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All sourcesNASA NTRSDOE OSTI
NASA NTRS2014

Operations of Suborbital Research Platforms to Obtain Remote Sensing Data

The Armstrong Flight Research Center (AFRC) operates six highly modified aircraft in support the NASA science mission.These include two ER-2 aircraft, a DC-8, a G-III, and two Global Hawks. The NASA science missions demands that these aircraft be deployed around the globe while carrying a variety of science instruments. The ER-2 reconnaissance aircraft provides routine access to altitudes over 70,000 ft (20km) for large payloads and with an endurance of over 10hours. Recently the ER-2s have conducted convective storm research missions in the mid-western United States and supported the development of new instruments. The DC-8 is a four-engine jetliner that operates for up to 12 hours ataltitudes that range from the surface to 42,000 ft (13 km). Although its flight envelope is equivalent to conventional.

unmanned aerial platforms↗
NASA NTRS2015

Real-Time Kennedy Space Center and Cape Canaveral Air Force Station High-Resolution Model Implementation and Verification

NASA's Launch Services Program, Ground Systems Development and Operations, Space Launch System and other programs at Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS) use the daily and weekly weather forecasts issued by the 45th Weather Squadron (45 WS) as decision tools for their day-to-day and launch operations on the Eastern Range (ER). Examples include determining if they need to limit activities such as vehicle transport to the launch pad, protect people, structures or exposed launch vehicles given a threat of severe weather, or reschedule other critical operations. The 45 WS uses numerical weather prediction models as a guide for these weather forecasts, particularly the Air Force Weather Agency (AFWA) 1.67 km Weather Research and Forecasting (WRF) model. Considering the 45 WS forecasters' and Launch Weather Officers' (LWO) extensive use of the AFWA model, the 45 WS proposed a task at the September 2013 Applied Meteorology Unit (AMU) Tasking Meeting requesting the AMU verify this model. Due to the lack of archived model data available from AFWA, verification is not yet possible. Instead, the AMU proposed to implement and verify the performance of an ER version of the high-resolution WRF Environmental Modeling System (EMS) model configured by the AMU (Watson 2013) in real time. Implementing a real-time version of the ER WRF-EMS would generate a larger database of model output than in the previous AMU task for determining model performance, and allows the AMU more control over and access to the model output archive. The tasking group agreed to this proposal; therefore the AMU implemented the WRF-EMS model on the second of two NASA AMU modeling clusters. The AMU also calculated verification statistics to determine model performance compared to observational data. Finally, the AMU made the model output available on the AMU Advanced Weather Interactive Processing System II (AWIPS II) servers, which allows the 45 WS and AMU staff to customize the model output display on the AMU and Range Weather Operations (RWO) AWIPS II client computers and conduct real-time subjective analyses.

Meteorology↗
NASA NTRS2015

High-Resolution Mesoscale Model Setup for the Eastern Range and Wallops Flight Facility

Mesoscale weather conditions can have an adverse effect on space launch, landing, ground processing, and weather advisories, watches, and warnings at the Eastern Range (ER) in Florida and Wallops Flight Facility (WFF) in Virginia. During summer, land-sea interactions across Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS) lead to sea breeze front formation, which can spawn deep convection that can hinder operations and endanger personnel and resources. Many other weak locally-driven low-level boundaries and their interactions with the sea breeze front and each other can also initiate deep convection in the KSC/CCAFS area. These convective processes often last 60 minutes or less and pose a significant challenge to the local forecasters. Surface winds during the transition seasons (spring and fall) pose the most difficulties for the forecasters at WFF. They also encounter problems forecasting convective activity and temperature during those seasons. Therefore, accurate mesoscale model forecasts are needed to better forecast a variety of unique weather phenomena. Global and national scale models cannot properly resolve important local-scale weather features at each location due to their horizontal resolutions being much too coarse. Therefore, a properly tuned local data assimilation (DA) and forecast model at a high resolution is needed to provide improved capability. To accomplish this, a number of sensitivity tests were performed using the Weather Research and Forecasting (WRF) model in order to determine the best DA/model configuration for operational use at each of the space launch ranges to best predict winds, precipitation, and temperature. A set of Perl scripts to run the Gridpoint Statistical Interpolation (GSI)/WRF in real-time were provided by NASA's Short-term Prediction Research and Transition Center (SPoRT). The GSI can analyze many types of observational data including satellite, radar, and conventional data. The GSI/WRF scripts use a cycled GSI system similar to the operational North American Mesoscale (NAM) model. The scripts run a 12-hour pre-cycle in which data are assimilated from 12 hours prior up to the model initialization time. A number of different model configurations were tested for both the ER and WFF by varying the horizontal resolution on which the data assimilation was done. Three different grid configurations were run for the ER and two configurations were run for WFF for archive cases from 27 Aug 2013 through 10 Nov 2013. To quantify model performance, standard model output will be compared to the Meteorological Assimilation Data Ingest System (MADIS) data. The MADIS observation data will be compared to the WRF forecasts using the Model Evaluation Tools (MET) verification package. In addition, the National Centers for Environmental Prediction's Stage IV precipitation data will be used to validate the WRF precipitation forecasts. The author will summarize the relative skill of the various WRF configurations and how each configuration behaves relative to the others, as well as determine the best model configuration for each space launch range.

