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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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NASA NTRS2022

Assimilation of NASA's Airborne Snow Observatory Snow Measurements for Improved Hydrological Modeling: A Case Study Enabled by the Coupled LIS/WRF-Hydro System

The NASA LIS/WRF-Hydro system is a coupled modeling framework that combines the modeling and data assimilation (DA) capabilities of the NASA Land Information System (LIS) with the multi-scale surface hydrological modeling capabilities of the WRF-Hydro model, both of which are widely used in both operations and research. This coupled modeling framework builds on the linkage between land surface models (LSMs), which simulate surface boundary conditions in atmospheric models, and distributed hydrologic models, which simulate horizontal surface and sub-surface flow, adding new land DA capabilities. In the present study, we employ this modeling framework in the Tuolumne River basin in central California. We demonstrate the added value of the assimilation of NASA Airborne Snow Observatory (ASO) snow water equivalent (SWE) estimates in the Tuolumne basin. This analysis is performed in both LIS as an LSM column model and LIS/WRF-Hydro, with hydrologic routing. Results demonstrate that ASO DA in the basin reduced snow bias by as much as 30% from an open-loop (OL) simulation compared to three independent datasets. It also reduces downstream streamflow runoff biases by as much as 40%, and improves streamflow skill scores in both wet and dry years. Analysis of soil moisture and evapotranspiration (ET) also reveals the impacts of hydrologic routing from WRF-Hydro in the simulations, which would otherwise not be resolved in an LSM column model. By demonstrating the beneficial impact of SWE DA on the improving streamflow forecasts, the article outlines the importance of such observational inputs for reservoir operations and related water management applications.

Timothy M. Lahmers↗
NASA NTRS2001

The Space Interferometry Mission (SIM) - Revolutionary astronomy, breakthrough technology

The Space Interferometry Mission (SIM), with a target launch date of 2009, will be one of the premiere missions in the Astronomical Search for Origins (ASO) Program, the bold NASA endeavor to understand the origins of galaxies, of planetary systems around distant stars, and perhaps the origins of life itself. This adventure of discovery will be enabled by an explosive growth of innovative technology, as exciting in its own right as the underlying scientific quest.

ASO↗
NASA NTRS1973

Study of airborne science experiment management concepts for application to space shuttle, volume 2

Airborne research management and shuttle sortie planning at the Ames Research Center are reported. Topics discussed include: basic criteria and procedures for the formulation and approval of airborne missions; ASO management structure and procedures; experiment design, development, and testing aircraft characteristics and experiment interfaces; information handling for airborne science missions; mission documentation requirements; and airborne science methods and shuttle sortie planning.

Mulholland, D. R.↗
NASA NTRS1974

ASSESS program: Shuttle Spacelab simulation using a Lear jet aircraft (mission no. 2)

The second shuttle Spacelab simulation mission of the ASSESS program was conducted at Ames Research Center by the Airborne Science Office (ASO) using a Lear jet aircraft based at a site remote from normal flight operations. Two experimenters and the copilot were confined to quarters on the site during the mission, departing only to do in-flight research in infrared astronomy. A total of seven flights were made in a period of 4 days. Results show that experimenters with relatively little flight experience can plan and carry out a successful research effort under isolated and physically rigorous conditions, much as would more experienced scientists. Perhaps the margin of success is not as great, but the primary goal of sustained acquisition of significant data over a 5-day period can be achieved.

Reller, J. O., Jr.↗
NASA NTRS1992

Science and application payloads in the 1990's

During the 90's with the operation of the Extended Duration Orbiter (EDO), Space Station Freedom (SSF), large platforms in polar and Geosynchronous orbits around the Earth, and supporting systems and technology, an infrastructure will exist that will offer a wide range of opportunities for science and applications payloads. The Marshall Space Flight Center (MSFC) is in a unique position of studying for NASA science missions for all of these systems. This paper will discuss a variety of payloads being studied for NASA at the MSFC that are scheduled for flight in the 90's, in support of space science and Mission to Planet Earth. These science payloads such as the Controls, Astrophysics and Structures Experiment in Space (CASES), Advanced Solar Observatory (ASO), Laser Atmospheric Wind Sounder (LAWS), and Lightning Imaging Sensor (LIS), etc. will fully utilize the capabilities of EDO, SSF, Earth Observing System (EOS), and Earth Science Geostationary Platform (ESGP). Emphasis will be placed on showing how these scientific payloads can fully exploit the great potential of these new capabilities for exciting new science and application missions.

