SHIVA Nd: glass disk-amplifier-assembly facility and special purpose fixtures

International Nuclear Information System (INIS)

Jones, W.A.; Patton, H.G.; Stowers, I.F.; Wentworth, D.E.

1977-09-01

The facility built to assemble and maintain the laser amplifiers in the SHIVA Laser System is described. The facility is a Class-100 clean room which includes a high pressure solvent spray box, optical inspection equipment, and several unique amplifier-assembly fixtures

ROSA-IV Large Scale Test Facility (LSTF) system description for second simulated fuel assembly

International Nuclear Information System (INIS)

1990-10-01

The ROSA-IV Program's Large Scale Test Facility (LSTF) is a test facility for integral simulation of thermal-hydraulic response of a pressurized water reactor (PWR) during small break loss-of-coolant accidents (LOCAs) and transients. In this facility, the PWR core nuclear fuel rods are simulated using electric heater rods. The simulated fuel assembly which was installed during the facility construction was replaced with a new one in 1988. The first test with this second simulated fuel assembly was conducted in December 1988. This report describes the facility configuration and characteristics as of this date (December 1988) including the new simulated fuel assembly design and the facility changes which were made during the testing with the first assembly as well as during the renewal of the simulated fuel assembly. (author)

Purification, biochemical characterization, and implications of an alkali-tolerant catalase from the spacecraft-associated and oxidation-resistant Acinetobacter gyllenbergii 2P01AA.

Science.gov (United States)

Muster, N; Derecho, I; Dallal, F; Alvarez, R; McCoy, K B; Mogul, R

2015-04-01

Herein, we report on the purification, characterization, and sequencing of catalase from Acinetobacter gyllenbergii 2P01AA, an extremely oxidation-resistant bacterium that was isolated from the Mars Phoenix spacecraft assembly facility. The Acinetobacter are dominant members of the microbial communities that inhabit spacecraft assembly facilities and consequently may serve as forward contaminants that could impact the integrity of future life-detection missions. Catalase was purified by using a 3-step chromatographic procedure, where mass spectrometry provided respective subunit and intact masses of 57.8 and 234.6 kDa, which were consistent with a small-subunit tetrameric catalase. Kinetics revealed an extreme pH stability with no loss in activity between pH 5 and 11.5 and provided respective kcat/Km and kcat values of ∼10(7) s(-1) M(-1) and 10(6) s(-1), which are among the highest reported for bacterial catalases. The amino acid sequence was deduced by in-depth peptide mapping, and structural homology suggested that the catalases from differing strains of A. gyllenbergii differ only at residues near the subunit interfaces, which may impact catalytic stability. Together, the kinetic, alkali-tolerant, and halotolerant properties of the catalase from A. gyllenbergii 2P01AA are significant, as they are consistent with molecular adaptations toward the alkaline, low-humidity, and potentially oxidizing conditions of spacecraft assembly facilities. Therefore, these results support the hypothesis that the selective pressures of the assembly facilities impact the microbial communities at the molecular level, which may have broad implications for future life-detection missions.

Spacecraft Spin Test Facility

Data.gov (United States)

Federal Laboratory Consortium — FUNCTION: Provides the capability to correct unbalances of spacecraft by using dynamic measurement techniques and static/coupled measurements to provide products of...

Launch Lock Assemblies Including Axial Gap Amplification Devices and Spacecraft Isolation Systems Including the Same

Science.gov (United States)

Barber, Tim Daniel (Inventor); Hindle, Timothy (Inventor); Young, Ken (Inventor); Davis, Torey (Inventor)

2014-01-01

Embodiments of a launch lock assembly are provided, as are embodiments of a spacecraft isolation system including one or more launch lock assemblies. In one embodiment, the launch lock assembly includes first and second mount pieces, a releasable clamp device, and an axial gap amplification device. The releasable clamp device normally maintains the first and second mount pieces in clamped engagement; and, when actuated, releases the first and second mount pieces from clamped engagement to allow relative axial motion there between. The axial gap amplification device normally residing in a blocking position wherein the gap amplification device obstructs relative axial motion between the first and second mount pieces. The axial gap amplification device moves into a non-blocking position when the first and second mount pieces are released from clamped engagement to increase the range of axial motion between the first and second mount pieces.

Operating procedures for the Pajarito Site Critical Assembly Facility

International Nuclear Information System (INIS)

Malenfant, R.E.

1983-03-01

Operating procedures consistent with DOE Order 5480.2, Chapter VI, and the American National Standard Safety Guide for the Performance of Critical Experiments are defined for the Pajarito Site Critical Assembly Facility of the Los Alamos National Laboratory. These operating procedures supersede and update those previously published in 1973 and apply to any criticality experiment performed at the facility

Device Assembly Facility (DAF) Glovebox Radioactive Waste Characterization

International Nuclear Information System (INIS)

Dominick, J L

2001-01-01

The Device Assembly Facility (DAF) at the Nevada Test Site (NTS) provides programmatic support to the Joint Actinide Shock Physics Experimental Research (JASPER) Facility in the form of target assembly. The target assembly activities are performed in a glovebox at DAF and include Special Nuclear Material (SNM). Currently, only activities with transuranic SNM are anticipated. Preliminary discussions with facility personnel indicate that primarily two distributions of SNM will be used: Weapons Grade Plutonium (WG-Pu), and Pu-238 enhanced WG-Pu. Nominal radionuclide distributions for the two material types are included in attachment 1. Wastes generated inside glove boxes is expected to be Transuranic (TRU) Waste which will eventually be disposed of at the Waste Isolation Pilot Plant (WIPP). Wastes generated in the Radioactive Material Area (RMA), outside of the glove box is presumed to be low level waste (LLW) which is destined for disposal at the NTS. The process knowledge quantification methods identified herein may be applied to waste generated anywhere within or around the DAF and possibly JASPER as long as the fundamental waste stream boundaries are adhered to as outlined below. The method is suitable for quantification of waste which can be directly surveyed with the Blue Alpha meter or swiped. An additional quantification methodology which requires the use of a high resolution gamma spectroscopy unit is also included and relies on the predetermined radionuclide distribution and utilizes scaling to measured nuclides for quantification

Upgraded Features of Newly Constructed Fuel Assembly Mechanical Characterization Test Facility in KAERI

Energy Technology Data Exchange (ETDEWEB)

Lee, Kang Hee; Kang, Heung Seok; Yoon, Kyung Ho; Kim, Hyung Kyu; Lee, Young Ho; Kim, Soo Ho; Yang, Jae Ho [KAERI, Daejeon (Korea, Republic of)

2016-05-15

Fuel assembly mechanical characterization test facility (FAMeCT) in KAERI is newly constructed with upgraded functional features such as increased loading capacity, under-water vibration testing and severe earthquake simulation for extended fuel design guideline. The facility building is compactly designed in the scale of 3rd floor building and has regions for assembly-wise mechanical test equipment, dynamic load (seismic) simulating test system, small scale hydraulic loop and component wise test equipment. Figure 1 shows schematic regional layout of the facility building. Mechanical test platform and system is designed to increase loading capacity for axial compression test. Structural stability of the support system of new upper core plate simulator is validated through a limit case functional test. Fuel assembly mechanical characterization test facility in KAERI is newly constructed and upgraded with advanced functional features such as uprated loading capacity, under-water vibration testing and severe earthquake simulation for extended fuel design guideline. This paper briefly introduce the test facility construction and scope of the facility and is focused on the upgraded design features of the facility. Authors hope to facilitate the facility more in the future and collaborate with the industry.

PLC based control system for RAM assembly test facility

International Nuclear Information System (INIS)

Kulkarni, S.S.; Kumar, Vinaya; Chandra, Umesh

1994-01-01

The flexibility, expandability, ease of programming and diagnostic features makes the programmable logic controller (PLC) suitable for a variety of control applications in engineering system test facilities. A PLC based control system for RAM assembly test facility (RATF) and for testing the related hydraulic components is being developed and installed at BARC. This paper describes the approach taken for meeting the control requirements and illustrates the PLC software that has been developed. (author). 1 fig

Reuse of assembly systems: a great ecological and economical potential for facility suppliers

Science.gov (United States)

Weule, Hartmut; Buchholz, Carsten

2001-02-01

In addition to the consumer goods, capital goods offer a great potential for ecological and economic optimization. In view of this fact the project WiMonDi (Re-Use of Assembly Systems as new Business Fields), started in September 1998, focuses a marketable Remanufacturing and Re-Use of modules and components of assembly systems by using technically and organizationally continuous concepts. The objective of the closed Facility-Management-System is to prolong the serviceable lifespan of assembly facilities through the organized dismantling, refurbishment and reconditioning of the assembly facilities as well as their components. Therefore, it is necessary to develop easible and methodical strategies to realize a workable Re-Use concept. Within the project the focus is based on the optimization of Re-Use-strategies - the direct Re-Use, the Re-Use including Refurbishment as well as Material Recycling. The decision for an optimal strategy depends on economical (e.g. residual value, cost/benefit of relevant processes, etc.), ecological (e.g. pollutant components /substances), etc.) and technical parameters (e.g. reliability, etc.). For the purpose to integrate the total cost-of-ownership of products or components, WiMonDi integrates the costs of the use of products as well as the Re-Use costs/benefits. To initiate the conception of new distribution and user models between the supplier and the user of assembly facilities the described approach is conducted in close cooperation between Industry and University.

An Artificial Gravity Spacecraft Approach which Minimizes Mass, Fuel and Orbital Assembly Reg

Science.gov (United States)

Bell, L.

2002-01-01

The Sasakawa International Center for Space Architecture (SICSA) is undertaking a multi-year research and design study that is exploring near and long-term commercial space development opportunities. Space tourism in low-Earth orbit (LEO), and possibly beyond LEO, comprises one business element of this plan. Supported by a financial gift from the owner of a national U.S. hotel chain, SICSA has examined opportunities, requirements and facility concepts to accommodate up to 100 private citizens and crewmembers in LEO, as well as on lunar/planetary rendezvous voyages. SICSA's artificial gravity Science Excursion Vehicle ("AGSEV") design which is featured in this presentation was conceived as an option for consideration to enable round-trip travel to Moon and Mars orbits and back from LEO. During the course of its development, the AGSEV would also serve other important purposes. An early assembly stage would provide an orbital science and technology testbed for artificial gravity demonstration experiments. An ultimate mature stage application would carry crews of up to 12 people on Mars rendezvous missions, consuming approximately the same propellant mass required for lunar excursions. Since artificial gravity spacecraft that rotate to create centripetal accelerations must have long spin radii to limit adverse effects of Coriolis forces upon inhabitants, SICSA's AGSEV design embodies a unique tethered body concept which is highly efficient in terms of structural mass and on-orbit assembly requirements. The design also incorporates "inflatable" as well as "hard" habitat modules to optimize internal volume/mass relationships. Other important considerations and features include: maximizing safety through element and system redundancy; means to avoid destabilizing mass imbalances throughout all construction and operational stages; optimizing ease of on-orbit servicing between missions; and maximizing comfort and performance through careful attention to human needs. A

A Design for an Orbital Assembly Facility for Complex Missions

Science.gov (United States)

Feast, S.; Bond, A.

A design is presented for an Operations Base Station (OBS) in low earth orbit that will function as an integral part of a space transportation system, enabling assembly and maintenance of a Cis-Lunar transportation infrastructure and integration of vehicles for other high energy space missions to be carried out. Construction of the OBS assumes the use of the SKYLON Single-Stage-to-Orbit (SSTO) spaceplane, which imposes design and assembly constraints due to its payload mass limits and payload bay dimensions. It is assumed that the space transport infrastructure and high mission energy vehicles would also make use of SKYLON to deploy standard transport equipment and stages bound by these same constraints. The OBS is therefore a highly modular arrangement, incorporating some of these other vehicle system elements in its layout design. Architecturally, the facilities of the OBS are centred around the Assembly Dock which is in the form of a large cylindrical spaceframe structure with two large doors on either end incorporating a skin of aluminised Mylar to enclose the dock. Longitudinal rails provide internal tether attachments to anchor vehicles and components while manipulators are used for the handling and assembling of vehicle structures. The exterior of the OBS houses the habitation modules for workforce and vehicle crews along with propellant farms and other operational facilities.

Simulation based assembly and alignment process ability analysis for line replaceable units of the high power solid state laser facility

International Nuclear Information System (INIS)

Wang, Junfeng; Lu, Cong; Li, Shiqi

2016-01-01

Highlights: • Discrete event simulation is applied to analyze the assembly and alignment process ability of LRUs in SG-III facility. • The overall assembly and alignment process of LRUs with specific characteristics is described. • An extended-directed graph is proposed to express the assembly and alignment process of LRUs. • Different scenarios have been simulated to evaluate assembling process ability of LRUs and decision making is supported to ensure the construction millstone. - Abstract: Line replaceable units (LRUs) are important components of the very large high power solid state laser facilities. The assembly and alignment process ability of LRUs will impact the construction milestone of facilities. This paper describes the use of discrete event simulation method for assembly and alignment process analysis of LRUs in such facilities. The overall assembly and alignment process for LRUs is presented based on the layout of the optics assembly laboratory and the process characteristics are analyzed. An extended-directed graph is proposed to express the assembly and alignment process of LRUs. Taking the LRUs of disk amplifier system in Shen Guang-III (SG-III) facility as the example, some process simulation models are built based on the Quest simulation platform. The constraints, such as duration, equipment, technician and part supply, are considered in the simulation models. Different simulation scenarios have been carried out to evaluate the assembling process ability of LRUs. The simulation method can provide a valuable decision making and process optimization tool for the optics assembly laboratory layout and the process working out of such facilities.

Simulation based assembly and alignment process ability analysis for line replaceable units of the high power solid state laser facility

Energy Technology Data Exchange (ETDEWEB)

Wang, Junfeng; Lu, Cong; Li, Shiqi, E-mail: sqli@hust.edu.cn

2016-11-15

Highlights: • Discrete event simulation is applied to analyze the assembly and alignment process ability of LRUs in SG-III facility. • The overall assembly and alignment process of LRUs with specific characteristics is described. • An extended-directed graph is proposed to express the assembly and alignment process of LRUs. • Different scenarios have been simulated to evaluate assembling process ability of LRUs and decision making is supported to ensure the construction millstone. - Abstract: Line replaceable units (LRUs) are important components of the very large high power solid state laser facilities. The assembly and alignment process ability of LRUs will impact the construction milestone of facilities. This paper describes the use of discrete event simulation method for assembly and alignment process analysis of LRUs in such facilities. The overall assembly and alignment process for LRUs is presented based on the layout of the optics assembly laboratory and the process characteristics are analyzed. An extended-directed graph is proposed to express the assembly and alignment process of LRUs. Taking the LRUs of disk amplifier system in Shen Guang-III (SG-III) facility as the example, some process simulation models are built based on the Quest simulation platform. The constraints, such as duration, equipment, technician and part supply, are considered in the simulation models. Different simulation scenarios have been carried out to evaluate the assembling process ability of LRUs. The simulation method can provide a valuable decision making and process optimization tool for the optics assembly laboratory layout and the process working out of such facilities.

A new facility for the determination of critical heat flux in nuclear fuel assemblies

Energy Technology Data Exchange (ETDEWEB)

Fortman, R A; Hadaller, G I; Hamilton, R C; Hayes, R C; Shin, K S; Stern, F [Stern Laboratories Inc., Hamilton, ON (Canada)

1993-11-01

A facility for the determination of critical heat flux in simulated reactor fuel assemblies has been constructed at Stern Laboratories for CANDU Owners` Group. This paper describes the facility and method of testing. 9 figs.

Design of a high-flux test assembly for the Fusion Materials Irradiation Test Facility

International Nuclear Information System (INIS)

Opperman, E.K.; Vogel, M.A.

1982-01-01

The Fusion Material Test Facility (FMIT) will provide a high flux fusion-like neutron environment in which a variety of structural and non-structural materials irradiations can be conducted. The FMIT experiments, called test assemblies, that are subjected to the highest neutron flux magnitudes and associated heating rates will require forced convection liquid metal cooling systems to remove the neutron deposited power and maintain test specimens at uniform temperatures. A brief description of the FMIT facility and experimental areas is given with emphasis on the design, capabilities and handling of the high flux test assembly

Opto-mechanical assembly procurement for the National Ignition Facility

International Nuclear Information System (INIS)

House, W.; Simon, T.

1999-01-01

A large number of the small optics procurements for the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) will be in the form of completely assembled, tested, and cleaned subsystems. These subsystems will be integrated into the NIF at LLNL. To accomplish this task, the procurement packages will include, optical and mechanical drawings, acceptance test and cleanliness requirements. In January 1999, the first such integrated opto-mechanical assembly was received and evaluated at LLNL. With the successful completion of this important trial procurement, we were able to establish the viability of purchasing clean, ready to install, opto-mechanical assemblies from vendors within the optics industry. 32 vendors were chosen from our supplier database for quote, then five were chosen to purchase from. These five vendors represented a cross section of the optics industry. From a ''value'' catalog supplier (that did the whole job internally) to a partnership between three specialty companies, these vendors demonstrated they have the ingenuity and capability to deliver cost competitive, NIF-ready, opto- mechanical assemblies. This paper describes the vendor selection for this procurement, technical requirements including packaging, fabrication, coating, and cleanliness specifications, then testing and verification. It also gives real test results gathered from inspections performed at LLNL that show how our vendors scored on the various requirements. Keywords: Opto-Mechanical, assembly, NIF, packaging, shipping, specifications, procurement, MIL-STD-1246C, surface cleanliness

Design of remote handled process assemblies for the process facility modifications project

International Nuclear Information System (INIS)

Smets, J.L.; Ajifu, D.A.

1987-01-01

The modular design philosophy for the process facility modification project utilizes an integrated design of components to facilitate operations and maintenance of nuclear fuel reprocessing equipment in a hot cell environment. The utilization of a matrix of remoteable base frames combines with process equipment designed as remote assemblies and sub-assemblies has simplified the overall design. Modularity will allow future flexibility while providing advantages for construction and maintenance in the initial installation

High Energy X-Ray System Specification for the Device Assembly Facility (DAF) at the NNSS

International Nuclear Information System (INIS)

Fry, David A.

2012-01-01

This specification establishes requirements for an X-Ray System to be used at the Device Assembly Facility (DAF) at the Nevada National Security Site (NNSS) to support radiography of experimental assemblies for Laboratory (LANL, LLNL, SNL) programs conducting work at the NNSS.

ATLAS facility fabrication and assembly

CERN Document Server

Ballard, E O; Davis, H A; Nielsen, K E; Parker, G V; Parsons, W M

2001-01-01

Summary form only given. Atlas is a pulsed-power facility recently completed at Los Alamos National Laboratory to drive hydrodynamic experiments. This new generation pulsed-power machine consists of a radial array of 24, 240-kV Marx modules and transmission lines supplying current to the load region at the machine center. The transmission lines, powered by the Marx modules, consist of cable headers, load protection switches and tri-plates interfacing to the center transition section through detachable current joints. A conical power-flow-channel attaches to the transition section providing an elevated interface to attach the experimental loads for diagnostic access. Fabrication and assembly of all components for the Atlas machine was completed in August 2000. The machine has also progressed through a test phase where the Marx module/transmission line units were fired, individually, into a test load. Progression continued with eight and sixteen lines being fired. Subsequently, an overall machine test was condu...

Materials Characterization at Utah State University: Facilities and Knowledge-base of Electronic Properties of Materials Applicable to Spacecraft Charging

Science.gov (United States)

Dennison, J. R.; Thomson, C. D.; Kite, J.; Zavyalov, V.; Corbridge, Jodie

2004-01-01

In an effort to improve the reliability and versatility of spacecraft charging models designed to assist spacecraft designers in accommodating and mitigating the harmful effects of charging on spacecraft, the NASA Space Environments and Effects (SEE) Program has funded development of facilities at Utah State University for the measurement of the electronic properties of both conducting and insulating spacecraft materials. We present here an overview of our instrumentation and capabilities, which are particularly well suited to study electron emission as related to spacecraft charging. These measurements include electron-induced secondary and backscattered yields, spectra, and angular resolved measurements as a function of incident energy, species and angle, plus investigations of ion-induced electron yields, photoelectron yields, sample charging and dielectric breakdown. Extensive surface science characterization capabilities are also available to fully characterize the samples in situ. Our measurements for a wide array of conducting and insulating spacecraft materials have been incorporated into the SEE Charge Collector Knowledge-base as a Database of Electronic Properties of Materials Applicable to Spacecraft Charging. This Database provides an extensive compilation of electronic properties, together with parameterization of these properties in a format that can be easily used with existing spacecraft charging engineering tools and with next generation plasma, charging, and radiation models. Tabulated properties in the Database include: electron-induced secondary electron yield, backscattered yield and emitted electron spectra; He, Ar and Xe ion-induced electron yields and emitted electron spectra; photoyield and solar emittance spectra; and materials characterization including reflectivity, dielectric constant, resistivity, arcing, optical microscopy images, scanning electron micrographs, scanning tunneling microscopy images, and Auger electron spectra. Further

Welding facilities for NPP assembling

International Nuclear Information System (INIS)

Rojtenberg, S.S.

1987-01-01

Recommendations concerning the choice of equipment for welding in pre-assembling work shops, in the enlarging assembling shops and at the assembling site, are given. Advanced production automatic welders and semiautomatic machines, applied during the NPP equipment assembling as well as automatic machines specially produced for welding the main reactor components and pipelines are described. Automatic and semiautomatic machine and manual welding post supply sources are considered

Automating a spacecraft electrical power system using expert systems

Science.gov (United States)

Lollar, L. F.

1991-01-01

Since Skylab, Marshall Space Flight Center (MSFC) has recognized the need for large electrical power systems (EPS's) in upcoming Spacecraft. The operation of the spacecraft depends on the EPS. Therefore, it must be efficient, safe, and reliable. In 1978, as a consequence of having to supply a large number of EPS personnel to monitor and control Skylab, the Electrical power Branch of MSFC began the autonomously managed power system (AMPS) project. This project resulted in the assembly of a 25-kW high-voltage dc test facility and provided the means of getting man out of the loop as much as possible. AMPS includes several embedded controllers which allow a significant level of autonomous operation. More recently, the Electrical Division at MSFC has developed the space station module power management and distribution (SSM/PMAD) breadboard to investigate managing and distributing power in the Space Station Freedom habitation and laboratory modules. Again, the requirement for a high level of autonomy for the efficient operation over the lifetime of the station and for the benefits of enhanced safety has been demonstrated. This paper describes the two breadboards and the hierarchical approach to automation which was developed through these projects.

Data base of reactor physics experimental results in Kyoto University critical assembly experimental facilities

International Nuclear Information System (INIS)

Ichihara, Chihiro; Fujine, Shigenori; Hayashi, Masatoshi

1986-01-01

The Kyoto University critical assembly experimental facilities belong to the Kyoto University Research Reactor Institute, and are the versatile critical assembly constructed for experimentally studying reactor physics and reactor engineering. The facilities are those for common utilization by universities in whole Japan. During more than ten years since the initial criticality in 1974, various experiments on reactor physics and reactor engineering have been carried out using many experimental facilities such as two solidmoderated cores, a light water-moderated core and a neutron generator. The kinds of the experiment carried out were diverse, and to find out the required data from them is very troublesome, accordingly it has become necessary to make a data base which can be processed by a computer with the data accumulated during the past more than ten years. The outline of the data base, the data base CAEX using personal computers, the data base supported by a large computer and so on are reported. (Kako, I.)

Ulysses spacecraft control and monitoring system

Science.gov (United States)

Hamer, P. A.; Snowden, P. J.

1991-01-01

The baseline Ulysses spacecraft control and monitoring system (SCMS) concepts and the converted SCMS, residing on a DEC/VAX 8350 hardware, are considered. The main functions of the system include monitoring and displaying spacecraft telemetry, preparing spacecraft commands, producing hard copies of experimental data, and archiving spacecraft telemetry. The SCMS system comprises over 20 subsystems ranging from low-level utility routines to the major monitoring and control software. These in total consist of approximately 55,000 lines of FORTRAN source code and 100 VMS command files. The SCMS major software facilities are described, including database files, telemetry processing, telecommanding, archiving of data, and display of telemetry.

Cassini Spacecraft In-Flight Swap to Backup Attitude Control Thrusters

Science.gov (United States)

Bates, David M.

2010-01-01

NASA's Cassini Spacecraft, launched on October 15th, 1997 and arrived at Saturn on June 30th, 2004, is the largest and most ambitious interplanetary spacecraft in history. In order to meet the challenging attitude control and navigation requirements of the orbit profile at Saturn, Cassini is equipped with a monopropellant thruster based Reaction Control System (RCS), a bipropellant Main Engine Assembly (MEA) and a Reaction Wheel Assembly (RWA). In 2008, after 11 years of reliable service, several RCS thrusters began to show signs of end of life degradation, which led the operations team to successfully perform the swap to the backup RCS system, the details and challenges of which are described in this paper. With some modifications, it is hoped that similar techniques and design strategies could be used to benefit other spacecraft.

Multi-Objective Optimization for Solid Amine CO2 Removal Assembly in Manned Spacecraft

Directory of Open Access Journals (Sweden)

Rong A

2017-07-01

Full Text Available Carbon Dioxide Removal Assembly (CDRA is one of the most important systems in the Environmental Control and Life Support System (ECLSS for a manned spacecraft. With the development of adsorbent and CDRA technology, solid amine is increasingly paid attention due to its obvious advantages. However, a manned spacecraft is launched far from the Earth, and its resources and energy are restricted seriously. These limitations increase the design difficulty of solid amine CDRA. The purpose of this paper is to seek optimal design parameters for the solid amine CDRA. Based on a preliminary structure of solid amine CDRA, its heat and mass transfer models are built to reflect some features of the special solid amine adsorbent, Polyethylenepolyamine adsorbent. A multi-objective optimization for the design of solid amine CDRA is discussed further in this paper. In this study, the cabin CO2 concentration, system power consumption and entropy production are chosen as the optimization objectives. The optimization variables consist of adsorption cycle time, solid amine loading mass, adsorption bed length, power consumption and system entropy production. The Improved Non-dominated Sorting Genetic Algorithm (NSGA-II is used to solve this multi-objective optimization and to obtain optimal solution set. A design example of solid amine CDRA in a manned space station is used to show the optimal procedure. The optimal combinations of design parameters can be located on the Pareto Optimal Front (POF. Finally, Design 971 is selected as the best combination of design parameters. The optimal results indicate that the multi-objective optimization plays a significant role in the design of solid amine CDRA. The final optimal design parameters for the solid amine CDRA can guarantee the cabin CO2 concentration within the specified range, and also satisfy the requirements of lightweight and minimum energy consumption.

Radioactive isotope production for medical applications using Kharkov electron driven subcritical assembly facility

International Nuclear Information System (INIS)

Talamo, A.; Gohar, Y.

2007-01-01

Kharkov Institute of Physics and Technology (KIPT) of Ukraine has a plan to construct an accelerator driven subcritical assembly. The main functions of the subcritical assembly are the medical isotope production, neutron thereby, and the support of the Ukraine nuclear industry. Reactor physics experiments and material research will be carried out using the capabilities of this facility. The United States of America and Ukraine have started collaboration activity for developing a conceptual design for this facility with low enrichment uranium (LEU) fuel. Different conceptual designs are being developed based on the facility mission and the engineering requirements including nuclear physics, neutronics, heat transfer, thermal hydraulics, structure, and material issues. Different fuel designs with LEU and reflector materials are considered in the design process. Safety, reliability, and environmental considerations are included in the facility conceptual design. The facility is configured to accommodate future design improvements and upgrades. This report is a part of the Argonne National Laboratory Activity within this collaboration for developing and characterizing the subcritical assembly conceptual design. In this study, the medical isotope production function of the Kharkov facility is defined. First, a review was carried out to identify the medical isotopes and its medical use. Then a preliminary assessment was performed without including the self-shielding effect of the irradiated samples. Finally, more detailed investigation was carried out including the self-shielding effect, which defined the sample size and irradiation location for producing each medical isotope. In the first part, the reaction rates were calculated as the multiplication of the cross section with the unperturbed neutron flux of the facility. Over fifty isotopes were considered and all transmutation channels are used including (n,γ), (n,2n), (n,p), and (γ,n). In the second part, the parent

Radioactive isotope production for medical applications using Kharkov electron driven subcritical assembly facility.

Energy Technology Data Exchange (ETDEWEB)

Talamo, A.; Gohar, Y.; Nuclear Engineering Division

2007-05-15

Kharkov Institute of Physics and Technology (KIPT) of Ukraine has a plan to construct an accelerator driven subcritical assembly. The main functions of the subcritical assembly are the medical isotope production, neutron thereby, and the support of the Ukraine nuclear industry. Reactor physics experiments and material research will be carried out using the capabilities of this facility. The United States of America and Ukraine have started collaboration activity for developing a conceptual design for this facility with low enrichment uranium (LEU) fuel. Different conceptual designs are being developed based on the facility mission and the engineering requirements including nuclear physics, neutronics, heat transfer, thermal hydraulics, structure, and material issues. Different fuel designs with LEU and reflector materials are considered in the design process. Safety, reliability, and environmental considerations are included in the facility conceptual design. The facility is configured to accommodate future design improvements and upgrades. This report is a part of the Argonne National Laboratory Activity within this collaboration for developing and characterizing the subcritical assembly conceptual design. In this study, the medical isotope production function of the Kharkov facility is defined. First, a review was carried out to identify the medical isotopes and its medical use. Then a preliminary assessment was performed without including the self-shielding effect of the irradiated samples. Finally, more detailed investigation was carried out including the self-shielding effect, which defined the sample size and irradiation location for producing each medical isotope. In the first part, the reaction rates were calculated as the multiplication of the cross section with the unperturbed neutron flux of the facility. Over fifty isotopes were considered and all transmutation channels are used including (n,{gamma}), (n,2n), (n,p), and ({gamma},n). In the second part

Nuclear-powered Hysat spacecraft: comparative design study

International Nuclear Information System (INIS)

Raab, B.

1975-08-01

The study shows that the all-nuclear spacecraft can have a substantial weight advantage over a hybrid (nuclear/solar) or all-solar spacecraft, owing to a further reduction in power requirement, and to the elimination of such equipment as the sensor gimbal and rotating joint assemblies. Because the need for a sun-oriented section is eliminated, the all-nuclear spacecraft can be designed as a monolithic structure, with the sensor and other payload firmly secured in a fixed position on the structure. This enhances attitude stability while minimizing structural weight and eliminating the need for flexible fluid lines. Sensor motion can be produced, varied, and controlled within the limits specified by the study contractors by moving the entire spacecraft in the prescribed pattern. A simple attitude control system using available hardware suffices to meet all requirements

Kodak Mirror Assembly Tested at Marshall Space Flight Center

Science.gov (United States)

2003-01-01

This photo (a frontal view) is of one of many segments of the Eastman-Kodak mirror assembly being tested for the James Webb Space Telescope (JWST) project at the X-Ray Calibration Facility at Marshall Space Flight Center (MSFC). MSFC is supporting Goddard Space Flight Center (GSFC) in developing the JWST by taking numerous measurements to predict its future performance. The tests are conducted in a vacuum chamber cooled to approximate the super cold temperatures found in space. During its 27 years of operation, the facility has performed testing in support of a wide array of projects, including the Hubble Space Telescope (HST), Solar A, Chandra technology development, Chandra High Resolution Mirror Assembly and science instruments, Constellation X-Ray Mission, and Solar X-Ray Imager, currently operating on a Geostationary Operational Environment Satellite. The JWST is NASA's next generation space telescope, a successor to the Hubble Space Telescope, named in honor of NASA's second administrator, James E. Webb. It is scheduled for launch in 2010 aboard an expendable launch vehicle. It will take about 3 months for the spacecraft to reach its destination, an orbit of 940,000 miles in space.

National Ignition Facility subsystem design requirements optics assembly building (OAB) SSDR 1.2.2.3

International Nuclear Information System (INIS)

Kempel, P.; Hands, J.

1996-01-01

This Subsystem Design Requirement (SSDR) document establishes the performance, design, and verification requirements 'for the conventional building systems and subsystems of the Optics Assembly Building (OAB). These building system requirements are associated with housing and supporting the operational flow of personnel and materials throughout the OAB for preparing and repairing optical and mechanical components used in the National Ignition Facility (NIF) Laser and Target Building (LTAB). This SSDR addresses the following subsystems associated with the OAB: * Structural systems for the building spaces and operational-support equipment and building- support equipment. * Architectural building features associated with housing the space, operational cleanliness, and functional operation of the facility. * Heating, Ventilating, and Air Conditioning (HVAC) systems for maintaining a clean and thermally stable ambient environment within the facility. * Plumbing systems that provide potable water and sanitary facilities for the occupants and stormwater drainage for transporting rainwater. * Fire Protection systems that guard against fire damage to the facility and its contents. * Material handling equipment for transferring optical assemblies and other materials within building areas and to the LTAB. * Mechanical process piping systems for liquids and gases that provide cooling, cleaning, and other service to optical and mechanical components. * Electrical power and grounding systems that provide service to the building and equipment, including lighting distribution and communications systems for the facilities. * Instrumentation and control systems that ensure the safe operation of conventional facilities systems, such as those listed above. Generic design criteria, such as siting data, seismic requirements, utility availability, and other information that contributes to the OAB design, are not addressed in this document

Hot target assembly at 14 UD Pelletron Accelerator Facility, BARC- TIFR, Mumbai

International Nuclear Information System (INIS)

Sharma, S.C.; Ramjilal; Ninawe, N.G.; Bhagwat, P.V.; Ahmeabadhai, P.; Kain, V.

2005-01-01

BARC-TIFR 14 UD Pelletron Accelerator Facility at Mumbai is operational since 1989 with progressively increased efficiency. The accelerator has been serving as major facility for heavy ion based research in India. There is an increased demand for high current proton beam, especially on heated targets for reactor physics based experiments. A proton beam setup is commissioned in the tower area of the existing facility itself, which provide proton beam of energy 2 MeV to 26 MeV with maximum 3 μA current. This setup is being used to produce radioisotopes and tracer packets. Proton beam of few MeV in μA current range is also needed to study radiation effects on metals at higher temperature, for use in reactors. For this purpose a hot target assembly has been designed and is being currently used at the Pelletron Accelerator

Time Frequency Analysis of Spacecraft Propellant Tank Spinning Slosh

Science.gov (United States)

Green, Steven T.; Burkey, Russell C.; Sudermann, James

2010-01-01

Many spacecraft are designed to spin about an axis along the flight path as a means of stabilizing the attitude of the spacecraft via gyroscopic stiffness. Because of the assembly requirements of the spacecraft and the launch vehicle, these spacecraft often spin about an axis corresponding to a minor moment of inertia. In such a case, any perturbation of the spin axis will cause sloshing motions in the liquid propellant tanks that will eventually dissipate enough kinetic energy to cause the spin axis nutation (wobble) to grow further. This spinning slosh and resultant nutation growth is a primary design problem of spinning spacecraft and one that is not easily solved by analysis or simulation only. Testing remains the surest way to address spacecraft nutation growth. This paper describes a test method and data analysis technique that reveal the resonant frequency and damping behavior of liquid motions in a spinning tank. Slosh resonant frequency and damping characteristics are necessary inputs to any accurate numerical dynamic simulation of the spacecraft.

Supplementary neutron-flux calculations for the ORNL Pool Critical Assembly Pressure Vessel Facility

International Nuclear Information System (INIS)

Maudlin, P.J.; Maerker, R.E.

1982-01-01

A three-dimensional Monte Carlo calculation using the MORSE code was performed to validate a procedure previously adopted in the ORNL discrete ordinate analysis of measurements made in the ORNL Pool Critical Assembly Pressure Vessel Facility. The results of these flux calculations agree, within statistical undertainties of about 5%, with those obtained from a discrete ordinate analysis employing the same procedure. This study therefore concludes that the procedure for combining several one- and two-dimensional discrete ordinate calculations into a three-dimensional flux is sufficiently accurate that it does not account for the existing discrepancies observed between calculations and measurements in this facility

Supplementary neutron-flux calculations for the ORNL Pool Critical Assembly Pressure Vessel Facility

Energy Technology Data Exchange (ETDEWEB)

Maudlin, P.J.; Maerker, R.E.

1982-01-01

A three-dimensional Monte Carlo calculation using the MORSE code was performed to validate a procedure previously adopted in the ORNL discrete ordinate analysis of measurements made in the ORNL Pool Critical Assembly Pressure Vessel Facility. The results of these flux calculations agree, within statistical undertainties of about 5%, with those obtained from a discrete ordinate analysis employing the same procedure. This study therefore concludes that the procedure for combining several one- and two-dimensional discrete ordinate calculations into a three-dimensional flux is sufficiently accurate that it does not account for the existing discrepancies observed between calculations and measurements in this facility.

Nondestructive measurement of spent fuel assemblies at the Tokai Reprocessing and Storage Facility

International Nuclear Information System (INIS)

Phillips, J.R.; Bosler, G.E.; Halbig, J.K.; Lee, D.M.

1979-12-01

Nondestructive verification of irradiated fuel assemblies is an integral part of any safeguards system for a reprocessing facility. Available techniques are discussed with respect to the level of verification provided by each. A combination of high-resolution gamma spectrometry, neutron detectors, and gross gamma activity profile monitors provide a maximum amount of information in a minimum amount of time

Mid Infrared Instrument cooler subsystem test facility overview

Science.gov (United States)

Moore, B.; Zan, J.; Hannah, B.; Chui, T.; Penanen, K.; Weilert, M.

2017-12-01

The Cryocooler for the Mid Infrared Instrument (MIRI) on the James Webb Space Telescope (JWST) provides cooling at 6.2K on the instrument interface. The cooler system design has been incrementally documented in previous publications [1][2][3][4][5]. It has components that traverse three primary thermal regions on JWST: Region 1, approximated by 40K; Region 2, approximated by 100K; and Region 3, which is at the allowable flight temperatures for the spacecraft bus. However, there are several sub-regions that exist in the transition between primary regions and at the heat reject interfaces of the Cooler Compressor Assembly (CCA) and Cooler Control Electronics Assembly (CCEA). The design and performance of the test facility to provide a flight representative thermal environment for acceptance testing and characterization of the complete MIRI cooler subsystem are presented.

Spacecraft Water Regeneration by Catalytic Wet Air Oxidation, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The objective of this project is to develop advanced catalysts for a volatile removal assembly used to purify spacecraft water. The innovation of the proposed...

Remote handling facility and equipment used for space truss assembly

International Nuclear Information System (INIS)

Burgess, T.W.

1987-01-01

The ACCESS truss remote handling experiments were performed at Oak Ridge National Laboratory's (ORNL's) Remote Operation and Maintenance Demonstration (ROMD) facility. The ROMD facility has been developed by the US Department of Energy's (DOE's) Consolidated Fuel Reprocessing Program to develop and demonstrate remote maintenance techniques for advanced nuclear fuel reprocessing equipment and other programs of national interest. The facility is a large-volume, high-bay area that encloses a complete, technologically advanced remote maintenance system that first began operation in FY 1982. The maintenance system consists of a full complement of teleoperated manipulators, manipulator transport systems, and overhead hoists that provide the capability of performing a large variety of remote handling tasks. This system has been used to demonstrate remote manipulation techniques for the DOE, the Power Reactor and Nuclear Fuel Development Corporation (PNC) of Japan, and the US Navy in addition to the National Aeronautics and Space Administration. ACCESS truss remote assembly was performed in the ROMD facility using the Central Research Laboratory's (CRL) model M-2 servomanipulator. The model M-2 is a dual-arm, bilateral force-reflecting, master/slave servomanipulator which was jointly developed by CRL and ORNL and represents the state of the art in teleoperated manipulators commercially available in the United States today. The model M-2 servomanipulator incorporates a distributed, microprocessor-based digital control system and was the first successful implementation of an entirely digitally controlled servomanipulator. The system has been in operation since FY 1983. 3 refs., 2 figs

Ultraviolet Light Generation and Transport in the Final Optics Assembly of the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Wegner, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hackel, L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Feit, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Parham, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kozlowski, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Whitman, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2015-02-12

The design of the National Ignition Facility (NIF) includes a Final Optics Assembly (FOA) subsystem for ultraviolet (UV) light generation and transport for each of the 192 beamlines. Analytical and experimental work has been done to help understand and predict the performance of FOA.

Spacecraft design project: Low Earth orbit communications satellite

Science.gov (United States)

Moroney, Dave; Lashbrook, Dave; Mckibben, Barry; Gardener, Nigel; Rivers, Thane; Nottingham, Greg; Golden, Bill; Barfield, Bill; Bruening, Joe; Wood, Dave

1991-01-01

This is the final product of the spacecraft design project completed to fulfill the academic requirements of the Spacecraft Design and Integration 2 course (AE-4871) taught at the U.S. Naval Postgraduate School. The Spacecraft Design and Integration 2 course is intended to provide students detailed design experience in selection and design of both satellite system and subsystem components, and their location and integration into a final spacecraft configuration. The design team pursued a design to support a Low Earth Orbiting (LEO) communications system (GLOBALSTAR) currently under development by the Loral Cellular Systems Corporation. Each of the 14 team members was assigned both primary and secondary duties in program management or system design. Hardware selection, spacecraft component design, analysis, and integration were accomplished within the constraints imposed by the 11 week academic schedule and the available design facilities.

Interim guidance risk assessment of the device assembly facility at the Nevada test site

International Nuclear Information System (INIS)

Altenbach, T.J.

1996-05-01

The risks of plutonium dispersal and/or high explosive detonation from nuclear explosive operations at the Device Assembly Facility were examined in accordance with DOE Order 5610.11 and the Interim Guidance. The assessment consisted of a qualitative task and hazards analysis, and a quantitative risk screening. Results are displayed on risk matrices for the major types of operations. Most accident scenarios were considered to have Low risk; a few scenarios have Moderate risk; and none have High risk. The highest risk scenarios (Moderate category) consist of a high explosive detonation during assembly operations in a cell, with bare conventional high explosive surrounding the pit

Commercial Application of In-Space Assembly

Science.gov (United States)

Lymer, John; Hanson, Mark; Tadros, Al; Boccio, Joel; Hollenstein, Bruno; Emerick, Ken; Doughtery, Sean; Doggett, Bill; Dorsey, John T.; King, Bruce D.;

Application of PLUTO Test Facility for U. S. NRC Licensing of a Fuel Assembly

Energy Technology Data Exchange (ETDEWEB)

Oh, Dongseok; Shin, Changhwan; Lee, Kanghee; Kang, Heungseok [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2013-10-15

The fuel assembly of the PLUS-7 loaded in the APR-1400 follows the same schedule. Meanwhile, In July 1998, the U.S. NRC adopted a research plan to address the effects of high burnup from a Loss of Coolant Accident (LOCA). From these programs, several important technical findings for rule revision were obtained. Based on the technical findings, the U. S. NRC has amended the 10 CFR 50.46 which will be proclaimed sooner or later. Through the amendment, a LOCA analysis on the fuel assembly has to show the safety at both a fresh and End of Life (EOL) state. The U. S. NRC has already required EOL effects on seismic/LOCA performance for a fuel assembly since 1998. To obtain U.S NRC licensing of a fuel assembly, based on the amendment of 10CFR50.46, a LOCA analysis of the fuel assembly has to show safety both fresh and EOL states. The proper damping factor of the fuel assembly measured at the hydraulic test loop for a dynamic model in a LOCA and a seismic analysis code are at least required. In this paper, we have examined the damping technologies and compared the test facility of PLUTO with others in terms of performance. PLUTO has a better performance on the operating conditions than any others.

Prevention of significant deterioration permit application for the Fueled Clad Fabrication System, the Radioisotope Power Systems Facility, and the Fuel Assembly Area

Energy Technology Data Exchange (ETDEWEB)

1989-08-01

This New Source Review'' has been submitted by the US Department of Energy-Richland Operations Office (PO Box 550, Richland, Washington 99352), pursuant to WAC 173-403-050 and in compliance with the Department of Ecology Guide to Processing A Prevention Of Significant Deterioration (PSD) Permit'' for three new sources of radionuclide emissions at the Hanford Site in Washington State. The three new sources, the Fueled Clad Fabrication System (FCFS), the Radioisotope Power Systems Facility (RPSF), and the Fuel Assembly Area (FAA), will be located in one facility, the Fuels and Materials Examination Facility (FMEF) of the 400 Area. The FMEF was originally designed to provide for post-irradiation examination and fabrication of breeder reactor fuels. These FMEF missions were cancelled before the introduction of any fuel materials or any irradiated material. The current plans are to use the facility to fabricate power supplies for use in space applications and to produce Fast Flux Test Facility (FFTF) fuel and target assemblies. The FCFS and the RPSF will produce materials and assemblies for application in space. The FAA project will produce FFTF fuel and target assemblies. The FCFS and the RPSF will share the same building, stack, and, in certain cases, the same floor space. Given this relationship, these systems will be dealt with separately to the extent possible. The FAA is a comparatively independent operation though it will share the FMEF complex.

Benchmark assemblies of the Los Alamos critical assemblies facility

International Nuclear Information System (INIS)

Dowdy, E.J.

1986-01-01

Several critical assemblies of precisely known materials composition and easily calculated and reproducible geometries have been constructed at the Los Alamos National Laboratory. Some of these machines, notably Jezebel, Flattop, Big Ten, and Godiva, have been used as benchmark assemblies for the comparison of the results of experimental measurements and computation of certain nuclear reaction parameters. These experiments are used to validate both the input nuclear data and the computational methods. The machines and the applications of these machines for integral nuclear data checks are described. (author)

Benchmark assemblies of the Los Alamos Critical Assemblies Facility

International Nuclear Information System (INIS)

Dowdy, E.J.

1985-01-01

Several critical assemblies of precisely known materials composition and easily calculated and reproducible geometries have been constructed at the Los Alamos National Laboratory. Some of these machines, notably Jezebel, Flattop, Big Ten, and Godiva, have been used as benchmark assemblies for the comparison of the results of experimental measurements and computation of certain nuclear reaction parameters. These experiments are used to validate both the input nuclear data and the computational methods. The machines and the applications of these machines for integral nuclear data checks are described

Benchmark assemblies of the Los Alamos critical assemblies facility

International Nuclear Information System (INIS)

Dowdy, E.J.

1985-01-01

Several critical assemblies of precisely known materials composition and easily calculated and reproducible geometries have been constructed at the Los Alamos National Laboratory. Some of these machines, notably Jezebel, Flattop, Big Ten, and Godiva, have been used as benchmark assemblies for the comparison of the results of experimental measurements and computation of certain nuclear reaction parameters. These experiments are used to validate both the input nuclear data and the computational methods. The machines and the applications of these machines for integral nuclear data checks are described

Supplemental information for a notice of construction for the Fueled Clad Fabrication System, the Radioisotope Power Systems Facility, and the Fuel Assembly Area

Energy Technology Data Exchange (ETDEWEB)

1989-08-01

This ''Notice of Construction'' has been submitted by the US Department of Energy-Richland Operations Office (P.O. Box 550, Richland, Washington 99352), pursuant to WAC 402-80-070, for three new sources of radionuclide emissions at the Hanford Site in Washington State (Figure 1). The three new sources, the Fueled Clad Fabrication System (FCFS) the Radioisotope Power Systems Facility (RPSF) and the Fuel Assembly Area (FAA) will be located in one facility, the Fuels and materials Examination Facility (FMEF) of the 400 Area. The FMEF was originally designed to provide for post- irradiation examination and fabrication of breeder reactor fuels. These FMEF missions were cancelled before the introduction of any fuel materials or any irradiated material. The current plans are to use the facility to fabricate power supplies to be used in space applications and to produce Fast Flux Test Facility (FFTF) fuel and target assemblies. The FCFS and the RPSF will produce materials and assemblies for application in space. The FAA project will produce FFTF fuel and target assemblies. The FCFS and the RPSF will share the same building, stack, and, in certain cases, the same floor space. Given this relationship, to the extent possible, these systems will be dealt with separately. The FAA is a comparatively independent operation though it will share the FMEF complex.

The 1993 baseline biological studies and proposed monitoring plan for the Device Assembly Facility at the Nevada Test Site

Energy Technology Data Exchange (ETDEWEB)

Woodward, B.D.; Hunter, R.B.; Greger, P.D.; Saethre, M.B.

1995-02-01

This report contains baseline data and recommendations for future monitoring of plants and animals near the new Device Assembly Facility (DAF) on the Nevada Test Site (NTS). The facility is a large structure designed for safely assembling nuclear weapons. Baseline data was collected in 1993, prior to the scheduled beginning of DAF operations in early 1995. Studies were not performed prior to construction and part of the task of monitoring operational effects will be to distinguish those effects from the extensive disturbance effects resulting from construction. Baseline information on species abundances and distributions was collected on ephemeral and perennial plants, mammals, reptiles, and birds in the desert ecosystems within three kilometers (km) of the DAF. Particular attention was paid to effects of selected disturbances, such as the paved road, sewage pond, and the flood-control dike, associated with the facility. Radiological monitoring of areas surrounding the DAF is not included in this report.

Rocket Assembly and Checkout Facility

Data.gov (United States)

Federal Laboratory Consortium — FUNCTION: Integrates, tests, and calibrates scientific instruments flown on sounding rocket payloads. The scientific instruments are assembled on an optical bench;...

Launch Lock Assemblies with Reduced Preload and Spacecraft Isolation Systems Including the Same

Science.gov (United States)

Barber, Tim Daniel (Inventor); Young, Ken (Inventor); Hindle, Timothy (Inventor)

2016-01-01

Launch lock assemblies with reduced preload are provided. The launch lock assembly comprises first and second mount pieces, a releasable clamp device, and a pair of retracting assemblies. Each retracting assembly comprises a pair of toothed members having interacting toothed surfaces. The releasable clamp device normally maintains the first and second mount pieces in clamped engagement. When the releasable clamp device is actuated, the first and second mount pieces are released from clamped engagement and one toothed member of each retracting assembly moves in an opposite direction relative to the other one toothed member of the other retracting assembly to define an axial gap on each side of the first mount piece.

The Stardust spacecraft arrives at KSC

Science.gov (United States)

1998-01-01

After arrival at the Shuttle Landing Facility in the early morning hours, the crated Stardust spacecraft waits to be unloaded from the aircraft. Built by Lockheed Martin Astronautics near Denver, Colo., for the Jet Propulsion Laboratory (JPL) NASA, the spacecraft Stardust will use a unique medium called aerogel to capture comet particles flying off the nucleus of comet Wild 2 in January 2004, plus collect interstellar dust for later analysis. Stardust will be launched aboard a Boeing Delta 7426 rocket from Complex 17, Cape Canaveral Air Station, targeted for Feb. 6, 1999. The collected samples will return to Earth in a re- entry capsule to be jettisoned from Stardust as it swings by in January 2006.

A facility to remotely assemble radioisotope thermoelectric generators

International Nuclear Information System (INIS)

Engstrom, J.W.; Goldmann, L.H.; Truitt, R.W.

1992-07-01

Radioisotope Thermoelectric Generators (RTGs) are electrical power sources that use heat from decaying radioisotopes to directly generate electrical power. The RTG assembly process is performed in an inert atmosphere inside a large glovebox, which is surrounded by radiation shielding to reduce exposure to neutron and gamma radiation from the radioisotope heat source. In the past, allowable dose rate limits have allowed direct, manual assembly methods; however, current dose rate limits require a thicker radiation shielding that makes direct, manual assembly infeasible. To minimize RTG assembly process modifications, telerobotic systems are being investigated to perform remote assembly tasks. Telerobotic systems duplicate human arm motion and incorporate force feedback sensitivity to handle objects and tools in a human-like manner. A telerobotic system with two arms and a three-dimensional (3-D) vision system can be used to perform remote RTG assembly tasks inside gloveboxes and cells using unmodified, normal hand tools

BRET fuel assembly dismantling machine

International Nuclear Information System (INIS)

Titzler, P.A.; Bennett, K.L.; Kelley, R.S. Jr.; Stringer, J.L.

1984-08-01

An automated remote nuclear fuel assembly milling and dismantling machine has been designed, developed, and demonstrated at the Hanford Engineering Development Laboratory (HEDL) in Richland, Washington. The machine can be used to dismantle irradiated breeder fuel assemblies from the Fast Flux Test Facility prior to fuel reprocessing. It can be installed in an existing remotely operated shielded hot cell facility, the Fuels and Materials Examination Facility (FMEF), at the Hanford Site in Richland, Washington

LDEF materials results for spacecraft applications: Executive summary

Science.gov (United States)

Whitaker, A. F.; Dooling, D.

1995-03-01

To address the challenges of space environmental effects, NASA designed the Long Duration Exposure Facility (LDEF) for an 18-month mission to expose thousands of samples of candidate materials that might be used on a space station or other orbital spacecraft. LDEF was launched in April 1984 and was to have been returned to Earth in 1985. Changes in mission schedules postponed retrieval until January 1990, after 69 months in orbit. Analyses of the samples recovered from LDEF have provided spacecraft designers and managers with the most extensive data base on space materials phenomena. Many LDEF samples were greatly changed by extended space exposure. Among even the most radially altered samples, NASA and its science teams are finding a wealth of surprising conclusions and tantalizing clues about the effects of space on materials. Many were discussed at the first two LDEF results conferences and subsequent professional papers. The LDEF Materials Results for Spacecraft Applications Conference was convened in Huntsville to discuss implications for spacecraft design. Already, paint and thermal blanket selections for space station and other spacecraft have been affected by LDEF data. This volume synopsizes those results.

Singular formalism and admissible control of spacecraft with rotating flexible solar array

Directory of Open Access Journals (Sweden)

Lu Dongning

2014-02-01

Full Text Available This paper is concerned with the attitude control of a three-axis-stabilized spacecraft which consists of a central rigid body and a flexible sun-tracking solar array driven by a solar array drive assembly. Based on the linearization of the dynamics of the spacecraft and the modal identities about the flexible and rigid coupling matrices, the spacecraft attitude dynamics is reduced to a formally singular system with periodically varying parameters, which is quite different from a spacecraft with fixed appendages. In the framework of the singular control theory, the regularity and impulse-freeness of the singular system is analyzed and then admissible attitude controllers are designed by Lyapunov’s method. To improve the robustness against system uncertainties, an H∞ optimal control is designed by optimizing the H∞ norm of the system transfer function matrix. Comparative numerical experiments are performed to verify the theoretical results.

Probing interferometric parallax with interplanetary spacecraft

Science.gov (United States)

Rodeghiero, G.; Gini, F.; Marchili, N.; Jain, P.; Ralston, J. P.; Dallacasa, D.; Naletto, G.; Possenti, A.; Barbieri, C.; Franceschini, A.; Zampieri, L.

2017-07-01

We describe an experimental scenario for testing a novel method to measure distance and proper motion of astronomical sources. The method is based on multi-epoch observations of amplitude or intensity correlations between separate receiving systems. This technique is called Interferometric Parallax, and efficiently exploits phase information that has traditionally been overlooked. The test case we discuss combines amplitude correlations of signals from deep space interplanetary spacecraft with those from distant galactic and extragalactic radio sources with the goal of estimating the interplanetary spacecraft distance. Interferometric parallax relies on the detection of wavefront curvature effects in signals collected by pairs of separate receiving systems. The method shows promising potentialities over current techniques when the target is unresolved from the background reference sources. Developments in this field might lead to the construction of an independent, geometrical cosmic distance ladder using a dedicated project and future generation instruments. We present a conceptual overview supported by numerical estimates of its performances applied to a spacecraft orbiting the Solar System. Simulations support the feasibility of measurements with a simple and time-saving observational scheme using current facilities.

Supplementary neutron flux calculations for the ORNL pool critical assembly pressure vessel facility

Energy Technology Data Exchange (ETDEWEB)

Maerker, R.E.; Maudlin, P.J.

1981-02-01

A three-dimensional Monte Carlo calculation was performed to estimate the neutron flux in the 8/7 configuration of the ORNL Pool Critical Assembly Pressure Vessel Facility. The calculational tool was the multigroup transport code MORSE operated in the adjoint mode. The MORSE flux results compared well with those using a previously adopted procedure for constructing a three-dimensional flux from one- and two-dimensional discrete ordinates calculations using the DOT-IV code. This study concluded that use of these discrete ordinates constructions in previous calculations is sufficiently accurate and does not account for the existing discrepancies between calculation and experiment.

Supplementary neutron flux calculations for the ORNL pool critical assembly pressure vessel facility

International Nuclear Information System (INIS)

Maerker, R.E.; Maudlin, P.J.

1981-02-01

A three-dimensional Monte Carlo calculation was performed to estimate the neutron flux in the 8/7 configuration of the ORNL Pool Critical Assembly Pressure Vessel Facility. The calculational tool was the multigroup transport code MORSE operated in the adjoint mode. The MORSE flux results compared well with those using a previously adopted procedure for constructing a three-dimensional flux from one- and two-dimensional discrete ordinates calculations using the DOT-IV code. This study concluded that use of these discrete ordinates constructions in previous calculations is sufficiently accurate and does not account for the existing discrepancies between calculation and experiment

Passive Plasma Contact Mechanisms for Small-Scale Spacecraft

Science.gov (United States)

McTernan, Jesse K.

