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This report documents the updated six-degree-of-freedom reentry simulation TMAGRA6C used in the Aerospace Nuclear Safety Program, ANSP. The simulation provides for the inclusion of the effects of ablation on the aerodynamic stability and drag of reentry bodies, specifically the General Purpose Heat Source, GPHS. The existing six-degree-of-freedom reentry body simulations (TMAGRA6A and TMAGRA6B) used in the JHU/APL Nuclear Safety Program do not include aerodynamic effects resulting from geometric changes to the configuration due to ablation from reentry flights. A wind tunnel test was conducted in 1989 to obtain the effects of ablation on the hypersonic aerodynamics of the GPHS module. The analyzed data were used to form data sets which are included herein in tabular form. These are used as incremental aerodynamic inputs in the new TMAGRA6C six-degree-of-freedom reentry simulation. 20 refs., 13 figs., 2 tabs.

A careful study of a specially formed thin silicon layer on TiB/sub 2/-coated sapphire reveals that the interaction layer of TiSi/sub 2/ is composed of larger grains. Processing steps were developed which lead closer to the goal of fabricating polycrystalline silicon photovoltaic devices completely by vacuum deposition. Both n-type and p-type silicon are now being deposited. New deposition masks were made for depositing the n-regions upon the p-layers. New electrode deposition masks were also made for a direct electroding process to replace the photolithographic process used previously. The TiB/sub 2/ bottom electrode fabrication has been achieved in a single vacuum chamber. Reaction constants and activation energy for TiB/sub 2/ layer formation were determined to be less than those reported by other authors for bulk material. Studies of crystallite growth and interfacial interactions have continued. Major sources of undesirable impurities have been identified and removed from the vacuum chambers. The changes made this quarter have not been incorporated into a completed photovoltaic device.

Reentry analyses consisting of ablation response, thermal response and thermal stress response have been conducted on the Light Weight Radioisotope Heater Unit for Galileo/VEEGA reentry conditions. Sequential ablation analyses of the LWRHU aeroshell, the fuel clad, and the fuel pellet have been conducted in reentry regimes where the aeroshell has been deemed to fail. The failure criterion for ablation is assumed to be recession corresponding to 50% of the wall thickness (the design criterion recommended in the DOE Overall Safety Manual). Although the analyses have been carried far beyond this limit (as presented and discussed herein), JHU/APL endorses the position that failure may occur at the time that this recession is achieved or at lower altitudes within the heat pulse considering the uncertainties in the aerodynamic, thermodynamic, and thermo-structural analyses and modeling. These uncertainties result mainly because of the high energies involved in the VEEGA reentries compared to orbital decay reentries. Risk evaluations should consider the fact that for shallow flight paths the unit may disassemble at high-altitude as a result of ablation or may remain intact until it impacts with a clad that had been molten. 80 refs., 46 figs., 16 tabs.

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This quarterly report summarizes work on the following tasks: OTEC methanol; approaches for financing OTEC proof-of-concept experimental vessels; investigation of OTEC-ammonia as an alternative fuel; review of electrolyzer development programs and requirements; hybrid geothermal-OTEC power plants: single-cycle performance; estimates; and hybrid geothermal-OTEC power plants: dual-cycle performance estimates.

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The Johns Hopkins University Applied Physics Laboratory, under contracts with several agencies of the federal government and an agency of the State of Maryland, is engaged in developing energy resources, utilization concepts, and monitoring and storage methods. This Quarterly Report summarizes the work on the various tasks as of 31 March 1980. The Energy Quarterly Report is divided into four sections. The first, Geothermal Energy Development Planning and Technical Assistance, supported by the Department of Energy/Division of Geothermal Energy (DOE/DGE), contains reports on the progress of geothermal-related tasks on which effort was concentrated during the quarter. The second section, Operational Research, Hydroelectric Power Development, supported by the Department of Energy/Resource Applications (DOE/DGE), contains reports on small-scale hydroelectric investigations in the southeastern states. The third section, Seismotectonic Investigation, supported by the Reactor Safety Research Division of the Nuclear Regulatory Commission, reports on a neotectonic investigation in Connecticut. The fourth section, Energy Conversion and Storage Techniques, contains two articles, the first on OTEC core unit testing supported by the Department of Energy/Division of Central Solar Technology (DOE/CST), and the second on an analysis of the Community Annual Storage Energy System at the U.S. Naval Air Station, Norfolk, Va. This work is supported …

The Johns Hopkins University Applied Physics Laboratory, under contracts with several agencies of the federal government and an agency of the State of Maryland, is engaged in developing energy resources, utilization concepts, and monitoring and storage methods. This Quarterly Report summarizes the work on the various tasks as of 30 June 1980. The Energy Quarterly Report is divided into three sections. The first, Geothermal Energy Development Planning and Technical Assistance, supported by the Department of Energy/Division of Geothermal Energy (DOE/DGE), contains reports on the progress of geothermal-related tasks on which effort was concentrated during the quarter. The second section, Operational Research, Hydroelectric Power Development, supported by the Department of Energy/Resource Applications (DOE/RA), contains reports on small-scale hydroelectric investigations in the southeastern states. The third section, Energy Conversion and Storage Techniques, contains three articles. The first is on data analysis of OTEC core unit condenser tests, and is supported by the Department of Energy/Division of Central Solar Technology (DOE/CST). The second is on the current status of the Community Annual Storage Energy System at the U.S. Naval Air Station, Norfolk, Va., and is supported by the Department of Energy and the Department of Defense, Naval Facilities Engineering Command/Atlantic Division. The third …

