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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 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1992

Small Explorer Data System MIL-STD-1773 fiber optic bus

The MIL-STD-1773 Fiber Optic Data Bus as implemented in the GSFC Small Explorer Data System (SEDS) for the Small Explorer Program is described. It provides an overview of the SEDS MIL-STD-1773 bus components system design considerations, reliability figures, acceptance and qualification testing requirements, radiation requirements and tests, error handling considerations, and component heritage. The first mission using the bus will be launched in June of 1992.

Flanegan, Mark↗
NASA NTRS1995

Description of a MIL-STD-1553B Data Bus Ada Driver for the LeRC EPS Testbed

This document describes the software designed to provide communication between control computers in the NASA Lewis Research Center Electrical Power System Testbed using MIL-STD-1553B. The software drivers are coded in the Ada programming language and were developed on a MSDOS-based computer workstation. The Electrical Power System (EPS) Testbed is a reduced-scale prototype space station electrical power system. The power system manages and distributes electrical power from the sources (batteries or photovoltaic arrays) to the end-user loads. The electrical system primary operates at 120 volts DC, and the secondary system operates at 28 volts DC. The devices which direct the flow of electrical power are controlled by a network of six control computers. Data and control messages are passed between the computers using the MIL-STD-1553B network. One of the computers, the Power Management Controller (PMC), controls the primary power distribution and another, the Load Management Controller (LMC), controls the secondary power distribution. Each of these computers communicates with two other computers which act as subsidiary controllers. These subsidiary controllers are, in turn, connected to the devices which directly control the flow of electrical power.

Mackin, Michael A.↗
NASA NTRS2014

NASA-STD-7009 Guidance Document for Human Health and Performance Models and Simulations

Rigorous verification, validation, and credibility (VVC) processes are imperative to ensure that models and simulations (MS) are sufficiently reliable to address issues within their intended scope. The NASA standard for MS, NASA-STD-7009 (7009) [1] was a resultant outcome of the Columbia Accident Investigation Board (CAIB) to ensure MS are developed, applied, and interpreted appropriately for making decisions that may impact crew or mission safety. Because the 7009 focus is engineering systems, a NASA-STD-7009 Guidance Document is being developed to augment the 7009 and provide information, tools, and techniques applicable to the probabilistic and deterministic biological MS more prevalent in human health and performance (HHP) and space biomedical research and operations.

numerical analysis↗
NASA NTRS2014

How to Develop and Interpret a Credibility Assessment of Numerical Models for Human Research: NASA-STD-7009 Demystified

In the wake of the Columbia accident, the NASA-STD-7009 [1] credibility assessment was developed as a unifying platform to describe model credibility and the uncertainties in its modeling predictions. This standard is now being adapted by NASAs Human Research Program to cover a wide range of numerical models for human research. When used properly, the standard can improve the process of code development by encouraging the use of best practices. It can also give management more insight in making informed decisions through a better understanding of the models capabilities and limitations.To a newcomer, the abstractions presented in NASA-STD-7009 and the sheer volume of information that must be absorbed can be overwhelming. This talk is aimed at describing the credibility assessment, which is the heart of the standard, in plain terms. It will outline how to develop a credibility assessment under the standard. It will also show how to quickly interpret the graphs and tables that result from the assessment and how to drill down from the top-level view to the foundation of the assessment. Finally, it will highlight some of the resources that are available for further study.

numerical analysis↗
DOE OSTI2024

Developing IEEE Std 2800-Compliant Algorithms for Transmission-Connected Inverter-Based Resources

This study addresses the compliance of Inverter-based Resources (IBRs) with IEEE Standard 2800, a leading standard that defines interconnection and interoperability requirements for IBRs integrated into transmission systems. Focusing on abnormal grid scenarios, the research evaluates the specific demands on IBRs, proposing a controller development framework for abnormal grid conditions. This framework caters to maintaining ride-through operation in line with IEEE Std 2800, alongside managing currents during voltage ride-through scenarios. The effectiveness of this proposed controller frame-work is rigorously validated through case studies, employing a MATLAB/Simulink model of an IBR to test its performance under diverse grid fault conditions, ensuring the IBRs' alignment with standard requirements and their robust performance in enhancing grid reliability.