Small-scale spacecraft represent a paradigm shift in how entities such as academia, industry, engineering firms, and the scientific community operate in space. However, although the paradigm shift produces unique opportunities to build satellites in unique ways for novel missions, there are also significant challenges that must be addressed. This research addresses two of the challenges associated with small-scale spacecraft: 1) the miniaturization of spacecraft and associated instrumentation and 2) the need to transport charge across the spacecraft-environment boundary. As spacecraft decrease in size, constraints on the size, weight, and power of on-board instrumentation increase--potentially limiting the instrument's functionality or ability to integrate with the spacecraft. These constraints drive research into mechanisms or techniques that use little or no power and efficiently utilize existing resources. One limited resource on small-scale spacecraft is outer surface area, which is often covered with solar panels to meet tight power budgets. This same surface area could also be needed for passive neutralization of spacecraft charging. This research explores the use of a transparent, conductive layer on the solar cell coverglass that is electrically connected to spacecraft ground potential. This dual-purpose material facilitates the use of outer surfaces for both energy harvesting of solar photons as well as passive ion collection. Mission capabilities such as in-situ plasma measurements that were previously infeasible on small-scale platforms become feasible with the use of indium tin oxide-coated solar panel coverglass. We developed test facilities that simulate the space environment in low Earth orbit to test the dual-purpose material and the various application of this approach. Particularly, this research is in support of two upcoming missions: OSIRIS-3U, by Penn State's Student Space Programs Lab, and MiTEE, by the University of Michigan. The purpose of

Spacecraft Fire Safety Research at NASA Glenn Research Center

Science.gov (United States)

Meyer, Marit

2016-01-01

Appropriate design of fire detection systems requires knowledge of both the expected fire signature and the background aerosol levels. Terrestrial fire detection systems have been developed based on extensive study of terrestrial fires. Unfortunately there is no corresponding data set for spacecraft fires and consequently the fire detectors in current spacecraft were developed based upon terrestrial designs. In low gravity, buoyant flow is negligible which causes particles to concentrate at the smoke source, increasing their residence time, and increasing the transport time to smoke detectors. Microgravity fires have significantly different structure than those in 1-g which can change the formation history of the smoke particles. Finally the materials used in spacecraft are different from typical terrestrial environments where smoke properties have been evaluated. It is critically important to detect a fire in its early phase before a flame is established, given the fixed volume of air on any spacecraft. Consequently, the primary target for spacecraft fire detection is pyrolysis products rather than soot. Experimental investigations have been performed at three different NASA facilities which characterize smoke aerosols from overheating common spacecraft materials. The earliest effort consists of aerosol measurements in low gravity, called the Smoke Aerosol Measurement Experiment (SAME), and subsequent ground-based testing of SAME smoke in 55-gallon drums with an aerosol reference instrument. Another set of experiments were performed at NASAs Johnson Space Center White Sands Test Facility (WSTF), with additional fuels and an alternate smoke production method. Measurements of these smoke products include mass and number concentration, and a thermal precipitator was designed for this investigation to capture particles for microscopic analysis. The final experiments presented are from NASAs Gases and Aerosols from Smoldering Polymers (GASP) Laboratory, with selected

ROSA-V large scale test facility (LSTF) system description for the third and fourth simulated fuel assemblies

Energy Technology Data Exchange (ETDEWEB)

Suzuki, Mitsuhiro; Nakamura, Hideo; Ohtsu, Iwao [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] [and others

2003-03-01

The Large Scale Test Facility (LSTF) is a full-height and 1/48 volumetrically scaled test facility of the Japan Atomic Energy Research Institute (JAERI) for system integral experiments simulating the thermal-hydraulic responses at full-pressure conditions of a 1100 MWe-class pressurized water reactor (PWR) during small break loss-of-coolant accidents (SBLOCAs) and other transients. The LSTF can also simulate well a next-generation type PWR such as the AP600 reactor. In the fifth phase of the Rig-of-Safety Assessment (ROSA-V) Program, eighty nine experiments have been conducted at the LSTF with the third simulated fuel assembly until June 2001, and five experiments have been conducted with the newly-installed fourth simulated fuel assembly until December 2002. In the ROSA-V program, various system integral experiments have been conducted to certify effectiveness of both accident management (AM) measures in beyond design basis accidents (BDBAs) and improved safety systems in the next-generation reactors. In addition, various separate-effect tests have been conducted to verify and develop computer codes and analytical models to predict non-homogeneous and multi-dimensional phenomena such as heat transfer across the steam generator U-tubes under the presence of non-condensable gases in both current and next-generation reactors. This report presents detailed information of the LSTF system with the third and fourth simulated fuel assemblies for the aid of experiment planning and analyses of experiment results. (author)

The effect of swelling in Inconel 600 on the performance of FFTF [Fast Flux Test Facility] reflector assemblies

International Nuclear Information System (INIS)

Makenas, B.J.; Trenchard, R.G.; Hecht, S.L.; McCarthy, J.M.; Garner, F.A.

1986-02-01

The Fast Flux Test Facility (FFTF) is designed with non-fueled outer row assemblies, each of which consists of a stack of Inconel 600 blocks penetrated by 316 stainless steel (SS) coolant tubes. These assemblies act as a radial neutron reflector and as a straight but flexible core boundary. During an FFTF refueling outage it was observed that the degree of difficulty in withdrawing an outer row driver fuel assembly was a function of the peak fast fluence of neighboring reflector assemblies. It was subsequently determined through various postirradiation examinations that the reflector assemblies were both bowed and stiff. Measurements of the individual Inconel 600 blocks indicated that the blocks had distorted into a trapezoidal cross section due to differential swelling of Inconel 600 in a steep radial flux gradient. Immersion density results indicate greater irradiation induced volumetric swelling than any previously reported data or correlation for Inconel 600 at equivalent fast fluence. The Inconel 600 swelled approximately the same amount as the SA 316 SS reflector components. Transmission electron microscopy studies on the Inconel blocks and swelling measurements on related materials have been performed and these data have been related to the performance of the reflector materials

Analysis and results of a hydrogen-moderated isotope production assembly in the Fast Flux Test Facility

International Nuclear Information System (INIS)

Wootan, D.W.; Rawlins, J.A.; Carter, L.L.; Brager, H.R.; Schenter, R.E.

1989-01-01

This paper reports on a cobalt test assembly containing yttrium hydride pins for neutron moderation irradiated in the Fast Flux Test Facility (FFTF) during cycle 9A for 137.7 equivalent full-power days at a power level of 291 MW. The 36 test pins consisted of a batch of 32 pins containing cobalt metal used to produce 60 Co and a set of four pins with europium oxide to produce 153 Gd, a radioisotope used in detection of the bone disease osteoporosis. Postirradiation examination of the cobalt pins determined the 60 Co production to be predictable to an accuracy of ∼ 5%. The measured 60 Co spatially distributed concentrations were within 20% of the calculated concentrations. The assembly average 60 Co measured activity was 4% less than the calculated value. The europium oxide pins were gamma scanned for the europium isotopes 152 Eu and 154 Eu to an absolute accuracy of ≅ 10%. The measured europium radioisotope and 153 Gd concentrations were within 20% of calculated values. The hydride assembly performed well and is an excellent vehicle for many FFTF isotope production applications. The results also demonstrate the accuracy of the calculational methods developed by the Westinghouse Hanford Company for predicting isotope production rates in this type of assembly

Pool critical assembly pressure vessel facility benchmark

International Nuclear Information System (INIS)

Remec, I.; Kam, F.B.K.

1997-07-01

This pool critical assembly (PCA) pressure vessel wall facility benchmark (PCA benchmark) is described and analyzed in this report. Analysis of the PCA benchmark can be used for partial fulfillment of the requirements for the qualification of the methodology for pressure vessel neutron fluence calculations, as required by the US Nuclear Regulatory Commission regulatory guide DG-1053. Section 1 of this report describes the PCA benchmark and provides all data necessary for the benchmark analysis. The measured quantities, to be compared with the calculated values, are the equivalent fission fluxes. In Section 2 the analysis of the PCA benchmark is described. Calculations with the computer code DORT, based on the discrete-ordinates method, were performed for three ENDF/B-VI-based multigroup libraries: BUGLE-93, SAILOR-95, and BUGLE-96. An excellent agreement of the calculated (C) and measures (M) equivalent fission fluxes was obtained. The arithmetic average C/M for all the dosimeters (total of 31) was 0.93 ± 0.03 and 0.92 ± 0.03 for the SAILOR-95 and BUGLE-96 libraries, respectively. The average C/M ratio, obtained with the BUGLE-93 library, for the 28 measurements was 0.93 ± 0.03 (the neptunium measurements in the water and air regions were overpredicted and excluded from the average). No systematic decrease in the C/M ratios with increasing distance from the core was observed for any of the libraries used

New Platforms for Suborbital Astronomical Observations and In Situ Atmospheric Measurements: Spacecraft, Instruments, and Facilities

Science.gov (United States)

Rodway, K.; DeForest, C. E.; Diller, J.; Vilas, F.; Sollitt, L. S.; Reyes, M. F.; Filo, A. S.; Anderson, E.

2014-12-01

Suborbital astronomical observations have over 50 years' history using NASA's sounding rockets and experimental space planes. The new commercial space industry is developing suborbital reusable launch vehicles (sRLV's) to provide low-cost, flexible, and frequent access to space at ~100 km altitude. In the case of XCOR Aerospace's Lynx spacecraft, the vehicle design and capabilities work well for hosting specially designed experiments that can be flown with a human-tended researcher or alone with the pilot on a customized mission. Some of the first-generation instruments and facilities that will conduct solar observations on dedicated Lynx science missions include the SwRI Solar Instrument Pointing Platform (SSIPP) and Atsa Suborbital Observatory, as well as KickSat sprites, which are picosatellites for in situ atmospheric and solar phenomena measurements. The SSIPP is a demonstration two-stage pointed solar observatory that operates inside the Lynx cockpit. The coarse pointing stage includes the pilot in the feedback loop, and the fine stage stabilizes the solar image to achieve arcsecond class pointing. SSIPP is a stepping-stone to future external instruments that can operate with larger apertures and shorter wavelengths in the solar atmosphere. The Planetary Science Institute's Atsa Suborbital Observatory combines the strengths of ground-based observatories and space-based observing to create a facility where a telescope is maintained and used interchangeably with either in-house facility instruments or user-provided instruments. The Atsa prototype is a proof of concept, hand-guided camera that mounts on the interior of the Lynx cockpit to test target acquisition and tracking for human-operated suborbital astronomy. KickSat sprites are mass-producible, one inch printed circuit boards (PCBs) populated by programmable off the shelf microprocessors and radios for real time data transmission. The sprite PCBs can integrate chip-based radiometers, magnetometers

Target Assembly to Check Boresight Alignment of Active Sensors

Science.gov (United States)

Ramos-Izquierdo, Luis; Scott, V. Stanley; Riris, Haris; Cavanaugh, John; Liiva, Peter; Rodriguez, Michael

2011-01-01

A compact and portable target assembly (Fig. 1) has been developed to measure the boresite alignment of LRO's Lunar Orbiter Laser Altimeter (LOLA) instrument at the spacecraft level. The concept for this target assembly has evolved over many years with earlier versions used to test the Mars Observer Laser Altimeter (MOLA), the Geoscience Laser Altimeter System (GLAS), and the Mercury Laser Altimeter (MLA) space-based instruments.

Multispectral Thermal Imager Optical Assembly Performance and Integration of the Flight Focal Plane Assembly

International Nuclear Information System (INIS)

Blake, Dick; Byrd, Don; Christensen, Wynn; Henson, Tammy; Krumel, Les; Rappoport, William; Shen, Gon-Yen

1999-01-01

The Multispectral Thermal Imager Optical Assembly (OA) has been fabricated, assembled, successfully performance tested, and integrated into the flight payload structure with the flight Focal Plane Assembly (FPA) integrated and aligned to it. This represents a major milestone achieved towards completion of this earth observing E-O imaging sensor that is to be operated in low earth orbit. The OA consists of an off-axis three mirror anastigmatic (TMA) telescope with a 36 cm unobscured clear aperture, a wide-field-of-view (WFOV) of 1.82 along the direction of spacecraft motion and 1.38 across the direction of spacecraft motion. It also contains a comprehensive on-board radiometric calibration system. The OA is part of a multispectral pushbroom imaging sensor which employs a single mechanically cooled focal plane with 15 spectral bands covering a wavelength range from 0.45 to 10.7 m. The OA achieves near diffraction-limited performance from visible to the long-wave infrared (LWIR) wavelengths. The two major design drivers for the OA are 80% enpixeled energy in the visible bands and radiometric stability. Enpixeled energy in the visible bands also drove the alignment of the FPA detectors to the OA image plane to a requirement of less than 20 m over the entire visible detector field of view (FOV). Radiometric stability requirements mandated a cold Lyot stop for stray light rejection and thermal background reduction. The Lyot stop is part of the FPA assembly and acts as the aperture stop for the imaging system. The alignment of the Lyot stop to the OA drove the centering and to some extent the tilt alignment requirements of the FPA to the OA

DOE Lab-to-Lab MPC ampersand A workshop for cooperative tasks with Russian institutes: Focus on critical assemblies and item facilities

International Nuclear Information System (INIS)

Bieber, A.M. Jr.; Fishbone, L.G.; Kato, W.Y.; Lazareth, O.W.; Suda, S.C.; Garcia, D.; Haga, R.

1995-01-01

Seventeen Russian scientists and engineers representing five different institutes participated in a Workshop on material control and accounting as part of the US-Russian Lab-to-Lab Cooperative Program in Nuclear Materials Protection, Control, and Accounting (MPC ampersand A). In addition to presentations and discussions, the Workshop included an exercise at Brookhaven National Laboratory (BNL) and demonstrations at the Zero Power Physics Reactor (critical-assembly facility) of Argonne National Laboratory-West (ANL-W). The Workshop particularly emphasized procedures for physical inventory-taking at critical assemblies and item facilities, with associated supporting techniques and methods. By learning these topics and applying the methods and experience at their own institutes, the Russian scientists and engineers will be able to determine and verify nuclear material inventories based on sound procedures, including measurements. This will constitute a significant enhancement to MPC ampersand A at the Russian institutes

Closed Loop In-Reactor Assembly (CLIRA): a fast flux test facility test vehicle

International Nuclear Information System (INIS)

Oakley, D.J.

1978-01-01

The Closed Loop In-Reactor Assembly (CLIRA) is a test vehicle for in-core material and fuel experiments in the Fast Flux Test Facility (FFTF). The FFTF is a fast flux nuclear test reactor operated for the Department of Energy (DOE) by Westinghouse Hanford Company in Richland, Washington. The CLIRA is a removable/replaceable part of the Closed Loop System (CLS) which is a sodium coolant system providing flow and temperature control independent of the reactor coolant system. The primary purpose of the CLIRA is to provide a test vehicle which will permit testing of nuclear fuels and materials at conditions more severe than exist in the FTR core, and to isolate these materials from the reactor core

Development of a Radio Frequency Space Environment Path Emulator for Evaluating Spacecraft Ranging Hardware

Science.gov (United States)

Mitchell, Jason W.; Baldwin, Philip J.; Kurichh, Rishi; Naasz, Bo J.; Luquette, Richard J.

2007-01-01

The Formation Flying Testbed (FFTB) at the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) provides a hardware-in-the-loop test environment for formation navigation and control. The facility is evolving as a modular, hybrid, dynamic simulation facility for end-to-end guidance, navigation and. control (GN&C) design and analysis of formation flying spacecraft. The core capabilities of the FFTB, as a platform for testing critical hardware and software algorithms in-the-loop, have expanded to include S-band Radio Frequency (RF) modems for inter-spacecraft communication and ranging. To enable realistic simulations that require RF ranging sensors for relative navigation, a mechanism is needed to buffer the RF signals exchanged between spacecraft that accurately emulates the dynamic environment through which the RF signals travel, including the effects of medium, moving platforms, and radiated power. The Path Emulator for RF Signals (PERFS), currently under development at NASA GSFC, provides this capability. The function and performance of a prototype device are presented.

Spacecraft System Integration and Test: SSTI Lewis critical design audit

Science.gov (United States)

Brooks, R. P.; Cha, K. K.

1995-01-01

The Critical Design Audit package is the final detailed design package which provides a comprehensive description of the SSTI mission. This package includes the program overview, the system requirements, the science and applications activities, the ground segment development, the assembly, integration and test description, the payload and technology demonstrations, and the spacecraft bus subsystems. Publication and presentation of this document marks the final requirements and design freeze for SSTI.

Printed Spacecraft Separation System

Energy Technology Data Exchange (ETDEWEB)

Dehoff, Ryan R [ORNL; Holmans, Walter [Planetary Systems Corporation

2016-10-01

In this project Planetary Systems Corporation proposed utilizing additive manufacturing (3D printing) to manufacture a titanium spacecraft separation system for commercial and US government customers to realize a 90% reduction in the cost and energy. These savings were demonstrated via “printing-in” many of the parts and sub-assemblies into one part, thus greatly reducing the labor associated with design, procurement, assembly and calibration of mechanisms. Planetary Systems Corporation redesigned several of the components of the separation system based on additive manufacturing principles including geometric flexibility and the ability to fabricate complex designs, ability to combine multiple parts of an assembly into a single component, and the ability to optimize design for specific mechanical property targets. Shock absorption was specifically targeted and requirements were established to attenuate damage to the Lightband system from shock of initiation. Planetary Systems Corporation redesigned components based on these requirements and sent the designs to Oak Ridge National Laboratory to be printed. ORNL printed the parts using the Arcam electron beam melting technology based on the desire for the parts to be fabricated from Ti-6Al-4V based on the weight and mechanical performance of the material. A second set of components was fabricated from stainless steel material on the Renishaw laser powder bed technology due to the improved geometric accuracy, surface finish, and wear resistance of the material. Planetary Systems Corporation evaluated these components and determined that 3D printing is potentially a viable method for achieving significant cost and savings metrics.

Estimating the Backup Reaction Wheel Orientation Using Reaction Wheel Spin Rates Flight Telemetry from a Spacecraft

Science.gov (United States)

Rizvi, Farheen

2013-01-01

A report describes a model that estimates the orientation of the backup reaction wheel using the reaction wheel spin rates telemetry from a spacecraft. Attitude control via the reaction wheel assembly (RWA) onboard a spacecraft uses three reaction wheels (one wheel per axis) and a backup to accommodate any wheel degradation throughout the course of the mission. The spacecraft dynamics prediction depends upon the correct knowledge of the reaction wheel orientations. Thus, it is vital to determine the actual orientation of the reaction wheels such that the correct spacecraft dynamics can be predicted. The conservation of angular momentum is used to estimate the orientation of the backup reaction wheel from the prime and backup reaction wheel spin rates data. The method is applied in estimating the orientation of the backup wheel onboard the Cassini spacecraft. The flight telemetry from the March 2011 prime and backup RWA swap activity on Cassini is used to obtain the best estimate for the backup reaction wheel orientation.

Three-dimensional assemblies of graphene prepared by a novel chemical reduction-induced self-assembly method

KAUST Repository

Zhang, Lianbin; Chen, Guoying; Hedhili, Mohamed N.; Zhang, Hongnan; Wang, Peng

2012-01-01

In this study, three-dimensional (3D) graphene assemblies are prepared from graphene oxide (GO) by a facile in situ reduction-assembly method, using a novel, low-cost, and environment-friendly reducing medium which is a combination of oxalic acid

Modeling and Analysis of Realistic Fire Scenarios in Spacecraft

Science.gov (United States)

Brooker, J. E.; Dietrich, D. L.; Gokoglu, S. A.; Urban, D. L.; Ruff, G. A.

2015-01-01

An accidental fire inside a spacecraft is an unlikely, but very real emergency situation that can easily have dire consequences. While much has been learned over the past 25+ years of dedicated research on flame behavior in microgravity, a quantitative understanding of the initiation, spread, detection and extinguishment of a realistic fire aboard a spacecraft is lacking. Virtually all combustion experiments in microgravity have been small-scale, by necessity (hardware limitations in ground-based facilities and safety concerns in space-based facilities). Large-scale, realistic fire experiments are unlikely for the foreseeable future (unlike in terrestrial situations). Therefore, NASA will have to rely on scale modeling, extrapolation of small-scale experiments and detailed numerical modeling to provide the data necessary for vehicle and safety system design. This paper presents the results of parallel efforts to better model the initiation, spread, detection and extinguishment of fires aboard spacecraft. The first is a detailed numerical model using the freely available Fire Dynamics Simulator (FDS). FDS is a CFD code that numerically solves a large eddy simulation form of the Navier-Stokes equations. FDS provides a detailed treatment of the smoke and energy transport from a fire. The simulations provide a wealth of information, but are computationally intensive and not suitable for parametric studies where the detailed treatment of the mass and energy transport are unnecessary. The second path extends a model previously documented at ICES meetings that attempted to predict maximum survivable fires aboard space-craft. This one-dimensional model implies the heat and mass transfer as well as toxic species production from a fire. These simplifications result in a code that is faster and more suitable for parametric studies (having already been used to help in the hatch design of the Multi-Purpose Crew Vehicle, MPCV).

Spacecraft radiator systems

Science.gov (United States)

Anderson, Grant A. (Inventor)

2012-01-01

A spacecraft radiator system designed to provide structural support to the spacecraft. Structural support is provided by the geometric "crescent" form of the panels of the spacecraft radiator. This integration of radiator and structural support provides spacecraft with a semi-monocoque design.

Assembly and handling apparatus for the EBFA Marx generator

International Nuclear Information System (INIS)

Staller, G.E.; Hiett, G.E.; Hamilton, I.D.; Aker, M.F.; Daniels, G.A.

1979-05-01

Marx generators, a major slow-pulsed power component in Sandia Laboratories' Electron Beam Fusion Accelerator (EBFA), were assembled at a remote facility modified to utilize an assembly-line technique. Due to the size and weight of the various components, as well as the final Marx generator assembly, special handling apparatus was designed. Time and manpower constraints required that this assembly be done in parallel with the construction of the Electron Beam Fusion Facility (EBFF). The completed Marx generators were temporarily stored and then moved from the assembly building to the EBFF using special transportation racks designed specifically for this purpose

Large Scale Experiments on Spacecraft Fire Safety

DEFF Research Database (Denmark)

Urban, David L.; Ruff, Gary A.; Minster, Olivier

2012-01-01

-based microgravity facilities or has been limited to very small fuel samples. Still, the work conducted to date has shown that fire behaviour in low-gravity is very different from that in normal-gravity, with differences observed for flammability limits, ignition delay, flame spread behaviour, flame colour and flame......Full scale fire testing complemented by computer modelling has provided significant knowhow about the risk, prevention and suppression of fire in terrestrial systems (cars, ships, planes, buildings, mines, and tunnels). In comparison, no such testing has been carried out for manned spacecraft due...... to the complexity, cost and risk associ-ated with operating a long duration fire safety experiment of a relevant size in microgravity. Therefore, there is currently a gap in knowledge of fire behaviour in spacecraft. The entire body of low-gravity fire research has either been conducted in short duration ground...

Modular head assembly and method of retrofitting existing nuclear reactor facilities

International Nuclear Information System (INIS)

Malandra, L.J.; Ledue, R.J.; Hankinson, M.F.; Kowalski, E.F.

1987-01-01

A method is described of retrofitting existing nuclear reactor facilities so as to form a modular closure head assembly for a nuclear reactor pressure vessel, where the existing nuclear reactor facilities comprise control rod drive mechanism cooling systems which include vertically extending elbow air ducts inter-connecting vertically spaced upper and lower air manifolds. The elbow air ducts extend radially beyond the peripheral envelope of the closure head, comprising the steps of: removing the upper air manifold; removing the vertically extending elbow air ducts; capping the air ports of the lower air manifold which ports were previously fluidically connecting the lower air manifold to the vertically extending elbow air ducts; disposing vertically upwardly extending air exhaust ducts above the lower air manifold in such an manner that the air exhaust ducts are disposed within the peripheral envelope of the closure head; fluidically connecting exhaust fans to the upper regions of the air exhaust ducts; fluidically connecting the lower regions of the air exhaust ducts the lower air manifold; permanently securing lift rods to the closure head at positions disposed radially outwardly of the lower air manifold; attaching a seismic support platform to the lift rods; proving fluidic passage of the vertically extending air exhaust ducts through the seismic support platform; attaching a missile shield plate to the lift rods; and proving fluidic passage of the vertically extending air exhaust ducts through the missile shield plate

1994 Baseline biological studies for the Device Assembly Facility at the Nevada Test Site

Energy Technology Data Exchange (ETDEWEB)

Townsend, Y.E. [ed.; Woodward, B.D.; Hunter, R.B.; Greger, P.D.; Saethre, M.B.

1995-02-01

This report describes environmental work performed at the Device Assembly Facility (DAF) in 1994 by the Basic Environmental Monitoring and Compliance Program (BECAMP). The DAF is located near the Mojave-Great Basin desert transition zone 27 km north of Mercury. The area immediately around the DAF building complex is a gentle slope cut by 1 to 3 m deep arroyos, and occupied by transitional vegetation. In 1994, construction activities were largely limited to work inside the perimeter fence. The DAF was still in a preoperational mode in 1994, and no nuclear materials were present. The DAF facilities were being occupied so there was water in the sewage settling pond, and the roads and lights were in use. Sampling activities in 1994 represent the first year in the proposed monitoring scheme. The proposed biological monitoring plan gives detailed experimental protocols. Plant, lizard, tortoise, small mammal, and bird surveys were performed in 1994. The authors briefly outline procedures employed in 1994. Studies performed on each taxon are reviewed separately then summarized in a concluding section.

Vibration and Acoustic Testing for Mars Micromission Spacecraft

Science.gov (United States)

Kern, Dennis L.; Scharton, Terry D.

1999-01-01

spacecraft and the test fixture, alleviates the severe overtest at spacecraft resonances inherent in rigid fixture vibration tests. It has the distinct advantage over response limiting that the method is not dependent on the accuracy of a detailed dynamic model of the spacecraft. Combined loads, vibration, and modal testing were recently performed on the QuikSCAT spacecraft. The combined tests were performed in a single test setup per axis on a vibration shaker, reducing test time by a factor of two or three. Force gages were employed to measure the true c.g. acceleration of the spacecraft for structural loads verification using a sine burst test, to automatically notch random vibration test input accelerations at spacecraft resonances based on predetermined force limits, and to directly measure modal masses in a base drive modal test. In addition to these combined tests on the shaker, the QuikSCAT spacecraft was subjected to a direct field acoustic test by surrounding the spacecraft, still on the vibration shaker, with rock concert type acoustic speakers. Since the spacecraft contractor does not have a reverberant field acoustic test facility, performing a direct field acoustic test -saved the program nearly two weeks schedule time that would have been required for packing / unpacking and shipping of the spacecraft. This paper discusses the rationale behind and advantages of the above test approaches and provides examples of their actual implementation and comparisons to flight data. The applicability of the test approaches to Mars Micromission spacecraft qualification is discussed.

Facilities of fuel transfer for nuclear reactors

International Nuclear Information System (INIS)

Wade, E.E.

1977-01-01

This invention relates to sodium cooled fast breeder reactors. It particularly concerns facilities for the transfer of fuel assemblies between the reactor core and a fuel transfer area. The installation is simple in construction and enables a relatively small vessel to be used. In greater detail, the invention includes a vessel with a head, fuel assemblies housed in this vessel, and an inlet and outlet for the coolant covering these fuel assemblies. The reactor has a fuel transfer area in communication with this vessel and gear inside the vessel for the transfer of these fuel assemblies. These facilities are borne by the vessel head and serve to transfer the fuel assemblies from the vessel to the transfer area; whilst leaving the fuel assemblies completely immersed in a continuous mass of coolant. A passageway is provided between the vessel and this transfer area for the fuel assemblies. Facilities are provided for closing off this passageway so that the inside of the reactor vessel may be isolated as desired from this fuel transfer area whilst the reactor is operating [fr

Development and experimentation of LQR/APF guidance and control for autonomous proximity maneuvers of multiple spacecraft

Science.gov (United States)

Bevilacqua, R.; Lehmann, T.; Romano, M.

2011-04-01

This work introduces a novel control algorithm for close proximity multiple spacecraft autonomous maneuvers, based on hybrid linear quadratic regulator/artificial potential function (LQR/APF), for applications including autonomous docking, on-orbit assembly and spacecraft servicing. Both theoretical developments and experimental validation of the proposed approach are presented. Fuel consumption is sub-optimized in real-time through re-computation of the LQR at each sample time, while performing collision avoidance through the APF and a high level decisional logic. The underlying LQR/APF controller is integrated with a customized wall-following technique and a decisional logic, overcoming problems such as local minima. The algorithm is experimentally tested on a four spacecraft simulators test bed at the Spacecraft Robotics Laboratory of the Naval Postgraduate School. The metrics to evaluate the control algorithm are: autonomy of the system in making decisions, successful completion of the maneuver, required time, and propellant consumption.

Mission operations for unmanned nuclear electric propulsion outer planet exploration with a thermionic reactor spacecraft.

Science.gov (United States)

Spera, R. J.; Prickett, W. Z.; Garate, J. A.; Firth, W. L.

1971-01-01

Mission operations are presented for comet rendezvous and outer planet exploration NEP spacecraft employing in-core thermionic reactors for electric power generation. The selected reference missions are the Comet Halley rendezvous and a Jupiter orbiter at 5.9 planet radii, the orbit of the moon Io. The characteristics of the baseline multi-mission NEP spacecraft are presented and its performance in other outer planet missions, such as Saturn and Uranus orbiters and a Neptune flyby, are discussed. Candidate mission operations are defined from spacecraft assembly to mission completion. Pre-launch operations are identified. Shuttle launch and subsequent injection to earth escape by the Centaur D-1T are discussed, as well as power plant startup and the heliocentric mission phases. The sequence and type of operations are basically identical for all missions investigated.

Component-Level Electronic-Assembly Repair (CLEAR) Spacecraft Circuit Diagnostics by Analog and Complex Signature Analysis

Science.gov (United States)

Oeftering, Richard C.; Wade, Raymond P.; Izadnegahdar, Alain

2011-01-01

The Component-Level Electronic-Assembly Repair (CLEAR) project at the NASA Glenn Research Center is aimed at developing technologies that will enable space-flight crews to perform in situ component-level repair of electronics on Moon and Mars outposts, where there is no existing infrastructure for logistics spares. These technologies must provide effective repair capabilities yet meet the payload and operational constraints of space facilities. Effective repair depends on a diagnostic capability that is versatile but easy to use by crew members that have limited training in electronics. CLEAR studied two techniques that involve extensive precharacterization of "known good" circuits to produce graphical signatures that provide an easy-to-use comparison method to quickly identify faulty components. Analog Signature Analysis (ASA) allows relatively rapid diagnostics of complex electronics by technicians with limited experience. Because of frequency limits and the growing dependence on broadband technologies, ASA must be augmented with other capabilities. To meet this challenge while preserving ease of use, CLEAR proposed an alternative called Complex Signature Analysis (CSA). Tests of ASA and CSA were used to compare capabilities and to determine if the techniques provided an overlapping or complementary capability. The results showed that the methods are complementary.

Particle Morphology and Elemental Composition of Smoke Generated by Overheating Common Spacecraft Materials

Science.gov (United States)

Meyer, Marit E.

2015-01-01

Fire safety in the indoor spacecraft environment is concerned with a unique set of fuels which are designed to not combust. Unlike terrestrial flaming fires, which often can consume an abundance of wood, paper and cloth, spacecraft fires are expected to be generated from overheating electronics consisting of flame resistant materials. Therefore, NASA prioritizes fire characterization research for these fuels undergoing oxidative pyrolysis in order to improve spacecraft fire detector design. A thermal precipitator designed and built for spacecraft fire safety test campaigns at the NASA White Sands Test Facility (WSTF) successfully collected an abundance of smoke particles from oxidative pyrolysis. A thorough microscopic characterization has been performed for ten types of smoke from common spacecraft materials or mixed materials heated at multiple temperatures using the following techniques: SEM, TEM, high resolution TEM, high resolution STEM and EDS. Resulting smoke particle morphologies and elemental compositions have been observed which are consistent with known thermal decomposition mechanisms in the literature and chemical make-up of the spacecraft fuels. Some conclusions about particle formation mechanisms are explored based on images of the microstructure of Teflon smoke particles and tar ball-like particles from Nomex fabric smoke.

Trace Contaminant Control During the International Space Station's On-Orbit Assembly and Outfitting

Science.gov (United States)

Perry, J. L.

2017-01-01

Achieving acceptable cabin air quality must balance competing elements during spacecraft design, assembly, ground processing, and flight operations. Among the elements that contribute to the trace chemical contaminant load and, therefore, the cabin air quality aboard crewed spacecraft are the vehicle configuration, crew size and activities, mission duration and objectives, materials selection, and vehicle manufacturing and preflight ground processing methods. Trace chemical contaminants produced from pervasive sources such as equipment offgassing, human metabolism, and cleaning fluids during preflight ground processing present challenges to maintaining acceptable cabin air quality. To address these challenges, both passive and active contamination control techniques are used during a spacecraft's design, manufacturing, preflight preparation, and operational phases. Passive contamination control methods seek to minimize the equipment offgassing load by selecting materials, manufacturing processes, preflight preparation processes, and in-flight operations that have low chemical offgassing characteristics. Passive methods can be employed across the spacecraft's entire life cycle from conceptual design through flight operations. However, because the passive contamination control techniques cannot fully eliminate the contaminant load, active contamination control equipment must be deployed aboard the spacecraft to purify and revitalize the cabin atmosphere during in-flight operations. Verifying that the passive contamination control techniques have successfully maintained the total trace contaminant load within the active contamination control equipment's capabilities occurs late in the preflight preparation stages. This verification consists of subjecting the spacecraft to an offgassing test to determine the trace contaminant load. This load is then assessed versus the active contamination control equipment's capabilities via trace contaminant control (TCC) engineering

Subcritical assemblies, use and their feasibility assessment

International Nuclear Information System (INIS)

Haroon, M.R.

1982-03-01

In developing countries, subcritical assemblies can be a useful tool for training and research in the field of nuclear technology with minimum cost. The historical development of subcritical assemblies and the reactor physics experiments which can be carried out using this facility are outlined. The different types of subcritical assemblies have been described and material requirements for each assembly have been pointed out. (author)

Spacecraft Charging and the Microwave Anisotropy Probe Spacecraft

Science.gov (United States)

Timothy, VanSant J.; Neergaard, Linda F.

1998-01-01

The Microwave Anisotropy Probe (MAP), a MIDEX mission built in partnership between Princeton University and the NASA Goddard Space Flight Center (GSFC), will study the cosmic microwave background. It will be inserted into a highly elliptical earth orbit for several weeks and then use a lunar gravity assist to orbit around the second Lagrangian point (L2), 1.5 million kilometers, anti-sunward from the earth. The charging environment for the phasing loops and at L2 was evaluated. There is a limited set of data for L2; the GEOTAIL spacecraft measured relatively low spacecraft potentials (approx. 50 V maximum) near L2. The main area of concern for charging on the MAP spacecraft is the well-established threat posed by the "geosynchronous region" between 6-10 Re. The launch in the autumn of 2000 will coincide with the falling of the solar maximum, a period when the likelihood of a substorm is higher than usual. The likelihood of a substorm at that time has been roughly estimated to be on the order of 20% for a typical MAP mission profile. Because of the possibility of spacecraft charging, a requirement for conductive spacecraft surfaces was established early in the program. Subsequent NASCAP/GEO analyses for the MAP spacecraft demonstrated that a significant portion of the sunlit surface (solar cell cover glass and sunshade) could have nonconductive surfaces without significantly raising differential charging. The need for conductive materials on surfaces continually in eclipse has also been reinforced by NASCAP analyses.

Fuel assembly transfer and storage system for nuclear reactors

International Nuclear Information System (INIS)

Allain, Albert; Thomas, Claude.

1981-01-01

Transfer and storage system on a site comprising several reactors and at least one building housing the installations common to all these reactors. The system includes: transfer and storage modules for the fuel assemblies comprising a containment capable of containing several assemblies carried on a transport vehicle, a set of tracks for the modules between the reactors and the common installations, handling facilities associated with each reactor for moving the irradiated assemblies from the reactor to a transfer module placed in loading position on a track serving the reactor and conversely to move the new assemblies from the transfer module to the reactor, and at least one handling facility located in the common installation building for loading the modules with new assemblies [fr

Navigating the MESSENGER Spacecraft through End of Mission

Science.gov (United States)

Bryan, C. G.; Williams, B. G.; Williams, K. E.; Taylor, A. H.; Carranza, E.; Page, B. R.; Stanbridge, D. R.; Mazarico, E.; Neumann, G. A.; O'Shaughnessy, D. J.; McAdams, J. V.; Calloway, A. B.

2015-12-01

The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft orbited the planet Mercury from March 2011 until the end of April 2015, when it impacted the planetary surface after propellant reserves used to maintain the orbit were depleted. This highly successful mission was led by the principal investigator, Sean C. Solomon, of Columbia University. The Johns Hopkins University Applied Physics Laboratory (JHU/APL) designed and assembled the spacecraft and served as the home for spacecraft operations. Spacecraft navigation for the entirety of the mission was provided by the Space Navigation and Flight Dynamics Practice (SNAFD) of KinetX Aerospace. Orbit determination (OD) solutions were generated through processing of radiometric tracking data provided by NASA's Deep Space Network (DSN) using the MIRAGE suite of orbital analysis tools. The MESSENGER orbit was highly eccentric, with periapsis at a high northern latitude and periapsis altitude in the range 200-500 km for most of the orbital mission phase. In a low-altitude "hover campaign" during the final two months of the mission, periapsis altitudes were maintained within a narrow range between about 35 km and 5 km. Navigating a spacecraft so near a planetary surface presented special challenges. Tasks required to meet those challenges included the modeling and estimation of Mercury's gravity field and of solar and planetary radiation pressure, and the design of frequent orbit-correction maneuvers. Superior solar conjunction also presented observational modeling issues. One key to the overall success of the low-altitude hover campaign was a strategy to utilize data from an onboard laser altimeter as a cross-check on the navigation team's reconstructed and predicted estimates of periapsis altitude. Data obtained from the Mercury Laser Altimeter (MLA) on a daily basis provided near-real-time feedback that proved invaluable in evaluating alternative orbit estimation strategies, and

Study of the space environmental effects on spacecraft engineering materials

Science.gov (United States)

Obrien, Susan K.; Workman, Gary L.; Smith, Guy A.

1995-01-01

The space environment in which the Space Station Freedom and other space platforms will orbit is truly a hostile environment. For example, the current estimates of the integral fluence for electrons above 1 Mev at 2000 nautical miles is above 2 x 10(exp 10) electrons/sq cm/day. and the proton integral fluence is above 1 x 109 protons/sq cm/day. At the 200 - 400 nautical miles, which is more representative of the altitude which will provide the environment for the Space Station, each of these fluences will be proportionately less; however, the data indicates that the radiation environment will obviously have an effect on structural materials exposed to the environment for long durations. The effects of this combined environment is the issue which needs to be understood for the long term exposure of structures in space. In order to better understand the effect of these hostile phenomena on spacecraft, several types of studies are worth performing in order to simulate at some level the effect of the environment. For example the effect of protons and electrons impacting structural materials are easily simulated through experiments using the Van de Graff and Pelletron accelerators currently housed in the Environmental Effects Facility at MSFC. Proton fluxes with energies of 700 Kev-2.5 Mev can be generated and used to impinge on sample targets to determine the effects of the particles. Also the Environmental Effects Facility has the capability to generate electron beams with energies from 700 Kev to 2.5 Mev. These facilities will be used in this research to simulate space environmental effects from energetic particles. Ultraviolet radiation, particularly in the ultraviolet (less than 400 nm wavelength) is less well characterized at this time. The Environmental Effects Facility has a vacuum system dedicated to studying the effects of ultraviolet radiation on specific surface materials. This particular system was assembled in a previous study (NAS8-38609) in order to

Spacecraft Charge Monitor

Science.gov (United States)

Goembel, L.

2003-12-01

We are currently developing a flight prototype Spacecraft Charge Monitor (SCM) with support from NASA's Small Business Innovation Research (SBIR) program. The device will use a recently proposed high energy-resolution electron spectroscopic technique to determine spacecraft floating potential. The inspiration for the technique came from data collected by the Atmosphere Explorer (AE) satellites in the 1970s. The data available from the AE satellites indicate that the SCM may be able to determine spacecraft floating potential to within 0.1 V under certain conditions. Such accurate measurement of spacecraft charge could be used to correct biases in space plasma measurements. The device may also be able to measure spacecraft floating potential in the solar wind and in orbit around other planets.

The Generic Data Capture Facility

Science.gov (United States)

Connell, Edward B.; Barnes, William P.; Stallings, William H.

1987-01-01

The Generic Data Capture Facility, which can provide data capture support for a variety of different types of spacecraft while enabling operations costs to be carefully controlled, is discussed. The data capture functions, data protection, isolation of users from data acquisition problems, data reconstruction, and quality and accounting are addressed. The TDM and packet data formats utilized by the system are described, and the development of generic facilities is considered.

Swarm Deployable Boom Assembly (DBA) Development of a Deployable Magnetometer Boom for the Swarm Spacecraft

Science.gov (United States)

McMahon, Paul; Jung, Hans-Juergen; Edwards, Jeff

2013-09-01

The Swarm programme consists of 3 magnetically clean satellites flying in close formation designed to measure the Earth's magnetic field using 2 Magnetometers mounted on a 4.3m long deployable boom.Deployment is initiated by releasing 3 HDRMs, once released the boom oscillates back and forth on a pair of pivots, similar to a restaurant kitchen door hinge, for around 120 seconds before coming to rest on 3 kinematic mounts which are used to provide an accurate reference location in the deployed position. Motion of the boom is damped through a combination of friction, spring hysteresis and flexing of the 120+ cables crossing the hinge. Considerable development work and accurate numerical modelling of the hinge motion was required to predict performance across a wide temperature range and ensure that during the 1st overshoot the boom did not damage itself, the harness or the spacecraft.Due to the magnetic cleanliness requirements of the spacecraft no magnetic materials could be used in the design of the hardware.

Contamination Impact of Station Brush Fire on Cleanroom Facilities

Science.gov (United States)

Carey, Phil; Blakkolb, Brian

2010-01-01

Brush and forest fires, both naturally occurring and anthropogenic in origin, in proximity to space flight hardware processing facilities raise concerns about the threat of contamination resulting from airborne particulate and molecular components of smoke. Perceptions of the severity of the threat are possibly heightened by the high sensitivity of the human sense of smell to some components present in the smoke of burning vegetation.On August 26th, 2009, a brushfire broke out north of Pasadena, California, two miles from the Jet Propulsion Laboratory. The Station Fire destroyed over 160,000 acres, coming within a few hundred yards of JPL. Smoke concentrations on Lab were very heavy over several days. All Lab operations were halted, and measures were taken to protect personnel, critical hardware, and facilities. Evaluation of real-time cleanroom monitoring data, visualinspection of facilities, filter systems, and analysis of surface cleanliness samples revealed facility environments andhardware were minimally effected.Outside air quality easily exceeded Class Ten Million. Prefilters captured most large ash and soot; multi-stage filtration greatly minimized the impact on the HEPA/ULPA filters. Air quality in HEPA filtered spacecraft assembly cleanrooms remained within Class 10,000 specification throughout. Surface cleanliness was inimally affected, as large particles were effectively removed from the airstream, and sub-micron particles have extremely long settling rates. Approximate particulate fallout within facilities was 0.00011% area coverage/day compared to 0.00038% area coverage/day during normal operations. Deposition of condensable airborne components, as measured in real time, peaked at approximately1.0 ng/cm2/day compared to 0.05 ng/cm2/day nominal.

Brayton Isotope Power System (BIPS) facility specification

International Nuclear Information System (INIS)

1976-01-01

General requirements for the Brayton Isotope Power System (BIPS)/Ground Demonstration System (GDS) assembly and test facility are defined. The facility will include provisions for a complete test laboratory for GDS checkout, performance, and endurance testing, and a contamination-controlled area for assembly, fabrication, storage, and storage preparation of GDS components. Specifications, schedules, and drawings are included

Brayton Isotope Power System (BIPS) facility specification

Energy Technology Data Exchange (ETDEWEB)

1976-05-31

General requirements for the Brayton Isotope Power System (BIPS)/Ground Demonstration System (GDS) assembly and test facility are defined. The facility will include provisions for a complete test laboratory for GDS checkout, performance, and endurance testing, and a contamination-controlled area for assembly, fabrication, storage, and storage preparation of GDS components. Specifications, schedules, and drawings are included.

Large Scale Experiments on Spacecraft Fire Safety

Science.gov (United States)

Urban, David; Ruff, Gary A.; Minster, Olivier; Fernandez-Pello, A. Carlos; Tien, James S.; Torero, Jose L.; Legros, Guillaume; Eigenbrod, Christian; Smirnov, Nickolay; Fujita, Osamu;

A Technology Program that Rescues Spacecraft

Science.gov (United States)

Deutsch, Leslie J.; Lesh, J. R.

2004-03-01

There has never been a long-duration deep space mission that did not have unexpected problems during operations. JPL's Interplanetary Network Directorate (IND) Technology Program was created to develop new and improved methods of communication, navigation, and operations. A side benefit of the program is that it maintains a cadre of human talent and experimental systems that can be brought to bear on unexpected problems that may occur during mission operations. Solutions fall into four categories: applying new technology during operations to enhance science performance, developing new operational strategies, providing domain experts to help find solutions, and providing special facilities to trouble-shoot problems. These are illustrated here using five specific examples of spacecraft anomalies that have been solved using, at least in part, expertise or facilities from the IND Technology Program: Mariner 10, Voyager, Galileo, SOHO, and Cassini/Huygens. In this era of careful cost management, and emphasis on returns-on-investment, it is important to recognize this crucial additional benefit from such technology program investments.

NASA Workshop on Hybrid (Mixed-Actuator) Spacecraft Attitude Control

Science.gov (United States)

Dennehy, Cornelius J.; Kunz, Nans

2014-01-01

At the request of the Science Mission Directorate Chief Engineer, the NASA Technical Fellow for Guidance, Navigation & Control assembled and facilitated a workshop on Spacecraft Hybrid Attitude Control. This multi-Center, academic, and industry workshop, sponsored by the NASA Engineering and Safety Center (NESC), was held in April 2013 to unite nationwide experts to present and discuss the various innovative solutions, techniques, and lessons learned regarding the development and implementation of the various hybrid attitude control system solutions investigated or implemented. This report attempts to document these key lessons learned with the 16 findings and 9 NESC recommendations.

Facility for the storage of spent, heat-emitting and container-enclosed nuclear reactor fuel assemblies

International Nuclear Information System (INIS)

Hennings, U.

1987-01-01

Patent for facility for the storage of spent, heat-emitting and container-enclosed nuclear reactor fuel assemblies, which are arranged within a building in a horizontal position and are cooled by a gas stream, whereby the building has a storage and a loading zone, characterized by the fact that pallet trucks arranged one above the other in a row and such that an interspace is left for the receiving positions for the containers, the the pallet trucks can be moved along rails that extend between two side walls arranged opposite to one another in the storage zone, that the storage zone can be loaded and unloaded by opening located in these two side walls, and that the gas stream only circulates within the building

Effects of non-latching blast valves on the source term and consequences of the design-basis accidents in the Device Assembly Facility (DAF)

International Nuclear Information System (INIS)

Nguyen, D.H.

1993-08-01

The analysis of the Design-Basis Accidents (DBA) involving high explosives (HE) and Plutonium (Pu) in the assembly cell of the Device Assembly Facility (DAF), which was completed earlier, assumed latching blast valves in the ventilation system of the assembly cell. Latching valves effectively sealed a release path through the ventilation duct system. However, the blast valves in the assembly cell, as constructed are actually non-latching valves, and would reopen when the gas pressure drops to 0.5 psi above one atmosphere. Because the reopening of the blast valves provides an additional release path to the environment, and affects the material transport from the assembly cell to other DAF buildings, the DOE/NV DAF management has decided to support an additional analysis of the DAF's DBA to account for the effects of non-latching valves. Three cases were considered in the DAF's DBA, depending on the amount of HE and Pu involved, as follows: Case 1 -- 423 number-sign HE, 16 kg Pu; Case 2 -- 150 number-sign HE 10 kg Pu; Case 3 -- 55 number-sign HE 5 kg Pu. The results of the analysis with non-latching valves are summarized

Large coil test facility

International Nuclear Information System (INIS)

Nelms, L.W.; Thompson, P.B.

1980-01-01

Final design of the facility is nearing completion, and 20% of the construction has been accomplished. A large vacuum chamber, houses the test assembly which is coupled to appropriate cryogenic, electrical, instrumentation, diagnostc systems. Adequate assembly/disassembly areas, shop space, test control center, offices, and test support laboratories are located in the same building. Assembly and installation operations are accomplished with an overhead crane. The major subsystems are the vacuum system, the test stand assembly, the cryogenic system, the experimental electric power system, the instrumentation and control system, and the data aquisition system

Enhancing Three-dimensional Movement Control System for Assemblies of Machine-Building Facilities

Science.gov (United States)

Kuzyakov, O. N.; Andreeva, M. A.

2018-01-01

Aspects of enhancing three-dimensional movement control system are given in the paper. Such system is to be used while controlling assemblies of machine-building facilities, which is a relevant issue. The base of the system known is three-dimensional movement control device with optical principle of action. The device consists of multi point light emitter and light receiver matrix. The processing of signals is enhanced to increase accuracy of measurements by switching from discrete to analog signals. Light receiver matrix is divided into four areas, and the output value of each light emitter in each matrix area is proportional to its luminance level. Thus, determing output electric signal value of each light emitter in corresponding area leads to determing position of multipoint light emitter and position of object tracked. This is done by using Case-based reasoning method, the precedent in which is described as integral signal value of each matrix area, coordinates of light receivers, which luminance level is high, and decision to be made in this situation.

Spacecraft fabrication and test MODIL. Final report

Energy Technology Data Exchange (ETDEWEB)

Saito, T.T.

1994-05-01

This report covers the period from October 1992 through the close of the project. FY 92 closed out with the successful briefing to industry and with many potential and important initiatives in the spacecraft arena. Due to the funding uncertainties, we were directed to proceed as if our funding would be approximately the same as FY 92 ($2M), but not to make any major new commitments. However, the MODIL`s FY 93 funding was reduced to $810K and we were directed to concentrate on the cryocooler area. The cryocooler effort completed its demonstration project. The final meetings with the cryocooler fabricators were very encouraging as we witnessed the enthusiastic reception of technology to help them reduce fabrication uncertainties. Support of the USAF Phillips Laboratory cryocooler program was continued including kick-off meetings for the Prototype Spacecraft Cryocooler (PSC). Under Phillips Laboratory support, Gill Cruz visited British Aerospace and Lucas Aerospace in the United Kingdom to assess their manufacturing capabilities. In the Automated Spacecraft & Assembly Project (ASAP), contracts were pursued for the analysis by four Brilliant Eyes prime contractors to provide a proprietary snap shot of their current status of Integrated Product Development. In the materials and structure thrust the final analysis was completed of the samples made under the contract (``Partial Automation of Matched Metal Net Shape Molding of Continuous Fiber Composites``) to SPARTA. The Precision Technologies thrust funded the Jet Propulsion Laboratory to prepare a plan to develop a Computer Aided Alignment capability to significantly reduce the time for alignment and even possibly provide real time and remote alignment capability of systems in flight.

Highlights from the assembly of the helical field coils for the Advanced Toroidal Facility

International Nuclear Information System (INIS)

Benson, R.D.

1985-01-01

The helical field (HF) coils in the Advanced Toroidal Facility (ATF) device consist of a set of 24 identical segments connected to form a continuous pair of helical coils wrapped around a toroidal vacuum vessel. Each segment weighs approximately 1364 kg (3000 lb) and is composed of 14 water-cooled copper plate conductors bolted to a cast stainless steel structural support member with a T-shape cross section (known as the structural tee). The segment components are electrically insulated with Kapton adhesive tape, G-10, Tefzel, and rubber to withstand 2.5 kV. As a final insulator and structural support, the entire segment is vacuum impregnated with epoxy. This paper offers a brief overview of the processes used to assemble the component parts into a completed segment, including identification of items that required special attention. 4 figs

Laboratory investigation of antenna signals from dust impacts on spacecraft

Science.gov (United States)

Sternovsky, Zoltan; Collette, Andrew; Malaspina, David M.; Thayer, Frederick

2016-04-01

Electric field and plasma wave instruments act as dust detectors picking up voltage pulses induced by impacts of particulates on the spacecraft body. These signals enable the characterization of cosmic dust environments even with missions without dedicated dust instruments. For example, the Voyager 1 and 2 spacecraft performed the first detection of dust particles near Uranus, Neptune, and in the outer solar system [Gurnett et al., 1987, 1991, 1997]. The two STEREO spacecraft observed distinct signals at high rate that were interpreted as nano-sized particles originating from near the Sun and accelerated to high velocities by the solar wind [MeyerVernet et al, 2009a, Zaslavsky et al., 2012]. The MAVEN spacecraft is using the antennas onboard to characterize the dust environment of Mars [Andersson et al., 2014] and Solar Probe Plus will do the same in the inner heliosphere. The challenge, however, is the correct interpretation of the impact signals and calculating the mass of the dust particles. The uncertainties result from the incomplete understanding of the signal pickup mechanisms, and the variation of the signal amplitude with impact location, the ambient plasma environment, and impact speed. A comprehensive laboratory study of impact generated antenna signals has been performed recently using the IMPACT dust accelerator facility operated at the University of Colorado. Dust particles of micron and submicron sizes with velocities of tens of km/s are generated using a 3 MV electrostatic analyzer. A scaled down model spacecraft is exposed to the dust impacts and one or more antennas, connected to sensitive electronics, are used to detect the impact signals. The measurements showed that there are three clearly distinct signal pickup mechanisms due to spacecraft charging, antenna charging and antenna pickup sensing space charge from the expanding plasma cloud. All mechanisms vary with the spacecraft and antenna bias voltages and, furthermore, the latter two

A spacecraft's own ambient environment: The role of simulation-based research

Energy Technology Data Exchange (ETDEWEB)

Ketsdever, Andrew D. [University of Colorado Colorado Springs, Department of Mechanical and Aerospace Engineering, Colorado Springs, CO (United States); Gimelshein, Sergey [University of Southern California, Department of Astronautical Engineering, Los Angeles, CA (United States)

2014-12-09

Spacecraft contamination has long been a subject of study in the rarefied gas dynamics community. Professor Mikhail Ivanov coined the term a spacecraft's 'own ambient environment' to describe the effects of natural and satellite driven processes on the conditions encountered by a spacecraft in orbit. Outgassing, thruster firings, and gas and liquid dumps all contribute to the spacecraft's contamination environment. Rarefied gas dynamic modeling techniques, such as Direct Simulation Monte Carlo, are well suited to investigate these spacebased environments. However, many advances were necessary to fully characterize the extent of this problem. A better understanding of modeling flows over large pressure ranges, for example hybrid continuum and rarefied numerical schemes, were required. Two-phase flow modeling under rarefied conditions was necessary. And the ability to model plasma flows for a new era of propulsion systems was also required. Through the work of Professor Ivanov and his team, we now have a better understanding of processes that create a spacecraft's own ambient environment and are able to better characterize these environments. Advances in numerical simulation have also spurred on the development of experimental facilities to study these effects. The relationship between numerical results and experimental advances will be explored in this manuscript.

Assembly of NASA's Most Powerful X-Ray Telescope Completed

Science.gov (United States)

1998-03-01

holes, many of which are invisible to us now. We may even see the processes that create the elements found here on Earth." Assembly of the observatory began in 1997 with the arrival of the high resolution mirror assembly at TRW Space and Electronics Group. In August 1997, the telescope's optical bench was mated with the mirrors, followed by integration of the telescope with the spacecraft in October. In February 1998, the observatory's science instrument module was mated to the top of the telescope. The complete observatory is 45 feet long, has a solar array wing span 64 feet wide, and weighs more than 5 tons. Using glass purchased from Schott Glaswerke, Mainz, Germany, the telescope's mirrors were built by Raytheon Optical Systems Inc., Danbury, Conn. The mirrors were coated by Optical Coating Laboratory Inc., Santa Rosa, Calif.; and assembled by Eastman-Kodak Co., Rochester, N.Y. The observatory's charged coupled device imaging spectrometer was developed by Pennsylvania State University at University Park, and the Massachusetts Institute of Technology (MIT), at Cambridge. One diffraction grating was developed by MIT, the other by the Space Research Organization Netherlands, Utrecht, in collaboration with the Max Planck Institute, Garching, Germany. The high resolution camera instrument was built by the Smithsonian Astrophysical Observatory. Ball Aerospace & Technologies Corporation of Boulder, Colo., developed the science instrument module. The Advanced X-ray Astrophysics Facility program is managed by the Marshall Center for the Office of Space Science, NASA Headquarters, Washington, D.C. The Smithsonian Astrophysical Observatory in Cambridge, Mass., will operate the observatory for NASA. NOTE TO EDITORS: A photo of the integrated telescope is available via the World Wide Web at URL: http://chandra.harvard.edu/press/images.html Prepared by John Bryk

The National Criticality Experiments Research Center at the Device Assembly Facility, Nevada National Security Site: Status and Capabilities, Summary Report

International Nuclear Information System (INIS)

Bragg-Sitton, S.; Bess, J.; Werner, J.