The Johns Hopkins University Applied Physics Laboratory, under contracts with several agencies of the federal government, is engaged in developing energy resources, utilization concepts, and monitoring and storage methods. This Quarterly Report summarizes the work on the various tasks as of 31 September 1980. The Energy Quarterly Report is divided into four sections. The first, Geothermal Energy Development Planning and Technical Assistance, supported by the Department of Energy/Division of Geothermal Energy (DOE/DGE), contains reports on the progress of geothermal-related tasks on which effort was concentrated during the quarter. The second section, Operational Research, Hydroelectric Power Development, supported by the Department of Energy/Resource Applications (DOE/RA), contains reports on small-scale hydroelectric investigations in the southeastern states. The third section, Seismotectonic Investigations, supported by the Reactor Safety Research Division of the Nuclear Regulatory Commission (NRC), reports on neotectonic investigations of the Manhattan Prong. The fourth section, Energy Conversion and Storage Techniques, contains three articles. The first is an evaluation of the Einstein refrigerator, supported by independent IR&D funds. The second concerns OTEC pilot plant performance calculations, supported by the Department of Energy/Division of Central Solar Technology (DOE/CST). The third, describing a study of landfill methane recovery, is supported by the National Park Service.

The Johns Hopkins University Applied Physics Laboratory, is engaged in developing energy resource, utilization concepts, and monitoring and storage methods. This Quarterly Report summarizes the work on the various tasks as of 31 March 1980. The Energy Quarterly Report is divided into four sections. The first, Geothermal Energy Development Planning and Technical Assistance, contains reports on the progress of geothermal-related tasks on which effort was concentrated during the quarter. The second section, Operational Research, Hydroelectric Power Development, contains reports on small-scale hydroelectric investigations in the southeastern states. The third section, Seismotectonic Investigation, reports on a neotectonic investigation in Connecticut. The fourth section, Energy Conversion and Storage Techniques, contains two articles, the first on OTEC core unit testing supported by the Department of Energy/Division of Central Solar Technology (DOE/CST), and the second on an analysis of the Community Annual Storage Energy System at the US Naval Air Station, Norfolk, Va.

The Johns Hopkins University Applied Physics Laboratory, under contracts with several agencies of the federal government and an agency of the State of Maryland, is engaged in developing energy resources, utilization concepts, and storage methods. This Quarterly Report summarizes the work on the various tasks as of 31 December 1979. The Energy Quarterly Report is divided into five sections. The first, Geothermal Energy Development Planning and Technical Assistance, supported by the Department of Energy/Resource Applications (DOE/RA), contains reports on the progress of those geothermal-related tasks where effort was concentrated during the quarter. The second section, Operational Research, Hydroelectric Power Development, also supported by DOE/RA, contains reports on small-scale hydroelectric investigations in the southeastern states. The third section, Seismotectonic Studies, supported by the Reactor Safety Research Division of the Nuclear Regulatory Commission, reports on neotectonic investigations in Connecticut. The fourth section, Energy Conversion and Storage Techniques, contains two articles, the first on OTEC core unit testing supported by the Department of Energy, Division of Central Solar Technology (DOE/CST), and the second on recovery of landfill methane, supported by the Argonne National Laboratory. The fifth section, New Energy Technologies, reports on Laboratory studies of an unconventional gas source--Eastern Devonian shales.

This quarterly report includes summaries of the following tasks: (1) OTEC pilot plant conceptual design review; (2) OTEC methanol; (3) management decision requirements for OTEC construction; (4) hybrid geothermal - OTEC (GEOTEC) power plant performance estimates; and (5) supervision of testing of pneumatic wave energy conversion system.

The objectives, methodologies, data, and analytical results of the Chalk Point Cooling Tower Program are reviewed. The overview intergrates the concepts and activities of the various program elements to provide a coherent view of the program in its entirety. Samples of the various data acquired are included together with very brief summaries of the conclusions. The report is extensively referenced to provide specific directions to the more extensive treatments of the program, data tabulations, and tape libraries available in the complete library of Chalk Point reports. The Chalk Point data is a resource for the study of cooling tower salt deposition processes and impacts in general. The methods used, while developed to facilitate the assessment of salt drift impact at Chalk Point, also have applicability to cooling tower impact analysis at other sites.

