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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 1,603 records · Page 89
All sourcesNASA NTRSDOE OSTI
NASA NTRS1991

Ground Systems Development Environment (GSDE) interface requirements analysis: Operations scenarios

This report is a preliminary assessment of the functional and data interface requirements to the link between the GSDE GS/SPF (Amdahl) and the Space Station Control Center (SSCC) and Space Station Training Facility (SSTF) Integration, Verification, and Test Environments (IVTE's). These interfaces will be involved in ground software development of both the control center and the simulation and training systems. Our understanding of the configuration management (CM) interface and the expected functional characteristics of the Amdahl-IVTE interface is described. A set of assumptions and questions that need to be considered and resolved in order to complete the interface functional and data requirements definitions are presented. A listing of information items defined to describe software configuration items in the GSDE CM system is included. It also includes listings of standard reports of CM information and of CM-related tools in the GSDE.

Church, Victor E.↗
NASA NTRS2007

Expanding Hardware-in-the-Loop Formation Navigation and Control with Radio Frequency Crosslink Ranging

The Formation Flying Testbed (FFTB) at the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) provides a hardware-in-the-loop test environment for formation navigation and control. The facility continues to evolve as a modular, hybrid, dynamic simulation facility for end-to-end guidance, navigation, and control (GN&C) design and analysis of formation flying spacecraft. The core capabilities of the FFTB, as a platform for testing critical hardware and software algorithms in-the-loop, are reviewed with a focus on recent improvements. With the most recent improvement, in support of Technology Readiness Level (TRL) 6 testing of the Inter-spacecraft Ranging and Alarm System (IRAS) for the Magnetospheric Multiscale (MMS) mission, the FFTB has significantly expanded its ability to perform realistic simulations that require Radio Frequency (RF) ranging sensors for relative navigation with the Path Emulator for RF Signals (PERFS). The PERFS, currently under development at NASA GSFC, modulates RF signals exchanged between spacecraft. The RF signals are modified to accurately reflect the dynamic environment through which they travel, including the effects of medium, moving platforms, and radiated power.

Mitchell, Jason W.↗
NASA NTRS2008

Marshall Space Flight Center's Impact Testing Facility Capabilities

Marshall Space Flight Center s (MSFC) Impact Testing Facility (ITF) serves as an important installation for space and missile related materials science research. The ITF was established and began its research in spacecraft debris shielding in the early 1960s, then played a major role in the International Space Station debris shield development. As NASA became more interested in launch debris and in-flight impact concerns, the ITF grew to include research in a variety of impact genres. Collaborative partnerships with the DoD led to a wider range of impact capabilities being relocated to MSFC as a result of the closure of Particle Impact Facilities in Santa Barbara, California. The Particle Impact Facility had a 30 year history in providing evaluations of aerospace materials and components during flights through rain, ice, and solid particle environments at subsonic through hypersonic velocities. The facility s unique capabilities were deemed a "National Asset" by the DoD. The ITF now has capabilities including environmental, ballistic, and hypervelocity impact testing utilizing an array of air, powder, and two-stage light gas guns to accommodate a variety of projectile and target types and sizes. Numerous upgrades including new instrumentation, triggering circuitry, high speed photography, and optimized sabot designs have been implemented. Other recent research has included rain drop demise characterization tests to obtain data for inclusion in on-going model development. The current and proposed ITF capabilities range from rain to micrometeoroids allowing the widest test parameter range possible for materials investigations in support of space, atmospheric, and ground environments. These test capabilities including hydrometeor, single/multi-particle, ballistic gas guns, exploding wire gun, and light gas guns combined with Smooth Particle Hydrodynamics Code (SPHC) simulations represent the widest range of impact test capabilities in the country.

Finchum, Andy↗
NASA NTRS2005

Heliophysics: The New Science of the Sun-Solar System Connection. Recommended Roadmap for Science and Technology 2005-2035

This is a Roadmap to understanding the environment of our Earth, from its life-sustaining Sun out past the frontiers of the solar system. A collection of spacecraft now patrols this space, revealing not a placid star and isolated planets, but an immense, dynamic, interconnected system within which our home planet is embedded and through which space explorers must journey. These spacecraft already form a great observatory with which the Heliophysics program can study the Sun, the heliosphere, the Earth, and other planetary environments as elements of a system--one that contains dynamic space weather and evolves in response to solar, planetary, and interstellar variability. NASA continually evolves the Heliophysics Great Observatory by adding new missions and instruments in order to answer the challenging questions confronting us now and in the future as humans explore the solar system. The three heliophysics science objectives: opening the frontier to space environment prediction; understanding the nature of our home in space, and safeguarding the journey of exploration, require sustained research programs that depend on combining new data, theory, analysis, simulation, and modeling. Our program pursues a deeper understanding of the fundamental physical processes that underlie the exotic phenomena of space.

