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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 415 records · Page 23
All sourcesNASA NTRSDOE OSTI
NASA NTRS2000

Distinct abscisic acid signaling pathways for modulation of guard cell versus mesophyll cell potassium channels revealed by expression studies in Xenopus laevis oocytes

Regulation of guard cell ion transport by abscisic acid (ABA) and in particular ABA inhibition of a guard cell inward K(+) current (I(Kin)) is well documented. However, little is known concerning ABA effects on ion transport in other plant cell types. Here we applied patch clamp techniques to mesophyll cell protoplasts of fava bean (Vicia faba cv Long Pod) plants and demonstrated ABA inhibition of an outward K(+) current (I(Kout)). When mesophyll cell protoplast mRNA (mesophyll mRNA) was expressed in Xenopus laevis oocytes, I(Kout) was generated that displayed similar properties to I(Kout) observed from direct analysis of mesophyll cell protoplasts. I(Kout) expressed by mesophyll mRNA-injected oocytes was inhibited by ABA, indicating that the ABA signal transduction pathway observed in mesophyll cells was preserved in the frog oocytes. Co-injection of oocytes with guard cell protoplast mRNA and cRNA for KAT1, an inward K(+) channel expressed in guard cells, resulted in I(Kin) that was similarly inhibited by ABA. However, oocytes co-injected with mesophyll mRNA and KAT1 cRNA produced I(Kin) that was not inhibited by ABA. These results demonstrate that the mesophyll-encoded signaling mechanism could not substitute for the guard cell pathway. These findings indicate that mesophyll cells and guard cells use distinct and different receptor types and/or signal transduction pathways in ABA regulation of K(+) channels.

NASA Discipline Plant Biology↗
NASA NTRS2005

Lunar and Planetary Science XXXVI, Part 18

Topics discussed include: PoDS: A Powder Delivery System for Mars In-Situ Organic, Mineralogic and Isotopic Analysis Instruments Planetary Differentiation of Accreting Planetesimals with 26Al and 60Fe as the Heat Sources Ground-based Observation of Lunar Surface by Lunar VIS/NIR Spectral Imager Mt. Oikeyama Structure: First Impact Structure in Japan? Central Mounds in Martian Impact Craters: Assessment as Possible Perennial Permafrost Mounds (Pingos) A Further Analysis of Potential Photosynthetic Life on Mars New Insight into Valleys-Ocean Boundary on Mars Using 128 Pixels per Degree MOLA Data: Implication for Martian Ocean and Global Climate Change; Recursive Topography Based Surface Age Computations for Mars: New Insight into Surficial Processes That Influenced Craters Distribution as a Step Toward the Formal Proof of Martian Ocean Recession, Timing and Probability; Laser-induced Breakdown Spectroscopy: A New Method for Stand-Off Quantitative Analysis of Samples on Mars; Milk Spring Channels Provide Further Evidence of Oceanic, >1.7-km-Deep Late Devonian Alamo Crater, Southern Nevada; Exploration of Martian Polar Residual Caps from HEND/ODYSSEY Data; Outflow Channels Influencing Martian Climate: Global Circulation Model Simulations with Emplaced Water; Presence of Nonmethane Hydrocarbons on Pluto; Difference in Degree of Space Weathering on the Newborn Asteroid Karin; Circular Collapsed Features Related to the Chaotic Terrain Formation on Mars; A Search for Live (sup 244)Pu in Deep-Sea Sediments: Preliminary Results of Method Development; Some Peculiarities of Quartz, Biotite and Garnet Transformation in Conditions of Step-like Shock Compression of Crystal Slate; Error Analysis of Remotely-Acquired Mossbauer Spectra; Cloud Activity on Titan During the Cassini Mission; Solar Radiation Pressure and Transient Flows on Asteroid Surfaces; Landing Site Characteristics for Europa 1: Topography; and The Crop Circles of Europa.