Watson, Leela R.↗
NASA NTRS2017

Analysis of Rawinsonde Spatial Separation for Space Launch Vehicle Applications at the Eastern Range

Space launch vehicles use day-of-launch steering commands based upon the upper-level (UL) atmospheric environments in order to alleviate wind induced structural loading and optimize ascent trajectory. Historically, UL wind measurements to support launch operations at the National Aeronautics and Space Administration's (NASA) Kennedy Space Center (KSC), co-located on the United States Air Force's Eastern Range (ER) at the Cape Canaveral Air Force Station use high-resolution (HR) rawinsondes. One inherent limitation with rawinsondes is the approximately one-hour sampling time necessary to measure tropospheric winds. Additionally, rawinsonde drift during ascent due to the ambient wind environment can result in the balloon being hundreds of kilometers down range, which results in questioning whether the measured winds represent the wind environment the vehicle will experience during ascent. This paper will describe the use of balloon profile databases to statistically assess the drift distance away from the ER launch complexes during HR rawinsonde ascent as a function of season. Will also discuss an alternative method to measure UL wind environments in closer proximity to the vehicle trajectory when launching from the ER.

Decker, Ryan K.↗
NASA NTRS2017

Analysis of Rawinsonde Spatial Separation for Space Launch Vehicle Applications at the Eastern Range

Space launch vehicles develop day-of-launch steering commands based upon the upper-level atmospheric environments in order to alleviate wind induced structural loading and optimize ascent trajectory. Historically, upper-level wind measurements to support launch operations at the National Aeronautics and Space Administration's (NASA's) Kennedy Space Center co-located on the United States Air Force's Eastern Range (ER) at the Cape Canaveral Air Force Station use high-resolution rawinsondes. One inherent limitation with rawinsondes consists of taking approximately one hour to generate a vertically complete wind profile. Additionally, rawinsonde drift during ascent by the ambient wind environment can result in the balloon being hundreds of kilometers down range, which results in questioning whether the measured winds represent the wind environment the vehicle will experience during ascent. This paper will describe the use of balloon profile databases to statistically assess the drift distance away from the ER launch complexes during rawinsonde ascent as a function of season and discuss an alternative method to measure upper level wind environments in closer proximity to the vehicle trajectory launching from the ER.

Decker, Ryan K.↗
NASA NTRS2018

Building a QC Database of Meteorological Data from NASA KSC and the United States Air Force's Eastern Range

The National Aeronautics and Space Administration's (NASA) Marshall Space Flight Center (MSFC) Natural Environments Branch (EV44) provides atmospheric databases and analysis in support of space vehicle design and day-of-launch operations for NASA and commercial launch vehicle programs launching from the NASA Kennedy Space Center (KSC), co-located on the United States Air Force's Eastern Range (ER) at the Cape Canaveral Air Force Station. The ER complex is one of the most heavily instrumented sites in the United States with over 31 towers measuring various atmospheric parameters on a continuous basis. An inherent challenge with large datasets consists of ensuring erroneous data are removed from databases, and thus excluded from launch vehicle design analyses. EV44 has put forth great effort in developing quality control (QC) procedures for individual meteorological instruments, however no standard QC procedures for all databases currently exists resulting in QC databases that have inconsistencies in variables, development methodologies, and periods of record. The goal of this activity is to use the previous efforts to develop a standardized set of QC procedures from which to build meteorological databases from KSC and the ER, while maintaining open communication with end users from the launch community to develop ways to improve, adapt and grow the QC database. Details of the QC procedures will be described. As the rate of launches increases with additional launch vehicle programs, It is becoming more important that weather databases are continually updated and checked for data quality before use in launch vehicle design and certification analyses.

