silkski/ENERAD huggingface dataset:
Superconducting Cavity Stabilized Oscillators ( SCSOs ) have produced the most stable clocks to date for integration times between 10(exp 2 ) and 10(exp 3 ) seconds , achieving a fractional frequency stability of 2 x 10(exp -16 ) for a sampling time of 100 s. The principal contributors to cavity frequency variations are : ( 1 ) acceleration effects due to gravity and vibrations ; ( 2 ) temperature variations ; ( 3 ) variations in the energy stored in the cavity ; and ( 4 ) noise introduced by the frequency stabilization circuit . We discuss the prospects for improvements in all these areas for both ground - based and space - based SCSOs , which may lead to SCSOs with fractional frequency stabilities below 10(exp -17 ) . SCSOs of this frequency stability will be useful for testing fundamental physical principles .
This paper builds on the computational aeroelastic results published previously and generated in support of the second Aeroelastic Prediction Workshop for the NASA Benchmark Supercritical Wing configuration . The computational results are obtained using FUN3D , an unstructured grid Reynolds - Averaged Navier - Stokes solver developed at the NASA Langley Research Center . The analysis results focus on understanding the dip in the transonic flutter boundary at a single Mach number ( 0.74 ) , exploring an angle of attack range of 􀀀1 to 8 and dynamic pressures from wind off to beyond flutter onset . The rigid analysis results are examined for insights into the behavior of the aeroelastic system . Both static and dynamic aeroelastic simulation results are also examined .
In my presentation , I will describe several approximation methods with different level of complexity ; they will be gradually applied to simple examples of horizontally inhomogeneous clouds . Understanding of photon horizontal transport and radiative smoothing can help to improve accuracy of the methods The accuracy of the methods will be compared with the full Monte Carlo calculations . The specifics of Monte Carlo in cloudy atmospheres will be also discussed . A special emphasis will be put on the strong forward scattering peak in the phase functions .
As demonstrated by ongoing concept designs and the recent ARTEMIS mission , there is , currently , significant interest in exploiting three - body dynamics in the design of trajectories for both robotic and human missions within the Earth - Moon system . The concept of an interactive and ' dynamic ' catalog of potential solutions in the Earth - Moon system is explored within this paper and analyzed as a framework to guide trajectory design . Characterizing and compiling periodic and quasi - periodic solutions that exist in the circular restricted three - body problem may offer faster and more efficient strategies for orbit design , while also delivering innovative mission design parameters for further examination .
Spacecraft flying in tetrahedron formations are excellent for electromagnetic and plasma studies . To better understand the Earth s magnetosphere and its interaction with the solar wind , the NASA Goddard Magnetospheric Multiscale ( MMS ) mission will fly a tetrahedron formation through different regions of the magnetosphere close to the magnetic equatorial plane . However , to explore regions that are almost perpendicular to the ecliptic plane a dramatic plane change is needed . To minimize fuel , a double lunar swingby can be used to perform the plane change . This paper investigates the feasibility of flying a four - spacecraft formation through the required double lunar swingby .
NASA s Chandra X - ray Observatory and ESA s XMM - Newton made their first observations over a decade ago . The unprecedented and complementary capabilities of these observatories to detect , image , and measure the energy of cosmic X - rays , achieved less than 50 years after the first detection of an extra - solar X - ray source , represent an increase in sensitivity comparable in going from naked - eye observations to the most powerful optical telescopes over the past 400 years . In this presentation we highlight some of the many discoveries made using these powerful X - ray observatories that have transformed 21st century astronomy . We briefly discuss future prospects for this truly exciting field .
