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At least 523 records · Page 29

Space Launch System Spacecraft and Payload Elements: Making Progress Toward First Launch

Significant and substantial progress continues to be accomplished in the design, development, and testing of the Space Launch System (SLS), the most powerful human-rated launch vehicle the United States has ever undertaken. Designed to support human missions into deep space, SLS is one of three programs being managed by the National Aeronautics and Space Administration's (NASA's) Exploration Systems Development directorate. The Orion spacecraft program is developing a new crew vehicle that will support human missions beyond low Earth orbit, and the Ground Systems Development and Operations (GSDO) program is transforming Kennedy Space Center (KSC) into next-generation spaceport capable of supporting not only SLS but also multiple commercial users. Together, these systems will support human exploration missions into the proving ground of cislunar space and ultimately to Mars. SLS will deliver a near-term heavy-lift capability for the nation with its 70 metric ton Block 1 configuration, and will then evolve to an ultimate capability of 130 metric tons. The SLS program marked a major milestone with the successful completion of the Critical Design Review in which detailed designs were reviewed and subsequently approved for proceeding with full-scale production. This marks the first time an exploration class vehicle has passed that major milestone since the Saturn V vehicle launched astronauts in the 1960s during the Apollo program. Each element of the vehicle now has flight hardware in production in support of the initial flight of the SLS - Exploration Mission-1 (EM-1), an uncrewed mission to orbit the moon and return, and progress in on track to meet the initial targeted launch date in 2018. In Utah and Mississippi, booster and engine testing are verifying upgrades made to proven shuttle hardware. At Michoud Assembly Facility (MAF) in Louisiana, the world's largest spacecraft welding tool is producing tanks for the SLS core stage. This paper will particularly focus on work taking place at Marshall Space Flight Center (MSFC) and United Launch Alliance (ULA) in Alabama, where upper stage and adapter elements of the vehicle are being constructed and tested. Providing the Orion crew capsule/launch vehicle interface and in-space propulsion via a cryogenic upper stage, the Spacecraft/Payload Integration and Evolution (SPIE) Element serves a key role in achieving SLS goals and objectives. The SPIE element marked a major milestone in 2014 with the first flight of original SLS hardware, the Orion Stage Adapter (OSA) which was used on Exploration Flight Test-1 with a design that will be used again on EM-1. Construction is already underway on the EM-1 Interim Cryogenic Propulsion Stage (ICPS), an in-space stage derived from the Delta Cryogenic Second Stage. Manufacture of the Orion Stage Adapter and the Launch Vehicle Stage Adapter is set to begin at the Friction Stir Facility located at MSFC while structural test articles are either completed (OSA) or nearing completion (Launch Vehicle Stage Adapter). An overview is provided of the launch vehicle capabilities, with a specific focus on SPIE Element qualification/testing progress, as well as efforts to provide access to deep space regions currently not available to the science community through a secondary payload capability utilizing CubeSat-class satellites.

