size, performance, and features of the NT format are of benefit primarily to those who desire improved portability and audio quality in a personal memo product. The NT Recorder is the result of over ten years of intensive, multi-disciplinary research and development. What follows is a discussion of the technologies that have made the NT possible: (1) NT format mechanics, (2) NT media, (3) NT circuitry and board.

Sasaki, Toshikazu↗

Research and applications in structural dynamics and aeroelasticity

Results of some recently completed research programs in aeroelasticity and structural dynamics at the NASA Langley Research Center are presented. It is shown that multifunctional active controls can be used to control flutter and loads on future advanced fighter configurations. A description and early results of an experimental program are presented in order to provide a well documented data base for validating unsteady aerodynamic codes. It is shown that the degradation in aeroelastic behavior due to thermal effects on a hypersonic vehicle can be offset by the use of active controls. The feasibility of using adaptive materials to control flutter is demonstrated experimentally. A description of the latest unstructured grid methods for use in advanced computational unsteady aerodynamic codes is presented. A program to improve the ability of FEMs to predict rotorcraft vibrational characteristics is described. The use of aeroelastic tailoring to improve the performance of tilt rotor vehicles is examined.

Abel, Irving↗

Sensor systems for regenerative life support systems

Successful operation of life support systems for space exploration missions of the future will require unique sophisticated sensor systems for highly dependable operation, i.e., autonomous and fault tolerant. These sensor systems will require the use of multifunctional in situ sensors that are strategically located throughout the life support systems. These sensors will communicate through control loops that are hierarchically interconnected at several levels of the life support system. Development of the sensor system must be done synergistically with the integration and testing of the subsystems, and their process units, as they are assembled and tested. The plan for proceeding with the sensor systems development and the integration with the test bed assembly and operation is described in this paper.

Voecks, Gerald E.↗

Preliminary experimental results for a cryogenic brush seal configuration

Preliminary fluid nitrogen flow data are reported for a five-brush, ceramic-coated-rub-runner brush seal system, where the brushes and the rub runner were placed at each end of a centrally pressurized multifunction tester ('back-to-back' set of brushes) and tested at rotor speeds of 0, 10, 18, and 22.5 krpm. After testing, both the brushes and the ceramic-coated rub runner appeared pristine. The coating withstood both the thermomechanical and dynamic loadings with minor wear track scarring. The bristle tips showed some indication of material shearing (smearing) wear. The Ergun (1952) porous flow equation was applied to the brush seal data. The Ergun relation fit the gaseous data but was in poor agreement with the fluid results. The brush seal exit conditions were two phase. Two-phase, choked-flow design charts were applied but required one data point at each rotor speed to define the flow and area coefficients. Reasonable agreement between prediction and data was found, but such methods are not to be construed as two-phase-flow brush seal analyses.

Carlile, J. A.↗

Superconductivity devices: Commercial use of space

The work described in this report covers various aspects of the Rainbow solid-state actuator technology. It is presented in six parts dealing with materials, processing, fabrication, properties and associated phenomena. The Rainbow actuator technology is a relatively new materials development which had its inception in 1992. It consists of a new processing technology for preparing piezoelectric and electrostrictive ceramic materials. It involves a high temperature chemical reduction process which leads to an internal pre-stressing of the oxide wafer, thus the name Rainbow, an acronym for Reduced And INternally Biased Oxide Wafer. Ceramics fabricated by this method produce bending-mode actuator devices which possess several times more displacement and load bearing capacity than present-day benders (unimorphs, bimorphs). It is anticipated that these solid-state, electromechanical actuators which can be used in a number of applications in space such as cryopump motors, anti-vibration active structures, autoleveling platforms, telescope mirror correctors and autofocusing devices. When considering any of these applications, the key to the development of a successful device is the successful development of a ceramic material which can produce maximum displacement per volt input; hence, this initiative involving a solid-state means for achieving unusually high electromechanical displacement can be significant and far reaching. An additional benefit obtained from employing the piezoelectric effect in these actuator devices is the ability to also utilize them as sensors; and, indeed, they can be used as both motor (actuator) and generator (sensor) in multifunction devices.

Haertling, Gene↗

Processing of Fine-Scale Piezoelectric Ceramic/Polymer Composites for Sensors and Actuators

The objective of the research effort at Rutgers is the development of lead zirconate titanate (PZT) ceramic/polymer composites with different designs for transducer applications including hydrophones, biomedical imaging, non-destructive testing, and air imaging. In this review, methods for processing both large area and multifunctional ceramic/polymer composites for acoustic transducers were discussed.

Janas, V. F.↗

Silicon Micromachined Sensor for Broadband Vibration Analysis

The development of a family of silicon based integrated vibration sensors capable of sensing mechanical resonances over a broad range of frequencies with minimal signal processing requirements is presented. Two basic general embodiments of the concept were designed and fabricated. The first design was structured around an array of cantilever beams and fabricated using the ARPA sponsored multi-user MEMS processing system (MUMPS) process at the Microelectronics Center of North Carolina (MCNC). As part of the design process for this first sensor, a comprehensive finite elements analysis of the resonant modes and stress distribution was performed using PATRAN. The dependence of strain distribution and resonant frequency response as a function of Young's modulus in the Poly-Si structural material was studied. Analytical models were also studied. In-house experimental characterization using optical interferometry techniques were performed under controlled low pressure conditions. A second design, intended to operate in a non-resonant mode and capable of broadband frequency response, was proposed and developed around the concept of a cantilever beam integrated with a feedback control loop to produce a null mode vibration sensor. A proprietary process was used to integrat a metal-oxide semiconductor (MOS) sensing device, with actuators and a cantilever beam, as part of a compatible process. Both devices, once incorporated as part of multifunction data acquisition and telemetry systems will constitute a useful system for NASA launch vibration monitoring operations. Satellite and other space structures can benefit from the sensor for mechanical condition monitoring functions.

