silkski/ENERAD huggingface dataset:
Fission fragment direct energy conversion has been considered in the past for the purpose of increasing nuclear power plant efficiency and for advanced space propulsion . Since the fragments carry electric charge ( typically in the order of 20 e ) and have 100 MeV - range kinetic energy , techniques utilizing very high - voltage DC electrodes have been considered . This study is focused on a different approach : the kinetic energy of the charged fission fragments is converted into alternating current by means of a traveling wave coupling scheme ( Traveling Wave Direct Energy Converter , TWDEC ) , thereby not requiring the utilization of high voltage technology . A preliminary feasibility analysis of the concept is introduced based on a conceptual level study and on a particle simulation model of the beam dynamics .
The paper describes an optical Alignment Mirror Mechanism ( AMM ) , and discusses its control scheme . The mirror 's angular positioning accuracy requirement is + /- 0.2 arc - sec . This requires the mirror 's linear positioning actuators to have a positioning accuracy of + /- 109 nm to enable the mirror to meet the angular tip / tilt accuracy requirement . Demonstrated capabilities are + /- 35 nm linear positioning capability at the actuator , which translates into + /- 0.07 arc - sec angular mirror positioning accuracy .
We evaluate with simulated data a new type of sample variance for the characterization of frequency stability . The new statistic ( referred to as TOTALVAR and its square root TOTALDEV ) is a better predictor of long - term frequency variations than the present sample Allan deviation . The statistical model uses the assumption that a time series of phase or frequency differences is wrapped ( periodic ) with overall frequency difference removed . We find that the variability at long averaging times is reduced considerably for the five models of power - law noise commonly encountered with frequency standards and oscillators .
The performance of six 88 Ah Nickel - Hydrogen ( Ni - H2 ) batteries that are used onboard in the Hubble Space Telescope ( Flight Spare Module ( FSM ) and Flight Module 2 ( FM2 ) ) is discussed . These batteries have 22 series cells per battery and a common bus that would enable them to operate at a common voltage . It is launched on April 24 , 1990 . This paper reviews : the cell design , battery specification , system constraints , operating parameters , onboard battery management , and battery performance .
The Compact Ocean Wind Vector Radiometer ( COWVR ) is a technology demonstration mission , developed at the Jet Propulsion Laboratory ( JPL ) , and scheduled for launch in 2016 . The goal of COWVR is to provide the same windvector retrieval accuracy of other instruments , like WindSat , while reducing the total mass and using less power . In this paper , we present an overview of the COWVR instrument , and a detailed description of the EM ( Electromagnetic ) modeling of the antenna system and the test campaign carried out at JPL to assess its performance . Special emphasis has been placed on assessing the accuracy of the predictions made with the RF ( Radio Frequency ) model . We will show that the predicted radiation patterns are accurate enough so one can use them for orbit radiometer calibration .
This viewgraph presentation reviews some of the techniques used to analyze the damage done to chromosome from ion radiation . Fluorescence in situ hybridization ( FISH ) , mFISH , mBAND , telomere and centromereprobes have been used to study chromosome aberrations induced in human cells exposed to low - and high - LET radiation in vitro . There is some comparison of the different results from the various techniques . The results of the study are summarized .
Halide and sulfate efflorescences are common on meteorite finds , especially those from cold deserts . Meanwhile , the late - stage sulfate veins in Orgueil are universally accepted as having originated by the action of late - stage high fO2 aqueous alteration on an asteroid . I suggest here that these phenomena have essentially the same origin .
Altered thermoregulation has been reported following spaceflight simulations such as water immersion and bedrest but it has never been evaluated immediately after actual spaceflight . Impaired thermoregulation may have significant impact during various spaceflight activities such as countermeasure exercise , extravehicular activity ( EVA ) , landing , and egress . It would be manifested as an increased body temperature and heart rate and decreased work capacity and endurance . In this study we evaluated the exercise responses of two crewmembers following a long duration spaceflight and measured their changes in body temperatures , skin blood flow , sweating and heat production during a mild submaximal exercise stress .
