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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 271 records · Page 15
All sourcesNASA NTRSDOE OSTI
NASA NTRS2005

Determining Important Nuclear Fragmentation Processes for Human Space Explorations

Space radiation from cosmic ray particles is a major risk for astronauts in long-term human space explorations such as a permanent moon base or a trip to Mars. Radiation shielding is needed to reduce the radiation hazard to astronauts, and models have been developed in order to evaluate the effectiveness of different shielding materials. In this talk we determine the nuclear fragmentation cross sections which will most affect the radiation risk behind typical radiation shielding materials. As a result, these cross sections need more theoretical studies and accurate experimental measurements in order for us to more precisely predict the radiation risk in human space explorations.

Lin, Zi-Wei↗
NASA NTRS1974

Nuclear Science Symposium, 20th, and Nuclear Power Systems Symposium, 5th, San Francisco, Calif., November 14-16, 1973, Proceedings

Subjects considered are in the areas of position sensitive detectors, semiconductor detector materials, semiconductor detector technology, biomedical instrumentation, reactor instrumentation, nuclear instrumentation, and data acquisition and processing. Topics related to photon detection are discussed together with methods for environmental radiation measurement, aspects of environmental gamma-ray analysis, and nuclear techniques for elemental analysis. Attention is also given to operation and design experience with systems at nuclear power plants. Individual items are announced in this issue.

Source record↗
NASA NTRS2006

The ALTCRISS Project On Board the International Space Station

The Altcriss project aims to perform a long term survey of the radiation environment on board the International Space Station. Measurements are being performed with active and passive devices in different locations and orientations of the Russian segment of the station. The goal is perform a detailed evaluation of the differences in particle fluence and nuclear composition due to different shielding material and attitude of the station. The Sileye-3/Alteino detector is used to identify nuclei up to Iron in the energy range above approximately equal to 60 MeV/n; a number of passive dosimeters (TLDs, CR39) are also placed in the same location of Sileye-3 detector. Polyethylene shielding is periodically interposed in front of the detectors to evaluate the effectiveness of shielding on the nuclear component of the cosmic radiation. The project was submitted to ESA in reply to the AO the Life and Physical Science of 2004 and was begun in December 2005. Dosimeters and data cards are rotated every six months: up to now three launches of dosimeters and data cards have been performed and have been returned with the end expedition 12 and 13.

Cucinotta, Francis A.↗
NASA NTRS1991

Automated technologies needed to prevent radioactive materials from reentering the atmosphere

Project SIREN (Search, Intercept, Retrieve, Expulsion Nuclear) was created to identify and evaluate the technologies and operational strategies needed to rendezvous with and capture aerospace radioactive materials (e.g., a distressed or spent space reactor core) before such materials can reenter the terrestrial atmosphere and then to safely move these captured materials to an acceptable space destination for proper disposal. A major component of the current project SIREN effort is the development of an interactive technology model (including a computerized data base) that explores, in building-block fashion, the interaction of the technologies and procedures needed to successfully accomplish a SIREN mission. The SIREN model will include appropriate national and international technology elements--both contemporary and projected into the next century. To obtain maximum flexibility and use, the SIREN technology data base is being programmed for use on 286-class PC's. The major technical elements for a successful SIREN mission include: ground and space-based tracking, launch vehicles of needed payload capacity, telerobotic systems, sensors, capture technologies, and space transport and disposal. However, Project SIREN also will impose specialized requirements including the use of dextrous aerospace systems capable of properly functioning in intense radiation and thermal environments.

Buden, David↗
NASA NTRS2004

Trajectory Analysis

The Systems Analysis Branch performs trajectory and systems analysis for next-generation launch vehicle and space transportation technologies. Currently the branch is supporting the Project Prometheus with analysis of nuclear electric and nuclear thermal propulsion missions to a variety of destinations. Within Project Prometheus a proposed mission to Jupiter and three of the planet sized icy moons that orbit it is developing. The Jupiter Icy Moons Orbiter (JIMO) as the project is being called will enable detailed scientific investigation of Jupiter's moons Callisto, Ganymede, and Europa. These moons were choose to orbit for intensive study in particular because they are each believed to have water, energy, and organic material. The JIMO mission will utilize nuclear fission power and electric propulsion in order to allow the spacecraft to orbit the moons at close range for long durations of time. My assignment this summer was to assist in developing a trajectory analysis for the spacecraft system the Jupiter Icy Moons Orbiter by rewriting an inefficient Excel file into a more efficient FORTRAN program. This program has been created for use planning the trajectory of the Jupiter Icy Moons Orbiter Mission. The program uses a database of thousands of data points representing flight time, burn time, thrust, mass of the propellant used, final mass of the spacecraft, ratio of finals mass to initial mass, and change in velocity that a spacecraft experiences during each phase in the Jupiter Icy Moons Orbiter Mission. The trajectory program is capable of taking a specific user entered specific impulse (isp), final mass fraction, and thrust (P(sub J)/m0) and through the use of cubic splines to fit specific data curves, the program can locate the exact flight time linked to the user specified values of specific impulse and final over initial mass fraction. Currently, the database used by the program to calculate flight times for a given thrust is only for isps in the range of 2000 to 9000 seconds. Although the program is specific to the Jupiter Icy Moons Orbiter mission, it can be easily modified to fit any mission with a propulsion system expected isp range between 2000 and 9000 seconds. This program performs the same tasks as the old Excel file but in a more timely fashion. Finally, this FORTRAN program will replace the Excel file as the tool used to calculate trajectory properties in missions and will provide valuable data to mission analysts for years to come.