Source record↗
NASA NTRS2005

Lightning Mapping and the Nowcasting of Severe Storms

This paper describes a successful research and operational collaboration between NASA scientists and NWS forecasters to improve severe stor m warnings using real-time data from a regional VHF total lightning mapping array (LMA). Key objectives of our research using LMA data ar e: a) Identification of intensifying and weakening storms using the time rate-of-change of total flash rate; b) Improved severe storm poten tial situational awareness; c) Evaluation of the potential of total f lash rate trend to improve severe storm probability of detection (POD ) and lead time; and d) Validation of mesoscale model forecasts of th understorm initiation. The LMA data are distributed for ingest and di splay in the WFO AWIPS decision support system, and archived at each WFO for case studies, event playbacks, and assessments using the NWS Warning Event Simulator. The Huntsville WFO has upgraded severe thund erstorm warnings to verified tornado warnings and avoided a false ala rm on a severe storm through the added information on storm growth, intensification, and decay that can be deduced from the magnitude and temporal trend of total flash rates. We present detailed case studies of the observed relationships between lightning activity and tornadi c storm development as determined by radar reflectivity and velocity fields, and thunderstorms forecast by the Weather Research and Foreca st (WRF) model. From these collaborative studies, forecasters can eva luate the added value of total lightning data within the forecast and warning decision-making process (http://weather.msfc.nasa.gov/sport) .

Goodman, S.↗
NASA NTRS2005

STS-114: Discovery Mission Status Briefing

Paul Hill, STS-114 Lead Shuttle Flight Director, talks about the imagery that was captured during the first twenty four hours in orbit. He expresses that new data was captured during ascent of the Space Shuttle Discovery through imagery and in-orbit handheld photographs of the Orbital Maneuvering system (OMS) pods were taken. Laser surveys were also taken of both the wing leading edges and nose caps using the Orbiter Boom and Sensor System (OBSS) instrument package. He presents raw footage from the Laser Dynamic Range Imager (LDRI) at the end of the OBSS showing RCC panels and tiles. He also answers questions from the news media about the possible damage to the Orbiter and debris during lift-off.

Source record↗
NASA NTRS2005

Effects of Volcanoes on the Natural Environment

The primary focus of this project has been on the development of techniques to study the thermal and gas output of volcanoes, and to explore our options for the collection of vegetation and soil data to enable us to assess the impact of this volcanic activity on the environment. We originally selected several volcanoes that have persistent gas emissions and/or magma production. The investigation took an integrated look at the environmental effects of a volcano. Through their persistent activity, basaltic volcanoes such as Kilauea (Hawaii) and Masaya (Nicaragua) contribute significant amounts of sulfur dioxide and other gases to the lower atmosphere. Although primarily local rather than regional in its impact, the continuous nature of these eruptions means that they can have a major impact on the troposphere for years to decades. Since mid-1986, Kilauea has emitted about 2,000 tonnes of sulfur dioxide per day, while between 1995 and 2000 Masaya has emotted about 1,000 to 1,500 tonnes per day (Duffel1 et al., 2001; Delmelle et al., 2002; Sutton and Elias, 2002). These emissions have a significant effect on the local environment. The volcanic smog ("vog" ) that is produced affects the health of local residents, impacts the local ecology via acid rain deposition and the generation of acidic soils, and is a concern to local air traffic due to reduced visibility. Much of the work that was conducted under this NASA project was focused on the development of field validation techniques of volcano degassing and thermal output that could then be correlated with satellite observations. In this way, we strove to develop methods by which not only our study volcanoes, but also volcanoes in general worldwide (Wright and Flynn, 2004; Wright et al., 2004). Thus volcanoes could be routinely monitored for their effects on the environment. The selected volcanoes were: Kilauea (Hawaii; 19.425 N, 155.292 W); Masaya (Nicaragua; 11.984 N, 86.161 W); and Pods (Costa Rica; 10.2OoN, 84.233 W).

Mouginis-Mark, Peter J.↗
NASA NTRS2004

Overview of the Aerothermodynamics Analysis Conducted in Support of the STS-107 Accident Investigation

A graphic presentation of the aerothermodynamics analysis conducted in support of the STS-107 accident investigation. Investigation efforts were conducted as part of an integrated AATS team (Aero, Aerothermal, Thermal, Stress) directed by OVEWG. Graphics presented are: STS-107 Entry trajectory and timeline (1st off-nominal event to Post-LOS); Indications from OI telemetry data; Aero/aerothermo/thermal analysis process; Selected STS-107 side fuselage/OMS pod off-nominal temperatures; Leading edge structural subsystem; Relevant forensics evidence; External aerothermal environments; STS-107 Pre-entry EOM3 heating profile; Surface heating and temperatures; Orbiter wing leading edge damage survey; Internal aerothermal environments; Orbiter wing CAD model; Aerodynamic flight reconstruction; Chronology of aerodynamic/aerothermoydynamic contributions; Acreage TPS tile damage; Larger OML perturbations; Missing RCC panel(s); Localized damage to RCC panel/missing T-seal; RCC breach with flow ingestion; and Aero-aerothermal closure. NAIT served as the interface between the CAIB and NASA investigation teams; and CAIB requests for study were addressed.