Schorr, Andrew A.↗

Payload Utilization in NASA's Space Launch System

A revitalized National Space Council has directed NASA to return to the moon, with a series of preparatory missions paving the way for eventual human exploration. NASA's new deep space exploration system -- the heavy-lift Space Launch System (SLS), the Orion crew spacecraft and revitalized launch facilities at Kennedy Space Center -- will enable NASA and its commercial and international partners to meet these goals for human deep space exploration. SLS will be the most capable launch vehicle for these efforts, with an initial Block 1 capability of at least 26 metric tons (t) to trans-lunar injection (TLI). A more powerful Block 1B, available in crew and cargo configurations, with have the power to loft more than 37 t to TLI; the ultimate Block 2 variant will lift more than 45 t to TLI. For payload utilization, the Block 1 vehicle will carry 13 6U CubeSats as secondary payloads while the Block 1B crew vehicle will provide as much volume as the space shuttle payload bay in a Universal Stage Adapter (USA). Block 1B cargo vehicles will offer 8.4 m fairings in 19.1 m and 27.4 m lengths, with enough volume to accommodate habitat modules and landers. For missions beyond the Earth-moon system, SLS offers greater characteristic energy (C3), enabling faster transit or heavier payloads to the outer planets. The first mission of SLS and Orion, launching no earlier than December 2019, will send Orion into lunar distant retrograde orbit (DRO) on an approximately 25-day shakedown cruise known as Exploration Mission-1 (EM-1), enabling NASA to verify and validate new systems before sending astronauts to deep space on the next exploration mission. The SLS program and its prime contractors have made significant progress toward first launch, with several major components of the vehicle completed and delivered to the Exploration Ground Systems (EGS) Program at Kennedy Space Center. Major forward work includes integrating tanks, engines and other major sections into the EM-1 core stage at Michoud Assembly Facility and then shipping the entire core stage assembly to Stennis Space Center. There, it will be installed in the refurbished B-2 test stand for a series of integrated stage tests culminating in a green run hotfire test. The Program's Spacecraft Payload Integration and Evolution (SPIE) Office, responsible for the in-space stage, adapters and payload interfaces, has largely completed its effort on the Block 1 vehicle and is supporting manufacture of the first Block 1B vehicle. This paper will provide an overview of the Block 1 vehicle, its expected capabilities, secondary payload accommodations and manufacturing status, including structural testing and the challenges of developing a new launch vehicle. A lookahead to the Block 1B vehicle and the payload utilization opportunities it will provide in the 2020s will also be discussed, including the unique capabilities of the vehicle.

Creech, Stephen D.↗

Total Dose Effects in Conventional Bipolar Transistors

This paper examines various factors in bipolar device construction and design, and discusses their impact on radiation hardness. The intent of the paper is to improve understanding of the underlying mechanisms for practical devices without special test structures, and to provide (1) guidance in ways to select transistor designs that are more resistant to radiation damage, and (2) methods to estimate the maximum amount of damage that might be expected from a basic transistor design. The latter factor is extremely important in assessing the risk that future lots of devices will be substantially below design limits, which are usually based on test data for older devices.

Bipolar Devices Cassini Ionizing radiation effects↗

Electron Beam Freeform Fabrication: A Fabrication Process that Revolutionizes Aircraft Structural Designs and Spacecraft Supportability

The technological inception and challenges, as well as current applications of the electron beam freeform fabrication (EBF3) process are outlined. The process was motivated by the need for a new metals technology that would be cost-effective, enable the production of new alloys and that would could be used for efficient, lightweight structures. EBF3 is a rapid metal fabrication, layer-additive process that uses no molds or tools and which yields properties equivalent to wrought. The benefits of EBF3 include it near-net shape which minimizes scrap and reduces part count; efficiency in design which allows for lighter weight and enhanced performance; and, its "green" manufacturing process which yields minimal waste products. EBF3 also has a high tensile strength, while a structural test comparison found that EBF3 panels performed 5% lower than machined panels. Technical challenges in the EBF3 process include a need for process control monitoring and an improvement in localized heat response. Currently, the EBF3 process can be used to add details onto forgings and to construct and form complex shapes. However, it has potential uses in a variety of industries including aerospace, automotive, sporting goods and medical implant devices. The novel structural design capabilities of EBF3 have the ability to yield curved stiffeners which may be optimized for performance, low weight, low noise and damage tolerance applications. EBF3 has also demonstrated its usefulness in 0-gravity environments for supportability in space applications.

Taminger, Karen M.↗

Investigation of Field Emitter Array Vacuum Microtriodes for Space Electronics Applications

Research into processing techniques for fabrication of vacuum microelectronic devices has been carried out, with special emphasis being given to the growth of silicon dioxide thin films. Oxide films ranging from 30 nm to approximately 2 micrometers have been grown on single crystal silicon wafers. Metal-oxide-semiconductor capacitor test structures have been made from some of these oxide films, and current-versus-voltage plots for these structures have been measured. It has been observed that the rate of applied voltage across the oxide films produces marked differences in measured leakage current. Breakdown fields across two of the thinnest oxide films have been measured and are comparable with highest values reported in literature. Several silicon wafers were processed to make field- emitter array diodes, and were delivered to collaborators at NASA-Lewis Research Center for final fabrication steps and testing.

