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Dual arm master controller development

Description: The advanced servomanipulator (ASM) slave was designed with an anthropomorphic stance, gear/torque tube power drives, and modular construction. These features resulted in increased inertia, friction, and backlash relative to tape-driven manipulators. Studies were performed which addressed the human factors design and performance trade-offs associated with the corresponding master controller best suited for the ASM. The results of these studies, as well as the conceptual design of the dual arm m… more
Date: January 1, 1985
Creator: Kuban, D. P. & Perkins, G. S.
Partner: UNT Libraries Government Documents Department
open access

Low Energy X-Ray Spectra Measured With a Mercuric Iodide Energy Dispersive Spectrometer in a Scanning Electron Microscope

Description: A mercuric iodide energy dispersive x-ray spectrometer, with Peltier cooling provided for the detector and input field effect transistor, has been developed and tested in a scanning electron microscope. X-ray spectra were obtained with the 15 keV electron beam. An energy resolution of 225 eV (FWHM) for Mn-K/sub ..cap alpha../ at 5.9 keV and 195 eV (FWHM) for Mg-K line at 1.25 keV has been measured. Overall system noise level was 175 eV (FWHM). The detector system characterization with a carbon … more
Date: January 1, 1985
Creator: Iwanczyk, J. S.; Dabrowski, A. J.; Huth, G. C.; Bradley, J. G.; Conley, J. M. & Albee, A. L.
Partner: UNT Libraries Government Documents Department
open access

Refractory materials for high-temperature thermoelectric energy conversion

Description: Theoretical work of two decades ago adequately explained the transport behavior and effectively guided the development of thermoelectric materials of high conversion efficiencies of conventional semiconductors (e.g., SiGe alloys). The more significant contributions involved the estimation of optimum doping concentrations, the reduction of thermal conductivity by solid solution doping and the development of a variety of materials with ZT approx. 1 in the temperature range 300 K to 1200 K. It was… more
Date: January 1, 1983
Creator: Wood, C. & Emin, D.
Partner: UNT Libraries Government Documents Department
open access

Interplanetary propulsion using inertial fusion

Description: Inertial fusion can be used to power spacecraft within the solar system and beyond. Such spacecraft have the potential for short-duration manned-mission performance exceeding other technologies. We are conducting a study to assess the systems aspects of inertial fusion as applied to such missions, based on the conceptual engine design of Hyde (1983) we describe the required systems for an entirely new spacecraft design called VISTA that is based on the use of DT fuel. We give preliminary design… more
Date: January 1, 1987
Creator: Orth, C.D.; Hogan, W.J.; Hoffman, N.; Murray, K.; Klein, G. & Diaz, F.C.
Partner: UNT Libraries Government Documents Department
open access

The VISTA spacecraft: Advantages of ICF (Inertial Confinement Fusion) for interplanetary fusion propulsion applications

Description: Inertial Confinement Fusion (ICF) is an attractive engine power source for interplanetary manned spacecraft, especially for near-term missions requiring minimum flight duration, because ICF has inherent high power-to-mass ratios and high specific impulses. We have developed a new vehicle concept called VISTA that uses ICF and is capable of round-trip manned missions to Mars in 100 days using A.D. 2020 technology. We describe VISTA's engine operation, discuss associated plasma issues, and descri… more
Date: October 2, 1987
Creator: Orth, C.D.; Klein, G.; Sercel, J.; Hoffman, N.; Murray, K. & Chang-Diaz, F.
Partner: UNT Libraries Government Documents Department
open access

Semiconductor processing with excimer lasers

Description: The advantages of pulsed excimer lasers for semiconductor processing are reviewed. Extensive comparisons of the quality of annealing of ion-implanted Si obtained with XeCl and ruby lasers have been made. The results indicate that irrespective of the large differences in the optical properties of Si at uv and visible wavelengths, the efficiency of usage of the incident energy for annealing is comparable for the two lasers. However, because of the excellent optical beam quality, the XeCl laser ca… more
Date: January 1, 1983
Creator: Young, R.T.; Narayan, J.; Christie, W.H.; van der Leeden, G.A.; Rothe, D.E. & Cheng, L.J.
Partner: UNT Libraries Government Documents Department
open access

