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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 253 records · Page 14
All sourcesNASA NTRSDOE OSTI
NASA NTRS1979

The High Energy X-ray Spectrum of 4U1700-37 Observed from OSO-8

The most intense hard X-ray source in the confused region in Scorpius is identified as 4U1700-37. The 3.4-day modulation is seen above 20 keV with the intensity during eclipse being consistent with zero flux. The photon-number spectrum from 20 to 150 keV is well represented by a single power law with a photo-number spectral index of -2.77 + or - 0.35 or by a thermal bremsstrahlung spectrum with kT = 27 96.8-min X-ray modulation previously reported at lower energies. Despite the difficulties in reconciling both the lack of periodic modulation in the emitted X-radiation and the orbital dynamics of the system with theories of the evolution and physical properties of neutron stars, the observed properties of 4U1700-37 are all consistent with the source being a spherically accreting neutron star rather than a black hole.

Dolan, J. F.↗
NASA NTRS1979

Recent observations of Hercules X-1 with HEAO-1 and OSO-8

HEAO 1 X-ray observations of Her X-1 near an onset of the high state are discussed. An X-ray light curve is determined which indicates that for about 0.5 day before the X-ray intensity turn-on there was 1.2-sec pulsed emission from the source at a level intermediate between the high- and low-state intensities. These results are taken as demonstrating the stability in the 35-day cycle when compared with previous observations. An inconclusive search for 58-keV line emission from Her X-1 is also reported.

Pravdo, S. H.↗
NASA NTRS1979

In-orbit evaluation of the control system/structural mode interactions of the OSO-8 spacecraft

The Orbiting Solar Observatory-8 experienced severe structural mode/control loop interaction problems during the spacecraft development. Extensive analytical studies, using the hybrid coordinate modeling approach, and comprehensive ground testing were carried out in order to achieve the system's precision pointing performance requirements. A recent series of flight tests were conducted with the spacecraft in which a wide bandwidth, high resolution telemetry system was utilized to evaluate the on-orbit flexible dynamics characteristics of the vehicle along with the control system performance. The paper describes the results of these tests, reviewing the basic design problem, analytical approach taken, ground test philosophy, and on-orbit testing. Data from the tests was used to determine the primary mode frequency, damping, and servo coupling dynamics for the on-orbit condition. Additionally, the test results have verified analytically predicted differences between the on-orbit and ground test environments, and have led to a validation of both the analytical modeling and servo design techniques used during the development of the control system.

Slafer, L. I.↗
NASA NTRS1980

On-orbit evaluation of the control system/structural mode interactions on OSO-8

The Orbiting Solar Observatory-8 experienced severe structural mode/control loop interaction problems during the spacecraft development. Extensive analytical studies, using the hybrid coordinate modeling approach, and comprehensive ground testing were carried out in order to achieve the system's precision pointing performance requirements. A recent series of flight tests were conducted with the spacecraft in which a wide bandwidth, high resolution telemetry system was utilized to evaluate the on-orbit flexible dynamics characteristics of the vehicle along with the control system performance. This paper describes the results of these tests, reviewing the basic design problem, analytical approach taken, ground test philosophy, and on-orbit testing. Data from the tests was used to determine the primary mode frequency, damping, and servo coupling dynamics for the on-orbit condition. Additionally, the test results have verified analytically predicted differences between the on-orbit and ground test environments. The test results have led to a validation of both the analytical modeling and servo design techniques used during the development of the control system, and also verified the approach taken to vehicle and servo ground testing.

Slafer, L. I.↗
NASA NTRS1980

Impulsive EUV bursts observed in C IV with OSO-8

Time sequences of profiles of the 1548 A line of C IV containing 51 EUV bursts observed in or near active regions are analyzed to determine the brightness, Doppler shift and line broadening characteristics of the bursts. The bursts have mean lifetimes of approximately 150 s, and mean increases in brightness at burst maximum of four-fold as observed with a field of view of 2 x 20 arc sec. Mean burst diameters are estimated to be 3 arc sec, or smaller. All but three of the bursts show Doppler shifts with velocities sometimes exceeding 75 km/s; 31 are dominated by red shifts and 17 are dominated by blue shifts. Approximately half of the latter group have red-shifted precursors. The bursts are interpreted as prominence material, such as surges and coronal rain, moving through the field of view of the spectrometer.

Athay, R. G.↗
NASA NTRS1980

The Lockheed OSO-8 program. Analysis of data from the mapping X-ray heliometer experiment

The final report describes the extent of the analysis effort, and other activities associated with the preservation and documentation of the data set are described. The main scientific results, which are related to the behavior of individual solar activity regions in the energy band 1.5 - 15 keV, are summarized, and a complete bibliography of publications and presentations is given. Copies of key articles are also provided.

