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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 199 records · Page 11
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NASA NTRS1986

Far-ultraviolet spectral images of comet Halley from sounding rockets

Far-ultraviolet images of comet Halley obtained from sounding rockets launched from White Sands Missile Range, New Mexico, on 24 February and 13 March, 1986, are presented. Direct electrographic images of the hydrogen coma of the comet were obtained at the Lyman-alpha wavelength along with objective spectra containing images of the coma at the oxygen, carbon, and sulfur resonance multiplets. Analysis of the Lyman-alpha images yields hydrogen atom production rates of 1.9 x 10 to the 30th/s and 1.4 x 120 to the 30th/s for the two observations. Images of oxygen, carbon, and sulfur emissions obtained with the objective grating spectrograph are presented for the first set of observations and preliminary production rates are derived for these elements.

Mccoy, R. P.↗
NASA NTRS1990

Active control of sound transmission/radiation from elastic plates by vibration inputs. I - Analysis

Active control of sound radiation from vibrating plates by oscillating forces applied directly to the structure is analytically studied. The model consists of a plane acoustic wave incident on a clamped elastic circular thin plate. Control is achieved by point forces, and quadratic optimization is used to calculate the optimal control gains necessary to minimize a cost function proportional to the radiated acoustic power (the transmitted field). The results show that global attenuation of broadband radiated sound levels for low to mid-range frequencies can be achieved with one or two control forces, irrespective of whether the system is on or off resonance. The efficiency of the control strategy is demonstrated to be related to the nature of the coupling between the plate modes of response and the radiated field.

Fuller, C. R.↗
NASA NTRS1992

Experimenter's data package for the descending layers rocket

In response to a proposal from Science Applications International Corporation (SAIC), NASA Headquarters has approved a sounding rocket mission designed to study the physics of intermediate layers in the Earth's ionosphere at middle latitudes. The experiment will be carried out by a team of scientists and engineers from the NASA Wallops Flight Facility, SAIC, the NASA Goddard Space Flight Center, and the Millstone Hill radar observatory. The mission will involve the launch of an instrumented sounding rocket from the Wallops Island rocket range in the summer of 1994, with the objective of penetrating a descending ionized layer in the E-region between altitudes of 115 and 140 km. Instrumentation aboard the rocket will measure the ion and neutral composition of the layer, its plasma density, driving wind and electric field forces, the thermal ion distribution function, and electron temperature. Depending on payload weight constraints and subject to availability, a particle detector to measure energetic ion and/or electron fluxes near the layer may also be included. This document was prepared as a reference for the NASA payload development and experiment teams, for distribution at the Project Initiation Conference (PIC). The design specifications discussed herein are therefore of a preliminary nature; the intent is to promote open discussions between experimenters and NASA engineers that will lead to a final design capable of achieving the experiment objectives.

Earle, Greg↗
NASA NTRS1992

The hydrogen coma of Comet P/Halley observed in Lyman-alpha using sounding rockets

Hydrogen Lyman-alpha (121.6 nm) images of Comet P/Halley were obtained using sounding rockets launched from White Sands Missile Range on 24.5 February and 13.5 March 1986. The second rocket was launched 13 hours before the fly-by of the Giotto spacecraft. An electrographic camera on both flights provided Lyman-alpha images covering a 20 field of view with 3 arcmin resolution. The data from both flights have been compared with a time-dependent model of hydrogen kinetics. To match the measured isophote contours, hydrogen sources with velocity components of 8 km/s and 20 km/s (from OH and H2O respectively) as well as a low velocity component (about 2 km/s) are required. This low velocity component is thought to result from thermalization of fast hydrogen atoms within the collision zone, providing an important diagnostic of temperature and density near the nucleus. Hydrogen production rates of 3.8 x 10 exp 30/s and 1.7 x 10 exp 30/s have been obtained for the two observations.

