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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 397 records · Page 22
All sourcesNASA NTRSDOE OSTI
NASA NTRS1993

Systems engineering and the user: Incorporation of user requirements into the SE process

This paper is organized into four parts. In the Gestation Phase, I describe the process of starting a new mission and establishing its rough boundaries. Next I show how the scientific experiments are selected. Then we enter the Preliminary Design Phase, where we incorporate the scientist's instruments into the systems engineering process. Finally, I show how the Preliminary Design Review (PDR) assures NASA management and the scientists that the scientific requirements have been incorporated into the systems engineering process to everyone's satisfaction.

Naugle, John E.↗
NASA NTRS1991

Requirements analysis notebook for the flight data systems definition in the Real-Time Systems Engineering Laboratory (RSEL)

A hybrid requirements analysis methodology was developed, based on the practices actually used in developing a Space Generic Open Avionics Architecture. During the development of this avionics architecture, a method of analysis able to effectively define the requirements for this space avionics architecture was developed. In this methodology, external interfaces and relationships are defined, a static analysis resulting in a static avionics model was developed, operating concepts for simulating the requirements were put together, and a dynamic analysis of the execution needs for the dynamic model operation was planned. The systems engineering approach was used to perform a top down modified structured analysis of a generic space avionics system and to convert actual program results into generic requirements. CASE tools were used to model the analyzed system and automatically generate specifications describing the model's requirements. Lessons learned in the use of CASE tools, the architecture, and the design of the Space Generic Avionics model were established, and a methodology notebook was prepared for NASA. The weaknesses of standard real-time methodologies for practicing systems engineering, such as Structured Analysis and Object Oriented Analysis, were identified.

Wray, Richard B.↗
DOE OSTI2020

Systems Theory Principles and Complex Systems Engineering Concepts for Protection and Resilience in Critical Infrastructure: Lessons from the Nuclear Sector

Part of the Presidential Policy Directive 21 (PPD-21) (PPD 2013) mandate includes evaluating safety, security, and safeguards (or nonproliferation) mechanisms traditionally implemented within the nuclear reactors, materials, and waste sector of critical infrastructure—including a complex, dynamic set of risks and threats within an all-hazards approach. In response, research out of Sandia National Laboratories (Sandia) explores the ability of systems theory principles (hierarchy and emergence) and complex systems engineering concepts (multidomain interdependence) to better understand and address these risks and threats. Herein, this Sandia research explores the safety, safeguards, and security risks of three different nuclear sector-related activities—spent nuclear fuel transportation, small modular reactors, and portable nuclear power reactors—to investigate the complex and dynamic risk related to the PPD-21-mandated all-hazards approach. This research showed that a systems-theoretic approach can better identify inter-dependencies, conflicts, gaps, and leverage points across traditional safety, security, and safeguards hazard mitigation strategies in the nuclear reactors, materials, and waste sector. Resulting from this, mitigation strategies from applying systems theoretic principles and complex systems engineering concepts can be (1) designed to better capture interdependencies, (2) implemented to better align with real-world operational uncertainties, and (3) evaluated as a systems-level whole to better identify, characterize, and manage PPD-21's all hazards strategies.

42 ENGINEERING↗
NASA NTRS2020

Pattern Identification - A Foundation for Research in the Emphasis of Design Patterns in Systems Engineering and Knowledge Capture

Pattern Language describes the morphology and functionality of a system in the absence of design particulars. Harnessing this capability will provide the Systems Engineering discipline a means of managing the development of increasingly complex systems with increasingly distributed design teams while capturing and retaining knowledge for future generations. Pattern Language is a syntax for describing, and structurally relating, design patterns. Design patterns contextually describe the application of domain knowledge in the engineered solution to the force balance problem. The parallels between pattern recognition and application, as a fundamental stage of human learning, and pattern observation within a complex system, suggests pattern language may be a valuable tool in the capture and dissemination of knowledge. Pattern application has enjoyed considerable study over the last several decades, however much of this work has focused on the replication of design particulars. This work returns to the roots of Pattern Language and explores the utility of patterns as an architectural description and guide, and knowledge capture method, for complex system development beginning with the identification of a time proven design pattern.