Heliophysics↗
NASA NTRS2014

Evolution of Software-Only-Simulation at NASA IV and V

Software-Only-Simulations have been an emerging but quickly developing field of study throughout NASA. The NASA Independent Verification Validation (IVV) Independent Test Capability (ITC) team has been rapidly building a collection of simulators for a wide range of NASA missions. ITC specializes in full end-to-end simulations that enable developers, VV personnel, and operators to test-as-you-fly. In four years, the team has delivered a wide variety of spacecraft simulations that have ranged from low complexity science missions such as the Global Precipitation Management (GPM) satellite and the Deep Space Climate Observatory (DSCOVR), to the extremely complex missions such as the James Webb Space Telescope (JWST) and Space Launch System (SLS).This paper describes the evolution of ITCs technologies and processes that have been utilized to design, implement, and deploy end-to-end simulation environments for various NASA missions. A comparison of mission simulators are discussed with focus on technology and lessons learned in complexity, hardware modeling, and continuous integration. The paper also describes the methods for executing the missions unmodified flight software binaries (not cross-compiled) for verification and validation activities.

Embedded↗
NASA NTRS2020

A GaN-based Four-Switch Buck-Boost Converter using Ripple Correlation Control for Maximum Power Point Tracking in Dynamic Deep Space Environments

As the demand for high-performance power conversion in spacecraft continues to grow and spacecraft mass and volume budgets become increasingly tight, it is essential to design DC-DC converters with higher efficiency and power density. Although photovoltaic (PV) efficiency has increased over time, solar irradiance and temperatures can fluctuate dramatically in deep space. This causes significant variations in the maximum power point (MPP) of the PV array, which can decrease the overall system efficiency unless accounted for. Thus, it is imperative to track the MPP of the PV panels to maintain optimal efficiency. This paper presents the experimental development of a four-switch, GaN-based buck-boost converter with an implementation of the Ripple Correlation Control (RCC) MPPT algorithm for dynamic deep space environments. Due to the use of GaN HEMTs, the experimental system achieves better efficiency and power density compared to the previous state of the art implementations. A simulation of the prototype buck-boost converter was implemented in SaberRD (Synopsis), and a digital design of the RCC-based MPPT controller utilizing the StateAMS tool is presented. The simulation results show that this controller swiftly and precisely converged to the MPP of the source PV panels in a dynamic solar irradiance condition.

Mahmud, Sadab↗
NASA NTRSDate not supplied

Developing New Tools for Modeling Rocket Plume-Surface Interactions

With NASA’s goal to land the next human on the lunar surface in the next few years, it has become vitally important that we have a better understanding of how future landing spacecraft will interact with the unique properties of regolith¬¬––the layer of loose, unconsolidated dust and rock on the lunar surface¬¬––which can cause hazards like visual obstructions, particulate clouds, and cratering of the landing zone. Researchers from the Fluid Dynamics Branch at NASA’s Marshall Space Flight Center are performing plume-surface interaction (PSI) simulations between lander engine plumes and unprepared regolith surfaces, and have developed new tools to provide predictive PSI environments for various NASA projects and missions, including the Human Lander System (HLS), Commercial Lunar Payload Services (CLPS), and future Mars landers. These tools allow the researchers to determine how to best meet the simulation and time requirements for each project by varying model fidelity. The highest fidelity tool is the Gas Granular Flow Solver (Loci/GGFS) that models gas-particle multi-phase interactions to predict regolith cratering and ejection of particles into the immediate surroundings of the lander. At its highest fidelity, it can model microscopic regolith particle interactions with a particle size/shape distribution that statistically replicates actual regolith, however, to be most effective with today’s computing resources, it is currently run using only one to three equivalent particle sizes/shapes. The team also incorporated engineering models into their software suite to create production-ready hybrid tools with reduced fidelity. At the lowest fidelity, the computational fluid dynamics (CFD) code Loci/CHEM+DIGGEM can predict crater depth over time by relating local CFD-predicted surface shear stresses to a model of erosion mass flux.

plume surface interaction↗
NASA NTRSDate not supplied

Advancements in Crosscutting Capabilities to Enable Science & Exploration

As NASA looks beyond Human Lunar Return and towards Foundational Exploration, there are several crosscutting capabilities necessary to achieve these goals. NASA’s Space Technology Mission Directorate (STMD) has worked with internal and external stakeholders to make advancements in the areas of dust mitigation, extreme environments, extreme access, interoperability, and lunar simulants.