Micro - Raman spectroscopy is one of the primary methods of mineralogical analysis in the laboratory , and more recently in the field . Because of its versatility and ability to interrogate rocks in their natural form it is one of the front runners for the next generation of in situ instruments designed to explore adverse set of solar system bodies ( e.g. Mars , Venus , the Moon , and other primitive bodies such as asteroids and the Martian moons Phobos and Deimos ) , as well as for pre - selection of rock and soil samples for potential cache and return missions .
A localized 3 - D roughness causes boundary - layer separation and ( weak ) shocks . Most importantly , streamwise vortices occur which induce streamwise ( low U , high T ) streaks . Immersed boundary method ( volume force ) suitable to represent roughness element in DNS . Favorable comparison between bi - global stability theory and DNS for a " y - mode " Outlook : Understand the flow physics ( investigate " z - modes " in DNS through sinuous spanwise forcing , study origin of the beat in DNS ) .
Extensive study of the near - limb solar filament eruption event on 2000 February 26 , involving coronal images from YOHKOH , SOHO EIT and photospheric magnetogram from MID have shown that that both " runaway - tether - cutting - type reconnection " and " fast breakout - type reconnection " may have occurred early in the fast phase of the eruption and may have played an important role in unleashing the explosion ( Sterling & Moore 2004 ) . That study did not identify which or if either of these types of reconnection actually triggered the fast phase . Here , together with a magnetogram and He1 10830 A filtergram from NSO / KP , we present Halpha filtergrams from Big Bear Solar Observatory , that show evidence of " tether - cutting - type reconnection " before and during the eruption of the southern filament , situated at one of the neutral lines of the quadrupole magnetic structure .
For the past three years , the MIT Haystack Observatory and the broadband team have been developing a proof - of - concept broadband geodetic VLBI microwave ( 2 - 12 GHz ) receiver . Also on - going at Haystack is the development of post - correlation processing needed to extract the geodetic observables . Using this processing , the first fully - phase - calibrated geodetic fringes have been produced from observations conducted with the proof - of - concept system . The results we present show that the phase - calibrated phase residuals from four 512 MHz bands spanning 2 GHz have an RMS phase variation of 8deg which corresponds to a delay uncertainty of 12 ps .
Enhanced , lightweight material systems , such as 17 - 4PH stainless steel sandwich panels are being developed for use as fan blades and fan containment material systems for next generation engines . In order to improve the production for these systems , nondestructive evaluation ( NDE ) techniques , such as ultrasonic spectroscopy , are being utilized to evaluate the brazing quality between the 17 - 4PH stainless steel face plates and the 17 - 4PH stainless steel foam core . Based on NDE data , shear tests are performed on sections representing various levels of brazing quality from an initial batch of these sandwich structures . Metallographic characterization of brazing is done to corroborate NDE findings and the observed shear failure mechanisms .
This slide presentation reviews the status of several NASA Dryden projects . These include : the Lift And Nozzle Change Effects on Tail Shock ( LANCETS ) , Integrated Resilient Aircraft Control ( IRAC ) F-18 # 853 Testbed X-48B , Blended Wing Body flights , Stratospheric Observatory for Infrared Astronomy ( SOFIA ) , Ikhana Project , and the Orion Crew Exploration Vehicle ( CEV ) Launch Abort Systems Tests
Following a failure in side 1 of the HST SI C&DH in September 2008 , HST Servicing Mission 4 ( SM-4 ) was delayed so that a SI C&DH Orbital Replacement Unit ( ORU ) could be qualified for flight . This second generation SI C&DH ( SI C&DH-2 ) included several enhancements which increased its thermal dissipation near critical components . In order to maintain the SI C&DH-2 within its operational temperature limits , several thermal modifications were installed prior to its final qualification testing . This paper presents the thermal modifications performed on the SI C&DH-2 , as well as the thermal ground test results and a correlation of the SI C&DH-2 thermal design to flight telemetry .