Mccoy, R. P.↗
NASA NTRS2001

Spread Across Liquids Continues to Fly

The physics and behavior of a flame spreading across a flammable liquid is an active area of research at the NASA Glenn Research Center. Spills of fuels and other liquids often result in considerable fire hazards, and much remains unknown about the details of how a flame, once ignited, moves across a pool. The depth of the liquid or size of the spill, the temperature, and wind, if any, can all complicate the combustion processes. In addition, with the advent of the International Space Station there may be fire hazards associated with cleaning, laboratory, or other fluids in space, and it is essential to understand the role that gravity plays in such situations. The Spread Across Liquids (SAL) experiment is an experimental and computational effort dedicated to understanding the detailed mechanisms of flame spread across a flammable liquid initially below its flashpoint temperature. The experimental research is being carried out in-house by a team of researchers from Glenn, the National Center for Microgravity Combustion, and Zin Technologies, with computer modeling being provided via a grant with the University of California, Irvine. Glenn's Zero Gravity Facility is used to achieve short microgravity periods, and normal gravity testing is done in the Space Experiments Laboratory. To achieve longer periods of microgravity, the showcase SAL hardware flies aboard a sounding rocket launched from White Sands Missile Range, New Mexico, approximately once per year. In addition to extended microgravity, this carrier allows the use of detailed diagnostics that cannot be employed in a drop tower.

Miller, Fletcher J.↗
NASA NTRS1990

CRRES Prelaunch Mission Operation Report

The overall NASA Combined Release and Radiation Effects Satellite (CRRES) program consists of a series of chemical releases from the PEGSAT spacecraft, the CRRES spacecraft and sounding rockets. The first chemical releases were made from the PEGSAT spacecraft in April, 1990 over northern Canada. In addition to the releases planned from the CRRES spacecraft there are releases from sounding rockets planned from the Kwajalein rocket range in July and August, 1990 and from Puerto Rico in June and July, 1991. It shows the major milestones in the overall CRRES program. This Mission Operations Report only describes the NASA mission objectives of the CRRES/Geosynchronous Transfer Orbit (GTO) mission.

Source record↗
NASA NTRS2003

Development of Laser-induced Grating Spectroscopy for Underwater Temperature Measurement in Shock Wave Focusing Regions

In Extracorporeal Shock Wave Lithotripsy (ESWL) underwater shock wave focusing generates high pressures at very short duration of time inside human body. However, it is not yet clear how high temperatures are enhanced at the spot where a shock wave is focused. The estimation of such dynamic temperature enhancements is critical for the evaluation of tissue damages upon shock loading. For this purpose in the Interdisciplinary Shock Wave Research Center a technique is developed which employs laser induced thermal acoustics or Laser Induced Grating Spectroscopy. Unlike most of gasdynamic methods of measuring physical quantities this provides a non-invasive one having spatial and temporal resolutions of the order of magnitude of 1.0 mm3 and 400 ns, respectively. Preliminary experiments in still water demonstrated that this method detected sound speed and hence temperature in water ranging 283 K to 333 K with errors of 0.5%. These results may be used to empirically establish the equation of states of water, gelatin or agar cells which will work as alternatives of human tissues.

Gojani, Ardian B.↗
NASA NTRS2014

Calibration of International Space Station (ISS) Node 1 Vibro-Acoustic Model-Report 2

Reported here is the capability of the Energy Finite Element Method (E-FEM) to predict the vibro-acoustic sound fields within the International Space Station (ISS) Node 1 and to compare the results with simulated leak sounds. A series of electronically generated structural ultrasonic noise sources were created in the pressure wall to emulate leak signals at different locations of the Node 1 STA module during its period of storage at Stennis Space Center (SSC). The exact sound source profiles created within the pressure wall at the source were unknown, but were estimated from the closest sensor measurement. The E-FEM method represents a reverberant sound field calculation, and of importance to this application is the requirement to correctly handle the direct field effect of the sound generation. It was also important to be able to compute the sound energy fields in the ultrasonic frequency range. This report demonstrates the capability of this technology as applied to this type of application.

Zhang, Weiguo↗
NASA NTRS2017

Pre-Launch Radiometric Performance Characterization of the Advanced Technology Microwave Sounder on the Joint Polar Satellite System-1 Satellite

The Advanced Technology Microwave Sounder (ATMS) is a space-based, cross-track radiometer for operational atmospheric temperature and humidity sounding, utilizing 22 channels over a frequency range from 23 to 183 gigahertz. The ATMS for the Joint Polar Satellite System-1 has undergone two rounds of re-work in 2014-2015 and 2016, following performance issues discovered during and following thermal vacuum chamber (TVAC) testing at the instrument and observatory level. Final shelf-level testing, including measurement of pass band characteristics and spectral response functions, was completed in December 2016. Final instrument-level TVAC testing and calibration occurred during February 2017. Here we will describe the instrument-level TVAC calibration process, and illustrate with results from the final TVAC calibration effort.

