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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 469 records · Page 26
All sourcesNASA NTRSDOE OSTI
NASA NTRS2007

International Space Station Remote Sensing Pointing Analysis

This paper analyzes the geometric and disturbance aspects of utilizing the International Space Station for remote sensing of earth targets. The proposed instrument (in prototype development) is SHORE (Station High-Performance Ocean Research Experiment), a multiband optical spectrometer with 15 m pixel resolution. The analysis investigates the contribution of the error effects to the quality of data collected by the instrument. This analysis supported the preliminary studies to determine feasibility of utilizing the International Space Station as an observing platform for a SHORE type of instrument. Rigorous analyses will be performed if a SHORE flight program is initiated. The analysis begins with the discussion of the coordinate systems involved and then conversion from the target coordinate system to the instrument coordinate system. Next the geometry of remote observations from the Space Station is investigated including the effects of the instrument location in Space Station and the effects of the line of sight to the target. The disturbance and error environment on Space Station is discussed covering factors contributing to drift and jitter, accuracy of pointing data and target and instrument accuracies.

Jacobson, Craig A.↗
NASA NTRS1993

Virtual egocenters as a function of display geometric field of view and eye station point

The accurate location of one's virtual egocenter in a geometric space is of critical importance for immersion technologies. This experiment was conducted to investigate the role of field of view (FOV) and observer station points in the perception of the location of one's egocenter (the personal viewpoint) in virtual space. Rivalrous cues to the accurate location of one's egocenter may be one factor involved in simulator sickness. Fourteen subjects viewed an animated 3D model, of the room in which they sat, binocularly, from Eye Station Points (ESP) of either 300 or 800 millimeters. The display was on a 190 by 245 mm monitor, at a resolution of 320 by 200 pixels with 256 colors. They saw four models of the room designed with four geometric field of view (FOVg) conditions of 18, 48, 86, and 140 degrees. They drew the apparent paths of the camera in the room on a bitmap of the room as seen from infinity above. Large differences in the paths of the camera were seen as a function of both FOVg and ESP. Ten of the subjects were then asked to find the position for each display that minimized camera motion. The results fit well with predictions from an equation that took the ratio of human FOV (roughly 180 degrees) to FOVg times the Geometric Eye Point (GEP) of the imager: Zero Station Point = (180/FOVg)*GEP

Psotka, Joseph↗
NASA NTRS1994

Networked differential GPS system

An embodiment of the present invention relates to a worldwide network of differential GPS reference stations (NDGPS) that continually track the entire GPS satellite constellation and provide interpolations of reference station corrections tailored for particular user locations between the reference stations Each reference station takes real-time ionospheric measurements with codeless cross-correlating dual-frequency carrier GPS receivers and computes real-time orbit ephemerides independently. An absolute pseudorange correction (PRC) is defined for each satellite as a function of a particular user's location. A map of the function is constructed, with iso-PRC contours. The network measures the PRCs at a few points, so-called reference stations and constructs an iso-PRC map for each satellite. Corrections are interpolated for each user's site on a subscription basis. The data bandwidths are kept to a minimum by transmitting information that cannot be obtained directly by the user and by updating information by classes and according to how quickly each class of data goes stale given the realities of the GPS system. Sub-decimeter-level kinematic accuracy over a given area is accomplished by establishing a mini-fiducial network.

Mueller, K. Tysen↗
DOE OSTI2023

Real-Time, Simultaneous Soil Water Content and Meteorological Data Measurement to Support TRACER over Harris County, Texas Field Campaign Report: Part II

The main purpose of this project was to provide ground-truth and satellite-based soil water content data in the Houston, Texas, area to support the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) user facility’s 2022 field campaign, the Tracking Aerosol Convection Interactions ExpeRiment (TRACER). This involved installing four soil monitoring stations at different locations in the Houston area, two of which were part of the ARM facility and two were ancillary. The two stations associated directly with ARM were installed alongside other facilities managed and maintained by the TRACER research team during the intensive operational period (IOP), one located at the La Porte, Texas airport and the other located near Guy, Texas. Data from these stations were assimilated with similar data collected by the Harris County Flood Control District (HCFCD) to improve the spatial coverage of the real-time monitoring network. The ground-truth data were compared to the satellite-based (National Aeronautics and Space Administration [NASA]’s Soil Moisture Active Passive [SMAP] mission) data in the TRACER area of interest, and analyzed further to nowcast gridded data over the Houston area. The nowcasted, gridded data product was made available to TRACER researchers for use in climate and land-atmosphere interaction modeling that can help understand formation and persistence of convective storms in dense urban areas, and predict possible environmental events such as floods.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2024