The geological boundary between Triassic and Permian strata coincides with the greatest life extinction in the Earth 's history . Although the cause of the extinction is still the subject of intense debates , recent discoveries in the P - T boundary layer of shocked quartz grains , fullerenes with the extraterrestrial noble gases , Fe metal nuggets , and chondritic meteorite fragments all point to a powerful collision of Earth with a celestial body in the late Permian . Here we report the discovery of magnetic Fe , Si , Al - rich impact spherules which accompany the chondritic meteorite fragments in some samples from the P - T boundary layer at Graphite Peak , Antarctica .
With many global earth observation systems and missions focused on climate systems and the associated large volumes of observational data available for exploring and explaining how climate is changing and why , there is an urgent need for climate services . Giovanni , the NASA GES DISC Interactive Online Visualization ANd ANalysis Infrastructure , is a simple to use yet powerful tool for analysing these data for research on global warming and climate change , as well as for applications to weather . air quality , agriculture , and water resources ,
The JEM - EUSO collaboration intends to study high energy cosmic ray showers using a large downward looking telescope mounted on the Japanese Experiment Module of the International Space Station . The telescope focal plane is instrumented with approx.300k pixels operating as a digital camera , taking snapshots at approx . 1MHz rate . We report an investigation of the trigger and reconstruction efficiency of various algorithms based on time and spatial analysis of the pixel images . Our goal is to develop trigger and reconstruction algorithms that will allow the instrument to detect energies low enough to connect smoothly to ground - based observations .
Identify simple fully validated cost models that provide estimation uncertainty with cost estimate . Based on COCOMO variable set . Use machine learning techniques to determine : a ) Minimum number of cost drivers required for NASA domain based cost models ; b ) Minimum number of data records required and c ) Estimation Uncertainty . Build a repository of software cost estimation information . Coordinating tool development and data collection with : a ) Tasks funded by PA&E Cost Analysis ; b ) IV&V Effort Estimation Task and c ) NASA SEPG activities .
The Mojave Volatiles Prospector ( MVP ) project is a science - driven field program with the goal of producing critical knowledge for conducting robotic exploration of the Moon . MVP feeds science , payload , and operational lessons learned to the development of a real - time , short - duration lunar polar volatiles prospecting mission . MVP achieved these goals through a simulated lunar rover mission to investigate the composition and distribution of surface and subsurface volatiles in a natural and a priori unknown environment within the Mojave Desert , improving our understanding of how to find , characterize , and access volatiles on the Moon .
Electrospun piezoelectric polymers are being developed for use as a component on lightweight wings for micro - air vehicles ( MAV ) . The goal is to incorporate fibers with tailored properties to permit dynamic control and maneuverability during flight . In particular , electrospun fiber mats of two piezoelectric polymers were investigated to ascertain their potential for the MAV application . In the work reported here , the typical experimental set - up for electrospinning was modified to induce fiber orientation in the spun mats . The morphologies of the resulting fibers and fiber mats were evaluated for various experimental conditions , and a comparison between oriented and unoriented fiber mats was carried out .
Terahertz is the primary frequency for line and continuum radiation from cool ( 5 - 100 K ) gas ( atoms and molecules ) and dust . This viewgraph presentation reviews the reasons for the interest in Terahertz Space Applications ; the Terahertz Space Missions : in the past , present and planned for the future , Terahertz source requirements and examples of some JPL instruments ; and a case study for a flight deliverable : THz Local Oscillators for ESA s Herschel Space Telescope
This DAA is for the Phase II webinar presentation of the ARMD - funded SMASH technology . A self - repairing aluminum - based composite system has been developed using liquid - assisted healing theory in conjunction with the shape memory effect of wire reinforcements . The metal matrix composite was thermodynamically designed to have a matrix with a relatively even dispersion of low - melting phase , allowing for repair of cracks at a pre - determined temperature . Shape memory alloy wire reinforcements were used within the composite to provide crack closure . Investigators focused the research on fatigue cracks propagating through the matrix in order to optimize and computer model the SMASH technology for aeronautical applications .