ATMS↗
NASA NTRSDate not supplied

Ceres Planetary Mission Concept Study: Exploration of Ceres' Habitability

Dwarf planet Ceres is a compelling target as an evolved ocean world with recent and potentially ongoing geological activity. As the most water-rich body in the inner solar system after Earth (in absolute abundance), it is a representative of the population of planetesimals that brought volatiles and organics to the inner solar system. And, situated in the Main Belt of Asteroids, it is accessible enough to return a sample from within the resources of a typical medium-class (New Frontiers) NASA mission. Habitability is addressed via a combination of geological, geophysical, and compositional investigations. Past and ongoing activity is addressed via high-resolution imaging and gravity measurements from orbit near landforms interpreted as volcanic structures based on the Dawn observations. The depth of deep brines would be probed via electromagnetic sounding. Sample return would enable a vast range of experimental techniques to be applied with sensitivities and accuracies beyond those feasible with in situ instruments and would benefit from future facilities developments. Sample return could be executed with a single flight system with solar electric propulsion. The baseline design of the sample return capsule is inherited from the OSIRIS-REx mission. This concept also relies on the availability of key technologies: an enhanced landing vision system leveraging investments for Mars 2020; retractable/redeployable solar arrays, which have been demonstrated on the International Space Station but not at Ceres’ gravity; and a new design for sample transfer from the pneumatic sampling system to the sample return capsule based off Honeybee Robotics’ design for the MMX mission. The authors acknowledge support from NASA’s Planetary Mission Concept Study program. The information in this abstract is pre-decisional and is provided for planning and discussion purposes only.

K. E. Miller↗
NASA NTRS1985

Sound generation by flow over relatively deep cylindrical cavities

To develop a system for acoustic coding of moving objects containing drilled cylindrical cavities, the production of high-intensity tones by deep cylindrical cavities in a flat surface at low (0.12-0.24) Mach numbers was investigated. The sound intensity and frequency have been determined as functions of flow velocity, diameter, and depth of the cavities. It is shown that whistles can be designed for a given frequency (in the range of 5-17 kHz) and flow, and the sound pressure levels can be calculated by the equations given. Using these equations a whistle producing 106 dB at a 30.5-cm distance from a cylindrical cavity of 0.508 cm in diameter and 1.32 cm in depth with an airflow of 57.7 m/s past the cavity was designed.

Parthasarathy, S. P.↗
NASA NTRS2022

Implementation of the NASA High Intensity Modal Impedance Tube

This paper provides a description of the High Intensity Modal Impedance Tube (HIMIT) and its use for the evaluation of acoustic liners. Tests conducted with two liners, one linear and one nonlinear, are used to evaluate the suitability of the HIMIT for evaluation at frequencies up to 6 kHz and sound pressure levels up to 155 dB. Two impedance eduction methods are used, one suitable for plane wave frequencies and the other applicable over the full frequency range. These educed impedances are compared against those computed with an impedance prediction method and against those educed with another zero-flow test rig. These results confirm that the HIMIT can be used with confidence for the evaluation of acoustic liners over these frequency and sound pressure level ranges.

impedance↗
NASA NTRS1978

Influence of internally generated pure tones on the broadband noise radiated from a jet

An experimental study was conducted to determine subsonic-jet-noise amplification by plane waves of sound (pure tones) generated upstream of the nozzle over wide ranges of frequency and amplitude. The data were used to evaluate the behavior of the pure tone and the broadband parts of the radiated sound in the far field. It is shown that a significant increase of broadband noise occurs only when the amplitude of the tone in the far field exceeds the sound pressure of the broadband noise at the same location in the far field. Therefore, the sensitivity of the jet to the pure-tone excitation is not large.

Parthasarathy, S. P.↗
NASA NTRS1995

The many facets of auditory display

In this presentation we will examine some of the ways sound can be used in a virtual world. We make the case that many different types of audio experience are available to us. A full range of audio experiences include: music, speech, real-world sounds, auditory displays, and auditory cues or messages. The technology of recreating real-world sounds through physical modeling has advanced in the past few years allowing better simulation of virtual worlds. Three-dimensional audio has further enriched our sensory experiences.