2011-01-01

The National Criticality Experiments Research Center (NCERC) was officially opened on August 29, 2011. Located within the Device Assembly Facility (DAF) at the Nevada National Security Site (NNSS), the NCERC has become a consolidation facility within the United States for critical configuration testing, particularly those involving highly enriched uranium (HEU). The DAF is a Department of Energy (DOE) owned facility that is operated by the National Nuclear Security Agency/Nevada Site Office (NNSA/NSO). User laboratories include the Lawrence Livermore National Laboratory (LLNL) and Los Alamos National Laboratory (LANL). Personnel bring their home lab qualifications and procedures with them to the DAF, such that non-site specific training need not be repeated to conduct work at DAF. The NNSS Management and Operating contractor is National Security Technologies, LLC (NSTec) and the NNSS Safeguards and Security contractor is Wackenhut Services. The complete report provides an overview and status of the available laboratories and test bays at NCERC, available test materials and test support configurations, and test requirements and limitations for performing sub-critical and critical tests. The current summary provides a brief summary of the facility status and the method by which experiments may be introduced to NCERC.

On the concept of survivability, with application to spacecraft and space-based networks

International Nuclear Information System (INIS)

Castet, Jean-Francois; Saleh, Joseph H.

2012-01-01

Survivability is an important attribute and requirement for military systems. Recently, survivability has become increasingly important for public infrastructure systems as well. In this work, we bring considerations of survivability to bear on space systems. We develop a conceptual framework and quantitative analyses based on stochastic Petri nets (SPN) to characterize and compare the survivability of different space architectures. The architectures here considered are a monolith spacecraft and a space-based network. To build the stochastic Petri net models for the degradations and failures of these two architectures, we conducted statistical analyses of historical multi-state failure data of spacecraft subsystems, and we assembled these subsystems, and their SPN models, in ways to create our monolith and networked systems. Preliminary results indicate, and quantify the extent to which, a space-based network is more survivable than the monolith spacecraft with respect to on-orbit anomalies and failures. For space systems, during the design and acquisition process, different architectures are benchmarked against several metrics; we argue that if survivability is not accounted for, then the evaluation process is likely to be biased in favor of the traditional dominant design, namely the monolith spacecraft. If however in a given context, survivability is a critical requirement for a customer, the survivability framework here proposed, and the stochastic modeling capability developed, can demonstrate the extent to which a networked space architecture may better satisfy this requirement than a monolith spacecraft. These results should be of interest to operators whose space assets require high levels of survivability, especially in the light of emerging threats.

Development of the solar array deployment and drive system for the XTE spacecraft

Science.gov (United States)

Farley, Rodger; Ngo, Son

1995-01-01

The X-ray Timing Explorer (XTE) spacecraft is a NASA science low-earth orbit explorer-class satellite to be launched in 1995, and is an in-house Goddard Space Flight Center (GSFC) project. It has two deployable aluminum honeycomb solar array wings with each wing being articulated by a single axis solar array drive assembly. This paper will address the design, the qualification testing, and the development problems as they surfaced of the Solar Array Deployment and Drive System.

Remote process connectors for the new waste calcining facility

International Nuclear Information System (INIS)

Jacobs, R.T.; Carter, J.A.; Hohback, A.C.

1978-01-01

The remote process connectors developed, used, and tested at the Remote Maintenance Development Facility are described. These connectors, including the three-bolt kinematic-graphite flange and watertight electrical connectors, are assembled on master jigs (holding-welding fixture) to form interchangeable pump and valve loop assemblies. These assemblies, with their guide-in platforms, make possible a method of performing remote maintenance at the New Waste Calcining Facility which is a departure from methods that until now have been the standard of the industry

Safeguards on MOX assemblies at LWRs

International Nuclear Information System (INIS)

Arenas Carrasco, J.; Koulikov, I.; Heinonen, O.J.; Arlt, R.; Grigoleit, K.; Clarke, R.; Swinhoe, M.

2000-01-01

Operating within the framework of the New Partnership Approach (NPA) for unirradiated MOX fuel assemblies in LWRs, the IAEA and EURATOM have gained experience in safeguarding 13 LWRs licensed to operate with MOX assemblies. In order to fulfil SIR requirements, verification methods and techniques capable of measuring MOX assemblies under water have been and are still being developed. These encompass both qualitative tests for the detection of plutonium (gross attribute tests) and quantitative tests for the measurement of the amount of plutonium (partial defect tests) and are based on gamma and neutron detection techniques. There are nine PWR and two BWR where the reactor and the spent fuel pond can be covered by the same surveillance device. These are Type I reactors where the reactor and the pond are located in the same hall. In these types of facilities relying on surveillance during the MOX refuelling is especially difficult at the BWRs due to the depth of the core pond. There are two PWR type facilities where the reactor and the spent fuel pond are located in different halls and cannot be covered by the same surveillance device (Type II). An open core camera has not been installed during refuelling and therefore indirect surveillance is currently used to survey MOX loading. Improvements are therefore required and are under consideration. After receipt at the facility, there are a few facilities which must keep the received fresh MOX fuel in wet storage, not only for a short period prior to refuelling, but for more than a year, until the next refuelling campaign. In these cases timely inspections for direct use fresh nuclear material require considerable inspection effort. Additionally, where human surveillance of core loading and finally core closure are necessary there is also a large demand for manpower. Either an agreement should be reached with the operators to delay the MOX loading until the end of the fuelling campaign, or alternative approaches should be

Spacecraft Software Maintenance: An Effective Approach to Reducing Costs and Increasing Science Return

Science.gov (United States)

Shell, Elaine M.; Lue, Yvonne; Chu, Martha I.

1999-01-01

Flight software is a mission critical element of spacecraft functionality and performance. When ground operations personnel interface to a spacecraft, they are typically dealing almost entirely with the capabilities of onboard software. This software, even more than critical ground/flight communications systems, is expected to perform perfectly during all phases of spacecraft life. Due to the fact that it can be reprogrammed on-orbit to accommodate degradations or failures in flight hardware, new insights into spacecraft characteristics, new control options which permit enhanced science options, etc., the on- orbit flight software maintenance team is usually significantly responsible for the long term success of a science mission. Failure of flight software to perform as needed can result in very expensive operations work-around costs and lost science opportunities. There are three basic approaches to maintaining spacecraft software--namely using the original developers, using the mission operations personnel, or assembling a center of excellence for multi-spacecraft software maintenance. Not planning properly for flight software maintenance can lead to unnecessarily high on-orbit costs and/or unacceptably long delays, or errors, in patch installations. A common approach for flight software maintenance is to access the original development staff. The argument for utilizing the development staff is that the people who developed the software will be the best people to modify the software on-orbit. However, it can quickly becomes a challenge to obtain the services of these key people. They may no longer be available to the organization. They may have a more urgent job to perform, quite likely on another project under different project management. If they havn't worked on the software for a long time, they may need precious time for refamiliarization to the software, testbeds and tools. Further, a lack of insight into issues related to flight software in its on

Final results of the Resonance spacecraft calibration effort

Science.gov (United States)

Sampl, Manfred; Macher, Wolfgang; Gruber, Christian; Oswald, Thomas; Rucker, Helmut O.

2010-05-01

We report our dedicated analyses of electrical field sensors onboard the Resonance spacecraft with a focus on the high-frequency electric antennas. The aim of the Resonance mission is to investigate wave-particle interactions and plasma dynamics in the inner magnetosphere of the Earth, with a focus on phenomena occurring along the same field line and within the same flux tube of the Earth's magnetic field. Four spacecraft will be launched, in the middle of the next decade, to perform these observations and measurements. Amongst a variety of instruments and probes several low- and high-frequency electric sensors will be carried which can be used for simultaneous remote sensing and in-situ measurements. The high-frequency electric sensors consist of cylindrical antennas mounted on four booms extruded from the central body of the spacecraft. In addition, the boom rods themselves are used together with the these sensors for mutual impedance measurements. Due to the parasitic effects of the conducting spacecraft body the electrical antenna representations (effective length vector, capacitances) do not coincide with their physical representations. The analysis of the reception properties of these antennas is presented, along with a contribution to the understanding of their impairment by other objects; in particular the influence of large magnetic loop sensors is studied. In order to analyse the antenna system, we applied experimental and numerical methods. The experimental method, called rheometry, is essentially an electrolytic tank measurement, where a scaled-down spacecraft model is immersed into an electrolytic medium (water) with corresponding measurements of voltages at the antennas. The numerical method consists of a numerical solution of the underlying field equations by means of computer programs, which are based on wire-grid and patch-grid models. The experimental and numerical results show that parasitic effects of the antenna-spacecraft assembly alter the

Spacecraft Attitude Tracking and Maneuver Using Combined Magnetic Actuators

Science.gov (United States)

Zhou, Zhiqiang

2012-01-01

A paper describes attitude-control algorithms using the combination of magnetic actuators with reaction wheel assemblies (RWAs) or other types of actuators such as thrusters. The combination of magnetic actuators with one or two RWAs aligned with different body axis expands the two-dimensional control torque to three-dimensional. The algorithms can guarantee the spacecraft attitude and rates to track the commanded attitude precisely. A design example is presented for nadir-pointing, pitch, and yaw maneuvers. The results show that precise attitude tracking can be reached and the attitude- control accuracy is comparable with RWA-based attitude control. When there are only one or two workable RWAs due to RWA failures, the attitude-control system can switch to the control algorithms for the combined magnetic actuators with the RWAs without going to the safe mode, and the control accuracy can be maintained. The attitude-control algorithms of the combined actuators are derived, which can guarantee the spacecraft attitude and rates to track the commanded values precisely. Results show that precise attitude tracking can be reached, and the attitude-control accuracy is comparable with 3-axis wheel control.

Operation of post-irradiation examination facility

Energy Technology Data Exchange (ETDEWEB)

Kim, Eun Ka; Park, Kwang Joon; Jeon, Yong Bum [and others; Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1995-02-01

In 1995, the post-irradiation examination (PIE) of nuclear fuels was performed as follows. The relation between burnup and top nozzle spring force of fuel assembly was obtained by measuring the holddown spring force on the Kori-1 reactor fuel assemblies. The resonance ultrasonic test for inspection of defect and moisture in fuel rod was carried out on fuel rods of C15 and J14 assemblies, and the change of fuel rod condition by storing in pool has been analyzed on the intentionally defected fuel rods (ID-C and ID-L) as well as intact fuel rod (1-2) by NDT in ht cell. The oxide layer thickness on cladding surface of J44-L12 fuel rod was measured by NDT method and metallography to reveal the oxidation as a function of temperature in the fuel rod, and the burnup of J44 fuel assembly was measured by chemical analysis. HVAC system and pool water treatment system of the PIE facility were continuously operated for air filtration and water purification. The monitoring of radiation and pool water in PIE facility has been carried out to maintain the facility safety, and electric power supply system was checked and maintained to supply the electric power to the facility normally. The developed measurement techniques of oxide layer thickness on fuel rod cladding and holddown spring force of top nozzle in fuel assembly were applied to examine the nuclear fuels. Besides, a radiation shielding glove box was designed and a hot cell compressor for volume reduction of radioactive materials was fabricated. 19 tabs., 38 figs., 7 refs. (Author) .new.

Technical specifications for the Oak Ridge Critical Experiments Facility

International Nuclear Information System (INIS)

Stinnett, R.M.

1986-01-01

These Technical Specifications for the Oak Ridge Critical Experiments Facility (CEF) delineate limiting conditions of operation for the facility. The CEF is used primarily for testing the High Flux Isotope Reactor (HFIR) fuel assemblies. Specifically, the Criticality Testing Unit, Liquid (CTUL), located in the CEF, is used for the HFIR fuel assembly test. The test is performed to satisfy the surveillance requirements of the HFIR Technical Specifications. The test is used to determine the water-submerged shutdown margin for each fuel assembly. 11 refs

Application of international safeguards to fast critical assembly facilities. FY 1980 summary report

International Nuclear Information System (INIS)

1980-12-01

Nuclear materials inventory-verification techniques for large split-table fast critical assemblies are being studied in this program. Emphasis has been given to techniques that minimize fuel handling in order to reduce facility downtime and radiation exposure to the inventory team. The techniques studied include drawer seals, autoradiography, and spectral index measurements. Two-drawer sealing techniques have been studied, and the relative strengths and weaknesses are pointed out. The rod-type locking mechanism would not disrupt the reactor cooling air flow or interfere with autoradiography but is more expensive to implement. Passive autoradiography was used in a ZPPR inventory to verify to a 93% confidence level that less than 8-kg Pu was missing. The inventory was completed in four days by a five-member team with radiation exposures well within acceptable limits. Two autoradiographic film packages were developed to distinguish HEU from a DU matrix. The 30-mil pack requires an exposure between 4 and 16 hours and fits into most of the drawers. The 40-mil pack requires only a two-hour exposure but fits into less than half the drawers

Characterization of a Prototype Radio Frequency Space Environment Path Emulator for Evaluating Spacecraft Ranging Hardware

Science.gov (United States)

Mitchell, Jason W.; Baldwin, Philip J.; Kurichh, Rishi; Naasz, Bo J.; Luquette, Richard J.

2007-01-01

The Formation Flying Testbed (FFTB) at the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) provides a hardware-in-the-loop test environment for formation navigation and control. The facility is evolving as a modular, hybrid, dynamic simulation facility for end-to-end guidance, navigation and control (GN&C) design and analysis of formation flying spacecraft. The core capabilities of the FFTB, as a platform for testing critical hardware and software algorithms in-the-loop, have expanded to include S-band Radio Frequency (RF) modems for interspacecraft communication and ranging. To enable realistic simulations that require RF ranging sensors for relative navigation, a mechanism is needed to buffer the RF signals exchanged between spacecraft that accurately emulates the dynamic environment through which the RF signals travel, including the effects of the medium, moving platforms, and radiated power. The Path Emulator for Radio Frequency Signals (PERFS), currently under development at NASA GSFC, provides this capability. The function and performance of a prototype device are presented.

The development of flow test technology for PWR fuel assembly

International Nuclear Information System (INIS)

Chung, Moon Ki; Cha, Chong Hee; Chung, Chang Hwan; Chun, Se Young; Song, Chul Hwa; Chung, Heung Joon; Won, Soon Yeun; Cho, Yeong Rho; Kim, Bok Deuk

1988-05-01

KAERI has an extensive program to develope PWR fuel assembly. In relation to the program, development of flow test technology is needed to evaluate the thermal hydraulic compactibility and mechanical integrity of domestically fabricated nuclear fuels. A high-pressure and high-temperature flow test facility was designed to test domestically fabricated fuel assembly. The test section of the facility has capacity of a 6x6 full length PWR fuel assembly. A flow test rig was designed and installed at Cold Test Loop to carry out model experiments with 5x5 rod assembly under atmosphere pressure to get information about the characteristics of pressure loss of spacer grids and velocity distribution in the subchannels. LDV measuring technology was established using TSI's Laser Dopper Velocimeter 9100-3 System

Accelerator-driven subcritical facility:Conceptual design development

Science.gov (United States)

Gohar, Yousry; Bolshinsky, Igor; Naberezhnev, Dmitry; Duo, Jose; Belch, Henry; Bailey, James

2006-06-01

A conceptual design development of an accelerator-driven subcritical facility has been carried out in the preparation of a joint activity with Kharkov Institute of Physics and Technology of Ukraine. The main functions of the facility are the medical isotope production and the support of the Ukraine nuclear industry. An electron accelerator is considered to drive the subcritical assembly. The neutron source intensity and spectrum have been studied. The energy deposition, spatial neutron generation, neutron utilization fraction, and target dimensions have been quantified to define the main target performance parameters, and to select the target material and beam parameters. Different target conceptual designs have been developed based the engineering requirements including heat transfer, thermal hydraulics, structure, and material issues. The subcritical assembly is designed to obtain the highest possible neutron flux level with a Keff of 0.98. Different fuel materials, uranium enrichments, and reflector materials are considered in the design process. The possibility of using low enrichment uranium without penalizing the facility performance is carefully evaluated. The mechanical design of the facility has been developed to maximize its utility and minimize the time for replacing the target and the fuel assemblies. Safety, reliability, and environmental considerations are included in the facility conceptual design. The facility is configured to accommodate future design improvements, upgrades, and new missions. In addition, it has large design margins to accommodate different operating conditions and parameters. In this paper, the conceptual design and the design analyses of the facility will be presented.

Partial Defect Verification of Spent Fuel Assemblies by PDET: Principle and Field Testing in Interim Spent Fuel Storage Facility (CLAB) in Sweden

Energy Technology Data Exchange (ETDEWEB)

Ham, Y.S.; Kerr, P.; Sitaraman, S.; Swan, R. [Global Security Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Rossa, R. [SCK-CEN, Mol (Belgium); Liljenfeldt, H. [SKB in Oskarshamn (Sweden)

2015-07-01

The need for the development of a credible method and instrument for partial defect verification of spent fuel has been emphasized over a few decades in the safeguards communities as the diverted spent fuel pins can be the source of nuclear terrorism or devices. The need is increasingly more important and even urgent as many countries have started to transfer spent fuel to so called 'difficult-to-access' areas such as dry storage casks, reprocessing or geological repositories. Partial defect verification is required by IAEA before spent fuel is placed into 'difficult-to-access' areas. Earlier, Lawrence Livermore National Laboratory (LLNL) has reported the successful development of a new, credible partial defect verification method for pressurized water reactor (PWR) spent fuel assemblies without use of operator data, and further reported the validation experiments using commercial spent fuel assemblies with some missing fuel pins. The method was found to be robust as the method is relatively invariant to the characteristic variations of spent fuel assemblies such as initial fuel enrichment, cooling time, and burn-up. Since then, the PDET system has been designed and prototyped for 17x17 PWR spent fuel assemblies, complete with data acquisition software and acquisition electronics. In this paper, a summary description of the PDET development followed by results of the first successful field testing using the integrated PDET system and actual spent fuel assemblies performed in a commercial spent fuel storage site, known as Central Interim Spent fuel Storage Facility (CLAB) in Sweden will be presented. In addition to partial defect detection initial studies have determined that the tool can be used to verify the operator declared average burnup of the assembly as well as intra-assembly burnup levels. (authors)

Extreme Ionizing-Radiation-Resistant Bacterium

Science.gov (United States)

Vaishampayan, Parag A.; Venkateswaran, Kasthuri J.; Schwendner, Petra

2013-01-01

There is a growing concern that desiccation and extreme radiation-resistant, non-spore-forming microorganisms associated with spacecraft surfaces can withstand space environmental conditions and subsequent proliferation on another solar body. Such forward contamination would jeopardize future life detection or sample return technologies. The prime focus of NASA s planetary protection efforts is the development of strategies for inactivating resistance-bearing micro-organisms. Eradi cation techniques can be designed to target resistance-conferring microbial populations by first identifying and understanding their physiologic and biochemical capabilities that confers its elevated tolerance (as is being studied in Deinococcus phoenicis, as a result of this description). Furthermore, hospitals, food, and government agencies frequently use biological indicators to ensure the efficacy of a wide range of radiation-based sterilization processes. Due to their resistance to a variety of perturbations, the nonspore forming D. phoenicis may be a more appropriate biological indicator than those currently in use. The high flux of cosmic rays during space travel and onto the unshielded surface of Mars poses a significant hazard to the survival of microbial life. Thus, radiation-resistant microorganisms are of particular concern that can survive extreme radiation, desiccation, and low temperatures experienced during space travel. Spore-forming bacteria, a common inhabitant of spacecraft assembly facilities, are known to tolerate these extreme conditions. Since the Viking era, spores have been utilized to assess the degree and level of microbiological contamination on spacecraft and their associated spacecraft assembly facilities. Members of the non-sporeforming bacterial community such as Deinococcus radiodurans can survive acute exposures to ionizing radiation (5 kGy), ultraviolet light (1 kJ/m2), and desiccation (years). These resistive phenotypes of Deinococcus enhance the

Mobile work station concept for assembly of large space structures (zero gravity simulation tests)

Science.gov (United States)

Heard, W. L., Jr.; Bush, H. G.; Wallsom, R. E.; Jensen, J. K.

1982-03-01

The concept presented is intended to enhance astronaut assembly of truss structure that is either too large or complex to fold for efficient Shuttle delivery to orbit. The potential of augmented astronaut assembly is illustrated by applying the result of the tests to a barebones assembly of a truss structure. If this structure were assembled from the same nestable struts that were used in the Mobile Work Station assembly tests, the spacecraft would be 55 meters in diameter and consist of about 500 struts. The struts could be packaged in less than 1/2% of the Shuttle cargo bay volume and would take up approximately 3% of the mass lift capability. They could be assembled in approximately four hours. This assembly concept for erectable structures is not only feasible, but could be used to significant economic advantage by permitting the superior packaging feature of erectable structures to be exploited and thereby reduce expensive Shuttle delivery flights.

Operational experience of the fuel cleaning facility of Joyo

International Nuclear Information System (INIS)

Mukaibo, R.; Matsuno, Y.; Sato, I.; Yoneda, Y.; Ito, H.

1978-01-01

Spent fuel assemblies in 'Joyo', after they are taken out of the core, are taken to the Fuel Cleaning Facility in the reactor service building and sodium removal is done. The cleaning process is done by cooling the assembly with argon gas, steam charging and rinsing by demineralized water. Deposited sodium was 50 ∼ 60 g per assembly. The sodium and steam reaction takes about 15 minutes to end and the total time the fuel is placed in the pot is about an hour. The total number of assemblies cleaned in the facility was 95 as of November 1977. In this report the operational experience together with discussions of future improvements are given. (author)

Operational experience of the fuel cleaning facility of Joyo

Energy Technology Data Exchange (ETDEWEB)

Mukaibo, R; Matsuno, Y; Sato, I; Yoneda, Y; Ito, H [O-arai Engineering Centre, PNC, Ibaraki-ken, Tokio (Japan)

1978-08-01

Spent fuel assemblies in 'Joyo', after they are taken out of the core, are taken to the Fuel Cleaning Facility in the reactor service building and sodium removal is done. The cleaning process is done by cooling the assembly with argon gas, steam charging and rinsing by demineralized water. Deposited sodium was 50 {approx} 60 g per assembly. The sodium and steam reaction takes about 15 minutes to end and the total time the fuel is placed in the pot is about an hour. The total number of assemblies cleaned in the facility was 95 as of November 1977. In this report the operational experience together with discussions of future improvements are given. (author)

Analysis of fuel management in the KIPT neutron source facility

Energy Technology Data Exchange (ETDEWEB)

Zhong Zhaopeng, E-mail: zzhong@anl.gov [Nuclear Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Gohar, Yousry; Talamo, Alberto [Nuclear Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States)

2011-05-15

Research highlights: > Fuel management of KIPT ADS was analyzed. > Core arrangement was shuffled in stage wise. > New fuel assemblies was added into core periodically. > Beryllium reflector could also be utilized to increase the fuel life. - Abstract: Argonne National Laboratory (ANL) of USA and Kharkov Institute of Physics and Technology (KIPT) of Ukraine have been collaborating on the conceptual design development of an experimental neutron source facility consisting of an electron accelerator driven sub-critical assembly. The neutron source driving the sub-critical assembly is generated from the interaction of 100 KW electron beam with a natural uranium target. The sub-critical assembly surrounding the target is fueled with low enriched WWR-M2 type hexagonal fuel assemblies. The U-235 enrichment of the fuel material is <20%. The facility will be utilized for basic and applied research, producing medical isotopes, and training young specialists. With the 100 KW electron beam power, the total thermal power of the facility is {approx}360 kW including the fission power of {approx}260 kW. The burnup of the fissile materials and the buildup of fission products continuously reduce the system reactivity during the operation, decrease the neutron flux level, and consequently impact the facility performance. To preserve the neutron flux level during the operation, the fuel assemblies should be added and shuffled for compensating the lost reactivity caused by burnup. Beryllium reflector could also be utilized to increase the fuel life time in the sub-critical core. This paper studies the fuel cycles and shuffling schemes of the fuel assemblies of the sub-critical assembly to preserve the system reactivity and the neutron flux level during the operation.

Application of Space Environmental Observations to Spacecraft Pre-Launch Engineering and Spacecraft Operations

Science.gov (United States)

Barth, Janet L.; Xapsos, Michael

2008-01-01

This presentation focuses on the effects of the space environment on spacecraft systems and applying this knowledge to spacecraft pre-launch engineering and operations. Particle radiation, neutral gas particles, ultraviolet and x-rays, as well as micrometeoroids and orbital debris in the space environment have various effects on spacecraft systems, including degradation of microelectronic and optical components, physical damage, orbital decay, biasing of instrument readings, and system shutdowns. Space climate and weather must be considered during the mission life cycle (mission concept, mission planning, systems design, and launch and operations) to minimize and manage risk to both the spacecraft and its systems. A space environment model for use in the mission life cycle is presented.

Benefits of Spacecraft Level Vibration Testing

Science.gov (United States)

Gordon, Scott; Kern, Dennis L.

2015-01-01

NASA-HDBK-7008 Spacecraft Level Dynamic Environments Testing discusses the approaches, benefits, dangers, and recommended practices for spacecraft level dynamic environments testing, including vibration testing. This paper discusses in additional detail the benefits and actual experiences of vibration testing spacecraft for NASA Goddard Space Flight Center (GSFC) and Jet Propulsion Laboratory (JPL) flight projects. JPL and GSFC have both similarities and differences in their spacecraft level vibration test approach: JPL uses a random vibration input and a frequency range usually starting at 5 Hz and extending to as high as 250 Hz. GSFC uses a sine sweep vibration input and a frequency range usually starting at 5 Hz and extending only to the limits of the coupled loads analysis (typically 50 to 60 Hz). However, both JPL and GSFC use force limiting to realistically notch spacecraft resonances and response (acceleration) limiting as necessary to protect spacecraft structure and hardware from exceeding design strength capabilities. Despite GSFC and JPL differences in spacecraft level vibration test approaches, both have uncovered a significant number of spacecraft design and workmanship anomalies in vibration tests. This paper will give an overview of JPL and GSFC spacecraft vibration testing approaches and provide a detailed description of spacecraft anomalies revealed.

Determining Spacecraft Reaction Wheel Friction Parameters

Science.gov (United States)

Sarani, Siamak

2009-01-01

Software was developed to characterize the drag in each of the Cassini spacecraft's Reaction Wheel Assemblies (RWAs) to determine the RWA friction parameters. This tool measures the drag torque of RWAs for not only the high spin rates (greater than 250 RPM), but also the low spin rates (less than 250 RPM) where there is a lack of an elastohydrodynamic boundary layer in the bearings. RWA rate and drag torque profiles as functions of time are collected via telemetry once every 4 seconds and once every 8 seconds, respectively. Intermediate processing steps single-out the coast-down regions. A nonlinear model for the drag torque as a function of RWA spin rate is incorporated in order to characterize the low spin rate regime. The tool then uses a nonlinear parameter optimization algorithm based on the Nelder-Mead simplex method to determine the viscous coefficient, the Dahl friction, and the two parameters that account for the low spin-rate behavior.

Small Spacecraft for Planetary Science

Science.gov (United States)

Baker, John; Castillo-Rogez, Julie; Bousquet, Pierre-W.; Vane, Gregg; Komarek, Tomas; Klesh, Andrew

2016-07-01

As planetary science continues to explore new and remote regions of the Solar system with comprehensive and more sophisticated payloads, small spacecraft offer the possibility for focused and more affordable science investigations. These small spacecraft or micro spacecraft (attitude control and determination, capable computer and data handling, and navigation are being met by technologies currently under development to be flown on CubeSats within the next five years. This paper will discuss how micro spacecraft offer an attractive alternative to accomplish specific science and technology goals and what relevant technologies are needed for these these types of spacecraft. Acknowledgements: Part of this work is being carried out at the Jet Propulsion Laboratory, California Institute of Technology under contract to NASA. Government sponsorship acknowledged.

User-oriented end-to-end transport protocols for the real-time distribution of telemetry data from NASA spacecraft

Science.gov (United States)

Hooke, A. J.

1979-01-01

A set of standard telemetry protocols for downlink data flow facilitating the end-to-end transport of instrument data from the spacecraft to the user in real time is proposed. The direct switching of data by autonomous message 'packets' that are assembled by the source instrument on the spacecraft is discussed. The data system consists thus of a format on a message rather than word basis, and such packet telemetry would include standardized protocol headers. Standards are being developed within the NASA End-to-End Data System (NEEDS) program for the source packet and transport frame protocols. The source packet protocol contains identification of both the sequence number of the packet as it is generated by the source and the total length of the packet, while the transport frame protocol includes a sequence count defining the serial number of the frame as it is generated by the spacecraft data system, and a field specifying any 'options' selected in the format of the frame itself.

Project assembling and commissioning of a rewetting test facility

International Nuclear Information System (INIS)

Rezende, H.C.

1985-08-01

A test facility (ITR - Instalacao de Testes de Remolhamento) has been erected at the Thermal-hydraulics Laboratory of CDTN, dedicated to the investigation of the basic phenomena that can occur during the reflood phase of a Loss of Coolant Accident (LOCA) in a Pressurized Water Reactor (PWR), utilizing tubular and annular test sections. The present work consists in a presentation of the facility design and a report of its commissioning. The mechanical aspects of the facility, its power supply system and its instrumentation are described. The results of the instruments calibration and two operational tests are presented and a comparison is done with calculations perfomed usign a computer code. (Author) [pt

NiO nanosheet assembles for supercapacitor electrode materials

OpenAIRE

Huanhao Xiao; Shunyu Yao; Hongda Liu; Fengyu Qu; Xu Zhang; Xiang Wu

2016-01-01

In this paper, large scale hierarchically assembled NiO nanosheets have been favorably fabricated through a facile hydrothermal route. The as-prepared NiO nanosheet assembles were characterized in detail by various analytical techniques. The results showed these nanosheets present the thickness of about 30 nm and the surface area is 116.9 m2 g−1. These NiO nanosheet assembles were used as the working electrode materials in electrochemical tests, which demonstrated a specific capacitance value...

Spacecraft Attitude Tracking and Maneuver Using Combined Magnetic Actuators

Science.gov (United States)

Zhou, Zhiqiang

2010-01-01

The accuracy of spacecraft attitude control using magnetic actuators only is low and on the order of 0.4-5 degrees. The key reason is that the magnetic torque is two-dimensional and it is only in the plane perpendicular to the magnetic field vector. In this paper novel attitude control algorithms using the combination of magnetic actuators with Reaction Wheel Assembles (RWAs) or other types of actuators, such as thrusters, are presented. The combination of magnetic actuators with one or two RWAs aligned with different body axis expands the two-dimensional control torque to three-dimensional. The algorithms can guarantee the spacecraft attitude and rates to track the commanded attitude precisely. A design example is presented for Nadir pointing, pitch and yaw maneuvers. The results show that precise attitude tracking can be reached and the attitude control accuracy is comparable with RWAs based attitude control. The algorithms are also useful for the RWAs based attitude control. When there are only one or two workable RWAs due to RWA failures, the attitude control system can switch to the control algorithms for the combined magnetic actuators with the RWAs without going to the safe mode and the control accuracy can be maintained.

Computer simulation of spacecraft/environment interaction

International Nuclear Information System (INIS)

Krupnikov, K.K.; Makletsov, A.A.; Mileev, V.N.; Novikov, L.S.; Sinolits, V.V.

1999-01-01

This report presents some examples of a computer simulation of spacecraft interaction with space environment. We analysed a set data on electron and ion fluxes measured in 1991-1994 on geostationary satellite GORIZONT-35. The influence of spacecraft eclipse and device eclipse by solar-cell panel on spacecraft charging was investigated. A simple method was developed for an estimation of spacecraft potentials in LEO. Effects of various particle flux impact and spacecraft orientation are discussed. A computer engineering model for a calculation of space radiation is presented. This model is used as a client/server model with WWW interface, including spacecraft model description and results representation based on the virtual reality markup language

Computer simulation of spacecraft/environment interaction

CERN Document Server

Krupnikov, K K; Mileev, V N; Novikov, L S; Sinolits, V V

1999-01-01

This report presents some examples of a computer simulation of spacecraft interaction with space environment. We analysed a set data on electron and ion fluxes measured in 1991-1994 on geostationary satellite GORIZONT-35. The influence of spacecraft eclipse and device eclipse by solar-cell panel on spacecraft charging was investigated. A simple method was developed for an estimation of spacecraft potentials in LEO. Effects of various particle flux impact and spacecraft orientation are discussed. A computer engineering model for a calculation of space radiation is presented. This model is used as a client/server model with WWW interface, including spacecraft model description and results representation based on the virtual reality markup language.

Analysis of fuel management in the KIPT neutron source facility

International Nuclear Information System (INIS)

Zhong Zhaopeng; Gohar, Yousry; Talamo, Alberto

2011-01-01

Research highlights: → Fuel management of KIPT ADS was analyzed. → Core arrangement was shuffled in stage wise. → New fuel assemblies was added into core periodically. → Beryllium reflector could also be utilized to increase the fuel life. - Abstract: Argonne National Laboratory (ANL) of USA and Kharkov Institute of Physics and Technology (KIPT) of Ukraine have been collaborating on the conceptual design development of an experimental neutron source facility consisting of an electron accelerator driven sub-critical assembly. The neutron source driving the sub-critical assembly is generated from the interaction of 100 KW electron beam with a natural uranium target. The sub-critical assembly surrounding the target is fueled with low enriched WWR-M2 type hexagonal fuel assemblies. The U-235 enrichment of the fuel material is <20%. The facility will be utilized for basic and applied research, producing medical isotopes, and training young specialists. With the 100 KW electron beam power, the total thermal power of the facility is ∼360 kW including the fission power of ∼260 kW. The burnup of the fissile materials and the buildup of fission products continuously reduce the system reactivity during the operation, decrease the neutron flux level, and consequently impact the facility performance. To preserve the neutron flux level during the operation, the fuel assemblies should be added and shuffled for compensating the lost reactivity caused by burnup. Beryllium reflector could also be utilized to increase the fuel life time in the sub-critical core. This paper studies the fuel cycles and shuffling schemes of the fuel assemblies of the sub-critical assembly to preserve the system reactivity and the neutron flux level during the operation.

Initial Validation of Robotic Operations for In-Space Assembly of a Large Solar Electric Propulsion Transport Vehicle

Science.gov (United States)

Komendera, Erik E.; Dorsey, John T.

2017-01-01

Developing a capability for the assembly of large space structures has the potential to increase the capabilities and performance of future space missions and spacecraft while reducing their cost. One such application is a megawatt-class solar electric propulsion (SEP) tug, representing a critical transportation ability for the NASA lunar, Mars, and solar system exploration missions. A series of robotic assembly experiments were recently completed at Langley Research Center (LaRC) that demonstrate most of the assembly steps for the SEP tug concept. The assembly experiments used a core set of robotic capabilities: long-reach manipulation and dexterous manipulation. This paper describes cross-cutting capabilities and technologies for in-space assembly (ISA), applies the ISA approach to a SEP tug, describes the design and development of two assembly demonstration concepts, and summarizes results of two sets of assembly experiments that validate the SEP tug assembly steps.

General Attitude Control Algorithm for Spacecraft Equipped with Star Camera and Reaction Wheels

DEFF Research Database (Denmark)

Wisniewski, Rafal; Kulczycki, P.

A configuration consisting of a star camera, four reaction wheels and magnetorquers for momentum unloading has become standard for many spacecraft missions. This popularity has motivated numerous agencies and private companies to initiate work on the design of an imbedded attitude control system...... realized on an integrated circuit. This paper considers two issues: slew maneuver with a feature of avoiding direct exposure of the camera's CCD chip to the Sun %, three-axis attitude control and optimal control torque distribution in a reaction wheel assembly. The attitude controller is synthesized...

Micro-Inspector Spacecraft for Space Exploration Missions

Science.gov (United States)

Mueller, Juergen; Alkalai, Leon; Lewis, Carol

2005-01-01

NASA is seeking to embark on a new set of human and robotic exploration missions back to the Moon, to Mars, and destinations beyond. Key strategic technical challenges will need to be addressed to realize this new vision for space exploration, including improvements in safety and reliability to improve robustness of space operations. Under sponsorship by NASA's Exploration Systems Mission, the Jet Propulsion Laboratory (JPL), together with its partners in government (NASA Johnson Space Center) and industry (Boeing, Vacco Industries, Ashwin-Ushas Inc.) is developing an ultra-low mass (missions. The micro-inspector will provide remote vehicle inspections to ensure safety and reliability, or to provide monitoring of in-space assembly. The micro-inspector spacecraft represents an inherently modular system addition that can improve safety and support multiple host vehicles in multiple applications. On human missions, it may help extend the reach of human explorers, decreasing human EVA time to reduce mission cost and risk. The micro-inspector development is the continuation of an effort begun under NASA's Office of Aerospace Technology Enabling Concepts and Technology (ECT) program. The micro-inspector uses miniaturized celestial sensors; relies on a combination of solar power and batteries (allowing for unlimited operation in the sun and up to 4 hours in the shade); utilizes a low-pressure, low-leakage liquid butane propellant system for added safety; and includes multi-functional structure for high system-level integration and miniaturization. Versions of this system to be designed and developed under the H&RT program will include additional capabilities for on-board, vision-based navigation, spacecraft inspection, and collision avoidance, and will be demonstrated in a ground-based, space-related environment. These features make the micro-inspector design unique in its ability to serve crewed as well as robotic spacecraft, well beyond Earth-orbit and into arenas such

The Atsa Suborbital Observatory: An Observatory for a Commercial Suborbital Spacecraft

Science.gov (United States)

Vilas, F.; Sollitt, L. S.

2012-12-01

The advantages of astronomical observations made above Earth's atmosphere have long been understood: free access to spectral regions inaccessible from Earth (e.g., UV) or affected by the atmosphere's content (e.g., IR). Most robotic, space-based telescopes maintain large angular separation between the Sun and an observational target in order to avoid accidental damage to instruments from the Sun. For most astronomical targets, this possibility is easily avoided by waiting until objects are visible away from the Sun. For the Solar System objects inside Earth's orbit, this is never the case. Suborbital astronomical observations have over 50 years' history using NASA's sounding rockets and experimental space planes. Commercial suborbital spacecraft are largely expected to go to ~100 km altitude above Earth, providing a limited amount of time for astronomical observations. The unique scientific advantage to these observations is the ability to point close to the Sun: if a suborbital spacecraft accidentally turns too close to the Sun and fries an instrument, it is easy to land the spacecraft and repair the hardware for the next flight. Objects uniquely observed during the short observing window include inner-Earth asteroids, Mercury, Venus, and Sun-grazing comets. Both open-FOV and target-specific observations are possible. Despite many space probes to the inner Solar System, scientific questions remain. These include inner-Earth asteroid size and bulk density informing Solar System evolution studies and efforts to develop methods of mitigation against imminent impactors to Earth; chemistry and dynamics of Venus' atmosphere addressing physical phenomena such as greenhouse effect, atmospheric super-rotation and global resurfacing on Venus. With the Atsa Suborbital Observatory, we combine the strengths of both ground-based observatories and space-based observing to create a facility where a telescope is maintained and used interchangeably with both in-house facility

EFTF cobalt test assembly results

International Nuclear Information System (INIS)

Rawlins, J.A.; Wootan, D.W.; Carter, L.L.; Brager, H.R.; Schenter, R.E.

1988-01-01

A cobalt test assembly containing yttrium hydride pins for neutron moderation was irradiated in the Fast Flux Test Facility during Cycle 9A for 137.7 equivalent full power days at a power level fo 291 MW. The 36 test pins consisted of a batch of 32 pins containing cobalt metal to produce Co-60, and a set of 4 pins with europium oxide to produce Gd-153, a radioisotope used in detection of the bone disease Osteoporosis. Post-irradiation examination of the cobalt pins determined the Co-60 produced with an accuracy of about 5 %. The measured Co-60 spatially distributed concentrations were within 20 % of the calculated concentrations. The assembly average Co-60 measured activity was 4 % less than the calculated value. The europium oxide pins were gamma scanned for the europium isotopes Eu-152 and Eu-154 to an absolute accuracy of about 10 %. The measured europium radioisotpe anc Gd-153 concentrations were within 20 % of calculated values. In conclusion, the hydride assembly performed well and is an excellent vehicle for many Fast Flux Test Facility isotope production applications. The results also demonstrate that the calculational methods developed by the Westinghouse Hanford Company are very accurate. (author)

Medical Isotope Production Analyses In KIPT Neutron Source Facility

International Nuclear Information System (INIS)

Talamo, Alberto; Gohar, Yousry

2016-01-01

Medical isotope production analyses in Kharkov Institute of Physics and Technology (KIPT) neutron source facility were performed to include the details of the irradiation cassette and the self-shielding effect. An updated detailed model of the facility was used for the analyses. The facility consists of an accelerator-driven system (ADS), which has a subcritical assembly using low-enriched uranium fuel elements with a beryllium-graphite reflector. The beryllium assemblies of the reflector have the same outer geometry as the fuel elements, which permits loading the subcritical assembly with different number of fuel elements without impacting the reflector performance. The subcritical assembly is driven by an external neutron source generated from the interaction of 100-kW electron beam with a tungsten target. The facility construction was completed at the end of 2015, and it is planned to start the operation during the year of 2016. It is the first ADS in the world, which has a coolant system for removing the generated fission power. Argonne National Laboratory has developed the design concept and performed extensive design analyses for the facility including its utilization for the production of different radioactive medical isotopes. 99 Mo is the parent isotope of 99m Tc, which is the most commonly used medical radioactive isotope. Detailed analyses were performed to define the optimal sample irradiation location and the generated activity, for several radioactive medical isotopes, as a function of the irradiation time.

Medical Isotope Production Analyses In KIPT Neutron Source Facility

Energy Technology Data Exchange (ETDEWEB)

Talamo, Alberto [Argonne National Lab. (ANL), Argonne, IL (United States); Gohar, Yousry [Argonne National Lab. (ANL), Argonne, IL (United States)

2016-01-01

Medical isotope production analyses in Kharkov Institute of Physics and Technology (KIPT) neutron source facility were performed to include the details of the irradiation cassette and the self-shielding effect. An updated detailed model of the facility was used for the analyses. The facility consists of an accelerator-driven system (ADS), which has a subcritical assembly using low-enriched uranium fuel elements with a beryllium-graphite reflector. The beryllium assemblies of the reflector have the same outer geometry as the fuel elements, which permits loading the subcritical assembly with different number of fuel elements without impacting the reflector performance. The subcritical assembly is driven by an external neutron source generated from the interaction of 100-kW electron beam with a tungsten target. The facility construction was completed at the end of 2015, and it is planned to start the operation during the year of 2016. It is the first ADS in the world, which has a coolant system for removing the generated fission power. Argonne National Laboratory has developed the design concept and performed extensive design analyses for the facility including its utilization for the production of different radioactive medical isotopes. ⁹⁹Mo is the parent isotope of ^99mTc, which is the most commonly used medical radioactive isotope. Detailed analyses were performed to define the optimal sample irradiation location and the generated activity, for several radioactive medical isotopes, as a function of the irradiation time.

Four-spacecraft determination of magnetopause orientation, motion and thickness: comparison with results from single-spacecraft methods

Directory of Open Access Journals (Sweden)

S. E. Haaland

2004-04-01

Full Text Available In this paper, we use Cluster data from one magnetopause event on 5 July 2001 to compare predictions from various methods for determination of the velocity, orientation, and thickness of the magnetopause current layer. We employ established as well as new multi-spacecraft techniques, in which time differences between the crossings by the four spacecraft, along with the duration of each crossing, are used to calculate magnetopause speed, normal vector, and width. The timing is based on data from either the Cluster Magnetic Field Experiment (FGM or the Electric Field Experiment (EFW instruments. The multi-spacecraft results are compared with those derived from various single-spacecraft techniques, including minimum-variance analysis of the magnetic field and deHoffmann-Teller, as well as Minimum-Faraday-Residue analysis of plasma velocities and magnetic fields measured during the crossings. In order to improve the overall consistency between multi- and single-spacecraft results, we have also explored the use of hybrid techniques, in which timing information from the four spacecraft is combined with certain limited results from single-spacecraft methods, the remaining results being left for consistency checks. The results show good agreement between magnetopause orientations derived from appropriately chosen single-spacecraft techniques and those obtained from multi-spacecraft timing. The agreement between magnetopause speeds derived from single- and multi-spacecraft methods is quantitatively somewhat less good but it is evident that the speed can change substantially from one crossing to the next within an event. The magnetopause thickness varied substantially from one crossing to the next, within an event. It ranged from 5 to 10 ion gyroradii. The density profile was sharper than the magnetic profile: most of the density change occured in the earthward half of the magnetopause.

Key words. Magnetospheric physics (magnetopause, cusp and

Development of Out-pile Test Technology for Fuel Assembly Performance Verification

Energy Technology Data Exchange (ETDEWEB)

Chun, Tae Hyun; In, W. K.; Oh, D. S. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)] (and others)

2007-03-15

Out-pile tests with full scale fuel assembly are to verify the design and to evaluate the performance of the final products. HTL for the hydraulic tests and FAMeCT for mechanical/structural tests were constructed in this project. The maximum operating conditions of HTL are 30 bar, 320 .deg. C, and 500 m3/hr. This facility can perform the pressure drop test, fuel assembly uplift test, and flow induced vibration test. FAMeCT can perform the bending and vibration tests. The verification of the developed facilities were carried out by comparing the reference data of the fuel assembly which was obtained at the Westinghouse Co. The compared data showed a good coincidence within uncertainties. FRETONUS was developed for high temperature and high pressure fretting wear simulator and performance test. A performance test was conducted for 500 hours to check the integrity, endurance, data acquisition capability of the simulator. The technology of turbulent flow analysis and finite element analysis by computation was developed. From the establishments of out-pile test facilities for full scale fuel assembly, the domestic infrastructure for PWR fuel development has been greatly upgraded.

Spacecraft Attitude Determination

DEFF Research Database (Denmark)

Bak, Thomas

This thesis describes the development of an attitude determination system for spacecraft based only on magnetic field measurements. The need for such system is motivated by the increased demands for inexpensive, lightweight solutions for small spacecraft. These spacecraft demands full attitude...... determination based on simple, reliable sensors. Meeting these objectives with a single vector magnetometer is difficult and requires temporal fusion of data in order to avoid local observability problems. In order to guaranteed globally nonsingular solutions, quaternions are generally the preferred attitude...... is a detailed study of the influence of approximations in the modeling of the system. The quantitative effects of errors in the process and noise statistics are discussed in detail. The third contribution is the introduction of these methods to the attitude determination on-board the Ørsted satellite...

Charging in the environment of large spacecraft

International Nuclear Information System (INIS)

Lai, S.T.

1993-01-01

This paper discusses some potential problems of spacecraft charging as a result of interactions between a large spacecraft, such as the Space Station, and its environment. Induced electric field, due to VXB effect, may be important for large spacecraft at low earth orbits. Differential charging, due to different properties of surface materials, may be significant when the spacecraft is partly in sunshine and partly in shadow. Triple-root potential jump condition may occur because of differential charging. Sudden onset of severe differential charging may occur when an electron or ion beam is emitted from the spacecraft. The beam may partially return to the ''hot spots'' on the spacecraft. Wake effects, due to blocking of ambient ion trajectories, may result in an undesirable negative potential region in the vicinity of a large spacecraft. Outgassing and exhaust may form a significant spacecraft induced environment; ionization may occur. Spacecraft charging and discharging may affect the electronic components on board

A Survey of LIDAR Technology and Its Use in Spacecraft Relative Navigation

Science.gov (United States)

Christian, John A.; Cryan, Scott P.

2013-01-01

This paper provides a survey of modern LIght Detection And Ranging (LIDAR) sensors from a perspective of how they can be used for spacecraft relative navigation. In addition to LIDAR technology commonly used in space applications today (e.g. scanning, flash), this paper reviews emerging LIDAR technologies gaining traction in other non-aerospace fields. The discussion will include an overview of sensor operating principles and specific pros/cons for each type of LIDAR. This paper provides a comprehensive review of LIDAR technology as applied specifically to spacecraft relative navigation. HE problem of orbital rendezvous and docking has been a consistent challenge for complex space missions since before the Gemini 8 spacecraft performed the first successful on-orbit docking of two spacecraft in 1966. Over the years, a great deal of effort has been devoted to advancing technology associated with all aspects of the rendezvous, proximity operations, and docking (RPOD) flight phase. After years of perfecting the art of crewed rendezvous with the Gemini, Apollo, and Space Shuttle programs, NASA began investigating the problem of autonomous rendezvous and docking (AR&D) to support a host of different mission applications. Some of these applications include autonomous resupply of the International Space Station (ISS), robotic servicing/refueling of existing orbital assets, and on-orbit assembly.1 The push towards a robust AR&D capability has led to an intensified interest in a number of different sensors capable of providing insight into the relative state of two spacecraft. The present work focuses on exploring the state-of-the-art in one of these sensors - LIght Detection And Ranging (LIDAR) sensors. It should be noted that the military community frequently uses the acronym LADAR (LAser Detection And Ranging) to refer to what this paper calls LIDARs. A LIDAR is an active remote sensing device that is typically used in space applications to obtain the range to one or more

Results from active spacecraft potential control on the Geotail spacecraft

International Nuclear Information System (INIS)

Schmidt, R.; Arends, H.; Pedersen, A.

1995-01-01

A low and actively controlled electrostatic potential on the outer surfaces of a scientific spacecraft is very important for accurate measurements of cold plasma electrons and ions and the DC to low-frequency electric field. The Japanese/NASA Geotail spacecraft carriers as part of its scientific payload a novel ion emitter for active control of the electrostatic potential on the surface of the spacecraft. The aim of the ion emitter is to reduce the positive surface potential which is normally encountered in the outer magnetosphere when the spacecraft is sunlit. Ion emission clamps the surface potential to near the ambient plasma potential. Without emission control, Geotail has encountered plasma conditions in the lobes of the magnetotail which resulted in surface potentials of up to about +70 V. The ion emitter proves to be able to discharge the outer surfaces of the spacecraft and is capable of keeping the surface potential stable at about +2 V. This potential is measured with respect to one of the electric field probes which are current biased and thus kept at a potential slightly above the ambient plasma potential. The instrument uses the liquid metal field ion emission principle to emit indium ions. The ion beam energy is about 6 keV and the typical total emission current amounts to about 15 μA. Neither variations in the ambient plasma conditions nor operation of two electron emitters on Geotail produce significant variations of the controlled surface potential as long as the resulting electron emission currents remain much smaller than the ion emission current. Typical results of the active potential control are shown, demonstrating the surface potential reduction and its stability over time. 25 refs., 5 figs

Design of radioisotope power systems facility

International Nuclear Information System (INIS)

Eschenbaum, R.C.; Wiemers, M.J.

1991-01-01

Radioisotope power systems currently produced for the U.S. Department of Energy Office of Special Applications by the Mound Laboratory at Miamisburg, Ohio, have been used in a variety of configurations by the Department of Defense and the National Aeronautics and Space Administration. A forecast of fugure radioisotope power systems requirements showed a need for an increased production rate beyond the capability of the existing Mound Laboratory. Westinghouse Hanford Company is modifying the Fuels and Materials Examination Facility on the Hanford Site near Richland, Washington, to install the new Radioisotope Power Systems Facility for assembling future radioisotope power systems. The facility is currently being prepared to assemble the radioisotope thermoelectric generators required by the National Aeronautics and Space Administration missions for Comet Rendezvous Asteroid Flyby in 1995 and Cassini, an investigation of Saturn and its moons, in 1996

Nondestructive Assay Data Integration with the SKB-50 Assemblies - FY16 Update

International Nuclear Information System (INIS)

Tobin, Stephen Joseph; Fugate, Michael Lynn; Trellue, Holly Renee; DeBaere, Paul; Sjoland, Anders; Liljenfeldt, Henrik; Hu, Jianwei; Backstrom, Ulrika; Bengtsson, Martin; Burr, Tomas; Eliasson, Annika; Favalli, Andrea; Gauld, Ian; Grogan, Brandon; Jansson, Peter; Junell, Henrik; Schwalbach, Peter; Vaccaro, Stefano; Vo, Duc Ta; Wildestrand, Henrik

2016-01-01

A project to research the application of non-destructive assay (NDA) techniques for spent fuel assemblies is underway at the Central Interim Storage Facility for Spent Nuclear Fuel (for which the Swedish acronym is Clab) in Oskarshamn, Sweden. The research goals of this project contain both safeguards and non-safeguards interests. These nondestructive assay (NDA) technologies are designed to strengthen the technical toolkit of safeguard inspectors and others to determine the following technical goals more accurately; Verify initial enrichment, burnup, and cooling time of facility declaration for spent fuel assemblies; Detect replaced or missing pins from a given spent fuel assembly to confirm its integrity; and Estimate plutonium mass and related plutonium and uranium fissile mass parameters in spent fuel assemblies. Estimate heat content, and measure reactivity (multiplication).

Nondestructive Assay Data Integration with the SKB-50 Assemblies - FY16 Update

Energy Technology Data Exchange (ETDEWEB)

Tobin, Stephen Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Fugate, Michael Lynn [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Trellue, Holly Renee [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); DeBaere, Paul [DG Energy, Luxembourg (Germany); Sjoland, Anders [Swedish Nuclear Fuel and Waste Management Company, Stockholm (Sweden); Liljenfeldt, Henrik [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hu, Jianwei [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Backstrom, Ulrika [Swedish Nuclear Fuel and Waste Management Company, Stockholm (Sweden); Vattenfall AB, Stockholm (Sweden); Bengtsson, Martin [Swedish Nuclear Fuel and Waste Management Company, Stockholm (Sweden); Vattenfall AB, Stockholm (Sweden); Burr, Tomas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); International Atomic Energy Agency, Vienna (Austria); Eliasson, Annika [Swedish Nuclear Fuel and Waste Management Company, Stockholm (Sweden); Favalli, Andrea [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gauld, Ian [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Grogan, Brandon [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jansson, Peter [Uppsala Univ. (Sweden); Junell, Henrik [Swedish Nuclear Fuel and Waste Management Company, Stockholm (Sweden); Schwalbach, Peter [DG Energy, Luxembourg (Germany); Vaccaro, Stefano [DG Energy, Luxembourg (Germany); Vo, Duc Ta [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wildestrand, Henrik [Swedish Nuclear Fuel and Waste Management Company, Stockholm (Sweden); Vattenfall AB, Stockholm (Sweden)

2016-10-28

A project to research the application of non-destructive assay (NDA) techniques for spent fuel assemblies is underway at the Central Interim Storage Facility for Spent Nuclear Fuel (for which the Swedish acronym is Clab) in Oskarshamn, Sweden. The research goals of this project contain both safeguards and non-safeguards interests. These nondestructive assay (NDA) technologies are designed to strengthen the technical toolkit of safeguard inspectors and others to determine the following technical goals more accurately; Verify initial enrichment, burnup, and cooling time of facility declaration for spent fuel assemblies; Detect replaced or missing pins from a given spent fuel assembly to confirm its integrity; and Estimate plutonium mass and related plutonium and uranium fissile mass parameters in spent fuel assemblies. Estimate heat content, and measure reactivity (multiplication).

Calibration of the TVO spent BWR reference fuel assembly

International Nuclear Information System (INIS)

Tarvainen, M.; Baecklin, A.; Haakanson, A.

1992-02-01

In 1989 the Support Programmes of Finland (FSP) and Sweden (SSP) initiated a joint task to cross calibrate the burnup of the IAEA spent BWR reference fuel assembly at the TVO AFR storage facility (TVO KPA-STORE) in Finland. The reference assembly, kept separately under the IAEA seal, is used for verification measurements of spent fuel by GBUV method (SG-NDA-38). The cross calibration was performed by establishing a calibration curve, 244 Cm neutron rate versus burnup, using passive neutron assay (PNA) measurements. The declared burnup of the reference assembly was compared with the burnup value deduced from the calibration curve. A calibration line was also established by using the GBUV method with the aid of high resolution gamma ray spectrometry (HRGS). Normalization between the two different facilities was performed using sealed neutron and gamma calibration sources. The results of the passive neutron assay show consistency, better than 1 %, between the declared mean burnup of the reference assembly and the burnup deduced from the calibration curve. The corresponding consistency is within +-2 % for the HRGS measurements

Simulation of facility operations and materials accounting for a combined reprocessing/MOX fuel fabrication facility

International Nuclear Information System (INIS)

Coulter, C.A.; Whiteson, R.; Zardecki, A.