IEEE Std 2800↗
NASA NTRS2019

ESD Control in the NASA STD-8739.6

This presentation covers the history of NASA using the industry ESD standard ANSI/ESD S20.20, the rationale for adding ESD control requirments to NASA STD-8739.6, and what many of those changes will look like.

NASA STD-8739.6↗
NASA NTRSDate not supplied

A Frank Discussion on Lessons Learned From Adopting and Applying NASA-STD-6030 for Spaceflight Systems

With the advancement and adoption of Additive Manufacturing (AM) for spaceflight systems, numerous lessons have been learned during the qualification and certification of AM components. The lessons learned covered in this presentation will provide an overview of the challenges faced by NASA centers and commercial partners working to design AM hardware that complies with NASA-STD-6030 Additive Manufacturing Requirements (AMR). Topics of interest include tailoring of requirements for specific projects, documentation requirements, and addressing conservative approaches towards mechanical property development and analysis. In addition to that, this presentation aims to impress that these lessons learned will influence the future revisions of the NASA technical standard to facilitate and advance AM technology adoption on NASA projects.

Additive Manufacturing↗
NASA NTRSDate not supplied

Off‑World Additive Manufacturing - Augmenting NASA‑STD‑6030

This slide presents a summary for a soon to be released white paper on augmenting NASA-STD-6030 for off-world manufacturing. It examines the driving need for in-space manufacturing and its corresponding risks, challenges, potential solutions, and technology development needed to qualify a process.

NASA-STD-6030↗
DOE OSTI2024

Technical Basis for Proposed Changes to DOE-STD-1194-2019, Nuclear Material Attractiveness Determination and Categorization

The Department of Energy (DOE)’s Technical Standard DOE-STD-1194-2019 (dated September 2019), Nuclear Materials Control and Accountability, provides key guidance for the determination of Special Nuclear Material (SNM) attractiveness levels. Attractiveness levels are a key component in the security categorization of SNM processed, used, and stored at DOE facilities. Upon review, the writing team identified specific components relating to the determination of attractiveness levels that could be modified to improve clarity, reduce burden on sites, and/or better align with the graded safeguards principle that is central to the DOE’s nuclear security program. The report outlines the original verbiage, issues with implementation of that verbiage, proposed new verbiage, and the expected benefits thus serving as the technical basis for the proposed changes.

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEF↗
DOE OSTI2026

Studying the Impact of Momentary Cessation of IBRs Compliant With IEEE Std. 2800-2022 on Transmission Line Protection Elements

This paper examines the impact of inverter-based resource (IBR) momentary cessation timing on transmission system protection relays. IEEE Std. 2800 mandates voltage ride-through, requiring IBRs to remain online during voltage disturbances. However, for severe voltage dips (|V| = 0.1 p.u.), the standard permits current blocking. In practice, vendors implement momentary cessation with varying delays, potentially affecting relay operation if IBRs cease too early. This article studies the impact of the time IBRs enter momentary cessation on transmission line protective relays. Using an electromagnetic transient (EMT) simulation, this study models IBR momentary cessation with tunable delays in a realistic transmission network. COMTRADE files generated from EMT simulations are analyzed in MATLAB using detailed protective relay models. Results indicate that IBRs must sustain operation for at least one cycle to ensure proper relay response; otherwise, relays may fail to oper- ate. These findings guide IBR vendors in optimizing momentary cessation settings to enhance transmission line protection.

24 POWER TRANSMISSION AND DISTRIBUTION↗
NASA NTRS1972

Evaluation of human engineering design standard (MSFC-STD-267A) in the design of manned space vehicles

The major conclusion of the detailed examination of the human factors engineering design standard is that it is unsuitable for future spacecraft design. The standard, published in 1966, was not intended to be a zero or reduced gravity standard and was directed primarily toward ground support equipment and technology. Futhermore, ambiguities, conflicts, and unenforceable requirements contribute to the difficulty. The role of man in future space missions and its impact on human engineering standards are also discussed, and it is concluded that greater standardization is vital to the success of future missions. A survey of NASA/MSFC contractors was made, and it was found that MSFC-STD-267A is largely ignored and the most significant problems are inaccessibility and nonspecificity of the data. The resistance of contract management and designer and of program managers is a primary reason for poor human engineering design. Specific recommendations for improvement of format and organization, including an interim solution, are given.

