Recursos de colección

NASA Technical Reports Server (NTRS) (686.326 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 1 - 20 de 321.783

  1. Demonstration of Numerical Equivalence of Ensemble and Spectral Averaging in Electromagnetic Scattering by Random Particulate Media

    Dlugach, Janna M.; Zakharova, Nadezhda T.; Mishchenko, Michael I.
    The numerically exact superposition T-matrix method is used to model far-field electromagnetic scattering by two types of particulate object. Object 1 is a fixed configuration which consists of N identical spherical particles (with N 200 or 400) quasi-randomly populating a spherical volume V having a median size parameter of 50. Object 2 is a true discrete random medium (DRM) comprising the same number N of particles randomly moving throughout V. The median particle size parameter is fixed at 4. We show that if Object 1 is illuminated by a quasi-monochromatic parallel beam then it generates a typical speckle pattern having...

  2. Microbial Monitoring from the Frontlines to Space: A Successful Validation of a Department of Defense (DoD) Funded Small Business Innovation Research (SBIR) Technology on Board the International Space Station (ISS)

    Roman, Monsi; Pollack, Lawrence; Ott, Mark; Oubre, Cherie; Khodadad, Christina; Castro, Victoria
    The RAZOR EX (Registered Trademark) PCR unit was initially developed by the DoD as part of an SBIR project to detect and identify biothreats during field deployment. The system was evaluated by NASA as a commercial technology for future microbial monitoring requirements and has been successfully demonstrated in microgravity on-board the International Space Station.

  3. TEM Analysis of Diffusion-Bonded Silicon Carbide Ceramics Joined Using Metallic Interlayers

    Tsuda, H.; Mori, S.; Hasegawa, Y; Halbig, M. C.; Ozaki, T.; Singh, M.; Asthana, R.
    Silicon Carbide (SiC) is a promising material for thermostructural applications due to its excellent high-temperature mechanical properties, oxidation resistance, and thermal stability. However, joining and integration technologies are indispensable for this material in order to fabricate large size and complex shape components with desired functionalities. Although diffusion bonding techniques using metallic interlayers have been commonly utilized to bond various SiC ceramics, detailed microstructural observation by Transmission Electron Microscopy (TEM) of the bonded area has not been carried out due to difficulty in preparing TEM samples. In this study, we tried to prepare TEM samples from joints of diffusion bonded SiC...

  4. Sensitivity of the Asteroid Redirect Robotic Mission (ARRM) to Launch Date and Asteroid Stay Time

    Burke, Laura M.; Vavrina, Matthew A.; Mcguire, Melissa L.; Strange, Nathan J.; Qu, Min; McCarty, Steven L.; Shen, Haijun
    National Aeronautics and Space Administrations (NASAs) proposed Asteroid Redirect Mission (ARM) is being designed to robotically capture and then redirect an asteroidal boulder into a stable orbit in the vicinity of the moon, where astronauts would be able to visit and study it. The current reference trajectory for the robotic portion, ARRM, assumes a launch on a Delta-IV H in the end of the calendar year 2021, with a return for astronaut operations in cislunar space in 2026. The current baseline design allocates 245 days of stay time at the asteroid for operations and boulder collection. This paper outlines analysis...

  5. Creep, Fatigue and Environmental Interactions and Their Effect on Crack Growth in Superalloys

    Ghosn, L. J.; Telesman, J.; Smith, T.; Gabb, T. P.
    Complex interactions of creep/fatigue/environment control dwell fatigue crack growth (DFCG) in superalloys. Crack tip stress relaxation during dwells significantly changes the crack driving force and influence DFCG. Linear Elastic Fracture Mechanics, Kmax, parameter unsuitable for correlating DFCG behavior due to extensive visco-plastic deformation. Magnitude of remaining crack tip axial stresses controls DFCG resistance due to the brittle-intergranular nature of the crack growth process. Proposed a new empirical parameter, Ksrf, which incorporates visco-plastic evolution of the magnitude of remaining crack tip stresses. Previous work performed at 704C, extend the work to 760C.

