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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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All sourcesNASA NTRSDOE OSTI
NASA NTRS1987

Instrument systems for the Upper Atmosphere Research Satellite

The NASA Upper Atmosphere Research Satellite program for improving both methods needed to maintain the physical and chemical integrity of the upper atmosphere and techniques for the early detection of harmful changes in the ozone layer is discussed. Through satellite measurements, theoretical studies, and model analyses, the program will provide integrated global measurements of the chemistry, dynamics, and energetics of the stratosphere, mesosphere, and lower thermosphere. The 10 state-of-the-art instrument systems employed in the program are described, including the solar UV spectral irradiance monitor, the particle environment monitor, the cryogenic limb array etalon spectrometer, the wind imaging interferometer, and the active cavity radiometer irradiance monitor.

Arnold, Ray J.↗
NASA NTRS1993

The Upper Atmosphere Research Satellite (UARS)

The Upper Atmosphere Research Satellite (UARS) was launched by the Space Shuttle on September 12, 1991 into a near circular orbit at 585 km altitude inclined 57 degrees to the Equator. Measurements were initiated a few days later, including solar energy inputs to the atmosphere and vertical profiles of temperature, important minor gas species, and wind fields. The orbital parameters, combined with the sensor measurements characteristics, yield a measurement pattern that produces near global coverage with a duty cycle that periodically favors the Northern or the Southern Hemispheres. A few spacecraft and instrument anomalies have impacted the total amount of data obtained to date, but the overall performance of the mission has been very good.

Reber, Carl A.↗
DOE OSTI2025

End-of-Century Changes in Orographic Precipitation with the Intermediate Complexity Atmospheric Research Model over the Western United States

Abstract Downscaled precipitation projections were created using the Intermediate Complexity Atmospheric Research (ICAR) model over the western United States to increase the physical realism in orographic precipitation changes. End-of-century simulations from eight models in phase 5 of the Coupled Model Intercomparison Project (CMIP5) were downscaled with ICAR and compared to the widely utilized statistically downscaled dataset, localized constructed analogs (LOCAs), to understand where and why projections of cool-season (September–May) precipitation differed. ICAR and LOCA precipitation projections were similar, but their sign differed in hydrologically relevant regions likely due to ICAR’s simulation of microphysics and mesoscale dynamics with high-resolution topography (6 km). In the Pacific Northwest, cool-season precipitation projections from ICAR showed an increase on the windward side of the Cascades and no significant change within the lee. This difference between the windward and leeward side was attributed to reduced zonal wind speeds, allowing more time for microphysical processes within ICAR. This contrast is enhanced by rain’s faster fall speed compared to snow, limiting transport into the lee. Meanwhile, LOCA projected an increase in precipitation across the Cascades. In the Upper Colorado River basin, LOCA projected an increase in precipitation in high elevation regions (>3000 m), but ICAR projected no significant change or a decrease in precipitation. High elevation differences were most evident in the spring and fall and were also attributed to a snow-to-rain transition and dynamical processes that impacted orographic enhancement within ICAR. Idealized, controlled studies are needed to better isolate individual processes, but these results underscore the importance of including microphysics and mesoscale dynamics within regional-scale precipitation projections. Significance Statement A set of global climate model simulations was downscaled using an atmospheric model that contains key physical equations, referred to as Intermediate Complexity Atmospheric Research (ICAR). ICAR was used to examine projected changes in end-of-century cool-season precipitation over mountains in the western United States. Precipitation projections from ICAR were similar to projections that used statistical relationships to downscale climate projections. However, projections differed between ICAR and statistically downscaled datasets in whether they increased, decreased, or stayed the same in specific, hydrologically relevant regions such as the eastern Cascades and high elevation areas of the Upper Colorado River basin. These differences were attributed to the simulation of physical processes in ICAR. The results highlight the importance of kilometer-scale atmospheric processes in regional climate projections.

Currier, William Ryan [NOAA/Physical Sciences Labo↗
NASA NTRS1990

The applications of chemical thermodynamics and chemical kinetics to planetary atmospheres research

A review of the applications of chemical thermodynamics and chemical kinetics to planetary atmospheres research during the past four decades is presented with an emphasis on chemical equilibrium models and thermochemical kinetics. Several current problems in planetary atmospheres research such as the origin of the atmospheres of the terrestrial planets, atmosphere-surface interactions on Venus and Mars, deep mixing in the atmospheres of the gas giant planets, and the origin of the atmospheres of outer planet satellites all require laboratory data on the kinetics of thermochemical reactions for their solution.

