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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 1,531 records · Page 85

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NASA NTRS1991

Geomagnetic model investigations for 1980 - 1989: A model for strategic defense initiative particle beam experiments and a study in the effects of data types and observatory bias solutions

Two suites of geomagnetic field models were generated at the request of Los Alamos National Lab. concerning Strategic Defense Initiative (SDI) research. The first is a progression of five models incorporating MAGSAT data and data from a sequence of batches as a priori information. The batch sequence is: post 1979.5 observatory data, post 1980 land survey and selected aeromagnetic and marine survey data, a special White Sands (NM) area survey by Project Magnet with some additional post 1980 marine survey data, and finally DE-2 satellite data. These models are of 13th deg and order in their main field terms, and deg and order 10 in their first derivative temporal terms. The second suite consists of four models based solely upon post 1983.5 observatory and survey data. They are of deg and order 10 in main field and 8 in a first deg Taylor series. A comprehensive error analysis was applied to both series, which accounted for error sources such as the truncated core and crustal fields, and the neglected Sq and low deg crustal fields. Comparison of the power spectrum of the MGST (10/81) model with those of this series show good agreement.

Langel, Robert A.↗

NASA NTRS1991

Tunnelling from non-localised initial states

An approach for calculating tunneling amplitudes from a nonlocalized initial state is presented. Generalizing the matching conditions and equations of motion to allow for complex momentum permits a description of tunneling in the presence of so-called classical motion. Possible applications of the method are presented.

Bowcock, Peter↗

NASA NTRS1991

Thermal control surfaces experiment: Initial flight data analysis

The behavior of materials in the space environment continues to be a limiting technology for spacecraft and experiments. The thermal control surfaces experiment (TCSE) aboard the Long Duration Exposure Facility (LDEF) is the most comprehensive experiment flown to study the effects of the space environment on thermal control surfaces. Selected thermal control surfaces were exposed to the LDEF orbital environment and the effects of this exposure were measured. The TCSE combined in-space orbital measurements with pre and post-flight analyses of flight materials to determine the effects of long term space exposure. The TCSE experiment objective, method, and measurements are described along with the results of the initial materials analysis. The TCSE flight system and its excellent performance on the LDEF mission is described. A few operational anomalies were encountered and are discussed.

Wilkes, Donald R.↗

NASA NTRS1991

West Antarctic Ice Sheet Initiative. Volume 2: Discipline Reviews

Seven discipline review papers are presented on the state of the knowledge of West Antarctica and opinions on how that knowledge must be increased to predict the future behavior of this ice sheet and to assess its potential to collapse, rapidly raising the global sea level. These are the goals of the West Antarctic Ice Sheet Initiative (WAIS).

Bindschadler, Robert A.↗

NASA NTRS1991

An initial investigation into methods of computing transonic aerodynamic sensitivity coefficients

Continuing studies associated with the development of the quasi-analytical (QA) sensitivity method for three dimensional transonic flow about wings are presented. Furthermore, initial results using the quasi-analytical approach were obtained and compared to those computed using the finite difference (FD) approach. The basic goals achieved were: (1) carrying out various debugging operations pertaining to the quasi-analytical method; (2) addition of section design variables to the sensitivity equation in the form of multiple right hand sides; (3) reconfiguring the analysis/sensitivity package in order to facilitate the execution of analysis/FD/QA test cases; and (4) enhancing the display of output data to allow careful examination of the results and to permit various comparisons of sensitivity derivatives obtained using the FC/QA methods to be conducted easily and quickly. In addition to discussing the above goals, the results of executing subcritical and supercritical test cases are presented.

Carlson, Leland A.↗

NASA NTRS1989

JPL initiative on historically black colleges and universities

Executive order number 12320 of September 15, 1981, established a program designed to significantly increase the participation of historically black colleges and universities (HBCU's) in Federal programs. Because of its geographical remoteness and position as a contractor operated center, JPL had not participated in grant and training programs with the HBCU's. In recognition of JPL's responsibility to the national commitment on behalf of the historically black colleges and universities, an initiative with effective, achievable guidelines and early progress for a better and more productive interaction between JPL and the HBCU's is described. Numerous areas of interaction with the historically black colleges and universities have been identified and are being inplemented. They have two broad objectives: research interactions and faculty/student interactions. Plans and progress to date for each specific area are summarized.