EVI-RoadTrip™: Electric Vehicle Infrastructure for Road Trips [SWR-22-17]

The EVI-RoadTrip™ tool offers high-resolution refueling network design and analysis to inform electric vehicle (EV) charging infrastructure development for road trips or long-distance travels. EVI-RoadTrip helps infrastructure planners, analysts, and decision makers evaluate EV energy consumption and corresponding charging demands along the routes-between origin and destination. It considers the projected location and characteristics of charging stations, potential electric grid impacts, and required infrastructure improvements. Strategically located charging stations for long-distance travel are critical to enabling the widespread adoption of EVs by allowing them to travel further beyond city or town boundaries. Sophisticated analysis and planning can identify the points (e.g., corridors) that may require increased availability of EV charging stations to support electrified road trips.

Wood, Eric↗
NASA NTRS2014

Analytical and Experimental Studies of Leak Location and Environment Characterization for the International Space Station

The International Space Station program is developing a robotically-operated leak locator tool to be used externally. The tool would consist of a Residual Gas Analyzer for partial pressure measurements and a full range pressure gauge for total pressure measurements. The primary application is to detect NH3 coolant leaks in the ISS thermal control system.An analytical model of leak plume physics is presented that can account for effusive flow as well as plumes produced by sonic orifices and thruster operations. This model is used along with knowledge of typical RGA and full range gauge performance to analyze the expected instrument sensitivity to ISS leaks of various sizes and relative locations (directionality).The paper also presents experimental results of leak simulation testing in a large thermal vacuum chamber at NASA Goddard Space Flight Center. This test characterized instrument sensitivity as a function of leak rates ranging from 1 lbmyr. to about 1 lbmday. This data may represent the first measurements collected by an RGA or ion gauge system monitoring off-axis point sources as a function of location and orientation. Test results are compared to the analytical model and used to propose strategies for on-orbit leak location and environment characterization using the proposed instrument while taking into account local ISS conditions and the effects of ramwake flows and structural shadowing within low Earth orbit.

Leak Locator↗
NASA NTRS2014

Analytical and Experimental Studies of Leak Location and Environment Characterization for the International Space Station

The International Space Station program is developing a robotically-operated leak locator tool to be used externally. The tool would consist of a Residual Gas Analyzer for partial pressure measurements and a full range pressure gauge for total pressure measurements. The primary application is to detect NH3 coolant leaks in the ISS thermal control system. An analytical model of leak plume physics is presented that can account for effusive flow as well as plumes produced by sonic orifices and thruster operations. This model is used along with knowledge of typical RGA and full range gauge performance to analyze the expected instrument sensitivity to ISS leaks of various sizes and relative locations ("directionality"). The paper also presents experimental results of leak simulation testing in a large thermal vacuum chamber at NASA Goddard Space Flight Center. This test characterized instrument sensitivity as a function of leak rates ranging from 1 lb-mass/yr. to about 1 lb-mass/day. This data may represent the first measurements collected by an RGA or ion gauge system monitoring off-axis point sources as a function of location and orientation. Test results are compared to the analytical model and used to propose strategies for on-orbit leak location and environment characterization using the proposed instrument while taking into account local ISS conditions and the effects of ram/wake flows and structural shadowing within low Earth orbit.

000000↗
NASA NTRS1979

Lightning location and lower-ionospheric height determination from two-station magnetic field measurements

Wide band magnetic direction finding from two stations is used to determine lightning locations and ionospheric height during two nocturnal maritime thunderstorms near Florida. A comparison of calculated lightning locations with radar reflectivity data of the two storms indicates systematic direction-finding errors to be on the order of 1 deg. From the lightning locations and measured arrival times of the first and second sky waves, ionospheric reflecting heights for both sky waves were determined. The effective heights for the first and second sky waves may differ, leading to large errors in single-station determinations of ionospheric height, such as in the method described by Kinzer (1974). The distribution of peak electric fields for the strokes studied is shown to be in reasonable agreement with other determinations, indicating the reliability of the present measurements.