Fegley, Bruce, Jr.↗
NASA NTRS1988

Comparison of circular orbit and Fourier power series ephemeris representations for backup use by the upper atmosphere research satellite onboard computer

The Upper Atmosphere Research Satellite (UARS) is a three-axis stabilized Earth-pointing spacecraft in a low-Earth orbit. The UARS onboard computer (OBC) uses a Fourier Power Series (FPS) ephemeris representation that includes 42 position and 42 velocity coefficients per axis, with position residuals at 10-minute intervals. New coefficients and 32 hours of residuals are uploaded daily. This study evaluated two backup methods that permit the OBC to compute an approximate spacecraft ephemeris in the event that new ephemeris data cannot be uplinked for several days: (1) extending the use of the FPS coefficients previously uplinked, and (2) switching to a simple circular orbit approximation designed and tested (but not implemented) for LANDSAT-D. The FPS method provides greater accuracy during the backup period and does not require additional ground operational procedures for generating and uplinking an additional ephemeris table. The tradeoff is that the high accuracy of the FPS will be degraded slightly by adopting the longer fit period necessary to obtain backup accuracy for an extended period of time. The results for UARS show that extended use of the FPS is superior to the circular orbit approximation for short-term ephemeris backup.

Kast, J. R.↗
NASA NTRS1993

The Upper Atmosphere Research Satellite (UARS) mission

The Upper Atmosphere Research Satellite (UARS) is a NASA program aimed at improving our knowledge of the physical and chemical processes controlling the stratosphere, mesosphere, and lower thermosphere, emphasizing those levels that are known to be particularly susceptible to change by human activities. The spacecraft was launched by the Space Shuttle Discovery on September 12, 1991 into a near-circular orbit at 585 km altitude and 57 deg inclination. Measurements include vertical profiles of temperature, many trace gases, and horizontal wind velocities, as well as solar energy inputs. Many of the limb-scanning instruments can measure to as high as 80 deg latitude, providing near-global coverage. The mission is supported by a large international correlative measurement program, yielding data both for validation of the UARS measurements and for complementary scientific studies. A dedicated data system provides rapid processing to geophysical quantities and makes these data available to UARS scientists.

Reber, Carl A.↗
NASA NTRS1995

A prototype Upper Atmospheric Research Collaboratory (UARC)

The National Collaboratory concept has great potential for enabling 'critical mass' working groups and highly interdisciplinary research projects. We report here on a new program to build a prototype collaboratory using the Sondrestrom Upper Atmospheric Research Facility in Kangerlussuaq, Greenland and a group of associated scientists. The Upper Atmospheric Research Collaboratory (UARC) is a joint venture of researchers in upper atmospheric and space science, computer science, and behavioral science to develop a testbed for collaborative remote research. We define the 'collaboratory' as an advanced information technology environment which enables teams to work together over distance and time on a wide variety of intellectual tasks. It provides: (1) human-to-human communications using shared computer tools and work spaces; (2) group access and use of a network of information, data, and knowledge sources; and (3) remote access and control of instruments for data acquisition. The UARC testbed is being implemented to support a distributed community of space scientists so that they have network access to the remote instrument facility in Kangerlussuaq and are able to interact among geographically distributed locations. The goal is to enable them to use the UARC rather than physical travel to Greenland to conduct team research campaigns. Even on short notice through the collaboratory from their home institutions, participants will be able to meet together to operate a battery of remote interactive observations and to acquire, process, and interpret the data.

Clauer, C. R.↗
NASA NTRS1983

Upper Atmosphere Research Satellite (UARS) trade analysis

The Upper Atmosphere Research Satellite (UARS) which will collect data pertinent to the Earth's upper atmosphere is described. The collected data will be sent to the central data handling facility (CDHF) via the UARS ground system and the data will be processed and distributed to the remote analysis computer systems (RACS). An overview of the UARS ground system is presented. Three configurations were developed for the CDHF-RACS system. The CDHF configurations are discussed. The IBM CDHF configuration, the UNIVAC CDHF configuration and the vax cluster CDHF configuration are presented. The RACS configurations, the IBM RACS configurations, UNIVAC RACS and VAX RACS are detailed. Due to the large on-line data estimate to approximately 100 GB, a mass storage system is considered essential to the UARS CDHF. Mass storage systems were analyzed and the Braegan ATL, the RCA optical disk, the IBM 3850 and the MASSTOR M860 are discussed. It is determined that the type of mass storage system most suitable to UARS is the automated tape/cartridge device. Two devices of this type, the IBM 3850 and the MASSTOR MSS are analyzed and the applicable tape/cartridge device is incorporated into the three CDHF-RACS configurations.

