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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 991 records · Page 55
All sourcesNASA NTRSDOE OSTI
NASA NTRS1989

Power from space for use on earth: An emerging global option

The concept of the Earth as a closed ecological system is addressed from the point of view of the availability and use of energy from space and its potential influence on the economies of both developed and developing countries. The results of past studies of the solar power satellite (SPS) are reviewed, and the current international activities exploring various aspects of an SPS are mentioned. The functions of an SPS, including collection of solar energy in orbit, conversion to an intermediate form of energy, transmission of energy from orbit to Earth, and conversion to useful energy in the most appropriate form are discussed. Directions for future developments are addressed including a suggested planning framework. Salient aspects of SPS technologies are presented, and the potential benefits of the uses of lunar materials for the SPS construction are outlined. Scenarios within the context of international participation in a global SPS system are presented. The conclusion is drawn that an SPS system is one of the few promising, globally applicable power generation options that has the potential to meet energy demands in the 21st Century and to achieve the inevitable transition to inexhaustible and renewable energy sources.

Glaser, Peter E.↗
NASA NTRS1990

Relations between the photospheric magnetic field and the emission from the outer atmospheres of cool stars. II - The C IV 1550 A doublet

Solar and stellar data are used to determine the relationship between C IV 1548 + 1551 A and magnetic flux densities. C IV SMM-UVSP spectroheliograms of solar quiet regions and plages are analyzed. Typical distribution functions of C IV flux densities over both quiet and active solar regions are presented. The C IV emission is shown to be dependent on magnetic flux density.

Schrijver, C. J.↗
NASA NTRS1992

Stress observations and driving force models for the South American plate

A comparison of stress observations to predictions of driving force models for the South American plate is presented. Conditions for dynamical equilibrium are used to estimate the magnitudes of forces as a function of age, with ridge push and slab pull as active forces, and plate drag and slab resistance as passive forces. The results are consistent with earlier published models, and it is found that the primary balance for an oceanic plate is between slab pull and the resisting drag forces. The model is generalized for the possible forces driving the South American plate, and it is compared with observed stress measurements and kinematics. The plate balance is found to be largely between ridge push and plate drag. The magnitude of a possible trench suction force is estimated using a model with an eddy between the Nazca slab and the overlying South American plate.

Stefanick, Michael↗
NASA NTRS1992

STS-44 Space Shuttle mission report

The STS-44 Space Shuttle Program Mission Report is a summary of the vehicle subsystem operations during the forty-fourth flight of the Space Shuttle Program and the tenth flight of the Orbiter vehicle Atlantis (OV-104). In addition to the Atlantis vehicle, the flight vehicle consisted of the following: an External Tank (ET) designated as ET-53 (LWT-46); three Space Shuttle main engines (SSME's) (serial numbers 2015, 2030, and 2029 in positions 1, 2, and 3, respectively); and two Solid Rocket Boosters (SRB's) designated as BI-047. The lightweight redesigned Solid Rocket Motors (RSRM's) installed in each one of the SRB's were designated as 360L019A for the left SRB and 360W019B for the right SRB. The primary objective of the STS-44 mission was to successfully deploy the Department of Defense (DOD) Defense Support Program (DSP) satellite/inertial upper stage (IUS) into a 195 nmi. earth orbit at an inclination of 28.45 deg. Secondary objectives of this flight were to perform all operations necessary to support the requirements of the following: Terra Scout, Military Man in Space (M88-1), Air Force Maui Optical System Calibration Test (AMOS), Cosmic Radiation Effects and Activation Monitor (CREAM), Shuttle Activation Monitor (SAM), Radiation Monitoring Equipment-3 (RME-3), Visual Function Tester-1 (VFT-1), and the Interim Operational Contamination Monitor (IOCM) secondary payloads/experiments.

