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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 19 records

Vehicle systems and payload requirements evaluation

Techniques developed for identifying launch vehicle system requirements for NASA automated space missions are discussed. Emphasis is placed on development of computer programs and investigation of astrionics for OSS missions and Scout. The Earth Orbit Mission Program - 1 which performs linear error analysis of launch vehicle dispersions for both vehicle and navigation system factors is described along with the Interactive Graphic Orbit Selection program which allows the user to select orbits which satisfy mission requirements and to evaluate the necessary injection accuracy.

Rea, F. G.↗

Quantitative nondestructive evaluation: Requirements for tomorrow's reliability

Quantitative Nondestructive Evaluation (QNDE) is the technology of measurement, analysis, and prediction of the state of material/structural systems for safety, reliability, and mission assurance. QNDE has impact on everyday life from the cars we drive, the planes we fly, the buildings we work or live in, literally to the infrastructure of our world. Here, researchers highlight some of the new sciences and technologies that are part of a safer, cost effective tomorrow. Specific technologies that are discussed are thermal QNDE of aircraft structural integrity, ultrasonic QNDE for materials characterization, and technology spinoffs from aerospace to the medical sector. In each case, examples are given of how new requirements result in enabling measurement technologies, which in turn change the boundaries of design/practice.

Heyman, Joseph S.↗

SLS Block-1B USA Separation Analysis and Requirements Evaluation Using the CLVTOPS Toolchain

Ensuring that rocket stage separation events provide positive clearance is critical to avoid loss of mission or crew. NASA's Marshall Space Flight Center (MSFC) has developed a cutting-edge toolchain to address this type of problem and it was used to set abstracted impulse requirements on, and to analyze the results of, the in-space separation event of the Universal Stage Adapter (USA) and the Exploration Upper Stage (EUS) of NASA's Space Launch System (SLS) Block-1B configuration. The toolchain is used as a hardware simulation to confirm positive body-to-body clearance during the separation event. It is also used to create a requirements-space simulation, which helps inform requirements as the hardware design matures.

Zach Muscha↗

Observational Data for Next-Generation Climate Model Evaluation: Requirements, Considerations, and Best Practices

Climate model simulations are an important source of information about our planet’s climate system and also enable informed decision-making under different future scenarios. As a new archive of results from the next generation of climate models is anticipated to become available with the Coupled Model Intercomparison Project phase 7 (CMIP7), the need to develop efficient and robust methods to evaluate models is paramount. Observations are an integral part of model evaluation, providing a means to quantify and understand the degree to which climate models can faithfully reproduce Earth system processes. Such analysis is critical for constraining climate projections, identifying areas of focus for model development, and assisting analysts in deciphering the utility of models for specific applications. Observations of Earth system come from a diversity of sources, span different space–time domains, and are produced by different communities, and each dataset features different data structures and formats, metadata standards, and its own unique uncertainties. Uncertainties in an observational dataset may stem from gaps in temporal and spatial coverage, instrumentation errors, or assumptions in retrieval and processing methods. How then does one ensure that observational data are ready for use and utilized in the most appropriate way for robust, rapid, and routine climate model evaluation? The CMIP7 Model Benchmarking Task Team with input from the broader climate modeling, model evaluation, and observational data communities present a vision and considerations for best practices toward the optimal and appropriate use of observational data to support next-generation climate model evaluation.

Climate models↗

Leveraging PHIL for Inverter Functionality Requirement Evaluation to Ensure a Reliable Grid

This presentation showcases NREL's ongoing research on advanced Multi-point Power Hardware-in-the-Loop (PHIL) systems, enabling comprehensive evaluation of interoperability, stability, and wide-area stability in complex power grids. Key features include high-power PHIL capabilities, seamless PHIL Interfaces for effortless Grid-Following (GFL) and Grid-Forming (GFM) mode switching, and advanced multi-domain PHIL/Controller Hardware-in-the-Loop (CHIL) capabilities for evaluating diverse technology mixes, facilitating rigorous testing and validation of emerging power systems for reliable integration, enhanced resilience, and optimal performance.

