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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 505 records · Page 28
All sourcesNASA NTRSDOE OSTI
NASA NTRS1983

A flight-test and simulation evaluation of the longitudinal final approach and landing performance of an automatic system for a light wing loading STOL aircraft

As part of a comprehensive flight-test program of STOL operating systems for the terminal area, an automatic landing system was developed and evaluated for a light wing loading turboprop aircraft. The aircraft utilized an onboard advanced digital avionics system. Flight tests were conducted at a facility that included a STOL runway site with a microwave landing system. Longitudinal flight-test results were presented and compared with available (basically CTOL) criteria. These comparisons were augmented by results from a comprehensive simulation of the controlled aircraft which included representations of navigation errors that were encountered in flight and atmospheric disturbances. Acceptable performance on final approach and at touchdown was achieved by the autoland (automatic landing) system for the moderate winds and turbulence conditions encountered in flight. However, some touchdown performance goals were marginally achieved, and simulation results suggested that difficulties could be encountered in the presence of more extreme atmospheric conditions. Suggestions were made for improving performance under those more extreme conditions.

Brown, S. C.↗
NASA NTRS1983

Statistical aspects of the 1980 solar flares. Part 3: Parametric comparison and final comments

The 1349 study flares are considered addressing relationships between pairs of specific study paremeters; namely, H alpha rise time versus H alpha importance, X-ray class and H alpha decay time; H alpha decay time versus H alpha importance and X-ray class; and H alpha importance versus X-ray class. Mean H alpha rise time and decay time versus X-ray class and H alpha importance will also be discussed, and some final comments regarding the study flares are given.

Wilson, R. M.↗
NASA NTRS1984

A flight-test and simulation evaluation of the longitudinal final approach and landing performance of an automatic system for a light wing loading STOL aircraft equipped with wing spoilers

As part of a comprehensive flight-test investigation of short takeoff and landing (STOL) operating systems for the terminal systems for the terminal area, an automatic landing system has been developed and evaluated for a light wing-loading turboprop-powered aircraft. An advanced digital avionics system performed display, navigation, guidance, and control functions for the test aircraft. Control signals were generated in order to command powered actuators for all conventional controls and for a set of symmetrically driven wing spoilers. This report describes effects of the spoiler control on longitudinal autoland (automatic landing) performance. Flight-test results, with and without spoiler control, are presented and compared with available (basically, conventional takeoff and landing) performance criteria. These comparisons are augmented by results from a comprehensive simulation of the controlled aircraft that included representations of the microwave landing system navigation errors that were encountered in flight as well as expected variations in atmospheric turbulence and wind shear. Flight-test results show that the addition of spoiler control improves the touchdown performance of the automatic landing system. Spoilers improve longitudinal touchdown and landing pitch-attitude performance, particularly in tailwind conditions. Furthermore, simulation results indicate that performance would probably be satisfactory for a wider range of atmospheric disturbances than those encountered in flight. Flight results also indicate that the addition of spoiler control during the final approach does not result in any measurable change in glidepath track performance, and results in a very small deterioration in airspeed tracking. This difference contrasts with simulations results, which indicate some improvement in glidepath tracking and no appreciable change in airspeed tracking. The modeling problem in the simulation that contributed to this discrepancy with flight was not resolved.

Brown, S. C.↗
NASA NTRS1985

Joint research effort on vibrations of twisted plates, phase 1: Final results

The complete theoretical and experimental results of the first phase of a joint government/industry/university research study on the vibration characteristics of twisted cantilever plates are given. The study is conducted to generate an experimental data base and to compare many different theoretical methods with each other and with the experimental results. Plates with aspect ratios, thickness ratios, and twist angles representative of current gas turbine engine blading are investigated. The theoretical results are generated by numerous finite element, shell, and beam analysis methods. The experimental results are obtained by precision matching a set of twisted plates and testing them at two laboratories. The second and final phase of the study will concern the effects of rotation.

