Nuclear space power safety and facility guidelines study

International Nuclear Information System (INIS)

Mehlman, W.F.

1995-01-01

This report addresses safety guidelines for space nuclear reactor power missions and was prepared by The Johns Hopkins University Applied Physics Laboratory (JHU/APL) under a Department of Energy grant, DE-FG01-94NE32180 dated 27 September 1994. This grant was based on a proposal submitted by the JHU/APL in response to an open-quotes Invitation for Proposals Designed to Support Federal Agencies and Commercial Interests in Meeting Special Power and Propulsion Needs for Future Space Missionsclose quotes. The United States has not launched a nuclear reactor since SNAP 10A in April 1965 although many Radioisotope Thermoelectric Generators (RTGs) have been launched. An RTG powered system is planned for launch as part of the Cassini mission to Saturn in 1997. Recently the Ballistic Missile Defense Office (BMDO) sponsored the Nuclear Electric Propulsion Space Test Program (NEPSTP) which was to demonstrate and evaluate the Russian-built TOPAZ II nuclear reactor as a power source in space. As of late 1993 the flight portion of this program was canceled but work to investigate the attributes of the reactor were continued but at a reduced level. While the future of space nuclear power systems is uncertain there are potential space missions which would require space nuclear power systems. The differences between space nuclear power systems and RTG devices are sufficient that safety and facility requirements warrant a review in the context of the unique features of a space nuclear reactor power system

Communicating with the public: space of nuclear technology

Energy Technology Data Exchange (ETDEWEB)

Maffei, Patricia Martinez; Aquino, Afonso Rodrigues; Gordon, Ana Maria Pinho Leite; Oliveira, Rosana Lagua de; Padua, Rafael Vicente de; Vieira, Martha Marques Ferreira; Vicente, Roberto, E-mail: pmaffei@ipen.br, E-mail: araquino@usp.br, E-mail: amgordon@ipen.br, E-mail: rloliveira@ipen.br, E-mail: rpadua@ipen.br, E-mail: mmvieira@ipen.br, E-mail: rvicente@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2011-07-01

For two decades the Nuclear and Energy Research Institute (IPEN) has been developing activities for popularization of its R and D activities in the nuclear field. Some of the initiatives already undertaken by IPEN are lectures at schools, guided visits to IPEN facilities, printed informative material, FAQ page in the Web, and displays in annual meetings and technology fairs highlighting its achievements. In order to consolidate these initiatives, IPEN is planning to have a permanent Space of Nuclear Technology (SNT), aiming at introducing students, teachers and the general public to the current applications of nuclear technology in medicine, industry, research, electric power generation, etc. It is intended as an open room to the public and will have a permanent exhibit with historical, scientific, technical and cultural developments of nuclear technology and will also feature temporary exhibitions about specific themes. The space will display scientific material in different forms to allow conducting experiments to demonstrate some of the concepts associated with the properties of nuclear energy, hands-on programs and activities that can be customized to the students' grade level and curriculum. (author)

Communicating with the public: space of nuclear technology

International Nuclear Information System (INIS)

Maffei, Patricia Martinez; Aquino, Afonso Rodrigues; Gordon, Ana Maria Pinho Leite; Oliveira, Rosana Lagua de; Padua, Rafael Vicente de; Vieira, Martha Marques Ferreira; Vicente, Roberto

2011-01-01

For two decades the Nuclear and Energy Research Institute (IPEN) has been developing activities for popularization of its R and D activities in the nuclear field. Some of the initiatives already undertaken by IPEN are lectures at schools, guided visits to IPEN facilities, printed informative material, FAQ page in the Web, and displays in annual meetings and technology fairs highlighting its achievements. In order to consolidate these initiatives, IPEN is planning to have a permanent Space of Nuclear Technology (SNT), aiming at introducing students, teachers and the general public to the current applications of nuclear technology in medicine, industry, research, electric power generation, etc. It is intended as an open room to the public and will have a permanent exhibit with historical, scientific, technical and cultural developments of nuclear technology and will also feature temporary exhibitions about specific themes. The space will display scientific material in different forms to allow conducting experiments to demonstrate some of the concepts associated with the properties of nuclear energy, hands-on programs and activities that can be customized to the students' grade level and curriculum. (author)

Space nuclear power and man's extraterrestrial civilization

International Nuclear Information System (INIS)

Angelo, J.J.; Buden, D.

1983-01-01

This paper examines leading space nuclear power technology candidates. Particular emphasis is given the heat-pipe reactor technology currently under development at the Los Alamos National Laboratory. This program is aimed at developing a 10-100 kWe, 7-year lifetime space nuclear power plant. As the demand for space-based power reaches megawatt levels, other nuclear reactor designs including: solid core, fluidized bed, and gaseous core, are considered

Environmental Development Plan (EDP): space applications

International Nuclear Information System (INIS)

1978-04-01

This Environmental Development Plan (EDP) identifies and examines the environmental, safety, health, and socioeconomic (ES and H) issues associated with the ongoing DOE Space Applications Program and the associated research, development, and demonstration programs. The EDP presents an ES and H research and development (R/D) program and strategy for timely resolutions of the issues and satisfaction of the associated requirements necessary for precluding impediments to the space nuclear systems technology. The EDP has been limited to the consideration of: (1) space nuclear power system nuclear fuel fabrication; (2) space nuclear power system heat source fabrication; (3) testing of subsystems and assembled systems; (4) R and D in support of space nuclear system development; (5) nuclear system responses to launch and reentry accidents; and (6) nuclear system environmental behavior and recovery

Legal Implications of Nuclear Propulsion for Space Objects

Science.gov (United States)

Pop, V.

2002-01-01

This paper is intended to examine nuclear propulsion concepts such as "Project Orion", "Project Daedalus", NERVA, VASIMIR, from the legal point of view. The UN Principles Relevant to the Use of Nuclear Power Sources in Outer Space apply to nuclear power sources in outer space devoted to the generation of electric power on board space objects for non-propulsive purposes, and do not regulate the use of nuclear energy as a means of propulsion. However, nuclear propulsion by means of detonating atomic bombs (ORION) is, in principle, banned under the 1963 Treaty Banning Nuclear Weapon Tests in the Atmosphere, in Outer Space, and Under Water. The legality of use of nuclear propulsion will be analysed from different approaches - historical (i.e. the lawfulness of these projects at the time of their proposal, at the present time, and in the future - in the light of the mutability and evolution of international law), spatial (i.e. the legal regime governing peaceful nuclear explosions in different spatial zones - Earth atmosphere, Earth orbit, Solar System, and interstellar space), and technical (i.e, the legal regime applicable to different nuclear propulsion techniques, and to the various negative effects - e.g. damage to other space systems as an effect of the electromagnetic pulse, etc). The paper will analyse the positive law, and will also come with suggestions "de lege ferenda".

Overview of nuclear waste disposal in space

International Nuclear Information System (INIS)

Rice, E.E.; Priest, C.C.

1981-01-01

One option receiving consideration by the Department of Energy (DOE) is the space disposal of certain high-level nuclear wastes. The National Aeronautics and Space Administration is assessing the space disposal option in support of DOE studies on alternatives for nuclear waste management. The space disposal option is viewed as a complement, since total disposal of fuel rods from commercial power plants is not considered to be economically practical with Space Shuttle technology. The space disposal of certain high-level wastes may, however, provide reduced calculated and perceived risks. The space disposal option in conjunction with terrestrial disposal may offer a more flexible and lower risk overall waste management system. For the space disposal option to be viable, it must be demonstrated that the overall long-term risks associated with this activity, as a complement to the mined geologic repository, would be significantly less than the long-term risk associated with disposing of all the high-level waste. The long-term risk benefit must be achieved within an acceptable short-term and overall program cost. This paper briefly describes space disposal alternatives, the space disposal destination, possible waste mixes and forms, systems and typical operations, and the energy and cost analysis

Transactions of the fifth symposium on space nuclear power systems

Energy Technology Data Exchange (ETDEWEB)

El-Genk, M.S.; Hoover, M.D. (eds.)

1988-01-01

This paper contains the presented papers at the fourth symposium on space nuclear power systems. Topics of these paper include: space nuclear missions and applications, reactors and shielding, nuclear electric and nuclear propulsion, high-temperature materials, instrumentation and control, energy conversion and storage, space nuclear fuels, thermal management, nuclear safety, simulation and modeling, and multimegawatt system concepts. (LSP)

Transactions of the fourth symposium on space nuclear power systems

Energy Technology Data Exchange (ETDEWEB)

El-Genk, M.S.; Hoover, M.D. (eds.)

1987-01-01

This paper contains the presented papers at the fourth symposium on space nuclear power systems. Topics of these papers include: space nuclear missions and applications, reactors and shielding, nuclear electric and nuclear propulsion, refractory alloys and high-temperature materials, instrumentation and control, energy conversion and storage, space nuclear fuels, thermal management, nuclear safety, simulation and modeling, and multimegawatt system concepts. (LSP)

Estimating inhalation hazards for space nuclear power systems

International Nuclear Information System (INIS)

Hoover, M.D.; Cuddihy, R.G.; Seiler, F.Z.

1989-01-01

Minimizing inhalation hazards is a major consideration in the design, development, transportation, handling, testing, storage, launch, use, and ultimate disposition of nuclear space power systems (NSPSs). An accidental dispersion of 238 Pu is of concern for missions involving the radioisotope thermoelectric generators (RTGs) or lightweight radioisotope heater units. Materials of concern for missions involving a nuclear reactor might include other radionuclides, such as uranium, or chemically toxic materials, such as beryllium or lithium. This paper provides an overview of some of the current approaches and uncertainties associated with estimating inhalation hazards from potential NSPS accidents. The question of whether inhalation risks can be acceptable for nuclear space power systems is still open and active. The inherently low toxicity of the uranium fuel of a space nuclear reactor is a desirable feature of that option. The extensive engineering and testing that have contributed to the current generation of plutonium RTGs provide a measure of confidence that dispersion of the RTG fuel would be unlikely in an accident. The use of nuclear reactors or RTGs in space, however, requires society to assume a risk (albeit low) for dispersion of the fuel material. It can be argued that any additional risks from the use of nuclear power in space are far less than the risks we face daily

System survivability in nuclear and space environments

International Nuclear Information System (INIS)

Rudie, N.J.

1987-01-01

Space systems must operate in the hostile natural environment of space. In the event of a war, these systems may also be exposed to the radiation environments created by the explosions of nuclear warheads. The effects of these environments on a space system and hardening techniques are discussed in the paper

Man--machine interface issues for space nuclear power systems

International Nuclear Information System (INIS)

Nelson, W.R.; Haugset, K.

1991-01-01

The deployment of nuclear reactors in space necessitates an entirely new set of guidelines for the design of the man--machine interface (MMI) when compared to earth-based applications such as commerical nuclear power plants. Although the design objectives of earth- and space-based nuclear power systems are the same, that is, to produce electrical power, the differences in the application environments mean that the operator's role will be significantly different for space-based systems. This paper explores the issues associated with establishing the necessary MMI guidelines for space nuclear power systems. The generic human performance requirements for space-based systems are described, and the operator roles that are utilized for the operation of current and advanced earth-based reactors are briefly summarized. The development of a prototype advanced control room, the Integrated Surveillance and Control System (ISACS) at the Organization for Economic Cooperation and Development (OECD) Halden Reactor Project is introduced. Finally, preliminary ideas for the use of the ISACS system as a test bed for establishing MMI guidelines for space nuclear systems are presented

Space nuclear reactors: energy gateway into the next millennium

International Nuclear Information System (INIS)

Angelo, J.A. Jr.; Buden, D.

1981-01-01

Power - reliable, abundant and economic - is the key to man's conquest of the Solar System. Space activities of the next few decades will be highlighted by the creation of the extraterrestrial phase of human civilization. Nuclear power is needed both to propel massive quantities of materials through cislunar and eventually translunar space, and to power the sophisticated satellites, space platforms, and space stations of tomorrow. To meet these anticipated future space power needs, the Los Alamos National Laboratory is developing components for a compact, 100-kW(e) heat pipe nuclear reactor. The objectives of this program are to develop components for a space nuclear power plant capable of unattended operation for 7 to 10 years; having a reliability of greater than 0.95; and weighing less than 1910 kg. In addition, this heat pipe reactor is also compatible for launch by the US Space Transportation System

Nuclear propulsion for the space exploration initiative

International Nuclear Information System (INIS)

Stanley, M.L.

1991-01-01

President Bush's speech of July 20, 1989, outlining a goal to go back to the moon and then Mars initiated the Space Exploration Initiative (SEI). The US Department of Defense (DOD), US Department of Energy (DOE), and NASA have been working together in the planning necessary to initiate a program to develop a nuclear propulsion system. Applications of nuclear technology for in-space transfer of personnel and cargo between Earth orbit and lunar or Martian orbit are being considered as alternatives to chemical propulsion systems. Mission and system concept studies conducted over the past 30 yr have consistently indicated that use of nuclear technology can substantially reduce in-space propellant requirements. A variety of nuclear technology options are currently being studied, including nuclear thermal rockets, nuclear electrical propulsion systems, and hybrid nuclear thermal rockets/nuclear electric propulsion concepts. Concept performance in terms of thrust, weight, power, and efficiency are dependent, and appropriate concept application is mission dependent (i.e., lunar, Mars, cargo, personnel, trajectory, transit time, payload). A comprehensive evaluation of mission application, technology performance capability and maturity, technology development programmatics, and safety characteristics is required to optimize both technology and mission selection to support the Presidential initiative

Space Nuclear Reactor Engineering

Energy Technology Data Exchange (ETDEWEB)

Poston, David Irvin [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-03-06

We needed to find a space reactor concept that could be attractive to NASA for flight and proven with a rapid turnaround, low-cost nuclear test. Heat-pipe-cooled reactors coupled to Stirling engines long identified as the easiest path to near-term, low-cost concept.

Nuclear Power in Space.

Science.gov (United States)

Department of Energy, Washington, DC. Nuclear Energy Office.

Research has shown that nuclear radioisotope power generators can supply compact, reliable, and efficient sources of energy for a broad range of space missions. These missions range from televising views of planetary surfaces to communicating scientific data to Earth. This publication presents many applications of the advancing technology and…

Nuclear space power and propulsion requirements and issues

International Nuclear Information System (INIS)

Swerdling, M.; Isenberg, L.

1995-01-01

The use of nuclear power in space is going through a low point. The kinds of missions that would use nuclear power are expensive and there are few new expensive missions. Both NASA and DoD are in a mode of cheaper, faster, better, which means using what is available as much as possible and only incorporating new technology to reduce mission cost. NASA is performing Mission to Planet Earth and detailed exploration missions of Mars. These NASA missions can be done with solar-battery power subsystems and there is no need for nuclear power. The NASA mission to Pluto does require nuclear radioisotope power. Ways to reduce the power subsystem cost and the power level are being investigated. NASA is studying ways to explore beyond Mars with solar-battery power because of the cost and uncertainty in the availability and launchability of nuclear space power systems. The DoD missions are all in earth orbit and can be done with solar-battery systems. The major DoD requirement at present is to reduce costs of all their space missions. One way to do this is to develop highly efficient upper stage boosters that can be integrated with lower cost Earth to low orbit stages and still place their payloads in to higher orbits. One attractive upper stage is a nuclear bimodal (propulsion and power) engine to accomplished lower booster cost to place space assets in GEO. However this is not being pursued because of DOE's new policy not to fund nuclear space power research and development as well as the difficulty in obtaining launch approval for nuclear propulsion and power systems

Safety Framework for Nuclear Power Source Applications in Outer Space

International Nuclear Information System (INIS)

2009-01-01

Nuclear power sources (NPS) for use in outer space have been developed and used in space applications where unique mission requirements and constraints on electrical power and thermal management precluded the use of non-nuclear power sources. Such missions have included interplanetary missions to the outer limits of the Solar System, for which solar panels were not suitable as a source of electrical power because of the long duration of these missions at great distances from the Sun. According to current knowledge and capabilities, space NPS are the only viable energy option to power some space missions and significantly enhance others. Several ongoing and foreseeable missions would not be possible without the use of space NPS. Past, present and foreseeable space NPS applications include radioisotope power systems (for example, radioisotope thermoelectric generators and radioisotope heater units) and nuclear reactor systems for power and propulsion. The presence of radioactive materials or nuclear fuels in space NPS and their consequent potential for harm to people and the environment in Earth's biosphere due to an accident require that safety should always be an inherent part of the design and application of space NPS. NPS applications in outer space have unique safety considerations compared with terrestrial applications. Unlike many terrestrial nuclear applications, space applications tend to be used infrequently and their requirements can vary significantly depending upon the specific mission. Mission launch and outer space operational requirements impose size, mass and other space environment limitations not present for many terrestrial nuclear facilities. For some applications, space NPS must operate autonomously at great distances from Earth in harsh environments. Potential accident conditions resulting from launch failures and inadvertent re-entry could expose NPS to extreme physical conditions. These and other unique safety considerations for the use of

Potential refractory alloy requirements for space nuclear power applications

International Nuclear Information System (INIS)

Cooper, R.H. Jr.

1984-01-01

In reviewing design requirements for refractory alloys for space nuclear applications, several key points are identified. First, the successful utilization of refractory alloys is considered an enabling requirement for the successful deployment of high efficiency, lightweight, and small space nuclear systems. Second, the recapture of refractory alloy nuclear technology developed in the 1960s and early 1970s appears to be a pacing activity in the successful utilization of refractory alloys. Third, the successful application of refractory alloys for space nuclear applications will present a significant challenge to both the materials and the systems design communities

Radionuclide inventories for short run-time space nuclear reactor systems

International Nuclear Information System (INIS)

Coats, R.L.

1993-01-01

Space Nuclear Reactor Systems, especially those used for propulsion, often have expected operation run times much shorter than those for land-based nuclear power plants. This produces substantially different radionuclide inventories to be considered in the safety analyses of space nuclear systems. This presentation describes an analysis utilizing ORIGEN2 and DKPOWER to provide comparisons among representative land-based and space systems. These comparisons enable early, conceptual considerations of safety issues and features in the preliminary design phases of operational systems, test facilities, and operations by identifying differences between the requirements for space systems and the established practice for land-based power systems. Early indications are that separation distance is much more effective as a safety measure for space nuclear systems than for power reactors because greater decay of the radionuclide activity occurs during the time to transport the inventory a given distance. In addition, the inventories of long-lived actinides are very low for space reactor systems

Preserving the nuclear option: The AIAA position paper on space nuclear power

International Nuclear Information System (INIS)

Allen, D.M.; Bennett, G.L.; El-Genk, M.S.; Newhouse, A.R.; Rose, M.F.; Rovang, R.D.

1996-01-01

In response to published reports about the decline in funding for space nuclear power, the Board of Directors of the American Institute of Aeronautics and Astronautics (AIAA) approved a position paper in March 1995 that recommends (1) development and support of an integrated space nuclear power program by DOE, NASA and DoD; (2) Congressional support for the program; (3) advocacy of the program by government and industry leaders; and (4) continuation of cooperation between the U.S. and other countries to advance nuclear power source technology and to promote safety. This position paper has been distributed to various people having oversight of the U.S. space nuclear power program. copyright 1996 American Institute of Physics

Wiener-Hopf operators on spaces of functions on R+ with values in a Hilbert space

OpenAIRE

Petkova, Violeta

2006-01-01

A Wiener-Hopf operator on a Banach space of functions on R+ is a bounded operator T such that P^+S_{-a}TS_a=T, for every positive a, where S_a is the operator of translation by a. We obtain a representation theorem for the Wiener-Hopf operators on a large class of functions on R+ with values in a separable Hilbert space.

The role of nuclear power and nuclear propulsion in the peaceful exploration of space

International Nuclear Information System (INIS)

2005-09-01

This publication has been produced within the framework of the IAEA's innovative reactor and fuel cycle technology development activities. It elucidates the role that peaceful space related nuclear power research and development could play in terrestrial innovative reactor and fuel cycle technology development initiatives. This review is a contribution to the Inter-Agency Meeting on Outer Space Activities, and reflects the stepped up efforts of the Scientific and Technical Subcommittee of the Committee on the Peaceful Uses of Outer Space to further strengthen cooperation between international organizations in space related activities. Apart from fostering information exchange within the United Nations organizations, this publication aims at finding new potential fields for innovative reactor and fuel cycle technology development. In assessing the status and reviewing the role of nuclear power in the peaceful exploration of space, it also aims to initiate a discussion on the potential benefits of space related nuclear power technology research and development to the development of innovative terrestrial nuclear systems

Legal and Regulatroy Obstacles to Nuclear Fission Technology in Space

Science.gov (United States)

Force, Melissa K.

2013-09-01

In forecasting the prospective use of small nuclear reactors for spacecraft and space-based power stations, the U.S. Air Force describes space as "the ultimate high ground," providing access to every part of the globe. But is it? A report titled "Energy Horizons: United States Air Force Energy Science &Technology Vision 2011-2026," focuses on core Air Force missions in space energy generation, operations and propulsion and recognizes that investments into small modular nuclear fission reactors can be leveraged for space-based systems. However, the report mentions, as an aside, that "potential catastrophic outcomes" are an element to be weighed and provides no insight into the monumental political and legal will required to overcome the mere stigma of nuclear energy, even when referring only to the most benign nuclear power generation systems - RTGs. On the heels of that report, a joint Department of Energy and NASA team published positive results from the demonstration of a uranium- powered fission reactor. The experiment was perhaps most notable for exemplifying just how effective the powerful anti-nuclear lobby has been in the United States: It was the first such demonstration of its kind in nearly fifty years. Space visionaries must anticipate a difficult war, consisting of multiple battles that must be waged in order to obtain a license to fly any but the feeblest of nuclear power sources in space. This paper aims to guide the reader through the obstacles to be overcome before nuclear fission technology can be put to use in space.

Soviet space nuclear reactor incidents - Perception versus reality

Science.gov (United States)

Bennett, Gary L.

1992-01-01

Since the Soviet Union reportedly began flying nuclear power sources in 1965 it has had four publicly known accidents involving space reactors, two publicly known accidents involving radioisotope power sources and one close call with a space reactor (Cosmos 1900). The reactor accidents, particularly Cosmos 954 and Cosmos 1402, indicated that the Soviets had adopted burnup as their reentry philosophy which is consistent with the U.S. philosophy from the 1960s and 1970s. While quantitative risk analyses have shown that the Soviet accidents have not posed a serious risk to the world's population, concerns still remain about Soviet space nuclear safety practices.

Nuclear Reactors for Space Power, Understanding the Atom Series.

Science.gov (United States)

Corliss, William R.

The historical development of rocketry and nuclear technology includes a specific description of Systems for Nuclear Auxiliary Power (SNAP) programs. Solar cells and fuel cells are considered as alternative power supplies for space use. Construction and operation of space power plants must include considerations of the transfer of heat energy to…

Space Nuclear Thermal Propulsion Test Facilities Subpanel. Final report

International Nuclear Information System (INIS)

Allen, G.C.; Warren, J.W.; Martinell, J.; Clark, J.S.; Perkins, D.

1993-04-01

On 20 Jul. 1989, in commemoration of the 20th anniversary of the Apollo 11 lunar landing, President George Bush proclaimed his vision for manned space exploration. He stated, 'First for the coming decade, for the 1990's, Space Station Freedom, the next critical step in our space endeavors. And next, for the new century, back to the Moon. Back to the future. And this time, back to stay. And then, a journey into tomorrow, a journey to another planet, a manned mission to Mars.' On 2 Nov. 1989, the President approved a national space policy reaffirming the long range goal of the civil space program: to 'expand human presence and activity beyond Earth orbit into the solar system.' And on 11 May 1990, he specified the goal of landing Astronauts on Mars by 2019, the 50th anniversary of man's first steps on the Moon. To safely and ever permanently venture beyond near Earth environment as charged by the President, mankind must bring to bear extensive new technologies. These include heavy lift launch capability from Earth to low-Earth orbit, automated space rendezvous and docking of large masses, zero gravity countermeasures, and closed loop life support systems. One technology enhancing, and perhaps enabling, the piloted Mars missions is nuclear propulsion, with great benefits over chemical propulsion. Asserting the potential benefits of nuclear propulsion, NASA has sponsored workshops in Nuclear Electric Propulsion and Nuclear Thermal Propulsion and has initiated a tri-agency planning process to ensure that appropriate resources are engaged to meet this exciting technical challenge. At the core of this planning process, NASA, DOE, and DOD established six Nuclear Propulsion Technical Panels in 1991 to provide groundwork for a possible tri-agency Nuclear Propulsion Program and to address the President's vision by advocating an aggressive program in nuclear propulsion. To this end the Nuclear Electric Propulsion Technology Panel has focused it energies

Recent advances in nuclear powered electric propulsion for space exploration

International Nuclear Information System (INIS)

Cassady, R. Joseph; Frisbee, Robert H.; Gilland, James H.; Houts, Michael G.; LaPointe, Michael R.; Maresse-Reading, Colleen M.; Oleson, Steven R.; Polk, James E.; Russell, Derrek; Sengupta, Anita

2008-01-01

Nuclear and radioisotope powered electric thrusters are being developed as primary in space propulsion systems for potential future robotic and piloted space missions. Possible applications for high-power nuclear electric propulsion include orbit raising and maneuvering of large space platforms, lunar and Mars cargo transport, asteroid rendezvous and sample return, and robotic and piloted planetary missions, while lower power radioisotope electric propulsion could significantly enhance or enable some future robotic deep space science missions. This paper provides an overview of recent US high-power electric thruster research programs, describing the operating principles, challenges, and status of each technology. Mission analysis is presented that compares the benefits and performance of each thruster type for high priority NASA missions. The status of space nuclear power systems for high-power electric propulsion is presented. The paper concludes with a discussion of power and thruster development strategies for future radioisotope electric propulsion systems

Recent advances in nuclear powered electric propulsion for space exploration

Energy Technology Data Exchange (ETDEWEB)

Cassady, R. Joseph [Aerojet Corp., Redmond, CA (United States); Frisbee, Robert H. [Jet Propulsion Laboratory, Pasadena, CA (United States); Gilland, James H. [Ohio Aerospace Institute, Cleveland, OH (United States); Houts, Michael G. [NASA Marshall Space Flight Center, Huntsville, AL 35812 (United States); LaPointe, Michael R. [NASA Marshall Space Flight Center, Huntsville, AL 35812 (United States)], E-mail: michael.r.lapointe@nasa.gov; Maresse-Reading, Colleen M. [Jet Propulsion Laboratory, Pasadena, CA (United States); Oleson, Steven R. [NASA Glenn Research Center, Cleveland, OH (United States); Polk, James E. [Jet Propulsion Laboratory, Pasadena, CA (United States); Russell, Derrek [Northrop Grumman Space Technology, Redondo Beach, CA (United States); Sengupta, Anita [Jet Propulsion Laboratory, Pasadena, CA (United States)

2008-03-15

Nuclear and radioisotope powered electric thrusters are being developed as primary in space propulsion systems for potential future robotic and piloted space missions. Possible applications for high-power nuclear electric propulsion include orbit raising and maneuvering of large space platforms, lunar and Mars cargo transport, asteroid rendezvous and sample return, and robotic and piloted planetary missions, while lower power radioisotope electric propulsion could significantly enhance or enable some future robotic deep space science missions. This paper provides an overview of recent US high-power electric thruster research programs, describing the operating principles, challenges, and status of each technology. Mission analysis is presented that compares the benefits and performance of each thruster type for high priority NASA missions. The status of space nuclear power systems for high-power electric propulsion is presented. The paper concludes with a discussion of power and thruster development strategies for future radioisotope electric propulsion systems.

Formulating state space models in R with focus on longitudinal regression models

DEFF Research Database (Denmark)

Dethlefsen, Claus; Lundbye-Christensen, Søren

  We provide a language for formulating a range of state space models. The described methodology is implemented in the R -package sspir available from cran.r-project.org . A state space model is specified similarly to a generalized linear model in R , by marking the time-varying terms in the form......  We provide a language for formulating a range of state space models. The described methodology is implemented in the R -package sspir available from cran.r-project.org . A state space model is specified similarly to a generalized linear model in R , by marking the time-varying terms...

Preliminary risk benefit assessment for nuclear waste disposal in space

Science.gov (United States)

Rice, E. E.; Denning, R. S.; Friedlander, A. L.; Priest, C. C.

1982-01-01

This paper describes the recent work of the authors on the evaluation of health risk benefits of space disposal of nuclear waste. The paper describes a risk model approach that has been developed to estimate the non-recoverable, cumulative, expected radionuclide release to the earth's biosphere for different options of nuclear waste disposal in space. Risk estimates for the disposal of nuclear waste in a mined geologic repository and the short- and long-term risk estimates for space disposal were developed. The results showed that the preliminary estimates of space disposal risks are low, even with the estimated uncertainty bounds. If calculated release risks for mined geologic repositories remain as low as given by the U.S. DOE, and U.S. EPA requirements continue to be met, then no additional space disposal study effort in the U.S. is warranted at this time. If risks perceived by the public are significant in the acceptance of mined geologic repositories, then consideration of space disposal as a complement to the mined geologic repository is warranted.

Opening up the future in space with nuclear power

International Nuclear Information System (INIS)

Buden, D.; Angelo, J. Jr.

1985-01-01

Man's extraterrestrial development is dependent on abundant power. For example, space-based manufacturing facilities are projected to have a power demand of 300 kWe by the end of this Century, and several megawatts in the early part of next millennium. The development of the lunar resource base will result in power needs ranging from an initial 100 kW(e) to many megawatts. Human visits to Mars could be achieved using a multimegawatt nuclear electric propulsion system or high thrust nuclear rockets. Detailed exploration of the solar system will also be greatly enhanced by the availability of large nuclear electric propulsion systems. All of these activities will require substantial increases in space power - hundreds of kilowatts to many megawatts. The challenge is clear: how to effectively use nuclear energy to support humanity's expansion into space

Future NASA mission applications of space nuclear power

International Nuclear Information System (INIS)

Bennett, G.L.; Mankins, J.; McConnell, D.G.; Reck, G.M.

1990-01-01

Recent studies sponsored by NASA show a continuing need for space nuclear power. A recently completed study considered missions such as a Jovian grand tour, a Uranus or Neptune orbiter and probe, and a Pluto flyby that can only be done with nuclear power. There are studies for missions beyond the outer boundaries of the solar system at distances of 100 to 1000 astronomical units. The NASA 90-day study on the space exploration initiative identified a need for nuclear reactors to power lunar surface bases and radioisotope power sources for use in lunar or Martian rovers, as well as considering options for advanced, nuclear propulsion systems for human missions to Mars

Proposed principles on the use of nuclear power sources in space

International Nuclear Information System (INIS)

Bennett, G.L.

1988-01-01

Since the 1978 reentry of the Soviet satellite Cosmos 954, the United Nations has been discussing the use of nuclear power sources in outer space. Most of these deliberations have taken place in the U.N. Committee on the Peaceful Uses of Outer Space, its two subcommittees (Scientific and Technical Subcommittee and Legal Subcommittee) and their associated working groups. This paper focuses on the technical agreements reached by the Working Group on the Use of Nuclear Power Sources in Outer Space (WGNPS), the legal principles agreed to by the Legal Subcommittee, and relevant treaties on the use of outer space and the use of nuclear power. To date the conclusion reached by the WGNPS in its 1981 report represents a succinct statement of U.N. consensus and of the U.S. position: The Working Group reaffirmed its previous conclusion that nuclear power sources can be used safely in outer space, provided that all necessary safety precautions are met

Thermophotovoltaic Energy Conversion in Space Nuclear Reactor Power Systems

National Research Council Canada - National Science Library

Presby, Andrew L

2004-01-01

.... This has potential benefits for space nuclear reactor power systems currently in development. The primary obstacle to space operation of thermophotovoltaic devices appears to be the low heat rejection temperatures which necessitate large radiator areas...

Nuclear power in space. Use of reactors and radioactive substances as power sources in satellites and space probes

International Nuclear Information System (INIS)

Hoestbaeck, Lars

2008-11-01

Today solar panels are the most common technique to supply power to satellites. Solar panels will work as long as the power demand of the satellite is limited and the satellite can be equipped with enough panels, and kept in an orbit that allows enough sunlight to hit the panels. There are various types of space missions that do not fulfil these criteria. With nuclear power these types of missions can be powered regardless of the sunlight and as early as 1961 the first satellite with a nuclear power source was placed in orbit. Out of seventy known space missions that has made use of nuclear power, ten have had some kind of failure. In no case has the failure been associated with the nuclear technology used. This report discusses to what degree satellites with nuclear power are a source for potential radioactive contamination of Swedish territory. It is not a discussion for or against nuclear power in space. Neither is it an assessment of consequences if radioactive material from a satellite would reach the earth's surface. Historically two different kinds of Nuclear Power Sources (NPS) have been used to generate electric power in space. The first is the reactor where the energy is derived from nuclear fission of 235 U and the second is the Radioisotope Thermoelectric Generator (RTG) where electricity is generated from the heat of naturally decaying radionuclides. NPS has historically only been used in space by United States and the Soviet Union (and in one failing operation Russia). Nuclear Power Sources have been used in three types of space objects: satellites, space probes and moon/Mars vehicles. USA has launched one experimental reactor into orbit, all other use of NPS by the USA has been RTG:s. The Soviet Union, in contrast, only launched a few RTG:s but nearly forty reactors. The Soviet use of NPS is less transparent than the use in USA and some data published on Soviet systems are more or less well substantiated assessments. It is likely that also future

Criterion for the nuclearity of spaces of functions of infinite number of variables

International Nuclear Information System (INIS)

Gali, I.M.

1977-08-01

The paper formulates a new necessary and sufficient condition for the nuclearity of spaces of infinite number of variables, and defines new nuclear spaces which play an important role in the field of functional analysis and quantum field theory. Also the condition for nuclearity of the infinite weighted tensor product of nuclear spaces is given

Outer space and nuclear deterrence: problems and prospects

International Nuclear Information System (INIS)

Gasparini Alves, P.

1993-01-01

The presentation deals with the role of outer-space applications and prospects for near future developments in nuclear deterrence. Outer space capabilities of United Sates, Russian Federation, Belarus, Kazakhstan, Ukraine, China, and United Kingdom as well as other states are analyzed. Conceptual problems of offensive and defensive doctrines are reviewed together with legal implications

Analysis of space systems study for the space disposal of nuclear waste study report. Volume 2: Technical report

Science.gov (United States)

1981-01-01

Reasonable space systems concepts were systematically identified and defined and a total system was evaluated for the space disposal of nuclear wastes. Areas studied include space destinations, space transportation options, launch site options payload protection approaches, and payload rescue techniques. Systems level cost and performance trades defined four alternative space systems which deliver payloads to the selected 0.85 AU heliocentric orbit destination at least as economically as the reference system without requiring removal of the protective radiation shield container. No concepts significantly less costly than the reference concept were identified.

The nuclear energy use in Space

International Nuclear Information System (INIS)

Raepsaet, X.

2002-01-01

Two ways of the nuclear energy use are possible in spatial applications. The first one is the electric power production to supply satellites, space vehicles or electric propulsion. The second one, less obvious, is the thermal-nuclear propulsion where the nuclear reactor is a thermal exchanger for a gas. These two applications are presented in this paper, with two examples of projects realized in collaboration of the CNES and the CEA: ERATO as an electrical generator and MAPS as the nucleo-thermal propulsion. (A.L.B.)

Evaluating Russian space nuclear reactor technology for United States applications

International Nuclear Information System (INIS)

Polansky, G.F.; Schmidt, G.L.; Voss, S.S.; Reynolds, E.L.

1994-01-01

Space nuclear power and nuclear electric propulsion are considered important technologies for planetary exploration, as well as selected earth orbit applications. The Nuclear Electric Propulsion Space Test Program (NEPSTP) was intended to provide an early flight demonstration of these technologies at relatively low cost through extensive use of existing Russian technology. The key element of Russian technology employed in the program was the Topaz II reactor. Refocusing of the activities of the Ballistic Missile Defense Organization (BMDO), combined with budgetary pressures, forced the cancellation of the NEPSTP at the end of the 1993 fiscal year. The NEPSTP was faced with many unique flight qualification issues. In general, the launch of a spacecraft employing a nuclear reactor power system complicates many spacecraft qualification activities. However, the NEPSTP activities were further complicated because the reactor power system was a Russian design. Therefore, this program considered not only the unique flight qualification issues associated with space nuclear power, but also with differences between Russian and United States flight qualification procedures. This paper presents an overview of the NEPSTP. The program goals, the proposed mission, the spacecraft, and the Topaz II space nuclear power system are described. The subject of flight qualification is examined and the inherent difficulties of qualifying a space reactor are described. The differences between United States and Russian flight qualification procedures are explored. A plan is then described that was developed to determine an appropriate flight qualification program for the Topaz II reactor to support a possible NEPSTP launch

Missions and planning for nuclear space power

International Nuclear Information System (INIS)

Buden, D.

1979-01-01

Requirements for electrical and propulsion power for space are expected to increase dramatically in the 1980s. Nuclear power is probably the only source for some deep space missions and a major competitor for many orbital missions, especially those at geosynchronous orbit. Because of the potential requirements, a technology program on reactor components has been initiated by the Department of Energy. The missions that are foreseen, the current reactor concept, and the technology program plan are described

Dual spaces of local Morrey-type spaces

Czech Academy of Sciences Publication Activity Database

Gogatishvili, Amiran; Mustafayev, Rza

2011-01-01

Roč. 61, č. 3 (2011), s. 609-622 ISSN 0011-4642 R&D Projects: GA ČR GA201/05/2033; GA ČR GA201/08/0383 Institutional research plan: CEZ:AV0Z10190503 Keywords : local Morrey-type spaces * complementary local Morrey-type spaces * associated spaces * dual spaces * multidimensional reverse Hardy inequalities Subject RIV: BA - General Mathematics Impact factor: 0.262, year: 2011 http://www.springerlink.com/content/3166vu5uht8713t3/

Progress in space nuclear reactor power systems technology development - The SP-100 program

Science.gov (United States)

Davis, H. S.

1984-01-01

Activities related to the development of high-temperature compact nuclear reactors for space applications had reached a comparatively high level in the U.S. during the mid-1950s and 1960s, although only one U.S. nuclear reactor-powered spacecraft was actually launched. After 1973, very little effort was devoted to space nuclear reactor and propulsion systems. In February 1983, significant activities toward the development of the technology for space nuclear reactor power systems were resumed with the SP-100 Program. Specific SP-100 Program objectives are partly related to the determination of the potential performance limits for space nuclear power systems in 100-kWe and 1- to 100-MW electrical classes. Attention is given to potential missions and applications, regimes of possible space power applicability, safety considerations, conceptual system designs, the establishment of technical feasibility, nuclear technology, materials technology, and prospects for the future.

Space Nuclear Thermal Propulsion (SNTP) Air Force facility

Science.gov (United States)

Beck, David F.

The Space Nuclear Thermal Propulsion (SNTP) Program is an initiative within the US Air Force to acquire and validate advanced technologies that could be used to sustain superior capabilities in the area or space nuclear propulsion. The SNTP Program has a specific objective of demonstrating the feasibility of the particle bed reactor (PBR) concept. The term PIPET refers to a project within the SNTP Program responsible for the design, development, construction, and operation of a test reactor facility, including all support systems, that is intended to resolve program technology issues and test goals. A nuclear test facility has been designed that meets SNTP Facility requirements. The design approach taken to meet SNTP requirements has resulted in a nuclear test facility that should encompass a wide range of nuclear thermal propulsion (NTP) test requirements that may be generated within other programs. The SNTP PIPET project is actively working with DOE and NASA to assess this possibility.

Titanium Loop Heat Pipes for Space Nuclear Radiators, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project will develop titanium Loop Heat Pipes (LHPs) that can be used in low-mass space nuclear radiators, such as...

The problem of space nuclear power sources collisions with artificial space objects in near-earth orbits

International Nuclear Information System (INIS)

Gafarov, A.A.

1993-01-01

Practically all space objects with onboard nuclear power sources stay in earth satellite orbits with an orbital lifetime long enough to reduce their radioactivity to levels presenting no danger for the Earth population. One of the reasons for orbit lifetime reduction can be collisions with other space objects in near-earth orbits. The possible consequence of collisions can be partial, or even complete, destruction of the spacecraft with an onboard nuclear power source; as well as delivery of additional impulse both to the spacecraft and its fragments. It is shown that collisions in orbit do not cause increase of radiation hazard for the Earth population if there is aerodynamic breakup of nuclear power sources into fragments of safe sizes during atmospheric reentry

Lightweight Radiator for in Space Nuclear Electric Propulsion

Science.gov (United States)

Craven, Paul; Tomboulian, Briana; SanSoucie, Michael

2014-01-01

Nuclear electric propulsion (NEP) is a promising option for high-speed in-space travel due to the high energy density of nuclear fission power sources and efficient electric thrusters. Advanced power conversion technologies may require high operating temperatures and would benefit from lightweight radiator materials. Radiator performance dictates power output for nuclear electric propulsion systems. Game-changing propulsion systems are often enabled by novel designs using advanced materials. Pitch-based carbon fiber materials have the potential to offer significant improvements in operating temperature, thermal conductivity, and mass. These properties combine to allow advances in operational efficiency and high temperature feasibility. An effort at the NASA Marshall Space Flight Center to show that woven high thermal conductivity carbon fiber mats can be used to replace standard metal and composite radiator fins to dissipate waste heat from NEP systems is ongoing. The goals of this effort are to demonstrate a proof of concept, to show that a significant improvement of specific power (power/mass) can be achieved, and to develop a thermal model with predictive capabilities making use of constrained input parameter space. A description of this effort is presented.

8th symposium on space nuclear power systems

International Nuclear Information System (INIS)

Brandhorst, H. W.

1991-01-01

The future appears rich in missions that will extend the frontiers of knowledge, human presence in space, and opportunities for profitable commerce. Key to the success of these ventures is the availability of plentiful, cost effective electric power and assured, low cost access to space. While forecasts of space power needs are problematic, an assessment of future needs based on terrestrial experience has been made. These needs fall into three broad categories: survival, self sufficiency, and industrialization. The cost of delivering payloads to orbital locations from LEO to Mars has been determined and future launch cost reductions projected. From these factors, then, projections of the performance necessary for future solar and nuclear space power options has been made. These goals are largely dependent upon orbital location and energy storage needs. Finally the cost of present space power systems has been determined and projections made for future systems

Wavelet analysis of the nuclear phase space

International Nuclear Information System (INIS)

Jouault, B.; Sebille, F.; Mota, V. de la.

1997-01-01

The description of transport phenomena in nuclear matter is addressed in a new approach based on the mathematical theory of wavelets and the projection methods of statistical physics. The advantage of this framework is to offer the opportunity to use information concepts common to both the formulation of physical properties and the mathematical description. This paper focuses on two features, the extraction of relevant informations using the geometrical properties of the underlying phase space and the optimization of the theoretical and numerical treatments based on convenient choices of the representation spaces. (author)

Wavelet analysis of the nuclear phase space

Energy Technology Data Exchange (ETDEWEB)

Jouault, B.; Sebille, F.; Mota, V. de la

1997-12-31

The description of transport phenomena in nuclear matter is addressed in a new approach based on the mathematical theory of wavelets and the projection methods of statistical physics. The advantage of this framework is to offer the opportunity to use information concepts common to both the formulation of physical properties and the mathematical description. This paper focuses on two features, the extraction of relevant informations using the geometrical properties of the underlying phase space and the optimization of the theoretical and numerical treatments based on convenient choices of the representation spaces. (author). 34 refs.

Applications of nuclear-powered thermoelectric generators in space

International Nuclear Information System (INIS)

Rowe, D.M.