Fricke, Robert W.↗
NASA NTRS1993

Revised prediction of LDEF exposure to trapped protons

The Long Duration Exposure Facility (LDEF) spacecraft flew in a 28.5 deg inclination circular orbit with an altitude in the range from 319.4 to 478.7 km. For this orbital altitude and inclination, two components contribute most of the penetrating charge particle radiation encountered - the galactic cosmic rays and the geomagnetically trapped Van Allen protons. Where shielding is less than 1.0 g/sq cm geomagnetically trapped electrons make a significant contribution. The 'Vette' models together with the associated magnetic field models and the solar conditions were used to obtain the trapped electron and proton omnidirectional fluences reported previously. Results for directional proton spectra using the MSFC anisotropy model for solar minimum and 463 km altitude (representative for the LDEF mission) were also reported. The directional trapped proton flux as a function of mission time is presented considering altitude and solar activity variation during the mission. These additional results represent an extension of previous calculations to provide a more definitive description of the LDEF trapped proton exposure.

Watts, John W.↗
NASA NTRS1993

STS-53 Space Shuttle mission report

The STS-53 Space Shuttle Program Mission Report provides a summary of the Orbiter, External Tank (ET), Solid Rocket Booster/Redesigned Solid Rocket Motor (SRB/RSRM), and the Space Shuttle Main Engine (SSME) subsystems performance during the fifty-second flight of the Space Shuttle Program, and the fifteenth flight of the Orbiter vehicle Discovery (OV-103). In addition to the Orbiter, the flight vehicle consisted of an ET, which was designated as ET-49/LWT-42; three SSME's, which were serial numbers 2024, 2012, and 2017 in positions 1, 2, and 3, respectively; and two SRB's, which were designated BI-055. The lightweight RSRM's that were installed in each SRB were designated 360L028A for the left SRB, and 360L028B for the right SRB. The primary objective of this flight was to successfully deploy the Department of Defense 1 (DOD-1) payload. The secondary objectives of this flight were to perform the operations required by the Glow Experiment/Cryogenic Heat Pipe Experiment Payload (GCP); the Hand-Held, Earth-Oriented, Real-Time, Cooperative, User-Friendly, Location-Targeting and Environmental System (HERCULES); the Space Tissue Loss (STL); the Battlefield Laser Acquisition Sensor Test (BLAST); the Radiation Monitoring Equipment-III (RME-III); the Microcapsules in Space-1 (MIS-1); the Visual Function Tester-2 (VFT-2); the Cosmic Radiation Effects and Activation Monitor (CREAM); the Clouds Logic to Optimize Use of Defense Systems-1A (CLOUDS-1A); the Fluids Acquisition and Resupply Experiment (FARE); and the Orbital Debris Radar Calibration Spheres (ODERACS). In addition to presenting a summary of subsystem performance, this report also discusses each Orbiter, ET, SSME, SRB, and RSRM in-flight anomaly in the applicable section of the report. Listed in the discussion of each anomaly is the officially assigned tracking number as published by each Project Office in their respective Problem Tracking List. All times given in this report are in Greenwich mean time (G.m.t.) as well as mission elapsed time (MET).

Fricke, Robert W., Jr.↗
NASA NTRS1993

Power Reactant Storage Assembly (PRSA) (Space Shuttle). PRSA hydrogen and oxygen DVT tank refurbishment

The Power Reactant Storage Assembly (PRSA) liquid hydrogen Development Verification Test (H2 DVT) tank assembly (Beech Aircraft Corporation P/N 15548-0116-1, S/N 07399000SHT0001) and liquid oxygen (O2) DVT tank assembly (Beech Aircraft Corporation P/N 15548-0115-1, S/N 07399000SXT0001) were refurbished by Ball Electro-Optics and Cryogenics Division to provide NASA JSC, Propulsion and Power Division, the capability of performing engineering tests. The refurbishments incorporated the latest flight configuration hardware and avionics changes necessary to make the tanks function like flight articles. This final report summarizes these refurbishment activities. Also included are up-to-date records of the pressure time and cycle histories.