Brenton, J. C.↗
NASA NTRS2018

Building a Quality Controlled Database of Meteorological Data from NASA Kennedy Space Center and the United States Air Force's Eastern Range

The National Aeronautics and Space Administration's (NASA) Marshall Space Flight Center (MSFC) Natural Environments Branch (EV44) has provided atmospheric databases and analysis in support of space vehicle design and day-of-launch operations for NASA and commercial launch vehicle programs launching from the NASA Kennedy Space Center (KSC), co-located on the United States Air Force's Eastern Range (ER) at the Cape Canaveral Air Force Station. The ER complex is one of the most heavily instrumented sites in the United States with over 31 towers measuring various atmospheric parameters on a continuous basis. An inherent challenge with large sets of data consists of ensuring erroneous data is removed from databases, and thus excluded from launch vehicle design analyses. EV44 has put forth great effort in developing quality control (QC) procedures for individual meteorological instruments, however no standard QC procedures for all databases currently exists resulting in QC databases that have inconsistencies in variables, methodologies, and periods of record. The goal of this activity is to use the previous efforts by EV44 to develop a standardized set of QC procedures from which to build meteorological databases from KSC and the ER, while maintaining open communication with end users from the launch community to develop ways to improve, adapt and grow the QC database. Details of the QC procedures will be described. As the rate of launches increases with additional launch vehicle programs, it is becoming more important that weather databases are continually updated and checked for data quality before use in launch vehicle design and certification analyses.

Brenton, James C.↗
NASA NTRS2018

Modeling the Effect of Damage on the Electrical Resistivity of Melt-Infiltrated SiC/SiC Composites

Electrical resistivity (ER) measurements are a possible health monitoring technique for CMC components in future aerospace applications. In order to use ER measurements to detect and identify damage, it is necessary to understand how each specific damage state will affect the ER response. In this paper, finite element models are developed and applied to quantify the effect of specific damage states on the electrical resistivity response in a melt-infiltrated silicon carbide (SiC) fiber-reinforced silicon carbide composite. The electrical resistivity of several damage states are calculated by simulating the electric current flow through the damaged micro-structure. This is achieved by performing the numerical solution of the steady-state conservation of charge density equation. Numerical results reveal that cracking of the inter-tow matrix has the most profound effect on the composite electrical resistivity. Also, fiber/matrix debonding at matrix cracks in the 0° tows (tows aligned with the loading direction) may cause a significant increase in the electrical resistivity, but only if the fiber coating resistivity is 1000 Ω-cm or less. Cracks in the 90° tows and the crack opening displacement have very little effect on the composite electrical resistivity.

finite element analysis↗
DOE OSTI2020

Establishing Maximal Core Excess Reactivity Envelope for TREAT Test Vehicle Insertion

The Transient Reactor Test (TREAT) Facility is an air-cooled reactor composed of graphite-urania fuel encapsulated in zirconium alloy canisters and surrounded by ~2 ft (~61 cm) of nuclear grade graphite. The primary role of TREAT is to provide in-pile nuclear-heated safety research via transient testing [1]. The following work represents further analyses building upon previously reported work to support larger volume test vehicles within TREAT [2]. The Broad Use Specimen Transient Experiment Rig (BUSTER) provides ample versatility for numerous transient test concepts. However, future testing and experiment needs will require testing environments of different in-core footprints. The versatility of TREAT allows for the development of variegated core layouts with key limitations emplaced as operational safety temperature restrictions and available core reactivity. The focus of this current effort is to gauge core arrangements for TREAT core loadings to support centralized experimental testing of varying dimensional capacity. The total core excess reactivity (ER) was computed for different arrangements to establish comparison tables that enable ready assessment of core ER available for future experiment concepts. Test vehicle worths would then be necessary to establish available ER to support transient testing requirements and to perform reactor performance and safety calculations [3,4].

