Effect of hydraulic fluid (MIL-H-83282) on selected commercial O-ring compounds

Acrylonitrile and fluorocarbon compounds were evaluated at various temperatures and time intervals in samples of the fluid obtained from three qualified suppliers. It was concluded that both polymers can function in hydraulic fluids within the conditions defined by this study. Hydraulic fluid from each manufacturer was similar in its effect upon each given O-ring material, with one exception. Similarly, there were no striking differences in the resistance of O-rings of the same generic rubber type when provided by the different manufacturers

Values of the photometric parameters of Mars and their interpretation

Photometric data for the Martian disk obtained by Thorpe from television-camera pictures taken by Mariner 9 were used to derive values for the parameters in the photometric function. The photometric function can be applied to Mars and to the design of cameras for photography of Mars. Values of the parameters are for one wavelength only, 0.56 micros and are average or effective values for the Martian disk. The values derived were interpreted to provide semi-quantitative information on the soil. The results do not disagree with other indications that the effective mean diameter of the surface particles is about 400 micros. Another result is that the mean intercenter spacing of adjacent particles may be about 4/3 of the mean diameter

Gradients and anisotropies of high energy cosmic rays in the outer heliosphere

Previous studies at lower energies have shown that the cosmic ray density gradients vary in space and time, and many authors currently are suggesting that the radial gradient associated with solar cycle modulation is supported largely by narrow barriers which encircle the Sun and propagate outward with the solar wind. If so, the anisotropy is a desirable way to detect spatial gradients, because it can be associated with the local solar wind and magnetic field conditions. With this in mind, the anisotropy measurements made by the UCSD Cerenkov detectors on Pioneers 10 and 11 are studied. It is shown that the local anisotropy varies greatly, but that the long term average is consistent with the global radial gradient measured between two spacecraft over a baseline of many AU

Gradients and anisotropies of high energy cosmic rays in the outer heliosphere

Two cosmic rays which pass through the same point going in opposite directions will, in the absence of scattering and inhomogeneities in the magnetic field, trace helices about adjacent flux tubes, whose centerlines are separated by one gyrodiameter. A directional anisotropy at the point suggests a difference in the number of cosmic rays loading the two flux tubes; that is, a density gradient over the baseline of a gyrodiameter. Previous studies at lower energies have shown that the cosmic ray density gradients vary in time and space. It is suggested that the radial gradient associated with solar cycle modulation is supported largely by narrow barriers which encircle the sun and propagate outward with the solar wind. If so, the anisotropy is a desirable way to detect spatial gradients, because it can be associated with the local solar wind and magnetic field conditions. Anisotropic measurements made by Cerenkov detectors on Pioneers 10 and 11 were studied. It was found that local anisotropy varies greatly, but that the long term average is consistent with the global radial gradient measured between two spacecraft over a baseline of many AU

Project management in the Apollo program Interim report

Project management in Apollo progra

Current-eddy interaction in the Agulhas Return Current region from the seismic oceanography perspective

Interleaving in the Agulhas Return Current (ARC) frontal region is commonly manifested in the form of thermohaline intrusions, as sub-tropical and sub-polar water masses of similar density meet. In Jan/Feb 2012, the Naval Research Laboratory and collaborators carried out a field experiment in which seismic and traditional hydrographic observations were acquired to examine frontal zone mixing processes. The high lateral resolution (10 m) of the seismic observations allowed fine-scale lateral tracking of thermal intrusions, which were corroborated with simultaneous XBT casts. Between seismic deployments both salinity and temperature data were acquired via CTD, Underway-CTD and microstructure profiles. This study focuses on analyzing seismic reflection data in a particular E-W transect where the northward flowing ARC interacted with the southward flowing portion of a large anticyclonic eddy. Strong reflectors were most prominent at the edge of a hyperbolic zone formed between the eddy and ARC, where sub-polar waters interacted with waters of sub-tropical origin on either side. Reflectors were shallow within the hyperbolic zone and extended to 1200 m below the ARC. The nature of the observed reflectors will be determined from comparison of seismic reflection and derived ∂T/∂z fields, and XBT and TS profiles from the available hydrographic data

NASA Low-Speed Centrifugal Compressor for Fundamental Research

A centrifugal compressor facility being built by the NASA Lewis Research Center is described; its purpose is to obtain benchmark experimental data for internal flow code verification and modeling. The facility will be heavily instrumented with standard pressure and temperature probes and have provisions for flow visualization and laser Doppler velocimetry. The facility will accommodate rotational speeds to 2400 rpm and will be rated at pressures to 1.25 atm. The initial compressor stage for testing is geometrically and dynamically representative of modern high-performance stages with the exception of Mach number levels. Design exit tip speed for the initial stage is 500 ft/sec with a pressure ratio of 1.17. The rotor exit backsweep is 55 deg from radial

Manned space flight in transition

A study was conducted to analyze the reorientation of NASA programs in the post-Apollo period. The study is an external view of NASA by unbiased observers as an input to and aid in the decision making process concerning near and long term planning. The subjects discussed are: (1) the near-term NASA scenario; (2) organization of field centers; (3) planning activities; and (4) operational activities. A summary of the recommendations arising as a result of the study is presented