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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 469 records · Page 26
All sourcesNASA NTRSDOE OSTI
NASA NTRS1991

A contribution with review to the description of mineralization of bone and other calcified tissues in vivo

This manuscript considers certain aspects of mineral deposition in bone and other vertebrate calcifying tissues in order to examine physical, chemical, and biological factors important in the mineralization process. The paper in a discussion format principally presents a new data and the formulation of concepts based on such data as well as a summary of background material as necessary review. Mineralization is found to occur at spatially independent sites throughout the organic extracellular tissue matrices. Matrix vesicles and collagen fibrils each may serve as independent nucleation centers for mineral with vesicle mineralization being local and collagen mineralization dominating the tissues as a whole. Collagen fibril organization is suggested to be such that hole zones are aligned in three dimensions, creating extensive channels for mineral accommodation. Nucleation occurs initially in hole zones and crystal growth leads to the development of plate-like mineral particles whose orientation, disposition, and sizes within fibrils are detailed. Effects of diffusion, crystallinity, and critical nucleation and growth events are described with respect to their influence on mineral deposition in bulk and local regions of tissue matrices.

Review↗
NASA NTRS1949

Lift Force of an Arrow-Shaped Wing

The flow about a conical body of an ideal compressible fluid is considered. Assume that the velocity of the oncoming flow at infinity W is directed along the z-axis. The system of Cartesian coordinates x, y, z with origin at the vertex of the cone O is shown. From the considerations,of the dimensional theory, it may be found that along any ray issuing from O the components of the velocity u, v, W+w along the coordinate axes will maintain a constant value. It is further assumed that the conical body has such shape and disposition relative to the flow that u, v, and w are small in comparison with W.

Gurevich, M. I.↗
NASA NTRS2005

[School-Based UV-B Monitoring Project in Support of EOS-CHEM]

This grant is an extension of Grant NAG5-8929 (Drexel Project Number 230026), resulting from extensions necessary to meet changing science objectives as described in the final report for NAG5-8929, a copy of which is attached. The instrument configuration resulting from NAG54929 has remained basically intact. Cosine response measurements conducted by James Slusser s group at Fort Collins, Colorado, in support of the proposal for Aura ground validation mentioned in the final report for NAG5-8929, indicated that there was significant light leakage to the detector through the sides of the nylon housing. This was easily remedied by machining a removable opaque collar (made from the dark same grey rigid plastic plumbing tubing as the collimating tube) that fits around the detector collar. Also during this grant period, data logging procedures were established for the UV-A instrument, to record irradiance before, during, and after an Aura overflight. This is required in order to compare spatial and temporal variability as required for ground validation of data products derived from the Ozone Monitoring Instrument (OMI). Standalone 12-bit loggers from Onset Computer Corporation (the U12 series), which were not available at the start of these projects, makes possible relatively inexpensive logging for these instruments at a usable resolution. configuration and disposition of these instruments, including the final version of a GLOBE protocol for using the instruments, currently depend on action taken on the Aura ground validation proposal submitted in 2004. A copy of that proposal is attached.

Brooks, David R.↗
NASA NTRS2004

Liquid flow and distribution in unsaturated porous media

Flow and transport in permeable or porous media and microchannels occurs in a variety of situations in micro- and reduced-gravity environments, many of them associated with environmental control and life support systems. While the role of gravity is limited, due to the typically small size scales associated permeable media, gravity, at the very least, affects the overall disposition of fluid in a macroscopic system. This presentation will discuss examples where the absence of gravity affects flow and phase distribution in selected examples of unsaturated flow and transport of heat and mass in porous media and microchannels that are pertinent to spacecraft systems.

Alexander, J. Iwan↗
NASA NTRS2006

Boundary Layer Transition Results From STS-114

The tool for predicting the onset of boundary layer transition from damage to and/or repair of the thermal protection system developed in support of Shuttle Return to Flight is compared to the STS-114 flight results. The Boundary Layer Transition (BLT) Tool is part of a suite of tools that analyze the aerothermodynamic environment of the local thermal protection system to allow informed disposition of damage for making recommendations to fly as is or to repair. Using mission specific trajectory information and details of each damage site or repair, the expected time of transition onset is predicted to help determine the proper aerothermodynamic environment to use in the subsequent thermal and stress analysis of the local structure. The boundary layer transition criteria utilized for the tool was developed from ground-based measurements to account for the effect of both protuberances and cavities and has been calibrated against flight data. Computed local boundary layer edge conditions provided the means to correlate the experimental results and then to extrapolate to flight. During STS-114, the BLT Tool was utilized and was part of the decision making process to perform an extravehicular activity to remove the large gap fillers. The role of the BLT Tool during this mission, along with the supporting information that was acquired for the on-orbit analysis, is reviewed. Once the large gap fillers were removed, all remaining damage sites were cleared for reentry as is. Post-flight analysis of the transition onset time revealed excellent agreement with BLT Tool predictions.