Campbell, Charles H.↗
NASA NTRS1998

Ultra-Wideband UHF Microstrip Array for GeoSAR Application

GeoSAR is a program sponsored by DARPA (Defense Advanced Research Projects Agency) and NASA (National Aeronautics and Space Administration) to develop an airborne, radar- based, commercial terrain mapping system for identification of geologic, seismic, and environmental information, it has two (dual-band at X and UHF) state-of-the-art interferometric synthetic aperture radar (SAR) ground mapping systems. The UHF interferometric system is utilized to penetrate the vegetation canopy and obtain true ground surface height information, while the Xband system will provide capability of mapping the top foliage surface. This paper presents the UHF antenna system where the required center frequency is 350 MHz with a 160 MHz of bandwidth (46% from 270 MHz to 430 MHz). The antenna is required to have dual-linear polarization with a peak gain of 10 dB at the center frequency and a minimum gain of 8 dB toward two ends of the frequency band. One of the most challenging tasks, in addition to achieving the 46% bandwidth, is to develop an antenna with small enough size to fit in the wing-tip pod of a Gulfstream II aircraft.

Thomas, Robert F.↗
NASA NTRS2005

REUSABLE PROPULSION ARCHITECTURE FOR SUSTAINABLE LOW-COST ACCESS TO SPACE

Two transportation architecture changes are presented at either end of a conventional two-stage rocket flight: 1) Air launch using a large, conventional, pod hauler design (i.e., Crossbow)ans 2) Momentum exchange tether (i.e., an in-space asset like MXER). Air launch has ana analytically justified cost reduction of approx. 10%, but its intangible benefits suggest real-world operations cost reductions much higher: 1) Inherent launch safety; 2) Mission Risk Reduction; 3) Favorable payload/rocket limitations; and 4) Leveraging the aircraft for other uses (military transport, commercial cargo, public outreach activities, etc.)

Bonometti, Joseph↗
NASA NTRS2006

The Relationship Between Global Mean Sea Level Rise and the Reference Frame

The Terrestrial Reference Frame is the fundamental means by which we relate observations in space and time. For example, in order to generate a homogeneous and consistent time series of geo-referenced altimeter measurements over the span of the Topex/Poseidon and Jason-1 missions, we must examine carefully the role of improvements in measurement modelling, force modelling, and improved reference frame realizations. In this paper, we quantify the effects of improvements in force modelling, for example the use of new GRACE-derived gravity models, the effect of time-variable gravity derived from GRACE on altimeter satellite orbits. In addition, we examine the effects of modelling geocenter in altimeteric satellite POD, and look at how the application of atmospheric loading might affect the time-series of precise orbits for Topex/Poseidon and Jason-1.

Lemoine, F.↗
NASA NTRS2006

Development and Sizing of the JWST Integrated Science Instrument Module (ISIM) Metering Structure

The JWST Integrated Science Instrument Module (ISIM) includes a large metering structure (approx. 2m x 2m x 1.5m) that houses the science instruments and guider. Stringent dimensional stability and repeatability requirements combined with mass limitations led to the selection of a composite bonded frame design comprised of biased laminate tubes. Even with the superb material specific stiffness, achieving the required frequency for the given mass allocations in conjunction with severe spatial limitations imposed by the instrument complement has proven challenging. In response to the challenge, the ISIM structure team considered literally over 100 primary structure topology and kinematic mount configurations, and settled on a concept comprised of over 70 m of tubes, over 50 bonded joint assemblies, and a "split bi-pod" kinematic mount configuration. In this paper, we review the evolution of the ISIM primary structure topology and kinematic mount configuration to the current baseline concept.

Johnston, John↗
NASA NTRS2005

Nutritional and Flavor Components of Brassica Xapa L. Grown on ISS

Brassica rapa L. cv. 'Astroplants' were grown on the International Space Station during April - June 2002 in the Biomass Production System. Plants were manually pollinated and were maturing seeds when they were harvested for preservation in flight by fixation or freezing. Overall growth and development were comparable between flight and ground control plants. Chlorophyll and carbohydrate content of the leaves were the same in the two treatments. Although comparable numbers of seeds were produced inside the seed pods, the developing seeds from the spaceflight treatment had only half of the dry weight of the ground controls and had altered storage components. Glucosinolate content of the stem tissue was also determined. The concentration of 3-butenyl-glucosinolate was on average 75% greater in the spaceflight samples than in the ground control. The results demonstrate how the spaceflight environment influences nutritional and flavor characteristics of a potential crop for use in a Biological Life Support System.

