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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
All sourcesNASA NTRSDOE OSTI
NASA NTRS1990

Gamma Ray Observatory (GRO) OBC attitude error analysis

This analysis involves an in-depth look into the onboard computer (OBC) attitude determination algorithm. A review of TRW error analysis and necessary ground simulations to understand the onboard attitude determination process are performed. In addition, a plan is generated for the in-flight calibration and validation of OBC computed attitudes. Pre-mission expected accuracies are summarized and sensitivity of onboard algorithms to sensor anomalies and filter tuning parameters are addressed.

Harman, R. R.↗
NASA NTRS1990

Project Exodus

Project Exodus is an in-depth study to identify and address the basic problems of a manned mission to Mars. The most important problems concern propulsion, life support, structure, trajectory, and finance. Exodus will employ a passenger ship, cargo ship, and landing craft for the journey to Mars. These three major components of the mission design are discussed separately. Within each component the design characteristics of structures, trajectory, and propulsion are addressed. The design characteristics of life support are mentioned only in those sections requiring it.

Source record↗
NASA NTRS1988

CASSINI. Report on the Phase A study: Saturn Orbiter and Titan probe

An in-depth, second phase exploration of Saturn is proposed. The scientific objectives involving Titan, Saturn's rings, icy satellites, magnetosphere, Jupiter, asteroids, and cruise science are covered. Other topics presented include: (1) the model payloads; (2) project requirements; (3) mission; (4) launch vehicle; (5) the orbiter system; (6) the Titan probe system; (7) mission operations; (8) management; and (9) development plan.

Source record↗
NASA NTRS1990

Revealing the microstructure of materials

The objectives are to demonstrate how the microstructure of materials may be revealed by abrasive polishing and chemical etching, and to illustrate how microstructural information is used to monitor manufacturing processes, provide in-depth inspection, and perform failure analysis. Microstructural analysis is the procedure used to reveal the internal microstructural details of a material or part by sectioning and polishing the cut surface so that it may be examined under a suitable microscope. A printed wiring board was selected as the test material because it contains both metals and nonmetals that have distinctive microstructures, and because this technique is used throughout the electronic industry as a key quality control tool. The three principle component materials in printed circuit boards are glass/epoxy laminates faced with copper foil; copper, deposited by both electroless and electrolytic plating; and tin/lead solder. Sample preparation, mounting, grinding, polishing, and examination and analysis are discussed.

Nelson, James A.↗
NASA NTRS1991

Portable Common Execution Environment (PCEE) project review: Peer review

The purpose of the review was to conduct an independent, in-depth analysis of the PCEE project and to provide the results of said review. The review team was tasked with evaluating the potential contribution of the PCEE project to the improvement of the life cycle support of mission and safety critical (MASC) computing components for large, complex, non-stop, distributed systems similar to those planned for such NASA programs as the space station, lunar outpost, and manned missions to Mars. Some conclusions of the review team are as follow: The PCEE project was given high marks for its breath of vision on the overall problem with MASC software; Correlated with the sweeping vision, the Review Team is very skeptical that any research project can successfully attack such a broad range of problems; and several recommendations are made such as to identify the components of the broad solution envisioned, prioritizing them with respect to their impact and the likely ability of the PCEE or others to attack them successfully, and to rewrite its Concept Document differentiating the problem description, objectives, approach, and results so that the project vision becomes assessible to others.

Locke, C. Douglass↗
NASA NTRS1991

Composite propellant technology research: Mechanical property characterization

Proof for the existence of a single Poisson's ratio function in isotropic linear viscoelastic materials is presented. An in-depth discussion is given of three dimensional viscoelastic material properties and their relationships to linear isotropic and orthotropic viscoelastic materials. A discussion of the alternate invariant definition as used by Abaqus and how it relates to the form used by Dr. S. Peng is presented.

Bower, Mark V.↗
NASA NTRS1991

Flow induced vibrations in the SSME injector heads

A description is given of the flowfield in the Space Shuttle Main Engine (SSME) powerhead, the mechanisms which control flow-induced vibrations, and previous experimental work. An in-depth description is given of the development phase of the program , which includes the analysis, design, and fabrication of liquid oxygen (LOX) posts models used in the experimental phase, as well as test facilities, equipment, and procedures used. Also covered is the experimental data analysis, which includes overall steady state powerhead flowfield as well as the high frequency response of the LOX posts.