The Amplification Factor Transport ( AFT ) transition model proposed by Coder and Maughmer is implemented in the unstructured and curvilinear Reynolds - Averaged Navier - Stokes ( RANS ) solvers of the Launch Ascent and Vehicle Aerodynamics ( LAVA ) platform . It is coupled to the Spalart - Allmaras ( SA ) turbulence model through a modified intermittency variable . As part of the model verification and validation phase , laminar - turbulent transition is studied over 2D flat plates , wind turbine and general aviation airfoils , as well as a 3D inclined prolate spheroid and the JAXA Standard Model ( JSM ) . This work will analyze the sensitivity of the results to grid refinement , grid paradigm , flow conditions and numerical schemes . The numerical efficiency of the unstructured and curvilinear solvers will be compared and convergence acceleration techniques will be explored to address a broad range of aerodynamics applications .
In this study , attributes are described for solid and liquid propulsion systems based on historical data . This study is not intended to compare liquid and solid propulsion system attributes , rather to present options for their use in various mission scenarios . US launch vehicle data from 1970 to 2008 was analyzed to assess solid and liquid propulsion development cost and schedule characteristics , performance features , and safety and mission success attributes . The study assessed historical trends for liquid and solid systems , and investigated implications of those trends . It was found that the two propulsion technologies have unique , common and complementary attributes that can be leveraged to meet mission requirements .
There is a need to derive a power spectral density ( PSD ) envelope for nonstationary acceleration time histories , including launch vehicle data , so that components can be designed and tested accordingly . This paper presents the results of the three methods for an actual flight accelerometer record . Guidelines are given for the application of each method to nonstationary data . The method can be extended to other scenarios , including transportation vibration .
We describe a processor which has been implemented to generate map products starting from C - band interferometric data . The first stage of the processor consists of the conventional interferometric synthetic aperture radar ( SAR ) processing producing a digital elevation model ( DEM ) and a SAR brightness image in sensor coordinates . In the second stage of processing , a land use classification map is obtained by using the DEM , brightness , and interferometric correlation layers . Auxiliary layers which include a drainage layer , a height gradient layer , a height error layer , an estimated penetration layer , and a shaded relief layer are also computed . In the final step , all UTM collocated layers are combined in a geographical information system ( GIS ) which allows for both hard copy map products and digital applications .
Robust , automated mesh generation for problems with deforming geometries , such as ice accreting on aerodynamic surfaces , remains a challenging problem . Here we describe a technique to deform a discrete surface as it evolves due to the accretion of ice . The surface evolution algorithm is based on a smoothed , face - offsetting approach . We also describe a fast algebraic technique to propagate the computed surface deformations into the surrounding volume mesh while maintaining geometric mesh quality . Preliminary results presented here demonstrate the ecacy of the approach for a sphere with a prescribed accretion rate , a rime ice accretion , and a more complex glaze ice accretion .
During the Puerto Rico Dust Experiment ( PRIDE ) upwelling and downwelling solar spectral irradiance was measured on board the SPAWAR Navajo and downwelling solar spectral flux was measured at a surface site using the NASA Ames Solar Spectral Flux Radiometer . These data will be used to determine the net solar radiative forcing of dust aerosol and to quantify the solar spectral radiative energy budget in the presence of elevated aerosol loading . We will assess the variability in spectral irradiance using formal principal component analysis procedures and relate the radiative variability to aerosol microphysical properties . Finally , we will characterize the sea surface reflectance to improve aerosol optical depth retrievals from the AVHRR satellite and to validate SeaWiFS ocean color products .
Must use earth 's most abundant natural resources - Biomass , Solar , Arid land ( 43 % ) , Seawater ( 97 % ) with nutrients ( 80 % ) plus brackish waters and nutrients resolve environmental triangle of conflicts energy - food - freshwater and ultrafine particulate hazards . Requires Paradigm Shift - Develop and Use Solar * for energy ; Biomass for aviation and hybrid - electric - compressed air mobility fueling with transition to hydrogen long term .
Two 22 - cells 19Ah Nickel - Hydrogen ( Ni - H2 ) Single Pressure Vessel ( SPV ) Qual batteries , one each from EPI / Joplin and EPI / Butler , were designed and procured . The two batteries differ in the cell encapsulation technology , stack preload , and activation procedure . Both the Butler and Joplin batteries met the specified requirements when subjected to qualification testing and completed 2100 and 1300 LEO cycles respectively , with nominal performance . This paper discusses advantages , design features , testing procedures , and results of the two single pressure vessel Ni - H2 batteries .
