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At least 811 records · Page 45

HEAO-B and -C engineering design and scientific objectives

The HEAO-B observatory will be launched in late 1978 for a one-year mission to analyze individual X-ray objects and extended sources in detail using a high precision X-ray telescope. The energy range of the telescope is 0.1 keV to 4 keV. Four interchangeable instruments are at the focal plane; a high resolution imaging instrument, an imaging proportional counter, a focal plane crystal spectrometer, and a solid state spectrometer. A monitor proportional counter will collect data independently of the telescope. The HEAO-C observatory is a scanning mission and will be launched in 1979 for six months operation. It will contain two cosmic ray experiments and a gamma ray spectrometer.

Dailey, C. C.↗

Atmospheric ozone measurements made from B-747 airliners - Spring 1975

Atmospheric ozone in the upper troposphere and lower stratosphere north of the equator has been registered aboard two commercial B-747 airliners during the Spring of 1975. This monitoring is part of a much broader and continuing project developed by NASA and known as the Global Atmospheric Sampling Program (GASP). Additional flight and meteorological conditions have also been automatically recorded on board concurrent with the ozone measurements. Independently-derived tropopause pressure information was available from NMC data archives and was used to identify stratospheric and tropospheric flight. The composite ozone, flight and meteorological data are reported for selected dates in March, April, and May. Attention is drawn particularly to the vertical profiles of atmospheric ozone mixing ratio as a function of both distance from the tropopause and curvature of the streamlines. The GASP observations suggest that ozone levels typical of the lower stratosphere are often embedded in the upper troposphere, principally during occasions when cyclonic wind curvature was noted.

Falconer, P. D.↗

The High Resolution Imaging Instrument for HEAO-B

The High Resolution Imaging Instrument for the HEAO-B X-ray Telescope satellite is designed to reproduce images of celestial X-ray sources in the range of 0.2 to 4.0 keV. It provides both imaging and temporal data. The basic detector is a two-stage microchannel plate with a crossed-grid charge detector. Preamplifiers, detector bias supplies, and some processing circuits are colocated with the detector. The remaining electronic circuits are located in a remote central electronic assembly. The processing system is designed for single-photon processing. The imaging data rate is limited to 100 data points per second. Non-imaging total-field count rate is acquired with a maximum dead time of 14 microseconds per event.

Kubierschky, K.↗

The Focal Plane Crystal Spectrometer for the HEAO-B satellite

The very low flux from even the brightest (non-solar) X-ray source has discouraged the use of instruments with high spectral resolution because of their inevitably low sensitivity. Mission B of the High Energy Astronomy Observatory will provide the first opportunity for moderate and high resolution spectral studies of celestial X-ray sources with high sensitivity. The Focal Plane Crystal Spectrometer (FPCS) described here is the instrument with the highest spectral resolution. It is designed to allow detailed spectral studies of both point and extended celestial sources in the energy range 0.2-3.3 keV with resolutions of 50 to 1000.

Donaghy, J. F.↗

Aspect system for HEAO-B

The aspect system for the HEAO-B Observatory provides the necessary absolute referencing of the Observatory coordinates to the celestial sphere with a precision of one arc second. In addition, it provides realtime data to the Spacecraft to permit pointing of the Observatory to one arc minute. The system is composed of three star trackers with associated shades, a pair of bright object detectors and a fiducial light system for referencing the experiment X-ray axis to the star tracker axes.

Koch, D.↗

On the theory of silicon spectra in O and B stars

Results of a previous calculation of a grid of predicted line profiles for 36 multiplets of Si II, III, and IV over a range of model atmospheres corresponding roughly to B0-B5 in spectral type and III-IV in luminosity class are analyzed and applied to observed spectra. The overall properties of the grid of Si line equivalent widths are reviewed, the diagnostic capability of this grid is discussed, and some results are presented for the parameters of 11 B stars derived from observed Si lines. The general fit of the predictions to the observations is evaluated, and test calculations are performed to examine the effect of varying a number of important parameters. Some systematic trends in the computational results are noted which can be expressed as phenomenological 'laws'. Special attention is given to problems arising from non-LTE effects as well as to the self-consistency of analytical results obtained from unblanketed models. It is found that the Si line calculations yield good agreement in two tests for main-sequence stars between B0 and B2, but both tests give somewhat negative results for spectral types later than B2.

