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Sample records for ldef tray clamps

  1. Surface characterization of selected LDEF tray clamps

    NASA Technical Reports Server (NTRS)

    Cromer, T. F.; Grammer, H. L.; Wightman, J. P.; Young, Philip R.; Slemp, Wayne S.

    1993-01-01

    The surface characterization of chromic acid anodized 6061-T6 aluminum alloy tray clamps has shown differences in surface chemistry depending upon the position on the Long Duration Exposure Facility (LDEF). Water contact angle results showed no changes in wettability of the tray clamps. The overall surface topography of the control, trailing edge(E3) and leading edge(D9) samples was similar. The thickness of the aluminum oxide layer for all samples determined by Auger depth profiling was less than one micron. X-ray photoelectron spectroscopy (XPS) analysis of the tray clamps showed significant differences in the surface composition. Carbon and silicon containing compounds were the primary contaminants detected.

  2. Spectral infrared hemispherical reflectance measurements for LDEF tray clamps

    NASA Technical Reports Server (NTRS)

    Cromwell, B. K.; Shepherd, S. D.; Pender, C. W.; Wood, B. E.

    1993-01-01

    Infrared hemispherical reflectance measurements that were made on 58 chromic acid anodized tray clamps from LDEF are described. The measurements were made using a hemiellipsoidal mirror reflectometer with interferometer for wavelengths between 2-15 microns. The tray clamps investigated were from locations about the entire spacecraft and provided the opportunity for comparing the effects of atomic oxygen at each location. Results indicate there was essentially no dependence on atomic oxygen fluence for the surfaces studied, but there did appear to be a slight dependence on solar radiation exposure. The reflectances of the front sides of the tray clamps consistently were slightly higher than for the protected rear tray clamp surfaces.

  3. Spectral infrared hemispherical reflectance measurements for LDEF tray clamps

    NASA Technical Reports Server (NTRS)

    Wood, Bobby E.; Cromwell, Brian K.; Pender, Charles W.; Shepherd, Seth D.

    1992-01-01

    This paper describes infrared hemispherical reflectance measurements (2-15 microns) that were made on 58 chromic acid anodized tray clamps retrieved from the LDEF spacecraft. These clamps were used for maintaining the experiments in place and were located at various locations about the spacecraft. Changes in reflectance of the tray clamps at these locations were compared with atomic oxygen fluxes at the same locations. A decrease in absorption band depth was seen for the surfaces exposed to space indicating that there was some surface layer erosion. In all of the surfaces measured, little evidence of contamination was observed and none of the samples showed evidence of the brown nicotine stain that was so prominent in other experiments. Total emissivity values were calculated for both exposed and unexposed tray clamp surfaces. Only small differences, usually less than 1 percent, were observed. The spectral reflectances were measured using a hemi-ellipsoidal mirror reflectometer matched with an interferometer spectrometer. The rapid scanning capability of the interferometer allowed the reflectance measurements to be made in a timely fashion. The ellipsoidal mirror has its two foci separated by 2 inches and located on the major axis. A blackbody source was located at one focus while the tray clamp samples were located at the conjugate focus. The blackbody radiation was modulated and then focused by the ellipsoid onto the tray clamps. Radiation reflected from the tray clamp was sampled by the interferometer by viewing through a hole in the ellipsoid. A gold mirror (reflectance approximately 98 percent) was used as the reference surface.

  4. Spectral infrared hemispherical reflectance measurements for LDEF tray clamps

    NASA Technical Reports Server (NTRS)

    Wood, Bobby E.; Cromwell, Brian K.; Pender, Charles W.; Shepherd, Seth D.

    1992-01-01

    This paper describes infrared hemispherical reflectance measurements (2-15 microns) that were made on 58 chromic acid anodized tray clamps retrieved from the LDEF spacecraft. These clamps were used for maintaining the experiments in place and were located at various locations about the spacecraft. Changes in reflectance of the tray clamps at these locations were compared with atomic oxygen fluxes at the same locations. A decrease in absorption band depth was seen for the surfaces exposed to space indicating that there was some surface layer erosion. In all of the surfaces measured, little evidence of contamination was observed and none of the samples showed evidence of the brown nicotine stain that was so prominent in other experiments. Total emissivity values were calculated for both exposed and unexposed tray clamp surfaces. Only small differences, usually less than 1 percent, were observed. The spectral reflectances were measured using a hemi-ellipsoidal mirror reflectometer matched with an interferometer spectrometer. The rapid scanning capability of the interferometer allowed the reflectance measurements to be made in a timely fashion. The ellipsoidal mirror has its two foci separated by 2 inches and located on the major axis. A blackbody source was located at one focus while the tray clamp samples were located at the conjugate focus. The blackbody radiation was modulated and then focused by the ellipsoid onto the tray clamps. Radiation reflected from the tray clamp was sampled by the interferometer by viewing through a hole in the ellipsoid. A gold mirror (reflectance approximately 98 percent) was used as the reference surface.

  5. Scanning electron microscope/energy dispersive x ray analysis of impact residues on LDEF tray clamps

    NASA Technical Reports Server (NTRS)

    Bernhard, Ronald P.; Durin, Christian; Zolensky, Michael E.

    1992-01-01

    To better understand the nature of particulates in low-Earth orbit (LEO), and their effects on spacecraft hardware, we are analyzing residues found in impacts on the Long Duration Exposure Facility (LDEF) tray clamps. LDEF experiment trays were held in place by 6 to 8 chromic-anodized aluminum (6061-T6) clamps that were fastened to the spacecraft frame using three stainless steel hex bolts. Each clamp exposed an area of approximately 58 sq cm (4.8 cm x 12.7 cm x .45 cm, minus the bolt coverage). Some 337 out of 774 LDEF tray clamps were archived at JSC and are available through the Meteoroid & Debris Special Investigation Group (M&D SIG). Optical scanning of clamps, starting with Bay/Row A01 and working toward H25, is being conducted at JSC to locate and document impacts as small as 40 microns. These impacts are then inspected by Scanning Electron Microscopy/Energy Dispersive X-ray Analysis (SEM/EDXA) to select those features which contain appreciable impact residue material. Based upon the composition of projectile remnants, and using criteria developed at JSC, we have made a preliminary discrimination between micrometeoroid and space debris residue-containing impact features. Presently, 13 impacts containing significant amounts of unmelted and semi-melted micrometeoritic residues were forwarded to Centre National d'Etudes Spatiales (CNES) in France. At the CNES facilities, the upgraded impacts were analyzed using a JEOL T330A SEM equipped with a NORAN Instruments, Voyager X-ray Analyzer. All residues were quantitatively characterized by composition (including oxygen and carbon) to help understand interplanetary dust as possibly being derived from comets and asteroids.

  6. Scanning electron microscope/energy dispersive x ray analysis of impact residues on LDEF tray clamps

    NASA Technical Reports Server (NTRS)

    Bernhard, Ronald P.; Durin, Christian; Zolensky, Michael E.

    1992-01-01

    To better understand the nature of particulates in low-Earth orbit (LEO), and their effects on spacecraft hardware, we are analyzing residues found in impacts on the Long Duration Exposure Facility (LDEF) tray clamps. LDEF experiment trays were held in place by 6 to 8 chromic-anodized aluminum (6061-T6) clamps that were fastened to the spacecraft frame using three stainless steel hex bolts. Each clamp exposed an area of approximately 58 sq cm (4.8 cm x 12.7 cm x .45 cm, minus the bolt coverage). Some 337 out of 774 LDEF tray clamps were archived at JSC and are available through the Meteoroid & Debris Special Investigation Group (M&D SIG). Optical scanning of clamps, starting with Bay/Row A01 and working toward H25, is being conducted at JSC to locate and document impacts as small as 40 microns. These impacts are then inspected by Scanning Electron Microscopy/Energy Dispersive X-ray Analysis (SEM/EDXA) to select those features which contain appreciable impact residue material. Based upon the composition of projectile remnants, and using criteria developed at JSC, we have made a preliminary discrimination between micrometeoroid and space debris residue-containing impact features. Presently, 13 impacts containing significant amounts of unmelted and semi-melted micrometeoritic residues were forwarded to Centre National d'Etudes Spatiales (CNES) in France. At the CNES facilities, the upgraded impacts were analyzed using a JEOL T330A SEM equipped with a NORAN Instruments, Voyager X-ray Analyzer. All residues were quantitatively characterized by composition (including oxygen and carbon) to help understand interplanetary dust as possibly being derived from comets and asteroids.

  7. Scanning electron microscope/energy dispersive x ray analysis of impact residues in LDEF tray clamps

    NASA Technical Reports Server (NTRS)

    Bernhard, Ronald P.; Durin, Christian; Zolensky, Michael E.

    1993-01-01

    Detailed optical scanning of tray clamps is being conducted in the Facility for the Optical Inspection of Large Surfaces at JSC to locate and document impacts as small as 40 microns in diameter. Residues from selected impacts are then being characterized by Scanning Electron Microscopy/Energy Dispersive X-ray Analysis at CNES. Results from this analysis will be the initial step to classifying projectile residues into specific sources.

  8. LDEF (Postflight), S1001 : Low-Temperature Heat Pipe Experiment Package (HEPP) for LDEF, Tray H01

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The postflight photograph of the Low Tem perature Heat Pipe Package (HEPP) power tray was taken in the SAEF II at KSC after an all up system checkout with interfacing experiments and removal of the tray from the LDEF. An outline of the experiment tray clamp blocks is clearly visible in the light brown stain on the experiment tray flanges. The Low Temperature Heat Pipe Package (HEPP) experiment occupies two 12 inch deep LDEF experiment trays connected with an inter-tray wiring harness. The HEPP Power tray, an end cor ner tray, occupies a location on the space end of the LDEF in tray location H01 and the HEPP Experiment tray, a peripheral tray, is located in the LDEF tray location F12. The power tray (H01) consist of four solar array panels, one nickel-cadmium (NiCd) battery, a Power System Electronics (PSE) unit, protective thermal blankets that line the tray interior and a thirty seven pound baseplate mounted on thermal isolators to provide a thermally stable mounting for the bat tery and the PSE. Thirteen strips of thin film thermal control materials, part of an experiment by NASA GSFC that consist of sixty-five samples located at three different LDEF tray locations (H01, F09 and F12), were attached to the experiment tray flanges with Kapton tape. The experi ment was assembled and mounted in the experiment tray with non-magnetic stainless steel fasten ers. The experiment hardware appears to be intact with no apparent changes other than stains along outer edges of the solar arrays. The light brown stains observed along the upper edges of the solar array mounting plates and around the outer edge of the baseplate in the flight photograph are not apparent in the postflight photo. The atomic oxygen experiment thin film strips appear to be in place with no apparent damage. The Kapton tape appears to be firmly adhered to the tray flanges in all thirteen locations.

  9. LDEF (Postflight), S1001 : Low-Temperature Heat Pipe Experiment Package (HEPP) for LDEF, Tray H01

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), S1001 : Low-Temperature Heat Pipe Experiment Package (HEPP) for LDEF, Tray H01 The post landing photograph of the Low Tempera ture Heat Pipe Package (HEPP) experiment was taken from the Orbiter's cargo bay access hatch during post landing operations to prepare the Orbiter for the ferry flight from the Dryden Flight Research Center to the Kennedy Space Center. The white paint dots on the center clamp blocks of the experiment trays right flange and upperer flange appear to be discolored. The discoloration diminishes as as the distance from the vent area of the thermal shields increases. The right and upper tray flanges also appear to be discolored. Finger prints are visible on the thermal panels in the vicinity of the panel mounting fasteners. The Low Temperature Heat Pipe Package (HEPP) experiment occupies two 12 inch deep LDEF experiment trays connected with an inter-tray wiring harness. The HEPP Power tray, an end cor ner tray, occupies a location on the space end of the LDEF in tray location H01 and the HEPP Experiment tray, a peripheral tray, is located in the LDEF tray location F12. The power tray (H01) consist of four solar array panels, one nickel-cadmium (NiCd) battery, a Power System Electronics (PSE) unit, protective thermal blankets that line the tray interior and a thirty seven pound baseplate mounted on thermal isolators to provide a thermally stable mounting for the bat tery and the PSE.. Thirteen strips of thin film thermal control materials, part of an experiment by NASA GSFC that consist of sixty-five samples located at three different LDEF tray locations (H01, F09 and F12), were attached to the experiment tray flanges with Kapton tape. The experi ment was assembled and mounted in the experiment tray with non-magnetic stainless steel fasten ers. The experiment hardware appears to be intact with no apparent changes other than stains along outer edges of the solar arrays. Light brown stains are visible along the upper edges of the

  10. LDEF (Postflight), S0001 : Space Debris Impact Experiment, Tray H05

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The Space Debris Impact Experiment con sists of a three sixteenth (3/16) of an inch thick chromic anodized aluminum panel mounted in a three (3) inch deep LDEF experiment tray. The side of the plate exposed to the LDEF interior is painted with Chemglaze Z-306 flat black paint over a Chemglaze 9924 wash primer. The panels are attached to the aluminum tray structure with non-magnetic stainless steel fasteners. The panel coatings, a thin layer of chromic anodize facing out and the Chemglaze Z-306 black paint facing the LDEF interior, contribute significantly to thermal control of the LDEF spacecraft. The postflight photograph was taken in SAEF II at the KSC after the experiment was removed from the LDEF. A brown discoloration can be seen on the upper tray flange and a lighter discol oration on the lower tray flange not covered by the experiment tray clamp blocks. Irregular shaped tan discolorations are also visible on the experiment tray sidewall with a darker stain in the right tray corners

  11. Silver Teflon blanket: LDEF tray C-08

    NASA Technical Reports Server (NTRS)

    Crutcher, E. Russ; Nishimura, L. S.; Warner, K. J.; Wascher, W. W.

    1992-01-01

    A study of the Teflon blanket surface at the edge of tray C-08 illustrates the complexity of the microenvironments on the Long Duration Exposure Facility (LDEF). The distribution of particulate contaminants varied dramatically over a distance of half a centimeter (quarter of an inch) near the edge of the blanket. The geometry and optical effects of the atomic oxygen erosion varied significantly over the few centimeters where the blanket folded over the edge of the tray resulting in a variety of orientations to the atomic oxygen flux. A very complex region of combined mechanical and atomic oxygen damage occurred where the blanket contacted the edge of the tray. A brown film deposit apparently fixed by ultraviolet light traveling by reflection through the Teflon film was conspicuous beyond the tray contract zone. Chemical and structural analysis of the surface of the brown film and beyond toward the protected edge of the blanket indicated some penetration of energetic atomic oxygen at least five millimeters past the blanket-tray contact interface.

  12. LDEF (Flight), S1001 : Low-Temperature Heat Pipe Experiment Package (HEPP) for LDEF, Tray H01

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The flight photograph of the Low Temperature Heat Pipe Package (HEPP) experiment was taken while the LDEF was attached to the Orbiter's RMS arm prior to berthing in the Orbiter's cargo bay. The white paint dots on the center clamp blocks of the experiment trays right flange and lower flange appear to be discolored. The discolor ation diminishes as as the distance from the vent area of the thermal shields increases. The right and lower tray flanges also appear to be discolored. Finger prints are visible on the thermal panels in the vicinity of the panel mounting fasteners. The Low Temperature Heat Pipe Package (HEPP) experiment occupies two 12 inch deep LDEF experiment trays connected with an inter-tray wiring harness. The HEPP Power tray, an end cor ner tray, occupies a location on the space end of the LDEF in tray location H01 and the HEPP Experiment tray, a peripheral tray, is located in the LDEF tray location F12. The power tray (H01) consist of four solar array panels, one nickel-cadmium (NiCd) battery, a Power System Electronics (PSE) unit, protective thermal blankets that line the tray interior and a thirty seven pound baseplate mounted on thermal isolators to provide a thermally stable mounting for the bat tery and the PSE. Thirteen strips of thin film thermal control materials, part of an experiment by NASA GSFC that consist of sixty-five samples located at three different LDEF tray locations (H01, F09 and F12), were attached to the experiment tray flanges with Kapton tape. The experi ment was assembled and mounted in the experiment tray with non-magnetic stainless steel fasten ers. The experiment hardware appears to be intact with no apparent changes other than stains along outer edges of the solar arrays. Light brown stains are visible along the upper edges of the solar array mounting plates with faint traces of a lighter colored stain around the outer edge of the base plate. The atomic oxygen experiment thin film strips appear to be in place with no

  13. LDEF (Postflight), AO139A : Growth of Crystals From Solutions in Low Gravity, Tray G06

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO139A : Growth of Crystals From Solutions in Low Gravity, Tray G06 The postflight photograph was taken in the SAEF II at KSC after the experiment tray was removed from the LDEF. The experiment tray flanges have become discolored with a light tan stain except where the tray clamp blocks were located. A darker stain appears to exist at the intersection of the white cover plate and the upper left flange of the experiment tray. The Crystal Growth experiment appears to have survived the extended mission with no visible damage. The experiment cover plate, originally white, appears to be discolored by a very light brown stain but is intact and securely in place.

  14. LDEF (Postflight), AO015 : Free-Flyer Biostack Experiment, Tray G02

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO015 : Free-Flyer Biostack Experiment, Tray G02 The post flight photograph was taken in the SAEF II at KSC after the experiment tray was removed from the LDEF. The experiment tray flanges and sidewalls have become discolored with a light tan stain except where the tray clamp blocks were located. The Biostack experiment appears to have survived the extended mission with no visible damage. The experiment housings are intact and all hardware is securely in place. The detector housings appear to be discolored with a stain similar to that on the tray hardware. The exposed Kapton H foil covering windows in two (2) detector housings do not appear to have sustained damage dur ing the extended mission. The perforated dome on two (2) of the detector housings has a slight tan discoloration but no indication of damage.

  15. LDEF (Postflight), S1001 : Low-Temperature Heat Pipe Experiment Package (HEPP) for LDEF, Tray F12

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), S1001 : Low-Temperature Heat Pipe Experiment Package (HEPP) for LDEF, Tray F12 EL-1994-00190 The postflight photograph of the Low Temperature Heat Pipe Package (HEPP) experiment was taken in the SAEF II at KSC prior to removal of the experiment from the LDEF. The color of the white paint dots on three of the experiment tray clamp blocks appears to be unchanged. The Low Temperature Heat Pipe Package (HEPP) experiment occupies two 12 inch deep LDEF experiment trays connected with an inter-tray wiring harness. The HEPP Experiment tray, a peripheral tray modified to accommodate radiator location and field of view requirements, is located in the LDEF tray location F12. The HEPP Power tray, an end corner tray, is located on the space end of the LDEF in tray location H01. The experiment tray (F12) contains a Constant ConductanceHeat Pipe, a Thermal Diode Low Temperature Heat Pipe, a radiator coupled with a phase change material canister, the data acquisition and control systems and the LDEF experiment power and data system (EPDS) for processing, recording and storing experiment data. The HEPP EPDS is also used to record and store thermal data from the CVCHPE (AO076) and the THERM (P0003) experiments. Fiberglass standoffs and internal multilayer insulation (MLI) blankets ther- mally isolated the experiment from the experiment tray and the LDEF interior. The radiator and radiator shield panels located in the left half of the tray were covered with silvered TEFLON® tape to provide the desired optical properties. The outside of the HEPP, except the radiator shield panels and the radiator, was covered with an aluminized Kapton multilayer insulation (MLI) blanket with the outer Kapton layer coated with vapor deposited aluminum on one side only. The two patches of thin film materials, part of an experiment byNASA GSFC that consist of five patches of thirteen samples each and located at three different places on the LDEF (F09, F12 and H01), were attached to

  16. LDEF (Postflight), AO044 : Holographic Data Storage Crystals for LDEF, Tray E05

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The postflight photograph was taken in SAEF II at KSC prior to removal of the experiment tray from the LDEF. The Holographic Data Storage Crystals for LDEF Experiment (AO044) consist of four crystals of lithium niobate, three crystals contain recorded holograms and one crystal is an unrecorded control sample. The Holographic Data Storage experiment is an integral part of the Active Optical System Component Experiment (S0050) that contains 136 test specimen and is located in a six (6) inch deep LDEF peripheral experiment tray. The experiment tray is divided into six sections, each consisting of a 1/4 inch thick chromic anodized aluminum base plate and a 1/16th inch thick aluminum hat shaped structure for mounting the test specimen. The test specimen are typically placed in fiberglass-epoxy retainer strip assemblies prior to installation on the hat shaped mounting structure. Five of the six sections are covered by a 1/8 inch thick anodized aluminum sun screen with openings that allowed 56 percent transmission over the central region. Two subexperiments, The Optical Materials and UV Detectors Experiment (S0050-01) consist of 15 optical windows, filters and detectors and occupies one of the trays six sub-sections and The Optical Substrates and Coatings Experiment (S0050-02 ) that includes 12 substrates and coatings and a secondary experiment, ThePyroelectric Infrared Detectors Experiment with twenty detectors, are also mounted in the integrated tray. The experiment structure was assembled with non-magnetic stainless steel fasteners. The experiment hardware appears to be intact with no apparent damage. The excess blue color in the flight photograph is no longer present. The paint dots on the tray clamp blocks, initially white, are brown and tray flanges appear to have a light tan discoloration. The experiment sun screens and base plate also appear to have the same discoloration. The exposed experiment test specimen and their fiberglass-epoxy mountings appear to have

  17. LDEF (Flight), S1001 : Low-Temperature Heat Pipe Experiment Package (HEPP) for LDEF, Tray F12

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), S1001 : Low-Temperature Heat Pipe Experiment Package (HEPP) for LDEF, Tray F12 EL-1994-00008 The flight photograph of the Low Temperature Heat Pipe Package (HEPP) experimentwas taken while the LDEF was attached to the Orbiter's RMS arm prior to berthing in the Orbiter's cargo bay. The white paint dots on the center clamp blocks of the experiment trays left flange and lower flange appear to be slightly discolored. The Low Temperature Heat Pipe Package (HEPP) experiment occupies two 12 inch deep LDEF experiment trays connected with an inter-tray wiring harness. The HEPP Experiment tray, a peripheral tray modified to accommodate radiator location and field of view requirements, is located in the LDEF tray location F12. The HEPP Power tray, an end corner tray, is located on the space end of the LDEF in tray location H01. The experiment tray (F12) contains a Constant ConductanceHeat Pipe, a Thermal Diode Low Temperature Heat Pipe, a radiator coupled with a phase change material canister, the data acquisition and control systems and the LDEF experiment power and data system (EPDS) for processing, recording and storing experiment data. The HEPP EPDS is also used to record and store thermal data from the CVCHPE (AO076) and the THERM (P0003) experiments. Fiberglass standoffs and internal multilayer insulation (MLI) blankets ther- mally isolated the experiment from the experiment tray and the LDEF interior. The radiator and radiator shield panels located in the left half of the tray were covered with silvered TEFLON® tape to provide the desired optical properties. The outside of the HEPP, except the radiator shield panels and the radiator, was covered with an aluminized Kapton multilayer insulation (MLI) blanket with the outer Kapton layer coated with vapor deposited aluminum on one side only. The two patches of thin film materials, part of an atomic oxygen experiment by NASA GSFC that consist of five patches of thirteen samples each and located at three

  18. Analysis of impactor residues in tray clamps from the Long Duration Exposure Facility. Part 1: Clamps from Bay A of the satellite

    NASA Technical Reports Server (NTRS)

    Zolensky, Michael E.; Bernhard, Ronald P.

    1993-01-01

    The Long Duration Exposure Facility (LDEF) was placed in low Earth orbit (LEO) in 1984 and was recovered 5.7 years later. The LDEF was host to several individual experiments that were specifically designed to characterize critical aspects of meteoroid and debris environment in LEO. It was realized from the beginning, however, that the most efficient use of the satellite would be to examine the entire surface of the Earth for impact features. In this regard, particular interest has centered on common exposed materials that faced in all LDEF pointing directions. Among the most important of these materials is the tray clamps. Therefore, in an effort to understand the nature of particulates in LEO and their effects on spacecraft hardware better, we are analyzing residues found in impact features on LDEF tray clamp surfaces. This catalog presents all data from clamps from Bay A of the LDEF. Subsequent catalogs will include clamps from succeeding bays of the satellite.

  19. Analysis of impactor residues in tray clamps from the Long Duration Exposure Facility. Part 1: Clamps from Bay A of the satellite

    SciTech Connect

    Zolensky, M.E.; Bernhard, R.P.

    1993-03-01

    The Long Duration Exposure Facility (LDEF) was placed in low Earth orbit (LEO) in 1984 and was recovered 5.7 years later. The LDEF was host to several individual experiments that were specifically designed to characterize critical aspects of meteoroid and debris environment in LEO. It was realized from the beginning, however, that the most efficient use of the satellite would be to examine the entire surface of the Earth for impact features. In this regard, particular interest has centered on common exposed materials that faced in all LDEF pointing directions. Among the most important of these materials is the tray clamps. Therefore, in an effort to understand the nature of particulates in LEO and their effects on spacecraft hardware better, residues found in impact features on LDEF tray clamp surfaces are being analyzed. This catalog presents all data from clamps from Bay A of the LDEF. Subsequent catalogs will include clamps from succeeding bays of the satellite.

  20. LDEF (Flight), AO038 : Interstellar Gas Experiment, Tray H09

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), AO038 : Interstellar Gas Experiment, Tray H09 The flight photograph of the Interstellar Gas Experiment was taken from the Orbiter aft flight deck during the LDEF retrieval. A very light contamination stain is present on the experiment tray flanges and on the most of the visible LDEF structure. The exception being a darker stain on the structure adjacent to thermal covers that provide venting for the LDEF interior. Both paint dots appear to be heavily coated with the brown contamination stain. The color of the white thermal control paint on the IGE has changed and now varies from off-white to a dark brown. The darker brown areas on the experiment baseplate, around the grid voltage cable connectors, appear to have come from contaminants flowing from inside the LDEF. A dark stain area can be seen on the lower half of the tray's right sidewall but a shadow hides most of the dark stain in the upper left corner of the tray. A lighter stain coats portions of the experiment baseplate and the outside of the canister housing. A beryllium copper collector foil is clearly visible in the lower left canister housing as are the baffles and reflected light from the fine wire mesh grid near the top of the canister housing. Due to an experi- ment system malfunction, the canister collector foils that are visible were exposed for the total mission.

  1. LDEF (Postflight), P0004-01 : Seeds in Space Experiment, Tray F02

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), P0004-01 : Seeds in Space Experiment, Tray F02 EL-1994-00704 The postflight photograph was taken in the SAEF II at KSC after the experiment was removed from the LDEF and the silvered TEFLON® thermal cover was removed from the experiment tray. The Seeds in Space Experiment (P0004-01) is one of three passive experiments located in a 6 inch deep LDEF peripheral tray. The experiment consist of 2 million seeds of 120 different varieties, one sealed canister, two smaller vented canisters, and a silvered TEFLON® thermal cover. Two other experiments, the Space Exposed Experiment Developed for Students (SEEDS) P0004-02 and the Linear Energy Transfer (LET) Experiment (P0006), were companion experiments in the tray. The experiment hardware was assembled and mounted in the experiment tray with non-magnetic stainless steel fasteners. Areas of the experiment tray flanges covered by the tray clamp blocks are unstained and clearly visible. The sealed Seeds in Space Experiment canister, a base portion and a dome portion, was machined from aluminum and assembled together with a butyl rubber o-ring seal. The machined interior was approximately 4 inches deep with a 12 inch internal diameter, providing a volume of approximately 1/3 cubic foot. the sealed canister was the center canister in the top row. The two vented canisters were also aluminum. One canister, 4 inches in diameter and 4 inches high, was mounted on the top side of the experiment tray at the lower right corner of the large sealed canister. The other vented canister was rectangular in shape and mounted on the bottom side of the tray, the side facing the LDEF interior. The exterior surfaces of all canisters located on the top side of the experiment tray were painted white with Chemglaze II A-276. The exterior surface of the rectangular canister on the bottom side of the experiment tray was coated with Chemglaze Z-306 flat black paint over a Chemglaze 9924 primer. Thermal control was accomplished by

  2. LEO space environmental effects: TRW LDEF experimental trays

    NASA Technical Reports Server (NTRS)

    Blakkolb, B. K.; Yaung, J. Y.; Ryan, L. E.; Taylor, W.

    1991-01-01

    Comprised of two identical trays, the TRW Long Duration Exposure Facility (LDEF) experiment (A0054) provided a unique opportunity to study long term space environmental effects on a variety of materials exposed to two different space environments. The leading edge tray saw micrometeors and anthropogenic space debris, ultraviolet radiation, and energetic atomic oxygen. In contrast, the trailing edge tray was exposed to ultraviolet and micrometeors but saw relatively little, if any, space debris fluence and no energetic atomic oxygen. The striking difference in appearance of the two experimental trays is directly attributable to the nonuniformity of the space environment about the LDEF. It is estimated that the majority of the erosion to the Kapton polyimide dielectric material occurred during the last month on orbit due to the sharply nonlinear increase in atomic oxygen number density as orbital altitude decayed over the life of the mission.

  3. LDEF (Flight), P0004-02 : Space-Exposed Experiment Developed for Students, Tray F02

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), P0004-02 : Space-Exposed Experiment Developed for Students, Tray F02 EL-1994-00132 The flight photograph was taken from the Orbiter aft flight deck during the LDEF retrieval and prior to the berthing of LDEF in the Orbiter's cargo bay. The Space Exposed Experiment Developed for Students (SEEDS) P0004-02 is one of three passive experiments located in a 6-inch deep LDEF peripheral tray. The experiment consist of 12.5 million Rutgers tomato seeds, five sealed canisters and a silvered TEFLON® thermal cover. Two other experiments, the Seeds in Space Experiment (P0004-01) and the Linear Energy Transfer (LET) Experiment (P0006), were companion experiments in the tray. The experiment hardware was assembled and mounted in the experiment tray with non-magnetic stainless steel fasteners. The paint dots, originally white, located on experiment tray clamp blocks now appear brown. The experiment tray flanges also appear to be discolored. The sealed SEEDS canisters, 5 bases and 5 domes, were machined from aluminum plate material and assembled together with a butyl rubber o-ring seal. The machined interior was approximately 4 inches deep with a 12 inch internal diameter, providing an open volume of approximately 1/3 cubic foot in each canister. The 5 canisters were were mounted in the experiment tray along with a similar canister containing the Seeds in Space Experiment. The exterior surfaces of all canisters were painted white with Chemglaze II A-276 and surfaces facing the LDEF interior were coated with Chemglaze Z-306 flat black paint over a Chemglaze 9924 primer. Thermal control was accomplished by placing the canisters on fiberglass isolators and covering the experiment tray with a thin (5 mil) silvered TEFLON® specular cover secured with Velcro pads located on each of the canister domes and on clips attached to the tray sidewalls. The silvered TEFLON® thermal cover appears to be intact with no apparent damage. The three dark spots appearing in a vertical

  4. LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray D05

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray D05 EL-1994-00311 LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray D05 The postflight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) was taken in SAEF II at KSC after removal of the experiment tray from the LDEF. The experiment tray flanges appear discolored by a brown stain. Outlines of experiment tray clamp blocks are clearly visible on the upper and lower tray flanges. The experiment tray holding fixture hardware covers the clamp block areas on the end flanges. The UHCRE detectors were contained in 16 peripheral LDEF trays with at least one UHCRE tray located on each row of the LDEF except row 3, row 9 and row 12. Each tray contains three cylindrical aluminum pressure vessels with an integral aluminum support structure. Each cylinder is filled with an Eccofoam insert that houses 4 UHCRE detector stacks. Each stack consist of layers of Lexan polycarbonate sheets (approximately 70) interleaved with several thin sheets of lead. Forty-seven of the 48 pressure vessels were pressurized to 1.0 bar of a dry gas mixture (oxygen, nitrogen and helium) and sealed. One of the units was left unsealed in order to investigate the effects of the vacuum environment on the detector materials. Thermal control was accomplished by attaching an aluminized Kapton thermal cover on the tray bottom (the Kapton facing the LDEF interior), placing the aluminum cylinder support structure on thermal isolators and covering the experiment with a thin (5 mil) silvered TEFLON® thermal cover. The silvered TEFLON® cover was supported by an aluminum frame, an integral part of the experiment structure, and held in place by Velcro pads selectively located on the frame and on the back of the cover. The copper colored strip extending over the trays lower flange is a copper coated pressure sensitive tape used to provide an electrical ground between the

  5. LDEF (Flight), AO187-01 : The Chemistry of Micrometeoroids, Tray A03

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), AO187-01 : The Chemistry of Micrometeoroids, Tray A03 EL-1994-00680 LDEF (Flight), AO187-01 : The Chemistry of Micrometeoroids, Tray A03 The flight photograph was taken with the LDEF on the Orbiter's RMS arm prior to berthing the spacecraft in the cargo bay. The canisters are in their open condition (they were expected to open about two (2) weeks after launch and close about eleven (11) months into the mission) with three (3) full panels and 3/4th of the fourth panel covered with a highly reflective gold foil (>99.99 percent pure).The remaining area is covered with strips of other detector materials: zirconium, beryllium, titanium, platium, aluminum, carbon, Kapton, polyethylene and TEFLON®. The exposed fasteners are non-magnetic stainless steel. All of the exposed materials seem to be secure and no damage is evident. The contamination stain that has changed the white paint dot on the tray clamp blocks to brown also coats the tray flanges and the aluminum canister hardware. The end support beam scuff plate in the photograph was a bright yellow prior to launch but is a much darker, mustard yellow after the space exposure.

  6. LDEF (Flight), AO201 : Interplanetary Dust Experiment, Tray G10

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), AO201 : Interplanetary Dust Experiment, Tray G10 The flight/on-orbit photograph of the G10 experi ment tray was taken from the Orbiter aft flight deck during the LDEF retrieval. A light brown stain can be seen on the experiment tray flanges and to a lesser degree on the IDE Chemglaze Z tained their integrity. A light tan stain on the solar sensor base plate, located in the center of the tray, is more easily seen than that on the IDE mounting plate. Surface defects are highly visible due to the lighting conditions existing at the time the photograph was taken. The lighting angle is such that many impact craters can be seen. Two (2) detectors, located in the twenty (20) detector layout in the lower left corner of the tray, seem to have defects. A triangular shaped discoloration appears on the second detector from the left and in the second row from the bottom. Another irregular shaped discoloration can be seen on the fourth detector from the left and in the third row from the bottom. These discolorations appear to be due to material and/or fabrication defects and not reflected light. The blue colors on the detector's mirror like surface are caused by reflections of the LDEF surroundings.

  7. LDEF (Flight), M0003 : Space Environment Effects on Spacecraft Materials, Tray D04

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), M0003 : Space Environment Effects on Spacecraft Materials, Tray D04 The flight photograph was taken from the Orbiter aft flight deck during the LDEF retrieval prior to berthing the LDEF in the Orbiter cargo bay. Experiment Power and Data Systems (EPDS), two Environment Exposure Control Canisters (EECC), twelve LiSO2 batteries and internal support structure, instrumentation and black anodized aluminum mounting plates for experiment samples. The experiment structural members were assembled using non-magnetic stainless steel fasteners. One six-inch tray and one three-inch tray with a connecting wiring harness, one EPDS, one EECC and six LiSO2 batteries were located in tray locations D08 and D09 near the LDEF leading edge and a similar set of hardware was located near the LDEF trailing edge in tray locations D03 and D04. The environmental exposure was similar with one significant exception, the trailing edge location was not exposed to continuous bombardment by the relativity high atomic oxygen flux. The white paint dots on the experiment tray clamp blocks appear to have changed significantly. The paint on the clamp block located in the center of the trays right flange is brown and the paint on the clamp block at the upper end of the left flange is gray. The trays right flange and clamp blocks appear to have a light tan discoloration. The experiment tray in the D04 location is divided into three sections.The top section provides space for the EPDS, the center section accommodates the Signal Conditioning Unit (SCU) and an experiment mounting plate, on an aluminum sub-structure, that is populated with composite material samples. The lower section houses the EECC with a complement of experiment samples that consist of coatings, thermal paints, polymers, glasses and semiconductors. Detectors within the experiment provide environmental data for use in postflight analyses. Batteries and the inter-tray wiring harness are located beneath the tray base plates

  8. LDEF (Prelaunch), S1001 : Low-Temperature Heat Pipe Experiment Package (HEPP) for LDEF, Tray H01

    NASA Technical Reports Server (NTRS)

    1983-01-01

    LDEF (Prelaunch), S1001 : Low-Temperature Heat Pipe Experiment Package (HEPP) for LDEF, Tray H01 The prelaunch photograph was taken during experiment functional checkout in SAEF II at the KSC prior to installation of the Low Temperature Heat Pipe Package (HEPP) experiment on the LDEF. The electrical cables in the photograph are cables that connect the HEPP Power tray with the HEPP experiment tray and the ground support test equipment and are non-flight cables. The Low Temperature Heat Pipe Package (HEPP) experiment occupies two 12 inch deep LDEF experiment trays connected with an inter-tray wiring harness. The HEPP Power tray, an end cor ner tray, occupies a location on the space end of the LDEF in tray location H01 and the HEPP Experiment tray, a peripheral tray, is located in the LDEF tray location F12. The power system tray is shown in the prelaunch photograph with the four red solar array protective covers installed on the aluminum baseplate. The power tray (H01) consist of four solar array panels, one nickel cadmium (NiCd) battery, a Power System Electronics (PSE) unit, protective thermal blankets and a thirty seven pound baseplate (thermal mass). Thirteen strips of thin film thermal control materi als, part of an experiment by NASA GSFC that consist of sixty-five samples located at three dif ferent LDEF tray locations (H01, F09 and F12), were attached to the experiment tray flanges with Kapton tape. The experiment was assembled and mounted in the experiment tray with non-mag netic stainless steel fasteners.