K K John↗
NASA NTRS2003

Propulsion Research at the Propulsion Research Center of the NASA Marshall Space Flight Center

The Propulsion Research Center of the NASA Marshall Space Flight Center is engaged in research activities aimed at providing the bases for fundamental advancement of a range of space propulsion technologies. There are four broad research themes. Advanced chemical propulsion studies focus on the detailed chemistry and transport processes for high-pressure combustion, and on the understanding and control of combustion stability. New high-energy propellant research ranges from theoretical prediction of new propellant properties through experimental characterization propellant performance, material interactions, aging properties, and ignition behavior. Another research area involves advanced nuclear electric propulsion with new robust and lightweight materials and with designs for advanced fuels. Nuclear electric propulsion systems are characterized using simulated nuclear systems, where the non-nuclear power source has the form and power input of a nuclear reactor. This permits detailed testing of nuclear propulsion systems in a non-nuclear environment. In-space propulsion research is focused primarily on high power plasma thruster work. New methods for achieving higher thrust in these devices are being studied theoretically and experimentally. Solar thermal propulsion research is also underway for in-space applications. The fourth of these research areas is advanced energetics. Specific research here includes the containment of ion clouds for extended periods. This is aimed at proving the concept of antimatter trapping and storage for use ultimately in propulsion applications. Another activity in this involves research into lightweight magnetic technology for space propulsion applications.

Blevins, John↗
NASA NTRS1997

Virtual Presence: One Step Beyond Reality

Our primary objective was to team up a group consisting of scientists and engineers from two different NASA cultures, and simulate an interactive teleoperated robot conducting geologic field work on the Moon or Mars. The information derived from the experiment will benefit both the robotics team and the planetary exploration team in the areas of robot design and development, and mission planning and analysis. The Earth Sciences and Space and Life Sciences Division combines the past with the future contributing experience from Apollo crews exploring the lunar surface, knowledge of reduced gravity environments, the performance limits of EVA suits, and future goals for human exploration beyond low Earth orbit. The Automation, Robotics. and Simulation Division brings to the table the technical expertise of robotic systems, the future goals of highly interactive robotic capabilities, treading on the edge of technology by joining for the first time a unique combination of telepresence with virtual reality.

Budden, Nancy Ann↗
NASA NTRS1978

Thermal math model analysis of FRSI test article subjected to cold soak and entry environments

A multi-objective test program was conducted at the NASA/JSC Radiant Heat Test Facility in which an aluminum skin/stringer test panel insulated with FRSI (Flexible Reusable Surface Insulation) was subjected to 24 simulated Space Shuttle Orbiter ascent/entry heating cycles with a cold soak in between in the 10th and 20th cycles. A two-dimensional thermal math model was developed and utilized to predict the thermal performance of the FRSI. Results are presented which indicate that the modeling techniques and property values have been proven adequate in predicting peak structure temperatures and entry thermal responses from both an ambient and cold soak condition of an FRSI covered aluminum structure.

Gallegos, J. J.↗
NASA NTRS1991

Regenerative life support systems (RLSS) test bed development at NASA-Johnson Space Center

NASA-Johnson's RLSS testbed employs higher plants in a closed environment, in conjunction with a physicochemically-based life-support system, to create an integrated, biological/physicochemical RLSS. Crew presence is simulated by a human metabolic simulator, and operation is sufficiently automated for crops to be grown from seed to harvest without human intervention. Attention is given to the Variable Pressure Growth Chamber, which will be operable at both ambient atmospheric pressures and at the reduced pressures representative of operations in lunar and Martian environments.

Tri, Terry O.↗
NASA NTRS1999

Effects of Promethazine on Performance During Simulated Shuttle Landings

Promethazine (PMZ) is the antimotion sickness drug of choice in the U.S. Space Shuttle program; however, virtually nothing is known about the bioavailability and performance effects of this drug in the microgravity environment. PMZ has detrimental side effects on human performance on Earth that could affect Shuttle operations. In a recent ground-based study we examined: 1) the effects of promethazine (PMZ) on Shuttle landing performance using the portable inflight landing operations trainer (PILOT), and 2) saliva and urine samples to determine the pharmacokinetics of PMZ. The PILOT performance data is presented here.