1991-01-01

The source of electrical power which enables information to be transmitted from the space crafts Voyager 1 and 2 back to Earth after a time period of more than a decade and at a distance of more than a billion miles is known as an RTG (radioisotope thermoelectric generator). It utilises the Seebeck effect in producing electricity from heat. In essence it consists of a large number of semiconductor thermocouples connected electrically in series and thermally in parallel. A temperature difference is maintained across the thermocouples by providing a heat source, which in the case of an RTG is a radioactive isotope, and the heat sink is space. The combination of an energy-conversion system, free of moving parts and a long-life, high energy-density heat source, provides a supply of electrical power typically in the range of tens to hundred of watts and which operates reliably over extended periods of time. An electric power source, based upon thermoelectric conversion by which utilises a nuclear reactor as a heat source, has also been deployed in space and a 100-kW system is being developed to provide electrical power to a variety of commercial and military projects including SDI. Developments in thermoelectrics that have taken place in the western world during the past 30 years are primarily due to United States interest and involvement in the exploration of space. This paper reviews US applications of nuclear-powered thermoelectric generators in space. (author)

Space - A unique environment for process modeling R&D

Science.gov (United States)

Overfelt, Tony

1991-01-01

Process modeling, the application of advanced computational techniques to simulate real processes as they occur in regular use, e.g., welding, casting and semiconductor crystal growth, is discussed. Using the low-gravity environment of space will accelerate the technical validation of the procedures and enable extremely accurate determinations of the many necessary thermophysical properties. Attention is given to NASA's centers for the commercial development of space; joint ventures of universities, industries, and goverment agencies to study the unique attributes of space that offer potential for applied R&D and eventual commercial exploitation.

Issues and insights of PRA methodology in nuclear and space applications

International Nuclear Information System (INIS)

Hsu, F.

2005-01-01

This paper presents some important issues and technical insights on the scope, conceptual framework, and essential elements of nuclear power plant Probabilistic Risk Assessments (PRAs) and that of the PRAs in general applications of the aerospace industry, such as the Space Shuttle PRA being conducted by NASA. Discussions are focused on various lessons learned in nuclear power plant PRA applications and their potential applicability to the PRAs in the aerospace and launch vehicle systems. Based on insights gained from PRA projects for nuclear power plants and from the current Space Shuttle PRA effort, the paper explores the commonalities and the differences between the conduct of the different PRAs and the key issues and risk insights derived from extensive modeling practices in both industries of nuclear and space. (author)

Analysis of space systems for the space disposal of nuclear waste follow-on study. Volume 2: Technical report

Science.gov (United States)

1982-01-01

The space option for disposal of certain high-level nuclear wastes in space as a complement to mined geological repositories is studied. A brief overview of the study background, scope, objective, guidelines and assumptions, and contents is presented. The determination of the effects of variations in the waste mix on the space systems concept to allow determination of the space systems effect on total system risk benefits when used as a complement to the DOE reference mined geological repository is studied. The waste payload system, launch site, launch system, and orbit transfer system are all addressed. Rescue mission requirements are studied. The characteristics of waste forms suitable for space disposal are identified. Trajectories and performance requirements are discussed.

Time-space structure of nuclear safety

International Nuclear Information System (INIS)

Miya, Kenzo

2003-01-01

New idea to analyze the structure of nuclear safety and to investigate functioning property of hierarchical principle is applied to nuclear safety in this paper. The nuclear safety is expressed by three principles such as 1) the action and subject are partitioned and classified by time and space, 2) introduction of hierarchy with three strata to the closed object and hierarchy with many strata to the open object and 3) application of 'element, relation and abstraction' to the engineering system as a framework of intellectual activity. For example, prevention of core melt is the closed object and it is obtained by acting hierarchies with three strata (operation stop, cooling and closing radiation) as the safety functions. Prevention of increase of accident is open object, so that, space hierarchy with many strata of prevention is used for the safety security of reactor. The safety security method of reactor consists of three processes, that is 1) the basic process to make clear the continuous operating time on the basis of regular inspection, 2) the action process of operating ECCS to prevent core damage accident, when a large leakage happens and 3) many strata prevention process of stopping a leak in the environment. (S.Y.)

GOES-R Space Weather Data: Achieving User Ready Products

Science.gov (United States)

Rowland, W. F.; Tilton, M.; Redmon, R. J.; Goodman, S. J.; Comerford, M.

2017-12-01

Forecasters and the science community will rely on improved Space Weather products from the next generation of Geostationary Operational Environmental Satellite (GOES-R Series) for decades to come. Many issues must be successfully addressed in order to produce useful products. The instruments themselves and their basic scientific measurements (Level 1b data, i.e. L1b) must be calibrated and validated. Algorithms must be created to transform L1b into the specific environmental parameters that are of interest to forecasters and the community (Level 2+, i.e. L2+). In the case of Space Weather data, because the L2+ products are not generated within the core GOES-R Ground Segment, a separate system had to be developed in order to implement the L2+ products. Finally, the products must be made available to real time and retrospective users, as well as preserved for future generations. We give an overview of the path to production of the GOES-R Space Weather products, and the role of the National Centers for Environmental Information (NCEI) in this process.

Nuclear systems in space? Does/will the public accept them?

Science.gov (United States)

Finger, Harold B.

1993-01-01

Public attitudes toward the use of nuclear energy on earth and in space are discussed. Survey data are presented which show that the public believes nuclear energy should play an important role in our energy supply. However, based on broad attitude research, there should be no expectation that the public will accept or support the use of nuclear energy unless it meets special needs and offers special and significant benefits. It is proposed that a public information program be adopted that results in getting recognition and support for the space program broadly and for the missions that benefit substantially from or require nuclear energy for their accomplishment.

Nuclear Waste Disposal in Space: BEP's Best Hope?

International Nuclear Information System (INIS)

Coopersmith, Jonathan

2006-01-01

The best technology is worthless if it cannot find a market Beam energy propulsion (BEP) is a very promising technology, but faces major competition from less capable but fully developed conventional rockets. Rockets can easily handle projected markets for payloads into space. Without a new, huge demand for launch capability, BEP is unlikely to gain the resources it needs for development and application. Launching tens of thousands of tons of nuclear waste into space for safe and permanent disposal will provide that necessary demand while solving a major problem on earth. Several options exist to dispose of nuclear waste, including solar orbit, lunar orbit, soft lunar landing, launching outside the solar system, and launching into the sun

Nuclear reactor power as applied to a space-based radar mission

Science.gov (United States)

Jaffe, L.; Beatty, R.; Bhandari, P.; Chow, E.; Deininger, W.; Ewell, R.; Fujita, T.; Grossman, M.; Bloomfield, H.; Heller, J.

1988-01-01

A space-based radar mission and spacecraft are examined to determine system requirements for a 300 kWe space nuclear reactor power system. The spacecraft configuration and its orbit, launch vehicle, and propulsion are described. Mission profiles are addressed, and storage in assembly orbit is considered. Dynamics and attitude control and the problems of nuclear and thermal radiation are examined.

Application of nuclear-physics methods in space materials science

Science.gov (United States)

Novikov, L. S.; Voronina, E. N.; Galanina, L. I.; Chirskaya, N. P.

2017-07-01

The brief history of the development of investigations at the Skobeltsyn Institute of Nuclear Physics, Moscow State University (SINP MSU) in the field of space materials science is outlined. A generalized scheme of a numerical simulation of the radiation impact on spacecraft materials and elements of spacecraft equipment is examined. The results obtained by solving some of the most important problems that modern space materials science should address in studying nuclear processes, the interaction of charged particles with matter, particle detection, the protection from ionizing radiation, and the impact of particles on nanostructures and nanomaterials are presented.

Review of Nuclear Physics Experiments for Space Radiation

Science.gov (United States)

Norbury, John W.; Miller, Jack; Adamczyk, Anne M.; Heilbronn, Lawrence H.; Townsend, Lawrence W.; Blattnig, Steve R.; Norman, Ryan B.; Guetersloh, Stephen B.; Zeitlin, Cary J.

2011-01-01

Human space flight requires protecting astronauts from the harmful effects of space radiation. The availability of measured nuclear cross section data needed for these studies is reviewed in the present paper. The energy range of interest for radiation protection is approximately 100 MeV/n to 10 GeV/n. The majority of data are for projectile fragmentation partial and total cross sections, including both charge changing and isotopic cross sections. The cross section data are organized into categories which include charge changing, elemental, isotopic for total, single and double differential with respect to momentum, energy and angle. Gaps in the data relevant to space radiation protection are discussed and recommendations for future experiments are made.

Various technical and legal aspects of nuclear power sources in outer space

International Nuclear Information System (INIS)

Boeck, H.; Summerer, L.

2001-12-01

Since the very first days of space exploration, nuclear power was considered as an alternative to solar cells for the generation of energy in space. Especially for larger exploration missions beyond Mars, nuclear power sources (NPS) are almost unavoidable. NPS are developed, produced and flown on a continuous basis since almost 40 years by the USA and the Soviet Union, now Russia. While the technological capabilities certainly exist within Europe, Europe has not developed space nuclear power sources. This work is structured in four parts, enlightening this subject from different viewpoints on the European level. In a first chapter, European centres researching in the broader field of this technology are listed. A second chapter deals with the properties and hazards connected with plutonium, the element used in Radioisotope Thermal Generators (RTG). Recent technological developments in the field of RTG are reviewed in chapter 4, while chapter 3 deals with the international legal implications of the use of nuclear power sources in outer space. Refs. 30 (author)

Application of nuclear photon engines for deep-space exploration

International Nuclear Information System (INIS)

Gulevich, Andrey V.; Ivanov, Eugeny A.; Kukharchuk, Oleg F.; Poupko, Victor Ya.; Zrodnikov, Anatoly V.

2001-01-01

Conception of using the nuclear photon rocket engines for deep space exploration is proposed. Some analytical estimations have been made to illustrate the possibility to travel to 100-10000 AU using a small thrust photon engine. Concepts of high temperature nuclear reactors for the nuclear photon engines are also discussed

Space and energy. [space systems for energy generation, distribution and control

Science.gov (United States)

Bekey, I.

1976-01-01

Potential contributions of space to energy-related activities are discussed. Advanced concepts presented include worldwide energy distribution to substation-sized users using low-altitude space reflectors; powering large numbers of large aircraft worldwide using laser beams reflected from space mirror complexes; providing night illumination via sunlight-reflecting space mirrors; fine-scale power programming and monitoring in transmission networks by monitoring millions of network points from space; prevention of undetected hijacking of nuclear reactor fuels by space tracking of signals from tagging transmitters on all such materials; and disposal of nuclear power plant radioactive wastes in space.

Impact loading of a space nuclear powerplant

Directory of Open Access Journals (Sweden)

Evgeny I. Kraus

2013-04-01

Full Text Available Preferred formulation of the problem in two space dimensions are described for solving the three fundamental equations of mechanics (conservation of mass, conservation of momentum, and conservation of energy. Models of the behavior of materials provide the closure to the three fundamentals equations for applications to problems in compressible fluid flow and solid mechanics. Models of fracture and damage are described. A caloric model of the equation of state is proposed to describe thermodynamic properties of solid materials with the phase transitions. Two-dimensional problems of a high-velocity impact of a space nuclear propulsion system reactor are solved. High-velocity impact problems of destruction of reactor are solved for the two cases: 1 at its crash landing on the Earth surface (the impact velocity being up to 400 m/s; 2 at its impact (with velocity up to 16 km/s with the space debris fragments.

Realizing spaces as path-component spaces

OpenAIRE

Banakh, Taras; Brazas, Jeremy

2018-01-01

The path component space of a topological space $X$ is the quotient space $\\pi_0(X)$ whose points are the path components of $X$. We show that every Tychonoff space $X$ is the path-component space of a Tychonoff space $Y$ of weight $w(Y)=w(X)$ such that the natural quotient map $Y\\to \\pi_0(Y)=X$ is a perfect map. Hence, many topological properties of $X$ transfer to $Y$. We apply this result to construct a compact space $X\\subset \\mathbb{R}^3$ for which the fundamental group $\\pi_1(X,x_0)$ is...

Formulating state space models in R with focus on longitudinal regression models

DEFF Research Database (Denmark)

Dethlefsen, Claus; Lundbye-Christensen, Søren

2006-01-01

We provide a language for formulating a range of state space models with response densities within the exponential family. The described methodology is implemented in the R-package sspir. A state space model is specified similarly to a generalized linear model in R, and then the time-varying terms...

Space Nuclear Power Plant Pre-Conceptual Design Report, For Information

Energy Technology Data Exchange (ETDEWEB)

B. Levine

2006-01-27

This letter transmits, for information, the Project Prometheus Space Nuclear Power Plant (SNPP) Pre-Conceptual Design Report completed by the Naval Reactors Prime Contractor Team (NRPCT). This report documents the work pertaining to the Reactor Module, which includes integration of the space nuclear reactor with the reactor radiation shield, energy conversion, and instrumentation and control segments. This document also describes integration of the Reactor Module with the Heat Rejection segment, the Power Conditioning and Distribution subsystem (which comprise the SNPP), and the remainder of the Prometheus spaceship.

The International Safety Framework for nuclear power source applications in outer space-Useful and substantial guidance

Science.gov (United States)

Summerer, L.; Wilcox, R. E.; Bechtel, R.; Harbison, S.

2015-06-01

In 2009, the International Safety Framework for Nuclear Power Source Applications in Outer Space was adopted, following a multi-year process that involved all major space faring nations under the auspices of a partnership between the UN Committee on the Peaceful Uses of Outer Space and the International Atomic Energy Agency. The Safety Framework reflects an international consensus on best practices to achieve safety. Following the 1992 UN Principles Relevant to the Use of Nuclear Power Sources in Outer Space, it is the second attempt by the international community to draft guidance promoting the safety of applications of nuclear power sources in space missions. NPS applications in space have unique safety considerations compared with terrestrial applications. Mission launch and outer space operational requirements impose size, mass and other space environment limitations not present for many terrestrial nuclear facilities. Potential accident conditions could expose nuclear power sources to extreme physical conditions. The Safety Framework is structured to provide guidance for both the programmatic and technical aspects of safety. In addition to sections containing specific guidance for governments and for management, it contains technical guidance pertinent to the design, development and all mission phases of space NPS applications. All sections of the Safety Framework contain elements directly relevant to engineers and space mission designers for missions involving space nuclear power sources. The challenge for organisations and engineers involved in the design and development processes of space nuclear power sources and applications is to implement the guidance provided in the Safety Framework by integrating it into the existing standard space mission infrastructure of design, development and operational requirements, practices and processes. This adds complexity to the standard space mission and launch approval processes. The Safety Framework is deliberately

Status of the CNES-CEA joint program on space nuclear Brayton systems

International Nuclear Information System (INIS)

Carre, F.; Proust, E.; Chaudourne, S.; Keirle, P.; Tilliette, Z.; Vrillon, B.

1989-01-01

A cooperative program between the French Centre National d'Etudes Spatiales (CNES) and the Commissariat a l'Energie Atomique (CEA) was initiated in 1983, to investigate the possible development of 20 to 200 kWe space nuclear power systems to be launched by the next version of the European launcher, Ariane V. After completion in 1986 of preliminary conceptual studies of a reference 200 kWe turbo-electric power system, an additional 3 year study phase was decided, with the double objective of assessing the potential advantage of nuclear power systems versus solar photovoltaic or dynamic systems in the 20 kWe power range, and comparing various reactor candidate technologies and system options for 20 kWe space nuclear power systems, likely to meet the projected energy needs of future European space missions. A comprehensive program including conceptual design studies, operating transient analyses and technology base assessment, is currently applied to a few reference concepts of 20 kWe nuclear Brayton and thermoelectric systems, in order to establish sound technical and economical bases for selecting the design options and the development strategy of a first space nuclear power system in Europe

White noise calculus and Fock space

CERN Document Server

Obata, Nobuaki

1994-01-01

White Noise Calculus is a distribution theory on Gaussian space, proposed by T. Hida in 1975. This approach enables us to use pointwise defined creation and annihilation operators as well as the well-established theory of nuclear space.This self-contained monograph presents, for the first time, a systematic introduction to operator theory on fock space by means of white noise calculus. The goal is a comprehensive account of general expansion theory of Fock space operators and its applications. In particular,first order differential operators, Laplacians, rotation group, Fourier transform and their interrelations are discussed in detail w.r.t. harmonic analysis on Gaussian space. The mathematical formalism used here is based on distribution theory and functional analysis , prior knowledge of white noise calculus is not required.

Recommendations for space reactor R ampersand D tasks

International Nuclear Information System (INIS)

Wiley, R.L.; Marshall, A.C.

1995-01-01

A rationale was developed to determine which technologies a space nuclear reactor technology based program pursue based on the fact that budgets would be limited. A preliminary evaluation was conducted to identify key technical issues and to recommend a prioritized set of candidate research projects that could be undertaken as part of the Defense Nuclear Agency (DNA) program in the near term. The recommendations made have not been adopted formally by the DNA's Topaz International Program process. (TIP), but serve as inputs to the program plannin process

Science opportunities through nuclear power in space

International Nuclear Information System (INIS)

Harris, H.M.

1995-01-01

With the downsizing or outright elimination of nuclear power capability in space in progress, it is important to understand what this means to science in therms of capability cost. This paper is a survey of the scientific possibilities inherent in the potential availability of between 15 to 30 kW through electrical nuclear power in space. The approach taken has been to interview scientists involved in space-research, especially those whose results are dependent or proportional to power availability and to survey previous work in high-power spacecraft and space-based science instruments. In addition high level studies were done to gather metrics about what kind and quantity of science could be achieved throughout the entire solar system assuming the availability in the power amounts quoted above. It is concluded that: (1) Sustained high power using a 10--30 kW reactor would allow the capture of an unprecedented amount of data on planetary objects through the entire solar system. (2) High power science means high qualtiy data through higher resolution of radars, optics and the sensitivity of many types of instruments. (3) In general, high power in the range of 10--30 kW provides for an order-of-magnitude increase of resolution of synthetic aperture radars over other planetary radars. (4) High power makes possible the use of particle accelerators to probe the atomic structure of planetary surface, particularly in the dim, outer regions of the solar system. (5) High power means active cooling is possible for devices that must operate at low temperature under adverse conditions. (6) High power with electric propulsion provides the mission flexibility to vary observational viewpoints and select targets of opportunity. copyright 1995 American Institute of Physics

Nuclear dynamics in phase space

International Nuclear Information System (INIS)

Di Toro, M.

1984-07-01

We present a unified semiclassical picture of nuclear dynamics, from collective states to heavy ion physics, based on a study of the time evolution of the Wigner distribution function. We discuss in particular the mean field dynamics, in this ''quantal'' phase space, which is ruled by the nuclear Vlasov equation. Simple approximate solutions are worked out for rotational and vibrational collective motions. Giant resonances are shown to be quite well described as scaling modes, which are equivalent to a lowest multipole (up to 1sub(max)=2) distortions of the momentum distribution. Applications are shown to heavy ion physics to study giant resonances on high spin states and dynamical collective effects in subthreshold π-production. Several possible extensions and in particular the inclusion of two-body collision terms are finally discussed

RECENT ACTIVITIES AT THE CENTER FOR SPACE NUCLEAR RESEARCH FOR DEVELOPING NUCLEAR THERMAL ROCKETS

International Nuclear Information System (INIS)

O'Brien, Robert C.

2001-01-01

Nuclear power has been considered for space applications since the 1960s. Between 1955 and 1972 the US built and tested over twenty nuclear reactors/ rocket-engines in the Rover/NERVA programs. However, changes in environmental laws may make the redevelopment of the nuclear rocket more difficult. Recent advances in fuel fabrication and testing options indicate that a nuclear rocket with a fuel form significantly different from NERVA may be needed to ensure public support. The Center for Space Nuclear Research (CSNR) is pursuing development of tungsten based fuels for use in a NTR, for a surface power reactor, and to encapsulate radioisotope power sources. The CSNR Summer Fellows program has investigated the feasibility of several missions enabled by the NTR. The potential mission benefits of a nuclear rocket, historical achievements of the previous programs, and recent investigations into alternatives in design and materials for future systems will be discussed.

Problems of space-time behaviour of nuclear reactors

International Nuclear Information System (INIS)

Obradovic, D.

1966-01-01

This paper covers a review of literature and mathematical methods applied for space-time behaviour of nuclear reactors. The review of literature is limited to unresolved problems and trends of actual research in the field of reactor physics [sr

Carbon-carbon turbopump concept for Space Nuclear Thermal Propulsion

Science.gov (United States)

Overholt, David M.

1993-06-01

The U.S. Air Force Space Nuclear Thermal Propulsion (SNTP) program is placing high priority on maximizing specific impulse (ISP) and thrust-to-weight ratio in the development of a practical high-performance nuclear rocket. The turbopump design is driven by these goals. The liquid hydrogen propellant is pressurized and pumped to the reactor inlet by the turbopump assembly (TPA). Rocket propulsion is from rapid heating of the propellant from 180 R to thousands of degrees in the particle bed reactor (PBR). The exhausted propellant is then expanded through a high-temperature nozzle. A high-performance approach is to use an uncooled carbon-carbon nozzle and duct turbine inlet. Carbon-carbon components are used throughout the TPA hot section to obtain the high-temperature capability. Several carbon-carbon components are in development including structural parts, turbine nozzles/stators, and turbine rotors. The technology spinoff is applicable to conventional liquid propulsion engines and many other turbomachinery applications.

Carbon-carbon turbopump concept for Space Nuclear Thermal Propulsion

International Nuclear Information System (INIS)

Overholt, D.M.

1993-06-01

The U.S. Air Force Space Nuclear Thermal Propulsion (SNTP) program is placing high priority on maximizing specific impulse (ISP) and thrust-to-weight ratio in the development of a practical high-performance nuclear rocket. The turbopump design is driven by these goals. The liquid hydrogen propellant is pressurized and pumped to the reactor inlet by the turbopump assembly (TPA). Rocket propulsion is from rapid heating of the propellant from 180 R to thousands of degrees in the particle bed reactor (PBR). The exhausted propellant is then expanded through a high-temperature nozzle. A high-performance approach is to use an uncooled carbon-carbon nozzle and duct turbine inlet. Carbon-carbon components are used throughout the TPA hot section to obtain the high-temperature capability. Several carbon-carbon components are in development including structural parts, turbine nozzles/stators, and turbine rotors. The technology spinoff is applicable to conventional liquid propulsion engines and many other turbomachinery applications. 3 refs

Nuclear data needs for the space exploration initiative

International Nuclear Information System (INIS)

Howe, S.D.; Auchampaugh, G.

1991-01-01

On July 20, 1989, the President of the United States announced a new direction for the US Space Program. The new Space Exploration Initiative (SEI) is intended to emplace a permanent base on the Lunar surface and a manned outpost on the Mars surface by 2019. In order to achieve this ambitious challenge, new, innovative and robust technologies will have to be developed to support crew operations. Nuclear power and propulsion have been recognized as technologies that are at least mission enhancing and, in some scenarios, mission enabling. Because of the extreme operating conditions present in a nuclear rocket core, accurate modeling of the rocket will require cross section data sets which do not currently exist. In order to successfully achieve the goals of the SEI, major obstacles inherent in long duration space travel will have to be overcome. One of these obstacles is the radiation environment to which the astronauts will be exposed. In general, an unshielded crew will be exposed to roughly one REM per week in free space. For missions to Mars, the total dose could exceed more than one-half the total allowed lifetime level. Shielding of the crew may be possible, but accurate assessments of shield composition and thickness are critical if shield masses are to be kept at acceptable levels. In addition, the entire ship design may be altered by the differential neutron production by heavy ions (Galactic Cosmic Rays) incident on ship structures. The components of the radiation environment, current modeling capability and envisioned experiments will be discussed

Radiation risk from the nuclear power installation of space vehicle in case of reentry to the atmosphere

International Nuclear Information System (INIS)

Mikheenko, S.G.

1994-01-01

Main directions of space using of nuclear power are considered. Nuclear energy has found many applications in space projects. The first application is the use of nuclear energy for the production of electricity in space and the second main application is the use of nuclear power for propulsion purposes in space flight. History of usage nuclear power systems in space technic is shown. Today there are 54 satellites with NPS in space near the Earth. The main principle of radical solution of the problem of radiation safety is based on the accommodation of space objects with nuclear units in orbits, such that the ballistic lifetime is greater than the time necessary for complete decay of the accumulated radioactivity. Radiation safety on various stages of space nuclear systems exploitation is discussed. If Main System Ensuring Radiation Safety is failed, it must operates Reserved System Ensuring Radiation Safety. Concrete development of a booster system for nuclear unit and a system for the reactor destruction in order to ensure aerodynamic destruction of fuel has been realized in satellite of 'Cosmos' series. The investigations on reserved system ensuring radiation safety in Moscow Physical - Engineering Institute are discussed. The results show that we can in principle ensure the radiation safety in accordance to ICRP recommendations. (author)

Space orbits of collaboration. [international cooperation and the U.S.S.R. space program

Science.gov (United States)

Petrov, B.

1978-01-01

The U.S.S.R. cooperative space efforts with other Socialist countries dating back to 1957 are reviewed. The Interkosmos program, which is divided into three series of satellites (solar, ionospheric and magnetospheric), is discussed as well as the Prognoz, Kosmos, Soyuz, and Molniya spacecraft. Collaboration with France, India, Sweden, and the United States is mentioned.

Survival of Spores of Trichoderma longibrachiatum in Space: data from the Space Experiment SPORES on EXPOSE-R

Science.gov (United States)

Neuberger, Katja; Lux-Endrich, Astrid; Panitz, Corinna

2015-01-01

In the space experiment `Spores in artificial meteorites' (SPORES), spores of the fungus Trichoderma longibrachiatum were exposed to low-Earth orbit for nearly 2 years on board the EXPOSE-R facility outside of the International Space Station. The environmental conditions tested in space were: space vacuum at 10-7-10-4 Pa or argon atmosphere at 105 Pa as inert gas atmosphere, solar extraterrestrial ultraviolet (UV) radiation at λ > 110 nm or λ > 200 nm with fluences up to 5.8 × 108 J m-2, cosmic radiation of a total dose range from 225 to 320 mGy, and temperature fluctuations from -25 to +50°C, applied isolated or in combination. Comparable control experiments were performed on ground. After retrieval, viability of spores was analysed by two methods: (i) ethidium bromide staining and (ii) test of germination capability. About 30% of the spores in vacuum survived the space travel, if shielded against insolation. However, in most cases no significant decrease was observed for spores exposed in addition to the full spectrum of solar UV irradiation. As the spores were exposed in clusters, the outer layers of spores may have shielded the inner part. The results give some information about the likelihood of lithopanspermia, the natural transfer of micro-organisms between planets. In addition to the parameters of outer space, sojourn time in space seems to be one of the limiting parameters.

Vital role of nuclear data in space missions

International Nuclear Information System (INIS)

Tripathi, R.K.

2008-01-01

Nasa has a new vision for space exploration in the 21. Century encompassing a broad range of human and robotic missions including missions to Moon, Mars and beyond. Exposure from the hazards of severe space radiation in deep space long duration missions is a critical design driver. Thus, protection from the hazards of severe space radiation is of paramount importance for the new vision. Accurate risk assessments critically depend on the accuracy of the input information about the interaction of ions with materials, electronics and tissues. We have discussed some of the state-of-the-art cross sections database at Nasa and have demonstrated the role nuclear interaction plays in space missions. The impact of the cross sections on space missions has been shown by the assessment of dose exposure on Moon surface behind a number of materials with increasing hydrogen contents known to be a better radiation shielding material. In addition we have examined an approach to introduce reliability based design methods into shield evaluation and optimization procedure as a means to assess and control the uncertainties in shield design. Applications to Lunar missions for short and long-term duration display a large impact on the design outcome and the choice of the materials. For short duration missions all the examined materials have similar performance. However, for career astronauts who are exposed to longer duration space radiation over the period of time the choice of material plays a very critical role. Computational procedures based on deterministic solution of the Boltzmann equation are well suited for such procedures allowing optimization processes to be implemented, evaluation of biologically important rare events,and rapid analysis of possible shield optimization outcomes resulting from the biological model uncertainty parameter space

Nuclear Energy for Space Exploration

Science.gov (United States)

Houts, Michael G.

2010-01-01

Nuclear power and propulsion systems can enable exciting space exploration missions. These include bases on the moon and Mars; and the exploration, development, and utilization of the solar system. In the near-term, fission surface power systems could provide abundant, constant, cost-effective power anywhere on the surface of the Moon or Mars, independent of available sunlight. Affordable access to Mars, the asteroid belt, or other destinations could be provided by nuclear thermal rockets. In the further term, high performance fission power supplies could enable both extremely high power levels on planetary surfaces and fission electric propulsion vehicles for rapid, efficient cargo and crew transfer. Advanced fission propulsion systems could eventually allow routine access to the entire solar system. Fission systems could also enable the utilization of resources within the solar system. Fusion and antimatter systems may also be viable in the future

Heat-electricity convertion systems for a Brazilian space micro nuclear reactor

Energy Technology Data Exchange (ETDEWEB)

Guimaraes, Lamartine N.F.; Marcelino, Natalia B.; Placco, Guilherme M.; Nascimento, Jamil A.; Borges, Eduardo M., E-mail: guimarae@ieav.cta.br, E-mail: lamartine.guimaraes@pq.cnpq.br, E-mail: jamil@ieav.cta.br, E-mail: jalnsgf@outlook.com, E-mail: borges.em@hotmail.com, E-mail: ecorborges@hotmail.com, E-mail: ivayolini@gmail.com, E-mail: guilherme_placco@ig.com.br [Instituto de Estudos Avancados (IEAv/DCTA), Sao Jose dos Campos, SP (Brazil); Barrios Junior, Ary Garcia, E-mail: arygarcia89@yahoo.com [Faculdade de Tecnologia Sao Francisco (FATESF), Jacarei, SP (Brazil)

2013-07-01

This contribution will discuss the evolution work in the development of thermal cycles to allow the development of heat-electricity conversion for the Brazilian space micro nuclear Reactor. Namely, innovative core and nuclear fuel elements, Brayton cycle, Stirling engine, heat pipes, passive multi-fluid turbine, among others. This work is basically to set up the experimental labs that will allow the specification and design of the space equipment. Also, some discussion of the cost so far, and possible other applications will be presented. (author)

Heat-electricity convertion systems for a Brazilian space micro nuclear reactor

International Nuclear Information System (INIS)

Guimaraes, Lamartine N.F.; Marcelino, Natalia B.; Placco, Guilherme M.; Nascimento, Jamil A.; Borges, Eduardo M.; Barrios Junior, Ary Garcia

2013-01-01

This contribution will discuss the evolution work in the development of thermal cycles to allow the development of heat-electricity conversion for the Brazilian space micro nuclear Reactor. Namely, innovative core and nuclear fuel elements, Brayton cycle, Stirling engine, heat pipes, passive multi-fluid turbine, among others. This work is basically to set up the experimental labs that will allow the specification and design of the space equipment. Also, some discussion of the cost so far, and possible other applications will be presented. (author)

Key issues in space nuclear power challenges for the future

Science.gov (United States)

Brandhorst, Henry W., Jr.

1991-01-01

The future appears rich in missions that will extend the frontiers of knowledge, human presence in space, and opportunities for profitable commerce. Key to the success of these ventures is the availability of plentiful, cost effective electric power and assured, low cost access to space. While forecasts of space power needs are problematic, an assessment of future needs based on terrestrial experience has been made. These needs fall into three broad categories: survival, self sufficiency, and industrialization. The cost of delivering payloads to orbital locations from LEO to Mars has been determined and future launch cost reductions projected. From these factors, then, projections of the performance necessary for future solar and nuclear space power options has been made. These goals are largely dependent upon orbital location and energy storage needs. Finally the cost of present space power systems has been determined and projections made for future systems.

Applicability of trends in nuclear safety analysis to space nuclear power systems

International Nuclear Information System (INIS)

Bari, R.A.

1992-01-01

A survey is presented of some current trends in nuclear safety analysis that may be relevant to space nuclear power systems. This includes: lessons learned from operating power reactor safety and licensing; approaches to the safety design of advanced and novel reactors and facilities; the roles of risk assessment, extremely unlikely accidents, safety goals/targets; and risk-benefit analysis and communication

Assessment of nuclear reactor concepts for low power space applications

Science.gov (United States)

Klein, Andrew C.; Gedeon, Stephen R.; Morey, Dennis C.

1988-01-01

The results of a preliminary small reactor concepts feasibility and safety evaluation designed to provide a first order validation of the nuclear feasibility and safety of six small reactor concepts are given. These small reactor concepts have potential space applications for missions in the 1 to 20 kWe power output range. It was concluded that low power concepts are available from the U.S. nuclear industry that have the potential for meeting both the operational and launch safety space mission requirements. However, each design has its uncertainties, and further work is required. The reactor concepts must be mated to a power conversion technology that can offer safe and reliable operation.

Telerobotic technology for nuclear and space applications

International Nuclear Information System (INIS)

Herndon, J.N.; Hamel, W.R.

1987-03-01

Telerobotic development efforts at Oak Ridge National Laboratory are extensive and relatively diverse. Current efforts include development of a prototype space telerobot system for the NASA Langley Research Center and development and large-scale demonstration of nuclear fuel cycle teleoperators in the Consolidated Fuel Reprocessing Program. This paper presents an overview of the efforts in these major programs. 10 refs., 8 figs

Atoms for space

Energy Technology Data Exchange (ETDEWEB)

Buden, D.

1990-10-01

Nuclear technology offers many advantages in an expanded solar system space exploration program. These cover a range of possible applications such as power for spacecraft, lunar and planetary surfaces, and electric propulsion; rocket propulsion for lunar and Mars vehicles; space radiation protection; water and sewage treatment; space mining; process heat; medical isotopes; and self-luminous systems. In addition, space offers opportunities to perform scientific research and develop systems that can solve problems here on Earth. These might include fusion and antimatter research, using the Moon as a source of helium-3 fusion fuel, and manufacturing perfect fusion targets. In addition, nuclear technologies can be used to reduce risk and costs of the Space Exploration Initiative. 1 fig.

Atoms for space

International Nuclear Information System (INIS)

Buden, D.

1990-10-01

Nuclear technology offers many advantages in an expanded solar system space exploration program. These cover a range of possible applications such as power for spacecraft, lunar and planetary surfaces, and electric propulsion; rocket propulsion for lunar and Mars vehicles; space radiation protection; water and sewage treatment; space mining; process heat; medical isotopes; and self-luminous systems. In addition, space offers opportunities to perform scientific research and develop systems that can solve problems here on Earth. These might include fusion and antimatter research, using the Moon as a source of helium-3 fusion fuel, and manufacturing perfect fusion targets. In addition, nuclear technologies can be used to reduce risk and costs of the Space Exploration Initiative. 1 fig

Overview of CNES-CEA joint programme on space nuclear Brayton systems

International Nuclear Information System (INIS)

Carre, F.; Proust, E.; Chaudourne, S.; Keirle, P.; Tilliette, Z.; Vrillon, B.

1990-01-01

In 1982, a cooperative programme on space nuclear power systems was initiated between the French Centre National d'Etudes Spatiales (CNES) and the Commissariat a l'Energie Atomique (CEA), to assess the feasibility, lead time, cost, competitiveness and development prospects for space nuclear power systems (SPS) in the 20 to 200 kWe range. The present three-year study phase is primarily oriented toward the assessment of various reactor candidate technologies and system design options for nuclear SPS in the 20 kWe class, which corresponds to the expected power needs of the first European space missions, anticipated to begin in 2005. This paper presents an overview of the present programme phase, with emphasis on design studies of three reference design concepts for 20 kWe turboelectric nuclear power systems selected so as to cover a wide range of reactor temperatures and corresponding technologies. The systems differ mainly in their nuclear reactors which are: the Liquid Metal Fast Breeder derivative or UO 2 /Na/Stainless steel -650 0 C; the High Temperature Gas-cooled derivative or UO 2 /direct cycle/super alloys - 850 0 C; and the UN/Li/MoRe alloy - 1120 0 C. All three systems use a Brayton cycle with recuperation for power conversion. (author)

Status of the CNES-CEA joint program on space nuclear Brayton systems

International Nuclear Information System (INIS)

Carre, F.; Proust, E.; Chaudourne, S.; Keirle, P.; Tilliette, Z.; Vrillon, B.

1989-01-01

A Cooperative program between the French Centre National d'Etudes Spatiales (CNES) and the Commissariat a l'Engergie Atomique (CEA) was initiated in 1983, to investigate the possible development of 20 to 200 kWe space nuclear power systems to be launched by the next version of the European launcher, Ariane V. After completion in 1986 of preliminary conceptual studies of a reference 200 kWe turboelectric power system, an additional 3 year study phase was decided, with the double objective of assessing the potential advantage of nuclear power systems versus solar photovoltaic or dynamic systems in the 20 kWe power range, and comparing various reactor candidate technologies and systems options for 20 kWe space nuclear power systems, likely to meet the projected energy needs of future European space missions. The results of this study are discussed by the authors

Human factors and nuclear space technology in long-term exploration

International Nuclear Information System (INIS)

Brown-VanHoozer, S.A.; VanHoozer, W.R.

2000-01-01

Allocation of manual versus automated tasks for operation and maintenance of nuclear power systems in space will be crucial at the onset and at the return of a space flight. Such factors as space adaptation syndrome (SAS), a temporary space motion sickness that has affected 40 to 50% of crew members on past space flights, can result in lost effort ranging from a few hours to a full day. This could have a significant impact on manual performance where high levels of execution are likely to be required in the very early stages of the mission. Other considerations involving higher-level behavioral phenomena such as interpersonal and group processes, individual belief systems, social and motivational factors, and (subjective) cognitive function have received little attention; nevertheless these will be essential elements for success in long-term exploration. Understanding that long-term space flight missions may create groups that become unique societies distinct unto themselves will test current ethical, moral, and social belief systems, requiring one to examine the amalgamation as well as organizational structures for the safety and balance of the crew

Topological properties of function spaces over ordinal spaces

Czech Academy of Sciences Publication Activity Database

Gabriyelyan, S.; Grebík, Jan; Kąkol, Jerzy; Zdomskyy, L.

2017-01-01

Roč. 111, č. 4 (2017), s. 1157-1161 ISSN 1578-7303 R&D Projects: GA ČR GF16-34860L Institutional support: RVO:67985840 Keywords : Ascoli * rK-space * ordinal space Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 0.690, year: 2016 https://link.springer.com/article/10.1007%2Fs13398-016-0354-7

Nuclear alkali metal Rankine power systems for space applications

International Nuclear Information System (INIS)

Moyers, J.C.; Holcomb, R.S.

1986-01-01

Nuclear power systems utilizing alkali metal Rankine power conversion cycles offer the potential for high efficiency, lightweight space power plants. Conceptual design studies are being carried out for both direct and indirect cycle systems for steady state space power applications. A computational model has been developed for calculating the performance, size, and weight of these systems over a wide range of design parameters. The model is described briefly and results from parametric design studies, with descriptions of typical point designs, are presented in this paper

A&R challenges for in-space operations. [Automation and Robotic technologies

Science.gov (United States)

Underwood, James

1990-01-01

Automation and robotics (A&R) challenges for in-space operations are examined, with emphasis on the interaction between developing requirements, developing solutions, design concepts, and the nature of the applicability of automation in robotic technologies. Attention is first given to the use of A&R in establishing outposts on the moon and Mars. Then emphasis is placed on the requirements for the assembly of transportation systems in low earth orbit. Concepts of the Space Station which show how the assembly, processing, and checkout of systems in LEO might be accommodated are examined.

The moduli space of two U(1) instantons on noncommutative $R^4$ and $R^3\\times S^1$

OpenAIRE

Lee, Kimyeong; Tong, David; Yi, Sangheon

2000-01-01

We employ the ADHM method to derive the moduli space of two instantons in U(1) gauge theory on a noncommutative space. We show by an explicit hyperK\\"ahler quotient construction that the relative metric of the moduli space of two instantons on $R^4$ is the Eguchi-Hanson metric and find a unique threshold bound state. For two instantons on $R^3\\times S^1$, otherwise known as calorons, we give the asymptotic metric and conjecture a completion. We further discuss the relationship of caloron modu...

SPACE MAINTENANCE OF NUCLEAR ROCKET PROPULSION VEHICLES

Energy Technology Data Exchange (ETDEWEB)

Marjon, P. L.

1963-08-15

Maintenance and repair of spacecraft are discussed from the hardware viewpoint. Interior operations are rather straight forward, but study results show that space suits are not sufficient for exterior repair work. Evaluation of worker requirements leads to a maintenance capsule concept. Capsule application is depicted in contrasting situations: repair of meteoroid damage and nuclear engine replacement. Radiation shielding is also considered. (D.C.W.)

Power conditioning for space nuclear reactor systems

Science.gov (United States)

Berman, Baruch

1987-01-01

This paper addresses the power conditioning subsystem for both Stirling and Brayton conversion of space nuclear reactor systems. Included are the requirements summary, trade results related to subsystem implementation, subsystem description, voltage level versus weight, efficiency and operational integrity, components selection, and shielding considerations. The discussion is supported by pertinent circuit and block diagrams. Summary conclusions and recommendations derived from the above studies are included.

Diff(S1)/SL(2,R) and Teichmueller space

International Nuclear Information System (INIS)

Nag, S.; Verjovsky, A.

1988-08-01

It is shown that the unique homogeneous Kaehler metric carried by M=Diff(S 1 )/SL(2,R) induces the Weil-Petersson metric on the Teichmueller space. This is via our identification of M as a holomorphic submanifold of universal Teichmueller space T(1). The identification was obtained simply by noting that every diffeomorphism of S 1 is a quasisymmetric homeomorphism. Our computations allow us also to prove that every T(G), G any infinite Fuchsian group, projects out of M transversely. This last assertion is related to the ''fractal'' nature of G-invariant quasicircles. (author). 12 refs

On Yang's Noncommutative Space Time Algebra, Holography, Area Quantization and C-space Relativity

CERN Document Server

Castro, C

2004-01-01

An isomorphism between Yang's Noncommutative space-time algebra (involving two length scales) and the holographic-area-coordinates algebra of C-spaces (Clifford spaces) is constructed via an AdS_5 space-time which is instrumental in explaining the origins of an extra (infrared) scale R in conjunction to the (ultraviolet) Planck scale lambda characteristic of C-spaces. Yang's space-time algebra allowed Tanaka to explain the origins behind the discrete nature of the spectrum for the spatial coordinates and spatial momenta which yields a minimum length-scale lambda (ultraviolet cutoff) and a minimum momentum p = (\\hbar / R) (maximal length R, infrared cutoff). The double-scaling limit of Yang's algebra : lambda goes to 0, and R goes to infinity, in conjunction with the large n infinity limit, leads naturally to the area quantization condition : lambda R = L^2 = n lambda^2 (in Planck area units) given in terms of the discrete angular-momentum eigenvalues n . The generalized Weyl-Heisenberg algebra in C-spaces is ...

Effluent Containment System for space thermal nuclear propulsion ground test facilities

International Nuclear Information System (INIS)

1995-08-01

This report presents the research and development study work performed for the Space Reactor Power System Division of the U.S. Department of Energy on an innovative ECS that would be used during ground testing of a space nuclear thermal rocket engine. A significant portion of the ground test facilities for a space nuclear thermal propulsion engine are the effluent treatment and containment systems. The proposed ECS configuration developed recycles all engine coolant media and does not impact the environment by venting radioactive material. All coolant media, hydrogen and water, are collected, treated for removal of radioactive particulates, and recycled for use in subsequent tests until the end of the facility life. Radioactive materials removed by the treatment systems are recovered, stored for decay of short-lived isotopes, or packaged for disposal as waste. At the end of the useful life, the facility will be decontaminated and dismantled for disposal

Space exploration and colonization - Towards a space faring society

Science.gov (United States)

Hammond, Walter E.

1990-01-01

Development trends of space exploration and colonization since 1957 are reviewed, and a five-phase evolutionary program planned for the long-term future is described. The International Geosphere-Biosphere program which is intended to provide the database on enviromental changes of the earth as a global system is considered. Evolution encompasses the anticipated advantages of such NASA observation projects as the Hubble Space Telescope, the Gamma Ray Observatory, the Advanced X-Ray Astrophysics Facility, and the Cosmic Background Explorer. Attention is given to requirements for space colonization, including development of artificial gravity and countermeasures to mitigate zero gravity problems; robotics and systems aimed to minimize human exposure to the space environment; the use of nuclear propulsion; and international collaboration on lunar-Mars projects. It is recommended that nuclear energy sources be developed for both propulsion and as extraterrestrial power plants.

Safety program considerations for space nuclear reactor systems

International Nuclear Information System (INIS)

Cropp, L.O.