  9. LDEF (Flight), S1005 : Transverse Flat-Plate Heat Pipe Experiment, Tray B10

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), S1005 : Transverse Flat-Plate Heat Pipe Experiment, Tray B10 EL-1994-00017 The Transverse Flat-Plate Heat Pipe Experiment flight photograph was taken while the LDEF was attached to the Orbiter's RMS arm prior to berthing in the Orbiter's cargo bay. No change in the color of the white paint dots on experiment tray clamp blocks is apparent. The Transverse Flat-Plate Heat Pipe Experiment consist of three (3) transverse flat heat-pipe modules , a power system for the heaters, a data acquisition and storage system and an aluminum support structure placed in a twelve (12) inch deep LDEF experiment tray. The surface of the experiment exposed to the space environment consist of the three heat pipe modules exterior surfaces, silver TEFLON®, and the thermal blankets covering the aluminum mounting hardware and openings between the hardware and the tray sidewalls. The raised surface at the top of each heat pipe module is the fluid reservoir. Five thermocouples, for monitoring the external surface temperature, are located on each module. The specular surface of the silver TEFLON® has become diffuse and appears white. Numerous impact craters, black specks, can be seen on the white surfaces of the modules. There appears to be a light tan discoloration on the surfaces of all three heat pipe modules. Two different types of discolorations can be seen at the top end of the center heat pipe; a dark brown color to the left of the thermocouple and what appears as two multi-color irregular shaped patterns to the right of the thermocouple. A square shaped light brown discoloration is seen near the left edge of the left thermal blanket, approximately half way between the tray bottom and center clamp blocks and also near the top of the thermal blanket between the left heat pipe module and the center heat pipe module.

  10. LDEF (Postflight), AO187-01 : The Chemistry of Micrometeoroids, Tray A03

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO187-01 : The Chemistry of Micrometeoroids, Tray A03 EL-1994-00266 LDEF (Postflight), AO187-01 : The Chemistry of Micrometeoroids, Tray A03 The experiment is shown in the postflight configuration before closing the canisters with ground support equipment that bypassed the experiments onboard electronics circuitry. Three full panels and approximately 3/4th of the other panel are covered with gold foil (>99.99 percent pure). The remaining area on the fourth panel is covered with strips of other detector materials: zirconium, beryllium, titanium, platium, aluminum, carbon, Kapton, polyethylene and TEFLON®. A brown stain is visible on the experiment tray flanges, however, most of the stains observed in the flight photograph are obscured by reflected light. All materials remain intact with no visual evidence of damage to the experiment. The reflection of a video camera on a tripod and light sources can be seen on the gold foil covered panels. The experiment canisters are shown after being closed by using the experiments ground support equipment. The stain buildup can be clearly seen at the vertical center of the right tray flange. The clean area was located under the experiment tray clamp block and was not exposed to the staining medium. The stain also coats other areas that were exposed during the mission but are not as noticeable. The experiment hardware seems to be intact and have no damage.

  11. LDEF (Postflight), AO171 : Solar-Array-Materials Passive LDEF Experiment, Tray A08

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO171 : Solar-Array-Materials Passive LDEF Experiment, Tray A08 EL-1994-00147 LDEF (Postflight), AO171 : Solar-Array-Materials Passive LDEF Experiment, Tray A08 The post flight photograph was taken in the SAEF II at KSC prior to removal of the experiment tray from the LDEF and shows the Solar Array Materials Passive LDEF Experiment (SAMPLE) on the LDEF. Six (6) plates of passive components, provided by various experiment organizations and designated plate I thru plate VI, are shown mounted in a three (3) inch deep LDEF peripheral tray. All six plates are aluminum and attach to the LDEF experiment tray with non-magnetic stainless steel fasteners. Plate I, located in the upper right corner, consist of a combination of solar cells with and without covers, solar cell modules and solar arrays assembled on the baseplate. Three of the four solar arrays are missing. Other components appear to be secure. Plate II in the top center section, has twenty seven (27) composite samples, carbon fiber and glass fiber, mounted on the baseplate. The composites appear to be intact with no physical damage. Plate III, in the upper left corner, consist of metallized and thin polymeric films (Kapton, Mylar, TEFLON® , white Tedlar,etc.). The thin films without protective coatings sustained significant damage and most were destroyed. The thin film specimen hanging by one end in the flight photograph is missing. The metallized film apparently survived the mission with minimum damage. Plate IV located in the lower right corner consist of metals and coatings mounted in an aluminum baseplate and covered with a thin aluminum coverplate that partially mask the specimen. Several of the coatings appear to have darkened and a unique pattern of light brown discoloration appears around the outer edges of the mounting plate and along the lower edge of the coverplates. Plate V, in the lower center section, contained thermal plastics and structural film configured into tensile and

  12. LDEF (Flight), AO171 : Solar-Array-Materials Passive LDEF Experiment, Tray A08

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), AO171 : Solar-Array-Materials Passive LDEF Experiment, Tray A08 EL-1994-00666 LDEF (Flight), AO171 : Solar-Array-Materials Passive LDEF Experiment, Tray A08 The flight photograph was taken from the Orbiter aft flight deck during the LDEF retrieval prior to berthing the LDEF in the Orbiter cargo bay and shows the Solar Array Materials Passive LDEF Experiment (SAMPLE) on the LDEF. Six (6) plates of passive components, provided by various experiment organizations and designated plate I thru plate VI, are shown mounted in a three (3) inch deep LDEF peripheral tray. All six plates are aluminum and attach to the LDEF experiment tray with non-magnetic stainless steel fasteners. Plate I, located in the upper left corner, consist of a combination of solar cells with and without covers, solar cell modules and solar arrays assembled on the baseplate. Two of the four solar arrays are missing and one appears to be attached at only one corner. Other components appear to be secure. Plate II in the left center section, has twenty-seven (27) composite samples, carbon fiber and glass fiber, mounted on the baseplate. The composites appear to be intact with no physical damage. Plate III, in the lower left corner, consist mostly of metallized and thin polymeric films (Kapton, Mylar, TEFLON® , white Tedlar,etc.). The thin films without protective coatings sustained significant damage and most were destroyed. The metallized film apparently survived with minimum damage. Plate IV located in the upper right corner consist of metals and coatings mounted in an aluminum baseplate and covered with a thin aluminum coverplate that partially mask the specimen. Several of the coatings appear to have changed to a darker color and a light brown discoloration appears around the outer edges of the mounting plate and along the right edge of the coverplates. Plate V, in the right center section, contained thermal plastics and structural film configured into tensile and shear specimen. All

  13. LDEF (Postflight), AO038 : Interstellar Gas Experiment, Tray H06

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO038 : Interstellar Gas Experiment, Tray H06 The post landing photograph was taken from the Orbiter's cargo bay access hatch during post landing operations to prepare the Orbiter for the ferry flight from the Dryden Flight Research Center to the Kennedy Space Center. A very light contamination stain is present on the experiment tray flanges and on the most of the visible LDEF structure. The exception being a much darker stain on the structure adjacent to thermal covers that provide venting for the LDEF interior. The paint dot adjacent to the thermal cover vent area is heavily coated with the brown contamination stain while the paint dot adjacent to the center end cover plate has a very light coating. The color of the white thermal control paint on the IGE has changed and now varies from offwhite to a dark brown. The darker brown areas on the experiment baseplate, around the grid voltage cable connectors, appear to have come from contaminants flowing from inside the LDEF. A dark stain area can be seen on the tray's lower sidewall and in the upper left corner of the tray. A lighter stain coats portions of the experiment baseplate and the outside of the canister housing. A beryllium copper collector foil is clearly visible within the canister housings as are the baffles and reflected light from the fine wire mesh grid near the top of the canister housing. Due to an experi- ment system malfunction, the canister collector foils that are visible were exposed for the total mission.

  14. Atomic oxygen exposure of LDEF experiment trays

    NASA Technical Reports Server (NTRS)

    Bourassa, R. J.; Gillis, J. R.

    1992-01-01

    Atomic oxygen exposures were determined analytically for rows, longerons, and end bays of the Long Duration Exposure Facility (LDEF). The calculations are based on an analytical model that accounts for the effects of thermal molecular velocity, atmospheric temperature, number density, spacecraft velocity, incidence angle, and atmospheric rotation on atomic oxygen flux. Results incorporate variations in solar activity, geomagnetic index, and orbital parameters occurring over the 6-year flight of the spacecraft. To facilitate use of the data, both detailed tabulations and summary charts for atomic oxygen fluences are presented.

  15. Solar exposure of LDEF experiment trays

    NASA Technical Reports Server (NTRS)

    Bourassa, R. J.; Gillis, J. R.

    1992-01-01

    Exposure to solar radiation is one of the primary causes of degradation of materials on spacecraft. Accurate knowledge of solar exposure is needed to evaluate the performance of materials carried on the Long Duration Exposure Facility (LDEF) during its nearly 6 year orbital flight. Presented here are tables and figures of calculated solar exposure for the experiment rows, longerons, and end bays of the spacecraft as functions of time in orbit. The data covers both direct solar and earth reflected radiation. Results are expressed in cumulative equivalent sun hours (CESH) or the hours of direct, zero incidence solar radiation that would cause the same irradiance of a surface. Space end bays received the most solar radiation, 14,000 CESH; earth end bays received the least, 4,500 CESH. Row locations received between 6,400 CESH and 11,200 CESH with rows facing either eastward or westward receiving the most radiation and rows facing northward or southward receiving the least.

  16. LDEF (Flight), AO076 : Cascade Variable-Conductance Heat Pipe, Tray F09

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), AO076 : Cascade Variable-Conductance Heat Pipe, Tray F09 EL-1994-00020 LDEF (Flight), AO076 : Cascade Variable-Conductance Heat Pipe, Tray F09 The flight photograph of the Cascade Variable Conductance Heat Pipe Experiment (CVCHPE) was taken while the LDEF was attached to the Orbiter's RMS arm prior to berthing in the Orbiter's cargo bay. The white paint dots on the center clamp blocks of the experiment trays right flange and lower flange appear to be slightly discolored. The LDEF structure, top intercostal, has a dark brown discoloration adjacent to the black thermal panel. Aluminum particles from the degraded CVCHPE thermal blanket are also visible in this area. The Cascade Variable Conductance Heat Pipe Experiment (CVCHPE) occupies a 6 inch deep LDEF peripheral experiment tray and consist of two series connected variable conductance heatpipes, a black chrome solar collector panel and a silvered TEFLON® radiator panel, a power source to support six thermistor-type temperature monitoring sensors and actuations of two valves. Fiberglass standoffs and internal insulation blankets thermally isolated the experiment from the experiment tray and the LDEF interior. The outside of the CVCHPE, except the collector and radiator panels, was covered with an aluminumized Kapton multilayer insulation (MLI) blanket with an outer layer of 0.076 mm thick Kapton. The two patches of thin film materials, part of an atomic oxygen experiment (see S1001) by NASA GSFC, were attached to the cover of the external thermal blanket with Kapton tape. The experiment was assembled and mounted in the experiment tray with non-magnetic stainless steel fasteners. The external CVCHPE materials have changed significantly. The Kapton on the thermal blanket aluminized Kapton cover appears to be completely eroded, except under Kel-F buttons used to secure the blanket, leaving only the very thin vapor deposited aluminum coating as a cover. Parts of the aluminum coating residue has moved to

  17. LDEF (Prelaunch), AO201 : Interplanetary Dust Experiment, Tray B12

    NASA Technical Reports Server (NTRS)

    1984-01-01

    LDEF (Prelaunch), AO201 : Interplanetary Dust Experiment, Tray B12 The prelaunch photograph shows the six (6) inch deep Interplanetary Dust Experiment (IDE) master control tray. The tray has three (3) mounting/cover plates elevated on fiberglass stand-offs to provide clearance and protection for hardware and electronics located underneath. The stand-offs also raise the plates to a level that minimizes shading of detectors by the tray sidewalls. The mounting plate located at the left hand end of the tray is populated with eighty (80) metaloxide-silicon (MOS) capacitor-type impact sensors and one (1) solar sensor that is located approximately in the center of the mounting plate. The IDE sensors are two (2) inch diameter MOS capacitor structures approximately 250 um thick. The detectors are formed by growing either 0.4um or 1.0um thick silicon oxide, SiO2, layer on the 250um thick, B-doped polished silicon wafer. The top metal contact, the visible surface, was formed by vapor deposition of 1000A of aluminum on the SiO2 surface. Aluminum was also vapor deposited on the backside to form the contact with the silicon substrate. Gold wires are bonded to the front and back aluminum layers for use in connecting the detectors to the circuits. The complete wafers, IDE detectors, are mounted on chromic anodized aluminum frames by bonding the detector backside to the aluminum frame with a space qualified RTV silicon adhesive, de-volatized RTV-511. The difference in colors of the detectors is caused by reflections in the metallized surfaces. A reflection of one of the technicians is visible in the three (3) rows of detector on the left hand side of the mounting plate. The solar sensor, located at the mounting plate center, consist of four (4) silicon solar cells connected in series and associated circuity bonded to an aluminum baseplate. The solar sensor registered each orbital sunrise independant of LDEF orientation at the time of sunrise. When IDE solar sensor data from the six

  18. LDEF (Postflight), S0001 : Space Debris Impact Experiment, Tray B02

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The postflight photograph was taken in the SAEF II at KSC prior to experiment removal from the LDEF. The originally white paint dot on clamp blocks around the perifery of the experiment tray show the results of contamination and exposure to the space environment. The variation in color, from tan along the top flange to brown at other locations, is attributed to variations in the atomic oxygen flux intensity. A surface exposed to a higher intensity of atomic oxygen flux will have less contamination due to the scrubbing or cleaning action that occurs when the atomic oxygen molecules impact that surface. The pink and the greenish-gray tints on the two (2) debris panels are a by-product of the chromic anodize coating process and not attributed to contamination and/or exposure to the space environ ment. The light band along the sides and across the bottom of the panels is caused by light reflecting from the tray sidewalls.

  19. LDEF (Flight), M0003 : Space Environment Effects on Spacecraft Materials, Tray D08

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), M0003 : Space Environment Effects on Spacecraft Materials, Tray D08 The flight photograph was taken from the Orbiter aft flight deck during the LDEF retrieval prior to berthing the LDEF in the Orbiter cargo bay. Experiment Power and Data Systems (EPDS), two Environment Exposure Control Canisters (EECC), twelve LiSO2 batteries and internal support structure, instrumentation and black anodized aluminum mounting plates for experiment samples. The experiment structural members were assembled using non-magnetic stainless steel fasteners. One six-inch tray and one three-inch tray with a connecting wiring harness, one EPDS, one EECC and six LiSO2 batteries were located in tray locations D08 and D09 near the LDEF leading edge and a similar set of hardware was located near the LDEF trailing edge in tray locations D03 and D04. The environmental exposure was similar with one significant exception, the trailing edge location was not exposed to continuous bombardment by the relativity high atomic oxygen flux. The white paint dots on the experiment tray clamp blocks appear to have no significant change in color. The experiment tray in the D08 location is divided into three sections.The top section provides space for the EPDS, the center section accommodates the Signal Conditioning Unit (SCU) and an experiment mounting plate, on an aluminum sub-structure, that is populated with composite material samples. The lower section houses the EECC with a complement of experiment samples that consist of coatings, thermal paints, polymers, glasses and semiconductors. Detectors within the experiment provide environmental data for use in postflight analyses. Batteries and the inter-tray wiring harness are located beneath the tray base plates. The EPDS is located under an aluminum cover that is coated with a white thermal control paint (Chemglaze II A-276) and thermally iso- lated from the tray structure by fiberglass clips. The SCU cover is also coated with a white thermal

  20. Analysis of impactor residues in tray clamps from the Long Duration Exposure Facility. Part 2: Clamps from Bay B of the satellite

    NASA Technical Reports Server (NTRS)

    Bernhard, Ronald P.; Zolensky, Michael E.

    1994-01-01

    The Long Duration Exposure Facility (LDEF) was placed in low-Earth orbit (LEO) in 1984 and recovered 5.7 years later. The LDEF was host to several individual experiments specifically designed to characterize critical aspects of meteoroid and debris environment in LEO. However, it was realized from the beginning that the most efficient use of the satellite would be to examine the entire surface for impact features. In this regard, particular interest centered on common exposed materials that faced in all LDEF pointing directions. Among the most important of these materials was the tray clamps. Therefore, in an effort to better understand the nature of particulates in LEO and their effects on spacecraft hardware, residues found in impact features on LDEF tray clamp surfaces are being analyzed. This catalog presents all data from clamps from Bay B of the LDEF. NASA Technical Memorandum 104759 has cataloged impacts that occurred on Bay B (published March 1993). Subsequent catalogs will include clamps from succeeding bays of the satellite.

  1. LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray C11

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray C11 EL-1994-00299 LDEF (Postflight), AO178 : A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei, Tray C11 The postflight photograph of the Ultra Heavy Cosmic Ray Experiment (UHCRE) was taken in SAEF II at KSC after removal of the experiment tray from the LDEF. The experiment tray flanges appear discolored by a light brown stain. Outlines of experiment tray clamp blocks are faint but visible on the upper and lower experiment tray flanges.The experiment tray holding fixture hardware covers the clamp block areas on the end flanges. The UHCRE detectors were contained in 16 peripheral LDEF trays with at least one UHCRE tray located on each row of the LDEF except row 3, row 9 and row 12. Each tray contains three cylindrical aluminum pressure vessels with an integral aluminum support structure. Each cylinder is filled with an Eccofoam insert that houses 4 UHCRE detector stacks. Each stack consist of layers of Lexan polycarbonate sheets (approximately 70) interleaved with several thin sheets of lead. Forty-seven of the 48 pressure vessels were pressurized to 1.0 bar of a dry gas mixture (oxygen, nitrogen and helium) and sealed. One of the units was left unsealed in order to investigate the effects of the vacuum environment on the detector materials. Thermal control was accomplished by attaching an aluminized Kapton thermal cover on the tray bottom (the Kapton facing the LDEF interior), placing the aluminum cylinder support structure on thermal isolators and covering the experiment with a thin (5 mil) silvered TEFLON® thermal cover. The silvered TEFLON® cover was supported by an aluminum frame, an integral part of the experiment structure, and held in place by Velcro pads selectively located on the frame and on the back of the cover. The copper colored strip extending over the trays lower flange is a copper coated pressure sensitive tape used to provide an electrical ground

  2. LDEF (Postflight), AO076 : Cascade Variable-Conductance Heat Pipe, Tray F09

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO076 : Cascade Variable-Conductance Heat Pipe, Tray F09 EL-1994-00354 LDEF (Postflight), AO076 : Cascade Variable-Conductance Heat Pipe, Tray F09 The postflight photograph was taken in the SAEF II at KSC prior to removal of the experiment from the LDEF. The color of the white paint dots on the exper- iment tray clamp blocks appear to be unchanged. The LDEF structure, the intercostal on the right, has a dark brown discoloration adjacent to the black Earth end thermal panel. Aluminum pieces of the degraded CVCHPE thermal cover that were shown lodged in the vent area between the intercostal and the black thermal panel in the flight photograph are gone. The Cascade Variable Conductance Heat Pipe Experiment (CVCHPE) occupies a 6 inch deep LDEF peripheral experiment tray and consist of two series connected variable conductance heatpipes, a black chrome solar collector panel and a silvered TEFLON® radiator panel, a power source to support six thermistor-type temperature monitoring sensors and actuations of two valves. Fiberglass standoffs and internal insulation blankets thermally isolated the experiment from the experiment tray and the LDEF interior. The outside of the CVCHPE, except the collector and radiator panels, was covered with an aluminized Kapton multilayer insulation (MLI) blanket with an outer layer of 0.076 mm thick Kapton. The two patches of thin film materials, part of Experiment S1001 by NASA GSFC, were attached to the cover of the external thermal blanket with Kapton tape. The experiment was assembled and mounted in the experiment tray with non-magnetic stainless steel fasteners. The external surface of the CVCHPE has changed from that observed in the flight photograph. The thin vapor deposited aluminum coating, left after the Kapton eroded, is essentially gone with only fragments left near the edges of the thermal blanket. Pieces of a layer of Dacron mesh (bridle vail) material, used to separate the thermal cover from the thermal

  3. LDEF (Postflight), AO201 : Interplanetary Dust Experiment, Tray H11

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO201 : Interplanetary Dust Experiment, Tray H11 The Interplanetary Dust Experiment hardware has a thin brown stain on the exposed surfaces. A deeper brown stain, probably from the material underneath the small electrical cover plate of the detector frame, can be seen in the upper right corner of some of the detectors. Stain that was seen on the solar sensor base plate in the flight photograph cannot be seen because of reflected light. The colors seen in the detector's mirror like surface are reflections of the surrounding area. A dark spot seen on a detector in the third row from the top in the flight photograph, was not found in a postflight inspection. A close inspection of this photograph does reveal several impact damage locations.

  4. View of one of the trays of experiments to be placed in the LDEF

    NASA Technical Reports Server (NTRS)

    1984-01-01

    View of one of the trays in the Long Duration Exposure Facility (LDEF). In this photo it is shown at the Langley Research center awaiting shipment to the Kennedy Space Center (KSC) where it will be installed in the LDEF. This tray, made up mostly of Deaprtment of Defense experiments, includes fiber optics, materials and coating, geophysics and other disciplines. The Langley Research Center alternative photo number is L-82-11,429.

  5. LDEF (Postflight), AO201 : Interplanetary Dust Experiment, Tray G10

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO201 : Interplanetary Dust Experiment, Tray G10 The IDE experiment appears to be in excellent condition in the postflight photograph. All bond joints seem to have survived the space environment and the experiment hardware seems to be intact. The direction and intensity of the artificial light source has caused hot spots and reflections that tend to wash out the brown stain on the exposed surfaces. A close inspection of individual detectors reveal locations where impacts have occurred and damage is present. In the detector layout in the lower left corner of the tray, two detectors continue to show the discolorations observed in the flight photograph. A triangular shape can be seen in the detector located in the second horizontal row from the bottom and the second vertical row from the left. The other detector, located in the third horizontal row from the bottom and the fourth vertical row from the left has an irregular shaped, very faint, discolora tion. The blue color in the detectors metallic surface is caused by reflections of the surrounding area.

  6. LDEF (Prelaunch), M0003 : Space Environment Effects on Spacecraft Materials, Tray D08

    NASA Technical Reports Server (NTRS)

    1984-01-01

    LDEF (Prelaunch), M0003 : Space Environment Effects on Spacecraft Materials, Tray D08 The prelaunch photograph was taken in SAEF II at KSC prior to installation of the integrated tray on the LDEF. The Spacecraft Materials Experiment hardware consist of four LDEF peripheral trays (two sets), two Experiment Power and Data Systems (EPDS), two Environment Exposure Control Canisters (EECC), twelve LiSO2 batteries and internal support structure, instrumentation and black anodized aluminum mounting plates for experiment samples. The experiment structural members were assembled using nonmagnetic stainless steel fasteners. One six inch tray and one three inch tray with a connecting wiring harness, one EPDS, one EECC and six LiSO2 batteries were located in tray locations D08 and D09 near the LDEF leading edge and a similar set of hardware was located near the LDEF trailing edge in tray locations D03 and D04. The environmental exposure was similar with one significant exception, the trailing edge location was not exposed to continuous bombardment by the relativity high atomic oxygen flux. The experiment tray in the D08 location is divided into three sections.The right section provides space for the EPDS and the center section accommodates the Signal Conditioning Unit (SCU) and an experiment mounting plate, on an aluminum sub-structure, populated with composite material samples. The left section houses the EECC with its complement of experiment samples consisting of coatings, thermal paints, polymers, glasses, semi-conductors. Detectors within the experiment provide environmental data for use in postflight analyses. Batteries and inter-tray connections are located beneath the tray base plates. The EPDS is under an aluminum cover, coated with a white thermal control paint (Chemglaze II A-276) and thermally isolated from the tray structure by fiberglass clips. The SCU cover is also coated with a white thermal control paint, IITRI S13G-LO, and the EECC is protected with a chromic

  7. LDEF (Prelaunch), M0003 : Space Environment Effects on Spacecraft Materials, Tray D04

    NASA Technical Reports Server (NTRS)

    1984-01-01

    LDEF (Prelaunch), M0003 : Space Environment Effects on Spacecraft Materials, Tray D04 The prelaunch photograph was taken in SAEF II at KSC prior to installation of the integrated tray on the LDEF. The Spacecraft Materials Experiment hardware consist of four LDEF peripheral trays (two sets), two Experiment Power and Data Systems (EPDS), two Environment Exposure Control Canisters (EECC), twelve LiSO2 batteries and internal support structure, instrumentation and black anodized aluminum mounting plates for experiment samples. The experiment structural members were assembled using nonmagnetic stainless steel fasteners. One six inch tray and one three inch tray with a connecting wiring harness, one EPDS, one EECC and six LiSO2 batteries were located in tray locations D08 and D09 near the LDEF leading edge and a similar set of hardware was located near the LDEF trailing edge in tray locations D03 and D04. The environmental exposure was similar with one significant exception, the trailing edge location was not exposed to continuous bombardment by the relativity high atomic oxygen flux. The experiment tray in the D04 location is divided into three sections.The right section provides space for the EPDS, the center section accommodates the Signal Conditioning Unit (SCU) and an experiment mounting plate, on an aluminum sub-structure, populated with a composite material samples. The left section houses the EECC with its complement of experiment samples consisting of coatings, thermal paints, polymers, glasses, semi-conductors. Detectors within the experiment provide environmental data for use in postflight analyses. Batteries and inter-tray connections are located beneath the tray base plates. The EPDS is underneath an aluminum cover, coated with a white thermal control paint (Chemglaze II A-276) and thermally isolated from the tray structure by fiberglass clips. The SCU cover is also coated with a white thermal control paint, IITRI S13G-LO, and the EECC is covered with a

  8. LDEF (Postflight), AO201 : Interplanetary Dust Experiment, Tray B12

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO201 : Interplanetary Dust Experiment, Tray B12 The postflight photograph shows little change of the exposed surfaces when compared with the prelaunch photograph. Although not noticable in the photograph, a light coating of contamination was seen on all experiment surfaces in this location. The difference in colors of the IDE detectors, located on the right hand mounting plate, is a result of the reflected surroundings and not related to space exposure. A close observation of the detector surfaces reveal that some damage has occured from meteroid and/or debris impacts. One impact crater can be seen, upper right quadrant, on the detector located in the sixth (6th) row down from the top and the fifth (5th) row from the right. Other impacts, smaller in size, show as small white dots on the detector surface. The solar sensor seems to have changed little, if any. However, the color of the solar array baseplate, showing indications of contamination, appears to be darker than the detector mounting plate. The center section cover plate shows little change when compared with the pre-launch photograph. However, during inspection, a light coat of the brown contamination has been observed on all surfaces. The color of the bonding material (RTV) used to secure several thin specimen, sapphire, to individual mounting plates has changed from pink to gold. At one location, that of a single specimen, the bonding material is more gray than gold in color. This has been attributed to the specimen being considerably thicker. The EPDS thermal cover in the right hand side of the tray shows a light coating of brown contamination on the Chemglaze II A-276 white paint.

  9. LDEF (Postflight), S0001 : Space Debris Impact Experiment, Tray G04

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), S0001 : Space Debris Impact Experiment, Tray G04 The Space Debris Impact Experiment con sist of a three sixteenth (3/16) of an inch thick chromic anodized aluminum panel mounted in a three (3) inch deep LDEF experiment tray. The side of the plate exposed to the LDEF interior is painted with Chemglaze Z-306 flat black paint over a Chemglaze #9924 wash primer. The panels are attached to the aluminum tray structure with non-magnetic stainless steel fasteners. The panel coatings, a thin layer of chromic anodize facing out and the Chemglaze Z-306 black paint facing the LDEF interior, contribute significantly to thermal control of the LDEF spacecraft. The photograph was taken in SAEF II at the KSC after the experiment was removed from the LDEF. The light pink tint of the debris panel is a by-product of the chromic anodize coating pro cess and not attributed to contamination and/or exposure to the space environment. A brown stain is located in the lower right corner of the tray.

  10. LDEF (Prelaunch), AO076 : Cascade Variable-Conductance Heat Pipe, Tray F09

    NASA Technical Reports Server (NTRS)

    1983-01-01

    LDEF (Prelaunch), AO076 : Cascade Variable-Conductance Heat Pipe, Tray F09 EL-1994-00302 LDEF (Prelaunch), AO076 : Cascade Variable-Conductance Heat Pipe, Tray F09 The prelaunch photograph was taken in SAEF II at KSC prior to installation of the Cascade Variable Conductance Heat Pipe Experiment (CVCHPE) on the LDEF. The Cascade Variable Conductance Heat Pipe Experiment (CVCHPE) occupies a 6 inch deep LDEF peripheral experiment tray and consist of two series connected variable conductance heatpipes, a black chrome solar collector panel and a silvered TEFLON® radiator panel, a power source to support six thermistor-type temperature monitoring sensors and actuations of two valves. Fiberglass standoffs and internal insulation blankets thermally isolated the experiment from the experiment tray and the LDEF interior. The outside of the CVCHPE, except the collector and radiator panels, was covered with an aluminumized Kapton multilayer insulation (MLI) blanket with an outer layer of 0.076 mm thick Kapton. The two patches of thin film materials, part of Experiment S1001 by NASA GSFC, were attached to the cover of the external thermal blanket with Kapton tape. The experiment was assembled and mounted in the experiment tray with non-magnetic stainless steel fasteners.

  11. LDEF (Flight), S0109 : Fiber Optic Data Transmission Experiment, Tray C12

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The Fiber Optic Data Transmission Experiment (FODTE) flight photograph was taken while the LDEF was attached to the Orbiter's RMS arm prior to berthing in the Orbiter's cargo bay. The white paint dots on clamp blocks at each end of the experiment tray lower flange appear to be discolored. The FODTE occupies a six (6) inch deep LDEF peripheral tray and consist of an aluminum internal support structure, four aluminum mounting plates, an aluminum cover plate, ten fiber optic cable samples with connectors, aluminum brackets and non-magnet fasteners required to assemble the experiment. Four optical fiber cables (two black, one blue and one bright orange), each configured in the form of a planar, helix coil, are attached to the thermally isolated mounting plates with black anodized aluminum clips cushioned with silicone-rubber spacers. The four mounting plates are coated with a Catalac off-white thermal control paint and the exposed surface of the cover plate is painted with Chemglaze II A-276 white to meet thermal control requirements. Six additional coils of optical fiber cable samples, secured with nylon cable ties, are located in the bottom of the tray, four below the mounting plates and two below the cover plate. Each sample terminates in connectors mounted in brackets located in the tray bottom or on the backside of the thermally isolated mounting plates. The FODTE appears to be intact with no apparent physical damage. A flow pattern of discoloration appears to the right of each fastener used to secure the four mounting plates. Colors of two of the four exposed coils of fiber optic cables have changed significantly. The cable located in the upper right corner, originally a bright orange, appears to be dark blue and the cable in the lower left position has faded from a light blue to a blue-gray color. The color of the silicone-rubber spacers under the coil attach clips appears to have changed from clear to brown. Two brown circular discolorations have appeared, one

  12. STS-32 photo survey of LDEF includes closeup of experiment tray

    NASA Technical Reports Server (NTRS)

    1990-01-01

    STS-32 onboard view shows one of many individual trays on the twelve-sided bus-sized Long Duration Exposure Facility (LDEF). This is the space end of LDEF, which spent 5 1/2 years in Earth orbit before STS-32 retrieval. In the center is the experiment titled 'Heavy Ions in Space' and was designed by the Laboratory for Cosmic Ray Physics at the Naval Research Laboratory in Washington, D.C.

  13. LDEF (Postflight), S0109 : Fiber Optic Data Transmission Experiment, Tray C12

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The Fiber Optic Data Transmission Experiment (FODTE) postflight photograph was taken in the SAEF II at KSC after the experiment was removed from the LDEF. The experiment trays lower flange has a light tan discoloration that is visible in areas not protected by the tray clamp blocks. Dark brown discolorations can be seen near the center of the tray left flange and on the upper and lower flanges near the corners of the white cover plate. The tray sidewalls appear to be heavily stained in corners, along the three areas adjacent to the white cover plate and at the intersection of the sidewalls with the experiment sup- port structure. The FODTE occupies a six (6) inch deep LDEF peripheral tray and consist of an aluminum internal support structure, four aluminum mounting plates, an aluminum cover plate, ten fiber optic cable samples with connectors, aluminum brackets and non-magnet fasteners required to assemble the experiment. Four optical fiber cables (two black, one blue and one bright orange), each configured in the form of a planar, helix coil, are attached to the thermally isolated mounting plates with black anodized aluminum clips cushioned with silicone-rubber spacers. The four mounting plates are coated with a Catalac off-white thermal control paint and the exposed surface of the cover plate is painted with Chemglaze II A-276 white to meet thermal control requirements. Six additional coils of optical fiber cable samples, secured with nylon cable ties, are located in the bottom of the tray, four below the mounting plates and two below the cover plate. Each sample terminates in connectors mounted in brackets located in the tray bottom or on the backside of the thermally isolated mounting plates. The FODTE appears to be intact with no apparent physical damage. A flow pattern of discoloration appears to flow in a downward direction from fasteners used to secure the four mounting plates. The colors of two coils of the externally mounted fiber optic cables have

  14. LDEF (Prelaunch), M0002-01 : Trapped-Proton Energy Spectrum Determination, Tray G12

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The prelaunch photograph was taken in SAEF II at KSC prior to installation of the integrated tray on the LDEF. The Trapped Proton Energy Spectrum Determination Experiment is one of four (4) experiments located in a three (3) inch deep LDEF end center tray. Additional Trapped Proton Energy Experiments are located in peripheral LDEF integrated experiment trays in the D03 and D09 tray locations. The identifica tion plate on the lower right corner of the experiment mounting plate identifies the experiments location and orientation in the experiment tray. The Trapped Proton Energy experiment, located in the upper left quadrant of the integrated tray, consist of a primary experiment and three (3) sub experiments mounted on an aluminum mount ing plate. The primary experiment components include six (6) stacks of CR-39 passive detectors in individual aluminum housings and an aluminum mounting structure, configured to provide the desired exposure for the detector stacks. The secondary experiments consist of the Neutron and Proton Activation experiment that expose metal samples to the ambient flux throughout the mis sion, the Microsphere Dosimetry experiment housed in a cylindrical aluminum container and the Flux Measurement by Ion Trapping experiment consisting of a variety of sample materials that are exposed to the space environment for the total mission. The exterior surfaces of the mounting plate, the experiment housings and the support structure are coated with IITRI S13G-LO white paint.The experiment is assembled using non-magnetic stainless steel fasteners and safety wire.