1991-01-01

We are developing a computer model of facility operations and nuclear materials accounting for a facility that reprocesses spent fuel and fabricates mixed oxide (MOX) fuel rods and assemblies from the recovered uranium and plutonium. The model will be used to determine the effectiveness of various materials measurement strategies for the facility and, ultimately, of other facility safeguards functions as well. This portion of the facility consists of a spent fuel storage pond, fuel shear, dissolver, clarifier, three solvent-extraction stages with uranium-plutonium separation after the first stage, and product concentrators. In this facility area mixed oxide is formed into pellets, the pellets are loaded into fuel rods, and the fuel rods are fabricated into fuel assemblies. These two facility sections are connected by a MOX conversion line in which the uranium and plutonium solutions from reprocessing are converted to mixed oxide. The model of the intermediate MOX conversion line used in the model is based on a design provided by Mike Ehinger of Oak Ridge National Laboratory (private communication). An initial version of the simulation model has been developed for the entire MOX conversion and fuel fabrication sections of the reprocessing/MOX fuel fabrication facility, and this model has been used to obtain inventory difference variance estimates for those sections of the facility. A significant fraction of the data files for the fuel reprocessing section have been developed, but these data files are not yet complete enough to permit simulation of reprocessing operations in the facility. Accordingly, the discussion in the following sections is restricted to the MOX conversion and fuel fabrication lines. 3 tabs

Fractionated Spacecraft Architectures Seeding Study

National Research Council Canada - National Science Library

Mathieu, Charlotte; Weigel, Annalisa

2006-01-01

.... Models were developed from a customer-centric perspective to assess different fractionated spacecraft architectures relative to traditional spacecraft architectures using multi-attribute analysis...

Internet Technology on Spacecraft

Science.gov (United States)

Rash, James; Parise, Ron; Hogie, Keith; Criscuolo, Ed; Langston, Jim; Powers, Edward I. (Technical Monitor)

2000-01-01

The Operating Missions as Nodes on the Internet (OMNI) project has shown that Internet technology works in space missions through a demonstration using the UoSAT-12 spacecraft. An Internet Protocol (IP) stack was installed on the orbiting UoSAT-12 spacecraft and tests were run to demonstrate Internet connectivity and measure performance. This also forms the basis for demonstrating subsequent scenarios. This approach provides capabilities heretofore either too expensive or simply not feasible such as reconfiguration on orbit. The OMNI project recognized the need to reduce the risk perceived by mission managers and did this with a multi-phase strategy. In the initial phase, the concepts were implemented in a prototype system that includes space similar components communicating over the TDRS (space network) and the terrestrial Internet. The demonstration system includes a simulated spacecraft with sample instruments. Over 25 demonstrations have been given to mission and project managers, National Aeronautics and Space Administration (NASA), Department of Defense (DoD), contractor technologists and other decisions makers, This initial phase reached a high point with an OMNI demonstration given from a booth at the Johnson Space Center (JSC) Inspection Day 99 exhibition. The proof to mission managers is provided during this second phase with year 2000 accomplishments: testing the use of Internet technologies onboard an actual spacecraft. This was done with a series of tests performed using the UoSAT-12 spacecraft. This spacecraft was reconfigured on orbit at very low cost. The total period between concept and the first tests was only 6 months! On board software was modified to add an IP stack to support basic IP communications. Also added was support for ping, traceroute and network timing protocol (NTP) tests. These tests show that basic Internet functionality can be used onboard spacecraft. The performance of data was measured to show no degradation from current

Reactor and fuel assembly

International Nuclear Information System (INIS)

Ishii, Yoshihiko; Bessho, Yasunori; Sano, Hiroki; Yokomizo, Osamu; Yamashita, Jun-ichi.

1990-01-01

The present invention realizes an effective spectral operation by applying an optimum pressure loss coefficient while taking the characteristics of a lower tie plate into consideration. That is, the pressure loss coefficient of the lower tie plate is optimized by varying the cross sectional area of a fuel assembly flow channel in the lower tie plate or varying the surface roughness of a coolant flow channel in the lower tie plate. Since there is a pressure loss coefficient to optimize the moderator density over a flow rate change region, the effect of spectral shift rods can be improved by setting the optimum pressure loss coefficient of the lower tie plate. According to the present invention, existent fuel assemblies can easily be changed successively to fuel assemblies having spectral shift rods of a great spectral shift effect by using existent reactor facilities as they are. (I.S.)

BRAHMMA - accelerator driven subcritical facility

International Nuclear Information System (INIS)

Roy, Tushar; Shukla, Shefali; Shukla, M.; Ray, N.K.; Kashyap, Y.S.; Patel, T.; Gadkari, S.C.

2017-01-01

Accelerator Driven Subcritical systems are being studied worldwide for their potential in burning minor actinides and reducing long term radiotoxicity of spent nuclear fuels. In order to pursue the physics studies of Accelerator Driven Subcritical systems, a thermal subcritical assembly BRAHMMA (BeOReflectedAndHDPeModeratedMultiplying Assembly) has been developed at Purnima Labs, BARC. The facility consists of two major components: Subcritical core and Accelerator (DT/ DD Purnima Neutron Generator)

Spacecraft momentum control systems

CERN Document Server

Leve, Frederick A; Peck, Mason A

2015-01-01

The goal of this book is to serve both as a practical technical reference and a resource for gaining a fuller understanding of the state of the art of spacecraft momentum control systems, specifically looking at control moment gyroscopes (CMGs). As a result, the subject matter includes theory, technology, and systems engineering. The authors combine material on system-level architecture of spacecraft that feature momentum-control systems with material about the momentum-control hardware and software. This also encompasses material on the theoretical and algorithmic approaches to the control of space vehicles with CMGs. In essence, CMGs are the attitude-control actuators that make contemporary highly agile spacecraft possible. The rise of commercial Earth imaging, the advances in privately built spacecraft (including small satellites), and the growing popularity of the subject matter in academic circles over the past decade argues that now is the time for an in-depth treatment of the topic. CMGs are augmented ...

Low-Cost, Class D Testing of Spacecraft Photovoltaic Systems Can Reduce Risk

Science.gov (United States)

Forgione, Joshua B.; Kojima, Gilbert K.; Hanel, Robert; Mallinson, Mark V.

2014-01-01

at the appropriate solar array switch in the power system. A metal-halide bulb, infrared imagers, and onboard spacecraft measurements are utilized to minimize risk of thermal damage during test. Data is provided to support test results for both passing and marginal panels. Prior to encapsulation in the launch vehicle, each panel is inspected for damage by the panel manufacturer. Cracked cells or other damage is amended on-site. Because the photovoltaic test system is inexpensive and portable, each repaired panel can be re-verified immediately. Post-launch, the photovoltaic system is again characterized for per-panel deviations from the manufacturer's performance test. This proved especially tricky as the LADEE spacecraft performs only one current measurement on the entire array. The algorithm for Matlab tools to assess panel performance based on spacecraft attitude is discussed. While not as precise and comprehensive as LAPSS, the LADEE approach leverages minimal resources into an ongoing assessment program that can be applied through numerous stages of the mission. The project takes a true Class D approach in assessing the technical value of a spacecraft level performance test versus the programmatic risk of shipping the spacecraft to another facility. The resources required are a fraction of that for a LAPSS test, and is easy to repeat. Further, the test equipment can be handed down to future projects without building an on-site facility.

Assembly and Design Miniaturization of Floating Spacecraft Simulator and Its Magnetic Docking Interface

Science.gov (United States)

2016-09-01

10cm with minimal height, using a static mount instead of a ball mounting screw end would mitigate this concern. Figure 24. New Way Air Bearing...required if the air being used to fill the tank is from a 40 compressor designed for scuba tanks, as is the case in the SRL, it may be prudent to...tape to the bottom. 65 Step (12) Screw the assembled tank filler attachment to the air tank

Thermal design of spacecraft solar arrays using a polyimide foam

International Nuclear Information System (INIS)

Bianco, N; Iasiello, M; Naso, V

2015-01-01

The design of the Thermal Control System (TCS) of spacecraft solar arrays plays a fundamental role. Indeed, the spacecraft components must operate within a certain range of temperature. If this doesn't occur, their performance is reduced and they may even break. Solar arrays, which are employed to recharge batteries, are directly exposed to the solar heat flux, and they need to be insulated from the earth's surface irradiation. Insulation is currently provided either with a white paint coating or with a Multi Layer Insulation (MLI) system [1]. A configuration based on an open-cell polyimide foam has also been recently proposed [2]. Using polyimide foams in TCSs looks very attractive in terms of costs, weight and assembling. An innovative thermal analysis of the above cited TCS configurations is carried out in this paper, by solving the porous media energy equation, under the assumption of Local Thermal Equilibrium (LTE) between the two phases. Radiation effects through the solar array are also considered by using the Rosseland approximation. Under a stationary daylight condition, temperature profiles are obtained by means of the finite-element based code COMSOL Multiphysics ® . Finally, since the weight plays an important role in aerospace applications, weights of the three TCS configurations are compared. (paper)

Thermal design of spacecraft solar arrays using a polyimide foam

Science.gov (United States)

Bianco, N.; Iasiello, M.; Naso, V.

2015-11-01

The design of the Thermal Control System (TCS) of spacecraft solar arrays plays a fundamental role. Indeed, the spacecraft components must operate within a certain range of temperature. If this doesn't occur, their performance is reduced and they may even break. Solar arrays, which are employed to recharge batteries, are directly exposed to the solar heat flux, and they need to be insulated from the earth's surface irradiation. Insulation is currently provided either with a white paint coating or with a Multi Layer Insulation (MLI) system [1]. A configuration based on an open-cell polyimide foam has also been recently proposed [2]. Using polyimide foams in TCSs looks very attractive in terms of costs, weight and assembling. An innovative thermal analysis of the above cited TCS configurations is carried out in this paper, by solving the porous media energy equation, under the assumption of Local Thermal Equilibrium (LTE) between the two phases. Radiation effects through the solar array are also considered by using the Rosseland approximation. Under a stationary daylight condition, temperature profiles are obtained by means of the finite-element based code COMSOL Multiphysics®. Finally, since the weight plays an important role in aerospace applications, weights of the three TCS configurations are compared.

Facile "modular assembly" for fast construction of a highly oriented crystalline MOF nanofilm.

Science.gov (United States)

Xu, Gang; Yamada, Teppei; Otsubo, Kazuya; Sakaida, Shun; Kitagawa, Hiroshi

2012-10-10

The preparation of crystalline, ordered thin films of metal-organic frameworks (MOFs) will be a critical process for MOF-based nanodevices in the future. MOF thin films with perfect orientation and excellent crystallinity were formed with novel nanosheet-structured components, Cu-TCPP [TCPP = 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin], by a new "modular assembly" strategy. The modular assembly process involves two steps: a "modularization" step is used to synthesize highly crystalline "modules" with a nanosized structure that can be conveniently assembled into a thin film in the following "assembly" step. With this method, MOF thin films can easily be set up on different substrates at very high speed with controllable thickness. This new approach also enabled us to prepare highly oriented crystalline thin films of MOFs that cannot be prepared in thin-film form by traditional techniques.

Fuel Assembly Damping Summary

Energy Technology Data Exchange (ETDEWEB)

Lee, Kanghee; Kang, Heungseok; Oh, Dongseok; Yoon, Kyungho; Kim, Hyungkyu; Kim, Jaeyong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2013-10-15

This paper summary the fuel assembly damping data in air/in still water/under flow, released from foreign fuel vendors, compared our data with the published data. Some technical issues in fuel assembly damping measurement testing are also briefly discussed. Understanding of each fuel assembly damping mechanisms according to the surrounding medium and flow velocity can support the fuel design improvement in fuel assembly dynamics and structural integrity aspect. Because the upgraded requirements of the newly-developed advanced reactor system will demands to minimize fuel design margin in integrity evaluation, reduction in conservatism of fuel assembly damping can contribute to alleviate the fuel design margin for sure. Damping is an energy dissipation mechanism in a vibrating mechanical structure and prevents a resonant structure from having infinite vibration amplitudes. The sources of fuel assembly damping are various from support friction to flow contribution, and it can be increased by the viscosity or drag of surrounding fluid medium or the average velocity of water flowing. Fuel licensing requires fuel design evaluation in transient or accidental condition. Dynamic response analysis of fuel assembly is to show fuel integrity and requires information on assembly-wise damping in dry condition and under wet or water flowing condition. However, damping measurement test for the full-scale fuel assembly prototype is not easy to carry out because of the scale (fuel prototype, test facility), unsteadiness of test data (scattering, random sampling and processing), instrumentation under water flowing (water-proof response measurement), and noise. LWR fuel technology division in KAERI is preparing the infra structure for damping measurement test of full-scale fuel assembly, to support fuel industries and related research activities. Here is a preliminary summary of fuel assembly damping, published in the literature. Some technical issues in fuel assembly damping

Preconceptual design for a Monitored Retrievable Storage (MRS) transfer facility

International Nuclear Information System (INIS)

Woods, W.D.; Jowdy, A.K.; Smith, R.I.

1990-09-01

The contract between the DOE and the utilities specifies that the DOE will receive spent fuel from the nuclear utilities in 1998. This study investigates the feasibility of employing a simple Transfer Facility which can be constructed quickly, and operate while the full-scale MRS facilities are being constructed. The Transfer Facility is a hot cell designed only for the purpose of transferring spent fuel assemblies from the Office of Civilian Radioactive Waste Management (OCRWM) transport casks (shipped from the utility sites) into onsite concrete storage casks. No operational functions other than spent fuel assembly transfers and the associated cask handling, opening, and closing would be performed in this facility. Radioactive waste collected in the Transfer Facility during operations would be stored until the treatment facilities in the full-scale MRS facility became operational, approximately 2 years after the Transfer Facility started operation. An alternate wherein the Transfer Facility was the only waste handling building on the MRS site was also examined and evaluated. 6 figs., 26 tabs

Air Force Research Laboratory Spacecraft Cryocooler Endurance Evaluation Facility Closing Report

Science.gov (United States)

Armstrong, J.; Martin, K. W.; Fraser, T.

2015-12-01

The Air Force Research Laboratory (AFRL) Spacecraft Component Thermal Research Group has been devoted to evaluating lifetime performance of space cryocooler technology for over twenty years. Long-life data is essential for confirming design lifetimes for space cryocoolers. Continuous operation in a simulated space environment is the only accepted method to test for degradation. AFRL has provided raw data and detailed evaluations to cryocooler developers for advancing the technology, correcting discovered deficiencies, and improving cryocooler designs. At AFRL, units of varying design and refrigeration cycles were instrumented in state-of-the-art experiment stands to provide spacelike conditions and were equipped with software data acquisition to track critical cryocooler operating parameters. This data allowed an assessment of the technology's ability to meet the desired lifetime and documented any long-term changes in performance. This paper will outline a final report of the various flight cryocoolers tested in our laboratory. The data summarized includes the seven cryocoolers tested during 2014-2015. These seven coolers have a combined total of 433,326 hours (49.5 years) of operation.

Determining initial enrichment, burnup, and cooling time of pressurized-water-reactor spent fuel assemblies by analyzing passive gamma spectra measured at the Clab interim-fuel storage facility in Sweden

Science.gov (United States)

Favalli, A.; Vo, D.; Grogan, B.; Jansson, P.; Liljenfeldt, H.; Mozin, V.; Schwalbach, P.; Sjöland, A.; Tobin, S. J.; Trellue, H.; Vaccaro, S.

2016-06-01

The purpose of the Next Generation Safeguards Initiative (NGSI)-Spent Fuel (SF) project is to strengthen the technical toolkit of safeguards inspectors and/or other interested parties. The NGSI-SF team is working to achieve the following technical goals more easily and efficiently than in the past using nondestructive assay measurements of spent fuel assemblies: (1) verify the initial enrichment, burnup, and cooling time of facility declaration; (2) detect the diversion or replacement of pins; (3) estimate the plutonium mass [which is also a function of the variables in (1)]; (4) estimate the decay heat; and (5) determine the reactivity of spent fuel assemblies. Since August 2013, a set of measurement campaigns has been conducted at the Central Interim Storage Facility for Spent Nuclear Fuel (Clab), in collaboration with Swedish Nuclear Fuel and Waste Management Company (SKB). One purpose of the measurement campaigns was to acquire passive gamma spectra with high-purity germanium and lanthanum bromide scintillation detectors from Pressurized Water Reactor and Boiling Water Reactor spent fuel assemblies. The absolute 137Cs count rate and the 154Eu/137Cs, 134Cs/137Cs, 106Ru/137Cs, and 144Ce/137Cs isotopic ratios were extracted; these values were used to construct corresponding model functions (which describe each measured quantity's behavior over various combinations of burnup, cooling time, and initial enrichment) and then were used to determine those same quantities in each measured spent fuel assembly. The results obtained in comparison with the operator declared values, as well as the methodology developed, are discussed in detail in the paper.

MOX Lead Assembly Fabrication at the Savannah River Site

Energy Technology Data Exchange (ETDEWEB)

Geddes, R.L. [Westinghouse Savannah River Company, AIKEN, SC (United States); Spiker, D.L.; Poon, A.P.

1997-12-01

The U. S. Department of Energy (DOE) announced its intent to prepare an Environmental Impact Statement (EIS) under the National Environmental Policy Act (NEPA) on the disposition of the nations weapon-usable surplus plutonium.This EIS is tiered from the Storage and Disposition of Weapons-Usable Fissile Material Programmatic Environmental Impact Statement issued in December 1996,and the associated Record of Decision issued on January, 1997. The EIS will examine reasonable alternatives and potential environmental impacts for the proposed siting, construction, and operation of three types of facilities for plutonium disposition. The three types of facilities are: a pit disassembly and conversion facility, a facility to immobilize surplus plutonium in a glass or ceramic form for disposition, and a facility to fabricate plutonium oxide into mixed oxide (MOX) fuel.As an integral part of the surplus plutonium program, Oak Ridge National Laboratory (ORNL) was tasked by the DOE Office of Fissile Material Disposition(MD) as the technical lead to organize and evaluate existing facilities in the DOE complex which may meet MD`s need for a domestic MOX fuel fabrication demonstration facility. The Lead Assembly (LA) facility is to produce 1 MT of usable test fuel per year for three years. The Savannah River Site (SRS) as the only operating plutonium processing site in the DOE complex, proposes two options to carry out the fabrication of MOX fuel lead test assemblies: an all Category I facility option and a combined Category I and non-Category I facilities option.

Fixed Base Modal Testing Using the NASA GRC Mechanical Vibration Facility

Science.gov (United States)

Staab, Lucas D.; Winkel, James P.; Suarez, Vicente J.; Jones, Trevor M.; Napolitano, Kevin L.

2016-01-01

The Space Power Facility at NASA's Plum Brook Station houses the world's largest and most powerful space environment simulation facilities, including the Mechanical Vibration Facility (MVF), which offers the world's highest-capacity multi-axis spacecraft shaker system. The MVF was designed to perform sine vibration testing of a Crew Exploration Vehicle (CEV)-class spacecraft with a total mass of 75,000 pounds, center of gravity (cg) height above the table of 284 inches, diameter of 18 feet, and capability of 1.25 gravity units peak acceleration in the vertical and 1.0 gravity units peak acceleration in the lateral directions. The MVF is a six-degree-of-freedom, servo-hydraulic, sinusoidal base-shake vibration system that has the advantage of being able to perform single-axis sine vibration testing of large structures in the vertical and two lateral axes without the need to reconfigure the test article for each axis. This paper discusses efforts to extend the MVF's capabilities so that it can also be used to determine fixed base modes of its test article without the need for an expensive test-correlated facility simulation.

Cluster PEACE observations of electrons of spacecraft origin

Directory of Open Access Journals (Sweden)

S. Szita

2001-09-01

Full Text Available The two PEACE (Plasma Electron And Current Experiment sensors on board each Cluster spacecraft sample the electron velocity distribution across the full 4 solid angle and the energy range 0.7 eV to 26 keV with a time resolution of 4 s. We present high energy and angular resolution 3D observations of electrons of spacecraft origin in the various environments encountered by the Cluster constellation, including a lunar eclipse interval where the spacecraft potential was reduced but remained positive, and periods of ASPOC (Active Spacecraft POtential Control operation which reduced the spacecraft potential. We demonstrate how the spacecraft potential may be found from a gradient change in the PEACE low energy spectrum, and show how the observed spacecraft electrons are confined by the spacecraft potential. We identify an intense component of the spacecraft electrons with energies equivalent to the spacecraft potential, the arrival direction of which is seen to change when ASPOC is switched on. Another spacecraft electron component, observed in the sunward direction, is reduced in the eclipse but unaffected by ASPOC, and we believe this component is produced in the analyser by solar UV. We find that PEACE anodes with a look direction along the spacecraft surfaces are more susceptible to spacecraft electron contamination than those which look perpendicular to the surface, which justifies the decision to mount PEACE with its field-of-view radially outward rather than tangentially.Key words. Magnetosheric physics (general or miscellaneous Space plasma physics (spacecraft sheaths, wakes, charging

Radioactivities of Long Duration Exposure Facility (LDEF) materials: Baggage and bonanzas

International Nuclear Information System (INIS)

Smith, A.R.; Hurley, D.L.

1991-08-01

Radioactivities in materials onboard the returned Long Duration Exposure Facility (LDEF) satellite have been studied by a variety of techniques. Among the most powerful is low-background Ge-semiconductor detector gamma-ray spectrometry, illustrated here by results obtained at the Lawrence Berkeley Laboratory's (LBL) Low Bakground Facilities, in a multi-laboratory collaboration coordinated by Dr. Thomas Parnell's team at the Marshall Spacecraft Center, Huntsville, Alabama

Facile preparation of luminescent and intelligent gold nanodots based on supramolecular self-assembly

International Nuclear Information System (INIS)

Shi Yunfeng; Li Sujuan; Zhou Yahui; Zhai Qingpan; Hu Mengyue; Cai Fensha; Du Jimin; Liang Jiamiao; Zhu Xinyuan

2012-01-01

A new strategy for preparing luminescent and intelligent gold nanodots based on supramolecular self-assembly is described in this paper. The supramolecular self-assembly was initiated through electrostatic interactions and ion pairing between palmitic acid and hyperbranched poly(ethylenimine). The resulting structures not only have the dynamic reversible properties of supramolecules but also possess torispherical and highly branched architectures. Thus they can be regarded as a new kind of ideal nanoreactor for preparing intelligent Au nanodots. By preparing Au nanodots within this kind of supramolecular self-assembly, the environmental sensitivity of intelligent polymers and the optical, electrical properties of Au nanodots can be combined, endowing the Au nanodots with intelligence. In this paper, a supramolecular self-assembly process based on dendritic poly(ethylenimine) and palmitic acid was designed and then applied to prepare fluorescent and size-controlled Au nanodots. The pH response of Au nanodots embodied by phase transfer from oil phase to water phase was also investigated. (paper)

STG-ET: DLR electric propulsion test facility

Directory of Open Access Journals (Sweden)

Andreas Neumann

2017-04-01

Full Text Available DLR operates the High Vacuum Plume Test Facility Göttingen – Electric Thrusters (STG-ET. This electric propulsion test facility has now accumulated several years of EP-thruster testing experience. Special features tailored to electric space propulsion testing like a large vacuum chamber mounted on a low vibration foundation, a beam dump target with low sputtering, and a performant pumping system characterize this facility. The vacuum chamber is 12.2m long and has a diameter of 5m. With respect to accurate thruster testing, the design focus is on accurate thrust measurement, plume diagnostics, and plume interaction with spacecraft components. Electric propulsion thrusters have to run for thousands of hours, and with this the facility is prepared for long-term experiments. This paper gives an overview of the facility, and shows some details of the vacuum chamber, pumping system, diagnostics, and experiences with these components.

Mechanical Design of Spacecraft

Science.gov (United States)

1962-01-01

In the spring of 1962, engineers from the Engineering Mechanics Division of the Jet Propulsion Laboratory gave a series of lectures on spacecraft design at the Engineering Design seminars conducted at the California Institute of Technology. Several of these lectures were subsequently given at Stanford University as part of the Space Technology seminar series sponsored by the Department of Aeronautics and Astronautics. Presented here are notes taken from these lectures. The lectures were conceived with the intent of providing the audience with a glimpse of the activities of a few mechanical engineers who are involved in designing, building, and testing spacecraft. Engineering courses generally consist of heavily idealized problems in order to allow the more efficient teaching of mathematical technique. Students, therefore, receive a somewhat limited exposure to actual engineering problems, which are typified by more unknowns than equations. For this reason it was considered valuable to demonstrate some of the problems faced by spacecraft designers, the processes used to arrive at solutions, and the interactions between the engineer and the remainder of the organization in which he is constrained to operate. These lecture notes are not so much a compilation of sophisticated techniques of analysis as they are a collection of examples of spacecraft hardware and associated problems. They will be of interest not so much to the experienced spacecraft designer as to those who wonder what part the mechanical engineer plays in an effort such as the exploration of space.

Concept Assessment of a Fission Fragment Rocket Engine (FFRE) Propelled Spacecraft

Science.gov (United States)

Werka, Robert; Clark, Rod; Sheldon, Rob; Percy, Tom

2012-01-01

The March, 2012 issue of Aerospace America stated that ?the near-to-medium prospects for applying advanced propulsion to create a new era of space exploration are not very good. In the current world, we operate to the Moon by climbing aboard a Carnival Cruise Lines vessel (Saturn 5), sail from the harbor (liftoff) shedding whole decks of the ship (staging) along the way and, having reached the return leg of the journey, sink the ship (burnout) and return home in a lifeboat (Apollo capsule). Clearly this is an illogical way to travel, but forced on Explorers by today's propulsion technology. However, the article neglected to consider the one propulsion technology, using today's physical principles that offer continuous, substantial thrust at a theoretical specific impulse of 1,000,000 sec. This engine unequivocally can create a new era of space exploration that changes the way spacecraft operate. Today's space Explorers could travel in Cruise Liner fashion using the technology not considered by Aerospace America, the novel Dusty Plasma Fission Fragment Rocket Engine (FFRE). This NIAC study addresses the FFRE as well as its impact on Exploration Spacecraft design and operation. It uses common physics of the relativistic speed of fission fragments to produce thrust. It radiatively cools the fissioning dusty core and magnetically controls the fragments direction to practically implement previously patented, but unworkable designs. The spacecraft hosting this engine is no more complex nor more massive than the International Space Station (ISS) and would employ the successful ISS technology for assembly and check-out. The elements can be lifted in "chunks" by a Heavy Lift Launcher. This Exploration Spacecraft would require the resupply of small amounts of nuclear fuel for each journey and would be an in-space asset for decades just as any Cruise Liner on Earth. This study has synthesized versions of the FFRE, integrated one concept onto a host spacecraft designed for

Progress towards a new Canadian irradiation-research facility

International Nuclear Information System (INIS)

Lee, A.G.; Lidstone, R.F.

1993-01-01

As reported at the second meeting of the International Group on Research Reactors, Atomic Energy of Canada Limited (AECL) is evaluating its options for future irradiation facilities. During the past year significant progress has been made towards achieving consensus on the irradiation requirements for AECL's major research programs and interpreting those requirements in terms of desirable characteristics for experimental facilities in a research reactor. The next stage of the study involves identifying near-term and long-term options for irradiation-research facilities to meet the requirements. The near-term options include assessing the availability of the NRU reactor and the capabilities of existing research reactors. The long-term options include developing a new irradiation-research facility by adapting the technology base for the MAPLE-X10 reactor design. Because materials testing in support of CANDU power reactors dominates AECL's irradiation requirements, the new reactor concept is called the MAPLE Materials Testing Reactor (MAPLE-MTR). Parametric physics and engineering studies are in progress on alternative MAPLE-MTR configurations to assess the capabilities for the following types of test facilities: - fast-neutron sites, that accommodate materials-irradiation assemblies, - small-diameter vertical fuel test loops that accommodate multielement assemblies, - large-diameter vertical fuel test loops, each able to hold one or more CANDU fuel bundles, - horizontal test loops, each able to hold full-size CANDU fuel bundles or small-diameter multi-element assemblies, and - horizontal beam tubes

NUPEC proves reliability of LWR fuel assemblies

International Nuclear Information System (INIS)

Anon.

1987-01-01

It is very important in assuring the safety of nuclear reactors to confirm the reliability of fuel assemblies. The test program of the Nuclear Power Engineering Center on the reliability of fuel assemblies has verified the high performance and reliability of Japanese LWR fuels, and confirmed the propriety of their design and fabrication. This claim is based on the data obtained from the fuel assemblies irradiated in commercial reactors. The NUPEC program includes irradiation test which has been conducted for 11 years since fiscal 1976, and the maximum thermal loading test using the out of pile test facilities simulating a real reactor which has been continued since fiscal 1978. The irradiation test on BWR fuel assemblies in No.3 reactor in Fukushima No.1 Nuclear Power Station, Tokyo Electric Power Co., Inc., and on PWR fuel assemblies in No.3 reactor in Mihama Power Station, Kansai Electric Power Co., Inc., and the maximum thermal loading test on BWR and PWR fuel assemblies are reported. The series of postirradiation examination of the fuel assemblies used for commercial reactors was conducted for the first time in Japan, and the highly systematic data on 27 items were obtained. (Kako, I.)

Spent Fuel Handling and Packaging Program: a survey of hot cell facilities

International Nuclear Information System (INIS)

Menon, M.N.

1978-07-01

Hot cell facilities in the United States were surveyed to determine their capabilities for conducting integral fuel assembly and individual fuel rod examinations that are required in support of the Spent Fuel Handling and Packaging Program. The ability to receive, handle, disassemble and reconstitute full-length light water reactor spent fuel assemblies, and the ability to conduct nondestructive and destructive examinations on full-length fuel rods were of particular interest. Three DOE-supported facilities and three commercial facilities were included in the survey. This report provides a summary of the findings

Determining initial enrichment, burnup, and cooling time of pressurized-water-reactor spent fuel assemblies by analyzing passive gamma spectra measured at the Clab interim-fuel storage facility in Sweden

Energy Technology Data Exchange (ETDEWEB)

Favalli, A., E-mail: afavalli@lanl.gov [Los Alamos National Laboratory, Los Alamos, NM (United States); Vo, D. [Los Alamos National Laboratory, Los Alamos, NM (United States); Grogan, B. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Jansson, P. [Uppsala University, Uppsala (Sweden); Liljenfeldt, H. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Mozin, V. [Lawrence Livermore National Laboratory, Livermore, CA (United States); Schwalbach, P. [European Commission, DG Energy, Euratom Safeguards Luxemburg, Luxemburg (Luxembourg); Sjöland, A. [Swedish Nuclear Fuel and Waste Management Company, Stockholm (Sweden); Tobin, S.J.; Trellue, H. [Los Alamos National Laboratory, Los Alamos, NM (United States); Vaccaro, S. [European Commission, DG Energy, Euratom Safeguards Luxemburg, Luxemburg (Luxembourg)

2016-06-01

The purpose of the Next Generation Safeguards Initiative (NGSI)–Spent Fuel (SF) project is to strengthen the technical toolkit of safeguards inspectors and/or other interested parties. The NGSI–SF team is working to achieve the following technical goals more easily and efficiently than in the past using nondestructive assay measurements of spent fuel assemblies: (1) verify the initial enrichment, burnup, and cooling time of facility declaration; (2) detect the diversion or replacement of pins; (3) estimate the plutonium mass [which is also a function of the variables in (1)]; (4) estimate the decay heat; and (5) determine the reactivity of spent fuel assemblies. Since August 2013, a set of measurement campaigns has been conducted at the Central Interim Storage Facility for Spent Nuclear Fuel (Clab), in collaboration with Swedish Nuclear Fuel and Waste Management Company (SKB). One purpose of the measurement campaigns was to acquire passive gamma spectra with high-purity germanium and lanthanum bromide scintillation detectors from Pressurized Water Reactor and Boiling Water Reactor spent fuel assemblies. The absolute {sup 137}Cs count rate and the {sup 154}Eu/{sup 137}Cs, {sup 134}Cs/{sup 137}Cs, {sup 106}Ru/{sup 137}Cs, and {sup 144}Ce/{sup 137}Cs isotopic ratios were extracted; these values were used to construct corresponding model functions (which describe each measured quantity’s behavior over various combinations of burnup, cooling time, and initial enrichment) and then were used to determine those same quantities in each measured spent fuel assembly. The results obtained in comparison with the operator declared values, as well as the methodology developed, are discussed in detail in the paper.

Air Purification in Closed Environments: An Overview of Spacecraft Systems

Science.gov (United States)

Perry, Jay L.; LeVan, Douglas; Crumbley, Robert (Technical Monitor)

2002-01-01

The primary goal for a collective protection system and a spacecraft environmental control and life support system (ECLSS) are strikingly similar. Essentially both function to provide the occupants of a building or vehicle with a safe, habitable environment. The collective protection system shields military and civilian personnel from short-term exposure to external threats presented by toxic agents and industrial chemicals while an ECLSS sustains astronauts for extended periods within the hostile environment of space. Both have air quality control similarities with various aircraft and 'tight' buildings. This paper reviews basic similarities between air purification system requirements for collective protection and an ECLSS that define surprisingly common technological challenges and solutions. Systems developed for air revitalization on board spacecraft are discussed along with some history on their early development as well as a view of future needs. Emphasis is placed upon two systems implemented by the National Aeronautics and Space Administration (NASA) onboard the International Space Station (ISS): the trace contaminant control system (TCCS) and the molecular sieve-based carbon dioxide removal assembly (CDRA). Over its history, the NASA has developed and implemented many life support systems for astronauts. As the duration, complexity, and crew size of manned missions increased from minutes or hours for a single astronaut during Project Mercury to days and ultimately months for crews of 3 or more during the Apollo, Skylab, Shuttle, and ISS programs, these systems have become more sophisticated. Systems aboard spacecraft such as the ISS have been designed to provide long-term environmental control and life support. Challenges facing the NASA's efforts include minimizing mass, volume, and power for such systems, while maximizing their safety, reliability, and performance. This paper will highlight similarities and differences among air purification systems

Deployable Brake for Spacecraft

Science.gov (United States)

Rausch, J. R.; Maloney, J. W.

1987-01-01

Aerodynamic shield that could be opened and closed proposed. Report presents concepts for deployable aerodynamic brake. Brake used by spacecraft returning from high orbit to low orbit around Earth. Spacecraft makes grazing passes through atmosphere to slow down by drag of brake. Brake flexible shield made of woven metal or ceramic withstanding high temperatures created by air friction. Stored until needed, then deployed by set of struts.

Three-dimensional assemblies of graphene prepared by a novel chemical reduction-induced self-assembly method

KAUST Repository

Zhang, Lianbin

2012-01-01

In this study, three-dimensional (3D) graphene assemblies are prepared from graphene oxide (GO) by a facile in situ reduction-assembly method, using a novel, low-cost, and environment-friendly reducing medium which is a combination of oxalic acid (OA) and sodium iodide (NaI). It is demonstrated that the combination of a reducing acid, OA, and NaI is indispensable for effective reduction of GO in the current study and this unique combination (1) allows for tunable control over the volume of the thus-prepared graphene assemblies and (2) enables 3D graphene assemblies to be prepared from the GO suspension with a wide range of concentrations (0.1 to 4.5 mg mL-1). To the best of our knowledge, the GO concentration of 0.1 mg mL-1 is the lowest GO concentration ever reported for preparation of 3D graphene assemblies. The thus-prepared 3D graphene assemblies exhibit low density, highly porous structures, and electrically conducting properties. As a proof of concept, we show that by infiltrating a responsive polymer of polydimethylsiloxane (PDMS) into the as-resulted 3D conducting network of graphene, a conducting composite is obtained, which can be used as a sensing device for differentiating organic solvents with different polarity. © 2012 The Royal Society of Chemistry.

Contemporary state of spacecraft/environment interaction research

CERN Document Server

Novikov, L S

1999-01-01

Various space environment effects on spacecraft materials and equipment, and the reverse effects of spacecrafts and rockets on space environment are considered. The necessity of permanent updating and perfection of our knowledge on spacecraft/environment interaction processes is noted. Requirements imposed on models of space environment in theoretical and experimental researches of various aspects of the spacecraft/environment interaction problem are formulated. In this field, main problems which need to be solved today and in the nearest future are specified. The conclusion is made that the joint analysis of both aspects of spacecraft/environment interaction problem promotes the most effective solution of the problem.

Spacecraft Jitter Attenuation Using Embedded Piezoelectric Actuators

Science.gov (United States)

Belvin, W. Keith

1995-01-01

Remote sensing from spacecraft requires precise pointing of measurement devices in order to achieve adequate spatial resolution. Unfortunately, various spacecraft disturbances induce vibrational jitter in the remote sensing instruments. The NASA Langley Research Center has performed analysis, simulations, and ground tests to identify the more promising technologies for minimizing spacecraft pointing jitter. These studies have shown that the use of smart materials to reduce spacecraft jitter is an excellent match between a maturing technology and an operational need. This paper describes the use of embedding piezoelectric actuators for vibration control and payload isolation. In addition, recent advances in modeling, simulation, and testing of spacecraft pointing jitter are discussed.

DUPIC facility engineering

Energy Technology Data Exchange (ETDEWEB)

Lee, J S; Choi, J W; Go, W I; Kim, H D; Song, K C; Jeong, I H; Park, H S; Im, C S; Lee, H M; Moon, K H; Hong, K P; Lee, K S; Suh, K S; Kim, E K; Min, D K; Lee, J C; Chun, Y B; Paik, S Y; Lee, E P; Yoo, G S; Kim, Y S; Park, J C

1997-09-01

In the early stage of the project, a comprehensive survey was conducted to identify the feasibility of using available facilities and of interface between those facilities. It was found out that the shielded cell M6 interface between those facilities. It was found out that the shielded cell M6 of IMEF could be used for the main process experiments of DUPIC fuel fabrication in regard to space adequacy, material flow, equipment layout, etc. Based on such examination, a suitable adapter system for material transfer around the M6 cell was engineered. Regarding the PIEF facility, where spent PWR fuel assemblies are stored in an annex pool, disassembly devices in the pool are retrofitted and spent fuel rod cutting and shipping system to the IMEF are designed and built. For acquisition of casks for radioactive material transport between the facilities, some adaptive refurbishment was applied to the available cask (Padirac) based on extensive analysis on safety requirements. A mockup test facility was newly acquired for remote test of DUPIC fuel fabrication process equipment prior to installation in the M6 cell of the IMEF facility. (author). 157 refs., 57 tabs., 65 figs.

DUPIC facility engineering

International Nuclear Information System (INIS)

Lee, J. S.; Choi, J. W.; Go, W. I.; Kim, H. D.; Song, K. C.; Jeong, I. H.; Park, H. S.; Im, C. S.; Lee, H. M.; Moon, K. H.; Hong, K. P.; Lee, K. S.; Suh, K. S.; Kim, E. K.; Min, D. K.; Lee, J. C.; Chun, Y. B.; Paik, S. Y.; Lee, E. P.; Yoo, G. S.; Kim, Y. S.; Park, J. C.

1997-09-01

In the early stage of the project, a comprehensive survey was conducted to identify the feasibility of using available facilities and of interface between those facilities. It was found out that the shielded cell M6 interface between those facilities. It was found out that the shielded cell M6 of IMEF could be used for the main process experiments of DUPIC fuel fabrication in regard to space adequacy, material flow, equipment layout, etc. Based on such examination, a suitable adapter system for material transfer around the M6 cell was engineered. Regarding the PIEF facility, where spent PWR fuel assemblies are stored in an annex pool, disassembly devices in the pool are retrofitted and spent fuel rod cutting and shipping system to the IMEF are designed and built. For acquisition of casks for radioactive material transport between the facilities, some adaptive refurbishment was applied to the available cask (Padirac) based on extensive analysis on safety requirements. A mockup test facility was newly acquired for remote test of DUPIC fuel fabrication process equipment prior to installation in the M6 cell of the IMEF facility. (author). 157 refs., 57 tabs., 65 figs

Gravity Probe B spacecraft description

International Nuclear Information System (INIS)

Bennett, Norman R; Burns, Kevin; Katz, Russell; Kirschenbaum, Jon; Mason, Gary; Shehata, Shawky

2015-01-01

The Gravity Probe B spacecraft, developed, integrated, and tested by Lockheed Missiles and Space Company and later Lockheed Martin Corporation, consisted of structures, mechanisms, command and data handling, attitude and translation control, electrical power, thermal control, flight software, and communications. When integrated with the payload elements, the integrated system became the space vehicle. Key requirements shaping the design of the spacecraft were: (1) the tight mission timeline (17 months, 9 days of on-orbit operation), (2) precise attitude and translational control, (3) thermal protection of science hardware, (4) minimizing aerodynamic, magnetic, and eddy current effects, and (5) the need to provide a robust, low risk spacecraft. The spacecraft met all mission requirements, as demonstrated by dewar lifetime meeting specification, positive power and thermal margins, precision attitude control and drag-free performance, reliable communications, and the collection of more than 97% of the available science data. (paper)

Fuel assembly cooling experience at the FFTF/IEM cell

International Nuclear Information System (INIS)

McGuinness, P.W.

1985-01-01

In the Fast Flux Test Facility (FFTF), sodium wetted irradiated fuel assemblies are discharged to the Interim Examination and Maintenance (IEM) Cell for disassembly and post-irradiation examination in an inert argon atmosphere. While in the IEM Cell, fuel assemblies are cooled by the IEM Cell Subassembly Cooling System. This paper describes the cooling system design, performance, and lessons learned, including a discussion of two overtemperature incidents. 2 refs., 6 figs

Extension of the ACE solar panels is tested in SAEF-II

Science.gov (United States)

1997-01-01

Extension of the solar panels is tested on the Advanced Composition Explorer (ACE) spacecraft in KSC's Spacecraft Assembly and Encapsulation Facility-II (SAEF-II). Scheduled for launch on a Delta II rocket from Cape Canaveral Air Station on Aug. 25, ACE will study low-energy particles of solar origin and high-energy galactic particles. The collecting power of instruments aboard ACE is 10 to 1,000 times greater than anything previously flown to collect similar data by NASA.

European accelerator facilities for single event effects testing

Energy Technology Data Exchange (ETDEWEB)

Adams, L; Nickson, R; Harboe-Sorensen, R [ESA-ESTEC, Noordwijk (Netherlands); Hajdas, W; Berger, G

1997-03-01

Single event effects are an important hazard to spacecraft and payloads. The advances in component technology, with shrinking dimensions and increasing complexity will give even more importance to single event effects in the future. The ground test facilities are complex and expensive and the complexities of installing a facility are compounded by the requirement that maximum control is to be exercised by users largely unfamiliar with accelerator technology. The PIF and the HIF are the result of experience gained in the field of single event effects testing and represent a unique collaboration between space technology and accelerator experts. Both facilities form an essential part of the European infrastructure supporting space projects. (J.P.N.)

Estimating Torque Imparted on Spacecraft Using Telemetry

Science.gov (United States)

Lee, Allan Y.; Wang, Eric K.; Macala, Glenn A.

2013-01-01

There have been a number of missions with spacecraft flying by planetary moons with atmospheres; there will be future missions with similar flybys. When a spacecraft such as Cassini flies by a moon with an atmosphere, the spacecraft will experience an atmospheric torque. This torque could be used to determine the density of the atmosphere. This is because the relation between the atmospheric torque vector and the atmosphere density could be established analytically using the mass properties of the spacecraft, known drag coefficient of objects in free-molecular flow, and the spacecraft velocity relative to the moon. The density estimated in this way could be used to check results measured by science instruments. Since the proposed methodology could estimate disturbance torque as small as 0.02 N-m, it could also be used to estimate disturbance torque imparted on the spacecraft during high-altitude flybys.

Skylab communications carrier 16536G and filter bypass adapter assembly 12535G. [development of communications equipment for use with Skylab spacecraft

Science.gov (United States)

1974-01-01

Communications equipment for use with the Skylab project is examined to show compliance with contract requirements. The items of equipment considered are: (1) communications carrier assemblies, (2) filter bypass adapter assemblies, and (3) sub-assemblies, parts, and repairs. Additional information is provided concerning contract requirements, test requirements, and failure investigation actions.

The design and development of a spacecraft appendage tie down mechanism

Science.gov (United States)

Nygren, W. D.; Head, R.

1985-01-01

The design and evolution is described of a spacecraft Appendage Tie Down Mechanism (ATDM). Particular emphasis is paid to the mechanical aspects of using dry lubricants to increase the efficiency of acme threads and worm gearing. The ATDM consists of five major components. These are a dc torque motor, a worm gear speed reducer, the tension bolt (or T-bolt), nut capture and centering jaws and the capture nut. In addition, there are several minor components such as limit switch assemblies and an antibackdrive mechanism which couples the drive motor to the worm shaft. A development model of the ATDM in various configurations was under test for some time. In its latest version, it has successfully completed thermal vacuum testing, vibration testing, and extended life testing.

Future spacecraft propulsion systems. Enabling technologies for space exploration. 2. ed.

Energy Technology Data Exchange (ETDEWEB)

Czysz, Paul A. [St. Louis Univ., MO (United States). Oliver L. Parks Endowed Chair in Aerospace Engineering; Bruno, Claudio [Univ. degli Studi di Roma (Italy). Dipt. di Meccanica e Aeronautica

2009-07-01

In this second edition of Future Spacecraft Propulsion Systems, the authors demonstrate the need to break free from the old established concepts of expendable rockets, using chemical propulsion, and to develop new breeds of launch vehicle capable of both launching payloads into orbit at a dramatically reduced cost and for sustained operations in low-Earth orbit. The next steps to establishing a permanent 'presence' in the Solar System beyond Earth are the commercialisation of sustained operations on the Moon and the development of advanced nuclear or high-energy space propulsion systems for Solar System exploration out to the boundary of interstellar space. In the future, high-energy particle research facilities may one day yield a very high-energy propulsion system that will take us to the nearby stars, or even beyond. Space is not quiet: it is a continuous series of nuclear explosions that provide the material for new star systems to form and provide the challenge to explore. This book provides an assessment of the industrial capability required to construct and operate the necessary spacecraft. Time and distance communication and control limitations impose robotic constraints. Space environments restrict human sustained presence and put high demands on electronic, control and materials systems. This comprehensive and authoritative book puts spacecraft propulsion systems in perspective, from earth orbit launchers to astronomical/space exploration vehicles. It includes new material on fusion propulsion, new figures and updates and expands the information given in the first edition. (orig.)

FMIT Test assemblies. Progress report

International Nuclear Information System (INIS)

Nygren, R.E.; Opperman, E.K.

1978-08-01

This progress report is a reference document for a number of inter-related tasks supporting the Fusion Materials Irradiation Test (FMIT) Facility being developed by the Hanford Engineering Development Laboratory. The report describes the basic configuration of test assemblies and supporting rationale based on the neutron flux distribution. Perturbed and unperturbed flux profiles are discussed as well as heating rates and cooling requirements

Adaptive Jacobian Fuzzy Attitude Control for Flexible Spacecraft Combined Attitude and Sun Tracking System

Science.gov (United States)

Chak, Yew-Chung; Varatharajoo, Renuganth

2016-07-01

Many spacecraft attitude control systems today use reaction wheels to deliver precise torques to achieve three-axis attitude stabilization. However, irrecoverable mechanical failure of reaction wheels could potentially lead to mission interruption or total loss. The electrically-powered Solar Array Drive Assemblies (SADA) are usually installed in the pitch axis which rotate the solar arrays to track the Sun, can produce torques to compensate for the pitch-axis wheel failure. In addition, the attitude control of a flexible spacecraft poses a difficult problem. These difficulties include the strong nonlinear coupled dynamics between the rigid hub and flexible solar arrays, and the imprecisely known system parameters, such as inertia matrix, damping ratios, and flexible mode frequencies. In order to overcome these drawbacks, the adaptive Jacobian tracking fuzzy control is proposed for the combined attitude and sun-tracking control problem of a flexible spacecraft during attitude maneuvers in this work. For the adaptation of kinematic and dynamic uncertainties, the proposed scheme uses an adaptive sliding vector based on estimated attitude velocity via approximate Jacobian matrix. The unknown nonlinearities are approximated by deriving the fuzzy models with a set of linguistic If-Then rules using the idea of sector nonlinearity and local approximation in fuzzy partition spaces. The uncertain parameters of the estimated nonlinearities and the Jacobian matrix are being adjusted online by an adaptive law to realize feedback control. The attitude of the spacecraft can be directly controlled with the Jacobian feedback control when the attitude pointing trajectory is designed with respect to the spacecraft coordinate frame itself. A significant feature of this work is that the proposed adaptive Jacobian tracking scheme will result in not only the convergence of angular position and angular velocity tracking errors, but also the convergence of estimated angular velocity to

Attitude coordination for spacecraft formation with multiple communication delays

Directory of Open Access Journals (Sweden)

Guo Yaohua

2015-04-01

Full Text Available Communication delays are inherently present in information exchange between spacecraft and have an effect on the control performance of spacecraft formation. In this work, attitude coordination control of spacecraft formation is addressed, which is in the presence of multiple communication delays between spacecraft. Virtual system-based approach is utilized in case that a constant reference attitude is available to only a part of the spacecraft. The feedback from the virtual systems to the spacecraft formation is introduced to maintain the formation. Using backstepping control method, input torque of each spacecraft is designed such that the attitude of each spacecraft converges asymptotically to the states of its corresponding virtual system. Furthermore, the backstepping technique and the Lyapunov–Krasovskii method contribute to the control law design when the reference attitude is time-varying and can be obtained by each spacecraft. Finally, effectiveness of the proposed methodology is illustrated by the numerical simulations of a spacecraft formation.

Large-Scale Spacecraft Fire Safety Tests

Science.gov (United States)

Urban, David; Ruff, Gary A.; Ferkul, Paul V.; Olson, Sandra; Fernandez-Pello, A. Carlos; T'ien, James S.; Torero, Jose L.; Cowlard, Adam J.; Rouvreau, Sebastien; Minster, Olivier;

SHARP - Automated monitoring of spacecraft health and status

Science.gov (United States)

Atkinson, David J.; James, Mark L.; Martin, R. G.

1990-01-01

Briefly discussed here are the spacecraft and ground systems monitoring process at the Jet Propulsion Laboratory (JPL). Some of the difficulties associated with the existing technology used in mission operations are highlighted. A new automated system based on artificial intelligence technology is described which seeks to overcome many of these limitations. The system, called the Spacecraft Health Automated Reasoning Prototype (SHARP), is designed to automate health and status analysis for multi-mission spacecraft and ground data systems operations. The system has proved to be effective for detecting and analyzing potential spacecraft and ground systems problems by performing real-time analysis of spacecraft and ground data systems engineering telemetry. Telecommunications link analysis of the Voyager 2 spacecraft was the initial focus for evaluation of the system in real-time operations during the Voyager spacecraft encounter with Neptune in August 1989.

SHARP: Automated monitoring of spacecraft health and status

Science.gov (United States)

Atkinson, David J.; James, Mark L.; Martin, R. Gaius

1991-01-01

Briefly discussed here are the spacecraft and ground systems monitoring process at the Jet Propulsion Laboratory (JPL). Some of the difficulties associated with the existing technology used in mission operations are highlighted. A new automated system based on artificial intelligence technology is described which seeks to overcome many of these limitations. The system, called the Spacecraft Health Automated Reasoning Prototype (SHARP), is designed to automate health and status analysis for multi-mission spacecraft and ground data systems operations. The system has proved to be effective for detecting and analyzing potential spacecraft and ground systems problems by performing real-time analysis of spacecraft and ground data systems engineering telemetry. Telecommunications link analysis of the Voyager 2 spacecraft was the initial focus for evaluation of the system in real-time operations during the Voyager spacecraft encounter with Neptune in August 1989.

A facile self-assembly approach to prepare palladium/carbon nanotubes catalyst for the electro-oxidation of ethanol

Science.gov (United States)

Wen, Cuilian; Zhang, Xinyuan; Wei, Ying; Zhang, Teng; Chen, Changxin

2018-02-01

A facile self-assembly approach is reported to prepare palladium/carbon nanotubes (Pd/CNTs) catalyst for the electro-oxidation of ethanol. In this method, the Pd-oleate/CNTs was decomposed into the Pd/CNTs at an optimal temperature of 195 °C in air, in which no inert gas is needed for the thermal decomposition process due to the low temperature used and the decomposed products are also environmental friendly. The prepared Pd/CNTs catalyst has a high metallic Pd0 content and the Pd particles in the catalyst are disperse, uniform-sized with an average size of ˜2.1 nm, and evenly distributed on the CNTs. By employing our strategy, the problems including the exfoliation of the metal particles from the CNTs and the aggregation of the metal particles can be solved. Comparing with the commercial Pd/C one, the prepared Pd/CNTs catalyst exhibits a much higher electrochemical activity and stability for the electro-oxidation of ethanol in the direct ethanol fuel cells.

NIF Target Assembly Metrology Methodology and Results

Energy Technology Data Exchange (ETDEWEB)

Alger, E. T. [General Atomics, San Diego, CA (United States); Kroll, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Dzenitis, E. G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Montesanti, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hughes, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Swisher, M. [IAP, Livermore, CA (United States); Taylor, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Segraves, K. [IAP, Livermore, CA (United States); Lord, D. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Reynolds, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Castro, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Edwards, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2011-01-01

During our inertial confinement fusion (ICF) experiments at the National Ignition Facility (NIF) we require cryogenic targets at the 1-cm scale to be fabricated, assembled, and metrologized to micron-level tolerances. During assembly of these ICF targets, there are physical dimensmetrology is completed using optical coordinate measurement machines that provide repeatable measurements with micron precision, while also allowing in-process data collection for absolute accuracy in assembly. To date, 51 targets have been assembled and metrologized, and 34 targets have been successfully fielded on NIF relying on these metrology data. In the near future, ignition experiments on NIF will require tighter tolerances and more demanding target assembly and metrology capability. Metrology methods, calculations, and uncertainty estimates will be discussed. Target diagnostic port alignment, target position, and capsule location results will be reviewed for the 2009 Energetics Campaign. The information is presented via control charts showing the effect of process improvements that were made during target production. Certain parameters, including capsule position, met the 2009 campaign specifications but will have much tighter requirements in the future. Finally, in order to meet these new requirements assembly process changes and metrology capability upgrades will be necessary.

A computer graphics pilot project - Spacecraft mission support with an interactive graphics workstation

Science.gov (United States)

Hagedorn, John; Ehrner, Marie-Jacqueline; Reese, Jodi; Chang, Kan; Tseng, Irene

1986-01-01

The NASA Computer Graphics Pilot Project was undertaken to enhance the quality control, productivity and efficiency of mission support operations at the Goddard Operations Support Computing Facility. The Project evolved into a set of demonstration programs for graphics intensive simulated control room operations, particularly in connection with the complex space missions that began in the 1980s. Complex mission mean more data. Graphic displays are a means to reduce the probabilities of operator errors. Workstations were selected with 1024 x 768 pixel color displays controlled by a custom VLSI chip coupled to an MC68010 chip running UNIX within a shell that permits operations through the medium of mouse-accessed pulldown window menus. The distributed workstations run off a host NAS 8040 computer. Applications of the system for tracking spacecraft orbits and monitoring Shuttle payload handling illustrate the system capabilities, noting the built-in capabilities of shifting the point of view and rotating and zooming in on three-dimensional views of spacecraft.

An assessment of the transportation costs of shipping non-fuel assembly hardware to FWMS facilities

International Nuclear Information System (INIS)

Shappert, L.B.; Joy, D.S.; Johnson, P.E.; Danese, F.L.; Best, R.E.

1991-01-01

This study examines the cost of using Department of Energy (DOE) Office of Civilian Radioactive Waste Management (OCRWM) Initiative I casks for transporting 62,700 MTU of spent fuel plus associated non-fuel assembly hardware (NFAH) between reactor sites and either a monitored retrievable storage (MRS) or a repository facility. The study further considers the benefits of increasing the cell size of the Initiative I BWR cask baskets to accommodate the fuel plus channels (which also would decrease the capacity of the cask to carry BWR fuel without channels) and the use of a commercial, non-spent-fuel cask to carry compacted NFAH that could not be shipped integrally. Costs that are developed involve transportation charges, capital costs for casks, and canning costs of NFAH that have been separated from the fuel. The results indicate that significant cost savings are possible if NFAH is accepted into the Federal Waste Management System (FWMS) that is either integral with the spent fuel, or consolidated if it has been separated. Shipment of unconsolidated NFAH is very expensive. Transportation costs for shipping to a western repository are approximately 50 to 75% higher than the costs for shipping to an eastern MRS

Description of the PMAD DC test bed architecture and integration sequence

Science.gov (United States)

Beach, R. F.; Trash, L.; Fong, D.; Bolerjack, B.