Kielb, R. E.↗
NASA NTRS1984

A final report on the extension of the MCSCF/CI method

For the period of July 1982 through January 1983, the research carried out focused on the nature of metal adsorbate bonding. Two main areas were investigated in detail: (1) the adsorption of CO on Al, Na, Mg and Ni; and (2) bonding in transition metal oxides, CuO, CrO and MoO. These theoretical studies have lead to a new understanding of CO-metal bonding as well as to a better understanding of the d involvement in the bonding in transition metal oxides. Four areas associated with cluster model studies are discussed in detail: hybridization and changing in cluster model studies, the adsorption of CO on metals (Al, Na, Mg), the adsorption of CO on Ni, and finally the use of effective core potentials (ECP) in cluster models.

Nelin, C. J.↗
NASA NTRS1987

Space station final study report. Volume 1: Executive summary

Volume 1 of the Final Study Report provides an Executive Summary of the Phase B study effort conducted under contract NAS8-36526. Space station Phase B implementation resulted in the timely establishment of preliminary design tasks, including trades and analyses. A comprehensive summary of project activities in conducting this study effort is included.

Source record↗
NASA NTRS1987

Shuttle Ground Operations Efficiencies/Technologies (SGOE/T) study. Volume 3: Final presentation material

Charts used in the Final Phase 1 Oral Briefing at Kennedy Space Center on April 6, 1987, and to the Space Transportation Architecture Study (SPAS) Interim Program Review (IPS-5) held at MSFC on April 8, 1987, are contained. Topics discussed include: identification of existing or new technologies to reduce cost; management approaches; recommendations for research or development of specific technology for future use; and identification of new management techniques.

Scholz, A. L.↗
NASA NTRS1986

An observational study of the final warming in the Southern Hemisphere stratosphere

The final warming in the Southern Hemisphere stratosphere during the period September 1-November 30 for the years 1978-1983 is studied. The change in zonally averaged temperatures during that period is almost the same for each year. However, there is substantial interannual variability in the time evolution of the warming as events of enhanced wave, mean-flow interaction associated with bursts of upward propagating planetary waves develop at different times in different years. Polar temperatures in the middle stratosphere can increase as much as about 20 K in 4 days during these events. Such dynamical processes can play a significant role in the interannual variability of stratospheric ozone and other constituents.

Farrara, John D.↗
NASA NTRS1988

Development of an advanced high-speed rotor - Final results from the Advanced Flight Research Rotor program

The final results of the Advanced Flight Research Rotor (AFRR) study, a NASA sponsored research program, are summarized. First, the results of the initial phase of the AFRR program, consisting of the definition of a conventional rotor with planform and prescribed twist distributions, are briefly reviewed. The mechanism of the calculated performance benefit is then explained, and a detailed analysis of the prescribed twist distribution is presented. Recommendations are made on the practical means of approximating the prescribed twist on the actual rotor.

Jenks, Mark↗
NASA NTRS1989

Design of a final approach spacing tool for TRACON air traffic control

This paper describes an automation tool that assists air traffic controllers in the Terminal Radar Approach Control (TRACON) Facilities in providing safe and efficient sequencing and spacing of arrival traffic. The automation tool, referred to as the Final Approach Spacing Tool (FAST), allows the controller to interactively choose various levels of automation and advisory information ranging from predicted time errors to speed and heading advisories for controlling time error. FAST also uses a timeline to display current scheduling and sequencing information for all aircraft in the TRACON airspace. FAST combines accurate predictive algorithms and state-of-the-art mouse and graphical interface technology to present advisory information to the controller. Furthermore, FAST exchanges various types of traffic information and communicates with automation tools being developed for the Air Route Traffic Control Center. Thus it is part of an integrated traffic management system for arrival traffic at major terminal areas.

Davis, Thomas J.↗
NASA NTRS1989

Final Environmental Impact Statement for the Galileo Mission (Tier 2)

This Final Environmental Impact Statement (FEIS) addresses the proposed action of completing the preparation and operation of the Galileo spacecraft, including its planned launch on the Space Transportation System (STS) Shuttle in October 1989, and the alternative of canceling further work on the mission. The Tier 1 (program level) EIS (NASA 1988a) considered the Titan IV launch vehicle as an alternative booster stage for launch in May 1991 or later. The May 1991 Venus launch opportunity is considered a planetary back-up for the Magellan (Venus Radar Mapper) mission, the Galileo mission, and the Ulysses mission. Plans were underway to enable the use of a Titan IV launch vehicle for the planetary back-up. However, in November 1988, the U.S. Air Force, which procures the Titan IV for NASA, notified NASA that it could not provide a Titan IV vehicle for the May 1991 launch opportunity due to high priority Department of Defense requirements. Consequently, NASA terminated all mission planning for the Titan IV planetary back-up. A minimum of 3 years is required to implement mission-specific modifications to the basic Titan IV launch configuration; therefore, insufficient time is available to use a Titan IV vehicle in May 1991. Thus, the Titan IV launch vehicle is no longer a feasible alternative to the STS/Inertial Upper Stage (IUS) for the May 1991 launch opportunity.

