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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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NASA NTRS1995

Implementing Multidisciplinary and Multi-Zonal Applications Using MPI

Multidisciplinary and multi-zonal applications are an important class of applications in the area of Computational Aerosciences. In these codes, two or more distinct parallel programs or copies of a single program are utilized to model a single problem. To support such applications, it is common to use a programming model where a program is divided into several single program multiple data stream (SPMD) applications, each of which solves the equations for a single physical discipline or grid zone. These SPMD applications are then bound together to form a single multidisciplinary or multi-zonal program in which the constituent parts communicate via point-to-point message passing routines. Unfortunately, simple message passing models, like Intel's NX library, only allow point-to-point and global communication within a single system-defined partition. This makes implementation of these applications quite difficult, if not impossible. In this report it is shown that the new Message Passing Interface (MPI) standard is a viable portable library for implementing the message passing portion of multidisciplinary applications. Further, with the extension of a portable loader, fully portable multidisciplinary application programs can be developed. Finally, the performance of MPI is compared to that of some native message passing libraries. This comparison shows that MPI can be implemented to deliver performance commensurate with native message libraries.

Fineberg, Samuel A.↗

NASA NTRS1989

DYSCO: A software system for modeling general dynamic systems

The DYSCO program has been under development since 1979. It has been funded by Army and Air Force laboratories and by the Kaman Aerospace Corporation. It is presently available at a number of government and nongovernment installations. It has been used to analyze a very broad range of dynamics problems. A principle feature of the software design of DYSCO is the separation of the executive from the technology. The executive, which controls all the operations, is intelligent in the sense that it knows that its function is to assemble differential equations and to prepare them for solution. The technology library contains FORTRAN routines which perform standard functions, such as, computing the equation coefficients of an element (or component) given the local state at any time. The technology library also contains algorithms and procedures for solving the coupled system equations. The system was designed to allow easy additional of technology to the library. Any linear or nonlinear structural entity, control system, or set of ordinary differential equations may be simply coded and added to the library, as well as algorithms for time or frequency domain solution. The program is described with emphasis on its usefulness in easily modeling unusual concepts and configurations, performing analysis of damage, evaluating new algorithms, and simulating dynamic tests.

Berman, Alex↗

NASA NTRS2012

LEGION: Lightweight Expandable Group of Independently Operating Nodes

LEGION is a lightweight C-language software library that enables distributed asynchronous data processing with a loosely coupled set of compute nodes. Loosely coupled means that a node can offer itself in service to a larger task at any time and can withdraw itself from service at any time, provided it is not actively engaged in an assignment. The main program, i.e., the one attempting to solve the larger task, does not need to know up front which nodes will be available, how many nodes will be available, or at what times the nodes will be available, which is normally the case in a "volunteer computing" framework. The LEGION software accomplishes its goals by providing message-based, inter-process communication similar to MPI (message passing interface), but without the tight coupling requirements. The software is lightweight and easy to install as it is written in standard C with no exotic library dependencies. LEGION has been demonstrated in a challenging planetary science application in which a machine learning system is used in closed-loop fashion to efficiently explore the input parameter space of a complex numerical simulation. The machine learning system decides which jobs to run through the simulator; then, through LEGION calls, the system farms those jobs out to a collection of compute nodes, retrieves the job results as they become available, and updates a predictive model of how the simulator maps inputs to outputs. The machine learning system decides which new set of jobs would be most informative to run given the results so far; this basic loop is repeated until sufficient insight into the physical system modeled by the simulator is obtained.

Burl, Michael C.↗

NASA NTRS1985

Library Information-Processing System

System works with Library of Congress MARC II format. System composed of subsystems that provide wide range of library informationprocessing capabilities. Format is American National Standards Institute (ANSI) format for machine-readable bibliographic data. Adaptable to any medium-to-large library.

Source record↗

NASA NTRS1985

Appendix E: Parallel Pascal development system

The Parallel Pascal Development System enables Parallel Pascal programs to be developed and tested on a conventional computer. It consists of several system programs, including a Parallel Pascal to standard Pascal translator, and a library of Parallel Pascal subprograms. The library includes subprograms for using Parallel Pascal on a parallel system with a fixed degree of parallelism, such as the Massively Parallel Processor, to conveniently manipulate arrays which have dimensions than the hardware. Programs can be conveninetly tested with small sized arrays on the conventional computer before attempting to run on a parallel system.