Burke, Laura M.↗
NASA NTRS1963

Nuclear Lunar Logistics Study

This document has been prepared to incorporate all presentation aid material, together with some explanatory text, used during an oral briefing on the Nuclear Lunar Logistics System given at the George C. Marshall Space Flight Center, National Aeronautics and Space Administration, on 18 July 1963. The briefing and this document are intended to present the general status of the NERVA (Nuclear Engine for Rocket Vehicle Application) nuclear rocket development, the characteristics of certain operational NERVA-class engines, and appropriate technical and schedule information. Some of the information presented herein is preliminary in nature and will be subject to further verification, checking and analysis during the remainder of the study program. In addition, more detailed information will be prepared in many areas for inclusion in a final summary report. This work has been performed by REON, a division of Aerojet-General Corporation under Subcontract 74-10039 from the Lockheed Missiles and Space Company. The presentation and this document have been prepared in partial fulfillment of the provisions of the subcontract. From the inception of the NERVA program in July 1961, the stated emphasis has centered around the demonstration of the ability of a nuclear rocket to perform safely and reliably in the space environment, with the understanding that the assignment of a mission (or missions) would place undue emphasis on performance and operational flexibility. However, all were aware that the ultimate justification for the development program must lie in the application of the nuclear propulsion system to the national space objectives.

Source record↗
NASA NTRS1959

NASA Reactor Facility Hazards Summary

The Lewis Research Center of the National Aeronautics and Space Administration proposes to build a nuclear research reactor which will be located in the Plum Brook Ordnance Works near Sandusky, Ohio. The purpose of this report is to inform the Advisory Committee on Reactor Safeguards of the U. S. Atomic Energy Commission in regard to the design Lq of the reactor facility, the characteristics of the site, and the hazards of operation at this location. The purpose of this research reactor is to make pumped loop studies of aircraft reactor fuel elements and other reactor components, radiation effects studies on aircraft reactor materials and equipment, shielding studies, and nuclear and solid state physics experiments. The reactor is light water cooled and moderated of the MTR-type with a primary beryllium reflector and a secondary water reflector. The core initially will be a 3 by 9 array of MTR-type fuel elements and is designed for operation up to a power of 60 megawatts. The reactor facility is described in general terms. This is followed by a discussion of the nuclear characteristics and performance of the reactor. Then details of the reactor control system are discussed. A summary of the site characteristics is then presented followed by a discussion of the larger type of experiments which may eventually be operated in this facility. The considerations for normal operation are concluded with a proposed method of handling fuel elements and radioactive wastes. The potential hazards involved with failures or malfunctions of this facility are considered in some detail. These are examined first from the standpoint of preventing them or minimizing their effects and second from the standpoint of what effect they might have on the reactor facility staff and the surrounding population. The most essential feature of the design for location at the proposed site is containment of the maximum credible accident.

Source record↗
NASA NTRS1991

Automated technologies needed to prevent radioactive materials from reentering the atmosphere

Project SIREN (Search, Intercept, Retrieve, Expulsion Nuclear) has been created to identify and evaluate the technologies and operational strategies needed to rendezvous with and capture aerospace radioactive materials (e.g., a distressed or spent space reactor core) before such materials can reenter the terrestrial atmosphere and then to safely move these captured materials to an acceptable space destination for proper disposal. A major component of the current Project SIREN effort is the development of an interactive technology model (including a computerized data base) that explores in building block fashion the interaction of the technologies and procedures needed to successfully accomplish a SIREN mission. This SIREN model will include appropriate national and international technology elements-both contemporary and projected into the next century. To permit maximum flexibility and use, the SIREN technology data base is being programmed for use on 386-class PC's.