Mcdonald, T. B., III↗
NASA NTRS2000

Automatic Weather Station (AWS) Lidar

An autonomous, low-power atmospheric lidar instrument is being developed at NASA Goddard Space Flight Center. This compact, portable lidar will operate continuously in a temperature controlled enclosure, charge its own batteries through a combination of a small rugged wind generator and solar panels, and transmit its data from remote locations to ground stations via satellite. A network of these instruments will be established by co-locating them at remote Automatic Weather Station (AWS) sites in Antarctica under the auspices of the National Science Foundation (NSF). The NSF Office of Polar Programs provides support to place the weather stations in remote areas of Antarctica in support of meteorological research and operations. The AWS meteorological data will directly benefit the analysis of the lidar data while a network of ground based atmospheric lidar will provide knowledge regarding the temporal evolution and spatial extent of Type la polar stratospheric clouds (PSC). These clouds play a crucial role in the annual austral springtime destruction of stratospheric ozone over Antarctica, i.e. the ozone hole. In addition, the lidar will monitor and record the general atmospheric conditions (transmission and backscatter) of the overlying atmosphere which will benefit the Geoscience Laser Altimeter System (GLAS). Prototype lidar instruments have been deployed to the Amundsen-Scott South Pole Station (1995-96, 2000) and to an Automated Geophysical Observatory site (AGO 1) in January 1999. We report on data acquired with these instruments, instrument performance, and anticipated performance of the AWS Lidar.

Rall, Jonathan A.R.↗
NASA NTRS1977

Machine for use in monitoring fatigue life for a plurality of elastomeric specimens

An improved machine is described for use in determining the fatigue life for elastomeric specimens. The machine is characterized by a plurality of juxtaposed test stations, specimen support means located at each of the test stations for supporting a plurality of specimens of elastomeric material, and means for subjecting the specimens at each of said stations to sinusoidal strain at a strain rate unique with respect to the strain rate at which the specimens at each of the other stations is subjected to sinusoidal strain.

Fitzer, G. E.↗
NASA NTRS2016

Mars Surface System Common Capabilities and Challenges for Human Missions

NASA has begun a process to identify and evaluate candidate locations where humans could land, live and work on the martian surface. These locations are referred to as Exploration Zones (EZs). Given current mission concepts, an EZ is a collection of Regions of Interest (ROIs) that are located within approximately 100 kilometers of a centralized landing site. ROIs are areas that are relevant for scientific investigation and/or development/maturation of capabilities and resources necessary for a sustainable human presence. The EZ also contains a landing site and a habitation site that will be used by multiple human crews during missions to explore and utilize the ROIs within the EZ. In parallel with this process, NASA continues to make progress on the Evolvable Mars Campaign examining alternatives that can pioneer an extended human presence on Mars that is Earth independent. This involves ongoing assessments of surface systems and operations to enable a permanent, sustainable human presence. Because of the difficulty in getting equipment and supplies to the surface of Mars, part of these assessments involve identifying those systems and processes that can perform in multiple, sometimes completely unrelated, situations. These assessments have been performed in a very generic surface mission carried out at a very generic surface location. As specific candidate EZs are identified it becomes important to evaluate the current suite of surface systems and operations as they are likely to perform for the specific locations and for the types of operations - both scientific and development - that are proposed for these EZs. It is also important to evaluate the proposed EZs for their suitability to be explored or developed given the range of capabilities and constraints for the types of surface systems and operations being considered within the EMC. This means looking at setting up and operating a field station at a central location within the EZ as well as traversing to and exploring the scientific ROIs within the boundaries of the EZ. The proposed paper will describe the current status of common systems and operations as they can be applied to actual EZ locations on Mars. Initially these EZs will be the four locations identified MEPAG's Human Exploration of Mars Science Analysis Group (HEM‐SAG) that will be used as representative of the EZs that will emerge from the process that NASA has initiated. An example process that could be commonly applied is an approach for developing a field station site plan that would be demonstrated by applying this process to each of the four HEM‐SAG sites. Examples of common systems include (a) mobility systems that can be used to off‐load and move payloads to specific locations at the central field station location that could also be used to traverse long distances to reach some of the more remote ROIs or (b) robotic systems that can support various activities (such as system set up and maintenance) at the field station that could also be used to explore scientific ROIs and used to support site‐specific ISRU production activities.

Hoffman, Stephen J.↗
DOE OSTI2023

How Good Is Your Location? Comparing and Understanding the Uncertainties in Location for the 1993 Rock Valley Sequence

Accurate event locations are important for many endeavors in seismology, and understanding the factors that contribute to uncertainties in those locations is complex. In this article, we present a case study that takes an in-depth look at the accuracy and precision possible for locating nine shallow earthquakes in the Rock Valley fault zone in southern Nevada. These events are targeted by the Rock Valley Direct Comparison phase of the Source Physics Experiment, as candidates for the colocation of a chemical explosion with an earthquake hypocenter to directly compare earthquake and explosion sources. For this comparison, it is necessary to determine earthquake hypocenters as accurately as possible so that different source types have nearly identical locations. Our investigations include uncertainty analysis from different sets of phase arrivals, stations, velocity models, and location algorithms. For a common set of phase arrivals and stations, we find that epicentral locations from different combinations of velocity models and algorithms are within 600 m of one another in most cases. Event depths exhibit greater uncertainties, but focusing on the S-P times at the nearest station allows for estimates within approximately 500 m.

