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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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A tabulation of calculated rotational line intensities, relative to the integrated intensity of a vibration-rotation band, is given for Sigma-Sigma, Pi-Sigma, Sigma-Pi, Pi-Pi, and Delta-Pi transitions of nitrous oxide. These calculations were made for temperatures of 250 K and 300 K. A summary of band-intensity measurements is also presented.
The ratio of intensities of hydrogen Balmer lines H-alpha/H-beta is proposed as an indicator of electron temperature in a nonequilibrium plasma. Although different from the equilibrium case, the intensity ratio is a unique function of electron temperature provided that the optical depth is small for the visible lines and the plasma is far out of equilibrium. For such a plasma, the H-alpha/H-beta intensity ratios are computed. The results are tabulated in the form of a conversion table between the measured excitation temperature and the true electron temperature. The ranges of applicability of the conversion table are also computed and are presented in separate tables. An example is shown in which particle densities are consistent with the Saha equilibrium condition at the apparent excitation temperature even though the plasma is in nonequilibrium at a different true electron temperature.
A flowing afterglow has been used to produce metastable He(2 super 3 S). It is shown that when He(2 super 3 S) interacts with a diatomic or triatomic molecule, its electronic excitation energy can be transferred to electronic and vibrational excitation of the molecule. To examine this mechanism, the rates for the production of electronically excited molecules, observed spectroscopically between 190 and 750 nm in the reaction of He(2 super 3 S) with CO2, have been measured. Results are tabulated.
A core model, consisting of a (12-4) central potential displaced from the origin, is suggested as a representation of the interaction of polyatomic ions with neutral molecules. The diffusion collision integral, which describes ion mobility, is computed and tabulated as a function of temperature and core size. The addition of the core reduces the maximum in the mobility against temperature curve, and eventually reduces the mobility below its polarization limit at all temperatures. These results are in accord with limited available experimental data. Comparison is made with other models of ion-neutral interactions.
Absolute excitation functions were measured for the NO(+) A l super Pi-Chi 1 super Sigma (+) molecular band system, the nitrogen 1200-, 1243-, and 1493-A multiplets, and oxygen 1304-A multiplet. Excitation was by electron impact on NO from threshold to approximately 250 eV. Results are plotted and tabulated.
The need for further development and reevaluation of current space-vehicle materials (intended for a single mission) to meet the long-time requirements of a space shuttle is demonstrated. Leading metallic material candidates and their properties are tabulated for a delta-wing space shuttle configuration with a metallic thermal protection system.
In order to provide insight for the selection of attitude- and stationkeeping propulsion systems for future communications satellites, current auxiliary-propulsion systems are surveyed. Thruster systems specifically considered are stored gas, vaporizing ammonia/electrothermal, catalytic monopropellant hydrazine, electrothermal monopropellant hydrazine, plenum monopropellant hydrazine, ion, colloid, and pulsed plasma. Each of the thruster types is discussed in three sections: (1) description of thruster system and how it functions, (2) space flight experience, and (3) survey of state-of-the-art thrusters. In addition, a qualitative tabulation of thruster characteristics is included.
By analyzing all existing frequency data of the oxygen molecule in microwave, submillimeter, and infrared spectroscopy, a new set of molecular parameters is obtained. The parameters are tabulated and compared with values obtained by other authors. Observed and calculated frequencies of oxygen lines are also given.
Results of a systematic search for bright nebulae that are likely to be emission regions in the vicinity of high-velocity gas, drawing attention to some interesting coincidences that have been found. It is apparent that there is a tendency for many of the high-latitude nebulae to cluster in the vicinity of the high-velocity gas. Some of the most prominent cases of overlap are tabulated. It is emphasized that measurement of the radial velocity of the emission nebulae could confirm the existence of a physical association between high-latitude emission nebulae and high-velocity gas. The fact that Johnson (1972) had used narrow-band filters to find indications of H beta emission in similar high-latitude nebulae suggests that H alpha should readily be detectable with Fabry-Perot interferometry.
Calculated spectral line profiles (intensity distributions) of the helium triplet diffuse series were obtained using the quasi-static approximation for ions and electrons. In these calculations, Doppler broadening, although negligible in most of the cases, was included as a device to avoid singularities. Plots and tabulations of the calculated profiles are presented, in addition to a discussion of the computational procedure and the validity of the calculations.
A description of the performance test to compare noise output from a quiet engine with acoustic nacelle to the noise output of the JT3D turbofan engine is presented. Tabulations depict comparative thrusts, bypass ratios, core jet velocities, and fan jet velocities for both engines during simulated takeoff and approach performances.
Available information on weight and inertia, aerodynamic derivatives, control characteristics, and stability augmentation systems is documented for 10 representative contemporary airplanes. Data sources are given for each airplane. Flight envelopes are presented and dimensional derivatives, transfer functions for control inputs, and several selected handling qualities parameters have been computed and are tabulated for 10 different flight conditions including the power approach configuration. The airplanes documented are the NT-33A, F-104A, F-4C, X-15, HL-10, Jetstar, CV-880M, B-747, C-5A, and XB-70A.
The evaluation is discussed of the terminal sterilization process for unmanned lander spacecraft. Results of biochemical test deviations encountered with the identification schemes are tabulated. Studies to examine the possibility of shifts in biochemical reaction patterns during storage and subculture of the environmental Bacillius isolates are also reported.
The instrumentation, calibration, and data observations of the NASA airborne auroral expedition during November and December 1969 are discussed. The observed data are tabulated along with graphical illustrations of various data correlations.
The characteristics of asteroids selected as possible space mission objectives are presented. The asteroids are described according to: (1) magnitude, (2) spectral reflectivity; (3) phase factors, (4) polarization, (5) light curve, and (6) physical parameters. The data are tabulated on specific formats for each asteroid considered.
The percentage levels of wind speed differences are presented computed from sequential FPS-16 radar/Jimsphere wind profiles. The results are based on monthly profiles obtained from December 1964 to July 1970 at Cape Kennedy, Florida. The profile sequences contain a series of three to ten Jimspheres released at approximately 1.5-hour intervals. The results given are the persistence analysis of wind speed difference at 1.5-hour intervals to a maximum time interval of 12 hours. The monthly percentage of wind speed differences and the annual percentage of wind speed differences are tabulated. The percentage levels are based on the scalar wind speed changes calculated over an altitude interval of approximately 50 meters and printed out every 25 meters as a function of initial wind speed within each five-kilometer layer from near sea level to 20 km. In addition, analyses were made of the wind speed difference for the 0.2 to 1 km layer as an aid for studies associated with take-off and landing of the space shuttle.
The trajectory of an orbiting spacecraft is determined from an orbit determination program. Two inputs to this program, among others, are the range and range rate relative to some known location. The arithmetic and measurement errors in the determinations of the range, range rate, and range differences were identified and evaluated. These uncertainties are tabulated for one way and two way systems. A comparison of the measurement error contributions illustrate the predominance of thermal noise effects under low power budget conditions, with the other error sources becoming relevent for the high power budget case. The evaluated uncertainties are summarized as root sum squared noise and bias errors.
The optical properties and optical constants of water and aqueous solutions were studied to develop an accurate tabulation of graphical representations of the optical constants through a broad spectrum. Manuscripts of articles are presented concerning extinction coefficients, relative specular reflectance, and temperature effect on the water spectrum. Graphs of absolute reflectance, phase shifts, index of refraction, and extinction coefficients for water, heavy water and aqueous solutions are included.