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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 451 records · Page 25

All sources NASA NTRS DOE OSTI

NASA NTRS1981

Commercial/industrial photovoltaic module and array requirement study. Low-cost solar array project engineering area

Design requirements for photovoltaic modules and arrays used in commercial and industrial applications were identified. Building codes and referenced standards were reviewed for their applicability to commercial and industrial photovoltaic array installation. Four general installation types were identified - integral (replaces roofing), direct (mounted on top of roofing), stand-off (mounted away from roofing), and rack (for flat or low slope roofs, or ground mounted). Each of the generic mounting types can be used in vertical wall mounting systems. This implies eight mounting types exist in the commercial/industrial sector. Installation costs were developed for these mounting types as a function of panel/module size. Cost drivers were identified. Studies were performed to identify optimum module shapes and sizes and operating voltage cost drivers. The general conclusion is that there are no perceived major obstacles to the use of photovoltaic modules in commercial/industrial arrays.

Source record↗

NASA NTRS1965

Big solids - seeking a new plateau.

Solid rocket motor development and problems in building larger motors

SOLID PROPELLANT ROCKET ENGINE↗

NASA NTRS1989

The Next Generation Space Telescope

In Space Science in the Twenty-First Century, the Space Science Board of the National Research Council identified high-resolution-interferometry and high-throughput instruments as the imperative new initiatives for NASA in astronomy for the two decades spanning 1995 to 2015. In the optical range, the study recommended an 8 to 16-meter space telescope, destined to be the successor of the Hubble Space Telescope (HST), and to complement the ground-based 8 to 10-meter-class telescopes presently under construction. It might seem too early to start planning for a successor to HST. In fact, we are late. The lead time for such major missions is typically 25 years, and HST has been in the making even longer with its inception dating back to the early 1960s. The maturity of space technology and a more substantial technological base may lead to a shorter time scale for the development of the Next Generation Space Telescope (NGST). Optimistically, one could therefore anticipate that NGST be flown as early as 2010. On the other hand, the planned lifetime of HST is 15 years. So, even under the best circumstances, there will be a five year gap between the end of HST and the start of NGST. The purpose of this first workshop dedicated to NGST was to survey its scientific potential and technical challenges. The three-day meeting brought together 130 astronomers and engineers from government, industry and universities. Participants explored the technologies needed for building and operating the observatory, reviewed the current status and future prospects for astronomical instrumentation, and discussed the launch and space support capabilities likely to be available in the next decade. To focus discussion, the invited speakers were asked to base their presentations on two nominal concepts, a 10-meter telescope in space in high earth orbit, and a 16-meter telescope on the moon. The workshop closed with a panel discussion focused mainly on the scientific case, siting, and the programmatic approach needed to bring NGST into being. The essential points of this panel discussion have been incorporated into a series of recommendations that represent the conclusions of the workshop. Speakers were asked to provide manuscripts of their presentation. Those received were reproduced here with only minor editorial changes. The few missing papers have been replaced by the presentation viewgraphs. The discussion that follows each speaker's paper was derived from the question and answer sheets, or if unavailable, from the tapes of the meeting. In the latter case, the editors have made every effort to faithfully represent the discussion.

Bely, Pierre-Yves↗

NASA NTRS2004

The Need for Analogue Missions in Scientific Human and Robotic Planetary Exploration

With the increasing challenges of planetary missions, and especially with the prospect of human exploration of the moon and Mars, the need for earth-based mission simulations has never been greater. The current focus on science as a major driver for planetary exploration introduces new constraints in mission design, planning, operations, and technology development. Analogue missions can be designed to address critical new integration issues arising from the new science-driven exploration paradigm. This next step builds on existing field studies and technology development at analogue sites, providing engineering, programmatic, and scientific lessons-learned in relatively low-cost and low-risk environments. One of the most important outstanding questions in planetary exploration is how to optimize the human and robotic interaction to achieve maximum science return with minimum cost and risk. To answer this question, researchers are faced with the task of defining scientific return and devising ways of measuring the benefit of scientific planetary exploration to humanity. Earth-based and spacebased analogue missions are uniquely suited to answer this question. Moreover, they represent the only means for integrating science operations, mission operations, crew training, technology development, psychology and human factors, and all other mission elements prior to final mission design and launch. Eventually, success in future planetary exploration will depend on our ability to prepare adequately for missions, requiring improved quality and quantity of analogue activities. This effort demands more than simply developing new technologies needed for future missions and increasing our scientific understanding of our destinations. It requires a systematic approach to the identification and evaluation of the categories of analogue activities. This paper presents one possible approach to the classification and design of analogue missions based on their degree of fidelity in ten key areas. Various case studies are discussed to illustrate the approach.