  6. Holographic Rovers: Augmented Reality and the Microsoft HoloLens

    Toler, Laura
    Augmented Reality is an emerging field in technology, and encompasses Head Mounted Displays, smartphone apps, and even projected images. HMDs include the Meta 2, Magic Leap, Avegant Light Field, and the Microsoft HoloLens, which is evaluated specifically. The Microsoft HoloLens is designed to be used as an AR personal computer, and is being optimized with that goal in mind. Microsoft allied with the Unity3D game engine to create an SDK for interested application developers that can be used in the Unity environment.

  7. Electronics and Software Engineer for Robotics Project Intern

    Teijeiro, Antonio
    I was assigned to mentor high school students for the 2017 First Robotics Competition. Using a team based approach, I worked with the students to program the robot and applied my electrical background to build the robot from start to finish. I worked with students who had an interest in electrical engineering to teach them about voltage, current, pulse width modulation, solenoids, electromagnets, relays, DC motors, DC motor controllers, crimping and soldering electrical components, Java programming, and robotic simulation. For the simulation, we worked together to generate graphics files, write simulator description format code, operate Linux, and operate SOLIDWORKS. Upon...

  8. Launch Control Network Engineer

    Medeiros, Samantha
    The Spaceport Command and Control System (SCCS) is being built at the Kennedy Space Center in order to successfully launch NASAs revolutionary vehicle that allows humans to explore further into space than ever before. During my internship, I worked with the Network, Firewall, and Hardware teams that are all contributing to the huge SCCS network project effort. I learned the SCCS network design and the several concepts that are running in the background. I also updated and designed documentation for physical networks that are part of SCCS. This includes being able to assist and build physical installations as well as...

  9. Oceanic convective systems: ASCAT and NEXRAD retrieval analysis

    Priftis, Georgios; Lang, Timothy J.; Chronis, Themis
    No abstract available

  10. Eclipse 2017: Partnering with NASA MSFC to Inspire Students

    Fry, Craig "Ghee"; Krause, Linda; Gallagher, Dennis; Adams, Mitzi
    NASA's Marshall Space Flight Center (MSFC) is partnering with the U.S. Space and Rocket Center (USSRC), and Austin Peay State University (APSU) to engage citizen scientists, engineers, and students in science investigations during the 2017 American Solar Eclipse. Investigations will support the Citizen Continental America Telescopic Eclipse (CATE), Ham Radio Science Citizen Investigation(HamSCI), and Interactive NASA Space Physics Ionosphere Radio Experiments (INSPIRE). All planned activities will engage Space Campers and local high school students in the application of the scientific method as they seek to explore a wide range of observations during the eclipse. Where planned experiments touch on current...

  11. One Giant Leap to Protect All Mankind: An Overview of the Lunar Receiving Laborator

    Hayes, Judith; Dooling, Jackson
    No abstract available

  12. Abstract - Belbas, Nicholas (EC2)

    Belbas, Nicholas
    Originally, I was brought into the Design and Analysis Branch in the Crew and Thermal Systems to work on administrative tasks like archiving and scheduling. However, I ended up splitting my time between secretarial tasks and a technical project. My technical project was originally meant to be a wireless sensor package for the 20ft Spacecraft Thermal Vacuum Chamber in the B7 High Bay. I would be using a miniature wifi development board and a temperature/humidity sensor along with custom 3D modeling to accomplish this. However, after some discussion with my technical mentor, the plan was changed to a mobile autonomous...