1991-01-01

NASA-LEWIS is responsible for the development, fabrication, and assembly of the electric power system (EPS) for the Space Station Freedom (SSF). The SSF power system is radically different from previous spacecraft power systems in both the size and complexity of the system. Unlike past spacecraft power systems, the SSF EPS will grow and be maintained on orbit and must be flexible to meet challenging user power needs. The SSF power system is also unique in comparison with terrestrial power systems because it is dominated by power electronic converters which regulate and control the power. A description is provided of the Power Management and Distribution DC Testbed which was assembled to support the design and early evaluation of the SSF EPS. A description of the integration process used in the assembly sequence is also given along with a description of the support facility.

Passive gamma analysis of the boiling-water-reactor assemblies

Energy Technology Data Exchange (ETDEWEB)

Vo, D., E-mail: ducvo@lanl.gov [Los Alamos National Laboratory, Los Alamos, NM (United States); Favalli, A. [Los Alamos National Laboratory, Los Alamos, NM (United States); Grogan, B. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Jansson, P. [Uppsala University, Uppsala (Sweden); Liljenfeldt, H. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Mozin, V. [Lawrence Livermore National Laboratory, Livermore, CA (United States); Schwalbach, P. [European Atomic Energy Community (EURATOM), Luxemburg (Luxembourg); Sjöland, A. [Swedish Nuclear Fuel and Waste Management Company, Stockholm (Sweden); Tobin, S.; Trellue, H. [Los Alamos National Laboratory, Los Alamos, NM (United States); Vaccaro, S. [European Atomic Energy Community (EURATOM), Luxemburg (Luxembourg)

2016-09-11

This research focused on the analysis of a set of stationary passive gamma measurements taken on the spent nuclear fuel assemblies from a boiling water reactor (BWR) using pulse height analysis data acquisition. The measurements were performed on 25 different BWR assemblies in 2014 at Sweden's Central Interim Storage Facility for Spent Nuclear Fuel (Clab). This study was performed as part of the Next Generation of Safeguards Initiative–Spent Fuel project to research the application of nondestructive assay (NDA) to spent fuel assemblies. The NGSI–SF team is working to achieve the following technical goals more easily and efficiently than in the past using nondestructive assay (NDA) measurements of spent fuel assemblies: (1) verify the initial enrichment, burnup, and cooling time of facility declaration; (2) detect the diversion or replacement of pins, (3) estimate the plutonium mass, (4) estimate the decay heat, and (5) determine the reactivity of spent fuel assemblies. The final objective of this project is to quantify the capability of several integrated NDA instruments to meet the aforementioned goals using the combined signatures of neutrons, gamma rays, and heat. This report presents a selection of the measured data and summarizes an analysis of the results. Specifically, trends in the count rates measured for spectral lines from the following isotopes were analyzed as a function of the declared burnup and cooling time: {sup 137}Cs, {sup 154}Eu, {sup 134}Cs, and to a lesser extent, {sup 106}Ru and {sup 144}Ce. From these measured count rates, predictive algorithms were developed to enable the estimation of the burnup and cooling time. Furthermore, these algorithms were benchmarked on a set of assemblies not included in the standard assemblies set used by this research team.

Geometric programming facilities of EusLisp and assembly goal planner

International Nuclear Information System (INIS)

Matsui, Toshihiro; Sakane, Shigeyuki; Hirukawa, Hirohisa

1994-01-01

For robots in power plants to accomplish intelligent tasks such as maintenance, inspection, and assembly, the robots must have planning capabilities based on shape models of the environment. Such shape models are defined and manipulated by a program called a geometric modeler or a solid modeler. Although there are commercial solid modelers in the market, they are not always suitable for robotics research, since it is hard to integrate higher level planning functions which frequently access internal model representation. In order to accelerate advanced robotics research, we need a generic, extensible, efficient, and integration-oriented geometric modeler. After reviewing available modelers, we concluded that the object-oriented Lisp can be the best implementation language for solid modeling. The next section introduces the programming language, 'EusLisp', tuned for implementing a solid modeler for intelligent robot programming. The design philosophy and the structure and functions of EusLisp are stated. In the following sections, EusLisp's applications, i.e., viewpoint and light-source location planning, derivation of motion constraint, and assembly goal planning, are discussed. (J.P.N.)

Spacecraft Charging: Hazard Causes, Hazard Effects, Hazard Controls

Science.gov (United States)

Koontz, Steve.

2018-01-01

Spacecraft flight environments are characterized both by a wide range of space plasma conditions and by ionizing radiation (IR), solar ultraviolet and X-rays, magnetic fields, micrometeoroids, orbital debris, and other environmental factors, all of which can affect spacecraft performance. Dr. Steven Koontz's lecture will provide a solid foundation in the basic engineering physics of spacecraft charging and charging effects that can be applied to solving practical spacecraft and spacesuit engineering design, verification, and operations problems, with an emphasis on spacecraft operations in low-Earth orbit, Earth's magnetosphere, and cis-Lunar space.

Management Prestart Review Phase 1 for the NIF Optics Assembly Building (OAB)

International Nuclear Information System (INIS)

Dragoo, V

2000-01-01

A Management Prestart Review (MPR) for the National Ignition Facility (NIF) Optics Assembly Building (OAB) was conducted from June, 2000, through October, 2000. This review was performed to determine readiness of the facility and management to transfer the facility from the construction to the commissioning and operations phase. This review process provides assurance that the appropriate line management is in place to effect the turnover. Completion and acceptance of this report constitutes a turnover of facility and equipment operational responsibility from the Beampath Infrastructure System Construction organization to the Assembly Installation and Refurbishment Operations (assembly equipment installation/activation and mechanical cleaning operations) and the Beampath Infrastructure System (BIS) Commissioning and Operations Organizations (conventional facility operations). The OAB MPR provides to the NIF Project Manager an independent, systematic assessment of: (1) Readiness of line management for the turnover to take place, (2) Completeness of the equipment and facility installation of the OAB, (3) Readiness of personnel to operate within the facility, and (4) Implementation and efficacy of key management control processes and procedures. The MPR process assures that the technical, cost, and schedule risk associated with the installation/activation of OAB special equipment, mechanical cleaning, and conventional facility operations within the OAB are evaluated and are acceptable. Specifically, the scope of the review addresses technical and operational attributes of the equipment and facility systems that have been determined to have significant project risk. This report implements the LLNL requirement that MPRs shall be conducted before all new facilities are brought into operation, Lawrence Livermore National Laboratory (LLNL) ES and H Manual (M-010), Section 2.2.5, Pre-Start Reviews. The MPR process is an essential part of the ISM work authorization and

Strategic facility planning improves capital decision making.

Science.gov (United States)

Reeve, J R

2001-03-01

A large, Midwestern IDS undertook a strategic facility-planning process to evaluate its facility portfolio and determine how best to allocate future investments in facility development. The IDS assembled a facility-planning team, which initiated the planning process with a market analysis to determine future market demands and identify service areas that warranted facility expansion. The team then analyzed each of the IDS's facilities from the perspective of uniform capacity measurements, highest and best use compared with needs, building condition and investment-worthiness, and facility growth and site development opportunities. Based on results of the analysis, the strategy adopted entailed, in part, shifting some space from inpatient care to ambulatory care services and demolishing and replacing the 11 percent of facilities deemed to be in the worst condition.

Automating Trend Analysis for Spacecraft Constellations

Science.gov (United States)

Davis, George; Cooter, Miranda; Updike, Clark; Carey, Everett; Mackey, Jennifer; Rykowski, Timothy; Powers, Edward I. (Technical Monitor)

2001-01-01

Spacecraft trend analysis is a vital mission operations function performed by satellite controllers and engineers, who perform detailed analyses of engineering telemetry data to diagnose subsystem faults and to detect trends that may potentially lead to degraded subsystem performance or failure in the future. It is this latter function that is of greatest importance, for careful trending can often predict or detect events that may lead to a spacecraft's entry into safe-hold. Early prediction and detection of such events could result in the avoidance of, or rapid return to service from, spacecraft safing, which not only results in reduced recovery costs but also in a higher overall level of service for the satellite system. Contemporary spacecraft trending activities are manually intensive and are primarily performed diagnostically after a fault occurs, rather than proactively to predict its occurrence. They also tend to rely on information systems and software that are oudated when compared to current technologies. When coupled with the fact that flight operations teams often have limited resources, proactive trending opportunities are limited, and detailed trend analysis is often reserved for critical responses to safe holds or other on-orbit events such as maneuvers. While the contemporary trend analysis approach has sufficed for current single-spacecraft operations, it will be unfeasible for NASA's planned and proposed space science constellations. Missions such as the Dynamics, Reconnection and Configuration Observatory (DRACO), for example, are planning to launch as many as 100 'nanospacecraft' to form a homogenous constellation. A simple extrapolation of resources and manpower based on single-spacecraft operations suggests that trending for such a large spacecraft fleet will be unmanageable, unwieldy, and cost-prohibitive. It is therefore imperative that an approach to automating the spacecraft trend analysis function be studied, developed, and applied to

An Application of the "Virtual Spacecraft" Concept in Evaluation of the Mars Pathfinder Lander Low Gain Antenna

Science.gov (United States)

Pogorzelski, R. J.; Beckon, R. J.

1997-01-01

The virtual spacecraft concept is embodied in a set of subsystems, either in the form of hardware or computational models, which together represent all, or a portion of, a spacecraft. For example, the telecommunications transponder may be a hardware prototype while the propulsion system may exist only as a simulation. As the various subsystems are realized in hardware, the spacecraft becomes progressively less virtual. This concept is enabled by JPL's Mission System Testbed which is a set of networked workstations running a message passing operating system called "TRAMEL" which stands for Task Remote Asynchronous Message Exchange Layer. Each simulation on the workstations, which may in fact be hardware controlled by the workstation, "publishes" its operating parameters on TRAMEL and other simulations requiring those parameters as input may "subscribe" to them. In this manner, the whole simulation operates as a single virtual system. This paper describes a simulation designed to evaluate a communications link between the earth and the Mars Pathfinder Lander module as it descends under a parachute through the Martian atmosphere toward the planet's surface. This link includes a transmitter and a low gain antenna on the spacecraft and a receiving antenna and receiver on the earth as well as a simulation of the dynamics of the spacecraft. The transmitter, the ground station antenna, the receiver and the dynamics are all simulated computationally while the spacecraft antenna is implemented in hardware on a very simple spacecraft mockup. The dynamics simulation is a record of one output of the ensemble of outputs of a Monte Carlo simulation of the descent. Additionally, the antenna/spacecraft mock-up system was simulated using APATCH, a shooting and bouncing ray code developed by Demaco, Inc. The antenna simulation, the antenna hardware, and the link simulation are all physically located in different facilities at JPL separated by several hundred meters and are linked via

Radiation Effects on Spacecraft Structural Materials

International Nuclear Information System (INIS)

Wang, Jy-An J.; Ellis, Ronald J.; Hunter, Hamilton T.; Singleterry, Robert C. Jr.

2002-01-01

Research is being conducted to develop an integrated technology for the prediction of aging behavior for space structural materials during service. This research will utilize state-of-the-art radiation experimental apparatus and analysis, updated codes and databases, and integrated mechanical and radiation testing techniques to investigate the suitability of numerous current and potential spacecraft structural materials. Also included are the effects on structural materials in surface modules and planetary landing craft, with or without fission power supplies. Spacecraft structural materials would also be in hostile radiation environments on the surface of the moon and planets without appreciable atmospheres and moons around planets with large intense magnetic and radiation fields (such as the Jovian moons). The effects of extreme temperature cycles in such locations compounds the effects of radiation on structural materials. This paper describes the integrated methodology in detail and shows that it will provide a significant technological advance for designing advanced spacecraft. This methodology will also allow for the development of advanced spacecraft materials through the understanding of the underlying mechanisms of material degradation in the space radiation environment. Thus, this technology holds a promise for revolutionary advances in material damage prediction and protection of space structural components as, for example, in the development of guidelines for managing surveillance programs regarding the integrity of spacecraft components, and the safety of the aging spacecraft. (authors)

Development and qualification of materials and processes for radiation shielding of Galileo spacecraft electronic components

International Nuclear Information System (INIS)

Hribar, F.; Bauer, J.L.; O'Donnell, T.P.

1990-01-01

Several materials and processing methods were evaluated for use on the JPL Galileo spacecraft in the area of radiation shielding for electronics. Development and qualification activities involving an aluminum structural laminate are described. These activities included requirements assessment, design tradeoffs, materials selection, adhesive bonding development, mechanical properties measurements, thermal stability assessment, and nondestructive evaluation. This paper presents evaluation of three adhesives for bonding tantalum to aluminum. The concept of combining a thin sheet of tantalum with two outer aluminum face sheets using adhesive bonding was developed successfully. This radiation shield laminate also provides a structural shear plate for mounting electronic assemblies

Assembly and maintenance of full scale NIF amplifiers in the amplifier module prototype laboratory (AMPLAB)

International Nuclear Information System (INIS)

Horvath, J. A.

1998-01-01

Mechanical assembly and maintenance of the prototype National Ignition Facility amplifiers in the Amplifier Module Prototype Laboratory (AMPLAB) at Lawrence Livermore National Laboratory requires specialized equipment designed to manipulate large and delicate amplifier components in a safe and clean manner. Observations made during the operation of this assembly and maintenance equipment in AMPLAB provide design guidance for similar tools being built for the National Ignition Facility. Fixtures used for amplifier frame installation, laser slab and flashlamp cassette assembly, transport, and installation, and in-situ blastshield exchange are presented. Examples include a vacuum slab gripper, slab handling clean crane, slab cassette assembly fixture, sealed transport vehicle for slab cassette movement between the cleanroom and amplifier, slab cassette transfer fixture between the cleanroom and transport vehicle, and equipment needed for frame assembly unit, blastshield, an d flashlamp cassette installation and removal. The use of these tools for amplifier assembly, system reconfiguration, reflector replacement, and recovery from an abnormal occurrence such as a flashlamp explosion is described. Observations are made on the design and operation of these tools and their contribution to the final design

Toroid magnet test facility

CERN Multimedia

2002-01-01

Because of its exceptional size, it was not feasible to assemble and test the Barrel Toroid - made of eight coils - as an integrated toroid on the surface, prior to its final installation underground in LHC interaction point 1. It was therefore decided to test these eight coils individually in a dedicated test facility.

Design Process of Flight Vehicle Structures for a Common Bulkhead and an MPCV Spacecraft Adapter

Science.gov (United States)

Aggarwal, Pravin; Hull, Patrick V.

2015-01-01

Design and manufacturing space flight vehicle structures is a skillset that has grown considerably at NASA during that last several years. Beginning with the Ares program and followed by the Space Launch System (SLS); in-house designs were produced for both the Upper Stage and the SLS Multipurpose crew vehicle (MPCV) spacecraft adapter. Specifically, critical design review (CDR) level analysis and flight production drawing were produced for the above mentioned hardware. In particular, the experience of this in-house design work led to increased manufacturing infrastructure for both Marshal Space Flight Center (MSFC) and Michoud Assembly Facility (MAF), improved skillsets in both analysis and design, and hands on experience in building and testing (MSA) full scale hardware. The hardware design and development processes from initiation to CDR and finally flight; resulted in many challenges and experiences that produced valuable lessons. This paper builds on these experiences of NASA in recent years on designing and fabricating flight hardware and examines the design/development processes used, as well as the challenges and lessons learned, i.e. from the initial design, loads estimation and mass constraints to structural optimization/affordability to release of production drawing to hardware manufacturing. While there are many documented design processes which a design engineer can follow, these unique experiences can offer insight into designing hardware in current program environments and present solutions to many of the challenges experienced by the engineering team.

Thermohydraulic analysis of assemblies containing up to 2/7 fuel rods

International Nuclear Information System (INIS)

Ferreira, W.J.; Luz, M.

1985-01-01

The COBRA IV-I computer code was tested using data from the Fast Flux Test Facility. Then this code was applied to the analysis of fuel assemblies from the Binary Breeder Reactor. Previously this analysis was carried out using the COBRA III-C code which allows only for the calculations of fuel assemblies having seven fuel pins. The COBRA IV-I permits the calculation of fuel assemblies containing up to 217 fuel pins and the inclusion of blanket and shielding effects. (F.E.) [pt

36 CFR 1234.10 - What are the facility requirements for all records storage facilities?

Science.gov (United States)

2010-07-01

... prevent water leaks and the piping assembly is inspected for potential leaks regularly. If drainage piping... facility must ensure that the roof membrane does not permit water to penetrate the roof. NARA strongly... the exception of fire protection sprinkler piping and storm water roof drainage piping) must not be...

Foot Pedals for Spacecraft Manual Control

Science.gov (United States)

Love, Stanley G.; Morin, Lee M.; McCabe, Mary

2010-01-01

Fifty years ago, NASA decided that the cockpit controls in spacecraft should be like the ones in airplanes. But controls based on the stick and rudder may not be best way to manually control a vehicle in space. A different method is based on submersible vehicles controlled with foot pedals. A new pilot can learn the sub's control scheme in minutes and drive it hands-free. We are building a pair of foot pedals for spacecraft control, and will test them in a spacecraft flight simulator.

Lifetime predictions for the Solar Maximum Mission (SMM) and San Marco spacecraft

Science.gov (United States)

Smith, E. A.; Ward, D. T.; Schmitt, M. W.; Phenneger, M. C.; Vaughn, F. J.; Lupisella, M. L.

1989-01-01

Lifetime prediction techniques developed by the Goddard Space Flight Center (GSFC) Flight Dynamics Division (FDD) are described. These techniques were developed to predict the Solar Maximum Mission (SMM) spacecraft orbit, which is decaying due to atmospheric drag, with reentry predicted to occur before the end of 1989. Lifetime predictions were also performed for the Long Duration Exposure Facility (LDEF), which was deployed on the 1984 SMM repair mission and is scheduled for retrieval on another Space Transportation System (STS) mission later this year. Concepts used in the lifetime predictions were tested on the San Marco spacecraft, which reentered the Earth's atmosphere on December 6, 1988. Ephemerides predicting the orbit evolution of the San Marco spacecraft until reentry were generated over the final 90 days of the mission when the altitude was less than 380 kilometers. The errors in the predicted ephemerides are due to errors in the prediction of atmospheric density variations over the lifetime of the satellite. To model the time dependence of the atmospheric densities, predictions of the solar flux at the 10.7-centimeter wavelength were used in conjunction with Harris-Priester (HP) atmospheric density tables. Orbital state vectors, together with the spacecraft mass and area, are used as input to the Goddard Trajectory Determination System (GTDS). Propagations proceed in monthly segments, with the nominal atmospheric drag model scaled for each month according to the predicted monthly average value of F10.7. Calibration propagations are performed over a period of known orbital decay to obtain the effective ballistic coefficient. Progagations using plus or minus 2 sigma solar flux predictions are also generated to estimate the despersion in expected reentry dates. Definitive orbits are compared with these predictions as time expases. As updated vectors are received, these are also propagated to reentryto continually update the lifetime predictions.

Spacecraft Thermal Management

Science.gov (United States)

Hurlbert, Kathryn Miller

2009-01-01

In the 21st century, the National Aeronautics and Space Administration (NASA), the Russian Federal Space Agency, the National Space Agency of Ukraine, the China National Space Administration, and many other organizations representing spacefaring nations shall continue or newly implement robust space programs. Additionally, business corporations are pursuing commercialization of space for enabling space tourism and capital business ventures. Future space missions are likely to include orbiting satellites, orbiting platforms, space stations, interplanetary vehicles, planetary surface missions, and planetary research probes. Many of these missions will include humans to conduct research for scientific and terrestrial benefits and for space tourism, and this century will therefore establish a permanent human presence beyond Earth s confines. Other missions will not include humans, but will be autonomous (e.g., satellites, robotic exploration), and will also serve to support the goals of exploring space and providing benefits to Earth s populace. This section focuses on thermal management systems for human space exploration, although the guiding principles can be applied to unmanned space vehicles as well. All spacecraft require a thermal management system to maintain a tolerable thermal environment for the spacecraft crew and/or equipment. The requirements for human rating and the specified controlled temperature range (approximately 275 K - 310 K) for crewed spacecraft are unique, and key design criteria stem from overall vehicle and operational/programatic considerations. These criteria include high reliability, low mass, minimal power requirements, low development and operational costs, and high confidence for mission success and safety. This section describes the four major subsystems for crewed spacecraft thermal management systems, and design considerations for each. Additionally, some examples of specialized or advanced thermal system technologies are presented

Optical Fiber Array Assemblies for Space Flight on the Lunar Reconnaissance Orbiter

Science.gov (United States)

Ott, Jelanie; Matuszeski, Adam

2011-01-01

Custom fiber optic bundle array assemblies developed by the Photonics Group at NASA Goddard Space Flight Center were an enabling technology for both the Lunar Orbiter Laser Altimeter (LOLA) and the Laser Ranging (LR) Investigation on the Lunar Reconnaissance Orbiter (LRO) currently in operation. The unique assembly array designs provided considerable decrease in size and weight and met stringent system level requirements. This is the first time optical fiber array bundle assemblies were used in a high performance space flight application. This innovation was achieved using customized Diamond Switzerland AVIM optical connectors. For LOLA, a five fiber array was developed for the receiver telescope to maintain precise alignment for each of the 200/220 micron optical fibers collecting 1,064 nm wavelength light being reflected back from the moon. The array splits to five separate detectors replacing the need for multiple telescopes. An image illustration of the LOLA instrument can be found at the top of the figure. For the laser ranging, a seven-optical-fiber array of 400/440 micron fibers was developed to transmit light from behind the LR receiver telescope located on the end of the high gain antenna system (HGAS). The bundle was routed across two moving gimbals, down the HGAS boom arm, over a deployable mandrel and across the spacecraft to a detector on the LOLA instrument. The routing of the optical fiber bundle and its end locations is identified in the figure. The Laser Ranging array and bundle is currently accepting light at a wavelength of 532 nm sent to the moon from laser stations at Greenbelt MD and other stations around the world to gather precision ranging information from the Earth to the LRO spacecraft. The LR bundle assembly is capable of withstanding temperatures down to -55 C at the connectors, and 20,000 mechanical gimbal cycles at temperatures as cold as -20 C along the length of the seven-fiber bundle (that is packaged into the gimbals). The total

On the spacecraft attitude stabilization in the orbital frame

Directory of Open Access Journals (Sweden)

Antipov Kirill A.

2012-01-01

Full Text Available The paper deals with spacecraft in the circular near-Earth orbit. The spacecraft interacts with geomagnetic field by the moments of Lorentz and magnetic forces. The octupole approximation of the Earth’s magnetic field is accepted. The spacecraft electromagnetic parameters, namely the electrostatic charge moment of the first order and the eigen magnetic moment are the controlled quasiperiodic functions. The control algorithms for the spacecraft electromagnetic parameters, which allows to stabilize the spacecraft attitude position in the orbital frame are obtained. The stability of the spacecraft stabilized orientation is proved both analytically and by PC computations.

Inspection experience with RA-3 spent nuclear fuel assemblies at CNEA's central storage facility

International Nuclear Information System (INIS)

Novara, Oscar; LaFuente, Jose; Large, Steve; Andes, Trent; Messick, Charles

2000-01-01

Aluminum-based spent nuclear fuel from Argentina's RA-3 research reactor is to be shipped to the Savannah River Site near Aiken, South Carolina, USA. The spent nuclear fuel contains highly enriched uranium of U.S. origin and is being returned under the US Department of Energy's Foreign Research Reactor/Domestic Research Reactor (FRR/DRR) Receipt Program. An intensive inspection of 207 stored fuel assemblies was conducted to assess shipping cask containment limitations and assembly handling considerations. The inspection was performed with video equipment designed for remote operation, high portability, easy setup and usage. Fuel assemblies were raised from their vertical storage tubes, inspected by remote video, and then returned to their original storage tube or transferred to an alternate location. The inspections were made with three simultaneous video systems, each with dedicated viewing, digital recording, and tele-operated control from a shielded location. All 207 fuel assemblies were safely and successfully inspected in fifteen working days. Total dose to personnel was about one-half of anticipated dose. (author)

Standardizing the information architecture for spacecraft operations

Science.gov (United States)

Easton, C. R.

1994-01-01

This paper presents an information architecture developed for the Space Station Freedom as a model from which to derive an information architecture standard for advanced spacecraft. The information architecture provides a way of making information available across a program, and among programs, assuming that the information will be in a variety of local formats, structures and representations. It provides a format that can be expanded to define all of the physical and logical elements that make up a program, add definitions as required, and import definitions from prior programs to a new program. It allows a spacecraft and its control center to work in different representations and formats, with the potential for supporting existing spacecraft from new control centers. It supports a common view of data and control of all spacecraft, regardless of their own internal view of their data and control characteristics, and of their communications standards, protocols and formats. This information architecture is central to standardizing spacecraft operations, in that it provides a basis for information transfer and translation, such that diverse spacecraft can be monitored and controlled in a common way.

A Strategic Study of Assembly Plant Establishment in the Kingdom of Saudi Arabia

OpenAIRE

Santamaria, Scott

2001-01-01

Preface: Traditionally, assembly plant establishment in foreign countries has been a way for corporations to avoid high import duties and/or gain access to free-trade zones. With World Trade Organization (WTO) membership rising, and consequently import duties falling, the role of the assembly plant is changing. Purpose Statement: This thesis concentrates on companies that contemplate on, or have ambitions of establishing industrial assembly facilities in the country of Saudi Arabia. The main ...

Chemical Pollution from Combustion of Modern Spacecraft Materials

Science.gov (United States)

Mudgett, Paul D.

2013-01-01

Fire is one of the most critical contingencies in spacecraft and any closed environment including submarines. Currently, NASA uses particle based technology to detect fires and hand-held combustion product monitors to track the clean-up and restoration of habitable cabin environment after the fire is extinguished. In the future, chemical detection could augment particle detection to eliminate frequent nuisance false alarms triggered by dust. In the interest of understanding combustion from both particulate and chemical generation, NASA Centers have been collaborating on combustion studies at White Sands Test Facility using modern spacecraft materials as fuels, and both old and new technology to measure the chemical and particulate products of combustion. The tests attempted to study smoldering pyrolysis at relatively low temperatures without ignition to flaming conditions. This paper will summarize the results of two 1-week long tests undertaken in 2012, focusing on the chemical products of combustion. The results confirm the key chemical products are carbon monoxide (CO), hydrogen cyanide (HCN), hydrogen fluoride (HF) and hydrogen chloride (HCl), whose concentrations depend on the particular material and test conditions. For example, modern aerospace wire insulation produces significant concentration of HF, which persists in the test chamber longer than anticipated. These compounds are the analytical targets identified for the development of new tunable diode laser based hand-held monitors, to replace the aging electrochemical sensor based devices currently in use on the International Space Station.

Report of the committee on a commercially developed space facility

Science.gov (United States)

Shea, Joseph F.; Stever, H. Guyford; Cutter, W. Bowman, III; Demisch, Wolfgang H.; Fink, Daniel J.; Flax, Alexander H.; Gatos, Harry C.; Glicksman, Martin E.; Lanzerotti, Louis J.; Logsdon, John M., III

1989-01-01

Major facilities that could support significant microgravity research and applications activity are discussed. The ground-based facilities include drop towers, aircraft flying parabolic trajectories, and sounding rockets. Facilities that are intrinsically tied to the Space Shuttle range from Get-Away-Special canisters to Spacelab long modules. There are also orbital facilities which include recoverable capsules launched on expendable launch vehicles, free-flying spacecraft, and space stations. Some of these existing, planned, and proposed facilities are non-U.S. in origin, but potentially available to U.S. investigators. In addition, some are governmentally developed and operated whereas others are planned to be privately developed and/or operated. Tables are provided to show the facility, developer, duration, estimated gravity level, crew interaction, flight frequency, year available, power to payload, payload volume, and maximum payload mass. The potential of direct and indirect benefits of manufacturing in space are presented.

URAM-2 Cryogenic Irradiation Facility

CERN Document Server

Shabalin, E P; Kulikov, S A; Kulagin, E N; Melihov, V V; Belyakov, A A; Golovanov, L B; Borzunov, Yu T; Konstantinov, V I; Androsov, A V

2002-01-01

The URAM-2 irradiation facility has been built and mounted at the channel No. 3 of the IBR-2 reactor. It was constructed for study of radiolysis effects by fast neutron irradiation in some suitable for effective cold neutron production materials (namely: solid methane, methane hydrate, water ice, etc.). The facility cooling system is based on using liquid helium as a coolant material. The original charging block of the rig allows the samples to be loaded by condensing gas into irradiation cavity or by charging beads of ice prepared before. Preliminary tests for each facility block and assembling them at the working position were carried out. Use of the facility for study accumulation of chemical energy under irradiation at low temperature in materials mentioned above and its spontaneous release was started.

NiO nanosheet assembles for supercapacitor electrode materials

Directory of Open Access Journals (Sweden)

Huanhao Xiao

2016-06-01

Full Text Available In this paper, large scale hierarchically assembled NiO nanosheets have been favorably fabricated through a facile hydrothermal route. The as-prepared NiO nanosheet assembles were characterized in detail by various analytical techniques. The results showed these nanosheets present the thickness of about 30 nm and the surface area is 116.9 m2 g−1. These NiO nanosheet assembles were used as the working electrode materials in electrochemical tests, which demonstrated a specific capacitance value of 81.67 F g−1 at the current density of 0.5 A g−1 and excellent long cycle-life stability with 78.5% of its discharge specific capacitance retention after 3000 cycles at the current density of 0.5 A g−1, revealing the as-synthesized NiO nanosheet assembles might be a promising electrode material for supercapacitor applications.

Yalina booster subcritical assembly performance with low enriched uranium fuel

International Nuclear Information System (INIS)

Talamo, Alberto; Gohar, Yousry

2011-01-01

The YALINA Booster facility is a subcritical assembly located in Minsk, Belarus. The facility has special features that result in fast and thermal neutron spectra in different zones. The fast zone of the assembly uses a lead matrix and uranium fuels with different enrichments: 90% and 36%, 36%, or 21%. The thermal zone of the assembly contains 10% enriched uranium fuel in a polyethylene matrix. This study discusses the performance of the three YALINA Booster configurations with the different fuel enrichments. In order to maintain the same subcriticality level in the three configurations, the number of fuel rods in the thermal zone is increased as the uranium fuel enrichment in the fast zone is decreased. The maximum number of fuel rods that can be loaded in the thermal zone is about 1185. Consequently, the neutron multiplication of the configuration with 21% enriched uranium fuel in the fast zone is enhanced by changing the position of the boron carbide and the natural uranium absorber rods, located between the fast and the thermal zones, to form an annular rather than a square arrangement. (author)

Yalina booster subcritical assembly performance with low enriched uranium fuel

Energy Technology Data Exchange (ETDEWEB)

Talamo, Alberto; Gohar, Yousry, E-mail: alby@anl.gov [Argonne National Laboratory, Lemont, IL (United States)

2011-07-01

The YALINA Booster facility is a subcritical assembly located in Minsk, Belarus. The facility has special features that result in fast and thermal neutron spectra in different zones. The fast zone of the assembly uses a lead matrix and uranium fuels with different enrichments: 90% and 36%, 36%, or 21%. The thermal zone of the assembly contains 10% enriched uranium fuel in a polyethylene matrix. This study discusses the performance of the three YALINA Booster configurations with the different fuel enrichments. In order to maintain the same subcriticality level in the three configurations, the number of fuel rods in the thermal zone is increased as the uranium fuel enrichment in the fast zone is decreased. The maximum number of fuel rods that can be loaded in the thermal zone is about 1185. Consequently, the neutron multiplication of the configuration with 21% enriched uranium fuel in the fast zone is enhanced by changing the position of the boron carbide and the natural uranium absorber rods, located between the fast and the thermal zones, to form an annular rather than a square arrangement. (author)

Guidance and control of swarms of spacecraft

Science.gov (United States)

Morgan, Daniel James

There has been considerable interest in formation flying spacecraft due to their potential to perform certain tasks at a cheaper cost than monolithic spacecraft. Formation flying enables the use of smaller, cheaper spacecraft that distribute the risk of the mission. Recently, the ideas of formation flying have been extended to spacecraft swarms made up of hundreds to thousands of 100-gram-class spacecraft known as femtosatellites. The large number of spacecraft and limited capabilities of each individual spacecraft present a significant challenge in guidance, navigation, and control. This dissertation deals with the guidance and control algorithms required to enable the flight of spacecraft swarms. The algorithms developed in this dissertation are focused on achieving two main goals: swarm keeping and swarm reconfiguration. The objectives of swarm keeping are to maintain bounded relative distances between spacecraft, prevent collisions between spacecraft, and minimize the propellant used by each spacecraft. Swarm reconfiguration requires the transfer of the swarm to a specific shape. Like with swarm keeping, minimizing the propellant used and preventing collisions are the main objectives. Additionally, the algorithms required for swarm keeping and swarm reconfiguration should be decentralized with respect to communication and computation so that they can be implemented on femtosats, which have limited hardware capabilities. The algorithms developed in this dissertation are concerned with swarms located in low Earth orbit. In these orbits, Earth oblateness and atmospheric drag have a significant effect on the relative motion of the swarm. The complicated dynamic environment of low Earth orbits further complicates the swarm-keeping and swarm-reconfiguration problems. To better develop and test these algorithms, a nonlinear, relative dynamic model with J2 and drag perturbations is developed. This model is used throughout this dissertation to validate the algorithms

Evaluation of existing United States' facilities for use as a mixed-oxide (MOX) fuel fabrication facility for plutonium disposition

International Nuclear Information System (INIS)

Beard, C.A.; Buksa, J.J.; Chidester, K.; Eaton, S.L.; Motley, F.E.; Siebe, D.A.

1995-01-01

A number of existing US facilities were evaluated for use as a mixed-oxide fuel fabrication facility for plutonium disposition. These facilities include the Fuels Material Examination Facility (FMEF) at Hanford, the Washington Power Supply Unit 1 (WNP-1) facility at Hanford, the Barnwell Nuclear Fuel Plant (BNFP) at Barnwell, SC, the Fuel Processing Facility (FPF) at Idaho National Engineering Laboratory (INEL), the Device Assembly Facility (DAF) at the Nevada Test Site (NTS), and the P-reactor at the Savannah River Site (SRS). The study consisted of evaluating each facility in terms of available process space, available building support systems (i.e., HVAC, security systems, existing process equipment, etc.), available regional infrastructure (i.e., emergency response teams, protective force teams, available transportation routes, etc.), and ability to integrate the MOX fabrication process into the facility in an operationally-sound manner that requires a minimum amount of structural modifications

Design and Testing of the Fusion Virtual Assembly System FVAS1.0

International Nuclear Information System (INIS)

Pengcheng Long; Songlin Liu; Yican Wu

2006-01-01

Virtual assembly (VA), utilizing virtual reality (VR) technologies to plan and evaluate assembly process, retains the benefits (time-saving, inexpensive and no hazardous) of VR technologies and conquers the shortcoming of physical prototypes, such as long circle, high cost, low precision, and so on. Presented in this paper is the Fusion Virtual Assembly System FVAS 1.0 that makes possible engineering application for assemblies of large-scale complex nuclear facilities. FVAS 1.0 is designed to support the planning, evaluation and demonstration of assembly process, and training assemblers, and to work on PC (personal computer) platform. In this paper, architecture and main features of FVAS are introduced firstly. Then, design of the key sections (such as collision detection, virtual roaming) are described in detail. Finally, some successful application cases are presented. To enhance the real-time performance for large-scale nuclear facilities simulation, a policy based on separation of display scene and collision detection scene has been adopted. The display scene can be predigested to reduce the time of scene refreshment, and the collision detection performance is greatly improved by using the mature interference check ability of commercial CAD systems. Convenient observation mechanism brings more practicability. So a multi-viewpoints roaming scheme has been utilized to facilitate users' assembly operation. Users can obtain much optical information from multiple angles by switching between multi-viewpoints. The ESAT superconducting tokamak is characterized by large volume, complicated constitution and high assembly precision, e.g. the strict precision requirement in the assembly for the three tori (the tori of vacuum vessel, thermal shield, and toroidal coil). FVAS 1.0 has succeeded in demonstrating the assembly process of ESAT components. Furthermore, FVAS 1.0 has been applied to evaluate FDS-I (Fusion-Driven Sub-critical system) concept from assembly point of

Trajectory Control of Rendezvous with Maneuver Target Spacecraft

Science.gov (United States)

Zhou, Zhinqiang

2012-01-01

In this paper, a nonlinear trajectory control algorithm of rendezvous with maneuvering target spacecraft is presented. The disturbance forces on the chaser and target spacecraft and the thrust forces on the chaser spacecraft are considered in the analysis. The control algorithm developed in this paper uses the relative distance and relative velocity between the target and chaser spacecraft as the inputs. A general formula of reference relative trajectory of the chaser spacecraft to the target spacecraft is developed and applied to four different proximity maneuvers, which are in-track circling, cross-track circling, in-track spiral rendezvous and cross-track spiral rendezvous. The closed-loop differential equations of the proximity relative motion with the control algorithm are derived. It is proven in the paper that the tracking errors between the commanded relative trajectory and the actual relative trajectory are bounded within a constant region determined by the control gains. The prediction of the tracking errors is obtained. Design examples are provided to show the implementation of the control algorithm. The simulation results show that the actual relative trajectory tracks the commanded relative trajectory tightly. The predicted tracking errors match those calculated in the simulation results. The control algorithm developed in this paper can also be applied to interception of maneuver target spacecraft and relative trajectory control of spacecraft formation flying.

Spacecraft command and control using expert systems

Science.gov (United States)

Norcross, Scott; Grieser, William H.

1994-01-01

This paper describes a product called the Intelligent Mission Toolkit (IMT), which was created to meet the changing demands of the spacecraft command and control market. IMT is a command and control system built upon an expert system. Its primary functions are to send commands to the spacecraft and process telemetry data received from the spacecraft. It also controls the ground equipment used to support the system, such as encryption gear, and telemetry front-end equipment. Add-on modules allow IMT to control antennas and antenna interface equipment. The design philosophy for IMT is to utilize available commercial products wherever possible. IMT utilizes Gensym's G2 Real-time Expert System as the core of the system. G2 is responsible for overall system control, spacecraft commanding control, and spacecraft telemetry analysis and display. Other commercial products incorporated into IMT include the SYBASE relational database management system and Loral Test and Integration Systems' System 500 for telemetry front-end processing.

Safety analysis of the Los Alamos critical experiments facility: burst operation of Skua

International Nuclear Information System (INIS)

Orndoff, J.D.; Paxton, H.C.; Wimett, T.F.

1979-05-01

A detailed consideration of the Skua burst assembly is presented, thereby supplementing the facility safety analysis report covering the operation of other critical assemblies at Los Alamos. As with these assemblies the small fission-product inventory, ambient pressure, and moderate temperatures in Skua are amenable to straightforward measures to ensure the protection of the public

Analysis of reconfigurable assembly system framing systems in automotive industry

Directory of Open Access Journals (Sweden)

Md Zain Mohamad Zamri

2017-01-01

Full Text Available Current trend in automotive industry shows increasing demand for multiple models with lean production. Prior to that, automotive manufacturing systems evolved from mass production to flexible automation. Material handling systems and equipment in a single assembly line with multiple models require high investment but with low throughput thus making production cost relatively high. Current assembly process of side structure and undercarriage with downtime occurrence during assembly process affecting production performance (quality, cost and delivery. Manufacturing facilities should allow more flexibility and increase intelligence evolving toward novel reconfigurable assembly systems (RAS. RAS is envisaged capable of increasing factor flexibility and responsiveness by incorporating assembly jig, robot and framing, which could be next generation of world class automotive assembly systems. This project research proposes a new methodology of framework reconfigurable assembly systems principles in automotive framing systems i.e. enhance assembly process between side structure assembly and undercarriage assembly which a new RAS is capable to reconfigure the assembly processes of multiple model on a single assembly line. Simulation software (Witness will be used to simulate and validate current and proposed assembly process. RAS is expected to be a solution for rapid change in structure and for a responsively adjustable production capacity. Quality, cost and delivery are production key parameters that can be achieved by implementing RAS.

Artist concept of Galileo spacecraft

Science.gov (United States)

1988-01-01

Galileo spacecraft is illustrated in artist concept. Gallileo, named for the Italian astronomer, physicist and mathematician who is credited with construction of the first complete, practical telescope in 1620, will make detailed studies of Jupiter. A cooperative program with the Federal Republic of Germany the Galileo mission will amplify information acquired by two Voyager spacecraft in their brief flybys. Galileo is a two-element system that includes a Jupiter-orbiting observatory and an entry probe. Jet Propulsion Laboratory (JPL) is Galileo project manager and builder of the main spacecraft. Ames Research Center (ARC) has responsibility for the entry probe, which was built by Hughes Aircraft Company and General Electric. Galileo will be deployed from the payload bay (PLB) of Atlantis, Orbiter Vehicle (OV) 104, during mission STS-34.

Addressing EO-1 Spacecraft Pulsed Plasma Thruster EMI Concerns

Science.gov (United States)

Zakrzwski, C. M.; Davis, Mitch; Sarmiento, Charles; Bauer, Frank H. (Technical Monitor)

2001-01-01

The Pulsed Plasma Thruster (PPT) Experiment on the Earth Observing One (EO-1) spacecraft has been designed to demonstrate the capability of a new generation PPT to perform spacecraft attitude control. Results from PPT unit level radiated electromagnetic interference (EMI) tests led to concerns about potential interference problems with other spacecraft subsystems. Initial plans to address these concerns included firing the PPT at the spacecraft level both in atmosphere, with special ground support equipment. and in vacuum. During the spacecraft level tests, additional concerns where raised about potential harm to the Advanced Land Imager (ALI). The inadequacy of standard radiated emission test protocol to address pulsed electromagnetic discharges and the lack of resources required to perform compatibility tests between the PPT and an ALI test unit led to changes in the spacecraft level validation plan. An EMI shield box for the PPT was constructed and validated for spacecraft level ambient testing. Spacecraft level vacuum tests of the PPT were deleted. Implementation of the shield box allowed for successful spacecraft level testing of the PPT while eliminating any risk to the ALI. The ALI demonstration will precede the PPT demonstration to eliminate any possible risk of damage of ALI from PPT operation.

SAF-BRET-FMEF: a developmental LMR fuel cycle facility

International Nuclear Information System (INIS)

Stradley, J.G.; Yook, H.R.; Gerber, E.W.; Lerch, R.E.; Rice, L.H.

1985-01-01

The SAF-BRET-FMEF complex represents a versatile fuel cycle facility for processing LMR fuel. While originally conceived for processing FFTF and CRBRP fuel, it represents a facility where LMR fuel from the first generation of innovative LMRs could be processed. The cost of transporting fuel from the LMR to the Hanford site would have to be assessed when the LMR site is identified. The throughput of BRET was set at 15 MTHM/yr during conceptual design of the facility, a rate which was adequate to process all of the fuel from FFTF and fuel and blanket material from CRBRP. The design is currently being reevaluated to see if BRET could be expanded to approx.35 MTHM/yr to process fuel and blanket material from approx.1300 MWe generating capacity of the innovative LMRs. This expanded throughput is possible by designing the equipment for an instantaneous throughput of 0.2 MTHM/d, and by selected additional modifications to the facility (e.g., expansion of shipping and receiving area, and addition of a second entry tunnel transporter), and by the fact that the LMR fuel assemblies contain more fuel than the FFTF assemblies (therefore, fewer assemblies must be handled for the same throughput). The estimated cost of such an expansion is also being assessed. As stated previously, the throughput of SAF and Fuel Assembly could be made to support typical LMRs at little additional cost. The throughput could be increased to support the fuel fabrication requirements for 1300 MWe generating capacity of the innovative LMRs. This added capacity may be achieved by increasing the number of operating shifts, and is affected by variables such as fuel design, fuel enrichment, and plutonium isotopic composition

Safety analysis of the Los Alamos critical experiments facility: burst operation of Skua

International Nuclear Information System (INIS)

Orndoff, J.D.; Paxton, H.C.; Wimett, T.F.

1980-12-01

Detailed consideration of the Skua burst assembly is provided, thereby supplementing the facility Safety Analysis Report covering the operation of other critical assemblies at the Los Alamos Scientific Laboratory. As with these assemblies the small fission-product inventory, ambient pressure, and moderate temperatures in Skua are amenable to straightforward measures to ensure the protection of the public

How Spacecraft Fly Spaceflight Without Formulae

CERN Document Server

Swinerd, Graham

2009-01-01

About half a century ago a small satellite, Sputnik 1, was launched. The satellite did very little other than to transmit a radio signal to announce its presence in orbit. However, this humble beginning heralded the dawn of the Space Age. Today literally thousands of robotic spacecraft have been launched, many of which have flown to far-flung regions of the Solar System carrying with them the human spirit of scientific discovery and exploration. Numerous other satellites have been launched in orbit around the Earth providing services that support our technological society on the ground. How Spacecraft Fly: Spaceflight Without Formulae by Graham Swinerd focuses on how these spacecraft work. The book opens with a historical perspective of how we have come to understand our Solar System and the Universe. It then progresses through orbital flight, rocket science, the hostile environment within which spacecraft operate, and how they are designed. The concluding chapters give a glimpse of what the 21st century may ...

One approach to accepting and transporting spent fuel from early-generation reactors with short fuel assemblies

International Nuclear Information System (INIS)

Peterson, R.W.; Bentz, E.J. Jr.; Bentz, C.B.

1993-01-01

In the early days of development of commercial nuclear power reactors in the U.S., the overall length and uranium loading of the fuel assemblies were considerably less than those of later generation facilities. In turn, some of these early facilities were designed for handling shorter casks than currently-certified casks. The spent fuel assemblies from these facilities are nearly all standard fuel within the definition in the Standard Contract (10 CFR 961) between the utilities and the U.S. Department of Energy (DOE) (the Big Rock Point fuel cross-section is outside the standard fuel dimension), and the utilities involved hold early delivery rights under DOE's oldest-fuel-first (OFF) allocation scenario. However, development of casks suitable for satisfying the acceptance and transportation requirements of some of these facilities is not currently underway in the DOE Cask System Development Program (CSDP). While the total MTU of these fuels is relatively small compared to the total program, the number of assemblies to be transported is significant, especially in the early years of operation according to the OFF allocation scenario. We therefore perceive a need for DOE to develop an approach and to implement plans to satisfy the unique acceptance and transportation requirements of these facilities. One such approach is outlined below. (author)

Optimal Autonomous Spacecraft Resiliency Maneuvers Using Metaheuristics

Science.gov (United States)

2014-09-15

This work was accepted for published by the American Institute of Aeronautics and Astronautics (AIAA) Journal of Spacecraft and Rockets in July 2014...publication in the AIAA Journal of Spacecraft and Rockets . Chapter 5 introduces an impulsive maneuvering strategy to deliver a spacecraft to its final...upon arrival r2 and v2 , respectively. The variable T2 determines the time of flight needed to make the maneuver, and the variable θ2 determines the

Integrating standard operating procedures with spacecraft automation, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Spacecraft automation has the potential to assist crew members and spacecraft operators in managing spacecraft systems during extended space missions. Automation can...

European Synchrotron Radiation Facility

International Nuclear Information System (INIS)

Buras, B.

1985-01-01

How a European Synchrotron Radiation Facility has developed into a detailed proposal recently accepted as the basis for construction of the facility at Grenoble is discussed. In November 1977, the General Assembly of the European Science Foundation (ESF) approved the report of the ESF working party on synchrotron radiation entitled Synchrotron Radiation - a Perspective View for Europe. This report contained as one of its principal recommendations that work should commence on a feasibility study for a European synchrotron radiation laboratory having a dedicated hard X-ray storage ring and appropriate advanced instrumentation. In order to prepare a feasibility study the European Science Foundation set up the Ad-hoc Committee on Synchrotron Radiation, which in turn formed two working groups: one for the machine and another for instrumentation. This feasibility study was completed in 1979 with the publication of the Blue Book describing in detail the so called 1979 European Synchrotron Radiation Facility. The heart of the facility was a 5 GeV electron storage ring and it was assumed that mainly the radiation from bending magnets will be used. The facility is described

Refitting of the 'Celimene' hot cell for following up the fuel assembly of 900 MWe PWR power reactors

International Nuclear Information System (INIS)

Lhermenier, Andre; Van Craeynest, J.-C.

1980-05-01

The 'Celimene' cell adjoining the EL3 reactor provides for the acceptance, handling and the examination of irradiated fuel assemblies from power reactors (length approximately 4m, weight approximately 700 kg). Within the framework of the PWR fuel behavior follow-up or reprocessing, it is possible to extract an assembly representative of the normal fuel cycle, carry out non destructive tests on this assembly, extract pencils from it and re-insert this assembly, after refitting the head, into the normal fuel cycle for handling in a reprocessing plant or storage pond. Given suitable refitting techniques, the re-irradiation of the assembly can be considered after examination. Significant changes have been made to the buildings and the hoist facilities for handling very heavy flasks. It was necessary to rearrange the handling, machining and in-cell storage facilities. The development of an inspection rig will make it possible, some time in 1980, to carry out non destructive tests of assemblies, optical and metrological examination of assemblies prior to dismantling or of the structure after dismantling [fr

Neutron collar calibration for assay of LWR [light-water reactor] fuel assemblies

International Nuclear Information System (INIS)

Menlove, H.O.; Pieper, J.E.

1987-03-01

The neutron-coincidence collar is used for the verification of the uranium content in light-water reactor fuel assemblies. An AmLi neutron source is used to give an active interrogation of the fuel assembly to measure the 235 U content, and the 238 U content is verified from a passive neutron-coincidence measurement. This report gives the collar calibration data of pressurized-water reactor and boiling-water reactor fuel assemblies. Calibration curves and correction factors are presented for neutron absorbers (burnable poisons) and different fuel assembly sizes. The data were collected at Exxon Nuclear, Franco-Belge de Fabrication de Combustibles, ASEA-Atom, and other nuclear fuel fabrication facilities

Porphyrin Diacid-Polyelectrolyte Assemblies: Effective Photocatalysts in Solution

Directory of Open Access Journals (Sweden)

Sabine Frühbeißer

2016-05-01

Full Text Available Developing effective and versatile photocatalytic systems is of great potential in solar energy conversion. Here we investigate the formation of supramolecular catalysts by electrostatic self-assembly in aqueous solution: Combining positively charged porphyrins with negatively charged polyelectrolytes leads to nanoscale assemblies where, next to electrostatic interactions, π–π interactions also play an important role. Porphyrin diacid-polyelectrolyte assemblies exhibit a substantially enhanced catalytic activity for the light-driven oxidation of iodide. Aggregates with the hexavalent cationic porphyrin diacids show up to 22 times higher catalytic activity than the corresponding aggregates under neutral conditions. The catalytic activity can be increased by increasing the valency of the porphyrin and by choice of the loading ratio. The structural investigation of the supramolecular catalysts took place via atomic force microscopy and small angle neutron scattering. Hence, a new facile concept for the design of efficient and tunable self-assembled photocatalysts is presented.

Capabilities of the Power Burst Facility

International Nuclear Information System (INIS)

Spencer, W.A.; Jensen, A.M.; McCardell, R.K.

1982-01-01

The unique and diverse test capabilities of the Power Burst Facility (PBF) are described in this paper. The PBF test reactor, located at the Idaho National Engineering Laboratory, simulates normal, off-normal, and accident operating conditions of light water reactor fuel rods. An overview description is given, with specific detail on design and operating characteristics of the driver core, experiment test loop, fission product detection system, test train assembly facility, and support equipment which make the testing capability of the PBF so versatile

Large experimental facilities of the UKAEA

International Nuclear Information System (INIS)

Hills, P.R.

1987-10-01

This list of UKAEA capital equipment was first assembled for the Interdepartmental Committee on Large Experimental Facilities as a contribution to a directory of national installations with a replacement value of Pound 1M or more. It is now being circulated in report form within the Authority, to assist staff to demonstrate to customers the wide range of facilities the Authority has available to carry out contract work, and to help them identify where customers' work can best be placed. (author)

Evaluation of Various Cleaning Methods to Remove Bacillus Spores from Spacecraft Hardware Materials

Science.gov (United States)

Venkateswaran, Kasthuri; Chung, Shirley; Allton, Judith; Kern, Roger

2004-09-01

A detailed study was made of the biological cleaning effectiveness, defined in terms of the ability to remove bacterial spores, of a number of methods used to clean hardware surfaces. Aluminum (Al 6061) and titanium (Ti 6Al-4V) were chosen for the study as they were deemed the two materials most likely to be used in spacecraft extraterrestrial sampler construction. Metal coupons (1 cm × 2.5 cm) were precleaned and inoculated with 5.8 × 103 cultivable Bacillus subtilis spores, which are commonly found on spacecraft surfaces and in the assembly environments. The inoculated coupons were subsequently cleaned using: (1) 70% isopropyl alcohol wipe; (2) water wipe; (3) multiple-solvent flight-hardware cleaning procedures used at the Jet Propulsion Laboratory (JPL); (4) Johnson Space Center-developed ultrapure water rinse; and (5) a commercial, semi-aqueous, multiple-solvent (SAMS) cleaning process. The biological cleaning effectiveness was measured by agar plate assay, sterility test (growing in liquid media), and epifluorescent microscopy. None of the cleaning protocols tested completely removed viable spores from the surface of the aluminum. In contrast, titanium was capable of being cleaned to sterility by two methods, the JPL standard and the commercial SAMS cleaning process. Further investigation showed that the passivation step employed in the JPL standard method is an effective surface sterilant on both metals but not compatible with aluminum. It is recommended that titanium (Ti 6Al-4V) be considered superior to aluminum (Al 6061) for use in spacecraft sampling hardware, both for its potential to be cleaned to sterilization and for its ability to withstand the most effective cleaning protocols.

Quick Spacecraft Thermal Analysis Tool, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — For spacecraft design and development teams concerned with cost and schedule, the Quick Spacecraft Thermal Analysis Tool (QuickSTAT) is an innovative software suite...

The European HST Science Data Archive. [and Data Management Facility (DMF)

Science.gov (United States)

Pasian, F.; Pirenne, B.; Albrecht, R.; Russo, G.

1993-01-01

The paper describes the European HST Science Data Archive. Particular attention is given to the flow from the HST spacecraft to the Science Data Archive at the Space Telescope European Coordinating Facility (ST-ECF); the archiving system at the ST-ECF, including the hardware and software system structure; the operations at the ST-ECF and differences with the Data Management Facility; and the current developments. A diagram of the logical structure and data flow of the system managing the European HST Science Data Archive is included.

Revamping Spacecraft Operational Intelligence

Science.gov (United States)

Hwang, Victor

2012-01-01

The EPOXI flight mission has been testing a new commercial system, Splunk, which employs data mining techniques to organize and present spacecraft telemetry data in a high-level manner. By abstracting away data-source specific details, Splunk unifies arbitrary data formats into one uniform system. This not only reduces the time and effort for retrieving relevant data, but it also increases operational visibility by allowing a spacecraft team to correlate data across many different sources. Splunk's scalable architecture coupled with its graphing modules also provide a solid toolset for generating data visualizations and building real-time applications such as browser-based telemetry displays.

Characterization of the 309 fuel examination facility

International Nuclear Information System (INIS)

Greenhalgh, W.O.; Cornwell, B.C.

1997-01-01

This document identifies radiological, chemical and physical conditions inside the Fuel Examination Facility. It is located inside the Plutonium Recycle Test Reactor containment structure (309 Building.) The facility was a hot cell used for examination of PRTR fuel and equipment during the 1960's. Located inside the cell is a PRTR shim rod assembly, reported are radiological conditions of the sample. The conditions were assessed as part of overall 309 Building transition

Design feasibility via ascent optimality for next-generation spacecraft

Science.gov (United States)

Miele, A.; Mancuso, S.

This paper deals with the optimization of the ascent trajectories for single-stage-sub-orbit (SSSO), single-stage-to-orbit (SSTO), and two-stage-to-orbit (TSTO) rocket-powered spacecraft. The maximum payload weight problem is studied for different values of the engine specific impulse and spacecraft structural factor. The main conclusions are that: feasibility of SSSO spacecraft is guaranteed for all the parameter combinations considered; feasibility of SSTO spacecraft depends strongly on the parameter combination chosen; not only feasibility of TSTO spacecraft is guaranteed for all the parameter combinations considered, but the TSTO payload is several times the SSTO payload. Improvements in engine specific impulse and spacecraft structural factor are desirable and crucial for SSTO feasibility; indeed, aerodynamic improvements do not yield significant improvements in payload. For SSSO, SSTO, and TSTO spacecraft, simple engineering approximations are developed connecting the maximum payload weight to the engine specific impulse and spacecraft structural factor. With reference to the specific impulse/structural factor domain, these engineering approximations lead to the construction of zero-payload lines separating the feasibility region (positive payload) from the unfeasibility region (negative payload).