Smith, Mark A.↗

Estimating the impact of tariff-driven behind-the-meter storage operation on distribution grid investments

Increasing growth of distributed solar photovoltaics (PV) and electric vehicles (EV) can strain local distribution networks and require costly upgrades. Distributed battery storage, often deployed alongside PV, can be used to mitigate those costs, depending on how batteries are operated. This study evaluates the potential deferral value of distributed battery storage across a range of tariff structures, focusing on the rate structures most commonly available to residential customers today and related variants. Deferrals are evaluated with a least-cost distribution grid expansion optimization model to identify requirements on line reconductoring, transformer upgrades, and voltage regulator installations under each tariff. Results show that TOU rates and net billing tariffs can yield meaningful deferral value, depending on specific tariff structure features. Under the best performing tariff structure tested, storage produced a median annualized deferral value of $7.18 per kW of storage capacity ( kW S ) across all feeders in the sample, though deferral values were considerably larger for feeders with peak loads that coincide with utility system peak, i.e., timing of TOU peak period. In contrast, under an unrestricted TOU design with no restrictions on grid charging or discharging, the median deferral value was $0/ kW S illustrating the critical importance of tariff structure details.

Rodriguez-Garcia, Luis↗

Model Development for the ACME Lab Modular Wall and A-Frame Assemblies

The structural frame used for conducting large structural tests was replaced by the ACME (Applied Combined Mechanical Environments) Lab in Building 860 of Sandia National Laboratories in Albuquerque, NM. This new design required simulation and analysis to verify maximum loads and corresponding factors of safety. Two major assemblies which are part of the ACME Lab, the Modular Wall and A-Frame, were designed to operate with a multitude of components in various configurations and with varying loads. Simulations of the Modular Wall and A-Frame structures were performed through explicit analysis to determine safety factors for numerous loading scenarios. The Modular Wall had safety factors of 1.1 for the lateral, diagonal, and gusset loading conditions. The A-Frame had safety factors of 2 for all loading conditions simulated.

42 ENGINEERING↗

Results from the Middeck 0-gravity Dynamics Experiment

The experimental results of the Middick Zero-gravity Dynamics Experiment (MODE) are presented. MODE investigated the dynamics of two key spacecraft components; contained fluids and jointed truss structures. The change in the lateral slosh behavior of contained fluids and the changes in the modal parameters of space structural test articles from one- to zero-gravity were studied. The experimental apparatus used to determine the dynamic characteristics is described. For the MODE fluid experiments, the forced response characteristics of silicone oil and distilled water in cylinder tanks with either a flat or spherical bottom are reported and discussed. A comparison of the measured earth and space results identifies and highlights the effects of gravity on the linear and nonlinear slosh behavior of these fluids. For the MODE structural experiments, an analytic and experimental study is presented. Deployable, erectable, and rotary modules were assembled to form three one- and two-dimensional structures in which variations in bracing wire and rotary joint preload could be introduced. Analysis is compared with ground experimental measurements made on a spring/wire suspension system with a nominal plunge frequency of one Hertz, and with measurements made on the Shuttle middeck. The degree of change in linear modal parameters as well as the change in nonlinear nature of the response is examined. Trends in modal parameters are presented as a function of force amplitude, joint preload, and ambient gravity level.

Van Schoor, M. C.↗

Selection and static calibration of the Marsh J1678 pressure gauge

During the experimental testing of the ultralight, it was determined that a pressure gauge would be required to monitor the simulated flight loads. After analyzing several factors, which are indicated in the discussion section of this report, the Marsh J1678 pressure gauge appeared to be the prominent candidate for the task. However, prior to the final selection, the Marsh pressure gauge was calibrated twice by two different techniques. As a result of the calibration, the Marsh gauge was selected as the appropriate measuring device during the structural testing of the ultralight. Although, there are commerical pressure gauges available on the market that would have proven to be more efficient and accurate. However, in order to obtain these characteristics in a gauge, one has to pay the price on the price tag, and this value is an exponential function of the degree of accuracy efficiency, precision, and many other features that may be designed into the gauge. After analyzing the extent of precision and accuracy that would be required, a more expensive gauge wouldn't have proven to be a financial benefit towards the outcome of the experiment.

