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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 1,045 records · Page 58
All sourcesNASA NTRSDOE OSTI
NASA NTRS1950

Ditching Investigation of a 1/24-Scale Model of the Boeing B-47 Airplane

An investigation of a 1/24-scale dynamically similar model of the Boeing B-47 airplane was made to determine the ditching characteristics and proper ditching technique for the airplane. Various conditions of damage, landing attitude, flap setting, and speed were investigated. The behavior of the model was determined from visual observations, motion-picture records, and time-history deceleration records. The results of the investigation are presented in table form, photographs, and curves. The airplane should be ditched at the lowest speed and highest attitude consistent with adequate control; the flaps should be full down. The airplane will probably make a deep but fairly smooth run. The fuselage bottom will be damaged and partially filled with water; consequently, crew members should be assigned ditching stations near an exit in the upper or forward part of the fuselage. The nacelles may be expected to be torn away from the wing. In calm water the maximum decelerations will be about 3g and the landing run will be about 6 fuselage lengths.

Fisher, Lloyd J.↗
NASA NTRS1949

Supplementary Ditching Investigation of a 1/18-Scale Model of the North American B-45 Airplane

A supplementary investigation of a 1/18-scale dynamically similar model of the North American B-45 airplane was made in calm water to observe the ditching behavior and to determine the effect of further conditions of simulated damage. The behavior of the model was determined from motion-picture records, time-history deceleration records, and visual observations. It was concluded that, during a ditching, the nose-wheel doors, bomb-bay doors, under surface of the aft fuselage and lower part of the bomb-bay aft bulkhead will be torn away. When such damage occurs, the diving found in the previous tests will not occur and the airplane will porpoise during the first third of the landing run and then run smoothly. Because of the extensive damage which occurs, the fuselage aft of the pilots' compartment will fill with water very rapidly and is, therefore, an undesirable ditching station. No change in the previously recommended ditching attitude and flap setting (6 deg attitude, flaps down) is indicated by these supplementary tests.

Fisher, Lloyd J.↗
NASA NTRS1995

B-ISBN Onboard Processing Fast Packet Switch Developed

Future satellite communications applications will require a packet-switched onboard satellite processing system to route packets at very high speeds from uplink beams to different downlink beams. The rapid emergence of point-to-multipoint services, and the important role of satellites in a national and global information infrastructure, makes the multicast function essential to a fast packet switch (FPS). NASA Lewis Research Center's Digital System Technology Branch has been studying possible architectures for high-speed onboard-processing satellite systems. As part of this research, COMSAT Laboratories developed a broadband integrated services digital network (B-ISDN) fast packet switch for Lewis that was delivered on December 1994. The fast packet switch consists of eight inputs and eight outputs that can receive and transmit data, respectively, at a rate of 155 Mbps. The switch features multiple priorities (three) and multiple-size (three) satellite virtual cells that are similar to ATM cells in length (52 bytes). In addition, the fast packet switch features a congestion-control algorithm that allows users to set different thresholds for individual destination ports, thus throttling back the traffic from the transmitting port.

Source record↗
NASA NTRS2005

Using Beta Cen to Probe the Photosphere-Wind Connection to B Stars

The goal of the project was to probe the connection between the photospheric pulsations and the X-ray production in the stellar winds of B stars. The B1 III star Beta Centauri is a Beta Cephei variable with a high X-ray count rate, and was observed by XMM. Analysis of XMM X-ray spectra showed characteristic plasma temperatures of 0.1, 0.2 and 0.6 keV. Analysis of He-like forbidden-to-intercombination lines was performed to determine the dominant locations of the X-ray emission. At Prism, work focused on developing and upgrading spectral models to calculate forbidden-to-intercombination line ratios using more detailed atomic models than the simple models typically used in the analysis of X-ray spectral lines, thereby allowing us to assess the effects of a broader variety of populating and depopulating channels for energy levels contributing to the observed X-ray line emission. Based on Ne IX lines, the source location was determined to be no farther than 4 stellar radii. Examination of the time variability of the XMM data for Beta Cen showed no significant correlation with the known optical pulsation period for the star, and also did not find any significant periods of variation at X-ray wavelengths.