Allen, Lew↗

NASA NTRS1991

The space exploration initiative

A number of view graph charts are presented which outline the presentation. Outlined are reasons for going to Mars, why it is necessary to go to the Moon first, and the presidential decision on the space exploration initiative. Other representative charts are entitled: Lunar transportation system requirement drivers; Mars transportation system requirement drivers; National space policy goals; Exploration hardware needed; Mars mission profile; Science on the Moon and Mars; and Two independent reviews.

Priest, Pete↗

NASA NTRS1991

Characterization of vertical electric fields and associated voltages induced on a overhead power line from close artificially initiated lightning

Measurements were characterized of simultaneous vertical electric fields and voltages induced at both ends of a 448 m overhead power line by artificially initiated lightning return strokes. The lightning discharges struck ground about 20 m from one end of the line. The measured line voltages could be grouped into two categories: those in which multiple, similarly shaped, evenly spaced pulses were observed, which are called oscillatory; and those dominated by a principal pulse with subsidiary oscillations of much smaller amplitude, which are called impulsive. Voltage amplitudes range from tens of kilovolts for oscillatory voltages to hundreds of kilovolts for impulsive voltages.

Rubinstein, Marcos↗

NASA NTRS1990

The Space Exploration Initiative and NASA Langley Research Center test facilities

The NASA Exploration Technology Program (ETP) will make possible the U.S. Space Exploration Initiative (SEI), and is structured according to mission thrusts that are based on technologies to be developed and tested or that will otherwise be utilized to support SEI. Twenty-seven technology projects have thus far been established, and NASA's Langley Research Center is responsible for six lead roles and four participating roles. This report briefly defines these ten Langley-assigned ETP technology projects, and it describes both existing and proposed test facilities capable of supporting the Center's responsibilities.

Mouring, John L.↗

NASA NTRS1990

Cryogenic liquid hydrogen reorientation activated by constant reverse gravity acceleration of geyser initiation

A key objective for cryogenic fluid management in a spacecraft propulsion system is development of the technology necessary for acquisition or positioning of liquid outflow or vapor venting. Numerical simulation of positive liquid acquisition is attempted by introducing a reverse gravity acceleration from the propulsive thrust of auxiliary engines which exceeds critical value for the initiation of a geyser. Based on the computer simulation of flow fields during the course of fluid reorientation, six dimensionless parameters resulted. These parameters hold near-constant values through the entire range of liquid filled levels, from 30 to 80 percent, during the course of fluid reorientation.

Hung, R. J.↗

NASA NTRS1990

Advanced life support technology development for the Space Exploration Initiative

An overview is presented of NASA's advanced life support technology development strategy for the Space Exploration Initiative. Three basic life support technology areas are discussed in detail: air revitalization, water reclamation, and solid waste management. It is projected that regenerative life support systems will become increasingly more complex as system closure is maximized. Advanced life support technology development will utilize three complementary elements, including the Research and Technology Program, the Regenerative Life Support Program, and the Technology Testbed Validations.

Evanich, Peggy L.↗

NASA NTRS1990

The JOVE initiative - A NASA/university Joint Venture in space science

The JOVE (NASA/university Joint Venture in space science) initiative is a point program between NASA and institutions of higher education whose aim is to bring about an extensive merger between these two communities. The project is discussed with emphasis on suggested contributions of partnership members, JOVE process timeline, and project schedules and costs. It is suggested that NASA provide a summer resident research associateship (one ten week stipend); scientific on-line data from space missions; an electronic network and work station, providing a link to the data base and to other scientists; matching student support, both undergraduate and graduate; matching summer salary for up to three faculty participants; and travel funds. The universities will be asked to provide research time for faculty participants, matching student support, matching summer salary for faculty participants, an instructional unit in space science, and an outreach program to pre-college students.