Acton, L. W.↗
NASA NTRS1981

OSO 8 observational limits to the acoustic coronal heating mechanism

An improved analysis of time-resolved line profiles of the C IV resonance line at 1548 A has been used to test the acoustic wave hypothesis of solar coronal heating. It is shown that the observed motions and brightness fluctuations are consistent with the existence of acoustic waves. Specific account is taken of the effect of photon statistics on the observed velocities, and a test is devised to determine whether the motions represent propagating or evanescent waves. It is found that on the average about as much energy is carried upward as downward such that the net acoustic flux density is statistically consistent with zero. The statistical uncertainty in this null result is three orders of magnitue lower than the flux level needed to heat the corona.

Bruner, E. C., Jr.↗
NASA NTRS1982

OSO-8 soft X-ray wheel experiment: Data analysis

The soft X-ray experiment hardware and its operation are described. The device included six X-ray proportional counters, two of which, numbers 1 and 4, were pressurized with on-board methane gas supplies. Number 4 developed an excessive leak rate early in the mission and was turned off on 1975 day number 282 except for brief (typically 2-hour) periods up to day 585 after which it as left off. Counter 1 worked satisfactorily until 1975 day number 1095 (January 1, 1978) at which time the on-board methane supply was depleted. The other four counters were sealed and all except number 3 worked satisfactorily throughout the mission which terminated with permanent satellie shut-down on day 1369. This was the first large area thin-window, gas-flow X-ray detector to be flown in orbit. The background problems were severe and consumed a very large portion of the data analysis effort. These background problems were associated with the Earth's trapped electron belts.

Kraushaar, W. L.↗
NASA NTRS1993

Comparative solar EUV flux for the San Marco ASSI

The Airglow and Solar Spectrometer Instrument (ASSI) on the San Marco D/L satellite has measured solar extreme ultraviolet irradiances. The data are currently being released for analysis. As a preliminary step in evaluating this important dataset, modeled solar irradiances from 4 to 105 nm are presented for comparison to the San Marco data. The comparable flux for March-December 1988 is obtained from a revised and extended empirical solar EUV model derived from OSO 1, OSO 3, OSO 4, OSO 6, AEROS A, and AE-E satellite and six rocket flight datasets. Solar rotational features are prominent on several occasions in the model time series. A useful example is the modeled integrated flux between 30-31 nm which includes the Si XI (30.3-nm) and He II (30.4-nm) irradiance. The modeled flux in this 1-nm range shows both an absolute 22 percent increase from beginning to end of mission and a solar rotational variability with a typical peak-to-valley ratio of 14 percent.

Tobiska, W. K.↗
DOE OSTI2025

Open-Source Offshore Airfoil Summary (V.1.0)

The Open-Source Offshore (OSO) airfoils have been developed for research purposes for offshore wind turbines, offering a set of airfoils that align with modern turbine design requirements and industry design practices without proprietary constraints on research use. The eventual airfoil family will target the IEA 22 MW reference wind turbine, which was originally developed with the FFA airfoils. The two airfoils summarized in Table 1 (OSO-21-WT1 and OSO-30-WT1) started development as part of a family of airfoils being designed to target the IEA 22 MW wind turbine. The criteria used to design these airfoils are summarized in Table 1, which aim to encapsulate requirements of modern airfoils for offshore wind turbine applications, and were developed with feedback from industry and research experts. The airfoils were designed using XFOIL and candidate airfoils were then analyzed in RFOIL, which is considered more accurate than XFoil for high lift predictions of thicker airfoils. The design process for a preliminary family of airfoils is available, including a more detailed explanation of the design requirements and metrics similar to those used for these airfoils. Most of the design criteria are met for these two airfoils, with two exceptions. For both airfoils, the L/D Roughness Loss metric is exceeded (42% > 40% goal) and the desired lift coefficient margin over the design value (“CL_Margin”) was moderately exceeded (0.43 > 0.3) while smooth-stall characteristics (computed) were achieved. Note that all of the metrics were computed using RFOIL, and like other new airfoils, these will need to be experimentally validated at a range of Reynolds numbers. The airfoil coordinates will be shared publicly on Sadia National Laboratories’ public Github repository:

17 WIND ENERGY↗
NASA NTRS1973

Orbiting solar observatory /OSO/

Description of the OSO spin-stabilized spacecraft capable of conducting eleven experiments in studying the sun, the earth, and other space objects. The OSO provides controlled electric power, thermal control, a telemetry and command interface, tape-recorded data storage, and precisely timed orbital and orientation information. A chart indicating experiments carried out on nine OSO missions is included.

