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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 469 records · Page 26
All sourcesNASA NTRSDOE OSTI
NASA NTRS1982

Spacelab software for science applications

The Spacelab onboard computer and software system offers a myriad of services and capabilities for those who wish to fly instruments without the expense of the new computers and software required for control, data manipulation, and telemetry handling. The needs of a wide variety of potential instrument developers have been taken into account in the development of standard but flexible interfaces from the computer to instruments. An early understanding of the basic software capabilities is advantageous to the potential Spacelab user as he begins his planning. This paper provides an introduction to these capabilities and gives reference to further more detailed technical information which will be needed as instrument planning and requirements mature.

Lokken, W. R.↗
NASA NTRS1987

Computer hardware and software for robotic control

The KSC has implemented an integrated system that coordinates state-of-the-art robotic subsystems. It is a sensor based real-time robotic control system performing operations beyond the capability of an off-the-shelf robot. The integrated system provides real-time closed loop adaptive path control of position and orientation of all six axes of a large robot; enables the implementation of a highly configurable, expandable testbed for sensor system development; and makes several smart distributed control subsystems (robot arm controller, process controller, graphics display, and vision tracking) appear as intelligent peripherals to a supervisory computer coordinating the overall systems.

Davis, Virgil Leon↗
NASA NTRS1992

Image-Processing Software For A Hypercube Computer

Concurrent Image Processing Executive (CIPE) is software system intended to develop and use image-processing application programs on concurrent computing environment. Designed to shield programmer from complexities of concurrent-system architecture, it provides interactive image-processing environment for end user. CIPE utilizes architectural characteristics of particular concurrent system to maximize efficiency while preserving architectural independence from user and programmer. CIPE runs on Mark-IIIfp 8-node hypercube computer and associated SUN-4 host computer.

Lee, Meemong↗
NASA NTRS2022

Building a lifeboat: MSL’s uplink and installation campaign to restore a failing backup computer

Flight software updates are among the hardest andmost dangerous activities for the Mars Science Laboratory(MSL) Curiosity team. While danger is often mitigated bybackups, fallback strategies, and incremental installation withground-in-the-loop cycles which provide a safety net for theinstallation process, the software update described in this paperwas unable to use many of the common practices due to thenature of the fault addressed by the update. The MSL rover(landed August 2012) encountered a problem with one of itscomputer’s non-volatile storage chips in 2019, requiring a swapto its backup computer and an urgent software upgrade calledR-Hope. R-Hope, a lifeboat to be used in the event of primarycomputer issues, was written, tested, and sent to the rover inlightning speed of just 19 months. Multi-mission and teamcoordination allowed the 49 flight software image files to beuplinked to the rover over a 6-week period, using multiple pathsand backup options for speedy delivery. In the end, the RHopesoftware upgrade returned the computer to operation asa backup flight computer. The flight software transition wasdesigned to impact science return as little as possible, and installationplans included science activities for the majority of MSLinstruments. This paper describes the uplink and installationcampaigns for R-Hope, and discusses the notable lessons learnedby the operations team.

Byrne, DJ↗
NASA NTRS2001

Geomagnetic Cutoff Rigidity Computer Program: Theory, Software Description and Example

The access of charged particles to the earth from space through the geomagnetic field has been of interest since the discovery of the cosmic radiation. The early cosmic ray measurements found that cosmic ray intensity was ordered by the magnetic latitude and the concept of cutoff rigidity was developed. The pioneering work of Stoermer resulted in the theory of particle motion in the geomagnetic field, but the fundamental mathematical equations developed have 'no solution in closed form'. This difficulty has forced researchers to use the 'brute force' technique of numerical integration of individual trajectories to ascertain the behavior of trajectory families or groups. This requires that many of the trajectories must be traced in order to determine what energy (or rigidity) a charged particle must have to penetrate the magnetic field and arrive at a specified position. It turned out the cutoff rigidity was not a simple quantity but had many unanticipated complexities that required many hundreds if not thousands of individual trajectory calculations to solve. The accurate calculation of particle trajectories in the earth's magnetic field is a fundamental problem that limited the efficient utilization of cosmic ray measurements during the early years of cosmic ray research. As the power of computers has improved over the decades, the numerical integration procedure has grown more tractable, and magnetic field models of increasing accuracy and complexity have been utilized. This report is documentation of a general FORTRAN computer program to trace the trajectory of a charged particle of a specified rigidity from a specified position and direction through a model of the geomagnetic field.

