Recursos de colección

NASA Technical Reports Server (NTRS) (686.496 recursos)

The NTRS is a valuable resource for students, educators, researchers, and the public for access to NASA's current and historical technical literature since it was first released in 1994. NTRS provides access to approximately 500K aerospace related citations, 90K full-text online documents, and 111K images and videos. NTRS numbers continues to grow over time as new scientific and technical information (STI) is created or funded by NASA. The type of information found in NTRS include: conference papers, images, journal articles, photos, meeting papers, movies, patents, research reports, and technical videos.

Mostrando recursos 41 - 60 de 321.855

  1. Meteorological Support in Scientific Ballooning

    Schwantes, Chris; Mullenax, Robert
    The weather affects every portion of a scientific balloon mission, from payload integration to launch, float, and impact and recovery. Forecasting for these missions is very specialized and unique in many aspects. CSBF Meteorology incorporates data from NWSNCEP, as well as several international meteorological organizations, and NCAR. This presentation will detail the tools used and specifics on how CSBF Meteorology produces its forecasts.

  2. NASA Super Pressure Balloon

    Fairbrother, Debbie
    NASA is in the process of qualifying the mid-size Super Pressure Balloon (SPB) to provide constant density altitude flight for science investigations at polar and mid-latitudes. The status of the development of the 18.8 million cubic foot SPB capable of carrying one-tone of science to 110,000 feet, will be given. In addition, the operating considerations such as launch sites, flight safety considerations, and recovery will be discussed.

  3. The Frequency of Snowline-Region Planets from Four Years of OGLE-MOA-Wise Second-Generation Microlensing

    Friedmann, M.; Sumi, T.; Poleski, R.; Freeman, M.; Maoz, D.; Kozlowski, S.; Soszynski, I.; Wyrzykowski, L.; Koshimoto, N.; Udalski, A.; Mroz, P.; Abe, F.; Ulaczyk, K.; Inayama, K.; Bennett, D. P.; Bond, I. A.; Bhattacharya, A.; Szymanski, M. K.; Pietrukowicz, P.; Pietrzynski, G.; Kaspi, S.; Barry, R. K.; Itow, Y.; Skowron, J.; Shvartzvald, Y.
    We present a statistical analysis of the first four seasons from a second-generation microlensing survey for extrasolar planets, consisting of near-continuous time coverage of 8 deg to the 2nd power of the Galactic bulge by the Optical Gravitational Lens Experiment (OGLE), Microlensing Observations in Astrophysics (MOA), and Wise microlensing surveys. During this period, 224 microlensing events were observed by all three groups. Over 12% of the events showed a deviation from single-lens microlensing, and for approx. 1/3 of those the anomaly is likely caused by a planetary companion. For each of the 224 events, we have performed numerical ray-tracing simulations...

  4. Scheduling Observations of Celestial Objects for Earth Observing Sensor Calibration

    Xiong, Xiaoxiong; Wilson, Truman
    Radiometric calibration of Earth-observing satellite sensors is critical for tracking on-orbit gain changes through- out the satellite's mission. The Moon, being a stable, well-characterized radiometric target, has been used effectively for tracking the relative gain changes of the reflective solar bands for the Moderate Resolution Imaging Spectroradiometer (MODIS) on board EOS AM-1 (Terra) and PM-1 (Aqua). The Moon is viewed through the MODIS space-view port, and the relative phase of the Moon is restricted to within 0.5 degrees of a chosen target phase to increase the accuracy of the calibration. These geometric restrictions require spacecraft maneuvers in order to bring...

  5. BRDF Characterization and Calibration Inter-Comparison between Terra MODIS, Aqua MODIS, and S-NPP VIIRS

    Angal, Amit; Wu, Aisheng; Chang, Tiejun; Xiong, Xiaoxiong (Jack)
    The inter-comparison of reflective solar bands (RSB) between Terra MODIS, Aqua MODIS, and SNPP VIIRS is very important for assessment of each instrument's calibration and to identify calibration improvements. One of the limitations of using their ground observations for the assessment is a lack of the simultaneous nadir overpasses (SNOs) over selected pseudo-invariant targets. In addition, their measurements over a selected Earth view target have significant difference in solar and view angles, and these differences magnify the effects of Bidirectional Reflectance Distribution Function (BRDF). In this work, an inter-comparison technique using a semi-empirical BRDF model is developed for reflectance correction....

