Engineering PapersSearch

SEARCH · Engineering Papers

Results for “Materials processing”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,027 records · Page 57

The ionization structure of planetary nebulae. Part 4: NGC 7662

Spectrophotometric observations of emission-line intensities over the spectral range 1400 to 7200 A were made in five positions in the planetary nebula NGC 7662. Standard equations used to correct for the existence of elements in other than the optically observable ionization stages show a consistent and approximate agreement with abundances calculated using ultraviolet lines. The abundances of C and N indicate that some mixing of CNO-processed material into the nebular shell may have occurred in NGC 7662; the low He abundance, however, indicates that little or no He enrichment occurred. The Ar, Ne, and O and S abundances appear to be low. It is suggested that the progenitor to NGC 7662 may have formed out of somewhat metal-poor material.

Barker, T.

The ionization structure of planetary nebulae. IV - NGC 6853

Upgraded UV and IR data were taken of the planetary nebula NGC 6853 in the same region as previous optical data to improve the data base on various ionized species in the nebula. The spectral range 1400-9600 A was scanned, and good agreement was obtained between UV and optical ionization abundance data, although the 4267 A C II line yielded a C(2+) abundance larger than indicated by the UV data. The discrepancy concentrated around the central star. Ionization abundances were determined for He, O, N, NC, C, Ar, and S relative to H, and the causes of discrepancies in the abundances compared to those of previous investigators are discussed. It is noted that, as in the planetary nebula NGC 6720, lighter element abundances are higher than solar values, which suggests mixing of processed materials in the envelope of the two nebulae.

Barker, T.

Shielding of CO from dissociating radiation in interstellar clouds

The paper investigates the photodissociation of CO in interstellar clouds in the light of recent laboratory studies which suggest that line rather than continuum processes dominate its dissociation by ultraviolet radiation. Using a simple radiative transfer model, the shielding of representative dissociating bands is estimated, including self-shielding, mutual shielding between different isotopes, and near coincidences with strong lines of H2. Each of these processes materially affects the photodestruction rates of the various isotopic species in the transition regions of molecular clouds. These results are combined with an appropriate gas phase chemical model to determine how the abundances of the CO isotopes vary with depth into the cloud. It is found that self-shielding and mutual shielding cause significant variations in isotopic ratios. In addition, fractionation enhances species containing C-13. The relationship between the column densities of CO and H2 is found to vary for the different isotopes and to be sensitive to local conditions.

Glassgold, A. E.

Space Shuttle mission extension capability

Space Shuttle missions are currently limited to 11 days, primarily due to depletion of the power reactants (hydrogen and oxygen). A power system Mission Extension Kit (MEK) is described which could provide the capability to stay on orbit 10 additional days. These extra days would benefit Space Station construction and missions such as materials processing, earth and celestial observation, and life science studies (Spacelab). Other constraints to longer missions which may dictate minor Orbiter modifications will be discussed. The power system MEK is particularly desirable because of its existing flight qualified hardware which can be delivered within 3 to 4 years.

Fraser, W. M., Jr.

From Mars to man - Biomedical research at the Jet Propulsion Laboratory

In the course of the unmanned exploration of the solar system, which the California Institute of Technology's Jet Propulsion Laboratory has managed for NASA, major advances in computerized image processing, materials research, and miniature electronics design have been accomplished. This presentation shows some of the imaging results from space exploration missions, as well as biomedical research tasks based in these technologies. Among other topics, the use of polymeric microspheres in cancer therapy is discussed. Also included are ceramic applications to prosthesis development, laser applications in the treatment of coronary artery disease, multispectral imaging as used in the diagnosis of thermal burn injury, and some examples of telemetry systems as they can be involved in biological systems.

Beckenbach, E. S.

The role of robotics in space system operations

The role of automation and robotics in support of man's activities in space is discussed, with emphasis given to satellite servicing functions on board the NASA Space Station (SS) or at remote locations. Consideration is given to four satellite servicing mission scenarios, including: low-earth-orbit (LEO) servicing of satellite in situ or on the Space Station following orbital transfer by means of an Orbital Maneuvering Vehicle (OMV); in situ servicing of a free-flying coorbiting materials processing platform; repair/refurbishment of Space Station payloads of substations; an in situ servicing of geostationary satellites by means of an Orbital Transfer Vehicle (OTV). The potential applications of three different automation technologies are examined, including: teleoperation; robotics; and artificial intelligence. Consideration is also given to the potential applications of the Space Station data system in support of servicing activities. A list of the more common terms of automation technology is provided.