Oxendine, Charles R.↗

Fan Noise Source Diagnostic Test: Tone Modal Structure Results

This investigation is part of a test series that was extremely comprehensive and included aerodynamic and acoustic testing of a fan stage using two different fan rotors and three different stator designs. The test series is known as the Source Diagnostic Test (SDT) and was conducted by NASA Glenn as part of the Advanced Subsonic Technology (AST) Noise Reduction Program. Tone mode measurements of one of the rotors with three different stators were made. The stator designs involve changes in vane count and sweep at constant solidity. The results of both inlet and exhaust tone mode measurements are presented in terms of mode power for both circumferential and radial mode orders. The results show benefits of vane sweep to be large, up to 13 dB in total tone power. At many conditions, the increase in power due to cutting on the rotor/stator interaction is more than offset by vane sweep. The rotor locked mode is shown as an important contributor to tone power when the blade tip speed is near and above Mach one. This is most evident in the inlet when the direct rotor field starts to cut on.

Heidelberg, Laurence J.↗

Optimization methods for passive damper placement and tuning

The effectiveness of viscous elements in introducing damping in a structure is a function of several variables, including their number, their location in the structure, and their physical properties. In this paper several optimization problems are posed to optimize these variables. The paper investigates various metrics to define the optimization problem, and compares the damping profiles that are obtained. Both discrete and continuous optimization problems are formulated and solved, corresponding, respectively, to the problems of placement of damping elements and to the tuning of their parameters. The paper particularly emphasizes techniques to make feasible the large scale problems resulting from the optimization formulations. Numerical results involving a lightly damped tested structure are presented.

Milman, M. H.↗

Motion Magnification to Visualize the Modes of Space Structures

Traditional structural testing involves using accelerometers and strain gages to measure the motion. While this traditional instrumentation suite has proven accurate, it is limited to capture data only in the discrete locations where the transducers are placed. Additionally, applying the instrumentation can be a difficult and labor intensive task. By using video cameras, the motion of the test article – such as a launch vehicle or launch vehicle payload – can be easily captured at any location in the field of view and easily visualized using a post-processing technique called Motion Magnification. It is also much easier to place video cameras to measure motion rather than having to place contact sensors, especially when placement locations can be limited on final flight hardware. Recently, a team of MIT Lincoln Laboratory (MITLL) and NASA Marshall Space Flight Center (MSFC) have been collaborating to use Motion Magnification to measure the dynamics of large space structures. This presentation will detail some of the results of this collaboration.

Eric Colby Stewart↗

Motion Magnification to Visualize the Modes of Space Structures

Traditional structural testing involves using accelerometers and strain gages to measure the motion. While this traditional instrumentation suite has proven accurate, it is limited to capture data only in the discrete locations where the transducers are placed. Additionally, applying the instrumentation can be a difficult and labor intensive task. By using video cameras, the motion of the test article – such as a launch vehicle or launch vehicle payload – can be easily captured at any location in the field of view and easily visualized using a post-processing technique called Motion Magnification. It is also much easier to place video cameras to measure motion rather than having to place contact sensors, especially when placement locations can be limited on final flight hardware. Recently, a team of MIT Lincoln Laboratory (MITLL) and NASA Marshall Space Flight Center (MSFC) have been collaborating to use Motion Magnification to measure the dynamics of large space structures. This presentation will detail some of the results of this collaboration.

Eric Colby Stewart↗

Fabricating with Crystalline Si to Improve Superconducting Detector Performance

We built and measured radio-frequency (RF) loss tangent, tan δ, evaluation structures using float-zone quality silicon-on-insulator (SOI) wafers with 5 μm thick device layers. Superconducting Nb components were fabricated on both sides of the SOI Si device layer. Our main goals were to develop a robust fabrication for using crystalline Si (c-Si) dielectric layers with superconducting Nb components in a wafer bonding process and to confirm that tan δ with c-Si dielectric layers was reduced at RF frequencies compared to devices fabricated with amorphous dielectrics, such as SiO2 and SixNy, where tan δ ~ 10(exp -3). Our primary test structure used a Nb coplanar waveguide (CPW) readout structure capacitively coupled to LC resonators, where the capacitors were defined as parallel-plate capacitors on both sides of a c-Si device layer using a wafer bonding process with benzocyclobutene (BCB) wafer bonding adhesive. Our control experiment, to determine the intrinsic tan δ in the SOI device layer without wafer bonding, also used Nb CPW readout coupled to LC resonators; however, the parallel-plate capacitors were fabricated on both sides of the Si device layer using a deep reactive ion etch (DRIE) to access the c-Si underside through the buried oxide and handle Si layers in the SOI wafers. We found that our wafer bonded devices demonstrated F· δ = (8 +/- 2) × 10(exp -5), where F is the filling fraction of two-level states (TLS). For the control experiment, F· δ = (2.0 +/- 0.6) × 10(exp -5), and we discuss what may be degrading the performance in the wafer bonded devices as compared to the control devices.