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2025

Basics of Electrorefining in the Fuel Cycle Facility

The basic electrochemical concepts that are relevant to the Fuel Cycle Facility electrorefiner (FCF ER) are discussed. Key points are developed in the report that equip the reader to examine the literature for the ER process, and these points are clearly identified. Basic electrochemical concepts are presented and definitions are given prior to a discussion of the energetics and rates of electrorefining. A brief explanation of power supply operation for the electrorefining operation is then given, followed by an elementary discussion of chemical equilibrium. With this background information, FCF ER operations are described in terms of typical operations, their sequence, and the attending chemical reactions.

11 - NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2026

Pushing the Limits of Pulse Shape Discrimination in a Large Liquid Xenon Detector

The LUX-ZEPLIN (LZ) experiment is a direct-detection dark matter experiment, optimized to search for weakly interacting massive particles (WIMPs) through WIMP-nucleon interactions. The main challenge in dark matter detection is differentiating between WIMP signals and background events. In LZ, the ratio of ionization to scintillation signals (charge-to-light) is the primary method for rejecting electronic recoil (ER) background. Pulse shape discrimination (PSD) offers a method for additional ER backgrounds rejection in liquid xenon detectors. In this paper, the discrimination power of PSD with the LZ experiment is discussed. To precisely characterize the scintillation pulse shape, an analysis framework is developed to reconstruct the detection time of individual photons. Using LZ calibration data, the photon-timing prompt fraction discriminator is optimized and achieves ER leakage as low as $15\%$. For specific background processes such as $^{124}$Xe double electron capture, the leakage is reduced further to about $5\%$. PSD is combined with charge-to-light to form two-factor discrimination (TFD). The optimized TFD performance is compared with the performance of the charge-to-light method, with the corresponding false positive rate reduced by up to a factor of two for large scintillation pulses. Finally, PSD and TFD are applied to data from LZ's WS2024 run and their performance is summarized.

Akerib, D. S. [SLAC; KIPAC, Menlo Park]↗
NASA NTRS1996

Advanced Techniques for Improving Wind Direction Ambiguity Removal in Scatterometry

The ambiguity removal algorithm currently planned for NSCAT utilizes a simple median filter?? will discuss techniques of ambiguity removal and outline two new algorithms which can be used to improve ambiguity removal performance without the inclusion of additional wind field information. The techniques are applied to simulated NSCAT data but can be generalized to other scatterometer instruments such as the ERS-1 and ERS-2 scatterometers, and Sea Winds to be launched aboard ADEOS-II in 1999.

ambiguity↗
DOE OSTI2024

Novel, Middle and Long Wave Infrared Laser Sources For Accelerator Applications

The main accomplishment during Years 2020-2024 of the DOE Accelerator Stewardship Program is proof-of-principle demonstration of amplification of an ultrashort 10 µm seed pulse in a multiatmosphere CO 2 laser optically pumped by nanosecond pulses of either a ~4.3 µm Fe:ZnSe laser or a 2.8 µm electro-optically (EO) Q-switched Er: Laser. This has been accomplished at the UCLA Neptune Laboratory by using about 100 mJ, ~100 ns long pulses generated by the pump laser built for this purpose by the UAB team. Implementation of EO Q-switching regime in the solid-state Er:laser system made possible nanosecond synchronization between the pump pulse and the 0.5 ps seed pulse produced by a commercial Ti:sapphire laser based mid-IR OPA/DFG. The injection mode-locking regime realized in a compact Mult atmosphere 3 Hz CO 2 -He regenerative amplifier enabled generation of a train of ultrashort pulses separated by the cavity round-trip time of ~3.2 ns. The measured gain lifetime of ~1 µs at a total pressure of ~12-15 atm indicates that lifetime of the upper laser level is a critical limiting factor in designing high-pressure CO 2 amplifiers. A single picosecond 10 mm pulse with an energy 0.1-0.2 mJ was extracted from the amplifier’s cavity using an ultrafast Ge semiconductor switch whose reflectivity was photo-induced by a femtosecond 800 nm pulse. For direct amplification regime, nonlinear absorption in Ge at 10 mm at GW/cm 2 intensities limited the extracted energy. Therefore, the generated energy could be further increased by minimizing losses in the switch and optimizing the cavity mode size. Based on the obtained data in collaboration with BNL colleagues, we have designed a high-pressure CO 2 amplifier to be used as a preamplifier for the future experiments at the ATF BNL. The latter work is the subject of funding availability.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2022