Status and future program of reactor physics experiments in JAERI Critical facilities, FCA and TCA

International Nuclear Information System (INIS)

Okajima, Shigeaki; Osugi, Toshitaka; Nakajima, Ken; Suzaki, Takenori; Miyoshi, Yoshinori

1999-01-01

The critical facilities in JAERI, FCA (Fast Critical Assembly) and TCA (Tank-type Critical Assembly), have been used to provide integral data for evaluation of nuclear data as well as for development of various types of reactor since they went critical in 1960's. In this paper a review is presented on the experimental programs in both facilities. And the experimental programs in next 5 years are also shown. (author)

Slew Maneuver Control for Spacecraft Equipped with Star Camera and Reaction Wheels

DEFF Research Database (Denmark)

Wisniewski, Rafal; Kulczycki, P.

2005-01-01

A configuration consisting of a star camera, four reaction wheels and magnetorquers for momentum unloading has become standard for many spacecraft missions. This popularity has motivated numerous agencies and private companies to initiate work on the design of an imbedded attitude control system...... realized on an integrated circuit. This paper provides an easily implementable control algorithm for this type of configuration. The paper considers two issues: slew maneuver with a feature of avoiding direct exposure of the camera's CCD chip to the Sun %, three-axis attitude control and optimal control...... torque distribution in a reaction wheel assembly. The attitude controller is synthesized applying the energy shaping technique, where the desired potential function is carefully designed using a physical insight into the nature of the problem. The system stability is thoroughly analyzed and the control...

Reusable fuel test assembly for the FFTF

International Nuclear Information System (INIS)

Pitner, A.L.; Dittmer, J.O.

1992-01-01

A fuel test assembly that provides re-irradiation capability after interim discharge and reconstitution of the test pin bundle has been developed for use in the Fast Flux Test Facility (FFTF). This test vehicle permits irradiation test data to be obtained at multiple exposures on a few select test pins without the substantial expense of fabricating individual test assemblies as would otherwise be required. A variety of test pin types can be loaded in the reusable test assembly. A reusable test vehicle for irradiation testing in the FFTF has long been desired, but a number of obstacles previously prevented the implementation of such an experimental rig. The MFF-8A test assembly employs a 169-pin bundle using HT-9 alloy for duct and cladding material. The standard driver pins in the fuel bundle are sodium-bonded metal fuel (U-10 wt% Zr). Thirty-seven positions in the bundle are replaceable pin positions. Standard MFF-8A driver pins can be loaded in any test pin location to fill the bundle if necessary. Application of the MFF-8A reusable test assembly in the FFTF constitutes a considerable cost-saving measure with regard to irradiation testing. Only a few well-characterized test pins need be fabricated to conduct a test program rather than constructing entire test assemblies

Construction of STACY (Static Experiment Critical Facility)

International Nuclear Information System (INIS)

Murakami, Kiyonobu; Onodera, Seiji; Hirose, Hideyuki

1998-08-01

Two critical assemblies, STACY (Static Experiment Critical Facility) and TRACY (Transient Experiment Critical Facility), were constructed in NUCEF (Nuclear Fuel Cycle Safety Engineering Research Facility) to promote researches on the criticality safety at a reprocessing facility. STACY aims at providing critical data of uranium nitrate solution, plutonium nitrate solution and their mixture while varying concentration of solution fuel, core tank shape and size and neutron reflecting condition. STACY achieved first criticality in February 1995, and passed the licensing inspection by STA (Science and Technology Agency of Japan) in May. After that a series of critical experiments commenced with 10 w/o enriched uranium solution. This report describes the outline of STACY at the end of FY 1996. (author)

Research-Based Monitoring, Prediction, and Analysis Tools of the Spacecraft Charging Environment for Spacecraft Users

Science.gov (United States)

Zheng, Yihua; Kuznetsova, Maria M.; Pulkkinen, Antti A.; Maddox, Marlo M.; Mays, Mona Leila

2015-01-01

The Space Weather Research Center (http://swrc. gsfc.nasa.gov) at NASA Goddard, part of the Community Coordinated Modeling Center (http://ccmc.gsfc.nasa.gov), is committed to providing research-based forecasts and notifications to address NASA's space weather needs, in addition to its critical role in space weather education. It provides a host of services including spacecraft anomaly resolution, historical impact analysis, real-time monitoring and forecasting, tailored space weather alerts and products, and weekly summaries and reports. In this paper, we focus on how (near) real-time data (both in space and on ground), in combination with modeling capabilities and an innovative dissemination system called the integrated Space Weather Analysis system (http://iswa.gsfc.nasa.gov), enable monitoring, analyzing, and predicting the spacecraft charging environment for spacecraft users. Relevant tools and resources are discussed.

Industry perspectives on Plug-& -Play Spacecraft Avionics

Science.gov (United States)

Franck, R.; Graven, P.; Liptak, L.

This paper describes the methodologies and findings from an industry survey of awareness and utility of Spacecraft Plug-& -Play Avionics (SPA). The survey was conducted via interviews, in-person and teleconference, with spacecraft prime contractors and suppliers. It focuses primarily on AFRL's SPA technology development activities but also explores the broader applicability and utility of Plug-& -Play (PnP) architectures for spacecraft. Interviews include large and small suppliers as well as large and small spacecraft prime contractors. Through these “ product marketing” interviews, awareness and attitudes can be assessed, key technical and market barriers can be identified, and opportunities for improvement can be uncovered. Although this effort focuses on a high-level assessment, similar processes can be used to develop business cases and economic models which may be necessary to support investment decisions.

Fuel assembly duct cutting in the FFTF/IEM Cell

International Nuclear Information System (INIS)

Gibbons, P.W.

1985-01-01

Two mill type slitting cutters are used in the Fast Flux Test Facility (FFTF) Interim Examination and Maintenance (IEM) Cell during the disassembly sequence of a Driver Fuel Assembly. This disassembly is necessary so that selected parts may be examined both in the IEM Cell and elsewhere. The cutters have been in use for two years. During this time eight Driver Fuel assemblies have been taken apart in the IEM Cell. The cutters' operating philosophy and characteristics, as well as lessons learned from a significant equipment failure are presented. 1 ref., 6 figs., 1 tab

Multiple spacecraft observations of interplanetary shocks: four spacecraft determination of shock normals

International Nuclear Information System (INIS)

Russell, C.T.; Mellott, M.M.; Smith, E.J.; King, J.H.

1983-01-01

ISEE 1,2,3 IMP8, and Prognoz 7 observations of interplanetary shocks in 1978 and 1979 provide five instances where a single shock is observed by four spacecraft. These observations are used to determine best-fit normals for these five shocks. In addition to providing well-documented shocks for furture techniques. When the angle between upstream and downstream magnetic field is greater than 20, magnetic coplanarity can be an accurate single spacecraft method. However, no technique based solely on the magnetic measurements at one or multiple sites was universally accurate. Thus, we recommend using overdetermined shock normal solutions whenever possible, utilizing plasma measurements, separation vectors, and time delays together with magnetic constraints

Low cost spacecraft computers: Oxymoron or future trend?

Science.gov (United States)

Manning, Robert M.

1993-01-01

Over the last few decades, application of current terrestrial computer technology in embedded spacecraft control systems has been expensive and wrought with many technical challenges. These challenges have centered on overcoming the extreme environmental constraints (protons, neutrons, gamma radiation, cosmic rays, temperature, vibration, etc.) that often preclude direct use of commercial off-the-shelf computer technology. Reliability, fault tolerance and power have also greatly constrained the selection of spacecraft control system computers. More recently, new constraints are being felt, cost and mass in particular, that have again narrowed the degrees of freedom spacecraft designers once enjoyed. This paper discusses these challenges, how they were previously overcome, how future trends in commercial computer technology will simplify (or hinder) selection of computer technology for spacecraft control applications, and what spacecraft electronic system designers can do now to circumvent them.

Developing Sustainable Spacecraft Water Management Systems

Science.gov (United States)

Thomas, Evan A.; Klaus, David M.

2009-01-01

It is well recognized that water handling systems used in a spacecraft are prone to failure caused by biofouling and mineral scaling, which can clog mechanical systems and degrade the performance of capillary-based technologies. Long duration spaceflight applications, such as extended stays at a Lunar Outpost or during a Mars transit mission, will increasingly benefit from hardware that is generally more robust and operationally sustainable overtime. This paper presents potential design and testing considerations for improving the reliability of water handling technologies for exploration spacecraft. Our application of interest is to devise a spacecraft wastewater management system wherein fouling can be accommodated by design attributes of the management hardware, rather than implementing some means of preventing its occurrence.

Relativistic Spacecraft Propelled by Directed Energy

Science.gov (United States)

Kulkarni, Neeraj; Lubin, Philip; Zhang, Qicheng

2018-04-01

Achieving relativistic flight to enable extrasolar exploration is one of the dreams of humanity and the long-term goal of our NASA Starlight program. We derive a relativistic solution for the motion of a spacecraft propelled by radiation pressure from a directed energy (DE) system. Depending on the system parameters, low-mass spacecraft can achieve relativistic speeds, thus enabling interstellar exploration. The diffraction of the DE system plays an important role and limits the maximum speed of the spacecraft. We consider “photon recycling” as a possible method to achieving higher speeds. We also discuss recent claims that our previous work on this topic is incorrect and show that these claims arise from an improper treatment of causality.

Dips spacecraft integration issues

International Nuclear Information System (INIS)

Determan, W.R.; Harty, R.B.

1988-01-01

The Department of Energy, in cooperation with the Department of Defense, has recently initiated the dynamic isotope power system (DIPS) demonstration program. DIPS is designed to provide 1 to 10 kW of electrical power for future military spacecraft. One of the near-term missions considered as a potential application for DIPS was the boost surveillance and tracking system (BSTS). A brief review and summary of the reasons behind a selection of DIPS for BSTS-type missions is presented. Many of these are directly related to spacecraft integration issues; these issues will be reviewed in the areas of system safety, operations, survivability, reliability, and autonomy

REQUIREMENTS FOR IMAGE QUALITY OF EMERGENCY SPACECRAFTS

Directory of Open Access Journals (Sweden)

A. I. Altukhov

2015-05-01

Full Text Available The paper deals with the method for formation of quality requirements to the images of emergency spacecrafts. The images are obtained by means of remote sensing of near-earth space orbital deployment in the visible range. of electromagnetic radiation. The method is based on a joint taking into account conditions of space survey, characteristics of surveillance equipment, main design features of the observed spacecrafts and orbital inspection tasks. Method. Quality score is the predicted linear resolution image that gives the possibility to create a complete view of pictorial properties of the space image obtained by electro-optical system from the observing satellite. Formulation of requirements to the numerical value of this indicator is proposed to perform based on the properties of remote sensing system, forming images in the conditions of outer space, and the properties of the observed emergency spacecraft: dimensions, platform construction of the satellite, on-board equipment placement. For method implementation the authors have developed a predictive model of requirements to a linear resolution for images of emergency spacecrafts, making it possible to select the intervals of space shooting and get the satellite images required for quality interpretation. Main results. To verify the proposed model functionality we have carried out calculations of the numerical values for the linear resolution of the image, ensuring the successful task of determining the gross structural damage of the spacecrafts and identifying changes in their spatial orientation. As input data were used with dimensions and geometric primitives corresponding to the shape of deemed inspected spacecrafts: Resurs-P", "Canopus-B", "Electro-L". Numerical values of the linear resolution images have been obtained, ensuring the successful task solution for determining the gross structural damage of spacecrafts.

Robust Spacecraft Component Detection in Point Clouds

Directory of Open Access Journals (Sweden)

Quanmao Wei

2018-03-01

Full Text Available Automatic component detection of spacecraft can assist in on-orbit operation and space situational awareness. Spacecraft are generally composed of solar panels and cuboidal or cylindrical modules. These components can be simply represented by geometric primitives like plane, cuboid and cylinder. Based on this prior, we propose a robust automatic detection scheme to automatically detect such basic components of spacecraft in three-dimensional (3D point clouds. In the proposed scheme, cylinders are first detected in the iteration of the energy-based geometric model fitting and cylinder parameter estimation. Then, planes are detected by Hough transform and further described as bounded patches with their minimum bounding rectangles. Finally, the cuboids are detected with pair-wise geometry relations from the detected patches. After successive detection of cylinders, planar patches and cuboids, a mid-level geometry representation of the spacecraft can be delivered. We tested the proposed component detection scheme on spacecraft 3D point clouds synthesized by computer-aided design (CAD models and those recovered by image-based reconstruction, respectively. Experimental results illustrate that the proposed scheme can detect the basic geometric components effectively and has fine robustness against noise and point distribution density.

Robust Spacecraft Component Detection in Point Clouds.

Science.gov (United States)

Wei, Quanmao; Jiang, Zhiguo; Zhang, Haopeng

2018-03-21

Automatic component detection of spacecraft can assist in on-orbit operation and space situational awareness. Spacecraft are generally composed of solar panels and cuboidal or cylindrical modules. These components can be simply represented by geometric primitives like plane, cuboid and cylinder. Based on this prior, we propose a robust automatic detection scheme to automatically detect such basic components of spacecraft in three-dimensional (3D) point clouds. In the proposed scheme, cylinders are first detected in the iteration of the energy-based geometric model fitting and cylinder parameter estimation. Then, planes are detected by Hough transform and further described as bounded patches with their minimum bounding rectangles. Finally, the cuboids are detected with pair-wise geometry relations from the detected patches. After successive detection of cylinders, planar patches and cuboids, a mid-level geometry representation of the spacecraft can be delivered. We tested the proposed component detection scheme on spacecraft 3D point clouds synthesized by computer-aided design (CAD) models and those recovered by image-based reconstruction, respectively. Experimental results illustrate that the proposed scheme can detect the basic geometric components effectively and has fine robustness against noise and point distribution density.

Large Field Photogrammetry Techniques in Aircraft and Spacecraft Impact Testing

Science.gov (United States)

Littell, Justin D.

2010-01-01

The Landing and Impact Research Facility (LandIR) at NASA Langley Research Center is a 240 ft. high A-frame structure which is used for full-scale crash testing of aircraft and rotorcraft vehicles. Because the LandIR provides a unique capability to introduce impact velocities in the forward and vertical directions, it is also serving as the facility for landing tests on full-scale and sub-scale Orion spacecraft mass simulators. Recently, a three-dimensional photogrammetry system was acquired to assist with the gathering of vehicle flight data before, throughout and after the impact. This data provides the basis for the post-test analysis and data reduction. Experimental setups for pendulum swing tests on vehicles having both forward and vertical velocities can extend to 50 x 50 x 50 foot cubes, while weather, vehicle geometry, and other constraints make each experimental setup unique to each test. This paper will discuss the specific calibration techniques for large fields of views, camera and lens selection, data processing, as well as best practice techniques learned from using the large field of view photogrammetry on a multitude of crash and landing test scenarios unique to the LandIR.

Automated constraint checking of spacecraft command sequences

Science.gov (United States)

Horvath, Joan C.; Alkalaj, Leon J.; Schneider, Karl M.; Spitale, Joseph M.; Le, Dang

1995-01-01

Robotic spacecraft are controlled by onboard sets of commands called "sequences." Determining that sequences will have the desired effect on the spacecraft can be expensive in terms of both labor and computer coding time, with different particular costs for different types of spacecraft. Specification languages and appropriate user interface to the languages can be used to make the most effective use of engineering validation time. This paper describes one specification and verification environment ("SAVE") designed for validating that command sequences have not violated any flight rules. This SAVE system was subsequently adapted for flight use on the TOPEX/Poseidon spacecraft. The relationship of this work to rule-based artificial intelligence and to other specification techniques is discussed, as well as the issues that arise in the transfer of technology from a research prototype to a full flight system.

YALINA-Thermal Facility Experiments

International Nuclear Information System (INIS)

Kiyavitskaya, H.; Bournos, V.; Fokov, Y.; Routkovskaya, C.; Sadovich, S.; Cintas, A.; Márquez Damián, J.I.; Lopasso, E.M.; Maiorino, J.R.; Carluccio, T.; Rossi, P.C.R.; Antunes, A.; Oliveira, F.L. de; Lee, S.M.; Xia, P.; Shi, Y.; Xia, H.; Zhu, Q.; Yu, T.; Wu, X.; Zhang, W.; Cao, J.; Luo, H.; Quan, Y.; Kulkarni, K.; Yadav, R.D.S.; Bajpai, A.; Degweker, S.B.; Modak, R.S.; Park, H.J.; Shim, H.J.; Kim, C.H.; Wojciechowski, A.; Zuta, M.; Pešić, M.; Avramović, I.; Beličev, P.; Gohar, Y.; Talamo, A.; Aliberti, G.

2017-01-01

This Section discussed the results obtained by the Member States participating in the IAEA coordinated research project on Analytical and Experimental Benchmark Analysis on Accelerator Driven Systems, and Low Enriched Uranium Fuel Utilization in Accelerator Driven Subcritical Assembly Systems for the YALINA Thermal facility. Member States used both Monte Carlo and deterministic computational tools to analyse the YALINA Thermal subcritical assembly, including: MCNP5, MCNPX, McCARD, PARTISN, and ERANOS computer programs. All calculations have been performed using the ENDF/B-VI (different modes) nuclear data libraries with the exception of Republic of Korea which used the ENDF/B-VII.0 nuclear data library. Generally, there is a good agreement between the results obtained by all the Member States. Deterministic codes perform space, energy, and angle discretization and materials homogenizations, which introduce approximations affecting the obtained results. In subcritical assemblies, the neutron multiplication and the detector counting rate depend strongly on the external neutron source. Cf and D-D sources provide similar results since they emit neutrons with similar average energy. D-T neutrons trigger (n,xn) reactions and have a longer mean free path, which increases the neutron leakage if the geometry dimensions of the assembly are small, as in the case of the YALINA-Thermal subcritical assembly. Close to criticality, the effect of the external neutron source diminishes since fission neutrons dominate the neutron population.

Optimal Neutron Source and Beam Shaping Assembly for Boron Neutron Capture Therapy

International Nuclear Information System (INIS)

Vujic, J.; Greenspan, E.; Kastenber, W.E.; Karni, Y.; Regev, D.; Verbeke, J.M.; Leung, K.N.; Chivers, D.; Guess, S.; Kim, L.; Waldron, W.; Zhu, Y.

2003-01-01

There were three objectives to this project: (1) The development of the 2-D Swan code for the optimization of the nuclear design of facilities for medical applications of radiation, radiation shields, blankets of accelerator-driven systems, fusion facilities, etc. (2) Identification of the maximum beam quality that can be obtained for Boron Neutron Capture Therapy (BNCT) from different reactor-, and accelerator-based neutron sources. The optimal beam-shaping assembly (BSA) design for each neutron source was also to e obtained. (3) Feasibility assessment of a new neutron source for NCT and other medical and industrial applications. This source consists of a state-of-the-art proton or deuteron accelerator driving and inherently safe, proliferation resistant, small subcritical fission assembly

DOE LeRC photovoltaic systems test facility

Science.gov (United States)

Cull, R. C.; Forestieri, A. F.

1978-01-01

The facility was designed and built and is being operated as a national facility to serve the needs of the entire DOE National Photovoltaic Program. The object of the facility is to provide a place where photovoltaic systems may be assembled and electrically configured, without specific physical configuration, for operation and testing to evaluate their performance and characteristics. The facility as a breadboard system allows investigation of operational characteristics and checkout of components, subsystems and systems before they are mounted in field experiments or demonstrations. The facility as currently configured consist of 10 kW of solar arrays built from modules, two inverter test stations, a battery storage system, interface with local load and the utility grid, and instrumentation and control necessary to make a flexible operating facility. Expansion to 30 kW is planned for 1978. Test results and operating experience are summaried to show the variety of work that can be done with this facility.

Advanced Solar-propelled Cargo Spacecraft for Mars Missions

Science.gov (United States)

Auziasdeturenne, Jacqueline; Beall, Mark; Burianek, Joseph; Cinniger, Anna; Dunmire, Barbrina; Haberman, Eric; Iwamoto, James; Johnson, Stephen; Mccracken, Shawn; Miller, Melanie

1989-01-01

Three concepts for an unmanned, solar powered, cargo spacecraft for Mars support missions were investigated. These spacecraft are designed to carry a 50,000 kg payload from a low Earth orbit to a low Mars orbit. Each design uses a distinctly different propulsion system: A Solar Radiation Absorption (SRA) system, a Solar-Pumped Laser (SPL) system and a solar powered magnetoplasmadynamic (MPD) arc system. The SRA directly converts solar energy to thermal energy in the propellant through a novel process. In the SPL system, a pair of solar-pumped, multi-megawatt, CO2 lasers in sunsynchronous Earth orbit converts solar energy to laser energy. The MPD system used indium phosphide solar cells to convert sunlight to electricity, which powers the propulsion system. Various orbital transfer options are examined for these concepts. In the SRA system, the mother ship transfers the payload into a very high Earth orbit and a small auxiliary propulsion system boosts the payload into a Hohmann transfer to Mars. The SPL spacecraft and the SPL powered spacecraft return to Earth for subsequent missions. The MPD propelled spacecraft, however, remains at Mars as an orbiting space station. A patched conic approximation was used to determine a heliocentric interplanetary transfer orbit for the MPD propelled spacecraft. All three solar-powered spacecraft use an aerobrake procedure to place the payload into a low Mars parking orbit. The payload delivery times range from 160 days to 873 days (2.39 years).

Standard Practice for Design and Construction of Aerospace Cleanrooms and Contamination Controlled Areas

CERN Document Server

American Society for Testing and Materials. Philadelphia

2002-01-01

1.1 The purpose of this practice is to provide design and construction guidelines for contamination controlled facilities used in the assembly and integration of aerospace hardware. The guidelines herein are intended to ensure that the facilities, when used properly, will meet the cleanliness requirements of aerospace hardware and processes. The objective is to limit contamination due to the deposition of particulate and molecular contaminants on flight hardware surfaces. 1.2 One cleanliness classification of a facility is the airborne particle concentrations in accordance with ISO 14644-1 and 14644-2. Airborne particle concentrations in accordance with FED-STD-209E are included for reference. This simple classification is inadequate to describe a facility that will support the assembly and integration of spacecraft. The extended duration of hardware exposure during fabrication and testing, the sensitivity of the hardware to hydrocarbons and other molecular contaminants, and the changing requirements during ...

The operation of post-irradiation examination facility

International Nuclear Information System (INIS)

Kim, Eun Ka; Min, Duk Ki; Lee, Young Kil

1994-12-01

The operation of post-irradiation examination facility was performed as follow. HVAC and pool water treatment system were continuously operated, and radiation monitoring in PIE facility has been carried out to maintain the facility safely. Inspection of the fuel assembly (F02) transported from Kori Unit 1 was performed in pool, and fuel rods extracted from the fuel assembly (J44) of Kori Unit 2 NPP were examined in hot cell. A part of deteriorated pipe line of drinking water was exchanged for stainless steel pipe to prevent leaking accidents. Halon gas system was also installed in the exhausting blower room for fire fighting. And IAEA inspection camera for safeguard of nuclear materials was fixed at the wall in pool area. Radiation monitoring system were improved to display the area radioactive value at CRT monitor in health physics control room. And automatic check system for battery and emergency diesel generator was developed to measure the voltage and current of them. The performance test of oxide thickness measuring device installed in hot cell for irradiated fuel rod and improvement of the device were performed, and good measuring results using standard sample were obtained. The safeguard inspection of nuclear materials and operation inspection of the facility were carried out through the annual operation inspection, quarterly IAEA inspection and quality assurance auditing. 26 tabs., 43 figs., 14 refs. (Author) .new

Tritium Systems Test Assembly operator training program

International Nuclear Information System (INIS)

Kerstiens, F.L.

1985-01-01

Proper operator training is needed to help ensure the safe operation of fusion facilities by personnel who are qualified to carry out their assigned responsibilities. Operators control and monitor the Tritium Systems Test Assembly (TSTA) during normal, emergency, and maintenance phases. Their performance is critical both to operational safety, assuring no release of tritium to the atmosphere, and to the successful simulation of the fusion reaction progress. Through proper training we are helping assure that TSTA facility operators perform their assignments in a safe and efficient manner and that the operators maintain high levels of operational proficiency through continuing training, retraining, requalification, and recertification

Plutonium assemblies in reload 1 of the Dodewaard Reactor

International Nuclear Information System (INIS)

Bairiot, H.; Deramaix, P.; Vandenberg, C.; Leenders, L.; Mostert, P.

1977-01-01

Since 1963, Belgonucleaire has been developing the design of plutonium assemblies of the island type (i.e., plutonium rods inserted in the control zone of the assembly and enriched uranium rods at the periphery) for light water reactors. The application to boiling water reactors (BWRs) led to the introduction, in April 1971, of two prototype plutonium island assemblies in the Dodewaard BWR (The Netherlands): Those assemblies incorporating plutonium in 42 percent of the rods are interchangeable with standard uranium assemblies of the same reload. Their design, which had to meet these criteria, was performed using the routine order in use at Belgonucleaire; experimental checks included a mock-up configuration simulated in the VENUS critical facility at Mol and open-vessel cold critical experiments performed in the Dodewaard core. The pelleted plutonium rods were fabricated and controlled by Belgonucleaire following the manufacturing procedures developed at the production plant. In one of the assemblies, three vibrated plutonium fuel rods with a lower fuel density were introduced in the three most highly rated positions to reduce the power rating. Those plutonium assemblies experienced peak pellet ratings up to 535 W/cm and were discharged in April 1974 after having reached a mean burnup of approximately 21,000 MWd/MT. In-core instrumentation during operation, visual examinations, and reactivity substitution experiments during reactor shutdown did not indicate any special feature for those assemblies compared to the standard uranium assemblies, thereby demonstrating their interchangeability

Modeling the fundamental characteristics and processes of the spacecraft functioning

Science.gov (United States)

Bazhenov, V. I.; Osin, M. I.; Zakharov, Y. V.

1986-01-01

The fundamental aspects of modeling of spacecraft characteristics by using computing means are considered. Particular attention is devoted to the design studies, the description of physical appearance of the spacecraft, and simulated modeling of spacecraft systems. The fundamental questions of organizing the on-the-ground spacecraft testing and the methods of mathematical modeling were presented.

Spacecraft Dynamics Should be Considered in Kalman Filter Attitude Estimation

Science.gov (United States)

Yang, Yaguang; Zhou, Zhiqiang

2016-01-01

Kalman filter based spacecraft attitude estimation has been used in some high-profile missions and has been widely discussed in literature. While some models in spacecraft attitude estimation include spacecraft dynamics, most do not. To our best knowledge, there is no comparison on which model is a better choice. In this paper, we discuss the reasons why spacecraft dynamics should be considered in the Kalman filter based spacecraft attitude estimation problem. We also propose a reduced quaternion spacecraft dynamics model which admits additive noise. Geometry of the reduced quaternion model and the additive noise are discussed. This treatment is more elegant in mathematics and easier in computation. We use some simulation example to verify our claims.

The application of Cold Atmospheric Plasma (CAP) for the sterilisation of spacecraft materials

Science.gov (United States)

Rettberg, Petra; Barczyk, Simon; Morfill, Gregor; Thomas, Hubertus; Satoshi Shimizu, .; Shimizu, Tetsuji; Klaempfl, Tobias

2012-07-01

Plasma, oft called the fourth state of matter after solid, liquid and gas, is defined by its ionized state. Ionization can be induced by different means, such as a strong electromagnetic field applied with a microwave generator. The concentration and composition of reactive atoms and molecules produced in Cold Atmospheric Plasma (CAP) depends on the gases used, the gas flow, the power applied, the humidity level etc.. In medicine, low-temperature plasma is already used for the sterilization of surgical instruments, implants and packaging materials as plasma works at the atomic level and is able to reach all surfaces, even the interior of small hollow items like needles. Its ability to sterilise is due to the generation of biologically active bactericidal agents, such as free radicals and UV radiation. In the project PLASMA-DECON (DLR/BMWi support code 50JR1005) a prototype of a device for sterilising spacecraft material and components was built based on the surface micro-discharge (SMD) plasma technology. The produced plasma species are directed into a closed chamber which contains the parts that need to be sterilised. To test the inactivation efficiency of this new device bacterial spores were used as model organisms because in the COSPAR Planetary Protection Policy all bioburden constraints are defined with respect to the number of spores (and other heat-tolerant aerobic microorganisms). Spores from different Bacillus species and strains, i.e. wildtype strains from culture collections and isolates from spacecraft assembly cleanrooms, were dried on three different spacecraft relevant materials and exposed to CAP. The specificity, linearity, precision, and effective range of the device was investigated. From the results obtained it can be concluded that the application of CAP proved to be a suitable method for bioburden reduction / sterilisation in the frame of planetary protection measures and the design of a larger plasma device is planned in the future.

Spacecraft Multiple Array Communication System Performance Analysis

Science.gov (United States)

Hwu, Shian U.; Desilva, Kanishka; Sham, Catherine C.

2010-01-01

The Communication Systems Simulation Laboratory (CSSL) at the NASA Johnson Space Center is tasked to perform spacecraft and ground network communication system simulations, design validation, and performance verification. The CSSL has developed simulation tools that model spacecraft communication systems and the space and ground environment in which the tools operate. In this paper, a spacecraft communication system with multiple arrays is simulated. Multiple array combined technique is used to increase the radio frequency coverage and data rate performance. The technique is to achieve phase coherence among the phased arrays to combine the signals at the targeting receiver constructively. There are many technical challenges in spacecraft integration with a high transmit power communication system. The array combining technique can improve the communication system data rate and coverage performances without increasing the system transmit power requirements. Example simulation results indicate significant performance improvement can be achieved with phase coherence implementation.

Spacecraft Swarm Coordination and Planning Tool, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Fractionated spacecraft architectures to distribute mission performance from a single, monolithic satellite across large number of smaller spacecraft, for missions...

A facile prestrain-stick-release assembly of stretchable supercapacitors based on highly stretchable and sticky hydrogel electrolyte

Science.gov (United States)

Tang, Qianqiu; Chen, Mingming; Wang, Gengchao; Bao, Hua; Saha, Petr

2015-06-01

A facile prestrain-stick-release assembly strategy for the stretchable supercapacitor device is developed based on a novel Na2SO4-aPUA/PAAM hydrogel electrolyte, saving the stretchable rubber base conventionally used. The Na2SO4-aPUA/PAAM hydrogel electrolyte exhibits high stretchability (>1000%), electrical conductivity (0.036 S cm-1) and stickiness. Due to the unique features of the hydrogel electrolyte, the carbon nanotube@MnO2 film electrodes can be firmly stuck to two sides of the prestrained hydrogel electrolyte. Then, by releasing the hydrogel electrolyte, homogenous buckles are formed for the film electrodes to get a full stretchable supercapacitor device. Besides, the high stickiness of the hydrogel electrolyte ensures its strong adhesion with the film electrodes, facilitating ion and electronic transfer of the supercapacitor. As a result, excellent electrochemical performance is achieved with the specific capacitance of 478.6 mF cm-2 at 0.5 mA cm-2 (corresponding to 201.1 F g-1) and capacitance retention of 91.5% after 3000 charging-discharging cycles under 150% strain, which is the best for the stretchable supercapacitors.

Attitude Estimation in Fractionated Spacecraft Cluster Systems

Science.gov (United States)

Hadaegh, Fred Y.; Blackmore, James C.

2011-01-01

An attitude estimation was examined in fractioned free-flying spacecraft. Instead of a single, monolithic spacecraft, a fractionated free-flying spacecraft uses multiple spacecraft modules. These modules are connected only through wireless communication links and, potentially, wireless power links. The key advantage of this concept is the ability to respond to uncertainty. For example, if a single spacecraft module in the cluster fails, a new one can be launched at a lower cost and risk than would be incurred with onorbit servicing or replacement of the monolithic spacecraft. In order to create such a system, however, it is essential to know what the navigation capabilities of the fractionated system are as a function of the capabilities of the individual modules, and to have an algorithm that can perform estimation of the attitudes and relative positions of the modules with fractionated sensing capabilities. Looking specifically at fractionated attitude estimation with startrackers and optical relative attitude sensors, a set of mathematical tools has been developed that specify the set of sensors necessary to ensure that the attitude of the entire cluster ( cluster attitude ) can be observed. Also developed was a navigation filter that can estimate the cluster attitude if these conditions are satisfied. Each module in the cluster may have either a startracker, a relative attitude sensor, or both. An extended Kalman filter can be used to estimate the attitude of all modules. A range of estimation performances can be achieved depending on the sensors used and the topology of the sensing network.

Critical factors for assembling a high volume of DNA barcodes

Science.gov (United States)

Hajibabaei, Mehrdad; deWaard, Jeremy R; Ivanova, Natalia V; Ratnasingham, Sujeevan; Dooh, Robert T; Kirk, Stephanie L; Mackie, Paula M; Hebert, Paul D.N

2005-01-01

Large-scale DNA barcoding projects are now moving toward activation while the creation of a comprehensive barcode library for eukaryotes will ultimately require the acquisition of some 100 million barcodes. To satisfy this need, analytical facilities must adopt protocols that can support the rapid, cost-effective assembly of barcodes. In this paper we discuss the prospects for establishing high volume DNA barcoding facilities by evaluating key steps in the analytical chain from specimens to barcodes. Alliances with members of the taxonomic community represent the most effective strategy for provisioning the analytical chain with specimens. The optimal protocols for DNA extraction and subsequent PCR amplification of the barcode region depend strongly on their condition, but production targets of 100K barcode records per year are now feasible for facilities working with compliant specimens. The analysis of museum collections is currently challenging, but PCR cocktails that combine polymerases with repair enzyme(s) promise future success. Barcode analysis is already a cost-effective option for species identification in some situations and this will increasingly be the case as reference libraries are assembled and analytical protocols are simplified. PMID:16214753

The forced flow high field test facility SULTAN

International Nuclear Information System (INIS)

Horvath, I.; Vecsey, G.; Weymuth, P.

1984-01-01

The construction of the 8 Tesla, 1 m bore Test Facility SULTAN - I, a common action of ENEA (I-Frascati), ECN (NL-Petten) and SIN (CH-Villigen), is completed. Results on assembly, cooldown and the first operation of the whole system are presented. The SULTAN facility provides a wide range of capability of parameter variations (field, current, cooling) for the investigation of steady state performance and stability of technical superconductors unders nominal and limiting conditions

Mesh Network Architecture for Enabling Inter-Spacecraft Communication

Science.gov (United States)

Becker, Christopher; Merrill, Garrick

2017-01-01

To enable communication between spacecraft operating in a formation or small constellation, a mesh network architecture was developed and tested using a time division multiple access (TDMA) communication scheme. The network is designed to allow for the exchange of telemetry and other data between spacecraft to enable collaboration between small spacecraft. The system uses a peer-to-peer topology with no central router, so that it does not have a single point of failure. The mesh network is dynamically configurable to allow for addition and subtraction of new spacecraft into the communication network. Flight testing was performed using an unmanned aerial system (UAS) formation acting as a spacecraft analogue and providing a stressing environment to prove mesh network performance. The mesh network was primarily devised to provide low latency, high frequency communication but is flexible and can also be configured to provide higher bandwidth for applications desiring high data throughput. The network includes a relay functionality that extends the maximum range between spacecraft in the network by relaying data from node to node. The mesh network control is implemented completely in software making it hardware agnostic, thereby allowing it to function with a wide variety of existing radios and computing platforms..

Airborne particulate matter in spacecraft

Science.gov (United States)

1988-01-01

Acceptability limits and sampling and monitoring strategies for airborne particles in spacecraft were considered. Based on instances of eye and respiratory tract irritation reported by Shuttle flight crews, the following acceptability limits for airborne particles were recommended: for flights of 1 week or less duration (1 mg/cu m for particles less than 10 microns in aerodynamic diameter (AD) plus 1 mg/cu m for particles 10 to 100 microns in AD); and for flights greater than 1 week and up to 6 months in duration (0.2 mg/cu m for particles less than 10 microns in AD plus 0.2 mg/cu m for particles 10 to 100 microns in AD. These numerical limits were recommended to aid in spacecraft atmosphere design which should aim at particulate levels that are a low as reasonably achievable. Sampling of spacecraft atmospheres for particles should include size-fractionated samples of 0 to 10, 10 to 100, and greater than 100 micron particles for mass concentration measurement and elementary chemical analysis by nondestructive analysis techniques. Morphological and chemical analyses of single particles should also be made to aid in identifying airborne particulate sources. Air cleaning systems based on inertial collection principles and fine particle collection devices based on electrostatic precipitation and filtration should be considered for incorporation into spacecraft air circulation systems. It was also recommended that research be carried out in space in the areas of health effects and particle characterization.

Fifty-one years of Los Alamos Spacecraft

Energy Technology Data Exchange (ETDEWEB)

Fenimore, Edward E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2014-09-04

From 1963 to 2014, the Los Alamos National Laboratory was involved in at least 233 spacecraft. There are probably only one or two institutions in the world that have been involved in so many spacecraft. Los Alamos space exploration started with the Vela satellites for nuclear test detection, but soon expanded to ionospheric research (mostly barium releases), radioisotope thermoelectric generators, solar physics, solar wind, magnetospheres, astrophysics, national security, planetary physics, earth resources, radio propagation in the ionosphere, and cubesats. Here, we present a list of the spacecraft, their purpose, and their launch dates for use during RocketFest

Training for spacecraft technical analysts

Science.gov (United States)

Ayres, Thomas J.; Bryant, Larry

1989-01-01

Deep space missions such as Voyager rely upon a large team of expert analysts who monitor activity in the various engineering subsystems of the spacecraft and plan operations. Senior teammembers generally come from the spacecraft designers, and new analysts receive on-the-job training. Neither of these methods will suffice for the creation of a new team in the middle of a mission, which may be the situation during the Magellan mission. New approaches are recommended, including electronic documentation, explicit cognitive modeling, and coached practice with archived data.

Predicting Chiral Nanostructures, Lattices and Superlattices in Complex Multicomponent Nanoparticle Self-Assembly

KAUST Repository

Hur, Kahyun; Hennig, Richard G.; Escobedo, Fernando A.; Wiesner, Ulrich

2012-01-01

"Bottom up" type nanoparticle (NP) self-assembly is expected to provide facile routes to nanostructured materials for various, for example, energy related, applications. Despite progress in simulations and theories, structure prediction of self

Low power arcjet system spacecraft impacts

Science.gov (United States)

Pencil, Eric J.; Sarmiento, Charles J.; Lichtin, D. A.; Palchefsky, J. W.; Bogorad, A. L.

1993-01-01

Potential plume contamination of spacecraft surfaces was investigated by positioning spacecraft material samples relative to an arcjet thruster. Samples in the simulated solar array region were exposed to the cold gas arcjet plume for 40 hrs to address concerns about contamination by backstreaming diffusion pump oil. Except for one sample, no significant changes were measured in absorptance and emittance within experimental error. Concerns about surface property degradation due to electrostatic discharges led to the investigation of the discharge phenomenon of charged samples during arcjet ignition. Short duration exposure of charged samples demonstrated that potential differences are consistently and completely eliminated within the first second of exposure to a weakly ionized plume. The spark discharge mechanism was not the discharge phenomenon. The results suggest that the arcjet could act as a charge control device on spacecraft.

Multi-spacecraft observations of solar hard X-ray bursts

International Nuclear Information System (INIS)

Kane, S.R.

1981-01-01

The role of multi-spacecraft observations in solar flare research is examined from the point of view of solar hard X-ray bursts and their implications with respect to models of the impulsive phase. Multi-spacecraft measurements provide a stereoscopic view of the flare region, and hence represent the only direct method of measuring directivity of X-rays. In absence of hard X-ray imaging instruments with high spatial and temporal resolution, multi-spacecraft measurements provide the only means of determining the radial (vertical) structure of the hard X-ray source. This potential of the multi-spacecraft observations is illustrated with an analysis of the presently available observations of solar hard X-ray bursts made simultaneously by two or more of the following spacecraft: International Sun Earth Explorer-3 (ISEE-3), Pioneer Venus Orbiter (PVO), Helios-B and High Energy Astrophysical Observatory-A (HEAO-A). In particular, some conclusions have been drawn about the spatial structure and directivity of 50-100 keV X-rays from impulsive flares. Desirable features of future multi-spacecraft missions are briefly discussed followed by a short description of the hard X-ray experiment on the International Solar Polar Mission which has been planned specifically for multi-spacecraft observations of the Sun. (orig.)

Multiple spacecraft observations of interplanetary shocks Four spacecraft determination of shock normals

Science.gov (United States)

Russell, C. T.; Mellott, M. M.; Smith, E. J.; King, J. H.

1983-01-01

ISEE 1, 2, 3, IMP 8, and Prognoz 7 observations of interplanetary shocks in 1978 and 1979 provide five instances where a single shock is observed by four spacecraft. These observations are used to determine best-fit normals for these five shocks. In addition to providing well-documented shocks for future investigations these data allow the evaluation of the accuracy of several shock normal determination techniques. When the angle between upstream and downstream magnetic field is greater than 20 deg, magnetic coplanarity can be an accurate single spacecraft method. However, no technique based solely on the magnetic measurements at one or multiple sites was universally accurate. Thus, the use of overdetermined shock normal solutions, utilizing plasma measurements, separation vectors, and time delays together with magnetic constraints, is recommended whenever possible.

Standardized spacecraft: a methodology for decision making. AMS report No. 1199

International Nuclear Information System (INIS)

Greenberg, J.S.; Nichols, R.A.

1974-01-01

As the space program matures, more and more attention is being focused on ways to reduce the costs of performing space missions. Standardization has been suggested as a way of providing cost reductions. The question of standardization at the system level, in particular, the question of the desirability of spacecraft standardization for geocentric space missions is addressed. The spacecraft is considered to be a bus upon which mission oriented equipment, the payload, is mounted. Three basic questions are considered: (1) is spacecraft standardization economically desirable; (2) if spacecraft standardization is economically desirable, what standardized spacecraft configuration or mix of configurations and technologies should be developed; and (3) if standardized spacecraft are to be developed, what power levels should they be designed for. A methodology which has been developed and which is necessary to follow if the above questions are to be answered and informed decisions made relative to spacecraft standardization is described. To illustrate the decision making problems and the need for the developed methodology and the data requirements, typical standardized spacecraft have been considered. Both standardized solar and nuclear-powered spacecraft and mission specialized spacecraft have been conceptualized and performance and cost estimates have been made. These estimates are not considered to be of sufficient accuracy to allow decisions regarding spacecraft mix and power levels to be made at this time. The estimates are deemed of sufficient accuracy so as to demonstrate the desirability of spacecraft standardization and the methodology (as well as the need for the methodology) which is necessary to decide upon the best mix of standardized spacecraft and their design power levels. (U.S.)

Spacecraft Material Outgassing Data

Data.gov (United States)

National Aeronautics and Space Administration — This compilation of outgassing data of materials intended for spacecraft use were obtained at the Goddard Space Flight Center (GSFC), utilizing equipment developed...

EUROFAB: fabrication of four MOX lead tests assemblies for the US DOE

International Nuclear Information System (INIS)

Jean-Pierre Bariteau

2006-01-01

In a multilateral agreement, the United States (US) and the Russian Federation agreed to reduce their respective weapons stockpiles by each country disposing of 34 tons of military origin plutonium. On behalf of the US government, the Department of Energy contracted with Duke, COGEMA, Stone and Webster (DCS) to design a Mixed Oxide Fuel Fabrication facility (MFFF) which would be built and operated at the DOE Savannah River Site near Aiken, South Carolina. This plant will transform the US excess weapons stockpile into MOX fuel, which will be used it in existing domestic commercial power reactors. The MFFF is based on a replication of AREVA existing facilities (La Hague for Pu polishing and Melox for MOX fabrication). In parallel with the design, construction and startup of the MFFF facility, DOE commissioned fabrication and irradiation of 4 lead test assemblies in one of the Mission Reactors to assist in obtaining NRC approval for MOX fuel loading in US NPPs prior to the production phase of the MFFF facility. This program was named 'EUROFAB', since fabrication had to be made in Europe because no facility implementing the MFFF technology was existing in the USA. The COGEMA Recycling Business unit transmitted a bid to DCS in April 2003, which proposed to perform Eurofab fabrication in its Cadarache (pellets and rods) and Melox (assembly mounting) facilities. In August 2003, the decision was made by DCS, on behalf of the DOE, to award the EUROFAB fabrication contract to COGEMA. (author)

The Hayabusa Curation Facility at Johnson Space Center

Science.gov (United States)

Zolensky, M.; Bastien, R.; McCann, B.; Frank, D.; Gonzalez, C.; Rodriguez, M.

2013-01-01

The Japan Aerospace Exploration Agency (JAXA) Hayabusa spacecraft made contact with the asteroid 25143 Itokawa and collected regolith dust from Muses Sea region of smooth terrain [1]. The spacecraft returned to Earth with more than 10,000 grains ranging in size from just over 300 µm to less than 10 µm [2, 3]. These grains represent the only collection of material returned from an asteroid by a spacecraft. As part of the joint agreement between JAXA and NASA for the mission, 10% of the Hayabusa grains are being transferred to NASA for parallel curation and allocation. In order to properly receive process and curate these samples, a new curation facility was established at Johnson Space Center (JSC). Since the Hayabusa samples within the JAXA curation facility have been stored free from exposure to terrestrial atmosphere and contamination [4], one of the goals of the new NASA curation facility was to continue this treatment. An existing lab space at JSC was transformed into a 120 sq.ft. ISO class 4 (equivalent to the original class 10 standard) clean room. Hayabusa samples are stored, observed, processed, and packaged for allocation inside a stainless steel glove box under dry N2. Construction of the clean laboratory was completed in 2012. Currently, 25 Itokawa particles are lodged in NASA's Hayabusa Lab. Special care has been taken during lab construction to remove or contain materials that may contribute contaminant particles in the same size range as the Hayabusa grains. Several witness plates of various materials are installed around the clean lab and within the glove box to permit characterization of local contaminants at regular intervals by SEM and mass spectrometry, and particle counts of the lab environment are frequently acquired. Of particular interest is anodized aluminum, which contains copious sub-mm grains of a multitude of different materials embedded in its upper surface. Unfortunately the use of anodized aluminum was necessary in the construction

High-Performance Fire Detector for Spacecraft, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The danger from fire aboard spacecraft is immediate with only moments for detection and suppression. Spacecraft are unique high-value systems where the cost of...

Electromagnetic Forces on a Relativistic Spacecraft in the Interstellar Medium

Energy Technology Data Exchange (ETDEWEB)

Hoang, Thiem [Korea Astronomy and Space Science Institute, Daejeon 34055 (Korea, Republic of); Loeb, Abraham, E-mail: thiemhoang@kasi.re.kr, E-mail: aloeb@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA (United States)

2017-10-10

A relativistic spacecraft of the type envisioned by the Breakthrough Starshot initiative will inevitably become charged through collisions with interstellar particles and UV photons. Interstellar magnetic fields would therefore deflect the trajectory of the spacecraft. We calculate the expected deflection for typical interstellar conditions. We also find that the charge distribution of the spacecraft is asymmetric, producing an electric dipole moment. The interaction between the moving electric dipole and the interstellar magnetic field is found to produce a large torque, which can result in fast oscillation of the spacecraft around the axis perpendicular to the direction of motion, with a period of ∼0.5 hr. We then study the spacecraft rotation arising from impulsive torques by dust bombardment. Finally, we discuss the effect of the spacecraft rotation and suggest several methods to mitigate it.

Autonomous Spacecraft Communication Interface for Load Planning

Science.gov (United States)

Dever, Timothy P.; May, Ryan D.; Morris, Paul H.

2014-01-01

Ground-based controllers can remain in continuous communication with spacecraft in low Earth orbit (LEO) with near-instantaneous communication speeds. This permits near real-time control of all of the core spacecraft systems by ground personnel. However, as NASA missions move beyond LEO, light-time communication delay issues, such as time lag and low bandwidth, will prohibit this type of operation. As missions become more distant, autonomous control of manned spacecraft will be required. The focus of this paper is the power subsystem. For present missions, controllers on the ground develop a complete schedule of power usage for all spacecraft components. This paper presents work currently underway at NASA to develop an architecture for an autonomous spacecraft, and focuses on the development of communication between the Mission Manager and the Autonomous Power Controller. These two systems must work together in order to plan future load use and respond to unanticipated plan deviations. Using a nominal spacecraft architecture and prototype versions of these two key components, a number of simulations are run under a variety of operational conditions, enabling development of content and format of the messages necessary to achieve the desired goals. The goals include negotiation of a load schedule that meets the global requirements (contained in the Mission Manager) and local power system requirements (contained in the Autonomous Power Controller), and communication of off-plan disturbances that arise while executing a negotiated plan. The message content is developed in two steps: first, a set of rapid-prototyping "paper" simulations are preformed; then the resultant optimized messages are codified for computer communication for use in automated testing.

Spacecraft Fire Safety Demonstration

Data.gov (United States)

National Aeronautics and Space Administration — The objective of the Spacecraft Fire Safety Demonstration project is to develop and conduct large-scale fire safety experiments on an International Space Station...

Conceptual Design of an Electric Sail Technology Demonstration Mission Spacecraft

Science.gov (United States)

Wiegmann, Bruce M.

2017-01-01

There is great interest in examining the outer planets of our solar system and Heliopause region (edge of Solar System) and beyond regions of interstellar space by both the Planetary and Heliophysics communities. These needs are well docu-mented in the recent National Academy of Sciences Decadal Surveys. There is significant interest in developing revolutionary propulsion techniques that will enable such Heliopause scientific missions to be completed within 10 to15 years of the launch date. One such enabling propulsion technique commonly known as Electric Sail (E-Sail) propulsion employs positively charged bare wire tethers that extend radially outward from a rotating spacecraft spinning at a rate of one revolution per hour. Around the positively charged bare-wire tethers, a Debye Sheath is created once positive voltage is applied. This sheath stands off of the bare wire tether at a sheath diameter that is proportional to the voltage in the wire coupled with the flux density of solar wind ions within the solar system (or the location of spacecraft in the solar system. The protons that are expended from the sun (solar wind) at 400 to 800 km/sec are electrostatically repelled away from these positively charged Debye sheaths and propulsive thrust is produced via the resulting momentum transfer. The amount of thrust produced is directly proportional to the total wire length. The Marshall Space Flight Center (MSFC) Electric Sail team is currently funded via a two year Phase II NASA Innovative Advanced Concepts (NIAC) awarded in July 2015. The team's current activities are: 1) Developing a Particle in Cell (PIC) numeric engineering model from the experimental data collected at MSFC's Solar Wind Facility on the interaction between simulated solar wind interaction with a charged bare wire that can be applied to a variety of missions, 2) The development of the necessary tether deployers and tethers to enable successful de-ployment of multiple, multi km length bare tethers

A generalized modal shock spectra method for spacecraft loads analysis. [internal loads in a spacecraft structure subjected to a dynamic launch environment

Science.gov (United States)

Trubert, M.; Salama, M.

1979-01-01

Unlike an earlier shock spectra approach, generalization permits an accurate elastic interaction between the spacecraft and launch vehicle to obtain accurate bounds on the spacecraft response and structural loads. In addition, the modal response from a previous launch vehicle transient analysis with or without a dummy spacecraft - is exploited to define a modal impulse as a simple idealization of the actual forcing function. The idealized modal forcing function is then used to derive explicit expressions for an estimate of the bound on the spacecraft structural response and forces. Greater accuracy is achieved with the present method over the earlier shock spectra, while saving much computational effort over the transient analysis.

Harnessing Thin-Film Continuous-Flow Assembly Lines.

Science.gov (United States)

Britton, Joshua; Castle, Jared W; Weiss, Gregory A; Raston, Colin L

2016-07-25

Inspired by nature's ability to construct complex molecules through sequential synthetic transformations, an assembly line synthesis of α-aminophosphonates has been developed. In this approach, simple starting materials are continuously fed through a thin-film reactor where the intermediates accrue molecular complexity as they progress through the flow system. Flow chemistry allows rapid multistep transformations to occur via reaction compartmentalization, an approach not amenable to using conventional flasks. Thin film processing can also access facile in situ solvent exchange to drive reaction efficiency, and through this method, α-aminophosphonate synthesis requires only 443 s residence time to produce 3.22 g h(-1) . Assembly-line synthesis allows unprecedented reaction flexibility and processing efficiency. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Operational Philosophy Concerning Manned Spacecraft Cabin Leaks

Science.gov (United States)

DeSimpelaere, Edward

2011-01-01

The last thirty years have seen the Space Shuttle as the prime United States spacecraft for manned spaceflight missions. Many lessons have been learned about spacecraft design and operation throughout these years. Over the next few decades, a large increase of manned spaceflight in the commercial sector is expected. This will result in the exposure of commercial crews and passengers to many of the same risks crews of the Space Shuttle have encountered. One of the more dire situations that can be encountered is the loss of pressure in the habitable volume of the spacecraft during on orbit operations. This is referred to as a cabin leak. This paper seeks to establish a general cabin leak response philosophy with the intent of educating future spacecraft designers and operators. After establishing a relative definition for a cabin leak, the paper covers general descriptions of detection equipment, detection methods, and general operational methods for management of a cabin leak. Subsequently, all these items are addressed from the perspective of the Space Shuttle Program, as this will be of the most value to future spacecraft due to similar operating profiles. Emphasis here is placed upon why and how these methods and philosophies have evolved to meet the Space Shuttle s needs. This includes the core ideas of: considerations of maintaining higher cabin pressures vs. lower cabin pressures, the pros and cons of a system designed to feed the leak with gas from pressurized tanks vs. using pressure suits to protect against lower cabin pressures, timeline and consumables constraints, re-entry considerations with leaks of unknown origin, and the impact the International Space Station (ISS) has had to the standard Space Shuttle cabin leak response philosophy. This last item in itself includes: procedural management differences, hardware considerations, additional capabilities due to the presence of the ISS and its resource, and ISS docking/undocking considerations with a

Safety analysis of the Los Alamos critical experiments facility

International Nuclear Information System (INIS)

Paxton, H.C.

1975-10-01

The safety of Pajarito Site critical assembly operations depends upon protection built into the facility, upon knowledgeable personnel, and upon good practice as defined by operating procedures and experimental plans. Distance, supplemented by shielding in some cases, would protect personnel against an extreme accident generating 10 19 fissions. During the facility's 28-year history, the direct cost of criticality accidents has translated to a risk of less than $200 per year

Report on operation of nuclear facilities in 1991

International Nuclear Information System (INIS)

1992-06-01

The Slovenian Nuclear Safety Administration (SNSA) prepared a report on nuclear safety in the republic of Slovenia in 1991 as part of its regular practice of reporting on its work to the Government and the National Assembly of the Republic of Slovenia. The report is divided into three thematic chapters covering the activities of the SNSA, the operation of nuclear facilities in Slovenia, the activity of international missions in Slovenia and the operation of nuclear facilities around the world.

Improving of spent fuel monitoring in condition of Slovak wet interim spent fuel storage facility

International Nuclear Information System (INIS)

Miklos, M.; Krsjak, V.; Bozik, M.; Vasina, D.