Buden, David↗
NASA NTRS2008

Flow Components in a NaK Test Loop Designed to Simulate Conditions in a Nuclear Surface Power Reactor

A test loop using NaK as the working fluid is presently in use to study material compatibility effects on various components that comprise a possible nuclear reactor design for use on the lunar surface. A DC electromagnetic (EM) pump has been designed and implemented as a means of actively controlling the NaK flow rate through the system and an EM flow sensor is employed to monitor the developed flow rate. These components allow for the matching of the flow rate conditions in test loops with those that would be found in a full-scale surface-power reactor. The design and operating characteristics of the EM pump and flow sensor are presented. In the EM pump, current is applied to a set of electrodes to produce a Lorentz body force in the fluid. A measurement of the induced voltage (back-EMF) in the flow sensor provides the means of monitoring flow rate. Both components are compact, employing high magnetic field strength neodymium magnets thermally coupled to a water-cooled housing. A vacuum gap limits the heat transferred from the high temperature NaK tube to the magnets and a magnetically-permeable material completes the magnetic circuit. The pump is designed to produce a pressure rise of 5 psi, and the flow sensor's predicted output is roughly 20 mV at the loop's nominal flow rate of 0.5 GPM.

Polzin, Kurt A.↗
NASA NTRS2004

Implementation Challenges for Ceramic Matrix Composites in High Temperature Applications

Ceramic matrix composites are leading candidate materials for a number of applications in aeronautics, space, energy, electronics, nuclear, and transportation industries. In the aeronautics and space exploration systems, these materials are being considered for applications in hot sections of jet engines such as the combustor liner, nozzle components, nose cones, leading edges of reentry vehicles and space propulsion components. Applications in the energy and environmental industries include radiant heater tubes, heat exchangers, heat recuperators, gas and diesel particulate filters (DPFs), and components for land based turbines for power generation. These materials are also being considered for use in the first wall and blanket components of fusion reactors. There are a number of critical issues and challenges related to successful implementation of composite materials. Fabrication of net and complex shape components with high density and tailorable matrix properties is quite expensive, and even then various desirable properties are not achievable. In this presentation, microstructure and thermomechanical properties of composites fabricated by two techniques (chemical vapor infiltration and melt infiltration), will be presented. In addition, critical need for robust joining and assembly technologies in successful implementation of these systems will be discussed. Other implementation issues will be discussed along with advantages and benefits of using these materials for various components in high temperature applications.

Singh, Mrityunjay↗
NASA NTRS1975

Accretion and the nova outburst

Evolutionary sequences of thermonuclear runaways in the hydrogen-rich envelopes of carbon-oxygen white dwarfs are presented which include the effects of accretion of infalling material, allow the initial envelope to be out of equilibrium, and reproduce the gross features of the nova outburst. The models show that massive infall rates produce strong shocks at the stellar surface, that material passing through the shocks reaches nuclear-ignition temperatures, and that the thermonuclear runaway proceeds with an extended envelope around the star in the most extreme cases. The major effect of accretion is found to be a reduction in the amount of material ejected for a given degree of CNO enhancement as compared with previous nonaccretion models. It is also found that all the heating that causes ejection occurs in the deeper layers and that the light curves produced by the present models are in closer agreement with observed nova light curves that the previous models.

Starrfield, S. G.↗
NASA NTRS1986

Materials Research Capabilities

Lewis Research Center, in partnership with U.S. industry and academia, has long been a major force in developing advanced aerospace propulsion and power systems. One key aspect that made many of these systems possible has been the availability of high-performance, reliable, and long-life materials. To assure a continuing flow of new materials and processing concepts, basic understanding to guide such innovation, and technological support for development of major NASA systems, Lewis has supported a strong in-house materials research activity. Our researchers have discovered new alloys, polymers, metallic composites, ceramics, coatings, processing techniques, etc., which are now also in use by U.S. industry. This brochure highlights selected past accomplishments of our materials research and technology staff. It also provides many examples of the facilities available with which we can conduct materials research. The nation is now beginning to consider integrating technology for high-performance supersonic/hypersonic aircraft, nuclear space power systems, a space station, and new research areas such as materials processing in space. As we proceed, I am confident that our materials research staff will continue to provide important contributions which will help our nation maintain a strong technology position in these areas of growing world competition. Lewis Research Center, in partnership with U.S. industry and academia, has long been a major force in developing advanced aerospace propulsion and power systems. One key aspect that made many of these systems possible has been the availability of high-performance, reliable, and long-life materials. To assure a continuing flow of new materials and processing concepts, basic understanding to guide such innovation, and technological support for development of major NASA systems, Lewis has supported a strong in-house materials research activity. Our researchers have discovered new alloys, polymers, metallic composites, ceramics, coatings, processing techniques, etc., which are now also in use by U.S. industry. This brochure highlights selected past accomplishments of our materials research and technology staff. It also provides many examples of the facilities available with which we can conduct materials research. The nation is now beginning to consider integrating technology for high-performance supersonic/hypersonic aircraft, nuclear space power systems, a space station, and new research areas such as materials processing in space.