Neutral sheet crossings in the distant magnetotail

Description: We have analyzed the magnetic field data from ISEE-3 in the distant magnetotail for 18 crossings of the cross-tail current sheet (or so-called natural sheet) to determine the direction of the normal component B/sub z/. The crossings occurred near the middle of the aberrated magnetotail (0 < y < 30 R/sub e, -10 < z < 5) in GSM coordinates, at a distance of about 220 R/sub e/, January 28 to February 12, 1983; in each case the plasma flow velocity was tailward. In 2 cases we found B/sub z/ negativ… more
Date: January 1, 1985
Creator: Heikkila, W. J.; Slavin, J. A.; Smith, E. J.; Baker, D. N. & Zwickl, R. D.
Partner: UNT Libraries Government Documents Department
open access

Transport vehicle for manned Mars missions powered by inertial confinement fusion

Description: Inertial confinement fusion (ICF) is an ideal engine power source for manned spacecraft to Mars because of its inherently high power-to-mass ratios and high specific impulses. We have produced a concept for a vehicle powered by ICF and utilizing a magnetic thrust chamber to avoid plasma thermalization with wall structures and the resultant degradation of specific impulse that are unavoidable with the use of mechanical thrust chambers. This vehicle is capable of 100-day manned Mars missions with… more
Date: June 26, 1987
Creator: Orth, C.D.; Klein, G.; Sercel, J.; Hoffman, N.; Murray, K. & Chang-Diaz, F.
Partner: UNT Libraries Government Documents Department
open access

Generation of a strong core-centering force in a submillimeter compound droplet system

Description: By amplitude-modulating the driving voltage of an acoustic levitating apparatus, a strong core-centering force can be generated in a submillimeter compound droplet system suspended by the radiation pressure in a gaseous medium. Depending on the acoustic characteristics of the droplet system, it has been found that the technique can be utilized advantageously in the multiple-layer coating of an inertial-confinement-fusion pellet.
Date: January 1, 1981
Creator: Lee, M. C.; Feng, I.; Elleman, D. D.; Wang, T. G. & Young, A. T.
Partner: UNT Libraries Government Documents Department
open access

Space nuclear power system and the design of the nuclear electric propulsion OTV

Description: Payload increases of three to five times that of the Shuttle/Centaur can be achieved using nuclear electric propulsion. Various nuclear power plant options being pursued by the SP-100 Program are described. These concepts can grow from 100 kW/sub e/ to 1MW/sub e/ output. Spacecraft design aspects are addressed, including thermal interactions, plume interactions, and radiation fluences. A baseline configuration is described accounting for these issues. Safety aspects of starting the OTV transfer… more
Date: January 1, 1984
Creator: Buden, D. & Garrison, P.W.
Partner: UNT Libraries Government Documents Department
open access

Plasma properties of driver gas following interplanetary shocks observed by ISEE-3

Description: Plasma fluid parameters calculated from solar wind and magnetic field data obtained on ISEE 3 were studied to determine the characteristic properties of driver gas following interplanetary shocks. Of 54 shocks observed from August 1978 to February 1980, 9 contained a well defined driver gas that was clearly identifiable by a discontinuous decrease in the average proton temperature across a tangential discontinuity. While helium enhancements were present in all of 9 of these events, only about h… more
Date: January 1, 1982
Creator: Zwickl, R. D.; Asbridge, J. R.; Bame, S. J.; Feldman, W. C.; Gosling, J. T. & Smith, E. J.
Partner: UNT Libraries Government Documents Department
open access

Dual arm master controller concept

Description: The Advanced Servomanipulator (ASM) slave was designed with an anthropomorphic stance, gear/torque tube power drives, and modular construction. These features resulted in increased inertia, friction, and backlash relative to tape-driven manipulators. Studies were performed which addressed the human factors design and performance trade-offs associated with the corresponding master controller best suited for the ASM. The results of these studies, as well as the conceptual design of the dual arm m… more
Date: January 1, 1984
Creator: Kuban, D.P. & Perkins, G.S.
Partner: UNT Libraries Government Documents Department
open access

Steepened magnetosonic waves in the high. beta. plasma surrounding Comet Giacobini-Zinner

Description: We extend the previous studies of intense hydromagnetic waves at Giacobini-Zinner to investigate the mode and direction of wave propagation. Simultaneous high-resolution measurements of electron density fluctuations demonstrate that the long period (approx.100 s) waves are propagating in the magnetosonic mode. Principal axis analyses of the long period waves and accompanying partial rotations show that the sum of the wave phase rotations is 360/sup 0/C, indicating that both are parts of the sam… more
Date: January 1, 1986
Creator: Tsurutani, B. T.; Smith, E. J.; Thorne, R. M.; Gosling, J. T. & Matsumoto, H.
Partner: UNT Libraries Government Documents Department
open access

