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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 289 records · Page 16

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NASA NTRS1974

Medical results of the Skylab program

The Skylab food system, waste management system, operational bioinstrumentation, personal hygiene provisions, in-flight medical support system, and the cardiovascular counterpressure garment worn during reentry are described. The medical experiments program provided scientific data and also served as the basis for real-time decisions on flight duration. Premission support, in-flight operational support, and postflight medical activities are surveyed. Measures devised to deal with possible food spoilage, medical instrument damage, and toxic atmosphere caused by the initial failures on the Orbital Workshop (OWS) are discussed. The major medical experiments performed in flight allowed the study of physiological changes as a function of exposure to weightless flight. The experiments included studies of the cardiovascular system, musculoskeletal and fluid/electrolyte balance, sleep, blood, vestibular system, and time and motion studies.

Johnston, R. S.↗

NASA NTRS1974

Experiments in determining the outgassing of spacecraft in the vacuum environment

As spacecraft become more sophisticated, their contamination becomes of increasing concern. The use of real-time monitors, such as the quartz crystal microbalance, and post-test methods such as the chemical analysis of residuals, has been combined with a number of analytical techniques in contamination-related investigations at the Goddard Space Flight Center. These include the establishment of the cause of an orbital failure, the determination of component outgassing rates, and the monitoring of contaminants in vacuum chambers and in orbit. Improved capabilities appear possible with measurement methods such as attenuated total reflectance and better analytical modeling of the contaminant flux environment.

Kruger, R.↗

NASA NTRS1975

New capabilities for the Wallops Island SPANDAR

Systems incorporated into the SPANDAR to increase spatial resolution and data processing capabilities are described. They include a minicomputer that performs real-time formatting of video data, rapid antenna scan control, and control of a digital integrator; a frequency diversity technique for faster accumulation of independent video samples; the on-line calibration system for insertion of high and low calibration signals during every PRF interval; and utilization of a large capacity, high speed computer. The resultant data will be used to create statistical thunderstorm models for designing microwave communications systems.

Kropfli, R. A.↗

NASA NTRS1974

Laser holographic detection of tiny thin tapes beneath a thick opaque composite structure

Real-time laser holographic interferometry technique has been applied successfully in the detection of 1mm x 1mm x 0.025mm duct tapes hidden beneath a 150mm x 150mm x 16mm ceramic-epoxy-fiberglass sandwiched structure. The experimental results clearly demonstrate future applicability of this technique in the optical nondestructive detection of debonds and flaws in such composite structures.

Liu, H.-K.↗

NASA NTRS1975

Acquisition and description of Mariner 10 television science data at Mercury

The Mariner 10 television science subsystem was an improved version of the Mariner 9 system, using 1500-mm-focal-length optics. An elaborate picture-taking sequence resulted in transmission of over 4000 frames back to earth during two flyby encounters with Mercury. These sequences utilized a real-time data rate of 117.6 kbit/s, resulting in coverage of about 75% of the lighted portion of Mercury's surface at a resolution of better than 2 km. The complete set of useful images, which amounted to about 3000 frames, was processed with three different types of digital image-processing enhancements.

Danielson, G. E., Jr.↗

NASA NTRS1974

Ways of achieving continuous service from computers

This paper outlines the methods used in the real-time computer complex to keep computers operating. Methods include selectover, high-speed restart, and low-speed restart. The hardware and software needed to implement these methods is discussed as well as the system recovery facility, alternate device support, and timeout. In general, methods developed while supporting the Gemini, Apollo, and Skylab space missions are presented.

Quinn, M. J., Jr.↗

NASA NTRS1974

Environment-sensitive manipulator control

Environment-sensitive manipulator control (control systems capable of controlling manipulator motion based on real-time response to sensor data obtained during the attempt to perform a requested task) is described, and experiments on (1) proximity control in manipulation and (2) application of an articulated and adaptively controlled hand-to-environment-sensitive manipulator control are reported. The efficiency of such systems is determined by the separation of control and data processing functions between operator and computer.

Bejczy, A. K.↗

NASA NTRS1975

A distributed data base management system

Major system design features of a distributed data management system for the NASA Deep Space Network (DSN) designed for continuous two-way deep space communications are described. The reasons for which the distributed data base utilizing third-generation minicomputers is selected as the optimum approach for the DSN are threefold: (1) with a distributed master data base, valid data is available in real-time to support DSN management activities at each location; (2) data base integrity is the responsibility of local management; and (3) the data acquisition/distribution and processing power of a third-generation computer enables the computer to function successfully as a data handler or as an on-line process controller. The concept of the distributed data base is discussed along with the software, data base integrity, and hardware used. The data analysis/update constraint is examined.