Stofan, Andrew J.↗
NASA NTRS2011

Low Cost Nuclear Thermal Rocket Cermet Fuel Element Environment Testing

Deep space missions with large payloads require high specific impulse and relatively high thrust to achieve mission goals in reasonable time frames.1,2 Conventional storable propellants produce average specific impulse. Nuclear thermal rockets capable of producing high specific impulse are proposed. Nuclear thermal rockets employ heat produced by fission reaction to heat and therefore accelerate hydrogen, which is then forced through a rocket nozzle providing thrust. Fuel element temperatures are very high (up to 3000 K), and hydrogen is highly reactive with most materials at high temperatures. Data covering the effects of high-temperature hydrogen exposure on fuel elements are limited.3 The primary concern is the mechanical failure of fuel elements that employ high-melting-point metals, ceramics, or a combination (cermet) as a structural matrix into which the nuclear fuel is distributed. The purpose of the testing is to obtain data to assess the properties of the non-nuclear support materials, as-fabricated, and determine their ability to survive and maintain thermal performance in a prototypical NTR reactor environment of exposure to hydrogen at very high temperatures. The fission process of the planned fissile material and the resulting heating performance is well known and does not therefore require that active fissile material be integrated in this testing. A small-scale test bed designed to heat fuel element samples via non-contact radio frequency heating and expose samples to hydrogen is being developed to assist in optimal material and manufacturing process selection without employing fissile material. This paper details the test bed design and results of testing conducted to date.

Bradley, D. E.↗
NASA NTRS1986

Heat Radiators for Electromagnetic Pumps

Report proposes use of carbon/carbon composite radiators in electromagnetic coolant pumps of nuclear reactors on spacecraft. Carbon/carbon composite materials function well at temperatures in excess of 2,200 K. Aluminum has melting temperature of only 880 K.

Campana, R. J.↗
NASA NTRS1990

Exotic power and propulsion concepts

The status of some exotic physical phenomena and unconventional spacecraft concepts that might produce breakthroughs in power and propulsion in the 21st Century are reviewed. The subjects covered include: electric, nuclear fission, nuclear fusion, antimatter, high energy density materials, metallic hydrogen, laser thermal, solar thermal, solar sail, magnetic sail, and tether propulsion.

Forward, Robert L.↗
NASA NTRS1991

Carbon and nitrogen abundances in the BN supergiant HD 93840, and their implications for normal Galactic supergiants

It is demonstrated how carbon and nitrogen abundances of luminous B stars can be determined by a combined analysis of their UV photospheric and wind lines. It is shown that HD 93840 has nearly the same temperature and surface gravity as the normal B1 Ib star Zeta Per. These two stars are compared on the basis of their UV photospheric silicon spectra and the differences in their photospheric CNO and metallic lines are discussed. A quantitative comparison between the wind profiles of the two stars is made. A simple model for the compositions of both atmospheres is used to derive the fraction of material in each atmosphere which has undergone CNO processing. It is argued that the enriched material must have resided in a nuclear burning core for only a very short time. Best estimates of 0.09 + or - 0.07 and 0.90 + or - 0.1 are made for the carbon abundances relative to cosmic ones for HD 93840 and Zeta Per, respectively.

Massa, D.↗
NASA NTRS2013

Induction Heating Model of Cermet Fuel Element Environmental Test (CFEET)

Deep space missions with large payloads require high specific impulse and relatively high thrust to achieve mission goals in reasonable time frames. Nuclear Thermal Rockets (NTR) are capable of producing a high specific impulse by employing heat produced by a fission reactor to heat and therefore accelerate hydrogen through a rocket nozzle providing thrust. Fuel element temperatures are very high (up to 3000 K) and hydrogen is highly reactive with most materials at high temperatures. Data covering the effects of high‐temperature hydrogen exposure on fuel elements are limited. The primary concern is the mechanical failure of fuel elements due to large thermal gradients; therefore, high‐melting‐point ceramics‐metallic matrix composites (cermets) are one of the fuels under consideration as part of the Nuclear Cryogenic Propulsion Stage (NCPS) Advance Exploration System (AES) technology project at the Marshall Space Flight Center. The purpose of testing and analytical modeling is to determine their ability to survive and maintain thermal performance in a prototypical NTR reactor environment of exposure to hydrogen at very high temperatures and obtain data to assess the properties of the non‐nuclear support materials. The fission process and the resulting heating performance are well known and do not require that active fissile material to be integrated in this testing. A small‐scale test bed; Compact Fuel Element Environmental Tester (CFEET), designed to heat fuel element samples via induction heating and expose samples to hydrogen is being developed at MSFC to assist in optimal material and manufacturing process selection without utilizing fissile material. This paper details the analytical approach to help design and optimize the test bed using COMSOL Multiphysics for predicting thermal gradients induced by electromagnetic heating (Induction heating) and Thermal Desktop for radiation calculations.

Gomez, C. F.↗