An Integrated Gate Turnaround Management ( IGTM ) prototype was developed at NASA Ames Simulation Laboratories ( SimLabs ) using Dallas Ft . Worth International Airport ( DFW ) to demonstrate the IGTM concepts feasibility and benefits . The simulation architecture includes : the IGTM controller , an Airline Operations Control ( AOC ) application , Big DataAnalytics Input ( BAI ) application , a terminal traffic simulation or known as NASA - developed Surface Operation Simulator and Scheduler ( SOSS ) , and a Database Server . ActiveMQ , a Java messaging service , was used to emulate the System Wide Information Management ( SWIM ) data network messaging . This paper describes the modeling and simulation of the IGTM concept , and illustrates selected use cases to demonstrate the feasibility and benefits of the IGTM concept for optimizing gate turnaround operations .
Several topics relating to premixed flame behavior at reduced gravity have been studied . These topics include : ( 1 ) flame balls ; ( 2 ) flame structure and stability at low Lewis number ; ( 3 ) experimental simulation of buoyancy effects in premixed flames using aqueous autocatalytic reactions ; and ( 4 ) premixed flame propagation in Hele - Shaw cells . Because of space limitations , only topic ( 1 ) is discussed here , emphasizing results from experiments on the recent STS-107 Space Shuttle mission , along with numerical modeling efforts .
The L - band ( 1 - 2 GHz ) microwave remote sensing has been widely acknowledged as the most promising method to monitor regional to global soil moisture . Consequently , the Soil Moisture Active Passive ( SMAP ) satellite applied this technique to provide global soil moisture every 2 to 3 days . To verify the performance of SMAP , the fourth and fifth campaign of SMAP Experiments ( SMAPEx-4 -5 ) were carried out at the beginning of the SMAP operational phase in the Murrumbidgee River catchment , southeast Australia . The airborne radar and radiometer observations together with ground sampling on soil moisture , vegetation water content , and surface roughness were collected in coincidence with SMAP overpasses . The SMAPEx-4 and -5 data sets will benefit to SMAP post - launch calibration andvalidation under Australian land surface conditions .
Emergent behavior , a subject of much research in biology , sociology , and economics , is a foundational element of Complex Systems Science and is apropos in the design of sensor network systems . To demonstrate engineering for emergent behavior , a novel approach in the design of a sensor / actuator network is presented maintaining optimal noise attenuation as an adaptation to changing acoustic conditions . Rather than use the conventional approach where sensors are managed by a central controller , this new paradigm uses a biomimetic model where sensor / actuators cooperate as a community of autonomous organisms , sharing with neighbors to control impedance based on local information . From the combination of all individual actions , an optimal attenuation emerges for the global system .
A commercially available surface vorticity flow solver ’s ability to model propeller - wing interaction effects was evaluated . First , a study was conducted to determine solution sensitivity to simulation parameters . Then , a deflected slipstream experiment was replicated with an actuator disk and wing model . Comparison with experimental data showed that predictions of lift and longitudinal force coefficients matched well at low flap deflections , but experienced offsets in magnitude with increasing flap deflection . Predictions of pitching moment differed significantly from experimental data largely due to the simple actuator disk model being insufficient for capturing the effects of non - zero flow incidence and non - uniform inflow .
We explore the magnetic sensing capabilities of two 4H - SiC n+p diodes fabricated by NASA Glenn which only differ in the implanted ion species , nitrogen and phosphorus , and the implant activation annealing time . We use low- and high - field electrically detected magnetic resonance ( EDMR ) to investigate the defect structure used to sense magnetic fields as well as to evaluate the sensitivity . In addition , we expose these devices to high energy electron radiation to evaluate the defect sensing capability in a harsh radiation environment . The results from this work will allow us to tailor our processing methods to design a more optimal 4H - SiC pn diode for magnetic field sensing in harsh environments .
