Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “technical assessment”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 181 records · Page 10

NASA Engineering and Safety Center Technical Bulletin No. 20-06: Material Compatibility Assessment of Spacecraft Oxidizer Systems

Recently designed oxidizer systems used in spacecraft propulsion are pushing the limits of materials and operating conditions. As a result, nitrogen tetroxide (NTO) oxidizer systems are exhibiting failures driven by ignition mechanisms similar to oxygen systems. Oxidizer systems (e.g., O 2 , N 2 O 4 , N 2 O H 2 O 2 ) have generally been designed and operated within industry experience for material corrosion concerns without a complete understanding or regard for the concerns regarding potential material ignition and burning. To compound the problem, the effects of varying parameters on ignition and the kindling chain have not been studied, and there is a very limited amount of published data to help with the understanding. NASA-sponsored testing is actively researching ignition mechanisms, determining thresholds, and defining operating envelopes to inform the aerospace community.

NESC↗

Observations on the State of NASA's GN&C Engineering Discipline: Results of an Independent Non-Advocate Study

The NASA Technical Fellows periodically conduct State-of-the-Discipline assessments. The GN&C Technical Fellow contracted Harlan Brown & Company in 2007 and 2009 to conduct independent, third party studies to gain unbiased insight and understanding into the attitudes and beliefs of NASA's GN&C Community of Practice (CoP). The paper first outlines the background, objectives and methodology of the studies. The paper then summarizes key study results of the 2007 baseline study, as well as the 2009 update. The update was then used to track and monitor perceptions, identify performance trends, identify areas where further improvement needs to be made in NASA's GN&C discipline. It also generated feedback on the recently developed GN&C CoP online knowledge capture and learning site.

Pawlikowski, Gerald J.↗

Spacelab user implementation assessment study. (Software requirements analysis). Volume 2: Technical report

The engineering analyses and evaluation studies conducted for the Software Requirements Analysis are discussed. Included are the development of the study data base, synthesis of implementation approaches for software required by both mandatory onboard computer services and command/control functions, and identification and implementation of software for ground processing activities.

Source record↗

Aerospace Systems Design in NASA's Collaborative Engineering Environment

Past designs of complex aerospace systems involved an environment consisting of collocated design teams with project managers, technical discipline experts, and other experts (e.g. manufacturing and systems operations). These experts were generally qualified only on the basis of past design experience and typically had access to a limited set of integrated analysis tools. These environments provided less than desirable design fidelity, often lead to the inability of assessing critical programmatic and technical issues (e.g., cost risk, technical impacts), and generally derived a design that was not necessarily optimized across the entire system. The continually changing, modern aerospace industry demands systems design processes that involve the best talent available (no matter where it resides) and access to the best design and analysis tools. A solution to these demands involves a design environment referred to as collaborative engineering. The collaborative engineering environment evolving within the National Aeronautics and Space Administration (NASA) is a capability that enables the Agency's engineering infrastructure to interact and use the best state-of-the-art tools and data across organizational boundaries. Using collaborative engineering, the collocated team is replaced with an interactive team structure where the team members are geographically distributed and the best engineering talent can be applied to the design effort regardless of physical location. In addition, a more efficient, higher quality design product is delivered by bringing together the best engineering talent with more up-to-date design and analysis tools. These tools are focused on interactive, multidisciplinary design and analysis with emphasis on the complete life cycle of the system, and they include nontraditional, integrated tools for life cycle cost estimation and risk assessment. NASA has made substantial progress during the last two years in developing a collaborative engineering environment. NASA is planning to use this collaborative engineering infrastructure to provide better aerospace systems life cycle design and analysis, which includes analytical assessment of the technical and programmatic aspects of a system from "cradle to grave." This paper describes the recent NASA developments in the area of collaborative engineering, the benefits (realized and anticipated) of using the developed capability, and the long-term plans for implementing this capability across the Agency.