  15. Closeup of LDEF experiment trays documented during STS-32 photo survey

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Closeup of Long Duration Exposure Facility (LDEF) experiment trays is documented during STS-32 retrieval activity and photo survey conducted by crewmembers onboard Columbia, Orbiter Vehicle (OV) 102. Partially visible is the Polymer Matrix Composite Materials Experiment. In the background is the surface of the Earth.

  16. Closeup of LDEF experiment trays documented during STS-32 photo survey

    NASA Image and Video Library

    1990-01-20

    Closeup of Long Duration Exposure Facility (LDEF) experiment trays is documented during STS-32 retrieval activity and photo survey conducted by crewmembers onboard Columbia, Orbiter Vehicle (OV) 102. Partially visible is the Polymer Matrix Composite Materials Experiment. In the background is the surface of the Earth.

  17. STS-32 photo survey of LDEF includes closeup of experiment tray

    NASA Technical Reports Server (NTRS)

    1990-01-01

    STS-32 onboard view shows one of many individual trays on the twelve-sided bus-sized Long Duration Exposure Facility (LDEF). In the center is the experiment tray representing the Dublin, Ireland, Institute for Advanced Studies and ESA-ESTEC, titled 'A High-Resolution Study of Ultra-heavy Cosmic-Ray Nuclei.' The experiment has 16 locations on the cylindrical spacecraft. Note the apparent micrometeoroid hits on the experiment. The light green adjacent tray is a JSC-based experiment on the chemistry of micrometeoroids.

  18. LDEF (Flight), M0004 : Space Environment Effects on Fiber Optics Systems, Tray F08

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The flight photograph was taken while the LDEF was attached to the Orbiter's RMS arm prior to berthing in the Orbiter's cargo bay. The white paint dot on the center clamp block of the experiment tray lower flange appears to be slightly discolored. The Space Environment Effects on Fiber Optic Systems Experiment occupies a six (6) inch deep LDEF peripheral tray and consist of an aluminum internal support structure, an Electronic Power and Data System (EPDS), three aluminum experiment mounting plates, two aluminum cover plates, four operational digital optical data links (lengths of 48 m, 45 m and two 20 m) exposed to the space environment, three passive cabled fiber optic links (each 10 m long) with electronic components and end connectors, aluminum brackets and non-magnet stainless steel fasteners required to assemble the experiment. Four active cabled optical fiber links (one black, one blue, one yellow and one light tan), each configured in the form of a planar, helix coil, are attached to thermally isolated mounting plates with black anodized aluminum clips cushioned with silicone-rubber spacers. The three mounting plates are coated with a Catalac off-white thermal control paint, the large cover plate is coated with Chemglaze II A-276 white paint and the smaller cover plate is coated with IITRI S13G-LO white paint to meet thermal control requirements. The three passive cabled optical fiber links and all emitters, detectors and associated electronics are located in the interior volume of the tray. All cabled optical fibers terminate in connectors mounted in brackets that are located in the tray bottom or on the backside of the thermally isolated mounting plates. The Space Environment Effects on Fiber Optic Systems Experiment appears to be intact with no apparent structural damage. Colors of all three exposed coils of fiber optic cables have changed significantly. The cable located in the upper right corner, originally glossy black, appears to be dark brown and the

  19. LDEF (Postflight), M0004 : Space Environment Effects on Fiber Optics Systems, Tray F08

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The postflight photograph was taken in the SAEF II at KSC prior to removal of the experiment from the LDEF. The color of the white paint dot on the center clamp block of the experiment tray lower flange appears to be unchanged. The Space Environment Effects on Fiber Optic Systems Experiment occupies a six (6) inch deep LDEF peripheral tray and consist of an aluminum internal support structure, an Electronic Power and Data System (EPDS), three aluminum experiment mounting plates, two aluminum cover plates, four operational digital optical data links (lengths of 48 m, 45 m and two 20 m) exposed to the space environment, three passive cabled fiber optic links (each 10 m long) with electronic components and end connectors, aluminum brackets and non-magnet stainless steel fasteners required to assemble the experiment. Four active cabled optical fiber links (one black, one blue, one yellow and one light tan), each configured in the form of a planar, helix coil, are attached to thermally isolated mounting plates with black anodized aluminum clips cushioned with silicone-rubber spacers. The three mounting plates are coated with a Catalac off-white thermal control paint, the large cover plate is coated with Chemglaze II A-276 white paint and the smaller cover plate is coated with IITRI S13G-LO white paint to meet thermal control requirements. The three passive cabled optical fiber links and all emitters, detectors and associated electronics are located in the interior volume of the tray. All cabled optical fibers terminate in connectors mounted in brackets that are located in the tray bottom or on the backside of the thermally isolated mounting plates. The Space Environment Effects on Fiber Optic Systems Experiment appears to be intact with no apparent structural damage. Colors of all three exposed coils of fiber optic cables have changed significantly. The cable located in the lower right corner, originally glossy black, appears to be dark brown and the cable in the lower

  20. LDEF (Prelaunch), S0010 : Exposure of Spacecraft Coatings, Tray B09

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The prelaunch photograph was taken in SAEF II at KSC prior to installation of the integrated tray on the LDEF and shows the locations of two (2) LDEF experiments integrated into a six (6) inch deep LDEF peripheral tray. The Exposure of Spacecraft Coatings Experiment (ESC) consist of two parts, one set of test specimen (49-2cm specimen and 12-4cm specimen) located in the upper right-half of the tray center section and the second set of test specimen (98-2cm specimen and 12-4cm specimen) in an Experiment Exposure Control Canister (EECC) located in the right section of the experiment tray. Both sets of specimen are mounted in aluminum base plates and are partially masked by a thin aluminum cover plate with circular openings. The cover plates and the support structure are assembled with non-magnetic fasteners. The EECC is in the closed position and specimen contained within cannot be seen. The visible parts of the canister consist of the larger anodized aluminum thermal cover attached to the canister body and sun shield attached to the canister drawer faceplate. The silver squares on the lower corners of the canister sun shield are pads of tape installed prior to launch.

  1. LDEF (Flight), S0010 : Exposure of Spacecraft Coatings, Tray B09

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The flight photograph was taken from the Orbiter aft flight deck during the LDEF retrieval prior to berthing the LDEF in the Orbiter cargo bay and shows the locations of two (2) LDEF experiments integrated into a six (6) inch deep LDEF peripheral tray. A brown discoloration is seen along the left half of the lower tray flange and also on the right half of the lower sidewall. The Experiment Exposure Control Canister (EECC), located in the lower section of the experiment tray, has a dark brown discoloration on the mounting structure in the bottom of the tray. Top and lower flanges appear to have very light discoloration and also have abrasions from prelaunch testing. The Exposure of Spacecraft Coatings Experiment (ESC) consist of two parts, one set of test specimen (49-2cm specimen and 12-4cm specimen) located in the lower right half of the tray center section and the second set of test specimen (98-2cm specimen and 12-4cm specimen) located in the EECC. Both sets of specimen are mounted in aluminum base plates and are partially masked by a thin aluminum cover plate with circular openings. The cover plates and the support structure are assembled with non-magnetic fasteners. Some exposed specimen coatings have changed colors and three of the larger (4cm) specimen appear to be severely degraded or missing. The EECC is in the closed position and specimen contained within cannot be viewed. The visible parts of the canister consist of the larger anodized aluminum thermal cover attached to the canister body and sun shield attached to the canister drawer faceplate. The silver squares on the lower corners of the canister sun shield are pads of tape installed prior to launch.

  2. LDEF (Prelaunch), AO135 : Effect of Space Exposure on Pyroelectric Infrared Detectors, Tray E05

    NASA Technical Reports Server (NTRS)

    1984-01-01

    LDEF (Prelaunch), AO135 : Effect of Space Exposure on Pyroelectric Infrared Detectors, Tray E05 The prelaunch photograph was taken in SAEF II at KSC prior to installation of the integrated tray on the LDEF. The Space Exposure on Pyroelectric Infrared Detectors Experiment (AO135) consist of twenty detectors of three different types of materials, lithium-tantalate, strontium-barium-niobate and triglycine-sulfide. The Pyroelectric infrered detector experiment is an integral part of the Active Optical System Component Experiment (S0050) that contains 136 test specimen and is located in a six (6) inch deep LDEF peripheral experiment tray. The experiment tray is divided into six sections, each consisting of a 1/4 inch thick chromic anodized aluminum base plate and a 1/16th inch thick aluminum hat shaped structure for mounting the test specimen. The test specimen are typi- cally placed in fiberglass-epoxy retainer strip assemblies prior to installation on the hat shaped mounting structure. Five of the six sections are covered by a 1/8 inch thick anodized aluminum sun screen with openings that allowed 56 percent transmission over the central region. Two subexperiments, The Optical Materials and UV Detectors Experiment (S0050-01) consist of 15 optical windows, filters and detectors and occupies one of the trays six sub-sections and The Optical Substrates and Coatings Experiment (S0050-02 ) that includes 12 substrates and coatings and a secondary experiment, The Holographic Data Storage Crystal Experiment (AO044) with four crystals, are also mounted in the integrated tray. The experiment structure was assembled with non-magnetic stainless steel fasteners.

  3. LDEF mechanical systems

    NASA Technical Reports Server (NTRS)

    Spear, W. Steve; Dursch, Harry W.

    1992-01-01

    Following LDEF retrieval, a number of studies were made of mechanical hardware and structure flown on the LDEF. The primary objectives are to determine the effects of long term space exposure on (1) mechanisms either used on LDEF or as part of individual experiments; (2) LDEF structural components; and (3) fasteners. Results from examination and testing of LDEF structure, fasteners, LDEF end support beam, environment exposure control canisters, experiment tray clamps, LDEF grapple fixtures, and viscous damper are presented. The most significant finding is the absence of space exposure related cold welding. The instances of seizure or removal difficulties initially attributed to cold welding were shown to have resulted from installation galling damage or improper removal techniques. Widespread difficulties encountered with removal of stainless steel fasteners underscore the need for effective thread lubrication schemes to ensure successful application of proposed orbital replacement units onboard Space Station Freedom.

  4. LDEF (Postflight), S0010 : Exposure of Spacecraft Coatings, Tray B09

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The postflight photograph was taken in SAEF II after the experiment tray was removed from the LDEF and shows the locations of two (2) experiments integrated into a six (6) inch deep LDEF peripheral tray. A brown discoloration is seen at the top end of the tray's left flange and also on the lower half of the tray's left sidewall. The Experiment Exposure Control Canister (EECC), located in the left section of the experiment tray, has a dark brown discoloration on the mounting structure in the bottom of the tray. The tray's right and left flanges and each end of the top flange have abrasions from prelaunch testing. The Exposure of Spacecraft Coatings Experiment (ESC)experiment consist of two parts, one set of test specimen (49-2cm specimen and 12-4cm specimen) located in the lower left half of the tray center section and the second set of test specimen (98-2cm specimen and 12-4cm specimen) located in the EECC. Both sets of specimen are mounted in aluminum base plates and are parially mask by a thin aluminum cover plate with circular openings. The cover plates and the sup- port structure are assembled with non-magnetic fasteners. Some exposed specimen coatings have changed colors and three of the larger (4cm) specimen appear to be severely degraded or missing. The EECC is in the closed position and specimen contained within cannot be viewed. The visible parts of the canister consist of the larger anodized aluminum thermal cover attached to the canister body and sun shield attached to the canister drawer faceplate. The silver squares on the lower corners of the canister sun shield are pads of tape installed prior to launch.

  5. LDEF (Postflight), M0003 : Space Environment Effects on Spacecraft Materials, Tray D08

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), M0003 : Space Environment Effects on Spacecraft Materials, Tray D08 The postflight photograph was taken in SAEF II at KSC prior to the experiment trays removal from the LDEF. The Spacecraft Materials Experiment hardware consist of four LDEF peripheral trays (two sets), two Experiment Power and Data Systems (EPDS), two Environment Exposure Control Canisters (EECC), twelve LiSO2 batteries and internal support structure, instrumentation and black anodized aluminum mounting plates for experiment samples. The experiment structural members were assembled using nonmagnetic stainless steel fasteners. One six inch tray and one three inch tray with a connecting wiring harness, one EPDS, one EECC and six LiSO2 batteries were located in tray locations D08 and D09 near the LDEF leading edge and a similar set of hardware was located near the LDEF trailing edge in tray locations D03 and D04. The environmental exposure was similar with one significant exception, the trailing edge location was not exposed to continuous bombardment by the relativity high atomic oxygen flux. The experiment tray in the D08 location is divided into three sections.The right section provides space for the EPDS, the center section accommodates the Signal Conditioning Unit (SCU) and an experiment mounting plate, on an aluminum sub-structure, that is populated with composite material samples. The left section houses the EECC with a complement of experiment samples that consist of coatings, thermal paints, polymers, glasses, semi-conductors. Detectors within the experiment provide environmental data for use in postflight analyses. Batteries and inter-tray wiring harness are located beneath the tray base plates. The EPDS is under an aluminum cover, coated with a white thermal control paint (Chemglaze II A-276) and thermally isolated from the tray structure by fiberglass clips. The SCU cover is also coated with a white thermal control paint, IITRI S13G-LO, and the EECC is covered with a

  6. LDEF (Postflight), M0003 : Space Environment Effects on Spacecraft Materials, Tray D04

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), M0003 : Space Environment Effects on Spacecraft Materials, Tray D04 The postflight photograph was taken in SAEF II at KSC after the experiment tray was removed from the LDEF. The Spacecraft Materials Experiment hardware consist of four LDEF peripheral trays (two sets), two Experiment Power and Data Systems (EPDS), two Environment Exposure Control Canisters (EECC), twelve LiSO2 batteries and internal support structure, instrumentation and black anodized aluminum mounting plates for experiment samples. The experiment structural members were assembled using nonmagnetic stainless steel fasteners. One six inch tray and one three inch tray with a connecting wiring harness, one EPDS, one EECC and six LiSO2 batteries were located in tray locations D08 and D09 near the LDEF leading edge and a similar set of hardware was located near the LDEF trailing edge in tray locations D03 and D04. The environmental exposure was similar with one significant exception, the trailing edge location was not exposed to continuous bombardment by the relativity high atomic oxygen flux. The experiment tray in the D04 location is divided into three sections.The right section provides space for the EPDS, the center section accommodates the Signal Conditioning Unit (SCU) and an experiment mounting plate, on an aluminum sub-structure, that is populated with composite material samples. The left section houses the EECC with a complement of experiment samples that consist of coatings, thermal paints, polymers, glasses, semi-conductors. Detectors within the experiment provide environmental data for use in postflight analyses. Batteries and inter-tray wiring harness are located beneath the tray base plates. The EPDS is underneath an aluminum cover, coated with a white thermal control paint (Chemglaze II A-276) and thermally isolated from the tray structure by fiberglas clips. The SCU cover is also coated with a white thermal control paint, IITRI S13G-LO, and the EECC is covered with a

  7. LDEF (Postflight), S1005 : Transverse Flat-Plate Heat Pipe Experiment, Tray B10

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), S1005 : Transverse Flat-Plate Heat Pipe Experiment, Tray B10 EL-1994-00123 The Transverse Flat-Plate Heat Pipe Experiment postflight photograph was taken in the Orbiter Processing Facility (OPF) at KSC during removal of the LDEF from the Orbiter's cargo bay. The thermal blanket (with the patches) across the lower edge of the photograph is part of the Orbiter thermal protection system and not associated with the heat pipe experiment. The Transverse Flat-Plate Heat Pipe Experiment consist of three (3) transverse flat heat-pipe modules , a power system for the heaters, a data acquisition and storage system and an aluminum support structure placed in a twelve (12) inch deep LDEF experiment tray. The surface of the experiment exposed to the space environment consist of the three heat pipe modules exterior surfaces, silver TEFLON®, and the thermal blankets covering the aluminum mounting hardware and openings between the hardware and the tray sidewalls. The raised surface at the left end of each heat pipe module is the fluid reservoir. The specular surface of the silver TEFLON® has become diffuse and appears white. Numerous impact craters, black specks, can be seen on the white surfaces of the modules and on the thermal blankets. A light tan discoloration is visible on the surfaces of all three heat pipe modules. Two different types of discolorations can be seen at the left end of the center heat pipe; a dark brown color below the thermocouple and what appears as two multi-color irregular shaped patterns above the thermocouple. A square shaped light brown discoloration is seen near the bottom edge of the thermal blanket between the lower heat pipe module and the tray sidewall and also near the left end of the thermal blanket located between the lower and the center heat pipe modules.

  8. LDEF (Prelaunch), M0004 : Space Environment Effects on Fiber Optics Systems, Tray F08

    NASA Technical Reports Server (NTRS)

    1984-01-01

    LDEF (Prelaunch), M0004 : Space Environment Effects on Fiber Optics Systems, Tray F08 The prelaunch photograph was taken in SAEF II at KSC prior to installation of the Space Environment Effects on Fiber Optic Systems Experiment on the LDEF. The Space Environment Effects on Fiber Optic Systems Experiment occupies a six (6) inch deep LDEF peripheral tray and consist of an aluminum internal support structure, an Electronic Power and Data System (EPDS), three aluminum experiment mounting plates, two aluminum cover plates, four operational digital optical data links (lengths of 48 m, 45 m and two 20 m) exposed to the space environment, three passive cabled fiber optic links (each 10 m long) with electronic components and end connectors, aluminum brackets and non-magnet stainless steel fasteners required to assemble the experiment. Four active cabled optical fiber links (one black, one blue, one yellow and one light tan), each configured in the form of a planar, helix coil, are attached to thermally isolated mounting plates with black anodized aluminum clips cushioned with silicone-rubber spacers. The three mounting plates are coated with a Catalac off-white thermal control paint, the large cover plate is coated with Chemglaze II A-276 white paint and the smaller cover plate is coated with IITRI S13G-LO white paint to meet thermal control requirements. The three passive cabled optical fiber links and all emitters, detectors and associated electronics are located in the interior volume of the tray. All cabled optical fibers terminate in connectors mounted in brackets that are located in the tray bottom or on the backside of the thermally isolated mounting plates.

  9. LDEF (Prelaunch), S0109 : Fiber Optic Data Transmission Experiment, Tray C12

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The prelaunch photograph was taken in SAEF II at KSC prior to installation of the Fiber Optic Data Transmission Experiment (FODTE) on the LDEF. The FODTE occupies a six (6) inch deep LDEF peripheral tray and consist of an aluminum internal support structure, four aluminum mounting plates, an aluminum cover plate, ten fiber optic cable samples with connectors, aluminum brackets and non-magnet fasteners required to assemble the experiment. Four optical fiber cables (two black, one blue and one bright orange), each configured in the form of a planar, helix coil, are attached to the thermally isolated mounting plates with black anodized aluminum clips cushioned with silicone-rubber spacers. The four mounting plates are coated with a Catalac off-white thermal control paint and the exposed surface of the cover plate is painted with Chemglaze II A-276 white to meet thermal control requirements. Six additional coils of optical fiber cable samples, secured with nylon cable ties, are located in the bottom of the tray, four below the mounting plates and two below the cover plate. Each sample terminates in connectors mounted in brackets located in the tray bottom or on the backside of the thermally isolated mounting plates.

  10. LDEF (Postflight), M0001 : Heavy Ions in Space, Tray H03

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), M0001 : Heavy Ions in Space, Tray H03 The post landing photograph of the Heavy Ions in Space Experiment was taken from the Orbiter's cargo bay access hatch during post landing opera tions to prepare the Orbiter for the ferry flight from the Dryden Flight Research Center to the Kennedy Space Center. The photograph shows extensive damage to the multi-layer thermal insulation blanket. The tape joints appear to have failed along two (2) sides of each experiment module and allowed the multi layer thermal insulation blanket to curled back over its self. The golden colored surfaces that have been exposed are the top sheet of the experiment's Lexan detector stacks that are held securely in place by the Z shaped aluminum structure. A light tan stain can be seen on the LDEF end structure along the upper edge of the experiment tray flange. Lighter stains that appear to be finger prints are also visible on the trays top flange. The paint on the top layer of the thermal blankets, origi nally white, now appears brown or light tan. The fragments of aluminum in the lower two quad rants appear to be the results of delamination of the vapor deposited aluminum from the thin aluminized Mylar thermal film.

  11. LDEF (Prelaunch), AO187-01 : The Chemistry of Micrometeoroids, Tray A03

    NASA Technical Reports Server (NTRS)

    1984-01-01

    LDEF (Prelaunch), AO187-01 : The Chemistry of Micrometeoroids, Tray A03 The prelaunch photograph shows the two (2) clam shell type canisters in their closed position. The canister shells are made of aluminum sheet material with end caps of diecast aluminum. The baseplate and support structure are fabricated from 6000 series aluminum. Fasteners are non-magnetic stainless steel. The electrical box and the stainless steel tubing located on the baseplate protect the drive system wiring. The experiment contains a timing mechanism that provides the intelligence to open the canisters after the Orbiter has departed the area and any initial outgassing or offgassing has occurred.

  12. LDEF (Flight), M0001 : Heavy Ions in Space, Tray H12

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), M0001 : Heavy Ions in Space, Tray H12 EL-1994-00676 The flight photograph of the Heavy Ions in Space Experiment was taken from the Orbiter's aft flight deck during LDEF retrieval operations. A light coating of the stain can be seen on the tray flange adjacent to the American flag. The photograph shows four (4) experiment modules mounted in the LDEF provided end center experiment tray.An experiment module consist of the thermal cover, a top stack of Lexan sheets for detecting low-energy ions, a honeycomb pressure cover and the main stack of CR-39 used to detect cosmic rays mounted in an aluminum housing. Three modules are identical while the fourth module has been divided into four smaller units that allows the use of pressure covers with a lower energy threshold to Ion penetration. The exposed surface of each module is a white paint overcoat, Chemglaze II A-276, that has been applied to the top layer, aluminized Kapton, of a multilayer thermal blanket. The frame around each of the four modules, a Z shaped aluminum structure, is covered with a silverized TEFLON® film secured with 3M Y966 acrylic transfer tape. The 3M Y966 tape on a silverized TEFLON® film is also used to attach the multi-layer thermal insulation blankets to the modules frame. The combination of the silverized TEFLON® and the white paint provides the appropriate optical properities needed to meet experiment thermal requirements. Extensive damage occurred to the experiment's multi-layer thermal blankets during the LDEF mission, prior to retrieval operations. It appears that the tape used attach the thermal blankets to the structure failed in tension. When the bond joint released along two (2) sides, the tension was releaved and the remaining tape continued to hold the blanket to the structure through out the rest mission and the post-flight operations. The outside blanket surfaces that were originally white are now coated with a glossy dark brown stain thought to be from

  13. Durability evaluation of photovoltaic blanket materials exposed on LDEF tray S1003

    NASA Technical Reports Server (NTRS)

    Rutledge, Sharon K.; Olle, Raymond M.

    1992-01-01

    Several candidate protective coatings on Kapton and uncoated Kapton were exposed to the low Earth orbital (LEO) environment on the Long Duration Exposure Facility (LDEF) to determine if the coatings could be used to protect polymeric substrates from degradation in the LEO environment. The coatings that were evaluated were 700 A of aluminum oxide, 650 A of silicon dioxide, and 650 A of a 4 percent polytetrafluoroethylene-96 percent silicon dioxide mixed coating. All of the coatings evaluated were ion beam sputter deposited. These materials were exposed to a very low atomic oxygen fluence (4.8 x 10 exp 19 atoms/sq. cm) as a result of the experiment tray being located 98 degrees from the ram direction. As a result of the low atomic oxygen fluence, determination of a change in mass was not possible for any of the samples including the uncoated Kapton. There was no evidence of spalling of any of the coatings after the approximately 33,600 thermal cycles recorded for LDEF. The surface of the uncoated Kapton, however, did show evidence of grazing incidence texturing. There was a 7-8 percent increase in solar absorptance for the silicon dioxide and aluminum oxide coated Kapton and only a 4 percent increase for the mixed coating. It appears that the addition of a small amount of fluoropolymer may reduce the magnitude of absorptance increase due to environmental exposure. Thermal emittance did not change significantly for any of the exposed samples. Scanning electron microscopy revealed few micrometeoroid or debris impacts, but the impact sites found indicated that the extent of damage or cracking of the coating around the defect site did not extend beyond a factor of three of the impact crater diameter. This limiting of impact damage is of great significance for the durability of thin film coatings used for protection against the LEO environment.

  14. Analytical electron microscopy of LDEF impactor residues

    SciTech Connect

    Bernhard, R.P.; Barrett, R.A.; Zolensky, M.E.

    1995-02-01

    The LDEF contained 57 individual experiment trays or tray portions specifically designed to characterize critical aspects of meteoroid and debris environment in low-Earth orbit (LEO). However, it was realized from the beginning that the most efficient use of the satellite would be to characterize impact features from the entire surface of the LDEF. With this in mind particular interest has focused on common materials facing in all 26 LDEF facing directions; among the most important of these materials has been the tray clamps. Therefore, in an effort to better understand the nature and flux of particulates in LEO, and their effects on spacecraft hardware, the authors are analyzing residues found in impact features on LDEF tray clamp surfaces. This paper summarizes all data from 79 clamps located on Bay A & B of the LDEF. The authors also describe current efforts to characterize impactor residues recovered from the impact craters, and they have found that a low, but significant, fraction of these residues have survived in a largely unmelted state. These residues can be characterized sufficiently to permit resolution of the impactor origin. The authors have concentrated on the residue from chondritic interplanetary dust particles (micrometeoroids), as these represent the harshest test of their analytical capabilities.

  15. Analytical electron microscopy of LDEF impactor residues

    NASA Technical Reports Server (NTRS)

    Bernhard, Ronald P.; Barrett, Ruth A.; Zolensky, Michael E.

    1995-01-01

    The LDEF contained 57 individual experiment trays or tray portions specifically designed to characterize critical aspects of meteoroid and debris environment in low-Earth orbit (LEO). However, it was realized from the beginning that the most efficient use of the satellite would be to characterize impact features from the entire surface of the LDEF. With this in mind particular interest has focused on common materials facing in all 26 LDEF facing directions; among the most important of these materials has been the tray clamps. Therefore, in an effort to better understand the nature and flux of particulates in LEO, and their effects on spacecraft hardware, we are analyzing residues found in impact features on LDEF tray clamp surfaces. This paper summarizes all data from 79 clamps located on Bay A & B of the LDEF. We also describe current efforts to characterize impactor residues recovered from the impact craters, and we have found that a low, but significant, fraction of these residues have survived in a largely unmelted state. These residues can be characterized sufficiently to permit resolution of the impactor origin. We have concentrated on the residue from chondritic interplanetary dust particles (micrometeoroids), as these represent the harshest test of our analytical capabilities.

  16. Collection and review of metals data obtained from LDEF experiment specimens and support hardware

    NASA Technical Reports Server (NTRS)

    Bourassa, Roger; Pippin, H. Gary

    1995-01-01

    LDEF greatly extended the range of data available for metals exposed to the low-Earth-orbital environment. The effects of low-Earth-orbital exposure on metals include meteoroid and debris impacts, solar ultraviolet radiation, thermal cycling, cosmic rays, solar particles, and surface oxidation and contamination. This paper is limited to changes in surface composition and texture caused by oxidation and contamination. Surface property changes afford a means to study the environments (oxidation and contamination) as well as in-space stability of metal surfaces. We compare thermal-optical properties for bare aluminum and anodized aluminum clamps flown on LDEF. We also show that the silicon observed on the LDEF tray clamps and tray clamp bolt heads is not necessarily evidence of silicon contamination of LDEF from the shuttle. The paper concludes with a listing of LDEF reports that have been published thus far that contain significant findings concerning metals.

  17. Surface characterization of LDEF materials

    NASA Technical Reports Server (NTRS)

    Wightman, J. P.; Grammer, Holly Little

    1993-01-01

    The NASA Long Duration Exposure Facility (LDEF), a passive experimental satellite, was placed into low-Earth orbit by the Shuttle Challenger in Apr. 1984. The LDEF spent an unprecedented 69 months in space. The flight and recovery of the LDEF provided a wealth of information on the longterm space environmental effects of a variety of materials exposed to the low-Earth orbit environment. Surface characterization of LDEF materials included polymers, composites, thermal control paints, and aluminum. X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), scanning electron microscopy (SEM), and contact angle analysis were used to document changes in both the surface composition and surface chemistry of these materials. Detailed XPS analysis of the polymer systems, such as Kapton, polyimide polysiloxane copolymers, and fluorinated ethylene propylene thermal blankets on the backside of the LDEF revealed significant changes in both the surface composition and surface chemistry as a result of exposure to the low-Earth orbit environment. Polymer systems such as Kapton, polyimide polysiloxane copolymers, and polysulfone showed a common trend of decreasing carbon content and increasing oxygen content with respect to the control sample. Carbon 1s curve fit XPS analysis of the composite samples, in conjunction with SEM photomicrographs, revealed significant ablation of the polymer matrix resin to expose the carbon fibers of the composite during exposure to the space environment. Surface characterization of anodized aluminum tray clamps, which were located at regular intervals over the entire LDEF frame, provided the first results to evaluate the extent of contamination with respect to position on the LDEF. The XPS results clearly showed that the amount and state of both silicon and fluorine contamination were directly dependent upon the position of the tray clamp on the LDEF.

  18. Durability evaluation of photovoltaic blanket materials exposed on LDEF tray S1003

    NASA Technical Reports Server (NTRS)

    Rutledge, Sharon K.; Olle, Raymond M.

    1991-01-01

    Several candidate protective coatings on Kapton and uncoated Kapton were exposed to the LEO environment on the LDEF in order to determine whether the coatings could be used to protect polymeric substrates from degradation in the LEO environment. These materials are used for flexible solar array panels in which the polymer is the structural member that supports the solar cell and current carriers. Arrays such as these are used on the Hubble Space Telescope and will be used on Space Station Freedom. The results of the experiments are presented.

  19. Durability evaluation of photovoltaic blanket materials exposed on LDEF tray S1003

    NASA Astrophysics Data System (ADS)

    Rutledge, Sharon K.; Olle, Raymond M.

    1991-06-01

    Several candidate protective coatings on Kapton and uncoated Kapton were exposed to the LEO environment on the LDEF in order to determine whether the coatings could be used to protect polymeric substrates from degradation in the LEO environment. These materials are used for flexible solar array panels in which the polymer is the structural member that supports the solar cell and current carriers. Arrays such as these are used on the Hubble Space Telescope and will be used on Space Station Freedom. The results of the experiments are presented.

  20. Vibration analysis of the Long Duration Exposure Facility (LDEF) using SPAR

    NASA Technical Reports Server (NTRS)

    Edighoffer, H.

    1980-01-01

    The structural modeling of the Long Duration Exposure Facility (LDEF) utilizing the SPAR system of computer programs for vibration analysis is discussed. The technical areas of interest were: (1) development of the LDEF finite element model; (2) derivation of tray effective panel stiffness matrix using finite element tray models; (3) assessment of attachment conditions and end fitting flexibility by comparing SPAR with test static displacements; (4) SPAR grouping; and (5) derivation of the LDEF frequencies and mode shapes and comparing them with tests. Special detailed finite element modeling was required to obtain good agreement between analytical and test vibration modes. An orthotropic panel in the overall model was developed. Orthotropic stiffness for this panel were obtained from finely detailed statically loaded SPAR models which included stiffness and allowed for partial relative sliding of the tray clamping attachments. Sensitivity to LDEF joint boundary conditions was determined, and static test data proved valuable in assessing modeling of local end fittings.

  1. LDEF materials data analysis: Representative examples

    NASA Technical Reports Server (NTRS)

    Pippin, Gary; Crutcher, Russ

    1993-01-01

    Part of the philosophy which guided the examination of hardware from the Long Duration Exposure Facility (LDEF) was that materials present at multiple locations should have fairly high priority for investigation. Properties of such materials were characterized as a function of exposure conditions to obtain as much data as possible for predicting performance lifetimes. Results from examination of several materials from interior locations of LDEF, selected measurements on silverized teflon blanket specimens, and detailed measurements on the copper grounding strap from tray D11 are summarized. Visual observations of interior locations of LDEF made during deintegration at KSC showed apparent changes in particular specimens. This inspection lead to testing of selected nylon clamps, fiberglass shims, and heat shrink tubing from wire harness clamps, and visually discolored silver coated hex nuts.

  2. Micrometeoroids and debris on LDEF comparison with MIR data

    NASA Technical Reports Server (NTRS)

    Mandeville, Jean-Claude; Berthoud, Lucinda

    1995-01-01

    Part of the LDEF tray allocated to French experiments (FRECOPA) has been devoted to the study of dust particles. The tray was located on the face of LDEF directly opposed to the velocity vector. Crater size distributions have made possible the evaluation of the incident microparticle flux in the near-Earth environment. Comparisons are made with measurements obtained on the other faces of LDEF (tray clamps), on the leading edge (MAP) and with results of a similar experiment flown on the MIR space station. The geometry of impact craters, depth in particular, provides useful information on the nature of impacting particles and the correlation of geometry with the chemical analysis of projectile remnants inside craters make possible a discrimination between meteoroids and orbital debris. Emphasis has been laid on the size distribution of small craters in order to assess a cut-off in the distribution of particles in LEO. Special attention has been paid to the phenomenon of secondary impacts. A comparison of flight data with current models of meteoroids and space debris shows a fair agreement for LDEF, except for the smaller particles: the possible contribution of orbital debris in GTO orbits to the LDEF trailing edge flux is discussed. For MIR, flight results show differences with current modeling: the possible enhancement of orbital debris could be due to the contaminating presence of a permanently manned space station.

  3. Organic contamination of LDEF

    NASA Technical Reports Server (NTRS)

    Harvey, Gale A.

    1992-01-01

    A brown stain of varying thickness was present on most of the exterior surface of the retrieved Long Duration Exposure Facility (LDEF). Tape lifts of Earth-end LDEF surfaces taken in Feb. 1990 showed that the surface particle cleanliness immediately after retrieval was very good, but faint footprints of the tape strips on the tested surfaces indicated a very faint film was removed by the tape. Solvent wipes of these surfaces showed that the stain was not amenable to standard organic solvent removal. Infrared spectra of optical windows from tray E5 and scrapings indicate that the film is primarily of organic composition, but is not similar to the oil that seeped from tray C12. Very dark and heavy deposits of the stain are present at openings and vents to the interior of the LDEF. Heavy brown and blue-green deposits are present in the interior of LDEF where sunlight penetrated through cracks and vent openings. Photographs of the deintegrated LDEF graphically show the stain distribution. The exterior of the LDEF had significant areas painted with a white polyurethane paint for thermal control, and almost all of the interior was painted with a black polyurethane paint for thermal control. The brown staining of the LDEF is consistent with long-term outgassing of hydrocarbons from these paints followed by rapid solar-ultraviolet-induced polymerization of the outgassed hydrocarbons when the outgassed molecules stuck to surfaces exposed to sunlight.

  4. LDEF materials overview

    NASA Technical Reports Server (NTRS)

    Stein, Bland A.

    1993-01-01

    The flight and retrieval of the National Aeronautics and Space Administration's Long Duration Exposure Facility (LDEF) provided an opportunity for the study of the low-Earth orbit (LEO) environment and long-duration space environmental effects (SEE) on materials that is unparalleled in the history of the U.S. Space Program. The 5-year, 9-month flight of LDEF greatly enhanced the potential value of all materials on LDEF to the international SEE community, compared to that of the original 1-year flight plan. The remarkable flight attitude stability of LDEF enables specific analyses of individual and combined effects of LEO environmental parameters on identical materials on the same space vehicle. NASA recognized this potential by forming the LDEF Space Environmental Effects on Materials Special Investigation Group (MSIG) to address the greatly expanded materials and LEO space environment analysis opportunities available in the LDEF structure, experiment trays, and corollary measurements so that the combined value of all LDEF materials data to current and future space missions will be addressed and documented. An overview of the interim LDEF materials findings of the principal investigators and the Materials Special Investigation Group is provided. These revelations are based on observations of LEO environmental effects on materials made in space during LDEF retrieval and during LDEF tray deintegration at the Kennedy Space Center, and on findings of approximately 1.5 years of laboratory analyses of LDEF materials by the LDEF materials scientists. These findings were extensively reviewed and discussed at the MSIG-sponsored LDEF Materials Workshop '91. The results are presented in a format that categorizes the revelations as 'clear findings' or 'obscure preliminary findings' (and progress toward their resolution), plus resultant needs for new space materials developments and ground simulation testing/analytical modeling, in seven categories: materials

  5. Induced activation study of LDEF

    NASA Technical Reports Server (NTRS)

    Harmon, B. A.; Fishman, G. J.; Parnell, T. A.; Laird, C. E.