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NASA NTRS1989

Long range geoid control through the European GPS traverse: Final results

The European north-south Global Positioning System (GPS)-traverse proposed by IAG SSG 3.88, should control and improve the European geoid. This traverse follows first order leveling lines, included in the United European Leveling Network. From May to August 1986 and in July 1987, the central and northern part of this traverse (approx. 3000 km) was observed using up to four TI 4100 receivers, covering Austria, Federal Republic of Germany, Denmark, Sweden and Norway. Both traverse parts contain 71 stations with distances of about 50 km. In addition, 8 stations have been occupied for overlapping connections, and traverse links were established for connecting the fundamental stations Wettzell (VLBI and SLR) and Onsala (VLBI). Final results show a GPS observation precision of a few cm for loops of some 100 km circumference. After transformation of the GPS results to geoid heights using the leveled heights, comparisons with different existing gravimetric geoid determinations including geopotential models were performed. In addition, new geopotential models complete to degree and order 360 tailored to gravity data in Europe, and gravimetric geoid solutions using 6 x 10' mean gravity anomalies were investigated. The comparison with GPS and leveling yields rms discrepancies of + or - 0.1...0.2 m over 1000 km traverse sections for the best solutions, but a strong slope is existing in Sweden and southern Norway in almost all solutions, which is probably caused by systematic errors in the available gravity data for Scandinavia. This is confirmed by a new geoid computation at the Danish Geodetic Institute where the slope has disappeared. If this new solution is taken for the northern traverse section and the best solution for the central part, the rms discrepancy reduces to approximately + or - 0.2 m over 3000 km. Thus, a + or - 10 (exp 7) relative height accuracy seems to be achievable over long distances with the GPS/leveling and the gravimetric geoid calculation techniques, applied in this experiment.

Torge, W.↗
NASA NTRS1988

Final (Tier 1) environmental impact statement for the Galileo and Ulysses Missions

Presented here is a Final (Tier 1) Environmental Impact Statement (EIS) addressing the potential environmental consequences associated with continuing the modifications of the Galileo and Ulysses spacecraft for launch using a booster/upper stage combination that is different from the one planned for use prior to the Challenger accident, while conducting the detailed safety and environmental analysis in order to preserve the October 1989 launch opportunity for Galileo and an October 1990 launch opportunity for Ulysses. While detailed safety and environmental analyses associated with the missions are underway, they currently are not complete. Nevertheless, sufficient information is available to enable a choice among the reconfiguration alternatives presented. Relevant assessments of the potential for environmental impacts are presented.

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NASA NTRS1989

Final environmental impact statement for the Galileo Mission (Tier 2)

This Final Environmental Impact Statement (FEIS) addresses the proposed action of completing the preparation and operation of the Galileo spacecraft, including its planned launch on the Space Transportation System (STS) Shuttle in October 1989, and the alternative of canceling further work on the mission. The only expected environmental effects of the proposed action are associated with normal launch vehicle operation, and are treated in published National Environmental Policy Act (NEPA) documents on the Shuttle (NASA 1978) and the Kennedy Space Center (NASA 1979), and in the KSC Environmental Resources Document (NASA 1986) and the Galileo Tier 1 EIS (NASA 1988a). The environmental impacts of a normal launch were deemed insufficient to preclude Shuttle operations. Environmental impacts may also result from launch or mission accidents that could release plutonium fuel used in the Galileo power system. Intensive analysis of the possible accidents associated with the proposed action reveal small health or environmental risks. There are no environmental impacts in the no-action alternative. The remote possibility of environmental impacts of the proposed action must be weighed against the large adverse fiscal and programmatic impacts inherent in the no-action alternative.