  6. Wallops Arc Second Pointer: WASP Description Subsystems X-Calibur Flight 2017 Test Flight Current Collaborations

    Stuchlik, David William
    WASP is a NASA developed Fine Pointing System adaptable to a variety of Science Instruments. Standardized System with Reusable Parts to Minimize the Cost to Users and NASA. Supports Multiple Science Disciplines and a wide range of Masses and Inertias. Currently Operational and Available for Science Collaborations.

  7. ISRU-Based Robotic Construction Technologies For Lunar And Martian Infrastructures

    Carlson, Anders; Khoshnevis, Behrokh; Thangavelu, Madhu
    Economically viable and reliable building systems and tool sets are being sought, examined and tested for extraterrestrial infrastructure buildup. This project utilizes a unique architecture weaving the robotic building construction technology with designs for assisting rapid buildup of initial operational capability Lunar and Martian bases. The project intends to develop and test methodologies to construct certain crucial infrastructure elements in order to evaluate the merits, limitations and feasibility of adapting and using such technologies for extraterrestrial application. High priority infrastructure elements suggested by our NASA advisors to be considered include landing pads and aprons, roads, blast walls and shade walls,...

  8. AMPR

    Lang, Timothy; Biswas, Sayak
    No abstract available

  9. Coupling of Charged Particles Via Coulombic Interactions: Numerical Simulations and Resultant Kappa-Like Velocity Space Distribution Functions

    Randol, Brent M.; Christian, Eric R.
    A parametric study is performed using the electrostatic simulations of Randol and Christian (2014) in which the number density, n, and initial thermal speed, theta, are varied. The range of parameters covers an extremely broad plasma regime, all the way from the very weak coupling of space plasmas to the very strong coupling of solid plasmas. The first result is that simulations at the same Lambda(sub D), where Lambda(sub D) is the plasma coupling parameter, but at different combinations of n and theta, behave exactly the same. As a function of Lambda(sub D), the form of p(v), the velocity distribution...

  10. Current and Upcoming NASA Hurricane Measurement Missions

    Zavodsky, Brad
    No abstract available

  11. The Scintillation Prediction Observations Research Task Formulation Meeting

    Spann, J.
    No abstract available

  12. Technology Transfer Program Bringing NASA Technology to Earth Welcome to the NASA Technology Transfer Booth

    Harkey, Ann Marie
    No abstract available

  13. Delay Tolerant Networking on NASA's Space Communication and Navigation Testbed

    Eddy, Wesley; Johnson, Sandra
    This presentation covers the status of the implementation of an open source software that implements the specifications developed by the CCSDS Working Group. Interplanetary Overlay Network (ION) is open source software and it implements specifications that have been developed by two international working groups through IETF and CCSDS. ION was implemented on the SCaN Testbed, a testbed located on an external pallet on ISS, by the GRC team. The presentation will cover the architecture of the system, high level implementation details, and issues porting ION to VxWorks.

  14. Black Swift Technologies LLC

    DiNardo, Anne Marie
    Colorado-based Black Swift Technologies (BST) created a small unmanned aircraft system(sUAS) to help NASA get a clearer picture of soil moisture through the Small Business Innovation Research (SBIR) program. Soil moisture is defined in terms of volume of water per unit volume of soil. Using BSTs sUAS, NASA scientists can gather ground truth measurements for a clearer observation by getting closer to the source. This can help rule out misleading results generated by satellite imagery.

  15. Europa Propulsion Valve Seat Material Testing

    Addona, Brad M.
    The Europa mission and spacecraft design presented unique challenges for selection of valve seat materials that met the fluid compatibility requirements, and combined fluid compatibility and high radiation exposure level requirements. The Europa spacecraft pressurization system valves will be exposed to fully saturated propellant vapor for the duration of the mission. The effects of Nitrogen Tetroxide (NTO) and Monomethylhydrazine (MMH) propellant vapors on heritage valve seat materials, such as Vespel SP-1 and Polychlorotrifluoroethylene (PCTFE), were evaluated to determine if an alternate material is required. In liquid system applications, Teflon is the only available compatible valve seat material. Radiation exposure data...