This viewgraph presentation reviews the simulation of Single Event Upset ( SEU ) cross sections using the membrane electrode assembly ( MEA ) resistance and electrode diffusion ( MRED ) tool using " Best guess " assumptions about the process and geometry , and direct ionization , low - energy beam test results . This work will also simulate SEU cross - sections including angular and high energy responses and compare the simulated results with beam test data for the validation of the model . Using MRED , we produced a reasonably accurate upset response model of a low - critical charge SRAM without detailed information about the circuit , device geometry , or fabrication process
We analyze the convergence of a substructuring iterative method with Lagrange multipliers , proposed recently by Farhat and Roux . The method decomposes finite element discretization of an elliptic boundary value problem into Neumann problems on the subdomains and a coarse problem for the subdomain nullspace components . For linear conforming elements and preconditioning by the Dirichlet problems on the subdomains , we prove the asymptotic bound on the condition number C(1 + log(H / h))(sup gamma ) , gamma = 2 or 3 , where h is the characteristic element size and H is the subdomain size .
We have updated our merged ozone data ( MOD ) set using the TOMS data from the new version 8 algorithm . We then analyzed these data for contributions from solar cycle , volcanoes , QBO , and halogens using a standard statistical time series model . We have recently completed a hindcast run of our 3D chemical - transport model for the same years . This model uses off - line winds from the finite - volume GCM , a full stratospheric photochemistry package , and time - varying forcing due to halogens , solar uv , and volcanic aerosols . We will report on a parallel analysis of these model results using the same statistical time series technique as used for the MOD data .
The James Webb Space Telescope ( JWST ) will be a large ( 6 m ) cold ( 50 K ) telescope launched to the second Earth - Sun Lagrange point . It is the successor to the Hubble Space Telescope , and is a partnership of NASA , ESA and CSA . It 's science goals are to detect and identify the first galaxies to form in the universe , to trace their assembly into the Hubble Sequence , and to study stellar and planetary system formation . JWST will have three instruments : The Near InfiaRed Camera ( NIRCam ) and the Near InfraRed multiobject Spectrometer ( NIRSpec ) will cover the wavelength range 0.6 to 5 microns , and the Mid InfraRed Instrument ( MIRI ) will do both imaging and spectroscopy from 5 to 28 microns .
Rocket motor components are primarily assembled by adhesion . a ) For example , the RSRM ( Reusable Solid Rocket Motor - part of the Space Shuttle Boosters ) system contains 10,000 sq ft of bondline area . b ) Rocket motors contain a variety of adhesive / substrate bond systems c ) Bond system performance requirements also vary . To assemble reliable components , ATK Space Systems and customers invest substantial resources to the study of bond assembly processes . a ) Surface and adhesion science ; b ) Adhesive chemistry ; c ) Process parameters ; d ) Contamination effects .
This work continues the analysis of data obtained during a 2017 NASA DGEN Aeropropulsion Research Turbofan ( DART ) core / combustor - noise baseline test in the NASA GRC Aero - Acoustic Propulsion Laboratory ( AAPL ) . The DART is a cost - efficient testbed for the study of core - noise physics and mitigation . Acoustic data were simultaneously acquired using the AAPL overhead microphone array in the engine aft - quadrant farfield , a single midfield microphone , and two infinite - tube - probe sensors for unsteady pressures at the core - nozzle exit . The data are here examined on an 1/3 - octave basis as a first step in extending and improving core - noise prediction capability .
This viewgraph presentation reports on the development of a high power 780 nm laser suitable for space applications of laser cooling . A possible solution is to use frequency doubling of high power 1560 nm telecom lasers . The presentation shows a diagram of the frequency conversion , and a graph of the second harmonic generation in one crystal , and the use of the cascading crystals . Graphs show the second harmonic power as a function of distance between crystals , second harmonic power vs. pump power , tunability of laser systems .
A linear model for gyroscopic waves in the base of the solar corona is proposed . The purpose was to point out possible observational manifestations of the phenomenon . According to the model , these waves move slowly around the sun along heliolatitude circles . The fact that the red line corona is fainter on the solar side facing the apex and north - south and east - west asymmetries of the red coronal emission line could be interpreted as a possible observational manifestation of the gyroscopic wave phenomenon in the coronal base .