  13. Presentation to New Albany High School

    Richey, Austin
    No abstract available

  14. Beyond DNA Sequencing in Space: Current and Future Omics Capabilities of the Biomolecule Sequencer Payload

    Wallace, Sarah
    Why do we need a DNA sequencer to support the human exploration of space? (A) Operational environmental monitoring; (1) Identification of contaminating microbes, (2) Infectious disease diagnosis, (3) Reduce down mass (sample return for environmental monitoring, crew health, etc.). (B) Research; (1) Human, (2) Animal, (3) Microbes/Cell lines, (4) Plant. (C) Med Ops; (1) Response to countermeasures, (2) Radiation, (3) Real-time analysis can influence medical intervention. (C) Support astrobiology science investigations; (1) Technology superiorly suited to in situ nucleic acid-based life detection, (2) Functional testing for integration into robotics for extraplanetary exploration mission.

  15. Results of the Alternative Water Processor Test, A Novel Technology for Exploration Wastewater Remediation

    Meyer, Caitlin; Vega, Leticia
    Biologically-based water recovery systems are a regenerative, low energy alternative to physiochemical processes to reclaim water from wastewater. This paper summarizes the results of the Alternative Water Processor (AWP) test conducted over one year. The AWP recovered 90% of water from four crewmembers using (4) membrane aerated bioreactors (MABRs) to remove carbon and nitrogen from an exploration mission wastewater, including urine, hygiene, laundry and humidity condensate. Downstream, a coupled forward and reverse osmosis system removed large organics and inorganic salts from the biological system effluent. The system exceeded the overall objectives of the test by recovering 90% of the influent...

  16. Small Particle Impact Damage on Different Glass Substrates

    Waxman, R.; Gray, P.; Guven, I.
    Impact experiments using sand particles were performed on four distinct glass substrates. The sand particles were characterized using the X-Ray micro-CT technique; 3-D reconstruction of the particles was followed by further size and shape analyses. High-speed video footage from impact tests was used to calculate the incoming and rebound velocities of the individual sand impact events, as well as particle volume. Further, video analysis was used in conjunction with optical and scanning electron microscopy to relate the incoming velocity and shape of the particles to subsequent fractures, including both radial and lateral cracks. Analysis was performed using peridynamic simulations.

  17. Water Hammer Simulations of Monomethylhydrazine Propellant

    Ramachandran, N.; Burkhardt, Zachary; Majumdar, A.
    Fluid Transient analysis is important for the design of spacecraft propulsion system to ensure structural stability of the system in the event of sudden closing or opening of the valve. Generalized Fluid System Simulation Program (GFSSP), a general purpose flow network code developed at NASA/MSFC is capable of simulating pressure surge due to sudden opening or closing of valve when thermodynamic properties of real fluid are available for the entire range of simulation. Specifically GFSSP needs an accurate representation of pressure density relationship in order to predict pressure surge during a fluid transient. Unfortunately, the available thermodynamic property programs such...

  18. In-Space and Extra-Terrestrial Plume Environments

    West, Jeff; Liever, Peter
    No abstract available

  19. A Comparison of Results from NASA's Meteoroid Engineering Model to the Long Duration Exposure Facility Cratering Record

    Moorhead, Althea; Cooke, William J.; Ehlert, Steven
    No abstract available

  20. Characterizing the 2016 Perseid Meteor Shower Outburst

    Stober, G.; Molau, S.; Blaauw, R. C.; Moser, D. E.; Schult, C.
    The Perseid meteor shower has been observed for millennia and is known for its visually spectacular meteors and occasional outbursts. Normal activity displays Zenithal Hourly Rates (ZHRs) of approximately100. The Perseids were expected to outburst in 2016, primarily due to particles released during the 1862 and 1479 revolutions of parent Comet Swift-Tuttle. NASA's Meteoroid Environment Office predicted the timing, strength and duration of the outburst for spacecraft risk using the MSFC Meteoroid Stream Model [1]. A double peak was predicted, with an outburst displaying a ZHR of 210 +/- 50 at 00:30 UTC Aug 12 (139.5deg Solar Longitude), and a...

Aviso de cookies: Usamos cookies propias y de terceros para mejorar nuestros servicios, para análisis estadístico y para mostrarle publicidad. Si continua navegando consideramos que acepta su uso en los términos establecidos en la Política de cookies.