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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 73 records · Page 4
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NASA NTRS1972

Seventh Annual Conference on Manual Control

The Seventh Annual NASA/AF/University Conference on Manual Control was held at the University of Southern California from June 2-4, 1971. Some eighty specialists, including colleagues from Canada, Netherlands and West Germany, attended the Conference, which was organized by the authors of this Summary. Generally at this conference there was less emphasis on theory and more on applications than at some previous meetings. In addition to the well-established areas of human operator modeling and display systems, this conference devoted considerable time to the extensions of manual control theory to such diverse areas as automobile driving, air traffic control and industrial management. This interest in meaningful applications of the existing theoretical knowledge in man-machine systems is encouraging and timely.

Source record↗
NASA NTRS1974

ANS hard X-ray experiment development program

The hard X-ray (HXX) experiment is one of three experiments included in the Dutch Astronomical Netherlands Satellite, which was launched into orbit on 30 August 1974. The overall objective of the HXX experiment is the detailed study of the emission from known X-ray sources over the energy range 1.5-30keV. The instrument is capable of the following measurements: (1) spectral content over the full energy range with an energy resolution of approximately 20% and time resolution down to 4 seconds; (2) source time variability down to 4 milliseconds; (3) silicon emission lines at 1.86 and 2.00keV; (4) source location to a limit of one arc minute in ecliptic latitude; and (5) spatial structure with angular resolution of the arc minutes. Scientific aspects of experiment, engineering design and implementation of the experiment, and program history are included.

Parsignault, D.↗
NASA NTRS1975

An evolution of X-ray astronomy instrumentation

This paper describes the growth of X-ray astronomy instrumentation from simple, single function, instruments performing survey measurements with crude spectral, spatial and temporal resolution to complex, multiple detector, instruments capable of observing selected phenomena and sources with extremely fine resolution. Examples of solar X-ray instrumentation that are discussed include OSO-IV, Apollo Telescope Mount and proposed Solar Maximum Mission instruments. Stellar X-ray instrumentation examples include UHURU, Astronomy Netherlands Satellite and HEAO-B instruments. Design details are provided and instrument parameters are compared to illustrate the evolutionary process.

Jagoda, N.↗
NASA NTRS1975

X-ray observations of Cyg X-1 with ANS

The equipment, method and results of the measurements performed with soft and hard X-ray detectors of the Space Research Laboratory in Utrecht and the Center for Astrophysics in Cambridge, Mass., are described. Cyg X-1 underwent an upward transition in its intensity, that seems to be the inverse of the downward transition seen by Uhuru in April 1971. The bulk of the increase, as observed by the Astronomical Netherlands Satellite instruments, from May 1 to May 8, 1975, occurs at low energy: between 1 and 2 keV, the intensity increased by a factor of 10 over the November 1974 intensity, while above 8 keV there is no significant change. The data suggest that Cyg X-1 has reverted to its high state.

Heise, J.↗
NASA NTRS1975

NASA/ESA CV-990 spacelab simulation

Due to interest in the application of simplified techniques used to conduct airborne science missions at NASA's Ames Research Center, a joint NASA/ESA endeavor was established to conduct an extensive Spacelab simulation using the NASA CV-990 airborne laboratory. The scientific payload was selected to perform studies in upper atmospheric physics and infrared astronomy with principal investigators from France, the Netherlands, England, and several groups from the United States. Communication links between the 'Spacelab' and a ground based mission operations center were limited consistent with Spacelab plans. The mission was successful and provided extensive data relevant to Spacelab objectives on overall management of a complex international payload; experiment preparation, testing, and integration; training for proxy operation in space; data handling; multiexperimenter use of common experimenter facilities (telescopes); multiexperiment operation by experiment operators; selection criteria for Spacelab experiment operators; and schedule requirements to prepare for such a Spacelab mission.

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NASA NTRS1975

ANS results on X-ray binaries

A short description is given of the Astronomical Netherlands Satellite ANS and the X-ray instruments of the Space Research Laboratory in Utrecht. ANS observed in February 1975 a soft _ KeV) X-ray flux in Her-x-I during the 'off'-state with an intensity of a factor I0 lower than observed previously in the 'on'-state. The measured uncorrected intensity is (1.1 ± 0.2)10^(-11) ergs/sq.cm sec in 0.2 - 0.28 keV at earth. The ANS observations on Cyg-X-I are summarized. Duping the May 75 flaring state a very high intensity at 0.5 keV is measured consistent with a power-law Ph0ton-spectrum with index 3.5 and an interstellar absorption of 7.10^(21) atoms/sq.cm, but not consistent with spectra that show an additional cut-off below 1KeV and an absorption of 7 10^(21) atoms/sq.cm. Intensity changes on a time scale of minutes, as observed in Cyg-X-1 lowstate, are not observed during the flaring state.

