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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 649 records · Page 36

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NASA NTRS1972

The 110 watt per kilogram lightweight solar array system

This ultralightweight solar array system is applied to three generic mission types: (1) interplanetary, (2) geosynchronous, and (3) manned space station. The requirements of each of these missions, as they pertain to the solar array, are presented. Existing lightweight solar array system concepts are reviewed, along with conclusions regarding the applicability of this technology to the feasibility of the ultralightweight solar array system. Several system concepts are included for further evaluation. The existing technology base, as it pertains to solar cells, solar cell covers, interconnects and substrates, and deployable booms, is reviewed. The attitude control of spacecraft with large flexible solar arrays is also discussed.

Shepard, N. F.↗

NASA NTRS1972

Orbital operations study. Executive summary

A summary of the analyses of the orbital operations study is presented. Objectives, scope of study, and technical documentation format are discussed. A summary of the mission analyses including generic mission models, element pair interactions, and interfacing activities are presented. The analyses associated with each interfacing activity are also summarized. Significant implications derived during the course of the study on the EOS orbiter, space tug, RAM, and MSS are indicated.

Hogan, L. R.↗

NASA NTRS1972

Integrated dynamic analysis simulation of space stations with controllable solar arrays (supplemental data and analyses)

Space station and solar array data and the analyses which were performed in support of the integrated dynamic analysis study. The analysis methods and the formulated digital simulation were developed. Control systems for space station altitude control and solar array orientation control include generic type control systems. These systems have been digitally coded and included in the simulation.

Heinrichs, J. A.↗

NASA NTRS1972

Integrated dynamic analysis simulation of space stations with controllable solar array

A methodology is formulated and presented for the integrated structural dynamic analysis of space stations with controllable solar arrays and non-controllable appendages. The structural system flexibility characteristics are considered in the dynamic analysis by a synthesis technique whereby free-free space station modal coordinates and cantilever appendage coordinates are inertially coupled. A digital simulation of this analysis method is described and verified by comparison of interaction load solutions with other methods of solution. Motion equations are simulated for both the zero gravity and artificial gravity (spinning) orbital conditions. Closed loop controlling dynamics for both orientation control of the arrays and attitude control of the space station are provided in the simulation by various generic types of controlling systems. The capability of the simulation as a design tool is demonstrated by utilizing typical space station and solar array structural representations and a specific structural perturbing force. Response and interaction load solutions are presented for this structural configuration and indicate the importance of using an integrated type analysis for the predictions of structural interactions.

Heinrichs, J. A.↗

NASA NTRS1971

Effects of cyclical environments on high-performance multi-layer insulation materials.

Results of a test program designed to determine the effects of 100 temperature and compressive loading cycles on several multilayer insulation materials and composites. A total of four reflector materials, four separator materials, eight face-sheet systems, and one fastener material were subjected to 100 temperature cycles from -320 to 400 or 650 F. Generic types of materials studied included Mylar, Kapton, Dacron, Nomex, and Beta Glass. The temperature cycling was followed by visual inspection, metal adhesion tests on the reflectors, and tensile tests of the face sheets, fastener, and separators. A total of six composites were subjected to compressive cycles between zero and 0.15 psi, and density changes were measured. Application of the experimental results to the shuttle orbiter is discussed.

Krause, D. R.↗

NASA NTRS1971

Equicontrollability and its application to model-following and decoupling.

Discussion of 'model following,' a term used to describe a class of problems characterized by having two dynamic systems, generically known as the 'plant' and the 'model,' it being required to find a controller to attach to the plant so as to make the resultant compensated system behave, in an input/output sense, in the same way as the model. The approach presented to the problem takes a structural point of view. The result is a complex but informative definition which solves the problem as posed. The application of both the algorithm and its basis, equicontrollability, to the decoupling problem is considered.

Curran, R. T.↗

NASA NTRS1972

Design review - A tool for all seasons.

The origins of design review are considered together with questions of definitions. The main characteristics which distinguish the concept of design review discussed from the basic master-apprentice relationship include competence, objectivity, formality, and a systematic approach. Preliminary, major, and final reviews are the steps used in the management of the design and development process in each company. It is shown that the design review is generically a systems engineering milestone review with certain unique characteristics.

Liberman, D. S.↗

NASA NTRS1973

A nonlinear-coherence receiver

Mathematical analysis and detailed study of generic model for coherent receiver has demonstrated that nonlinear coherence between given biphase-modulated input signal and supplied reference signal can be used in receivers to improve telecommunication systems.

Simon, M. K.↗

NASA NTRS1972

Meteor research program, executive summary

A framework statement is provided of three problems together with brief comments on advances made during the course of this research. The problems discussed are: (1) generic relationships among comets, asteroids, meteorites, and meteoroids; (2) meteor physics; and (3) meteoroid hazard and the spatial distribution of meteoroid material. A summary of results is included.