Six, F.↗

NASA NTRS1990

A technology assessment of alternative communications systems for the space exploration initiative

Telecommunications, Navigation, and Information Management (TNIM) services are vital to accomplish the ambitious goals of the Space Exploration Initiative (SEI). A technology assessment is provided for four alternative lunar and Mars operational TNIM systems based on detailed communications link analyses. The four alternative systems range from a minimum to a fully enhanced capability and use frequencies from S-band, through ka-band, and up to optical wavelengths. Included are technology development schedules as they relate to present SEI mission architecture time frames.

Ponchak, Denise S.↗

NASA NTRS1990

Heavy-lift launch vehicle options for future space exploration initiatives

A review of present heavy-lift launch vehicles (HLLV) capable of placing heavy payloads in earth orbit is presented and the basis for an emerging consensus that an HLLV will be required in the near future is discussed. Some of the factors for the policies governing the roles and requirements for these vehicles in the future, such as cost, technology development, and lead time to first use are addressed. Potential Space Station Freedom application is discussed as well as application to the proposed initiatives for human exploration of Mars and the moon.

Branscome, Darrell R.↗

NASA NTRS1990

NASA's commercial space program - Initiatives for the future

NASA's commercial development of the space program aimed at the stimulation and assistance of expanded private sector involvement and investment in civil space activities is discussed, focusing on major new program initiatives and their implementation. NASA's Centers for the Commercial Development of Space (CCDS) program, composed of competitively selected consortia of universities, industries, and government involved in early research and testing phases of potentially commercially viable technologies is described. The 16 centers concentrate on seven different technical areas such as automation and robotics; remote sensing; life sciences; and space power, propulsion, and structures. Private sector participation, CCDS technology development, government and commercially supplied access to space in support of CCDS programs, CCDS hardware development, and CCDS spinoffs are discussed together with various cooperative and reimbursable agreements between NASA and the private sector.

Rose, James T.↗

NASA NTRS1991

On the initiation of subduction

Estimates of shear resistance associated with lithospheric thrusting and convergence represent lower bounds on the force necessary to promote trench formation. Three environments proposed as preferential sites of incipient subduction are investigated: passive continental margins, transform faults/fracture zones, and extinct ridges. None of these are predicted to convert into subduction zones simply by the accumulation of local gravitational stresses. Subduction cannot initiate through the foundering of dense oceanic lithosphere immediately adjacent to passive continental margins. The attempted subduction of buoyant material at a mature trench can result in large compressional forces in both subducting and overriding plates. This is the only tectonic force sufficient to trigger the nucleation of a new subduction zone. The ubiquitous distribution of transform faults and fracture zones, combined with the common proximity of these features to mature subduction complexes, suggests that they may represent the most likely sites of trench formation if they are even marginally weaker than normal oceanic lithosphere.

Mueller, Steve↗

NASA NTRS1991

Reactor safety for the Space Exploration Initiative

A task force was created by the National Aeronautics and Space Administration to conduct a 90-day study to support efforts to determine requirements to meet the goals of the Space Exploration Initiative. The task force identified the need for a nuclear reactor to provide the electrical power required as the outpost power demands on the moon and Mars evolve into hundreds of kilowatts. A preliminary hazards analysis has been performed to examine safety aspects of nuclear reactor power systems for representative missions to the moon and Mars. Mission profiles were defined for reference lunar and Martian flights. Potential alternatives to each mission phase were also defined. Accident scenarios were qualitatively defined for the mission phases. The safety issues decay heat removal, reactor control, disposal, criticality, end-of-mission shutdown, radiation exposure, the Martian environment, high speed impact on the surfaces of the moon or Mars, and return flyby trajectories were identified.

Dix, Terry E.↗

NASA NTRS1990

The role of Space Station Freedom in the Human Exploration Initiative

Exploration accommodation requirements for Space Station Freedom (SSF) and mission-supporting capabilities have been studied. For supporting the Human Exploration Initiative (HEI), SSF will accommodate two functions with augmentations to the baseline Assembly Complete configuration. First, it will be an earth-orbiting transportation node providing facilities and resources (crew, power, communications) for space vehicle assembly, testing, processing and postflight servicing. Second, it will be an in-space laboratory for science research and technology development. The evolutionary design of SSF will allow the on-orbit addition of pressurized laboratory and habitation modules, power generation equipment, truss structure, and unpressurized vehicle processing platforms.

Ahlf, P. R.↗