Fox, M. M.↗
NASA NTRS1976

The NASA program on upper atmospheric research

The purpose of the NASA Upper Atmospheric Research Program is to develop a better understanding of the physical and chemical processes that occur in the earth's upper atmosphere with emphasis on the stratosphere.

Source record↗
NASA NTRS1994

Operational support for Upper Atmosphere Research Satellite (UARS) attitude sensors

The Upper Atmosphere Research Satellite (UARS) has several sensors that can provide observations for attitude determination: star trackers, Sun sensors (gimbaled as well as fixed), magnetometers, Earth sensors, and gyroscopes. The accuracy of these observations is important for mission success. Analysts on the Flight Dynamics Facility (FDF) UARS Attitude task monitor these data to evaluate the performance of the sensors taking corrective action when appropriate. Monitoring activities range from examining the data during real-time passes to constructing long-term trend plots. Increasing residuals (differences) between the observed and expected quantities is a prime indicator of sensor problems. Residual increases may be due to alignment shifts and/or degradation in sensor output. Residuals from star tracker data revealed and anomalous behavior that contributes to attitude errors. Compensating for this behavior has significantly reduced the attitude errors. This paper discusses the methods used by the FDF UARS attitude task for maintenance of the attitude sensors, including short- and long-term monitoring, trend analysis, and calibration methods, and presents the results obtained through corrective action.

Lee, M.↗
NASA NTRS1997

The Upper Atmosphere Research Satellite In-Flight Dynamics

Upper Atmosphere Research Satellite flight data from the first 737 days after launch (September 1991) was used to investigate spacecraft disturbances and responses. The investigation included two in-flight dynamics experiments (approximately three orbits each). Orbital and configuration influences on spacecraft dynamic response were also examined. Orbital influences were due to temperature variation from crossing the Earth's terminator and variation of the solar incident energy as the orbit precessed. During the terminator crossing, the rapid ambient temperature change caused the spacecraft's two flexible appendages to experience thermal elastic bending (thermal snap). The resulting response was dependent upon the orientation of the solar array and the solar incident energy. Orbital influences were also caused by on-board and environmental disturbances and spacecraft configuration changes resulting in dynamic responses which were repeated each orbit. Configuration influences were due to solar array rotation changing spacecraft modal properties. The investigation quantified the spacecraft dynamic response produced by the solar array and high gain antenna harmonic drive disturbances. The solar array's harmonic drive output resonated two solar array modes. Friction in the solar array gear drive provided sufficient energy dissipation which prevented the solar panels from resonating catastrophically; however, the solar array vibration amplitude was excessively large. The resulting vibration had a latitude-specific pattern.

Woodard, Stanley E.↗
NASA NTRS1990

The Upper Atmosphere Research Satellite

The scientific aims of the Upper Atmosphere Research Satellite are discussed. Individual experiments studying energy input to the atmosphere, temperature and important trace chemical species, winds, the global morphology of ozone and of major trace species families, and the thermal structure of the middle atmosphere are described. The data processing and analysis on the ground are addressed along with correlative measurements and prelaunch theoretical studies.

Reber, Carl A.↗
NASA NTRS1992

NASA's upper atmosphere research satellite: A program to study global ozone change

The Upper Atmosphere Research Satellite (UARS) is a major initiative in the NASA Office of Space Science and Applications, and is the prototype for NASA's Earth Observing System (EOS) planned for launch in the 1990s. The UARS combines a balanced program of experimental and theoretical investigations to perform diagnostic studies, qualitative model analysis, and quantitative measurements and comparative studies of the upper atmosphere. UARS provides theoretical and experimental investigations which pursue four specific research topics: atmospheric energy budget, chemistry, dynamics, and coupling processes. An international cadre of investigators was assembled by NASA to accomplish those scientific objectives. The observatory, its complement of ten state of the art instruments, and the ground system are nearing flight readiness. The timely UARS program will play a major role in providing data to understand the complex physical and chemical processes occurring in the upper atmosphere and answering many questions regarding the health of the ozone layer.