Snook, K. J.↗

NASA NTRS2004

Technology Innovations from NASA's Next Generation Launch Technology Program

NASA's Next Generation Launch Technology Program has been on the cutting edge of technology, improving the safety, affordability, and reliability of future space-launch-transportation systems. The array of projects focused on propulsion, airframe, and other vehicle systems. Achievements range from building miniature fuel/oxygen sensors to hot-firings of major rocket-engine systems as well as extreme thermo-mechanical testing of large-scale structures. Results to date have significantly advanced technology readiness for future space-launch systems using either airbreathing or rocket propulsion.

Cook, Stephen A.↗

NASA NTRS2009

Formal Methods for Automated Diagnosis of Autosub 6000

This is a progress report on applying formal methods in the context of building an automated diagnosis and recovery system for Autosub 6000, an Autonomous Underwater Vehicle (AUV). The diagnosis task involves building abstract models of the control system of the AUV. The diagnosis engine is based on Livingstone 2, a model-based diagnoser originally built for aerospace applications. Large parts of the diagnosis model can be built without concrete knowledge about each mission, but actual mission scripts and configuration parameters that carry important information for diagnosis are changed for every mission. Thus we use formal methods for generating the mission control part of the diagnosis model automatically from the mission script and perform a number of invariant checks to validate the configuration. After the diagnosis model is augmented with the generated mission control component model, it needs to be validated using verification techniques.

Ernits, Juhan↗

NASA NTRS2011

Cryogenic Thermal Vacuum Testing with Remote Optical Metrology

Flexure Engineering was awarded an SBIR to research and develop technology needed to build a thermal vacuum chamber made to take laser radar metrology through a window. The XATF test is proof of concept for this, and demonstrated the need for such a chamber. XATF refers to two pieces of critical ground support equipment for NASA's JWST (James Webb Space Telescope) Integrated Science Instrument Module (ISIM), the ISIM Alignment Target Fixture (IATF) and the Master Alignment Target Fixture (MATF). These optical alignment assemblies require characterization while under cryogenic temperature. A thermal vacuum chamber equipped with a shroud cooled with gaseous and liquid nitrogen was used. An inner shroud was cooled with liquid helium to approximately 30K. The XATF assemblies were kinematically mounted and oriented inside the inner shroud such that the optical targets were visible from outside an optical window on one of the chamber ports. Laser radar and theodolite mounted outside the window took measurements of various optical targets. Two cold cycles were completed. A third cycle was aborted. Metrology was successfully taken. There were some problems with the helium system. The cryo pumps were turned off to reduce vibrations during metrology. Many new technologies and testing methods must be developed for JWST and future programs that will require precision measurements. These technologies will be applicable to other cold temperature applications, such as lunar missions and superconductors. Remote metrology technologies can also be applicable to testing in harsh environments. Facilities with remote metrology capability will be valuable.

Boyd, Guinevere↗

NASA NTRS2009

Test Rack Development for Extended Operation of Advanced Stirling Convertors at NASA Glenn Research Center

The U.S. Department of Energy (DOE), Lockheed Martin Space Company (LMSC), Sun power Inc., and NASA Glenn Research Center (GRC) have been developing an Advanced Stirling Radioisotope Generator (ASRG) for use as a power system on space science missions. This generator will make use of free-piston Stirling convertors to achieve higher conversion efficiency than currently available alternatives. NASA GRC's support of ASRG development includes extended operation testing of Advanced Stirling Convertors (ASCs) developed by Sunpower Inc. In the past year, NASA GRC has been building a test facility to support extended operation of a pair of engineering level ASCs. Operation of the convertors in the test facility provides convertor performance data over an extended period of time. Mechanical support hardware, data acquisition software, and an instrumentation rack were developed to prepare the pair of convertors for continuous extended operation. Short-term tests were performed to gather baseline performance data before extended operation was initiated. These tests included workmanship vibration, insulation thermal loss characterization, low-temperature checkout, and fUll-power operation. Hardware and software features are implemented to ensure reliability of support systems. This paper discusses the mechanical support hardware, instrumentation rack, data acquisition software, short-term tests, and safety features designed to support continuous unattended operation of a pair of ASCs.