Desanctis, Carmine E.↗
NASA NTRS1992

Extraterrestrial applications of solar optics for interior illumination

Solar optics is a terrestrial technology that has potential extraterrestrial applications. Active solar optics (ASO) and passive solar optics (PSO) are two approaches to the transmission of sunlight to remote interior spaces. Active solar optics is most appropriate for task illumination, while PSO is most appropriate for general illumination. Research into solar optics, motivated by energy conservation, has produced lightweight and low-cost materials, products that have applications to NASA's Controlled Ecological Life Support System (CELSS) program and its lunar base studies. Specifically, prism light guides have great potential in these contexts. Several applications of solar optics to lunar base concepts are illustrated.

Eijadi, David A.↗
NASA NTRS1995

The proximity profile of intergalactic He II resonance absorption toward high-redshift QSOs

The Gunn-Peterson effect predicts that an absorption trough should be associated with any resonance line arising in the intergalactic medium (IGM), extending blueward of the line in the QSO's rest frame. We show that such an absorption trough will not generally have a sharp edge at the QSO's redshift but should develop gradually toward shorter wavelengths. This proximity profile of the Gunn-Peterson trough arises because diffuse intergalactic gas in the vicinity of the QSO is more highly ionized than the general IGM. We consider the case of a uniform IGM in approximate photoionization equilibrium with a metagalactic UV background and investigate the proximity profile of He II lambda 304, which might be observable in QSOs with Z(sub Q) approximately 3. Assuming the QSO continuum extends beyond the He II ionization edge, the proximity profile has a characteristic width of delta z(sub p) = delta lambda/304 is approximately 0.1 f is the QSO Lyman limit luminosity in units of 10(exp 31) ergs/s/Hz averaged over the past approximately 10(exp 7) yr, omega(sub I) is the IGM density near (is less than or equal to 10 Mpc) the QSO, omega(sub b) is the normalized baryon density predicted by standard big band necleosynthesis, and f is a factor of order unity which depends weakly on several other factors. Application of this result to the reported detection of the He II Gunn-Peterson effect in Q0302-003 (Jakobsen et al. 1994) suggests that omega(sub I) is approximately equal to omega(sub b), some three orders of magnitude larger than the minimum density that may be inferred from application of the ordinary Gunn-Peterson effect to this QSO. Future observations of the He II proximity profile at higher resolution and signal-to-noise ratio in serveral ASOs should provide the means to measure the IGM density accurately.

Zheng, Wei↗
NASA NTRS1995

Atlas Centaur/GOES-J News Conference

Live footage includes a continuation of the discussions on Geostationary Satellites, the Automatic Surface Observation System (ASOS), and the Doppler Radar Network lead by Frederick Ostby, Director of the National Severe Storms Forecast Center. Live Coverage also shows the question and answer session between the panelists and the audience. This abstract describes the content of tape 2 of 2, 1 having a Report Number of NONP-NASA-VT-2000000038.

Source record↗
NASA NTRS1999

Multi-Configuration and Aeroelastic Shape Design

This presentation describes the advances being made with the Aerodynamic Shape Optimization (ASO) and high-fidelity Multidisciplinary Optimization (MDO) software used in the High Speed Research Program at NASA Ames Research Center. The description starts with the motivation for continued ASO/MDO development. Objectives of the current work are then presented. A list of ingredients deemed necessary for a flexible design environment is discussed, and the HSR requirement for different geometries at different design points is explained. Multiple design disciplines within a high-fidelity design environment are demonstrated. Finally, progress so far is summarized and planned future work is outlined.

Reuther, James↗
NASA NTRS2006

SIM PlanetQuest: Mili-Kelvin Analysis of the Collector Sub-system Thermal Model

Space Interferometry Mission (SIM) PlanetQuest is part of the NASA Astronomical Search for Origins (ASO) program. It will use a Michelson Interferometer to locate extrasolar planets, among other objectives. The spacecraft's subsystems, temperature requirements, and thermal control approach are discussed. The current SIM thermal design is analyzed using a Milli-Kelvin approach and appears to meet temperature stability requirements on the OOPCC optic. SIM absolute temperature requirements are met through the robustness of the thermal design (i.e., PIC control).