Berry, Scott A.↗
NASA NTRS2006

Overview of Boundary Layer Transition Research in Support of Orbiter Return To Flight

A predictive tool for estimating the onset of boundary layer transition resulting from damage to and/or repair of the thermal protection system was developed in support of Shuttle Return to Flight. The boundary layer transition tool is part of a suite of tools that analyze the aerothermodynamic environment to the local thermal protection system to allow informed disposition of damage for making recommendations to fly as is or to repair. Using mission specific trajectory information and details of each damage site or repair, the expected time (and thus Mach number) at transition onset is predicted to help define the aerothermodynamic environment to use in the subsequent thermal and stress analysis of the local thermal protection system and structure. The boundary layer transition criteria utilized for the tool was developed from ground-based measurements to account for the effect of both protuberances and cavities and has been calibrated against select flight data. Computed local boundary layer edge conditions were used to correlate the results, specifically the momentum thickness Reynolds number over the edge Mach number and the boundary layer thickness. For the initial Return to Flight mission, STS-114, empirical curve coefficients of 27, 100, and 900 were selected to predict transition onset for protuberances based on height, and cavities based on depth and length, respectively.

Berry, Scott A.↗
NASA NTRS2006

Imaging Thermal He(+) from the Lunar Surface

Extreme ultraviolet observations of He(+) ions by the EUV instrument on the IMAGE spacecraft have dramatically improved our ability to observe plasmasphere dynamics in the inner magnetosphere. These primarily high latitude observations have revealed the phenomenology of thermal density structures and continue to lead us toward a more complete understanding of inner magnetospheric electric fields and plasmaspheric refilling. Recent analyses have brought attention to the disposition of thermal plasma eroded from the plasmasphere and convected into the outer dayside magnetosphere. The extent to which this plasma is lost into the solar wind or recirculated across the polar cap or through the magnetospheric flanks is an important outstanding question that relates to the influence this plasma has on space weather processes in Geospace. A concept for implementation of enhanced EUV observations from the lunar surface to resolve questions about the global circulation of He(+) plasma in the magnetosphere will be presented. The instrument and science package subsystem elements, including anticipated component capabilities and limitations will be discussed. Attention will also be given to the potential impact of dust contamination.

Gallagher, D. L.↗
NASA NTRS1991

Two-stage earth-to-orbit transport with translating oblique wings for booster recovery

A two-stage earth-to-orbit transport includes an orbiter vehicle and a pair of boosters, each having a depolyable oblique wing located along a longitudinal axis of the booster. The wing is deployed in an oblique disposition in supersonic and hypersonic speeds, and disposed at 90.degree. for subsonic speeds encountered during entry. The oblique wing is driven axially and rotated by means of a turret mounted on rails.

MacConochie, Ian O.↗
NASA NTRS2008

Developing a NASA Lead-Free Policy for Electronics - Lessons Learned

The National Aeronautics and Space Administration (NASA) is not required by United States or international law to use lead-free (Pb-free) electronic systems but international pressure in the world market is making it increasingly important that NASA have a Pb-free policy. In fact, given the international nature of the electronics market, all organizations need a Pb-free policy. This paper describes the factors which must be taken into account in formulating the policy, the tools to aid in structuring the policy and the unanticipated and difficult challenges encountered. NASA is participating in a number of forums and teams trying to develop effective approaches to controlling Pb-free adoption in high reliability systems. The activities and status of the work being done by these teams will be described. NASA also continues to gather information on metal whiskers, particularly tin based, and some recent examples will be shared. The current lack of a policy is resulting in "surprises" and the need to disposition undesirable conditions on a case-by-case basis. This is inefficient, costly and can result in sub-optimum outcomes.