Kamp, L. W.↗

Design, fabrication and expected performance of the HEAO-B X ray telescope

The X-ray telescope of the second High Energy Astronomy Observatory (HEAO-B) is described. The design consists of four concentric paraboloid/hyperboloid pairs. Focal length is 3.44 meters, paraboloid diameters vary from 580-336 mm, grazing angles vary from 70 to 40 arcmin for paraxial rays, segment lengths are 511 mm. The reflecting surfaces are nickel-coated fused quartz and the resolution is limited by assembly errors (for small field angles) and design aberrations (for large field angles). The local slope, roundness, and surface roughness are identified as the primary optical tolerances connected with the individual elements.

Van Speybroeck, L. P.↗

Load and dynamic assessment of B-52B-008 carrier aircraft for finned configuration 1 space shuttle solid rocket booster decelerator subsystem drop test vehicle. Volume 2: Airplane flutter and load analysis results

The airplane flutter and maneuver-gust load analysis results obtained during B-52B drop test vehicle configuration (with fins) evaluation are presented. These data are presented as supplementary data to that given in Volume 1 of this document. A brief mathematical description of airspeed notation and gust load factor criteria are provided as a help to the user. References are defined which provide mathematical description of the airplane flutter and load analysis techniques. Air-speed-load factor diagrams are provided for the airplane weight configurations reanalyzed for finned drop test vehicle configuration.

Quade, D. A.↗

Vestibular Function Research (VFR) experiment. Phase B: Design definition study

The Vestibular Functions Research (VFR) Experiment was established to investigate the neurosensory and related physiological processes believed to be associated with the space flight nausea syndrome and to develop logical means for its prediction, prevention and treatment. The VFR Project consists of ground and spaceflight experimentation using frogs as specimens. The phase B Preliminary Design Study provided for the preliminary design of the experiment hardware, preparation of performance and hardware specification and a Phase C/D development plan, establishment of STS (Space Transportation System) interfaces and mission operations, and the study of a variety of hardware, experiment and mission options. The study consist of three major tasks: (1) mission mode trade-off; (2) conceptual design; and (3) preliminary design.

Source record↗

B-52B-008/DTV (Drop Test Vehicle) configuration 1 (with and without fins) flight test results - captive flight and drop test missions

The B-52B-008 drop test consisted of one takeoff roll to 60 KCAS, two captive flights to accomplish limited safety of flight flutter and structural demonstration testing, and seven drop test flights. Of the seven drop test missions, one flight was aborted due to the failure of the hook mechanism to release the drop test vehicle (DTV); but the other six flights successfully dropped the DTV.

Quade, D. A.↗

Determination of subcritical frequency and damping from B-1 flight flutter test data

The application of the time-lag products correlation/frequency analysis procedure to determine subcritical frequency and damping from structural response measurements made during flight flutter test of the B-1 prototype airplane is described. The analysis procedure, the test airplane, and flight test procedures are discussed. Summary frequency and damping results are presented for six transonic flight conditions. Illustrative results obtained by applying various options and variations of the analysis method are included for one flight condition.

Dobbs, S. K.↗

Meteorological and operational aspects of 46 clear air turbulent sampling missions with an instrumented B-57B aircraft. Volume 2, appendix C: Turbulence missions

The results of 46 clear air turbulence (CAT) probing missions conducted with an extensively instrumented B-57B aircraft are summarized from a meteorological viewpoint in a two-volume technical memorandum. The missions were part of the NASA Langley Research Center's MAT (Measurement of Atmospheric Turbulence) program, which was conducted between March 1974, and September 1975, at altitudes ranging up to 15 km. Turbulence samples were obtained under diverse conditions including mountain waves, jet streams, upper level fronts and troughs, and low altitude mechanical and thermal turbulence. CAT was encountered on 20 flights comprising 77 data runs. In all, approximately 4335 km were flown in light turbulence, 1415 km in moderate turbulence, and 255 km in severe turbulence during the program.