Source record↗

NASA NTRS1972

Investigation of the plastic fracture of high strength steels

An investigation of the plastic fracture process to improve tensile strength in high strength steels is presented. Two generic types of steels are considered: a quenched and tempered grade and a maraging grade, in order to compare two different matrix microstructures. Each type of steel was studied in commercial grade purity and in special melted high purity form, low in residual and impurity elements. The specific alloys dealt with include AISI 4340 and 18 Ni, 200 grade maraging steel, both heat treated to the same yield strength level of approximately 200 ksi.

Cox, T. B.↗

NASA NTRS1972

Development of KSC program for investigating and generating field failure rates. Volume 2: Recommended format for reliability handbook for ground support equipment

Field failure rates and confidence factors are presented for 88 identifiable components of the ground support equipment at the John F. Kennedy Space Center. For most of these, supplementary information regarding failure mode and cause is tabulated. Complete reliability assessments are included for three systems, eight subsystems, and nine generic piece-part classifications. Procedures for updating or augmenting the reliability results presented in this handbook are also included.

Bloomquist, C. E.↗

NASA NTRS1973

Environmental control system transducer development study

A failure evaluation of the transducers used in the environmental control systems of the Apollo command service module, lunar module, and portable life support system is presented in matrix form for several generic categories of transducers to enable identification of chronic failure modes. Transducer vendors were contacted and asked to supply detailed information. The evaluation data generated for each category of transducer were compiled and published in failure design evaluation reports. The evaluation reports also present a review of the failure and design data for the transducers and suggest both design criteria to improve reliability of the transducers and, where necessary, design concepts for required redesign of the transducers. Remedial designs were implemented on a family of pressure transducers and on the oxygen flow transducer. The design concepts were subjected to analysis, breadboard fabrication, and verification testing.

Brudnicki, M. J.↗

NASA NTRS1973

A study of psychrophilic organisms isolated from the manufacture and assembly areas of spacecraft to be used in the Viking mission, 1 January - 30 June 1973

Soil samples from the areas associated with the Viking spacecraft were analyzed for major generic groups of microorganisms and the percentage of obligate psychrophiles. Results are presented which show the distribution of organisms isolated at low temperatures and the methods employed for subjecting samples to simulated Martian conditions. Emphasis is placed on application of these results to the objectives of the quarantine program.

Foster, T. L.↗

NASA NTRS1972

High-frequency sound waves to eliminate a horizon in the mixmaster universe.

From the linear wave equation for small-amplitude sound waves in a curved space-time, there is derived a geodesiclike differential equation for sound rays to describe the motion of wave packets. These equations are applied in the generic, nonrotating, homogeneous closed-model universe (the 'mixmaster universe,' Bianchi type IX). As for light rays described by Doroshkevich and Novikov (DN), these sound rays can circumnavigate the universe near the singularity to remove particle horizons only for a small class of these models and in special directions. Although these results parallel those of DN, different Hamiltonian methods are used for treating the Einstein equations.

Chitre, D. M.↗

NASA NTRS1973

Mission building blocks for outer solar system exploration.

Description of the technological building blocks required for exploring the outer planets with maximum scientific yields under stringent resource constraints. Two generic spacecraft types are considered: the Mariner and the Pioneer. Following a discussion of the outer planet mission constraints, the evolutionary development of spacecraft, probes, and propulsion building blocks is presented. Then, program genealogies are shown for Pioneer and Mariner missions and advanced propulsion systems to illustrate the soundness of a program based on spacecraft modification rather than on the development of new spacecraft for each mission. It is argued that, for minimum costs, technological advancement should occur in an evolutionary manner from mission to mission. While this strategy is likely to result in compromises on specific missions, the realization of the overall objectives calls for an advance commitment to the entire mission series.

Herman, D.↗

NASA NTRS1973

On the nature of the infrared point source in the Orion Nebula.

New photometric observations of the BN infrared source in the Orion Nebula eliminate the possibility that it is simply a highly reddened star, and undermine the conclusion that there are 80 mag of visual extinction to the source. We suggest that there is a generic relationship between it and the infrared source IRS 5 in the H II region W3.

Becklin, E. E.↗

NASA NTRS1974

Dynamic analysis of a system of hinge-connected rigid bodies with nonrigid appendages

Equations of motion are derived for use in simulating a spacecraft or other complex electromechanical system amenable to idealization as a set of hinge-connected rigid bodies of tree topology, with rigid axisymmetric rotors and nonrigid appendages attached to each rigid body in the set. In conjunction with a previously published report on finite-element appendage vibration equations, this report provides a complete minimum-dimension formulation suitable for generic programming for digital computer numerical integration.

Likins, P. W.↗

NASA NTRS1973

Advanced C and D techniques and application study

A study was conducted to identify a broad base of payload control and display requirements for space missions. The subjects discussed are: (1) functional requirements and allocation analysis, (2) control and display generic device matrix, (3) control functional requirements, and (4) display functional requirements. Specific applications of payload control and display requirements for various disciplines are defined.

Kendall, K.↗