Beyer, A. D↗

Fabricating with Crystalline Si to Improve Superconducting Detector Performance

We built and measured radio-frequency (RF) loss tangent, tan d, evaluation structures using float-zone quality silicon-on-insulator (SOI) wafers with 5 µ m thick device layers. Superconducting Nb components were fabricated on both sides of the SOI Si device layer. Our main goals were to develop a robust fabrication for using crystalline Si (c-Si) dielectric layers with superconducting Nb components in a wafer bonding process and to confirm that tan d with c-Si dielectric layers was reduced at RF frequencies compared to devices fabricated with amorphous dielectrics, such as SiO2 and SixNy, where tan d ~ 10-3. Our primary test structure used a Nb coplanar waveguide (CPW) readout structure capacitively coupled to LC resonators, where the capacitors were defined as parallel-plate capacitors on both sides of a c-Si device layer using a wafer bonding process with benzocyclobutene (BCB) wafer bonding adhesive. Our control experiment, to determine the intrinsic tan d in the SOI device layer without wafer bonding, also used Nb CPW readout coupled to LC resonators; however, the parallel-plate capacitors were fabricated on both sides of the Si device layer using a deep reactive ion etch (DRIE) to access the c-Si underside through the buried oxide and handle Si layers in the SOI wafers. We found that our wafer bonded devices demonstrated F· d = (8 ± 2) × 10-5, where F is the filling fraction of two-level states (TLS). For the control experiment, F· d = (2.0 ± 0.6) × 10-5, and we discuss what may be degrading the performance in the wafer bonded devices as compared to the control devices.

Beyer, A D↗

Lockheed Martin Skunk Works Single Stage to Orbit/Reusable Launch Vehicle

Lockheed Martin Skunk Works has compiled an Annual Performance Report of the X-33/RLV Program. This report consists of individual reports from all industry team members, as well as NASA team centers. This portion of the report is comprised of a status report of Lockheed Martin's contribution to the program. The following is a summary of the Lockheed Martin Centers involved and work reviewed under their portion of the agreement: (1) Lockheed Martin Skunk Works - Vehicle Development, Operations Development, X-33 and RLV Systems Engineering, Manufacturing, Ground Operations, Reliability, Maintainability/Testability, Supportability, & Special Analysis Team, and X-33 Flight Assurance; (2) Lockheed Martin Technical Operations - Launch Support Systems, Ground Support Equipment, Flight Test Operations, and RLV Operations Development Support; (3) Lockheed Martin Space Operations - TAEM and A/L Guidance and Flight Control Design, Evaluation of Vehicle Configuration, TAEM and A/L Dispersion Analysis, Modeling and Simulations, Frequency Domain Analysis, Verification and Validation Activities, and Ancillary Support; (4) Lockheed Martin Astronautics-Denver - Systems Engineering, X-33 Development; (5) Sanders - A Lockheed Martin Company - Vehicle Health Management Subsystem Progress, GSS Progress; and (6) Lockheed Martin Michoud Space Systems - X-33 Liquid Oxygen (LOX) Tank, Key Challenges, Lessons Learned, X-33/RLV Composite Technology, Reusable Cyrogenic Insulation (RCI) and Vehicle Health Monitoring, Main Propulsion Systems (MPS), Structural Testing, X-33 System Integration and Analysis, and Cyrogenic Systems Operations.