  16. Failure Analysis and Recovery of a 50 MM Highly Elastic Intermetallic NiTi Ball Bearing for an ISS Application

    Howard, S. Adam; DellaCorte, Christopher; Moore, Lewis E., III
    The ISS Distillation Assembly centrifuge is the pathfinder application for 50mm bore, deep-groove ball bearings made from the highly elastic intermetallic material 60NiTi. Superior corrosion and shock resistance are required to withstand the acidic wastewater exposure and heavy spacecraft launch related loads that challenge conventional steel bearings. During early ground testing one bearing unexpectedly and catastrophically failed after operating for only 200 hours of run time. A second bearing running on the same shaft was completely unaffected. A thorough investigation into the root cause of the failure determined that an excessively tight press-fit of the bearing outer race coupled with...

  17. Light Microscopy Module: International Space Station Premier Automated Microscope

    Neff, Tracy A.; Loucks, Brian C.; Otoole, Martin A.; Dombrosky, Deena Marie; Chestney, Louis S.; Stroh, James R.; Pestak, Mark W.; Sicker, Ronald J.; Bodzioney, Christopher; Meyer, William V.; Chiaramonte, Francis P.; Rogers, Christopher Rinehart; Fletcher, William A.; Werner, Christopher; Samrani, Joseph T.; Abbott-Hearn, Amber; Beltram, Alexander; Grant, Nechelle M.; Krauss, Amber S.; Zoldak, John T.; Brown, Daniel F.; Foster, William M.; Smith, Teresa A.; Reinke, Sharon A.; Shumway, Steven; Lorik, Tibor; Dial, William B.; Farinacci, Cody Wayne; Eustace, John G.; Czernec, Richard P.; Wilkinson, Myron A.; Brinkman, John; Storck, Jennifer L.; Motil, Brian J.; Atherton, Arthur; Reid, Ryan James; Plastow, RIchard A.; Lant, Christian T.
    The Light Microscopy Module (LMM) was launched to the International Space Station (ISS) in 2009 and began hardware operations in 2010. It continues to support Physical and Biological scientific research on ISS. During 2016, if all goes as planned, three experiments will be completed: [1] Advanced Colloids Experiments with Heated base-2 (ACE-H2) and [2] Advanced Colloids Experiments with Temperature control (ACE-T1). Preliminary results, along with an overview of present and future LMM capabilities will be presented; this includes details on the planned data imaging processing and storage system, along with the confocal upgrade to the core microscope. [1] a consortium...

  18. Challenges in a Changing Environment: Insights from NASA's Goddard Space Flight Center

    Shinn, Stephen
    No abstract available

  19. Far-UV Spectroscopy of Two Extremely Hot, Helium-Rich White Dwarfs

    Kruk, J. W.; Werner, K.; Rauch, T.
    A large proportion of hot post-asymptotic giant branch stars and white dwarfs (WDs) are hydrogen-deficient. Two distinct evolutionary sequences have been identified. One of them comprises stars of spectral type [WC] and PG1159, and it originates from a late helium-shell flash, creating helium-rich stellar atmospheres with significant admixtures of carbon (up to about 50, mass fraction). The other sequence comprises stars of spectral type O(He) and luminous subdwarf O stars which possibly are descendants of RCrB stars and extreme helium stars. Their carbon abundances are significantly lower (of the order of 1 or less) and it is thought that they...

  20. The Far-Ultraviolet Spectra of "Cool" PG1159 Stars

    Rauch, T.; Kruk, J. W.; Werner, K.
    We present a comprehensive study of Far Ultraviolet Spectroscopic Explorer (FUSE) spectra (912-1190 A) of two members of the PG1159 spectral class, which consists of hydrogen-deficient (pre-) white dwarfs with effective temperatures in the range T(sub eff) = 75000-200000 K. As two representatives of the cooler objects, we have selected PG1707+427 (T(sub eff) = 85000 K) and PG1424+535 (T(sub eff) = 110000 K), complementing a previous study of the hotter prototype PG1159-035 (T(sub eff) = 140000 K). The helium-dominated atmospheres are strongly enriched in carbon and oxygen, therefore, their spectra are dominated by lines from C III-IV and O III-VI,...

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