    1992-01-01

    Analysis of the induced radioactivity of LDEF is continuing with extraction of specific activities for various spacecraft materials. Data and results of activation measurements from eight national facilities are being collected for interpretation. The major activation mechanisms in LDEF components is the proton flux in the South Atlantic Anomaly (SAA) inner radiation belt. This flux is highly anisotropic, and exposes the west side of the spacecraft to higher radiation doses. The directionally dependent activation due to these protons has clearly been observed in the data from Al experiment tray clamps, steel trunnions, and is also indicated by the presence of a variety of radioisotopes in other materials. A secondary production mechanism, thermal neutron capture, was observed in two materials having large capture cross sections, Co and Ta. The neutrons could be thermalized in nearby low Z material, although this has yet to be verified. Specific activities are presented for a number of materials which show SAA effects and thermal neutron capture. Trends are examined in the measured results that show the effect of shielding and non-SAA related activation.

  6. Induced activation study of LDEF

    NASA Technical Reports Server (NTRS)

    Harmon, B. A.; Fishman, G. J.; Parnell, T. A.; Laird, C. E.

    1993-01-01

    Analysis of the induced radioactivity of the Long Duration Exposure Facility (LDEF) is continuing with extraction of specific activities for various spacecraft materials. Data and results of activation measurements from eight facilities are being collected for interpretation at Eastern Kentucky University and NASA/Marshall Space Flight Center. The major activation mechanism in LDEF components is the proton flux in the South Atlantic Anomaly (SAA). This flux is highly anisotropic, and could be sampled by taking advantage of the gravity-gradient stabilization of the LDEF. The directionally-dependent activation due to these protons was clearly observed in the data from aluminum experiment tray clamps (reaction product Na-22), steel trunnions (reaction product Mn-54 and others) and is also indicated by the presence of a variety of nuclides in other materials. A secondary production mechanism, thermal neutron capture, was observed in cobalt, indium, and tantalum, which are known to have large capture cross sections. Experiments containing samples of these metals and significant amounts of thermalizing low atomic number (Z) material showed clear evidence of enhanced activation of Co-60, In-114m, and Ta-182. Other mechanisms which activate spacecraft material that are not as easily separable from SAA proton activation, such as galactic proton bombardment and secondary production by fast neutrons, are being investigated by comparison to radiation environmental calculations. Deviations from one-dimensional radiation models indicate that these mechanisms are more important at greater shielding depths. The current status of the induced radioactivity measurements as of mid-year 1992 are reviewed. Specific activities for a number of materials which show SAA effects and thermal neutron capture are presented. The results for consistency by combining data from the participating institutions is also examined.

  7. Effects of long-term exposure on LDEF fastener assemblies

    NASA Technical Reports Server (NTRS)

    Spear, Steve; Dursch, Harry

    1992-01-01

    This presentation summarizes the Systems Special Investigations Group (SIG) findings from testing and analysis of fastener assemblies used on the Long Duration Exposure Facility (LDEF) structure, the tray mounting clamps, and by the various experimenters. The LDEF deintegration team and several experimenters noted severe fastener damage and hardware removal difficulties during post-flight activities. The System SIG has investigated all reported instances, and in all cases examined to date, the difficulties were attributed to galling during installation or post-flight removal. To date, no evidence of coldwelding was found. Correct selection of materials and lubricants as well as proper mechanical procedures is essential to ensure successful on-orbit or post-flight installation and removal of hardware.

  8. Organic contamination of LDEF

    NASA Technical Reports Server (NTRS)

    Harvey, Gale A.

    1991-01-01

    A brown stain of varying thickness was present on most of the exterior surface of the retrieved Long Duration Exposure Facility (LDEF). Tape lifts of Earth-end LDEF surfaces taken showed that the surface particle cleanliness immediately after retrieval was very good, but faint footprints of the tape strips on the tested surfaces indicated a very faint film was removed by the tape. Solvent wipes of these surfaces showed that the stain was not amenable to standard organic solvent removal. Infrared spectra of optical windows from tray E5 show that the organic film is hydrocarbon in composition, but is not similar to the oil that seeped from tray C12. Very dark and heavy deposits of the stain is present at openings and vents to the interior of LDEF. Heavy brown and blue-green deposits are present in the interior of LDEF where sunlight penetrated through cracks and vent openings. The exterior of LDEF had significant areas painted with a white polyurethane paint for thermal control, and almost all of the interior was painted with a black polyurethane paint. Brown staining is consistent with outgassing of hydrocarbons from these paints by rapid solar UV induced polymerization of the outgassed hydrocarbons when they hit sunlight exposed areas.

  9. Manual for LDEF tensile tests

    NASA Technical Reports Server (NTRS)

    Witte, W. G., Jr.

    1985-01-01

    One of the experiments aboard the NASA Long Duration Exposure Facility (LDEF) consists of a tray of approximately one hundred tensile specimens of several candidate space structure composite materials. During the LDEF flight the materials will be subjected to the space environment and to possible contamination during launch and recovery. Tensile tests of representative samples were made before the LDEF flight to obtain baseline data. Similar tests will be made on control specimens stored on earth for the length of the LDEF flight and on recovered flight specimens. This manual codifies the details of testing, data acquisition, and handling used in obtaining the baseline data so that the same procedures and equipment will be used on the subsequent tests.

  10. Ionizing radiation exposure of LDEF

    NASA Technical Reports Server (NTRS)

    Benton, E. V. (Editor); Heinrich, W. (Editor)

    1990-01-01

    The Long Duration Exposure Facility (LDEF) was launched into orbit by the Space Shuttle 'Challenger' mission 41C on 6 April 1984 and was deployed on 8 April 1984. The original altitude of the circular orbit was 258.5 nautical miles (479 km) with the orbital inclination being 28.5 degrees. The 21,500 lb NASA Langley Research Center satellite, having dimensions of some 30x14 ft was one of the largest payloads ever deployed by the Space Shuttle. LDEF carried 57 major experiments and remained in orbit five years and nine months (completing 32,422 orbits). It was retrieved by the Shuttle 'Columbia' on January 11, 1990. By that time, the LDEF orbit had decayed to the altitude of 175 nm (324 km). The experiments were mounted around the periphery of the LDEF on 86 trays and involved the representation of more than 200 investigators, 33 private companies, 21 universities, seven NASA centers, nine Department of Defense laboratories and eight foreign countries. The experiments covered a wide range of disciplines including basic science, electronics, optics, materials, structures, power and propulsion. The data contained in the LDEF mission represents an invaluable asset and one which is not likely to be duplicated in the foreseeable future. The data and the subsequent knowledge which will evolve from the analysis of the LDEF experiments will have a very important bearing on the design and construction of the Space Station Freedom and indeed on other long-term, near-earth orbital space missions. A list of the LDEF experiments according to experiment category and sponsor is given, as well as a list of experiments containing radiation detectors on LDEF including the LDEF experiment number, the title of the experiment, the principal investigator, and the type of radiation detectors carried by the specific experiment.

  11. Particle types and sources associated with LDEF

    NASA Technical Reports Server (NTRS)

    Crutcher, E. R.; Wascher, W. W.

    1992-01-01

    The particulate contamination history of the Long Duration Exposure Facility (LDEF) can be resolved by careful analysis of particle types, the LDEF time line, evidence of the relationship between particles and the surface of the LDEF, and a consideration of probable sources. This work is far from complete but was initiated as part of the characterization of the condition of experimental trays that were returned to principle investigators for their analysis. The work presented in this photo-essay is continuing and will be updated in subsequent reports to NASA and at future technical meetings.

  12. Exposure of LDEF materials to atomic oxygen: Results of EOIM 3

    NASA Technical Reports Server (NTRS)

    Jaggers, C. H.; Meshishnek, M. J.

    1995-01-01

    The third Effects of Oxygen Atom Interaction with Materials (EOIM 3) experiment flew on STS-46 from July 31 to August 8, 1992. The EOIM-3 sample tray was exposed to the low-earth orbit space environment for 58.55 hours at an altitude of 124 nautical miles resulting in a calculated total atomic oxygen (AO) fluence of 1.99 x 10(exp 20) atoms/sq cm. Five samples previously flown on the Long Duration Exposure Facility (LDEF) Experiment M0003 were included on the Aerospace EOIM 3 experimental tray: (1) Chemglaze A276 white thermal control paint from the LDEF trailing edge (TE); (2) S13GLO white thermal control paint from the LDEF TE; (3) S13GLO from the LDEF leading edge (LE) with a visible contamination layer from the LDEF mission; (4) Z306 black thermal control paint from the LDEF TE with a contamination layer from the LDEF mission; and (5) anodized aluminum from the LDEF TE with a contamination layer from the LDEF mission. The purpose of this experiment was twofold: (l) investigate the response of trailing edge LDEF materials to atomic oxygen exposure, thereby simulating LDEF leading edge phenomena; (2) investigate the response of contaminated LDEF samples to atomic oxygen in attempts to understand LDEF contamination-atomic oxygen interactions. This paper describes the response of these materials to atomic oxygen exposure, and compares the results of the EOIM 3 experiment to the LDEF mission and to ground-based atomic oxygen exposure studies.

  13. LDEF (Prelaunch)

    NASA Technical Reports Server (NTRS)

    1983-01-01

    LDEF (Prelaunch) The LDEF structure is shown mounted on the LDEF Assembly and Transport System in Building 1250 at the Langley Research Center (LaRC), Hampton Virginia, during pre-ship wiring checks. The structure is a welded / bolted assembly fab- ricated from aluminum alloy 6061-T6 extrusions, forgings, tubing and plate materials and assembled with stainless steel fasteners. The eight (8) internal tubular diagonals between the center ring structure and the two end frames provide torsional stiffness to the structure.

  14. LDEF (Flight), S0050 : Investigation of the Effects of Long-Duration Exposure on Active Optical Syst

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Flight), S0050 : Investigation of the Effects of Long-Duration Exposure on Active Optical System Components, Tray E05 The flight photograph was taken from the Orbiter aft flight deck during the LDEF retrieval and prior to berthing the LDEF in the Orbiter cargo bay. The Active Optical System Component Experiment (S0050) contained 136 test specimen located in a six (6) inch deep LDEF peripheral experiment tray. The complement of specimen included optical and electro-optical components, glasses and samples of various surface finishes. The experiment tray was divided into six sections, each consisting of a 1/4 inch thick chromic anodized aluminum base plate and a 1/16th inch thick aluminum hat-shaped structure for mounting the test specimens. The test specimens were typically placed in fiberglass-epoxy retainer strip assemblies prior to installation on the hat-shaped mounting structure. Five of the six sections were covered by a 1/8 inch thick anodized aluminum sun screen with openings that allowed 56 percent transmission over the central region. Two sub-experiments, The Optical Materials and UV Detectors Experiment (S0050-01) consist of 15 optical windows, filters and detectors and occupies one of the trays six sub-sections and The Optical Substrates and Coatings Experiment (S0050-02 ) that includes 12 substrates and coatings and two secondary experiments,The Holographic Data Storage Experiment (AO044) consisting of four crystals of lithium niobate and ThePyroelectric Infrared Detectors Experiment (AO135) with twenty detectors, are also mounted in the integrated tray. The experiment structure was assembled with non-magnetic stainless steel fasteners. The experiment hardware appears to be intact with no apparent damage. The excess blue color in the photograph makes a detailed assessment of color changes difficult. The paint dots on the tray clamp blocks, initially white, appear to have darkened and tray flanges appear discolored. The experiment sun screens and

  15. Results of examination of the A276 white and Z306 black thermal control paint disks flown on LDEF

    NASA Technical Reports Server (NTRS)

    Golden, Johnny L.

    1992-01-01

    Specimens of A276 white and Z306 black thermal control paints were analyzed for the effects of space environmental exposure as part of the Long Duration Exposure Facility (LDEF) Materials Special Investigation Group activity. The specimens, actually disks or spots of paint on tray clamps, were located at regular intervals on all LDEF longerons and intercostals. The principle conclusions from the analysis are: UV exposure degraded the surface resin of A276 paint, with coating solar absorptance increasing with UV exposure; contamination, though detected, was not enough to have adversely affected optical properties; atomic oxygen eroded resin on specimens with incidence angles of up to 100 deg; the erosion of Z306 paint on leading edge specimens removed a minimum of 10 microns of that coating; and the erosion of A276 paint at up to 80 deg incidence angle resulted in near original condition solar absorptance readings.

  16. Results of examination of the A276 white and Z306 black thermal control paint disks flown on LDEF

    NASA Technical Reports Server (NTRS)

    Golden, Johnny L.

    1992-01-01

    Specimens of A276 white and Z306 black thermal control paints were analyzed for the effects of space environmental exposure as part of the Long Duration Exposure Facility (LDEF) Materials Special Investigation Group activity. The specimens, actually disks or spots of paint on tray clamps, were located at regular intervals on all LDEF longerons and intercostals. The principle conclusions from the analysis are: UV exposure degraded the surface resin of A276 paint, with coating solar absorptance increasing with UV exposure; contamination, though detected, was not enough to have adversely affected optical properties; atomic oxygen eroded resin on specimens with incidence angles of up to 100 deg; the erosion of Z306 paint on leading edge specimens removed a minimum of 10 microns of that coating; and the erosion of A276 paint at up to 80 deg incidence angle resulted in near original condition solar absorptance readings.

  17. Imaging analysis of LDEF craters

    NASA Technical Reports Server (NTRS)

    Radicatidibrozolo, F.; Harris, D. W.; Chakel, J. A.; Fleming, R. H.; Bunch, T. E.

    1991-01-01

    Two small craters in Al from the Long Duration Exposure Facility (LDEF) experiment tray A11E00F (no. 74, 119 micron diameter and no. 31, 158 micron diameter) were analyzed using Auger electron spectroscopy (AES), time-of-flight secondary ion mass spectroscopy (TOF-SIMS), low voltage scanning electron microscopy (LVSEM), and SEM energy dispersive spectroscopy (EDS). High resolution images and sensitive elemental and molecular analysis were obtained with this combined approach. The result of these analyses are presented.

  18. Holographic data storage crystals for the LDEF

    NASA Technical Reports Server (NTRS)

    Callen, W. Russell; Gaylord, Thomas K.

    1993-01-01

    Crystals of lithium niobate were passively exposed to the space environment of the Long Duration Exposure Facility (LDEF). Three of the four crystals contained volume holograms. Although the crystals suffered the surface damage characteristic of that suffered by other components on the Georgia Tech tray, the crystals remained suitable for the formation of volume holograms.

  19. The LDEF ultra heavy cosmic ray experiment

    NASA Technical Reports Server (NTRS)

    Osullivan, D.; Thompson, A.; Bosch, J.; Keegan, R.; Wenzel, K.-P.; Smit, A.; Domingo, C.

    1991-01-01

    The Long Duration Exposure Facility (LDEF) Ultra Heavy Cosmic Ray Experiment (UHCRE) used 16 side viewing LDEF trays giving a total geometry factor for high energy cosmic rays of 30 sq m sr. The total exposure factor was 170 sq m sr y. The experiment is based on a modular array of 192 solid state nuclear track detector stacks, mounted in sets of 4 pressure vessels (3 experiment tray). The extended duration of the LDEF mission has resulted in a greatly enhanced potential scientific yield from the UHCRE. Initial scanning results indicate that at least 2000 cosmic ray nuclei with Z greater than 65 were collected, including the world's first statistically significant sample of actinides. Postflight work to date and the current status of the experiment are reviewed. Provisional results from analysis of preflight and postflight calibrations are presented.

  20. LDEF yaw and pitch angle estimates

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A.; Gebauer, Linda

    1992-01-01

    Quantification of the LDEF yaw and pitch misorientations is crucial to the knowledge of atomic oxygen exposure of samples placed on LDEF. Video camera documentation of the LDEF spacecraft prior to grapple attachment, atomic oxygen shadows on experiment trays and longerons, and a pinhole atomic oxygen camera placed on LDEF provided sources of documentation of the yaw and pitch misorientation. Based on uncertainty-weighted averaging of data, the LDEF yaw offset was found to be 8.1 plus or minus 0.6 degrees, allowing higher atomic oxygen exposure of row 12 than initially anticipated. The LDEF pitch angle offset was found to be 0.8 plus or minus 0.4 degrees, such that the space end was tipped forward toward the direction of travel. The resulting consequences of the yaw and pitch misorientation of LDEF on the atomic oxygen fluence is a factor of 2.16 increase for samples located on row 12, and a factor of 1.18 increase for samples located on the space end compared to that which would be expected for perfect orientation.

  1. Duplication and analysis of meteoroid damage on LDEF and advanced spacecraft materials

    NASA Technical Reports Server (NTRS)

    Hill, David C.; Rose, M. Frank

    1995-01-01

    The analysis of exposed surfaces on LDEF since its retrieval in 1990 has revealed a wide range of meteoroid and debris (M&D) impact features in the sub-micron to millimeter size range, ranging from quasi-infinite target cratering in LDEF metallic structural members (e.g. inter-costals, tray clamps, etc.) to non-marginal perforations in metallic experimental surfaces (e.g. thin foil detectors, etc.). Approximately 34,000 impact features are estimated to exist on the exposed surfaces of LDEF. The vast majority of impact craters in metal substrates exhibit circular footprints, with approximately 50 percent retaining impactor residues in varying states of shock processing. The fundamental goals of this project were to duplicate and analyze meteoroid impact damage on spacecraft metallic materials with a view to quantifying the residue retention and oblique impact morphology characteristics. Using the hypervelocity impact test facility established at Auburn University a series of impact tests (normal and oblique incidence) were executed producing consistently high (11-12 km/s) peak impact velocities, the results of which were subsequently analyzed using Scanning Electron Microscope (SEM) and Energy Dispersive X-ray Spectroscopy (EDXS) facilities at Auburn University.

  2. Radioactive 7Be materials flown on LDEF

    NASA Technical Reports Server (NTRS)

    Gregory, John C.

    1992-01-01

    Following the discovery of the atmospheric cosmogenic radionuclide Be-7 on the Long Duration Exposure Facility (LDEF), we began a search for other known nuclides produced by similar mechanisms. None of the others have the narrow gamma-ray line emission of Be-7 decay which enable its rapid detection and quantification. A search for Be-10 atoms on LDEF clamp plates using accelerator mass spectrometry is described. An unexpected result was obtained.

  3. Micrometeoroids and debris on LDEF

    NASA Technical Reports Server (NTRS)

    Mandeville, Jean-Claude

    1992-01-01

    Part of the LDEF tray allocated to French Experiments (FRECOPA) was devoted to the study of dust particles. The tray was located on the face of LDEF directly opposed to the velocity vector. Two passive experiments were flown: a set of glass and metallic samples; and multilayer thin foil detectors. Crater size distribution made possible the evaluation of the incident microparticle flux in the near environment. Comparisons are made with measurements obtained on the other faces of LDEF and with results from similar experiments on the MIR. Of interest was the study of impact features on stacked thin foil detectors. The top foil acted as a shield, fragmenting the projectiles and spreading the fragments over the surface of the thick plate located underneath. EDS analysis has provided evidence of impactor fragments. Detectors consisting of a thin shield and thick bottom plate appear to offer a significantly higher return of data concerning chemical analysis of impactor residues than single plate detectors. The samples of various materials offer a unique opportunity for the study of the many processes involved upon hypervelocity impact phenomena.

  4. Micrometeoroids and debris on LDEF

    NASA Astrophysics Data System (ADS)

    Mandeville, Jean-Claude

    1992-06-01

    Part of the LDEF tray allocated to French Experiments (FRECOPA) was devoted to the study of dust particles. The tray was located on the face of LDEF directly opposed to the velocity vector. Two passive experiments were flown: a set of glass and metallic samples; and multilayer thin foil detectors. Crater size distribution made possible the evaluation of the incident microparticle flux in the near environment. Comparisons are made with measurements obtained on the other faces of LDEF and with results from similar experiments on the MIR. Of interest was the study of impact features on stacked thin foil detectors. The top foil acted as a shield, fragmenting the projectiles and spreading the fragments over the surface of the thick plate located underneath. EDS analysis has provided evidence of impactor fragments. Detectors consisting of a thin shield and thick bottom plate appear to offer a significantly higher return of data concerning chemical analysis of impactor residues than single plate detectors. The samples of various materials offer a unique opportunity for the study of the many processes involved upon hypervelocity impact phenomena.

  5. LDEF Update

    NASA Technical Reports Server (NTRS)

    1990-01-01

    This video explores the research being done on the Long Duration Exposure Facility (LDEF), a satellite carrying 57 experiments designed to study the effects of the space environment, which had been in orbit for almost 6 years, and was retrieved and brought back to Earth by the Space Shuttle astronauts. The video shows scenes of the retrieval of LDEF, as well as scenes of ongoing research into the data returned with the satellite from experiments on external coating, contamination of optical materials by thermal control paint, the effects of cosmic rays on different materials, and the effect of the space environment on 12 million tomato seeds that have since been planted.

  6. LDEF Update

    NASA Technical Reports Server (NTRS)

    1990-01-01

    This video explores the research being done on the Long Duration Exposure Facility (LDEF), a satellite carrying 57 experiments designed to study the effects of the space environment, which had been in orbit for almost 6 years, and was retrieved and brought back to Earth by the Space Shuttle astronauts. The video shows scenes of the retrieval of LDEF, as well as scenes of ongoing research into the data returned with the satellite from experiments on external coating, contamination of optical materials by thermal control paint, the effects of cosmic rays on different materials, and the effect of the space environment on 12 million tomato seeds that have since been planted.

  7. LDEF: A bibliography with abstracts

    NASA Technical Reports Server (NTRS)

    Gouger, H. Garland (Editor)

    1992-01-01

    The Long Duration Exposure Facility (LDEF) was a free-flying cylindrical structure that housed self-contained experiments in trays mounted on the exterior of the structure. Launched into orbit from the Space Shuttle Challenger in 1984, the LDEF spent almost six years in space before being recovered in 1990. The 57 experiments investigated the effects of the low earth orbit environment on materials, coatings, electronics, thermal systems, seeds, and optics. It also carried experiments that measured crystals growth, cosmic radiation, and micrometeoroids. This bibliography contains 435 selected records from the NASA aerospace database covering the years 1973 through June of 1992. The citations are arranged within subject categories by author and date of publication.

  8. LDEF: A bibliography with abstracts

    NASA Astrophysics Data System (ADS)

    Gouger, H. Garland

    1992-11-01

    The Long Duration Exposure Facility (LDEF) was a free-flying cylindrical structure that housed self-contained experiments in trays mounted on the exterior of the structure. Launched into orbit from the Space Shuttle Challenger in 1984, the LDEF spent almost six years in space before being recovered in 1990. The 57 experiments investigated the effects of the low earth orbit environment on materials, coatings, electronics, thermal systems, seeds, and optics. It also carried experiments that measured crystals growth, cosmic radiation, and micrometeoroids. This bibliography contains 435 selected records from the NASA aerospace database covering the years 1973 through June of 1992. The citations are arranged within subject categories by author and date of publication.

  9. Proceedings of the LDEF Materials Data Analysis Workshop

    NASA Technical Reports Server (NTRS)

    Stein, Bland A. (Compiler); Young, Philip R. (Compiler)

    1990-01-01

    The 5-year, 10-month flight of the Long Duration Exposure Facility (LDEF) greatly enhanced the potential value of most LDEF materials, compared to the original 1-year flight plan. NASA recognized this potential by forming the LDEF Space Environmental Effects on Materials Special Investigation Group in early 1989 to address the expanded opportunities available in the LDEF structure and on experimental trays, so that the value of all LDEF materials to current and future space missions would be assessed and documented. The LDEF Materials Data Analysis Workshop served as one step toward the realization of that responsibility and ran concurrently with activities surrounding the successful return of the spacecraft to the NASA Kennedy Space Center. A compilation of visual aids utilized by speakers at the workshop is presented. Session 1 summarized current information on analysis responsibilities and plans and was aimed at updating the workshop attendees: the LDEF Advisory Committee, Principle Investigators, Special Investigation Group Members, and others involved in LDEF analyses or management. Sessions 2 and 3 addressed materials data analysis methodology, specimen preparation, shipment and archival, and initial plans for the LDEF Materials Data Base. A complementary objective of the workshop was to stimulate interest and awareness of opportunities to vastly expand the overall data base by considering the entire spacecraft as a materials experiment.

  10. The LDEF ultra heavy cosmic ray experiment

    NASA Technical Reports Server (NTRS)

    Osullivan, D.; Thompson, A.; Bosch, J.; Keegan, R.; Wenzel, K.-P.; Smit, A.; Domingo, C.

    1992-01-01

    The LDEF Ultra Heavy Cosmic Ray Experiment (UHCRE) used 16 side viewing LDEF trays giving a total geometry factor for high energy cosmic rays of 30 sq m sr. The total exposure factor was 170 sq m sr y. The experiment is based on a modular array of 192 solid state nuclear track detector stacks, mounted in sets of four in 48 pressure vessels. The extended duration of the LDEF mission has resulted in a greatly enhanced potential scientific yield from the UHCRE. Initial scanning results indicate that at least 1800 cosmic ray nuclei with Z greater than 65 were collected, including the world's first statistically significant sample of actinides. Post flight work to date and the current status of the experiment are reviewed.

  11. LDEF (Postflight)

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight) The viscous magnetic damper housing is shown after removal from the interior of the LDEF. The spherical dome is fabricated from 1/32 inch thick 6061-T6 aluminum alloy sheet and is attached to the cylindrical base with aluminum screws. The cylindrical portion of the housing is a fiberglass (181 cloth / epon 828 resin) structure is covered with an aluminum tape, both inside and outside, to meet thermal control requirements. The mounting plate material is 6061-T6 aluminum alloy, with the top and bottom surfaces covered with aluminum tape. A thermistor is mounted in the top center of the dome to provide house keeping data. The lead wire, covered with a strip of aluminum tape, can be seen along the housing periphery. The assembled damper housing, with the damper inside, is mounted to the space end frame with stainless steel fasteners.

  12. LDEF materials: An overview of the interim findings

    NASA Technical Reports Server (NTRS)

    Stein, Bland A.

    1992-01-01

    The flight and retrieval of the National Aeronautics and Space Administration's Long Duration Exposure Facility (LDEF) provided an opportunity for the study of the low-Earth orbit (LEO) environment and long-duration space environmental effect (SEE) on materials that are unparalleled in the history of the U.S. space program. The 5.8-year flight of LDEF greatly enhanced the potential value of materials data from LDEF to the international SEE community, compared to that of the original 1-year flight plan. The remarkable flight attitude stability of LDEF enables specific analyses of various individual and combined effects of LEO environmental parameters on identical materials of the same space vehicle. NASA recognized the potential by forming the LDEF Space Environmental Effects on Materials Special Investigation Group (MSIG) to address the greatly expanded materials and LEO space environment parameter analysis opportunities available in the LDEF structure, experiment trays, and corollary measurements, so that the combined value of all LDEF materials data to current and future space missions will be assessed and documented. This paper provides an overview of the interim LDEF materials findings of the Principal Investigators and the Materials Special Investigation Group. These revelations are based on observations of LEO environmental effects on materials made in-space during LDEF retrieval and during LDEF tray deintegration at the Kennedy Space Center, and on findings of approximately 1.5 years of laboratory analyses of LDEF materials by the LDEF materials scientists. These findings were extensively reviewed and discussed at the MSIG-sponsored LDEF Materials Workshop '91. The results are presented in a format which categorizes the revelations as 'clear findings' or 'confusing/unexplained findings' and resultant needs for new space materials developments and ground simulation testing/analytical modeling in seven categories: environmental parameters and data bases; LDEF

  13. Optical characterization of LDEF contaminant film

    NASA Technical Reports Server (NTRS)

    Blakkolb, Brian K.; Ryan, Lorraine E.; Bowen, Howard S.; Kosic, Thomas J.

    1993-01-01

    Dark brown molecular film deposits were found at numerous locations on the Long Duration Exposure Facility (LDEF) and have been documented in great detail by several investigators. The exact deposition mechanism for these deposits is as yet unknown, although direct and scattered atomic oxygen, and solar radiation interacting with materials outgassing products have all been implicated in the formation process. Specimens of the brown molecular film were taken from below the flange of the experimental tray located at position D10 on the LDEF. The tray was one of two, comprising the same experiment, the other being located on the wake facing side of the LDEF satellite at position B4. Having access to both trays, we were able to directly compare the effect that orientation with respect to the atomic oxygen flux vector had on the formation of the brown molecular film deposits. The film is thickest on surfaces facing toward the exterior, i.e. the tray corner, as can be seen by comparing the lee and wake aspects of the rivets. The patterns appear to be aligned not with the velocity vector but with the corner of the tray suggesting that flux to the surface is due to scattered atomic oxygen rather than direct ram impingement. The role of scattered flux is further supported by more faint plume patterns on the sides of the tray. The angle of these plumes is strongly aligned with the ram direction but the outline of the deposit implies that incident atoms are scattered by collisions with the edges of the opening resulting in a directed, but diffuse, flux of atomic oxygen to the surface. Spectral reflectance measurements in the 2 to 10 micron (4000 to 1000 wavenumbers) spectral range are presented for the film in the 'as deposited' condition and for the free standing film. The material was analyzed by FTIR (Fourier Transform Infrared) microspectroscopy using gold as the reference standard. The 'as deposited' specimen was on an aluminum rivet taken from beneath the tray flange

  14. Analysis of materials from MSFC LDEF experiments

    NASA Technical Reports Server (NTRS)

    Johnson, R. Barry

    1991-01-01

    In preparation for the arrival of the Long Duration Exposure Facility (LDEF) samples, a material testing and handling approach was developed for the evaluation of the materials. A configured lab was made ready for the de-integration of the LDEF experiments. The lab was prepared to clean room specifications and arranged with the appropriate clean benches, tables, lab benches, clean room tools, particulate counter, and calibrated and characterized analytical instrumentation. Clean room procedures were followed. Clean room attire and shoe cleaning equipment were selected and installed for those entering. Upon arrival of the shipping crates they were taken to the lab, logged in, and opened for examination. The sample trays were then opened for inspection and test measurements. The control sample measurements were made prior to placement into handling and transport containers for the flight sample measurements and analysis. Both LDEF flight samples and LDEF type materials were analyzed and tested for future flight candidate material evaluation. Both existing and newly purchased equipment was used for the testing and evaluation. Existing Space Simulation Systems had to be upgraded to incorporate revised test objectives and approaches. Fixtures such as special configured sample holders, water, power and LN2 feed-throughs, temperature measurement and control, front surface mirrors for reflectance and deposition, and UV grade windows had to be designed, fabricated, and installed into systems to achieve the revised requirements. New equipment purchased for LDEF analysis was incorporated into and/or used with existing components and systems. A partial list of this equipment includes a portable monochromator, enhanced UV System, portable helium leak detector for porosity and leak measurements, new turbo pumping system, vacuum coaster assembly, cryopumps, and analytical and data acquisition equipment. A list of materials tested, equipment designed, fabricated and installed

  15. Cosmogenic radionuclides on LDEF: An unexpected Be-10 result

    NASA Technical Reports Server (NTRS)

    Gregory, J. C.; Albrecht, A.; Herzog, G.; Klein, J.; Middleton, R.; Dezfouly-Arjomandy, B.; Harmon, B. A.

    1993-01-01

    Following the discovery of the atmospheric derived cosmogenic radionuclide Be-7 on the Long Duration Exposure Facility (LDEF), a search began for other known nuclides produced by similar mechanisms. None of the others have the narrow gamma-ray line emission of Be-7 decay which enabled its rapid detection and quantification. A search for Be-10 atoms on LDEF clamp plates using accelerator mass spectrometry is described. An unexpected result was obtained.

  16. LDEF microenvironments, observed and predicted

    NASA Technical Reports Server (NTRS)

    Bourassa, R. J.

    1992-01-01

    Complex protrusions and surface indentations on spacecraft equipment alter exposure environments by casting shadows, producing reflections and scattering incident atomic oxygen flux and UV radiation. A computer model is being developed to predict these effects. The model accounts for any arbitrary shape, size, orientation, or curvature of exposed objects. LDEF offers a unique opportunity to compare model prediction with observations. For this purpose, a study is underway on twelve of LDEF's copper grounding straps. These straps were exposed at various angles from the ram vector during the LDEF flight. Microenvironment variables include shadowing and reflections from clamps and fasteners, and varying exposure caused by bending of the straps. Strap measurements include optical properties, surface film composition by ESCA, and film thickness measurements by optical interference techniques. The features of the microenvironment model and the analytical methods used to examine the straps are discussed. Data are presented showing predicted microenvironmental variations. These variations are compared with observed point to point differences in surface properties of the straps.

  17. LDEF mechanical systems

    NASA Technical Reports Server (NTRS)

    Spear, Steve; Dursch, Harry

    1991-01-01

    Following the Long Duration Exposure Facility (LDEF), the Systems Special Investigation Group (SIG) was involved in a considerable amount of testing of mechanical hardware flown on the LDEF. The primary objectives were to determine the effects of the long term exposure on: (1) mechanisms employed both on the LDEF or as part of individual experiments; (2) structural components; and (3) fasteners. Results of testing the following LDEF hardware are presented: LDEF structure, fasteners, trunnions, end support beam, environment exposure control cannisters, motors, and lubricants. A limited discussion of PI test results is included. The lessons learned are discussed along with the future activities of the System SIG.

  18. Heavy ion measurement on LDEF

    NASA Technical Reports Server (NTRS)

    Beaujean, R.; Jonathal, D.; Enge, W.

    1991-01-01

    The Kiel Long Duration Exposure Facility (LDEF) experiment M0002, mounted on experiment tray E6, was designed to measure the heavy ion environment by means of CR-39 plastic solid state track detectors. The detector stack with a size of 40x34x4.5 cu cm was exposed in vacuum covered by thermal protection foils with a total thickness of approx. 14 mg/sq cm. After etching small samples of the detector foils tracks with Z greater than or = 6 could be easily detected on a background of small etch pits, which were probably produced by secondaries from proton interactions. The LDEF orientation with respect to the magnetic field lines within the South Atlantic Anomaly (SAA) is expected to be constant during the mission. Therefore, the azimuth angle distribution was measured on the detector foils for low energy stopping particles. All detected arrival directions are close to a plane perpendicular to the magnetic field line of -20 deg declination and -40 deg inclination at location 34 deg W and 27 deg S. Together with the steep energy spectrum, this spatial distribution close to the mirror plane in the SAA is an evidence that heavy ions were detected from a radiation belt population.

  19. Oxygen isotopes implanted in the LDEF spacecraft

    NASA Technical Reports Server (NTRS)

    Saxton, J. M.; Lyon, I. C.; Chatzitheodoridis, E.; Vanlierde, P.; Gilmour, J. D.; Turner, G.

    1993-01-01

    Secondary ion mass spectrometry was used to study oxygen implanted in the surface of copper from the Long Duration Exposure Facility (LDEF). Oxidation that occurred in orbit shows a characteristic oxygen isotope composition, depleted in O-18. The measured depletion is comparable to the predicted depletion (45 percent) based on a model of the gravitational separation of the oxygen isotopes. The anomalous oxygen was contained within 10nm of the surface. Tray E10 was calculated to have received 5.14 x 10(exp 21) atoms of oxygen cm(sup -2) during the LDEF mission and so there is sufficient anomalous implanted oxygen present in the surface to obtain a reliable isotopic profile.

  20. LDEF (Postflight)

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight) The viscous magnetic damper housing is shown after removal of the thermistor and aluminum spherical dome. The cylindrical portion of the housing is a fiberglass (181 cloth / epon 828 resin) structure covered with an aluminum tape, both inside and outside, to meet thermal control requirements. The viscous magnetic damper covered with a gold colored coating is shown, with mounting bolts removed, resting on a support and positioning structure. The structureis assembled using phenolic rolled tubing with 6061-T6 aluminum end fittings bonded in place with an epoxy adhesive. The support structure terminates at brackets on a base plate material of 1/4 inch thick fiberglass (181 cloth / epon 828 resin), with the top and bottom surfaces covered with aluminum tape. The venting system consist of a non-magnetic stainless steel mesh screen and an aluminum baffle plate. All fasteners use in the assembly are either aluminum screws and bolts or non-magnetic stainless steel nut plates. The portions of gold coating missing from the upper section of the damper shell were missing at prelaunch inspection and did not result from the mission environment or postflight handling.