1984-08-01

This report discusses the necessity for in-depth safety program planning for space nuclear reactor systems. The objectives of the safety program and a proposed task structure is presented for meeting those objectives. A proposed working relationship between the design and independent safety groups is suggested. Examples of safety-related design philosophies are given

Elementare Bildungseinrichtungen als safe spaces für (religiöse Differenz

Directory of Open Access Journals (Sweden)

Helena Stockinger

2016-12-01

Full Text Available ENGLISH: Educational institutions sometimes do not offer a space for (religious difference. Based on this fact the term safe space is theoretically specified. It seems important to develop kindergartens as safe spaces in wich learning, belonging and recognizing are possible. As one characteristic of the culture of safe spaces the recognition of (religious difference is pointed out, especially being sensitive about and broaching the issue of difference. DEUTSCH: Bildungseinrichtungen stellen teilweise keinen Artikulationsraum für (religiöse Differenz bereit, wodurch einzelne Kinder organisational benachteiligt werden. Elementare Bildungseinrichtungen könnten aber Räume sein, in denen Lernen, Zugehörigkeit und Anerkennung möglich sind. Hierzu wird der Begriff des safe space beleuchtet und auf elementare Bildungseinrichtungen übertragen. Als ein Merkmal der Kultur der safe spaces gilt die Anerkennung der (religiösen Differenz, indem diese sensibel wahrgenommen und thematisiert wird.

Nuclear safety as applied to space power reactor systems

International Nuclear Information System (INIS)

Cummings, G.E.

1987-01-01

Current space nuclear power reactor safety issues are discussed with respect to the unique characteristics of these reactors. An approach to achieving adequate safety and a perception of safety is outlined. This approach calls for a carefully conceived safety program which makes uses of lessons learned from previous terrestrial power reactor development programs. This approach includes use of risk analyses, passive safety design features, and analyses/experiments to understand and control off-design conditions. The point is made that some recent accidents concerning terrestrial power reactors do not imply that space power reactors cannot be operated safety

Nuclear spectroscopy in large shell model spaces: recent advances

International Nuclear Information System (INIS)

Kota, V.K.B.

1995-01-01

Three different approaches are now available for carrying out nuclear spectroscopy studies in large shell model spaces and they are: (i) the conventional shell model diagonalization approach but taking into account new advances in computer technology; (ii) the recently introduced Monte Carlo method for the shell model; (iii) the spectral averaging theory, based on central limit theorems, in indefinitely large shell model spaces. The various principles, recent applications and possibilities of these three methods are described and the similarity between the Monte Carlo method and the spectral averaging theory is emphasized. (author). 28 refs., 1 fig., 5 tabs

Feasibility of space disposal of radioactive nuclear waste. 2: Technical summary

Science.gov (United States)

1974-01-01

The feasibility of transporting radioactive waste produced in the process of generating electricity in nuclear powerplants into space for ultimate disposal was investigated at the request of the AEC as a NASA in-house effort. The investigation is part of a broad AEC study of methods for long-term storage or disposal of radioactive waste. The results of the study indicate that transporting specific radioactive wastes, particularly the actinides with very long half-lives, into space using the space shuttle/tug as the launch system, appears feasible from the engineering and safety viewpoints. The space transportation costs for ejecting the actinides out of the solar system would represent less than a 5-percent increase in the average consumer's electric bill.

Application and optimization of input parameter spaces in mass flow modelling: a case study with r.randomwalk and r.ranger

Science.gov (United States)

Krenn, Julia; Zangerl, Christian; Mergili, Martin

2017-04-01

r.randomwalk is a GIS-based, multi-functional, conceptual open source model application for forward and backward analyses of the propagation of mass flows. It relies on a set of empirically derived, uncertain input parameters. In contrast to many other tools, r.randomwalk accepts input parameter ranges (or, in case of two or more parameters, spaces) in order to directly account for these uncertainties. Parameter spaces represent a possibility to withdraw from discrete input values which in most cases are likely to be off target. r.randomwalk automatically performs multiple calculations with various parameter combinations in a given parameter space, resulting in the impact indicator index (III) which denotes the fraction of parameter value combinations predicting an impact on a given pixel. Still, there is a need to constrain the parameter space used for a certain process type or magnitude prior to performing forward calculations. This can be done by optimizing the parameter space in terms of bringing the model results in line with well-documented past events. As most existing parameter optimization algorithms are designed for discrete values rather than for ranges or spaces, the necessity for a new and innovative technique arises. The present study aims at developing such a technique and at applying it to derive guiding parameter spaces for the forward calculation of rock avalanches through back-calculation of multiple events. In order to automatize the work flow we have designed r.ranger, an optimization and sensitivity analysis tool for parameter spaces which can be directly coupled to r.randomwalk. With r.ranger we apply a nested approach where the total value range of each parameter is divided into various levels of subranges. All possible combinations of subranges of all parameters are tested for the performance of the associated pattern of III. Performance indicators are the area under the ROC curve (AUROC) and the factor of conservativeness (FoC). This

Safety considerations for the use of nuclear power in space

International Nuclear Information System (INIS)

Sewell, D.C.

1985-01-01

A little over twenty years ago Norris Bradbury, then Director of the Los Alamos Scientific Laboratory, gave a luncheon speech at the American Nuclear Society Meeting on Aerospace Nuclear Safety here in Albuquerque, New Mexico. His subject was Safety in Science. His opening statement is well worth recalling. He said, ''...science - by which I mean both science and technology - has historically generated new hazards and, equally historically, invented new safeties for mankind. It has produced a safer way of life, a lesser dependence on man's physical frailities.'' He went on to say, ''Wherever science has made an advance it has developed a new hazard, but in general the new hazards have been less overall than the hazards made obsolete by the new development.'' I think that these are excellent thoughts to keep in mind as we embark on a program for increased use of nuclear power in space. That does not mean that the safe operation of new nuclear space power systems will come automatically. It will not. We must work at it continually to make these new systems meet acceptable safety standards

An improvement of dimension-free Sobolev imbeddings in r spaces

Czech Academy of Sciences Publication Activity Database

Fiorenza, A.; Krbec, Miroslav; Schmeisser, H.-J.

2014-01-01

Roč. 267, č. 1 (2014), s. 243-261 ISSN 0022-1236 R&D Projects: GA ČR GAP201/10/1920 Institutional support: RVO:67985840 Keywords : imbedding theorem * small Lebesgue space * rearrangement-invariant Banach Subject RIV: BA - General Mathematics Impact factor: 1.322, year: 2014 http://www.sciencedirect.com/science/article/pii/S0022123614001724

Analysis of experimental data on relativistic nuclear collisions in the Lobachevsky space

International Nuclear Information System (INIS)

Baldin, A.A.; Baldina, Eh.G.; Kladnitskaya, E.N.; Rogachevskij, O.V.

2004-01-01

Relativistic nuclear collisions are considered in terms of relative 4-velocity and rapidity space (the Lobachevsky space). The connection between geometric relations in the Lobachevsky space and measurable (experimentally determined) kinematic characteristics (transverse momentum, longitudinal rapidity, square relative 4-velocity b ik , etc.) is discussed. The experimental data obtained using the propane bubble chamber are analyzed on the basis of triangulation in the Lobachevsky space. General properties of relativistic invariants distributions characterizing the geometric position of particles in the Lobachevsky space are discussed. The transition energy region is considered on the basis of relativistic approach to experimental data on multiparticle processes. Possible applications of the obtained results for planning of experimental research and analysis of data on multiple particle production are discussed

The TERRA project, a space nuclear micro-reactor case study

International Nuclear Information System (INIS)

Guimaraes, Lamartine N.F.; Nascimento, Jamil A.; Borges, Eduardo M.; Lobo, Paulo D. Castro; Placco, Guilherme M.; Barrios Junior, Ary G.

2011-01-01

The TEcnologia de Reatores Rapidos Avancados project, also known as TERRA Project is been conducted by the Institute for Advanced Studies IEAv. The TERRA project has a general objective of understanding and developing the key technologies that will allow (Brazil) the use of nuclear technology to generate electricity in space. This electricity may power several space systems and/or a type of plasma based engine. Also, the type of reactor intended for space may be used for power generation in very inhospitable environment such as the ocean floor. Some of the mentioned technologies may include: Brayton cycles, Stirling engines, heat pipes and its coupled systems, nuclear fuel technology, new materials and several others. Once there is no mission into which apply this technology, at this moment, this research may be conducted in many forms and ways. The fact remains that when this technology becomes needed there will be no way that we (Brazilians) will be able to buy it from. This technology, in this sense, is highly strategic and will be the key to commercially explore deep space. Therefore, there is the need to face the development problems and solve them, to gain experience with our own rights and wrongs. This paper will give a brief overview of what has been done so far, on experimental facilities and hardware that could support space system development, including a Brayton cycle test facility, Tesla turbine testing, and Stirling engine development and modeling. Our great problem today is lack of human resources. To attend that problem we are starting a new graduate program that will allow overcoming that, given the proper time frame. (author)

The TERRA project, a space nuclear micro-reactor case study

Energy Technology Data Exchange (ETDEWEB)

Guimaraes, Lamartine N.F.; Nascimento, Jamil A.; Borges, Eduardo M.; Lobo, Paulo D. Castro, E-mail: guimarae@ieav.cta.br, E-mail: jamil@ieav.cta.br, E-mail: eduardo@ieav.cta.br [Divisao de Energia Nuclear. Instituto de Estudos Avancados, Sao Jose dos Campos, SP (Brazil); Placco, Guilherme M.; Barrios Junior, Ary G. [Faculdade de Tecnologia Sao Francisco (FATESF), Jacarei, SP (Brazil)

2011-07-01

The TEcnologia de Reatores Rapidos Avancados project, also known as TERRA Project is been conducted by the Institute for Advanced Studies IEAv. The TERRA project has a general objective of understanding and developing the key technologies that will allow (Brazil) the use of nuclear technology to generate electricity in space. This electricity may power several space systems and/or a type of plasma based engine. Also, the type of reactor intended for space may be used for power generation in very inhospitable environment such as the ocean floor. Some of the mentioned technologies may include: Brayton cycles, Stirling engines, heat pipes and its coupled systems, nuclear fuel technology, new materials and several others. Once there is no mission into which apply this technology, at this moment, this research may be conducted in many forms and ways. The fact remains that when this technology becomes needed there will be no way that we (Brazilians) will be able to buy it from. This technology, in this sense, is highly strategic and will be the key to commercially explore deep space. Therefore, there is the need to face the development problems and solve them, to gain experience with our own rights and wrongs. This paper will give a brief overview of what has been done so far, on experimental facilities and hardware that could support space system development, including a Brayton cycle test facility, Tesla turbine testing, and Stirling engine development and modeling. Our great problem today is lack of human resources. To attend that problem we are starting a new graduate program that will allow overcoming that, given the proper time frame. (author)

Space commercialization: Analysis of R and D investments with long time horizons

Science.gov (United States)

Sheahen, T. P.

1984-01-01

By following a single hypothetical example through a series of variations, the way different potential investors might look at the opportunity to participate in space commercialization is described. The example itself is fairly typical of commercial opportunities in space. The chief characteristics are a steadily increasing requirement for capital infusion over an 8 year period, followed by a very generous stream of profits running another decade or more beyond. There is a decision point at 3 years, at the conclusion of laboratory R&D; and another at 6 years, following 2 initial space flights.

The role of nuclear reactors in space exploration and development

International Nuclear Information System (INIS)

Lipinski, R.J.

2000-01-01

The United States has launched more than 20 radioisotopic thermoelectric generators (RTGs) into space over the past 30 yr but has launched only one nuclear reactor, and that was in 1965. Russia has launched more than 30 reactors. The RTGs use the heat of alpha decay of 238 Pu for power and typically generate 235 U; typical designs are for 100 to 1000 kW of electricity. The only US space reactor launch (SNAP-10A) was a demonstration mission. One reason for the lack of space reactor use by the United States was the lack of space missions that required high power. But, another was the assumed negative publicity that would accompany a reactor launch. The net result is that all space reactor programs after 1970 were terminated before an operating space reactor could be developed, and they are now many years from recovering the ability to build them. Two major near-term needs for space reactors are the human exploration of Mars and advanced missions to and beyond the orbit of Jupiter. To help obtain public acceptance of space reactors, one must correct some of the misconceptions concerning space reactors and convey the following facts to the public and to decision makers: Space reactors are 1000 times smaller in power and size than a commercial power reactor. A space reactor at launch is only as radioactive as a pile of dirt 60 m (200 ft) across. A space reactor contains no plutonium at launch. It does not become significantly radioactive until it is turned on, and it will be engineered so that no launch accident can turn it on, even if that means fueling it after launch. The reactor will not be turned on until it is in a high stable orbit or even on an earth-escape trajectory for some missions. The benefits of space reactors are that they give humanity a stairway to the planets and perhaps the stars. They open a new frontier for their children and their grandchildren. They pave the way for all life on earth to move out into the solar system. At one time, humans built

History of Los Alamos Participation in Active Experiments in Space

Energy Technology Data Exchange (ETDEWEB)

Pongratz, Morris B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2018-02-06

Beginning with the Teak nuclear test in 1958, Los Alamos has a long history of participation in active experiments in space. The last pertinent nuclear tests were the five explosions as part of the Dominic series in 1962. The Partial Test Ban Treaty signed in August 1963 prohibited all test detonations of nuclear weapons except for those conducted underground. Beginning with the “Apple” thermite barium release in June 1968 Los Alamos has participated in nearly 100 non-nuclear experiments in space, the last being the NASA-sponsored “AA-2” strontium and europium doped barium thermite releases in the Arecibo beam in July of 1992. The rationale for these experiments ranged from studying basic plasma processes such as gradientdriven structuring and velocity-space instabilities to illuminating the convection of plasmas in the ionosphere and polar cap to ionospheric depletion experiments to the B.E.A.R. 1-MeV neutral particle beam test in 1989. This report reviews the objectives, techniques and diagnostics of Los Alamos participation in active experiments in space.

Space Nuclear Facility test capability at the Baikal-1 and IGR sites Semipalatinsk-21, Kazakhstan

Science.gov (United States)

Hill, T. J.; Stanley, M. L.; Martinell, J. S.

1993-01-01

The International Space Technology Assessment Program was established 1/19/92 to take advantage of the availability of Russian space technology and hardware. DOE had two delegations visit CIS and assess its space nuclear power and propulsion technologies. The visit coincided with the Conference on Nuclear Power Engineering in Space Nuclear Rocket Engines at Semipalatinsk-21 (Kurchatov, Kazakhstan) on Sept. 22-25, 1992. Reactor facilities assessed in Semipalatinski-21 included the IVG-1 reactor (a nuclear furnace, which has been modified and now called IVG-1M), the RA reactor, and the Impulse Graphite Reactor (IGR), the CIS version of TREAT. Although the reactor facilities are being maintained satisfactorily, the support infrastructure appears to be degrading. The group assessment is based on two half-day tours of the Baikals-1 test facility and a brief (2 hr) tour of IGR; because of limited time and the large size of the tour group, it was impossible to obtain answers to all prepared questions. Potential benefit is that CIS fuels and facilities may permit USA to conduct a lower priced space nuclear propulsion program while achieving higher performance capability faster, and immediate access to test facilities that cannot be available in this country for 5 years. Information needs to be obtained about available data acquisition capability, accuracy, frequency response, and number of channels. Potential areas of interest with broad application in the U.S. nuclear industry are listed.

Space polypropulsion

Science.gov (United States)

Kellett, B. J.; Griffin, D. K.; Bingham, R.; Campbell, R. N.; Forbes, A.; Michaelis, M. M.

2008-05-01

Hybrid space propulsion has been a feature of most space missions. Only the very early rocket propulsion experiments like the V2, employed a single form of propulsion. By the late fifties multi-staging was routine and the Space Shuttle employs three different kinds of fuel and rocket engines. During the development of chemical rockets, other forms of propulsion were being slowly tested, both theoretically and, relatively slowly, in practice. Rail and gas guns, ion engines, "slingshot" gravity assist, nuclear and solar power, tethers, solar sails have all seen some real applications. Yet the earliest type of non-chemical space propulsion to be thought of has never been attempted in space: laser and photon propulsion. The ideas of Eugen Saenger, Georgii Marx, Arthur Kantrowitz, Leik Myrabo, Claude Phipps and Robert Forward remain Earth-bound. In this paper we summarize the various forms of nonchemical propulsion and their results. We point out that missions beyond Saturn would benefit from a change of attitude to laser-propulsion as well as consideration of hybrid "polypropulsion" - which is to say using all the rocket "tools" available rather than possibly not the most appropriate. We conclude with three practical examples, two for the next decades and one for the next century; disposal of nuclear waste in space; a grand tour of the Jovian and Saturnian moons - with Huygens or Lunoxod type, landers; and eventually mankind's greatest space dream: robotic exploration of neighbouring planetary systems.

Identification of (R)-selective ω-aminotransferases by exploring evolutionary sequence space.

Science.gov (United States)

Kim, Eun-Mi; Park, Joon Ho; Kim, Byung-Gee; Seo, Joo-Hyun

2018-03-01

Several (R)-selective ω-aminotransferases (R-ωATs) have been reported. The existence of additional R-ωATs having different sequence characteristics from previous ones is highly expected. In addition, it is generally accepted that R-ωATs are variants of aminotransferase group III. Based on these backgrounds, sequences in RefSeq database were scored using family profiles of branched-chain amino acid aminotransferase (BCAT) and d-alanine aminotransferase (DAT) to predict and identify putative R-ωATs. Sequences with two profile analysis scores were plotted on two-dimensional score space. Candidates with relatively similar scores in both BCAT and DAT profiles (i.e., profile analysis score using BCAT profile was similar to profile analysis score using DAT profile) were selected. Experimental results for selected candidates showed that putative R-ωATs from Saccharopolyspora erythraea (R-ωAT_Sery), Bacillus cellulosilyticus (R-ωAT_Bcel), and Bacillus thuringiensis (R-ωAT_Bthu) had R-ωAT activity. Additional experiments revealed that R-ωAT_Sery also possessed DAT activity while R-ωAT_Bcel and R-ωAT_Bthu had BCAT activity. Selecting putative R-ωATs from regions with similar profile analysis scores identified potential R-ωATs. Therefore, R-ωATs could be efficiently identified by using simple family profile analysis and exploring evolutionary sequence space. Copyright © 2017 Elsevier Inc. All rights reserved.

SP-100 space nuclear power system

International Nuclear Information System (INIS)

Given, R.W.; Morgan, R.E.; Chi, J.W.H.; Westinghouse Electric Corp., Madison, PA)

1984-01-01

A baseline design concept for a 100 kWe nuclear reactor space power system is described. The concept was developed under contract from JPL as part of a joint program of the DOE, DOD, and NASA. The major technical and safety constraints influencing the selection of reactor operating parameters are discussed. A lithium-cooled compact fast reactor was selected as the best candidate system. The material selected for the thermoelectric conversion system was silicon germanium (SiGe) with gallium phosphide doping. Attention is given to the improved safety of the seven in-core control rod configuration

Nuclear Cross Sections for Space Radiation Applications

Science.gov (United States)

Werneth, C. M.; Maung, K. M.; Ford, W. P.; Norbury, J. W.; Vera, M. D.

2015-01-01

The eikonal, partial wave (PW) Lippmann-Schwinger, and three-dimensional Lippmann-Schwinger (LS3D) methods are compared for nuclear reactions that are relevant for space radiation applications. Numerical convergence of the eikonal method is readily achieved when exact formulas of the optical potential are used for light nuclei (A = 16) and the momentum-space optical potential is used for heavier nuclei. The PW solution method is known to be numerically unstable for systems that require a large number of partial waves, and, as a result, the LS3D method is employed. The effect of relativistic kinematics is studied with the PW and LS3D methods and is compared to eikonal results. It is recommended that the LS3D method be used for high energy nucleon-nucleus reactions and nucleus-nucleus reactions at all energies because of its rapid numerical convergence and stability for both non-relativistic and relativistic kinematics.

Space Agriculture for Recovery of Fukushima from the Nuclear Disaster

Science.gov (United States)

Yamashita, Masamichi; Tomita-Yokotani, Kaori; Hasegawa, Katsuya; Kanazawa, Shinjiro; Oshima, Tairo

2012-07-01

Space agriculture is an engineering challenge to realize life support functions on distant planetary bodies under their harsh environment. After the nuclear disaster in Fukushima, its land was heavily contaminated by radioactive cesium and other nuclei. We proposed the use of space agriculture to remediate the contaminated land. Since materials circulation in the human dominant system should remove sodium from metabolic waste at processing fertilizer for crop plants, handling of sodium and potassium ions in agro-ecosystem has been one of major research targets of space agriculture. Cesium resembles to potassium as alkaline metal. Knowledge on behavior of sodium/potassium in agro-ecosystem might contribute to Fukushima. Reduction of volume of contaminated biomass made by hyperthermophilic aerobic composting bacterial system is another proposal from space agriculture. Volume and mass of plant bodies should be reduced for safe storage of nuclear wastes. Capacity of the storage facility will be definitely limited against huge amount of contaminated soil, plants and others. For this purpose, incineration of biomass first choice. The process should be under the lowered combustion temperature and with filters to confine radioactive ash to prevent dispersion of radioactive cesium. Biological combustion made by hyperthermophilic aerobic composting bacterial system might offer safe alternative for the volume reduction of plant biomass. Scientific evidence are demanded for Fukushima in order to to judge health risks of the low dose rate exposure and their biological mechanism. Biology and medicine for low dose rate exposure have been intensively studied for space exploration. The criteria of radiation exposure for general public should be remained as 1 mSv/year, because people has no merit at being exposed. However, the criteria of 1,200 mSv for life long, which is set to male astronaut, age of his first flight after age 40, might be informative to people for understanding

Nuclear space power systems for orbit raising and maneuvering

International Nuclear Information System (INIS)

Buden, D.; Sullivan, J.A.

1984-01-01

Reference is made to recent studies which have shown that direct thrust nuclear rockets for routine orbit raising and near-earth space tug missions are probably not cost-effective. The need for additional trade-off studies and comparisons of direct-thrust nuclear systems with chemical systems to clarify the role of nuclear rockets in missions requiring rapid orbit maneuvering is stressed. Attention is confined here to nuclear electric propulsion considerations. Low-mass nuclear power plants are constructed to optimize nuclear electric propulsion systems. Electric power levels from 100 kilowatts to as much as several megawatts are desirable. The goals for the power plant specific mass are 20-30 kg/kW at the lower powers to 2-4 kg/kW at the higher powers

A Review of Tribomaterial Technology for Space Nuclear Power Systems

Science.gov (United States)

Stanford, Malcolm K.

2007-01-01

The National Aeronautics and Space Administration (NASA) has recently proposed a nuclear closed-cycle electric power conversion system for generation of 100-kW of electrical power for space exploration missions. A critical issue is the tribological performance of sliding components within the power conversion unit that will be exposed to neutron radiation. This paper presents a review of the main considerations that have been made in the selection of solid lubricants for similar applications in the past as well as a recommendations for continuing development of the technology.

Dream missions space colonies, nuclear spacecraft and other possibilities

CERN Document Server

van Pelt, Michel

2017-01-01

This book takes the reader on a journey through the history of extremely ambitious, large and complex space missions that never happened. What were the dreams and expectations of the visionaries behind these plans, and why were they not successful in bringing their projects to reality thus far? As spaceflight development progressed, new technologies and ideas led to pushing the boundaries of engineering and technology though still grounded in real scientific possibilities. Examples are space colonies, nuclear-propelled interplanetary spacecraft, space telescopes consisting of multiple satellites and canon launch systems. Each project described in this book says something about the dreams and expectations of their time, and their demise was often linked to an important change in the cultural, political and social state of the world. For each mission or spacecraft concept, the following will be covered: • Description of the design. • Overview of the history of the concept and the people involved. • Why it...

The role of nuclear reactors in space exploration and development

Energy Technology Data Exchange (ETDEWEB)

Lipinski, R.J.

2000-07-01

The United States has launched more than 20 radioisotopic thermoelectric generators (RTGs) into space over the past 30 yr but has launched only one nuclear reactor, and that was in 1965. Russia has launched more than 30 reactors. The RTGs use the heat of alpha decay of {sup 238}Pu for power and typically generate <1 kW of electricity. Apollo, Pioneer, Voyager, Viking, Galileo, Ulysses, and Cassini all used RTGs. Space reactors use the fission energy of {sup 235}U; typical designs are for 100 to 1000 kW of electricity. The only US space reactor launch (SNAP-10A) was a demonstration mission. One reason for the lack of space reactor use by the United States was the lack of space missions that required high power. But, another was the assumed negative publicity that would accompany a reactor launch. The net result is that all space reactor programs after 1970 were terminated before an operating space reactor could be developed, and they are now many years from recovering the ability to build them. Two major near-term needs for space reactors are the human exploration of Mars and advanced missions to and beyond the orbit of Jupiter. To help obtain public acceptance of space reactors, one must correct some of the misconceptions concerning space reactors and convey the following facts to the public and to decision makers: Space reactors are 1000 times smaller in power and size than a commercial power reactor. A space reactor at launch is only as radioactive as a pile of dirt 60 m (200 ft) across. A space reactor contains no plutonium at launch. It does not become significantly radioactive until it is turned on, and it will be engineered so that no launch accident can turn it on, even if that means fueling it after launch. The reactor will not be turned on until it is in a high stable orbit or even on an earth-escape trajectory for some missions. The benefits of space reactors are that they give humanity a stairway to the planets and perhaps the stars. They open a new

12th Symposium on Space Nuclear Power and Propulsion. Conference on Alternative Power from Space (APFS),Conference on Accelerator-Driven Transmutation Technologies and Applications (A-DTTA)

International Nuclear Information System (INIS)

Mohamed, S.E.

1995-01-01

These proceedings represent papers presented at the 12th symposium on Space Nuclear Power and Propulsion held in Albuquerque, New Mexico. The symposium theme was ''commercialization and technology transfer''. The topics discussed include: wireless power transmission, solar power from space next generation spacecraft, space power electronics and power management, flight testing of components, manufacturing and processing of materials, nuclear propulsion, reactors and shielding and many others of interest to the scientific community representing industry, government and academic institutions. There were 163 papers presented at the conference and 60 have been abstracted for the Energy Science and Technology database

The Picard group of the moduli space of r-Spin Riemann surfaces

DEFF Research Database (Denmark)

Randal-Williams, Oscar

2012-01-01

An r-Spin Riemann surface is a Riemann surface equipped with a choice of rth root of the (co)tangent bundle. We give a careful construction of the moduli space (orbifold) of r-Spin Riemann surfaces, and explain how to establish a Madsen–Weiss theorem for it. This allows us to prove the “Mumford...... conjecture” for these moduli spaces, but more interestingly allows us to compute their algebraic Picard groups (for g≥10, or g≥9 in the 2-Spin case). We give a complete description of these Picard groups, in terms of explicitly constructed line bundles....

Nuclear reactor descriptions for space power systems analysis

Science.gov (United States)

Mccauley, E. W.; Brown, N. J.

1972-01-01

For the small, high performance reactors required for space electric applications, adequate neutronic analysis is of crucial importance, but in terms of computational time consumed, nuclear calculations probably yield the least amount of detail for mission analysis study. It has been found possible, after generation of only a few designs of a reactor family in elaborate thermomechanical and nuclear detail to use simple curve fitting techniques to assure desired neutronic performance while still performing the thermomechanical analysis in explicit detail. The resulting speed-up in computation time permits a broad detailed examination of constraints by the mission analyst.

Application of Recommended Design Practices for Conceptual Nuclear Fusion Space Propulsion Systems

Science.gov (United States)

Williams, Craig H.

2004-01-01

An AIAA Special Project Report was recently produced by AIAA's Nuclear and Future Flight Propulsion Technical Committee and is currently in peer review. The Report provides recommended design practices for conceptual engineering studies of nuclear fusion space propulsion systems. Discussion and recommendations are made on key topics including design reference missions, degree of technological extrapolation and concomitant risk, thoroughness in calculating mass properties (nominal mass properties, weight-growth contingency and propellant margins, and specific impulse), and thoroughness in calculating power generation and usage (power-flow, power contingencies, specific power). The report represents a general consensus of the nuclear fusion space propulsion system conceptual design community and proposes 15 recommendations. This paper expands on the Report by providing specific examples illustrating how to apply each of the recommendations.

Primary loop simulation of the SP-100 space nuclear reactor

International Nuclear Information System (INIS)

Borges, Eduardo M.; Braz Filho, Francisco A.; Guimaraes, Lamartine N.F.

2011-01-01

Between 1983 and 1992 the SP-100 space nuclear reactor development project for electric power generation in a range of 100 to 1000 kWh was conducted in the USA. Several configurations were studied to satisfy different mission objectives and power systems. In this reactor the heat is generated in a compact core and refrigerated by liquid lithium, the primary loops flow are controlled by thermoelectric electromagnetic pumps (EMTE), and thermoelectric converters produce direct current energy. To define the system operation point for an operating nominal power, it is necessary the simulation of the thermal-hydraulic components of the space nuclear reactor. In this paper the BEMTE-3 computer code is used to EMTE pump design performance evaluation to a thermalhydraulic primary loop configuration, and comparison of the system operation points of SP-100 reactor to two thermal powers, with satisfactory results. (author)

Nuclear energy for space: Past CEA activities and ongoing OPUS studies

International Nuclear Information System (INIS)

Raepsaet, Xavier; Marion, Denis; Valentian, Dominique

2006-01-01

Since the beginning of space activities, solar and nuclear energy have been identified as the only available options for extended missions according to present knowledge. Both types have been used extensively for missions on Earth orbit, interplanetary space and planetary/lunar surface. However, the intensity of solar irradiation decreases with the square of the distance from the Sun. Future scientific and human explorations will take benefits of using a safe in-space nuclear reactor for providing both sufficient electric energy and efficient performance for a space propulsion. The first part of the paper presents a brief status of the different types of nuclear power sources, their characteristics and their field of applications. Previous CEA's projects of space nuclear fission reactors that have been studied in the past will also be discussed; the ERATO project in the 80's (design of a Nuclear Electric Propulsion system of 20 to 200 kWe) and the MAPS project in the 90's (definition of a Nuclear Thermal Propulsion system of 300 MWth for 72 kN of thrust). According to the recent road-maps, CEA decided to maintain a waking state in its spatial nuclear activities by carrying out some conceptual design studies of Nuclear Electric Power systems in the range of 100-500 kWe. The second part of the paper describes the main characteristics of this Optimized Propulsion Unit System (OPUS studies) and its different components. These characteristics, the basic options of the OPUS system that have been selected and the reasons associated to those choices are examined. Especially, the nuclear reactor has been defined considering the possible synergies with the next generation of terrestrial nuclear reactor (International Generation IV Forum). After two successive sets of studies, two different versions of this nuclear system have emerged. The first one is a fast, high-temperature helium cooled reactor, coupled to a direct reheated Brayton cycle. This version is technically the

Historical perspectives - The role of the NASA Lewis Research Center in the national space nuclear power programs

Science.gov (United States)

Bloomfield, H. S.; Sovie, R. J.

1991-01-01

The history of the NASA Lewis Research Center's role in space nuclear power programs is reviewed. Lewis has provided leadership in research, development, and the advancement of space power and propulsion systems. Lewis' pioneering efforts in nuclear reactor technology, shielding, high temperature materials, fluid dynamics, heat transfer, mechanical and direct energy conversion, high-energy propellants, electric propulsion and high performance rocket fuels and nozzles have led to significant technical and management roles in many natural space nuclear power and propulsion programs.

Historical perspectives: The role of the NASA Lewis Research Center in the national space nuclear power programs

Science.gov (United States)

Bloomfield, H. S.; Sovie, R. J.

1991-01-01

The history of the NASA Lewis Research Center's role in space nuclear power programs is reviewed. Lewis has provided leadership in research, development, and the advancement of space power and propulsion systems. Lewis' pioneering efforts in nuclear reactor technology, shielding, high temperature materials, fluid dynamics, heat transfer, mechanical and direct energy conversion, high-energy propellants, electric propulsion and high performance rocket fuels and nozzles have led to significant technical and management roles in many national space nuclear power and propulsion programs.

Characterizations of Besov and Triebel–Lizorkin spaces on metric measure spaces

Czech Academy of Sciences Publication Activity Database

Gogatishvili, Amiran; Koskela, P.; Zhou, Y.

2013-01-01

Roč. 25, č. 4 (2013), s. 787-819 ISSN 0933-7741 R&D Projects: GA ČR GA201/08/0383 Institutional research plan: CEZ:AV0Z10190503 Keywords : Besov space * Triebel-Lizorkin space * Hajłasz-Besov space Subject RIV: BA - General Mathematics Impact factor: 0.733, year: 2013 http://www.degruyter.com/view/j/form.2013.25.issue-4/form.2011.135/form.2011.135. xml ?format=INT

Characterizations of Besov and Triebel–Lizorkin spaces on metric measure spaces

Czech Academy of Sciences Publication Activity Database

Gogatishvili, Amiran; Koskela, P.; Zhou, Y.

2013-01-01

Roč. 25, č. 4 (2013), s. 787-819 ISSN 0933-7741 R&D Projects: GA ČR GA201/08/0383 Institutional research plan: CEZ:AV0Z10190503 Keywords : Besov space * Triebel-Lizorkin space * Hajłasz-Besov space Subject RIV: BA - General Mathematics Impact factor: 0.733, year: 2013 http://www.degruyter.com/view/j/form.2013.25.issue-4/form.2011.135/form.2011.135.xml?format=INT

Space weapon technology and policy

Science.gov (United States)

Hitchens, Theresa

2017-11-01

The military use of space, including in support of nuclear weapons infrastructure, has greatly increased over the past 30 years. In the current era, rising geopolitical tensions between the United States and Russia and China have led to assumptions in all three major space powers that warfighting in space now is inevitable, and possible because of rapid technological advancements. New capabilities for disrupting and destroying satellites include radio-frequency jamming, the use of lasers, maneuverable space objects and more capable direct-ascent anti-satellite weapons. This situation, however, threatens international security and stability among nuclear powers. There is a continuing and necessary role for diplomacy, especially the establishment of normative rules of behavior, to reduce risks of misperceptions and crisis escalation, including up to the use of nuclear weapons. U.S. policy and strategy should seek a balance between traditional military approaches to protecting its space assets and diplomatic tools to create a more secure space environment.

Proceedings of the Tenth Symposium on Space Nuclear Power and Propulsion

International Nuclear Information System (INIS)

El-Genk, M.S.; Hoover, M.D.

1993-01-01

This symposium included topics on space nuclear power. Various aspectsof design of propulsion and power systems were presented. From theProceedings, two hundred and twelve papers were abstracted for the database

Probing electron correlation and nuclear dynamics in Momentum Space

International Nuclear Information System (INIS)

Deleuze, M S; Hajgato, B; Morini, F; Knippenberg, S

2010-01-01

Orbital imaging experiments employing Electron Momentum Spectroscopy are subject to many complications, such as distorted wave effects, conformational mobility in the electronic ground state, ultra-fast nuclear dynamics in the final state, or a dispersion of the ionization intensity over electronically excited (shake-up) configurations of the cation. The purpose of the present contribution is to illustrate how a proper treatment of these complications enables us to probe in momentum space the consequences of electron correlation and nuclear dynamics in neutral and cationic states.

Technology development for nuclear power generation for space application

Energy Technology Data Exchange (ETDEWEB)

Guimaraes, Lamartine N.F.; Ribeiro, Guilherme B.; Braz Filho, Francisco A.; Nascimento, Jamil A.; Placco, Guilherme M., E-mail: guimarae@ieav.cta.br, E-mail: lamartine.guimaraes@pq.cnpq.br [Instituto de Estudos Avancados (IEAv), Sao Jose dos Campos, SP (Brazil). Divisao de Energia Nuclear; Faria, Saulo M. de [Instituto Tecnologico de Aeronautica (ITA), Sao Jose dos Campos, SP (Brazil)

2015-07-01

For a few years now, the TERRA project is developing several technology pieces to foster nuclear space applications. In this way, a nuclear reactor concept has been developed as a first proposal. Together, the problem of heat to electricity conversion has been addressed. A closed Brayton cycle is being built and a Stirling machine is being worked out and perfected. In addition, two types of heat pipes are being look at. One related with high temperature made of Mo13Re, an especial alloy. And a second one made of copper, which mainly could be used as a passive heat rejection. In this way, all major areas of interest in a micro station to be used in space has been addressed. A new passive technology has been inferred and is related with Tesla turbine or its evolution, known as multi fluid passive turbine. This technology has the potential to either: improve the Brayton cycle or its efficiency. In this paper, some details are discussed and some will be shown during the presentation, as the work evolve. (author)

Technology development for nuclear power generation for space application

International Nuclear Information System (INIS)

Guimaraes, Lamartine N.F.; Ribeiro, Guilherme B.; Braz Filho, Francisco A.; Nascimento, Jamil A.; Placco, Guilherme M.

2015-01-01

For a few years now, the TERRA project is developing several technology pieces to foster nuclear space applications. In this way, a nuclear reactor concept has been developed as a first proposal. Together, the problem of heat to electricity conversion has been addressed. A closed Brayton cycle is being built and a Stirling machine is being worked out and perfected. In addition, two types of heat pipes are being look at. One related with high temperature made of Mo13Re, an especial alloy. And a second one made of copper, which mainly could be used as a passive heat rejection. In this way, all major areas of interest in a micro station to be used in space has been addressed. A new passive technology has been inferred and is related with Tesla turbine or its evolution, known as multi fluid passive turbine. This technology has the potential to either: improve the Brayton cycle or its efficiency. In this paper, some details are discussed and some will be shown during the presentation, as the work evolve. (author)

Space proliferation versus space-type dissemination: from semantic issues to political issues

International Nuclear Information System (INIS)

Gaillard-Sborowsky, Florence

2015-01-01

The space and ballistic capabilities relationships are regularly revisited in forums on international security, in particular about Iran and North Korea cases. The term 'space proliferation' is commonly used by analogy with nuclear proliferation. However, is this analogy relevant? Beyond the semantic aspects, this shift raises political issues that this paper will consider. The study of the assumptions regarding the analysis of nuclear and missile proliferation and their space counterparts will highlight some approximations and presuppositions, such as the amalgam between sounding rockets, launchers and missiles technologies, in order to suggest new thinking of these sensitive issues. (author)

Propulsion of space ships by nuclear explosion

Science.gov (United States)

Linhart, J. G.; Kravárik, J.

2005-01-01

Recent progress in the research on deuterium-tritium (D-T) inertially confined microexplosions encourages one to reconsider the nuclear propulsion of spaceships based on the concept originally proposed in the Orion project. We discuss first the acceleration of medium-sized spaceships by D-T explosions whose output is in the range of 0.1 10 t of TNT. The launching of such a ship into an Earth orbit or beyond by a large nuclear explosion in an underground cavity is sketched out in the second section of the paper, and finally we consider a hypothetical Mars mission based on these concepts. In the conclusion it is argued that propulsion based on the Orion concept only is not the best method for interplanetary travel owing to the very large number of nuclear explosion required. A combination of a super gun and subsequent rocket propulsion using advanced chemical fuels appears to be the best solution for space flights of the near future.

On spaces of functions of smoothness zero

International Nuclear Information System (INIS)

Besov, Oleg V

2012-01-01

The paper is concerned with the new spaces B-bar p,q 0 of functions of smoothness zero defined on the n-dimensional Euclidean space R n or on a subdomain G of R n . These spaces are compared with the spaces B p,q 0 (R n ) and bmo(R n ). The embedding theorems for Sobolev spaces are refined in terms of the space B-bar p,q 0 with the limiting exponent. Bibliography: 8 titles.

Space radiation dosimetry

International Nuclear Information System (INIS)

Reitz, G.; Beaujean, R.; Heilmann, C.; Kopp, J.; Strauch, K.; Heinrich, W.

1996-01-01

Detector packages consisting of plastic nuclear track detectors, nuclear emusions, and thermoluminescence detectors were exposed at different locations inside the space laboratory Spacelab and at the astronauts' body and in different sections of the MIR space station. Total dose measurements, particle fluence rate and linear energy transfer (LET) spectra of heavy ions, number of nuclear disintegrations and fast neutron fluence rate from this exposure are given in this report. The dose equivalent received by the PSs were calculated from the measurements and range from 190 μSv d -1 to 770 μSv d -3 . (orig.) [de

Validation of nuclear models used in space radiation shielding applications

International Nuclear Information System (INIS)

Norman, Ryan B.; Blattnig, Steve R.

2013-01-01

A program of verification and validation has been undertaken to assess the applicability of models to space radiation shielding applications and to track progress as these models are developed over time. In this work, simple validation metrics applicable to testing both model accuracy and consistency with experimental data are developed. The developed metrics treat experimental measurement uncertainty as an interval and are therefore applicable to cases in which epistemic uncertainty dominates the experimental data. To demonstrate the applicability of the metrics, nuclear physics models used by NASA for space radiation shielding applications are compared to an experimental database consisting of over 3600 experimental cross sections. A cumulative uncertainty metric is applied to the question of overall model accuracy, while a metric based on the median uncertainty is used to analyze the models from the perspective of model development by examining subsets of the model parameter space.

Characterization of associate spaces of weighted Lorentz spaces with applications

Czech Academy of Sciences Publication Activity Database

Gogatishvili, Amiran; Pick, L.; Soudský, F.

2014-01-01

Roč. 224, č. 1 (2014), s. 1-23 ISSN 0039-3223 R&D Projects: GA ČR GA13-14743S Institutional support: RVO:67985840 Keywords : weighted Lorentz spaces * weighted inequalities * non-increasing rearragement * Banach function space Subject RIV: BA - General Mathematics Impact factor: 0.610, year: 2014 http://journals.impan.gov.pl/sm/Inf/224-1-1.html

Shutdown and degradation: Space computers for nuclear application, verification of radiation hardness. Final report

International Nuclear Information System (INIS)

Eichhorn, E.; Gerber, V.; Schreyer, P.

1995-01-01

(1) Employment of those radiation hard electronics which are already known in military and space applications. (2) The experience in space-flight shall be used to investigate nuclear technology areas, for example, by using space electronics to prove the range of applications in nuclear radiating environments. (3) Reproduction of a computer developed for telecommunication satellites; proof of radiation hardness by radiation tests. (4) At 328 Krad (Si) first failure of radiation tolerant devices with 100 Krad (Si) hardness guaranteed. (5) Using radiation hard devices of the same type you can expect applications at doses of greater than 1 Mrad (Si). Electronic systems applicable for radiation categories D, C and lower part of B for manipulators, vehicles, underwater robotics. (orig.) [de

Comparison of urea space, deuterium oxide space and body composition in growing pigs

International Nuclear Information System (INIS)

Mitchell, A.D.; Steele, N.C.

1987-01-01

Urea and deuterium oxide (D 2 O) space were compared by simultaneous infusion into pigs weighing approximately 55 or 90 kg. Urea was cleared from the plasma pool more rapidly than D 2 O and appeared to equilibrate at a relative concentration which was lower than that of D 2 O. Consequently, urea and D 2 O space values were closest when extrapolated to zero time values. Correlations between urea space and D 2 O space were highest at 15 minutes post infusion (R2 = .75) or between urea space at 15 minutes and D 2 O at equilibrium (R2 = .86). Results of urea and D 2 O space measurements were compared with water, lipid and protein content of the carcass. Urea space at 15 minutes and D 2 O space at 35 minutes most closely approximated total body water while D 2 O space at 15 minutes was nearly equivalent to empty body water. Overall, D 2 O space at equilibrium had the highest correlations with carcass values of water, lipid and protein and appears to be preferable to urea space for estimating carcass composition in pigs

Space nuclear-power reactor design based on combined neutronic and thermal-fluid analyses

International Nuclear Information System (INIS)

Koenig, D.R.; Gido, R.G.; Brandon, D.I.

1985-01-01

The design and performance analysis of a space nuclear-power system requires sophisticated analytical capabilities such as those developed during the nuclear rocket propulsion (Rover) program. In particular, optimizing the size of a space nuclear reactor for a given power level requires satisfying the conflicting requirements of nuclear criticality and heat removal. The optimization involves the determination of the coolant void (volume) fraction for which the reactor diameter is a minimum and temperature and structural limits are satisfied. A minimum exists because the critical diameter increases with increasing void fraction, whereas the reactor diameter needed to remove a specified power decreases with void fraction. The purpose of this presentation is to describe and demonstrate our analytical capability for the determination of minimum reactor size. The analysis is based on combining neutronic criticality calculations with OPTION-code thermal-fluid calculations

An evaluation of some special techniques for nuclear waste disposal in space

Science.gov (United States)

Mackay, J. S.