Sampson, Michael J.↗
NASA NTRS2009

Prototype Interoperability Document between NASA-JSC and DLR-GSOC Describing the CCSDS SM and C Mission Operations Prototype

The purpose of the PROTOTYPE INTEROPERABILITY DOCUMENT is to document the design and interfaces for the service providers and consumers of a Mission Operations prototype between JSC-OTF and DLR-GSOC. The primary goal is to test the interoperability sections of the CCSDS Spacecraft Monitor & Control (SM&C) Mission Operations (MO) specifications between both control centers. An additional goal is to provide feedback to the Spacecraft Monitor and Control (SM&C) working group through the Review Item Disposition (RID) process. This Prototype is considered a proof of concept and should increase the knowledge base of the CCSDS SM&C Mission Operations standards. No operational capabilities will be provided. The CCSDS Mission Operations (MO) initiative was previously called Spacecraft Monitor and Control (SM&C). The specifications have been renamed to better reflect the scope and overall objectives. The working group retains the name Spacecraft Monitor and Control working group and is under the Mission Operations and Information Services Area (MOIMS) of CCSDS. This document will refer to the specifications as SM&C Mission Operations, Mission Operations or just MO.

Lucord, Steve A.↗
NASA NTRS2009

ANSI/AIAA S-081A, Pressure Vessel Standards Implementation Guidelines

The stress rupture specification for Composite Overwrapped Pressure Vessels (COPV) is discussed. The composite shell of the COPV shall be designed to meet the design life considering the time it is under sustained load. A Mechcanical Damage Control Plan (MDCP) shall be created and implemented that assures the COPV will not fail due to mechanical damage due to manufacturing, testing, shipping, installation, or flight. Proven processes and procedures for fabrication and repair shall be used to preclude damage or material degradation during material processing, manufacturing operations, and refurbushment.Selected NDI techniques for the liner and/or boss(es) shall be performed before overwrapping with composite. When visual inspection reveals mechanical damage or defects exceeding manufacturing specification levels (and standard repair procedures), the damaged COPV shall be submitted to a material review board (MRB) for disposition. Every COPV shall be subjected to visual and other non-destructive inspection (NDI), per the inspection plan.

Greene, Nathanael J.↗
NASA NTRS2009

Lessons Learned for Cx PRACA. Constellation Program Problem Reporting, Analysis and Corrective Action Process and System

This slide presentation reviews the Constellation Program Problem Reporting, Analysis and Corrective Action Process and System (Cx PRACA). The goal of the Cx PRACA is to incorporate Lessons learned from the Shuttle, ISS, and Orbiter programs by creating a single tool for managing the PRACA process, that clearly defines the scope of PRACA applicability and what must be reported, and defines the ownership and responsibility for managing the PRACA process including disposition approval authority. CxP PRACA is a process, supported by a single information gathering data module which will be integrated with a single CxP Information System, providing interoperability, import and export capability making the CxP PRACA a more effective and user friendly technical and management tool.

Kelle, Pido I.↗
NASA NTRS2009

Developing a Gap Taxonomy to Address Crew Health Risks in NASA's Human Research Program

The mission of NASA's Human Research Program (HRP) is to understand and reduce the risk to crew health and performance in exploration missions. The HRP addresses 27 specific risks by identifying and then filling gaps in understanding the risks and in the ability to disposition the risks. The primary bases for identifying gaps have been past experience and requirements definition. This approach has been very effective in identifying some important, relevant gaps, but may be inadequate for identifying gaps outside the past experience base. We are exploring the use of a gap taxonomy as a comprehensive, underlying conceptual framework that allows a more systematic identification of gaps. The taxonomy is based on these stages in medical care: prediction, prevention, detection/diagnosis, treatment, monitoring, rehabilitation, and lifetime surveillance. This gap taxonomy approach identifies new gaps in HRP health risks. Many of the new gaps suggest risk reduction approaches that are more cost effective than present approaches. A major benefit of the gap taxonomy approach is to identify new, economical approaches that reduce the likelihood and/or consequence of a risk.

