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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 433 records · Page 24
All sourcesNASA NTRSDOE OSTI
NASA NTRS1991

Effect of periodic accelerations on interface stability in a multilayered fluid configuration

The increasing number of research opportunities in a microgravity environment will benefit not only fundamental studies in fluid dynamics, but also technological applications such as those involving materials processing. In particular, fluid configurations that involve fluid-fluid interfaces would occur in a variety of experimental investigations. This work investigates the stability of a configuration involving fluid-fluid interfaces in the presence of a time-dependent (periodic) forcing. The fluid configuration is multilayered and infinite in extent. The analysis is linear and inviscid, and the acceleration vector is oriented perpendicular to each interface. A Floquent analysis is employed, and the resulting algebraic eigensystem is truncated. Nondimensional parameters appear in the algebraic system. A numerical study is performed to elucidate the regions of instability and the effect of parameter variation on the fluid configuration stability.

Lyell, M. J.↗
NASA NTRS1988

Microgravity robotics technology program

A research program to develop technology for robots operating in the microgravity environment of the space station laboratory is described. These robots must be capable of manipulating payloads without causing them to experience harmful levels of acceleration, and the motion of these robots must not disturb adjacent experiments and operations by transmitting reactions that translate into damaging effects throughout the laboratory. Solutions to these problems, based on both mechanism technology and control strategies, are discussed. Methods are presented for reduction of robot base reactions through the use of redundant degrees of freedom, and the development of smoothly operating roller-driven robot joints for microgravity manipulators is discussed.

Rohn, Douglas A.↗
NASA NTRS1984

OTV propulsion tecnology programmatic overview

An advanced orbit transfer vehicles (OTV) which will be an integral part of the national space transportation system to carry men and cargo between low Earth orbit and geosynchronous orbit will perform planetary transfers and deliver large acceleration limited space structures to high Earth orbits is reviewed. The establishment of an advanced propulsion technology base for an OTV for the mid 1990's is outlined. The program supports technology for three unique engine concepts. Work is conducted to generic technologies which benefit all three concepts and specific technology which benefits only one of the concepts. Concept and technology definitions to identify propulsion innovations, and subcomponent research to explore and validate their potential benefits are included.

Cooper, L. P.↗
NASA NTRS1991

An advanced hypervelocity aerophysics facility - A ground-based flight-test range

The paper discusses a concept for a ground-based flight-test facility, a large aeroballistic range capable of launching models large enough to permit the installation of significant amounts of onboard instrumentation. The large model size would also provide thick shock/boundary layers, thus providing the opportunity to measure flow-field properties via advanced offboard diagnostics. Current fabrication technology should permit the construction of a two-stage light-gas gun capable of accelerating 20 to 25 cm diameter models to velocities on the order of 6 km/sec. An electromagnetic launcher or a ram accelerator is considered as a potential means for achieving larger model sizes and/or greater launch velocities. Possible methods for obtaining and recording data are discussed as are the test chamber and model deceleration section requirements.

Witcofski, R. D.↗
NASA NTRS1993

A modular, programmable measurement system for physiological and spaceflight applications

The NASA-Ames Sensors 2000! Program has developed a small, compact, modular, programmable, sensor signal conditioning and measurement system, initially targeted for Life Sciences Spaceflight Programs. The system consists of a twelve-slot, multi-layer, distributed function backplane, a digital microcontroller/memory subsystem, conditioned and isolated power supplies, and six application-specific, physiological signal conditioners. Each signal condition is capable of being programmed for gains, offsets, calibration and operate modes, and, in some cases, selectable outputs and functional modes. Presently, the system has the capability for measuring ECG, EMG, EEG, Temperature, Respiration, Pressure, Force, and Acceleration parameters, in physiological ranges. The measurement system makes heavy use of surface-mount packaging technology, resulting in plug in modules sized 125x55 mm. The complete 12-slot system is contained within a volume of 220x150x70mm. The system's capabilities extend well beyond the specific objectives of NASA programs. Indeed, the potential commercial uses of the technology are virtually limitless. In addition to applications in medical and biomedical sensing, the system might also be used in process control situations, in clinical or research environments, in general instrumentation systems, factory processing, or any other applications where high quality measurements are required.

Hines, John W.↗
NASA NTRS1994

High temperature polymer dielectric film-wire insulation

The highlights of the program are outlined including two major accomplishments. TRW identified and demonstrated the potential of two aromatic/heterocyclic polymers to have an outstanding and superior combination of electrical, thermal, and chemical resistance properties versus state-of-the-art Kapton for spacecraft and/or aircraft dielectric insulation applications. (Supporting data is provided in tables.) Feasibility was demonstrated for supporting/enabling technologies such as ceramic coatings, continuous film casting, and conductor wire wrapping, which are designed to accelerate qualification and deployment of the new wire insulation materials for USAF systems applications during the mid- to late-1990's.