  1. Continual LDEF program

    NASA Technical Reports Server (NTRS)

    Jones, James L.

    1985-01-01

    The long-duration-exposure-facility (LDEF) experiment underway as of November 1985 is presented in drawings, diagrams, photographs, and tables and briefly characterized. The 57 LDEF experiments include studies of diffusion crystal growth; photovoltaic degradation of solar cells; thermal-coating performance; heat pipes; and cosmic-ray effects on seeds, spores, and eggs. Also included are answers to questions about LDEF retrieval posed at the conference.

  2. LDEF archival system plan

    NASA Technical Reports Server (NTRS)

    Wilson, Brenda K.

    1993-01-01

    The Long Duration Exposure Facility (LDEF) has provided the first significant opportunity to extensively study the space environment and its effects upon spacecraft systems and materials. The long-term value of the data obtained from LDEF, which is applicable to a wide range of areas including space environment definition, space environmental effects, and spacecraft design, will depend upon the system developed to archive and retrieve the data. Therefore, in addition to the large effort undertaken to analyze LDEF data, a substantial effort is also necessary in order to retain and disseminate LDEF resources for future research and design. W. J. Schafer Associates, Inc., has a task subcontract to develop the LDEF archival system. The LDEF resources include data, hardware, photographic records, and publications which cover the 20-year history of LDEF from concept design through data analysis. Chronologically, prelaunch resources include documentation of facility and experiment development, testing integration, and operation. Post-retrieval resources are the observations, testing, analysis, and publications since the January 1990 retrieval of LDEF. A third set of resources is the experiment and facility hardware and specimens, including more than 10,000 test specimens flown on LDEF and subsequently divided and distributed among investigators at numerous laboratories. Many valuable science and technology investigations were undertaken with LDEF experiments and hardware, and many more investigations are being identified in areas not yet explored. LDEF data applications encompass primarily low-Earth orbit spacecraft and structures. The nearly six-year space exposure of LDEF has provided data to evaluate materials, systems, and living specimens exposed to radiation, meteoroids, debris, and other constituents of the low-Earth environment. Structural, mechanical, electrical, optical, and thermal systems were studied, and materials with applications in all aspects of space

  3. Space environment durability of beta cloth in LDEF thermal blankets

    NASA Technical Reports Server (NTRS)

    Linton, Roger C.; Whitaker, Ann F.; Finckenor, Miria M.

    1993-01-01

    Beta cloth performance for use on long-term space vehicles such as Space Station Freedom (S.S. Freedom) requires resistance to the degrading effects of the space environment. The major issues are retention of thermal insulating properties through maintaining optical properties, preserving mechanical integrity, and generating minimal particulates for contamination-sensitive spacecraft surfaces and payloads. The longest in-flight test of beta cloth's durability was on the Long Duration Exposure Facility (LDEF), where it was exposed to the space environment for 68 months. The LDEF contained 57 experiments which further defined the space environment and its effects on spacecraft materials. It was deployed into low-Earth orbit (LEO) in Apr. 1984 and retrieved Jan. 1990 by the space shuttle. Among the 10,000 plus material constituents and samples onboard were thermal control blankets of multilayer insulation with a beta cloth outer cover and Velcro attachments. These blankets were exposed to hard vacuum, thermal cycling, charged particles, meteoroid/debris impacts, ultraviolet (UV) radiation, and atomic oxygen (AO). Of these space environmental exposure elements, AO appears to have had the greatest effect on the beta cloth. The beta cloth analyzed in this report came from the MSFC Experiment S1005 (Transverse Flat-Plate Heat Pipe) tray oriented approximately 22 deg from the leading edge vector of the LDEF satellite. The location of the tray on LDEF and the placement of the beta cloth thermal blankets are shown. The specific space environment exposure conditions for this material are listed.

  4. A final look at LDEF electro-optic systems components

    NASA Technical Reports Server (NTRS)

    Blue, M. D.

    1995-01-01

    Postrecovery characteristics of LDEF electro-optic components from the GTRI tray are compared with their prelaunch characteristics and with the characteristics of similar components from related experiments. Components considered here include lasers, light-emitting diodes, semiconducting radiation detectors and arrays, optical substrates, filters, and mirrors, and specialized coatings. Our understanding of the physical effects resulting from low earth orbit are described, and guidelines and recommendations for component and materials choices are presented.

  5. Cosmogenic radioisotopes on LDEF surfaces

    NASA Technical Reports Server (NTRS)

    Gregory, J. C.; Albrecht, A.; Herzog, G.; Klein, J.; Middleton, R.

    1992-01-01

    The radioisotope Be-7 was discovered in early 1990 on the front surface, and the front surface only, of the LDEF. A working hypothesis is that the isotope, which is known to be mainly produced in the stratosphere by spallation of nitrogen and oxygen nuclei with cosmic ray protons or secondary neutrons, diffuses upward and is absorbed onto metal surfaces of spacecraft. The upward transport must be rapid, that is, its characteristic time scale is similar to, or shorter than, the 53 day half-life of the isotope. It is probably by analogy with meteoritic metal atmospheric chemistry, that the form of the Be at a few 100 km altitude is as the positive ion Be(+) which is efficiently incorporated into the ionic lattice of oxides, such as Al2O3, Cr2O3, Fe2O3, etc., naturally occurring on surfaces of Al and stainless steel. Other radioisotopes of Be, Cl, and C are also produced in the atmosphere, and a search was begun to discover these. Of interest are Be-10 and C-14 for which the production cross sections are well known. The method of analysis is accelerator mass spectrometry. Samples from LDEF clamp plates are being chemically extracted, purified, and prepared for an accelerator run.

  6. LDEF (Prelaunch), S1002 : Investigation of Critical Surface Degradation Effects on Coating and Solar

    NASA Technical Reports Server (NTRS)

    1984-01-01

    LDEF (Prelaunch), S1002 : Investigation of Critical Surface Degradation Effects on Coating and Solar Cells Developed in Germany, Tray E03 The prelaunch photograph provides a view of the two (2) experiments located in a six (6) inch LDEF experiment tray. The A0187-02 is located in the right two thirds (2/3rd) of the tray and the EECC containing the S1002 experiment occupies the remaining section. The tan colored strips on the tray flanges are protective coatings that are removed prior to tray testing. S1002 - The Effects on Coatings and Solar Cells experiment is contained within the Experiment Exposure Control Canister (EECC) that is located in the left one third (1/3rd) of the experiment tray. The EECC hardware consists of the housing, the drawer that contains the experiment samples, the drawer opening and closing mechanism (a screw drive system) and chromic anodized aluminum thermal covers that are seen in the photograph. The hardware is fabricated from aluminum or non-magnetic steels and is assembled with non-magnetic stainless steel fasteners. The canister will be opened in orbit after the LDEF has been deployed, the Orbiter has departed and initial outgassing of materials on the LDEF has occurred. The canister is programmed to close approximately nine (9) months after opening and prior to the scheduled LDEF retrieval. Experiment samples located in the EECC consist of Second Surface Mirrors (SSM), SSM with Interference Filters (SSM/IF), SSM/IF with a Conductive Layer (SSM/IF/LS, Optical Solar Reflectors (OSR), Quartz Crystal Microbalance (QCM), Coatings and Solar Cell Modules of the types flown on the GEOS and OTS satellites.

  7. LDEF (Postflight), AO133 : Effect of Space Environment on Space-Based Radar Phased-Array Antenna, Tr

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), AO133 : Effect of Space Environment on Space-Based Radar Phased-Array Antenna, Tray H07 The postflight photograph was taken in the KSC SAEF II facility after the experiment was removed from the LDEF. The Space-Based Radar (SBR) Phased-Array Antenna occupies a six (6) inch deep LDEF end corner tray located on the space end of the LDEF. A light tan discoloration is visible on the left and lower flanges of the experiment tray and also on the unpainted aluminum filler to the left of the passive part of the experiment. A darker stain has discolored the lower corners of the tray structure. The SBR Phased-Array Antenna experiment, consisting of an active part in the upper half of the tray and a passive part located in the lower half of the experiment tray, appears to be intact with no apparent physical damage. The black thermal coating on the active part of the experiment appears to have changed from a flat black to a dark gray while the coating on the passive part of the experiment appears less degraded. The exposed Kapton specimen surfaces in both the active and passive parts of the experiment appear to have changed from specular to diffuse from exposure to the space environment.

  8. Ammunition Separator Tray.

    DTIC Science & Technology

    1979-09-28

    TRAY ABSTRACT OF THE DISCLOSURE A tray concept is used to stack rounds of ammunition in layers which alternate in direction. Maximum packing density is...achieved through use of separators which are 5 contoured on both sides with altering layering arrangement. The projectile end of the tray cavity is...open which allows the contents of the tray to be dumped into ammunition loading equipment. By making the trays of stiff plastic, it is possible to

  9. LDEF environment modeling updates

    NASA Technical Reports Server (NTRS)

    Gordon, Tim; Rantanen, Ray; Whitaker, Ann F.

    1995-01-01

    An updated gas dynamics model for gas interactions around the LDEF is presented that includes improved scattering algorithms. The primary improvement is more accurate predictions of surface fluxes in the wake region. The code used is the Integrated Spacecraft Environments Model (ISEM). Additionally, initial results of a detailed ISEM prediction model of the Solar Array Passive LDEF Experiment (SAMPLE), A0171, is presented. This model includes details of the A0171 geometry and outgassing characteristics of the many surfaces on the experiment. The detailed model includes the multiple scattering that exists between the ambient atmosphere, LDEF outgassing, and atomic oxygen erosion products. Predictions are made for gas densities, surface fluxes and deposition at three different time periods of the LDEF mission.

  10. Mechanisms flown on LDEF

    NASA Technical Reports Server (NTRS)

    Dursch, Harry; Spear, Steve

    1992-01-01

    A wide variety of mechanisms were flown on the Long Duration Exposure Facility (LDEF). These include canisters, valves, gears, drive train assemblies, and motors. This report will provide the status of the Systems SIG effort into documenting, integrating, and developing 'lessons learned' for the variety of mechanisms flown on the LDEF. Results will include both testing data developed by the various experimenters and data acquired by testing of hardware at Boeing.

  11. LDEF materials data analysis: Representative examples

    NASA Technical Reports Server (NTRS)

    Pippin, H. Gary; Crutcher, E. R.

    1992-01-01

    Results of measurements on silverized teflon, heat shrink tubing and nylon tie downs on the wire harness clamps, silvered hex nuts, and contamination deposits are presented. We interpret the results in terms of our microenvironments exposure model and locations on the Long Duration Exposure Facility (LDEF). Distinct changes in the surface properties of FEP were observed as a function of UV exposure. Significant differences in outgassing characteristics were detected for hardware on the interior row 3 relative to identical hardware on the interior row 3 relative to identical hardware on nearby rows. The implications for in service performance are reviewed.

  12. LDEF post-retrieval evaluation of exobiology interests

    NASA Technical Reports Server (NTRS)

    Bunch, T. E.; Radicatldibrozolo, F.; Fitzgerald, Ray

    1991-01-01

    Cursory examination of the Long Duration Exposure Facility (LDEF) shows the existence of thousands of impact craters of which less than 1/3 exceed 0.3 mm in diameter; the largest crater is 5.5 mm. Few craters show oblique impact morphology and, surprisingly, only a low number of craters have recognizable impact debris. Study of this debris could be of interest to exobiology in terms of C content and carbonaceous materials. All craters greater that 0.3 mm have been imaged and recorded into a data base by the preliminary examination team. Various portions of the LDEF surfaces are contaminated by outgassed materials from experimenters trays, in addition to the LDEF autocontamination and impact with orbital debris not of extraterrestrial origin. Because interplanetary dust particles (IDP's) nominally impacted the LDEF at velocities greater than 3 km/s, the potential for intact survival of carbonaceous compounds is mostly unknown for hypervelocity impacts. Calculations show that for solid phthalic acid (a test impactor), molecular dissociation would not necessarily occur below 3 km/s, if all of the impact energy was directed at breaking molecular bonds, which is not the case. Hypervelocity impact experiments (LDEF analogs) were performed using the Ames Vertical Gun Facility. Grains of phthalic acid and the Murchison meteorite (grain diameter = 0.2 for both) were fired into an Al plate at 2.1 and 4.1 km/s respectively. The results of the study are presented, and it is concluded that meaningful biogenic elemental and compound information can be obtained from IDP impacts on the LDEF.

  13. Post clamp

    NASA Technical Reports Server (NTRS)

    Ramsey, John K. (Inventor); Meyn, Erwin H. (Inventor)

    1990-01-01

    A pair of spaced collars are mounted at right angles on a clamp body by retaining rings which enable the collars to rotate with respect to the clamp body. Mounting posts extend through aligned holes in the collars and clamp body. Each collar can be clamped onto the inserted post while the clamp body remains free to rotate about the post and collar. The clamp body is selectively clamped onto each post.

  14. Evaluation of Mail Trays

    DTIC Science & Technology

    1993-06-01

    787-4519 Commercial (513) 257-4519 AUG I 1993 EVALUATION OF MAIL TRAYS HQ AFMC/LGTP AIR FORCE PACKAGING EVALUATION ACTIVITY 5215 THURLOW ST WRIGHT...13 not to be Sead in whOle or in part for advertising or Sales purposel, PROJECT # 92-119 TITLE: Evaluation of Mail Trays ABSTRACT The Air Force...conducted container testing and’ materials testing on mail trays and their plastic corrugated material from three manufacturers. The trays were tested

  15. Second LDEF Post-Retrieval Symposium interim results of experiment A0034

    NASA Technical Reports Server (NTRS)

    Linton, Roger C.; Kamenetzky, Rachel R.

    1993-01-01

    Thermal control coatings and contaminant collector mirrors were exposed on the leading and trailing edge modules of Long Duration Exposure Facility (LDEF) experiment A0034 to provide a basis of comparison for investigating the role of atomic oxygen in the stimulation of volatile outgassing products. The exposure of identical thermal coatings on both the leading and trailing edges of the LDEF and the additional modified exposure of identical coatings under glass windows and metallic covers in each of the flight modules provided multiple combinations of space environmental exposure to the coatings and the contaminant collector mirrors. Investigations were made to evaluate the effects of the natural space and the induced environments on the thermal coatings and the collector mirrors to differentiate the sources of observed material degradation. Two identical flight units were fabricated for the LDEF mission, each of which included twenty-five thermal control coatings mounted in isolated compartments, each with an adjacent contaminant collector mirror mounted on the wall. The covers of the flight units included apertures for each compartment, exposing the thermal coatings directly to the space environment. Six of these compartments were sealed with ultraviolet-grade transmitting quartz windows and four other compartments were sealed with aluminum covers. One module of this passive LDEF experiment, occupying one-sixth of a full tray, was mounted in Tray C9 (leading edge), while the other identical module was mounted in Tray C3 (trailing edge).

  16. LDEF Satellite Radiation Analyses

    NASA Technical Reports Server (NTRS)

    Armstrong, T. W.; Colborn, B. L.

    1996-01-01

    This report covers work performed by Science Applications International Corporation (SAIC) under contract NAS8-39386 from the NASA Marshall Space Flight Center entitled LDEF Satellite Radiation Analyses. The basic objective of the study was to evaluate the accuracy of present models and computational methods for defining the ionizing radiation environment for spacecraft in Low Earth Orbit (LEO) by making comparisons with radiation measurements made on the Long Duration Exposure Facility (LDEF) satellite, which was recovered after almost six years in space. The emphasis of the work here is on predictions and comparisons with LDEF measurements of induced radioactivity and Linear Energy Transfer (LET) measurements. These model/data comparisons have been used to evaluate the accuracy of current models for predicting the flux and directionality of trapped protons for LEO missions.

  17. LDEF satellite radiation study

    NASA Technical Reports Server (NTRS)

    Armstrong, T. W.; Colborn, B. L.

    1994-01-01

    Some early results are summarized from a program under way to utilize LDEF satellite data for evaluating and improving current models of the space radiation environment in low earth orbit. Reported here are predictions and comparisons with some of the LDEF dose and induced radioactivity data, which are used to check the accuracy of current models describing the magnitude and directionality of the trapped proton environment. Preliminary findings are that the environment models underestimate both dose and activation from trapped protons by a factor of about two, and the observed anisotropy is higher than predicted.

  18. The Fixture Device of the Horizontal Machining Center for the Input Tray Part Processing

    NASA Astrophysics Data System (ADS)

    Zhou, Ping

    The input tray part is key parts on the production of auto parts of the on the automatic line, this paper mainly studies on the horizontal machining center using the fixture device, the device to ensure the machining accuracy of the input tray part. Through the analysis of the positioning and clamping of the input tray part, design a clamp device, the device is applied in on the horizontal machining center, and on the basis of the fixture add auxiliary support device, in order to improve the input tray part rigidity and stability of processing.

  19. First radiobiological results of LDEF-1 experiment A0015 with Arabidopsis seed embryos and Sordaria fungus spores.

    PubMed

    Zimmermann, M W; Gartenbach, K E; Kranz, A R

    1994-10-01

    This article highlights the first results of investigations on the general vitality and damage endpoints caused by cosmic ionizing radiation in dry, dormant plant seeds of the crucifer plant Arabidopsis thaliana (L.) Heynh. and the ascomycete Sordaria fimicola after 69 month stay in space. Wild-type and mutant gene marker lines were included in Free Flyer Biostack containers and exposed on earth and side tray of the LDEF-1 satellite. The damage in biological endpoints observed in the seeds increased in the side tray sample compared to the earth tray sample. For the ascospores we found different effects depending on the biological endpoints investigated for both expositions.

  20. First radiobiological results of LDEF-1 experiment A0015 with Arabidopsis seed embryos and Sordaria fungus spores

    NASA Astrophysics Data System (ADS)

    Zimmermann, M. W.; Gartenbach, K. E.; Kranz, A. R.

    1994-10-01

    This article highlights the first results of investigations on the general vitality and damage endpoints caused by cosmic ionizing radiation in dry, dormant plant seeds of the crucifer plant Arabidopsis thaliana (L.) Hennh. and the ascomycete Sordaria fimicola after 69 month stay in space. Wild-type and mutant gene marker lines were included in Free Flyer Biostack containers and exposed on earth and side tray of the LDEF-1 satellite. The damage in biological endpoints observed in the seeds increased in the side tray sample compared to the earth tray sample. For the ascospores we found different effects depending on the biological endpoints investigated for both expositions.

  1. Status of LDEF radiation modeling

    NASA Technical Reports Server (NTRS)

    Watts, John W.; Armstrong, T. W.; Colborn, B. L.

    1995-01-01

    The current status of model prediction and comparison with LDEF radiation dosimetry measurements is summarized with emphasis on major results obtained in evaluating the uncertainties of present radiation environment model. The consistency of results and conclusions obtained from model comparison with different sets of LDEF radiation data (dose, activation, fluence, LET spectra) is discussed. Examples where LDEF radiation data and modeling results can be utilized to provide improved radiation assessments for planned LEO missions (e.g., Space Station) are given.

  2. Modeling of LDEF contamination environment

    NASA Technical Reports Server (NTRS)

    Carruth, M. Ralph, Jr.; Rantanen, Ray; Gordon, Tim

    1993-01-01

    The Long Duration Exposure Facility (LDEF) satellite was unique in many ways. It was a large structure that was in space for an extended period of time and was stable in orientation relative to the velocity vector. There are obvious and well documented effects of contamination and space environment effects on the LDEF satellite. In order to examine the interaction of LDEF with its environment and the resulting effect on the satellite, the Integrated Spacecraft Environments Model (ISEM) was used to model the LDEF-induced neutral environment at several different times and altitudes during the mission.

  3. LDEF space optics handbook

    NASA Astrophysics Data System (ADS)

    Champetier, Robert J.; Atkinson, Dale R.; Kemp, William T.

    1992-06-01

    There is a need to present design guidelines derived from the Long Duration Exposure Facility (LDEF) space optics experiments to hardware designers. In response to this need, a small study program has been started. The objective is to prepare a top level review of available results on the behavior of certain optical components in the LDEF space experiments. The optics interest centers on optical surfaces and coatings, and fabrication processes for laser windows and mirrors. The program has two main parts: the first phase, consists of identifying and acquiring data from appropriate investigators. The second phase, comprises report preparation as well as selected, prioritized, additional characterization of certain samples, coordinated with the principal investigators. This short paper outlines the program under way.

  4. Solar Array Passive LDEF Experiment

    NASA Technical Reports Server (NTRS)

    1992-01-01

    A Marshall researcher examines a sample from the Solar Array Passive Long Duration Exposure Facility (LDEF). LDEF, which flew in space, measured the number, severity, and effects of micrometeroid hits on various materials. The data will lead to improved spacecraft design in the future.

  5. LDEF materials data bases

    NASA Technical Reports Server (NTRS)

    Funk, Joan G.; Strickland, John W.; Davis, John M.

    1993-01-01

    The Long Duration Exposure Facility (LDEF) and the accompanying experiments were composed of and contained a wide variety of materials representing the largest collection of materials flown in low Earth orbit (LEO) and retrieved for ground based analysis to date. The results and implications of the mechanical, thermal, optical, and electrical data from these materials are the foundation on which future LEO space missions will be built. The LDEF Materials Special Investigation Group (MSIG) has been charged with establishing and developing data bases to document these materials and their performance to assure not only that the data are archived for future generations but also that the data are available to the spacecraft user community in an easily accessed, user-friendly form. This paper discusses the format and content of the three data bases developed or being developed to accomplish this task. The hardware and software requirements for each of these three data bases are discussed along with current availability of the data bases. This paper also serves as a user's guide to the MAPTIS LDEF Materials Data Base.

  6. Comparison of Contamination Model Predictions to LDEF Surface Measurements

    NASA Technical Reports Server (NTRS)

    Gordon, Tim; Rantanen, Ray; Pippin, Gary; Finckenor, Miria

    1998-01-01

    Contaminant deposition measurements have been made on species content and depth profiles on three experiments trays from the Long Duration Exposure Facility (LDEF), Auger, Argon sputtering, Electron Spectroscopy for Chemical Analysis (ESCA) and Scanning Electron Microscopy (SEM) analysis. The integrated spacecraft environment model (ISEM) was used to predict the deposition levels of the contaminants measured on the three trays. The details of the modeling and assumptions used are presented along with the predictions for the deposition on select surfaces on the trays. These are compared to the measured results. The trays represent surfaces that have a high atomic oxygen flux, and intermediate oxygen flux, and no oxygen flux. All surfaces received significant solar Ultraviolet flux. It appears that the atomic oxygen was the primary agent that caused significant deposition to occur. Surfaces that saw significant contaminant flux solar UV and no atomic oxygen did not show any appreciable levels of observable deposition. The implications of the atom ic oxygen interaction with contaminant deposits containing silicon contaminant sources is discussed. The primary contaminant sources are DC61104 adhesive and Z306 paint. The results and interpretation of the findings have a potential significant impact on spacecraft surfaces that are exposed to solar UV and atomic oxygen in low Earth orbit.

  7. The Long Duration Exposure Facility (LDEF) photographic survey special publication

    NASA Technical Reports Server (NTRS)

    Oneal, Robert L.; Levine, Arlene S.; Kiser, Carol C.

    1995-01-01

    During the construction, integration, launch, retrieval and deintegration of the Long Duration Exposure Facility (LDEF), photographic surveys were made. Approximately 10,000 photographs were taken during the various phases of the LDEF project. These surveys are of technical and scientific importance because they revealed the pre and post flight conditions of the experiment trays as well as the spacecraft. Visual inspection of the photographs reveal valuable data such as space environment's effects and the earth atmosphere's effects post-retrieval. Careful files and records have been kept of these photographs. Each photograph has a Kennedy Space Center photo number or a Johnson Spaceflight Center photo number as well as a Langley Research Center photo number. The tray number, row number, and experiment number are also noted. Out of the 10,000 photographs taken, approximately 700 selected photographs were chosen for publication in a NASA Special Publication (SP) because they reveal the effects of space exposure to the viewer. These photographs will give researchers and spacecraft designers visual images of the effects of the space environment on specific materials, systems and spacecraft in general. One can visually see the degradation of thermal blankets, meteoroid craters, outgassing discoloration, atomic oxygen erosion, etc.

  8. Oxygen isotopes implanted in the LDEF spacecraft

    NASA Technical Reports Server (NTRS)

    Saxton, J. M.; Lyon, I. C.; Chatzitheodoredis, E.; Gilmour, J. D.; Turner, G.

    1992-01-01

    Depth profiles of O-16 and O-18/O-16 were measured on stainless steel nuts and copper sheet (from a grounding strap) recovered from the leading edge of LDEF (Tray E10). The measurements were obtained by dynamic SIMS (secondary ion mass spectrometry) using a VG Isolab 54 ion microprobe. Plots of O-18/O-16 against time, show large depletions of up to a factor of 2 compared to the O-18/O-16 value at sea level. The O-16 current decreases by 2 orders of magnitude in the interior of the metal, and the corresponding profile of anomalous O-16 is strongly peaked in the outer few tens of nanometers of the surface. This depth scale is a tentative one based on estimated sputtering rates. Plots of O-18/O-16 against 1/O-16 should be linear if two isotopically distinct components, one of variable concentration (orbital component) and one of fixed concentration (normal oxygen), are mixed. Data to be presented at the meeting show departures from linearity which result from variability in the concentration of normal oxygen, but may also arise from the implantation of oxygen with a range of fractionation due to the decaying orbit of the LDEF, sputtering of the surface by atomic oxygen, and the different momenta of the two isotopes due to their equal velocities. The potential for using this method as a means of identifying exposure to low-Earth orbit, de-convoluting the effects of space exposure from terrestrial contamination, and using the implanted anomolous oxygen as a means of studying the atomic oxygen density and upper atmosphere temperature height profile will be discussed at the meeting.

  9. Data bases for LDEF results

    NASA Technical Reports Server (NTRS)

    Bohnhoff-Hlavacek, Gail

    1993-01-01

    The Long Duration Exposure Facility (LDEF) carried 57 experiments and 10,000 specimens for some 200 LDEF experiment investigators. The external surface of LDEF had a large variety of materials exposed to the space environment which were tested preflight, during flight, and post flight. Thermal blankets, optical materials, thermal control paints, aluminum, and composites are among the materials flown. The investigations have produced an abundance of analysis results. One of the responsibilities of the Boeing Support Contract, Materials and Systems Special Investigation Group, is to collate and compile that information into an organized fashion. The databases developed at Boeing to accomplish this task is described.

  10. LDEF Satellite Radiation Analyses

    NASA Technical Reports Server (NTRS)

    Armstrong, T. W.; Colborn, B. L.

    1996-01-01

    Model calculations and analyses have been carried out to compare with several sets of data (dose, induced radioactivity in various experiment samples and spacecraft components, fission foil measurements, and LET spectra) from passive radiation dosimetry on the Long Duration Exposure Facility (LDEF) satellite, which was recovered after almost six years in space. The calculations and data comparisons are used to estimate the accuracy of current models and methods for predicting the ionizing radiation environment in low earth orbit. The emphasis is on checking the accuracy of trapped proton flux and anisotropy models.

  11. Rigid clamp

    DOEpatents

    Benavides, Gilbert L.; Burt, Jack D.

    1994-01-01

    The invention relates to a clamp mechanism that can be used to attach or temporarily support objects inside of tubular goods. The clamp mechanism can also be modified so that it grips objects. The clamp has a self-centering feature to accommodate out-of-roundness or other internal defections in tubular objects such as pipe. A plurality of clamping shoes are expanded by a linkage which is preferably powered by a motor to contact the inside of a pipe. The motion can be reversed and jaw elements can be connected to the linkage so as to bring the jaws together to grab an object.

  12. Rigid clamp

    DOEpatents

    Benavides, G.L.; Burt, J.D.

    1994-07-12

    The invention relates to a clamp mechanism that can be used to attach or temporarily support objects inside of tubular goods. The clamp mechanism can also be modified so that it grips objects. The clamp has a self-centering feature to accommodate out-of-roundness or other internal defections in tubular objects such as pipe. A plurality of clamping shoes are expanded by a linkage which is preferably powered by a motor to contact the inside of a pipe. The motion can be reversed and jaw elements can be connected to the linkage so as to bring the jaws together to grab an object. 12 figs.

  13. LDEF Space Plasma-High Voltage Drainage Experiment post-flight results

    NASA Technical Reports Server (NTRS)

    Yaung, J. Y.; Blakkolb, B. K.; Wong, W. C.; Ryan, L. E.; Schurig, H. J.; Taylor, W. W. L.

    1993-01-01

    The Space Plasma-High Voltage Drainage Experiment (SP-HVDE) was comprised of two identical experimental trays. With one tray located on the leading (ram facing, B10) edge and the other located on the trailing (wake facing, D4) edge of the Long Duration Exposure Facility (LDEF), it was possible to directly compare the effects of ram and wake spacecraft environments on charged dielectric materials. Six arrays of Kapton dielectric samples of 2 mil, 3 mil, and 5 mil thicknesses maintained at +/- 300, +/- 500, and +/- 1000 voltage bias formed the experimental matrix of each tray. In addition, each tray carried two solar cell strings, one biased at +300 volts and the other at -300 volts, to study current leakage from High Voltage Solar Arrays (HVSA). The SP-HVDE provides the first direct, long-term, in-flight measurements of average leakage current through dielectric materials under electric stress. The experiment also yields information on the long term stability of the bulk dielectric properties of such materials. Data and findings of the SP-HVDE are an extension of those from shorter term flight experiments such as the PIX-1 (Plasma Interaction Experiment) and PIX-2 and are therefore valuable in the design and evaluation of long-lived space systems with high voltage systems exposed to the low earth orbital environment. A summary of the SP-HVDE post flight analysis final report delivered to the LDEF Project Office under contract to the National Aeronautics and Space Administration is presented.

  14. LDEF (Postflight), S1002 : Investigation of Critical Surface Degradation Effects on Coating and Sola

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), S1002 : Investigation of Critical Surface Degradation Effects on Coating and Solar Cells Developed in Germany, Tray E03 The postflight photograph was taken in the SAEF II at KSC after the experiment was removed from the LDEF. The capture cells of experiment A0187-02 are in the left two thirdsThe Experiment Exposure Control Canister containing experiment S1002 is the item located in the right one third section of the tray. Details of the EECC containing the experiment cannot be defined due to the glare of the lights on the aluminum surfaces. The brown stain is clearly visible on the left end of the bottom tray flange. Note the spring collar near the lower end of the lead screw. The collar, pushed along the lead screw as the door opens, is an indication that the EECC did open and close while in orbit. The green tint on the two (2) debris panels is a by-product of the chromic anodize coating process and not attributed to contamination and/or exposure to the space environment. A light colored irregular shaped vertical streak is seen on the right debris panel. The light band across the top and bottom edges of the panels is caused by light reflecting from the tray sidewalls.

  15. Databases for LDEF results

    NASA Technical Reports Server (NTRS)

    Bohnhoff-Hlavacek, Gail

    1992-01-01

    One of the objectives of the team supporting the LDEF Systems and Materials Special Investigative Groups is to develop databases of experimental findings. These databases identify the hardware flown, summarize results and conclusions, and provide a system for acknowledging investigators, tracing sources of data, and future design suggestions. To date, databases covering the optical experiments, and thermal control materials (chromic acid anodized aluminum, silverized Teflon blankets, and paints) have been developed at Boeing. We used the Filemaker Pro software, the database manager for the Macintosh computer produced by the Claris Corporation. It is a flat, text-retrievable database that provides access to the data via an intuitive user interface, without tedious programming. Though this software is available only for the Macintosh computer at this time, copies of the databases can be saved to a format that is readable on a personal computer as well. Further, the data can be exported to more powerful relational databases, capabilities, and use of the LDEF databases and describe how to get copies of the database for your own research.

  16. LDEF space optics handbook

    NASA Astrophysics Data System (ADS)

    Champetier, Robert J.; Atkinson, Dale R.; Kemp, William T.

    1993-04-01

    There is a need to present design guidelines derived from the Long Duration Exposure Facility (LDEF) space optics experiments to hardware designers. In response to this need a small study program was just started by SAIC and POD Associates for the Phillips Laboratory. The objective is to prepare a top-level review of available results on the behavior of certain optical components in the LDEF space experiments. The optics interest centers on optical surfaces and coatings, and fabrication processes for laser windows and mirrors. The program has two main parts: the first phase, to be completed by the end of 1992, consists of identifying and acquiring data from the appropriate investigators. The second phase, ending in December 1993, comprises report preparation as well as selected, prioritized, additional characterization of certain samples, coordinated with the principal investigators and the Phillips Laboratory. This program is getting under way at the time of the Symposium and does not warrant more than the present summary at this time.

  17. Space Station WP-2 application of LDEF MLI results

    NASA Technical Reports Server (NTRS)

    Smith, Charles A.; Hasegawa, Mark M.; Jones, Cherie A.

    1993-01-01

    The Cascaded Variable Conductance Heat Pipe Experiment, which was developed by Michael Grote of McDonnell Douglas Electronic Systems Company, was located in Tray F-9 of the Long Duration Exposure Facility (LDEF), where it received atomic oxygen almost normal to its surface. The majority of the tray was covered by aluminized Kapton polyimide multilayer insulation (MLI), which showed substantial changes from atomic oxygen erosion. Most of the outermost Kapton layer of the MLI and the polyester scrim cloth under it were lost, and there was evidence of contaminant deposition which discolored the edges of the MLI blanket. Micrometeoroid and orbital debris (MM/OD) hits caused small rips in the MLI layers, and in some cases left cloudy areas where the vapor plume caused by a hit condensed on the next layer. The MLI was bent gradually through 90 deg at the edges to enclose the experiment, and the Kapton that survived along the curved portion showed the effects of atomic oxygen erosion at oblique angles. In spite of space environment effects over the period of the LDEF mission, the MLI blanket remained functional. The results of the analysis of LDEF MLI were used in developing the standard MLI blanket for Space Station Work Package-2 (WP-2). This blanket is expected to last 30 years when exposed to the low Earth orbit (LEO) environment constituents of atomic oxygen and MM/OD, which are the most damaging to MLI materials. The WP-2 standard blanket consists of an outer cover made from Beta-cloth glass fiber fabric which is aluminized on the interior surface, and an inner cover of 0.076-mm (0.003-in) double-side-aluminized perforated Kapton. The inner reflector layers are 0.0076-mm (0.0003-in) double-side aluminized, perforated Kapton separated by layers of Dacron polyester fabric. The outer cover was selected to be resistant to the LEO environment and durable enough to survive in orbit for 30 years. This paper describes the analyses of the LDEF MLI results, and how these

  18. Protein crystal growth tray assembly

    NASA Technical Reports Server (NTRS)

    Carter, Daniel C. (Inventor); Miller, Teresa Y. (Inventor)

    1992-01-01

    A protein crystal growth tray assembly includes a tray that has a plurality of individual crystal growth chambers. Each chamber has a movable pedestal which carries a protein crystal growth compartment at an upper end. The several pedestals for each tray assembly are ganged together for concurrent movement so that the solutions in the various pedestal growth compartments can be separated from the solutions in the tray's growth chambers until the experiment is to be activated.