Smart, D. F.↗
NASA NTRS2007

Software Tool for Computing Maximum Von Mises Stress

The maximum Van Mises stress and stress direction are of interest far analyzing launch accelerations such as with the Mass Acceleration Curves developed by JPL. Maximum launch stresses can be combined with appropriate load cases at consistent locations with resulting stress tensors. Maximum Van Mises stress is also of interest for understanding maximum operational loading such as traverse events. - For example, planetary traversing simulations may prescribe bounding acceleration values during traverse for a rover such as Mars Science Lab (MSL) in (X,Y,Z) of the rover. - Such accelerations can be really in any directions for many parts such as a mast or head mounted components which can be in numerous configurations and orientations when traversing a planet surface.

software↗
NASA NTRS1988

PLOT300: A Tektronics PLOT10 emulator for HP 9000 series 200/300 computers

A software package which emulates the Tektronics PLOT10 Graphics package on Hewlett-Packard 9000 Series 200/300 computers is described. The Software is written in HP Rocky Mountain BASIC and can be run under BASIC revisions 3.0 and 4.0. Although this subroutine library emulates a subset of PLOT10, several subroutines have been added which enhance basic plot generation. Example codes using PLOT300 and descriptions of the subroutines are included in the text.

Kjelgaard, Scott O.↗
NASA NTRS1994

General-Purpose Plotting Software

TADPLOT computer program gives researcher general-purpose plotting software package easy to use, quickly creates X-Y plots, and powerful enough to create full-feature publication-quality plots. Enables user to save selected plot information displayed subsequently on several different devices, including "hard-copy" plotters. Postprocessing features that enable user to manipulate and combine plots also available. Written in ANSI STANDARD FORTRAN 77.

Hammond, Dana P.↗
NASA NTRS2020

Single Board Computer Radiation Test Results and Radiation Test Software

Single Board Computers (SBCs) are quickly evolving and gaining capability as their cost comes down. As their footprints, cost, and power requirements decrease, their processing power increases. This makes them very attractive for use on space missions and an enabling technology as spacecraft size decreases and computational demand increases. One of the major challenges electronics face in the space environment is radiation. In 2019, the NASA Johnson Space Center (JSC) tested a selection of SBCs to low Earth orbit (LEO) radiation levels and evaluated their susceptibility and survivability. For this test campaign, JSC developed a Python software suite to better characterize the SBCs performance and intends to share the software.

Pedrotty, Samuel M.↗
NASA NTRS1985

Orbits: Computer simulation

In rotating machinery dynamics an orbit (Lissajous curve) represents the dynamic path of the shaft centerline motion during shaft rotation and resulting precession. The orbit can be observed with an oscilloscope connected to XY promixity probes. The orbits can also be simulated by a computer. The software for HP computer simulates orbits for two cases: (1) Symmetric orbit with four frequency components with different radial amplitudes and relative phase angles; and (2) Nonsymmetric orbit with two frequency components with two different vertical/horizontal amplitudes and two different relative phase angles. Each orbit carries a Keyphasor mark (one-per-turn reference). The frequencies, amplitudes, and phase angles, as well as number of time steps for orbit computation, have to be chosen and introduced to the computer by the user. The orbit graphs can be observed on the computer screen.

Muszynska, A.↗
NASA NTRS1985

Books and monographs on finite element technology

The present paper proviees a listing of all of the English books and some of the foreign books on finite element technology, taking into account also a list of the conference proceedings devoted solely to finite elements. The references are divided into categories. Attention is given to fundamentals, mathematical foundations, structural and solid mechanics applications, fluid mechanics applications, other applied science and engineering applications, computer implementation and software systems, computational and modeling aspects, special topics, boundary element methods, proceedings of symmposia and conferences on finite element technology, bibliographies, handbooks, and historical accounts.