Lepore, Frank A.↗
NASA NTRS1990

Spacecraft Doppler tracking with a VLBI antenna

Preliminary results are reported from Doppler-shift measurements to the Voyager-2 spacecraft at a distance of 26 AU, obtained using the 32-m VLBI antenna at Medicina (Italy) during July and August 1988. The apparatus comprises the el-az antenna, an S-X-band receiver, a hydrogen maser to generate the reference signal, a Mark III VLBI terminal, and a digital tone extractor capable of isolating a tone of known frequency from a noisy signal and giving its phase and amplitude. A signal transmitted in S-band from the NASA Deep Space Network (DSN) station in Australia and retransmitted coherently in X-band by Voyager, was received 7 h 6 min later at Medicina and at the DSN station in Madrid. Sample data are presented graphically and shown to be of generally high quality; further in-depth analysis is under way.

Comoretto, G.↗
NASA NTRS1990

NASA's space physics theory program - An opportunity for collaboration

The field of theoretical space physics offers a unique opportunity to Latin American scientists for collaborative participation in NASA programs where the greatly increased complexity of both experimental observations and theoretical simulations requires in-depth comparisons between theory and observational data. The key problem areas identified by NASA for aggressive work in the decade of the 1990s are the nature of flows and turbulence, acceleration and transport of particles, the coupling of microphysics and macrophysics, the coupling of local and global dynamics, and nonclassical plasmas.

Vinas, Adolfo F.↗
NASA NTRS1991

Phenomenological and experimental study of the thermal response of low density silica ablators to high enthalpy plasma flows

A complete analysis of the melting-ablator governing equations is carried out for porous ablators with the purpose of establishing an approximate analytical model capable of determining surface recession, temperature, and heat flux as well as in-depth temperature profiles. A detailed dimensional analysis of the melt-flow governing equations is performed for parameters applicable to high-enthalpy flows. Results of arc-jet flow experiments performed on NASA Reusable Surface Insulation materials of different densities and over a range of stagnation pressures and heat fluxes are discussed. A dimensionless correlation for melt run-offs is derived in terms of material and flow parameters; however, it is pointed out that the accuracy of the current data is sufficient to conclude the compliance with the model.

Henline, William D.↗
NASA NTRS1991

Using CLIPS as the cornerstone of a graduate expert systems course

The effective use of the C Language Integrated Production System (CLIPS) as a cornerstone in a graduate expert systems course is described. The course include 8 or 9 hours of in-depth lecturing in CLIPS, as well as a broad coverage of major topics and techniques in expert systems. As part of the requirements of the course, students solved two small yet non-trival problems in CLIPS before going on to develop a toy expert system in CLIPS in an incremental manner as the term project. Furthermore, students were required to evaluate CLIPS programs written by their classmates. An anonymous questionnaire at the end of the semester revealed that the students responded very favorably to the course, especially their experience with CLIPS.

Yue, Kwok-Bun↗
NASA NTRS1990

Investigation of micro-gravity effects on heat pipe thermal performance and working fluid behavior, phase B

The purpose of this experiment is to develop an in-depth understanding of the behavior of heat pipes in space. Both fixed conductance heat pipes (FCHPs) with axial grooves and variable conductance heat pipes (VCHPs) with porous wicks will be investigated. This understanding will be applied to the development of improved performance heat pipes subjected to various accelerations in space, including those encountered on a lunar base or Mars mission. More efficient, reliable, and lighter weight spacecraft thermal control systems should result from these investigations.

Gier, K. D.↗
NASA NTRS1992

The NASA hypersonic research engine program

An overview is provided of the NASA Hypersonic Research Engine Program. The engine concept is described which was evolved, and the accomplishments of the program are summarized. The program was undertaken as an in-depth program of hypersonic airbreathing propulsion research to provide essential inputs to future prototype engine development and decision making. An airbreathing liquid hydrogen fueled research oriented scramjet was to be developed to certain performance goals. The work was many faceted, required aerodynamic design evaluation, structures development, and development of flight systems such as the fuel and control system, but the main objective was the study of the internal aerothermodynamics of the propulsion system.