PlanetQuest↗
NASA NTRS2008

A Probabilistic Wake Vortex Lateral Transport Model Using Data from SFO and DEN

In a previous report, we considered the behavior of the lateral position of vortices as a function of time after vortex formation for Out of Ground Effects (OGE) data for aircraft landing at San Francisco International Airport (SFO). We quantified the spread in lateral position as a function of time and examined how predictable lateral position is under a variety of assumptions. The combination of spread and predictability allowed us to derive probability distribution functions (PDFs) for lateral position given observed crosswind (CW) velocities. In this study, we examine the portability of these PDFs with respect to other landing sites. To this end, we consider OGE data obtained by the Federal Aviation Administration for landings at Denver International Airport (DEN) between 04/05/2006 and 06/03/2006. We consider vortices from both B733 (Boeing 737 models 200-500) and B757 (Boeing 757) aircraft. The data set contains 635 B733 landings and 506 B757 landings. The glide slope altitude for these measurements was 280 m, determined by the average initial vortex observation adjusted for a 3-second delay in the initial observation. The comparable SFO altitude was 158 m. We note that the principal mechanism for lateral transport in the OGE regime is advection by the ambient wind. This implies that a simple crosswind correction may be effective in explaining much of the variation in the lateral transport data. In this study, we again consider the use of ASOS data and average Lidar crosswind data over the vortex altitude range to predict vortex location as a function of time.

Mellman, George R.↗
NASA NTRS1985

Mesospheric Winds at Jicamaraca, Peru (12 Deg S, 77 Deg SW), November 19-21, 1981

The altitude of mean zonal wind in the mesosphere during the whole daytime observations is given. Positive value refers to eastward. At around 70 km, wind corresponds to summer easterly, and changes to westerly with increasing altitude above about 77 km. These are fairly compatible with known features of zonal wind at this latitude. Contour plot shows local time variations of zonal wind with daytime mean subtracted and averaged over three days. Shaded area designated westward wind with contour level of 2 m/s. The daily variation is almost in phase with altitude in the 65 to 80 km region. Thus the semidiurnal tide with long vertical wavelength is inferred to exist. Above 80 km, phase tilt occurs which indicates the contribution of the propagating diurnal component. Here the combination of dc and 12-hr component is fitted to the data below 80 km. The altitude profiles of the amplitude and phase of this semidiurnal component are shown.

Aso, T.↗
NASA NTRS1986

Measurement of heat-transfer coefficients in shock wave-turbulent boundary layer interaction regions with a multi-layered thin film heat transfer gauge

A thin film heat transfer gauge is applied to the measurement of heat transfer coefficients in the interaction regions of incident shock waves and fully developed turbulent boundary layers. It was developed to measure heat flux with high spatial resolution and fast response for wind tunnels with long flow duration. To measure the heat transfer coefficients in the interaction region in detail, experiments were performed under the conditions of Mach number = 4, total pressure = 1.2 MPa, 0.59 to approximately 0.65. Reynolds number = 1.3 to approximately 1.5 x 10 to the 7th power and incident shock angles from 17.8 to 22.8 degrees. The results show that the heat transfer coefficient changes complicatedly in the interaction region. At the beginning the interaction region, the heat transfer coefficient decreases at first, reaches its minimum value at the point where the pressure begins to increase, and then increases sharply. When the boundary layer begins to separate, even a small separation bubble causes significant changes in the heat transfer coefficient, while the pressure does not show any changes which suggests that the boundary layer begins to separate.

Hayashi, M.↗
NASA NTRS1986

Atmospheric Tides Middle Atmosphere Program (ATMAP): Report of the workshop, Kyoto, Japan, December 5-6, 1984

Experimentalists, data analysts, and theoreticians were brought together to study and interpret the results of four solstice campaigns conducted prior to the symposium. Emphasis was placed on campaigns III and V. Topics discussed included: review of the data and evaluation of the consistency with available theoretical models; interpretation of the data; recommendations on how the Atmospheric Tides Middle Atmosphere Program (ATMAP) results should reach the open literature such that the advancement of middle atmosphere science and the proprietary rights of the individual experimenters are best served; and recommendations concerning future campaigns and the future emphasis of ATMAP.