Source record↗
NASA NTRS1993

Nearly steady flows in GONG prototype data

Doppler velocity images obtained with the GONG prototype instrument were analyzed to measure the nearly steady photospheric flows. The data consists of 88 images each of velocity, intensity, and modulation obtained at 20:00 UT on 88 days from July 1992 to February 1994. Each velocity image was temporally filtered to remove the p-mode oscillations, masked to exclude active regions, and then analyzed using spherical harmonics and orthogonal functions as described by Hathaway (1992). The spectral coefficients show very consistent results for the entire time interval with some evidence of year-to-year variations. The rotation profile agrees well with previous results and exhibits a north-south asymmetry that reverses sign during the 20 month interval. The residual rotation velocities exhibit structures with amplitudes of approximately 5 m/s that may be related to torsional oscillations. The meridional circulation is directed from the equator toward the poles with a peak velocity in the photosphere of approximately 50 m/s. The higher order components are very weak but indicate a divergent flow from the mid-latitudes (opposite that found for the June 1989 data). The convective limb shift is well fit by a 3rd order polynomial. The convection spectrum has a prominent peak at spherical harmonic degrees of l approximately 150 with very little signal in the low degree modes. Analysis of this signal shows that there is no evidence for giant cell convection at the level of approximately 10 m/s for all modes up to l = 32.

Hathaway, David H.↗
NASA NTRS1994

The stellar population of the Lupus clouds

We present photometric and spectroscopic observations of the H alpha emission stars in the Lupus dark cloud complex. We estimate the effective temperatures of the stars from their spectral types and calculate the reddening towards each object from the (R-I) colors. From these data, we derive mass and age distributions for the Lupus stars using a new set of pre-main sequence evolutionar tracks. We compare the results for the Lupus stars with those for a similar population of young stellar objects in Taurus-Auriga and Chamaeleon and with the initial mass function for field stars in the solar neighborhood. From the H-R diagrams, Lupus appears to contain older stars than Taurus. The Lupus dark clouds form a greater proportion of low mass stars than the Taurus complex. Also, the proportion of low mass stars in Lupus is higher than that predicted by the Miller-Scalo initial mass function, and the lowest mass stars in Lupus are less active than similar T Tauri stars in other regions.

Hughes, Joanne↗
NASA NTRS1995

Computer-Assisted Monitoring Of A Complex System

Propulsion System Advisor (PSA) computer-based system assists engineers and technicians in analyzing masses of sensory data indicative of operating conditions of space shuttle propulsion system during pre-launch and launch activities. Designed solely for monitoring; does not perform any control functions. Although PSA developed for highly specialized application, serves as prototype of noncontrolling, computer-based subsystems for monitoring other complex systems like electric-power-distribution networks and factories.

Beil, Bob J.↗
NASA NTRS1998

Performance Testing of a Trace Contaminant Control Subassembly for the International Space Station

As part of the International Space Station (ISS) Trace Contaminant Control Subassembly (TCCS) development, a performance test has been conducted to provide reference data for flight verification analyses. This test, which used the U.S. Habitation Module (U.S. Hab) TCCS as the test article, was designed to add to the existing database on TCCS performance. Included in this database are results obtained during ISS development testing; testing of functionally similar TCCS prototype units; and bench scale testing of activated charcoal, oxidation catalyst, and granular lithium hydroxide (LiOH). The present database has served as the basis for the development and validation of a computerized TCCS process simulation model. This model serves as the primary means for verifying the ISS TCCS performance. In order to mitigate risk associated with this verification approach, the U.S. Hab TCCS performance test provides an additional set of data which serve to anchor both the process model and previously-obtained development test data to flight hardware performance. The following discussion provides relevant background followed by a summary of the test hardware, objectives, requirements, and facilities. Facility and test article performance during the test is summarized, test results are presented, and the TCCS's performance relative to past test experience is discussed. Performance predictions made with the TCCS process model are compared with the U.S. Hab TCCS test results to demonstrate its validation.