MacFarlane, Joseph J.↗
NASA NTRS2005

STS-114: Discovery TCDT Flight Crew Test Media Event at Pad 39-B

The STS-114 Space Shuttle Discovery Terminal Countdown Demonstration Test (TCDT) flight crew is shown at Pad 39-B. Eileen Collins, Commander introduces the astronauts. Andrew Thomas, mission specialist talks about his primary responsibility of performing boom inspections, Wendy Lawrence, Mission Specialist 4 (MS4) describes her role as the robotic arm operator supporting Extravehicular Activities (EVA), Stephen Robinson, Mission Specialist 3 (MS3) talks about his role as flight engineer, Charlie Camarda, Mission Specialist 5 (MS5) says that his duties are to perform boom operations, transfer operations from the space shuttle to the International Space Station and spacecraft rendezvous. Soichi Noguchi, Mission Specialist 1 (MS1) from JAXA, introduces himself as Extravehicular Activity 1 (EVA1), and Jim Kelley, Pilot will operate the robotic arm and perform pilot duties. Questions from the news media about the safety of the external tank, going to the International Space Station and returning, EVA training, and thoughts about the Space Shuttle Columbia crew are answered.

Source record↗
NASA NTRS1967

Pre-Launch Mission Operation Report: San Marco B

On or about April 23, 1967, the Italian Space Commission of the National Council of Research (I.S.C.) will launch the San Marco B satellite from the I.S.C. launch range located off the coast of Kenya, Africa. It is planned that the spacecraft will be placed into an equatorial orbit by the four-stage Scout vehicle, number S-153. The San Marco program is a joint NASA-I.S.C. effort being carried out in accordance with a Memorandum of Understanding dated 31 May 1962. Under this agreement the I .S.C. has established the equatorial launch site, has designed and fabricated the satellite, and will conduct the launch operation. The NASA has provided the Scout launch vehicle, training for I.S.C. personnel, technical consultation,and tracking and data acquisition for the operational satellite.

Source record↗
NASA NTRS2006

Overview of the Solar-B Mission

The Solar-B mission is a collaboration between the Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, the National Aeronautics and Space Administration (NASA) and the Particle Physics and Astronomy Research Council (PPARC) of the United Kingdom and the European Space Agency. The principal scientific goals of the mission are to understand the processes of magnetic field generation, transport and ultimate dissipation of solar magnetic fields and how the release of magnetic energy is responsible for the heating and structuring of the chromosphere and corona. The scientific payload consists of three instruments: the Solar Optical Telescope that consists of the Optical Telescope Assembly and the Focal Plane Package (FPP), the X-ray Telescope and the EUV Imaging Spectrometer Each instrument is a result of the combined talents of all the members of the international team and their design and performance is described in separate papers in this session. The instruments are designed to work together as an 'observatory' simultaneously studying the target, at which the spacecraft is pointed, at different levels in the atmosphere. The spacecraft is scheduled for launch in September 2006 from the Uchinoura Space Center into a 600 km circular, sun-synchronous, polar orbit with a nominal elevation of 97.9 degrees. The orbit provides at least two morning and two evening contacts in Japan. Morning contacts are used for recovering quick look science data and the evening contacts for uploading commands. In addition ESA will provide 15 contacts per day from the Norwegian high latitude (78deg 14' N) ground station at Svalbard. The data downloads are transmitted to the ISAS Sirius database. They will be reformatted into FITS files and archived as Level 0 data on the ISAS DARTS system and made available to the scientific community. Scientific operations will be conducted from the IS AS facility located in Sagamihara, Japan. They are separated into planning, implementation and archiving. The planning process involves monthly, weekly and daily planning meetings. All scientific data will be made available after the first six month approximately one week after its collection.