Bryan, A. I.↗

NASA NTRS1975

Comparison of inferred and observed interplanetary magnetic field polarities, 1970-1972

The inferred polarity (toward or away from the sun) of the interplanetary magnetic field at earth using polar observations of the geomagnetic field has been compared with spacecraft observations. A list published by Svalgaard (1974) of the inferred field polarities in the period from 1970 to 1972 is found to be correct on 82% of the days. A near real-time (same day) method of inferring the polarity of the interplanetary magnetic field using geomagnetic observations at Vostok and Thule is in use at the NOAA Space Environment Laboratory, Boulder, Colorado. During 1972, this method is found to be correct on 87% of the days. A list of 'well-defined' sector boundaries at earth from 1970 to 1972 is given.

Wilcox, J. M.↗

NASA NTRS1975

Design and simulation of a descent controller for strategic four-dimensional aircraft navigation

A time-controlled navigation system applicable to the descent phase of flight for airline transport aircraft was developed and simulated. The design incorporates the linear discrete-time sampled-data version of the linearized continuous-time system describing the aircraft's aerodynamics. Using optimal linear quadratic control techniques, an optimal deterministic control regulator which is implementable on an airborne computer is designed. The navigation controller assists the pilot in complying with assigned times of arrival along a four-dimensional flight path in the presence of wind disturbances. The strategic air traffic control concept is also described, followed by the design of a strategic control descent path. A strategy for determining possible times of arrival at specified waypoints along the descent path and for generating the corresponding route-time profiles that are within the performance capabilities of the aircraft is presented. Using a mathematical model of the Boeing 707-320B aircraft along with a Boeing 707 cockpit simulator interfaced with an Adage AGT-30 digital computer, a real-time simulation of the complete aircraft aerodynamics was achieved. The strategic four-dimensional navigation controller for longitudinal dynamics was tested on the nonlinear aircraft model in the presence of 15, 30, and 45 knot head-winds. The results indicate that the controller preserved the desired accuracy and precision of a time-controlled aircraft navigation system.

Lax, F. M.↗

NASA NTRS1975

A flexible flight display research system using a ground-based interactive graphics terminal

Requirements and research areas for the air transportation system of the 1980 to 1990's were reviewed briefly to establish the need for a flexible flight display generation research tool. Specific display capabilities required by aeronautical researchers are listed and a conceptual system for providing these capabilities is described. The conceptual system uses a ground-based interactive graphics terminal driven by real-time radar and telemetry data to generate dynamic, experimental flight displays. These displays are scan converted to television format, processed, and transmitted to the cockpits of evaluation aircraft. The attendant advantages of a Flight Display Research System (FDRS) designed to employ this concept are presented. The detailed implementation of an FDRS is described. The basic characteristics of the interactive graphics terminal and supporting display electronic subsystems are presented and the resulting system capability is summarized. Finally, the system status and utilization are reviewed.

Hatfield, J. J.↗

NASA NTRS1975

Landmark tracking technology

This paper summarizes the justification and technical approach of an experimental plan for landmark recognition and tracking from the Advanced Technology Laboratory (ATL). The primary experimental approach is that of near real-time pattern recognition by means of coherent optical techniques. An experiment development plan would lead to a flight test in 1981.

Welch, J. D.↗

NASA NTRS0992

Current status: Animal models of nausea

The advantages, and possible benefits of a valid, reliable animal model for nausea are discussed, and difficulties inherent to the development of a model are considered. A principle problem for developing models arises because nausea is a subjective sensation that can be identified only in humans. Several putative measures of nausea in animals are considered, with more detailed consideration directed to variation in cardiac rate, levels of vasopressin, and conditioned taste aversion. Demonstration that putative measures are associated with reported nausea in humans is proposed as a requirement for validating measures to be used in animal models. The necessity for a 'real-time' measure of nausea is proposed as an important factor for future research; and the need for improved understanding of the neuroanatomy underlying the emetic syndrome is discussed.

Robert A Fox↗

NASA NTRS1961

Project Echo: Antenna Steering System

The Project Echo communications experiment employed large, steerable,transmitting and receiving antennas at the ground terminals. It was necessary that these highly directional antennas be continuously and accurately pointed at the passing satellite. This paper describes a new type of special purpose data converter for directing narrow-beam communication antennas on the basis of predicted information. The system is capable of converting digital input data into real-time analog voltage commands with a dynamic accuracy of +/- 0.05 degree, which meets the requirements of the present antennas.