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NASA NTRS1990

Final Environmental Impact Statement for the Ulysses Mission (Tier 2)

This Final (Tier 2) Environmental Impact Statement (FEIS) addresses the environmental impacts which may be caused by implementation of the Ulysses mission, a space flight mission to observe the polar regions of the Sun. The proposed action is completion of preparation and operation of the Ulysses spacecraft, including its planned launch at the earliest available launch opportunity on the Space Transportation System (STS) Shuttle in October 1990 or in the backup opportunity in November 1991. The alternative is canceling further work on the mission. The Tier 1 EIS included a delay alternative which considered the Titan 4 launch vehicle as an alternative booster stage for launch in 1991 or later. This alternative was further evaluated and eliminated from consideration when, in November 1988, the U.S. Air Force, which procures the Titan 4, notified that it could not provide a Titan 4 vehicle for the 1991 launch opportunity because of high priority Department of Defense requirements. The Titan 4 launch vehicle is no longer a feasible alternative to the STS/Inertial Upper Stage (IUS)/Payload Assist Module-Special (PAM-S) for the November 1991 launch opportunity. The only expected environment effects of the proposed action are associated with normal launch vehicle operation and are treated elsewhere. The environmental impacts of normal Shuttle launches were addressed in existing NEPA documentation and are briefly summarized. These impacts are limited largely to the near-field at the launch pad, except for temporary stratospheric ozone effects during launch and occasional sonic boom effects near the landing site. These effects were judged insufficient to preclude Shuttle launches. There could also be environmental impacts associated with the accidental release of radiological material during launch, deployment, or interplanetary trajectory injection of the Ulysses spacecraft. Intensive analysis indicates that the probability of release is small. There are no environmental impacts in the no-action alternative; however, the U.S. Government and the European Space Agency would suffer adverse fiscal and programmatic impacts if this alternative were adopted. The scientific benefits of the mission would be delayed and possibly lost. There could be significant impacts on the ability of the U.S. to negotiate international agreements for cooperative space activities.

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NASA NTRS1989

Anatomical study of the final common pathway for vocalization in the cat

Results are presented of an anatomical study of the neuronal pathways in the cat, via which the periaqueductal gray (PAG) produces excitation of motoneurons involved in vocalization. It is shown that a specific cell group in the lateral part of the caudal PAG and in the tegmentum just lateral to it projects bilaterally to the nucleus retroambiguus (NRA) in the caudal medulla oblongata. Neurons in the NRA in turn project, via a contralateral pathway through the ventral funiculus of the spinal cord, to the motoneuronal cell groups innervating intercostal and abdominal muscles. In the brainstem, the NRA neurons project to the motoneuronal cell groups innervating mouth-opening and perioral muscles as well as to motoneurons innervating the pharynx, soft palate, and tongue. These results indicate that the projections from PAG via NRA to vocalization motoneurons form the final common pathway in vocalization.

Holstege, Gert↗
NASA NTRS1990

Final shuttle-derived atmospheric database: Development and results from thirty-two flights

The final Shuttle-derived atmospheric data base is presented. The relational data base is comprised of data from 32 Space Transportation System (STS) descent flights, to include available meteorology data taken in support of each flight. For the most part, the available data are restricted to the middle atmosphere. In situ accelerations, sensed by the tri-redundant Inertial Measurement Unit (IMU) to an accuracy better than 1 mg, are combined with post-flight Best Estimate Trajectory (BET) information and predicted, flight-substantiated Orbiter aerodynamics to provide determinations up to altitudes of 95 km. In some instances, alternate accelerometry data with micro-g resolution were utilized to extend the data base well into the thermosphere. Though somewhat limited, the ensemble of flights permit a reasonable sampling of monthly, seasonal, and latitudinal variations which can be utilized for atmospheric science investigations and model evaluations and upgrades as appropriate. More significantly, the unparallel vertical resolution in the Shuttle-derived results indicate density shears normally associated with internal gravity waves or local atmospheric instabilities. Consequently, these atmospheres can also be used as stress-atmospheres for Guidance, Navigation and Control (GN and C) system development and analysis as part of any advanced space vehicle design activities.

Findlay, John T.↗