1973-01-01

A preliminary examination is reported of several special ways for space disposal of nuclear waste material which utilize the radioactive heat in the waste to assist in the propulsion for deep space trajectories. These include use of the wastes in a thermoelectric generator (RTG) which operates an electric propulsion device and a radioisotope - thermal thruster which uses hydrogen or ammonia as the propellant. These propulsive devices are compared to the space tug and the space tug/solar electric propulsion combination for disposal of waste on a solar system escape trajectory. Such comparisons indicate that the waste-RTG approach has considerable potential provided the combined specific mass of the waste container - RTG system does not exceed approximately 150 kg/kw sub e. Several exploratory numerical calculations have been made for high earth orbit and Earth escape destinations.

B→τν: Opening up the charged Higgs parameter space with R-parity violation

International Nuclear Information System (INIS)

Bose, Roshni; Kundu, Anirban

2012-01-01

The theoretically clean channel B + →τ + ν shows a close to 3σ discrepancy between the Standard Model prediction and the data. This in turn puts a strong constraint on the parameter space of a two-Higgs doublet model, including R-parity conserving supersymmetry. The constraint is so strong that it almost smells of fine-tuning. We show how the parameter space opens up with the introduction of suitable R-parity violating interactions, and release the tension between data and theory.

New characterization of Morrey spaces

Czech Academy of Sciences Publication Activity Database

Gogatishvili, Amiran; Mustafayev, R.Ch.

2013-01-01

Roč. 4, č. 1 (2013), s. 54-64 ISSN 2077-9879 R&D Projects: GA ČR GA201/08/0383; GA ČR GA13-14743S Institutional support: RVO:67985840 Keywords : local Morrey-type spaces * complementary local Morrey-type spaces * associate spaces Subject RIV: BA - General Mathematics http://www.mathnet.ru/php/archive.phtml?wshow=paper&jrnid=emj&paperid=114&option_lang=eng

Space Science at Los Alamos National Laboratory

Science.gov (United States)

Smith, Karl

2017-09-01

The Space Science and Applications group (ISR-1) in the Intelligence and Space Research (ISR) division at the Los Alamos National Laboratory lead a number of space science missions for civilian and defense-related programs. In support of these missions the group develops sensors capable of detecting nuclear emissions and measuring radiations in space including γ-ray, X-ray, charged-particle, and neutron detection. The group is involved in a number of stages of the lifetime of these sensors including mission concept and design, simulation and modeling, calibration, and data analysis. These missions support monitoring of the atmosphere and near-Earth space environment for nuclear detonations as well as monitoring of the local space environment including space-weather type events. Expertise in this area has been established over a long history of involvement with cutting-edge projects continuing back to the first space based monitoring mission Project Vela. The group's interests cut across a large range of topics including non-proliferation, space situational awareness, nuclear physics, material science, space physics, astrophysics, and planetary physics.

Proposal of space reactor for nuclear electric propulsion system

International Nuclear Information System (INIS)

Nishiyama, Takaaki; Nagata, Hidetaka; Nakashima, Hideki

2009-01-01

A nuclear reactor installed in spacecrafts is considered here. The nuclear reactor could stably provide an enough amount of electric power in deep space missions. Most of the nuclear reactors that have been developed up to now in the United States and the former Soviet Union have used uranium with 90% enrichment of 235 U as a fuel. On the other hand, in Japan, because the uranium that can be used is enriched to below 20%, the miniaturization of the reactor core is difficult. A Light-water nuclear reactor is an exception that could make the reactor core small. Then, the reactor core composition and characteristic are evaluated for the cases with the enrichment of the uranium fuel as 20%. We take up here Graphite reactor, Light-water reactor, and Sodium-cooled one. (author)

Canadian space agency discipline working group for space dosimetry and radiation science

International Nuclear Information System (INIS)

Waker, Anthony; Waller, Edward; Lewis, Brent; Bennett, Leslie; Conroy, Thomas

2008-01-01

Full text: One of the great technical challenges in the human and robotic exploration of space is the deleterious effect of radiation on humans and physical systems. The magnitude of this challenge is broadly understood in terms of the sources of radiation, however, a great deal remains to be done in the development of instrumentation, suitable for the space environment, which can provide real-time monitoring of the complex radiation fields encountered in space and a quantitative measure of potential biological risk. In order to meet these research requirements collaboration is needed between experimental nuclear instrumentation scientists, theoretical scientists working on numerical modeling techniques and radiation biologists. Under the auspices of the Canadian Space Agency such a collaborative body has been established as one of a number of Discipline Working Groups. Members of the Space Dosimetry and Radiation Science working group form a collaborative network across Canada including universities, government laboratories and the industrial sector. Three central activities form the core of the Space Dosimetry and Radiation Science DWG. An instrument sub-group is engaged in the development of instruments capable of gamma ray, energetic charged particle and neutron dosimetry including the ability to provide dosimetric information in real-time. A second sub-group is focused on computer modeling of space radiation fields in order to assess the performance of conceptual designs of detectors and dosimeters or the impact of radiation on cellular and sub-cellular biological targets and a third sub-group is engaged in the study of the biological effects of space radiation and the potential of biomarkers as a method of assessing radiation impact on humans. Many working group members are active in more than one sub-group facilitating communication throughout the whole network. A summary progress-report will be given of the activities of the Discipline Working Group and the

Space nuclear power systems for extraterrestrial basing

International Nuclear Information System (INIS)

Lance, J.R.; Chi, J.W.H.

1989-01-01

Previous studies of nuclear and non-nuclear power systems for lunar bases are compared with recent studies by others. Power levels from tens of kW e for early base operation up to 2000 kW e for a self-sustaining base with a Closed Environment Life Support System (CELSS) are considered. Permanent lunar or Martian bases will require the use of multiple nuclear units connected to loads with a power transmission and distribution system analogous to earth-based electric utility systems. A methodology used for such systems is applied to the lunar base system to examine the effects of adding 100 kW e SP-100 class and/or larger nuclear units when a reliability criterion is imposed. The results show that resource and logistic burdens can be reduced by using 1000 kW e units early in the base growth scenario without compromising system reliability. Therefore, both technologies being developed in two current programs (SP-100 and NERVA Derivative Reactor (NDR) technology for space power) can be used effectively for extraterrestrial base power systems. Recent developments in NDR design that result in major reductions in reactor mass are also described. (author)

Human Factors and Information Operation for a Nuclear Power Space Vehicle

International Nuclear Information System (INIS)

Trujillo, Anna C.; Brown-Van Hoozer, S. Alenka

2002-01-01

This paper describes human-interactive systems needed for a crew nuclear-enabled space mission. A synthesis of aircraft engine and nuclear power plant displays, biofeedback of sensory input, virtual control, brain mapping for control process and manipulation, and so forth are becoming viable solutions. These aspects must maintain the crew's situation awareness and performance, which entails a delicate function allocation between crew and automation. (authors)

Optimal Embeddings of Bessel-Potential-Type Spaces into Generalized Hölder Spaces Involving k-Modulus of Smoothness

Czech Academy of Sciences Publication Activity Database

Gogatishvili, Amiran; Neves, J. S.; Opic, Bohumír

2010-01-01

Roč. 32, č. 3 (2010), s. 201-228 ISSN 0926-2601 R&D Projects: GA ČR GA201/05/2033; GA ČR GA201/08/0383 Institutional research plan: CEZ:AV0Z10190503 Keywords : slowly varying functions * Lorentz-Karamata spaces * Rearrangement-invariant Banach function spaces * Bessel potentials * (fractional) Sobolev-type spaces * Hölder-type spaces * Zygmund-type spaces Subject RIV: BA - General Mathematics Impact factor: 0.853, year: 2010 http://link.springer.com/article/10.1007%2Fs11118-009-9148-2

Nuclear reactor refuelable in space

International Nuclear Information System (INIS)

El-Genk, M.S.; Buden, D.; Mims, J.E.

1992-01-01

This patent describes a gas cooled nuclear reactor suitable for use in space. It comprises a lightweight structure comprising a plurality of at least three sections, each sector comprising a container for a reactor core separate and distinct from the reactor cores of the other sectors, each sector being capable of operating on its own and in cooperation with one or more of the other sectors and each sector having a common juncture with every other structure; and means associated with each sector independently introducing gas coolant into and extracting coolant from each sector to cool the core therein, wherein in event of failure of the cooling system of a core in a sector, one or more of the other sectors comprise means for conducting heat away from the failed sector core and means for convecting the heat away, and wherein operation of the one or more other sectors is maintained

Systems aspects of a space nuclear reactor power system

Science.gov (United States)

Jaffe, L.; Fujita, T.; Beatty, R.; Bhandari, P.; Chow, E.; Deininger, W.; Ewell, R.; Grossman, M.; Bloomfield, H.; Heller, J.

1988-01-01

Various system aspects of a 300-kW nuclear reactor power system for spacecraft have been investigated. Special attention is given to the cases of a reusable OTV and a space-based radar. It is demonstrated that the stowed length of the power system is important to mission design, and that orbital storage for months to years may be needed for missions involving orbital assembly.

Space-charge effects in Penning ion traps

Czech Academy of Sciences Publication Activity Database

Porobic, T.; Beck, M.; Breitenfeldt, M.; Couratin, C.; Finlay, P.; Knecht, A.; Fabian, X.; Friedag, P.; Flechard, X.; Lienard, E.; Ban, G.; Zákoucký, Dalibor; Soti, G.; Van Gorp, S.; Weinheimer, C.; Wursten, E.; Severijns, N.

2015-01-01

Roč. 785, JUN (2015), s. 153-162 ISSN 0168-9002 R&D Projects: GA MŠk LA08015; GA MŠk(CZ) LG13031 Institutional support: RVO:61389005 Keywords : Penning trap * space-charge * magnetron motion * ion trapping * buffer gas cooling * ion cyclotron resonance Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.200, year: 2015

Space nuclear reactor safety

International Nuclear Information System (INIS)

Damon, D.; Temme, M.; Brown, N.

1990-01-01

Definition of safety requirements and design features of the SP-100 space reactor power system has been guided by a mission risk analysis. The analysis quantifies risk from accidental radiological consequences for a reference mission. Results show that the radiological risk from a space reactor can be made very low. The total mission risk from radiological consequences for a shuttle-launched, earth orbit SP-100 mission is estimated to be 0.05 Person-REM (expected values) based on a 1 mREM/yr de Minimus dose. Results are given for each mission phase. The safety benefits of specific design features are evaluated through risk sensitivity analyses

Technical Guidance from the International Safety Framework for Nuclear Power Source Applications in Outer Space for Design and Development Phases

Science.gov (United States)

Summerer, Leopold

2014-08-01

In 2009, the International Safety Framework for Nuclear Power Source Applications in Outer Space [1] has been adopted, following a multi-year process that involved all major space faring nations in the frame of the International Atomic Energy Agency and the UN Committee on the Peaceful Uses of Outer Space. The safety framework reflects an international consensus on best practices. After the older 1992 Principles Relevant to the Use of Nuclear Power Sources in Outer Space, it is the second document at UN level dedicated entirely to space nuclear power sources.This paper analyses aspects of the safety framework relevant for the design and development phases of space nuclear power sources. While early publications have started analysing the legal aspects of the safety framework, its technical guidance has not yet been subject to scholarly articles. The present paper therefore focuses on the technical guidance provided in the safety framework, in an attempt to assist engineers and practitioners to benefit from these.

Space power station. Uchu hatsuden

Energy Technology Data Exchange (ETDEWEB)

Kudo, I. (Electrotechnical Laboratory, Tsukuba (Japan))

1993-02-20

A calculation tells that the amount of electric power the world will use in the future will require 100 to 500 power plants each with an output of 5-GW class. If this conception is true, it is beyond dispute that utilizing nuclear power will constitute a core of the power generation even though the geographical conditions are severe for nuclear power plants. It is also certain that power generation using clean solar energy will play important roles if power supply stability can be achieved. This paper describes plans to develop space solar power generation and space nuclear power generation that can supply power solving problems concerning geographical conditions and power supply stability. The space solar power generation is a system to arrest solar energy on a static orbit. According to a result of discussions in the U.S.A., the plan calls for solar cell sheets spread over the surface of a structure with a size of 5 km [times] 10 km [times] 0.5 km thick, and electric power obtained therefrom is transmitted to a rectenna with a size of 10 km [times] 13 km, a receiving antenna on the ground. The space nuclear power generation will be constructed similarly on a static orbit. Researches on space nuclear reactors have already begun. 10 refs., 8 figs., 1 tab.

A probabilistic approach to safety/reliability of space nuclear power systems

International Nuclear Information System (INIS)

Medford, G.; Williams, K.; Kolaczkowski, A.

1989-01-01

An ongoing effort is investigating the feasibility of using probabilistic risk assessment (PRA) modeling techniques to construct a living model of a space nuclear power system. This is being done in conjunction with a traditional reliability and survivability analysis of the SP-100 space nuclear power system. The initial phase of the project consists of three major parts with the overall goal of developing a top-level system model and defining initiating events of interest for the SP-100 system. The three major tasks were performing a traditional survivability analysis, performing a simple system reliability analysis, and constructing a top-level system fault-tree model. Each of these tasks and their interim results are discussed in this paper. Initial results from the study support the conclusion that PRA modeling techniques can provide a valuable design and decision-making tool for space reactors. The ability of the model to rank and calculate relative contributions from various failure modes allows design optimization for maximum safety and reliability. Future efforts in the SP-100 program will see data development and quantification of the model to allow parametric evaluations of the SP-100 system. Current efforts have shown the need for formal data development and test programs within such a modeling framework

Nuclear power plant wastes in space?

International Nuclear Information System (INIS)

Gertsenshtejn, M.E.; Klavdiev, V.V.

1992-01-01

Project of radioactive waste disposal into space by electric gun is discussed. The basic disadvantages of the project should include contamination of the near-the-earth space with radioactive containers as well as physical and technical difficulties related to developing electrical gun the shell of which should have the velocity exceeding 5 km/s. Idea of actinide gas atomization in the faraway space by multiply usable apparatus is proposed as alternative solution for the problem of radioactive waste disposal

Nuclear Thermal Propulsion (NTP) Development Activities at the NASA Marshall Space Flight Center - 2006 Accomplishments

Science.gov (United States)

Ballard, Richard O.

2007-01-01

In 2005-06, the Prometheus program funded a number of tasks at the NASA-Marshall Space Flight Center (MSFC) to support development of a Nuclear Thermal Propulsion (NTP) system for future manned exploration missions. These tasks include the following: 1. NTP Design Develop Test & Evaluate (DDT&E) Planning 2. NTP Mission & Systems Analysis / Stage Concepts & Engine Requirements 3. NTP Engine System Trade Space Analysis and Studies 4. NTP Engine Ground Test Facility Assessment 5. Non-Nuclear Environmental Simulator (NTREES) 6. Non-Nuclear Materials Fabrication & Evaluation 7. Multi-Physics TCA Modeling. This presentation is a overview of these tasks and their accomplishments

Improved Nuclear Reactor and Shield Mass Model for Space Applications

Science.gov (United States)

Robb, Kevin

2004-01-01

New technologies are being developed to explore the distant reaches of the solar system. Beyond Mars, solar energy is inadequate to power advanced scientific instruments. One technology that can meet the energy requirements is the space nuclear reactor. The nuclear reactor is used as a heat source for which a heat-to-electricity conversion system is needed. Examples of such conversion systems are the Brayton, Rankine, and Stirling cycles. Since launch cost is proportional to the amount of mass to lift, mass is always a concern in designing spacecraft. Estimations of system masses are an important part in determining the feasibility of a design. I worked under Michael Barrett in the Thermal Energy Conversion Branch of the Power & Electric Propulsion Division. An in-house Closed Cycle Engine Program (CCEP) is used for the design and performance analysis of closed-Brayton-cycle energy conversion systems for space applications. This program also calculates the system mass including the heat source. CCEP uses the subroutine RSMASS, which has been updated to RSMASS-D, to estimate the mass of the reactor. RSMASS was developed in 1986 at Sandia National Laboratories to quickly estimate the mass of multi-megawatt nuclear reactors for space applications. In response to an emphasis for lower power reactors, RSMASS-D was developed in 1997 and is based off of the SP-100 liquid metal cooled reactor. The subroutine calculates the mass of reactor components such as the safety systems, instrumentation and control, radiation shield, structure, reflector, and core. The major improvements in RSMASS-D are that it uses higher fidelity calculations, is easier to use, and automatically optimizes the systems mass. RSMASS-D is accurate within 15% of actual data while RSMASS is only accurate within 50%. My goal this summer was to learn FORTRAN 77 programming language and update the CCEP program with the RSMASS-D model.

Symmetry-adapted Liouville space. Pt. 7

International Nuclear Information System (INIS)

Temme, F.P.

1990-01-01

In examining nuclear spin dynamics of NMR spin clusters in density operator/generalized torque formalisms over vertical strokekqv>> operator bases of Liouville space, it is necessary to consider the symmetry mappings and carrier spaces under a specialized group for such (k i = 1) nuclear spin clusters. The SU2 X S n group provides the essential mappings and the form of H carrier space, which allows one to: (a) draw comparisons with Hilbert space duality, and (b) outline the form of the Coleman-Kotani genealogical hierarchy under induced S n -symmetry. (orig.)

"Lomonosov" Satellite—Space Observatory to Study Extreme Phenomena in Space

Science.gov (United States)

Sadovnichii, V. A.; Panasyuk, M. I.; Amelyushkin, A. M.; Bogomolov, V. V.; Benghin, V. V.; Garipov, G. K.; Kalegaev, V. V.; Klimov, P. A.; Khrenov, B. A.; Petrov, V. L.; Sharakin, S. A.; Shirokov, A. V.; Svertilov, S. I.; Zotov, M. Y.; Yashin, I. V.; Gorbovskoy, E. S.; Lipunov, V. M.; Park, I. H.; Lee, J.; Jeong, S.; Kim, M. B.; Jeong, H. M.; Shprits, Y. Y.; Angelopoulos, V.; Russell, C. T.; Runov, A.; Turner, D.; Strangeway, R. J.; Caron, R.; Biktemerova, S.; Grinyuk, A.; Lavrova, M.; Tkachev, L.; Tkachenko, A.; Martinez, O.; Salazar, H.; Ponce, E.

2017-11-01

The "Lomonosov" space project is lead by Lomonosov Moscow State University in collaboration with the following key partners: Joint Institute for Nuclear Research, Russia, University of California, Los Angeles (USA), University of Pueblo (Mexico), Sungkyunkwan University (Republic of Korea) and with Russian space industry organizations to study some of extreme phenomena in space related to astrophysics, astroparticle physics, space physics, and space biology. The primary goals of this experiment are to study: Ultra-high energy cosmic rays (UHECR) in the energy range of the Greizen-Zatsepin-Kuzmin (GZK) cutoff; Ultraviolet (UV) transient luminous events in the upper atmosphere; Multi-wavelength study of gamma-ray bursts in visible, UV, gamma, and X-rays; Energetic trapped and precipitated radiation (electrons and protons) at low-Earth orbit (LEO) in connection with global geomagnetic disturbances; Multicomponent radiation doses along the orbit of spacecraft under different geomagnetic conditions and testing of space segments of optical observations of space-debris and other space objects; Instrumental vestibular-sensor conflict of zero-gravity phenomena during space flight. This paper is directed towards the general description of both scientific goals of the project and scientific equipment on board the satellite. The following papers of this issue are devoted to detailed descriptions of scientific instruments.

(r, s-(τ12,τ12*-θ-Generalized double fuzzy closed sets in bitopological spaces

Directory of Open Access Journals (Sweden)

E. El-Sanousy

2016-10-01

Full Text Available In this paper, we introduce the notion of (r, s-(i, j-θ-generalized double fuzzy closed sets in double fuzzy bitopological spaces. A new θ-double fuzzy closure C12θ on double fuzzy bitopological spaces by using double supra fuzzy topological spaces are defined. Furthermore, generalized double fuzzy θ-continuous (resp. irresolute and double fuzzy strongly θ-continuous mappings are introduced and some of their properties studied.

Co-H-spaces and almost localization

OpenAIRE

Costoya, Cristina; Iwase, Norio

2012-01-01

Apart from simply-connected spaces, a non simply-connected co-H-space is a typical example of a space X with a co-action of $B\\pi_1(X)$ along $r^X : X \\rightarrow B\\pi_{1}(X)$ the classifying map of the universal covering. If such a space X is actually a co-H-space, then the fibrewise p-localization of $r^X$ (or the `almost' p-localization of X) is a fibrewise co-H-space (or an `almost' co-H-space, resp.) for every prime p. In this paper, we show that the converse statement is true, i.e., for...

MYTHONYMICAL SPACE PECULIARITIES IN FOREIGH FANTASY LITERATURE (BASED ON LITERARY WORKS BY J.R.R. TOLKIEN AND G.R.R. MARTIN

Directory of Open Access Journals (Sweden)

Kharitonova, E.V.

2017-12-01

Full Text Available The paper aims at exemplifying the characteristic features of onomastic space of a fantasy text. The authors examine the notion of a ‘mythonym’, systemize different approaches to classifying mythonymical units. The conducted study permitted to work out a thematic classification of mythonyms from the novels “The Lord of the Rings: The Fellowship of the Ring” by J.R.R. Tolkien and “A Song of Ice and Fire: A Game of Thrones” by G.R.R. Martin and to draw the conclusion on mythonyms’ role in fantasy literature.

Space reactors, a prospective for the future

International Nuclear Information System (INIS)

Wahlquist, E.; Voss, S.S.

1989-01-01

The power requirements for future space missions are increasing and alternate power systems will be required to meet these needs. Therefore, in the early 1980's a tri-agency space reactor program, the SP-100, was initiated that is capable of meeting the higher power requirements. To understand the current space reactor program, it is important to review it in the context of past space nuclear programs - including radioisotopes, nuclear rockets and reactors. Initial effort on these programs began in the mid-1950's. Radioisotope generators have been flown on a variety of missions and are continuing to be used. The space reactor and nuclear rocket programs were technically successful but were both terminated in 1973. The current SP-100 program builds on those earlier programs

Management of outer space

Science.gov (United States)

Perek, Lubos

1993-10-01

Various aspects of space-environment management are discussed. Attention is called to the fact that, while space radio communications are already under an adequate management by the International Communications Union, the use of nuclear power sources is regulated by the recently adopted set of principles, and space debris will be discussed in the near future at the UN COPUOS, other aspects of management of outer space received little or no attention of the international community. These include the competency of crews and technical equipment of spacecraft launched by newcomers to space exploration; monitoring of locations and motions of space objects (now in national hands), with relevant data made accessible through a computer network; and the requirement to use space only for beneficial purposes and not for promoting narrow and debatable interests damaging the outer space environment and impeding on astronomical observations. It is suggested that some of these tasks would be best performed by an international space agency within the UN system of organizations.

Space reactors - past, present, and future

International Nuclear Information System (INIS)

Buden, D.; Angelo, J.

1983-01-01

In the 1990s and beyond, advanced-design nuclear reactors could represent the prime source of both space power and propulsion. Many sophisticated military and civilian space missions of the future will require first kilowatt and then megawatt levels of power. This paper reviews key technology developments that accompanied past US space nuclear power development efforts, describes on-going programs, and then explores reactor technologies that will satisfy megawatt power level needs and beyond

Wastes in space

International Nuclear Information System (INIS)

2011-01-01

As human space activities have created more wastes on low and high Earth orbits over the past 50 years than the solar system injected meteorites over billions of years, this report gives an overview of this problem. It identifies the origins of these space debris and wastes (launchers, combustion residues, exploitation wastes, out-of-use satellites, accidental explosions, accidental collisions, voluntary destructions, space erosion), and proposes a stock list of space wastes. Then, it distinguishes the situation for the different orbits: low Earth orbit or LEO (traffic, presence of the International Space Station), medium Earth orbits or MEO (traffic, operating satellites, wastes), geostationary Earth orbit or GEO (traffic, operating satellites, wastes). It also discusses wastes and bacteria present on the moon (due to Apollo missions or to crash tests). It evokes how space and nuclear industry is concerned, and discusses the re-entry issue (radioactive boomerang, metallic boomerang). It also indicates elements of international law

Realizing "2001: A Space Odyssey": Piloted Spherical Torus Nuclear Fusion Propulsion

Science.gov (United States)

Williams, Craig H.; Dudzinski, Leonard A.; Borowski, Stanley K.; Juhasz, Albert J.

2005-01-01

A conceptual vehicle design enabling fast, piloted outer solar system travel was created predicated on a small aspect ratio spherical torus nuclear fusion reactor. The initial requirements were satisfied by the vehicle concept, which could deliver a 172 mt crew payload from Earth to Jupiter rendezvous in 118 days, with an initial mass in low Earth orbit of 1,690 mt. Engineering conceptual design, analysis, and assessment was performed on all major systems including artificial gravity payload, central truss, nuclear fusion reactor, power conversion, magnetic nozzle, fast wave plasma heating, tankage, fuel pellet injector, startup/re-start fission reactor and battery bank, refrigeration, reaction control, communications, mission design, and space operations. Detailed fusion reactor design included analysis of plasma characteristics, power balance/utilization, first wall, toroidal field coils, heat transfer, and neutron/x-ray radiation. Technical comparisons are made between the vehicle concept and the interplanetary spacecraft depicted in the motion picture 2001: A Space Odyssey.

Space nonweaponization. An urgent task for arms control

International Nuclear Information System (INIS)

Du Xiangwan; Pan Jusheng; Zhang Xinwei; Du Shuhua; Xu Changgen

1990-05-01

The authors attempt to expound the basic points of veiw and put forward a proposal on the space nonweaponization. The authors analyse the nature of space weaponry and its impact on arms race and point out that the space nonweaponization is an urgent task for arms control. The relations between prohibition of space and ASAT weapons, between prohibition of space weapons and reduction of nuclear weapons and between space weapon and nuclear test are all analysed. The inadequacy of the existing space treaties is made clear based on the evaluation. It is hoped that a verifiable treaty on the prohibition of space weapons should be made and international cooperation on peaceful use of outer space is necessary

A Programmatic and Engineering Approach to the Development of a Nuclear Thermal Rocket for Space Exploration

Science.gov (United States)

Bordelon, Wayne J., Jr.; Ballard, Rick O.; Gerrish, Harold P., Jr.

2006-01-01

With the announcement of the Vision for Space Exploration on January 14, 2004, there has been a renewed interest in nuclear thermal propulsion. Nuclear thermal propulsion is a leading candidate for in-space propulsion for human Mars missions; however, the cost to develop a nuclear thermal rocket engine system is uncertain. Key to determining the engine development cost will be the engine requirements, the technology used in the development and the development approach. The engine requirements and technology selection have not been defined and are awaiting definition of the Mars architecture and vehicle definitions. The paper discusses an engine development approach in light of top-level strategic questions and considerations for nuclear thermal propulsion and provides a suggested approach based on work conducted at the NASA Marshall Space Flight Center to support planning and requirements for the Prometheus Power and Propulsion Office. This work is intended to help support the development of a comprehensive strategy for nuclear thermal propulsion, to help reduce the uncertainty in the development cost estimate, and to help assess the potential value of and need for nuclear thermal propulsion for a human Mars mission.

Advanced Thermophotovoltaic Devices for Space Nuclear Power Systems

International Nuclear Information System (INIS)

Wernsman, Bernard; Mahorter, Robert G.; Siergiej, Richard; Link, Samuel D.; Wehrer, Rebecca J.; Belanger, Sean J.; Fourspring, Patrick; Murray, Susan; Newman, Fred; Taylor, Dan; Rahmlow, Tom

2005-01-01

Advanced thermophotovoltaic (TPV) modules capable of producing > 0.3 W/cm2 at an efficiency > 22% while operating at a converter radiator and module temperature of 1228 K and 325 K, respectively, have been made. These advanced TPV modules are projected to produce > 0.9 W/cm2 at an efficiency > 24% while operating at a converter radiator and module temperature of 1373 K and 325 K, respectively. Radioisotope and nuclear (fission) powered space systems utilizing these advanced TPV modules have been evaluated. For a 100 We radioisotope TPV system, systems utilizing as low as 2 general purpose heat source (GPHS) units are feasible, where the specific power for the 2 and 3 GPHS unit systems operating in a 200 K environment is as large as ∼ 16 We/kg and ∼ 14 We/kg, respectively. For a 100 kWe nuclear powered (as was entertained for the thermoelectric SP-100 program) TPV system, the minimum system radiator area and mass is ∼ 640 m2 and ∼ 1150 kg, respectively, for a converter radiator, system radiator and environment temperature of 1373 K, 435 K and 200 K, respectively. Also, for a converter radiator temperature of 1373 K, the converter volume and mass remains less than 0.36 m3 and 640 kg, respectively. Thus, the minimum system radiator + converter (reactor and shield not included) specific mass is ∼ 16 kg/kWe for a converter radiator, system radiator and environment temperature of 1373 K, 425 K and 200 K, respectively. Under this operating condition, the reactor thermal rating is ∼ 1110 kWt. Due to the large radiator area, the added complexity and mission risk needs to be weighed against reducing the reactor thermal rating to determine the feasibility of using TPV for space nuclear (fission) power systems

Space Station Freedom - Accommodation for technology R&D

Science.gov (United States)

Holt, Alan C.

1989-01-01

The paper examines the features of the accommodation equipment designed for the candidate technology payloads of the Space Station, which include magnetic plasma thruster systems and a hypothetical advanced electromagnetic propulsion system utilizing high-temperature superconductivity materials. The review of the accommodation-equipment concepts supports the assumption that some propulsion technologies can be tested on the Space Station while being attached externally to the station's truss structure. For testing technologies with inherent operation or performance hazards, space platforms and smaller free-flyers coordinated with the Space Station can be used. Diagrams illustrating typical accommodation equipment configurations are included.

Characterization of associate spaces of generalized weighted weak-Lorentz spaces and embeddings

Czech Academy of Sciences Publication Activity Database

Gogatishvili, Amiran; Aykol, C.; Guliyev, V.S.

2015-01-01

Roč. 228, č. 3 (2015), s. 223-233 ISSN 0039-3223 R&D Projects: GA ČR GA13-14743S Institutional support: RVO:67985840 Keywords : generalized weighted weak-Lorentz spaces * reverse Hardy inequalities * associate spaces * embeddings Subject RIV: BA - General Mathematics Impact factor: 0.623, year: 2015 http://journals.impan.gov.pl/sm/Inf/228-3-2.html

EXPOSE-R2: The Astrobiological ESA Mission on Board of the International Space Station

Directory of Open Access Journals (Sweden)

Elke Rabbow

2017-08-01

Full Text Available On July 23, 2014, the Progress cargo spacecraft 56P was launched from Baikonur to the International Space Station (ISS, carrying EXPOSE-R2, the third ESA (European Space Agency EXPOSE facility, the second EXPOSE on the outside platform of the Russian Zvezda module, with four international astrobiological experiments into space. More than 600 biological samples of archaea, bacteria (as biofilms and in planktonic form, lichens, fungi, plant seeds, triops eggs, mosses and 150 samples of organic compounds were exposed to the harsh space environment and to parameters similar to those on the Mars surface. Radiation dosimeters distributed over the whole facility complemented the scientific payload. Three extravehicular activities later the chemical samples were returned to Earth on March 2, 2016, with Soyuz 44S, having spent 588 days in space. The biological samples arrived back later, on June 18, 2016, with 45S, after a total duration in space of 531 days. The exposure of the samples to Low Earth Orbit vacuum lasted for 531 days and was divided in two parts: protected against solar irradiation during the first 62 days, followed by exposure to solar radiation during the subsequent 469 days. In parallel to the space mission, a Mission Ground Reference (MGR experiment with a flight identical Hardware and a complete flight identical set of samples was performed at the premises of DLR (German Aerospace Center in Cologne by MUSC (Microgravity User Support Center, according to the mission data either downloaded from the ISS (temperature data, facility status, inner pressure status or provided by RedShift Design and Engineering BVBA, Belgium (calculated ultra violet radiation fluence data. In this paper, the EXPOSE-R2 facility, the experimental samples, mission parameters, environmental parameters, and the overall mission and MGR sequences are described, building the background for the research papers of the individual experiments, their analysis and results.

Reflected kinetics model for nuclear space reactor kinetics and control scoping calculations

Energy Technology Data Exchange (ETDEWEB)

Washington, K.E.

1986-05-01

The objective of this research is to develop a model that offers an alternative to the point kinetics (PK) modelling approach in the analysis of space reactor kinetics and control studies. Modelling effort will focus on the explicit treatment of control drums as reactivity input devices so that the transition to automatic control can be smoothly done. The proposed model is developed for the specific integration of automatic control and the solution of the servo mechanism problem. The integration of the kinetics model with an automatic controller will provide a useful tool for performing space reactor scoping studies for different designs and configurations. Such a tool should prove to be invaluable in the design phase of a space nuclear system from the point of view of kinetics and control limitations.

Reflected kinetics model for nuclear space reactor kinetics and control scoping calculations

International Nuclear Information System (INIS)

Washington, K.E.

1986-05-01

The objective of this research is to develop a model that offers an alternative to the point kinetics (PK) modelling approach in the analysis of space reactor kinetics and control studies. Modelling effort will focus on the explicit treatment of control drums as reactivity input devices so that the transition to automatic control can be smoothly done. The proposed model is developed for the specific integration of automatic control and the solution of the servo mechanism problem. The integration of the kinetics model with an automatic controller will provide a useful tool for performing space reactor scoping studies for different designs and configurations. Such a tool should prove to be invaluable in the design phase of a space nuclear system from the point of view of kinetics and control limitations

Multidimensional Space-Time Methodology for Development of Planetary and Space Sciences, S-T Data Management and S-T Computational Tomography

Science.gov (United States)

Andonov, Zdravko

This R&D represent innovative multidimensional 6D-N(6n)D Space-Time (S-T) Methodology, 6D-6nD Coordinate Systems, 6D Equations, new 6D strategy and technology for development of Planetary Space Sciences, S-T Data Management and S-T Computational To-mography. . . The Methodology is actual for brain new RS Microwaves' Satellites and Compu-tational Tomography Systems development, aimed to defense sustainable Earth, Moon, & Sun System evolution. Especially, extremely important are innovations for monitoring and protec-tion of strategic threelateral system H-OH-H2O Hydrogen, Hydroxyl and Water), correspond-ing to RS VHRS (Very High Resolution Systems) of 1.420-1.657-22.089GHz microwaves. . . One of the Greatest Paradox and Challenge of World Science is the "transformation" of J. L. Lagrange 4D Space-Time (S-T) System to H. Minkovski 4D S-T System (O-X,Y,Z,icT) for Einstein's "Theory of Relativity". As a global result: -In contemporary Advanced Space Sciences there is not real adequate 4D-6D Space-Time Coordinate System and 6D Advanced Cosmos Strategy & Methodology for Multidimensional and Multitemporal Space-Time Data Management and Tomography. . . That's one of the top actual S-T Problems. Simple and optimal nD S-T Methodology discovery is extremely important for all Universities' Space Sci-ences' Education Programs, for advances in space research and especially -for all young Space Scientists R&D!... The top ten 21-Century Challenges ahead of Planetary and Space Sciences, Space Data Management and Computational Space Tomography, important for successfully de-velopment of Young Scientist Generations, are following: 1. R&D of W. R. Hamilton General Idea for transformation all Space Sciences to Time Sciences, beginning with 6D Eukonal for 6D anisotropic mediums & velocities. Development of IERS Earth & Space Systems (VLBI; LLR; GPS; SLR; DORIS Etc.) for Planetary-Space Data Management & Computational Planetary & Space Tomography. 2. R&D of S. W. Hawking Paradigm for 2D

Optimality of embeddings of Bessel-potential-type spaces into generalized Hölder spaces

Czech Academy of Sciences Publication Activity Database

Gogatishvili, Amiran; Neves, J. S.; Opic, Bohumír

2005-01-01

Roč. 49, č. 2 (2005), s. 297-327 ISSN 0214-1493 R&D Projects: GA ČR(CZ) GA201/01/0333 Institutional research plan: CEZ:AV0Z10190503 Keywords : slowly varying functions * Lorentz-Karamata spaces * (fractional) Sobolev-type spaces Subject RIV: BA - General Mathematics Impact factor: 0.659, year: 2005

Space reactors - past, present, and future

International Nuclear Information System (INIS)

Buden, D.; Angelo, J.A.

1983-01-01

The successful test flights of the Space Shuttle mark the start of a new era--an era of routine manned access into cislunar space. Human technical development at the start of the next Millenium will be highlighted by the creation of Man's extraterrestrial civilization with off-planet expansion of the human resource base. In the 1990s and beyond, advanced-design nuclear reactors could represent the prime source of both space power and propulsion. Many sophisticated military and civilian space missions of the future will require first kilowatt and then megawatt levels of power. This paper reviews key technology developments that accompanied past US space nuclear power development efforts, describes on-going programs, and then explores reactor technologies that will satisfy megawatt power level needs and beyond

Proposed advanced satellite applications utilizing space nuclear power systems

International Nuclear Information System (INIS)

Bailey, P.G.; Isenberg, L.

1990-01-01

A review of the status of space nuclear reactor systems and their possible applications is presented. Such systems have been developed over the past twenty years and are capable of use in various military and civilian applications in the 5-1000 kWe power range. The capabilities and limitations of the currently proposed nuclear reactor systems are summarized. Safety issues are shown to be identified, and if properly addressed should not pose a hindrance. Applications are summarized for the federal and civilian community. These applications include both low and high altitude satellite surveillance missions, communications satellites, planetary probes, low and high power lunar and planetary base power systems, broad-band global telecommunications, air traffic control, and high-definition television

CVD refractory metals and alloys for space nuclear power application

International Nuclear Information System (INIS)

Yang, L.; Gulden, T.D.; Watson, J.F.

1984-01-01

CVD technology has made significant contributions to the development of space nuclear power systems during the period 1962 to 1972. For the in-core thermionic concept, CVD technology is essential to the fabrication of the tungsten electron emitter. For the liquid metal cooled fuel pin using uranium nitride as fuel and T-111 and Nb-1 Zr as cladding, a tungsten barrier possibly produced by CVD methods is essential to the fuel-cladding compatibility at the designed operating temperature. Space power reactors may use heat pipes to transfer heat from the reactor core to the conversion system. CVD technology has been used for fabricating the heat pipe used as cross-flow heat exchanger, including the built-in channels on the condenser wall for liquid lithium return. 28 references, 17 figures

Space Ethics and Protection of the Space Environment

Science.gov (United States)

Williamson, Mark

2002-01-01

The construction of the International Space Station in low Earth orbit and the formulation of plans to search for life on Mars - one day by means of manned missions - indicate that mankind is intent on making the space environment part of its domain. Publicity surrounding space tourism, in-space `burials' and the sale of lunar `real estate' suggests that, some time in the 21st century, the space environment will become an extraterrestrial extension of our current business and domestic environment. This prompts the question of our collective attitude towards the space environment and the degree to which we should regulate its use and protect it for future generations. What, indeed, are the ethical considerations of space exploration and development? Ethics can be defined as "the philosophical study of the moral value of human conduct, and of the rules or principles that ought to govern it". More practically, it represents "an approved code of behaviour" adopted, for example, by a group or profession. If a set of ethics is to be developed for space, it is important that what we refer to as the `space community', or `space profession', is intimately involved. Indeed, if it is not, the profession risks having the job done for it, for example by politicians and members of the general public, who for their own reasons may wish to place restrictions on space development, or ban it altogether. The terrestrial nuclear power industry, for example, has already suffered this fate, while widespread ignorance of the subject has led to a moratorium on the use of RTGs in spacecraft. However, there is a danger in the discussion of ethics that consideration is confined to the philosophical aspects, thus excusing those involved from providing practical solutions to the problems that emerge. The fact that mankind has already affected, and arguably damaged, the space environment transports the discussion beyond the philosophical realm. This paper offers a pragmatic analysis of one

Thermionic reactors for space nuclear power

Science.gov (United States)

Homeyer, W. G.; Merrill, M. H.; Holland, J. W.; Fisher, C. R.; Allen, D. T.

1985-01-01

Thermionic reactor designs for a variety of space power applications spanning the range from 5 kWe to 3 MWe are described. In all of these reactors, nuclear heat is converted directly to electrical energy in thermionic fuel elements (TFEs). A circulating reactor coolant carries heat from the core of TFEs directly to a heat rejection radiator system. The recent design of a thermionic reactor to meet the SP-100 requirements is emphasized. Design studies of reactors at other power levels show that the same TFE can be used over a broad range in power, and that design modifications can extend the range to many megawatts. The design of the SP-100 TFE is similar to that of TFEs operated successfully in test reactors, but with design improvements to extend the operating lifetime to seven years.

The metric approximation property and Lipschitz-free spaces over subsets of R-N

Czech Academy of Sciences Publication Activity Database

Pernecká, Eva; Smith, R.J.

2015-01-01

Roč. 199, November (2015), s. 29-44 ISSN 0021-9045 R&D Projects: GA ČR(CZ) GAP201/11/0345 Institutional support: RVO:67985840 Keywords : Lipschitz-free space * approximation property Subject RIV: BA - General Mathematics Impact factor: 0.921, year: 2015 http://www.sciencedirect.com/science/article/pii/S0021904515000970

Preliminary neutronic design of spock reactor: A nuclear system for space power generation

International Nuclear Information System (INIS)

Burgio, N.; Santagata, A.; Cumo, M.; Fasano, A.; Frullini, M.

2007-01-01

Aim of this paper is to preliminary investigates the neutronic features of an upgrade of the MAUS [1] nuclear reactor whose core will be able to supply a thermoelectric converter in order to generate 30 kW of electricity for space applications. The neutronic layout of SPOCK (Space Power Core Ka) is a compact, MOX fuelled, liquid metal cooled and totally reflected fast reactor with a control system based on neutron absorption. Spock, that during the heart and launch operation must be maintained in sub-critical state, has to start up in the outer space at 40 K temperatures with the coolant in a solid state and it will reach the operating steady condition at the maximum temperature of 1300 K with the coolant in the liquid state. The main design goal is to maintains, in the operating conditions of a typical space mission, the control of the appropriate criticality margin versus temperature and coolant physical state. For this purpose, a neutronic/thermal-hydraulic calculation chain able to assists the entire design process must be set up. As preliminary recognition, MCNPX 2.5.0 and FLUENT calculations were carried out. The emerging key features of SPOCK are: an equilateral triangular mesh of 91 cylindrical UO 2 fuel rods with a Molybdenum clad ensured by two grids of the same material, cooled by liquid Sodium and contained in an AISI 316 L vessel. The core is totally wrapped by a Beryllium reflector that hosts six absorber (B 4 C) rotating control rods. The reactor shape is cylindrical (radius = 30 cm and height = 60 cm) with a total mass of 275 kg. The excess reactivity was of 5000 PCM at 1300 K. A preliminary evaluation of the control rods worth and a power spatial distribution were also discussed. Through the definition of an ideal reference K e ff value at 300 K for the actual SPOCK configuration, a sensitivity analysis on various cross sections data and material physical properties was performed for the given mission temperature range, allowing consideration on

Availability of niobium and tantalum-base alloy products for space nuclear reactors

International Nuclear Information System (INIS)

Kumar, P.K.; Huber, L.H.