Klahn, R.↗

NASA NTRS1971

Detecting Oil on Water: A Comparison of Known Techniques

This paper reviews new developments in oil pollution detection and compares available techniques according to their effectiveness. Emphasis is on in situ and remote sensing techniques, with a potential for real-time, automated operation. No mention is made of traditional methods, requiring that a sample be taken to a laboratory for tests of solubility, chemical reactions, or other properties.

Klemas, Vytautas↗

NASA NTRS1968

The Use of Large Lithium-Drifted, Germanium Diodes for Gamma-Ray Spectral Measurements at Balloon Altitudes

A series of balloon-borne experiments has been initiated at the Oak Ridge National Laboratory (ORNL) in cooperation with the Space Sciences Laboratory of the NASA G. C. Marshall Space Flight Center to determine the feasibility of using large (greater than 20 cc) lithium-drifted, germanium diodes to investigate the spectrum of atmospheric gamma rays (60 keV < E < 1.5 MeV) at altitudes corresponding to a few grams per cm (sup 2) residual atmosphere. The results of these measurements will also provide a basis for designing an appropriate shield for a multi-diode, highly directional gamma-ray spectrometer for use in astrophysical measurements. Two flights were accomplished during 1967 using the same two diodes and basic instrument package. Both flights were launched at the NCAR Scientific Balloon Flight Base, Palestine, Texas, and attained a float altitude of 117, 000 ft. The measured atmospheric gamma-ray spectrum shows at least one distinct line at 511 keV (annihilation radiation) superimposed on a continuous distribution of gamma rays attributable to both energy-degraded gamma rays and brems-strahlung photons. A second diode, encased in a passive shield of plastic and lead, shows the expected lines resulting from both neutron inelastic scattering and capture in the germanium. Data acquisition was accomplished on an event-by-event basis through the use of 512-channel, on-board ADC and word-generator circuits and a ground-based, on-line telemetry decoder. The decoder makes it possible to store the data in the memory of a modified pulse-height analyzer simultaneously with storage on magnetic tape. This provides a real-time visual observation of the data as it is accumulated and greatly facilitates preflight calibrations.

Chapman, G. T.↗

NASA NTRS1966

Manned Space-Flight Experiments: Gemini V Mission (Interim Report)

This compilation of papers constitutes an interim report on the results of experiments conducted during the Gemini V manned space flight. The results of experiments conducted on Gemini III and IV manned space flights have been published previously in a similar interim report, "Manned Space Flight Experiments Symposium, Gemini Missions III and IV," which is available upon request from MSC Experiments Program Office, Houston, Texas (Code EX, Attention of R. Kinard). The Gemini V mission provided the greatest opportunity to date for conducting experiments; the increased mission duration of eight days provided this added capability. The total mission experiment complement was seventeen. Five experiments were designed to obtain basic scientific knowledge, five were medical, and seven were technological and engineering in nature. Six of the experiments had flown previously on Gemini IV, and eleven were new. The results of the experiments, including real-time modification to preflight plans made necessary by abnormal spacecraft system operation, are presented.

Source record↗

NASA NTRS1972

A Holographic Interferometer System for Measuring Density Profiles in High-Velocity Flows

This paper describes a holographic interferometric technique for obtaining density measurements across a test gas that is traveling at a velocity of over 5500 meters per second in an expansion tube facility. Interferometric data describing the flow in the test section are obtained using a long coherence length cw argon laser in a holographic system and a rotating drum camera recorder. The object beam, which passes through the test section, intersects the reference beam at a small angle (5 degrees) to form an interference pattern of about 170 lines per millimeter, and is recorded as a hologram. Before a test, this hologram is placed in its original position and rotated slightly so that an interference pattern is generated by the intersection of the reconstructed and real-time object beams. This interference pattern is adjusted to a series of bright, horizontal fringes having a spatial frequency of about 5 fringes per centimeter. During the few milliseconds it takes the test gas to pass through the test section, variations in the gas density across the 8.4-centimeter test section produce phase variations in the object beam and result in a varying interference pattern. A rotating drum camera with a 0.15-millimeter slit aligned perpendicular to the fringes is used to record the varying fringe shifts with a time resolution of about 3 microseconds. The average gas density across the test section is determined by measuring these fringe shifts.

Burner, Alpheus W.↗