Rogers, J. G.↗
NASA NTRS1980

Military standards and SCATHA program update of MIL-STD-1541

The elctromagnetic compatability requirements for space systems, 15 October 1973, to be met by industry contractors for spacecraft launch vehicles and other special space systems, are considered. Deficiencies in the existing standard with respect to spacecraft charge and discharge phenomena, the technical ramifications for generating a new standard, and the upgrading of MIL-STD-1541 with requirements supplied as a result of the SCATHA program are discussed.

Frankos, D. T.↗
NASA NTRS1986

Implementation of Ada protocols on Mil-STD-1553 B data bus

Standardization activity of data communication in avionic systems started in 1968 for the purpose of total system integration and the elimination of heavy wire bundles carrying signals between various subassemblies. The growing complexity of avionic systems is straining the capabilities of MIL-STD-1553 B (first issued in 1973), but a much greater challenge to it is posed by Ada, the standard language adopted for real-time, computer embedded-systems. Hardware implementation of Ada communication protocols in a contention/token bus or token ring network is proposed. However, during the transition period when the current command/response multiplex data bus is still flourishing and the development environment for distributed multi-computer Ada systems is as yet lacking, a temporary accomodation of the standard language with the standard bus could be very useful and even highly desirable. By concentrating all status informtion and decisions at the bus controller, it was found to be possible to construct an elegant and efficient harware impelementation of the Ada protocols at the bus interface. This solution is discussed.

Ruhman, Smil↗
NASA NTRS1991

Evaluation of advanced microelectronics for inclusion in MIL-STD-975

The approach taken by NASA and JPL (Jet Propulsion Laboratory) in the development of a MIL-STD-975 section which contains advanced technology such as Large Scale Integration and Very Large Scale Integration (LSI/VLSI) microelectronic devices is described. The parts listed in this section are recommended as satisfactory for NASA flight applications, in the absence of alternate qualified devices, based on satisfactory results of a vendor capability audit, the availability of sufficient characterization and reliability data from the manufacturers and users and negotiated detail procurement specifications. The criteria used in the selection and evaluation of the vendors and candidate parts, the preparation of procurement specifications, and the status of this activity are discussed.

Scott, W. Richard↗
NASA NTRS1992

Interface For Dual-Channel MIL-STD-1553 Data Bus

Digital electronic subsystem made of commercially available programmable logic arrays and discrete logic devices serves as interface between microprocessor and dual-channel MIL-STD-1553 data bus. Subsystem consumes only 800 mW of power. Provides flexibility in that it is controllable via firmware. Includes only two reading-and-writing ports: one for status and control signals, other for transmission and reception of data.

Davies, Bryan L.↗
NASA NTRS1993

Interface For MIL-STD-1553B Data Bus

Electronic control-logic subsystem acts as interface between microcontroller and MIL-STD-1553B data bus. Subsystem made of relatively small number of integrated circuits. Advantages include low power, few integrated-circuit chips, and little need for control signals.

Davies, Bryan L.↗
NASA NTRS1992

A real time data acquisition system using the MIL-STD-1553B bus

A flight digital data acquisition system that uses the MIL-STD-1553B bus for transmission of data to a host computer for control law processing is described. The instrument, the Remote Interface Unit (RIU), can accommodate up to 16 input channels and eight output channels. The RIU employs a digital signal processor to perform local digital filtering before sending data to the host. The system allows flexible sensor and actuator data organization to facilitate quick control law computations on the host computer. The instrument can also run simple control laws autonomously without host intervention. The RIU and host computer together have replaced a similar larger, ground minicomputer system with favorable results.

Peri, Frank, Jr.↗