Nairus, John G.↗
NASA NTRS1998

Summary of Rocketdyne Engine A5 Rocket Based Combined Cycle Testing

Rocketdyne Propulsion and Power (RPP) has completed a highly successful experimental test program of an advanced rocket based combined cycle (RBCC) propulsion system. The test program was conducted as part of the Advanced Reusable Technology program directed by NASA-MSFC to demonstrate technologies for low-cost access to space. Testing was conducted in the new GASL Flight Acceleration Simulation Test (FAST) facility at sea level (Mach 0), Mach 3.0 - 4.0, and vacuum flight conditions. Significant achievements obtained during the test program include 1) demonstration of engine operation in air-augmented rocket mode (AAR), ramjet mode and rocket mode and 2) smooth transition from AAR to ramjet mode operation. Testing in the fourth mode (scramjet) is scheduled for November 1998.

Ketchum. A.↗
NASA NTRS1995

Accelerating Commercial Remote Sensing

Through the Visiting Investigator Program (VIP) at Stennis Space Center, Community Coffee was able to use satellites to forecast coffee crops in Guatemala. Using satellite imagery, the company can produce detailed maps that separate coffee cropland from wild vegetation and show information on the health of specific crops. The data can control coffee prices and eventually may be used to optimize application of fertilizers, pesticides and irrigation. This would result in maximal crop yields, minimal pollution and lower production costs. VIP is a mechanism involving NASA funding designed to accelerate the growth of commercial remote sensing by promoting general awareness and basic training in the technology.

Source record↗
NASA NTRS2010

Florida Tech CubeSat Experiment Feasibility Study

CubeSats are a relatively new type of satellite. Smaller than long-term (5+ year life expectancy) satellites, these pico-satellites are comparatively cheap, small (10x10x10 cm), and are very versatile. Universities world-wide are using CubeSats to conduct a variety of experiments in space without the need for a large experimental platform. Today CubeSats are considered to be one of the most effective ways to send a small payload into space and has attracted the attention of many educational and non-profit organizations. As this pico-satellite model continues to gain penetration into the satellite build and launch industry, it is expected that more governmental, educational, and commercial interests will emerge. As an example, more of the space-related items of high interest to the National Science Foundation may be tackled with a CubeSat platform resulting in lower life cycle costs than traditional satellite options. NASA LSP, in cooperation with the Florida Institute of Technology, has initiated a feasibility study to investigate the technical aspects of measuring and transferring vibration, acceleration, temperature, and video data from a CubeSat to NASA Hanger AE on Cape Canaveral Air Force Station (CCAFS) a.k.a. Kennedy Space Center (KSC). This report provides a technical feasibility analysis to determine whether-or-not a specific set of NASA/LSP requirements can be accomplished. Our approach has been to provide a "notional" component layout to determine the feasibility of the NASA/LSP stakeholder requirements. The notional layout is used to consider component level technical issues such as size, weight, & power (SWaP), bandwidth, and other critical technical parameters. Even though the notional components may satisfy the stated requirements and thereby demonstrate feasibility, the notional layout is NOT considered a design since no component optimization and design trade-off analysis has taken place. This activity should be accomplished in an appropriate design phase that is outside of the scope of this effort.

Arrasmith, William W.↗
NASA NTRS2013

Forecasting Propagation and Evolution of CMEs in an Operational Setting: What Has Been Learned

One of the major types of solar eruption, coronal mass ejections (CMEs) not only impact space weather, but also can have significant societal consequences. CMEs cause intense geomagnetic storms and drive fast mode shocks that accelerate charged particles, potentially resulting in enhanced radiation levels both in ions and electrons. Human and technological assets in space can be endangered as a result. CMEs are also the major contributor to generating large amplitude Geomagnetically Induced Currents (GICs), which are a source of concern for power grid safety. Due to their space weather significance, forecasting the evolution and impacts of CMEs has become a much desired capability for space weather operations worldwide. Based on our operational experience at Space Weather Research Center at NASA Goddard Space Flight Center (http://swrc.gsfc.nasa.gov), we present here some of the insights gained about accurately predicting CME impacts, particularly in relation to space weather operations. These include: 1. The need to maximize information to get an accurate handle of three-dimensional (3-D) CME kinetic parameters and therefore improve CME forecast; 2. The potential use of CME simulation results for qualitative prediction of regions of space where solar energetic particles (SEPs) may be found; 3. The need to include all CMEs occurring within a ~24 h period for a better representation of the CME interactions; 4. Various other important parameters in forecasting CME evolution in interplanetary space, with special emphasis on the CME propagation direction. It is noted that a future direction for our CME forecasting is to employ the ensemble modeling approach.