Meissinger, H. F.

Advanced Optical Measurement Techniques

This research analyzes four areas: (1) Improved Techniques for Optical Measurement; (2) KC-135 Low Gravity Simulation Flight Preparation; (3) In-Line Holographic Microscopy; and (4) Holographic Optical Schlieren System (HOSS). The first task provides for laboratory breadboarding of advanced optical measurement techniques which appear promising for use in Material Processing System (MPS) flight experiments. A laboratory schlieren system has been constructed which simulates a similar optical system on the Fluids Experiment System (FES) which is to be flown on Spacelab 3. The second task allows improved optical systems and breadboards to be built for experiments and hardware tests on the KC-135 aircraft. A new, more stable Mach-Zehnder interferometer has been developed and components have been ordered. The third task is concerned with improvements on the optical system being used to study immiscible fluids. Experiments studying the dynamics of nucleation and the separation of immiscible fluids have been conducted. The four task involves building breadboard reconstruction systems for holograms taken in the HOSS. The HOSS is an early prototype of the Fluids Experiments System (FES) which is scheduled to fly on Spacelab 3.

Owen, R. B.

Space station data system analysis/architecture study. Task 2: Options development DR-5. Volume 1: Technology options

The second task in the Space Station Data System (SSDS) Analysis/Architecture Study is the development of an information base that will support the conduct of trade studies and provide sufficient data to make key design/programmatic decisions. This volume identifies the preferred options in the technology category and characterizes these options with respect to performance attributes, constraints, cost, and risk. The technology category includes advanced materials, processes, and techniques that can be used to enhance the implementation of SSDS design structures. The specific areas discussed are mass storage, including space and round on-line storage and off-line storage; man/machine interface; data processing hardware, including flight computers and advanced/fault tolerant computer architectures; and software, including data compression algorithms, on-board high level languages, and software tools. Also discussed are artificial intelligence applications and hard-wire communications.

Source record

Project Explorer's unique experiments: Get Away Special #007

The Project Explorer payload represents the first attempt at broadcasting digitized voice signals via a Space Shuttle flight on amateur radio frequencies. These amateur ham-radio frequencies will be transmitting real time data while the experiments are operating. Experiments 1, 2, and 3 represent the work of students ranging from materials processing to the science of biology. Experiment 1 will study the solidification of two hypereutectic alloys, lead-antimony and aluminum-copper. Experiment 2 will investigate the examination and growth of radish seeds in space. Experiment 3 will examine the electrochemical growth process of potassium tetrocyonoplatinate hydrate crystals and Experiment 4 involves amateur radio transmissions, monitoring and support of the entire Get Away Special (GAS) 007 payload.

Arthur J. Henderson, Jr.

Tethered constellations, their utilization as microgravity platforms and relevant features

The gravitational, thermal, and dynamic docking effects on tethered platforms were studied. The near-earth environment has gravitational effects such a g-jitters and intermittencies, g-noise, and frequency and amplitude features which may influence life science, materials processing, and fluid processes research and commercial activities. Artificial gravity is produced by minute accelerations imparted by tethers. The magnitudes of gravitational forces produced by tethers 100 and 100,000 m long at various altitudes from 463 to 35,786 km are calculated. Thermal analyses were performed for stainless steel and Kevlar tethers, showing the steel tether could vary 300 m in length and the polyamide 25 m during one orbit. Finally, consideration given to docking with a tethered platform revealed that the center of mass could change, which would produce, however, negligible changes in orbit and therefore gravity.

Napolitano, L. G.

Proceedings of the 25th Project Integration Meeting

Topics addressed include: silicon sheet growth and characterization, silicon material, process development, high-efficiency cells, environmental isolation, engineering sciences, and reliability physics.

Phillips, M.