Finding new friends and revisiting old ones – how plant lipid droplets connect with other subcellular structures

Summary The number of described contact sites between different subcellular compartments and structures in eukaryotic cells has increased dramatically in recent years and, as such, has substantially reinforced the well‐known premise that these kinds of connections are essential for overall cellular organization and the proper functioning of cellular metabolic and signaling pathways. Here, we discuss contact sites involving plant lipid droplets (LDs), including LD‐endoplasmic reticulum (ER) connections that mediate the biogenesis of new LDs at the ER, LD‐peroxisome connections, that facilitate the degradation of LD‐stored triacylglycerols (TAGs), and the more recently discovered LD‐plasma membrane connections, which involve at least three novel proteins, but have a yet unknown physiological function(s).

60 APPLIED LIFE SCIENCES↗
DOE OSTI2020

Materials Data on Er2SO2 by Materials Project

Er2O2S crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. Er3+ is bonded in a 7-coordinate geometry to three equivalent S2- and four equivalent O2- atoms. All Er–S bond lengths are 2.86 Å. There are three shorter (2.25 Å) and one longer (2.28 Å) Er–O bond lengths. S2- is bonded to six equivalent Er3+ atoms to form distorted SEr6 octahedra that share corners with twelve equivalent OEr4 tetrahedra, edges with six equivalent SEr6 octahedra, and edges with six equivalent OEr4 tetrahedra. O2- is bonded to four equivalent Er3+ atoms to form OEr4 tetrahedra that share corners with six equivalent SEr6 octahedra, corners with six equivalent OEr4 tetrahedra, edges with three equivalent SEr6 octahedra, and edges with three equivalent OEr4 tetrahedra. The corner-sharing octahedra tilt angles range from 26–50°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Er2C(NO)2 by Materials Project

Er2C(NO)2 crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. Er3+ is bonded in a 7-coordinate geometry to three equivalent N3- and four equivalent O2- atoms. All Er–N bond lengths are 2.55 Å. There are three shorter (2.21 Å) and one longer (2.28 Å) Er–O bond lengths. C4+ is bonded in a linear geometry to two equivalent N3- atoms. Both C–N bond lengths are 1.24 Å. N3- is bonded in a 1-coordinate geometry to three equivalent Er3+ and one C4+ atom. O2- is bonded to four equivalent Er3+ atoms to form a mixture of edge and corner-sharing OEr4 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ErSF by Materials Project

SFEr is Matlockite structured and crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Er3+ is bonded in a 9-coordinate geometry to five equivalent S2- and four equivalent F1- atoms. There are four shorter (2.79 Å) and one longer (2.83 Å) Er–S bond lengths. All Er–F bond lengths are 2.44 Å. S2- is bonded in a 5-coordinate geometry to five equivalent Er3+ atoms. F1- is bonded to four equivalent Er3+ atoms to form a mixture of distorted corner and edge-sharing FEr4 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NaErPO4F by Materials Project

NaErPO4F crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Na1+ is bonded in a 6-coordinate geometry to four O2- and two equivalent F1- atoms. There are two shorter (2.50 Å) and two longer (2.63 Å) Na–O bond lengths. Both Na–F bond lengths are 2.46 Å. Er3+ is bonded in a 8-coordinate geometry to six O2- and two equivalent F1- atoms. There are a spread of Er–O bond distances ranging from 2.28–2.44 Å. There are one shorter (2.26 Å) and one longer (2.28 Å) Er–F bond lengths. P5+ is bonded in a tetrahedral geometry to four O2- atoms. There is two shorter (1.54 Å) and two longer (1.56 Å) P–O bond length. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Er3+ and one P5+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Na1+, one Er3+, and one P5+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Na1+, one Er3+, and one P5+ atom. F1- is bonded to two equivalent Na1+ and two equivalent Er3+ atoms to form distorted edge-sharing FNa2Er2 tetrahedra.

36 MATERIALS SCIENCE↗

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