Davis, John M.↗
NASA NTRS1994

Observation of CH A->X, Cn B->X, and NH A->X Emissions in Gas-phase Collisions of Fast O ((sup 3)P) Atoms with Hydrazines

Optical emissions in single-collision reactions of fast (20 eV laboratory translational energy) O((sup 3)P) atoms with hydrazine, methylhydrazine, and 1,1-dimethylhydrazine have been measured in a crossed-beams geometry. The emissions were observed in the wavelength range 325-440 nm, and were identified as the CH (A 2(sub A))-->X(sup 2)pi(sub r), (for methylhydrazine), CN (B sup 2) Sigma(sup +) --> X(sup 2) Sigma(sup +) (for methylhydrazine)and NH(A(sup 3)pi --> X(sup3 Sigma) transitions (for all three hydraz vibration-rotation bands were fit to a synthetic spectrum of CH, CN and NH with given vibrational and rotational temperatures.

chemical reactions↗
NASA NTRS2007

Documentation and Control of Flow Separation on a Low Pressure Turbine Linear Cascade of Pak-B Blades Using Plasma Actuators

This work involved the documentation and control of flow separation that occurs over low pressure turbine (LPT) blades at low Reynolds numbers. A specially constructed linear cascade was utilized to study the flow field over a generic LPT cascade consisting of Pratt & Whitney "Pak-B" shaped blades. Flow visualization, surface pressure measurements, LDV measurements, and hot-wire anemometry were conducted to examine the flow fields with and without separation control. Experimental conditions were chosen to give a range of chord Reynolds numbers (based on axial chord and inlet velocity) from 10,000 to 100,000, and a range of freestream turbulence intensities from u'/U(infinity) = 0.08 to 2.85 percent. The blade pressure distributions were measured and used to identify the region of separation that depends on Reynolds number and the turbulence intensity. Separation control was performed using dielectric barrier discharge (DBD) plasma actuators. Both steady and unsteady actuation were implemented and found to work well. The comparison between the steady and unsteady actuators showed that the unsteady actuators worked better than the steady ones. For the steady actuators, it was found that the separated region is significantly reduced. For the unsteady actuators, where the signal was pulsed, the separation was eliminated. The total pressure losses (a low Reynolds number) was reduced by approximately a factor of two. It was also found that lowest plasma duty cycle (10 percent in this work) was as effective as the highest plasma duty cycle (50 percent in this work). The mechanisms of the steady and unsteady plasma actuators were studied. It was suggested by the experimental results that the mechanism for the steady actuators is turbulence tripping, while the mechanism for the unsteady actuators is to generate a train of spanwise structures that promote mixing.

Corke, Thomas c.↗
NASA NTRS2006

The Solar-B Mission: First Light, Future Plans and Community Participation

The Solar-B spacecraft was launched from the Uchinoura Space Center into a circular, sun-synchronous, polar orbit by the Japanese Aerospace Exploration Agency in late September 2006. The spacecraft carries thee scientific instruments designed to follow the flow of magnetic energy from the photosphere to the corona to improve our understanding of both steady state and transient energy release. This goal will be achieved through coordinated observations of three highly advanced solar telescopes developed cooperatively by teams from Japan, the United States and the United Kingdom. The three telescopes are a 0.5m aperture, diffraction limited, solar optical telescope (SOT), an X-ray telescope (XRT) designed for full sun imaging with 1.0 arcsec pixels and an EUV imaging spectrometer (EIS) with an order of magnitude improvement in sensitivity over past instruments. The SOT focal plane contains three instruments, a spectropolarimeter for measuring vector magnetic fields, a broadband filter imager for recording images of the photosphere and chromosphere at the highest resolution the telescope is capable of, and a narrow band filter imager that will record Doppler grams and vector magnetograms. The XRT has broad temperature coverage and a spatial a resolution three times as high as Yohkoh. EIS covers a broad range of transition region and coronal temperatures in two spectral bands. Both XRT and EIS have 2 arcsec spatial resolution (1 arcsec pixels). Instrument first light occurred after five weeks on orbit to allow for out gassing and the opening of the telescopes doors. The initial observation sequences are designed to test the functionality of the different operating modes and for calibration. After this commissioning phase is complete a series of observations are planned to demonstrate the ability of the instruments to meet NASA's mission minimum success criteria. Data is downloaded every orbit to the Norwegian high latitude ground station at Svalbard. The data are transmitted to ISAS where they are reformatted into FITS files and archived as Level 0 data on the ISAS DARTS system. Once the initial observation period is complete, approximately six months after launch, the mission data will be open and freely available to researchers shortly after receipt at the DARTS data archive hosted in Japan and at NASA s Solar Data Analysis Center at the Goddard Space Flight Center. Scientific operations will be conducted from the ISAS facility in Sagamihara, Japan and the observatory will become available for performing joint operations with both ground and space based instruments and for conducting observing programs proposed by non-team members. This process will be described together with a status report from the initial operation of the observatory, showing examples of the first observations.