lab capabilities↗

Radiation Hardness Assurance (RHA): Challenges and New Considerations

Radiation Hardness Assurance (RHA) challenges associated with the use of commercial-off-the-shelf (COTS) components and emerging technologies are cause for risk acceptance in space flight missions. The RHA flow includes environment definition, hazard evaluation, requirements definition, evaluation of design, and design trades to accommodate the risk a project or program takes. The varied missions profiles and environments don't necessarily benefit from the same risk reduction efforts or cost reduction attempts. The level of effort within the RHA flow can be tailored to minimize risk based on the environment or design criticality.

Space Technology↗

The case for applying an early-lifecycle technology evaluation methodology to comparative evaluation of requirements engineering research

The premise of this paper is taht there is a useful analogy between evaluation of proposed problem solutions and evaluation of requirements engineering research itself. Both of these application areas face the challenges of evaluation early in the lifecycle, of the need to consider a wide variety of factors, and of the need to combine inputs from multiple stakeholders in making thse evaluation and subsequent decisions.

technology transfer↗

Flight program language requirements. Volume 2: Requirements and evaluations

The efforts and results are summarized for a study to establish requirements for a flight programming language for future onboard computer applications. Several different languages were available as potential candidates for future NASA flight programming efforts. The study centered around an evaluation of the four most pertinent existing aerospace languages. Evaluation criteria were established, and selected kernels from the current Saturn 5 and Skylab flight programs were used as benchmark problems for sample coding. An independent review of the language specifications incorporated anticipated future programming requirements into the evaluation. A set of detailed language requirements was synthesized from these activities. The details of program language requirements and of the language evaluations are described.

Source record↗

Space solar power. Description of concept, results of preliminary studies, requirements for evaluation

The nation is actively pursuing alternate sources of energy because of the problems or concerns related to obtaining required energy for the future from oil, gas, nuclear, and coal sources. Solar energy is an obvious candidate for consideration. Its use in the past has been limited by the relative cost of collecting and converting solar energy into electrical power. The increasing costs of other energy sources will make solar energy more attractive. During recent years a new concept for the collection of solar energy has been developed. This concept involves the location of solar power stations in space. The concept, results of preliminary studies, and requirements for space evaluation of such a project are discussed.

Source record↗

A Methodology for Writing High Quality Requirements Specification and Evaluating Existing Ones

Requirements development and management have always been critical in the implementation of software systems; engineers are unable to build what analysts can't define. It is generally accepted that the earlier in the life cycle potential risks are identified the easier it is to eliminate or manage the conditions that introduce that risk. Problems that are not found until testing are approximately 14 times more costly to fix than if the problem was found in the requirement phase. The requirements specification, as the first tangible representation of the capability to be produced, establishes the basis for all of the project's engineering management and assurance functions. If the quality of the requirements specification is poor it can give rise to risks in all areas of the project. Recently, automated tools have become available to support requirements management. The use of these tools not only provides support in the definition and tracing of requirements, but it also opens the door to effective use of metrics in characterizing and assessing the quality of the requirement specifications.

Rosenberg, Linda↗

Methodology for Evaluating Commercial Energy Code Updates

This document lays out the Department of Energy’s (DOE’s) methodology for evaluating the cost-effectiveness of energy code and standard proposals and editions. The evaluation is applied to new provisions or editions of ANSI/ASHRAE/IES Standard 90.1 and the International Energy Conservation Code. The methodology follows standard lifecycle cost (LCC) economic analysis procedures. A cost-effectiveness evaluation requires three steps: 1) evaluating the energy and energy cost savings of code changes; 2) evaluating the incremental and replacement costs related to the changes; and 3) determining the cost-effectiveness of energy code changes based on those costs and savings over time.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Methodology for Evaluating Energy Savings, Cost-Effectiveness, and Societal Impacts of Commercial Energy Code Changes