Perry, J. L.↗
NASA NTRS1999

Thermal Control Using Electrochromism

The applicability of a charge balanced electrochromic device to modulate the frequencies in the thermal infrared region is examined in this study. The device consisted of a transparent conductor, WO3, anode, PMMA/LiClO4 electrolyte, V2O5 cathode and transparent conductor. The supporting structure in the device is SnO2 coated glass and the edges are sealed with epoxy to reduce moisture absorption. The performance evaluation comprised of cyclic voltammetric measurements and determination of transmittance at various wavelengths. The device was subjected to anodic and cathodic polarization by sweeping the potential at a rate of 10 mV/sec from -0.8V to 1.8V. The current versus voltage profile indicated no reaction between -0.5 and +0.5 V. The device is colored green at 1.8 V with a transmittance of 5% at a wavelength, lambda = 900 nm and colorless at -0.8 V with a transmittance of 74% at lambda = 500 nm. The optical modulation is limited to 400-1500 nm and there is no activity in the thermal infrared. The switching time is a function of temperature and time for coloring reaction was slower than the bleaching reaction. The device yielded reproducible values for transmittance when cycled between colored and bleached states by application of 1.8V and -0.8V, respectively.

Vaidyanathan, Hari↗
NASA NTRS1977

Light-Activated Amino Acid Transport Systems in Halobacterium halobium Envelope Vesicles: Role of Chemical and Electrical Gradients

The accumulation of 20 commonly occurring L-amino acids by cell envelope vesicles of Halobacterium halobium, in response to light-induced membrane potential and an artificially created sodium gradient, has been studied. Nineteen of these amino acids are actively accumulated under either or both of these conditions. Glutamate is unique in that its uptake is driven only by a chemical gradient for sodium. Amino acid concentrations at half-maximal uptake rates (Km) and maximal transport rates (V(sub max) have been determined for the uptake of all 19 amino acids. The transport systems have been partially characterized with respect to groups of amino acids transported by common carriers, cation effects, and relative response to the electrical and chemical components of the sodium gradient, the driving forces for uptake. The data presented clearly show that the carrier systems, which are responsible for uptake of individual amino acids, are as variable in their properties as those found in other organisms, i. e., some are highly specific for individual amino acids, some transport several amino acids competitively, some are activated by a chemical gradient of sodium only, and some function also in the complete absence of such a gradient. For all amino acids, Na(+) and K(+) are both required for maximal rate of uptake. The carriers for L-leucine and L-histidine are symmetrical in that these amino acids are transported in both directions across the vesicle membrane. It is suggested that coupling of substrate transport to metabolic energy via transient ionic gradients may be a general phenomenon in procaryotes.

MacDonald, Russell E.↗
NASA NTRS2002

Inter-Satellite Communications Considerations and Requirements for Distributed Spacecraft and Formation Flying Systems

In order to avoid selecting inadequate inter-spacecraft cross-link communications standards for Distributed Spacecraft System (DSS) missions, it is first necessary to identify cross-link communications strategies and requirements common to a cross-section of proposed missions. This paper addresses the cross-link communication strategies and requirements derived from a survey of 39 DSS mission descriptions that are projected for potential launch within the next 20 years. The inter-spacecraft communications strategies presented are derived from the topological and communications constraints from the DSS missions surveyed. Basic functional requirements are derived from an analysis of the fundamental activities that must be undertaken to establish and maintain a cross-link between two DSS spacecraft. Cross-link bandwidth requirements are derived from high-level assessments of mission science objectives and operations concepts. Finally, a preliminary assessment of possible cross-link standards is presented within the context of the basic operational and interoperability requirements.