Noor, A. K.↗
NASA NTRS1987

Parallel software support for computational structural mechanics

The application of the parallel programming methodology known as the Force was conducted. Two application issues were addressed. The first involves the efficiency of the implementation and its completeness in terms of satisfying the needs of other researchers implementing parallel algorithms. Support for, and interaction with, other Computational Structural Mechanics (CSM) researchers using the Force was the main issue, but some independent investigation of the Barrier construct, which is extremely important to overall performance, was also undertaken. Another efficiency issue which was addressed was that of relaxing the strong synchronization condition imposed on the self-scheduled parallel DO loop. The Force was extended by the addition of logical conditions to the cases of a parallel case construct and by the inclusion of a self-scheduled version of this construct. The second issue involved applying the Force to the parallelization of finite element codes such as those found in the NICE/SPAR testbed system. One of the more difficult problems encountered is the determination of what information in COMMON blocks is actually used outside of a subroutine and when a subroutine uses a COMMON block merely as scratch storage for internal temporary results.

Jordan, Harry F.↗
NASA NTRS1989

Environmental concept for engineering software on MIMD computers

The issues related to developing an environment in which engineering systems can be implemented on MIMD machines are discussed. The problem is presented in terms of implementing the finite element method under such an environment. However, neither the concepts nor the prototype implementation environment are limited to this application. The topics discussed include: the ability to schedule and synchronize tasks efficiently; granularity of tasks; load balancing; and the use of a high level language to specify parallel constructs, manage data, and achieve portability. The objective of developing a virtual machine concept which incorporates solutions to the above issues leads to a design that can be mapped onto loosely coupled, tightly coupled, and hybrid systems.

Lopez, L. A.↗
NASA NTRS1999

NASA HPCC Technology for Aerospace Analysis and Design

The Computational Aerosciences (CAS) Project is part of NASA's High Performance Computing and Communications Program. Its primary goal is to accelerate the availability of high-performance computing technology to the US aerospace community-thus providing the US aerospace community with key tools necessary to reduce design cycle times and increase fidelity in order to improve safety, efficiency and capability of future aerospace vehicles. A complementary goal is to hasten the emergence of a viable commercial market within the aerospace community for the advantage of the domestic computer hardware and software industry. The CAS Project selects representative aerospace problems (especially design) and uses them to focus efforts on advancing aerospace algorithms and applications, systems software, and computing machinery to demonstrate vast improvements in system performance and capability over the life of the program. Recent demonstrations have served to assess the benefits of possible performance improvements while reducing the risk of adopting high-performance computing technology. This talk will discuss past accomplishments in providing technology to the aerospace community, present efforts, and future goals. For example, the times to do full combustor and compressor simulations (of aircraft engines) have been reduced by factors of 320:1 and 400:1 respectively. While this has enabled new capabilities in engine simulation, the goal of an overnight, dynamic, multi-disciplinary, 3-dimensional simulation of an aircraft engine is still years away and will require new generations of high-end technology.

Schulbach, Catherine H.↗
NASA NTRS1993

Synthesis of Optimal Nonlinear Feedback Laws for Dynamic Systems Using Neural Networks

Open-loop solutions of dynamical optimization problems can be numerically computed usingexisting software packages. The computed time histories of the state and control variables, formultiple sets of end conditions can then be used to train a neural network to 'recognize' the optimal,nonlinear feedback relation between the states and controls of the system. The 'learned' network canthen be used to output an approximate optimal control given a full set (or a partial set) of measuredsystem states. With simple neural networks, we have successfully demonstrated the efficacy of theproposed approach using a minimum-time orbit injection problem. The usefulness and limitations ofthis novel approach on real-life optimal guidance and control problems, with many state and control variables as well as path inequality constraints, remain to be seen.

Orbit injection problem↗
NASA NTRS2011

NASA Applications for Computational Electromagnetic Analysis

Computational Electromagnetic Software is used by NASA to analyze the compatibility of systems too large or too complex for testing. Recent advances in software packages and computer capabilities have made it possible to determine the effects of a transmitter inside a launch vehicle fairing, better analyze the environment threats, and perform on-orbit replacements with assured electromagnetic compatibility.

Lewis, Catherine C.↗