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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 361 records · Page 20

Analysis and performance of paralleling circuits for modular inverter-converter systems

As part of a modular inverter-converter development program, control techniques were developed to provide load sharing among paralleled inverters or converters. An analysis of the requirements of paralleling circuits and a discussion of the circuits developed and their performance are included in this report. The current sharing was within 5.6 percent of rated-load current for the ac modules and 7.4 percent for the dc modules for an initial output voltage unbalance of 5 volts.

Birchenough, A. G.↗

Modular space station phase B extension

The system safety analyses and requirements developed for the modular space station during the phase B extension are reviewed. Residual hazards and unresolved safety issues are summarized. Hazards resulting from equipment failures or malfunctions, operations, or credible accidents are identified and evaluated. Special safety trade studies are presented.

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Functional requirements for design of the Space Ultrareliable Modular Computer (SUMC) system simulator

The functional requirements for the design of an interpretive simulator for the space ultrareliable modular computer (SUMC) are presented. A review of applicable existing computer simulations is included along with constraints on the SUMC simulator functional design. Input requirements, output requirements, and language requirements for the simulator are discussed in terms of a SUMC configuration which may vary according to the application.

Curran, R. T.↗

Modular space station detailed preliminary design. Volume 1: Sections 1 through 4.4

Detailed configuration and subsystems preliminary design data are presented for the modular space station concept. Each module comprising the initial space station is described in terms of its external and internal configuration, its functional responsibilities to the initial cluster, and its orbital build up sequence. Descriptions of the subsequent build up to the growth space station are also presented. Analytical and design techniques, tradeoff considerations, and depth of design detail are discussed for each subsystem. The subsystems include the following: structural/mechanical; crew habitability and protection; experiment support; electrical power; environmental control/life support; guidance, navigation, and control; propulsion; communications; data management; and onboard checkout subsystems. The interfaces between the station and other major elements of the program are summarized. The rational for a zero-gravity station, in lieu of one with artificial-gravity capability, is also summarized.

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Gravity gradient torque profiles over an orbit for arbitrary modular space station configurations in the Y-POP and inertial hold modes

For several proposed configurations of the modular space station, the gravity gradient torque distribution is examined for both Y-POP and inertial hold orbits. The necessary equations are derived to allow for solar panel gimbaling, and a procedure is established which will allow any desired space station configuration to be built up. Results indicated that solar panel gimbaling can be a significant factor in the torque distribution in Y-POP orbits. In addition, for the two configurations that were plotted, bias torque magnitudes varied widely in inertial hold modes.

Mcgill, D. J.↗

Modular space station Phase B extension

The modular space station concept and preliminary design are outlined. The premission operations, reference programs, baseline program costs, sortie analysis, and program options are covered.

Cole, E. G.↗

Modular space station Phase B extension NASA administrator's review

The preliminary design, reference program, costs, and sortie and program options for the modular space station are outlined. The Phase B has a barbell configuration baseline with a manipulator. The baseline includes two capability plateaus, a 6-man station followed after five years by growth to a 12-man station. It is concluded that a common development approach is the most cost effective and flexible system. The system includes a module to support automated payload servicing, a set of sortie labs, and the cargo modules, RAMs, and space station modules. These would be developed and operated in conjunction with the space shuttle.

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Modularized instrument system for turbojet engine test facilities

A modular instrument system is being developed to handle the many data channels encountered in turbojet engine testing. Each module contains a group of transducers and all the signal conditioning multiplexing, and digitizing electronics necessary for direct interface with a digital computer. The digital interface within each module is the same for all modules; in addition, each module provides a controlled environment for its contents. A minicomputer in the control room gathers the data, performs on-line calculation and display, and interfaces with a shared recording and computing system. The advantages of this system are: (1) reduced manpower for system installation, setup, and checkout; (2) standardized equipment interfaces; (3) increased reliability through automatic system testing and minimization of manual adjustments; and (4) reduced cost through minimization of wiring and simplification of control room display.

Nieberding, W. C.↗

Modular space station, phase B extension. Information management advanced development. Volume 4: Data processing assembly

The computation and logical functions which are performed by the data processing assembly of the modular space station are defined. The subjects discussed are: (1) requirements analysis, (2) baseline data processing assembly configuration, (3) information flow study, (4) throughput simulation, (5) redundancy study, (6) memory studies, and (7) design requirements specification.

Gerber, C. R.↗

Modular space station, phase B extension. Information management advanced development. Volume 5: Software assembly

The development of uniform computer program standards and conventions for the modular space station is discussed. The accomplishments analyzed are: (1) development of computer program specification hierarchy, (2) definition of computer program development plan, and (3) recommendations for utilization of all operating on-board space station related data processing facilities.

Gerber, C. R.↗

Modular checkout and test system.

Description of the development and performance of a new modular checkout and test system that represents a new concept proposed for the operational support of the space shuttle. The system is shown to have reached an advanced stage of experimental development and to be capable of meeting the requirements of the shuttle orbiter and booster with a minimum of equipment, facility, personnel, and time costs.

Warzecha, L. W.↗

Space Ultrareliable Modular Computer (SUMC) instruction simulator

The design principles, description, functional operation, and recommended expansion and enhancements are presented for the Space Ultrareliable Modular Computer interpretive simulator. Included as appendices are the user's manual, program module descriptions, target instruction descriptions, simulator source program listing, and a sample program printout. In discussing the design and operation of the simulator, the key problems involving host computer independence and target computer architectural scope are brought into focus.

Curran, R. T.↗

Design of a modular digital computer system

A design tradeoff study is reported for a modular spaceborne computer system that is responsive to many mission types and phases. The computer uses redundancy to maximize reliability, and multiprocessing to maximize processing capacity. Fault detection and recovery features provide optimal reliability.

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Modular arithmetic weight and cyclic shifting.

This note shows that the modular arithmetic weight of an integer is invariant to the cyclic shifts of its radix-2 form. This result leads to a reduced search for the minimum weight codeword in a cyclic AN-code as well as to a better understanding of previous work.

Hartman, W. F.↗

Modular space station facilities.

The modular space station will operate as a general purpose laboratory (GPL). In addition, the space station will be able to support many attached or free-flying research and application modules that would be dedicated to specific projects like astronomy or earth observations. The GPL primary functions have been organized into functional laboratories including an electrical/electronics laboratory, a mechanical sciences laboratory, an experiment and test isolation laboratory, a hard data process facility, a data evaluation facility, an optical sciences laboratory, a biomedical and biosciences laboratory, and an experiment/secondary command and control center.

Parker, P. J.↗

Design of a modular digital computer system DRL 4 and 5

Design and development efforts for a spaceborne modular computer system are reported. An initial baseline description is followed by an interface design that includes definition of the overall system response to all classes of failure. Final versions for the register level designs for all module types were completed. Packaging, support and control executive software, including memory utilization estimates and design verification plan, were formalized to insure a soundly integrated design of the digital computer system.

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