The National Polar - orbiting Operational Environmental Satellite System ( NPOESS ) Preparatory Project ( NPP ) Science Data Segment ( SDS ) will make daily data requests for approximately six terabytes of NPP science products for each of its six environmental assessment elements from the operational data providers . As a result , issues associated with duplicate data requests , data transfers of large volumes of diverse products , and data transfer failures raised concerns with respect to the network traffic and bandwidth consumption . The NPP SDS Data Depository and Distribution Element ( SD3E ) was developed to provide a mechanism for efficient data exchange , alleviate duplicate network traffic , and reduce operational costs .
Radio Frequency Interference ( RFI ) is a persistent and growing problem experienced by spaceborne microwave radiometers . Recent missions such as SMOS , SMAP , and GPM have detected RFI in L , C , X , and K bands . To proactively deal with this issue , microwave radiometers must ( 1 ) Utilize new algorithms for RFI detection ( 2 ) Utilize fast digital back - ends that sample at hundreds of MHz . The wideband digital signal processing testbed ( WB - RFI ) is a platform that allows rapid development and testing various RFI detection and mitigation algorithms .
L3 Technologies Electron Devices Division , ( L3 EDD ) and L3 Technologies Narda Microwave West ( L3 NMW ) , are completing space - flight qualification for a 200 - watt Q - band linearized channelized traveling - wave tube amplifier ( LCTWTA ) capable of over 5 GHz instantaneous bandwidth in a conduction - cooled package . This paper will discuss the LCTWTA performance , manufacturing and flight qualification test results .
We review the current state of knowledge concerning microbial extremophiles and comets and the potential significance of comets to Astrobiology . We model the thermal history of a cometary body , regarded as an assemblage of boulders , dust , ices and organics , as it approaches a perihelion distance of - IAU . The transfer of incident energy from sunlight into the interior leads to the melting of near surface ices , some under stable porous crust , providing possible habitats for a wide range of microorganisms . We provide data concerning new evidence for indigenous microfossils in CI meteorites , which may be the remains of extinct cometary cores . We discuss the dominant microbial communities of polar sea - ice , Antarctic ice sheet , and cryoconite environments as possible analogs for microbial ecosystems that may grow in sub - crustal pools or in ice / water films in comets .
One of the many technological hurdles that must be overcome in future missions is the challenge of validating as - built systems against the models used for design . We propose a technique composed of intelligent parameter exploration in concert with automated failure analysis as a scalable method for the validation of complex space systems . The technique is impervious to discontinuities and linear dependencies in the data , and can handle dimensionalities consisting of hundreds of variables over tens of thousands of experiments .
The capabilities of a heated tube facility used for testing rocket engine coolant channels at the NASA Lewis Research Center are presented . The facility uses high current , low voltage power supplies to resistively heat a test section to outer wall temperatures as high as 730 C ( 1350 F ) . Liquid or gaseous nitrogen , gaseous helium , or combustible liquids can be used as the test section coolant . The test section is enclosed in a vacuum chamber to minimize heat loss to the surrounding system . Test section geometry , size , and material ; coolant properties ; and heating levels can be varied to generate heat transfer and coolant performance data bases .
As autonomous Unmanned Aerial Systems ( UAS ) become more prevalent , improvements in airworthiness assessments , data security , establishing vehicle trust , and more will become necessary to make fleet operations of these systems routine . Currently , these are verified for every UAS vehicle through a time - intensive manual inspection performed by human individuals . This process becomes infeasible when introduced into large - scale operations , so the Fit2Fly project is attempting to address these concerns . Fit2Fly is a multi - year project with a large scope , so we chose to narrow our focus to building a proof - of - concept feasibility simulation in tandem with physical UAS demonstration . This work resulted in a software simulation capable of running asynchronous commercial operations with persistent data modeling in coordination with several autonomous drones using integrated radio and GPS configurations .