Davis, John M.↗
NASA NTRS2007

A Spitzer Infrared Radius for the Transiting Extrasolar Planet HD 209458 b

We have measured the infrared transit of the extrasolar planet HD 209458 b using the Spitzer Space Telescope. We observed two primary eclipse events (one partial and one complete transit) using the 24 micrometer array of the Multiband Imaging Photometer for Spitzer (MIPS). We analyzed a total of 2392 individual images (10-second integrations) of the planetary system, recorded before, during, and after transit. We perform optimal photometry on the images and use the local zodiacal light as a short-term flux reference. At this long wavelength, the transit curve has a simple box-like shape, allowing robust solutions for the stellar and planetary radii independent of stellar limb darkening, which is negligible at 24 micrometers. We derive a stellar radius of R(sub *) = 1.06 plus or minus 0.07 solar radius, a planetary radius of R(sub p) = 1.26 plus or minus 0.08 R(sub J), and a stellar mass of 1.17 solar mass. Within the errors, our results agree with the measurements at visible wavelengths. The 24 micrometer radius of the planet therefore does not differ significantly compared to the visible result. We point out the potential for deriving extrasolar transiting planet radii to high accuracy using transit photometry at slightly shorter IR wavelengths where greater photometric precision is possible.

Richardson, L. Jeremy↗
NASA NTRS2004

Examination of B. subtilis var. niger Spore Killing by Dry Heat Methods

Dry heat microbial reduction is the only NASA approved sterilization method to reduce the microbial bioburden on space-flight hardware prior to launch. Reduction of the microbial bioburden on spacecraft is necessary to meet planetary protection requirements specific for the mission. Microbial bioburden reduction also occurs if a spacecraft enters a planetary atmosphere (e.g., Mars) and is heated due to frictional forces. Temperatures reached during atmospheric entry events (>200 C) are sufficient to damage or destroy flight hardware and also kill microbial spores that reside on the in-bound spacecraft. The goal of this research is to determine the survival rates of bacterial spores when they are subjected to conditions similar to those the spacecraft would encounter (i.e., temperature, pressure, etc.). B. subtilis var. niger spore coupons were exposed to a range of temperatures from 125 C to 200 C in a vacuum oven (at <1 Torr). After the exposures, the spores were removed by sonication, dilutions were made, and the spores were plated using the pour plate method with tryptic soy agar. After 3 days incubation at 32 C, the number of colony-forming units was counted. Lethality rate constants and D-values were calculated at each temperature. The calculated D-values were: 27 minutes (at 125 C), 13 minutes (at 135 C), and <0.1 minutes (at 150 C). The 125 C and 135 C survivor curves appeared as concavedownward curves. The 150 C survivor curve appeared as a straight-line. Due to the prolonged ramp-up time to the exposure conditions, spore killing during the ramp-up resulted in insufficient data to draw curves for exposures at 160 C, 175 C, and 200 C. Exploratory experiments using novel techniques, with short ramp times, for performing high temperature exposures were also examined. Several of these techniques, such as vacuum furnaces, thermal spore exposure vessels, and laser heating of the coupons, will be discussed.

bacillus subtilis var niger↗
NASA NTRS2003

Electron Collisional Excitation Rates for OI USING the B-Spline R-Matrix Approach

The B-spline R-matrix approach has been used to calculate electron collisional excitation strengths and rates for transitions between the 3P, 1D, and 1S states of ground configuration and from these states to the states of the excited 2s(sup 2)2p(sup 3)ns (n = 3-5), 2s(sup 2)2p(sup 3)np (n = 3-4), 2s(sup 2)2p(sup 3)nd (n = 3-4), 2s(sup 2)2p(sup 3)4f, and 2s2p(sup 5) configurations. The nonorthogonal orbitals are used for an accurate description of both the target wave functions and the R-matrix basis functions. The thermally averaged collision strengths are obtained from the collision strengths by integrating over a Maxwellian velocity distribution of electron energies, and these are tabulated over a temperature range from 1000 to 60,000 K. The parametric functions of scaled energy have also been obtained to represent collision strengths over a wide energy range or thermally averaged collision strengths at any desired temperature.