This presentation will show how NASA KSC controls interfaces for Modular Product Architecture ( MPA ) using Locator Skeletons , Interface Skeletons , and Product Structure , to be combined together within a Motion Skeleton . The user will learn how to utilize skeleton models to communicate interface data , as successfully done at NASA KSC in their use of Motion Skeletons to control interfaces for multi - launch systems . There will be discussion of the methodology used to control design requirements through WTParts , and how to utilize product structure for non - CAD documents .
Solidification Using a Baffle in Sealed Ampoules ( SUBSA ) is the first investigation conducted in the Microgravity Science Glovebox ( MSG ) Facility at the International Space Station ( ISS ) Alpha . In July , August and September of 2002 , 8 single crystals of InSb , doped with Te and Zn , were directionally solidified in microgravity . Ground based tests , related numerical modeling and images of the growth process obtained in microgravity are presented .
Contents include following : ( 1 ) Organizational Changes at MSFC . ( 2 ) Recent Program Support & Technology Development : analysis & cold flow testing : Fastrac , X-34 , X-33 , RLV , LFBB . ( 3 ) Ongoing Activities : RLV focused technology , RBCC concepts development , methodology & code development . ( 4 ) Future Activities and Direction : hardware design and development ; tools development . ( 5 ) Concluding remarks : constraints , cooperation , opportunities .
Arrays of cryogenic microbolometers and other cryogenic detectors are being developed for infrared imaging . If the signal from each sensor is amplified , multiplexed , and digitized using superconducting electronics , then this data can be efficiently read out to ambient temperature with a minimum of noise and thermal load . HYPRES is developing an integrated system based on SQUID amplifiers , a high - resolution analog - to - digital converter ( ADC ) based on RSFQ ( rapid single flux quantum ) logic , and a clocked RSFQ multiplexer . The ADC and SQUIDs have already been demonstrated for other projects , so this paper will focus on new results of a digital multiplexer . Several test circuits have been fabricated using Nb Josephson technology and are about to be tested at T = 4.2 K , with a more complete prototype in preparation .
The use of premixed , shock - induced combustion in the context of a hypervelocity , airbreathing vehicle requires effective injection and mixing of hydrogen fuel and air on the vehicle forebody . Three dimensional computational simulations of fuel injection and mixing from flush - wall and modified ramp and strut injectors are reported in this study . A well - established code , VULCAN , is used to conduct nonreacting , viscous , turbulent simulations on a flat plate at conditions relevant to a Mach 12 flight vehicle forebody . In comparing results of various fuel injection strategies , it is found that strut injection provides the greatest balance of performance between mixing efficiency and stream thrust potential .
A new NanoTCAD - to - Spectre interface is applied to perform mixed - mode SEU simulations of an SRAM cell . Results using newly calibrated TCAD cold temperature substrate mobility models , and BSIM3 compact models extracted explicitly for the cold temperature designs , indicate a 33 % reduction in SEU threshold for the range of temperatures simulated .
This presentation focuses on spatial resolution characterization for QuickBird panochromatic images in 2003 - 2004 and presents data measurements and analysis of SSC edge target deployment and edge response extraction and modeling . The results of the characterization are shown as values of the Modulation Transfer Function ( MTF ) at the Nyquist spatial frequency and as the Relative Edge Response ( RER ) components . The results show that RER is much less sensitive to accuracy of the curve fitting than the value of MTF at Nyquist frequency . Therefore , the RER / edge response slope is a more robust estimator of the digital image spatial resolution than the MTF . For the QuickBird panochromatic images , the RER is consistently equal to 0.5 for images processed with the Cubic Convolution resampling and to 0.8 for the MTF resampling .
A conventional NSI ( NASA Standard Initiator ) normally employs a hot - wire ignition element to ignite ZPP ( zirconium potassium perchlorate ) . With minor modifications to the interior of a header similar to an NSI device to accommodate an SCB ( semiconductor bridge ) , a low cost initiator was obtained . In addition , the ZPP was replaced with THKP ( titanium sub - hydride potassium perchlorate ) to obtain increased overall gas production and reduced static - charge sensitivity . This paper reports on the all - fire and no - fire levels obtained and on a dual mix device that uses THKP as the igniter mix and a thermite as the output mix .