Blattner, Meera M.↗
NASA NTRS1976

Baseline meteorological soundings for parametric environmental investigations at Kennedy Space Center and Vandenberg Air Force Base

Meteorological soundings representative of the atmospheric environment at the Kennedy Space Center, Florida and Vandenberg Air Force Base, California, are presented. Synthetic meteorological soundings at Kennedy Space Center, including fall, spring, and a sea breeze, and at Vandenberg Air Force Base (sea breeze with low and high level inversion and stationary upper level troughs) are shown. Soundings of frontal passages are listed. The Titan launch soundings at Kennedy Space Center present a wide range of meteorological conditions, both seasonal and time of day variations. The meteorological data input of altitude, wind speed, wind direction, temperature, and pressure may be used as meteorological inputs for the NASA/MSFC Multilayer Diffusion Model or other models to obtain quantitative estimates of effluent concentrations associated with the potential emission of major combustion products in the lower atmosphere to simulate actual launches of space vehicles. The Titan launch soundings are also of value in terms of rocket effluent measurements for analysis purposes.

Susko, M.↗
NASA NTRS1973

The design and development of an automatic control system for the in-duct cancellation of spinning modes of sound

The reduction is discussed of the discrete tones generated by jet engines which is essential for jet aircraft to meet present and proposed noise standards. The discrete tones generated by the blades and vanes propagate in the inlet and exhaust duct in the form of spiraling acoustic waves, or spinning modes. The reduction of these spinning modes by the cancellation effect of the combination of two acoustic fields was investigated. The spinning mode synthesizer provided the means for effective study of this noise reduction scheme. Two sets of electrical-acoustical transducers located in an equally-spaced circular array simultaneously generate a specified spinning mode and the cancelling mode. Analysis of the wave equation for the synthesizer established the optimum cancelling array acoustic parameters for maximum sound pressure level reduction. The parameter dependence of the frequency ranges of propagation of single, specified circumferential modes generated by a single array, and of effective cancellation of the modes generated by two arrays, was determined. Substantial sound pressure level reduction was obtained for modes within these limits.

Harrington, W. W.↗
NASA NTRS2001

Overview of Propulsion Systems for a Mars Aircraft

The capabilities and performance of an aircraft depends greatly on the ability of the propulsion system to provide thrust. Since the beginning of powered flight, performance has increased in step with advancements in aircraft propulsion systems. These advances in technology from combustion engines to jets and rockets have enabled aircraft to exploit our atmospheric environment and fly at altitudes near the Earth's surface to near orbit at speeds ranging from hovering to several times the speed of sound. One of the main advantages of our atmosphere for these propulsion systems is the availability of oxygen. Getting oxygen basically "free" from the atmosphere dramatically increases the performance and capabilities of an aircraft. This is one of the reasons our present-day aircraft can perform such a wide range of tasks. But this advantage is limited to Earth; if we want to fly an aircraft on another planetary body, such as Mars, we will either have to carry our own source of oxygen or use a propulsion system that does not require it. The Mars atmosphere, composed mainly of carbon dioxide, is very thin. Because of this low atmospheric density, an aircraft flying on Mars will most likely be operating, in aerodynamical terms, within a very low Reynolds number regime. Also, the speed of sound within the Martian environment is approximately 20 percent less than it is on Earth. The reduction in the speed of sound plays an important role in the aerodynamic performance of both the aircraft itself and the components of the propulsion system, such as the propeller. This low Reynolds number-high Mach number flight regime is a unique flight environment that is very rarely encountered here on Earth.

Colozza, Anthony J.↗
NASA NTRS1974

Quasitrapped electrons in the low L region. Preliminary results of a rocket observation on 22 January 1972

Suprathermal electrons in the energy range 5 - 100 keV were measured with thin-window proportional counters on board a sounding rocket. The flux of the electrons was found to increase with altitude in the range .100 - 550 km, corresponding to L = 1.15 - 1.22, the angular distribution to be peaked in the direction perpendicular to the geomagnetic line of force, and the energy to be represented by a power law.

Hayakawa, S.↗