J. Heise↗
NASA NTRS1976

Airborne simulation of Shuttle/Spacelab management and operation

The ASSESS (Airborne Science/Spacelab Experiments System Simulation) program is discussed. A simulated Spacelab operation was carried out aboard the CV-990 airborne laboratory at Ames Research Center. A scientific payload was selected to conduct studies in upper atmospheric physics and infrared astronomy with principal investigators from France, the Netherlands, England and the U.S. Two experiment operators (EOs) from the U.S. and two from Europe were trained to function as proxies for the principal investigators in operating, maintaining, and repairing the scientific instruments. The simulated mission, in which the EOs and a Mission Manager were confined to the aircraft and living quarters for a 1-week period while making scientific observations during nightly flights, provided experience in the overall management of a complex international payload, experiment preparation, testing, and integration, the training and selection of proxy operators, and data handling.

Mulholland, D. R.↗
NASA NTRS1976

Discovery of intense X-ray bursts from the globular cluster NGC 6624

A new type of time variation of cosmic X-ray sources has been found from the Astronomical Netherlands Satellite (ANS) observations of the source 3U 1820-30, associated with the globular cluster NGC 6624. Two bursts in the 1-30 keV X-ray intensity of this source are reported. Each displayed a rapid rise in flux (no more than 1 s) by a factor of 20-30 followed by an approximately 8-s exponential decay. These bursts appear to be qualitatively different from short time variations previously reported for X-ray sources. Analysis for further source variability, energy spectra, and position is presented. The characteristics of these events may imply the existence of a collapsed core in the globular cluster.

Grindlay, J.↗
NASA NTRS1976

Improved position for the X-ray source associated with the globular cluster NGC 6441

The X-ray source 3U 1746-37 was observed by the hard X-ray experiment on the Astronomical Netherlands Satellite (ANS) in March and September 1975. The one-dimensional position band (+ or - 2 arcmin, 90% confidence) obtained reduces the Uhuru error-box area by a factor of 3 and includes the nucleus of the globular cluster NGC 6441.

Grindlay, J. E.↗
NASA NTRS1976

ANS observations of Cygnus X-1

Cygnus X-1 was observed from 3 November until 9 November 1974, using the hard X-ray (1-28 keV) and soft X-ray (1-8 keV) experiment on board the Astronomical Netherlands Satellite. On three occasions, on 4 and 5 November, the X-ray spectrum was observed to be harder, while the flux intensity in the 1-7 keV ranges decreased by about 50% from its quiescent value. These events occurred near and following the time of superior conjunction of the likely optical counterpart HDE 226 868. These events appear to be the same as previously reported absorption dips and reveal this phenomenon to be more complex than had been believed. A systematic study of the X-ray spectral variations in these energy bands, on a time scale of 64 seconds over the period of the spectroscopic binary, is presented.

Parsignault, D. R.↗
NASA NTRS1976

NASA/ESA CT-990 Spacelab simulation. Appendix A: The experiment operator

A joint NASA/ESA endeavor was established to conduct an extensive spacelab simulation using the NASA CV-990 airborne laboratory. The scientific payload was selected to perform studies in upper atmospheric physics and infrared astronomy with principal investigators from France, the Netherlands, England, and several groups from the United States. Two experiment operators from Europe and two from the U.S. were selected to live aboard the aircraft along with a mission manager for a six-day period and operate the experiments in behalf of the principal scientists. This appendix discusses the experiment operators and their relationship to the joint mission under the following general headings: selection criteria, training programs, and performance. The performance of the proxy operators was assessed in terms of adequacy of training, amount of scientific data obtained, quality of data obtained, and reactions to problems that arose in experiment operation.