Russell, Samuel P.↗
NASA NTRS2005

ESMD Risk Management Workshop: Systems Engineering and Integration Risks

This report has been developed by the National Aeronautics and Space Administration (NASA) Exploration Systems Mission Directorate (ESMD) Risk Management team in close coordination with the Systems Engineering Team. This document provides a point-in-time, cumulative, summary of key lessons learned derived from the SE RFP Development process. Lessons learned invariably address challenges and risks and the way in which these areas have been addressed. Accordingly the risk management thread is woven throughout the document.

Systems Engineering↗
NASA NTRS1997

General Aviation Propulsion (GAP) Program, Turbine Engine System Element

The goal of the General Aviation Propulsion (GAP) Program Turbine Engine System Elements is to conduct a shared resource project to develop an affordable gas turbine engine for use on 4 to 6 place, light aircraft that will lead to revitalization of the general aviation industry in the United States, creating many new, high-quality jobs.

Source record↗
NASA NTRS2002

CloudSat system engineering: techniques that point to a future success

Over the past three years the CloutSat Project, a NASA Earth System Science Pathfinder mission to provide from space the first global survey of cloud profiles and cloud physical properties, has implemented a successful project system engineering approach. Techniques learned through heuristic reasoning of past project events and professional experience were applied along with select methods recently touted to increase effectiveness without compromising effiency.

CloudSat system engineering project management↗
NASA NTRS1993

Optimization in the systems engineering process

The essential elements of the design process consist of the mission definition phase that provides the system requirements, the conceptual design, the preliminary design and finally the detailed design. Mission definition is performed largely by operations analysts in conjunction with the customer. The result of their study is handed off to the systems engineers for documentation as the systems requirements. The document that provides these requirements is the basis for the further design work of the design engineers at the Lockheed-Georgia Company. The design phase actually begins with conceptual design, which is generally conducted by a small group of engineers using multidisciplinary design programs. Because of the complexity of the design problem, the analyses are relatively simple and generally dependent on parametric analyses of the configuration. The result of this phase is a baseline configuration from which preliminary design may be initiated.

Lemmerman, Loren A.↗
NASA NTRS1997

The MUSES Satellite Team and Multidisciplinary System Engineering

In a unique partnership between three minority-serving institutions and NASA's Jet Propulsion Laboratory, a new course sequence, including a multidisciplinary capstone design experience, is to be developed and implemented at each of the schools with the ambitious goal of designing, constructing and launching a low-orbit Earth-resources satellite. The three universities involved are North Carolina A&T State University (NCA&T), University of Texas, El Paso (UTEP), and California State University, Los Angeles (CSULA). The schools form a consortium collectively known as MUSES - Minority Universities System Engineering and Satellite. Four aspects of this project make it unique: (1) Including all engineering disciplines in the capstone design course, (2) designing, building and launching an Earth-resources satellite, (3) sustaining the partnership between the three schools to achieve this goal, and (4) implementing systems engineering pedagogy at each of the three schools. This paper will describe the partnership and its goals, the first design of the satellite, the courses developed at NCA&T, and the implementation plan for the course sequence.

Chen, John C.↗
NASA NTRS1993

Appendix C: Rapid development approaches for system engineering and design

Conventional system architectures, development processes, and tool environments often produce systems which exceed cost expectations and are obsolete before they are fielded. This paper explores some of the reasons for this and provides recommendations for how we can do better. These recommendations are based on DoD and NASA system developments and on our exploration and development of system/software engineering tools.