Monell, Donald W.↗

Aerospace Systems Design in NASA's Collaborative Engineering Environment

Past designs of complex aerospace systems involved an environment consisting of collocated design teams with project managers, technical discipline experts, and other experts (e.g., manufacturing and systems operation). These experts were generally qualified only on the basis of past design experience and typically had access to a limited set of integrated analysis tools. These environments provided less than desirable design fidelity, often lead to the inability of assessing critical programmatic and technical issues (e.g., cost, risk, technical impacts), and generally derived a design that was not necessarily optimized across the entire system. The continually changing, modern aerospace industry demands systems design processes that involve the best talent available (no matter where it resides) and access to the the best design and analysis tools. A solution to these demands involves a design environment referred to as collaborative engineering. The collaborative engineering environment evolving within the National Aeronautics and Space Administration (NASA) is a capability that enables the Agency's engineering infrastructure to interact and use the best state-of-the-art tools and data across organizational boundaries. Using collaborative engineering, the collocated team is replaced with an interactive team structure where the team members are geographical distributed and the best engineering talent can be applied to the design effort regardless of physical location. In addition, a more efficient, higher quality design product is delivered by bringing together the best engineering talent with more up-to-date design and analysis tools. These tools are focused on interactive, multidisciplinary design and analysis with emphasis on the complete life cycle of the system, and they include nontraditional, integrated tools for life cycle cost estimation and risk assessment. NASA has made substantial progress during the last two years in developing a collaborative engineering environment. NASA is planning to use this collaborative engineering engineering infrastructure to provide better aerospace systems life cycle design and analysis, which includes analytical assessment of the technical and programmatic aspects of a system from "cradle to grave." This paper describes the recent NASA developments in the area of collaborative engineering, the benefits (realized and anticipated) of using the developed capability, and the long-term plans for implementing this capability across Agency.

Monell, Donald W.↗

A superfluid helium system for an LST IR experiment

The results are presented of a study program directed toward evaluating the problems associated with cooling an LST instrument to 2 K for a year by using superfluid helium as the cooling means. The results include the parametric analysis of systems using helium only, and systems using helium plus a shield cryogen. A baseline system, using helium only is described. The baseline system is sized for an instrument heat leak of 50 mw. It contains 71 Kg of superfluid helium and has a total, filled weight of 217 Kg. A brief assessment of the technical problems associated with a long life, spaceborne superfluid helium storage system is also made. It is concluded that a one year life, superfluid helium cooling system is feasible, pending experimental verification of a suitable low g vent system.

Breckenridge, R. W., Jr.↗

Atmospheric science facility pallet-only mode space transportation system payload (feasibility study), Volume 1

The economic and technical feasibility is assessed of employing a pallet-only mode for conducting Atmospheric Magnetospheric Plasmas-in-Space experiments. A baseline design incorporating the experiment and instrument descriptions is developed. The prime instruments are packaged into four pallets in a physical and functional manner compatible with the Space Transportation System capabilities and/or constraints and an orbiter seven-day mission timeline. Operational compatibility is verified between the orbiter/payload and supporting facilities. The development status and the schedule requirements applicable to the Atmospheric Science Facility mission are identified. Conclusions and recommendations are presented and discussed.

Source record↗

Analysis and evalaution in the production process and equipment area of the low-cost solar array project

The manufacturing methods for photovoltaic solar energy utilization are assessed. Economic and technical data on the current front junction formation processes of gaseous diffusion and ion implantation are presented. Future proposals, including modifying gaseous diffusion and using ion implantation, to decrease the cost of junction formation are studied. Technology developments in current processes and an economic evaluation of the processes are included.

Goldman, H.↗

Solid Rocket Motor Technology

These Conference Proceedings contain the 36 papers presented at the AGARD Propulsion and Energetics Panel 53rd Symposium on "Solid Rocket Motor Technology", which was held in Oslo, Norway, 2-5 April 1979. The questions and answers after the various presentations are included as well as the Round Table Discussion. The Symposium was organized into seven sessions: Survey Papers (2); Ignition, Extinction and Internal Ballistics (8); Burn Rate Modelling and Combustion of Metal (5); New Propellants (5); Combustion Instability (7); Heat Transfer and Materials (3); and Testing and Instrumentation (6).The Symposium provided a forum for discussion and exchange between research scientists ,propellant formulators and motor technologists. Though main emphasis was placed on transient processes like ignition and extinction and on combustion instability with the various related aspects there were a number of papers dealing with propellants, their characteristics and their development. Whether the symposium achieved its initial aim, i.e. furnishing a comprehensive survey of the technology available for solid propellant rocket motors and its further development capabilities, will be assessed in a Technical Evaluation Report, to be published as AGARD Advisory Report AR 151.