Reller, J. O., Jr.↗
NASA NTRS1979

Mission design for the infrared astronomical satellite /IRAS/

IRAS, a joint United States, Netherlands, United Kingdom astronomical satellite, is scheduled to be launched early in 1981 with the purpose of completing an all-sky survey in the infrared wavelengths from 8 to 120 microns and to observe objects of special interest. The mission design is driven by thermal constraints primarily determined by the Sun and Earth; the orbit and survey strategy must be chosen so as to satisfy the mission requirements before the cryogenic system is depleted of its liquid helium. Computer graphics help the designer choose valid survey strategies and evaluate resulting sky coverage.

Lundy, S. A.↗
NASA NTRS1979

Jupiter's radiation belts and atmosphere

Maps and stripscans of the radio emission from Jupiter were made during the Pioneer 10 flyby in December 1973 at wavelengths of 6 cm, 21 cm, and 50 cm using the Westerbork telescope in the Netherlands. With this instrument the disk of the planet was resolved at 6 and 21 cm. The pictures are averaged over 15 deg of Jovian longitude. At 21 cm the stripscans clearly show the existence of a 'hot region' in the radiation belts at a System III longitude (1965.0) of 255 + or - 10 deg. Its flux is about 9% of the total nonthermal flux, and it has a volume emissivity enhanced by a factor of about 1.6 with respect to the general radiation belts. The temperature of the thermal disk at 21 cm appears to be 290 + or - 20 K. This is likely due to a high ammonia mixing ratio in the atmosphere, a factor of 4-5 larger than the expected solar value of 0.00015.

De Pater, I.↗
NASA NTRS1978

Design of a superfluid helium dewar for the IRAS telescope

The Infrared Astronomy Satellite (IRAS) is planned for launch in 1981, and is a joint project of the Netherlands, the United Kingdom and the United States. The instrument will consist of a superfluid helium-cooled 60 cm telescope with a large array of infrared detectors at the focal plane. The primary purpose of the mission is to perform an all-sky survey in the infrared region from 8 to 120 micrometers. The dewar contains 70 kg of superfluid helium which will maintain the telescope and detectors at 2K for one year. The dewar contains a supercritical helium cover tank which will be ejected after the experiment has been in orbit for two weeks.

Urbach, A. R.↗
NASA NTRS1979

Design of a one-year lifetime, spaceborne superfluid helium dewar

The Infrared Astronomical Satellite is an Explorer Mission and a joint venture of the Netherlands, the United Kingdom, and the United States scheduled for launch into earth orbit in 1981. The cryogenic system is a major part of the satellite; it incorporated many unique and state-of-the-art design features to satisfy the requirements of a one-year orbital lifetime, a focal plane temperature less than 4K, minimal launch weight, and zero-gravity operation. The 60-centimeter diameter telescope is contained within a superfluid helium dewar having a capacity of 540 liters. The telescope aperture cover employs an independent cryogenic system containing a 54-liter supercritical helium tank. The aperture cover, which is ejected two weeks after launch, protects the telescope from contamination and provides the low-temperature background needed to perform focal plane health checks. Design and predicted performance of the cryogenic systems are discussed in detail.

Hopkins, R. A.↗
NASA NTRS1980

Ultraviolet albedos of Uranus and Neptune

Observations on Uranus, Neptune, and four G-type stars which were obtained with the five channel ultraviolet spectrometer aboard the Astronomical Netherlands Satellite are reported. The paper uses these data to derive geometric albedos between 1800 and 3300 A for Uranus and between 2200 and 3300 A for Neptune. It is shown that the albedos are in good agreement with ground measurements near 3300 A and with OAO 2 measurements near 2500 A. In addition, it is noted that the albedos are smaller than theoretical predictions for deep pure H2 Rayleigh-Raman scattering atmospheres, which confirms earlier predictions that additional sources of ultraviolet absorption are required in the upper atmosphere of these planets. Consideration is given to the possibility that the Uranian atmosphere contains an extra absorber, noting that the identification of this absorber is difficult from broad-band spectrophotometric measurements.

Savage, B. D.↗
NASA NTRS1980

Transport jet aircraft noise abatement in foreign countries: Growth, structure, impact. Volume 1: Europe, July 1980

The development and implementation of aircraft noise control regulations in various European states are described. The countries include the United Kingdom, France, Switzerland, Federal Republic of Germany, Sweden, Denmark, and the Netherlands. Topics discussed include noise monitoring, airport curfews, land use planning, and the government structure for noise regulation.

Spencer, F. A.↗