Zatsarinny, O.↗
NASA NTRS2007

The Hinode(Solar-B)Mission: An Overview

The Hinode satellite (formerly Solar-B) of the Japan Aerospace Exploration Agency's Institute of Space and Astronautical Science (ISAS/JAXA) was successfully launched in September 2006. As the successor to the Yohkoh mission, it aims to understand how magnetic energy is transferred from the photosphere to the upper atmospheres and resulting in explosive energy releases. Hinode is an observatory style mission, with all the instruments being designed and built to work together to address the science aims. There are three instruments onboard: the Solar Optical Telescope (SOT), the EUV Imaging Spectrometer (EIS), and the X-ray Telescope (XRT). This paper overviews the mission, including the satellite, the scientific payload and operations. It will conclude with discussions on how the international science community can participate in the analysis of the mission data.

Kosugi, T.↗
NASA NTRS2007

Hypervelocity Impact (HVI): WLE Small-Scale Fiberglass Panel Flat Multi-Layer Targets A-1, A-2, and B-1 - Volume 2

During 2003 and 2004, the Johnson Space Center's White Sands Testing Facility in Las Cruces, New Mexico conducted hypervelocity impact tests on the space shuttle wing leading edge. Hypervelocity impact tests were conducted to determine if Micro-Meteoroid/Orbital Debris impacts could be reliably detected and located using simple passive ultrasonic methods. The objective of Targets A-1, A-2, and B-2 was to study hypervelocity impacts through multi-layered panels simulating Whipple shields on spacecraft. Impact damage was detected using lightweight, low power instrumentation capable of being used in flight.

Gorman, Michael R.↗
NASA NTRS2007

Hypervelocity Impact (HVI): Tile Small Targets A-1, Ag-1, B-1, and Bg-1 - Volume 8

During 2003 and 2004, the Johnson Space Center's White Sands Testing Facility in Las Cruces, New Mexico conducted hypervelocity impact tests on the space shuttle wing leading edge. Hypervelocity impact tests were conducted to determine if Micro-Meteoroid/Orbital Debris impacts could be reliably detected and located using simple passive ultrasonic methods. The objective of Targets A-1, Ag-1, B-1, and Bg-1 was to study hypervelocity impacts on the reinforced Shuttle Heat Shield Tiles of the Wing. Impact damage was detected using lightweight, low power instrumentation capable of being used in flight.

Gorman, Michael R.↗
NASA NTRS2008

Relationships Between TRMM Precipitation and Upper-Tropospheric Hydrometeors as Seen From AMSU-B/MHS and A-Train Sensors

Tropical rainfall as seen by the TRMM radar has multiple scales of organization, one prominent example of which is mesoscale deep convection that supports the production of strong, widespread anvil systems important to the planet's water and energy balance. TRMM PR precipitation retrievals (i.e. the 2A25 algorithm) are reliable down to rates below 1.0 mm/h which captures the majority of near-surface rainfall. However, much of the precipitating hydrometeor mass above the freezing level in these anvil systems may be associated with particles where TRMM PR s/n is low. In our analysis we are examining the question of "What portions of the total hydrometeor spectrum can we see individually with TRMM, CloudSat, high frequency passive microwave (e.g. AMSU-B, MHS) and MODIS". This will allow us to pursue fundamental issues of precipitation efficiency, maintenance of upper-tropospheric humidity, and cloud forcing variability in the tropical climate system. We do this by generating frequency distributions of ice water content (IWC), integrated IWC (IWP), and precipitation as appropriate for these sensors and relate these to TRMM near-surface rainfall. Joint frequency distributions are developed from more limited coincidence between TRMM and these sensors. We interpret these results in terms of a climate regime descriptor and as an index of precipitation efficiency for tropical rain systems.

Robertson, Franklin↗