Waco, D. E.↗

Flight performance of the TCV B-737 airplane at Kennedy Airport using TRSB/MLS guidance

The terminal configured vehicle (TCV) B 737 was flown in demonstration of the time reference scanning beam/microwave landing system (TRSB/MLS). The flight performance of the TCV airplane during the demonstration automatic approaches and landings while utilizing TRSB/MLS guidance is reported. The TRSB/MLS is shown to provide the terminal area guidance necessary for flying curved automatic approaches with short finals.

White, W. F.↗

Rotary balance data for a typical single-engine general aviation design for an angle-of-attack range of 8 deg to 90 deg. 2: Low-wing model B

Aerodynamic characteristics obtained in a rotational flow environment utilizing a rotary balance located in the spin tunnel are presented in plotted form for a 1/6.5 scale, single engine, low wing, general aviation airplane model. The configurations tested included the basic airplane, various wing leading-edge devices, tail designs, and rudder control settings as well as airplane components. Data are presented without analysis for an angle-of-attack range of 8 deg to 90 deg and clockwise and counter-clockwise rotations covering an (omega)(b)/2V range from 0 to 0.85.

Bihrle, W., Jr.↗

Simultaneous measurements of ozone outside and inside cabins of two B-747 airliners and a Gates Learjet business jet

Recently, passengers and crew members on long-distance commercial flights have filed complaints after suffering symptoms of ozone sickness. Studies were conducted to determine the frequency and concentration of ozone in commercial jet transports. The airliner problem with ozone prompted NASA to determine the ozone concentrations that might be encountered in the cabin of a small business jet. Simultaneous measurements of atmospheric ozone levels and ozone levels in the cabins of jet aircraft were necessary because of the wide and rapid variability of atmospheric ozone in flight. It was found that the atmospheric ozone concentrations in the case of B-747 airliners vary widely during a flight. A constant difference, or ratio, between ozone concentrations outside and inside the cabin does not exist.

Perkins, P. J.↗

Measurements of carbon monoxide, condensation nuclei, and ozone on a B 747SP aircraft flight around the world

Measurements of carbon monoxide, condensation nuclei, and ozone concentrations were obtained during a 54 hour polar flight around the world by an automated instrument package carried by a B-747SP commercial aircraft. These and other data were obtained as part of the NASA Global Atmospheric Sampling Program. All data exhibited longitudinal and hemispheric differences. Analysis of the data indicate increased concentrations of carbon monoxide and condensation nuclei at flight levels in the troposphere over tropical land masses. A background concentration for condensation nuclei was found to be 200 per cu cm for tropical tropospheric maritime air.

Gauntner, D. J.↗

Azimuthal brightness variations of Saturn's rings. III - Observations at tilt angle B approximately equal to 11.5 deg

The brightness variation in Saturn's ring A with orbital phase of the ring particles does not change significantly as the declination of the earth, B, decreases from about 16.5 to 11.5 deg and is noticeably more pronounced than when the rings are fully open. The present data are also not inconsistent with earlier results suggesting that the amplitude of this azimuthal effect diminishes near opposition.

Lumme, K.↗

Analyses and tests of the B-1 aircraft structural mode control system

Analyses and flight tests of the B-1 structural mode control system (SMCS) are presented. Improvements in the total dynamic response of a flexible aircraft and the benefits to ride qualities, handling qualities, crew efficiency, and reduced dynamic loads on the primary structures, were investigated. The effectiveness and the performance of the SMCS, which uses small aerodynamic surfaces at the vehicle nose to provide damping to the structural modes, were evaluated.

Wykes, J. H.↗