Dugala, Gina M.↗

NASA NTRS2018

Application of PoF Based Virtual Qualification Methods for Reliability Assessment of Mission Critical PCBs

Reliability is the ability of a product to perform the function for which it was intended for a specified period of time (or cycles) for a given set of life cycle conditions. In today's compressed mission development cycles where designing, building and testing the physical models has to occur in a matter of months not years, Projects don't have the luxury of iteratively building and testing those models. Physics of failure (PoF) is an engineering-based approach to reliability that begins with an understanding of materials, processes, physical interactions, degradation and failure mechanisms, as well as identifying failure models. The PoF approach uses modeling and simulation to qualify a design and manufacturing process, with the ultimate intent of eliminating failures early in the design process by addressing the root cause. The physics-of-failure analysis proactively incorporates reliability into the design process by establishing a scientific basis for evaluating new materials, structures and technologies. Virtual physics-of-failure modeling allows engineers to determine if new technological node can be added to an existing system. This presentation will illustrate an application of a PoF based tool during the initial phases of a printed circuit board assembly development and how the NASA GSFC team was able to dynamically study the effects of electronics parts and printed circuit board material configuration changes under simulated thermal and vibrational stresses

Electronics packaging↗

NASA NTRS2018

Application of PoF Based Virtual Qualification Methods for Reliability Assessment of Mission Critical PCBs

Physics of Failure↗

NASA NTRSDate not supplied

NGHT-1X Pole Cover Erosion Measurements on Xenon and Krypton

Northrop Grumman’s NGHT-1X Hall thruster has completed the Engineering Model development phase and is progressing towards qualification and flight unit build and test. First flight of the NGHT-1X will occur in 2025 on Northrop Grumman’s Mission Extension Pod spacecraft. The NGHT-1X is a state of the art 1 kW-class Hall thruster which implements magnetic shielding to increase thruster lifetime by reducing discharge channel wall erosion. As a result, like other magnetically shielded Hall thrusters, the NGHT-1X exhibits erosion of the front-facing pole covers, which is the primary life-limiting failure mode of the thruster. During the development of the NGHT-1X, several Short Duration Wear Tests were performed to characterize erosion rates and forecast compliance to lifetime requirements in advance of the ongoing full-life Long Duration Wear Test. Erosion rate measurements from four tests at different operating conditions are presented and comparisons made between tests. Two tests were performed in the same background pressure environment at 700 W 300 V and 900 W 350 V throttle conditions, both using xenon propellant. A third test was performed again at 900 W 350 V with xenon propellant, but at a lower background pressure. Lastly, to assess the viability of potential future applications with alternate propellants, a wear test was conducted using krypton propellant at 900 W 250 V, the results of which are presented here. The erosion measurements from each test are compared with one another, and insights are discussed. All xenon wear tests support a thruster lifetime capability in excess of 16,000 hours, or 3.3 MNs at 900 W 350 V, which supports the Mission Extension Pod mission with margin as well as many other potential applications on small- to medium-sized spacecraft.

Hall↗

NASA NTRS1993

Spiral Survey Expedition: A proposal to organize for the Survey, exploration and eventual colonization of the Milky Way Galaxy

This paper details a plan to explore the galaxy. Areas of interest to an era of cyberspace include the Tech-Index information system for the expedition and the role cyberspace has in increasing expedition productivity and increasing the capabilities of cyberspace by expanding the goals and data set. The paper offers lists of projects for the cybermarket pool. The expedition is described also as a developers tool for cyberspace to acknowledge the scope of the human mind far surpasses present engineering yet guides our direction of energies and materials. Maintaining the biological capability to reproduce the Terran biosphere via Evolution park conservation areas is discussed. The ecological repair of Spaceship Earth and the build up of an interstellar industrial base from simple recyling and educational programs is meshed with a proposed 'reverse engineering cyberspace' plan. A set of constructive contests are proposed with 3 new currencies offered as prizes. The Planet, The Solar System, The Galaxy are 3 areas of focus. Each of these areas are considered in a cyberspectrum of (1) Sentience; (2) Biological diversity; and (3) Energy/Matter resources.