1986-01-01

In order to provide orbiting electrical power generators for use in Space, current US efforts are focusing on fast neutron flux nuclear power systems; these systems would generate in excess of 100 kW, yet be compact enough to be economically carried into Space by NASA's Space Shuttle. Considerable data on physical, mechanical and corrosion properties are available for the Nb and Ta-base alloys that are prime candidates for such structural components. However, most of these data pertain to the metallurgical state of the art of the 1965-1975 time period; therefore, they have to be reviewed and updated as appropriate to reflect present processing and manufacturing technology. This article summarizes this state of the art, making reasonable projections as well for ongoing improvements and their probable impact on alloy properties achievable in the 1990's

A constructive presentation of rigged Hilbert spaces

International Nuclear Information System (INIS)

Celeghini, Enrico

2015-01-01

We construct a rigged Hilbert space for the square integrable functions on the line L2(R) adding to the generators of the Weyl-Heisenberg algebra a new discrete operator, related to the degree of the Hermite polynomials. All together, continuous and discrete operators, constitute the generators of the projective algebra io(2). L 2 (R) and the vector space of the line R are shown to be isomorphic representations of such an algebra and, as both these representations are irreducible, all operators defined on the rigged Hilbert spaces L 2 (R) or R are shown to belong to the universal enveloping algebra of io(2). The procedure can be extended to orthogonal and pseudo-orthogonal spaces of arbitrary dimension by tensorialization.Circumventing all formal problems the paper proposes a kind of toy model, well defined from a mathematical point of view, of rigged Hilbert spaces where, in contrast with the Hilbert spaces, operators with different cardinality are allowed. (paper)

Y spaces and global smooth solution of fractional Navier-Stokes equations with initial value in the critical oscillation spaces

Science.gov (United States)

Yang, Qixiang; Yang, Haibo

2018-04-01

For fractional Navier-Stokes equations and critical initial spaces X, one used to establish the well-posedness in the solution space which is contained in C (R+ , X). In this paper, for heat flow, we apply parameter Meyer wavelets to introduce Y spaces Y m , β where Y m , β is not contained in C (R+, B˙∞ 1 - 2 β , ∞). Consequently, for 1/2 global well-posedness of fractional Navier-Stokes equations with small initial data in all the critical oscillation spaces. The critical oscillation spaces may be any Besov-Morrey spaces (B˙p,q γ1 ,γ2 (Rn)) n or any Triebel-Lizorkin-Morrey spaces (F˙p,q γ1 ,γ2 (Rn)) n where 1 ≤ p , q ≤ ∞ , 0 ≤γ2 ≤ n/p, γ1 -γ2 = 1 - 2 β. These critical spaces include many known spaces. For example, Besov spaces, Sobolev spaces, Bloch spaces, Q-spaces, Morrey spaces and Triebel-Lizorkin spaces etc.

A nuclear waste deposit in space - the ultimate solution for low-cost and safe disposal

International Nuclear Information System (INIS)

Ruppe, H.O.; Hayn, D.; Braitinger, M.; Schmucker, R.H.

1980-01-01

The disposal of nuclear high-active waste (HAW) is representative for the problem of burdening the environment with highly active or toxic waste products at present and in the future. Safe disposal methods on Earth are technically very difficult to achieve and the costs of establishment and maintenance of such plants are extremely high. Furthermore the emotionally based rejection by a wide sector of the population gives sufficient reason to look for new solutions. Here, space technology can offer a real alternative - a waste deposit in space. With the Space Transportation System, which shall soon be operative, and the resulting high flight frequencies it will be possible to transport all future HAW into space at economical casts. (orig.) [de

Spacing grid intended for nuclear reactor fuel assemblies

International Nuclear Information System (INIS)

Patterson, J.F.; Flora, B.S.

1977-01-01

This invention concerns a new improved type of spacing grid that can be used in nuclear reactor fuel assemblies. Under the invention a spacing grid is provided, preferably of the bimetallic type. This grid includes a set of flexible inconel strips positioned by structural 'zircalloy' fittings, having relatively low neutron absorption characteristics in comparison with systems where the flexible strips are welded in position, or where the spring forms an integral part of the structure. The openings for the fuel elements which are defined by the structural fittings intercrossing are fitted internally with bosses which work in conjunction with a spring directed downwards as from the flexible strip so as to position the individual fuel rods in their respective openings inside the grid structure. These flexible strips are arranged in rows extending in directions which depend on the particular design of the fuel asembly and which contain flexible components so distributed that the loads of the individual springs tend to equalize each other mutually. The reaction load exerting itself on the supporting structure is reduced to the minimum, and this results in a lesser distortion in the reactor and an equalisation of the spring loads [fr

A generalization of the spaces lp

International Nuclear Information System (INIS)

Lubuma, M.S.

1989-05-01

The classical spaces l p =l p (N,R) are generalized into topological vector spaces l 0 (I,Y) by replacing N and R by a non empty set I and a topological vector space Y respectively. Various topological and order structures are considered by showing that l p (I,Y) satisfies a given property if Y does so. For normed spaces, a characterization of the reflexivity and of the dual of l p (I,Y) is given. (author). 10 refs

Linearized Navier-Stokes equations in R3: an approach in weighted Sobolev spaces

Czech Academy of Sciences Publication Activity Database

Amrouche, Ch.; Meslameni, M.; Nečasová, Šárka

2014-01-01

Roč. 7, č. 5 (2014), s. 901-916 ISSN 1937-1632 R&D Projects: GA ČR(CZ) GAP201/11/1304 Institutional support: RVO:67985840 Keywords : generalized Oseen equations * weighted Sobolev spaces * generalized solutions Subject RIV: BA - General Mathematics Impact factor: 0.567, year: 2014 http://www.aimsciences.org/journals/displayArticlesnew.jsp?paperID=9871

New generation of reactors for space power

International Nuclear Information System (INIS)

Boudreau, J.E.; Buden, D.

1982-01-01

Space nuclear reactor power is expected to enable many new space missions that will require several times to several orders of magnitude anything flown in space to date. Power in the 100-kW range may be required in high earth orbit spacecraft and planetary exploration. The technology for this power system range is under development for the Department of Energy with the Los Alamos National Laboratory responsible for the critical components in the nuclear subsystem. The baseline design for this particular nuclear sybsystem technology is described in this paper; additionally, reactor technology is reviewed from previous space power programs, a preliminary assessment is made of technology candidates covering an extended power spectrum, and the status is given of other reactor technologies

The Impact Analysis of Direct Public R&D and Innovation Investments in Turkish Space Sector

Science.gov (United States)

Kaya, Derya; Cakir, Serhat

2016-07-01

According to The Organisation for Economic Co-operation and Development (OECD), space sector plays a pivotal role in the functioning of modern societies and their economic development. It is in the scope of OECD's International Futures Programme. The global space economy, as defined by the OECD Space Forum, comprises the space industry's core activities in space manufacturing and in satellite operations, plus other consumer activities that have been derived over the years from governmental research and development. In 2013 commercial revenues generated by the space economy amounted to USD 256.2 billion globally that is huge amount of space investment in the world. Recently, Turkey has also entered to the sector and it has growing strategic interest in space. First satellite project was started with a technology transfer from UK by TUBITAK Space Technologies Research Institute in 2001 and it launched to its orbit in 2003. Then RASAT and GÖKTÜRK-2 satellites were developed and launched to their orbits respectively in 2011 and 2012. Today, we have other satellite projects that are going on, too. However, we do not have a mechanism or a model to assess the impacts of those projects. What kind of model can be used to measure the impact of direct public R&D and innovation investments in Turkish space sector? The aim of this study is to develop a model which would be useful for monitoring the performance of R&D and Innovation investments that are conducted through government policies and strategies and so on to give feedback for effective strategy making. When we look at the impact analysis studies in Turkey, we see a few such as TUBITAK (Özçelik and Taymaz, 2008; Erden, 2010; Tandoǧan, 2011), İşkur (World Bank Report, 2013), Ministry of Economy (TTGV, 2013), Development Agencies (İZKA, 2011; Elçi vd., 2011; Pınar, 2014; Meydan, 2014). There is need for a systematic approach to impact analysis. Since there is no data for this study, we would develop a model with

Status of SPACE Safety Analysis Code Development

International Nuclear Information System (INIS)

Lee, Dong Hyuk; Yang, Chang Keun; Kim, Se Yun; Ha, Sang Jun

2009-01-01

In 2006, the Korean the Korean nuclear industry started developing a thermal-hydraulic analysis code for safety analysis of PWR(Pressurized Water Reactor). The new code is named as SPACE(Safety and Performance Analysis Code for Nuclear Power Plant). The SPACE code can solve two-fluid, three-field governing equations in one dimensional or three dimensional geometry. The SPACE code has many component models required for modeling a PWR, such as reactor coolant pump, safety injection tank, etc. The programming language used in the new code is C++, for new generation of engineers who are more comfortable with C/C++ than old FORTRAN language. This paper describes general characteristics of SPACE code and current status of SPACE code development

Parovičenko spaces with structures

Czech Academy of Sciences Publication Activity Database

Kubiś, Wieslaw; Kucharski, A.; Turek, S.

2014-01-01

Roč. 108, č. 2 (2014), s. 989-1004 ISSN 1578-7303 R&D Projects: GA ČR(CZ) GAP201/12/0290 Institutional support: RVO:67985840 Keywords : structured compact space * normally supercompact space * median space Subject RIV: BA - General Mathematics Impact factor: 0.776, year: 2014 http://link.springer.com/article/10.1007%2Fs13398-013-0156-0

Performance Criteria of Nuclear Space Propulsion Systems

Science.gov (United States)

Shepherd, L. R.

Future exploration of the solar system on a major scale will require propulsion systems capable of performance far greater than is achievable with the present generation of rocket engines using chemical propellants. Viable missions going deeper into interstellar space will be even more demanding. Propulsion systems based on nuclear energy sources, fission or (eventually) fusion offer the best prospect for meeting the requirements. The most obvious gain coming from the application of nuclear reactions is the possibility, at least in principle, of obtaining specific impulses a thousandfold greater than can be achieved in chemically energised rockets. However, practical considerations preclude the possibility of exploiting the full potential of nuclear energy sources in any engines conceivable in terms of presently known technology. Achievable propulsive power is a particularly limiting factor, since this determines the acceleration that may be obtained. Conventional chemical rocket engines have specific propulsive powers (power per unit engine mass) in the order of gigawatts per tonne. One cannot envisage the possibility of approaching such a level of performance by orders of magnitude in presently conceivable nuclear propulsive systems. The time taken, under power, to reach a given terminal velocity is proportional to the square of the engine's exhaust velocity and the inverse of its specific power. An assessment of various nuclear propulsion concepts suggests that, even with the most optimistic assumptions, it could take many hundreds of years to attain the velocities necessary to reach the nearest stars. Exploration within a range of the order of a thousand AU, however, would appear to offer viable prospects, even with the low levels of specific power of presently conceivable nuclear engines.

Nuclear power supplies: their potential and the practical problems to their achievement for space missions

International Nuclear Information System (INIS)

Colston, B.W.; Brehm, R.L.

1985-01-01

The anticipated growth of the space station power requirement provides a good example of the problem the space nuclear power supply developers have to contend with: should a reactor power supply be developed that attempts to be all things to all missions, i.e., is highly flexible in its ability to meet a wide variety of missions, or should the development of a reactor system await a specific mission definition and be customized to this mission. This leads, of course, to a chicken-and-egg situation. For power requirements of several hundreds of kilowatts or more, no nuclear power source exists or is even far enough along in the definition stage (much less the development stage) for NASA to reasonably assume probable availability within the next 10 years. The real problem of space nuclear power is this ''chicken-and-egg'' syndrome: DOE will not develop a space reactor system for NASA without a firm mission, and NASA will not specify a firm mission requiring a space reactor because such a system doesn't exist and is perceived not to be developable within the time frame of the mission. The problem is how to break this cycle. The SP-100 program has taken an important first step to breaking this cycle, but this program is much more design-specific than what is required to achieve a broad technology base and latitude in achievable power level. In contrast to the SP-100 approach, a wider perspective is required: the development of the appropriate technologies for power levels can be broken into ranges, say, from 100 kWe to 1000 kWe, and from 1000 kWe to 10,000 kWe

Current questions concerning Space Law

International Nuclear Information System (INIS)

Courteix, Simone.

1978-01-01

This report covers in part the legal problems connected with the use of nuclear sources in space. These problems were highlighted by the accidental fall of the Soviet statellite Cosmos-954 in Canadian territory in January 1978. The author describes the status of international law on the subject, the work in the United Nations and discusses the measures to be taken to define a code of practice use of nuclear sources in space. (NEA) [fr

Assessing and Adapting Scientific Results for Space Weather Research to Operations (R2O)

Science.gov (United States)

Thompson, B. J.; Friedl, L.; Halford, A. J.; Mays, M. L.; Pulkkinen, A. A.; Singer, H. J.; Stehr, J. W.

2017-12-01

Why doesn't a solid scientific paper necessarily result in a tangible improvement in space weather capability? A well-known challenge in space weather forecasting is investing effort to turn the results of basic scientific research into operational knowledge. This process is commonly known as "Research to Operations," abbreviated R2O. There are several aspects of this process: 1) How relevant is the scientific result to a particular space weather process? 2) If fully utilized, how much will that result improve the reliability of the forecast for the associated process? 3) How much effort will this transition require? Is it already in a relatively usable form, or will it require a great deal of adaptation? 4) How much burden will be placed on forecasters? Is it "plug-and-play" or will it require effort to operate? 5) How can robust space weather forecasting identify challenges for new research? This presentation will cover several approaches that have potential utility in assessing scientific results for use in space weather research. The demonstration of utility is the first step, relating to the establishment of metrics to ensure that there will be a clear benefit to the end user. The presentation will then move to means of determining cost vs. benefit, (where cost involves the full effort required to transition the science to forecasting, and benefit concerns the improvement of forecast reliability), and conclude with a discussion of the role of end users and forecasters in driving further innovation via "O2R."

Topological properties of function spaces $C_k(X,2)$ over zero-dimensional metric spaces $X$

OpenAIRE

Gabriyelyan, S.

2015-01-01

Let $X$ be a zero-dimensional metric space and $X'$ its derived set. We prove the following assertions: (1) the space $C_k(X,2)$ is an Ascoli space iff $C_k(X,2)$ is $k_\\mathbb{R}$-space iff either $X$ is locally compact or $X$ is not locally compact but $X'$ is compact, (2) $C_k(X,2)$ is a $k$-space iff either $X$ is a topological sum of a Polish locally compact space and a discrete space or $X$ is not locally compact but $X'$ is compact, (3) $C_k(X,2)$ is a sequential space iff $X$ is a Pol...

Space space space

CERN Document Server

Trembach, Vera

2014-01-01

Space is an introduction to the mysteries of the Universe. Included are Task Cards for independent learning, Journal Word Cards for creative writing, and Hands-On Activities for reinforcing skills in Math and Language Arts. Space is a perfect introduction to further research of the Solar System.

On convergence of nuclear and correlation operators in Hilbert space

International Nuclear Information System (INIS)

Kubrusly, C.S.

1985-01-01

The convergence of sequences of nuclear operators on a separable Hilbert space is studied. Emphasis is given to trace-norm convergence, which is a basic property in stochastic systems theory. Obviously trace-norm convergence implies uniform convergence. The central theme of the paper focus the opposite way, by investigating when convergence in a weaker topology turns out to imply convergence in a stronger topology. The analysis carried out here is exhaustive in the following sense. All possible implications within a selected set of asymptotic properties for sequences of nuclear operators are established. The special case of correlation operators is also considered in detail. (Author) [pt

Lessons Learned for Space Safety from the Fukushima Nuclear Power Plant Accident

Science.gov (United States)

Nogami, Manami; Miki, Masami; Mitsui, Masami; Kawada, Ysuhiro; Takeuchi, Nobuo

2013-09-01

On March 11 2011, Tohoku Region Pacific Coast Earthquake hit Japan and caused the devastating damage. The Fukushima Nuclear Power Station (NPS) was also severely damaged.The Japanese NPSs are designed based on the detailed safety requirements and have multiple-folds of hazard controls to the catastrophic hazards as in space system. However, according to the initial information from the Tokyo Electric Power Company (TEPCO) and the Japanese government, the larger-than-expected tsunami and subsequent events lost the all hazard controls to the release of radioactive materials.At the 5th IAASS, Lessons Learned from this disaster was reported [1] mainly based on the "Report of the Japanese Government to the IAEA Ministerial Conference on Nuclear Safety" [2] published by Nuclear Emergency Response Headquarters in June 2011, three months after the earthquake.Up to 2012 summer, the major investigation boards, including the Japanese Diet, the Japanese Cabinet and TEPCO, published their final reports, in which detailed causes of this accident and several recommendations are assessed from each perspective.In this paper, the authors examine to introduce the lessons learned to be applied to the space safety as findings from these reports.

Nuclear power in space. Use of reactors and radioactive substances as power sources in satellites and space probes; Kaernkraft i rymden. Anvaendningen av reaktorer och radioaktiva aemnen som kraftkaellor i satelliter och rymdsonder

Energy Technology Data Exchange (ETDEWEB)

Hoestbaeck, Lars

2008-11-15

Today solar panels are the most common technique to supply power to satellites. Solar panels will work as long as the power demand of the satellite is limited and the satellite can be equipped with enough panels, and kept in an orbit that allows enough sunlight to hit the panels. There are various types of space missions that do not fulfil these criteria. With nuclear power these types of missions can be powered regardless of the sunlight and as early as 1961 the first satellite with a nuclear power source was placed in orbit. Out of seventy known space missions that has made use of nuclear power, ten have had some kind of failure. In no case has the failure been associated with the nuclear technology used. This report discusses to what degree satellites with nuclear power are a source for potential radioactive contamination of Swedish territory. It is not a discussion for or against nuclear power in space. Neither is it an assessment of consequences if radioactive material from a satellite would reach the earth's surface. Historically two different kinds of Nuclear Power Sources (NPS) have been used to generate electric power in space. The first is the reactor where the energy is derived from nuclear fission of 235U and the second is the Radioisotope Thermoelectric Generator (RTG) where electricity is generated from the heat of naturally decaying radionuclides. NPS has historically only been used in space by United States and the Soviet Union (and in one failing operation Russia). Nuclear Power Sources have been used in three types of space objects: satellites, space probes and moon/Mars vehicles. USA has launched one experimental reactor into orbit, all other use of NPS by the USA has been RTG:s. The Soviet Union, in contrast, only launched a few RTG:s but nearly forty reactors. The Soviet use of NPS is less transparent than the use in USA and some data published on Soviet systems are more or less well substantiated assessments. It is likely that also future

Gaseous-fuel nuclear reactor research for multimegawatt power in space

Science.gov (United States)

Thom, K.; Schneider, R. T.; Helmick, H. H.

1977-01-01

In the gaseous-fuel reactor concept, the fissile material is contained in a moderator-reflector cavity and exists in the form of a flowing gas or plasma separated from the cavity walls by means of fluid mechanical forces. Temperatures in excess of structural limitations are possible for low-specific-mass power and high-specific-impulse propulsion in space. Experiments have been conducted with a canister filled with enriched UF6 inserted into a beryllium-reflected cavity. A theoretically predicted critical mass of 6 kg was measured. The UF6 was also circulated through this cavity, demonstrating stable reactor operation with the fuel in motion. Because the flowing gaseous fuel can be continuously processed, the radioactive waste in this type of reactor can be kept small. Another potential of fissioning gases is the possibility of converting the kinetic energy of fission fragments directly into coherent electromagnetic radiation, the nuclear pumping of lasers. Numerous nuclear laser experiments indicate the possibility of transmitting power in space directly from fission energy. The estimated specific mass of a multimegawatt gaseous-fuel reactor power system is from 1 to 5 kg/kW while the companion laser-power receiver station would be much lower in specific mass.

A design study of reactor core optimization for direct nuclear heat-to-electricity conversion in a space power reactor

Energy Technology Data Exchange (ETDEWEB)

Yoshikawa, Hidekazu; Takahashi, Makoto; Shimoda, Hiroshi; Takeoka, Satoshi [Kyoto Univ. (Japan); Nakagawa, Masayuki; Kugo, Teruhiko

1998-01-01

To propose a new design concept of a nuclear reactor used in the space, research has been conducted on the conceptual design of a new nuclear reactor on the basis of the following three main concepts: (1) Thermionic generation by thermionic fuel elements (TFE), (2) reactivity control by rotary reflector, and (3) reactor cooling by liquid metal. The outcomes of the research are: (1) A calculation algorithm was derived for obtaining convergent conditions by repeating nuclear characteristic calculation and thermal flow characteristic calculation for the space nuclear reactor. (2) Use of this algorithm and the parametric study established that a space nuclear reactor using 97% enriched uranium nitride as the fuel and lithium as the coolant and having a core with a radius of about 25 cm, a height of about 50 cm and a generation efficiency of about 7% can probably be operated continuously for at least more than ten years at 100 kW only by reactivity control by rotary reflector. (3) A new CAD/CAE system was developed to assist design work to optimize the core characteristics of the space nuclear reactor comprehensively. It is composed of the integrated design support system VINDS using virtual reality and the distributed system WINDS to collaboratively support design work using Internet. (N.H.)

Power conversion for a microreactor: a nuclear space application

International Nuclear Information System (INIS)

Guimaraes, Lamartine N.F.; Camillo, Giannino P.; Nascimento, Jamil A.; Borges, Eduardo M.; Placco, Guilherme M.

2009-01-01

Generating nuclear power in space is of fundamental importance if it is desired to realize some aggressive type of exploration. Basically, at Earth orbit (either LEO or GEO) most applications tend to use solar panels, which are just fine, in spite of problems such as vibration, non optimal light incidence angle and non electricity generation due to Earth's shadow. For deep space exploration the nuclear power is been considered as a strong candidate and maybe the only one. The Institute for Advanced Studies is conducting the TERRA project that tracks the developments in the area and, also, intends to develop the key technologies that will allow such a machine to be build with indigenous technology. TERRA stands for TEcnologia de Reatores Rapidos Avancados. This project, at its first stage aims at the specification of the microreactor fuel element with its possible geometrical arrangements. Also for this stage a gas Brayton closed cycle is being considered as a heat conversion to electricity and/or propulsion effect. The basic idea is to adapt an open loop aeronautic gas turbine to operate as a closed loop gas Turbine. This arrangement will use heat pipes as a cold source, or a heat rejection passive system. Up to this point a lot has been done in terms of numerical and graphical development. It is expected that some built up will be happening during this year. An account of this work will be presented at the conference. (author)

Quasi-equilibria in reduced Liouville spaces.

Science.gov (United States)

Halse, Meghan E; Dumez, Jean-Nicolas; Emsley, Lyndon

2012-06-14

The quasi-equilibrium behaviour of isolated nuclear spin systems in full and reduced Liouville spaces is discussed. We focus in particular on the reduced Liouville spaces used in the low-order correlations in Liouville space (LCL) simulation method, a restricted-spin-space approach to efficiently modelling the dynamics of large networks of strongly coupled spins. General numerical methods for the calculation of quasi-equilibrium expectation values of observables in Liouville space are presented. In particular, we treat the cases of a time-independent Hamiltonian, a time-periodic Hamiltonian (with and without stroboscopic sampling) and powder averaging. These quasi-equilibrium calculation methods are applied to the example case of spin diffusion in solid-state nuclear magnetic resonance. We show that there are marked differences between the quasi-equilibrium behaviour of spin systems in the full and reduced spaces. These differences are particularly interesting in the time-periodic-Hamiltonian case, where simulations carried out in the reduced space demonstrate ergodic behaviour even for small spins systems (as few as five homonuclei). The implications of this ergodic property on the success of the LCL method in modelling the dynamics of spin diffusion in magic-angle spinning experiments of powders is discussed.

Ultrahigh temperature vapor core reactor-MHD system for space nuclear electric power

Science.gov (United States)

Maya, Isaac; Anghaie, Samim; Diaz, Nils J.; Dugan, Edward T.

1991-01-01

The conceptual design of a nuclear space power system based on the ultrahigh temperature vapor core reactor with MHD energy conversion is presented. This UF4 fueled gas core cavity reactor operates at 4000 K maximum core temperature and 40 atm. Materials experiments, conducted with UF4 up to 2200 K, demonstrate acceptable compatibility with tungsten-molybdenum-, and carbon-based materials. The supporting nuclear, heat transfer, fluid flow and MHD analysis, and fissioning plasma physics experiments are also discussed.

Hyperon interaction in free space and nuclear matter

Energy Technology Data Exchange (ETDEWEB)

Dhar, Madhumita [Justus-Liebig University Giessen (Germany); Lenske, Horst [Justus-Liebig University Giessen (Germany); GSI, Darmstadt (Germany)

2016-07-01

A new approach to the SU(3) flavour symmetric meson-exchange model is introduced to describe free space baryon-baryon interaction. The Bethe-Salpeter equations are solved in a 3-D reduction scheme. The coupling of the various channels of total strangeness S and conserved total charge Q is studied in detail. Special attention is paid to the physical thresholds. The derived vacuum interaction has then been used to derive nuclear medium effect by employing the Pauli projector operator in 3-D reduced Bethe-Salpeter equation. The in-medium properties of the interaction are clearly seen in the variation of the in-medium low-energy parameters as a function of density.

Technical aspects of the Space Telescope Imaging Spectrograph Repair (STIS-R)

Science.gov (United States)

Rinehart, S. A.; Domber, J.; Faulkner, T.; Gull, T.; Kimble, R.; Klappenberger, M.; Leckrone, D.; Niedner, M.; Proffitt, C.; Smith, H.; Woodgate, B.

2008-07-01

In August 2004, the Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) ceased operation due to a failure of the 5V mechanism power converter in the Side 2 Low Voltage Power Supply (LVPS2). The failure precluded movement of any STIS mechanism and, because of the earlier (2001) loss of the Side 1 electronics chain, left the instrument shuttered and in safe mode after 7.5 years of science operations. A team was assembled to analyze the fault and to determine if STIS repair (STIS-R) was feasible. The team conclusively pinpointed the Side 2 failure to the 5V mechanism converter, and began studying EVA techniques for opening STIS during Servicing Mission 4 (SM4) to replace the failed LVPS2 board. The restoration of STIS functionality via surgical repair by astronauts has by now reached a mature and final design state, and will, along with a similar repair procedure for the Advanced Camera for Surveys (ACS), represent a first for Hubble servicing. STIS-R will restore full scientific functionality of the spectrograph on Side 2, while Side 1 will remain inoperative. Because of the high degree of complementarity between STIS and the new Cosmic Origins Spectrograph (COS, to be installed during SM4)), successful repair of the older spectrograph is an important scientific objective. In this presentation, we focus on the technical aspects associated with STIS-R.

The Austrian Space Plan

Science.gov (United States)

Pseiner, K.; Balogh, W.

2002-01-01

After several years of preparation and discussion among the involved players, the Austrian Space Plan was approved for implementation in November 2001. Based on careful benchmarking and analysis of the capabilities of the Austrian space sector it aims to create excellent conditions for the sector's further development. The new space strategy embraces Austria's participation in the mandatory and optional programmes of the European Space Agency and establishes a National Space Programme supported by separate funding opportunities. A set of clearly-defined indicators ensures that the progress in implementing the Space Plan can be objectively judged through independent, annual reviews. The National Space Programme promotes international cooperation in space research and space activities with the aim to strengthen the role of space science and to better prepare Austrian space industry for the commercial space market. In the framework of the Space Plan the Austrian Space Agency has been tasked with integrating the industry's growing involvement in aeronautics activities to better utilize synergies with the space sector. This paper reviews the various steps leading to the approval of the new space strategy and discusses the hurdles mastered in this process. It reports on the Space Plan's first results, specifically taking into account projects involving international cooperation. For the first the Austria aerospace-sector can rely on an integrated strategy for aeronautics- and space activities which is firmly rooted in the efforts to enhance the country's R&D activities. It may also act as a useful example for other small space- using countries planning to enhance their involvement in space activities.

Space development and space science together, an historic opportunity

Science.gov (United States)

Metzger, P. T.

2016-11-01

The national space programs have an historic opportunity to help solve the global-scale economic and environmental problems of Earth while becoming more effective at science through the use of space resources. Space programs will be more cost-effective when they work to establish a supply chain in space, mining and manufacturing then replicating the assets of the supply chain so it grows to larger capacity. This has become achievable because of advances in robotics and artificial intelligence. It is roughly estimated that developing a lunar outpost that relies upon and also develops the supply chain will cost about 1/3 or less of the existing annual budgets of the national space programs. It will require a sustained commitment of several decades to complete, during which time science and exploration become increasingly effective. At the end, this space industry will capable of addressing global-scale challenges including limited resources, clean energy, economic development, and preservation of the environment. Other potential solutions, including nuclear fusion and terrestrial renewable energy sources, do not address the root problem of our limited globe and there are real questions whether they will be inadequate or too late. While industry in space likewise cannot provide perfect assurance, it is uniquely able to solve the root problem, and it gives us an important chance that we should grasp. What makes this such an historic opportunity is that the space-based solution is obtainable as a side-benefit of doing space science and exploration within their existing budgets. Thinking pragmatically, it may take some time for policymakers to agree that setting up a complete supply chain is an achievable goal, so this paper describes a strategy of incremental progress. The most crucial part of this strategy is establishing a water economy by mining on the Moon and asteroids to manufacture rocket propellant. Technologies that support a water economy will play an

Systems integration processes for space nuclear electric propulsion systems

International Nuclear Information System (INIS)

Olsen, C.S.; Rice, J.W.; Stanley, M.L.

1991-01-01

The various components and subsystems that comprise a nuclear electric propulsion system should be developed and integrated so that each functions ideally and so that each is properly integrated with the other components and subsystems in the optimum way. This paper discusses how processes similar to those used in the development and intergration of the subsystems that comprise the Multimegawatt Space Nuclear Power System concepts can be and are being efficiently and effectively utilized for these purposes. The processes discussed include the development of functional and operational requirements at the system and subsystem level; the assessment of individual nuclear power supply and thruster concepts and their associated technologies; the conduct of systems integration efforts including the evaluation of the mission benefits for each system; the identification and resolution of concepts development, technology development, and systems integration feasibility issues; subsystem, system, and technology development and integration; and ground and flight subsystem and integrated system testing

Atomic Power in Space: A History

Science.gov (United States)

1987-03-01

"Atomic Power in Space," a history of the Space Isotope Power Program of the United States, covers the period from the program's inception in the mid-1950s through 1982. Written in non-technical language, the history is addressed to both the general public and those more specialized in nuclear and space technologies. Interplanetary space exploration successes and achievements have been made possible by this technology, for which there is no known substitue.

Responsive Space Program Brief

Energy Technology Data Exchange (ETDEWEB)

Dors, Eric E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2014-03-11

The goal of the Responsive Space program is to make significant, integrated science and technology contributions to the end-to-end missions of the U.S. Government that protect against global emerging and nuclear threats, from the earliest adversary planning through resilient event response report describes the LANL space program, mission, and other activities. The report describes some of their activities.

Atomic power in space: A history

International Nuclear Information System (INIS)

1987-03-01

''Atomic Power in Space,'' a history of the Space Isotope Power Program of the United States, covers the period from the program's inception in the mid-1950s through 1982. Written in non-technical language, the history is addressed to both the general public and those more specialized in nuclear and space technologies. 19 figs., 3 tabs

Multimegawatt space nuclear power open-cycle MHD-facility

International Nuclear Information System (INIS)

Pavshuk, V.A.; Panchenko, V.P.

2008-01-01

Paper presents the results of the efforts to calculate the characteristics, the layout and the engineering design of the open cycle space power propulsion on the basis of the high-temperature nuclear reactor for a nuclear rocket engine and the Faraday 20 MW capacity MHD-generator. The IVG-1 heterogeneous channel-vessel reactor ensuring in the course of the experiments hydrogen heating up to 3100 K, up to 5 MPa pressure at the reactor core outlet, up to 5 kg/s flowsheet, up to 220 MW thermal power served as a reactor is considered. One determined the MHD-generator basic parameters, namely: the portion of Cs dope was equal to 20%, the outlet stagnation pressure - 2 MPa, the electric conductivity - ≅30 S/m, the Mach number - ≅0.7, the magnetic field induction - 6 T, the capacity - 20 MW, the specific power removal - ∼4 MJ/kg. Paper describes the design of the MHD-facility with the working fluid momentless discharge and its basic characteristics [ru

Non-Compact and Sharp Embeddings of Logarithmic Bessel Potential Spaces into Hölder-Type Spaces

Czech Academy of Sciences Publication Activity Database

Edmunds, D. E.; Gurka, P.; Opic, Bohumír

2006-01-01

Roč. 25, č. 1 (2006), s. 73-80 ISSN 0232-2064 R&D Projects: GA ČR(CZ) GA201/01/0333 Institutional research plan: CEZ:AV0Z10190503 Keywords : generalized Lorentz-Zygmund spaces * logarithmic Bessel potential spaces * Hölder-continuous functions Subject RIV: BA - General Mathematics Impact factor: 0.360, year: 2006

Space grating optical structure of the retina and RGB-color vision.

Science.gov (United States)

Lauinger, Norbert

2017-02-01

Diffraction of light at the spatial cellular phase grating outer nuclear layer of the retina could produce Fresnel near-field interferences in three RGB diffraction orders accessible to photoreceptors (cones/rods). At perpendicular light incidence the wavelengths of the RGB diffraction orders in photopic vision-a fundamental R-wave with two G+B-harmonics-correspond to the peak wavelengths of the spectral brightness sensitivity curves of the cones at 559 nmR, 537 nmG, and 447 nmB. In scotopic vision the R+G diffraction orders optically fuse at 512 nm, the peak value of the rod's spectral brightness sensitivity curve. The diffractive-optical transmission system with sender (resonator), space waves, and receiver antennae converts the spectral light components involved in imaging into RGB space. The colors seen at objects are diffractive-optical products in the eye, as the German philosopher A. Schopenhauer predicted. They are second related to the overall illumination in object space. The RGB transmission system is the missing link optically managing the spectral tuning of the RGB photopigments.

Multimegawatt Space Reactor Safety

International Nuclear Information System (INIS)

Stanley, M.L.

1989-01-01

The Multimegawatt (MMW) Space Reactor Project supports the Strategic Defense Initiative Office requirement to provide reliable, safe, cost-effective, electrical power in the MMW range. Specifically, power may be used for neutral particle beams, free electron lasers, electromagnetic launchers, and orbital transfer vehicles. This power plant technology may also apply to the electrical power required for other uses such as deep-space probes and planetary exploration. The Multimegawatt Space Reactor Project, the Thermionic Fuel Element Verification Program, and Centaurus Program all support the Multimegawatt Space Nuclear Power Program and form an important part of the US Department of Energy's (DOE's) space and defense power systems activities. A major objective of the MMW project is the development of a reference flight system design that provides the desired levels of public safety, health protection, and special nuclear material (SNM) protection when used during its designated missions. The safety requirements for the MMW project are a hierarchy of requirements that consist of safety requirements/regulations, a safety policy, general safety criteria, safety technical specifications, safety design specifications, and the system design. This paper describes the strategy and philosophy behind the development of the safety requirements imposed upon the MMW concept developers. The safety organization, safety policy, generic safety issues, general safety criteria, and the safety technical specifications are discussed

Direct Estimation of Power Distribution in Reactors for Nuclear Thermal Space Propulsion

Science.gov (United States)

Aldemir, Tunc; Miller, Don W.; Burghelea, Andrei

2004-02-01

A recently proposed constant temperature power sensor (CTPS) has the capability to directly measure the local power deposition rate in nuclear reactor cores proposed for space thermal propulsion. Such a capability reduces the uncertainties in the estimated power peaking factors and hence increases the reliability of the nuclear engine. The CTPS operation is sensitive to the changes in the local thermal conditions. A procedure is described for the automatic on-line calibration of the sensor through estimation of changes in thermal .conditions.

Space-Based Counterforce in the Second Nuclear Age

Science.gov (United States)

2015-04-01

but also open wide the gates of the solar system to large-scale human exploration and development. Instead of offering only a dark age of...by the Scaled Composites SpaceShipOne vehicle that won the Ansari X-PRIZE in 2004 or Virgin Galactic’s space tourism vehicle SpaceShipTwo. It was

Wigner-Kirkwood expansion of the phase-space density for half infinite nuclear matter

International Nuclear Information System (INIS)

Durand, M.; Schuck, P.

1987-01-01

The phase space distribution of half infinite nuclear matter is expanded in a ℎ-series analogous to the low temperature expansion of the Fermi function. Besides the usual Wigner-Kirkwood expansion, oscillatory terms are derived. In the case of a Woods-Saxon potential, a smallness parameter is defined, which determines the convergence of the series and explains the very rapid convergence of the Wigner-Kirkwood expansion for average (nuclear) binding energies

System modeling for the advanced thermionic initiative single cell thermionic space nuclear reactor

International Nuclear Information System (INIS)

Lee, H.H.; Lewis, B.R.; Klein, A.C.; Pawlowski, R.A.

1993-01-01

Incore thermionic space reactor design concepts which operate in a nominal power output range of 20 to 40 kWe are described. Details of the neutronics, thermionic, shielding, and heat rejection performance are presented. Two different designs, ATI-Driven and ATI-Driverless, are considered. Comparison of the core overall performance of these two configurations are described. The comparison of these two cores includes the overall conversion efficiency, reactor mass, shield mass, and heat rejection mass. An overall system design has been developed to model the advanced incore thermionic energy conversion based nuclear reactor systems for space applications in this power range

Atomic power in space: A history

Energy Technology Data Exchange (ETDEWEB)

1987-03-01

''Atomic Power in Space,'' a history of the Space Isotope Power Program of the United States, covers the period from the program's inception in the mid-1950s through 1982. Written in non-technical language, the history is addressed to both the general public and those more specialized in nuclear and space technologies. 19 figs., 3 tabs.

Overview of the U. S. flight safety process for space nuclear power

International Nuclear Information System (INIS)

Bennett, G.L.

1981-01-01

The two current types of nuclear power sources used in U. S. spacecraft are described along with the flight safety philosophies governing their use. In the case of radioisotope thermoelectric generators, the design philosophy consists of containment, immobilization, and recovery of the nuclear materials. For reactors, the emphasis is on maintaining a subcritical configuration in all credible accident environments. To document the safety activities, a safety analysis report is prepared for each mission. These reports, which are based on the probabilistic risk assessment methodology pioneered by the space nuclear safety community, are subjected to an interagency safety review before a recommendation is made to approve the launch of a nuclear-powered spacecraft

The Ascoli property for function spaces and the weak topology of Banach and Fréchet spaces

Czech Academy of Sciences Publication Activity Database

Gabriyelyan, S.; Kąkol, Jerzy; Plebanek, G.

2016-01-01

Roč. 233, č. 2 (2016), s. 119-139 ISSN 0039-3223 R&D Projects: GA ČR GF16-34860L Institutional support: RVO:67985840 Keywords : locally convex-space Subject RIV: BA - General Mathematics Impact factor: 0.535, year: 2016 https://www.impan.pl/pl/wydawnictwa/czasopisma-i-serie-wydawnicze/studia-mathematica/all/233/2/91577/the-ascoli-property-for-function-spaces- and -the-weak-topology-of-banach- and -frechet-spaces

Some thoughts on the commercial use of reactors in space

International Nuclear Information System (INIS)

Buden, D.; Lee, J.

1986-01-01

The purpose of this paper is to illuminate the major regulatory issues associated with commercialization of space nuclear power. Currently, space reactors are government-owned and approved through the Interagency Nuclear Safety Review Panel (INSRP) and the President while commercial reactors are licensed by the Nuclear Regulatory Commission. The commercial use of reactors in space will open a new regime of regulation; that is public intervenors could enter the space licensing process for the first time. The major issue is responsibility for licensing and operations, but related considerations involve controlling special nuclear materials from aborted launches or abandoned platforms, determining final shutdown and disposal tactics, and solving new design issues such as the need for longer life of space reactor power plants

Space-time of class one

International Nuclear Information System (INIS)

Villasenor, R.F.; Bonilla, J.L.L.; Zuniga, G.O.; Matos, T.

1989-01-01

The authors study space-times embedded in E 5 (that means, pseudo-euclidean five-dimensional spaces) in the intrinsic rigidity case, i.e., when the second fundamental form b if can be determined by the internal geometry of the four-dimensional Riemannian space R 4 . They write down the Gauss and Codazzi equations determining the local isometric embedding of R 4 in E 5 and give some consequences of it. They prove that when there exists intrinsic rigidity, then b if is a linear combination of the metric and Ricci tensor; it is given some applications for the de Sitter and Einstein models

A closed Brayton power conversion unit concept for nuclear electric propulsion for deep space missions

International Nuclear Information System (INIS)

Joyner, Claude Russell II; Fowler, Bruce; Matthews, John

2003-01-01

In space, whether in a stable satellite orbit around a planetary body or traveling as a deep space exploration craft, power is just as important as the propulsion. The need for power is especially important for in-space vehicles that use Electric Propulsion. Using nuclear power with electric propulsion has the potential to provide increased payload fractions and reduced mission times to the outer planets. One of the critical engineering and design aspects of nuclear electric propulsion at required mission optimized power levels is the mechanism that is used to convert the thermal energy of the reactor to electrical power. The use of closed Brayton cycles has been studied over the past 30 or years and shown to be the optimum approach for power requirements that range from ten to hundreds of kilowatts of power. It also has been found to be scalable to higher power levels. The Closed Brayton Cycle (CBC) engine power conversion unit (PCU) is the most flexible for a wide range of power conversion needs and uses state-of-the-art, demonstrated engineering approaches. It also is in use with many commercial power plants today. The long life requirements and need for uninterrupted operation for nuclear electric propulsion demands high reliability from a CBC engine. A CBC engine design for use with a Nuclear Electric Propulsion (NEP) system has been defined based on Pratt and Whitney's data from designing long-life turbo-machines such as the Space Shuttle turbopumps and military gas turbines and the use of proven integrated control/health management systems (EHMS). An integrated CBC and EHMS design that is focused on using low-risk and proven technologies will over come many of the life-related design issues. This paper will discuss the use of a CBC engine as the power conversion unit coupled to a gas-cooled nuclear reactor and the design trends relative to its use for powering electric thrusters in the 25 kWe to 100kWe power level

Systems aspects of a space nuclear reactor power system

International Nuclear Information System (INIS)

Jaffe, L.; Fujita, T.; Beatty, R.

1988-01-01

Selected systems aspects of a 300 kW nuclear reactor power system for spacecraft have been studied. The approach included examination of two candidate missions and their associated spacecraft, and a number of special topics dealing with the power system design and operation. The missions considered were a reusable orbital transfer vehicle and a space-based radar. The special topics included: Power system configuration and scaling, launch vehicle integration, operating altitude, orbital storage, start-up, thawing, control, load following, procedures in case of malfunction, restart, thermal and nuclear radiation to other portions of the spacecraft, thermal stresses between subsystems, boom and cable designs, vibration modes, attitude control, reliability, and survivability. Among the findings are that the stowed length of the power system is important to mission design and that orbital storage for months to years may be needed for missions involving orbital assembly

Anthropogenic Space Weather

Science.gov (United States)

Gombosi, T. I.; Baker, D. N.; Balogh, A.; Erickson, P. J.; Huba, J. D.; Lanzerotti, L. J.

2017-11-01

Anthropogenic effects on the space environment started in the late 19th century and reached their peak in the 1960s when high-altitude nuclear explosions were carried out by the USA and the Soviet Union. These explosions created artificial radiation belts near Earth that resulted in major damages to several satellites. Another, unexpected impact of the high-altitude nuclear tests was the electromagnetic pulse (EMP) that can have devastating effects over a large geographic area (as large as the continental United States). Other anthropogenic impacts on the space environment include chemical release experiments, high-frequency wave heating of the ionosphere and the interaction of VLF waves with the radiation belts. This paper reviews the fundamental physical process behind these phenomena and discusses the observations of their impacts.

Space reactor safety, 1985--1995 lessons learned

International Nuclear Information System (INIS)

Marshall, A.C.

1995-01-01

Space reactor safety activities and decisions have evolved over the last decade. Important safety decisions have been made in the SP-100, Space Exploration Initiative, NEPSTP, SNTP, and Bimodal Space Reactor programs. In addition, international guidance on space reactor safety has been instituted. Space reactor safety decisions and practices have developed in the areas of inadvertent criticality, reentry, radiological release, orbital operation, programmatic, and policy. In general, the lessons learned point out the importance of carefully reviewing previous safety practices for appropriateness to space nuclear programs in general and to the specific mission under consideration

Space reactor safety, 1985--1995 lessons learned

Energy Technology Data Exchange (ETDEWEB)

Marshall, A.C.