The P/Giacobini-Zinner Magnetotail

Description: On September 11, 1985 the International Cometary Explorer passed behind Comet Giacobini-Zinner with a closest approach distance of 7800 km. In agreement with Alfven's interplanetary magnetic field line draping model of cometary type I tails, a well defined 1 x 10/sup 4/ km diameter magnetotail was observed downstream of the inner coma. This study uses the ICE magnetic field, plasma electron, plasma wave, and energetic ion observations to investigate the structure and stability of the Giacobini-… more
Date: January 1, 1986
Creator: Slavin, J. A.; Smith, E. J.; Daly, P. W.; Flammer, K. R.; Gloeckler, G.; Goldberg, B. A. et al.
Partner: UNT Libraries Government Documents Department
open access

The comet Giacobini-Zinner magnetotail: Axial stresses and inferred near-nucleus properties

Description: Utilizing the electron and magnetic field data from the ICE tail traversal of Comet Giacobini-Zinner along with the MHD equations, we have developed a steady state, stress balance model of the cometary magnetotail. With it we infer many important but unmeasured ion properties within the G-Z magnetotail both at ICE and upstream at the average point along each streamline where cometary ions are picked-up. The derived tailward ion flow speed at ICE is quite constant at approx.-20 to -30 km/sec acr… more
Date: October 1, 1986
Creator: McComas, D. J.; Gosling, J. T.; Bame, S. J.; Slavin, J. A.; Smith, E. J. & Steinberg, J. L.
Partner: UNT Libraries Government Documents Department
open access

MHD waves detected by ice at distances > 28 x 10/sup 6/ km from Comet Halley: Cometary or solar wind origin

Description: Spectral analyses of the high resolution magnetic field data are employed to determine if there is evidence of cometary heavy ion pickup when ICE was closest to Halley, approx.28 x 10/sup 6/ km. No evidence is found for the presence of heavy ion cyclotron waves. However, from this search, two new wave modes are discovered in the solar wind: electromagnetic ion cyclotron waves and drift mirror mode waves. Both modes have scales of 10 to 60 s (1 to 6 T/sub p/) in the spacecraft frame. The possibi… more
Date: January 1, 1986
Creator: Tsurutani, B. T.; Brinca, A. L.; Smith, E. J.; Thorne, R. M.; Scarf, F. L.; Gosling, J. T. et al.
Partner: UNT Libraries Government Documents Department
open access

SP-100, a project manager`s view. Technical information report

Description: Born to meet the special needs of America`s space effort, the SP-100 Program testifies to the cooperation among government agencies. The Department of Energy (DOE), the National Aeronautics and Space Administration (NASA), and the Defense Advanced Research Projects Agency (DARPA) are working together to produce a 100-kW power system for use in outer space. At this point in the effort, it is appropriate to review: The approach to meet program goals; the status of activities of the Project Office… more
Date: December 1, 1983
Creator: Truscello, V. C.
Partner: UNT Libraries Government Documents Department
open access

External flow radiators for reduced space powerplant temperatures. Technical information report

Description: Nuclear space powerplants can operate at temperatures below 900 K and use stainless steel construction without a weight penalty if new radiator concepts can achieve radiator weights of 1-3 kg/m{sup 2}. Conventional tube-and-fin radiators weight about 10 kg/m{sup 2} because of heavy tube walls to prevent meteroid puncture. Radiator designs that do not require meteroid protection are possible; they operate with fluids of low vapor pressure that can be exposed directly to space in external-flow ra… more
Date: January 1, 1984
Creator: Elliott, D. G.
Partner: UNT Libraries Government Documents Department
open access

PEGASUS: a multi-megawatt nuclear electric propulsion system

Description: With the Space Transportation System (STS), the advent of space station Columbus and the development of expertise at working in space that this will entail, the gateway is open to the final frontier. The exploration of this frontier is possible with state-of-the-art hydrogen/oxygen propulsion but would be greatly enhanced by the higher specific impulse of electric propulsion. This paper presents a concept that uses a multi-megawatt nuclear power plant to drive an electric propulsion system. The… more
Date: June 1, 1985
Creator: Coomes, Edmund P.; Cuta, Judith M.; Webb, Brent J. & King, David Q.
Partner: UNT Libraries Government Documents Department
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