Rubert, Kennedy F.↗
NASA NTRS1992

Generating the complete control environment interface for EASIE

The Environment for Application Software Integration and Execution (EASIE) was designed to meet the needs of conceptual design engineers that face the task of integrating the results of many stand alone engineering analysis programs. EASIE is a set of utility programs which supports rapid integration and execution of programs about a central relational database, and it provides users with two basic modes of executing operations: Application Derived Executive (ADE), a menu-driven execution mode which provides users with sufficient guidance to quickly review data, select menu action items, and execute application programs, and Complete Control Executive (CCE), which provides a full executive interface, allowing users in-depth control of the design process. Users can switch between these modes as needed. This project will consider the CCE mode interface. Two objectives of this project are to redesign the selecting menus by using a windowing system and to reorganize the selecting structures of the selecting menus. The project will be implemented in the C window system, OSF/Motif version.

Tsai, Chia-Lin↗
NASA NTRS1992

MARSNET surface and atmosphere investigations

Following an ESA preliminary study on the possible areas of European participation in the future international exploration of Mars and a recent ESA in-depth scientific and technical assessment study, MARSNET was selected for further phase-A studies as a potential European contribution to such exploration. The MARSNET mission consists of a network of small stations to be landed on the surface of Mars. All surface stations will have identical design and payload, and will be located several thousand km apart from each other. The required operational lifetime on the surface of Mars for all landers is one Martian year (687 days) to carry out long-term meteorological and seismological measurements. The availability of a data relay orbiter at low altitude is assumed. The instruments are mounted on a platform under the semi-hard lander solar array. The main scientific goals of the mission during the atmospheric descent and on the surface are outlined.

Chicarro, A. F.↗
NASA NTRS1991

Nondestructive inspection perspectives

This paper presents ideas for consideration by those concerned with commercial aircraft nondestructive inspection (NDI). The perspective is that of an individual with a background in military aircraft NDI, and important differences are indicated between the commercial NDI and military NDI activities. In particular, it is significantly more expensive to implement some new NDI technology, and therefore, in-depth cost-benifit studies for commercial users are recommended.

Aging Aircraft↗
NASA NTRS1991

Evaluation of GPS/UTC steering performance

The Global Positioning System (GPS) is required to maintain GPS time to Universal Coordinated Time (UTC) to an accuracy of one microsecond and broadcast to the user the offset between GPS and UTC to an accuracy of 100 nanoseconds (1 sigma). On 25 Jun. 1990, an automatic steering algorithm was implemented to control GPS time to synchronize it with UTC. The description of the steering laws and predicted performance results were presented at the 1989 Precise Time and Time Interval (PTTI) conference, while preliminary performance results were presented at the 1990 PTTI conference. The initial performance was not as predicted, resulting in an in-depth analysis of the observed performance and a more thorough sensitivity analysis. In addition, responses to anomalies were investigated. This paper will describe these analyses and results, and evaluate actual steering performance from Jun. 1990 to Nov. 1991. Although anomalies were observed during the initial phase of steering, recent experience is more in line with expectations.

W. A. Feess↗
NASA NTRS1991

A mission design for International Manned Mars Mission - From the 1991 International Space University (ISU) Design Project

The International Space University (ISU) conducted a study of an international program to support human exploration of Mars as its annual Design Project activity during its 1991 summer session in Toulouse, France. Although an ISU Design Project strives to produce an in-depth analysis during the intense 10-week summer session, the International Mars Mission (IMM) project was conducted in a manner designed to provide a learning experience for young professionals working in an unusual multidisciplinary and multinational environment. The breadth of the IMM study exceeds that of most Mars mission studies of the past, encompassing political organization for long-term commitment, multinational management structure, cost analysis, mission architecture, vehicle configuration, crew health, life support, Mars surface infrastructure, mission operations, technology evaluation, risk assessment, scientific planning, exploration, communication networks, and Martian resource utilization. The IMM Final Report has particular value for those seeking insight into the choices made by a multinational group working in an apolitical environment on the problems of international cooperation in space.

Mendell, Wendell W.↗