1995-12-31

Space reactor safety activities and decisions have evolved over the last decade. Important safety decisions have been made in the SP-100, Space Exploration Initiative, NEPSTP, SNTP, and Bimodal Space Reactor programs. In addition, international guidance on space reactor safety has been instituted. Space reactor safety decisions and practices have developed in the areas of inadvertent criticality, reentry, radiological release, orbital operation, programmatic, and policy. In general, the lessons learned point out the importance of carefully reviewing previous safety practices for appropriateness to space nuclear programs in general and to the specific mission under consideration.

Overview of some projects of SNPS for global space communication

International Nuclear Information System (INIS)

Ivanov, E.; Ghitaykin, V.; Ionkin, V.; Dubinin, A.; Pyshko, A.

2001-01-01

In this presentation we focused on three variants of prospective concepts of SNPS. They are intended to solve tasks of global space communication (GSC) as nearest future tasks in space. Modern concepts of the application of power technology in space believe in using an onboard source of energy for maintenance of self-transportation of the vehicle into geostationary orbit (GSO). There are three more prospective systems as follows: gas cooled nuclear reactor with hybrid thermal engine and machine power converter; nuclear reactor cooled by liquid metal and with a thermoelectric power generating system; nuclear reactor with Li cooling and a thermionic and thermoelectric power generator on board. The choice of a concept must fit strong requirements such as: space nuclear power unit is aimed to be used in a powerful mission; space power unit must be able to maintain the dual - mode regime of vehicle operation (self - transportation and long life in geosynchronous orbit [GEO]); nuclear rector of unit must be safety and it must be designed in such a way that it will ensure minimum size of the complete system; the elements of the considered technology can be used for the creation of NPPI and with other sources of heat (for example, radioisotope); the degree of technical and technological readiness of units of the thermal and power circuit of installation is estimated to be high and is defined by a number of technological developments in air, space and nuclear branches; nuclear reactor and heat transfer equipment should work in a normal mode, which can be very reliably confirmed for other high-temperature nuclear systems. Considering these concepts we practically consider one of possible strategy of developing of complex system of nuclear power engineering. It is the strategy of step-by-step development of space engineering with real application of them in commercial, scientific and other powerful missions in the nearest and deep space. As starting point of this activity is

Innovative nuclear thermal rocket concept utilizing LEU fuel for space application

International Nuclear Information System (INIS)

Nam, Seung Hyun; Venneri, Paolo; Choi, Jae Young; Jeong, Yong Hoon; Chang, Soon Heung

2015-01-01

Space is one of the best places for humanity to turn to keep learning and exploiting. A Nuclear Thermal Rocket (NTR) is a viable and more efficient option for human space exploration than the existing Chemical Rockets (CRs) which are highly inefficient for long-term manned missions such as to Mars and its satellites. NERVA derived NTR engines have been studied for the human missions as a mainstream in the United States of America (USA). Actually, the NERVA technology has already been developed and successfully tested since 1950s. The state-of-the-art technology is based on a Hydrogen gas (H_2) cooled high temperature reactor with solid core utilizing High-Enriched Uranium (HEU) fuel to reduce heavy metal mass and to use fast or epithermal neutron spectrums enabling simple core designs. However, even though the NTR designs utilizing HEU is the best option in terms of rocket performance, they inevitably provoke nuclear proliferation obstacles on all Research and Development (R and D) activities by civilians and non-nuclear weapon states, and its eventual commercialization. To surmount the security issue to use HEU fuel for a NTR, a concept of the innovative NTR engine, Korea Advanced NUclear Thermal Engine Rocket utilizing Low-Enriched Uranium fuel (KANUTER-LEU) is presented in this paper. The design goal of KANUTER-LEU is to make use of a LEU fuel for its compact reactor, but does not sacrifice the rocket performance relative to the traditional NTRs utilizing HEU. KANUTER-LEU mainly consists of a fission reactor utilizing H_2 propellant, a propulsion system and an optional Electricity Generation System as a bimodal engine. To implement LEU fuel for the reactor, the innovative engine adopts W-UO_2 CERMET fuel to drastically increase uranium density and thermal neutron spectrum to improve neutron economy in the core. The moderator and structural material selections also consider neutronic and thermo-physical characteristics to reduce non-fission neutron loss and

Weaponisation of Space - Some Legal Considerations

Science.gov (United States)

Jolly, C.

2002-01-01

, negation of adversarial use of space and a fully-capable National Missile Defense (NMD). [American] ICBMs will continue to provide a credible strategic deterrence, while advanced, conventional weapons operating in or through space will provide our National Command Authorities (NCA) with formidable and flexible options for prompt, global, conventional strike." As we will see in this paper, the current international legal framework restricting the stationing and use of weapons in space is composed mainly of three treaties. They are: the Treaty between the United States of America and the Union of Soviet Socialist Republics on the Limitation of Anti-Ballistic Missile Systems (1972), called commonly the `ABM treaty', the `Outer Space Treaty' (1967) and the Treaty Banning Nuclear Weapon Tests in the Atmosphere, in Outer Space and Under Water (1963). We will also see that - contrary to public opinion - those current legal instruments, even coupled with other international legal texts, do not prohibit the `weaponisation' of space. For instance, The Article Four of the Outer Space Treaty is often cited as the main legal argument against militarisation of space. This article does indeed prohibit the installation or stationing of "any objects carrying nuclear weapons or any other kinds of weapons of mass destruction", "in orbit around the Earth", "on celestial bodies", "in outer space" and "in any other manner". But, aside from the weapons identified (nuclear weapons and weapons of mass destruction), nothing prohibits a government signatory to the Outer Space Treaty, to actually station other types of weapons in space, such as laser-based systems. In this paper, the current situation of potential `weaponisation' of space, the international impacts of such a policy and the gaps of the international legal framework concerning the militarisation of space, will prompt some comments and practical recommendations.

Nuclear safety policy working group recommendations on nuclear propulsion safety for the space exploration initiative

Science.gov (United States)

Marshall, Albert C.; Lee, James H.; Mcculloch, William H.; Sawyer, J. Charles, Jr.; Bari, Robert A.; Cullingford, Hatice S.; Hardy, Alva C.; Niederauer, George F.; Remp, Kerry; Rice, John W.

1993-01-01

An interagency Nuclear Safety Working Group (NSPWG) was chartered to recommend nuclear safety policy, requirements, and guidelines for the Space Exploration Initiative (SEI) nuclear propulsion program. These recommendations, which are contained in this report, should facilitate the implementation of mission planning and conceptual design studies. The NSPWG has recommended a top-level policy to provide the guiding principles for the development and implementation of the SEI nuclear propulsion safety program. In addition, the NSPWG has reviewed safety issues for nuclear propulsion and recommended top-level safety requirements and guidelines to address these issues. These recommendations should be useful for the development of the program's top-level requirements for safety functions (referred to as Safety Functional Requirements). The safety requirements and guidelines address the following topics: reactor start-up, inadvertent criticality, radiological release and exposure, disposal, entry, safeguards, risk/reliability, operational safety, ground testing, and other considerations.

Weighted local Hardy spaces associated with operators

Indian Academy of Sciences (India)

RUMING GONG

2018-04-24

5 days ago ... Studies 116 (1985) (Amsterdam: North Holland). [12] Gong R M and Yan L X, Littlewood–Paley and spectral multipliers on weighted L p spaces, J. Geom. Anal. 24 (2014) 873–900. [13] Gong R M, Li J and Yan L X, A local version of Hardy spaces associated with operators on metric spaces, Sci. China Math.

Analysis of nuclear waste disposal in space, phase 3. Volume 2: Technical report

Science.gov (United States)

Rice, E. E.; Miller, N. E.; Yates, K. R.; Martin, W. E.; Friedlander, A. L.

1980-01-01

The options, reference definitions and/or requirements currently envisioned for the total nuclear waste disposal in space mission are summarized. The waste form evaluation and selection process is documented along with the physical characteristics of the iron nickel-base cermet matrix chosen for disposal of commercial and defense wastes. Safety aspects of radioisotope thermal generators, the general purpose heat source, and the Lewis Research Center concept for space disposal are assessed as well as the on-pad catastrophic accident environments for the uprated space shuttle and the heavy lift launch vehicle. The radionuclides that contribute most to long-term risk of terrestrial disposal were determined and the effects of resuspension of fallout particles from an accidental release of waste material were studied. Health effects are considered. Payload breakup and rescue technology are discussed as well as expected requirements for licensing, supporting research and technology, and safety testing.

Gymnastics in Phase Space

Energy Technology Data Exchange (ETDEWEB)

Chao, Alexander Wu; /SLAC

2012-03-01

As accelerator technology advances, the requirements on accelerator beam quality become increasingly demanding. Facing these new demands, the topic of phase space gymnastics is becoming a new focus of accelerator physics R&D. In a phase space gymnastics, the beam's phase space distribution is manipulated and precision tailored to meet the required beam qualities. On the other hand, all realization of such gymnastics will have to obey accelerator physics principles as well as technological limitations. Recent examples of phase space gymnastics include Emittance exchanges, Phase space exchanges, Emittance partitioning, Seeded FELs and Microbunched beams. The emittance related topics of this list are reviewed in this report. The accelerator physics basis, the optics design principles that provide these phase space manipulations, and the possible applications of these gymnastics, are discussed. This fascinating new field promises to be a powerful tool of the future.

Test Facilities and Experience on Space Nuclear System Developments at the Kurchatov Institute

International Nuclear Information System (INIS)

Ponomarev-Stepnoi, Nikolai N.; Garin, Vladimir P.; Glushkov, Evgeny S.; Kompaniets, George V.; Kukharkin, Nikolai E.; Madeev, Vicktor G.; Papin, Vladimir K.; Polyakov, Dmitry N.; Stepennov, Boris S.; Tchuniyaev, Yevgeny I.; Tikhonov, Lev Ya.; Uksusov, Yevgeny I.

2004-01-01

The complexity of space fission systems and rigidity of requirement on minimization of weight and dimension characteristics along with the wish to decrease expenditures on their development demand implementation of experimental works which results shall be used in designing, safety substantiation, and licensing procedures. Experimental facilities are intended to solve the following tasks: obtainment of benchmark data for computer code validations, substantiation of design solutions when computational efforts are too expensive, quality control in a production process, and 'iron' substantiation of criticality safety design solutions for licensing and public relations. The NARCISS and ISKRA critical facilities and unique ORM facility on shielding investigations at the operating OR nuclear research reactor were created in the Kurchatov Institute to solve the mentioned tasks. The range of activities performed at these facilities within the implementation of the previous Russian nuclear power system programs is briefly described in the paper. This experience shall be analyzed in terms of methodological approach to development of future space nuclear systems (this analysis is beyond this paper). Because of the availability of these facilities for experiments, the brief description of their critical assemblies and characteristics is given in this paper

Radiation protection considerations in space station missions

International Nuclear Information System (INIS)

Peddicord, K.L.; Bolch, W.E.

1991-01-01

The National Aeronautics and Space Administration (NASA) is currently studying the degree to which the baseline design of space station Freedom (SSF) would permit its evolution to a transportation node for lunar or Mars expeditions. To accomplish NASA's more ambitious exploration goals, nuclear-powered vehicles could be used in SSF's vicinity. This enhanced radiation environment around SSF could necessitate additional crew shielding to maintain cumulative doses below recommended limits. This paper presents analysis of radiation doses received upon the return and subsequent unloading of Mars vehicles utilizing either nuclear electric propulsion (NEP) or nuclear thermal rocket (NTR) propulsion systems. No inherent shielding by the vehicle structure or space station is assumed; consequently, the only operational parameters available to control radiation doses are the source-to-target distance and the reactor shutdown time prior to the exposure period. For the operations planning, estimated doses are shown with respect to recommended dose limits and doses due solely to the natural space environment in low Earth orbit

Moderator configuration options for a low-enriched uranium fueled Kilowatt-class Space Nuclear Reactor

International Nuclear Information System (INIS)

King, Jeffrey C.; Mencarini, Leonardo de Holanda; Guimaraes, Lamartine N. F.

2015-01-01

The Brazilian Air Force, through its Institute for Advanced Studies (Instituto de Estudos Avancados, IEAv/DCTA), and the Colorado School of Mines (CSM) are studying the feasibility of a space nuclear reactor with a power of 1-5 kW e and fueled with Low-Enriched Uranium (LEU). This type of nuclear reactor would be attractive to signatory countries of the Non-Proliferation Treaty (NPT) or commercial interests. A LEU-fueled space reactor would avoid the security concerns inherent with Highly Enriched Uranium (HEU) fuel. As an initial step, the HEU-fueled Kilowatt Reactor Using Stirling Technology (KRUSTY) designed by the Los Alamos National Laboratory serves as a basis for a similar reactor fueled with LEU fuel. Using the computational code MCNP6 to predict the reactor neutronics performance, the size of the resulting reactor fueled with 19.75 wt% enriched uranium-10 wt% molybdenum alloy fuel is adjusted to match the excess reactivity of KRUSTY. Then, zirconium hydride moderator is added to the core to reduce the size of the reactor. This work presents the preliminary results of the computational modeling, with special emphasis on the comparison between homogeneous and heterogeneous moderator systems, in terms of the core diameter required to meet a specific multiplication factor (k eff = 1.035). This comparison illustrates the impact of moderator configuration on the size and performance of a LEU-fueled kilowatt-class space nuclear reactor. (author)

Moderator configuration options for a low-enriched uranium fueled Kilowatt-class Space Nuclear Reactor

Energy Technology Data Exchange (ETDEWEB)

King, Jeffrey C., E-mail: kingjc@mines.edu [Nuclear Science and Engineering Program, Colorado School of Mines (CSM), Golden, CO (United States); Mencarini, Leonardo de Holanda; Guimaraes, Lamartine N. F., E-mail: guimaraes@ieav.cta.br, E-mail: mencarini@ieav.cta.br [Instituto de Estudos Avancados (IEAV), Sao Jose dos Campos, SP (Brazil). Divisao de Energia Nuclear

2015-07-01

The Brazilian Air Force, through its Institute for Advanced Studies (Instituto de Estudos Avancados, IEAv/DCTA), and the Colorado School of Mines (CSM) are studying the feasibility of a space nuclear reactor with a power of 1-5 kW{sub e} and fueled with Low-Enriched Uranium (LEU). This type of nuclear reactor would be attractive to signatory countries of the Non-Proliferation Treaty (NPT) or commercial interests. A LEU-fueled space reactor would avoid the security concerns inherent with Highly Enriched Uranium (HEU) fuel. As an initial step, the HEU-fueled Kilowatt Reactor Using Stirling Technology (KRUSTY) designed by the Los Alamos National Laboratory serves as a basis for a similar reactor fueled with LEU fuel. Using the computational code MCNP6 to predict the reactor neutronics performance, the size of the resulting reactor fueled with 19.75 wt% enriched uranium-10 wt% molybdenum alloy fuel is adjusted to match the excess reactivity of KRUSTY. Then, zirconium hydride moderator is added to the core to reduce the size of the reactor. This work presents the preliminary results of the computational modeling, with special emphasis on the comparison between homogeneous and heterogeneous moderator systems, in terms of the core diameter required to meet a specific multiplication factor (k{sub eff} = 1.035). This comparison illustrates the impact of moderator configuration on the size and performance of a LEU-fueled kilowatt-class space nuclear reactor. (author)

Non-nuclear power sources for deep space

Energy Technology Data Exchange (ETDEWEB)

Kennel, E.B.; Tang, C.; Santarius, J.F.

1998-07-01

Electric propulsion and non-nuclear power can be used in tandem as a replacement for the current chemical booster and radioisotope thermoelectric generators now in use for deep space applications (i.e., to the asteroid belt and beyond). In current generation systems, electric propulsion is usually considered to be impractical because of the lack of high power for deep space, and non-nuclear power is thought to be impractical partly due to its high mass. However, when taken in combination, a solar powered electric upper stage can provide ample power and propulsion capability for use in deep space. Radioisotope thermoelectric generator (RTG) systems have generally been selected for missions only when other systems are absolutely unavailable. The disadvantages of radioisotopes include the need for nuclear safety as another dimension of concern in payload integration; the lack of assured availability of plutonium in the post-cold-war world; the enormous cost of plutonium-238; and the system complexity introduced by the need to continuously cool the system during the pre-launch phase. A conservative estimate for the total power for the solar array at beginning of life (BOL) may be in the range of 25 kW in order to provide 500 W continuous power at Jupiter. The availability of {approximately} 25 kW(e) in earth orbit raises the interesting possibility of coupling electric propulsion units to this free electric power. If electric propulsion is used to raise the probe from low-earth-orbit to an earth-escape trajectory, the system could actually save on low-earth orbit mass. Electric propulsion could be used by itself in a spiral trajectory orbit raising maneuver to earth escape velocity, or it could be used in conjunction with a chemical upper stage (either solid rocket or liquid), which would boost the payload to an elliptical orbit. The concept is to begin the Earth-Jupiter trip with a swing-by near the Sun close to the orbit of Venus and perhaps even closer if thermal

Powering the Space Exploration Initiative

International Nuclear Information System (INIS)

Bennett, G.L.

1991-01-01

The Space Exploration Initiative (SEI) establishes the long-term goal of returning to the Moon and then exploring Mars. One of the prerequisites of SEI is the Exploration Technology Program which includes program elements on space nuclear power and surface solar power. These program elements in turn build upon the ongoing NASA research and technology base program in space energy conversion. There is a wide range of missions in NASA's strategic planning and most would benefit from power sources with improved efficiency, lighter weight and reduced cost

Spaces of positive and negative frequency solutions of field equations in curved space--times. I. The Klein--Gordon equation in stationary space--times

International Nuclear Information System (INIS)

Moreno, C.

1977-01-01

In stationary space--times V/sub n/ x R with compact space-section manifold without boundary V/sub n/, the Klein--Gordon equation is solved by the one-parameter group of unitary operators generated by the energy operator i -1 T -1 in the Sobolev spaces H/sup l/(V/sub n/) x H/sup l/(V/sub n/). The canonical symplectic and complex structures of the associated dynamical system are calculated. The existence and the uniqueness of the Lichnerowicz kernel are established. The Hilbert spaces of positive and negative frequency-part solutions defined by means of this kernel are constructed

Miniature Active Space Radiation Dosimeter, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Space Micro will extend our Phase I R&D to develop a family of miniature, active space radiation dosimeters/particle counters, with a focus on biological/manned...

Space-resolved vacuum ultra-violet spectroscopy on T.F.R. Tokamak plasmas

International Nuclear Information System (INIS)

1978-01-01

Results are reported of space-resolved vacuum-ultraviolet spectroscopy (between 100 A and 2000A) on T.F.R. Tokamak plasmas and examples are given of profiles for both heavy and light impurity ions. The experimental method and the associated uncertainties and problems are stressed. The great importance of numerical calculations in the interpretation of the impurity profiles is pointed out. (author)

Challenges for future space power systems

International Nuclear Information System (INIS)

Brandhorst, H.W. Jr.

1989-01-01

Forecasts of space power needs are presented. The needs fall into three broad categories: survival, self-sufficiency, and industrialization. The cost of delivering payloads to orbital locations and from Low Earth Orbit (LEO) to Mars are determined. Future launch cost reductions are predicted. From these projections the performances necessary for future solar and nuclear space power options are identified. The availability of plentiful cost effective electric power and of low cost access to space are identified as crucial factors in the future extension of human presence in space

A primer on Hilbert space theory linear spaces, topological spaces, metric spaces, normed spaces, and topological groups

CERN Document Server

Alabiso, Carlo

2015-01-01

This book is an introduction to the theory of Hilbert space, a fundamental tool for non-relativistic quantum mechanics. Linear, topological, metric, and normed spaces are all addressed in detail, in a rigorous but reader-friendly fashion. The rationale for an introduction to the theory of Hilbert space, rather than a detailed study of Hilbert space theory itself, resides in the very high mathematical difficulty of even the simplest physical case. Within an ordinary graduate course in physics there is insufficient time to cover the theory of Hilbert spaces and operators, as well as distribution theory, with sufficient mathematical rigor. Compromises must be found between full rigor and practical use of the instruments. The book is based on the author's lessons on functional analysis for graduate students in physics. It will equip the reader to approach Hilbert space and, subsequently, rigged Hilbert space, with a more practical attitude. With respect to the original lectures, the mathematical flavor in all sub...

Static and dynamic high power, space nuclear electric generating systems

International Nuclear Information System (INIS)

Wetch, J.R.; Begg, L.L.; Koester, J.K.

1985-01-01

Space nuclear electric generating systems concepts have been assessed for their potential in satisfying future spacecraft high power (several megawatt) requirements. Conceptual designs have been prepared for reactor power systems using the most promising static (thermionic) and the most promising dynamic conversion processes. Component and system layouts, along with system mass and envelope requirements have been made. Key development problems have been identified and the impact of the conversion process selection upon thermal management and upon system and vehicle configuration is addressed. 10 references

Role of the Space Station in Private Development of Space

Science.gov (United States)

Uhran, M. L.

2002-01-01

The International Space Station (ISS) is well underway in the assembly process and progressing toward completion. In February 2001, the United States laboratory "Destiny" was successfully deployed and the course of space utilization, for laboratory-based research and development (R&D) purposes, entered a new era - continuous on-orbit operations. By completion, the ISS complex will include pressurized laboratory elements from Europe, Japan, Russia and the U.S., as well as external platforms which can serve as observatories and technology development test beds serviced by a Canadian robotic manipulator. The international vision for a continuously operating, full service R&D complex in the unique environment of low-Earth orbit is becoming increasingly focused. This R&D complex will offer great opportunities for economic return as the basic research program proceeds on a global scale and the competitive advantages of the microgravity and ultravacuum environments are elucidated through empirical studies. In parallel, the ISS offers a new vantage point, both as a source for viewing of Earth and the Cosmos and as the subject of view for a global population that has grown during the dawning of the space age. In this regard, the ISS is both a working laboratory and a powerful symbol for human achievement in science and technology. Each of these aspects bears consideration as we seek to develop the beneficial attributes of space and pursue innovative approaches to expanding this space complex through private investment. Ultimately, the success of the ISS will be measured by the outcome at the end of its design lifetime. Will this incredible complex be de-orbited in a fiery finale, as have previous space platforms? Will another, perhaps still larger, space station be built through global government funding? Will the ISS ownership be transferred to a global, non-government organization for refurbishment and continuation of the mission on a privately financed basis? Steps taken

Cosmiclike domain walls in superfluid 3He-B: Instantons and diabolical points in (k,r) space

International Nuclear Information System (INIS)

Salomaa, M.M.; Volovik, G.E.

1988-01-01

The possible planar superfluid B-B boundaries between inequivalent B-phase vacua are considered; such B-B interfaces provide an analogy with the cosmic domain walls that are believed to have precipitated in the phase transitions of the early Universe. Several of them display nontrivial structure in (k,r) space (i.e., the union of the momentum and real spaces). Such a wall represents an instanton connecting two B-phase vacua with different k-space topology. The transition between the vacua occurs through the formation of a pointlike defect either in the (k,r) space, or in the (k,t) space. These defects are so-called diabolical points of codimension 4, at which the fermionic energy tends to zero, thus providing the fermionic zero modes. Such points are new examples (within condensed-matter physics) of the peculiar diabolical points, which are characterized by the occurrence of a contact between the different branches of the quasiparticle spectra; in the present case, the branches of particles and holes, respectively. These points are here discussed for the case of the superfluid phases of liquid 3 He in close analogy with the quantum field theory of fermions interacting with classical bosonic fields. The cosmiclike domain walls in superfluid 3 He-B are observable in principle; in particular, the motion of the superfluid A-B interface is governed at low temperatures by the periodical emission of these topological excitation planes

Preliminary Thermo-hydraulic Core Design Analysis of Korea Advanced Nuclear Thermal Engine Rocket for Space Application

Energy Technology Data Exchange (ETDEWEB)

Nam, Seung Hyun; Lee, Jeong Ik; Chang, Soon Heung [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

2014-05-15

Nclear rockets improve the propellant efficiency more than twice compared to CRs and thus significantly reduce the propellant requirement. The superior efficiency of nuclear rockets is due to the combination of the huge energy density and a single low molecular weight propellant utilization. Nuclear Thermal Rockets (NTRs) are particularly suitable for manned missions to Mars because it satisfies a relatively high thrust as well as a high propellant efficiency. NTRs use thermal energy released from a nuclear fission reactor to heat a single low molecular weight propellant, i. e., Hydrogen (H{sub 2}) and then exhausted the extremely heated propellant through a thermodynamic nozzle to produce thrust. A propellant efficiency parameter of rocket engines is specific impulse (I{sub sp}) which represents the ratio of the thrust over the rate of propellant consumption. The difference of I{sub sp} makes over three times propellant savings of NTRs for a manned Mars mission compared to CRs. NTRs can also be configured to operate bimodally by converting the surplus nuclear energy to auxiliary electric power required for the operation of a spacecraft. Moreover, the concept and technology of NTRs are very simple, already proven, and safe. Thus, NTRs can be applied to various space missions such as solar system exploration, International Space Station (ISS) transport support, Near Earth Objects (NEOs) interception, etc. Nuclear propulsion is the most promising and viable option to achieve challenging deep space missions. Particularly, the attractions of a NTR include excellent thrust and propellant efficiency, bimodal capability, proven technology, and safe and reliable performance. The ROK has also begun the research for space nuclear systems as a volunteer of the international space race and a major world nuclear energy country. KANUTER is one of the advanced NTR engines currently under development at KAIST. This bimodal engine is operated in two modes of propulsion with 100 MW

Uncertainties in linear energy transfer spectra measured with track-etched detectors in space

Czech Academy of Sciences Publication Activity Database

Pachnerová Brabcová, Kateřina; Ambrožová, Iva; Kolísková, Zlata; Malušek, Alexandr

2013-01-01

Roč. 713, JUN 11 (2013), s. 5-10 ISSN 0168-9002 R&D Projects: GA ČR GA205/09/0171; GA AV ČR IAA100480902; GA AV ČR KJB100480901; GA ČR GD202/09/H086 Institutional research plan: CEZ:AV0Z10480505 Institutional support: RVO:61389005 Keywords : CR-39 * linear energy transfer * uncertainty model * space dosimetry Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.316, year: 2013

Preliminary risk assessment for nuclear waste disposal in space. Volume I. Executive summary of technical report

International Nuclear Information System (INIS)

Rice, E.E.; Denning, R.S.; Friedlander, A.L.

1982-01-01

Three major conclusions come from this preliminary risk assessment of nuclear waste disposal in space. Preliminary estimates of space disposal risk are low, even with the estimated uncertainty bounds. If calculated mined geologic repository (MGR) release risks remain low, and the EPA requirements continue to be met, then no additional space disposal study effort is warranted. If risks perceived by the public are significant in the acceptance of mined geologic repositories, then consideration of space disposal as an MGR complement is warranted. As a result of this study, the following recommendations are made to NASA and the US DOE: During the continued evaluation of the mined geologic repository risk over the years ahead by DOE, if any significant increase in the calculated health risk is predicted for the MGR, then space disposal should be reevaluated at that time. The risks perceived by the public for the MGR should be evaluated on a broad basis by an independent organization to evaluate acceptance. If, in the future, MGR risks are found to be significant due to some presently unknown technical or social factor, and space disposal is selected as an alternative that may be useful in mitigating the risks, then the following space disposal study activities are recommended: improvement in chemical processing technology for wastes; payload accident response analysis; risk uncertainty analysis for both MGR and space disposal; health risk modeling that includes pathway and dose estimates; space disposal cost modeling; assessment of space disposal perceived (by public) risk benefit; and space systems analysis supporting risk and cost modeling

Advanced materials for space nuclear power systems

International Nuclear Information System (INIS)

Titran, R.H.; Grobstein, T.L.

1991-01-01

Research on monolithic refractory metal alloys and on metal matrix composites is being conducted at the NASA Lewis Research Center, Cleveland, Ohio, in support of advanced space power systems. The overall philosophy of the research is to develop and characterize new high-temperature power conversion and radiator materials and to provide spacecraft designers with material selection options and design information. Research on three candidate materials (carbide strengthened niobium alloy PWC-11 for fuel cladding, graphite fiber reinforced copper matrix composites (Gr/Cu) for heat rejection fins, and tungsten fiber reinforced niobium matrix composites (W/NB) for fuel containment and structural supports) considered for space power system applications is discussed. Each of these types of materials offers unique advantages for space power applications

Nuclear safety considerations in the conceptual design of a fast reactor for space electric power and propulsion

Science.gov (United States)

Hsieh, T.-M.; Koenig, D. R.

1977-01-01

Some nuclear safety aspects of a 3.2 mWt heat pipe cooled fast reactor with out-of-core thermionic converters are discussed. Safety related characteristics of the design including a thin layer of B4C surrounding the core, the use of heat pipes and BeO reflector assembly, the elimination of fuel element bowing, etc., are highlighted. Potential supercriticality hazards and countermeasures are considered. Impacts of some safety guidelines of space transportation system are also briefly discussed, since the currently developing space shuttle would be used as the primary launch vehicle for the nuclear electric propulsion spacecraft.

An interagency space nuclear propulsion safety policy for SEI - Issues and discussion

Science.gov (United States)

Marshall, A. C.; Sawyer, J. C., Jr.

1991-01-01

An interagency Nuclear Safety Policy Working Group (NSPWG) was chartered to recommend nuclear safety policy, requirements, and guidelines for the Space Exploration Initiative nuclear propulsion program to facilitate the implementation of mission planning and conceptual design studies. The NSPWG developed a top level policy to provide the guiding principles for the development and implementation of the nuclear propulsion safety program and the development of Safety Functional Requirements. In addition, the NSPWG reviewed safety issues for nuclear propulsion and recommended top level safety requirements and guidelines to address these issues. Safety topics include reactor start-up, inadvertent criticality, radiological release and exposure, disposal, entry, safeguards, risk/reliability, operational safety, ground testing, and other considerations. In this paper the emphasis is placed on the safety policy and the issues and considerations that are addressed by the NSPWG recommendations.

Why Not Space Tethers?

Science.gov (United States)

Stone, Noble H.

2007-01-01

The Tethered Satellite System Space Shuttle missions, TSS-1 in 1993 and TSS-1R in 1996, were the height of space tether technology development. Since NASA's investment of some $200M and two Shuttle missions in those two pioneering missions, there have been several smaller tether flight experiments, but interest in this promising technology has waned within NASA as well as the DOD agencies. This is curious in view of the unique capabilities of space tether systems and the fact that they have been flight validated and shown to perform as, or better than, expected in earth orbit. While it is true that the TSS-1, TSS-1R and SEDS-2 missions experienced technical difficulties, the causes of these early developmental problems are now known to be design or materials flaws that are (1) unrelated to the basic viability of space tether technology, and (2) they are readily corrected. The purpose of this paper is to review the dynamic and electrodynamic fundamentals of space tethers and the unique capabilities they afford (that are enabling to certain types of space missions); to elucidate the nature, cause, and solution of the early developmental problems; and to provide an update on progress made in development of the technology. Finally, it is shown that (1) all problems experienced during early development of the technology now have solutions; and (2) the technology has been matured by advances made in strength and robustness of tether materials, high voltage engineering in the space environment, tether health and status monitoring, and the elimination of the broken tether hazard. In view of this, it is inexplicable why this flight-validated technology has not been utilized in the past decade, considering the powerful and unique capabilities that space tethers can afford that are, not only required to carryout, otherwise, unobtainable missions, but can also greatly reduce the cost of certain on-going space operations.

Electromagnetic-field equations in the six-dimensional space-time R6

International Nuclear Information System (INIS)

Teli, M.T.; Palaskar, D.

1984-01-01

Maxwell's equations (without monopoles) for electromagnetic fields are obtained in six-dimensional space-time. The equations possess structural symmetry in space and time, field and source densities. Space-time-symmetric conservation laws and field solutions are obtained. The results are successfully correlated with their four-dimensional space-time counterparts

Heat resistant materials and their feasibility issues for a space nuclear transportation system

International Nuclear Information System (INIS)

Olsen, C.S.

1991-01-01

A number of nuclear propulsion concepts based on solid-core nuclear propulsion are being evaluated for a nuclear propulsion transportation system to support the Space Exploration Initiative (SEI) involving the reestablishment of a manned lunar base and the subsequent exploration of Mars. These systems will require high-temperature materials to meet the operating conditions with appropriate reliability and safety built into these systems through the selection and testing of appropriate materials. The application of materials for nuclear thermal propulsion (NTP) and nuclear electric propulsion (NEP) systems and the feasibility issues identified for their use will be discussed. Some mechanical property measurements have been obtained, and compatibility tests were conducted to help identify feasibility issues. 3 refs., 1 fig., 4 tabs

Space nuclear power plant technology development philosophy for a ground engineering phase

International Nuclear Information System (INIS)

Buden, D.; Trapp, T.J.; Los Alamos National Lab., NM)

1985-01-01

The development of a space qualified nuclear power plant is proceeding from the technical assessment and advancement phase to the ground engineering phase. In this new phase, the selected concept will be matured by the completion of activities needed before protoflight units can be assembled and qualified for first flight applications. This paper addresses a possible philosophy to arrive at the activities to be performed during the ground engineering phase. The philosophy is derived from what we believe a potential user of nuclear power would like to see completed before commitment to a flight development phase. 5 references

Space nuclear power plant technology development philosophy for a ground engineering phase

International Nuclear Information System (INIS)

Buden, D.; Trapp, T.J.

1985-01-01

The development of a space qualified nuclear power plant is proceeding from the Technical Assessment and Advancement Phase to the Ground Engineering Phase. In this new phase, the selected concept will be matured by the completion of activities needed before protoflight units can be assembled and qualified for first flight applications. This paper addresses a possible philosophy to arrive at the activities to be performed during the Ground Engineering Phase. The philosophy is derived from what we believe a potential user of nuclear power would like to see completed before commitment to a flight development phase

Mission needs and system commonality for space nuclear power and propulsion

International Nuclear Information System (INIS)

Buden, D.; Zuppero, A.; Redd, L.

1993-01-01

Nuclear power enables or significantly enhances a variety of space missions whether near-Earth, or for solar system exploration, lunar-Mars exploration and recovery of near-Earth resources. Performance optimizations for individual missions leads to a large number of power and propulsion systems to be developed. However, the realities of the budget and schedules indicates that the number of nuclear systems that will be developed are limited. One needs to seek the ''minimum requirements'' to do a job rather than the last ounce of performance, and areas of commonality. To develop a minimum number of systems to meet the overall DoD, NASA, and commercial needs, the broad spectrum of requirements has been examined along with cost drivers

Thermal control of high energy nuclear waste, space option. [mathematical models

Science.gov (United States)

Peoples, J. A.

1979-01-01

Problems related to the temperature and packaging of nuclear waste material for disposal in space are explored. An approach is suggested for solving both problems with emphasis on high energy density waste material. A passive cooling concept is presented which utilized conduction rods that penetrate the inner core. Data are presented to illustrate the effectiveness of the rods and the limit of their capability. A computerized thermal model is discussed and developed for the cooling concept.

Gamow state vectors as functionals over subspaces of the nuclear space

International Nuclear Information System (INIS)

Bohm, A.

1979-12-01

Exponentially decaying Gamow state vectors are obtained from S-matrix poles in the lower half of the second sheet, and are defined as functionals over a subspace of the nuclear space, PHI. Exponentially growing Gamow state vectors are obtained from S-matrix poles in the upper half of the second sheet, and are defined as functionals over another subspace of PHI. On functionals over these two subspaces the dynamical group of time development splits into two semigroups

High-temperature turbopump assembly for space nuclear thermal propulsion

Science.gov (United States)

Overholt, David M.

1993-01-01

The development of a practical, high-performance nuclear rocket by the U.S. Air Force Space Nuclear Thermal Propulsion (SNTP) program places high priority on maximizing specific impulse (ISP) and thrust-to-weight ratio. The operating parameters arising from these goals drive the propellant-pump design. The liquid hydrogen propellant is pressurized and pumped to the reactor inlet by the turbopump assembly (TPA). Rocket propulsion is effected by rapid heating of the propellant from 100 K to thousands of degrees in the particle-bed reactor (PBR). The exhausted propellant is then expanded through a high-temperature nozzle. One approach to achieve high performance is to use an uncooled carbon-carbon nozzle and duct turbine inlet. The high-temperature capability is obtained by using carbon-carbon throughout the TPA hot section. Carbon-carbon components in development include structural parts, turbine nozzles/stators, and turbine rotors. The technology spinoff is applicable to conventional liquid propulsion engines plus a wide variety of other turbomachinery applications.

High-temperature turbopump assembly for space nuclear thermal propulsion

International Nuclear Information System (INIS)

Overholt, D.M.

1993-01-01

The development of a practical, high-performance nuclear rocket by the U.S. Air Force Space Nuclear Thermal Propulsion (SNTP) program places high priority on maximizing specific impulse (ISP) and thrust-to-weight ratio. The operating parameters arising from these goals drive the propellant-pump design. The liquid hydrogen propellant is pressurized and pumped to the reactor inlet by the turbopump assembly (TPA). Rocket propulsion is effected by rapid heating of the propellant from 100 K to thousands of degrees in the particle-bed reactor (PBR). The exhausted propellant is then expanded through a high-temperature nozzle. One approach to achieve high performance is to use an uncooled carbon-carbon nozzle and duct turbine inlet. The high-temperature capability is obtained by using carbon-carbon throughout the TPA hot section. Carbon-carbon components in development include structural parts, turbine nozzles/stators, and turbine rotors. The technology spinoff is applicable to conventional liquid propulsion engines plus a wide variety of other turbomachinery applications

Recipes for stable linear embeddings from Hilbert spaces to R^m

OpenAIRE

Puy, Gilles; Davies, Mike; Gribonval, Rémi

2015-01-01

We consider the problem of constructing a linear map from a Hilbert space $\\mathcal{H}$ (possibly infinite dimensional) to $\\mathbb{R}^m$ that satisfies a restricted isometry property (RIP) on an arbitrary signal model $\\mathcal{S} \\subset \\mathcal{H}$. We present a generic framework that handles a large class of low-dimensional subsets but also unstructured and structured linear maps. We provide a simple recipe to prove that a random linear map satisfies a general RIP on $\\mathcal{S}$ with h...

The space distribution of neutrons generated in massive lead target by relativistic nuclear beam

International Nuclear Information System (INIS)

Chultem, D.; Damdinsuren, Ts.; Enkh-Gin, L.; Lomova, L.; Perelygin, V.; Tolstov, K.

1993-01-01

The present paper is devoted to implementation of solid state nuclear track detectors in the research of the neutron generation in extended lead spallation target. Measured neutrons space distribution inside the lead target and neutron distribution in the thick water moderator are assessed. (Author)

Hyperon interaction in free space and nuclear matter

Energy Technology Data Exchange (ETDEWEB)

Dhar, Madhumita; Lenske, Horst [Institute for Theoretical Physics, Justus- Liebig-University Giessen (Germany)

2015-07-01

Baryon-baryon interactions within the SU(3)-octet are investigated in free space and nuclear matter.A meson exchange model based on SU(3) symmetry is used for determining the interaction. The Bethe-Salpeter equations are solved in a 3-D reduction scheme. In-medium effect has been incorporated by including a two particle Pauli projector operator in the scattering equation. The coupling of the various channels of total strangeness S and conserved total charge is studied in detail. Special attention is paid to the physical thresholds. The density dependence of interaction is clearly seen in the variation of the in-medium low-energy parameters. The approach is compared to descriptions derived from chiral-EFT and other meson-exchange models e.g. the Nijmegen and the Juelich model.

Validation of comprehensive space radiation transport code

International Nuclear Information System (INIS)

Shinn, J.L.; Simonsen, L.C.; Cucinotta, F.A.

1998-01-01

The HZETRN code has been developed over the past decade to evaluate the local radiation fields within sensitive materials on spacecraft in the space environment. Most of the more important nuclear and atomic processes are now modeled and evaluation within a complex spacecraft geometry with differing material components, including transition effects across boundaries of dissimilar materials, are included. The atomic/nuclear database and transport procedures have received limited validation in laboratory testing with high energy ion beams. The codes have been applied in design of the SAGE-III instrument resulting in material changes to control injurious neutron production, in the study of the Space Shuttle single event upsets, and in validation with space measurements (particle telescopes, tissue equivalent proportional counters, CR-39) on Shuttle and Mir. The present paper reviews the code development and presents recent results in laboratory and space flight validation

General-purpose heat source project and space nuclear safety and fuels program. Progress report

International Nuclear Information System (INIS)

Maraman, W.J.

1979-12-01

This formal monthly report covers the studies related to the use of 238 PuO 2 in radioisotopic power systems carried out for the Advanced Nuclear Systems and Projects Division of the Los Alamos Scientific Laboratory. The two programs involved are general-purpose heat source development and space nuclear safety and fuels. Most of the studies discussed hear are of a continuing nature. Results and conclusions described may change as the work continues

Space dosimetry measurement results using the Pille instrument during the EUROMIR/NASAMIR space flights

International Nuclear Information System (INIS)

Hejja, I.; Apathy, J.; Deme, S.

1997-01-01

The Pille dosimeter developed in Hungary for space applications is described briefly, and its two versions are presented for the two space flights. The results of the EUROMIR mission in 1995-1996 are discussed for positional dosimetric applications. The characteristic dose rates at various space stations in the Salyut range are displayed. The NASAMIR4 mission between January 1997 and September 1998 are also discussed from the dosimetric point of view. The results of the measurements are presented and a preliminary analysis is reported. (R.P.)

Equilibrium phase-space distributions and space charge limits in linacs

International Nuclear Information System (INIS)

Lysenko, W.P.

1977-10-01

Limits on beam current and emittance in proton and heavy ion linear accelerators resulting from space charge forces are calculated. The method involves determining equilibrium distributions in phase space using a continuous focusing, no acceleration, model in two degrees of freedom using the coordinates r and z. A nonlinear Poisson equation must be solved numerically. This procedure is a matching between the longitudinal and transverse directions to minimize the effect of longitudinal-transverse coupling which is believed to be the main problem in emittance growth due to space charge in linacs. Limits on the Clinton P. Anderson Meson Physics Facility (LAMPF) accelerator performance are calculated as an example. The beam physics is described by a few space charge parameters so that accelerators with different physical parameters can be compared in a natural way. The main result of this parameter study is that the requirement of a high-intensity beam is best fulfilled with a low-frequency accelerator whereas the requirement of a high-brightness beam is best fulfilled with a high-frequency accelerator

The algebraic approach to space-time geometry

International Nuclear Information System (INIS)

Heller, M.; Multarzynski, P.; Sasin, W.

1989-01-01

A differential manifold can be defined in terms of smooth real functions carried by it. By rejecting the postulate, in such a definition, demanding the local diffeomorphism of a manifold to the Euclidean space, one obtains the so-called differential space concept. Every subset of R n turns out to be a differential space. Extensive parts of differential geometry on differential spaces, developed by Sikorski, are reviewed and adapted to relativistic purposes. Differential space as a new model of space-time is proposed. The Lorentz structure and Einstein's field equations on differential spaces are discussed. 20 refs. (author)

Space nuclear power requirements for ozone layer modification

International Nuclear Information System (INIS)

Dolan, T.J.

1991-01-01

This work estimates the power requirements for using photochemical processes driven by space nuclear power to counteract the Earth's ozone layer depletion. The total quantity of ozone (O 3 ) in the Earth's atmosphere is estimated to be about 4.7 x 10 37 molecules. The ozone production and destruction rates in the stratosphere are both on the order of 4.9 x 10 31 molecules/s, differing by a small fraction so that the net depletion rate is about 0.16 to 0.26% per year. The delivered optical power requirement for offsetting this depletion is estimated to be on the order of 3 GW. If the power were produced by satellite reactors at 800 km altitude (orbit decay time ∼ 300 years), some means of efficient power beaming would be needed to deliver the power to stratospheric levels (10--50 km). Ultraviolet radiation at 140--150 nm could have higher absorption rates in O 2 (leading to production of atomic oxygen, which can combine with O 2 to form O 3 ) than in ozone (leading to photodissociation of O 3 ). Potential radiation sources include H 2 lasers and direct nuclear pumping of ultraviolet fluorescers. 5 refs

Multiparametric quantum symplectic phase space

International Nuclear Information System (INIS)

Parashar, P.; Soni, S.K.