  19. LDEF (Postflight), S0050 : Investigation of the Effects of Long-Duration Exposure on Active Optical

    NASA Technical Reports Server (NTRS)

    1990-01-01

    LDEF (Postflight), S0050 : Investigation of the Effects of Long-Duration Exposure on Active Optical System Components, Tray E05 The postflight photograph was taken in SAEF II at KSC after the experiment tray was removed from the LDEF and the sun screens removed. The Active Optical System Component Experiment (S0050) contained 136 test specimen located in a six (6) inch deep LDEF peripheral experiment tray. The complement of specimen included optical and electro-optical components, glasses and samples of various surface finishes. The experiment tray was divided into six sections, each consisting of a 1/4 inch thick chromic anodized aluminum base plate and a 1/16th inch thick aluminum hat shaped structure for mounting the test specimen. The test specimen were typically placed in fiberglass-epoxy retainer strip assemblies prior to installation on the hat shaped mounting structure. Five of the six sections were covered by a 1/8 inch thick anodized aluminum sun screen with openings that allowed 56 percent transmission over the central region. Two sub-experiments, The Optical Materials and UV Detectors Experiment (S0050-01) consist of 15 optical windows, filters and detectors and occupies one of the trays six sub-sections and The Optical Substrates and Coatings Experiment (S0050-02 ) that includes 12 substrates and coatings and two secondary experiments,The Holographic Data Storage Experiment (AO044) consisting of four crystals of lithium niobate and ThePyroelectric Infrared Detectors Experiment (AO135) with twenty detectors, are also mounted in the integrated tray. The experiment structure was assembled with non-magnetic stainless steel fasteners. The experiment hardware appears to be intact with no apparent damage. A brown discoloration is clearly visible on the tray flanges. The location of experiment test specimen and their mountings are shown in this photograph. The fiberglass-epoxy mounting strip colors vary from the typical greenish-gray to a slate gray in

  20. Some results of the oxidation investigation of copper and silver samples flown on LDEF

    NASA Technical Reports Server (NTRS)

    Derooij, A.

    1992-01-01

    The Long Duration Exposure Facility (LDEF) Mission provides a unique opportunity to study the long term effects of the space environment on materials. The LDEF has been deployed in orbit on 7 April 1984 by the shuttle Challenger in an almost circular orbit with a mean altitude of 477 km and an inclination of 28.5 degrees. It was retrieved from its decayed orbit of 335 km by the shuttle Columbia on 12 January 1990 after almost 6 years in space. The LDEF is a 12-sided, 4.267 m diameter, and 9.144 m long structure. The experiments, placed on trays, are attached to the twelve sides and the two ends of the spacecraft. The LDEF was passively stabilized with one end of the spacecraft always pointing towards the earth center and one of the sides (row 9) always facing the flight direction. The materials investigated originate from the Ultra-Heavy Cosmic Ray Experiment (UHCRE). The main objective is a detailed study of the charge spectra of ultraheavy cosmic-ray nuclei from zinc to uranium and beyond, using solid-state track detectors. Besides the aluminium alloy used for the experiment, UHCRE comprises several other materials. The results of space exposure for two of them, the copper grounding strips and the thermal covers (FEP Teflon/Ag/Inconel) painted black on the inner side (Chemglaze Z306), are presented.

  1. LDEF impact craters formed by carbon-rich impactors

    NASA Technical Reports Server (NTRS)

    Bunch, T. E.; Dibrozolo, F. Radicati; Fleming, Ronald H.; Harris, David W.; Brownlee, Don E.; Reilly, Terrence W.

    1991-01-01

    Two small craters (number 74, 119 microns, and number 31, 158 microns in diameter) with depth to diameter ratios of about 0.59 and 0.8, respectively, were found in Al from the Long Duration Exposure Facility (LDEF) experiment tray A11EOOF). Both craters have residues concentrated in the crater bottoms, along the walls, and on top of the overturned rims. Low voltage scanning electron electron microscopy, Auger electron spectroscopy, time of flight secondary ion mass spectroscopy and energy dispersive x-ray spectroscopy were used to obtain high resolution imagery and elemental analysis. Analyses indicate that the impactor for both craters was carbon-rich, as the residues contain mostly C. Silicon, S, and F in low concentrations are present on the Al surface away from the craters and may be, in part, contaminants.

  2. LDEF meteoroid and debris database

    NASA Technical Reports Server (NTRS)

    Dardano, C. B.; See, Thomas H.; Zolensky, Michael E.

    1994-01-01

    The Long Duration Exposure Facility (LDEF) Meteoroid and Debris Special Investigation Group (M&D SIG) database is maintained at the Johnson Space Center (JSC), Houston, Texas, and consists of five data tables containing information about individual features, digitized images of selected features, and LDEF hardware (i.e., approximately 950 samples) archived at JSC. About 4000 penetrations (greater than 300 micron in diameter) and craters (greater than 500 micron in diameter) were identified and photodocumented during the disassembly of LDEF at the Kennedy Space Center (KSC), while an additional 4500 or so have subsequently been characterized at JSC. The database also contains some data that have been submitted by various PI's, yet the amount of such data is extremely limited in its extent, and investigators are encouraged to submit any and all M&D-type data to JSC for inclusion within the M&D database. Digitized stereo-image pairs are available for approximately 4500 features through the database.

  3. Induced radioactivity in LDEF components

    NASA Technical Reports Server (NTRS)

    Harmon, B. A.; Fishman, G. J.; Parnell, T. A.; Laird, C. E.

    1992-01-01

    A systematic study of the induced radioactivity of the Long Duration Exposure Facility (LDEF) is being carried out in order to gather information about the low earth orbit radiation environment and its effects on materials. The large mass of the LDEF spacecraft, its stabilized configuration, and long mission duration have presented an opportunity to determine space radiation-induced radioactivities with a precision not possible before. Data presented include preliminary activities for steel and aluminum structural samples, and activation subexperiment foils. Effects seen in the data show a clear indication of the trapped proton anisotropy in the South Atlantic Anomaly and suggest contributions from different sources of external radiation fluxes.

  4. Charlie's Clamp.

    ERIC Educational Resources Information Center

    Tarino, Janet Z.

    1998-01-01

    Presents a version of the crush-the-can demonstration which is a hands-on activity in which students use an inexpensive, easily made holder for the can called Charlie's clamp. Includes some suggestions for the follow-up discussion. (DDR)

  5. Aerospace Food Tray

    NASA Technical Reports Server (NTRS)

    Aragon, Maureen A.; Fohey, Michael F.

    1990-01-01

    Lightweight tray designed for use in microgravity. Provides restraint and thermal insulation for modular packages of food. Magnetic utensils restrained by attraction to ferrous plate mounted underneath. Restraints for pouch and spring clips also provided. Surfaces made smooth to facilitate cleaning, and number of cracks, crevices, and pits where food residues collect kept to minimum. Useful for serving meals in airplanes, boats, hospitals, and facilities that care for children.

  6. Aerospace Food Tray

    NASA Technical Reports Server (NTRS)

    Aragon, Maureen A.; Fohey, Michael F.

    1990-01-01

    Lightweight tray designed for use in microgravity. Provides restraint and thermal insulation for modular packages of food. Magnetic utensils restrained by attraction to ferrous plate mounted underneath. Restraints for pouch and spring clips also provided. Surfaces made smooth to facilitate cleaning, and number of cracks, crevices, and pits where food residues collect kept to minimum. Useful for serving meals in airplanes, boats, hospitals, and facilities that care for children.

  7. Surface Analysis of LDEF Materials

    NASA Technical Reports Server (NTRS)

    Wightman, J. P. (Principal Investigator)

    1996-01-01

    The abstract to the M.S. thesis included as appendix to this report contains the details of the research performed under this grant. Presentations and publications resulting from the research are listed as the main content of the report itself. The thesis describes the surface characterization procedures and analysis of materials flown in the NASA Long Duration Exposure Facility (LDEF).

  8. LDEF Materials Results for Spacecraft Applications

    NASA Technical Reports Server (NTRS)

    Whitaker, Ann F. (Compiler); Gregory, John (Compiler)

    1993-01-01

    These proceedings describe the application of LDEF data to spacecraft and payload design, and emphasize where space environmental effects on materials research and development is needed as defined by LDEF data. The LDEF six years of exposure of materials has proven to be by far the most comprehensive source of information ever obtained on the long-term performance of materials in the space environment. The conference provided a forum for materials scientists and engineers to review and critically assess the LDEF results from the standpoint of their relevance, significance, and impact on spacecraft design practice. The impact of the LDEF findings on materials selection and qualification, and the needs and plans for further study, were addressed from several perspectives. Many timely and needed changes and modifications in external spacecraft materials selection have occurred as a result of LDEF investigations.

  9. Transmittance measurements of ultra violet and visible wavelength interference filters flown aboard LDEF

    NASA Technical Reports Server (NTRS)

    Mooney, Thomas A.; Smajkiewicz, Ali

    1991-01-01

    A set of ten interference filters for the UV and VIS spectral region were flown on the surface of the Long Duration Exposure Facility (LDEF) Tray B-8 along with earth radiation budget (ERB) components from the Eppley Laboratory. Transmittance changes and other degradation observed after the return of the filters to Barr are reported. Substrates, coatings, and (where applicable) cement materials are identified. In general, all filters except those containing lead compounds survived well. Metal dielectric filters for the UV developed large numbers of pinholes which caused an increase in transmittance. Band shapes and spectral positioning, however, did not change.

  10. Analysis of materials from MSFC LDEF experiments. Final report, February 1990-July 1991

    SciTech Connect

    Johnson, R.B.

    1991-07-01

    In preparation for the arrival of the Long Duration Exposure Facility (LDEF) samples, a material testing and handling approach was developed for the evaluation of the materials. A configured lab was made ready for the de-integration of the LDEF experiments. The lab was prepared to clean room specifications and arranged with the appropriate clean benches, tables, lab benches, clean room tools, particulate counter, and calibrated and characterized analytical instrumentation. Clean room procedures were followed. Clean room attire and shoe cleaning equipment were selected and installed for those entering. Upon arrival of the shipping crates they were taken to the lab, logged in, and opened for examination. The sample trays were then opened for inspection and test measurements. The control sample measurements were made prior to placement into handling and transport containers for the flight sample measurements and analysis. Both LDEF flight samples and LDEF type materials were analyzed and tested for future flight candidate material evaluation. Both existing and newly purchased equipment was used for the testing and evaluation. Existing Space Simulation Systems had to be upgraded to incorporate revised test objectives and approaches. Fixtures such as special configured sample holders, water, power and LN2 feed-throughs, temperature measurement and control, front surface mirrors for reflectance and deposition, and UV grade windows had to be designed, fabricated, and installed into systems to achieve the revised requirements. New equipment purchased for LDEF analysis was incorporated into and/or used with existing components and systems. A partial list of this equipment includes a portable monochromator, enhanced UV System, portable helium leak detector for porosity and leak measurements, new turbo pumping system, vacuum coaster assembly, cryopumps, and analytical and data acquisition equipment.

  11. Changes in oxidation state of chromium during LDEF exposure

    NASA Technical Reports Server (NTRS)

    Golden, Johnny L.

    1992-01-01

    The solar collector used for the McDonnell-Douglas Cascade Variable Heat Pipe, Experiment A0076 (Michael Grote - Principal Investigator) was finished with black chromium plating as a thermal control coating. The coating is metallic for low emittance, and is finely microcrystalline to a dimension which yields its high absorptivity. An underplate of nickel was applied to the aluminum absorber plate in order to achieve optimal absorptance characteristics from the black chromium plate surface. Experiment A0076 was located at tray position F9, receiving a projected 8.7 x 10 exp 21 atomic oxygen atoms/sq cm and 11,200 ESH solar radiation. During retrieval, it was observed that the aluminized kapton thermal blankets covering most of the tray were severely eroded by atomic oxygen, and that a 'flap' of aluminum foil was overlaying a roughly triangular shaped portion of the absorber panel. The aluminum foil 'flap' was lost sometime between the Long Duration Exposure Facility (LDEF) retrieval and deintegration. At deintegration, the black chromium was observed to have discolored where it had been covered by the foil 'flap'. A summary of the investigation into the cause of the discoloration is presented.

  12. Long Duration Exposure Facility (LDEF) Archive System

    NASA Technical Reports Server (NTRS)

    Wilson, Brenda K.

    1995-01-01

    The Long Duration Exposure Facility (LDEF) Archive System is designed to provide spacecraft designers and space environment researchers single point access to all available resources from LDEF. These include data, micrographs, photographs, technical reports, papers, hardware and test specimens, as well as technical expertise. Further, the LDEF Archive System is planned such that it could be the foundation for a NASA Space Environments and Effects (SEE) Archive System, with the addition of other spaceflight, laboratory and theoretical space environments and effects data and associated materials. This paper describes the current status and plans of the LDEF Archive System.

  13. Space Shuttle food tray

    NASA Image and Video Library

    1983-11-28

    STS009-05-0153 (28 Nov. - 8 Dec. 1983) --- Though STS-9 was the space shuttle Columbia's sixth spaceflight, it was the first opportunity for an onboard galley, some of the results of which are shown in this 35mm scene on the flight deck. The metal tray makes for easy preparation and serving of in-space meals for crew members. This crewman is seated at the pilot's station on the flight deck. The actual galley is located in the middeck. Photo credit: NASA

  14. Automatic agar tray inoculation device

    NASA Technical Reports Server (NTRS)

    Wilkins, J. R.; Mills, S. M.

    1972-01-01

    Automatic agar tray inoculation device is simple in design and foolproof in operation. It employs either conventional inoculating loop or cotton swab for uniform inoculation of agar media, and it allows technician to carry on with other activities while tray is being inoculated.

  15. Heavy ion measurement on LDEF

    NASA Technical Reports Server (NTRS)

    Jonathal, D.; Beaujean, R.; Enge, W.

    1993-01-01

    Heavy ions with nuclear charge Z = 6 to Z = 26 are detected in a stack of plastic track detectors. The measured energies in the range of 10-240 MeV/nuc are well below the geomagnetic cut off value of the Long Duration Exposure Facility (LDEF) orbit. The arrival directions of the low energy particles (Z = 6-26, E less than 40 MeV/nuc) are consistent with a trapped component incident in the South Atlantic Anomaly.

  16. An interim overview of LDEF materials findings

    SciTech Connect

    Stein, B.A.

    1992-12-01

    The flight and retrieval of the National Aeronautics and Space Administration's Long Duration Exposure Facility (LDEF) provided an opportunity for the study of the low-Earth orbit (LEO) environment and long-duration space environmental effects (SEE) on materials that is unparalleled in the history of the U.S. Space Program. The remarkable flight attitude stability of LDEF enables specific analyses of various individual and combined effects of LEO environmental parameters on identical materials on the same space vehicle. This paper provides an overview of the interim LDEF materials findings of the Principal Investigators and the Materials Special Investigation Group. In general, the LDEF data is remarkably consistent; LDEF will provide a benchmark for materials design data bases for satellites in low-Earth orbit. Some materials were identified to be encouragingly resistant to LEO SEE for 5.8 years; other space qualified materials displayed significant environmental degradation. Molecular contamination was widespread; LDEF offers an unprecedented opportunity to provide a unified perspective of unmanned LEO spacecraft contamination mechanisms. New material development requirements for long-term LEO missions have been identified and current ground simulation testing methods/data for new, durable materials concepts can be validated with LDEF results. LDEF findings are already being integrated into the design of Space Station Freedom.

  17. An interim overview of LDEF materials findings

    NASA Technical Reports Server (NTRS)

    Stein, Brad A.

    1992-01-01

    The flight and retrieval of the National Aeronautics and Space Administration's Long Duration Exposure Facility (LDEF) provided an opportunity for the study of the low-Earth orbit (LEO) environment and long-duration space environmental effects (SEE) on materials that is unparalleled in the history of the U.S. Space Program. The remarkable flight attitude stability of LDEF enables specific analyses of various individual and combined effects of LEO environmental parameters on identical materials on the same space vehicle. This paper provides an overview of the interim LDEF materials findings of the Principal Investigators and the Materials Special Investigation Group. In general, the LDEF data is remarkably consistent; LDEF will provide a 'benchmark' for materials design data bases for satellites in low-Earth orbit. Some materials were identified to be encouragingly resistant to LEO SEE for 5.8 years; other 'space qualified' materials displayed significant environmental degradation. Molecular contamination was widespread; LDEF offers an unprecedented opportunity to provide a unified perspective of unmanned LEO spacecraft contamination mechanisms. New material development requirements for long-term LEO missions have been identified and current ground simulation testing methods/data for new, durable materials concepts can be validated with LDEF results. LDEF findings are already being integrated into the design of Space Station Freedom.

  18. Third LDEF Post-Retrieval Symposium Abstracts

    NASA Technical Reports Server (NTRS)

    Levine, Arlene S. (Compiler)

    1993-01-01

    This volume is a compilation of abstracts submitted to the Third Long Duration Exposure Facility (LDEF) Post-Retrieval Symposium. The abstracts represent the data analysis of the 57 experiments flown on the LDEF. The experiments include materials, coatings, thermal systems, power and propulsion, science (cosmic ray, interstellar gas, heavy ions, micrometeoroid, etc.), electronics, optics, and life science.

  19. LDEF meteoroid and debris database

    NASA Astrophysics Data System (ADS)

    Dardano, C. B.; See, Thomas H.; Zolensky, Michael E.

    The Long Duration Exposure Facility (LDEF) Meteoroid and Debris Special Investigation Group (M&D SIG) database is maintained at the Johnson Space Center (JSC), Houston, Texas, and consists of five data tables containing information about individual features, digitized images of selected features, and LDEF hardware (i.e., approximately 950 samples) archived at JSC. About 4000 penetrations (greater than 300 micron in diameter) and craters (greater than 500 micron in diameter) were identified and photo-documented during the disassembly of LDEF at the Kennedy Space Center (KSC), while an additional 4500 or so have subsequently been characterized at JSC. The database also contains some data that have been submitted by various PI's, yet the amount of such data is extremely limited in its extent, and investigators are encouraged to submit any and all M&D-type data to JSC for inclusion within the M&D database. Digitized stereo-image pairs are available for approximately 4500 features through the database.

  20. Micrometeoroids and debris on LDEF

    NASA Technical Reports Server (NTRS)

    Mandeville, Jean-Claude

    1993-01-01

    Two experiments within the French Cooperative Payload (FRECOPA) and devoted to the detection of cosmic dust were flown on the Long Duration Exposure Facility (LDEF). A variety of sensors and collecting devices have made possible the study of impact processes on dedicated sensors and on materials of technological interest. Examination of hypervelocity impact features on these experiments gives valuable information on the size distribution and nature of interplanetary dust particles in low-Earth orbit (LEO), within the 0.5-300 micrometer size range. However no crater smaller than 1.5 microns has been observed, thus suggesting a cut-off in the near Earth particle distribution. Chemical investigation of craters by EDX clearly shows evidence of elements (Na, Mg, Si, S, Ca, and Fe) consistent with cosmic origin. However, remnants of orbital debris have been found in a few craters; this can be the result of particles in eccentric orbits about the Earth and of the 8 deg offset in the orientation of LDEF. Crater size distribution is compared with results from other dust experiments flown on LDEF and with current models. Possible origin and orbital evolution of micrometeoroids is discussed. Use of thin foil detectors for the chemical study of particle remnants looks promising for future experiments.

  1. Examples of current cooperative projects in space flight LDEF and Giotto

    NASA Astrophysics Data System (ADS)

    Kuczera, H.

    The long-duration-exposure facility (LDEF) to be placed in orbit by STS-41-C for a 10-month mission and the ESA Giotto spacecraft to be Ariane launched in July 1985, for rendezvous with Comet Halley are characterized, with a focus on dust-detection instruments. LDEF carries 86 experiment trays containing 48 experiments, of which seven (occupying 37 trays) are to investigate cosmic dust. The 240 10 x 10-cm dust detectors consist mainly of a 2.5-micron-thick mylar foil coated with 100 nm of Ta and 5 nm of Au/Pd (on the underside and external surface, respectively) and Ge target plates. The overall plan of the Giotto mission and the history of Halley observations are reviewed; the spacecraft (based on the GEOS satellite) is described; and the instruments and experiments are listed. The impact-plasma monitor, particle-impact analyzer (a mass spectrograph), and dust-impact detector are discussed in detail and illustrated with photographs.

  2. Distillation tray structural parameter study: Phase 1

    NASA Technical Reports Server (NTRS)

    Winter, J. Ronald

    1991-01-01

    The purpose here is to identify the structural parameters (plate thickness, liquid level, beam size, number of beams, tray diameter, etc.) that affect the structural integrity of distillation trays in distillation columns. Once the sensitivity of the trays' dynamic response to these parameters has been established, the designer will be able to use this information to prepare more accurate specifications for the construction of new trays. Information is given on both static and dynamic analysis, modal response, and tray failure details.

  3. Fluid dynamics on sieve trays

    SciTech Connect

    Hag, M.A.

    1982-08-01

    A study was conducted to investigate the effects of fluid properties on the hydrodynamics of sieve tray columns. The study showed that changes in liquid viscosity influenced froth height, while changes in liquid surface tension and density influenced total pressure drop across the trays. Liquid holdup was independent of these solution properties. The liquid systems used for the study were: water/glycerol for viscosity, water/ethanol for surface tension and methanol/chloroform for density.

  4. A Search for Meteor Shower Signatures in the LDEF IDE Data

    NASA Technical Reports Server (NTRS)

    Cooke, William J.; McNamara, Heather A.

    2005-01-01

    For 346 days after the deployment of the LDEF satellite on April 7, 1984, the tape recorder belonging to the Interplanetary Dust Experiment (DE) stored information on over 15,000 impacts made by submicron and larger-size particles on its metal oxide silicon (MOS) detectors. These detectors were mounted on trays facing in six orthogonal directions - LDEF ram and trailing edge, the poles of the LDEF orbit (north and south), and radially inward (towards the Earth) and outward (towards space). The 13.1 second time resolution provided by the IDE electronics, combined with the high sensitivity of the MOS detectors and large collecting area (approximately 1 sq.m) of the experiment, conclusively showed that the small particle environment at the LDEF altitude of 480 km was highly time-variable, with particle fluxes spanning over four orders of magnitude. A large number of the 15,000 impacts recorded by IDE occurred in groups, which were of two types - the spikes, single, isolated events of high intensity and the multiple orbit event sequences (MOES), which were series of events separated in time by integer multiples of the LDEF orbital period. Even though the spikes were generally more intense, the MOES could be quite long-lived, some lasting for many days. A previous paper by Cooke et al. attributed the MOES to impacts by man-made debris particles in orbits intersecting that of LDEF. The 20 day longevity of one of these events - termed the May Swarm - led to the suggestion that the debris particles must be con- stantly replenished by their source, as the orbits of micron sized particles will rapidly decay under the influence of radiation pressure and other non-gravitational forces, entering Earth's atmosphere after only a few revolutions. However, the date of onset of the May Swarm (May 22) and the long duration of this event may indicate a possible correlation with the annual Arietid meteor shower, which peaks around June 8. As this seemed to hold the promise of a less

  5. A Search for Meteor Shower Signatures in the LDEF IDE Data

    NASA Technical Reports Server (NTRS)

    Cooke, William J.; McNamara, Heather A.

    2005-01-01

    For 346 days after the deployment of the LDEF satellite on April 7, 1984, the tape recorder belonging to the Interplanetary Dust Experiment (DE) stored information on over 15,000 impacts made by submicron and larger-size particles on its metal oxide silicon (MOS) detectors. These detectors were mounted on trays facing in six orthogonal directions - LDEF ram and trailing edge, the poles of the LDEF orbit (north and south), and radially inward (towards the Earth) and outward (towards space). The 13.1 second time resolution provided by the IDE electronics, combined with the high sensitivity of the MOS detectors and large collecting area (approximately 1 sq.m) of the experiment, conclusively showed that the small particle environment at the LDEF altitude of 480 km was highly time-variable, with particle fluxes spanning over four orders of magnitude. A large number of the 15,000 impacts recorded by IDE occurred in groups, which were of two types - the spikes, single, isolated events of high intensity and the multiple orbit event sequences (MOES), which were series of events separated in time by integer multiples of the LDEF orbital period. Even though the spikes were generally more intense, the MOES could be quite long-lived, some lasting for many days. A previous paper by Cooke et al. attributed the MOES to impacts by man-made debris particles in orbits intersecting that of LDEF. The 20 day longevity of one of these events - termed the May Swarm - led to the suggestion that the debris particles must be con- stantly replenished by their source, as the orbits of micron sized particles will rapidly decay under the influence of radiation pressure and other non-gravitational forces, entering Earth's atmosphere after only a few revolutions. However, the date of onset of the May Swarm (May 22) and the long duration of this event may indicate a possible correlation with the annual Arietid meteor shower, which peaks around June 8. As this seemed to hold the promise of a less

  6. A photon phreak digs the LDEF happenings

    SciTech Connect

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

    1992-06-01

    A year ago at the First LDEF Post-Retrieval Symposium, we reported detailed measurements on trunnion sections, as well as results from ``intentional`` samples (Co, Ni, In, Ta, and V) and spacecraft parts. For this year`s Symposium we re-evaluate some of these findings in combination with more recent results, to cast a longer perspective on the LDEF experience, and to sketch some promising avenues toward more effective participation in future missions. The LDEF analysis effort has been a superb training exercise, from which lessons learned needs be applied to future missions -- right back to the early phases of mission planning.

  7. A photon phreak digs the LDEF happenings

    SciTech Connect

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

    1992-06-01

    A year ago at the First LDEF Post-Retrieval Symposium, we reported detailed measurements on trunnion sections, as well as results from intentional'' samples (Co, Ni, In, Ta, and V) and spacecraft parts. For this year's Symposium we re-evaluate some of these findings in combination with more recent results, to cast a longer perspective on the LDEF experience, and to sketch some promising avenues toward more effective participation in future missions. The LDEF analysis effort has been a superb training exercise, from which lessons learned needs be applied to future missions -- right back to the early phases of mission planning.

  8. A photon phreak digs the LDEF happening

    NASA Technical Reports Server (NTRS)

    Smith, Alan R.; Hurley, Donna L.

    1993-01-01

    A year ago at the First Long Duration Exposure Facility (LDEF) Post-Retrieval Symposium, detailed measurements on trunnion sections, as well as results from 'intentional' samples (Co, Ni, In, Ta, and V) and spacecraft parts were reported. For this year's Symposium, some of these findings are re-evaluated in combination with more recent results, to cast a longer perspective on the LDEF experience, and to sketch some promising avenues toward more effective participation in future missions. The LDEF analysis effort has been a superb training exercise, from which lessons learned need to be applied to future missions - right back to the early phases of mission planning.

  9. Summary of LDEF battery analyses

    NASA Technical Reports Server (NTRS)

    Johnson, Chris; Thaller, Larry; Bittner, Harlin; Deligiannis, Frank; Tiller, Smith; Sullivan, David; Bene, James

    1992-01-01

    Tests and analyses of NiCd, LiSO2, and LiCf batteries flown on the Long Duration Exposure Facility (LDEF) includes results from NASA, Aerospace, and commercial labs. The LiSO2 cells illustrate six-year degradation of internal components acceptable for space applications, with up to 85 percent battery capacity remaining on discharge of some returned cells. LiCf batteries completed their mission, but lost any remaining capacity due to internal degradation. Returned NiCd batteries tested an GSFC showed slight case distortion due to pressure build up, but were functioning as designed.

  10. Trapped iron measured on LDEF

    NASA Technical Reports Server (NTRS)

    Beaujean, R.; Jonathal, D.; Barz, S.; Enge, W.

    1995-01-01

    Heavy ions far below the cutoff energy were detected on the 28.5 deg inclination orbit of LDEF in a plastic track detector experiment. The Fe-group particles show a constant energy spectrum at 50 less than or equal to E less than or equal to 200 MeV/nuc. The steep energy spectrum of Fe-particles at 20 less than or equal to E less than or equal to 50 MeV/nuc and the arrival directions of these ions is consistent with a trapped component incident in the South Atlantic Anomaly at values of L=1.4-1.6.

  11. Induced radioactivity in LDEF components

    NASA Technical Reports Server (NTRS)

    Harmon, B. A.; Fishman, G. J.; Parnell, T. A.; Laird, C. E.

    1991-01-01

    The systematics of induced radioactivity on the Long Duration Exposure Facility (LDEF) were studied in a wide range of materials using low level background facilities for detection of gamma rays. Approx. 400 samples of materials processed from structural parts of the spacecraft, as well as materials from onboard experiments, were analyzed at national facilities. These measurements show the variety of radioisotopes that are produced with half-lives greater than 2 wks, most of which are characteristic of proton induced reactions above 20 MeV. For the higher activity, long lived isotopes, it was possible to map the depth and directional dependences of the activity. Due to the stabilized configuration of the LDEF, the induced radioactivity data clearly show contributions from the anisotropic trapped proton flux in the South Atlantic Anomaly. This effect is discussed, along with evidence for activation by galactic protons and thermal neutrons. The discovery of Be-7 was made on leading side parts of the spacecraft, although this was though not to be related to the in situ production of radioisotopes from external particle fluxes.

  12. LDEF systems special investigation group overview

    NASA Technical Reports Server (NTRS)

    Mason, Jim; Dursch, Harry

    1995-01-01

    The Systems Special Investigation Group (Systems SIG), formed by the LDEF Project Office to perform post-flight analysis of LDEF systems hardware, was chartered to investigate the effects of the extended LDEF mission on both satellite and experiment systems and to coordinate and integrate all systems related analyses performed during post-flight investigations. The Systems SIG published a summary report in April, 1992 titled 'Analysis of Systems Hardware Flown on LDEF - Results of the Systems Special Investigation Group' that described findings through the end of 1991. The Systems SIG, unfunded in FY 92 and FY93, has been funded in FY 94 to update this report with all new systems related findings. This paper provides a brief summary of the highlights of earlier Systems SIG accomplishments and describes tasks the Systems SIG has been funded to accomplish in FY 94.

  13. Clamp usable as jig and lifting clamp

    DOEpatents

    Tsuyama, Yoshizo

    1976-01-01

    There is provided a clamp which is well suited for use as a lifting clamp for lifting and moving materials of assembly in a shipyard, etc. and as a pulling jig in welding and other operations. The clamp comprises a clamp body including a shackle for engagement with a pulling device and a slot for receiving an article, and a pair of jaws provided on the leg portions of the clamp body on the opposite sides of the slot to grip the article in the slot, one of said jaws consisting of a screw rod and the other jaw consisting of a swivel jaw with a spherical surface, whereby when the article clamped in the slot by the pair of jaws tends to slide in any direction with respect to the clamp body, the article is more positively gripped by the pair of jaws.

  14. Development of the Thermostabilized Meal Tray

    DTIC Science & Technology

    1991-07-01

    having a rigid base plate at a 900 angle to the direction of the fall (see Figure 2). The height of the drop was adjusted so that the tray struck the...abuse test was used to test trays , however, in this test the drop height varied for different weight trays to allow each tray to strike the base plate ... trays was approximately 1 pound per second. Trays were supported on a base plate but were not restrained at the time air was 14 introduced. The pressure

  15. Florida Peninsula, LDEF Deploy-RMS

    NASA Image and Video Library

    1984-04-13

    41C-36-1618 (7 April 1984) --- The Remote Manipulator System (RMS) arm suspends the giant Long Duration Exposure Facility (LDEF) high above the Gulf of Mexico prior to releasing it into space. Carried into Earth orbit with the STS-41C crew by the Space Shuttle Challenger, LDEF will remain in space until retrieved by a future Shuttle mission, in nine or ten months. Florida and the Bahama Banks are visible near the Earth's horizon in the 70mm frame.

  16. Portable, Folding Tray Retainer and Stand (Multipurpose).

    DTIC Science & Technology

    The invention relates generally to the field of service tray supports and, in particular, to an improved combined portable tray support and stand especially adaptable for use with a litter-borne patient.

  17. LDEF fiber optic exposure experiment

    NASA Technical Reports Server (NTRS)

    Johnston, Alan R.; Bergman, Larry A.; Hartmayer, Ron

    1991-01-01

    Ten fiber optic cable samples of different types were exposed in low Earth orbit for over 5.5 years on the Long Duration Exposure Facility (LDEF). Four of the samples were mounted externally, and the remaining six were internal, under approximately .5 gc/sq m of aluminum. The experiment was recovered in January of 1990, and laboratory evaluation of the effects of the exposure has continued since. An increase in loss, presumed to be from radiation darkening, aging effects on polymer materials used in cabling, unique contamination effects on connector terminations, and micrometeoroid impacts were observed on some of the samples. In addition, the dependence of sample loss was measured as a function of temperature before and after the flight. All cable samples were functional, and the best exhibited no measurable change in performance, indicating that conventional fiber optic cables can perform satisfactorily in spacecraft. Experimental results obtained to date will be presented and discussed.

  18. Damage areas due to impact craters on LDEF aluminum panels

    NASA Technical Reports Server (NTRS)

    Coombs, Cassandra R.; Atkinson, Dale R.; Allbrooks, Martha; Wagner, J. D.

    1992-01-01

    Because of its exposure time and total exposed surface area, the LDEF provides a unique opportunity to analyze the effects of the natural and man-made particle populations in low earth orbit (LEO). This study concentrated on collecting and analyzing measurements of impact craters from seven painted aluminum surfaces at different locations on the satellite. These data are being used to: (1) update the current theoretical micrometeoroid and debris models for LEO; (2) characterize the effects of the LEO micrometeoroid and debris environment of satellite components and designs; (3) help assess the probability of collision between spacecraft in LEO and already resident debris and the survivability of those spacecraft that must travel through, or reside in, LEO; and (4) help define and evaluate future debris mitigation and disposal methods. Measurements were collected from one aluminum experiment tray cover (Bay C-12), two aluminum grapple plates (Bays C-01, C-10), and four aluminum experiment sun-shields (Bay E-09), all of which were coated with thermal paint. These measurements were taken at the Facility for Optical Interpretation of Large Surfaces (FOILS) Lab at JSC. Virtually all features greater than 0.2 mm in diameter possessed a spall zone in which all of the paint was removed from the aluminum surface, and which varied in size from 2-5 crater diameters. The actual craters vary from central pits without raised rims to morphologies more typical of craters formed in aluminum under hypervelocity impact conditions for larger features. Most craters exhibit a shock zone that varies in size from approximately 1-20 crater diameters. In general, only the outermost layer of paint was affected by this impact-related phenomenon, with several impacts possessing ridge-like structures encircling the area in which this outer-most paint layer was removed. Overall, there were no noticeable penetrations or bulges on the underside of the trays. One tray from the E-09 bay exhibited a

  19. Damage areas due to impact craters on LDEF aluminum panels

    NASA Astrophysics Data System (ADS)

    Coombs, Cassandra R.; Atkinson, Dale R.; Allbrooks, Martha; Wagner, J. D.

    1992-06-01

    Because of its exposure time and total exposed surface area, the LDEF provides a unique opportunity to analyze the effects of the natural and man-made particle populations in low earth orbit (LEO). This study concentrated on collecting and analyzing measurements of impact craters from seven painted aluminum surfaces at different locations on the satellite. These data are being used to: (1) update the current theoretical micrometeoroid and debris models for LEO; (2) characterize the effects of the LEO micrometeoroid and debris environment of satellite components and designs; (3) help assess the probability of collision between spacecraft in LEO and already resident debris and the survivability of those spacecraft that must travel through, or reside in, LEO; and (4) help define and evaluate future debris mitigation and disposal methods. Measurements were collected from one aluminum experiment tray cover (Bay C-12), two aluminum grapple plates (Bays C-01, C-10), and four aluminum experiment sun-shields (Bay E-09), all of which were coated with thermal paint. These measurements were taken at the Facility for Optical Interpretation of Large Surfaces (FOILS) Lab at JSC. Virtually all features greater than 0.2 mm in diameter possessed a spall zone in which all of the paint was removed from the aluminum surface, and which varied in size from 2-5 crater diameters. The actual craters vary from central pits without raised rims to morphologies more typical of craters formed in aluminum under hypervelocity impact conditions for larger features. Most craters exhibit a shock zone that varies in size from approximately 1-20 crater diameters. In general, only the outermost layer of paint was affected by this impact-related phenomenon, with several impacts possessing ridge-like structures encircling the area in which this outer-most paint layer was removed. Overall, there were no noticeable penetrations or bulges on the underside of the trays. One tray from the E-09 bay exhibited a

  20. Flexible Interior-Impression-Molding Tray

    NASA Technical Reports Server (NTRS)

    Anders, Jeffrey E.

    1991-01-01

    Device used inside combustion chamber of complicated shape for nondestructive evaluation of qualities of welds, including such features as offset, warping, misalignment of parts, and dropthrough. Includes flexible polypropylene tray trimmed to fit desired interior surface contour. Two neodymium boron magnets and inflatable bladder attached to tray. Tray and putty inserted in cavity to make mold of interior surface.

  1. Flexible Interior-Impression-Molding Tray

    NASA Technical Reports Server (NTRS)

    Anders, Jeffrey E.