Musgrave, M. E.↗
NASA NTRS2006

The Crossbow Air Launch Trade Space

Effective air launching of a rocket is approached from a broad systems engineering viewpoint. The elementary reasons for why and how a rocket might be launched from a carrier aircraft are examined. From this, a carefully crafted set of guiding principles is presented. Rules are generated from a fundamental foundation, derived from NASA systems study analyses and from an academic vantage point. The Appendix includes the derivation of a revised Mass Multiplier Equation, useful in understanding the rocket equation as it applies to real vehicles, without the need of complicated weight and sizing programs. The rationale for air launching, being an enormously advantageous Earth-To-Orbit (ETO) methodology, is presented along with the realization that the appropriate air launch solution may lie in a very large class of carrier aircraft; the pod-hauler. Finally, a unique area of the system trade space is defined and branded Crossbow. Crossbow is not a specific hardware design for air launch, but represents a comprehensive vision for commercial, military and space transportation. This document serves as a starting point for future technical papers that evaluate the air launch hypotheses and assertions produced during the past several years of study on the subject.

Bonometti, Joseph A.↗
NASA NTRS2007

Application of Carbon Based Nano-Materials to Aeronautics and Space Lubrication

The tribology program at NASA Glenn Research Center in Cleveland, Ohio, is investigating carbon based nano-particles for their potential in advanced concept lubrication products. Service conditions range from high temperature atmospheric to low temperature vacuum. Some of the lubricants and surface coatings of tribological significance that we have evaluated include neat nano-particles, both grown in-situ and as bulk material deposited on the substrate, and nano-particles dispersed in oils which are all highly substrate interactive. We discuss results of testing these systems in a spiral orbit tribometer (SOT) and a unidirectional pin-on-disc (PoD) tribometer. A nano-onions/Krytox mixture evaluated as a lubricant for angular contact bearings in air caused a marked lowering of the coefficient of friction (CoF) (0.04 to 0.05) for the mixture with an eight-fold improvement in lifetime over that of the Krytox alone. In vacuum, no effect was observed from the nano-onions. Multi-walled nanotubes (MWNT) and graphitized MWNT were tested under sliding friction in both air and vacuum. The MWNT which were grown in-situ oriented normal to the sliding surface exhibited low CoF (0.04) and long wear lives. Bulk MWNT also generate low CoF (0.01 to 0.04, vacuum; and 0.06, air) and long wear life (>1 million orbits, vacuum; and >3.5 million, air). Dispersed graphitized MWNT were superior to MWNT and both were superior to aligned MWNT indicating that orientation is not an issue for solid lubrication. Single-walled nanotubes (SWNT) were modified by cutting into shorter segments and by fluorination. All SWNTs exhibited low CoF in air, with good wear lives. The SWNT with slight fluorination yielded an ultra-low CoF of 0.002 although the best wear life was attributed to the nascent SWNT.

Street, Kenneth W., Jr.↗
NASA NTRS2006

Wireless Command-and-Control of UAV-Based Imaging LANs

Dual airborne imaging system networks were operated using a wireless line-of-sight telemetry system developed as part of a 2002 unmanned aerial vehicle (UAV) imaging mission over the USA s largest coffee plantation on the Hawaiian island of Kauai. A primary mission objective was the evaluation of commercial-off-the-shelf (COTS) 802.11b wireless technology for reduction of payload telemetry costs associated with UAV remote sensing missions. Predeployment tests with a conventional aircraft demonstrated successful wireless broadband connectivity between a rapidly moving airborne imaging local area network (LAN) and a fixed ground station LAN. Subsequently, two separate LANs with imaging payloads, packaged in exterior-mounted pressure pods attached to the underwing of NASA's Pathfinder-Plus UAV, were operated wirelessly by ground-based LANs over independent Ethernet bridges. Digital images were downlinked from the solar-powered aircraft at data rates of 2-6 megabits per second (Mbps) over a range of 6.5 9.5 km. An integrated wide area network enabled payload monitoring and control through the Internet from a range of ca. 4000 km during parts of the mission. The recent advent of 802.11g technology is expected to boost the system data rate by about a factor of five.