This document lays out the Department of Energy’s (DOE’s) methodology for evaluating the cost-effectiveness of energy code and standard proposals and editions. The evaluation is applied to new provisions or editions of ANSI/ASHRAE/IES Standard 90.1 and the International Energy Conservation Code. The methodology follows standard lifecycle cost (LCC) economic analysis procedures. A cost-effectiveness evaluation requires three steps: 1) evaluating the energy and energy cost savings of code changes; 2) evaluating the incremental and replacement costs related to the changes; and 3) determining the cost-effectiveness of energy code changes based on those costs and savings over time.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

System Analysis and Generative Design for Icenode, a Buoyant Vehicle for Measuring Melt Rate Under Ice Shelves

Antarctic ice shelves buttress the Antarctic Ice Sheet from sliding into the ocean, and their collapse could trigger a meter or more of global sea level rise by the end of the century. Current state-of-the-art predictions for ice shelf behavior in a warming climate have large uncertainty, significantly hindered by a lack of in situ melt rate observations under ice shelves, especially near grounding zones. IceNode is a novel robotic vehicle under development at the NASA Jet Propulsion Laboratory to acquire such measurements, but presents a complex design problem owing to the large design space and conflicting performance requirements. Evaluating a preliminary design requires several types of tedious analysis which prevents rapid iteration and exploration of the design space. We present the implementation of a custom system analysis framework which was used to automate analysis such as resource budgeting, mission simulation, mass and buoyancy balancing, and static landing stability analysis of a given design configuration. Using this framework, we selected parameters which had the largest effects on design success and conducted a generative design study in which we programmatically varied a handful of parameters to generate 1540 different design candidates and test them across 160 different environmental scenarios. The custom built system analysis tool enabled rapid development of critical analysis and automated exploration of a large design space to guide preliminary design of the IceNode vehicle.

Gebara, Christine↗

Radiation Hardness Assurance (RHA): Challenges and New Considerations

Use of commercial-off-the-shelf (COTS) components and emerging technologies often require space flight missions to accept elevated risk. The Radiation Hardness Assurance (RHA) flow includes environment definition, hazard evaluation, requirements definition, evaluation of design, and design trades to accommodate and mitigate the risk a project or program takes. Depending on the mission profile and environment, different missions may not necessarily benefit from the same risk reduction efforts or cost reduction attempts. While this poses challenges for the radiation engineer, it also presents opportunities to tailor the RHA flow to minimize risk based on the environment or design criticality while remaining within budget. This presentation will focus on an approach to RHA amidst the present challenges, using the same RHA flow as in the past, with examples from recent radiation test results. The current challenges and the types of risk will be identified. How these risks drive requirements development and realization will be explained with examples of device results and data for single event effects (SEE) and in one case total ionizing dose (TID).

Radiation Hardness Assurance (RHA); Risk Managemen↗

DSN Array Simulator

The DSN Array Simulator (wherein 'DSN' signifies NASA's Deep Space Network) is an updated version of software previously denoted the DSN Receive Array Technology Assessment Simulation. This software (see figure) is used for computational modeling of a proposed DSN facility comprising user-defined arrays of antennas and transmitting and receiving equipment for microwave communication with spacecraft on interplanetary missions. The simulation includes variations in spacecraft tracked and communication demand changes for up to several decades of future operation. Such modeling is performed to estimate facility performance, evaluate requirements that govern facility design, and evaluate proposed improvements in hardware and/or software. The updated version of this software affords enhanced capability for characterizing facility performance against user-defined mission sets. The software includes a Monte Carlo simulation component that enables rapid generation of key mission-set metrics (e.g., numbers of links, data rates, and date volumes), and statistical distributions thereof as functions of time. The updated version also offers expanded capability for mixed-asset network modeling--for example, for running scenarios that involve user-definable mixtures of antennas having different diameters (in contradistinction to a fixed number of antennas having the same fixed diameter). The improved version also affords greater simulation fidelity, sufficient for validation by comparison with actual DSN operations and analytically predictable performance metrics.

Tikidjian, Raffi↗