1992-07-01

We formulate a consistent multiparametric differential calculus on the quadratic coordinate algebra of the quantum vector space and use this as a tool to obtain a deformation of the associated symplectic phase space involving n(n-1)/2+1 deformation parameters. A consistent calculus on the relation subspace is also constructed. This is achieved with the help of a restricted ansatz and solving the consistency conditions to directly arrive at the main commutation structures without any reference to the R-matrix. However, the non-standard R-matrices for GL r,qij (n) and Sp r,qij (2n) can be easily read off from the commutation relations involving coordinates and derivatives. (author). 9 refs

Nuclear safety as applied to space power reactor systems

International Nuclear Information System (INIS)

Cummings, G.E.

1987-01-01

To develop a strategy for incorporating and demonstrating safety, it is necessary to enumerate the unique aspects of space power reactor systems from a safety standpoint. These features must be differentiated from terrestrial nuclear power plants so that our experience can be applied properly. Some ideas can then be developed on how safe designs can be achieved so that they are safe and perceived to be safe by the public. These ideas include operating only after achieving a stable orbit, developing an inherently safe design, ''designing'' in safety from the start and managing the system development (design) so that it is perceived safe. These and other ideas are explored further in this paper

Thermohydraulic Design Analysis Modeling for Korea Advanced NUclear Thermal Engine Rocket for Space Application

Energy Technology Data Exchange (ETDEWEB)

Nam, Seung Hyun; Choi, Jae Young; Venneria, Paolo F.; Jeong, Yong Hoon; Chang, Soon Heung [KAIST, Daejeon (Korea, Republic of)

2015-05-15

Space exploration is a realistic and profitable goal for long-term humanity survival, although the harsh space environment imposes lots of severe challenges to space pioneers. To date, almost all space programs have relied upon Chemical Rockets (CRs) rating superior thrust level to transit from the Earth's surface to its orbit. However, CRs inherently have insurmountable barrier to carry out deep space missions beyond Earth's orbit due to its low propellant efficiency, and ensuing enormous propellant requirement and launch costs. Meanwhile, nuclear rockets typically offer at least two times the propellant efficiency of a CR and thus notably reduce the propellant demand. Particularly, a Nuclear Thermal Rocket (NTR) is a leading candidate for near-term manned missions to Mars and beyond because it satisfies a relatively high thrust as well as a high efficiency. The superior efficiency of NTRs is due to both high energy density of nuclear fuel and the low molecular weight propellant of Hydrogen (H{sub 2}) over the chemical reaction by-products. A NTR uses thermal energy released from a nuclear fission reactor to heat the H{sub 2} propellant and then exhausted the highly heated propellant through a propelling nozzle to produce thrust. A propellant efficiency parameter of rocket engines is specific impulse (I{sub s}p) which represents the ratio of the thrust over the propellant consumption rate. If the average exhaust H{sub 2} temperature of a NTR is around 3,000 K, the I{sub s}p can be achieved as high as 1,000 s as compared with only 450 - 500 s of the best CRs. For this reason, NTRs are favored for various space applications such as orbital tugs, lunar transports, and manned missions to Mars and beyond. The best known NTR development effort was conducted from 1955 to1974 under the ROVER and NERVA programs in the USA. These programs had successfully designed and tested many different reactors and engines. After these projects, the researches on NERVA derived

R and T report: Goddard Space Flight Center

Science.gov (United States)

Soffen, Gerald A. (Editor)

1993-01-01

The 1993 Research and Technology Report for Goddard Space Flight Center is presented. Research covered areas such as (1) flight projects; (2) space sciences including cosmology, high energy, stars and galaxies, and the solar system; (3) earth sciences including process modeling, hydrology/cryology, atmospheres, biosphere, and solid earth; (4) networks, planning, and information systems including support for mission operations, data distribution, advanced software and systems engineering, and planning/scheduling; and (5) engineering and materials including spacecraft systems, material and testing, optics and photonics and robotics.

On spaces Cb(X) weakly K-analytic

Czech Academy of Sciences Publication Activity Database

Ferrando, J.C.; Kąkol, Jerzy; López-Pellicer, M.

2017-01-01

Roč. 290, č. 16 (2017), s. 2612-2618 ISSN 0025-584X R&D Projects: GA ČR GF16-34860L Institutional support: RVO:67985840 Keywords : K-analytic space * pseudocompact space * rainwater set Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 0.742, year: 2016

UNIGE in space... hunting astroparticles

CERN Multimedia

2016-01-01

Switzerland has a long history of involvement in cosmic-ray physics and space research projects: some of the most notable examples are its pioneering research since the beginning of the 20th century; its co-founding of major European space organisations; its provision of state-of-the-art scientific equipment to major international space agencies and the missions of a Swiss astronaut in the 1990s.   The Alpha Magnetic Spectrometer (AMS) project, whose control centre is at CERN, has benefitted from the cutting-edge knowhow of the Nuclear and Corpuscular Physics Department (DNPC) of the University of Geneva (UNIGE). An extremely sensitive, high-resolution spectrometer was built for the project and was installed on the International Space Station (ISS) in 2011. The DNPC was responsible for designing the particle tracker – the device at the heart of both the AMS 01 prototype and the final model sent into space, AMS 02. The aim of this research project is to advance humankind’s kno...

Megawatt Class Nuclear Space Power Systems (MCNSPS) conceptual design and evaluation report. Volume 2, technologies 1: Reactors, heat transport, integration issues

Science.gov (United States)

Wetch, J. R.

1988-01-01

The objectives of the Megawatt Class Nuclear Space Power System (MCNSPS) study are summarized and candidate systems and subsystems are described. Particular emphasis is given to the heat rejection system and the space reactor subsystem.

Nuclear modules for space electric propulsion

International Nuclear Information System (INIS)

Difilippo, F.C.

1998-01-01

The analysis of interplanetary cargo and piloted missions requires the calculations of the performances and masses of subsystems to be integrated in a final design. In a preliminary and scoping stage the designer needs to evaluate options in an iterative way by using simulations that run fast on a computer. As a consequence of a collaborative agreement between the National Aeronautic and Space Administration (NASA) and the Oak Ridge National Laboratory (ORNL), ORNL has been involved in the development of models and calculational procedures for the analysis (neutronic and thermal hydraulic) of power sources for nuclear electric propulsion. The nuclear modules will be integrated into the whole simulation of the nuclear electric propulsion system. The vehicles use either a Brayton direct-conversion cycle, using the heated helium from a NERVA-type reactor, or a potassium Rankine cycle, with the working fluid heated on the secondary side of a heat exchanger and lithium on the primary side coming from a fast reactor. Given a set of input conditions, the codes calculate composition, dimensions, volumes, and masses of the core, reflector, control system, pressure vessel, neutron and gamma shields, as well as the thermal hydraulic conditions of the coolant, clad and fuel. Input conditions are power, core life, pressure and temperature of the coolant at the inlet of the core, either the temperature of the coolant at the outlet of the core or the coolant mass flow and the fluences and integrated doses at the cargo area. Using state-of-the-art neutron cross sections and transport codes, a database was created for the neutronic performance of both reactor designs. The free parameters of the models are the moderator/fuel mass ratio for the NERVA reactor and the enrichment and the pitch of the lattice for the fast reactor. Reactivity and energy balance equations are simultaneously solved to find the reactor design. Thermalhydraulic conditions are calculated by solving the one

HZE dosimetry in space using plastic track detectors

CERN Document Server

Kopp, J; Reitz, G; Enge, W

1999-01-01

Plastic nuclear track detectors were used to measure the contribution of High charge Z and energy E (HZE) particles to the radiation exposure of manned space missions. Results from numerous space missions in the orbit planned for the International Space Station are compared. The measurements cover the declining phase of the last solar cycle during the past 7 years and various shielding conditions inside the US Space Shuttle and the Russian MIR-station.

Metrics in Keplerian orbits quotient spaces

Science.gov (United States)

Milanov, Danila V.

2018-03-01

Quotient spaces of Keplerian orbits are important instruments for the modelling of orbit samples of celestial bodies on a large time span. We suppose that variations of the orbital eccentricities, inclinations and semi-major axes remain sufficiently small, while arbitrary perturbations are allowed for the arguments of pericentres or longitudes of the nodes, or both. The distance between orbits or their images in quotient spaces serves as a numerical criterion for such problems of Celestial Mechanics as search for common origin of meteoroid streams, comets, and asteroids, asteroid families identification, and others. In this paper, we consider quotient sets of the non-rectilinear Keplerian orbits space H. Their elements are identified irrespective of the values of pericentre arguments or node longitudes. We prove that distance functions on the quotient sets, introduced in Kholshevnikov et al. (Mon Not R Astron Soc 462:2275-2283, 2016), satisfy metric space axioms and discuss theoretical and practical importance of this result. Isometric embeddings of the quotient spaces into R^n, and a space of compact subsets of H with Hausdorff metric are constructed. The Euclidean representations of the orbits spaces find its applications in a problem of orbit averaging and computational algorithms specific to Euclidean space. We also explore completions of H and its quotient spaces with respect to corresponding metrics and establish a relation between elements of the extended spaces and rectilinear trajectories. Distance between an orbit and subsets of elliptic and hyperbolic orbits is calculated. This quantity provides an upper bound for the metric value in a problem of close orbits identification. Finally the invariance of the equivalence relations in H under coordinates change is discussed.

Ghost-Free Massive $f(R)$ Theories Modelled as Effective Einstein Spaces and Cosmic Acceleration

CERN Document Server

Vacaru, Sergiu I

2014-01-01

We study how massive ghost-free gravity $f(R)$-modified theories, MGFTs, can be encoded into generic off-diagonal Einstein spaces. Using "auxiliary" connections completely defined by the metric fields and adapted to nonholonomic frames with associated to nonlinear connection structure, we decouple and integrate in certain general forms the field equations in MGFT. Imposing additional nonholonomic constraints, we can generate Levi--Civita, LC, configurations and mimic MGFT effects via off-diagonal interactions of effective Einstein and/or Einstein-Cartan gravity with nonholonomically induced torsion. The cosmological evolution of ghost-free off--diagonal Einstein spaces is investigated. Certain compatibility of MGFT cosmology to small off-diagonal deformations of $\\Lambda $CDM models is established. %

Shielding considerations for advanced space nuclear reactor systems

International Nuclear Information System (INIS)

Angelo, J.P. Jr.; Buden, D.

1982-01-01

To meet the anticipated future space power needs, the Los Alamos National Laboratory is developing components for a compact, 100 kW/sub e/-class heat pipe nuclear reactor. The reactor uses uranium dioxide (UO 2 ) as its fuel, and is designed to operate around 1500 k. Heat pipes are used to remove thermal energy from the core without the use of pumps or compressors. The reactor heat pipes transfer mal energy to thermoelectric conversion elements that are advanced versions of the converters used on the enormously successful Voyager missions to the outer planets. Advanced versions of this heat pipe reactor could also be used to provide megawatt-level power plants. The paper reviews the status of this advanced heat pipe reactor and explores the radiation environments and shielding requirements for representative manned and unmanned applications

Enabling autonomous control for space reactor power systems

International Nuclear Information System (INIS)

Wood, R. T.

2006-01-01

The application of nuclear reactors for space power and/or propulsion presents some unique challenges regarding the operations and control of the power system. Terrestrial nuclear reactors employ varying degrees of human control and decision-making for operations and benefit from periodic human interaction for maintenance. In contrast, the control system of a space reactor power system (SRPS) employed for deep space missions must be able to accommodate unattended operations due to communications delays and periods of planetary occlusion while adapting to evolving or degraded conditions with no opportunity for repair or refurbishment. Thus, a SRPS control system must provide for operational autonomy. Oak Ridge National Laboratory (ORNL) has conducted an investigation of the state of the technology for autonomous control to determine the experience base in the nuclear power application domain, both for space and terrestrial use. It was found that control systems with varying levels of autonomy have been employed in robotic, transportation, spacecraft, and manufacturing applications. However, autonomous control has not been implemented for an operating terrestrial nuclear power plant nor has there been any experience beyond automating simple control loops for space reactors. Current automated control technologies for nuclear power plants are reasonably mature, and basic control for a SRPS is clearly feasible under optimum circumstances. However, autonomous control is primarily intended to account for the non optimum circumstances when degradation, failure, and other off-normal events challenge the performance of the reactor and near-term human intervention is not possible. Thus, the development and demonstration of autonomous control capabilities for the specific domain of space nuclear power operations is needed. This paper will discuss the findings of the ORNL study and provide a description of the concept of autonomy, its key characteristics, and a prospective

Convergence of Hybrid Space Mapping Algorithms

DEFF Research Database (Denmark)

Madsen, Kaj; Søndergaard, Jacob

2004-01-01

may be poor, or the method may even fail to converge to a stationary point. We consider a convex combination of the space mapping technique with a classical optimization technique. The function to be optimized has the form \\$H \\$\\backslash\\$circ f\\$ where \\$H: \\$\\backslash\\$dR\\^m \\$\\backslash......\\$mapsto \\$\\backslash\\$dR\\$ is convex and \\$f: \\$\\backslash\\$dR\\^n \\$\\backslash\\$mapsto \\$\\backslash\\$dR\\^m\\$ is smooth. Experience indicates that the combined method maintains the initial efficiency of the space mapping technique. We prove that the global convergence property of the classical technique is also...

Prospects for the use of thermionic nuclear power plants for interorbital transfers of space vehicles in near space

International Nuclear Information System (INIS)

Andreev, P.V.; Zhabotinskii, E.E.; Nikonov, A.M.

1993-01-01

In a previous study the authors considered the use of thermionic nuclear power plants with a thermal reactor for interorbital transfers of space vehicles by electrojet propulsion systems (EJPSs), opening up broad prospects for putting payloads into a high orbit with relatively inexpensive means for a launch into a reference orbit, e.g., the Proton launch vehicle. This is of major importance for the commercial use of space technology, in particular, for erecting technological platforms for the production of various materials. In the work reported here the authors continue the study of interorbital transfers and explore the potentialities of thermionic NPPs with a thermal reactor and with a fast reactor. In boosted operation the electrical power of the latter may reach several hundred kilowatts. What type of NPP is desirable for testing an electrojet propulsion system in interorbital transfers from a reference orbit to a high orbit, providing that the time is limited, depends on the class of the launch vehicle characterized by the mass M o that the vehicle can carry into the reference orbit, where radiation safety conditions allow the NPP to be started up. Results of studies are presented that give an idea of the rational choice of type of thermionic NPP for the organization in interorbital transfers

National Space Agencies vs. Commercial Space: Towards Improved Space Safety

Science.gov (United States)

Pelton, J.

2013-09-01

Traditional space policies as developed at the national level includes many elements but they are most typically driven by economic and political objectives. Legislatively administered programs apportion limited public funds to achieve "gains" that can involve employment, stimulus to the economy, national defense or other advancements. Yet political advantage is seldom far from the picture.Within the context of traditional space policies, safety issues cannot truly be described as "afterthoughts", but they are usually, at best, a secondary or even tertiary consideration. "Space safety" is often simply assumed to be "in there" somewhere. The current key question is can "safety and risk minimization", within new commercial space programs actually be elevated in importance and effectively be "designed in" at the outset. This has long been the case with commercial aviation and there is at least reasonable hope that this could also be the case for the commercial space industry in coming years. The cooperative role that the insurance industry has now played for centuries in the shipping industry and for decades in aviation can perhaps now play a constructive role in risk minimization in the commercial space domain as well. This paper begins by examining two historical case studies in the context of traditional national space policy development to see how major space policy decisions involving "manned space programs" have given undue primacy to "political considerations" over "safety" and other factors. The specific case histories examined here include first the decision to undertake the Space Shuttle Program (i.e. 1970-1972) and the second is the International Space Station. In both cases the key and overarching decisions were driven by political, schedule and cost considerations, and safety seems absence as a prime consideration. In publicly funded space programs—whether in the United States, Europe, Russia, Japan, China, India or elsewhere—it seems realistic to

Curved twistor spaces and H-space

International Nuclear Information System (INIS)

Tod, K.P.

1980-01-01

The curved twistor space construction of Penrose for anti-self-dual solutions to the Einstein vacuum equations is described. Curved twistor spaces are defined and it is shown with the aid of an example how to obtain them by deforming the complex structure of regions of flat twistor space. The connection of this procedure with Newman's H-space construction via asymptotic twistor space is outlined. (Auth.)

Large size space construction for space exploitation

Science.gov (United States)

Kondyurin, Alexey

2016-07-01

Space exploitation is impossible without large space structures. We need to make sufficient large volume of pressurized protecting frames for crew, passengers, space processing equipment, & etc. We have to be unlimited in space. Now the size and mass of space constructions are limited by possibility of a launch vehicle. It limits our future in exploitation of space by humans and in development of space industry. Large-size space construction can be made with using of the curing technology of the fibers-filled composites and a reactionable matrix applied directly in free space. For curing the fabric impregnated with a liquid matrix (prepreg) is prepared in terrestrial conditions and shipped in a container to orbit. In due time the prepreg is unfolded by inflating. After polymerization reaction, the durable construction can be fitted out with air, apparatus and life support systems. Our experimental studies of the curing processes in the simulated free space environment showed that the curing of composite in free space is possible. The large-size space construction can be developed. A project of space station, Moon base, Mars base, mining station, interplanet space ship, telecommunication station, space observatory, space factory, antenna dish, radiation shield, solar sail is proposed and overviewed. The study was supported by Humboldt Foundation, ESA (contract 17083/03/NL/SFe), NASA program of the stratospheric balloons and RFBR grants (05-08-18277, 12-08-00970 and 14-08-96011).

Compact and continuous embeddings of logarithmic Bessel potential spaces

Czech Academy of Sciences Publication Activity Database

Edmunds, D. E.; Gurka, P.; Opic, Bohumír

2005-01-01

Roč. 168, č. 3 (2005), s. 229-250 ISSN 0039-3223 R&D Projects: GA ČR(CZ) GA201/01/0333 Institutional research plan: CEZ:AV0Z10190503 Keywords : Bessel potential spaces * spaces of Hölder-continuous functions * Lorentz-Zygmund spaces Subject RIV: BA - General Mathematics Impact factor: 0.538, year: 2005

The coadjoint orbit spaces of Diff(S1) and Teichmueller spaces

International Nuclear Information System (INIS)

Nag, S.; Verjovsky, A.

1989-09-01

Precisely two of the homogeneous spaces that appear as coadjoint orbits of the group of string reparametrizations (Diff (S 1 )) carry in a natural way the structure of infinite dimensional, holomorphically homogeneous complex analytic Kaehler manifolds. These are N = Diff (S 1 )/Rot (S 1 ) and M = Diff (S 1 )/Moeb (S 1 ). Note that N is a holomorphic disc fiber space over M. Now, M can be naturally considered as embedded in the classical universal Teichmueller space T(1), simply by noting that a diffeomorphism of S 1 is a quasisymmetric homeomorphism. T(1) is itself a homomorphically homogeneous complex Banach manifold. We prove in the first part of the paper that the inclusion of M in T(1) is complex analytic. In the latter portion of this paper it is shown that the unique homogeneous Kaehler metric carried by M = Diff (S 1 )/SL(2, R) induces precisely the Weil-Petersson metric on the Teichmueller space. This is via our identification of M as a holomorphic submanifold of universal Teichmueller space. Now recall that every Teichmueller space T(G) of finite or infinite dimension is contained canonically and holomorphically within T(1). Our computations allow us also to prove that every T(G), G any infinite Fuchsian group, projects out of M transversely. This last assertion is related to the ''fractal'' nature of G-invariant quasicircles, and to Mostow rigidity on the line. Our results thus connect the loop space approach to bosonic string theory with the sumover moduli (Polyakov path integral) approach. (author). 21 refs

Integration of Space Weather Forecasts into Space Protection

Science.gov (United States)

Reeves, G.

2012-09-01

How would the US respond to a clandestine attack that disabled one of our satellites? How would we know that it was an attack, not a natural failure? The goal of space weather programs as applied to space protection are simple: Provide a rapid and reliable assessment of the probability that satellite or system failure was caused by the space environment. Achieving that goal is not as simple. However, great strides are being made on a number of fronts. We will report on recent successes in providing rapid, automated anomaly/attack assessment for the penetrating radiation environment in the Earth's radiation belts. We have previously reported on the Dynamic Radiation Environment Assimilation Model (DREAM) that was developed at Los Alamos National Laboratory to assess hazards posed by the natural and by nuclear radiation belts. This year we will report on recent developments that are moving this program from the research, test, and evaluation phases to real-time implementation and application. We will discuss the challenges of leveraging space environment data sets for applications that are beyond the scope of mission requirements, the challenges of moving data from where they exist to where they are needed, the challenges of turning data into actionable information, and how those challenges were overcome. We will discuss the state-of-the-art as it exists in 2012 including the new capabilities that have been enabled and the limitations that still exist. We will also discuss how currently untapped data resources could advance the state-of-the-art and the future steps for implementing automatic real-time anomaly forensics.

Free piston space Stirling technology program

Science.gov (United States)

Dochat, G. R.; Dhar, M.

1989-01-01

MTI recently completed an initial technology feasibility program for NASA by designing, fabricating and testing a space power demonstrator engine (SPDE). This program, which confirms the potential of free-piston Stirling engines, provided the major impetus to initiate a free-piston Stirling space engine (SSE) technology program. The accomplishments of the SPDE program are reviewed, and an overview of the SSE technology program and technical status to date is provided. It is shown that progress in both programs continues to justify its potential for either nuclear or solar space power missions.

The Role of Nuclear Fragmentation in Particle Therapy and Space Radiation Protection.

Science.gov (United States)

Zeitlin, Cary; La Tessa, Chiara

2016-01-01

The transport of the so-called HZE particles (those having high charge, Z, and energy, E) through matter is crucially important both in space radiation protection and in the clinical setting where heavy ions are used for cancer treatment. HZE particles are usually considered those having Z > 1, though sometimes Z > 2 is meant. Transport physics is governed by two types of interactions, electromagnetic (ionization energy loss) and nuclear. Models of transport, such as those used in treatment planning and space mission planning must account for both effects in detail. The theory of electromagnetic interactions is well developed, but nucleus-nucleus collisions are so complex that no fundamental physical theory currently describes them. Instead, interaction models are generally anchored to experimental data, which in some areas are far from complete. The lack of fundamental physics knowledge introduces uncertainties in the calculations of exposures and their associated risks. These uncertainties are greatly compounded by the much larger uncertainties in biological response to HZE particles. In this article, we discuss the role of nucleus-nucleus interactions in heavy charged particle therapy and in deep space, where astronauts will receive a chronic low dose from galactic cosmic rays (GCRs) and potentially higher short-term doses from sporadic, unpredictable solar energetic particles (SEPs). GCRs include HZE particles; SEPs typically do not and we, therefore, exclude them from consideration in this article. Nucleus-nucleus collisions can result in the breakup of heavy ions into lighter ions. In space, this is generally beneficial because dose and dose equivalent are, on the whole, reduced in the process. The GCRs can be considered a radiation field with a significant high-LET component; when they pass through matter, the high-LET component is attenuated, at the cost of a slight increase in the low-LET component. Not only are the standard measures of risk

Neutron dose study with bubble detectors aboard the International Space Station as part of the Matroshka-R experiment

International Nuclear Information System (INIS)

Machrafi, R.; Garrow, K.; Ing, H.; Smith, M. B.; Andrews, H. R.; Akatov, Yu; Arkhangelsky, V.; Chernykh, I.; Mitrikas, V.; Petrov, V.; Shurshakov, V.; Tomi, L.; Kartsev, I.; Lyagushin, V.

2009-01-01

As part of the Matroshka-R experiments, a spherical phantom and space bubble detectors (SBDs) were used on board the International Space Station to characterise the neutron radiation field. Seven experimental sessions with SBDs were carried out during expeditions ISS-13, ISS-14 and ISS-15. The detectors were positioned at various places throughout the Space Station, in order to determine dose variations with location and on/in the phantom in order to establish the relationship between the neutron dose measured externally to the body and the dose received internally. Experimental data on/in the phantom and at different locations are presented. (authors)

SpaceTech—Postgraduate space education

Science.gov (United States)

de Bruijn, Ferdi J.; Ashford, Edward W.; Larson, Wiley J.

2008-07-01

SpaceTech is a postgraduate program geared primarily for mid-career space professionals seeking to gain or improve their expertise in space systems engineering and in business engineering. SpaceTech provides a lifelong impact on its participants by broadening their capabilities, encouraging systematic "end-to-end" thinking and preparing them for any technical or business-related engineering challenges they may encounter. This flexible 1-year program offers high competency gain and increased business skills. It is held in attractive locations in a flexible, multi-cultural environment. SpaceTech is a highly effective master's program certified by the esteemed Technical University of Delft (TUD), Netherlands. SpaceTech provides expert instructors who place no barriers between themselves and participants. The program combines innovative and flexible new approaches with time-tested methods to give participants the skills required for future missions and new business, while allowing participants to meet their work commitments at the same time as they study for their master's degree. The SpaceTech program is conducted in separate sessions, generally each of 2-week duration, separated by periods of some 6-8 weeks, during which time participants may return to their normal jobs. It also includes introductory online course material that the participants can study at their leisure. The first session is held at the TUD, with subsequent sessions held at strategic space agency locations. By participating at two or more of these sessions, attendees can earn certificates of satisfactory completion from TU Delft. By participating in all of the sessions, as well as taking part in the companion Central Case Project (CCP), participants earn an accredited and highly respected master's degree in Space Systems Engineering from the TUD. Seven distinct SpaceTech modules are provided during these sessions: Space Mission Analysis and Design, Systems Engineering, Business Engineering

Phase-space exploration in nuclear giant resonance decay

International Nuclear Information System (INIS)

Drozdz, S.; Nishizaki, S.; Wambach, J.; Speth, J.

1995-01-01

The rate of phase-space exploration in the decay of isovector and isoscalar giant quadrupole resonances in 40 Ca is analyzed. The study is based on the time dependence of the survival probability and of the spectrum of generalized entropies evaluated in the space of one-particle--one-hole (1p-1h) and 2p-2h states. Three different cases for the level distribution of 2p-2h background states, corresponding to (a) high degeneracy, (b) classically regular motion, and (c) classically chaotic motion, are studied. In the latter case the isovector excitation evolves almost statistically while the isoscalar excitation remains largely localized, even though it penetrates the whole available phase space

Quasi-Banach spaces of almost universal disposition

Czech Academy of Sciences Publication Activity Database

Sánchez, C. F.; Garbulińska, J.; Kubiś, Wieslaw

2014-01-01

Roč. 267, č. 3 (2014), s. 744-771 ISSN 0022-1236 R&D Projects: GA ČR(CZ) GAP201/12/0290 Institutional support: RVO:67985840 Keywords : p-Gurarii space * space of universal disposition * isometry Subject RIV: BA - General Mathematics Impact factor: 1.322, year: 2014 http://www.sciencedirect.com/science/article/pii/S0022123614002043

Importance-truncated shell model for multi-shell valence spaces

Energy Technology Data Exchange (ETDEWEB)

Stumpf, Christina; Vobig, Klaus; Roth, Robert [Institut fuer Kernphysik, TU Darmstadt (Germany)

2016-07-01

The valence-space shell model is one of the work horses in nuclear structure theory. In traditional applications, shell-model calculations are carried out using effective interactions constructed in a phenomenological framework for rather small valence spaces, typically spanned by one major shell. We improve on this traditional approach addressing two main aspects. First, we use new effective interactions derived in an ab initio approach and, thus, establish a connection to the underlying nuclear interaction providing access to single- and multi-shell valence spaces. Second, we extend the shell model to larger valence spaces by applying an importance-truncation scheme based on a perturbative importance measure. In this way, we reduce the model space to the relevant basis states for the description of a few target eigenstates and solve the eigenvalue problem in this physics-driven truncated model space. In particular multi-shell valence spaces are not tractable otherwise. We combine the importance-truncated shell model with refined extrapolation schemes to approximately recover the exact result. We present first results obtained in the importance-truncated shell model with the newly derived ab initio effective interactions for multi-shell valence spaces, e.g., the sdpf shell.

SRTC criticality safety technical review: Nuclear criticality safety evaluation 94-02, uranium solidification facility pencil tank module spacing

International Nuclear Information System (INIS)

Rathbun, R.

1994-01-01

Review of NMP-NCS-94-0087, ''Nuclear Criticality Safety Evaluation 94-02: Uranium Solidification Facility Pencil Tank Module Spacing (U), April 18, 1994,'' was requested of the SRTC Applied Physics Group. The NCSE is a criticality assessment to show that the USF process module spacing, as given in Non-Conformance Report SHM-0045, remains safe for operation. The NCSE under review concludes that the module spacing as given in Non-Conformance Report SHM-0045 remains in a critically safe configuration for all normal and single credible abnormal conditions. After a thorough review of the NCSE, this reviewer agrees with that conclusion

Preliminary assessment of the thermal effects of an annular air space surrounding an emplaced nuclear waste canister

International Nuclear Information System (INIS)

Davis, B.W.

1979-01-01

Modeling results have previously shown that the presence of a large air space (e.g., a repository room) within a nuclear waste repository is expected to cause a waste canister's temperature to remain cooler than it would otherwise be. Results presented herein show that an annular air space surrounding the waste canisters can have similar cooling effects under certain prescribable conditions; for a 16 ft x 1 ft diameter canister containing 650 PWR rods which initially generate a total of 4.61 kw, analysis will show that annular air spaces greater than 11 in will permit the canister surface to attain peak temperatures lower than that which would result from a zero-gap/perfect thermal contact. It was determined that the peak radial temperature gradient in the salt varies in proportion to the inverse of the drill hole radius. Thermal radiation is shown to be the dominant mode of heat transfer across an annular air space during the first two years after emplacement. Finally, a methodology is presented which will allow investigators to easily model radiation and convection heat transfer through air spaces by treating the space as a conduction element that possesses non-linear temperature dependent conductivity

Optimality of embeddings of Bessel-potential-type spaces into Lorentz-Karamata spaces

Czech Academy of Sciences Publication Activity Database

Gogatishvili, Amiran; Opic, Bohumír; Neves, J. S.

2004-01-01

Roč. 134, č. 6 (2004), s. 1127-1147 ISSN 0308-2105 R&D Projects: GA ČR GA201/01/0333 Institutional research plan: CEZ:AV0Z1019905 Keywords : slowly varying functions * Lorentz-Karamata spaces * Bessel potentials Subject RIV: BA - General Mathematics Impact factor: 0.487, year: 2004

String cohomology groups of complex projective spaces

DEFF Research Database (Denmark)

Ottosen, Iver; Bökstedt, Marcel

2007-01-01

Let X be a space and write LX for its free loop space equipped with the action of the circle group T given by dilation. The equivariant cohomology H*(LXhT;Z/p) is a module over H*(BT;Z/p). We give a computation of this module when X=CPr for any positive integer r and any prime number p. The compu......Let X be a space and write LX for its free loop space equipped with the action of the circle group T given by dilation. The equivariant cohomology H*(LXhT;Z/p) is a module over H*(BT;Z/p). We give a computation of this module when X=CPr for any positive integer r and any prime number p...

Nuclear reactor power for a space-based radar. SP-100 project

Science.gov (United States)

Bloomfield, Harvey; Heller, Jack; Jaffe, Leonard; Beatty, Richard; Bhandari, Pradeep; Chow, Edwin; Deininger, William; Ewell, Richard; Fujita, Toshio; Grossman, Merlin

1986-01-01

A space-based radar mission and spacecraft, using a 300 kWe nuclear reactor power system, has been examined, with emphasis on aspects affecting the power system. The radar antenna is a horizontal planar array, 32 X 64 m. The orbit is at 61 deg, 1088 km. The mass of the antenna with support structure is 42,000 kg; of the nuclear reactor power system, 8,300 kg; of the whole spacecraft about 51,000 kg, necessitating multiple launches and orbital assembly. The assembly orbit is at 57 deg, 400 km, high enough to provide the orbital lifetime needed for orbital assembly. The selected scenario uses six Shuttle launches to bring the spacecraft and a Centaur G upper-stage vehicle to assembly orbit. After assembly, the Centaur places the spacecraft in operational orbit, where it is deployed on radio command, the power system started, and the spacecraft becomes operational. Electric propulsion is an alternative and allows deployment in assembly orbit, but introduces a question of nuclear safety.

A new class of Banach spaces

International Nuclear Information System (INIS)

Gill, T L; Zachary, W W

2008-01-01

In this paper, we construct a new class of separable Banach spaces KS p , for 1 ≤ p ≤ ∞, each of which contains all of the standard L p spaces, as well as the space of finitely additive measures, as compact dense embeddings. Equally important is the fact that these spaces contain all Henstock-Kurzweil integrable functions and, in particular, the Feynman kernel and the Dirac measure, as norm bounded elements. As a first application, we construct the elementary path integral in the manner originally intended by Feynman. We then suggest that KS 2 is a more appropriate Hilbert space for quantum theory, in that it satisfies the requirements for the Feynman, Heisenberg and Schroedinger representations, while the conventional choice only satisfies the requirements for the Heisenberg and Schroedinger representations. As a second application, we show that the mixed topology on the space of bounded continuous functions, C b [R n ], used to define the weak generator for a semigroup T(t), is stronger than the norm topology on KS p . (This means that, when extended to KS p , T(t) is strongly continuous, so that the weak generator on C b [R n ] becomes a strong generator on KS p .)

State-space model predictive control method for core power control in pressurized water reactor nuclear power stations

Energy Technology Data Exchange (ETDEWEB)

Wang, Guo Xu; Wu, Jie; Zeng, Bifan; Wu, Wangqiang; Ma, Xiao Qian [School of Electric Power, South China University of Technology, Guangzhou (China); Xu, Zhibin [Electric Power Research Institute of Guangdong Power Grid Corporation, Guangzhou (China)

2017-02-15

A well-performed core power control to track load changes is crucial in pressurized water reactor (PWR) nuclear power stations. It is challenging to keep the core power stable at the desired value within acceptable error bands for the safety demands of the PWR due to the sensitivity of nuclear reactors. In this paper, a state-space model predictive control (MPC) method was applied to the control of the core power. The model for core power control was based on mathematical models of the reactor core, the MPC model, and quadratic programming (QP). The mathematical models of the reactor core were based on neutron dynamic models, thermal hydraulic models, and reactivity models. The MPC model was presented in state-space model form, and QP was introduced for optimization solution under system constraints. Simulations of the proposed state-space MPC control system in PWR were designed for control performance analysis, and the simulation results manifest the effectiveness and the good performance of the proposed control method for core power control.

MCNP benchmark analyses of critical experiments for space nuclear thermal propulsion

International Nuclear Information System (INIS)

Selcow, E.C.; Cerbone, R.J.; Ludewig, H.

1993-01-01

The particle-bed reactor (PBR) system is being developed for use in the Space Nuclear Thermal Propulsion (SNTP) Program. This reactor system is characterized by a highly heterogeneous, compact configuration with many streaming pathways. The neutronics analyses performed for this system must be able to accurately predict reactor criticality, kinetics parameters, material worths at various temperatures, feedback coefficients, and detailed fission power and heating distributions. The latter includes coupled axial, radial, and azimuthal profiles. These responses constitute critical inputs and interfaces with the thermal-hydraulics design and safety analyses of the system

Nuclear geophysics in space and atmospheric reserch at INPE/BRAZIl

International Nuclear Information System (INIS)

Nordemann, D.J.R.; Pereira, E.B.; Marinho, E.V.A.; Sircilli Neto, F.

1986-05-01

During the last years, INPE's research in Nuclear Geophysics has developed in fields of interest to the Institute, the scientific community and the society in general. In the space research field it may be considered as a contribution to the history of meteorite falls in our planet or possible collision with big meteorites which may have been the cause of important effects such as biological extinction and extraterrestrial matter gathering. In the atmospheric research field, spatial and temporal variations of radon measurements in the lower atmosphere allow correlations from micrometeorology to worlwide scale through mesoscale, in the interpretation of phenomena which deal with the dynamics of air masses. (Author) [pt

Research-to-operations (R2O) for the Space Environmental Effects Fusion System (SEEFS) system-impact products

Science.gov (United States)

Quigley, Stephen

The Space Vehicles Directorate of the Air Force Research Laboratory (AFRL/RVBX) and the Space Environment Branch of the Space and Missile Systems Center (SMC SLG/WMLE) have combined efforts to design, develop, test, implement, and validate numerical and graphical products for Air Force Space Command's (AFSPC) Space Environmental Effects Fusion System (SEEFS). These products are generated to analyze, specify, and forecast the effects of the near-earth space environment on Department of Defense weapons, navigation, communications, and surveillance systems. Jointly developed projects that have been completed as prototypes and are undergoing development for real-time operations include a SEEFS architecture and database, five system-impact products, and a high-level decision aid product. This first round of SEEFS products includes the Solar Radio Burst Effects (SoRBE) on radar and satellite communications, Radar Auroral Clutter (RAC), Scintillation Effects on radar and satellite communications (RadScint and SatScint), and Satellite Surface and Deep Charge/Discharge (Char/D) products. This presentation will provide overviews of the current system impact products, along with plans and potentials for future products expected for the SEEFS program. The overviews will include information on applicable research-to-operations (R2O) issues, to include input data coverage and quality control, output confidence levels, modeling standards, and validation efforts.

Flow of ideal fluid through a central region of a nuclear reactor wire-spaced fuel subassembly

International Nuclear Information System (INIS)

Schmid, J.

1991-04-01

The results are given of calculations of the flow of an ideal fluid through the central region of a nuclear reactor wire-spaced fuel subassembly. The computer code used is briefly described. (author). 10 figs., 4 refs

Evaluations of average level spacings

International Nuclear Information System (INIS)

Liou, H.I.

1980-01-01

The average level spacing for highly excited nuclei is a key parameter in cross section formulas based on statistical nuclear models, and also plays an important role in determining many physics quantities. Various methods to evaluate average level spacings are reviewed. Because of the finite experimental resolution, to detect a complete sequence of levels without mixing other parities is extremely difficult, if not totally impossible. Most methods derive the average level spacings by applying a fit, with different degrees of generality, to the truncated Porter-Thomas distribution for reduced neutron widths. A method that tests both distributions of level widths and positions is discussed extensivey with an example of 168 Er data. 19 figures, 2 tables

Noncommutative products of Euclidean spaces

Science.gov (United States)

Dubois-Violette, Michel; Landi, Giovanni

2018-05-01

We present natural families of coordinate algebras on noncommutative products of Euclidean spaces R^{N_1} × _R R^{N_2} . These coordinate algebras are quadratic ones associated with an R -matrix which is involutive and satisfies the Yang-Baxter equations. As a consequence, they enjoy a list of nice properties, being regular of finite global dimension. Notably, we have eight-dimensional noncommutative euclidean spaces R4 × _R R4 . Among these, particularly well behaved ones have deformation parameter u \\in S^2 . Quotients include seven spheres S7_u as well as noncommutative quaternionic tori TH_u = S^3 × _u S^3 . There is invariance for an action of {{SU}}(2) × {{SU}}(2) on the torus TH_u in parallel with the action of U(1) × U(1) on a `complex' noncommutative torus T^2_θ which allows one to construct quaternionic toric noncommutative manifolds. Additional classes of solutions are disjoint from the classical case.

Sharp Embeddings of Besov Spaces with Logarithmic Smoothness

Czech Academy of Sciences Publication Activity Database

Gurka, P.; Opic, Bohumír

2005-01-01

Roč. 18, č. 1 (2005), s. 81-110 ISSN 1139-1138 R&D Projects: GA ČR(CZ) GA201/01/0333 Institutional research plan: CEZ:AV0Z10190503 Keywords : Besov spaces wirh logarithmic smoothness * Lorentz-Zygmund spaces * sharp embeddings Subject RIV: BA - General Mathematics

Underground spaces/cybernetic spaces

Directory of Open Access Journals (Sweden)

Tomaž Novljan

2000-01-01

Full Text Available A modern city space is a space where in the vertical and horizontal direction dynamic, non-linear processes exist, similar as in nature. Alongside the “common” city surface, cities have underground spaces as well that are increasingly affecting the functioning of the former. It is the space of material and cybernetic communication/transport. The psychophysical specifics of using underground places have an important role in their conceptualisation. The most evident facts being their limited volume and often limited connections to the surface and increased level of potential dangers of all kinds. An efficient mode for alleviating the effects of these specific features are artistic interventions, such as: shape, colour, lighting, all applications of the basic principles of fractal theory.

Common fixed point theorems in intuitionistic fuzzy metric spaces and L-fuzzy metric spaces with nonlinear contractive condition

International Nuclear Information System (INIS)

Jesic, Sinisa N.; Babacev, Natasa A.

2008-01-01

The purpose of this paper is to prove some common fixed point theorems for a pair of R-weakly commuting mappings defined on intuitionistic fuzzy metric spaces [Park JH. Intuitionistic fuzzy metric spaces. Chaos, Solitons and Fractals 2004;22:1039-46] and L-fuzzy metric spaces [Saadati R, Razani A, Adibi H. A common fixed point theorem in L-fuzzy metric spaces. Chaos, Solitons and Fractals, doi:10.1016/j.chaos.2006.01.023], with nonlinear contractive condition, defined with function, first observed by Boyd and Wong [Boyd DW, Wong JSW. On nonlinear contractions. Proc Am Math Soc 1969;20:458-64]. Following Pant [Pant RP. Common fixed points of noncommuting mappings. J Math Anal Appl 1994;188:436-40] we define R-weak commutativity for a pair of mappings and then prove the main results. These results generalize some known results due to Saadati et al., and Jungck [Jungck G. Commuting maps and fixed points. Am Math Mon 1976;83:261-3]. Some examples and comments according to the preceding results are given

Technology R&D for space commerce

Science.gov (United States)

Sadin, Stanley R.; Christensen, Carissa B.; Steen, Robert G.

1992-01-01

The potential effects of reserach conducted by the NASA Office of Aeronautics and Space Technology, OAST, on the aerospace industry are addressed. Program elements aimed at meeting commercial needs and those aimed at meeting NASA needs which have secondary effects benefiting aerospace firms are considered. Particular attention is given to current and future NASA programs for cooperating with industry and the potential effects of OAST research on nonaerospace industries.

Vector-valued Lizorkin-Triebel spaces and sharp trace theory for functions in Sobolev spaces with mixed \\pmb{L_p}-norm for parabolic problems

Science.gov (United States)

Weidemaier, P.

2005-06-01

The trace problem on the hypersurface y_n=0 is investigated for a function u=u(y,t) \\in L_q(0,T;W_{\\underline p}^{\\underline m}(\\mathbb R_+^n)) with \\partial_t u \\in L_q(0,T; L_{\\underline p}(\\mathbb R_+^n)), that is, Sobolev spaces with mixed Lebesgue norm L_{\\underline p,q}(\\mathbb R^n_+\\times(0,T))=L_q(0,T;L_{\\underline p}(\\mathbb R_+^n)) are considered; here \\underline p=(p_1,\\dots,p_n) is a vector and \\mathbb R^n_+=\\mathbb R^{n-1} \\times (0,\\infty). Such function spaces are useful in the context of parabolic equations. They allow, in particular, different exponents of summability in space and time. It is shown that the sharp regularity of the trace in the time variable is characterized by the Lizorkin-Triebel space F_{q,p_n}^{1-1/(p_nm_n)}(0,T;L_{\\widetilde{\\underline p}}(\\mathbb R^{n-1})), \\underline p=(\\widetilde{\\underline p},p_n). A similar result is established for first order spatial derivatives of u. These results allow one to determine the exact spaces for the data in the inhomogeneous Dirichlet and Neumann problems for parabolic equations of the second order if the solution is in the space L_q(0,T; W_p^2(\\Omega)) \\cap W_q^1(0,T;L_p(\\Omega)) with p \\le q.