Frozen orbits are orbits which have only short - period changes in their mean eccentricity and argument of periapse , so that they basically keep a fixed orientation within their plane of motion . Nearly frozen orbits are those whose eccentricity and argument of periapse have values close to those of a frozen orbit . We call them " nearly " frozen because their eccentricity vector ( a vector whose polar coordinates are eccentricity and argument of periapse ) will stay within a bounded distance from the frozen orbit eccentricity vector , circulating around it over time . For highly inclined orbits around the Earth , this distance is effectively constant over time . Furthermore , frozen orbit eccentricity values are low enough that these orbits are essentially eccentric ( i.e. , off center ) circles , so that nearly frozen orbits around Earth are bounded above and below by frozen orbits .
We present the description of a processor which has been implemented to generate map products starting from C - band interferometric data . The first stage of the processor consists of the conventional interferometric SAR processing producing a Digital Elevation Model ( DEMs ) and a SAR brightness image in sensor coordinates . In the second stage of processing , a land use classification map is obtained by using the DEM , brightness , and interferometric correlation layers . Auxiliary layers which include a drainage layer , a height gradient layer , a height error layer , an estimated penetration layer , and a shaded relief layer are also computed . In the final step , all UTM collocated layers are combined in a GIS system which allows for both hard copy map products and for digital applications .
Controlling Carbon Dioxide ( CO2 ) partial pressure in the habitable vehicle environment is a critical part of operations on the International Space Station ( ISS ) . On the United States segment of ISS , CO2 levels are primarily controlled by the Carbon Dioxide Removal Assembly ( CDRA ) . There are two CDRAs on ISS ; one in the United States Laboratory module , and one in the Node3 module . CDRA has been through several significant operational issues , performance issues and subsequent re - design of various components , primarily involving the Desiccant Adsorbent Bed ( DAB ) assembly and Air Selector Valves ( ASV ) . This paper will focus on significant operational and performance issues experienced by the CDRA team from 2008 - 2012 .
A technology demonstration of free space optical communication at interplanetary distances is planned via one or more future NASA deep - space missions . Such demonstrations will “ pave the way ” for operational use of optical communications on future robotic / potential Human missions . Hence , the Deep Space Network architecture will need to evolve . Preliminary attempts to model the anticipated future mission set and simulate how well it loads onto assumed architectures with combinations of RF and optical apertures have been evaluated . This paper discusses the results of preliminary loading simulations for hybrid RF - optical network architectures and highlights key mission and ground infrastructure considerations that emerge .
There is a limited amount of hypervelocity impact ( HVI ) data on pressurized composite overwrapped pressure vessels ( COPV ) . In recent years , NASA has performed HVI tests to characterize impact conditions resulting in either leak or burst of the COPVs representative of spacecraft hardware . This paper reports on the results of 40 tests that have been conducted on several types of COPV configurations , pressurized by inert gas to near the vessels rated maximum expected operating pressure ( MEOP ) . These tests were used to better understand COPV response under HVI conditions and develop ballistic limit equations ( BLE ) related to these tests .
To continue to build broadly based consensus on the future of human space exploration , the Fourth Community Workshop on Achievability and Sustainability of Human Exploration of Mars ( AM IV ) , organized by Explore Mars , Inc. and the American Astronautical Society , was held at the Double Tree Inn in Monrovia , CA . , December 68 , 2016 . Approximately 60 invited professionals from the industrial and commercial sectors , academia , and NASA , along with international colleagues , participated in the workshop . These individuals were chosen to be representative of the breadth of interests in astronaut and robotic Mars exploration .
This paper describes the quantitative application of the theory of System Health Management and its operational subset , Fault Management , to the selection of Abort Triggers for a human - rated launch vehicle , the United States ' National Aeronautics and Space Administration 's ( NASA ) Space Launch System ( SLS ) . The results demonstrate the efficacy of the theory to assess the effectiveness of candidate failure detection and response mechanisms to protect humans from time - critical and severe hazards . The quantitative method was successfully used on the SLS to aid selection of its suite of Abort Triggers .