Kundrot, Craig E.↗
NASA NTRS2010

Orbiter Boundary Layer Transition Prediction Tool Enhancements

Updates to an analytic tool developed for Shuttle support to predict the onset of boundary layer transition resulting from thermal protection system damage or repair are presented. The boundary layer transition tool is part of a suite of tools that analyze the local aerothermodynamic environment to enable informed disposition of damage for making recommendations to fly as is or to repair. Using mission specific trajectory information and details of each d agmea site or repair, the expected time (and thus Mach number) of transition onset is predicted to help define proper environments for use in subsequent thermal and stress analysis of the thermal protection system and structure. The boundary layer transition criteria utilized within the tool were updated based on new local boundary layer properties obtained from high fidelity computational solutions. Also, new ground-based measurements were obtained to allow for a wider parametric variation with both protuberances and cavities and then the resulting correlations were calibrated against updated flight data. The end result is to provide correlations that allow increased confidence with the resulting transition predictions. Recently, a new approach was adopted to remove conservatism in terms of sustained turbulence along the wing leading edge. Finally, some of the newer flight data are also discussed in terms of how these results reflect back on the updated correlations.

Berry, Scott A.↗
NASA NTRS2010

Metal Vapor Arcing Risk Assessment Tool

The Tin Whisker Metal Vapor Arcing Risk Assessment Tool has been designed to evaluate the risk of metal vapor arcing and to help facilitate a decision toward a researched risk disposition. Users can evaluate a system without having to open up the hardware. This process allows for investigating components at risk rather than spending time and money analyzing every component. The tool points to a risk level and provides direction for appropriate action and documentation.

Hill, Monika C.↗
NASA NTRS2010

Investment in Open Innovation Service Providers: NASA's Innovative Strategy for Solving Space Exploration Challenges

In an effort to expand routes for open communication and create additional opportunities for public involvement with NASA, Open Innovation Service Provider (OISP) methodologies have been incorporated as a tool in NASA's problem solving strategy. NASA engaged the services of two OISP providers, InnoCentive and Yet2.com, to test this novel approach and its feasibility in solving NASA s space flight challenges. The OISPs were chosen based on multiple factors including: network size and knowledge area span, established process, methodology, experience base, and cost. InnoCentive and Yet2.com each met the desired criteria; however each company s approach to Open Innovation is distinctly different. InnoCentive focuses on posting individual challenges to an established web-based network of approximately 200,000 solvers; viable solutions are sought and granted a financial award if found. Based on a specific technological need, Yet2.com acts as a talent scout providing a broad external network of experts as potential collaborators to NASA. A relationship can be established with these contacts to develop technologies and/or maintained as an established network of future collaborators. The results from the first phase of the pilot study have shown great promise for long term efficacy of utilizing the OISP methodologies. Solution proposals have been received for the challenges posted on InnoCentive and are currently under review for final disposition. In addition, Yet2.com has identified new external partners for NASA and we are in the process of understanding and acting upon these new opportunities. Compared to NASA's traditional routes for external problem solving, the OISP methodologies offered NASA a substantial savings in terms of time and resources invested. In addition, these strategies will help NASA extend beyond its current borders to build an ever expanding network of experts and global solvers.

Fogarty, Jennifer A.↗
NASA NTRS2010

Automated Computer Access Request System

The Automated Computer Access Request (AutoCAR) system is a Web-based account provisioning application that replaces the time-consuming paper-based computer-access request process at Johnson Space Center (JSC). Auto- CAR combines rules-based and role-based functionality in one application to provide a centralized system that is easily and widely accessible. The system features a work-flow engine that facilitates request routing, a user registration directory containing contact information and user metadata, an access request submission and tracking process, and a system administrator account management component. This provides full, end-to-end disposition approval chain accountability from the moment a request is submitted. By blending both rules-based and rolebased functionality, AutoCAR has the flexibility to route requests based on a user s nationality, JSC affiliation status, and other export-control requirements, while ensuring a user s request is addressed by either a primary or backup approver. All user accounts that are tracked in AutoCAR are recorded and mapped to the native operating system schema on the target platform where user accounts reside. This allows for future extensibility for supporting creation, deletion, and account management directly on the target platforms by way of AutoCAR. The system s directory-based lookup and day-today change analysis of directory information determines personnel moves, deletions, and additions, and automatically notifies a user via e-mail to revalidate his/her account access as a result of such changes. AutoCAR is a Microsoft classic active server page (ASP) application hosted on a Microsoft Internet Information Server (IIS).

Snook, Bryan E.↗