Advisory Group for Aerospace Research and Developm↗

Technology and development requirements for advanced coal conversion systems

A compendium of coal conversion process descriptions is presented. The SRS and MC data bases were utilized to provide information paticularly in the areas of existing process designs and process evaluations. Additional information requirements were established and arrangements were made to visit process developers, pilot plants, and process development units to obtain information that was not otherwise available. Plant designs, process descriptions and operating conditions, and performance characteristics were analyzed and requirements for further development identified and evaluated to determine the impact of these requirements on the process commercialization potential from the standpoint of economics and technical feasibility. A preliminary methodology was established for the comparative technical and economic assessment of advanced processes.

Source record↗

Preliminary technical results review of FY81 experiments. Volume 1: Fiscal year 1981/82 spring small grains pilot experiment

Technical progress made in the foreign commodity production forecasting for the advancement of spring small grains (SSG) area estimation is reported with emphasis on results achieved since the last AgRISTARS level semiannual review. Major objectives and accomplishments are reviewed and the experiment is described. The technical approach data assessment, and data systems used are considered. Results of the group approach comparison study are presented along with preliminary aggregation results for SSG processing procedures. The outlook for the future is assessed.

Source record↗

Lidar technology measurements and technology: Report of panel

Lidar is ready to make an important contribution to tropospheric chemistry research with a variety of spaceborne measurements that complement the measurements from passive instruments. Lidar can now be considered for near-term and far-term space missions dealing with a number of scientifically important issues in tropospheric chemistry. The evolution in the lidar missions from space are addressed and details of these missions are given. The laser availability for space missions based upon the technical data is assessed.

Browell, Edward V.↗

Supersonic laminar flow control on commercial transports

This paper provides an overview of the status of supersonic laminar flow control. Existing research into the aerodynamic problems of subsonic and supersonic laminar flow control is first reviewed to provide a prospective for subsequent discussions of recent studies to evaluate the potential performance benefits of the application of laminar flow control to supersonic transports. A flight research program to provide a realistic assessment of the technical feasibility is then described.

Wagner, R. D.↗

Management Practices and Tools: 2000-2004

This custom bibliography from the NASA Scientific and Technical Information Program lists a sampling of records found in the NASA Aeronautics and Space Database. The scope of this topic is divided into four parts and covers the adoption of proven personnel and management reforms to implement the national space exploration vision, including the use of "system-of-systems" approach; policies of spiral, evolutionary development; reliance upon lead systems integrators; and independent technical and cost assessments. This area of focus is one of the enabling technologies as defined by NASA s Report of the President s Commission on Implementation of United States Space Exploration Policy, published in June 2004.

Source record↗

An Update on the Role of Systems Modeling in the Design and Verification of the James Webb Space Telescope

The James Web Space Telescope (JWST) is a large, infrared-optimized space telescope scheduled for launch in 2014. System-level verification of critical performance requirements will rely on integrated observatory models that predict the wavefront error accurately enough to verify that allocated top-level wavefront error of 150 nm root-mean-squared (rms) through to the wave-front sensor focal plane is met. The assembled models themselves are complex and require the insight of technical experts to assess their ability to meet their objectives. This paper describes the systems engineering and modeling approach used on the JWST through the detailed design phase.

Muheim, Danniella↗

How Can You Support RIDM/CRM/RM Through the Use of PRA

Probabilistic Risk Assessment (PRA) is one of key Risk Informed Decision Making (RIDM) tools. It is a scenario-based methodology aimed at identifying and assessing Safety and Technical Performance risks in complex technological systems.

DoVemto. Tpmu↗