Galloway, Scott↗

NASA NTRS1990

Satellite sound broadcast propagation studies and measurements

Satellite Sound Broadcasting is an attractive satellite application. Before regulatory decisions can be made in 1992, the propagation effects encountered have to be characterized. The Electrical Engineering Research Laboratory has nearly completed a system which will allow amplitude measurements to be made over 10 MHz bandwidths in the 800 to 1800 MHz frequency range. The system uses transmission from a transportable tower, and reception inside buildings or in the shadow of trees or utility poles. The goal is to derive propagation models for use by systems engineers who are about to design satellite broadcast systems. The advance of fiber-optics technology has helped to focus future development of satellite services into areas where satellites are uniquely competitive. One of these preferred satellite applications is the broadcasting of high-quality sound for stationary or mobile reception by listeners using low-cost, consumer-grade receivers. Before such services can be provided, however, the political hurdles of spectrum allocation have to be surmounted and the technical questions of standardization for world-wide compatibility have to be resolved. In order to arrive at an optimal system design, efficient in the use of our scarce spectral resources, affordable both to the broadcaster and the listener, and providing predictable performance, the propagation effects to which the service is subjected have to be characterized. Consequently, the objective of the research project is to make basic propagation measurements for direct Satellite Sound Broadcasting Service (SSBS). The data obtained should allow the development of propagation models to be used by communications engineers designing the operational systems. Such models shall describe the effects of shadowing and multipath propagation on SSBS receivers operating in a specified environment, such as inside commercial or residential buildings of various construction and also in the shadow of trees or utility poles as might be encountered by transporting or mobile listeners.

Vogel, Wolfhard J.↗

NASA NTRS2002

Continuing Development of a Collaborative Plan to Further Engage South Dakota in NASA's Earth Science Enterprise

An ongoing set of research planning activities have occurred in South Dakota as a consequence of the past two years of NASA-EPSCoR Preparation Grants. During this time a group of approximately 60 scientists, engineers, and university administrators in South Dakota have been directly involved as "theme team" members in a series of five all-day meetings to identify the research and technological priorities that are consistent both with NASA-ESE's interests and the State's expertise. Institutions represented within the group's membership include: South Dakota School of Mines & Technology, South Dakota State University, Augustana College, University of South Dakota, USGS EROS Data Center, Si ranks College, Santa Gleska University, Sisseton Wahpeton Community College, USGS Water Resources Division, US National Weather Service, and the SD Department of Environment & Natural Resources. Many of these organizations are also members and affiliates of the SD Space Grant Consortium. The evolving plan has been guided by the following desirable actions: 1. To establish new contacts and strengthen existing linkages with NASA Centers, relevant NASA researchers, and key personnel at the USGS EROS Data Center. 2. To promote participation from the State's major research institutions, State agencies, and relevant businesses in South Dakota that are interested in strengthening our scientific and technological enterprises. 3. To develop the State's scientific talent and infrastructure for enhanced competitiveness in research, development, and technology-based economic development. 4. To encourage greater participation by under represented groups, especially Native Americans, in scientific education and research. 5. To build greater public and political support in South Dakota for the overall science, engineering, and technology enterprise. 6. To communicate the benefits of current and future NASA programs to the progress and development of South Dakota, the Northern Great Plains Region, and the Nation.

Farwell, Sherry O.↗

NASA NTRS1991

NASA information systems commonality and convergence

Efforts to identify high payback functions performed by the Office of Space Science Applications (OSSA) data systems package existing operationally proven implementations as system building blocks and foster their use in the OSSA environment. An overview is given of the current state of OSSA data systems and the major challenges facing system developers over the next five years. Current trends in system commonality are discussed, and development is examined in the context of system design. Central system engineering approaches to solving the commonality and interoperability challenges are described. Efforts to package three diverse building blocks and to foster their reuse are documented.