Oertel, G. K.↗
NASA NTRS1982

X-ray properties of the Be/X-ray systems 2S0114+650 = LSI+65 deg 010

Results are presented from experiments on the Einstein Observatory, HEAO-1 and OSO-8 on the temporal and spectral properties of 2S0114+650. In a 12 hour Einstein MPC and SSS observation two episodes of flaring occurred by an order of magnitude over about 1 hour. Variability on shorter time scales showed a preferred period of 14.9 minutes, but periodic pulsations were not seen in the HEAO-1 and OSO-8 data. There is some evidence that the spectrum is steeper when the source is quiescent at low luminosity, but no large spectral changes attended the flares. Absorption column densities were consistent with interstellar reddening of the proposed companion, the Be star LSI+65 deg 010. In the minute and hour variability and in the spectral character, 2S0114+650 is similar to other Be star-neutron star binary X-ray sources. Variations over several days in the OSO-8 data suggest orbital effects.

Koenigsberger, G.↗
NASA NTRS1983

X-ray properties of the Be/X-ray system 28 0114+650 = LSI +65deg 010

Results are presented from experiments on the Einstein Observatory, HEAO 1, and OSO 8 on the temporal and spectral properties of 2S 0114+650. In a 12 hr Einstein monitor proportional counter and solid state spectrometer observation, two episodes of flaring occurred by an order of magnitude over about 1 hr. Variability on shorter time scales showed a preferred period of 14.9 minutes, but periodic pulsations were not seen in the HEAO 1 and OSO 8 data. The spectra above 1 keV were typical of accreting X-ray pulsars; the power law was E exp -alpha with alpha of about 1.2 for the number spectrum up to a cutoff at 14 keV. There is some evidence that the spectrum is steeper when the source is quiescent at low luminosity, but no large spectral changes attended the flares. Absorption column densities were consistent with interstellar reddening of the proposed companion, the Be star LSI +65 deg010. In the minute and hour variability and in the spectral character, 2S0114+650 is similar to other Be star-neutron star binary X-ray sources. Variations over several days in the OSO 8 data suggest orbital effects.

Koenigsberger, G.↗
NASA NTRS1986

Ultraviolet spectrometer and polarimeter (UVSP) software development and hardware tests for the solar maximum mission

The Ultraviolet Spectrometer/Polarimeter Instrument (UVSP) for the Solar Maximum Mission (SMM) was based on the re-use of the engineering model of the high resolution ultraviolet spectrometer developed for the OSO-8 mission. Lockheed assumed four distinct responsibilities in the UVSP program: technical evaluation of the OSO-8 engineering model; technical consulting on the electronic, optical, and mechanical modifications to the OSO-8 engineering model hardware; design and development of the UVSP software system; and scientific participation in the operations and analysis phase of the mission. Lockheed also provided technical consulting and assistance with instrument hardware performance anomalies encountered during the post launch operation of the SMM observatory. An index to the quarterly reports delivered under the contract are contained, and serves as a useful capsule history of the program activity.

Bruner, M. E.↗
NASA NTRS1978

Sound Guard

Lubrication technology originally developed for a series of NASA satellites has produced a commercial product for protecting the sound fidelity of phonograph records. Called Sound Guard, the preservative is a spray-on fluid that deposits a microscopically thin protective coating which reduces friction and prevents the hard diamond stylus from wearing away the softer vinyl material of the disc. It is marketed by the Consumer Products Division of Ball Corporation, Muncie, Indiana. The lubricant technology on which Sound Guard is based originated with NASA's Orbiting Solar Observatory (OSO), an Earth-orbiting satellite designed and built by Ball Brothers Research Corporation, Boulder, Colorado, also a division of Ball Corporation. Ball Brothers engineers found a problem early in the OSO program: known lubricants were unsuitable for use on satellite moving parts that would be exposed to the vacuum of space for several months. So the company conducted research on the properties of materials needed for long life in space and developed new lubricants. They worked successfully on seven OSO flights and attracted considerable attention among other aerospace contractors. Ball Brothers now supplies its "Vac Kote" lubricants and coatings to both aerospace and non-aerospace industries and the company has produced several hundred variations of the original technology. Ball Corporation expanded its product line to include consumer products, of which Sound Guard is one of the most recent. In addition to protecting record grooves, Sound Guard's anti-static quality also retards particle accumulation on the stylus. During comparison study by a leading U.S. electronic laboratory, a record not treated by Sound Guard had to be cleaned after 50 plays and the stylus had collected a considerable number of small vinyl particles. The Sound Guard-treated disc was still clean after 100 plays, as was its stylus.

Source record↗