Data bus to serviced equipment and sensor interface
Development and application of data bus techniques for space shuttle data management systems
Yolken, B. S.↗
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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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Self-sequencing data bus techniques for space shuttle
Application of self-sequencing data bus techniques for space shuttle data management system
Hardin, R. H.↗
A conceptual study of the SSV/GN&C system data bus
Development of time shared data bus concept for use with space shuttle guidance, navigation, and control system
Proch, G. E.↗
Solar bus regulator and battery charger for IMP's H, I, and J
Interplanetary Monitoring Probe (IMP) spacecrafts H, I, and J utilize a direct energy transfer (DET) type of power system operating from a solar array source. A shunt type of regulator prevents the bus voltage from exceeding a preset voltage level. The power system utilizes a single differential amplifier with dual outputs to control the battery charge/shunt regulator and the discharge regulator. A two-voltage level, current limited, series charger and a current sensor control battery state of charge of the silver-cadmium battery pack. Premature termination of the battery charge is prevented by a power available gate that also initiates charge current to the battery upon availability of excess power.
Paulkovich, J.↗
Digital data command bus
Command bus constructed from coaxial cable has short segments of its outer jacket and shield removed and replaced with small ferrite cores carrying multiturn windings connected to decoder. Device reduces number of wire pairs required to communicate command data to systems and subsystems.
Milligan, G. C.↗
System design of the Pioneer Venus spacecraft. Volume 4: Probe bus and orbiter spacecraft vehicle studies
The requirements, trades, and design descriptions for the probe bus and orbiter spacecraft configurations, structure, thermal control, and harness are defined. Designs are developed for Thor/Delta and Atlas/Centaur launch vehicles with the latter selected as the final baseline. The major issues examined in achieving the baseline design are tabulated. The importance of spin axis orientation because of the effect on science experiments and earth communications is stressed.
Bozajian, J. M.↗
Error protection capability of space shuttle data bus designs
Error protection assurance in the reliability of digital data communications is discussed. The need for error protection on the space shuttle data bus system has been recognized and specified as a hardware requirement. The error protection techniques of particular concern are those designed into the Shuttle Main Engine Interface (MEI) and the Orbiter Multiplex Interface Adapter (MIA). The techniques and circuit design details proposed for these hardware are analyzed in this report to determine their error protection capability. The capability is calculated in terms of the probability of an undetected word error. Calculated results are reported for a noise environment that ranges from the nominal noise level stated in the hardware specifications to burst levels which may occur in extreme or anomalous conditions.
Proch, G. E.↗
Low-inductance bus lines
Laminated bus strips and bifilar litz cable connectors for high-power rectifiers, thrisistors, and transistors provide low inductance and eliminate electromagnetic interference in high-power circuits. These techniques offer significant cost advantages because of ease of assembly and consistent high quality of product. Effectiveness makes general usage in static power conversion likely.
Kernick, A.↗
Orbiter multiplexer-demultiplexer (MDM)/Space Lab Bus Interface Unit (SL/BIU) serial data interface evaluation, volume 2
Tests were performed to evaluate the operating characteristics of the interface between the Space Lab Bus Interface Unit (SL/BIU) and the Orbiter Multiplexer-Demultiplexer (MDM) serial data input-output (SIO) module. This volume contains the test equipment preparation procedures and a detailed description of the Nova/Input Output Processor Simulator (IOPS) software used during the data transfer tests to determine word error rates (WER).
Tobey, G. L.↗
Electrical characterization of standard and radiation-hardened RCA CDP1856D 4-BIT, CMOS, bus buffer/separator
Tests performed to determine accuracy and efficiency of bus separators used in microprocessors are presented. Functional, AC parametric, and DC parametric tests were performed in a Tektronix S-3260 automated test system. All the devices passed the functional tests and yielded nominal values in the parametric test.
Stokes, R. L.↗
Bennett ion mass spectrometers on the Pioneer Venus Bus and Orbiter
Identical Bennett radio-frequency ion mass spectrometer instruments on the Pioneer Venus Bus and Orbiter have provided the first in-situ measurements of the detailed composition of the planet's ionosphere. The sensitivity, resolution, and dynamic range are sufficient to provide measurements of the solar-wind-induced bow-shock, the ionopause, and highly structured distributions of up to 16 thermal ion species within the ionosphere. The use of adaptive scan and detection circuits and servo-controlled logic for ion mass and energy analysis permits detection of ion concentrations as low as 5 ions/cu cm and ion flow velocities as large as 9 km/sec for O(+). A variety of commandable modes provides ion sampling rates ranging from 0.1 to 1.6 sec between measurements of a single constituent. A lightweight sensor and electronics housing are features of a compact instrument package.
Taylor, H. A., Jr.↗
"Ruggedized" Microcomputer Bus
"Ruggedized" version of the STD microcomputer bus withstands rigors of space-flight. Could be used as a basis for microcomputers in other hazardous environments, including those at high and low temperatures, those in vacuum, or those subject to extreme shock and vibration.
Budney, T. J.↗
Testing the bus guardian unit of the FTMP
Fault-tolerant multiprocessor (FTMP) operation is discussed. Fault-modeling in the bus guardian units (BGUs) is covered. Testing the BGU is discussed. A testing algorithm is proposed.
Jha, M. K.↗
Data systems - Optical bus will connect distributed system
The fiber optics buses currently under consideration for the NASA space station program will have data rates of at least 20 Mb/sec. The network interconnection scheme that will eventually be used is, however, uncertain. A NASA-Langley effort on graph networks includes adaptive, fault-tolerant and self-correcting operations. A breadboard program at NASA-Johnson includes evaluations of standard devices, called 'bus interface units', in an adaptive and fault-correcting chordal or concentric ring type of network. Fiber optics would allow an evolution to wavelength modulation techniques in such systems.
Swingle, W. L.↗
Three-phase, high-voltage, high-frequency distributed bus system for advanced aircraft
A three phase, high voltage, high frequency distributed bus system for advanced aircraft is discussed. A system model is given. Available components are described. Recommendations are given.
Finke, R. C.↗
Synchronizing Data-Bus Messages
Adapter allows communications among as many as 30 data processors without central bus controller. Adapter improves reliability of multiprocessor system by eliminating point of failure that causes entire system to fail. Scheme prevents data collisions and eliminates nonessential polling, thereby reducing power consumption.
Harris, L. H.↗
A program downloader and other utility software for the DATAC bus monitor unit
A set or programs designed to facilitate software testing on the DATAC Bus Monitor is described. By providing a means to simplify program loading, firmware generation, and subsequent testing of programs, the overhead involved in software evaluation is reduced and that time is used more productively in performance, analysis and improvement of current software.
Novacki, Stanley M., III↗
Global system data bus using the Digital Autonomous Terminal Access Communication protocol
Modern digital avionic systems with distributed processing require networking to connect the many elements. Digital Autonomous Terminal Access Communication (DATAC) is one of many such networks. DATAC has been implemented on the Transport Systems Research Vehicle (TSRV), a Boeing 737 aircraft operated by the National Aeronautics and Space Administration's Advanced Transport Operating Systems Program Office (ATOPS). This paper presents the TSRV implementation of the DATAC bus, a description of the DATAC system, a synchronization mechanism, details of data flow throughout the system, and a discussion of the modes available with DATAC. Numerous flight tests have been conducted using DATAC as the only means of communication between systems with outstanding results. DATAC is now an integral part of the TSRV and is expected to satisfy near term as well as future requirements for growth and flexibility.
Holmes, David C. E.↗