Herwitz, Stanley↗
NASA NTRS2007

Advanced Image Processing for NASA Applications

The future of space exploration will involve cooperating fleets of spacecraft or sensor webs geared towards coordinated and optimal observation of Earth Science phenomena. The main advantage of such systems is to utilize multiple viewing angles as well as multiple spatial and spectral resolutions of sensors carried on multiple spacecraft but acting collaboratively as a single system. Within this framework, our research focuses on all areas related to sensing in collaborative environments, which means systems utilizing intracommunicating spatially distributed sensor pods or crafts being deployed to monitor or explore different environments. This talk will describe the general concept of sensing in collaborative environments, will give a brief overview of several technologies developed at NASA Goddard Space Flight Center in this area, and then will concentrate on specific image processing research related to that domain, specifically image registration and image fusion.

LeMoign, Jacqueline↗
NASA NTRS2005

Analysis of Thrust Vectoring Capabilities for the Jupiter Icy Moons Orbiter

A strategy to mitigate the impact of the trajectory design of the Jupiter Icy Moons Orbiter (JIMO) on the attitude control design is described in this paper. This paper shows how the thrust vectoring control torques, i.e. the torques required to steer the vehicle, depend on various parameters (thrust magnitude, thrust pod articulation angles, and thrust moment arms). Rather than using the entire reaction control system (RCS) system to steer the spacecraft, we investigate the potential utilization of only thrust vectoring of the main ion engines for the required attitude control to follow the representative trajectory. This study has identified some segments of the representative trajectory where the required control torque may exceed the designed ion engine capability, and how the proposed mitigation strategy succeeds in reducing the attitude control torques to within the existing capability.

low thrust↗
NASA NTRS2007

NASA ER-2: Flying Laboratory for Earth Science Studies

This viewgraph presentation gives an overview of the NASA ER-2 aircraft. The contents include: 1) ER-2 Specifications; 2) ER-2 Basic Configuration; 3) ER-2 Payload Areas: Nose Area; 4) ER-2 Payload Areas: SuperPod Fore and Aftbody; 5) ER-2 Payload Areas: SuperPod Midbody; 6) ER-2 Payload Areas: Q-Bay; 7) ER-2 Payload Areas: Q-Bay Hatch Designs; 8) ER-2 Payload Areas: External Pods; 9) ER-2 Electrical/Control Interface; 10) ER-2 Typical Flight Profile; 11) Tropical Composition, Cloud and Climate Coupling TC-4; 12) TC-4 Timeline; 13) TC4 Area of Interest; 14) ER-2 TC4 Payload; 15) A/C ready for fuel; 16) ER-2 Pilot being suited; 17) ER-2 Taxing; 18) ER-2 Pilot post flight debrief; and 19) NASA ER-2: Flying Laboratory for Earth Science Studies and Remote Sensing.

Navarro, Robert↗
NASA NTRS2008

Linear FMCW Laser Radar for Precision Range and Vector Velocity Measurements

An all fiber linear frequency modulated continuous wave (FMCW) coherent laser radar system is under development with a goal to aide NASA s new Space Exploration initiative for manned and robotic missions to the Moon and Mars. By employing a combination of optical heterodyne and linear frequency modulation techniques and utilizing state-of-the-art fiber optic technologies, highly efficient, compact and reliable laser radar suitable for operation in a space environment is being developed. Linear FMCW lidar has the capability of high-resolution range measurements, and when configured into a multi-channel receiver system it has the capability of obtaining high precision horizontal and vertical velocity measurements. Precision range and vector velocity data are beneficial to navigating planetary landing pods to the preselected site and achieving autonomous, safe soft-landing. The all-fiber coherent laser radar has several important advantages over more conventional pulsed laser altimeters or range finders. One of the advantages of the coherent laser radar is its ability to measure directly the platform velocity by extracting the Doppler shift generated from the motion, as opposed to time of flight range finders where terrain features such as hills, cliffs, or slopes add error to the velocity measurement. Doppler measurements are about two orders of magnitude more accurate than the velocity estimates obtained by pulsed laser altimeters. In addition, most of the components of the device are efficient and reliable commercial off-the-shelf fiber optic telecommunication components. This paper discusses the design and performance of a second-generation brassboard system under development at NASA Langley Research Center as part of the Autonomous Landing and Hazard Avoidance (ALHAT) project.

Pierrottet, Diego↗