2008-01-01

Monitoring of WWER fuel assemblies condition in Slovakia is presented in the paper. The leak tightness results of fuel assemblies used in Slovak WWER units in last 20 years are analyzed. Good experiences with the 'Sipping system' are described. The Slovak wet interim spent fuel storage facility in NPP Jaslovske Bohunice was build and put in operation in 1986. Since 1999, leak tests of WWER-440 fuel assemblies are provided by special leak tightness detection system 'Sipping in Pool' delivered by Framatome-ANP facility with external heating for the precise detection of active specimens. Another system for monitoring of fuel assemblies condition was implemented in December 2006 under the name 'SVYPP-440'. First non-active tests started at February 2007 and are described in the paper. Although those systems seems to be very effective, the detection time of all fuel assemblies in one storage pool is too long (several months). Therefore, a new 'on-line' detection system, based on new sorbent KNiFC-PAN for effective 134 Cs and 137 Cs activity was developed. This sorbent was compared with another type of sorbent NIFSIL and results are presented. The design of this detection system and its possible application in the Slovak wet spent fuel storage facility is discussed. For completeness, the initial results of the new system are also presented. (authors)

Iodine Plasma (Electric Propulsion) Interaction with Spacecraft Materials

Science.gov (United States)

2016-12-28

Teflon (AGT5, Ag-FEP) Thermal control surface (radiator) Spacecraft Exposure Soda-lime glass (74% SiO2 , 13% Na2O, 8% CaO, 4% MgO, 1% other oxide... Glass Solar panel cover Spacecraft Exposure Buna-N (acrylonitrile butadiene rubber) Seals Iodine Feed System Carbon fiber composite (epoxy resin...Fe Propellant isolator Spacecraft Exposure Lanthanum Hexaboride, LaB6 Cathode emitter Inside Cathode Yes MACOR (46% SiO2 , 17% MgO, 16% Al2O3, 10

Final configuration with assembly assessment of the 100 kV high voltage bushing for the Indian test facility

International Nuclear Information System (INIS)

Sharma, Dheeraj Kumar; Shah, Sejal; Venkata Nagaraju, M.; Bandyopadhyay, Mainak; Rotti, Chandramouli; Chakraborty, Arun Kumar

2015-01-01

The Indian Test Facility (INTF) of Neutral Beam (NB) system is an Indian voluntary effort for the full characterization of the diagnostic neutral beam which is the part of ITER's neutral beam system. The design activities of INTF NB system are completed. The INTF High Voltage Bushing (HVB), which is one of the component of NB system, is designed to connect all the required feedlines, e.g. electrical busbars, RF co-axial lines, diagnostic lines and hydraulic and gas feed lines, carried by the transmission line from the HV deck to the Beam Source of NB system. It forms the primary vacuum boundary and provides 100 kV isolation for INTF beam operation. The entire feedlines pass through a metallic plate of HVB called Dished Head (DH) where all the feedlines converge. The overall diameter of DH is 847 mm which is governed by the diameter of the Porcelain insulator which is meant for 100 kV isolation. The effective diameter where all the feedlines converge at the dished head is ∼ 600 mm which is quite a challenge to accommodate 26 feedlines each of average diameter 60 mm. Electrical feedlines require Vacuum-Electrical feedthroughs for voltage isolation whereas water and gas lines are considered to be directly welded with the DH except one water line which requires 12 kV voltage isolation with respect to DH. For RF lines, different scheme is considered which includes separate Electrical Feedthrough and Vacuum Barrier. To provide connection to electrical cables of heaters and thermocouples, 4 numbers of multipin vacuum compatible electrical feedthroughs are provided which can accommodate ∼250 cables. Due to space constraints, Vacuum-Electrical Feedthroughs are considered to be welded with the DH and therefore they shall be of metal-ceramic-metal configuration to allow welding. To avoid undue loading on the ceramic part, the feedlines are supported additionally at DH using vacuum compatible and electrically insulating material. One more important aspect of the INTF

Experiments study on attitude coupling control method for flexible spacecraft

Science.gov (United States)

Wang, Jie; Li, Dongxu

2018-06-01

High pointing accuracy and stabilization are significant for spacecrafts to carry out Earth observing, laser communication and space exploration missions. However, when a spacecraft undergoes large angle maneuver, the excited elastic oscillation of flexible appendages, for instance, solar wing and onboard antenna, would downgrade the performance of the spacecraft platform. This paper proposes a coupling control method, which synthesizes the adaptive sliding mode controller and the positive position feedback (PPF) controller, to control the attitude and suppress the elastic vibration simultaneously. Because of its prominent performance for attitude tracking and stabilization, the proposed method is capable of slewing the flexible spacecraft with a large angle. Also, the method is robust to parametric uncertainties of the spacecraft model. Numerical simulations are carried out with a hub-plate system which undergoes a single-axis attitude maneuver. An attitude control testbed for the flexible spacecraft is established and experiments are conducted to validate the coupling control method. Both numerical and experimental results demonstrate that the method discussed above can effectively decrease the stabilization time and improve the attitude accuracy of the flexible spacecraft.

Conceptual development of a test facility for spent fuel management

Energy Technology Data Exchange (ETDEWEB)

Park, S.W.; Lee, H.H.; Lee, J.Y.; Lee, J.S.; Ro, S.G. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1997-12-31

Spent fuel management is an important issue for nuclear power program, requiring careful planning and implementation. With the wait-and-see policy on spent fuel management in Korea, research efforts are directed at KAERI to develop advanced technologies for safer and more efficient management of the accumulating spent fuels. In support of these research perspectives, a test facility of pilot scale is being developed with provisions for integral demonstration of a multitude of technical functions required for spent fuel management. The facility, baptized SMART (Spent fuel MAnagement technology Research and Test facility), is to be capable of handling full size assembly of spent PWR fuel (as well as CANDU fuel) with a maximum capacity of 10 MTU/y (about 24 assemblies of PWR type). Major functions of the facility are consolidation of spent PWR fuel assembly into a half-volume package and optionally transformation of the fuel rod into a fuel of CANDU type (called DUPIC). Objectives of these functions are to demonstrate volume reduction of spent fuel (for either longer-term dry storage or direct disposal ) in the former case and direct refabrication of the spent PWR fuel into CANDU-type DUPIC fuel for reuse in CANDU reactors in the latter case, respectively. In addition to these major functions, there are other associated technologies to be demonstrated : such as waste treatment, remote maintenance, safeguards, etc. As the facility is to demonstrate not only the functional processes but also the safety and efficiency of the test operations, engineering criteria equivalent to industrial standards are incorporated in the design concept. The hot cell structure enclosing the radioactive materials is configured in such way to maximize costs within the given functional and operational requirements. (author). 3 tabs., 4 figs.

Conceptual development of a test facility for spent fuel management

International Nuclear Information System (INIS)

Park, S.W.; Lee, H.H.; Lee, J.Y.; Lee, J.S.; Ro, S.G.

1997-01-01

Spent fuel management is an important issue for nuclear power program, requiring careful planning and implementation. With the wait-and-see policy on spent fuel management in Korea, research efforts are directed at KAERI to develop advanced technologies for safer and more efficient management of the accumulating spent fuels. In support of these research perspectives, a test facility of pilot scale is being developed with provisions for integral demonstration of a multitude of technical functions required for spent fuel management. The facility, baptized SMART (Spent fuel MAnagement technology Research and Test facility), is to be capable of handling full size assembly of spent PWR fuel (as well as CANDU fuel) with a maximum capacity of 10 MTU/y (about 24 assemblies of PWR type). Major functions of the facility are consolidation of spent PWR fuel assembly into a half-volume package and optionally transformation of the fuel rod into a fuel of CANDU type (called DUPIC). Objectives of these functions are to demonstrate volume reduction of spent fuel (for either longer-term dry storage or direct disposal ) in the former case and direct refabrication of the spent PWR fuel into CANDU-type DUPIC fuel for reuse in CANDU reactors in the latter case, respectively. In addition to these major functions, there are other associated technologies to be demonstrated : such as waste treatment, remote maintenance, safeguards, etc. As the facility is to demonstrate not only the functional processes but also the safety and efficiency of the test operations, engineering criteria equivalent to industrial standards are incorporated in the design concept. The hot cell structure enclosing the radioactive materials is configured in such way to maximize costs within the given functional and operational requirements. (author). 3 tabs., 4 figs

Conceptual study of dry storage method for spent fuel assemblies based on honeycomb concrete overpack (COP). Phase 1

International Nuclear Information System (INIS)

Hida, Yoshio; Hayashi, Shigeki; Katsuyama, Yoshiaki; Hashimoto, Hirohide; Murata, Takashi

2017-01-01

The amount of spent fuel assemblies currently stored in Japan is approximately 15,000 tU. Most of these are stored in storage pools, although dry storage method will be safer, as was revealed in the accident of the Fukushima Daiichi Nuclear Power Plant. In addition, Japan has established a national policy of the nuclear fuel cycle. All spent fuel assemblies are designated for reprocessing. However, the reprocessing plant in Japan is currently under regulatory review for compliance with newly established safety standards. Beyond this, shortfalls in its processing capacity mean interim storage facilities for spent fuel are required. The Tokyo Electric Power Company Holdings, Incorporated and the Japan Atomic Power Company are currently building an interim dry storage facility with a storage capacity of 5,000 tU in Aomori Prefecture, while Chubu Electric Power Company, Inc. is currently building a dry storage facility with a storage capacity of 400 tU in the Hamaoka Nuclear Power Station. These facilities consist of earthquake-resistant buildings and dry storage casks. Within the buildings, metal transportable storage casks loaded with spent fuel assemblies are placed vertically with spaces between the casks and supported by earthquake-proof measures that prevent toppling or other movement. These structures entail significant cost and construction efforts. At the Fukushima Daiichi Nuclear Power Plant, a temporary dry storage facility has been built within the premises to store spent fuel generated during decommissioning. Part of this facility is already in operation. Here, each metal cask containing spent fuel is mounted on an earthquake-resistant concrete mat, which is anchored to the ground. Each cask is enclosed in a concrete box for additional radiation shielding, and the casks are spaced at intervals. This approach requires a large plot of land. The dry storage method for spent fuel presented here does not require a building. The dry metal casks containing spent

Performance of silvered Teflon (trademark) thermal control blankets on spacecraft

Science.gov (United States)

Pippin, Gary; Stuckey, Wayne; Hemminger, Carol

1993-01-01

Silverized Teflon (Ag/FEP) is a widely used passive thermal control material for space applications. The material has a very low alpha/e ratio (less than 0.1) for low operating temperatures and is fabricated with various FEP thicknesses (as the Teflon thickness increases, the emittance increases). It is low outgassing and, because of its flexibility, can be applied around complex, curved shapes. Ag/FEP has achieved multiyear lifetimes under a variety of exposure conditions. This has been demonstrated by the Long Duration Exposure Facility (LDEF), Solar Max, Spacecraft Charging at High Altitudes (SCATHA), and other flight experiments. Ag/FEP material has been held in place on spacecraft by a variety of methods: mechanical clamping, direct adhesive bonding of tapes and sheets, and by Velcro(TM) tape adhesively bonded to back surfaces. On LDEF, for example, 5-mil blankets held by Velcro(TM) and clamping were used for thermal control over 3- by 4-ft areas on each of 17 trays. Adhesively bonded 2- and 5-mil sheets were used on other LDEF experiments, both for thermal control and as tape to hold other thermal control blankets in place. Performance data over extended time periods are available from a number of flights. The observed effects on optical properties, mechanical properties, and surface chemistry will be summarized in this paper. This leads to a discussion of performance life estimates and other design lessons for Ag/FEP thermal control material.

Microbiomes of the Dust Particles Collected from the International Space Station and Spacecraft Assembly Facilities

Data.gov (United States)

National Aeronautics and Space Administration — The safety of the International Space Station (ISS) crewmembers and maintenance of ISS hardware are the primary rationale for monitoring microorganisms in this...

Criticality safety evaluation report for FFTF 42% fuel assemblies

International Nuclear Information System (INIS)

Richard, R.F.

1997-01-01

An FFTF tritium/isotope production mission will require a new fuel supply. The reference design core will use a mixed oxide fuel nominally enriched to 40 wt% Pu. This enrichment is significantly higher than that of the standard Driver Fuel Assemblies used in past operations. Consequently, criticality safety for handling and storage of this fuel must be addressed. The purpose of this document is to begin the process by determining the minimum critical number for these new fuel assemblies in water, sodium and air. This analysis is preliminary and further work can be done to refine the results reported here. Analysis was initially done using 45 wt 5 PuO. Additionally, a preliminary assessment is done concerning storage of these fuel assemblies in Interim Decay Storage (IDS), Fuel Storage Facility (FSF), and Core Component Containers/Interim Storage Casks (CCC/ISC)

Development of a Solar Array Drive Assembly for CubeSat

Science.gov (United States)

Passaretti, Mike; Hayes, Ron

2010-01-01

Small satellites and in particular CubeSats, have increasingly become more viable as platforms for payloads typically requiring much larger bus structures. As advances in technology make payloads and instruments for space missions smaller, lighter and more power efficient, a niche market is emerging from the university community to perform rapidly developed, low-cost missions on very small spacecraft - micro, nano, and picosatellites. In just the last few years, imaging, biological and new technology demonstration missions have been either proposed or have flown using variations of the CubeSat structure as a basis. As these missions have become more complex, and the CubeSat standard has increased in both size (number of cubes) and mass, available power has become an issue. Body-mounted solar cells provide a minimal amount of power; deployable arrays improve on that baseline but are still limited. To truly achieve maximum power, deployed tracked arrays are necessary. To this end, Honeybee Robotics Spacecraft Mechanisms Corporation, along with MMA of Nederland Colorado, has developed a solar array drive assembly (SADA) and deployable solar arrays specifically for CubeSat missions. In this paper, we discuss the development of the SADA.

Flow analysis of HANARO flow simulated test facility

International Nuclear Information System (INIS)

Park, Yong-Chul; Cho, Yeong-Garp; Wu, Jong-Sub; Jun, Byung-Jin

2002-01-01

The HANARO, a multi-purpose research reactor of 30 MWth open-tank-in-pool type, has been under normal operation since its initial critical in February, 1995. Many experiments should be safely performed to activate the utilization of the NANARO. A flow simulated test facility is being developed for the endurance test of reactivity control units for extended life times and the verification of structural integrity of those experimental facilities prior to loading in the HANARO. This test facility is composed of three major parts; a half-core structure assembly, flow circulation system and support system. The half-core structure assembly is composed of plenum, grid plate, core channel with flow tubes, chimney and dummy pool. The flow channels are to be filled with flow orifices to simulate core channels. This test facility must simulate similar flow characteristics to the HANARO. This paper, therefore, describes an analytical analysis to study the flow behavior of the test facility. The computational flow analysis has been performed for the verification of flow structure and similarity of this test facility assuming that flow rates and pressure differences of the core channel are constant. The shapes of flow orifices were determined by the trial and error method based on the design requirements of core channel. The computer analysis program with standard k - ε turbulence model was applied to three-dimensional analysis. The results of flow simulation showed a similar flow characteristic with that of the HANARO and satisfied the design requirements of this test facility. The shape of flow orifices used in this numerical simulation can be adapted for manufacturing requirements. The flow rate and the pressure difference through core channel proved by this simulation can be used as the design requirements of the flow system. The analysis results will be verified with the results of the flow test after construction of the flow system. (author)

Aptamer-assembled nanomaterials for fluorescent sensing and imaging

Science.gov (United States)

Lu, Danqing; He, Lei; Zhang, Ge; Lv, Aiping; Wang, Ruowen; Zhang, Xiaobing; Tan, Weihong

2017-01-01

Aptamers, which are selected in vitro by a technology known as the systematic evolution of ligands by exponential enrichment (SELEX), represent a crucial recognition element in molecular sensing. With advantages such as good biocompatibility, facile functionalization, and special optical and physical properties, various nanomaterials can protect aptamers from enzymatic degradation and nonspecific binding in living systems and thus provide a preeminent platform for biochemical applications. Coupling aptamers with various nanomaterials offers many opportunities for developing highly sensitive and selective sensing systems. Here, we focus on the recent applications of aptamer-assembled nanomaterials in fluorescent sensing and imaging. Different types of nanomaterials are examined along with their advantages and disadvantages. Finally, we look toward the future of aptamer-assembled nanomaterials.

Spacecraft 3D Augmented Reality Mobile App

Science.gov (United States)

Hussey, Kevin J.; Doronila, Paul R.; Kumanchik, Brian E.; Chan, Evan G.; Ellison, Douglas J.; Boeck, Andrea; Moore, Justin M.

2013-01-01

The Spacecraft 3D application allows users to learn about and interact with iconic NASA missions in a new and immersive way using common mobile devices. Using Augmented Reality (AR) techniques to project 3D renditions of the mission spacecraft into real-world surroundings, users can interact with and learn about Curiosity, GRAIL, Cassini, and Voyager. Additional updates on future missions, animations, and information will be ongoing. Using a printed AR Target and camera on a mobile device, users can get up close with these robotic explorers, see how some move, and learn about these engineering feats, which are used to expand knowledge and understanding about space. The software receives input from the mobile device's camera to recognize the presence of an AR marker in the camera's field of view. It then displays a 3D rendition of the selected spacecraft in the user's physical surroundings, on the mobile device's screen, while it tracks the device's movement in relation to the physical position of the spacecraft's 3D image on the AR marker.

Treatment planning capability assessment of a beam shaping assembly for accelerator-based BNCT

International Nuclear Information System (INIS)

Herrera, M.S.; González, S.J.; Burlon, A.A.; Minsky, D.M.; Kreiner, A.J.

2011-01-01

Within the frame of an ongoing project to develop a folded Tandem-Electrostatic-Quadrupole accelerator facility for Accelerator-Based Boron Neutron Capture Therapy (AB-BNCT) a theoretical study was performed to assess the treatment planning capability of different configurations of an optimized beam shaping assembly for such a facility. In particular this study aims at evaluating treatment plans for a clinical case of Glioblastoma.

Space Station services and design features for users

Science.gov (United States)

Kurzhals, Peter R.; Mckinney, Royce L.

1987-01-01

The operational design features and services planned for the NASA Space Station will furnish, in addition to novel opportunities and facilities, lower costs through interface standardization and automation and faster access by means of computer-aided integration and control processes. By furnishing a basis for large-scale space exploitation, the Space Station will possess industrial production and operational services capabilities that may be used by the private sector for commercial ventures; it could also ultimately support lunar and planetary exploration spacecraft assembly and launch facilities.

Monte Carlo analyses of the source multiplication factor of the YALINA booster facility

Energy Technology Data Exchange (ETDEWEB)

Talamo, Alberto; Gohar, Y.; Kondev, F.; Aliberti, Gerardo [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Bolshinsky, I. [Idaho National Laboratory, P. O. Box 2528, Idaho Falls, Idaho 83403 (United States); Kiyavitskaya, Hanna; Bournos, Victor; Fokov, Yury; Routkovskaya, Christina; Serafimovich, Ivan [Joint Institute for Power and Nuclear Research-Sosny, National Academy of Sciences, Minsk, acad. Krasin, 99, 220109 (Belarus)

2008-07-01

The multiplication factor of a subcritical assembly is affected by the energy spectrum and spatial distribution of the neutron source. In a critical assembly, neutrons emerge from the fission reactions with an average energy of approx2 MeV; in a deuteron accelerator driven subcritical assembly, neutrons emerge from the fusion target with a fixed energy of 2.45 or 14.1 MeV, from the Deuterium-Deuterium (D-D) and Deuterium-Tritium (D-T) reactions respectively. This study aims at generating accurate neutronics models for the YALINA Booster facility, based on the use of different Monte Carlo neutron transport codes, at defining the facility key physical parameters, and at comparing the neutron multiplication factor for three different neutron sources: fission, D-D and D-T. The calculated values are compared with the experimental results. (authors)

Monte Carlo analyses of the source multiplication factor of the YALINA booster facility

International Nuclear Information System (INIS)

Talamo, Alberto; Gohar, Y.; Kondev, F.; Aliberti, Gerardo; Bolshinsky, I.; Kiyavitskaya, Hanna; Bournos, Victor; Fokov, Yury; Routkovskaya, Christina; Serafimovich, Ivan

2008-01-01

The multiplication factor of a subcritical assembly is affected by the energy spectrum and spatial distribution of the neutron source. In a critical assembly, neutrons emerge from the fission reactions with an average energy of ∼2 MeV; in a deuteron accelerator driven subcritical assembly, neutrons emerge from the fusion target with a fixed energy of 2.45 or 14.1 MeV, from the Deuterium-Deuterium (D-D) and Deuterium-Tritium (D-T) reactions respectively. This study aims at generating accurate neutronics models for the YALINA Booster facility, based on the use of different Monte Carlo neutron transport codes, at defining the facility key physical parameters, and at comparing the neutron multiplication factor for three different neutron sources: fission, D-D and D-T. The calculated values are compared with the experimental results. (authors)

Time maintenance system for the BMDO MSX spacecraft

Science.gov (United States)

Hermes, Martin J.

1994-01-01

The Johns Hopkins University Applied Physics Laboratory (APL) is responsible for designing and implementing a clock maintenance system for the Ballistic Missile Defense Organizations (BMDO) Midcourse Space Experiment (MSX) spacecraft. The MSX spacecraft has an on-board clock that will be used to control execution of time-dependent commands and to time tag all science and housekeeping data received from the spacecraft. MSX mission objectives have dictated that this spacecraft time, UTC(MSX), maintain a required accuracy with respect to UTC(USNO) of +/- 10 ms with a +/- 1 ms desired accuracy. APL's atomic time standards and the downlinked spacecraft time were used to develop a time maintenance system that will estimate the current MSX clock time offset during an APL pass and make estimates of the clock's drift and aging using the offset estimates from many passes. Using this information, the clock's accuracy will be maintained by uplinking periodic clock correction commands. The resulting time maintenance system is a combination of offset measurement, command/telemetry, and mission planning hardware and computing assets. All assets provide necessary inputs for deciding when corrections to the MSX spacecraft clock must be made to maintain its required accuracy without inhibiting other mission objectives. The MSX time maintenance system is described as a whole and the clock offset measurement subsystem, a unique combination of precision time maintenance and measurement hardware controlled by a Macintosh computer, is detailed. Simulations show that the system estimates the MSX clock offset to less than+/- 33 microseconds.

An Orbit Propagation Software for Mars Orbiting Spacecraft

Directory of Open Access Journals (Sweden)

Young-Joo Song

2004-12-01

Full Text Available An orbit propagation software for the Mars orbiting spacecraft has been developed and verified in preparations for the future Korean Mars missions. Dynamic model for Mars orbiting spacecraft has been studied, and Mars centered coordinate systems are utilized to express spacecraft state vectors. Coordinate corrections to the Mars centered coordinate system have been made to adjust the effects caused by Mars precession and nutation. After spacecraft enters Sphere of Influence (SOI of the Mars, the spacecraft experiences various perturbation effects as it approaches to Mars. Every possible perturbation effect is considered during integrations of spacecraft state vectors. The Mars50c gravity field model and the Mars-GRAM 2001 model are used to compute perturbation effects due to Mars gravity field and Mars atmospheric drag, respectively. To compute exact locations of other planets, JPL's DE405 ephemerides are used. Phobos and Deimos's ephemeris are computed using analytical method because their informations are not released with DE405. Mars Global Surveyor's mapping orbital data are used to verify the developed propagator performances. After one Martian day propagation (12 orbital periods, the results show about maximum ±5 meter errors, in every position state components(radial, cross-track and along-track, when compared to these from the Astrogator propagation in the Satellite Tool Kit. This result shows high reliability of the developed software which can be used to design near Mars missions for Korea, in future.

3D Display of Spacecraft Dynamics Using Real Telemetry

Directory of Open Access Journals (Sweden)

Sanguk Lee

2002-12-01

Full Text Available 3D display of spacecraft motion by using telemetry data received from satellite in real-time is described. Telemetry data are converted to the appropriate form for 3-D display by the real-time preprocessor. Stored playback telemetry data also can be processed for the display. 3D display of spacecraft motion by using real telemetry data provides intuitive comprehension of spacecraft dynamics.

Numerical Analysis of Magnetic Sail Spacecraft

International Nuclear Information System (INIS)

Sasaki, Daisuke; Yamakawa, Hiroshi; Usui, Hideyuki; Funaki, Ikkoh; Kojima, Hirotsugu

2008-01-01

To capture the kinetic energy of the solar wind by creating a large magnetosphere around the spacecraft, magneto-plasma sail injects a plasma jet into a strong magnetic field produced by an electromagnet onboard the spacecraft. The aim of this paper is to investigate the effect of the IMF (interplanetary magnetic field) on the magnetosphere of magneto-plasma sail. First, using an axi-symmetric two-dimensional MHD code, we numerically confirm the magnetic field inflation, and the formation of a magnetosphere by the interaction between the solar wind and the magnetic field. The expansion of an artificial magnetosphere by the plasma injection is then simulated, and we show that the magnetosphere is formed by the interaction between the solar wind and the magnetic field expanded by the plasma jet from the spacecraft. This simulation indicates the size of the artificial magnetosphere becomes smaller when applying the IMF.

The operation of post-irradiation examination facility

Energy Technology Data Exchange (ETDEWEB)

Kim, Eun Ka; Park, Kwang Jun; Lee, Won Sang [and others; Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1994-01-01

The operation and management of PIE facility was executed in 1993. An indigenous 16 x 16 PWR type fuel assembly (ID No. J44) which was discharged from Kori unit 2 power reactor was transported to KAERI`s PIE facility and in-pool nondestructive examination and hot cell examination for the fuel were carried out. Because the above-mentioned 16 x 16 fuel is different from 14 x 14 fuel in its size and array of fuel rods, several examination and handling equipment for the 16 x 16 type fuel were designed and fabricated. PIE facility was operated in normal condition with the periodical check and inspection of the devices. The filter housing on the roof hood in chemical analysis hot cell was modified mounting air pressure gauge to indicate the optimal filter exchanging time. The burst air heating coil plate and the broken blowing fan of the HVAC system were repaired. The defaced grand packing in pool water circulation pump was replaced with the mechanical seal to prevent the leakage from the pump shaft sealing. The radiation monitoring in the facility was carried out to maintain the safe working condition and several radiation monitors were repaired. Spare parts for the radiation monitoring system were prepared to maintain the facility safely. The performance test of the emergency electric power supply system including UPS, battery and diesel generator was carried out. Oxide layer thickness measuring device for the performance test. Several devices including spent fuel handling equipment for the 17 x 17 PWR type fuel assembly were designed and fabricated for the subsequent PIE of nuclear fuels. 35 tabs., 17 figs., 7 refs. (Author) .new.

Quick spacecraft charging primer

International Nuclear Information System (INIS)

Larsen, Brian Arthur

2014-01-01

This is a presentation in PDF format which is a quick spacecraft charging primer, meant to be used for program training. It goes into detail about charging physics, RBSP examples, and how to identify charging.

Research on intelligent power distribution system for spacecraft

Science.gov (United States)

Xia, Xiaodong; Wu, Jianju

2017-10-01

The power distribution system (PDS) mainly realizes the power distribution and management of the electrical load of the whole spacecraft, which is directly related to the success or failure of the mission, and hence is an important part of the spacecraft. In order to improve the reliability and intelligent degree of the PDS, and considering the function and composition of spacecraft power distribution system, this paper systematically expounds the design principle and method of the intelligent power distribution system based on SSPC, and provides the analysis and verification of the test data additionally.

Methodology of thermalhydraulic tests of fuel assemblies for WWER-1000

International Nuclear Information System (INIS)

Archipov, A.; Kolochko, V.N.

2001-01-01

At present 11 units with WWER-1000 are in operation in Ukraine. The NPPs are provided with nuclear fuel from Russia. The fuel assemblies are fabricated and delivered to Ukrainian NPPs from Russia. However the contemporary tendencies of nuclear energy development in the world assume a diversification of nuclear fuel vendors. Therefore the creation of the own nuclear fuel cycle of Ukraine is in mind in the strategy of nuclear energy development of Ukraine. As a part of the fuel assemblies fabrication process complex of the thermalhydraulic tests should be carried out to confirm design characteristics of the fuel assemblies before they are loaded in the reactor facility. The experimental basis and scientific infrastructure for the thermalhydraulic tests arrangement and realization of the programs and procedures for the core equipment examination are under consideration. (author)

Fuels and materials testing capabilities in Fast Flux Test Facility

International Nuclear Information System (INIS)

Baker, R.B.; Chastain, S.A.; Culley, G.E.; Ethridge, J.L.; Lovell, A.J.; Newland, D.J.; Pember, L.A.; Puigh, R.J.; Waltar, A.E.

1989-01-01

The Fast Flux Test Facility (FFTF) reactor, which started operating in 1982, is a 400 MWt sodium-cooled fast neutron reactor located in Hanford, Washington State, and operated by Westinghouse Hanford Co. under contract with U.S. Department of Energy. The reactor has a wide variety of functions for irradiation tests and special tests, and its major purpose is the irradiation of fuel and material for liquid metal reactor, nuclear reactor and space reactor projects. The review first describes major technical specifications and current conditions of the FFTF reactor. Then the plan for irradiation testing is outlined focusing on general features, fuel pin/assembly irradiation tests, and absorber irradiation tests. Assemblies for special tests include the material open test assembly (MOTA), fuel open test assembly (FOTA), closed loop in-reactor assembly (CLIRA), and other special fuel assemblies. An interim examination and maintenance cell (FFTF/IEM cell) and other hot cells are used for nondestructive/destructive tests and physical/mechanical properties test of material after irradiation. (N.K.)

The Use of Liquid Isopropyl Alcohol and Hydrogen Peroxide Gas Plasma to Biologically Decontaminate Spacecraft Electronics

Science.gov (United States)

Bonner, J. K.; Tudryn, Carissa D.; Choi, Sun J.; Eulogio, Sebastian E.; Roberts, Timothy J.; Tudryn, Carissa D.

2006-01-01

Legitimate concern exists regarding sending spacecraft and their associated hardware to solar system bodies where they could possibly contaminate the body's surface with terrestrial microorganisms. The NASA approved guidelines for sterilization as set forth in NPG 8020.12C, which is consistent with the biological contamination control objectives of the Committee on Space Research (COSPAR), recommends subjecting the spacecraft and its associated hardware to dry heat-a dry heat regimen that could potentially employ a temperature of 110(deg)C for up to 200 hours. Such a temperature exposure could prove detrimental to the spacecraft electronics. The stimulated growth of intermetallic compounds (IMCs) in metallic interconnects and/or thermal degradation of organic materials composing much of the hardware could take place over a prolonged temperature regimen. Such detrimental phenomena would almost certainly compromise the integrity and reliability of the electronics. Investigation of sterilization procedures in the medical field suggests that hydrogen peroxide (H202) gas plasma (HPGP) technology can effectively function as an alternative to heat sterilization, especially for heat-sensitive items. Treatment with isopropyl alcohol (IPA) in liquid form prior to exposure of the hardware to HPGP should also prove beneficial. Although IPA is not a sterilant, it is frequently used as a disinfectant because of its bactericidal properties. The use of IPA in electronics cleaning is widely recognized and has been utilized for many years with no adverse affects reported. In addition, IPA is the principal ingredient of the test fluid used in ionic contamination testers to assess the amount of ionic contamination found on the surfaces of printed wiring assemblies. This paper will set forth experimental data confirming the feasibility of the IPA/H202 approach to reach acceptable microbial reduction (MR) levels of spacecraft electronic hardware. In addition, a proposed process flow in

Flaw detection of welded joints in NPP equipment assembly

International Nuclear Information System (INIS)

Kesler, N.A.; Polevik, V.A.; Orlov, N.S.

1984-01-01

State of the art and prospects of development of ultrasonic and radiography testing of welded joints for quality used in NPP equipment assembly are considered. Recommendations are given on reducing the labour content with the use of these methods. Specifications for the developed facilities intended for automation and mechanization of the described quality control methods are presented

Power requirements for commercial communications spacecraft

Science.gov (United States)

Billerbeck, W. J.

1985-01-01

Historical data on commercial spacecraft power systems are presented and their power requirements to the growth of satellite communications channel usage are related. Some approaches for estimating future power requirements of this class of spacecraft through the year 2000 are proposed. The key technology drivers in satellite power systems are addressed. Several technological trends in such systems are described, focusing on the most useful areas for research and development of major subsystems, including solar arrays, energy storage, and power electronics equipment.

A Self-Assembling Protein Hydrogel Technology for Enzyme Incorporation onto Electrodes in Biofuel Cells

Science.gov (United States)

2015-10-26

an ordered 3-dimentional space. In the first stage, we constructed protein building blocks able to self-assemble into 3D protein hydrogel upon...Chem 23, 1891-1901 (2012). 26. Jung, S. & Yi, H. Facile Strategy for Protein Conjugation with Chitosan -Poly(ethylene glycol) Hybrid Microparticle...multiple enzymes in an ordered 3-dimentional space. In the first stage, we constructed protein building blocks able to self-assemble into 3D protein

Ice condenser testing facility and plans

International Nuclear Information System (INIS)

Kannberg, L.D.; Ross, B.A.; Eschbach, E.J.; Ligotke, M.W.

1987-01-01

A facility is being constructed to experimentally validate the ICEDF computer code. The code was developed to estimate the extent of fission product retention in the ice compartments of pressurized water reactor ice condenser containment systems during severe accidents. The design and construction of the facility is based on a test design that addresses the validation needs of the code for conditions typical of those expected to occur during severe pressurized water reactor accidents. Detailed facility design has followed completion of a test design (i.e., assembled test cases each involving a different set of aerosol and thermohydraulic flow conditions). The test design was developed with the aid of statistical test design software and was scrutinized for applicability with the aid of ICEDF simulations. The test facility will incorporate a small section of a prototypic ice condenser (e.g., a cross section comprising the equivalent of four 1-ft-diameter ice baskets to their full prototypic height of 48 ft). The development of the test design, the detailed facility design, and the construction progress are described in this paper

Modeling SMAP Spacecraft Attitude Control Estimation Error Using Signal Generation Model

Science.gov (United States)

Rizvi, Farheen

2016-01-01

Two ground simulation software are used to model the SMAP spacecraft dynamics. The CAST software uses a higher fidelity model than the ADAMS software. The ADAMS software models the spacecraft plant, controller and actuator models, and assumes a perfect sensor and estimator model. In this simulation study, the spacecraft dynamics results from the ADAMS software are used as CAST software is unavailable. The main source of spacecraft dynamics error in the higher fidelity CAST software is due to the estimation error. A signal generation model is developed to capture the effect of this estimation error in the overall spacecraft dynamics. Then, this signal generation model is included in the ADAMS software spacecraft dynamics estimate such that the results are similar to CAST. This signal generation model has similar characteristics mean, variance and power spectral density as the true CAST estimation error. In this way, ADAMS software can still be used while capturing the higher fidelity spacecraft dynamics modeling from CAST software.

Hierarchical nanostructures assembled from ultrathin Bi2WO6 nanoflakes and their visible-light induced photocatalytic property

International Nuclear Information System (INIS)

Wang, Xiong; Tian, Peng; Lin, Ying; Li, Li

2015-01-01

Graphical abstract: Hierarchical Bi 2 WO 6 nanostructures assembled from nanoflakes were successfully synthesized by a facile hydrothermal method. The excellent photocatalytic activity and recycling performance might be mainly ascribed to the unique hierarchical nanostructures and are expected to offer the nanostructures promising applications in the field of wastewater treatment. - Highlights: • Hierarchical Bi 2 WO 6 nanostructures assembled from nanoflakes were successfully synthesized by a facile hydrothermal method. • Visible-light-induced photocatalytic efficiency of the obtained nanoarchitectures was enhanced about 6 times. • A possible mechanism was proposed. - Abstract: With the aid of ethylene glycol and sodium dodecylbenzene sulfonate, the hierarchical Bi 2 WO 6 nanoarchitectures assembled from nanoflakes could be attained by a facile solvothermal method. The synthetic strategy is versatile and environmentally friendly and a plausible growth-assembly process was proposed for the formation of the hierarchical nanostructures. The visible-light-irradiated photocatalytic activity was estimated by the degradation of rhodamine B. Compared with the sample prepared by a solid-state reaction, the visible-light-induced photocatalytic efficiency of the nanostructures was enhanced about 6 times. The photocatalysis tests show that the nanostructures exhibit excellent photocatalytic activity and recycling performance, which were mainly ascribed to the unique hierarchical nanostructures and are expected to offer promising applications in the field of wastewater treatment

A Sampling Based Approach to Spacecraft Autonomous Maneuvering with Safety Specifications

Science.gov (United States)

Starek, Joseph A.; Barbee, Brent W.; Pavone, Marco

2015-01-01

This paper presents a methods for safe spacecraft autonomous maneuvering that leverages robotic motion-planning techniques to spacecraft control. Specifically the scenario we consider is an in-plan rendezvous of a chaser spacecraft in proximity to a target spacecraft at the origin of the Clohessy Wiltshire Hill frame. The trajectory for the chaser spacecraft is generated in a receding horizon fashion by executing a sampling based robotic motion planning algorithm name Fast Marching Trees (FMT) which efficiently grows a tree of trajectories over a set of probabillistically drawn samples in the state space. To enforce safety the tree is only grown over actively safe samples for which there exists a one-burn collision avoidance maneuver that circularizes the spacecraft orbit along a collision-free coasting arc and that can be executed under potential thrusters failures. The overall approach establishes a provably correct framework for the systematic encoding of safety specifications into the spacecraft trajectory generations process and appears amenable to real time implementation on orbit. Simulation results are presented for a two-fault tolerant spacecraft during autonomous approach to a single client in Low Earth Orbit.

Status and operational experience report of spent fuel storage facility in Kozloduy NPP for the period 1990 - 1994

Energy Technology Data Exchange (ETDEWEB)

Kalimanov, M [Kombinat Atomna Energetika, Kozloduj (Bulgaria)

1994-12-31

Spent Fuel Storage Facility (SFSF) of Kozloduy NPP is designed for a long-term storage of 4920 spent fuel assemblies which are generated by all units for ten year operational period. The assemblies are stored in SFSF after 3 year storage in the reactor cooling pool. The SFSF operational safety is ensured by a number of strictly followed regulations related to: arrangement of the assemblies and conditions at which they are stored; transportation of the assemblies to the facility; residual heat removal; quality of the water used in the storage pool; water temperature and level control. Two independent groups of experts have carried out investigations to study the building safety. Their reports have been considered and accepted by the council of the Ministry of Environment which was the final step in licensing the SFSF.

Effects of low heterogeneity in fast critical assemblies

International Nuclear Information System (INIS)

Belov, S.P.; Dulin, V.A.; Zhukov, A.V.; Kuzin, E.N.; Mozhaev, V.K.; Sitnikov, V.I.; Tsibulya, A.M.; Shapar', A.V.; Zayfert, E.; Kuntsman, B.; Khayntsel'man, B.

1989-01-01

The problem of the low heterogeneity of fast critical assemblies, which are used to simulate fast reactors that are under design, has begun to assume increasing importance as the errors in nuclear data and group constants decrease and the capabilities of design codes improve. The design of the fuel channels of the fast critical assemblies of a BFS differs from that of the fuel subassemblies of a power reactor. The principal difference is that critical assemblies have a more heterogeneous structure than a reactor core does. As a result, the effects of this heterogeneity turn out to be appreciable for a number of functionals. Of particular interest was the measurement of the main neutronic characteristics of a fast reactor in its actual design and in the mockup produced by using BFS facilities. The authors measured and calculated the most important functionals (the ratios of the average cross sections of the main absorbing and fissioning elements, etc.) for both a homogeneous medium (fuel assemblies) and a heterogeneous medium (slugs, tubes) of practically identical composition. The objective of this work was to compare the discrepancy between experiment and calculations for the central functionals in the homogeneous and heterogeneous cases after corrections. This is a check of the accuracy of the simulation of homogeneous cores in fast power reactors by using the tools of the BFS fast critical assembly

Software for Engineering Simulations of a Spacecraft

Science.gov (United States)

Shireman, Kirk; McSwain, Gene; McCormick, Bernell; Fardelos, Panayiotis

2005-01-01

Spacecraft Engineering Simulation II (SES II) is a C-language computer program for simulating diverse aspects of operation of a spacecraft characterized by either three or six degrees of freedom. A functional model in SES can include a trajectory flight plan; a submodel of a flight computer running navigational and flight-control software; and submodels of the environment, the dynamics of the spacecraft, and sensor inputs and outputs. SES II features a modular, object-oriented programming style. SES II supports event-based simulations, which, in turn, create an easily adaptable simulation environment in which many different types of trajectories can be simulated by use of the same software. The simulation output consists largely of flight data. SES II can be used to perform optimization and Monte Carlo dispersion simulations. It can also be used to perform simulations for multiple spacecraft. In addition to its generic simulation capabilities, SES offers special capabilities for space-shuttle simulations: for this purpose, it incorporates submodels of the space-shuttle dynamics and a C-language version of the guidance, navigation, and control components of the space-shuttle flight software.

Special Semaphore Scheme for UHF Spacecraft Communications

Science.gov (United States)

Butman, Stanley; Satorius, Edgar; Ilott, Peter

2006-01-01

A semaphore scheme has been devised to satisfy a requirement to enable ultrahigh- frequency (UHF) radio communication between a spacecraft descending from orbit to a landing on Mars and a spacecraft, in orbit about Mars, that relays communications between Earth and the lander spacecraft. There are also two subsidiary requirements: (1) to use UHF transceivers, built and qualified for operation aboard the spacecraft that operate with residual-carrier binary phase-shift-keying (BPSK) modulation at a selectable data rate of 8, 32, 128, or 256 kb/s; and (2) to enable low-rate signaling even when received signals become so weak as to prevent communication at the minimum BPSK rate of 8 kHz. The scheme involves exploitation of Manchester encoding, which is used in conjunction with residual-carrier modulation to aid the carrier-tracking loop. By choosing various sequences of 1s, 0s, or 1s alternating with 0s to be fed to the residual-carrier modulator, one would cause the modulator to generate sidebands at a fundamental frequency of 4 or 8 kHz and harmonics thereof. These sidebands would constitute the desired semaphores. In reception, the semaphores would be detected by a software demodulator.

Environmentally-induced discharge transient coupling to spacecraft

Science.gov (United States)

Viswanathan, R.; Barbay, G.; Stevens, N. J.

1985-01-01

The Hughes SCREENS (Space Craft Response to Environments of Space) technique was applied to generic spin and 3-axis stabilized spacecraft models. It involved the NASCAP modeling for surface charging and lumped element modeling for transients coupling into a spacecraft. A differential voltage between antenna and spun shelf of approx. 400 V and current of 12 A resulted from discharge at antenna for the spinner and approx. 3 kv and 0.3 A from a discharge at solar panels for the 3-axis stabilized Spacecraft. A typical interface circuit response was analyzed to show that the transients would couple into the Spacecraft System through ground points, which are most vulnerable. A compilation and review was performed on 15 years of available data from electron and ion current collection phenomena. Empirical models were developed to match data and compared with flight data of Pix-1 and Pix-2 mission. It was found that large space power systems would float negative and discharge if operated at or above 300 V. Several recommendations are given to improve the models and to apply them to large space systems.

Optical Property Requirements for Glasses, Ceramics and Plastics in Spacecraft Window Systems

Science.gov (United States)

Estes, Lynda

2011-01-01

This is a preliminary draft of a standard published by the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) that is intended to provide uniform window optical design requirements in support of the development of human-rated spaceflight hardware. The material covered in this standard is based on data from extensive testing by the Advanced Sensing and Optical Measurement Branch at NASA Langley Research Center, and compiled into requirements format by the NASA JSC Structural Engineering Division. At the time of this initial document release, a broader technical community has not reviewed this standard. The technical content of this standard is primarily based on the Constellation Program Orion Crew Exploration Vehicle Window Optical Properties Requirements, CxP 72407, Baseline. Unlike other optical requirements documents available for human rated spacecraft, this document includes requirements that ensure functionality for windows that contain glass/ceramic and/or plastic window substrate materials. These requirements were derived by measuring the optical properties of fused silica and aluminosilicate glass window assemblies and ensuring that the performance of any window assembly that includes a plastic pane or panes will meet the performance level of the all-glass assemblies. The resulting requirements are based upon the performance and parameter metrology testing of a variety of materials, including glass, transparent ceramics, acrylics, and polycarbonates. In general, these requirements are minimum specifications for each optical parameter in order to achieve the function specified for each functional category, A through D. Because acrylic materials perform at a higher level than polycarbonates in the optics regime, and CxP/Orion is planning to use acrylic in the Orion spacecraft, these requirements are based heavily on metrology from that material. As a result, two of the current Category D requirements for plastics are cited in

Development of a hardware-in-the-loop testbed to demonstrate multiple spacecraft operations in proximity

Science.gov (United States)

Eun, Youngho; Park, Sang-Young; Kim, Geuk-Nam

2018-06-01

This paper presents a new state-of-the-art ground-based hardware-in-the-loop test facility, which was developed to verify and demonstrate autonomous guidance, navigation, and control algorithms for space proximity operations and formation flying maneuvers. The test facility consists of two complete spaceflight simulators, an aluminum-based operational arena, and a set of infrared motion tracking cameras; thus, the testbed is capable of representing space activities under circumstances prevailing on the ground. The spaceflight simulators have a maximum of five-degree-of-freedom in a quasi-momentum-free environment, which is produced by a set of linear/hemispherical air-bearings and a horizontally leveled operational arena. The tracking system measures the real-time three-dimensional position and attitude to provide state variables to the agents. The design of the testbed is illustrated in detail for every element throughout the paper. The practical hardware characteristics of the active/passive measurement units and internal actuators are identified in detail from various perspectives. These experimental results support the successful development of the entire facility and enable us to implement and verify the spacecraft proximity operation strategy in the near future.

Nanosheet-Assembled ZnO Microflower Photocatalysts

Directory of Open Access Journals (Sweden)

Siwen Zhang

2014-01-01

Full Text Available Large scale ZnO microflowers assembled by numerous nanosheets are synthesized through a facile and effective hydrothermal route. The structure and morphology of the resultant products are characterized by X-ray diffraction (XRD and scanning electron microscope (SEM. Photocatalytic properties of the as-synthesized products are also investigated. The results demonstrate that eosin red aqueous solution can be degraded over 97% after 110 min under UV light irradiation. In addition, methyl orange (MO and Congo red (CR aqueous solution degradation experiments also are conducted in the same condition, respectively. It showed that nanosheet-assembled ZnO microflowers represent high photocatalytic activities with a degradation efficiency of 91% for CR with 90 min of irradiation and 90% for MO with 60 min of irradiation. The reported ZnO products may be promising candidates as the photocatalysts in waste water treatment.

Safeguards approach for conditioning facility for spent fuel

International Nuclear Information System (INIS)

Younkin, J.M.; Barham, M.; Moran, B.W.

1999-01-01

A safeguards approach has been developed for conditioning facilities associated with the final disposal of spent fuel in geologic repositories. The proposed approach is based on a generic conditioning facility incorporating common features of conditioning facility designs currently proposed. The generic facility includes a hot cell for consolidation of spent fuel pins and repackaging of spent fuel items such as assemblies and cans of pins. The consolidation process introduces safeguards concerns which have not previously been addressed in traditional safeguards approaches. In developing the safeguards approach, diversion of spent fuel was assessed in terms of potential target items, operational activities performed on the items, containment of the items, and concealment activities performed on the items. The combination of these factors defines the potential diversion pathways. Diversion pathways were identified for spent fuel pellets, pins, assemblies, canisters, and casks. Diversion activities provide for opportunities of detection along the diversion paths. Potential detection methods were identified at several levels of diversion activities. Detection methods can be implemented through safeguards measures. Safeguards measures were proposed for each of the primary safeguards techniques of design information verification (DIV), containment and surveillance (C/S), and material accountancy. Potential safeguards approaches were developed by selection of appropriate combinations of safeguards measures. For all candidate safeguards approaches, DIV is a fundamental component. Variations in the approaches are mainly in the degree of C/S measures and in the types and numbers of material accountancy verification measures. The candidate safeguards approaches were evaluated toward the goal of determining a model safeguards approach. This model approach is based on the integrated application of selected safeguards measures to use International Atomic Energy Agency resources

Structural Polymorphism in a Self-Assembled Tri-Aromatic Peptide System.

Science.gov (United States)

Brown, Noam; Lei, Jiangtao; Zhan, Chendi; Shimon, Linda J W; Adler-Abramovich, Lihi; Wei, Guanghong; Gazit, Ehud

2018-04-24

Self-assembly is a process of key importance in natural systems and in nanotechnology. Peptides are attractive building blocks due to their relative facile synthesis, biocompatibility, and other unique properties. Diphenylalanine (FF) and its derivatives are known to form nanostructures of various architectures and interesting and varied characteristics. The larger triphenylalanine peptide (FFF) was found to self-assemble as efficiently as FF, forming related but distinct architectures of plate-like and spherical nanostructures. Here, to understand the effect of triaromatic systems on the self-assembly process, we examined carboxybenzyl-protected diphenylalanine (z-FF) as a minimal model for such an arrangement. We explored different self-assembly conditions by changing solvent compositions and peptide concentrations, generating a phase diagram for the assemblies. We discovered that z-FF can form a variety of structures, including nanowires, fibers, nanospheres, and nanotoroids, the latter were previously observed only in considerably larger or co-assembly systems. Secondary structure analysis revealed that all assemblies possessed a β-sheet conformation. Additionally, in solvent combinations with high water ratios, z-FF formed rigid and self-healing hydrogels. X-ray crystallography revealed a "wishbone" structure, in which z-FF dimers are linked by hydrogen bonds mediated by methanol molecules, with a 2-fold screw symmetry along the c-axis. All-atom molecular dynamics (MD) simulations revealed conformations similar to the crystal structure. Coarse-grained MD simulated the assembly of the peptide into either fibers or spheres in different solvent systems, consistent with the experimental results. This work thus expands the building block library for the fabrication of nanostructures by peptide self-assembly.

LLNL Site plan for a MOX fuel lead assembly mission in support of surplus plutonium disposition

Energy Technology Data Exchange (ETDEWEB)

Bronson, M.C.

1997-10-01

The principal facilities that LLNL would use to support a MOX Fuel Lead Assembly Mission are Building 332 and Building 334. Both of these buildings are within the security boundary known as the LLNL Superblock. Building 332 is the LLNL Plutonium Facility. As an operational plutonium facility, it has all the infrastructure and support services required for plutonium operations. The LLNL Plutonium Facility routinely handles kilogram quantities of plutonium and uranium. Currently, the building is limited to a plutonium inventory of 700 kilograms and a uranium inventory of 300 kilograms. Process rooms (excluding the vaults) are limited to an inventory of 20 kilograms per room. Ongoing operations include: receiving SSTS, material receipt, storage, metal machining and casting, welding, metal-to-oxide conversion, purification, molten salt operations, chlorination, oxide calcination, cold pressing and sintering, vitrification, encapsulation, chemical analysis, metallography and microprobe analysis, waste material processing, material accountability measurements, packaging, and material shipping. Building 334 is the Hardened Engineering Test Building. This building supports environmental and radiation measurements on encapsulated plutonium and uranium components. Other existing facilities that would be used to support a MOX Fuel Lead Assembly Mission include Building 335 for hardware receiving and storage and TRU and LLW waste storage and shipping facilities, and Building 331 or Building 241 for storage of depleted uranium.

LLNL Site plan for a MOX fuel lead assembly mission in support of surplus plutonium disposition

International Nuclear Information System (INIS)

Bronson, M.C.

1997-01-01

The principal facilities that LLNL would use to support a MOX Fuel Lead Assembly Mission are Building 332 and Building 334. Both of these buildings are within the security boundary known as the LLNL Superblock. Building 332 is the LLNL Plutonium Facility. As an operational plutonium facility, it has all the infrastructure and support services required for plutonium operations. The LLNL Plutonium Facility routinely handles kilogram quantities of plutonium and uranium. Currently, the building is limited to a plutonium inventory of 700 kilograms and a uranium inventory of 300 kilograms. Process rooms (excluding the vaults) are limited to an inventory of 20 kilograms per room. Ongoing operations include: receiving SSTS, material receipt, storage, metal machining and casting, welding, metal-to-oxide conversion, purification, molten salt operations, chlorination, oxide calcination, cold pressing and sintering, vitrification, encapsulation, chemical analysis, metallography and microprobe analysis, waste material processing, material accountability measurements, packaging, and material shipping. Building 334 is the Hardened Engineering Test Building. This building supports environmental and radiation measurements on encapsulated plutonium and uranium components. Other existing facilities that would be used to support a MOX Fuel Lead Assembly Mission include Building 335 for hardware receiving and storage and TRU and LLW waste storage and shipping facilities, and Building 331 or Building 241 for storage of depleted uranium

The single SNR fuel assembly container (ESBB) to transport unirradiated SNR 300 fuel assemblies

International Nuclear Information System (INIS)

Hilbert, F.; Hottenrott, G.

1998-01-01

In this paper a new type B(U) package design is presented. The Single SNR Fuel Assembly Container (ESBB) is designed for the transport and storage of a single SNR 300 fuel assembly. This package is the main component for the future interim storage of the fuel assemblies in heavy storage casks. Its benefits are that it is compatible with the Category I transport system of Nuclear Cargo + Service NCS) used in Germany and that it can be easily handled at the current storage locations as well as in an interim storage facility. In total 205 fuel assemblies are currently stored in Hanau, Germany and Dounreay, U.K. Former studies have shown, that heavy transport and storage casks can be handled there only with considerable efforts. But the required category I transport to an interim storage is not reasonably feasible. To overcome these problems the ESBB was designed. It consists of a stainless steel tube with welded bottom, a welded plug as closure system and shock absorbers 26 packages at maximum can be transported in one batch with the NCS security vehicle. The safety analysis shows that the package complies with IAEA 1996. Standard calculations methods and computer codes like HEATING 7.2 (Childs 1993) have been used for the analysis. Criticality safety assessment is based on conservative assumptions as required in IAEA 1996. Drop tests carried out by BAM will be used to verify the design. These tests are scheduled for mid 1998. For the validation of the design prototypes have already been manufactured. Handling tests show that the design complies with the requirements. Preliminary drop tests show that the certification drop tests will be passed positively. (authors)

The passive nondestructive assay of the plutonium content of spent-fuel assemblies from the BN-350 fast-breeder reactor in the city of Aqtau, Kazakhstan

CERN Document Server

Lestone, J P; Rennie, J A; Sprinkle, J K; Staples, P; Grimm, K N; Hill, R N; Cherradi, I; Islam, N; Koulikov, J; Starovich, Z

2002-01-01

The International Atomic Energy Agency is presently interested in developing equipment and techniques to measure the plutonium content of breeder reactor spent-fuel assemblies located in storage ponds before they are relocated to more secure facilities. We present the first quantitative nondestructive assay of the plutonium content of fast-breeder reactor spent-fuel assemblies while still underwater in their facility storage pond. We have calibrated and installed an underwater neutron coincidence counter (Spent Fuel Coincidence Counter (SFCC)) in the BN-350 reactor spent-fuel pond in Aqtau, Kazakhstan. A procedure has been developed to convert singles and doubles (coincidence) neutron rates observed by the SFCC into the total plutonium content of a given BN-350 spent-fuel assembly. The plutonium content has been successfully determined for spent-fuel assemblies with a contact radiation level as high as approx 10 sup 5 Rads/h. Using limited facility information and multiple measurements along the length of spe...

Component-Level Electronic-Assembly Repair (CLEAR) Operational Concept

Science.gov (United States)

Oeftering, Richard C.; Bradish, Martin A.; Juergens, Jeffrey R.; Lewis, Michael J.; Vrnak, Daniel R.

2011-01-01

This Component-Level Electronic-Assembly Repair (CLEAR) Operational Concept document was developed as a first step in developing the Component-Level Electronic-Assembly Repair (CLEAR) System Architecture (NASA/TM-2011-216956). The CLEAR operational concept defines how the system will be used by the Constellation Program and what needs it meets. The document creates scenarios for major elements of the CLEAR architecture. These scenarios are generic enough to apply to near-Earth, Moon, and Mars missions. The CLEAR operational concept involves basic assumptions about the overall program architecture and interactions with the CLEAR system architecture. The assumptions include spacecraft and operational constraints for near-Earth orbit, Moon, and Mars missions. This document addresses an incremental development strategy where capabilities evolve over time, but it is structured to prevent obsolescence. The approach minimizes flight hardware by exploiting Internet-like telecommunications that enables CLEAR capabilities to remain on Earth and to be uplinked as needed. To minimize crew time and operational cost, CLEAR exploits offline development and validation to support online teleoperations. Operational concept scenarios are developed for diagnostics, repair, and functional test operations. Many of the supporting functions defined in these operational scenarios are further defined as technologies in NASA/TM-2011-216956.

Telemetry Timing Analysis for Image Reconstruction of Kompsat Spacecraft

Directory of Open Access Journals (Sweden)

Jin-Ho Lee

2000-06-01

Full Text Available The KOMPSAT (KOrea Multi-Purpose SATellite has two optical imaging instruments called EOC (Electro-Optical Camera and OSMI (Ocean Scanning Multispectral Imager. The image data of these instruments are transmitted to ground station and restored correctly after post-processing with the telemetry data transferred from KOMPSAT spacecraft. The major timing information of the KOMPSAT is OBT (On-Board Time which is formatted by the on-board computer of the spacecraft, based on 1Hz sync. pulse coming from the GPS receiver involved. The OBT is transmitted to ground station with the house-keeping telemetry data of the spacecraft while it is distributed to the instruments via 1553B data bus for synchronization during imaging and formatting. The timing information contained in the spacecraft telemetry data would have direct relation to the image data of the instruments, which should be well explained to get a more accurate image. This paper addresses the timing analysis of the KOMPSAT spacecraft and instruments, including the gyro data timing analysis for the correct restoration of the EOC and OSMI image data at ground station.

RFP to work on formation flying capabilities for spacecrafts for the GRACE project

DEFF Research Database (Denmark)

Riis, Troels; Thuesen, Gøsta; Kilsgaard, Søren

1999-01-01

The National Aeronautics and Space Agency of USA, NASA, are working on formation flying capabilities for spacecrafts, GRACE Project. IAU and JPL are developing the inter spacecraft attitude link to be used on the two spacecrafts.......The National Aeronautics and Space Agency of USA, NASA, are working on formation flying capabilities for spacecrafts, GRACE Project. IAU and JPL are developing the inter spacecraft attitude link to be used on the two spacecrafts....