forecasting↗
NASA NTRS2016

Improved Convergence and Robustness of USM3D Solutions on Mixed-Element Grids

Several improvements to the mixed-elementUSM3Ddiscretization and defect-correction schemes have been made. A new methodology for nonlinear iterations, called the Hierarchical Adaptive Nonlinear Iteration Method, has been developed and implemented. The Hierarchical Adaptive Nonlinear Iteration Method provides two additional hierarchies around a simple and approximate preconditioner of USM3D. The hierarchies are a matrix-free linear solver for the exact linearization of Reynolds-averaged Navier-Stokes equations and a nonlinear control of the solution update. Two variants of the Hierarchical Adaptive Nonlinear Iteration Method are assessed on four benchmark cases, namely, a zero-pressure-gradient flat plate, a bump-in-channel configuration, the NACA 0012 airfoil, and a NASA Common Research Model configuration. The new methodology provides a convergence acceleration factor of 1.4 to 13 over the preconditioner-alone method representing the baseline solver technology.

Pandya, Mohagna J.↗
NASA NTRS2016

Improved Convergence and Robustness of USM3D Solutions on Mixed-Element Grids

Several improvements to the mixed-element USM3D discretization and defect-correction schemes have been made. A new methodology for nonlinear iterations, called the Hierarchical Adaptive Nonlinear Iteration Method, has been developed and implemented. The Hierarchical Adaptive Nonlinear Iteration Method provides two additional hierarchies around a simple and approximate preconditioner of USM3D. The hierarchies are a matrix-free linear solver for the exact linearization of Reynolds-averaged Navier-Stokes equations and a nonlinear control of the solution update. Two variants of the Hierarchical Adaptive Nonlinear Iteration Method are assessed on four benchmark cases, namely, a zero-pressure-gradient flat plate, a bump-in-channel configuration, the NACA 0012 airfoil, and a NASA Common Research Model configuration. The new methodology provides a convergence acceleration factor of 1.4 to 13 over the preconditioner-alone method representing the baseline solver technology.

Pandya, Mohagna J.↗
NASA NTRS1997

Lunar and Planetary Missions Launched from a Geosynchronous Transfer Orbit

Lithium Lorentz Force Accelerators (LFA's) are capable of processing very high power levels and are therefore applicable to a wide range of challenging missions. For this class of missions, the emphasis must be on achieving high efficiency at an Isp of 4000-5000s at power levels of 200-250 kWe. The engines must demonstrate very reliable operation for a service life of about 3000 hours.

Lithium↗
NASA NTRSDate not supplied

Analysis of Alternative Architectures for Cargo Lunar Landers

NASA’s Human Landing System (HLS) program has been working with commercial partners to develop human-class lunar landers to return the first American woman and next American man to the lunar surface in the mid 2020’s. In an effort to expand human presence beyond low Earth orbit, NASA’s Artemis program aims to facilitate a sustainable, long-term human presence in cis-lunar space. A component of this will require significant infrastructure to be delivered to the lunar surface. Delivering this infrastructure will require a significant lander capability that has yet to be developed. A thorough understanding of cargo lunar lander architectures is required such that select alternatives can be identified that best support the Artemis program’s objective of sustainability. The goal of this study is to aid NASA and its partners in the understanding of the cargo lunar lander trades space, as well as identify potential robust alternatives. The results will support NASA as it moves forward with key activities such as requirements formulation, agency strategic planning, and potential cargo lunar lander procurements. The study builds off of recent work performed by the Human Landing System program’s Architecture and Systems Analysis group to encompass a broad trade space of cargo lunar lander architecture alternatives. The current trade space as depicted by the morphological matrix and mission graph in Fig. 1 and Fig. 2, respectively, includes key alternative options that have become highly relevant due to current HLS activities and include on-orbit refueling, active cryogenic fluid management, Earth orbit aggregation, and global lunar access. The authors believe that there is also a statistically relevant impact of lander-payload configuration on the primary structure of the vehicle that could greatly impact alternative selection. Because of this, several conceptual lander-payload configurations will be evaluated to determine the level of impact. The current set of conceptual configurations are shown in Fig. 3 and Fig. 4. To aid the conceptual evaluation of these configurations, a catalogue of notional payloads has been developed that represent a wide range of masses and volumes that are expected to be delivered in support of a sustained human lunar presence, including pressurized and unpressurized rovers, surface habitats, power systems, and other support infrastructure. In order to execute this study in a timely fashion, a similar approach to that utilized in a similar 2019 study focused on 2024 human lunar sorties will be employed [1]. The team utilized a novel architecture synthesis framework currently being developed by NASA/MSFC to evaluate over 600,000 lunar lander architectures over a two month time frame [2]. From this large data set, varying ground rules and assumptions were applied as filters to explore the trade space to identify alternatives which exhibited robustness, as measured by launch vehicle payload margin, to absorb the natural growth that occurs during design maturation. The set of Earth-Moon system Delta-Vs assumed from the 2019 study, shown in Fig. 5, will be repurposed to accelerate model formulation for this effort. Additionally, current efforts in collaboration with the Georgia Institute of Technology’s Aerospace System Design Lab will be integrated to provide probabilistic modeling of the cargo lunar lander architectures to aid in identifying robust design alternatives [3]. The approach will help minimize potential impacts due to large levels of uncertainty inherent to pre phase-A conceptual design. By leveraging these past and present studies and partnerships, a highly detailed set of data can be generated in a short time period to aid NASA in the coming years to support the goal of a sustained human lunar presence.