As asked by the U. S. Department of Energy/Office of Special Applications, and in support of the Environmental Impact Statement for the Cassini mission, The Johns Hopkins University/Applied Physics Laboratory (JHU/APL) has conducted preliminary one-dimensional ablation and thermal analyses of the General Purpose Heat Source (GPHS). The predicted earth entry conditions provided by the Jet Propulsion Laboratory (JPL) for a Cassini Venus-Venus-Earth-Jupiter Gravity Assist (VVEJGA) trajectory were used as initial conditions. The results of this study which constitute the initial reentry analysis assessment leading to the Cassini Updated Safety, Analysis Report (USAR) are discussed in this document.

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Motion studies of the General Purpose Heat Source Module, GPHS, which were conducted in the heat pulse intervals associated with entries from earth gravity assist trajectories. The APL six-degree-of-freedom reentry program designated TMAGRA6C was used. The objectives of the studies were to (1) determine whether the GPHS module entering the earth`s atmosphere from an earth-gravity-assist trajectory has a preferred orientation during the heat pulse of reentry, (2) determine the effect of magnus force on the roll rate and angle of attack of the GPHS during an EGA entry, (3) determine the effect of the magnitude of pitch and roll damping on the GPHS motion.

Motion studies of the General Purpose Heat Source Module, GPHS, which were conducted in the heat pulse intervals associated with entries from earth gravity assist trajectories. The APL six-degree-of-freedom reentry program designated TMAGRA6C was used. The objectives of the studies were to (1) determine whether the GPHS module entering the earth's atmosphere from an earth-gravity-assist trajectory has a preferred orientation during the heat pulse of reentry, (2) determine the effect of magnus force on the roll rate and angle of attack of the GPHS during an EGA entry, (3) determine the effect of the magnitude of pitch and roll damping on the GPHS motion.

The Johns Hopkins University/Applied Physics Laboratory, JHU/API, in support of Lawrence Livermore National Laboratory, LLNL, is conducting aerodynamic, trajectory, and structural analysis of the Advanced Single Stage Technology Rapid Insertion Demonstration (ASTRID) vehicle, being launched out of Vandenberg Air Force Base (VAFB) in February 1994. The launch is designated ASTRID-1 and is the first in a series of three that will be launched out of VAFB. Launch dates for the next two flights have not been identified, but they are scheduled for the 1994-1995 time frame. The primary goal of the ASTRID-1 flight is to test the LLNL light weight thrust on demand bi-propellant pumped divert propulsion system. The system is employed as the main thrusters for the ASTRID-1 vehicle and uses hydrazine as the mono-propellant. The major conclusions are: (1) The vehicle is very stable throughout flight (stability margin = 17 to 24 inches); (2) The aerodynamic frequency and the roll rate are such that pitch-roll interactions will be small; (3) The high stability margin combined with the high launcher elevation angle makes the vehicle flight path highly sensitive to perturbations during the initial phase of flight, i.e., during the first second of flight after leaving the rail; (4) …

Motion studies of the General Purpose Heat Source Module, GPHS, were conducted in the heat pulse interval associated with entries from earth gravity assist trajectories. The APL six-degree-of-freedom reentry program designated TMAGRA6C was used. The objectives of the studies were to (1) determine the effect of ablation on GPHS motion, and (2) determine whether the GPHS module entering the earth`s atmosphere from an earth-gravity-assist trajectory has a preferred orientation during the heat pulse phase of reentry. The results are given in summary form for easy visualization of the initial conditions investigated and to provide a quick-look of the resulting motion. Detail of the motion is also given for the parameters of interest for each case studied. Selected values of initial pitch rate, roll rate, and combinations of these within the range 0{degree} to 1000{degrees}/sec were investigated for initial reentry angles of -7{degrees} (shallow) and -90{degrees} (steep) and initial angles of attack of 0{degree} (broadface to the wind) and 90{degrees}. Although the studies are not exhaustive, a sufficient number of reentry conditions (initial altitude, reentry angle, angle of attack, rotational motion) have been investigated to deduce certain trends. The results also provide information on additional reentry conditions that need to be …

Motion studies of the General Purpose Heat Source Module, GPHS, were conducted in the heat pulse interval associated with entries from earth gravity assist trajectories. The APL six-degree-of-freedom reentry program designated TMAGRA6C was used. The objectives of the studies were to (1) determine the effect of ablation on GPHS motion, and (2) determine whether the GPHS module entering the earth's atmosphere from an earth-gravity-assist trajectory has a preferred orientation during the heat pulse phase of reentry. The results are given in summary form for easy visualization of the initial conditions investigated and to provide a quick-look of the resulting motion. Detail of the motion is also given for the parameters of interest for each case studied. Selected values of initial pitch rate, roll rate, and combinations of these within the range 0[degree] to 1000[degrees]/sec were investigated for initial reentry angles of -7[degrees] (shallow) and -90[degrees] (steep) and initial angles of attack of 0[degree] (broadface to the wind) and 90[degrees]. Although the studies are not exhaustive, a sufficient number of reentry conditions (initial altitude, reentry angle, angle of attack, rotational motion) have been investigated to deduce certain trends. The results also provide information on additional reentry conditions that need to be …