Source record↗
NASA NTRS2006

Decision Making Methods in Space Economics and Systems Engineering

This viewgraph presentation reviews various methods of decision making and the impact that they have on space economics and systems engineering. Some of the methods discussed are: Present Value and Internal Rate of Return (IRR); Cost-Benefit Analysis; Real Options; Cost-Effectiveness Analysis; Cost-Utility Analysis; Multi-Attribute Utility Theory (MAUT); and Analytic Hierarchy Process (AHP).

trade studies↗
NASA NTRS2014

A Systems Engineering Approach to Architecture Development

Architecture development is conducted prior to system concept design when there is a need to determine the best-value mix of systems that works collectively in specific scenarios and time frames to accomplish a set of mission area objectives. While multiple architecture frameworks exist, they often require use of unique taxonomies and data structures. In contrast, this presentation characterizes architecture development using terminology widely understood within the systems engineering community. Using a notional civil space architecture example, it employs a multi-tier framework to describe the enterprise level architecture and illustrates how results of lower tier, mission area architectures integrate into the enterprise architecture. It also presents practices for conducting effective mission area architecture studies, including establishing the trade space, developing functions and metrics, evaluating the ability of potential design solutions to meet the required functions, and expediting study execution through the use of iterative design cycles.

Architecture Development↗
NASA NTRS2012

Systems Engineering and Technology Considerations of a Mars Ascent Vehicle

A Mars Ascent Vehicle (MAV) systems engineering study is underway to define the driving requirements, system architecture, major risks, and required technology developments to support the launch of a rock core sample to a specified delivery orbit for later retrieval and return to Earth. The proposed MAV would essentially be a small-scale launch vehicle, the first of its kind to be launched autonomously from another planet. The MAV would be a flight element of the proposed Mars Sample Return (MSR) campaign architecture, which currently assumes a 2018 launch of the sample caching mission and a 2024 (Earth) launch date of the MAV and lander, with arrival on Mars in 2025. After 9 months on the surface the MAV would be erected and launched to a specified delivery orbit. In the delivery orbit it would release its payload, a 5 kg sphere containing the rock core sample. An orbiter would rendezvous and capture the payload, returning it to Earth a year later.

entry, descent, and landing (EDL)↗
NASA NTRS2006

Observations, Ideas, and Opinions: Systems Engineering and Integration for Return to Flight

This presentation addresses project management and systems engineering and integration challenges for return to flight, focusing on the Thermal Protection System Tile Repair Project (TRP). The program documentation philosophy, communication with program requirements flow and philosophy and planned deliverables and documentation are outlined. The development of TRP 'use-as-is' analytical tools is also highlighted and emphasis is placed on the use flight history to assess pre-flight and real-time risk. Additionally, an overview is provided of the repair procedure, including an outline of the logistics deployment chart.

Gafka, George K.↗
NASA NTRS1996

Computer-Aided System Engineering and Analysis (CASE/A) Programmer's Manual, Version 5.0

The Computer Aided System Engineering and Analysis (CASE/A) Version 5.0 Programmer's Manual provides the programmer and user with information regarding the internal structure of the CASE/A 5.0 software system. CASE/A 5.0 is a trade study tool that provides modeling/simulation capabilities for analyzing environmental control and life support systems and active thermal control systems. CASE/A has been successfully used in studies such as the evaluation of carbon dioxide removal in the space station. CASE/A modeling provides a graphical and command-driven interface for the user. This interface allows the user to construct a model by placing equipment components in a graphical layout of the system hardware, then connect the components via flow streams and define their operating parameters. Once the equipment is placed, the simulation time and other control parameters can be set to run the simulation based on the model constructed. After completion of the simulation, graphical plots or text files can be obtained for evaluation of the simulation results over time. Additionally, users have the capability to control the simulation and extract information at various times in the simulation (e.g., control equipment operating parameters over the simulation time or extract plot data) by using "User Operations (OPS) Code." This OPS code is written in FORTRAN with a canned set of utility subroutines for performing common tasks. CASE/A version 5.0 software runs under the VAX VMS(Trademark) environment. It utilizes the Tektronics 4014(Trademark) graphics display system and the VTIOO(Trademark) text manipulation/display system.

Knox, J. C.↗