Gutierrez, Adolfo↗

AOPA Survey Summary of AGATE Concepts Demonstration October 17-19, 1996: Basic Report - Volume 1

An AGATE Concepts Demonstration was conducted at the Annual Aircraft Owners and Pilots Association (AOPA) Convention in 1996. The demonstration consisted of an interactive simulation of a single-pilot, single-engine aircraft in which the participant took off, flew a brief enroute segment and then flew a Global Positioning System (GPS) approach and landing. The participant was provided an advanced 'pathway-in-the-sky' presentation on both a head-up display and a head-down display to follow throughout the flight. A single lever power control and display concept was also provided for control of the engine throughout the flight. A second head-down, multifunction display in the instrument panel provided a moving map display for navigation purposes and monitoring of the status of the aircraft's systems. An estimated 352 people observed or participated in the demonstration, and 144 surveys were collected. The pilot ratings of the participants ranged from student to Air Transport Rating with an average of 1850 hours total flight time. The performance of the participants was surprisingly good, considering the minimal training in a completely new system concept. The overwhelming response was that technologies that simplify piloting tasks are enthusiastically welcomed by pilots of all experience levels. The increase in situation awareness and reduction in pilot workload were universally accepted and lauded as steps in the right direction.

Source record↗

AOPA Survey Summary of AGATE Concepts Demonstration, October 17-19, 1996: Original Survey Data - Volume 2

An AGATE Concepts Demonstration was conducted at the Annual Aircraft Owners and Pilots Association (AOPA) Convention in 1996. The demonstration consisted of an interactive simulation of a single-pilot, single-engine aircraft in which the participant took off, flew a brief enroute segment and then flew a Global Positioning System (GPS) approach and landing. The participant was provided an advanced 'pathway-in-the-sky' presentation on both a head-up display and a head-down display to follow throughout the flight. A single lever power control and display concept was also provided for control of the engine throughout the flight A second head-down, multifunction display in the instrument panel provided a moving map display for navigation purposes and monitoring of the status of the aircraft's systems. An estimated 352 people observed or participated in the demonstration, and 144 surveys were collected. The pilot ratings of the participants ranged from student to Air Transport Rating with an average of 1850 hours total flight time. The performance of the participants was surprisingly good, considering the minimal training in a completely new system concept. The overwhelming response was that technologies that simplify piloting tasks are enthusiastically welcomed by pilots of all experience levels. The increase in situation awareness and reduction in pilot workload were universally accepted and lauded as steps in the right direction.

Source record↗

Dual Regulation of a Chimeric Plant Serine/Threonine Kinase by Calcium and Calcium/Calmodulin

A chimeric Ca(2+)/calmodulin-dependent protein kinase (CCaMK) gene characterized by a catalytic domain, a calmodulin-binding domain, and a neural visinin-like Ca(2+)-binding domain was recently cloned from plants. The Escherichia coli-expressed CCaMK phosphorylates various protein and peptide substrates in a Ca(2+)/calmodulin-dependent manner. The calmodulin-binding region of CCAMK has similarity to the calmodulin-binding region of the alpha-subunit of multifunctional Ca(2+)/calmodulin-dependent protein kinase (CaMKII). CCaMK exhibits basal autophosphorylation at the threonine residue(s) (0.098 mol of P-32/mol) that is stimulated 3.4-fold by Ca(2+) (0.339 mol of P-32/mol), while calmodulin inhibits Ca(2+)-stimulated autophosphorylation to the basal level. A deletion mutant lacking the visinin-like domain did not show Ca(2+)-simulated autophosphorylation activity but retained Ca(2+)/calmodulin-dependent protein kinase activity at a reduced level. Ca(2+)-dependent mobility shift assays using E.coli-expressed protein from residues 358-520 revealed that Ca(2+) binds to the visinin-like domain. Studies with site-directed mutants of the visinin-like domain indicated that EF-hands II and III are crucial for Ca(2+)-induced conformational changes in the visinin-like domain. Autophosphorylation of CCaMK increases Ca(2+)/calmodulin-dependent protein kinase activity by about 5-fold, whereas it did not affect its C(2+)-independent activity. This report provides evidence for the existence of a protein kinase in plants that is modulated by Ca(2+) and Ca(2+)/calmodulin. The presence of a visinin-like Ca(2+)-binding domain in CCaMK adds an additional Ca(2+)-sensing mechanism not previously known to exist in the Ca(2+)/calmodulin-mediated signaling cascade in plants.

Takezawa, D.↗

Automated Liquid-Level Control of a Nutrient Reservoir for a Hydroponic System

A microprocessor-based system for control of the liquid level of a nutrient reservoir for a plant hydroponic growing system has been developed. The system uses an ultrasonic transducer to sense the liquid level or height. A National Instruments' Multifunction Analog and Digital Input/Output PC Kit includes NI-DAQ DOS/Windows driver software for an IBM 486 personal computer. A Labview Full Development system for Windows is the graphical programming system being used. The system allows liquid level control to within 0.1 cm for all levels tried between 8 and 36 cm in the hydroponic system application. The detailed algorithms have been developed and a fully automated microprocessor based nutrient replenishment system has been described for this hydroponic system.

Smith, Boris↗