    1991-01-01

    Device used inside combustion chamber of complicated shape for nondestructive evaluation of qualities of welds, including such features as offset, warping, misalignment of parts, and dropthrough. Includes flexible polypropylene tray trimmed to fit desired interior surface contour. Two neodymium boron magnets and inflatable bladder attached to tray. Tray and putty inserted in cavity to make mold of interior surface.

  2. Development of a Multipurpose Aeromedical Tray Holder.

    DTIC Science & Technology

    The multipurpose aeromedical tray holder was designed and developed to provide a simple and safe method to support a tray , with food or medical...evaluation on world-wide aeromedical missions. Evaluations indicated that the multipurpose aeromedical tray holder met design and performance specifications and fulfilled the development objective. (Author)

  3. The influence of tibial tray design on the wear of fixed-bearing total knee replacements.

    PubMed

    Galvin, A; Jennings, L M; McEwen, H M; Fisher, J

    2008-11-01

    Debris-induced osteolysis due to surface wear is a potential long-term problem in total knee replacements (TKRs). Wear between the tibial tray and ultra-high molecular weight polyethylene insert is thought to contribute to the wear. This study investigated the influence of tibial tray design on the wear of fixed-bearing TKRs. Specifically, this study investigated the influence of the material's surface finish and design characteristics of the locking mechanism of the tibial tray on the wear in fixed-bearing knees for both cruciate-retaining (CR) and posterior-stabilized designs. A new fixed-bearing tibial tray design using Co-Cr and with an improved locking mechanism significantly reduced polyethylene wear from 22.8 +/- 6.0 mm3 per 10(6) cycles to 15.9 +/- 2.9 mm3 per 10(6) cycles compared with a previous titanium alloy tray with a CR design. The wear rates were similar to those of a fixed-bearing insert clamped into a tibial tray, suggesting that the decrease in wear was due to a reduction in backside wear. There was no significant difference between the wear rates of a cruciate-retaining design and a posterior-stabilized design under the two kinematic conditions tested.

  4. Force-Measuring Clamps

    NASA Technical Reports Server (NTRS)

    Nunnelee, Mark

    2003-01-01

    Force-measuring clamps have been invented to facilitate and simplify the task of measuring the forces or pressures applied to clamped parts. There is a critical need to measure clamping forces or pressures in some applications for example, while bonding sensors to substrates or while clamping any sensitive or delicate parts. Many manufacturers of adhesives and sensors recommend clamping at specific pressures while bonding sensors or during adhesive bonding between parts in general. In the absence of a force-measuring clamp, measurement of clamping force can be cumbersome at best because of the need for additional load sensors and load-indicating equipment. One prior method of measuring clamping force involved the use of load washers or miniature load cells in combination with external power sources and load-indicating equipment. Calibrated spring clamps have also been used. Load washers and miniature load cells constitute additional clamped parts in load paths and can add to the destabilizing effects of loading mechanisms. Spring clamps can lose calibration quickly through weakening of the springs and are limited to the maximum forces that the springs can apply. The basic principle of a force-measuring clamp can be implemented on a clamp of almost any size and can enable measurement of a force of almost any magnitude. No external equipment is needed because the component(s) for transducing the clamping force and the circuitry for supplying power, conditioning the output of the transducers, and displaying the measurement value are all housed on the clamp. In other words, a force-measuring clamp is a complete force-application and force-measurement system all in one package. The advantage of unitary packaging of such a system is that it becomes possible to apply the desired clamping force or pressure with precision and ease.

  5. Apparatus for feeding nuclear fuel pellets to a loading tray

    SciTech Connect

    Huggins, T.B.

    1981-12-08

    Apparatus for feeding nuclear fuel pellets at a uniform, predetermined rate between pellet centering and grinding apparatus and a tray used for loading pellets into a nuclear fuel rod are described. Pellets discharged from the grinder are conveyed by a woven wire belt to a drive wheel which develops a force available to be applied to pellets preceding it on the belt. The pellets pass under the drive wheel which adds additional weight acting vertically on each pellet. This total weight of pellet and drive wheel coupled with wire belt linear movement acts to push a line of about 36 pellets onto a pellet dumping mechanism. As the dumping mechanism is actuated to dump the pellets on to a loading tray, the pellets moving toward the mechanism are clamped in a stationary position and the drive wheel simultaneously is lifted from its pellet contacting position until the pellet dumping process is completed. The clamping device is then lifted from its pellet and the drive wheel simultaneously is lowered into a pellet contacting position.

  6. Holographic data storage crystals for the LDEF. [long duration exposure facility

    NASA Technical Reports Server (NTRS)

    Callen, W. Russell; Gaylord, Thomas K.

    1992-01-01

    Lithium niobate is a significant electro-optic material, with potential applications in ultra high capacity storage and processing systems. Lithium niobate is the material of choice for many integrated optical devices and holographic mass memory systems. For crystals of lithium niobate were passively exposed to the space environment of the Long Duration Exposure Facility (LDEF). Three of these crystals contained volume holograms. Although the crystals suffered the surface damage characteristics of most of the other optical components on the Georgia Tech tray, the crystals were recovered intact. The holograms were severely degraded because of the lengthy exposure, but the bulk properties are being investigated to determine the spaceworthiness for space data storage and retrieval systems.

  7. Holographic data storage crystals for the LDEF. [long duration exposure facility

    NASA Technical Reports Server (NTRS)

    Callen, W. Russell; Gaylord, Thomas K.

    1992-01-01

    Lithium niobate is a significant electro-optic material, with potential applications in ultra high capacity storage and processing systems. Lithium niobate is the material of choice for many integrated optical devices and holographic mass memory systems. For crystals of lithium niobate were passively exposed to the space environment of the Long Duration Exposure Facility (LDEF). Three of these crystals contained volume holograms. Although the crystals suffered the surface damage characteristics of most of the other optical components on the Georgia Tech tray, the crystals were recovered intact. The holograms were severely degraded because of the lengthy exposure, but the bulk properties are being investigated to determine the spaceworthiness for space data storage and retrieval systems.

  8. Force-Measuring Clamp

    NASA Technical Reports Server (NTRS)

    Nunnelee, Mark (Inventor)

    2004-01-01

    A precision clamp that accurately measures force over a wide range of conditions is described. Using a full bridge or other strain gage configuration. the elastic deformation of the clamp is measured or detected by the strain gages. Thc strain gages transmit a signal that corresponds to the degree of stress upon the clamp. Thc strain gage signal is converted to a numeric display. Calibration is achieved by ero and span potentiometers which enable accurate measurements by the force-measuring clamp.

  9. Force-Measuring Clamp

    NASA Technical Reports Server (NTRS)

    Nunnelee, Mark (Inventor)

    2004-01-01

    A precision clamp that accurately measures force over a wide range of conditions is described. Using a full bridge or other strain gage configuration. the elastic deformation of the clamp is measured or detected by the strain gages. Thc strain gages transmit a signal that corresponds to the degree of stress upon the clamp. Thc strain gage signal is converted to a numeric display. Calibration is achieved by ero and span potentiometers which enable accurate measurements by the force-measuring clamp.

  10. LDEF Materials Workshop 1991, part 2

    NASA Technical Reports Server (NTRS)

    Stein, Bland A. (Compiler); Young, Philip R. (Compiler)

    1992-01-01

    The LDEF Materials Workshop 1991 was a follow-on to the Materials Sessions at the First LDEF Post-Retrieval Symposium held in Kissimmee, Florida, June 1991. The workshop comprised a series of technical sessions on materials themes, followed by theme panel meetings. Themes included materials, environmental parameters, and data bases; contamination; thermal control and protective coating and surface treatments; polymers and films; polymer matrix composites; metals, ceramics, and optical materials; lubricants adhesives, seals, fasteners, solar cells, and batteries. This document continues the LDEF Space Environmental Effects on Materials Special Investigation Group (MSIG) pursuit to investigate the effects of LEO exposure on materials which were not originally planned to be test specimens. Papers from the technical sessions are presented.

  11. Overview of the LDEF MSIG databasing activities

    NASA Technical Reports Server (NTRS)

    Funk, Joan G.

    1995-01-01

    The Long Duration Exposure Facility (LDEF) and the accompanying experiments were composed of and contained a wide variety of materials, representing the largest collection of materials flown in low earth orbit (LEO) and retrieved for ground-based analysis to date. The results and implications of the mechanical, thermal, optical, and electrical data from these materials are the foundation on which future LEO spacecraft and missions will be built. The LDEF Materials Special Investigation Group (MSIG) has been charged with establishing and developing databases to document these materials and their performance to assure not only that the data are archived for future generations but also that the data are available to the spacecraft user community in an easily accessed, user-friendly form. This paper gives an overview of the current LDEF Materials Databases, their capabilities, and availability. An overview of the philosophy and format of a developing handbook on LEO effects on materials is also described.

  12. Status of LDEF activation measurements and archive

    SciTech Connect

    Harmon, B.A.; Parnell, T.A.; Laird, C.E.

    1995-02-01

    The authors review the status of induced radioactivity measurements for the LDEF spacecraft which includes studies of the nuclide, target, directional and depth dependences of the activation. Analysis of the data has focused on extraction of the specific activities for many materials to develop a global picture of the low Earth orbital environment to which the LDEF was subjected. Preliminary comparisons of data in a previous review showed that it was possible to make meaningful intercomparisons between results obtained at different facilities. Generally these comparisons were good and gave results to within 10-20 percent, although some analysis remains. These results clearly provide constraints for recent calculations being performed of the radiation environment of the LDEF. The authors are not anticipating a period of production of final activation results. An archive is being prepared jointly between NASA/Marshall and Eastern Kentucky University which will include gamma ray spectra and other intermediate results.

  13. Partial analysis of LDEF experiment A-0114

    NASA Technical Reports Server (NTRS)

    Gregory, John C.

    1991-01-01

    During the contract period, work concentrated on four main components. Data from the UAH silver pin hole camera was analyzed for determination of the mean Long Duration Exposure Facility (LDEF) satellite attitude and stability in orbit, to include pitch and yaw. Chemical testing performed on the AO-114 hot plate determined the form and locus of absorption of cosmogenic beryllium-7. Reaction rates of atomic oxygen with Kapton and other polymeric solids integrated over the whole LDEF orbital lifetime were analyzed. These rates were compared with the JSC estimated values for Space Station exposures. Metal and polymer films exposed on A0114 (C-9 and C-3 plates) were also analyzed.

  14. (VDA) Vapor Diffusion Apparatus Tray

    NASA Technical Reports Server (NTRS)

    1994-01-01

    These Vapor Diffusion Apparatus (VDA) trays were first flown in the Thermal Enclosure System (TES) during the USMP-2 (STS-62) mission. Each tray can hold 20 protein crystal growth chambers. Each chamber contains a double-barrel syringe; one barrel holds protein crystal solution and the other holds precipitant agent solution. During the microgravity mission, a torque device is used to simultaneously retract the plugs in all 20 syringes. The two solutions in each chamber are then mixed. After mixing, droplets of the combined solutions are moved onto the syringe tips so vapor diffusion can begin. During the length of the mission, protein crystals are grown in the droplets. Shortly before the Shuttle's return to Earth, the experiment is deactivated by retracting the droplets containing protein crystals, back into the syringes.

  15. TRAY MOUNTAIN ROADLESS AREA, GEORGIA.

    USGS Publications Warehouse

    Nelson, Arthur E.; Chatman, Mark L.

    1984-01-01

    A mineral survey indicates that the Tray Mountain Roadless Area, Georgia has little promise for the occurrence of metallic mineral resources. Rocks underlying the Tray Mountain Roadless Area are suitable for crushed rock or aggregate; however, other sources for these materials are available closer to present markets. There is a possibility for the occurrence of hydrocarbon resources underlying the area at great depth, but no hydrocarbon potential was identified. Detailed studies are needed to establish the presence or absence and mineral-resource potential of olivine, nickel, cobalt, and chrome in the two mafic-ultramafic bodies in the Hayesville thrust sheet. The cause of the lead anomaly in pan concentrate samples taken from the southwest part of the roadless area has not been established; the mineral residence and source of the anomaly remain to be determined.

  16. Photovoltaic panel clamp

    SciTech Connect

    Mittan, Margaret Birmingham; Miros, Robert H. J.; Brown, Malcolm P; Stancel, Robert

    2012-06-05

    A photovoltaic panel clamp includes an upper and lower section. The interface between the assembled clamp halves and the module edge is filled by a flexible gasket material, such as EPDM rubber. The gasket preferably has small, finger like protrusions that allow for easy insertion onto the module edge while being reversed makes it more difficult to remove them from the module once installed. The clamp includes mounting posts or an integral axle to engage a bracket. The clamp also may include a locking tongue to secure the clamp to a bracket.

  17. Photovoltaic panel clamp

    SciTech Connect

    Brown, Malcolm P.; Mittan, Margaret Birmingham; Miros, Robert H. J.; Stancel, Robert

    2013-03-19

    A photovoltaic panel clamp includes an upper and lower section. The interface between the assembled clamp halves and the module edge is filled by a flexible gasket material, such as EPDM rubber. The gasket preferably has small, finger like protrusions that allow for easy insertion onto the module edge while being reversed makes it more difficult to remove them from the module once installed. The clamp includes mounting posts or an integral axle to engage a bracket. The clamp also may include a locking tongue to secure the clamp to a bracket.

  18. Clamping in Boltzmann machines.

    PubMed

    Livesey, M

    1991-01-01

    A certain assumption that appears in the proof of correctness of the standard Boltzmann machine learning procedure is investigated. The assumption, called the clamping assumption, concerns the behavior of a Boltzmann machine when some of its units are clamped to a fixed state. It is argued that the clamping assumption is essentially an assertion of the time reversibility of a certain Markov chain underlying the behavior of the Boltzmann machine. As such, the clamping assumption is generally false, though it is certainly true of the Boltzmann machines themselves. The author also considers how the concept of the Boltzmann machine may be generalized while retaining the validity of the clamping assumption.

  19. LDEF microenvironments, observed and predicted

    NASA Technical Reports Server (NTRS)

    Bourassa, R. J.; Pippin, H. G.; Gillis, J. R.

    1993-01-01

    A computer model for prediction of atomic oxygen exposure of spacecraft in low earth orbit, referred to as the primary atomic oxygen model, was originally described at the First Long Duration Exposure Facility (LDEF) Post-Retrieval Symposium. The primary atomic oxygen model accounts for variations in orbit parameters, the condition of the atmosphere, and for the orientation of exposed surfaces relative to the direction of spacecraft motion. The use of the primary atomic oxygen model to define average atomic oxygen exposure conditions for a spacecraft is discussed and a second microenvironments computer model is described that accounts for shadowing and scattering of atomic oxygen by complex surface protrusions and indentations. Comparisons of observed and predicted erosion of fluorinated ethylene propylene (FEP) thermal control blankets using the models are presented. Experimental and theoretical results are in excellent agreement. Work is in progress to expand modeling capability to include ultraviolet radiation exposure and to obtain more detailed information on reflecting and scattering characteristics of material surfaces.

  20. Custom-made titanium mandibular reconstruction tray.

    PubMed

    Samman, N; Luk, W K; Chow, T W; Cheung, L K; Tideman, H; Clark, R K

    1999-09-01

    Reconstruction of the mandible after ablative surgery can be achieved by using preformed trays or trays formed from models produced by computer-assisted modelling systems. The former presents difficulty in matching the required facial contour, jaw relationship and condylar position; while the latter is expensive. This paper presents a simple and inexpensive method of fabricating a custom-made titanium bone grafting tray. The dimensions of the patient's mandible are obtained by clinical measurement. Such measurements are used to construct a mandibular replica. The region to be reconstructed is carved to produce the ideal shape and dimensions of an edentulous segment. The tray is made either by casting or by swaging. Twenty-one custom-made titanium bone grafting trays have been fitted in patients with encouraging results. This method of bone grafting tray construction is a simple, inexpensive technique for achieving excellent facial contour and functional reconstruction after mandibulectomy.

  1. Disinfection effect of dental impression tray adhesives.

    PubMed

    Bensel, Tobias; Pollak, Rita; Stimmelmayr, Michael; Hey, Jeremias

    2013-03-01

    Iatrogenic infections are serious problems in dental offices. Impression tray adhesives are delivered in glass containers with a fixed brush attached inside the cap. Using the brush for application of the impression tray adhesive on a contaminated impression tray or prostheses, pathogen transmission by replacing the cap with the brush is possible. Bacterial strains (patient strains and in vitro strains) were supervaccinated on Columbia agar. The bacterial solution was diluted with TSB and aerobically grown, and starting concentration was 1 × 10(7) cfu/ml. The stock solution was placed on Columbia agar. Alginate, polyether, and silicon impression tray adhesives were applied to the center of the particular blood agar plates and incubated for 48 h. The expansion of the inhibition zone assays were measured using a microscope. Twenty-one different bacterial strains were selected in the saliva samples of 20 patients. The growth inhibition for alginate impression tray adhesive was 1.1 % (±0.3) of the patient strains. The overgrowth of polyether impression tray adhesive was 30.6 % (±9.3) and for silicon impression tray adhesive 11.8 % (±5.0). In in vitro strains, alginate impression tray adhesive performed an inhibition of 0.7 % (±0.3). The overgrowth of polyether impression tray adhesive was 7.0 % (±1.6) and for silicon impression tray adhesive was 6.5 % (±1.3). Using the fixed brush for application of the impression tray adhesive on multiple patients, a cross-contamination cannot be ruled out. An application of the impression tray adhesive with a pipette and a single-use brush would eliminate the contamination.

  2. Metallurgical Analysis of Leaking Tray Packs

    DTIC Science & Technology

    1990-05-01

    i j L Copyi MTL TR 90-30 JAD AD-A223 157 METALLURGICAL ANALYSIS OF LEAKING TRAY PACKS KUAN S. LEI GEO-CENTERS, INC. NEWTON, MA FRANK C. CHANG and...RECIPIENTS CATALOG NUMBER 4. TITLE (and Subute) 5. TYPE OF REPORT & PERIOD COVERED Final Report METALLURGICAL ANALYSIS OF LEAKING TRAY PACKS 6...CLASSIFICATION OF THIS PAGE (Wihn Daa Entend) Block No. 20 ABSTRACT A metallurgical analysis was performed to determine the cause of leaking tray packs and the

  3. Photographic Survey of the LDEF Mission

    NASA Technical Reports Server (NTRS)

    ONeal, Robert L.; Levine, Arlene S.; Kiser, Carol C.

    1996-01-01

    This publication documents a selected number of pre-flight, in-flight, and postflight photographs of the LDEF and experiments. Changes in condition of the experiments caused by space exposure are discussed. Accompanying this black and white publication it a CD-ROM that contains the color version of the photographs as well as the text.

  4. LDEF data: Comparisons with existing models

    NASA Technical Reports Server (NTRS)

    Coombs, Cassandra R.; Watts, Alan J.; Wagner, John D.; Atkinson, Dale R.

    1993-01-01

    The relationship between the observed cratering impact damage on the Long Duration Exposure Facility (LDEF) versus the existing models for both the natural environment of micrometeoroids and the man-made debris was investigated. Experimental data was provided by several LDEF Principal Investigators, Meteoroid and Debris Special Investigation Group (M&D SIG) members, and by the Kennedy Space Center Analysis Team (KSC A-Team) members. These data were collected from various aluminum materials around the LDEF satellite. A PC (personal computer) computer program, SPENV, was written which incorporates the existing models of the Low Earth Orbit (LEO) environment. This program calculates the expected number of impacts per unit area as functions of altitude, orbital inclination, time in orbit, and direction of the spacecraft surface relative to the velocity vector, for both micrometeoroids and man-made debris. Since both particle models are couched in terms of impact fluxes versus impactor particle size, and much of the LDEF data is in the form of crater production rates, scaling laws have been used to relate the two. Also many hydrodynamic impact computer simulations were conducted, using CTH, of various impact events, that identified certain modes of response, including simple metallic target cratering, perforations and delamination effects of coatings.

  5. Gamma radiation survey of the LDEF spacecraft

    NASA Technical Reports Server (NTRS)

    Phillips, G. W.; King, S. E.; August, R. A.; Ritter, J. C.; Cutchin, J. H.; Haskins, P. S.; Mckisson, J. E.; Ely, D. W.; Weisenberger, A. G.; Piercey, R. B.

    1991-01-01

    The retrieval of the Long Duration Exposure Facility (LDEF) spacecraft after nearly 6 years in orbit offered a unique opportunity to study the long term buildup of induced radioactivity in the variety of materials on board. The first complete gamma ray survey was conducted of a large spacecraft on LDEF shortly after its return to Earth. A surprising observation was the large Be-7 activity which was seen primarily on the leading edge of the satellite, implying that it was picked up by LDEF in orbit. This is the first known evidence for accretion of a radioactive isotope onto an orbiting spacecraft. Other isotopes seen during the survey, the strongest being Na-22 and Mn-54, are all attributed to activation of spacecraft components in orbit. Be-7 is a spallation product of cosmic rays on nitrogen and oxygen in the upper atmosphere. However, the observed density is much greater than expected due to cosmic ray production in situ. This implies transport of Be-7 from much lower altitudes up to the LDEF orbit.

  6. Long Duration Exposure Facility (LDEF) contamination modeling

    NASA Technical Reports Server (NTRS)

    Gordon, Tim; Rantanen, Ray

    1992-01-01

    The Integrated Spacecraft Environments Model (ISEM) was used to model the LDEF induced neutral molecular environment at several different times and altitudes during the mission. The purpose of this effort was to provide the community with an estimate of the neutral molecular environment to assist in phenomenology studies.

  7. Selected results for LDEF thermal control coatings

    NASA Technical Reports Server (NTRS)

    Golden, Johnny L.

    1993-01-01

    Several different thermal control coatings were analyzed as part of the Long Duration Exposure Facility (LDEF) Materials Special Investigation Group activity and as part of the Space Environment Effects on Spacecraft Materials Experiment M0003. A brief discussion of the results obtained for these materials is presented.

  8. The preliminary Long Duration Exposure Facility (LDEF) materials data base

    NASA Technical Reports Server (NTRS)

    Funk, Joan G.; Strickland, John W.; Davis, John M.

    1992-01-01

    A preliminary Long Duration Exposure Facility (LDEF) Materials Data Base was developed by the LDEF Materials Special Investigation Group (MSIG). The LDEF Materials Data Base is envisioned to eventually contain the wide variety and vast quantity of materials data generated for LDEF. The data is searchable by optical, thermal, and mechanical properties, exposure parameters (such as atomic oxygen flux), and author(s) or principal investigator(s). The LDEF Materials Data Base was incorporated into the Materials and Processes Technical Information System (MAPTIS). MAPTIS is a collection of materials data which was computerized and is available to engineers, designers, and researchers in the aerospace community involved in the design and development of spacecraft and related hardware. This paper describes the LDEF Materials Data Base and includes step-by-step example searches using the data base. Information on how to become an authorized user of the system is included.

  9. The preliminary Long Duration Exposure Facility (LDEF) materials data base

    SciTech Connect

    Funk, J.G.; Strickland, J.W.; Davis, J.M.

    1992-10-01

    A preliminary Long Duration Exposure Facility (LDEF) Materials Data Base was developed by the LDEF Materials Special Investigation Group (MSIG). The LDEF Materials Data Base is envisioned to eventually contain the wide variety and vast quantity of materials data generated for LDEF. The data is searchable by optical, thermal, and mechanical properties, exposure parameters (such as atomic oxygen flux), and author(s) or principal investigator(s). The LDEF Materials Data Base was incorporated into the Materials and Processes Technical Information System (MAPTIS). MAPTIS is a collection of materials data which was computerized and is available to engineers, designers, and researchers in the aerospace community involved in the design and development of spacecraft and related hardware. This paper describes the LDEF Materials Data Base and includes step-by-step example searches using the data base. Information on how to become an authorized user of the system is included.

  10. Molecular films associated with LDEF

    NASA Technical Reports Server (NTRS)

    Crutcher, E. R.; Warner, K. J.

    1992-01-01

    The molecular films deposited on the surface of the Long Duration Exposure Facility (LDEF) originated from the paints and room-temperature-vulcanized (RTV) silicone materials intentionally used on the satellite and not from residual contaminants. The high silicone content of most of the films and the uniformity of the films indicates a homogenization process in the molecular deposition and suggests a chemically most favored composition for the final film. The deposition on interior surfaces and vents indicated multiple bounce trajectories or repeated deposition-reemission cycles. Exterior surface deposits indicated a significant return flux. Ultraviolet light exposure was required to fix the deposited film as is indicated by the distribution of the films on interior surfaces and the thickness of films at the vent locations. Thermal conditions at the time of exposure to ultraviolet light seems to be an important factor in the thickness of the deposit. Sunrise facing (ram direction) surfaces always had the thicker film. These were the coldest surfaces at the time of their exposure to ultraviolet light. The films have a layered structure suggesting cyclic deposition. As many as 34 distinct layers were seen in the films. The cyclic nature of the deposition and the chemical uniformity of the film one layer to the next suggest an early deposition of the films though there is evidence for the deposition of molecular films throughout the nearly six year exposure of the satellite. A final 'spray' of an organic material associated with water soluble salts occurred very late in the mission. This may have been the result of one of the shuttle dump activities.

  11. Contamination on LDEF: Sources, distribution, and history

    NASA Technical Reports Server (NTRS)

    Pippin, Gary; Crutcher, Russ

    1993-01-01

    An introduction to contamination effects observed on the Long Duration Exposure Facility (LDEF) is presented. The activities reported are part of Boeing's obligation to the LDEF Materials Special Investigation Group. The contamination films and particles had minimal influence on the thermal performance of the LDEF. Some specific areas did have large changes in optical properties. Films also interfered with recession rate determination by reacting with the oxygen or physically shielding underlying material. Generally, contaminant films lessen the measured recession rate relative to 'clean' surfaces. On orbit generation of particles may be an issue for sensitive optics. Deposition on lenses may lead to artifacts on photographic images or cause sensors to respond inappropriately. Particles in the line of sight of sensors can cause stray light to be scattered into sensors. Particles also represent a hazard for mechanisms in that they can physically block and/or increase friction or wear on moving surfaces. LDEF carried a rather complex mixture of samples and support hardware into orbit. The experiments were assembled under a variety of conditions and time constraints and stored for up to five years before launch. The structure itself was so large that it could not be baked after the interior was painted with chemglaze Z-306 polyurethane based black paint. Any analysis of the effects of molecular and particulate contamination must account for a complex array of sources, wide variation in processes over time, and extreme variation in environment from ground to launch to flight. Surface conditions at certain locations on LDEF were established by outgassing of molecular species from particular materials onto adjacent surfaces, followed by alteration of those species due to exposure to atomic oxygen and/or solar radiation.

  12. Summary of materials and hardware performance on LDEF

    NASA Technical Reports Server (NTRS)

    Dursch, Harry; Pippin, Gary; Teichman, Lou

    1993-01-01

    A wide variety of materials and experiment support hardware were flown on the Long Duration Exposure Facility (LDEF). Postflight testing has determined the effects of the almost 6 years of low-earth orbit (LEO) exposure on this hardware. An overview of the results are presented. Hardware discussed includes adhesives, fasteners, lubricants, data storage systems, solar cells, seals, and the LDEF structure. Lessons learned from the testing and analysis of LDEF hardware is also presented.

  13. Effects of the LDEF orbital environment on the reflectance of optical mirror materials

    NASA Technical Reports Server (NTRS)

    Herzig, Howard; Fleetwood, Charles, Jr.

    1995-01-01

    Specimens of eight different optical mirror materials were flown in low earth orbit as part of the Long Duration Exposure Facility (LDEF) manifest to determine their ability to withstand exposure to the residual atomic oxygen and other environmental effects at those altitudes. Optical thin films of aluminum, gold, iridium, osmium, platinum, magnesium fluoride-overcoated aluminum and reactively deposited, silicon monoxide-protected aluminum, all of which were vacuum deposited on polished fused silica substrates, were included as part of Experiment S0010, Exposure of Spacecraft Coatings. Two specimens of polished, chemical vapor deposited (CVD) silicon carbide were installed in sites available in Experiment A0114, Interaction of Atomic Oxygen with Solid Surfaces at Orbital Altitudes, which included trays in two of the spacecraft bays, one on the leading edge and the other on the trailing edge. One of the silicon carbide samples was located in each of these trays. This paper will compare specular reflectance data from the preflight and postflight measurements made on each of these samples and attempt to explain the changes in light of the specific environments to which the experiments were exposed.

  14. Radial wedge flange clamp

    DOEpatents

    Smith, Karl H.

    2002-01-01

    A radial wedge flange clamp comprising a pair of flanges each comprising a plurality of peripheral flat wedge facets having flat wedge surfaces and opposed and mating flat surfaces attached to or otherwise engaged with two elements to be joined and including a series of generally U-shaped wedge clamps each having flat wedge interior surfaces and engaging one pair of said peripheral flat wedge facets. Each of said generally U-shaped wedge clamps has in its opposing extremities apertures for the tangential insertion of bolts to apply uniform radial force to said wedge clamps when assembled about said wedge segments.

  15. 21 CFR 872.3670 - Resin impression tray material.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... custom impression tray for use in cases in which a preformed impression tray is not suitable, such as the... and gums is made. The resin impression tray material is applied to this preliminary study model...

  16. Ionizing radiation calculations and comparisons with LDEF data

    NASA Technical Reports Server (NTRS)

    Armstrong, T. W.; Colborn, B. L.; Watts, J. W., Jr.

    1992-01-01

    In conjunction with the analysis of LDEF ionizing radiation dosimetry data, a calculational program is in progress to aid in data interpretation and to assess the accuracy of current radiation models for future mission applications. To estimate the ionizing radiation environment at the LDEF dosimeter locations, scoping calculations for a simplified (one dimensional) LDEF mass model were made of the primary and secondary radiations produced as a function of shielding thickness due to trapped proton, galactic proton, and atmospheric (neutron and proton cosmic ray albedo) exposures. Preliminary comparisons of predictions with LDEF induced radioactivity and dose measurements were made to test a recently developed model of trapped proton anisotropy.

  17. Long Duration Exposure Facility (LDEF) space optics handbook

    NASA Technical Reports Server (NTRS)

    Kemp, William T.; Taylor, Edward; Champetier, Robert; Watts, Alan; Atkinson, Dale

    1995-01-01

    The overall objective of this effort is to construct a top-level space optics handbook that provides design guidelines based upon data collected from the Long Duration Exposure Facility (LDEF) experiment. The content of the handbook would cover optical coatings, surfaces, fiber optics, and fabricating process for lenses, windows and mirrors that were used on LDEF. The goal of this program (and handbook) is to ensure that the space community can derive the maximum benefit from the LDEF experiment relative to future optics designs for space applications. The summary of this handbook is 'What did we learn from the LDEF experiment?'

  18. Long Duration Exposure Facility (LDEF) space optics handbook

    NASA Technical Reports Server (NTRS)

    Kemp, William T.; Taylor, Edward; Champetier, Robert; Watts, Alan; Atkinson, Dale

    1995-01-01

    The overall objective of this effort is to construct a top-level space optics handbook that provides design guidelines based upon data collected from the Long Duration Exposure Facility (LDEF) experiment. The content of the handbook would cover optical coatings, surfaces, fiber optics, and fabricating process for lenses, windows and mirrors that were used on LDEF. The goal of this program (and handbook) is to ensure that the space community can derive the maximum benefit from the LDEF experiment relative to future optics designs for space applications. The summary of this handbook is 'What did we learn from the LDEF experiment?'

  19. Sand Tray Group Counseling with Adolescents

    ERIC Educational Resources Information Center

    Draper, Kay; Ritter, Kelli B.; Willingham, Elizabeth U.

    2003-01-01

    Sand tray group counseling with adolescents is an activity-based intervention designed to help participants address specific intrapersonal concerns, learn important skills of socialization, and develop a caring community. The main focus of the group is building small worlds with miniature figures in individual trays of sand and having an…

  20. Mastracchio removing dewar tray from MELFI

    NASA Image and Video Library

    2013-11-21

    ISS038-E-006765 (21 Nov. 2013) --- In the International Space Station's Destiny laboratory, NASA astronaut Rick Mastracchio, Expedition 38 flight engineer, prepares to replace a dewar tray in the Minus Eighty Laboratory Freezer for ISS (MELFI) after inserting biological samples into the trays.

  1. Quick action clamp

    NASA Technical Reports Server (NTRS)

    Calco, Frank S. (Inventor)

    1991-01-01

    A quick release toggle clamp that utilizes a spring that requires a deliberate positive action for disengagement is presented. The clamp has a sliding bolt that provides a latching mechanism. The bolt is moved by a handle that tends to remain in an engaged position while under tension.

  2. First LDEF Post-Retrieval Symposium abstracts

    NASA Technical Reports Server (NTRS)

    Levine, Arlene S. (Compiler)

    1991-01-01

    The LDE facility was designed to better understand the environments of space and the effects of prolonged exposure in these environments on future spacecraft. The symposium abstracts presented here are organized according to the symposium agenda into five sessions. The first session provides an overview of the LDEF, the experiments, the mission, and the natural and induced environments the spacecraft and experiments encountered during the mission. The second session presents results to date from studies to better define the environments of near-Earth space. The third session addresses studies of the effects of the space environments on spacecraft materials. The fourth session addresses studies of the effects of the space environments on spacecraft systems. And the fifth session addresses other subjects such as results of the LDEF life science and crystal growth experiments.

  3. LDEF Materials Workshop 1991, part 1

    NASA Technical Reports Server (NTRS)

    Stein, Bland A. (Compiler); Young, Philip R. (Compiler)

    1992-01-01

    The workshop comprised a series of technical sessions on materials themes, followed by theme panel meetings. Themes included materials, environmental parameters, and data bases; contamination; thermal control and protective coatings and surface treatments; polymers and films; polymer matrix composites; metals, ceramics, and optical materials; lubricants adhesives, seals, fasteners, solar cells, and batteries. This report contains most of the papers presented at the technical sessions. It also contains theme panel reports and visual aids. This document continues the LDEF Space Environmental Effects on Materials Special Investigation Group (MSIG) pursuit of its charter to investigate the effects of LEO exposure on materials which where not originally planned to be test specimens and to integrate this information with data generated by principal investigators into an LDEF materials data base.

  4. LDEF materials special investigation group's data bases

    NASA Technical Reports Server (NTRS)

    Strickland, John W.; Funk, Joan G.; Davis, John M.

    1993-01-01

    The Long Duration Exposure Facility (LDEF) was composed of and contained a wide array of materials, representing the largest collection of materials flown for space exposure and returned for ground-based analyses to date. The results and implications of the data from these materials are the foundation on which future space missions will be built. The LDEF Materials Special Investigation Group (MSIG) has been tasked with establishing and developing data bases to document these materials and their performance to assure not only that the data are archived for future generations but also that the data are available to the space user community in an easily accessed, user-friendly form. The format and content of the data bases developed or being developed to accomplish this task are discussed. The hardware and software requirements for each of the three data bases are discussed along with current availability of the data bases.

  5. LDEF Interplanetary Dust Experiment (IDE) results

    NASA Technical Reports Server (NTRS)

    Oliver, John P.; Singer, S. F.; Weinberg, J. L.; Simon, C. G.; Cooke, W. J.; Kassel, P. C.; Kinard, W. H.; Mulholland, J. D.; Wortman, J. J.

    1995-01-01

    The Interplanetary Dust Experiment (IDE) provided high time resolution detection of microparticle impacts on the Long Duration Exposure Facility satellite. Particles, in the diameter range from 0.2 microns to several hundred microns, were detected impacting on six orthogonal surfaces of the gravity-gradient stabilized LDEF spacecraft. The total sensitive surface area was about one square meter, distributed between LDEF rows 3 (Wake or West), 6 (South), 9 (Ram or East), 12 (North), as well as the Space and Earth ends of LDEF. The time of each impact is known to an accuracy that corresponds to better than one degree in orbital longitude. Because LDEF was gravity-gradient stabilized and magnetically damped, the direction of the normal to each detector panel is precisely known for each impact. The 11 1/2 month tape-recorded data set represents the most extensive record gathered of the number, orbital location, and incidence direction for microparticle impacts in low Earth orbit. Perhaps the most striking result from IDE was the discovery that microparticle impacts, especially on the Ram, South, and North surfaces, were highly episodic. Most such impacts occurred in localized regions of the orbit for dozens or even hundreds of orbits in what we have termed Multiple Orbit Event Sequences (MOES). In addition, more than a dozen intense and short-lived 'spikes' were seen in which impact fluxes exceeded the background by several orders of magnitude. These events were distributed in a highly non-uniform fashion in time and terrestrial longitude and latitude.