Dark current spectroscopy of space and nuclear environment induced displacement damage defects in pinned photodiode based CMOS image sensors

International Nuclear Information System (INIS)

Belloir, Jean-Marc

2016-01-01

CMOS image sensors are envisioned for an increasing number of high-end scientific imaging applications such as space imaging or nuclear experiments. Indeed, the performance of high-end CMOS image sensors has dramatically increased in the past years thanks to the unceasing improvements of microelectronics, and these image sensors have substantial advantages over CCDs which make them great candidates to replace CCDs in future space missions. However, in space and nuclear environments, CMOS image sensors must face harsh radiation which can rapidly degrade their electro-optical performances. In particular, the protons, electrons and ions travelling in space or the fusion neutrons from nuclear experiments can displace silicon atoms in the pixels and break the crystalline structure. These displacement damage effects lead to the formation of stable defects and to the introduction of states in the forbidden bandgap of silicon, which can allow the thermal generation of electron-hole pairs. Consequently, non ionizing radiation leads to a permanent increase of the dark current of the pixels and thus a decrease of the image sensor sensitivity and dynamic range. The aim of the present work is to extend the understanding of the effect of displacement damage on the dark current increase of CMOS image sensors. In particular, this work focuses on the shape of the dark current distribution depending on the particle type, energy and fluence but also on the image sensor physical parameters. Thanks to the many conditions tested, an empirical model for the prediction of the dark current distribution induced by displacement damage in nuclear or space environments is experimentally validated and physically justified. Another central part of this work consists in using the dark current spectroscopy technique for the first time on irradiated CMOS image sensors to detect and characterize radiation-induced silicon bulk defects. Many types of defects are detected and two of them are identified

Energy and legislation in outer space

International Nuclear Information System (INIS)

Hurtak, J.J.

1984-01-01

In this paper, the different energy resources applicable in cosmic space are considered with respect to their function (energy acquiring, energy conversion, energy transmission and energy storage). Among these, nuclear energy is paid attention to (fission and fusion in rocket engines and the use of radioisotopes in energy conversion and storage). Approximate system performance parameters are listed. Furthermore, space law concerning new resources is discussed. (Auth.)

Harmonic analysis on symmetric spaces

CERN Document Server

Terras, Audrey

This text explores the geometry and analysis of higher rank analogues of the symmetric spaces introduced in volume one. To illuminate both the parallels and differences of the higher rank theory, the space of positive matrices is treated in a manner mirroring that of the upper-half space in volume one. This concrete example furnishes motivation for the general theory of noncompact symmetric spaces, which is outlined in the final chapter. The book emphasizes motivation and comprehensibility, concrete examples and explicit computations (by pen and paper, and by computer), history, and, above all, applications in mathematics, statistics, physics, and engineering. The second edition includes new sections on Donald St. P. Richards’s central limit theorem for O(n)-invariant random variables on the symmetric space of GL(n, R), on random  matrix theory, and on advances in the theory of automorphic forms on arithmetic groups.

Rich families and projectional skeletons in Asplund WCG spaces

Czech Academy of Sciences Publication Activity Database

Cúth, M.; Fabian, Marián

2017-01-01

Roč. 448, č. 2 (2017), s. 1618-1632 ISSN 0022-247X R&D Projects: GA ČR(CZ) GAP201/12/0290 Institutional support: RVO:67985840 Keywords : Asplund space * weakly compactly generated space * weakly Lindelöf determined space Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 1.064, year: 2016 http://www.sciencedirect.com/science/article/pii/S0022247X16307715

Thermodynamics Properties of Binary Gas Mixtures for Brayton Space Nuclear Power System

International Nuclear Information System (INIS)

You Ersheng; Shi Lei; Zhang Zuoyi

2014-01-01

Space nuclear power system with closed Brayton cycle has the potential advantages of high cycle efficiency. It can be achieved to limit the specific mass of the system with a competitive design scheme, so as to strengthen the advantage of the nuclear energy applying in space propulsion and electric generating compared to solar or chemical propellant. Whereby, the thermodynamic properties of working fluids have a significant influence on the performance of the plant. Therefore, two binary mixtures helium-nitrogen and helium-carbon dioxide are introduced to analysis the variation in the transport and heat transfer capacity of working fluids. Based on the parameters of pure gases, the heat transfer coefficient, pressure losses and aerodynamic loading are calculated as a function of mole fraction at the temperature of 400 K and 1200 K, as well as the typical operating pressure of 2 MPa. Results indicated that the mixture of helium-carbon dioxide with a mole fraction of 0.4 is a more attractive choice for the high heat transfer coefficient, low aerodynamic loading and acceptable pressure losses in contrast to helium-nitrogen and other mixing ratios of helium-carbon dioxide. Its heat transfer coefficient is almost 20% more than that of pure helium and the normalized aerodynamic loading is less than 34% at 1200 K. However; the pressure losses are a little higher with ~3.5 times those of pure helium. (author)

Isometries on Banach spaces function spaces

CERN Document Server

Fleming, Richard J

2002-01-01

Fundamental to the study of any mathematical structure is an understanding of its symmetries. In the class of Banach spaces, this leads naturally to a study of isometries-the linear transformations that preserve distances. In his foundational treatise, Banach showed that every linear isometry on the space of continuous functions on a compact metric space must transform a continuous function x into a continuous function y satisfying y(t) = h(t)x(p(t)), where p is a homeomorphism and |h| is identically one.Isometries on Banach Spaces: Function Spaces is the first of two planned volumes that survey investigations of Banach-space isometries. This volume emphasizes the characterization of isometries and focuses on establishing the type of explicit, canonical form given above in a variety of settings. After an introductory discussion of isometries in general, four chapters are devoted to describing the isometries on classical function spaces. The final chapter explores isometries on Banach algebras.This treatment p...

Alternative power generation concepts for space

International Nuclear Information System (INIS)

Brandhorst, H.W. Jr.; Juhasz, A.J.; Jones, B.I.

1994-01-01

With the advent of the NASA Space Station, there has emerged a general realization that large quantities of power in space are necessary and, in fact, enabling. This realization has led to the examination of alternative options to the ubiquitous solar array/battery power system. Several factors led to the consideration of solar dynamic and nuclear power systems. These include better scaling to high power levels, higher efficiency conversion and storage subsystems, and lower system specific mass. The objective of this paper is to present the results of trade and optimization studies that high-light the potential of solar and nuclear dynamic systems relative to photovoltaic power systems

SpacePy - a Python-based library of tools for the space sciences

International Nuclear Information System (INIS)

Morley, Steven K.; Welling, Daniel T.; Koller, Josef; Larsen, Brian A.; Henderson, Michael G.

2010-01-01

Space science deals with the bodies within the solar system and the interplanetary medium; the primary focus is on atmospheres and above - at Earth the short timescale variation in the the geomagnetic field, the Van Allen radiation belts and the deposition of energy into the upper atmosphere are key areas of investigation. SpacePy is a package for Python, targeted at the space sciences, that aims to make basic data analysis, modeling and visualization easier. It builds on the capabilities of the well-known NumPy and MatPlotLib packages. Publication quality output direct from analyses is emphasized. The SpacePy project seeks to promote accurate and open research standards by providing an open environment for code development. In the space physics community there has long been a significant reliance on proprietary languages that restrict free transfer of data and reproducibility of results. By providing a comprehensive, open-source library of widely used analysis and visualization tools in a free, modern and intuitive language, we hope that this reliance will be diminished. SpacePy includes implementations of widely used empirical models, statistical techniques used frequently in space science (e.g. superposed epoch analysis), and interfaces to advanced tools such as electron drift shell calculations for radiation belt studies. SpacePy also provides analysis and visualization tools for components of the Space Weather Modeling Framework - currently this only includes the BATS-R-US 3-D magnetohydrodynamic model and the RAM ring current model - including streamline tracing in vector fields. Further development is currently underway. External libraries, which include well-known magnetic field models, high-precision time conversions and coordinate transformations are wrapped for access from Python using SWIG and f2py. The rest of the tools have been implemented directly in Python. The provision of open-source tools to perform common tasks will provide openness in the

The Morse oscillator in position space, momentum space, and phase space

DEFF Research Database (Denmark)

Dahl, Jens Peder; Springborg, Michael

1988-01-01

We present a unified description of the position-space wave functions, the momentum-space wave functions, and the phase-space Wigner functions for the bound states of a Morse oscillator. By comparing with the functions for the harmonic oscillator the effects of anharmonicity are visualized....... Analytical expressions for the wave functions and the phase space functions are given, and it is demonstrated how a numerical problem arising from the summation of an alternating series in evaluating Laguerre functions can be circumvented. The method is applicable also for other problems where Laguerre...... functions are to be calculated. The wave and phase space functions are displayed in a series of curves and contour diagrams. An Appendix discusses the calculation of the modified Bessel functions of real, positive argument and complex order, which is required for calculating the phase space functions...

Dual spaces of local Morrey-type spaces

OpenAIRE

Gogatishvili, A. (Amiran); Mustafayev, R. (Rza)

2011-01-01

In this paper we show that associated spaces and dual spaces of the local Morrey-type spaces are so called complementary local Morrey-type spaces. Our method is based on an application of multidimensional reverse Hardy inequalities.

Game-theoretic characterization of the Gurarii space

Czech Academy of Sciences Publication Activity Database

Kubiś, Wieslaw

2018-01-01

Roč. 110, č. 1 (2018), s. 53-59 ISSN 0003-889X R&D Projects: GA ČR(CZ) GA17-27844S Institutional support: RVO:67985840 Keywords : normed space * Banach–Mazur game * Gurarii space Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 0.591, year: 2016 https://link.springer.com/article/10.1007%2Fs00013-017-1088-2

Game-theoretic characterization of the Gurarii space

Czech Academy of Sciences Publication Activity Database

Kubiś, Wieslaw

2018-01-01

Roč. 110, č. 1 (2018), s. 53-59 ISSN 0003-889X R&D Projects: GA ČR(CZ) GA17-27844S Institutional support: RVO:67985840 Keywords : normed space * Banach–Mazur game * Gurarii space Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 0.591, year: 2016 https://link.springer.com/ article /10.1007%2Fs00013-017-1088-2

The Legal Regime of Nuclear Power Satellites-A Problem at the Cross-Roads of Nuclear Law and Space Law

International Nuclear Information System (INIS)

Courteix, S.

1992-01-01

The number of nuclear-powered satellites rises constantly and, recalling the fear generated by the crash of the Cosmos 954 satellite, the author points out that radioactive debris falling on earth could represent as great a hazard as accidental releases of radioactive material from land-based nuclear installations. Such satellites, therefore, can be governed by both space law and nuclear law. On the basis of international conventions applicable in the two fields and also with reference to the Law of the Sea and environmental law, the article analyses preventive and radiation protection measures as well as emergency plans and also raises the problem of liability and compensation for damage. (NEA)

Close-Spaced High Temperature Knudsen Flow.

Science.gov (United States)

1984-06-15

study of discharge processes in Knudsen mode (collisionless), thermionic energy converters. Areas of research involve mechanism for reducing the...The mechanisms we have chosen to study are: reduction of space-charge through a very close inter- electrode gap (less than 10 microns); transport and...AD-AI4U 471 :NNTIM R~ A Rl M ,i; ,11 , i J)W R8 1070 1 I~ "i E~Hhhh IIt Ll ~ : RASOR ASSOCIATES, INC.- AFOSR.TR. 84-1070 NSR-22-2 CLOSE -SPACED HIGH

NUCLEAR THERMIONIC SPACE POWER SYSTEMS

Energy Technology Data Exchange (ETDEWEB)

Howard, R. C.; Rasor, N. S.

1963-03-15

The various concepts for utilizing thermionic conversion in space reactor power plants are described and evaluated. The problems (and progress toward their solution) of the in-core concept, particularly, are considered. Progress in thermionic conversion technology is then reviewed from both the hardware and research points of view. Anticipated progress in thermionic conversion and the possible consequences for the performance of electrical propulsion systems are summarized. 46 references. (D.C.W.)

Banach spaces of continuous functions as dual spaces

CERN Document Server

Dales, H G; Lau, A T -M; Strauss, D

2016-01-01

This book gives a coherent account of the theory of Banach spaces and Banach lattices, using the spaces C_0(K) of continuous functions on a locally compact space K as the main example. The study of C_0(K) has been an important area of functional analysis for many years. It gives several new constructions, some involving Boolean rings, of this space as well as many results on the Stonean space of Boolean rings. The book also discusses when Banach spaces of continuous functions are dual spaces and when they are bidual spaces.

Space Radiation Peculiarities in the Extra Vehicular Environment of the International Space Station (ISS)

Science.gov (United States)

Dachev, Tsvetan; Bankov, Nikolay; Tomov, Borislav; Matviichuk, Yury; Dimitrov, Plamen

2013-12-01

The space weather and the connected with it ionizing radiation were recognized as a one of the main health concern to the International Space Station (ISS) crew. Estimation the effects of radiation on humans in ISS requires at first order accurate knowledge of the accumulated by them absorbed dose rates, which depend of the global space radiation distribution and the local variations generated by the 3D surrounding shielding distribution. The R3DE (Radiation Risks Radiometer-Dosimeter (R3D) for the EXPOSE-E platform on the European Technological Exposure Facility (EuTEF) worked successfully outside of the European Columbus module between February 2008 and September 2009. Very similar instrument named R3DR for the EXPOSE-R platform worked outside Russian Zvezda module of ISS between March 2009 and August 2010. Both are Liulin type, Bulgarian build miniature spectrometers-dosimeters. They accumulated about 5 million measurements of the flux and absorbed dose rate with 10 seconds resolution behind less than 0.41 g cm-2 shielding, which is very similar to the Russian and American space suits [1-3] average shielding. That is why all obtained data can be interpreted as possible doses during Extra Vehicular Activities (EVA) of the cosmonauts and astronauts. The paper first analyses the obtained long-term results in the different radiation environments of: Galactic Cosmic Rays (GCR), inner radiation belt trapped protons in the region of the South Atlantic Anomaly (SAA) and outer radiation belt (ORB) relativistic electrons. The large data base was used for development of an empirical model for calculation of the absorbed dose rates in the extra vehicular environment of ISS at 359 km altitude. The model approximate the averaged in a grid empirical dose rate values to predict the values at required from the user geographical point, station orbit or area in geographic coordinate system. Further in the paper it is presented an intercomparison between predicted by the model dose

Elementare Bildungseinrichtungen als safe spaces für (religiöse) Differenz

OpenAIRE

Helena Stockinger

2016-01-01

ENGLISH: Educational institutions sometimes do not offer a space for (religious) difference. Based on this fact the term safe space is theoretically specified. It seems important to develop kindergartens as safe spaces in wich learning, belonging and recognizing are possible. As one characteristic of the culture of safe spaces the recognition of (religious) difference is pointed out, especially being sensitive about and broaching the issue of difference. DEUTSCH: Bildungseinrichtungen stellen...

Results of dosimetric measurements in space missions

Science.gov (United States)

Reitz, G.; Beaujean, R.; Heilmann, C.; Kopp, J.; Leicher, M.; Strauch, K.

Detector packages consisting of plastic nuclear track detectors, nuclear emulsions, and thermoluminescence detectors were exposed at different locations inside the space laboratory Spacelab and at the astronauts' body and in different sections of the MIR space station. Total dose, particle fluence rate and linear energy transfer (LET) spectra of heavy ions, number of nuclear disintegrations and fast neutron fluence rates were determined of each exposure. The dose equivalent received by the Payload specialists (PSs) were calculated from the measurements, they range from 190 muSv d^-1 to 770 muSv d^-1. Finally, a preliminary investigation of results from a particle telescope of two silicon detectors, first used in the last BIORACK mission on STS 76, is reported.

FLRW cosmology in Weyl-integrable space-time

Energy Technology Data Exchange (ETDEWEB)

Gannouji, Radouane [Department of Physics, Faculty of Science, Tokyo University of Science, 1–3, Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan); Nandan, Hemwati [Department of Physics, Gurukula Kangri Vishwavidayalaya, Haridwar 249404 (India); Dadhich, Naresh, E-mail: gannouji@rs.kagu.tus.ac.jp, E-mail: hntheory@yahoo.co.in, E-mail: nkd@iucaa.ernet.in [IUCAA, Post Bag 4, Ganeshkhind, Pune 411 007 (India)

2011-11-01

We investigate the Weyl space-time extension of general relativity (GR) for studying the FLRW cosmology through focusing and defocusing of the geodesic congruences. We have derived the equations of evolution for expansion, shear and rotation in the Weyl space-time. In particular, we consider the Starobinsky modification, f(R) = R+βR{sup 2}−2Λ, of gravity in the Einstein-Palatini formalism, which turns out to reduce to the Weyl integrable space-time (WIST) with the Weyl vector being a gradient. The modified Raychaudhuri equation takes the form of the Hill-type equation which is then analysed to study the formation of the caustics. In this model, it is possible to have a Big Bang singularity free cyclic Universe but unfortunately the periodicity turns out to be extremely short.

Space-Time Crystal and Space-Time Group.

Science.gov (United States)

Xu, Shenglong; Wu, Congjun

2018-03-02

Crystal structures and the Bloch theorem play a fundamental role in condensed matter physics. We extend the static crystal to the dynamic "space-time" crystal characterized by the general intertwined space-time periodicities in D+1 dimensions, which include both the static crystal and the Floquet crystal as special cases. A new group structure dubbed a "space-time" group is constructed to describe the discrete symmetries of a space-time crystal. Compared to space and magnetic groups, the space-time group is augmented by "time-screw" rotations and "time-glide" reflections involving fractional translations along the time direction. A complete classification of the 13 space-time groups in one-plus-one dimensions (1+1D) is performed. The Kramers-type degeneracy can arise from the glide time-reversal symmetry without the half-integer spinor structure, which constrains the winding number patterns of spectral dispersions. In 2+1D, nonsymmorphic space-time symmetries enforce spectral degeneracies, leading to protected Floquet semimetal states. We provide a general framework for further studying topological properties of the (D+1)-dimensional space-time crystal.

Challenges for future space power systems

International Nuclear Information System (INIS)

Brandhorst, H.W. Jr.

1989-01-01

The future appears rich in missions that will extend the frontiers of knowledge, human presence in space, and opportunities for profitable commerce. The key to success of these ventures is the availability of plentiful, cost effective electric power and assured, low cost access to space. While forecasts of space power needs are problematic, an assessment of future needs based on terrestrial experience was made. These needs fall into three broad categories-survival, self sufficiency and industrialization. The cost of delivering payloads to orbital locations from low earth orbit (LEO) to Mars was determined and future launch cost reductions projected. From these factors, then, projections of the performance necessary for future solar and nuclear space power options were made. These goals are largely dependent upon orbital location and energy storage needs

Preliminary feasibility assessment for Earth-to-space electromagnetic (Railgun) launchers

Science.gov (United States)

Rice, E. E.; Miller, L. A.; Earhart, R. W.

1982-01-01

An Earth to space electromagnetic (railgun) launcher (ESRL) for launching material into space was studied. Potential ESRL applications were identified and initially assessed to formulate preliminary system requirements. The potential applications included nuclear waste disposal in space, Earth orbital applications, deep space probe launchers, atmospheric research, and boost of chemical rockets. The ESRL system concept consisted of two separate railgun launcher tubes (one at 20 deg from the horizontal for Earth orbital missions, the other vertical for solar system escape disposal missions) powered by a common power plant. Each 2040 m launcher tube is surrounded by 10,200 homopolar generator/inductor units to transmit the power to the walls. Projectile masses are 6500 kg for Earth orbital missions and 2055 kg for nuclear waste disposal missions. For the Earth orbital missions, the projectile requires a propulsion system, leaving an estimated payload mass of 650 kg. For the nuclear waste disposal in space mission, the high level waste mass was estimated at 250 kg. This preliminary assessment included technical, environmental, and economic analyses.

Lunar South Pole space water extraction and trucking system

International Nuclear Information System (INIS)

Zuppero, A.; Zupp, G.; Schnitzler, B.; Larson, T.K.; Rice, J.W.

1998-03-01

This concept proposes to use thermal processes alone to extract water from the lunar South Pole and launch payloads to low lunar orbit. Thermal steam rockets would use water propellant for space transportation. The estimated mass of a space water tanker powered by a nuclear heated steam rocket suggests it can be designed for launch in the Space Shuttle bay. The performance depends on the feasibility of a nuclear reactor rocket engine producing steam at 1,100 degrees Kelvin, with a power density of 150 Megawatts per ton of rocket, and operating for thousands of 20 minute cycles. An example uses reject heat from a small nuclear electric power supply to melt 17,800 tons per year of lunar ice. A nuclear heated steam rocket would use the propellant water to launch and deliver 3,800 tons of water per year to a 100 km low lunar orbit

The nuclear energy use in Space; Utilisation de l'energie nucleaire dans l'espace

Energy Technology Data Exchange (ETDEWEB)

Raepsaet, X. [CEA Saclay, 91 - Gif sur Yvette (France). Dept. de Mecanique et de Technologie; Pempie, P. [Centre National d' Etudes Spatiales (CNES), 91 - Evry (France)

2002-07-01

Two ways of the nuclear energy use are possible in spatial applications. The first one is the electric power production to supply satellites, space vehicles or electric propulsion. The second one, less obvious, is the thermal-nuclear propulsion where the nuclear reactor is a thermal exchanger for a gas. These two applications are presented in this paper, with two examples of projects realized in collaboration of the CNES and the CEA: ERATO as an electrical generator and MAPS as the nucleo-thermal propulsion. (A.L.B.)

Free loop spaces and cyclohedra

Czech Academy of Sciences Publication Activity Database

Markl, Martin

2003-01-01

Roč. 71, - (2003), s. 151-157 R&D Projects: GA AV ČR IAA1019203 Institutional research plan: CEZ:AV0Z1019905; CEZ:AV0Z1019905 Keywords : cyclohedron * free loop space * recognition Subject RIV: BA - General Mathematics

NewSpace: The Emerging Commercial Space Industry

Science.gov (United States)

Martin, Gary

2016-01-01

A lecture to students at the International Space University. Topics include: - We are at a turning point in the history of space exploration and development the cusp of a revolution, new industries are being born that use space in many non-traditional ways - The established military industrial space sector is no longer the only game in town - Increased competition and new capabilities will change the marketplace forever - Everyone interested in working in the space sector will be affected.

R A Cowley, the "Golden Hour," the "Momentary Pause," and the "Third Space".

Science.gov (United States)

Clark, David E

2017-12-01

R Adams Cowley (1917-1991), the Baltimore thoracic and trauma surgeon, was an outstanding politician and promoter of emergency medical services. His skills included the effective use of language, for example, identifying the critical time immediately after injury as a "golden hour," and describing shock as a "momentary pause in the act of death." Conversely, Cowley avoided the tendency of some contemporaries to justify massive crystalloid infusion by invoking a "third space." Cowley is often assumed to have originated the first two phrases, but, in fact, their histories go back at least to the 19th century and illustrate the development of surgical science. The "third space" is often assumed to have originated with Cowley's contemporary, Tom Shires (1925-2007), but, in fact, neither of them used the phrase to describe Shires' controversial theories about an extracellular fluid deficit after trauma. Reviewing the actual etymology of these terms may help clarify the history of the underlying scientific ideas and enable more effective communication in the future.

Space Commercialization and the Development of Space Law

Science.gov (United States)

Yun, Zhao

2017-05-01

Shortly after the launch of the first manmade satellite in 1957, the United Nations (UN) took the lead in formulating international rules governing space activities. The five international conventions (i.e., the 1967 Outer Space Treaty, the 1968 Rescue Agreement, the 1972 Liability Convention, the 1975 Registration Convention, and the 1979 Moon Agreement) within the UN framework constitute the nucleus of space law; laying a solid legal foundation for securing the smooth development of space activities over the next few decades. Outer space was soon found to be a place with abundant opportunities for commercialization: with telecommunications services the first and most successful commercial application followed by remote sensing and global navigation services. In the last decade, the rapid development of space technologies brought space tourism and space mining to the forefront as well. With more and more commercial activities taking place on a daily basis from the 1980s on, existing space law faces severe challenges. The five conventions, which were enacted at a time when space was monopolized by two superpowers—the United States and the former Soviet Union—also failed to take into account the commercial aspect of space activities. Although there are urgent needs for new rules to deal with the ongoing trend of space commercialization, the international society faces difficulties in adopting new rules due to diversified national interests. As a result, it adjusts legislative strategies by enacting soft laws. In view of the difficulty in adopting binding rules at the international level, states are encouraged to enact their own national space legislation providing sufficient guidance for their domestic space commercial activities. It is expected that the development of soft laws and national space legislation will be the mainstream regulatory activities in the space field for the foreseeable future.

Polynomial approximation of functions in Sobolev spaces

International Nuclear Information System (INIS)

Dupont, T.; Scott, R.

1980-01-01

Constructive proofs and several generalizations of approximation results of J. H. Bramble and S. R. Hilbert are presented. Using an averaged Taylor series, we represent a function as a polynomical plus a remainder. The remainder can be manipulated in many ways to give different types of bounds. Approximation of functions in fractional order Sobolev spaces is treated as well as the usual integer order spaces and several nonstandard Sobolev-like spaces

Space nuclear reactor system diagnosis: Knowledge-based approach

International Nuclear Information System (INIS)

Ting, Y.T.D.

1990-01-01

SP-100 space nuclear reactor system development is a joint effort by the Department of Energy, the Department of Defense and the National Aeronautics and Space Administration. The system is designed to operate in isolation for many years, and is possibly subject to little or no remote maintenance. This dissertation proposes a knowledge based diagnostic system which, in principle, can diagnose the faults which can either cause reactor shutdown or lead to another serious problem. This framework in general can be applied to the fully specified system if detailed design information becomes available. The set of faults considered herein is identified based on heuristic knowledge about the system operation. The suitable approach to diagnostic problem solving is proposed after investigating the most prevalent methodologies in Artificial Intelligence as well as the causal analysis of the system. Deep causal knowledge modeling based on digraph, fault-tree or logic flowgraph methodology would present a need for some knowledge representation to handle the time dependent system behavior. A proposed qualitative temporal knowledge modeling methodology, using rules with specified time delay among the process variables, has been proposed and is used to develop the diagnostic sufficient rule set. The rule set has been modified by using a time zone approach to have a robust system design. The sufficient rule set is transformed to a sufficient and necessary one by searching the whole knowledge base. Qualitative data analysis is proposed in analyzing the measured data if in a real time situation. An expert system shell - Intelligence Compiler is used to develop the prototype system. Frames are used for the process variables. Forward chaining rules are used in monitoring and backward chaining rules are used in diagnosis

Preparing future space leaders - International Space University

Science.gov (United States)

Stone, Barbara A.; Van Reeth, George P.

1992-01-01

The International Space University (ISU) concept of developing a cadre of space professionals that will lead the universities and industries into space is discussed. ISU is an innovative, permanent worldwide organization for training and academic instruction in all aspects of space studies. ISU's major goal is to provide the young professional academic instruction in technical and nontechnical areas of modern space exploration and research, and a forum to exchange ideas and develop both personal and professional ties at an international level.

Assessment of the SPACE Code Using the ATLAS SLB-GB-01 Test

International Nuclear Information System (INIS)

Kim, Yo Han; Yang, Chang Keun; Kim, Seyun

2013-01-01

The Korea Nuclear Hydro and Nuclear Power Co. (KHNP) has developed a safety analysis code, called the Safety and Performance Analysis Code for Nuclear Power Plants (SPACE) by collaborative works with other Korean nuclear industries. The SPACE is a general-purpose best-estimated two-phase three-field thermal-hydraulic analysis code to analyze the safety and performance of pressurized water reactors (PWRs). The SPACE code has sufficient functions and capabilities to replace outdated vendor supplied codes and to be used for the safety analysis of operating PWRs and the design of advanced reactors. As a result of the second phase of the SPACE code development project, the 2.14 version of the code was released through the successive various V and V works using integral loop test data or plant operating data. In this study, the ATLAS main steam-line break (MSLB) test, SLB-GB-01, was simulated as a V and V work. The results were compared with the measured data. The ATALS MSLB test, SLB-GB-01, was simulated using the SPACE code. The results were compared with experimental data. Through the simulation, it was concluded that the SPACE code can effectively simulate MSLB accidents

Yearbook on space policy 2015 access to space and the evolution of space activities

CERN Document Server

Baranes, Blandina; Hulsroj, Peter; Lahcen, Arne

2017-01-01

The Yearbook on Space Policy, edited by the European Space Policy Institute (ESPI), is the reference publication analysing space policy developments. Each year it presents issues and trends in space policy and the space sector as a whole. Its scope is global and its perspective is European. The Yearbook also links space policy with other policy areas. It highlights specific events and issues, and provides useful insights, data and information on space activities. The first part of the Yearbook sets out a comprehensive overview of the economic, political, technological and institutional trends that have affected space activities. The second part of the Yearbook offers a more analytical perspective on the yearly ESPI theme and consists of external contributions written by professionals with diverse backgrounds and areas of expertise. The third part of the Yearbook carries forward the character of the Yearbook as an archive of space activities. The Yearbook is designed for government decision-makers and agencies...

NASA universities advanced space design program, focus on nuclear engineering

International Nuclear Information System (INIS)

Lyon, W.F. III; George, J.A.; Alred, J.W.; Peddicord, K.L.

1987-01-01

In January 1985, the National Aeronautics and Space Administration (NASA), in affiliation with the Universities Space Research Association (USRA), inaugurated the NASA Universities Advanced Space Design Program. The purpose of the program was to encourage participating universities to utilize design projects for the senior and graduate level design courses that would focus on topics relevant to the nation's space program. The activities and projects being carried out under the NASA Universities Advanced Space Design Program are excellent experiences for the participants. This program is a well-conceived, well-planned effort to achieve the maximum benefit out of not only the university design experience but also of the subsequent summer programs. The students in the university design classes have the opportunity to investigate dramatic and new concepts, which at the same time have a place in a program of national importance. This program could serve as a very useful model for the development of university interaction with other federal agencies

A new approach to the analysis of the phase space of f(R)-gravity

Energy Technology Data Exchange (ETDEWEB)

Carloni, S., E-mail: sante.carloni@tecnico.ulisboa.pt [Centro Multidisciplinar de Astrofisica—CENTRA, Instituto Superior Tecnico – IST, Universidade de Lisboa – UL, Avenida Rovisco Pais 1, 1049-001 (Portugal)

2015-09-01

We propose a new dynamical system formalism for the analysis of f(R) cosmologies. The new approach eliminates the need for cumbersome inversions to close the dynamical system and allows the analysis of the phase space of f(R)-gravity models which cannot be investigated using the standard technique. Differently form previously proposed similar techniques, the new method is constructed in such a way to associate to the fixed points scale factors, which contain four integration constants (i.e. solutions of fourth order differential equations). In this way a new light is shed on the physical meaning of the fixed points. We apply this technique to some f(R) Lagrangians relevant for inflationary and dark energy models.

Space Science in Action: Space Exploration [Videotape].

Science.gov (United States)

1999

In this videotape recording, students learn about the human quest to discover what is out in space. Students see the challenges and benefits of space exploration including the development of rocket science, a look back at the space race, and a history of manned space travel. A special section on the Saturn V rocket gives students insight into the…

Space Nuclear Power and Propulsion - a basic Tool for the manned Exploration of the Solar System

International Nuclear Information System (INIS)

Frischauf, Norbert; Hamilton, Booz Allen

2004-01-01

Humanity has started to explore space more than 40 years ago. Numerous spacecraft have left the Earth in this endeavour, but while unmanned spacecraft were already sent out on missions, where they would eventually reach the outer limits of the Solar System, manned exploration has always been confined to the tiny bubble of the Earth's gravitational well, stretching out at maximum to our closest celestial companion - the Moon - during the era of the Apollo programme in the late 60's and early 70's. When mankind made its giant leap, the exploration of our cosmic neighbour was seen as the initial step for the manned exploration of the whole Solar System. Consequently ambitious research and development programmes were undertaken at that time to enable what seemed to be the next logical steps: the establishment of a permanent settled base on the Moon and the first manned mission to Mars in the 80's. Nuclear space power and propulsion played an important role in these entire future scenarios, hence ambitious development programmes were undertaken to make these technologies available. Unfortunately the 70's-paradigm shift in space policies did not only bring an end to the Apollo programme, but it also brought a complete halt to all of these technology programmes and confined the human presence in space to a tiny bubble including nothing more than the Earth's sphere and a mere shell of a few hundred kilometres of altitude, too small to even include the Moon. Today, after more than three decades, manned exploration of the Solar System has become an issue again and so are missions to Moon and Mars. However, studies and analyses show that all of these future plans are hampered by today's available propulsion systems and by the problematic of solar power generation at distances at and beyond of Mars, a problem, however, that can readily be solved by the utilisation of space nuclear reactors and propulsion systems. This paper intends to provide an overview on the various fission

Differential calculi on quantum vector spaces with Hecke-type relations

International Nuclear Information System (INIS)

Baez, J.C.

1991-01-01

From a vector space V equipped with a Yang-Baxter operator R one may form the r-symmetric algebra S R V=TV/ , which is a quantum vector space in the sense of Manin, and the associated quantum matrix algebra M R V=T(End(V))/ -1 >. In the case when R satisfies a Hecke-type identity R 2 =(1-q)R+q, we construct a differential calculus Ω R V for S R V which agrees with that constructed by Pusz, Woronowicz, Wess, and Zumino when R is essentially the R-matrix of GL q (n). Elements of Ω R V may be regarded as differential forms on the quantum vector space S R V. We show that Ω R V is M R V-covariant in the sense that there is a coaction Φ * :Ω R V→M R VxΩ R V with Φ * d=(1xd)Φ * extending the natural coaction Φ:S R V→M R VxS R V. (orig.)

Spacing grids for a fuel pencil bundle in a nuclear reactor assembly

International Nuclear Information System (INIS)

Feutrel, Claude.

1977-01-01

This invention relates to the lattices forming the spacing of a bundle of clad fuel pencils in a nuclear reactor assembly, particularly in a water cooled or fast reactor, the purpose of such lattices being to maintain these pencils parallel with respect to each other and according to a given lattice arrangement, whilst also providing these pencils with a flexible support according to different successive areas apportioned with their length in order to present them from vibrating under the effect of the circulation of a liquid coolant environment flowing in contact with these pencils [fr

Twistor space, Minkowski space and the conformal group

International Nuclear Information System (INIS)

Broek, P.M. van den

1983-01-01

It is shown that the conformal group of compactified Minkowski space is isomorphic to a group of rays of semilinear transformations of twistor space. The action of the conformal group on twistor space is given by an explicit realisation of this isomorphism. In this way we determine the transformation of twistor space under space inversion and time inversion. (orig.)

A simple in-surge pressure analysis using the SPACE code

International Nuclear Information System (INIS)

Youn, Bum Soo; Kim, Yo Han; Lee, Dong Hyuk; Yang, Chang Keun; Kim, Se Yun; Ha, Sang Jun

2010-01-01

Currently, nuclear safety analysis codes used in Korea are developed by all the overseas. These codes are paying huge fee and permission must be obtained for use in the country. In addition, orders for nuclear power plants must ensure the safety analysis code for independent domestic technology. Therefore, Korea Electric Power Research Institute(KEPRI) is developing the domestic nuclear power safety analysis, SPACE(Safety and Performance Analysis Code for nuclear power plants). To determine the computational power of pressurizer model in development SPACE code, it was compared with existing commercial nuclear power safety analysis code, RETRAN

Efimov spaces and the separable quotient problem for spaces C-P(K)

Czech Academy of Sciences Publication Activity Database

Kąkol, Jerzy; Śliwa, W.

2018-01-01

Roč. 457, č. 1 (2018), s. 104-113 ISSN 0022-247X R&D Projects: GA ČR GF16-34860L Institutional support: RVO:67985840 Keywords : spaces of continuous functions * pointwise topology * separable quotient problem Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 1.064, year: 2016 http://www. science direct.com/ science /article/pii/S0022247X17307588?via%3Dihub

Efimov spaces and the separable quotient problem for spaces C-P(K)

Czech Academy of Sciences Publication Activity Database

Kąkol, Jerzy; Śliwa, W.

2018-01-01

Roč. 457, č. 1 (2018), s. 104-113 ISSN 0022-247X R&D Projects: GA ČR GF16-34860L Institutional support: RVO:67985840 Keywords : spaces of continuous functions * pointwise topology * separable quotient problem Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 1.064, year: 2016 http://www.sciencedirect.com/science/article/pii/S0022247X17307588?via%3Dihub

Kinetic solvers with adaptive mesh in phase space

Science.gov (United States)

Arslanbekov, Robert R.; Kolobov, Vladimir I.; Frolova, Anna A.

2013-12-01

An adaptive mesh in phase space (AMPS) methodology has been developed for solving multidimensional kinetic equations by the discrete velocity method. A Cartesian mesh for both configuration (r) and velocity (v) spaces is produced using a “tree of trees” (ToT) data structure. The r mesh is automatically generated around embedded boundaries, and is dynamically adapted to local solution properties. The v mesh is created on-the-fly in each r cell. Mappings between neighboring v-space trees is implemented for the advection operator in r space. We have developed algorithms for solving the full Boltzmann and linear Boltzmann equations with AMPS. Several recent innovations were used to calculate the discrete Boltzmann collision integral with dynamically adaptive v mesh: the importance sampling, multipoint projection, and variance reduction methods. We have developed an efficient algorithm for calculating the linear Boltzmann collision integral for elastic and inelastic collisions of hot light particles in a Lorentz gas. Our AMPS technique has been demonstrated for simulations of hypersonic rarefied gas flows, ion and electron kinetics in weakly ionized plasma, radiation and light-particle transport through thin films, and electron streaming in semiconductors. We have shown that AMPS allows minimizing the number of cells in phase space to reduce the computational cost and memory usage for solving challenging kinetic problems.

Space Threat Warning: Foundation for Space Superiority, Avoiding a Space Pearl Harbor

National Research Council Canada - National Science Library

Burke, Alan W

2006-01-01

... have stated the US must avoid a space Pearl Harbor. This concern is due to the idea that a decrease in the perceived threat to space assets after the demise of the Soviet Union coupled with a competition for space resources has resulted...

Statistical convergence on intuitionistic fuzzy normed spaces

International Nuclear Information System (INIS)

Karakus, S.; Demirci, K.; Duman, O.

2008-01-01

Saadati and Park [Saadati R, Park JH, Chaos, Solitons and Fractals 2006;27:331-44] has recently introduced the notion of intuitionistic fuzzy normed space. In this paper, we study the concept of statistical convergence on intuitionistic fuzzy normed spaces. Then we give a useful characterization for statistically convergent sequences. Furthermore, we display an example such that our method of convergence is stronger than the usual convergence on intuitionistic fuzzy normed spaces

The outlook for application of powerful nuclear thermionic reactor -powered space electric jet propulsion engines

International Nuclear Information System (INIS)

Semyonov, Y.P.; Bakanov, Y.A.; Synyavsky, V.V.; Yuditsky, V.D.

1997-01-01

This paper summarizes main study results for application of powerful space electric jet propulsion unit (EJPUs) which is powered by Nuclear Thermionic Power Unit (NTPU). They are combined in Nuclear Power/Propulsion Unit (NPPU) which serves as means of spacecraft equipment power supply and spacecraft movement. Problems the paper deals with are the following: information satellites delivery and their on-orbit power supply during 10-15 years, removal of especially hazardous nuclear wastes, mining of asteroid resources and others. Evaluations on power/time/mass relationship for this type of mission are given. EJPU parameters are compatible with Russian existent or being under development launch vehicle. (author)

The Status of Development of Electromagnetic Pumps for Space Application

International Nuclear Information System (INIS)

Kwak, J. S.; Kim, K. H.; Jeong, J. S.; Kim, Hee Reyoung

2013-01-01

Korea lunched this research as a part of the small nuclear power generation technology development for space. In this study, investigated are the basic principle and types of electromagnetic pump and the trend of electromagnetic pump technology development in foreign nations. The survey and analysis give the understanding of the suitability and prospect of electromagnetic pumps as space application technology in Korea. The analysis on the status of the development of electromagnetic pumps was carried out for the application to space environment. It was found that USA was approaching the research and development of electromagnetic pumps for space application. Most electromagnetic pumps surveyed have the efficiency between 35% and 50% where that of AC conduction pump is less than 6%. Further study was thought to have to be given for the mechanical and material characteristics, and the applicability of electromagnetic pumps for space nuclear reactor

Additive subgroups of topological vector spaces

CERN Document Server

Banaszczyk, Wojciech

1991-01-01

The Pontryagin-van Kampen duality theorem and the Bochner theorem on positive-definite functions are known to be true for certain abelian topological groups that are not locally compact. The book sets out to present in a systematic way the existing material. It is based on the original notion of a nuclear group, which includes LCA groups and nuclear locally convex spaces together with their additive subgroups, quotient groups and products. For (metrizable, complete) nuclear groups one obtains analogues of the Pontryagin duality theorem, of the Bochner theorem and of the Lévy-Steinitz theorem on rearrangement of series (an answer to an old question of S. Ulam). The book is written in the language of functional analysis. The methods used are taken mainly from geometry of numbers, geometry of Banach spaces and topological algebra. The reader is expected only to know the basics of functional analysis and abstract harmonic analysis.

Risk knowledge and risk attitudes regarding nuclear energy sources in space

International Nuclear Information System (INIS)

Maharik, M.; Fischhoff, B.

1993-01-01

A series of four studies examined the relationship between how much people know about the risks of using nuclear energy sources in space and how they feel about the technology. The authors found that the more people know, the more favorable they are -- except for two groups of people selected from organizations with strong pro-industry or pro-environment positions. These results suggest that a technology will get a more favorable hearing if it can get its message out -- providing that it has a legitimate story to tell and that the situation has not become too polarized already. The limits to these conclusions are discussed. 19 refs., 3 figs., 1 tab

Space Sustainment: A New Approach for America in Space

Science.gov (United States)

2014-12-01

international community toward promoting market incentives in international space law. This would open up the competitive space for new entrants ...announces- new -space-situational-awareness-satellite-program.aspx. 29. Gruss, “U.S. Space Assets Face Growing Threat .” 30. McDougall, Heavens and the...November–December 2014 Air & Space Power Journal | 117 SCHRIEVER ESSAY WINNER SECOND PLACE Space Sustainment A New Approach for America in Space Lt

Total space in resolution

Czech Academy of Sciences Publication Activity Database

Bonacina, I.; Galesi, N.; Thapen, Neil

2016-01-01

Roč. 45, č. 5 (2016), s. 1894-1909 ISSN 0097-5397 R&D Projects: GA ČR GBP202/12/G061 EU Projects: European Commission(XE) 339691 - FEALORA Institutional support: RVO:67985840 Keywords : total space * resolution random CNFs * proof complexity Subject RIV: BA - General Mathematics Impact factor: 1.433, year: 2016 http://epubs.siam.org/doi/10.1137/15M1023269

Analysis of launch site processing effectiveness for the Space Shuttle 26R payload

Science.gov (United States)

Flores, Carlos A.; Heuser, Robert E.; Pepper, Richard E., Jr.; Smith, Anthony M.

1991-01-01

A trend analysis study has been performed on problem reports recorded during the Space Shuttle 26R payload's processing cycle at NASA-Kennedy, using the defect-flow analysis (DFA) methodology; DFA gives attention to the characteristics of the problem-report 'population' as a whole. It is established that the problem reports contain data which distract from pressing problems, and that fully 60 percent of such reports were caused during processing at NASA-Kennedy. The second major cause of problem reports was design defects.

NASA Space Environments Technical Discipline Team Space Weather Activities

Science.gov (United States)

Minow, J. I.; Nicholas, A. C.; Parker, L. N.; Xapsos, M.; Walker, P. W.; Stauffer, C.

2017-12-01

The Space Environment Technical Discipline Team (TDT) is a technical organization led by NASA's Technical Fellow for Space Environments that supports NASA's Office of the Chief Engineer through the NASA Engineering and Safety Center. The Space Environments TDT conducts independent technical assessments related to the space environment and space weather impacts on spacecraft for NASA programs and provides technical expertise to NASA management and programs where required. This presentation will highlight the status of applied space weather activities within the Space Environment TDT that support development of operational space weather applications and a better understanding of the impacts of space weather on space systems. We will first discuss a tool that has been developed for evaluating space weather launch constraints that are used to protect launch vehicles from hazardous space weather. We then describe an effort to better characterize three-dimensional radiation transport for CubeSat spacecraft and processing of micro-dosimeter data from the International Space Station which the team plans to make available to the space science community. Finally, we will conclude with a quick description of an effort to maintain access to the real-time solar wind data provided by the Advanced Composition Explorer satellite at the Sun-Earth L1 point.