58 GEOSCIENCES↗
DOE OSTI2023

Real-Time, Simultaneous Soil Water Content and Meteorological Data Measurement to Support TRACER over Harris County, Texas (Field Campaign Report: Part I)

The main purpose of this project was to provide ground-truth and satellite-based soil water content data in the Houston, Texas, area to support the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) user facility’s 2022 field campaign, the Tracking Aerosol Convection Interactions ExpeRiment (TRACER). This involved installing four soil monitoring stations at different locations in the Houston area, two of which were part of the ARM facility and two were ancillary. The two stations associated directly with ARM were installed alongside other facilities managed and maintained by the TRACER research team during the intensive operational period (IOP), one located at the La Porte, Texas airport and the other near Guy, Texas. Data from these stations were assimilated with similar data collected by the Harris County Flood Control District (HCFCD) to improve the spatial coverage of the real-time monitoring network. The ground-truth data were compared to the satellite-based (National Aeronautics and Space Administration [NASA]’s Soil Moisture Active Passive [SMAP] mission) data in the TRACER area of interest, and analyzed further to nowcast gridded data over the Houston area. The nowcasted, gridded data product was made available to TRACER researchers for use in climate and land-atmosphere interaction modeling that can help understand formation and persistence of convective storms in dense urban areas, and predict possible environmental events such as floods.

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS2013

Conducting Research on the International Space Station Using the EXPRESS Rack Facilities

Conducting Research on the International Space Station using the EXPRESS Rack Facilities. Sean W. Thompson and Robert E. Lake. NASA Marshall Space Flight Center, Huntsville, AL, USA. Eight "Expedite the Processing of Experiments to Space Station" (EXPRESS) Rack facilities are located within the International Space Station (ISS) laboratories to provide standard resources and interfaces for the simultaneous and independent operation of multiple experiments within each rack. Each EXPRESS Rack provides eight Middeck Locker Equivalent locations and two drawer locations for powered experiment equipment, also referred to as sub-rack payloads. Payload developers may provide their own structure to occupy the equivalent volume of one, two, or four lockers as a single unit. Resources provided for each location include power (28 Vdc, 0-500 W), command and data handling (Ethernet, RS-422, 5 Vdc discrete, +/- 5 Vdc analog), video (NTSC/RS 170A), and air cooling (0-200 W). Each rack also provides water cooling (500 W) for two locations, one vacuum exhaust interface, and one gaseous nitrogen interface. Standard interfacing cables and hoses are provided on-orbit. One laptop computer is provided with each rack to control the rack and to accommodate payload application software. Four of the racks are equipped with the Active Rack Isolation System to reduce vibration between the ISS and the rack. EXPRESS Racks are operated by the Payload Operations Integration Center at Marshall Space Flight Center and the sub-rack experiments are operated remotely by the investigating organization. Payload Integration Managers serve as a focal to assist organizations developing payloads for an EXPRESS Rack. NASA provides EXPRESS Rack simulator software for payload developers to checkout payload command and data handling at the development site before integrating the payload with the EXPRESS Functional Checkout Unit for an end-to-end test before flight. EXPRESS Racks began supporting investigations onboard ISS on April 24, 2001 and will continue through the life of the ISS.

Thompson, Sean W.↗
NASA NTRS2013

Conducting Research on the International Space Station Using the EXPRESS Rack Facilities

Eight "Expedite the Processing of Experiments to Space Station" (EXPRESS) Rack facilities are located within the International Space Station (ISS) laboratories to provide standard resources and interfaces for the simultaneous and independent operation of multiple experiments within each rack. Each EXPRESS Rack provides eight Middeck Locker Equivalent locations and two drawer locations for powered experiment equipment, also referred to as sub-rack payloads. Payload developers may provide their own structure to occupy the equivalent volume of one, two, or four lockers as a single unit. Resources provided for each location include power (28 Vdc, 0-500 W), command and data handling (Ethernet, RS-422, 5 Vdc discrete, +/- 5 Vdc analog), video (NTSC/RS 170A), and air cooling (0-200 W). Each rack also provides water cooling (500 W) for two locations, one vacuum exhaust interface, and one gaseous nitrogen interface. Standard interfacing cables and hoses are provided on-orbit. One laptop computer is provided with each rack to control the rack and to accommodate payload application software. Four of the racks are equipped with the Active Rack Isolation System to reduce vibration between the ISS and the rack. EXPRESS Racks are operated by the Payload Operations Integration Center at Marshall Space Flight Center and the sub-rack experiments are operated remotely by the investigating organization. Payload Integration Managers serve as a focal to assist organizations developing payloads for an EXPRESS Rack. NASA provides EXPRESS Rack simulator software for payload developers to checkout payload command and data handling at the development site before integrating the payload with the EXPRESS Functional Checkout Unit for an end-to-end test before flight. EXPRESS Racks began supporting investigations onboard ISS on April 24, 2001 and will continue through the life of the ISS.