The National Symposium and Workshop on Optical Platforms, Huntsville, AL, June 12-14, 1984, Proceedings

The present conference is concerned with space-based observatories (including future systems), interplanetary observation platforms, Space Station optical utilization, orbital earth viewing systems, and Spacelab's use as an observations platform. Attention is given to the pointing system for the Space Telescope, the Advanced X-ray Astrophysics Facility, the conceptual definition of the Space IR Telescope Facility's spacecraft, satellite servicing in light of the Solar Maximum Repair Mission, a large deployable reflector telescope concept, moon-based astronomical observatories, Space Station-based remote sensing of the earth, optical systems is geosynchronous orbit, multispectral linear array detector technology, Spacelab-based space plasma and materials processing investigations, and space construction technology for large space observatories. Also discussed are military optical platforms for sea, land and air stationing.

Wyman, C. L.

The First Spacelab Mission

The role of the mission manager in coordinating the payload with the space transportation system is studied. The establishment of the investigators working group to assist in achieving the mission objectives is examined. Analysis of the scientific requirements to assure compatibility with available resources, and analysis of the payload in order to define orbital flight requirements are described. The training of payload specialists, launch site integration, and defining the requirements for the operation of the integrated payload and the payload operations control center are functions of the mission manager. The experiences gained from the management of the Spacelab One Mission, which can be implemented in future missions, are discussed. Examples of material processing, earth observations, and life sciences advances from the First Spacelab Mission are presented.

Craft, H.

The challenge of the US Space Station

The U.S. Space Station program is described. The objectives of the present national space policy are reviewed. International involvement and commercial use of space are the two strategies involved in the development of the Space Station. The Space Station is to be a multifunctional, modular, permanent facility with manned and unmanned platforms. The functions of the Space Station for space research projects, such as material processing and electrophoresis, are examined. The infrastructure required for commercialization of space is analyzed. NASA's space policy aimed at stimulating space commerce is discussed. NASA's plans to reduce the financial, institutional, and technical risks of space research are studied.

Beggs, J. M.

Supernova nucleosynthesis in low-metallicity populations

The mass loss rate in low-metallicity stars is discussed, and the consequences of that rate for the fate of such stars are considered. It is shown that, if radiation pressure on dust is important in driving the mass loss from red giants, and if these stars do not dredge up large amounts of processed material during their evolution, then the total amount of mass lost by Population II stars with low metallicity is small. Consequently, the rate of supernovae in populations of low metallicity is much higher than in populations of solar abundances. This conclusion leads to the prediction that the supernova rate should be high in galaxies that have some intermediate mass stars and have metallicity less than about 0.1 of the solar value.

Jura, M.

Commerce Lab - A program of commercial flight opportunities

Commerce Lab is conceived as an adjunct to the National Space Transportation System (NSTS) by providing a focal point for commercial missions which could utilize existing NSTS carrier and resource capabilities for on-orbit experimentation in the microgravity sciences. In this context, the Commerce Lab program provides mission planning for private sector involvement in the space program, in general, and the commercial exploitation of the microgravity environment for materials processing research and development. It is expected that Commerce Lab will provide a logical transition between currently planned NSTS missions and future microgravity science and commercial R&D missions centered around the Space Station. The present study identifies candidate Commerce Lab flight experiments and their development status and projects a mission traffic model that can be used in commercial mission planning.

Robertson, J.

Space Station crew workload - Station operations and customer accommodations

The features of the Space Station which permit crew members to utilize work time for payload operations are discussed. The user orientation, modular design, nonstressful flight regime, in space construction, on board control, automation and robotics, and maintenance and servicing of the Space Station are examined. The proposed crew size, skills, and functions as station operator and mission specialists are described. Mission objectives and crew functions, which include performing material processing, life science and astronomy experiments, satellite and payload equipment servicing, systems monitoring and control, maintenance and repair, Orbital Maneuvering Vehicle and Mobile Remote Manipulator System operations, on board planning, housekeeping, and health maintenance and recreation, are studied.

Shinkle, G. L.

Business in orbit - The commercial use of space

Current and proposed business opportunities in space are discussed. The advantages offered by the zero gravity environment of space are examined. The roles of the Space Shuttle and the Space Station in space commercialization are described. International development and use of the Space Station is proposed. It is observed that the communications satellite industry is a successful space venture, and opportunities for materials processing and pharmaceuticals production in space are considered. The relationship between NASA's Office of Commercial Programs, which assists businesses in space commercialization, and industry is studied. The impact of space commercialization on the national economy and international trade is analyzed.

Gillam, I. T., IV