Luther, Michael R.↗
NASA NTRS1991

Determination of design and operation parameters for upper atmospheric research instrumentation to yield optimum resolution with deconvolution

The final report for work on the determination of design and operation parameters for upper atmospheric research instrumentation to yield optimum resolution with deconvolution is presented. Papers and theses prepared during the research report period are included. Among all the research results reported, note should be made of the specific investigation of the determination of design and operation parameters for upper atmospheric research instrumentation to yield optimum resolution with deconvolution. A methodology was developed to determine design and operation parameters for error minimization when deconvolution is included in data analysis. An error surface is plotted versus the signal-to-noise ratio (SNR) and all parameters of interest. Instrumental characteristics will determine a curve in this space. The SNR and parameter values which give the projection from the curve to the surface, corresponding to the smallest value for the error, are the optimum values. These values are constrained by the curve and so will not necessarily correspond to an absolute minimum in the error surface.

Ioup, George E.↗
NASA NTRS1988

Accuracy study of the Upper Atmosphere Research Satellite (UARS) definitive attitude determination

The Upper Atmosphere Research Satellite (UARS) has two definitive attitude determination requirements: the definitive attitude of the Modular Attitude Control Subsystem (MACS) and the definitive attitude of the gimbaled Solar-Stellar Pointing Platform (SSPP). The onboard computer (OBC) will compute the MACS attitude using a Kalman filter and will transform this attitude solution through the SSPP gimbals to calculate the SSPP attitude. The attitude ground support system (AGSS) will compute the MACS attitude using a batch least-squares differential corrector algorithm and will also transform this solution through the gimbals to obtain the SSPP attitude. This paper reports the results of a prelaunch study to predict the accuracy of the OBC attitude solutions and the accuracy of the AGSS attitude solutions. The OBC and AGSS solution accuracies are then compared to establish the relative quality. The effects of star observability, sensor noise, and sensor misalignment uncertainties on attitude determination accuracy are analyzed for each case.

Snow, Frank↗
NASA NTRS2003

Overview of the Upper Atmosphere Research Satellite: Observations from 1991 to 2002

The Upper Atmosphere Research Satellite (UARS) was launched in September 1991 by the Space Shuttle Discovery and continues to make relevant atmospheric measurements (as of October 2002). This successful satellite has fostered a better understanding of the middle atmospheric processes, especially those important in the control of ozone. Seven of the original ten instruments aboard the UARS are still functional and six instruments regularly make measurements. The UARS is in a stable observing configuration, in spite of experiencing several anomalies over its lifetime. It is expected that the UARS will overlap the Earth Observing System (EOS) Aura satellite (scheduled launch in January 2004) for several months before the end of the UARS mission.

Jackman, Charles H.↗
NASA NTRS2002

Overview of the Upper Atmosphere Research Satellite: Observations from 1991 to 2002

The Upper Atmosphere Research Satellite (UARS) was launched in September 1991 by the Space Shuttle Discovery. Seven of the original ten instruments aboard the UARS are functional and six instruments regularly take measurements. The UARS is in a stable observing configuration, in spite of experiencing several anomalies which have impacted the data tape storage and power available. Power sharing and "real-time" operations using the Tracking and Data Relay Satellites have reduced the data collection over the past five years. Although the UARS measurements have not been continuous, the UARS instruments HALOE, SUSIM, SOLSTICE, HRDI, WINDII, and PEM have provided important observations over an entire solar cycle. The UARS HALOE instrument measures ozone and other constituents important in understanding ozone variations. The UARS SUSIM and SOLSTICE instruments observe ultraviolet light between 120 and 420 nm, which influence middle atmospheric constituent fluctuations. The UARS HRDI and WINDII instruments measure winds in the stratosphere, mesosphere, and thermosphere, which move constituents among the various atmospheric regions. The UARS PEM instrument provides observations of input precipitating charged particles, including both electrons and protons. This paper will provide an overview about the UARS mission and its relevant atmospheric measurements.

Jackman, Charles H.↗