Forbes, J. M.↗
NASA NTRS2008

Ultra-Stable Beacon Source for Laboratory Testing of Optical Tracking

The ultra-stable beacon source (USBS) provides a laser-beam output with a very low angular jitter and can be used as an absolute angular reference to simulate a beacon in the laboratory. The laser is mounted on the top of a very short (approximately equal to 1 m) inverted pendulum (IP) with its optical axis parallel to the carbon fiber pendulum leg. The 85-cm, carbon fiber rods making up the leg are very lightweight and rigid, and are supported by a flex-joint at the bottom (see figure). The gimbal-mounted laser is a weight-adjustable load of about 1.5 kg with its center of rotation co-located with the center of percussion of the inverted pendulum. This reduces the coupling of transverse motion at the base of the pendulum to angular motion of the laser at the top. The inverted pendulum is mounted on a gimbal with its center of rotation coinciding with the pivot position of the inverted pendulum flexure joint. This reduces coupling of ground tilt at the inverted pendulum base to motion of the laser mounted at the top. The mass of the top gimbal is adjusted to give the pendulum a very low resonant frequency (approximately equal to 10 mHz) that filters transverse seismic disturbances from the ground where the base is attached. The motion of the IP is monitored by an optical-lever sensor. The laser light is reflected by the mirror on the IP, and then is detected by a quadrant photo-detector (QPD). The position of the beam spot on the QPD corresponds to the tilt of the IP. Damping of this motion is provided by two coil and magnet pairs. The bottom gimbal mount consists of two plates. The IP is mounted on the second plate. The first plate is supported by two posts through needles and can be rotated about the axis connecting the tips of the needles. The second plate hangs from the first plate and can be rotated about the axis perpendicular to the first plate. As a result, the second plate acts as a two-axis rotation stage. Its center of rotation is located at the effective bending point of the flex-joint. The second plate is pressed against two screw actuators by the weight of the IP. The screw actuators are orthogonal to each other and are used to adjust the inclination of the second plate. The actuators are driven by stepper motors. The whole IP system is housed in a box made of Lexan plastic plates to provide isolation from air currents and temperature variations. The signals from the sensors are processed and recorded with a PC using the xPC Target realtime environment of Math- Works. The control algorithms are written using the Simulink package from The MathWorks.

Aso, Yoichi↗
NASA NTRS2011

Directional Limits on Persistent Gravitational Waves Using LIGO S5 Science Data

The gravitational-wave (GW) sky may include nearby pointlike sources as well as astrophysical and cosmological stochastic backgrounds. Since the relative strength and angular distribution of the many possible sources of GWs are not well constrained, searches for GW signals must be performed in a model-independent way. To that end we perform two directional searches for persistent GWs using data from the LIGO S5 science run: one optimized for pointlike sources and one for arbitrary extended sources. The latter result is the first of its kind. Finding no evidence to support the detection of GWs, we present 90% confidence level (CL) upper-limit maps of GW strain power with typical values between 2 - 20 X 10 (exp -50) strain2Hz(exp -1) and 5 - 35 X 10 (exp -49) strain2Hz(exp -1)/sr for pointlike and extended sources respectively. The limits on pointlike sources constitute a factor of 30 improvement over the previous best limits. We also set 90% CL limits on the narrow-band root-mean-square GW strain from interesting targets including Sco X-1, SN1987A and the Galactic Center as low as approximately equal 7 X 10(exp -25) in the most sensitive frequency range near 160Hz. These limits are the most constraining to date and constitute a factor of 5 improvement over the previous best limits.

Abadie, J.↗
NASA NTRS2010

Search for Gravitational Waves from Compact Binary Coalescence in LIGO and Virgo Data from S5 and VSR1

We report the results of the first search for gravitational waves from compact binary coalescence using data from the Laser Interferometer Gravitational-wave Observatory (LIGO) and Virgo detectors. Five months of data were collected during the concurrent S5 (UGO) and VSRI (Virgo) science runs. The search focused on signals from binary mergers with a total mass between 2 and 35 Solar Mass. No gravitational waves are identified. The cumulative 90%-confidence upper limits on the rate of compact binary coalescence are calculated for non-spinning binary neutron stars, black hole-neutron star systems, and binary black holes to be 8.7 x 10(exp -3) / yr-1/L(sub 10) 2.2 x 10-3 yr-1L101, and 4.4 x 10(exp -4)3) / yr-1/L(sub 10) respectively, where L (sub 10) is 10(exp 10) times the blue solar luminosity. These upper limits are compared with astrophysical expectations.

Abadie, J.↗