Harm, D. L.↗
NASA NTRS2004

Meshing, Visualization, and Computational Environments

There was probably no higher profile application of meshing, visualization, and computational software this past year than that performed in support of the space shuttle's Return to Flight activities. After heavy use of simulation during the accident investigation, these same tools are now helping address safety and operational issues. In turn, these applications are raising the bar for computational tools in terms of simulation fidelity and turnaround time.

Chawner, John R.↗
NASA NTRS2006

Recent Advances in Solar Sail Propulsion at NASA

Supporting NASA's Science Mission Directorate, the In-Space Propulsion Technology Program is developing solar sail propulsion for use in robotic science and exploration of the solar system. Solar sail propulsion will provide longer on-station operation, increased scientific payload mass fraction, and access to previously inaccessible orbits for multiple potential science missions. Two different 20-meter solar sail systems were produced and successfully completed functional vacuum testing last year in NASA Glenn's Space Power Facility at Plum Brook Station, Ohio. The sails were designed and developed by ATK Space Systems and L'Garde, respectively. These sail systems consist of a central structure with four deployable booms that support the sails. This sail designs are robust enough for deployments in a one atmosphere, one gravity environment, and are scalable to much larger solar sails-perhaps as much as 150 meters on a side. In addition, computation modeling and analytical simulations have been performed to assess the scalability of the technology to the large sizes (>150 meters) required for first generation solar sails missions. Life and space environmental effects testing of sail and component materials are also nearly complete. This paper will summarize recent technology advancements in solar sails and their successful ambient and vacuum testing.

Johnson, Les↗
DOE OSTI2021

Kinetic Simulations of Electron Pre-energization by Magnetized Collisionless Shocks in Expanding Laboratory Plasmas

Collisionless shocks are common features in space and astrophysical systems where supersonic plasma flows interact, such as in the solar wind, the heliopause, and supernova remnants. Recent experimental capabilities and diagnostics allow detailed laboratory investigations of high-Mach-number shocks, which therefore can become a valuable way to understand shock dynamics in various astrophysical environments. Using 2D particle-in-cell simulations with a Coulomb binary collision operator, we demonstrate the mechanism for generation of energetic electrons and experimental requirements for detecting this process in the laboratory high-Mach-number collisionless shocks. We show through a parameter study that electron acceleration by magnetized collisionless shocks is feasible in laboratory experiments with laser-driven expanding plasmas.

79 ASTRONOMY AND ASTROPHYSICS↗
NASA NTRS2009

A Methodology for Training International Space Station Crews to Respond to On-Orbit Emergencies

Most spaceflight crewmembers agree that emergency training is among the most important training they receive. If an emergency event occurs on-orbit crewmembers want to be able to rely on a thorough and proficient knowledge of emergency operations and procedures. The inherent complexity of ISS and the international nature of the onboard operations have resulted in emergency procedures that are complex by any measure; as a result, a very robust apparatus has been developed to give crewmembers initial training on emergency procedures and ensure proficiency up to (and even after) launch. One of the most important aspects of complex onboard operations in general, and emergency operations specifically, is learning how to coordinate roles and responsibilities with fellow crewmembers. A primary goal of NASA s emergency training program is to allow the crewmembers who will actually be together on-orbit to practice executing the emergency responses together before they fly. As with any operation that includes the use of software and hardware, the fidelity of the simulation environment is a critical element to successful training. The NASA training division has spent considerable time and effort to develop a simulator that addresses the most important aspects of emergency response, working within very difficult space and budgetary constraints.

Balmain, Clinton↗
NASA NTRS1978

Simulated null-gravity environments as applied to electrophoretic separations of biological species

The scale-up of electrophoretic separations to provide preparative quantities of materials has been hampered by gravity induced convection and sedimentation. The separation of biologically important species may be significantly enhanced by electrophoretic space processing. Simple demonstrations on past space flights have proven some principles. Several techniques have been evolved to study electrophoretic separations where the effects of gravity have been nullified or significantly reduced. These techniques employ mechanical design, density gradients and computer modeling. Utilization of these techniques for ground based studies will yield clues as to which biological species can be considered prime candidates for electrophoretic processing in zero-G.

Giannovario, J. A.↗