Controlled assembly of multi-segment nanowires by histidine-tagged peptides

Energy Technology Data Exchange (ETDEWEB)

Wang, Aijun A; Lee, Joun; Jenikova, Gabriela; Mulchandani, Ashok; Myung, Nosang V; Chen, Wilfred [Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521 (United States)

2006-07-28

A facile technique was demonstrated for the controlled assembly and alignment of multi-segment nanowires using bioengineered polypeptides. An elastin-like-polypeptide (ELP)-based biopolymer consisting of a hexahistine cluster at each end (His{sub 6}-ELP-His{sub 6}) was generated and purified by taking advantage of the reversible phase transition property of ELP. The affinity between the His{sub 6} domain of biopolymers and the nickel segment of multi-segment nickel/gold/nickel nanowires was exploited for the directed assembly of nanowires onto peptide-functionalized electrode surfaces. The presence of the ferromagnetic nickel segments on the nanowires allowed the control of directionality by an external magnetic field. Using this method, the directed assembly and positioning of multi-segment nanowires across two microfabricated nickel electrodes in a controlled manner was accomplished with the expected ohmic contact.

Characterization of dust aggregates in the vicinity of the Rosetta spacecraft

Science.gov (United States)

Güttler, C.; Hasselmann, P. H.; Li, Y.; Fulle, M.; Tubiana, C.; Kovacs, G.; Agarwal, J.; Sierks, H.; Fornasier, S.; Hofmann, M.; Gutiérrez Marqués, P.; Ott, T.; Drolshagen, E.; Bertini, I.; Osiris Team

2017-09-01

In a Rosetta/OSIRIS imaging activity in June 2015, we have observed the dynamic motion of particles close to the spacecraft. Due to the focal setting of the OSIRIS Wide Angle Camera (WAC), these particles were blurred, which can be used to measure their distances to the spacecraft. We detected 108 dust aggregates over a 130 minutes long sequence, and find that their sizes are around a millimetre and their distances cluster between 2 m and 40 m from the spacecraft. Their number densities are about a factor 10 higher than expected for the overall coma and highly fluctuating. Their velocities are small compared to the spacecraft orbital motion and directed away from the spacecraft, towards the comet. From this we conclude that they have interacted with the spacecraft and assess three possible scenarios. We prefer a scenario where centimeter-sized aggregates collide with the spacecraft and we would observe the fragments. Ablation of a dust layer on the spacecraft's z panel when rotated towards the sun is a reasonable alternative. We could also measure an acceleration for a subset of 18 aggregates, which is directed away from the sun and can be explain by a rocket effect, which requires a minimum ice fraction in the order of 0.1%

Evaluation of Brine Processing Technologies for Spacecraft Wastewater

Science.gov (United States)

Shaw, Hali L.; Flynn, Michael; Wisniewski, Richard; Lee, Jeffery; Jones, Harry; Delzeit, Lance; Shull, Sarah; Sargusingh, Miriam; Beeler, David; Howard, Jeanie;

Spacecraft charging: incoming and outgoing electrons

CERN Document Server

Lai, Shu T.

2013-04-22

This paper presents an overview of the roles played by incoming and outgoing electrons in spacecraft surface and stresses the importance of surface conditions for spacecraft charging. The balance between the incoming electron current from the ambient plasma and the outgoing currents of secondary electrons, backscattered electrons, and photoelectrons from the surfaces determines the surface potential. Since surface conditions significantly affect the outgoing currents, the critical temperature and the surface potential are also significantly affected. As a corollary, high level differential charging of adjacent surfaces with very different surface conditions is a space hazard.

Robust Parametric Control of Spacecraft Rendezvous

Directory of Open Access Journals (Sweden)

Dake Gu

2014-01-01

Full Text Available This paper proposes a method to design the robust parametric control for autonomous rendezvous of spacecrafts with the inertial information with uncertainty. We consider model uncertainty of traditional C-W equation to formulate the dynamic model of the relative motion. Based on eigenstructure assignment and model reference theory, a concise control law for spacecraft rendezvous is proposed which could be fixed through solving an optimization problem. The cost function considers the stabilization of the system and other performances. Simulation results illustrate the robustness and effectiveness of the proposed control.

Worldwide Spacecraft Crew Hatch History

Science.gov (United States)

Johnson, Gary

2009-01-01

The JSC Flight Safety Office has developed this compilation of historical information on spacecraft crew hatches to assist the Safety Tech Authority in the evaluation and analysis of worldwide spacecraft crew hatch design and performance. The document is prepared by SAIC s Gary Johnson, former NASA JSC S&MA Associate Director for Technical. Mr. Johnson s previous experience brings expert knowledge to assess the relevancy of data presented. He has experience with six (6) of the NASA spacecraft programs that are covered in this document: Apollo; Skylab; Apollo Soyuz Test Project (ASTP), Space Shuttle, ISS and the Shuttle/Mir Program. Mr. Johnson is also intimately familiar with the JSC Design and Procedures Standard, JPR 8080.5, having been one of its original developers. The observations and findings are presented first by country and organized within each country section by program in chronological order of emergence. A host of reference sources used to augment the personal observations and comments of the author are named within the text and/or listed in the reference section of this document. Careful attention to the selection and inclusion of photos, drawings and diagrams is used to give visual association and clarity to the topic areas examined.

A user's guide to the Flexible Spacecraft Dynamics and Control Program

Science.gov (United States)

Fedor, J. V.

1984-01-01

A guide to the use of the Flexible Spacecraft Dynamics Program (FSD) is presented covering input requirements, control words, orbit generation, spacecraft description and simulation options, and output definition. The program can be used in dynamics and control analysis as well as in orbit support of deployment and control of spacecraft. The program is applicable to inertially oriented spinning, Earth oriented or gravity gradient stabilized spacecraft. Internal and external environmental effects can be simulated.

Space Launch System Spacecraft and Payload Elements: Progress Toward Crewed Launch and Beyond

Science.gov (United States)

Schorr, Andrew A.; Smith, David Alan; Holcomb, Shawn; Hitt, David

2017-01-01

While significant and substantial progress continues to be accomplished toward readying the Space Launch System (SLS) rocket for its first test flight, work is already underway on preparations for the second flight - using an upgraded version of the vehicle - and beyond. Designed to support human missions into deep space, SLS is the most powerful human-rated launch vehicle the United States has ever undertaken, and is one of three programs being managed by the National Aeronautics and Space Administration's (NASA's) Exploration Systems Development division. The Orion spacecraft program is developing a new crew vehicle that will support human missions beyond low Earth orbit (LEO), and the Ground Systems Development and Operations (GSDO) program is transforming Kennedy Space Center (KSC) into a next-generation spaceport capable of supporting not only SLS but also multiple commercial users. Together, these systems will support human exploration missions into the proving ground of cislunar space and ultimately to Mars. For its first flight, SLS will deliver a near-term heavy-lift capability for the nation with its 70-metric-ton (t) Block 1 configuration. Each element of the vehicle now has flight hardware in production in support of the initial flight of the SLS, which will propel Orion around the moon and back. Encompassing hardware qualification, structural testing to validate hardware compliance and analytical modeling, progress is on track to meet the initial targeted launch date. In Utah and Mississippi, booster and engine testing are verifying upgrades made to proven shuttle hardware. At Michoud Assembly Facility (MAF) in Louisiana, the world's largest spacecraft welding tool is producing tanks for the SLS core stage. Providing the Orion crew capsule/launch vehicle interface and in-space propulsion via a cryogenic upper stage, the Spacecraft/Payload Integration and Evolution (SPIE) element serves a key role in achieving SLS goals and objectives. The SPIE element

Formation of disintegration particles in spacecraft recorders

International Nuclear Information System (INIS)

Kurnosova, L.V.; Fradkin, M.I.; Razorenov, L.A.

1986-01-01

Experiments performed on the spacecraft Salyut 1, Kosmos 410, and Kosmos 443 enable us to record the disintegration products of particles which are formed in the material of the detectors on board the spacecraft. The observations were made by means of a delayed coincidence method. We have detected a meson component and also a component which is apparently associated with the generation of radioactive isotopes in the detectors

Preliminary thermal design of the COLD-SAT spacecraft

Science.gov (United States)

Arif, Hugh

1991-01-01

The COLD-SAT free-flying spacecraft was to perform experiments with LH2 in the cryogenic fluid management technologies of storage, supply and transfer in reduced gravity. The Phase A preliminary design of the Thermal Control Subsystem (TCS) for the spacecraft exterior and interior surfaces and components of the bus subsystems is described. The TCS was composed of passive elements which were augmented with heaters. Trade studies to minimize the parasitic heat leakage into the cryogen storage tanks are described. Selection procedure for the thermally optimum on-orbit spacecraft attitude was defined. TRASYS-2 and SINDA'85 verification analysis was performed on the design and the results are presented.

Spacecraft charging and related effects during Halley encounter

International Nuclear Information System (INIS)

Young, D.T.

1983-01-01

Hypervelocity (69 km/s) impact of cometary material with surfaces of the GIOTTO spacecraft will induce a number of spurious and possibly harmful phenomena. The most serious of these is likely to be spacecraft charging that results from impact-produced plasma distributions surrounding GIOTTO. The ESA Plasma Environment Working Group, whose studies are the basis for this report, finds that charging may become significant within approx. 10 5 km of the nucleus where potentials of approx. = +20 V are to be expected. In addition to spacecraft charging, impact produced plasma may interfere with in situ plasma measurements, particularly those of ion plasma analyzers and mass spectrometers

Idaho National Engineering Laboratory irradiation facilities and their applications

International Nuclear Information System (INIS)

Gupta, V.P.; Herring, J.S.; Korenke, R.E.; Harker, Y.D.

1986-05-01

Although there is a growing need for neutron and gamma irradiation by governmental and industrial organizations in the United States and in other countries, the number of facilities providing such irradiations are limited. At the Idaho National Engineering Laboratory, there are several unique irradiation facilities producing high neutron and gamma radiation environments. These facilities could be readily used for nuclear research, materials testing, radiation hardening studies on electronic components/circuitry and sensors, and production of neutron transmutation doped (NTD) silicon and special radioisotopes. In addition, a neutron radiography unit, suitable for examining irradiated materials and assemblies, is also available. This report provides a description of the irradiation facilities and the neutron radiography unit as well as examples of their unique applications

Development of a Hardware-In-Loop (HIL Simulator for Spacecraft Attitude Control Using Momentum Wheels

Directory of Open Access Journals (Sweden)

Dohee Kim

2008-12-01

Full Text Available In this paper, a Hardware-In-the-Loop simulator to simulate attitude control of spacecraft using momentum wheels is developed. The simulator consists of a spherical air bearing system allowing rotation and tilt in all three axes, three momentum wheels for actuation, and an AHRS (Attitude Heading Reference System. The simulator processes various types of data in PC104 and wirelessly communicates with a host PC using TCP/IP protocol. A simple low-cost momentum wheel assembly set and its drive electronics are also developed. Several experiments are performed to test the performance of the momentum wheels. For the control performance test of the simulator, a PID controller is implemented. The results of experimental demonstrations confirm the feasibility and validity of the Hardware-In-the-Loop simulator developed in the current study.

Treatment planning capability assessment of a beam shaping assembly for accelerator-based BNCT.

Science.gov (United States)

Herrera, M S; González, S J; Burlon, A A; Minsky, D M; Kreiner, A J

2011-12-01

Within the frame of an ongoing project to develop a folded Tandem-Electrostatic-Quadrupole accelerator facility for Accelerator-Based Boron Neutron Capture Therapy (AB-BNCT) a theoretical study was performed to assess the treatment planning capability of different configurations of an optimized beam shaping assembly for such a facility. In particular this study aims at evaluating treatment plans for a clinical case of Glioblastoma. Copyright © 2011 Elsevier Ltd. All rights reserved.

Organization and staffing of the regulatory body for nuclear facilities. Safety guide

International Nuclear Information System (INIS)

2005-01-01

The purpose of this safety guide is to provide recommendations for national authorities on the appropriate management system, organization and staffing for the regulatory body responsible for the regulation of nuclear facilities in order to achieve compliance with the applicable safety requirements. This safety guide covers the organization and staffing in relation to nuclear facilities such as: enrichment and fuel manufacturing plants. Nuclear power plants. Other reactors such as research reactors and critical assemblies. Spent fuel reprocessing plants. And radioactive waste management facilities such as treatment, storage and disposal facilities. This safety guide also covers issues related to the decommissioning of nuclear facilities, the closure of waste disposal facilities and site rehabilitation

Qualification tests and facilities for the ITER superconductors

International Nuclear Information System (INIS)

Bruzzone, P.; Wesche, R.; Stepanov, B.; Cau, F.; Bagnasco, M.; Calvi, M.; Herzog, R.; Vogel, M.

2009-01-01

All the ITER superconductors are tested as short length samples in the SULTAN test facility at CRPP. Twenty-four TF conductor samples with small layout variations were tested since February 2007 with the aim of verifying the design and qualification of the manufacturers. The sample assembly and the measurement techniques at CRPP are discussed. Starting in 2010, another test facility for ITER conductors, named EDIPO, will be operating at CRPP to share with SULTAN the load of the samples for the acceptance tests during the construction of ITER.

Survey of tritium wastes and effluents in near-term fusion-research facilities

International Nuclear Information System (INIS)

Bickford, W.E.; Dingee, D.A.; Willingham, C.E.

1981-08-01

The use of tritium control technology in near-term research facilities has been studied for both the magnetic and inertial confinement fusion programs. This study focused on routine generation of tritium wastes and effluents, with little referene to accidents or facility decommissioning. This report serves as an independent review of the effectiveness of planned control technology and radiological hazards associated with operation. The facilities examined for the magnetic fusion program included Fusion Materials Irradiation Testing Facility (FMIT), Tritium Systems Test Assembly (TSTA), and Tokamak Fusion Test Reactor (TFTR) in the magnetic fusion program, while NOVA and Antares facilities were examined for the inertial confinement program

33 CFR 105.305 - Facility Security Assessment (FSA) requirements.

Science.gov (United States)

2010-07-01

... evacuation routes and assembly stations; and (viii) Existing security and safety equipment for protection of... protection systems; (iv) Procedural policies; (v) Radio and telecommunication systems, including computer... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Facility Security Assessment (FSA...

Injection of an electron beam into a plasma and spacecraft charging

International Nuclear Information System (INIS)

Okuda, H.; Kan, J.R.

1987-01-01

Injection of a nonrelativistic electron beam into a fully ionized plasma from a spacecraft including the effect of charging has been studied using a one-dimensional particle simulation model. It is found that the spacecraft charging remains negligible and the beam can propagate into a plasma, if the beam density is much smaller than the ambient density. When the injection current is increased by increasing the beam density, significant spacecraft charging takes place and the reflection of beam electrons back to the spacecraft reduces the beam current significantly. On the other hand, if the injection current is increased by increasing the beam energy, spacecraft charging remains negligible and a beam current much larger than the thermal return current can be injected. It is shown that the electric field caused by the beam--plasma instability accelerates the ambient electrons toward the spacecraft thereby enhancing the return current

Advanced satellite servicing facility studies

Science.gov (United States)

Qualls, Garry D.; Ferebee, Melvin J., Jr.

1988-01-01

A NASA-sponsored systems analysis designed to identify and recommend advanced subsystems and technologies specifically for a manned Sun-synchronous platform for satellite management is discussed. An overview of system design, manned and unmanned servicing facilities, and representative mission scenarios are given. Mission areas discussed include facility based satellite assembly, checkout, deployment, refueling, repair, and systems upgrade. The ferrying of materials and consumables to and from manufacturing platforms, deorbit, removal, repositioning, or salvage of satellites and debris, and crew rescue of any other manned vehicles are also examined. Impacted subsytems discussed include guidance navigation and control, propulsion, data management, power, thermal control, structures, life support, and radiation management. In addition, technology issues which would have significant impacts on the system design are discussed.

Material accountancy and control practice at a research reactor facility

International Nuclear Information System (INIS)

Bouchard, J.; Maurel, J.J.; Tromeur, Y.

1982-01-01

This session surveys the regulations, organization, and accountancy practice that compose the French State System of Accountancy and Control. Practical examples are discussed showing how inventories are verified at a critical assembly facility and at a materials testing reactor

Enabling Advanced Automation in Spacecraft Operations with the Spacecraft Emergency Response System

Science.gov (United States)

Breed, Julie; Fox, Jeffrey A.; Powers, Edward I. (Technical Monitor)

2001-01-01

True autonomy is the Holy Grail of spacecraft mission operations. The goal of launching a satellite and letting it manage itself throughout its useful life is a worthy one. With true autonomy, the cost of mission operations would be reduced to a negligible amount. Under full autonomy, any problems (no matter the severity or type) that may arise with the spacecraft would be handled without any human intervention via some combination of smart sensors, on-board intelligence, and/or smart automated ground system. Until the day that complete autonomy is practical and affordable to deploy, incremental steps of deploying ever-increasing levels of automation (computerization of once manual tasks) on the ground and on the spacecraft are gradually decreasing the cost of mission operations. For example, NASA's Goddard Space Flight Center (NASA-GSFC) has been flying spacecraft with low cost operations for several years. NASA-GSFC's SMEX (Small Explorer) and MIDEX (Middle Explorer) missions have effectively deployed significant amounts of automation to enable the missions to fly predominately in 'light-out' mode. Under light-out operations the ground system is run without human intervention. Various tools perform many of the tasks previously performed by the human operators. One of the major issues in reducing human staff in favor of automation is the perceived increased in risk of losing data, or even losing a spacecraft, because of anomalous conditions that may occur when there is no one in the control center. When things go wrong, missions deploying advanced automation need to be sure that anomalous conditions are detected and that key personal are notified in a timely manner so that on-call team members can react to those conditions. To ensure the health and safety of its lights-out missions, NASA-GSFC's Advanced Automation and Autonomy branch (Code 588) developed the Spacecraft Emergency Response System (SERS). The SERS is a Web-based collaborative environment that enables

On-orbit supervisor for controlling spacecraft

Science.gov (United States)

Vandervoort, Richard J.

1992-07-01

Spacecraft systems of the 1990's and beyond will be substantially more complex than their predecessors. They will have demanding performance requirements and will be expected to operate more autonomously. This underscores the need for innovative approaches to Fault Detection, Isolation and Recovery (FDIR). A hierarchical expert system is presented that provides on-orbit supervision using intelligent FDIR techniques. Each expert system in the hierarchy supervises the operation of a local set of spacecraft functions. Spacecraft operational goals flow top down while responses flow bottom up. The expert system supervisors have a fairly high degree of autonomy. Bureaucratic responsibilities are minimized to conserve bandwidth and maximize response time. Data for FDIR can be acquired local to an expert and from other experts. By using a blackboard architecture for each supervisor, the system provides a great degree of flexibility in implementing the problem solvers for each problem domain. In addition, it provides for a clear separation between facts and knowledge, leading to an efficient system capable of real time response.

Measurements of decay heat and gamma-ray intensity of spent LWR fuel assemblies

International Nuclear Information System (INIS)

Vogt, J.; Agrenius, L.; Jansson, P.; Baecklin, A.; Haakansson, A.; Jacobsson, S.

1999-01-01

Calorimetric measurements of the decay heat of a number of BWR and PWR fuel assemblies have been performed in the pools at the Swedish Central Interim Storage Facility for Spent Nuclear Fuel, CLAB. Gamma-ray measurements, using high-resolution gamma-ray spectroscopy (HRGS), have been carried out on the same fuel assemblies in order to test if it is possible to find a simple and accurate correlation between the 137 CS -intensity and the decay heat for fuel with a cooling time longer than 10-12 years. The results up to now are very promising and may ultimately lead to a qualified method for quick and accurate determination of the decay heat of old fuel by gamma-ray measurements. By means of the gamma spectrum the operator declared data on burnup, cooling time and initial enrichment can be verified as well. CLAB provides a unique opportunity in the world to follow up the decay heat of individual fuel assemblies during several decades to come. The results will be applicable for design and operation of facilities for wet and dry interim storage and subsequent encapsulation for final disposal of the fuel. (author)

Microbiological sampling of spacecraft cabling, antennas, solar panels and thermal blankets

Science.gov (United States)

Koukol, R. C.

1973-01-01

Sampling procedures and techniques described resulted from various flight project microbiological monitoring programs of unmanned planetary spacecraft. Concurrent with development of these procedures, compatibility evaluations were effected with the cognizant spacecraft subsystem engineers to assure that degradation factors would not be induced during the monitoring program. Of significance were those areas of the spacecraft configuration for which special handling precautions and/or nonstandard sample gathering techniques were evolved. These spacecraft component areas were: cabling, high gain antenna, solar panels, and thermal blankets. The compilation of these techniques provides a historical reference for both the qualification and quantification of sampling parameters as applied to the Mariner Spacecraft of the late 1960's and early 1970's.

Cooper-Harper Experience Report for Spacecraft Handling Qualities Applications

Science.gov (United States)

Bailey, Randall E.; Jackson, E. Bruce; Bilimoria, Karl D.; Mueller, Eric R.; Frost, Chad R.; Alderete, Thomas S.

2009-01-01

A synopsis of experience from the fixed-wing and rotary-wing aircraft communities in handling qualities development and the use of the Cooper-Harper pilot rating scale is presented as background for spacecraft handling qualities research, development, test, and evaluation (RDT&E). In addition, handling qualities experiences and lessons-learned from previous United States (US) spacecraft developments are reviewed. This report is intended to provide a central location for references, best practices, and lessons-learned to guide current and future spacecraft handling qualities RDT&E.

Overview of SDCM - The Spacecraft Design and Cost Model

Science.gov (United States)

Ferebee, Melvin J.; Farmer, Jeffery T.; Andersen, Gregory C.; Flamm, Jeffery D.; Badi, Deborah M.

1988-01-01

The Spacecraft Design and Cost Model (SDCM) is a computer-aided design and analysis tool for synthesizing spacecraft configurations, integrating their subsystems, and generating information concerning on-orbit servicing and costs. SDCM uses a bottom-up method in which the cost and performance parameters for subsystem components are first calculated; the model then sums the contributions from individual components in order to obtain an estimate of sizes and costs for each candidate configuration within a selected spacecraft system. An optimum spacraft configuration can then be selected.

Improving Energy Efficiency for the Vehicle Assembly Industry: A Discrete Event Simulation Approach

Science.gov (United States)

Oumer, Abduaziz; Mekbib Atnaw, Samson; Kie Cheng, Jack; Singh, Lakveer

2016-11-01

This paper presented a Discrete Event Simulation (DES) model for investigating and improving energy efficiency in vehicle assembly line. The car manufacturing industry is one of the highest energy consuming industries. Using Rockwell Arena DES package; a detailed model was constructed for an actual vehicle assembly plant. The sources of energy considered in this research are electricity and fuel; which are the two main types of energy sources used in a typical vehicle assembly plant. The model depicts the performance measurement for process- specific energy measures of painting, welding, and assembling processes. Sound energy efficiency model within this industry has two-fold advantage: reducing CO2 emission and cost reduction associated with fuel and electricity consumption. The paper starts with an overview of challenges in energy consumption within the facilities of automotive assembly line and highlights the parameters for energy efficiency. The results of the simulation model indicated improvements for energy saving objectives and reduced costs.

Historical Mass, Power, Schedule, and Cost Growth for NASA Spacecraft

Science.gov (United States)

Hayhurst, Marc R.; Bitten, Robert E.; Shinn, Stephen A.; Judnick, Daniel C.; Hallgrimson, Ingrid E.; Youngs, Megan A.

2016-01-01

Although spacecraft developers have been moving towards standardized product lines as the aerospace industry has matured, NASA's continual need to push the cutting edge of science to accomplish unique, challenging missions can still lead to spacecraft resource growth over time. This paper assesses historical mass, power, cost, and schedule growth for multiple NASA spacecraft from the last twenty years and compares to industry reserve guidelines to understand where the guidelines may fall short. Growth is assessed from project start to launch, from the time of the preliminary design review (PDR) to launch and from the time of the critical design review (CDR) to launch. Data is also assessed not just at the spacecraft bus level, but also at the subsystem level wherever possible, to help obtain further insight into possible drivers of growth. Potential recommendations to minimize spacecraft mass, power, cost, and schedule growth for future missions are also discussed.

Iterative Repair Planning for Spacecraft Operations Using the Aspen System

Science.gov (United States)

Rabideau, G.; Knight, R.; Chien, S.; Fukunaga, A.; Govindjee, A.

2000-01-01

This paper describes the Automated Scheduling and Planning Environment (ASPEN). ASPEN encodes complex spacecraft knowledge of operability constraints, flight rules, spacecraft hardware, science experiments and operations procedures to allow for automated generation of low level spacecraft sequences. Using a technique called iterative repair, ASPEN classifies constraint violations (i.e., conflicts) and attempts to repair each by performing a planning or scheduling operation. It must reason about which conflict to resolve first and what repair method to try for the given conflict. ASPEN is currently being utilized in the development of automated planner/scheduler systems for several spacecraft, including the UFO-1 naval communications satellite and the Citizen Explorer (CX1) satellite, as well as for planetary rover operations and antenna ground systems automation. This paper focuses on the algorithm and search strategies employed by ASPEN to resolve spacecraft operations constraints, as well as the data structures for representing these constraints.

A Quantized State Approach to On-line Simulation for Spacecraft Autonomy

DEFF Research Database (Denmark)

Alminde, Lars; Stoustrup, Jakob; Bendtsen, Jan Dimon

2006-01-01

Future space applications will require an increased level of operational autonomy. This calls for declarative methods for spacecraft state estimation and control, so that the spacecraft engineer can focus on modeling the spacecraft rather than implementing all details of the on-line system. Celeb...

Standardization and Economics of Nuclear Spacecraft, Final Report, Phase I, Sense Study

Energy Technology Data Exchange (ETDEWEB)

1973-03-01

Feasibility and cost benefits of nuclear-powered standardized spacecraft are investigated. The study indicates that two shuttle-launched nuclear-powered spacecraft should be able to serve the majority of unmanned NASA missions anticipated for the 1980's. The standard spacecraft include structure, thermal control, power, attitude control, some propulsion capability and tracking, telemetry, and command subsystems. One spacecraft design, powered by the radioisotope thermoelectric generator, can serve missions requiring up to 450 watts. The other spacecraft design, powered by similar nuclear heat sources in a Brayton-cycle generator, can serve missions requiring up to 21000 watts. Design concepts and trade-offs are discussed. The conceptual designs selected are presented and successfully tested against a variety of missions. The thermal design is such that both spacecraft are capable of operating in any earth orbit and any orientation without modification. Three-axis stabilization is included. Several spacecraft can be stacked in the shuttle payload compartment for multi-mission launches. A reactor-powered thermoelectric generator system, operating at an electric power level of 5000 watts, is briefly studied for applicability to two test missions of divers requirements. A cost analysis indicates that use of the two standardized spacecraft offers sizable savings in comparison with specially designed solar-powered spacecraft. There is a duplicate copy.

A Reconfigurable Testbed Environment for Spacecraft Autonomy

Science.gov (United States)

Biesiadecki, Jeffrey; Jain, Abhinandan

1996-01-01

A key goal of NASA's New Millennium Program is the development of technology for increased spacecraft on-board autonomy. Achievement of this objective requires the development of a new class of ground-based automony testbeds that can enable the low-cost and rapid design, test, and integration of the spacecraft autonomy software. This paper describes the development of an Autonomy Testbed Environment (ATBE) for the NMP Deep Space I comet/asteroid rendezvous mission.

Progress in FMIT test assembly development

International Nuclear Information System (INIS)

Opperman, E.K.; Vogel, M.A.; Shen, E.J.; Trego, A.L.

1983-08-01

Research and development supporting the completed design of the Fusion Materials Irradiation Test (FMIT) Facility is continuing at the Hanford Engineering Development Laboratory (HEDL) in Richland, Washington. The FMIT, a deuteron accelerator based (d + Li) neutron source, will produce an intense flux of high energy neutrons for use in radiation damage studies of fusion reactor materials. The most intense flux magnitude of greater than 10 15 n/cm 2 -s is located close to the neutron producing lithium target and is distributed within a volume about the size of an American football. The conceptual design and development of FMIT experiments called Test Assemblies has progressed over the past five years in parallel with the design of the FMIT. The paper will describe the recent accomplishments made in developing test assemblies appropriate for use in the limited volume close to the FMIT target where high neutron flux and heating rates and the associated spacial gradients significantly impact design considerations

Spacecraft Hybrid (Mixed-Actuator) Attitude Control Experiences on NASA Science Missions

Science.gov (United States)

Dennehy, Cornelius J.

2014-01-01

There is a heightened interest within NASA for the design, development, and flight implementation of mixed-actuator hybrid attitude control systems for science spacecraft that have less than three functional reaction wheel actuators. This interest is driven by a number of recent reaction wheel failures on aging, but what could be still scientifically productive, NASA spacecraft if a successful hybrid attitude control mode can be implemented. Over the years, hybrid (mixed-actuator) control has been employed for contingency attitude control purposes on several NASA science mission spacecraft. This paper provides a historical perspective of NASA's previous engineering work on spacecraft mixed-actuator hybrid control approaches. An update of the current situation will also be provided emphasizing why NASA is now so interested in hybrid control. The results of the NASA Spacecraft Hybrid Attitude Control Workshop, held in April of 2013, will be highlighted. In particular, the lessons learned captured from that workshop will be shared in this paper. An update on the most recent experiences with hybrid control on the Kepler spacecraft will also be provided. This paper will close with some future considerations for hybrid spacecraft control.

Tritium systems test assembly stabilization

International Nuclear Information System (INIS)

Jasen, William G.; Michelotti, Roy A.; Anast, Kurt R.; Tesch, Charles

2004-01-01

The Tritium Systems Test Assembly (TSTA) was a facility dedicated to tritium technology Research and Development (R and D) primarily for future fusion power reactors. The facility was conceived in mid 1970's, operations commenced in early 1980's, stabilization and deactivation began in 2000 and were completed in 2003. The facility will remain in a Surveillance and Maintenance (S and M) mode until the Department of Energy (DOE) funds demolition of the facility, tentatively in 2009. A safe and stable end state was achieved by the TSTA Facility Stabilization Project (TFSP) in anticipation of long term S and M. At the start of the stabilization project, with an inventory of approximately 140 grams of tritium, the facility was designated a Hazard Category (HC) 2 Non-Reactor Nuclear facility as defined by US Department of Energy standard DOE-STD-1027-92 (1997). The TSTA facility comprises a laboratory area, supporting rooms, offices and associated laboratory space that included more than 20 major tritium handling systems. The project's focus was to reduce the tritium inventory by removing bulk tritium, tritiated water wastes, and tritium-contaminated high-inventory components. Any equipment that remained in the facility was stabilized in place. All of the gloveboxes and piping were rendered inoperative and vented to atmosphere. All equipment, and inventoried tritium contamination, remaining in the facility was left in a safe-and-stable state. The project used the End Points process as defined by the DOE Office of Environmental Management (web page http://www.em.doe.- gov/deact/epman.htmtlo) document and define the end state required for the stabilization of TSTA Facility. The End Points process added structure that was beneficial through virtually all phases of the project. At completion of the facility stabilization project the residual tritium inventory was approximately 3,000 curies, considerably less than the 1.6-gram threshold for a HC 3 facility. TSTA is now

Technical study of a thermally dense long term interim storage facility

International Nuclear Information System (INIS)

Le Duigou, A.; Badie, M.; Duret, B.; Bricard, A.

2001-01-01

The COFRE concept is aimed at the surface and thermal densification of the interim storage facility for irradiated fuels. The facility provides the biological shielding. A conditioning cell is used to load and retrieve the fuel assemblies. The facility container is the second containment barrier. The high power levels are managed by an auxiliary cooling system whose original feature is the passive use of a water evaporation-condensation cycle in a sealed circuit. The removable evaporator abuts the container. The air cooled condenser is placed outside the facility. Contact resistance and heat pipe mode were successfully modelled and are undergoing experimental validation on the THERESE and REBECA loops. (author)

Deep Space Networking Experiments on the EPOXI Spacecraft

Science.gov (United States)

Jones, Ross M.

2011-01-01

NASA's Space Communications & Navigation Program within the Space Operations Directorate is operating a program to develop and deploy Disruption Tolerant Networking [DTN] technology for a wide variety of mission types by the end of 2011. DTN is an enabling element of the Interplanetary Internet where terrestrial networking protocols are generally unsuitable because they rely on timely and continuous end-to-end delivery of data and acknowledgments. In fall of 2008 and 2009 and 2011 the Jet Propulsion Laboratory installed and tested essential elements of DTN technology on the Deep Impact spacecraft. These experiments, called Deep Impact Network Experiment (DINET 1) were performed in close cooperation with the EPOXI project which has responsibility for the spacecraft. The DINET 1 software was installed on the backup software partition on the backup flight computer for DINET 1. For DINET 1, the spacecraft was at a distance of about 15 million miles (24 million kilometers) from Earth. During DINET 1 300 images were transmitted from the JPL nodes to the spacecraft. Then, they were automatically forwarded from the spacecraft back to the JPL nodes, exercising DTN's bundle origination, transmission, acquisition, dynamic route computation, congestion control, prioritization, custody transfer, and automatic retransmission procedures, both on the spacecraft and on the ground, over a period of 27 days. The first DINET 1 experiment successfully validated many of the essential elements of the DTN protocols. DINET 2 demonstrated: 1) additional DTN functionality, 2) automated certain tasks which were manually implemented in DINET 1 and 3) installed the ION SW on nodes outside of JPL. DINET 3 plans to: 1) upgrade the LTP convergence-layer adapter to conform to the international LTP CL specification, 2) add convergence-layer "stewardship" procedures and 3) add the BSP security elements [PIB & PCB]. This paper describes the planning and execution of the flight experiment and the

Attitude Fusion Techniques for Spacecraft

DEFF Research Database (Denmark)

Bjarnø, Jonas Bækby

Spacecraft platform instability constitutes one of the most significant limiting factors in hyperacuity pointing and tracking applications, yet the demand for accurate, timely and reliable attitude information is ever increasing. The PhD research project described within this dissertation has...... served to investigate the solution space for augmenting the DTU μASC stellar reference sensor with a miniature Inertial Reference Unit (IRU), thereby obtaining improved bandwidth, accuracy and overall operational robustness of the fused instrument. Present day attitude determination requirements are met...... of the instrument, and affecting operations during agile and complex spacecraft attitude maneuvers. As such, there exists a theoretical foundation for augmenting the high frequency performance of the μASC instrument, by harnessing the complementary nature of optical stellar reference and inertial sensor technology...

Molecular Contamination Investigation Facility (MCIF) Capabilities

Science.gov (United States)

Soules, David M.

2013-01-01

This facility was used to guide the development of ASTM E 1559 center dot Multiple Quartz Crystal Microbalances (QCMs), large sample and spectral effects capability center dot Several instrumented, high vacuum chamber systems are used to evaluate the molecular outgassing characteristics of materials, flight components and other sensitive surfaces. Test materials for spacecraft/instrument selection center.Test flight components for acceptable molecular outgas levels center dot Determine time/temperature vacuum bake-out requirements center. Data used to set limits for use of materials and specific components center. Provide Input Data to Contamination Transport Models -Applied to numerous flight projects over the past 20 years.

Fast Flux Test Facility core system

International Nuclear Information System (INIS)

Ethridge, J.L.; Baker, R.B.; Leggett, R.D.; Pitner, A.L.; Waltar, A.E.

1990-11-01

A review of Liquid Metal Reactor (LMR) core system accomplishments provides an excellent road map through the maze of issues that faced reactor designers 10 years ago. At that time relatively large uncertainties were associated with fuel pin and fuel assembly performance, irradiation of structural materials, and performance of absorber assemblies. The extensive core systems irradiation program at the US Department of Energy's Fast Flux Test Facility (FFTF) has addressed each of these principal issues. As a result of the progress made, the attention of long-range LMR planners and designers can shift away from improving core systems and focus on reducing capital costs to ensure the LMR can compete economically in the 21st century with other nuclear reactor concepts. 3 refs., 6 figs., 1 tab

International Space Station Research and Facilities for Life Sciences

Science.gov (United States)

Robinson, Julie A.; Ruttley, Tara M.

2009-01-01

Assembly of the International Space Station is nearing completion in fall of 2010. Although assembly has been the primary objective of its first 11 years of operation, early science returns from the ISS have been growing at a steady pace. Laboratory facilities outfitting has increased dramatically 2008-2009 with the European Space Agency s Columbus and Japanese Aerospace Exploration Agency s Kibo scientific laboratories joining NASA s Destiny laboratory in orbit. In May 2009, the ISS Program met a major milestone with an increase in crew size from 3 to 6 crewmembers, thus greatly increasing the time available to perform on-orbit research. NASA will launch its remaining research facilities to occupy all 3 laboratories in fall 2009 and winter 2010. To date, early utilization of the US Operating Segment of the ISS has fielded nearly 200 experiments for hundreds of ground-based investigators supporting international and US partner research. With a specific focus on life sciences research, this paper will summarize the science accomplishments from early research aboard the ISS- both applied human research for exploration, and research on the effects of microgravity on life. We will also look ahead to the full capabilities for life sciences research when assembly of ISS is complete in 2010.

A Shaftless Magnetically Levitated Multifunctional Spacecraft Flywheel Storage System

Science.gov (United States)

Stevens, Ken; Thornton, Richard; Clark, Tracy; Beaman, Bob G.; Dennehy, Neil; Day, John H. (Technical Monitor)

2002-01-01

Presently many types of spacecraft use a Spacecraft Attitude Control System (ACS) with momentum wheels for steering and electrochemical batteries to provide electrical power for the eclipse period of the spacecraft orbit. Future spacecraft will use Flywheels for combined use in ACS and Energy Storage. This can be done by using multiple wheels and varying the differential speed for ACS and varying the average speed for energy storage and recovery. Technology in these areas has improved since the 1990s so it is now feasible for flywheel systems to emerge from the laboratory for spacecraft use. This paper describes a new flywheel system that can be used for both ACS and energy storage. Some of the possible advantages of a flywheel system are: lower total mass and volume, higher efficiency, less thermal impact, improved satellite integration schedule and complexity, simplified satellite orbital operations, longer life with lower risk, less pointing jitter, and greater capability for high-rate slews. In short, they have the potential to enable new types of missions and provide lower cost. Two basic types of flywheel configurations are the Flywheel Energy Storage System (FESS) and the Integrated Power and Attitude Control System (IPACS).

Distributed Autonomous Control of Multiple Spacecraft During Close Proximity Operations

National Research Council Canada - National Science Library

McCamish, Shawn B

2007-01-01

This research contributes to multiple spacecraft control by developing an autonomous distributed control algorithm for close proximity operations of multiple spacecraft systems, including rendezvous...

Spacecraft Environmental Interactions Technology, 1983

Science.gov (United States)

1985-01-01

State of the art of environment interactions dealing with low-Earth-orbit plasmas; high-voltage systems; spacecraft charging; materials effects; and direction of future programs are contained in over 50 papers.

Spacecraft operations

CERN Document Server

Sellmaier, Florian; Schmidhuber, Michael

2015-01-01

The book describes the basic concepts of spaceflight operations, for both, human and unmanned missions. The basic subsystems of a space vehicle are explained in dedicated chapters, the relationship of spacecraft design and the very unique space environment are laid out. Flight dynamics are taught as well as ground segment requirements. Mission operations are divided into preparation including management aspects, execution and planning. Deep space missions and space robotic operations are included as special cases. The book is based on a course held at the German Space Operation Center (GSOC).

Event-triggered attitude control of spacecraft

Science.gov (United States)

Wu, Baolin; Shen, Qiang; Cao, Xibin

2018-02-01

The problem of spacecraft attitude stabilization control system with limited communication and external disturbances is investigated based on an event-triggered control scheme. In the proposed scheme, information of attitude and control torque only need to be transmitted at some discrete triggered times when a defined measurement error exceeds a state-dependent threshold. The proposed control scheme not only guarantees that spacecraft attitude control errors converge toward a small invariant set containing the origin, but also ensures that there is no accumulation of triggering instants. The performance of the proposed control scheme is demonstrated through numerical simulation.

Streamlined Modeling for Characterizing Spacecraft Anomalous Behavior

Science.gov (United States)

Klem, B.; Swann, D.

2011-09-01

Anomalous behavior of on-orbit spacecraft can often be detected using passive, remote sensors which measure electro-optical signatures that vary in time and spectral content. Analysts responsible for assessing spacecraft operational status and detecting detrimental anomalies using non-resolved imaging sensors are often presented with various sensing and identification issues. Modeling and measuring spacecraft self emission and reflected radiant intensity when the radiation patterns exhibit a time varying reflective glint superimposed on an underlying diffuse signal contribute to assessment of spacecraft behavior in two ways: (1) providing information on body component orientation and attitude; and, (2) detecting changes in surface material properties due to the space environment. Simple convex and cube-shaped spacecraft, designed to operate without protruding solar panel appendages, may require an enhanced level of preflight characterization to support interpretation of the various physical effects observed during on-orbit monitoring. This paper describes selected portions of the signature database generated using streamlined signature modeling and simulations of basic geometry shapes apparent to non-imaging sensors. With this database, summarization of key observable features for such shapes as spheres, cylinders, flat plates, cones, and cubes in specific spectral bands that include the visible, mid wave, and long wave infrared provide the analyst with input to the decision process algorithms contained in the overall sensing and identification architectures. The models typically utilize baseline materials such as Kapton, paints, aluminum surface end plates, and radiators, along with solar cell representations covering the cylindrical and side portions of the spacecraft. Multiple space and ground-based sensors are assumed to be located at key locations to describe the comprehensive multi-viewing aspect scenarios that can result in significant specular reflection

THERESA FRANCO INSPECTS THE SOLAR PANELS OF THE MARS GLOBAL SURVEYOR

Science.gov (United States)

1996-01-01

Theresa Franco of SPECTROLAB Inc. carefully inspects the solar panels of the Mars Global Surveyor spacecraft, undergoing preflight assembly and checkout in the Payload Hazardous Servicing Facility in KSC's Industrial Area. The four solar array panels will play a crucial role in the Mars Global Surveyor mission by providing the electrical power required to operate the spacecraft and its complement of scientific instruments. The Surveyor is slated for launch November 6 aboard a Delta II expendable launch vehicle. After arriving at the Red Planet in September 1997, the Surveyor will carry out an extensive study of Mars, gathering data about the planet's topography, magnetism, mineral composition and atmosphere.

Cryogenic polarized-target facility. Progress report, July 1, 1981-June 30, 1982

International Nuclear Information System (INIS)

Gould, C.R.; Haase, D.G.

1982-01-01

The goal of this three-year research project is to build a cryogenically polarized target facility for measuring total neutron cross sections for polarized neutrons incident on polarized nuclei. The components of the system have been assembled at TUNL during the current contract period. These include the dilution-refrigerator support assembly, the dilution-refrigerator itself, the dewar, the beam line, the shielding cave for the neutron source, and the neutron-detector shield and rolling-cart assembly. The dilution refrigerator is presently undergoing testing at liquid-nitrogen and liquid-helium temperatures. Experiments with aluminum and copper targets are scheduled for the coming contract period

On the Automatic Generation of Plans for Life Cycle Assembly Processes

Energy Technology Data Exchange (ETDEWEB)

CALTON,TERRI L.

2000-01-01

Designing products for easy assembly and disassembly during their entire life cycles for purposes including product assembly, product upgrade, product servicing and repair, and product disposal is a process that involves many disciplines. In addition, finding the best solution often involves considering the design as a whole and by considering its intended life cycle. Different goals and manufacturing plan selection criteria, as compared to initial assembly, require re-visiting significant fundamental assumptions and methods that underlie current assembly planning techniques. Previous work in this area has been limited to either academic studies of issues in assembly planning or to applied studies of life cycle assembly processes that give no attention to automatic planning. It is believed that merging these two areas will result in a much greater ability to design for, optimize, and analyze the cycle assembly processes. The study of assembly planning is at the very heart of manufacturing research facilities and academic engineering institutions; and, in recent years a number of significant advances in the field of assembly planning have been made. These advances have ranged from the development of automated assembly planning systems, such as Sandia's Automated Assembly Analysis System Archimedes 3.0{copyright}, to the startling revolution in microprocessors and computer-controlled production tools such as computer-aided design (CAD), computer-aided manufacturing (CAM), flexible manufacturing systems (EMS), and computer-integrated manufacturing (CIM). These results have kindled considerable interest in the study of algorithms for life cycle related assembly processes and have blossomed into a field of intense interest. The intent of this manuscript is to bring together the fundamental results in this area, so that the unifying principles and underlying concepts of algorithm design may more easily be implemented in practice.

Precise Relative Positioning of Formation Flying Spacecraft using GPS

NARCIS (Netherlands)

Kroes, R.

2006-01-01

Spacecraft formation flying is considered as a key technology for advanced space missions. Compared to large individual spacecraft, the distribution of sensor systems amongst multiple platforms offers improved flexibility, shorter times to mission, and the prospect of being more cost effective.

Evaluation of residual radioactivity and dose rate of a target assembly in an IBA cyclotron

Energy Technology Data Exchange (ETDEWEB)

Hwang, Seon Yong; Kim, Young Ju; Lee, Seung Wook [School of Mechanical Engineering, Pusan National University (Korea, Republic of)

2016-12-15

When a cyclotron produces 18F-, accelerated protons interact with metal parts of the cyclotron machine and induces radioactivity. Especially, the target window and chamber of the target assembly are the main parts where long-lived radionuclides are generated as they are incident by direct beams. It is of great importance to identify radionuclides induced in the target assembly for the safe operation and maintenance of a cyclotron facility. In this study, we analyzed major radionuclides generated in the target assembly by an operation of the Cyclotron 18/9 machine and measured dose rates after the operation to establish the radiation safety guideline for operators and maintenance personnel of the machine. Gamma spectroscopy with HPGe was performed on samples from the target chamber and Havar foil target window to identify the radionuclides generated during the operation for production of 18F-- isotope and their specific activity. Also, the dose rates from the target were measured as a function of time after an operation. These data will help improve radiological safety of operating the cyclotron facilities.

Embedded Thermal Control for Spacecraft Subsystems Miniaturization

Science.gov (United States)

Didion, Jeffrey R.

2014-01-01

Optimization of spacecraft size, weight and power (SWaP) resources is an explicit technical priority at Goddard Space Flight Center. Embedded Thermal Control Subsystems are a promising technology with many cross cutting NSAA, DoD and commercial applications: 1.) CubeSatSmallSat spacecraft architecture, 2.) high performance computing, 3.) On-board spacecraft electronics, 4.) Power electronics and RF arrays. The Embedded Thermal Control Subsystem technology development efforts focus on component, board and enclosure level devices that will ultimately include intelligent capabilities. The presentation will discuss electric, capillary and hybrid based hardware research and development efforts at Goddard Space Flight Center. The Embedded Thermal Control Subsystem development program consists of interrelated sub-initiatives, e.g., chip component level thermal control devices, self-sensing thermal management, advanced manufactured structures. This presentation includes technical status and progress on each of these investigations. Future sub-initiatives, technical milestones and program goals will be presented.

Preliminary Design of the AEGIS Test Facility

CERN Document Server

Dassa, Luca; Cambiaghi, Danilo

2010-01-01

The AEGIS experiment is expected to be installed at the CERN Antiproton Decelerator in a very close future, since the main goal of the AEGIS experiment is the measurement of gravity impact on antihydrogen, which will be produced on the purpose. Antihydrogen production implies very challenging environmental conditions: at the heart of the AEGIS facility 50 mK temperature, 1e-12 mbar pressure and a 1 T magnetic field are required. Interfacing extreme cryogenics with ultra high vacuum will affect very strongly the design of the whole facility, requiring a very careful mechanical design. This paper presents an overview of the actual design of the AEGIS experimental facility, paying special care to mechanical aspects. Each subsystem of the facility – ranging from the positron source to the recombination region and the measurement region – will be shortly described. The ultra cold region, which is the most critical with respect to the antihydrogen formation, will be dealt in detail. The assembly procedures will...

Heterogeneous Electronics – Wafer Level Integration, Packaging, and Assembly Facility

Data.gov (United States)

Federal Laboratory Consortium — This facility integrates active electronics with microelectromechanical (MEMS) devices at the miniature system scale. It obviates current size-, weight-, and power...

Definition of the topological structure of the automatic control system of spacecrafts

International Nuclear Information System (INIS)

KrasnoyarskiyRabochiy prospect, Krasnoyarsk, 660014 (Russian Federation))" data-affiliation=" (Siberian State Aerospace University named after Academician M.F.Reshetnev 31 KrasnoyarskiyRabochiy prospect, Krasnoyarsk, 660014 (Russian Federation))" >Zelenkov, P V; KrasnoyarskiyRabochiy prospect, Krasnoyarsk, 660014 (Russian Federation))" data-affiliation=" (Siberian State Aerospace University named after Academician M.F.Reshetnev 31 KrasnoyarskiyRabochiy prospect, Krasnoyarsk, 660014 (Russian Federation))" >Karaseva, M V; KrasnoyarskiyRabochiy prospect, Krasnoyarsk, 660014 (Russian Federation))" data-affiliation=" (Siberian State Aerospace University named after Academician M.F.Reshetnev 31 KrasnoyarskiyRabochiy prospect, Krasnoyarsk, 660014 (Russian Federation))" >Tsareva, E A; Tsarev, R Y

2015-01-01

The paper considers the problem of selection the topological structure of the automated control system of spacecrafts. The integer linear model of mathematical programming designed to define the optimal topological structure for spacecraft control is proposed. To solve the determination problem of topological structure of the control system of spacecrafts developed the procedure of the directed search of some structure variants according to the scheme 'Branch and bound'. The example of the automated control system of spacecraft development included the combination of ground control stations, managing the spacecraft of three classes with a geosynchronous orbit with constant orbital periods is presented

PWR and BWR spent fuel assembly gamma spectra measurements

Energy Technology Data Exchange (ETDEWEB)

Vaccaro, S. [European Commission, DG Energy, Directorate EURATOM Safeguards Luxembourg (Luxembourg); Tobin, S.J.; Favalli, A. [Los Alamos National Laboratory, Los Alamos, NM (United States); Grogan, B. [Oak Ridge National Laboratory, Oak Ridge (United States); Jansson, P. [Uppsala University, Uppsala (Sweden); Liljenfeldt, H. [Oak Ridge National Laboratory, Oak Ridge (United States); Mozin, V. [Lawrence Livermore National Laboratory, Livermore, CA (United States); Hu, J. [Oak Ridge National Laboratory, Oak Ridge (United States); Schwalbach, P. [European Commission, DG Energy, Directorate EURATOM Safeguards Luxembourg (Luxembourg); Sjöland, A. [Swedish Nuclear Fuel and Waste Management Company (SKB) (Sweden); Trellue, H.; Vo, D. [Los Alamos National Laboratory, Los Alamos, NM (United States)

2016-10-11

A project to research the application of nondestructive assay (NDA) to spent fuel assemblies is underway. The research team comprises the European Atomic Energy Community (EURATOM), embodied by the European Commission, DG Energy, Directorate EURATOM Safeguards; the Swedish Nuclear Fuel and Waste Management Company (SKB); two universities; and several United States national laboratories. The Next Generation of Safeguards Initiative–Spent Fuel project team is working to achieve the following technical goals more easily and efficiently than in the past using nondestructive assay measurements of spent fuel assemblies: (1) verify the initial enrichment, burnup, and cooling time of facility declaration; (2) detect the diversion or replacement of pins, (3) estimate the plutonium mass, (4) estimate the decay heat, and (5) determine the reactivity of spent fuel assemblies. This study focuses on spectrally resolved gamma-ray measurements performed on a diverse set of 50 assemblies [25 pressurized water reactor (PWR) assemblies and 25 boiling water reactor (BWR) assemblies]; these same 50 assemblies will be measured with neutron-based NDA instruments and a full-length calorimeter. Given that encapsulation/repository and dry storage safeguards are the primarily intended applications, the analysis focused on the dominant gamma-ray lines of {sup 137}Cs, {sup 154}Eu, and {sup 134}Cs because these isotopes will be the primary gamma-ray emitters during the time frames of interest to these applications. This study addresses the impact on the measured passive gamma-ray signals due to the following factors: burnup, initial enrichment, cooling time, assembly type (eight different PWR and six different BWR fuel designs), presence of gadolinium rods, and anomalies in operating history. To compare the measured results with theory, a limited number of ORIGEN-ARP simulations were performed.

LANL MOX fuel lead assemblies data report for the surplus plutonium disposition environmental impact statement

International Nuclear Information System (INIS)

Fisher, S.E.; Holdaway, R.; Ludwig, S.B.

1998-08-01

The purpose of this document is to support the US Department of Energy (DOE) Fissile Materials Disposition Program's preparation of the draft surplus plutonium disposition environmental impact statement. This is one of several responses to data call requests for background information on activities associated with the operation of the lead assembly (LA) mixed-oxide (MOX) fuel fabrication facility. LANL has proposed an LA MOX fuel fabrication approach that would be done entirely inside an S and S Category 1 area. This includes receipt and storage of PuO 2 powder, fabrication of MOX fuel pellets, assembly of fuel rods and bundles, and shipping of the packaged fuel to a commercial reactor site. Support activities will take place within both Category 1 and 2 areas. Technical Area (TA) 55/Plutonium Facility 4 will be used to store the bulk PuO 2 powder, fabricate MOX fuel pellets, assemble rods, and store fuel bundles. Bundles will be assembled at a separate facility, several of which have been identified as suitable for that activity. The Chemistry and Metallurgy Research Building (at TA-3) will be used for analytical chemistry support. Waste operations will be conducted in TA-50 and TA-54. Only very minor modifications will be needed to accommodate the LA program. These modifications consist mostly of minor equipment upgrades. A commercial reactor operator has not been identified for the LA irradiation. Postirradiation examination (PIE) of the irradiated fuel will take place at either Oak Ridge National Laboratory or ANL-W. The only modifications required at either PIE site would be to accommodate full-length irradiated fuel rods. Results from this program are critical to the overall plutonium distribution schedule

A small spacecraft for multipoint measurement of ionospheric plasma

Science.gov (United States)

Roberts, T. M.; Lynch, K. A.; Clayton, R. E.; Weiss, J.; Hampton, D. L.

2017-07-01

Measurement of ionospheric plasma is often performed by a single in situ device or remotely using cameras and radar. This article describes a small, low-resource, deployed spacecraft used as part of a local, multipoint measurement network. A B-field aligned sounding rocket ejects four of these spin-stabilized spacecraft in a cross pattern. In this application, each spacecraft carries two retarding potential analyzers which are used to determine plasma density, flow, and ion temperature. An inertial measurement unit and a light-emitting diode array are used to determine the position and orientation of the devices after deployment. The design of this spacecraft is first described, and then results from a recent test flight are discussed. This flight demonstrated the successful operation of the deployment mechanism and telemetry systems, provided some preliminary plasma measurements in a simple mid-latitude environment, and revealed several design issues.

Needs of Advanced Safeguards Technologies for Future Nuclear Fuel Cycle (FNFC) Facilities and a Trial Application of SBD Concept to Facility Design of a Hypothetical FNFC Facility

International Nuclear Information System (INIS)

Seya, M.; Hajima, R.; Nishimori, N.; Hayakawa, T.; Kikuzawa, N.; Shizuma, T.; Fujiwara, M.

2010-01-01

Some of future nuclear fuel cycle (FNFC) facilities are supposed to have the characteristic features of very large throughput of plutonium, low decontamination reprocessing (no purification process; existence of certain amount of fission products (FP) in all process material), full minor actinides (MA) recycle, and treatment of MOX with FP and MA in fuel fabrication. In addition, the following international safeguards requirements have to be taken into account for safeguards approaches of the FNFC facilities. -Application of integrated safeguards (IS) approach; -Remote (unattended) verification; - 'Safeguards by Design' (SBD) concept. These features and requirements compel us to develop advanced technologies, which are not emerged yet. In order to realize the SBD, facility designers have to know important parts of design information on advanced safeguards systems before starting the facility design. The SBD concept requires not only early start of R and D of advanced safeguards technologies (before starting preliminary design of the facility) but also interaction steps between researchers working on safeguards systems and nuclear facility designers. The interaction steps are follows. Step-1; researchers show images of advanced safeguards systems to facility designers based on their research. Step-2; facility designers take important design information on safeguards systems into process systems of demonstration (or test) facility. Step-3; demonstration and improvement of both systems based on the conceptual design. Step-4; Construction of a FNFC facility with the advanced safeguards systems We present a trial application of the SBD concept to a hypothetical FNFC facility with an advanced hybrid K-edge densitometer and a Pu NDA system for spent nuclear fuel assembly using laser Compton scattering (LCS) X-rays and γ-rays and other advanced safeguards systems. (author)

A method for development of efficient 3D models for neutronic calculations of ASTRA critical facility using experimental information

Energy Technology Data Exchange (ETDEWEB)

Balanin, A. L.; Boyarinov, V. F.; Glushkov, E. S.; Zimin, A. A.; Kompaniets, G. V.; Nevinitsa, V. A., E-mail: Neviniza-VA@nrcki.ru; Moroz, N. P.; Fomichenko, P. A.; Timoshinov, A. V. [National Research Center Kurchatov Institute (Russian Federation); Volkov, Yu. N. [National Research Nuclear University MEPhI (Russian Federation)

2016-12-15