Kwadrat, Carl F.↗
NASA NTRS2003

Non-Invasive Investigation of Bone Adaptation in Humans to Cumulative Daily Mechanical Loading

The goal of our research is to better understand the functional relationship between cumulative daily skeletal loading generated by daily activity and the regulation of bone density and bone structure. We have proposed the calcaneus and tibia as useful model bone sites loaded by internal forces in equilibrium with the ground reaction force during gait. The daily history of the ground reaction force is a good relative measure of daily lower limb and calcaneal loading that can be compared to bone density and structure of the calcaneus and cross-sectional geometry of the tibia and fibula. Over the past several years, we have developed image-processing technologies to improve our ability to measure bone density and structure in the calcaneus and lower leg non-invasively with computed tomography and bone densitometry, or DXA. The objective of our current research effort is to determine the accuracy and precision of our CT and DXA image processing methods.

Whalen, Robert↗
NASA NTRS1993

Mechanosensory calcium-selective cation channels in epidermal cells

This paper explores the properties and likely functions of an epidermal Ca(2+)-selective cation channel complex activated by tension. As many as eight or nine linked or linkable equivalent conductance units or co-channels can open together. Open time for co-channel quadruplets and quintuplets tends to be relatively long with millimolar Mg2+ (but not millimolar Ca2+) at the cytosolic face of excised plasma membrane. Sensitivity to tension is regulated by transmembrane voltage and temperature. Under some circumstances channel activity is sychronized in rhythmic pulses. Certain lanthanides and a cytoskeleton-disturbing herbicide that inhibit gravitropic reception act on the channel system at low concentrations. Specifically, ethyl-N-phenylcarbamate promotes tension-dependent activity at micromolar levels. With moderate suction, Gd3+ provided at about 0.5 micromole at the extracellular face of the membrane promotes for several seconds but may then become inhibitory. Provision at 1-2 micromoles promotes and subsequently inhibits more vigorously (often abruptly and totally), and at high levels inhibits immediately. La3+, a poor gravitropic inhibitor, acts similarly but much more gradually and only at much higher concentrations. These properties, particularly these susceptibilities to modulation, indicate that in vivo the mechanosensitive channel must be mechanosensory and mechanoregulatory. It could serve to transduce the shear forces generated in the integrated wall-membrane-cytoskeleton system during turgor changes and cell expansion as well as transducing the stresses induced by gravity, touch and flexure. In so far as such transduction is modulated by voltage and temperature, the channels would also be sensors for these modalities as long as the wall-membrane-cytoskeleton system experiences mechanical stress.

NASA Discipline Number 40-50↗
NASA NTRS1992

ATP synthesis in Halobacterium saccharovorum: evidence that synthesis may be catalysed by an F0F1-ATP synthase

Halobacterium saccharovorum synthesized ATP in response to a pH shift from 8 to 6.2. Synthesis was inhibited by carbonyl cyanide m-chloro-phenylhydrazone, dicyclohexylcarbodiimide, and azide. Nitrate, an inhibitor of the membrane-bound ATPase previously isolated from this organism, did not inhibit ATP synthesis. N-Ethymaleimide, which also inhibited this ATPase, stimulated the production of ATP. These observations suggested that H. saccharovorum synthesized and hydrolysed ATP using different enzymes and that the vacuolar-like ATPase activity previously described in H. saccharovorum was an ATPase whose function is yet to be identified.

NASA Discipline Exobiology↗
NASA NTRS2004

Meteor Outbursts and Storms from the Spacecraft Hazard Perspective

The recent Leonid meteor storms have propelled meteor shower forecasting from an idea into the realm of practical application, invoked several times per year by numerous spacecraft. This paper will describe shower activity predictions, which give zenith hourly rate (ZHR) as a function of time, and how these are translated into spacecraft risks. Common spacecraft meteor shower mitigation strategies will also be discussed, and the important issue as to when to implement such operations considered. It should be noted that, while the recent meteor storms did not result in the loss of a vehicle, there were a few spacecraft anomalies attributed to Leonid strikes, and the nature of these will be commented upon. Finally, we assess the current state of the art in shower forecasting, and take a look "down the road" at some possible outbursts in the near future.

Cooke, William↗