Source record↗

matsim-agents v1.0

matsim-agents is a multi-agent AI framework for atomistic materials simulation and discovery. It orchestrates large language models (LLMs), machine-learned interatomic potentials (MLIPs), and DFT codes into a single agentic loop running on laptops and DOE leadership-class supercomputers. MULTI-AGENT ORCHESTRATION A LangGraph state machine with three nodes: a Planner that converts a natural-language research objective into structured tasks; an Executor that dispatches atomistic tools and loops until the queue is empty; and an Analyst that summarizes results into a human-readable report. State is checkpointed after every step and human-in-the-loop gates can be inserted at any edge. HYPOTHESIS-DRIVEN DISCOVERY CHAT An interactive REPL (matsim-agents chat) that couples LLM dialogue with atomistic simulation. Chemical formulas are automatically detected in conversation turns and trigger a full crystal-phase exploration: structure generation → relaxation → stability scoring → result injection back into the conversation, creating a closed hypothesis-refinement loop. CRYSTAL PHASE ENUMERATION Given a composition, the phase explorer enumerates prototypes by stoichiometry: elemental (fcc/bcc/hcp/sc/diamond), binary 1:1 (rocksalt/CsCl/zincblende/ wurtzite/fluorite/rutile), ternary 1:1:3 (cubic perovskite), ternary 1:2:4 (perovskite + spinel), quaternary 1:1:2:6 (Fm-3m double perovskite). 2-D prototypes (graphene, h-BN, MoS2 2H/1T) and multilayer stacking are also supported via --include-2d and --num-layers. SUPERCELL GENERATION AND SITE DECORATION Auto-tiling to a minimum atom count (--min-atoms), explicit NxNxN tiling (--supercell), symmetry-distinct site decorations (--n-orderings), and isotropic lattice-scale sweeps (--lattice-scales) for volume bracketing. MLFF RELAXATION AND STABILITY SCORING HydraGNN (multi-headed GNN) drives structure relaxation via ASE with FIRE, BFGS, or BFGSLineSearch. Stability output: delta-E/atom ranking across phases and a max-residual-force dynamical-stability proxy. Other MLIPs (MACE, NequIP, Orb) can be plugged in through the same interface. DFT BACKENDS Quantum ESPRESSO pw.x and VASP 6.6 are first-class labellers. Both have validated GPU builds and SLURM/PBS launchers for three DOE platforms: Frontier (AMD MI250X, ROCm), Aurora (Intel PVC, oneAPI), Perlmutter (NVIDIA A100, CUDA). QE produces ~100 binaries (pw.x, ph.x, epw.x, ...). VASP supports scf, relax, vc-relax, and vc-relax-shape run types. ACTIVE-LEARNING LOOP matsim-agents al run CONFIG.yaml drives an iterative HydraGNN-DFT loop: MD generates candidates → ensemble/MC-dropout uncertainty selects the most informative → DFT labels them in parallel inside one allocation → dataset grows → HydraGNN retrains → repeat. DFT backend is a single YAML toggle (dft.backend: vasp | qe). LLM-generated seed structures are supported (no curated POSCAR library needed). Config uses ${VAR}, ${VAR:-default}, ${VAR:?msg} shell-style substitution for cross-user/cross-site portability. LLM BACKENDS Ollama (local, default), vLLM (HPC multi-GPU serving), OpenAI, Anthropic, HuggingFace Transformers+Accelerate. Selected at runtime via flag or env var with no code changes. HPC PORTABILITY Same Python entry points run on Frontier (ROCm 7.2), Aurora (oneAPI), and Perlmutter (CUDA 12). DFT and ML stacks are never co-loaded in the same shell; they couple through the scheduler and filesystem. Advanced multi-node launchers (serve, discovery-chat, single-relaxation, active-learning, QE warm-start) are provided for all three platforms. CODABENCH COMPETITION BUNDLE A self-contained benchmark: 159 atomistic test structures across 11 material classes, 5 tasks (formation energy, forces, ML relaxation, AI-DFT relaxation, phase stability ranking), public/private leaderboard split (30/70), and four ready-to-run baselines: MACE-MP-0, HydraGNN, UMA, AllScAIP.

Lupo Pasini, Massimiliano [Oak Ridge National Labo↗