Architectures↗
NASA NTRSDate not supplied

Initial Exploratory Study of the Impacts of Climate Change on Air Traffic Operations

Climate change is already happening and is projected to accelerate in the future. It will persist for the foreseeable future, even with optimistic projections of technological advances and behavior changes. It will make aviation more and more challenging over time. Among other things, it is expected to cause increased severe weather, more extreme temperatures, and rising sea levels that constrain when, where, and how aircraft can fly. NASA has many prior, ongoing, and upcoming efforts towards mitigating the impacts of aviation on climate change. There is also a need to perform a comprehensive investigation of the reverse: that is, the impacts of climate change on aviation. This is an initial exploratory study on this topic utilizing the NAS Digital Twin—composed of the ATM TestBed simulation platform and NAS Digital Twin airspace management algorithms—to run NAS-wide simulations with Convective Weather Avoidance Model polygons at different avoidance thresholds to emulate the increase in severe weather that could manifest due to climate change. It was found that air traffic management may be able to limit the impact of climate change in terms of delay and fuel burn. However, increased severe weather due to climate change can make separation—particularly, aircraft-to-weather separation—more challenging by reducing available airspace and constraining the solution space. Challenging situations were identified and corresponding potential solutions were proposed towards ensuring air traffic operations continue to be robust and resilient to the impacts of increased severe weather due to climate change.

climate change, weather, air traffic operations↗
NASA NTRS1984

Basic principles of coaxial launch technology

Already in the 1930s, a discrete-coil mechanically synchronized launcher was built. At the present time, research is almost entirely directed towards railguns. However, although coaxial accelerators are more complex than railguns, they have certain unique advantages. Some of these advantages are related to the absence of physical contact requirements with the projectile, the possibility of a scale-up to very large projectile size, and the availability of up to 100 times more thrust for a given current. The price of the advantages is the need for a drive current in the form of pulses synchronized precisely with transit of each projectile coil through each drive coil. At high velocities, high voltages are required, and high voltage switching represents the technology limit on launch velocity. Attention is given to inductance gradients, the double hump, methods of excitation, methods of synchronization, projectile configuration, energy supply, fundamental limits, trends, and research needs.

Kolm, H.↗
NASA NTRS2006

Status of Solar Sail Propulsion: Moving Toward an Interstellar Probe

NASA's In-Space Propulsion Technology Program has developed the first-generation of solar sail propulsion systems sufficient to accomplish inner solar system science and exploration missions. These first-generation solar sails, when operational, will range in size from 40 meters to well over 100 meters in diameter and have an areal density of less than 13 grams-per-square meter. A rigorous, multiyear technology development effort culminated last year in the testing of two different 20-meter solar sail systems under thermal vacuum conditions. This effort provided a number of significant insights into the optimal design and expected performance of solar sails as well as an understanding of the methods and costs of building and using them. In a separate effort, solar sail orbital analysis tools for mission design were developed and tested. Laboratory simulations of the effects of long-term space radiation exposure were also conducted on two candidate solar sail materials. Detailed radiation and charging environments were defined for mission trajectories outside the protection of the earth's magnetosphere, in the solar wind environment. These were used in other analytical tools to prove the adequacy of sail design features for accommodating the harsh space environment. Preceding, and in conjunction with these technology efforts, NASA sponsored several mission application studies for solar sails, including one that would use an evolved sail capability to support humanity's first mission into nearby interstellar space. The proposed mission is called the Interstellar Probe. The Interstellar Probe might be accomplished in several ways. A 200-meter sail, with an areal density approaching 1 gram-per-square meter, could accelerate a robotic probe to the very edge of the solar system in just under 20 years from launch. A sail using the technology just demonstrated could make the same mission, but take significantly longer. Conventional chemical propulsion systems would require even longer flight times. Spinner sails of the type being explored by the Japanese may also be a good option, but the level of maturity in that technology is not clear. While the technology to support a 200-meter, ultralightweight sail mission is not yet in hand, the recent NASA investments in solar sail technology are an essential first step toward making it a reality. This paper will describe the status of solar sail propulsion within NASA, near-term solar sail mission applications, and the plan to advance the technology to the point where the Interstellar Probe mission can be flown.

Johnson, Les↗