Source record↗

NASA NTRS1998

Navier-Stokes Computations on Commodity Computers

In this paper we discuss and demonstrate the feasibility of solving high-fidelity, nonlinear computational fluid dynamics (CFD) problems of practical interest on commodity machines, namely Pentium Pro PC's. Such calculations have now become possible due to the progress in computational power and memory of the off-the-shelf commodity computers, along with the growth in bandwidth and communication speeds of networks. A widely used CFD code known as TLNS3D, which was developed originally on large shared memory computers was selected for this effort. This code has recently been ported to massively parallel processor (MPP) type machines, where natural partitioning along grid blocks is adopted in which one or more blocks are distributed to each of the available processors. In this paper, a similar approach is adapted to port this code to a cluster of Pentium Pro computers. The message passing among the processors is accomplished through the use of standard message passing interface (MPI) libraries. Scaling studies indicate fairly high level of parallelism on such clusters of commodity machines, thus making solutions to Navier-Stokes equations for practical problems more affordable.

Vatsa, Veer N.↗

NASA NTRS2007

Constraining Galaxy Evolution Using Observed UV-Optical Spectra

Our understanding of galaxy evolution depends on model spectra of stellar populations, and the models are only as good as the observed spectra and stellar parameters that go into them. We are therefore evaluating modem UV-optical model spectra using Hubble's Next Generation Spectral Library (NGSL) as the reference standard. The NGSL comprises intermediate-resolution (R is approximately 1000) STIS spectra of 378 stars having a wide range in metallicity and age. Unique features of the NGSL include its broad wavelength coverage (1,800-10,100 A) and high-S/N, absolute spectrophotometry. We will report on a systematic comparison of model and observed UV-blue spectra, describe where on the HR diagram significant differences occur, and comment on current approaches to correct the models for these differences.

Heap, Sally↗

NASA NTRS1994

Application Reuse Library for Software, Requirements, and Guidelines

Better designs are needed for expert systems and other operations automation software, for more reliable, usable and effective human support. A prototype computer-aided Application Reuse Library shows feasibility of supporting concurrent development and improvement of advanced software by users, analysts, software developers, and human-computer interaction experts. Such a library expedites development of quality software, by providing working, documented examples, which support understanding, modification and reuse of requirements as well as code. It explicitly documents and implicitly embodies design guidelines, standards and conventions. The Application Reuse Library provides application modules with Demo-and-Tester elements. Developers and users can evaluate applicability of a library module and test modifications, by running it interactively. Sub-modules provide application code and displays and controls. The library supports software modification and reuse, by providing alternative versions of application and display functionality. Information about human support and display requirements is provided, so that modifications will conform to guidelines. The library supports entry of new application modules from developers throughout an organization. Example library modules include a timer, some buttons and special fonts, and a real-time data interface program. The library prototype is implemented in the object-oriented G2 environment for developing real-time expert systems.

Malin, Jane T.↗

NASA NTRS2008

Generic Spacecraft Model for Real-Time Simulation

Generic Spacecraft is the name of an evolving library of software that provides for simulation of a generic spacecraft that can orbit the Earth and land on the Moon (and, eventually, on Mars). This library is incorporated into the Langley Standard Realtime Simulation in C++ (LaSRS++) software framework. The generic-spacecraft simulation serves as a test bed for modeling spacecraft dynamics, propulsion, control systems, guidance, and displays. The Generic Spacecraft library supplements the LaSRS++ framework with an interface that facilitates the connection of new models into the LaSRS++ simulation by eliminating what would otherwise be the necessity of writing additional C++ classes to record data from the models and code to display values on graphical user interfaces (GUIs): The library includes routines for integrating new models into the LaSRS++ framework, identifying model inputs and outputs with full descriptions and units identified, recording data, and automatically generating graphical user interfaces (GUIs). The library is designed to be used in a manner similar to that of LaSRS++ software components for simulating vehicles other than the generic spacecraft. The user specifies (1) a spacecraft and individual models to be constructed and (2) connections between individual model inputs and outputs.

