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Advanced Numerical Integration Techniques for High-Fidelity SDE Spacecraft Simulation

Goddard Space Flight Center, Greenbelt, Maryland Simulation study is an integral part of the validation of navigation algorithms for spacecraft. While it is possible to come up with an estimate of a navigation algorithm’s performance with a low-fidelity system model, the mathematical analysis is intractable for higher-fidelity models that include fuel slosh, flexible booms, sensor saturation, etc. Thus simulation study is a vital step in validating navigation algorithms before an actual satellite is launched.

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Launch Environment Water Flow Simulations Using Smoothed Particle Hydrodynamics

This method has been used in applications involving ocean modeling, volcanic lava, sloshing, and fuel pumps. John F. Kennedy Space Center, Florida One of the crucial ground structures employed at the launch pad during the Space Shuttle program is the rainbird nozzle system, whose primary objective is to suppress acoustic energy generated by the launch vehicle during pad abort and nominal operations. It is important that the rainbird water flow does not impinge on the rocket nozzles and other sensitive ground support elements. For the new Space Launch System (SLS) vehicle, the operation is similar, regardless of the new mobile launcher and new engine configurations. The goal of the rainbird nozzle system remains sound suppression (SS), and the rocket engines still cannot get wet. However, the rearrangement of the rainbird water system for the SLS mobile launcher locates the rainbirds closer to the first-stage rocket engines, which are positioned above the exhaust hole. The close proximity of the rainbird nozzle system could potentially cause vehicle wetting during liftoff.

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The Space Station Modulator: A Configurable Surface Mesh Geometry Model for Aeroscience Analyses

Computational manipulation with solid bodies is improving ISS aeroscience analyses. Lyndon B. Johnson Space Center, Houston, Texas Numerical simulations of plume impingement heating to the International Space Station (ISS) and its visiting vehicles require a specific way to represent the space station geometry in 3D. The tools that are used for plume impingement analyses at NASA’s Johnson Space Center — the Reaction Control System (RCS) Plume Model 3D (RPM3D) and Direct Simulation Monte Carlo (DSMC) Analysis Code (DAC) — need the analysis geometry to be in the form of a triangulated surface mesh and water-tight (no gaps or holes). Until recently, 3D geometries for such analyses had to be generated manually, took a long time, and used very-low-fidelity geometry components, and as a result, the aeroscience analyses in 3D were not very frequent.

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Submersible Phase Change Float Sizing

NASA’s Jet Propulsion Laboratory, Pasadena, California This software allows sizing of submersibles powered by hydraulic generators that are pressurized by ocean thermal gradients at various depths. The software allows the operator to input the fixed size of the vessels containing the phase change material (PCM). The effective expansion of the PCM is also input, along with the phase change heat required and other various solid and liquid parameters. The electromechanical efficiency is also input, and the total power produced is calculated, along with system mass and volumes, and approximate time constant.

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DAWN: a Simulation Model for Evaluating Costs and Tradeoffs of Big Data Science Architectures

NASA’s Jet Propulsion Laboratory, Pasadena, California Data science is emerging as a critical area of research and technology to advance scientific discovery, knowledge, and decision-making through systematic computational approaches to analyzing massive data sets. The sheer volume of data increase, coupled with the highly distributed and heterogeneous nature of scientific data sets, is requiring new approaches to how the data will be ultimately managed and analyzed. This requires evaluating the scalability and distribution of complex software architectures. DAWN (Distributed Analytics, Workflows and Numeric) is a model for simulating the execution of data processing workflows on arbitrary data system architectures. DAWN was developed to provide NASA and the scientific community at large with an additional tool to prepare for the upcoming Big Data deluge in science.

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EXOS Software

Lyndon B. Johnson Space Center, Houston, Texas An improved version of EXOS software allows for the modeling of fabrics, mixtures, and porous materials, and also provides the ability to accept hex mesh geometries. The code employs a novel numerical method, a hybrid particle finite element approach, as well as particles and elements in tandem, each modeling distinct aspects of the physics. Ellipsoidal particles are used to model contact-impact and volumetric thermomechanical response (Euler parameters provide a singularity-free description of particle rotations). Elements are used to model “strength” effects; namely, tensile inter-particle forces and elastic-plastic deviatoric deformation.

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JLAB Tracking Tool (JTRAK)

Goddard Space Flight Center, Greenbelt, Maryland The JLAB Tracking Tool (JTRAK) is a Web-enabled database tool designed to automate the tracking of James Webb Space Telescope (JWST) Integrated Ground Support System (IGSS) and Integrated Test Support System (ITSS) configured items. These configured items consist of IGSS and ITSS equipment and materials; hardware and software revisions including patch releases of the Science Instrument Development Units (SIDUs) and the Science Instrument Test Sets (SITS); ground lab COTS software license versions and maintenance schedules; and other miscellaneous documents.

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