Handley, Thomas H., Jr.↗

NASA NTRS1992

FIBER-TEX 1991: The Fifth Conference on Advanced Engineering Fibers and Textile Structures for Composites

This document is a compilation of papers presented at a joint NASA/North Carolina State University/DoD/Clemson University/Drexel University conference on Fibers, Textile Technology, and Composites Structures held at the College of Textiles Building on Centennial Campus of North Carolina State University, Raleigh, North Carolina on October 15-17, 1991. Conference papers presented information on advanced engineering fibers, textile processes and structures, structural fabric production, mechanics and characteristics of woven composites, pultruded composites, and the latest requirements for the use of textiles in the production of composite materials and structures.

Buckley, John D.↗

NASA NTRS2000

NASA's Design and Development of a Field Goniometer Instrument Using Solid Works

With NASA suffering severe funding cutbacks, engineers at NASA are required to produce state-of-the-art hardware with limited personnel and financial resources. In light of these constraints, the new NASA mandate is to build better, faster and cheaper. In April of 1998, Stennis Space Center's Commercial Remote Sensing Program contracted to the Systems Engineering Division at NASA Ames Research Center to develop a device known as a Field Goniometer. A Field Goniometer is a device that measures bi-directional reflectance of a target, such as vegetation, relative to the sun and an imaging system in an aircraft or spacecraft. The device is able to provide a spectral fingerprint of the surface it is measuring in wavelengths from 350nm-2500nm using a hyperspectral imager. To accomplish this project, several obstacles had to be overcome. First, the design had to be completed in less than four months. Second, due to the complexity of the design, the use of solid modeling was highly desirable but most of the group's solid modelers were assigned to other jobs. Third, the amount of funding available from the customer was one half to one third the funding typically expended for a job of this nature. Our choices for this project were to design with standard 2-D CAD systems currently used in-house or train additional engineers on our existing solids package or purchase a new solid model package. The use of a 2D CAD system was very undesirable due to the complexity of the design. Using our existing solids modeler would have required a learning curve for our engineers that would be incompatible with our schedule. Prior to this project, a member of our design group researched the solid modeling industry and decided to purchase SolidWorks. After examining the product for ease of use, modeling capability, training time required and cost, we decided our highest probability of success would be to design with Solidworks. During the design phase, our fabrication group was able to provide input at the very early stages, which added significant benefit to the final product. Fabrication cost and schedule savings have been realized by having complex part geometries translated directly from the SolidWorks design models to Surfcam and other computer-aided manufacturing (CAM) software. This direct model translation capability optimized the fabrication processes. The end result was that we were able to successfully complete the project on time and on budget. Other advantages of using SolidWorks, as cited by the design team, include a rapid negotiation of the initial learning curve, the ability to develop solid model hardware prototypes (used to communicate the design intent to both the customer and the fabricator), and the ability to work as a team collaborating on a large, complex model. These types of tools and efforts represent our response to NASA's challenge to produce higher quality products within shorter design and fabrication times.

Turner, Mark↗

NASA NTRSDate not supplied

Lean Model-Based Systems Engineering on the NASA High-Density Vertiplex Subproject

The High Density Vertiplex (HDV) subproject of NASA’s Advanced Air Mobility (AAM) project adopted Model-Based Systems Engineering (MBSE) in July of 2020, prior to subproject formulation. A small and lean team of HDV Systems Engineers (SE) are utilizing MagicDraw to execute NASA SE processes via MBSE. The SEs learned how to use MagicDraw from scratch and HDV is the first project for which the SEs have utilized MagicDraw. This presentation will demonstrate project technical execution via MBSE, utilizing the digital elements built into the SysML (Systems Modeling Language). SysML provides a model-centric means of carrying out the NASA SE common technical processes by providing tools for complete system modeling, including requirements and interface management and design capture. The authors also leverage and extend SysML to perform other SE tasks, such as Verification and Validation (V&V) tracking. MBSE has two main purposes for HDV: 1) documenting the subproject’s logical architecture for distribution outside of the subproject, 2) capturing the subproject’s physical architecture in a single-source-of-truth for use by the subproject’s members. This presentation details the challenges, lessons learned, and solutions that were encountered in implementing MBSE in the first iteration on a multi-iteration, full-lifecycle design, build, fly project.

systems engineering↗