Kenney, Patrick S.↗

NASA NTRS2005

Towards the Development of a Unified Distributed Date System for L1 Spacecraft

The purpose of this grant, 'Towards the Development of a Unified Distributed Data System for L1 Spacecraft', is to take the initial steps towards the development of a data distribution mechanism for making in-situ measurements more easily accessible to the scientific community. Our obligations as subcontractors to this grant are to add our Faraday Cup plasma data to this initial study and to contribute to the design of a general data distribution system. The year 1 objectives of the overall project as stated in the GSFC proposal are: 1) Both the rsync and Perl based data exchange tools will be fully developed and tested in our mixed, Unix, VMS, Windows and Mac OS X data service environment. Based on the performance comparisons, one will be selected and fully deployed. Continuous data exchange between all L1 solar wind monitors initiated. 2) Data version metadata will be agreed upon, fully documented, and deployed on our data sites. 3) The first version of the data description rules, encoded in a XML Schema, will be finalized. 4) Preliminary set of library routines will be collected, documentation standards and formats agreed on, and desirable routines that have not been implemented identified and assigned. 5) ViSBARD test site implemented to independently validate data mirroring procedures. The specific MIT tasks over the duration of this project are the following: a) implement mirroring service for WIND plasma data b) participate in XML Schema development c) contribute toward routine library.

Lazarus, Alan J.↗

NASA NTRSDate not supplied

Celestial Mapping System for Lunar Surface Mapping and Analytics

Celestial Mapping System (CMS) is a software platform to generate virtual 3D globe for celestial bodies within our solar system. Various layers are built on top of the virtual globe to provide visualization of high resolution imagery, enable precise measurements, build analytical capabilities and broad range of functionalities to assist planetary scientists and mission planners. CMS is built using OpenJDK 11 and will run on a wide variety of platforms such as Linux, Windows, OSX, etc. It has a thick client with less overhead to access hardware resources. This allows features such as terrain profiling and distance calculations to be performed on the client and on the fly. The present focus of CMS is on developing lunar mapping tool kits to provide features such as - 3D first person view with zoom and navigational capabilities, realistic terrain visualization based on LRO data, measurement tools, Apollo landing site annotations, stereoscopic view, elevation profiles, line of sight analysis and many more. The application is developed to provide situational and domain awareness on Lunar surface, planning capabilities for equipment placements and traverse path optimization. As data becomes available, CMS has the capabilities to integrate data sets that change dynamically in real-time, which will be useful for monitoring satellites and remotely-sensed data on Lunar surface. CMS utilizes NASA WorldWind Java library and OpenGL to achieve high-performance rendering of data and measurements, and also adheres to OGC standards. CMS supports importing synthetic features in a variety of 3D, 2D, vector and raster formats. Nomenclature is pulled from USGS Moon IAU2000 database, and lunar parameters are based of the standardized IAU2000 Moon ellipsoid. GDAL (Geospatial Data Abstraction Library) was used to modify and test the accuracy of datasets before integrating into the application. Our high-resolution global elevation model was compared with the LRO LOLA DEM elevation values and tested to ensure accuracy. Celestial Mapping System has several potential use cases for NASA including subsurface lava tubes visualization and analysis, soil analysis, resource visualization and representation on 3D globe.

GIS system↗

NASA NTRS1998

Knowledge Preservation and Web-tools

We propose a library of "netbooks" as part of a national effort, preserving the wisdom of the early Space Program. NASA is losing its rocket scientists who designed the great systems of the past. Few new systems of similar ambition are being built; much of the expertise that took us to the Moon is evaporating. With retiring NASA designers, we work to preserve something of the expertise of these individuals, developed at great national cost. We show others the tools that make preservation easy and cheap. Retiring engineers and scientists can be coached into speaking (without charge) into recording devices about ideas not widely appreciated but of potential future value. Transcripts of the recordings and the audio itself are combined (cheaply) in netbooks accessible via a standard web-browser (free). Selected netbooks are indexed into a rapidly searchable system, an electronic Library. We recruit support in establishing a standards committee for that Library. The system is to be a model for access by the blind as well as for preservation of important, technical knowledge.

Moreman, Douglas↗

NASA NTRS1997

Automated Reuse of Scientific Subroutine Libraries through Deductive Synthesis

Systematic software construction offers the potential of elevating software engineering from an art-form to an engineering discipline. The desired result is more predictable software development leading to better quality and more maintainable software. However, the overhead costs associated with the formalisms, mathematics, and methods of systematic software construction have largely precluded their adoption in real-world software development. In fact, many mainstream software development organizations, such as Microsoft, still maintain a predominantly oral culture for software development projects; which is far removed from a formalism-based culture for software development. An exception is the limited domain of safety-critical software, where the high-assuiance inherent in systematic software construction justifies the additional cost. We believe that systematic software construction will only be adopted by mainstream software development organization when the overhead costs have been greatly reduced. Two approaches to cost mitigation are reuse (amortizing costs over many applications) and automation. For the last four years, NASA Ames has funded the Amphion project, whose objective is to automate software reuse through techniques from systematic software construction. In particular, deductive program synthesis (i.e., program extraction from proofs) is used to derive a composition of software components (e.g., subroutines) that correctly implements a specification. The construction of reuse libraries of software components is the standard software engineering solution for improving software development productivity and quality.