Thompson, Sean W.↗
NASA NTRS2016

Conducting Research on the International Space Station using the EXPRESS Rack Facilities

Eight "Expedite the Processing of Experiments to Space Station" (EXPRESS) Rack facilities are located within the International Space Station (ISS) laboratories to provide standard resources and interfaces for the simultaneous and independent operation of multiple experiments within each rack. Each EXPRESS Rack provides eight Middeck Locker Equivalent locations and two drawer locations for powered experiment equipment, also referred to as sub-rack payloads. Payload developers may provide their own structure to occupy the equivalent volume of one, two, or four lockers as a single unit. Resources provided for each location include power (28 Vdc, 0-500 W), command and data handling (Ethernet, RS-422, 5 Vdc discrete, +/- 5 Vdc analog), video (NTSC/RS 170A), and air cooling (0-200 W). Each rack also provides water cooling for two locations (500W ea.), one vacuum exhaust interface, and one gaseous nitrogen interface. Standard interfacing cables and hoses are provided on-orbit. One laptop computer is provided with each rack to control the rack and to accommodate payload application software. Four of the racks are equipped with the Active Rack Isolation System to reduce vibration between the ISS and the rack. EXPRESS Racks are operated by the Payload Operations Integration Center at Marshall Space Flight Center and the sub-rack experiments are operated remotely by the investigating organization. Payload Integration Managers serve as a focal to assist organizations developing payloads for an EXPRESS Rack. NASA provides EXPRESS Rack simulator software for payload developers to checkout payload command and data handling at the development site before integrating the payload with the EXPRESS Functional Checkout Unit for an end-to-end test before flight. EXPRESS Racks began supporting investigations onboard ISS on April 24, 2001 and will continue through the life of the ISS.

Thompson, Sean W.↗
NASA NTRS1997

Crew Member Interface with Space Station Furnace Facility

The Space Station Furnace Facility (SSFF) is a facility located in the International Space Station United States Laboratory (ISS US Lab) for materials research in the microgravity environment. The SSFF will accommodate basic research, commercial applications, and studies of phenomena of metals and alloys, electronic and photonic materials, and glasses and ceramics. To support this broad base of research requirements, the SSFF will operate, regulate, and support a variety of Experiment Modules (EMs). To meet station requirements concerning the microgravity level needed for experiments, station is providing an active vibration isolation system, and SSFF provides the interface. SSFF physically consists of a Core Rack and two instrument racks (IRs) that occupy three adjacent ISS US Lab rack locations within the International Space Station (ISS). All SSFF racks are modified International Standard Payload Racks (ISPR). SSFF racks will have a 50% larger pass through area on the lower sides than ISPRs to accommodate the many rack to rack interconnections. The Instrument Racks are further modified with lowered floors and an additional removable panel (15" x 22") on top of the rack for access if needed. The Core Rack shall contain all centralized Core subsystems and ISS subsystem equipment. The two Instrument Racks shall contain the distributed Core subsystem equipment, ISS subsystem equipment, and the EMs. The Core System, which includes the Core Rack, the IR structures, and subsystem components located in the IRs serves as the central control and management for the IRs and the EMs. The Core System receives the resources provided by the International Space Station (ISS) and modifies, allocates, and distributes these resources to meet the operational requirements of the furnace. The Core System is able to support a total of four EMs and can control, support, and activate/deactivate the operations of two EMs, simultaneously. The IRs can be configured to house two small EMs or one tall vertical EM, and serve as the interface between the Core and the respective EM. The Core Rack and an adjacent Instrument Rack (containing one or more furnaces) will be delivered to the ISS in one launch. This is Integrated Configuration One (ICI). The Core Rack and IRI will be passive during transport in the Mini Pressurized Logistics Module (MPLM): Any subsequent EMs to operate within IRI are installed on-orbit. The second IR (containing one or more furnaces) is delivered to ISS on a subsequent launch which will establish Integrated Configuration Two (IC2). Additional integrated configurations will be established with the replacement of EMs or Instrument Racks.

Cash, Martha B.↗