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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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To maximize salability, spaceborne interferometer designs must minimize actuator cost while maximizing science quality and quantity. Interferometer designers must have the knowledge to design a system with the simplist, most reliable, and least expensive actuators possible.
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Approaches used for manned applications include limited items such as CD-players evaluated for safety to high criticality applications where the COTs hardware is evaluated on a case-by-case basis for the application and commensurate screening and qualification testing. COTS hardware is successfully implemented in both the International Space Station and Space Shuttle but requires evaluation and modifications for the application. Screening and qualification of COTs hardware used in critical applications may need to be more extensive and stringent than traditional military screening. Evaluation for: a) Suitability for the application; b) Safety; c) Reliability and maintainability; and d) Workmanship.
This slide presentation reviews risk assessment and its role in risk-informed decision making. It includes information on probabilistic risk assessment, typical risk management process, origins of risk matrix, performance measures, performance objectives and Bayes theorem.
An XML Telemetry Command Exchange (XTCE) tutoral oriented towards packets or minor frames is shown. The contents include: 1) The Basics; 2) Describing Telemetry; 3) Describing the Telemetry Format; 4) Commanding; 5) Forgotten Elements; 6) Implementing XTCE; and 7) GovSat.
In order to rank bearing materials, lubricants and other design variables using rolling-element bench type fatigue testing of bearing components and full-scale rolling-element bearing tests, the investigator needs to be cognizant of the variables that affect rolling-element fatigue life and be able to maintain and control them within an acceptable experimental tolerance. Once these variables are controlled, the number of tests and the test conditions must be specified to assure reasonable statistical certainty of the final results. There is a reasonable correlation between the results from elemental test rigs with those results obtained with full-scale bearings. Using the statistical methods of W. Weibull and L. Johnson, the minimum number of tests required can be determined. This paper brings together and discusses the technical aspects of rolling-element fatigue testing and data analysis as well as making recommendations to assure quality and reliable testing of rolling-element specimens and full-scale rolling-element bearings.
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UQTools is the short name for the Uncertainty Quantification Toolbox, a software package designed to efficiently quantify the impact of parametric uncertainty on engineering systems. UQTools is a MATLAB-based software package and was designed to be discipline independent, employing very generic representations of the system models and uncertainty. Specifically, UQTools accepts linear and nonlinear system models and permits arbitrary functional dependencies between the system s measures of interest and the probabilistic or non-probabilistic parametric uncertainty. One of the most significant features incorporated into UQTools is the theoretical development centered on homothetic deformations and their application to set bounding and approximating failure probabilities. Beyond the set bounding technique, UQTools provides a wide range of probabilistic and uncertainty-based tools to solve key problems in science and engineering.