Lowry, Michael R.↗

NASA NTRS2004

Open-systems architecture of a standardized command interface chip-set for switching and control of a spacecraft power bus

The Jet Propulsion Laboratory (JPL) has developed a command interface chip-set that primarily consists of two mixed-signal ASICs'; the Command Interface ASIC (CIA) and Analog Interface ASIC (AIA). The Open-systems architecture employed during the design of this chip-set enables its use as both an intelligent gateway between the system's flight computer and the control, actuation, and activation of the spacecraft's loads, valves, and pyrotechnics respectfully as well as the regulator of the spacecraft power bus. Furthermore, the architecture is highly adaptable and employed fault-tolerant design methods enabling a host of other mission uses including reliable remote data collection. The objective of this design is to both provide a needed flight component that meets the stringent environmental requirements of current deep space missions and to add a new element to a growing library that can be used as a standard building block for future missions to the outer planets.

flight computers↗

NASA NTRS2014

Cross Support Transfer Service (CSTS) Framework Library

Within the Consultative Committee for Space Data Systems (CCSDS), there is an effort to standardize data transfer between ground stations and control centers. CCSDS plans to publish a collection of transfer services that will each address the transfer of a particular type of data (e.g., tracking data). These services will be called Cross Support Transfer Services (CSTSs). All of these services will make use of a common foundation that is called the CSTS Framework. This library implements the User side of the CSTS Framework. "User side" means that the library performs the role that is typically expected of the control center. This library was developed in support of the Goddard Data Standards program. This technology could be applicable for control centers, and possibly for use in control center simulators needed to test ground station capabilities. The main advantages of this implementation are its flexibility and simplicity. It provides the framework capabilities, while allowing the library user to provide a wrapper that adapts the library to any particular environment. The main purpose of this implementation was to support the inter-operability testing required by CCSDS. In addition, it is likely that the implementation will be useful within the Goddard mission community (for use in control centers).

Ray, Timothy↗

NASA NTRS2023

Orbital Debris Quarterly News, August 2023

- IOC II Announces Program and Venue - Continuing Development of ISO Debris Mitigation Standards - DAS Release - MEO Releases New Example Library - Updated Flux Interpolation in ORDEM - Evolution of Major Debris Clouds in LEO - ODPO Receives the 2022 Agency Group Achievement Honor Award - Upcoming Meetings - Orbital Debris Environment Plot - Space Missions and Satellite Box Score

Heather Cowardin↗

NASA NTRS2006

Programs for Testing Processor-in-Memory Computing Systems

The Multithreaded Microbenchmarks for Processor-In-Memory (PIM) Compilers, Simulators, and Hardware are computer programs arranged in a series for use in testing the performances of PIM computing systems, including compilers, simulators, and hardware. The programs at the beginning of the series test basic functionality; the programs at subsequent positions in the series test increasingly complex functionality. The programs are intended to be used while designing a PIM system, and can be used to verify that compilers, simulators, and hardware work correctly. The programs can also be used to enable designers of these system components to examine tradeoffs in implementation. Finally, these programs can be run on non-PIM hardware (either single-threaded or multithreaded) using the POSIX pthreads standard to verify that the benchmarks themselves operate correctly. [POSIX (Portable Operating System Interface for UNIX) is a set of standards that define how programs and operating systems interact with each other. pthreads is a library of pre-emptive thread routines that comply with one of the POSIX standards.]

Katz, Daniel S.↗

NASA NTRS1995

Generalized Support Software: Domain Analysis and Implementation

For the past five years, the Flight Dynamics Division (FDD) at NASA's Goddard Space Flight Center has been carrying out a detailed domain analysis effort and is now beginning to implement Generalized Support Software (GSS) based on this analysis. GSS is part of the larger Flight Dynamics Distributed System (FDDS), and is designed to run under the FDDS User Interface / Executive (UIX). The FDD is transitioning from a mainframe based environment to systems running on engineering workstations. The GSS will be a library of highly reusable components that may be configured within the standard FDDS architecture to quickly produce low-cost satellite ground support systems. The estimates for the first release is that this library will contain approximately 200,000 lines of code. The main driver for developing generalized software is development cost and schedule improvement. The goal is to ultimately have at least 80 percent of all software required for a spacecraft mission (within the domain supported by the GSS) to be configured from the generalized components.

Stark, Mike↗