  6. An LDEF follow-on spacecraft concept

    NASA Technical Reports Server (NTRS)

    Keller, Vernon; Breazeale, Larry; Perkinson, Don; Kinard, William H.

    1995-01-01

    The successful flight, retrieval, and analyses of the Long Duration Exposure Facility (LDEF) experiments demonstrated the value of long duration space exposure for a broad spectrum of science and engineering investigations. The original LDEF was an excellent gravity gradient spacecraft, but because of its 9 m length and 9,700 kg mass it was difficult to manifest on the Shuttle, for either launch or retrieval, in conjunction with other payloads. This paper discusses an LDEF follow-on spacecraft concept whose short stowed length (approximately 3 m) greatly improves Shuttle manifesting opportunities while still providing very large surface area exposure for experiments. Deployable 'wings' on each end of the short, 'cylindrical' main body of this new spacecraft provide the means for gravity gradient stabilization while greatly increasing the spacecraft surface area. The center section of the spacecraft is oriented with the end faces of the twelve sided, 4.2 m diameter 'cylinder' perpendicular to the velocity vector thus providing large areas for experiments in both the ram and anti-ram directions as well as additional exposure area around the periphery of the cylinder. When deployed and properly oriented with the Shuttle's Remote Manipulator System (RMS), both wings of the spacecraft are oriented edge on to the direction of motion and lie in the plane which contains the local gravity vector. The relatively thin wings readily accommodate dual side exposure of glass plate stacks for cosmic ray detection. Flat surfaces mounted normal to and on the periphery of the wings provide additional areas in both the ram and anti-ram directions for cosmic dust, micrometeoroid, and orbital debris collection free of contamination from 'splatter' off secondary surfaces. The baseline concept provides enhancements not available on the original LDEF such as solar array generated electrical power and data telemetry. Status of the efforts to promote support for and ultimately space flight

  7. Gamma radiation survey of the LDEF spacecraft

    NASA Technical Reports Server (NTRS)

    Phillips, G. W.; King, S. E.; August, R. A.; Ritter, J. C.; Cutchin, J. H.; Haskins, P. S.; Mckisson, J. E.; Ely, D. W.; Weisenberger, A. G.; Piercey, R. B.

    1992-01-01

    The retrieval of the Long Duration Exposure Facility spacecraft in January 1990 after nearly six years in orbit offered a unique opportunity to study the long term buildup of induced radioactivity in the variety of materials on board. We conducted the first complete gamma-ray survey of a large spacecraft on LDEF shortly after its return to earth. A surprising observation was the Be-7 activity which was seen primarily on the leading edge of the satellite, implying that it was picked up by LDEF in orbit. This is the first known evidence for accretion of a radioactive isotope onto an orbiting spacecraft. Other isotopes observed during the survey, the strongest being Na-22, are all attributed to activation of spacecraft components. Be-7 is a spallation product of cosmic rays on nitrogen and oxygen in the upper atmosphere. However, the observed density is much greater than expected due to cosmic-ray production in situ. This implies transport of Be-7 from much lower altitudes up to the LDEF orbit.

  8. Performance of selected polymeric materials on LDEF

    NASA Technical Reports Server (NTRS)

    Young, Philip R.; Slemp, Wayne S.; Stein, Bland A.

    1993-01-01

    The NASA Long Duration Exposure Facility (LDEF) provided a unique environmental exposure of a wide variety of materials for potential advanced spacecraft application. This paper examines the molecular level response of selected polymeric materials which flew onboard this vehicle. Polymers include epolyimide, polysulfone, and polystyrene film and polyimide, polysulfone, and epoxy matrix resin/graphite fiber reinforced composites. Several promising experimental films were also studied. Most specimens received 5.8 years of low Earth orbital (LEO) exposure on LDEF. Several samples received on 10 months of exposure. Chemical characterization techniques included ultraviolet-visible and infrared spectroscopy, thermal analysis, x-ray photoelectron spectroscopy, and selected solution property measurements. Results suggest that many molecular level effects present during the first 10 months of exposure were not present after 5.8 years of exposure for specimens on or near Row 9. Increased AO fluence near the end of the mission likely eroded away much environmentally induced surface phenomena. The objective of this work is to provide fundamental information for use in improving the performance of polymeric materials for LEO application. A secondary objective is to gain an appreciation for the constraints and limitations of results from LDEF polymeric materials experiments.

  9. Radioactivities induced in some LDEF samples

    NASA Technical Reports Server (NTRS)

    Reedy, Robert C.; Moss, Calvin E.; Bobias, S. George; Masarik, Jozef

    1993-01-01

    Radioactivities induced in several Long Duration Exposure Facilities (LDEF) samples were measured by low-level counting at Los Alamos and elsewhere. These radionuclides have activities similar to those observed in meteorites and lunar samples. Some trends were observed in these measurements in terms of profiles in trunnion layers and as a function of radionuclide half-life. Several existing computer codes were used to model the production by the protons trapped in the Earth's radiation belts and by the galactic cosmic rays of some of these radionuclides, Mn-54 and Co-57 in steel, Sc-46 in titanium, and Na-22 in alloys of titanium and aluminum. Production rates were also calculated for radionuclides possibly implanted in LDEF, Be-7, Be-10, and C-14. Enhanced concentrations of induced isotopes in the surfaces of trunnion sections relative to their concentrations in the center are caused by the lower-energy protons in the trapped radiation. Secondary neutrons made by high-energy trapped protons and by galactic cosmic rays produce much of the observed radioactivities, especially deep in an object. Comparisons of the observed to calculated activities of several radionuclides with different half-lives indicate that the flux of trapped protons at LDEF decreased significantly at the end of the mission.

  10. Evaluation of seals, lubricants, and adhesives used on LDEF

    NASA Technical Reports Server (NTRS)

    Dursch, Harry; Keough, Bruce; Pippin, Gary

    1993-01-01

    A wide variety of seals, lubricants, and adhesives were used on the Long Duration Exposure Facility (LDEF). The results, to date, of the Systems Special Investigation Group (SIG) and the Materials SIG investigation into the effect of the long term low Earth orbit (LEO) exposure on these materials is discussed. Results of this investigation show that if the material was shielded from exposure to LDEF's external environment, the 69 month exposure to LEO had minimal effect on the material. However, if the material was on LDEF's exterior surface, a variety of events occurred ranging from no material change, to changes in mechanical or physical properties, to complete disappearance of the material. The results are from the following sources: (1) visual examinations and/or testing of materials performed by various LDEF experimenters, (2) testing done at Boeing in support of the Materials or Systems SIG investigations, (3) testing done at Boeing on Boeing hardware flown on LDEF.

  11. Predictions of LDEF radioactivity and comparison with measurements

    NASA Technical Reports Server (NTRS)

    Armstrong, T. W.; Colborn, B. L.; Harmon, B. A.; Laird, C. E.

    1995-01-01

    As part of the program to utilize LDEF data for evaluation and improvement of current ionizing radiation environmental models and related predictive methods for future LEO missions, calculations have been carried out to compare with the induced radioactivity measured in metal samples placed on LDEF. The predicted activation is about a factor of two lower than observed, which is attributed to deficiencies in the AP8 trapped proton model. It is shown that this finding based on activation sample data is consistent with comparisons made with other LDEF activation and dose data. Plans for confirming these results utilizing additional LDEF data sets, and plans for model modifications to improve the agreement with LDEF data, are discussed.

  12. Develop and Manufacture an airlock sliding tray

    SciTech Connect

    Lawton, Cindy M.

    2014-02-26

    Objective: The goal of this project is to continue to develop an airlock sliding tray and then partner with an industrial manufacturing company for production. The sliding tray will be easily installed into and removed from most glovebox airlocks in a few minutes. Technical Approach: A prototype of a sliding tray has been developed and tested in the LANL cold lab and 35 trays are presently being built for the plutonium facility (PF-4). The current, recently approved design works for a 14-inch diameter round airlock and has a tray length of approximately 20 inches. The grant will take the already tested and approved round technology and design for the square airlock. These two designs will be suitable for the majority of the existing airlocks in the multitude of DOE facilities. Partnering with an external manufacturer will allow for production of the airlock trays at a much lower cost and increase the availability of the product for all DOE sites. Project duration is estimated to be 12-13 months. Benefits: The purpose of the airlock sliding trays is fourfold: 1) Mitigate risk of rotator cuff injuries, 2) Improve ALARA, 3) Reduce risk of glovebox glove breaches and glove punctures, and 4) Improve worker comfort. I have had the opportunity to visit many other DOE facilities including Savannah, Y-12, ORNL, Sandia, and Livermore for assistance with ergonomic problems and/or injuries. All of these sites would benefit from the airlock sliding tray and I can assume all other DOE facilities with gloveboxes built prior to 1985 could also use the sliding trays.

  13. A monogenean without clamps

    USDA-ARS?s Scientific Manuscript database

    Ectoparasites face a daily challenge: to remain attached to their host. Polyopisthocotylean monogeneans attach to the surface of fish gills by highly specialized structures, the sclerotized clamps. In the original description of the protomicrocotylid species Lethacotyle fijiensis, described 50 years...

  14. Laser beam guard clamps

    DOEpatents

    Dickson, Richard K.

    2010-09-07

    A quick insert and release laser beam guard panel clamping apparatus having a base plate mountable on an optical table, a first jaw affixed to the base plate, and a spring-loaded second jaw slidably carried by the base plate to exert a clamping force. The first and second jaws each having a face acutely angled relative to the other face to form a V-shaped, open channel mouth, which enables wedge-action jaw separation by and subsequent clamping of a laser beam guard panel inserted through the open channel mouth. Preferably, the clamping apparatus also includes a support structure having an open slot aperture which is positioned over and parallel with the open channel mouth.

  15. Sperm Patch-Clamp

    PubMed Central

    Lishko, Polina; Clapham, David E.; Navarro, Betsy; Kirichok, Yuriy

    2014-01-01

    Sperm intracellular pH and calcium concentration ([Ca2+]i) are two central factors that control sperm activity within the female reproductive tract. As such, the ion channels of the sperm plasma membrane that alter intracellular sperm [Ca2+] and pH play important roles in sperm physiology and the process of fertilization. Indeed, sperm ion channels regulate sperm motility, control sperm chemotaxis toward the egg in some species, and may trigger the acrosome reaction. Until recently, our understanding of these important molecules was rudimentary due to the inability to patch-clamp spermatozoa and directly record the activity of these ion channels under voltage clamp. Recently, we overcame this technical barrier and developed a method for reproducible application of the patch-clamp technique to mouse and human spermatozoa. This chapter covers important aspects of application of the patch-clamp technique to spermatozoa, such as selection of the electrophysiological equipment, isolation of spermatozoa for patch-clamp experiments, formation of the gigaohm seal with spermatozoa, and transition into the whole-cell mode of recording. We also discuss potential pitfalls in application of the patch-clamp technique to flagellar ion channels. PMID:23522465

  16. Results of examination of the A-276 white and Z-306 black thermal control paint discs flown on LDEF

    NASA Technical Reports Server (NTRS)

    Golden, Johnny L.

    1991-01-01

    Measurements of optical properties and surface characterization of paint discs on selected tray clamps were carried out and are reported. Analysis shows the loss of organic binder for those specimens exposed to atomic oxygen. A visibly darkened layer up to 2 microns thick exists on the outer surfaces of specimens exposed only to solar radiation. Properties of ground control specimens and flight control specimens, as a function of spacecraft location are reported. Representative examples from a photomicrograph survey and SEM examination are shown.

  17. View of food tray to be used in Skylab program

    NASA Technical Reports Server (NTRS)

    1972-01-01

    A close-up view of a food tray which is scheduled to be used in the Skylab program. Several packages of space food lie beside the tray. The food in the tray is ready to eat. Out of tray, starting from bottom left: grape drink, beef pot roast, chicken and rice, beef sandwiches and sugar cookie cubes, In tray, from back left: orange drink, strawberries, asparagus, prime rib, dinner roll and butterscotch pudding in the center.

  18. View of food tray to be used in Skylab program

    NASA Technical Reports Server (NTRS)

    1972-01-01

    A close-up view of a food tray which is scheduled to be used in the Skylab program. Several packages of space food lie beside the tray. The food in the tray is ready to eat. Out of tray, starting from bottom left: grape drink, beef pot roast, chicken and rice, beef sandwiches and sugar cookie cubes, In tray, from back left: orange drink, strawberries, asparagus, prime rib, dinner roll and butterscotch pudding in the center.

  19. Overhead tray for cable test system

    NASA Technical Reports Server (NTRS)

    Saltz, K. T.

    1976-01-01

    System consists of overhead slotted tray, series of compatible adapter cables, and automatic test set which consists of control console and cable-switching console. System reduces hookup time and also reduces cost of fabricating and storing test cables.

  20. Skylab Food Heating and Serving Tray

    NASA Technical Reports Server (NTRS)

    1970-01-01

    Shown here is the Skylab food heating and serving tray in its stowed position. The Marshall Space Flight Center had program management responsibility for the development of Skylab hardware and experiments.

  1. A New Idea for Dissecting Tray

    ERIC Educational Resources Information Center

    Branham, Arthur

    1976-01-01

    A method of preparing a special dissecting tray to be used with transmitted light as well as reflected light is presented. It may also be used with an overhead projector to illustrate some skeletal structures in vertebrates. (Author/EB)

  2. Scooped Material on Rover Observation Tray

    NASA Image and Video Library

    2012-10-25

    Sample material from the fourth scoop of Martian soil collected by NASA Mars rover Curiosity is on the rover observation tray in this image taken during the mission 78th Martian sol, Oct. 24, 2012 by Curiosity left Navigation Camera.

  3. A New Idea for Dissecting Tray

    ERIC Educational Resources Information Center

    Branham, Arthur

    1976-01-01

    A method of preparing a special dissecting tray to be used with transmitted light as well as reflected light is presented. It may also be used with an overhead projector to illustrate some skeletal structures in vertebrates. (Author/EB)

  4. LDEF active optical system components experiment

    NASA Technical Reports Server (NTRS)

    Blue, M. D.

    1992-01-01

    A preliminary report on the Active Optical System Components Experiment is presented. This experiment contained 136 components in a six inch deep tray including lasers, infrared detectors and arrays, ultraviolet light detectors, light-emitting diodes, a light modulator, flash lamps, optical filters, glasses, and samples of surface finishes. Thermal, mechanical, and structural considerations leading to the design of the tray hardware are discussed. In general, changes in the retested component characteristics appear as much related to the passage of time as to the effects of the space environment, but organic materials, multilayer optical interference filters, and extreme-infrared reflectivity of black paints show unexpected changes.

  5. LDEF materials results for spacecraft applications: Executive summary

    NASA Technical Reports Server (NTRS)

    Whitaker, A. F. (Compiler); Dooling, D. (Compiler)

    1995-01-01

    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.

  6. The Long Duration Exposure Facility (LDEF) annotated bibliography

    NASA Technical Reports Server (NTRS)

    Levine, Arlene S.

    1995-01-01

    A major objective of the Space Act of 1958 which led to the establishment of the National Aeronautics and Space Administration (NASA) was the dissemination of science and technology. Today, under NASA administrator Daniel Goldin and the White House, there is a reemphasis on the dissemination and transfer of NASA science and technology to U.S. industry: both aerospace and non aerospace. The goal of this transfer of science and technology is to aid U.S. industries, making them more competitive in the global economy. After 69 months in space, LDEF provided new and important information on the space environment and how this hostile environment impacts spacecraft materials and systems. The space environment investigated by the LDEF researchers included: ionizing radiation, ultraviolet radiation, meteoroid and debris, atomic oxygen, thermal cycling, vacuum, microgravity, induced contamination and various synergistic effects. The materials used as part of LDEF and its experiments include polymers, metals, glass, paints and coatings. Fiber optic, mechanical, electrical, and optical systems were also used on LDEF. As part of the effort to disseminate and transfer LDEF science and technology, an annotated bibliographic database is being developed. This bibliography will be available electronically, as well as in hard copy. All LDEF domestic and foreign publications in the open literature, including scientific journals, the NASA LDEF Symposia volumes, books, technical reports and unrestricted contractor reports will be included in this database. The hard copy, as well as the electronic database, will be categorized by section in the scientific and technical discipline.

  7. Future directions for LDEF ionizing radiation modeling and assessments

    NASA Technical Reports Server (NTRS)

    Armstrong, T. W.; Colborn, B. L.

    1992-01-01

    Data from the ionizing radiation dosimetry aboard LDEF provide a unique opportunity for assessing the accuracy of current space radiation models and in identifying needed improvements for future mission applications. Details are given of the LDEF data available for radiation model evaluations. The status is given of model comparisons with LDEF data, along with future directions of planned modeling efforts and data comparison assessments. The methodology is outlined which is related to modeling being used to help insure that the LDEF ionizing radiation results can be used to address ionizing radiation issues for future missions. In general, the LDEF radiation modeling has emphasized quick-look predictions using simplified methods to make comparisons with absorbed dose measurements and induced radioactivity measurements of emissions. Modeling and LDEF data comparisons related to linear energy transfer spectra are of importance for several reasons which are outlined. The planned modeling and LDEF data comparisons for LET spectra is discussed, including components of the LET spectra due to different environment sources, contribution from different production mechanisms, and spectra in plastic detectors vs silicon.

  8. Surface contamination on LDEF exposed materials

    NASA Technical Reports Server (NTRS)

    Hemminger, Carol S.

    1992-01-01

    X-ray photoelectron spectroscopy (XPS) has been used to study the surface composition and chemistry of Long Duration Exposure Facility (LDEF) exposed materials including silvered Teflon (Ag/FEP), Kapton, S13GLO paint, quartz crystal monitors (QCM's), carbon fiber/organic matrix composites, and carbon fiber/Al Alloy composites. In each set of samples, silicones were the major contributors to the molecular film accumulated on the LDEF exposed surfaces. All surfaces analyzed have been contaminated with Si, O, and C; most have low levels (less than 1 atom percent) of N, S, and F. Occasionally observed contaminants included Cl, Na, K, P, and various metals. Orange/brown discoloration observed near vent slots in some Ag/FEP blankets were higher in carbon, sulfur, and nitrogen relative to other contamination types. The source of contamination has not been identified, but amine/amide functionalities were detected. It is probable that this same source of contamination account for the low levels of sulfur and nitrogen observed on most LDEF exposed surfaces. XPS, which probes 50 to 100 A in depth, detected the major sample components underneath the contaminant film in every analysis. This probably indicates that the contaminant overlayer is patchy, with significant areas covered by less that 100 A of molecular film. Energy dispersive x-ray spectroscopy (EDS) of LDEF exposed surfaces during secondary electron microscopy (SEM) of the samples confirmed contamination of the surfaces with Si and O. In general, particulates were not observed to develop from the contaminant overlayer on the exposed LDEF material surfaces. However, many SiO2 submicron particles were seen on a masked edge of an Ag/FEP blanket. In some cases such as the carbon fiber/organic matrix composites, interpretation of the contamination data was hindered by the lack of good laboratory controls. Examination of laboratory controls for the carbon fiber/Al alloy composites showed that preflight contamination was

  9. The composition of meteoroids impacting LDEF

    NASA Technical Reports Server (NTRS)

    Brownlee, D. E.; Horz, Friedrich; Laurance, M.; Bernhard, R. P.; Warren, J.; Bradley, J. P.

    1991-01-01

    So far we have completed an initial scanning electron microscopy (SEM) survey of craters on the exterior of the Long Duration Exposure Facility (LDEF) in the 100 micron to 1mm size range and done some quantitative analysis. In typical craters, the residue appears to be a mixture of glass and FeNi and sulfide beads with an overall chondritic elemental composition. In less than 10 percent of the craters, there is a substantial amount of meteoroid debris that also contains unmelted mineral grains. The relatively high abundance of forsterite and enststite among these irregular grains suggests that a high melting point probably plays a role in surviving impact without melting.

  10. FNAS/LDEF Radiation Data Analysis

    NASA Technical Reports Server (NTRS)

    Gregory, John

    1998-01-01

    The radioactive isotope Be-7 was discovered on the forward-facing side of the LDEF satellite in amounts far exceeding that expected from direct cosmic ray activation of the spacecraft material. This prompted an examination of the production of cosmogenic isotopes in the atmosphere and of the processes by which they may be transported to orbital altitudes and absorbed by a spacecraft. Be-7 is only one of several atmospheric cosmogenic isotopes which might be detectable at orbital altitudes and which might prove to be as useful as tracers of atmospheric circulation processes in the mesosphere and thermosphere, as they have been in the lower layers of the atmosphere.

  11. Clamping characteristics study on different types of clamping unit

    SciTech Connect

    Jiao, Zhiwei; Liu, Haichao; Xie, Pengcheng; Yang, Weimin

    2015-05-22

    Plastic products are becoming more and more widely used in aerospace, IT, digital electronics and many other fields. With the development of technology, the requirement of product precision is getting higher and higher. However, type and working performance of clamping unit play a decisive role in product precision. Clamping characteristics of different types of clamping unit are discussed in this article, which use finite element numerical analysis method through the software ABAQUS to study the clamping uniformity, and detect the clamping force repeatability precision. The result shows that compared with toggled three-platen clamping unit, clamping characteristics of internal circulation two-platen clamping unit are better, for instance, its mold cavity deformation and force that bars and mold parting surface suffered are more uniform, and its clamping uniformity and repeatability precision is also better.

  12. Comparing surgical trays with redundant instruments with trays with reduced instruments: a cost analysis

    PubMed Central

    John-Baptiste, A.; Sowerby, L.J.; Chin, C.J.; Martin, J.; Rotenberg, B.W.

    2016-01-01

    Background: When prearranged standard surgical trays contain instruments that are repeatedly unused, the redundancy can result in unnecessary health care costs. Our objective was to estimate potential savings by performing an economic evaluation comparing the cost of surgical trays with redundant instruments with surgical trays with reduced instruments ("reduced trays"). Methods: We performed a cost-analysis from the hospital perspective over a 1-year period. Using a mathematical model, we compared the direct costs of trays containing redundant instruments to reduced trays for 5 otolaryngology procedures. We incorporated data from several sources including local hospital data on surgical volume, the number of instruments on redundant and reduced trays, wages of personnel and time required to pack instruments. From the literature, we incorporated instrument depreciation costs and the time required to decontaminate an instrument. We performed 1-way sensitivity analyses on all variables, including surgical volume. Costs were estimated in 2013 Canadian dollars. Results: The cost of redundant trays was $21 806 and the cost of reduced trays was $8803, for a 1-year cost saving of $13 003. In sensitivity analyses, cost savings ranged from $3262 to $21 395, based on the surgical volume at the institution. Variation in surgical volume resulted in a wider range of estimates, with a minimum of $3253 for low-volume to a maximum of $52 012 for high-volume institutions. Interpretation: Our study suggests moderate savings may be achieved by reducing surgical tray redundancy and, if applied to other surgical specialties, may result in savings to Canadian health care systems. PMID:27975045

  13. Clamp for detonating fuze

    NASA Technical Reports Server (NTRS)

    Holderman, E. J.

    1968-01-01

    Quick acting clamp provides physical support for a closely confined detonating fuse in an application requiring removal and replacement at frequent intervals during test. It can be designed with a base of any required strength and configuration to permit the insertion of an object.

  14. Prediction of LDEF ionizing radiation environment

    NASA Technical Reports Server (NTRS)

    Watts, John W.; Parnell, T. A.; Derrickson, James H.; Armstrong, T. W.; Benton, E. V.

    1992-01-01

    The Long Duration Exposure Facility (LDEF) spacecraft flew in a 28.5 deg inclination circular orbit with an altitude in the range from 172 to 258.5 nautical miles. For this orbital altitude and inclination two components contribute most of the penetrating charge particle radiation encountered - the galactic cosmic rays and the geomagnetically trapped Van Allen protons. Where shielding is less than 1.0 g/sq cm geomagnetically trapped electrons make a significant contribution. The 'Vette' models together with the associated magnetic filed models were used to obtain the trapped electron and proton fluences. The mission proton doses were obtained from the fluence using the Burrell proton dose program. For the electron and bremsstrahlung dose we used the Marshall Space Flight Center (MSFC) electron dose program. The predicted doses were in general agreement with those measured with on-board thermoluminescent detector (TLD) dosimeters. The NRL package of programs, Cosmic Ray Effects on MicroElectronics (CREME), was used to calculate the linear energy transfer (LET) spectrum due to galactic cosmic rays (GCR) and trapped protons for comparison with LDEF measurements.

  15. The LEO Particulate Environment as Determined by LDEF

    NASA Technical Reports Server (NTRS)

    See, Thomas H.; Zolensky, Michael E.; Hoerz, Friedrick; Bernhard, P.; Leago, Kimberly S.; Warren, Jack L.; Sapp, Clyde A.; Foster, Tammy R.; Kinard, William H.

    1993-01-01

    The Meteoroid & Debris Special Investigation Group has been studying the low-Earth orbit particulate environment by examining and documenting impact craters that occurred on the Long Duration Exposure Facility (LDEF) during its 5.7 year stay in orbit.

  16. Geometrical analysis of the microcraters found on LDEF samples

    NASA Technical Reports Server (NTRS)

    Yamakoshi, Kazuo; Ohashi, Hideo; Noma, Motosaku; Sakurai, Hirohisa; Nakashima, Kazuo; Nogami, Kenichi; Omori, Rie

    1993-01-01

    Diameters (D) and depths (T) of microcraters found on LDEF samples were measured and their origins were deduced by the (D/T) ratios, which distinguish projectile materials. From the results, one iron and several stony projectiles could be recognized.

  17. Long Duration Exposure Facility (LDEF) structural verification test report

    NASA Technical Reports Server (NTRS)

    Jones, T. C.; Lucy, M. H.; Shearer, R. L.

    1983-01-01

    Structural load tests on the Long Duration Exposure Facility's (LDEF) primary structure were conducted. These tests had three purposes: (1) demonstrate structural adequacy of the assembled LDEF primary structure when subjected to anticipated flight loads; (2) verify analytical models and methods used in loads and stress analysis; and (3) perform tests to comply with the Space Transportation System (STS) requirements. Test loads were based on predicted limit loads which consider all flight events. Good agreement is shown between predicted and observed load, strain, and deflection data. Test data show that the LDEF structure was subjected to 1.2 times limit load to meet the STS requirements. The structural adequacy of the LDEF is demonstrated.

  18. Ionizing radiation exposure of LDEF (pre-recovery estimates)

    NASA Technical Reports Server (NTRS)

    Benton, E. V.; Heinrich, W.; Parnell, T. A.; Armstrong, T. W.; Derrickson, J. H.; Fishman, G. J.; Frank, A. L.; Watts, J. W. Jr; Wiegel, B.

    1992-01-01

    The long duration exposure facility (LDEF), launched into a 258 nautical mile orbit with an inclination of 28.5 degrees, remained in space for nearly 6 yr. The 21,500 lb NASA satellite was one of the largest payloads ever deployed by the Space Shuttle. LDEF completed 32,422 orbits and carried 57 major experiments representing more than 200 investigators from 33 private companies, 21 universities and nine countries. The experiments covered a wide range of disciplines including basic science, electronics, optics, materials, structures and power and propulsion. A number of the experiments were specifically designed to measure the radiation environment. These experiments are of specific interest, since the LDEF orbit is essentially the same as that of the Space Station Freedom. Consequently, the radiation measurements on LDEF will play a significant role in the design of radiation shielding of the space station. The contributions of the various authors presented here attempt to predict the major aspects of the radiation exposure received by the various LDEF experiments and therefore should be helpful to investigators who are in the process of analyzing experiments which may have been affected by exposure to ionizing radiation. The paper discusses the various types and sources of ionizing radiation including cosmic rays, trapped particles (both protons and electrons) and secondary particles (including neutrons, spallation products and high-LET recoils), as well as doses and LET spectra as a function of shielding. Projections of the induced radioactivity of LDEF are also discussed.

  19. Ionizing radiation exposure of LDEF (pre-recovery estimates).

    PubMed

    Benton, E V; Heinrich, W; Parnell, T A; Armstrong, T W; Derrickson, J H; Fishman, G J; Frank, A L; Watts, J W; Wiegel, B

    1992-01-01

    The long duration exposure facility (LDEF), launched into a 258 nautical mile orbit with an inclination of 28.5 degrees, remained in space for nearly 6 yr. The 21,500 lb NASA satellite was one of the largest payloads ever deployed by the Space Shuttle. LDEF completed 32,422 orbits and carried 57 major experiments representing more than 200 investigators from 33 private companies, 21 universities and nine countries. The experiments covered a wide range of disciplines including basic science, electronics, optics, materials, structures and power and propulsion. A number of the experiments were specifically designed to measure the radiation environment. These experiments are of specific interest, since the LDEF orbit is essentially the same as that of the Space Station Freedom. Consequently, the radiation measurements on LDEF will play a significant role in the design of radiation shielding of the space station. The contributions of the various authors presented here attempt to predict the major aspects of the radiation exposure received by the various LDEF experiments and therefore should be helpful to investigators who are in the process of analyzing experiments which may have been affected by exposure to ionizing radiation. The paper discusses the various types and sources of ionizing radiation including cosmic rays, trapped particles (both protons and electrons) and secondary particles (including neutrons, spallation products and high-LET recoils), as well as doses and LET spectra as a function of shielding. Projections of the induced radioactivity of LDEF are also discussed.

  20. 106. INTERIOR OF CABLE TRAY TUNNEL, FROM LANDLINE INSTRUMENTATION ROOM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    106. INTERIOR OF CABLE TRAY TUNNEL, FROM LANDLINE INSTRUMENTATION ROOM (106), LSB (BLDG. 770), TOWARDS CABLE TRAY SHED - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  1. Skylab Food Heating and Serving Tray

    NASA Technical Reports Server (NTRS)

    1970-01-01

    Shown here is the Skylab food heating and serving tray with food, drink, and utensils. The tray contained heating elements for preparing the individual food packets. The food on Skylab was a great improvement over that on earlier spaceflights. It was no longer necessary to squeeze liquified food from plastic tubes. Skylab's kitchen in the Orbital Workshop wardroom was so equipped that each crewman could select his own menu and prepare it to his own taste. The Marshall Space Flight Center had program management responsibility for the development of Skylab hardware and experiments.

  2. Skylab Food Heating and Serving Tray

    NASA Technical Reports Server (NTRS)

    1970-01-01

    Shown here is the Skylab food heating and serving tray with food, drink, and utensils. The tray contained heating elements for preparing the individual food packets. The food on Skylab was a great improvement over that on earlier spaceflights. It was no longer necessary to squeeze liquified food from plastic tubes. Skylab's kitchen in the Orbital Workshop wardroom was so equipped that each crewman could select his own menu and prepare it to his own taste. The Marshall Space Flight Center had program management responsibility for the development of Skylab hardware and experiments.

  3. Analysis of systems hardware flown on LDEF. Results of the systems special investigation group

    NASA Technical Reports Server (NTRS)

    Dursch, Harry W.; Spear, W. Steve; Miller, Emmett A.; Bohnhoff-Hlavacek, Gail L.; Edelman, Joel

    1992-01-01

    The Long Duration Exposure Facility (LDEF) was retrieved after spending 69 months in low Earth orbit (LEO). LDEF carried a remarkable variety of mechanical, electrical, thermal, and optical systems, subsystems, and components. The Systems Special Investigation Group (Systems SIG) was formed to investigate the effects of the long duration exposure to LEO on systems related hardware and to coordinate and collate all systems analysis of LDEF hardware. Discussed here is the status of the LDEF Systems SIG investigation through the end of 1991.

  4. Analysis of systems hardware flown on LDEF. Results of the systems special investigation group

    SciTech Connect

    Dursch, H.W.; Spear, W.S.; Miller, E.A.; Bohnhoff-Hlavacek, G.L.; Edelman, J.

    1992-04-01

    The Long Duration Exposure Facility (LDEF) was retrieved after spending 69 months in low Earth orbit (LEO). LDEF carried a remarkable variety of mechanical, electrical, thermal, and optical systems, subsystems, and components. The Systems Special Investigation Group (Systems SIG) was formed to investigate the effects of the long duration exposure to LEO on systems related hardware and to coordinate and collate all systems analysis of LDEF hardware. Discussed here is the status of the LDEF Systems SIG investigation through the end of 1991.

  5. LDEF impact craters formed by carbon-rich impactors: A preliminary report

    NASA Technical Reports Server (NTRS)

    Bunch, T. E.; Dibrozolo, F. Radicati; Fleming, Ronald H.; Harris, David W.; Brownlee, Don; Reilly, Terrence W.

    1992-01-01

    Two impact craters found in Al from the Long Duration Exposure Facility (LDEF) experiment tray have residues concentrated in the bottoms, along the walls, and on top of overturned rims. Analyses indicate a 'chondritic' compositional signature (Si, S, Ca, Fe, Mg, and Ni) for the bulk residue. In one crater (number 74), round to irregular silicate grains are overlain by carbon. In addition, carbon also partially covers the crater walls, the top of the raised overturned rim, and extends outward from the crater. The second crater (number 31) also contains carbon with similar distribution in and about the crater, although the silicate residue appears to be glassy. Silver, I, K, and F (possibly some of the Ca, S, and Cl) appear to be contaminants as well as analyzed aromatic carbonaceous species associated with the raised rim and the area surrounding the crater. The origin of the impactors is assumed to be extraterrestrial. The existence of impactor residue in two craters implies impact velocities less than or equal to 6 km, based on experimental hypervelocity studies.

  6. Control-Chain Safety Tray and Friction Pull

    NASA Technical Reports Server (NTRS)

    Hajdik, G.; Peek, C. R.

    1984-01-01

    Tray mounted above suspended ceiling keeps sprinkler-system control chain safely out of way of pedestrian traffic below. Tray reached easily by using fireman's hook short stepladder, or chair or by jumping up to grasp chain. Safety tray used for infrequently used control chains on vents and dampers.

  7. 21 CFR 884.1550 - Amniotic fluid sampler (amniocentesis tray).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Amniotic fluid sampler (amniocentesis tray). 884... Diagnostic Devices § 884.1550 Amniotic fluid sampler (amniocentesis tray). (a) Identification. The amniotic fluid sampler (amniocentesis tray) is a collection of devices used to aspirate amniotic fluid from...

  8. 21 CFR 884.1550 - Amniotic fluid sampler (amniocentesis tray).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Amniotic fluid sampler (amniocentesis tray). 884... Diagnostic Devices § 884.1550 Amniotic fluid sampler (amniocentesis tray). (a) Identification. The amniotic fluid sampler (amniocentesis tray) is a collection of devices used to aspirate amniotic fluid from...

  9. 21 CFR 884.1550 - Amniotic fluid sampler (amniocentesis tray).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Amniotic fluid sampler (amniocentesis tray). 884... Diagnostic Devices § 884.1550 Amniotic fluid sampler (amniocentesis tray). (a) Identification. The amniotic fluid sampler (amniocentesis tray) is a collection of devices used to aspirate amniotic fluid from...

  10. Control-Chain Safety Tray and Friction Pull

    NASA Technical Reports Server (NTRS)

    Hajdik, G.; Peek, C. R.

    1984-01-01

    Tray mounted above suspended ceiling keeps sprinkler-system control chain safely out of way of pedestrian traffic below. Tray reached easily by using fireman's hook short stepladder, or chair or by jumping up to grasp chain. Safety tray used for infrequently used control chains on vents and dampers.

  11. 21 CFR 872.3670 - Resin impression tray material.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3670 Resin impression tray material. (a) Identification. Resin impression tray material is a device intended for use in a two-step dental mold fabricating... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Resin impression tray material. 872.3670 Section...

  12. 21 CFR 884.1550 - Amniotic fluid sampler (amniocentesis tray).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Amniotic fluid sampler (amniocentesis tray). 884... Diagnostic Devices § 884.1550 Amniotic fluid sampler (amniocentesis tray). (a) Identification. The amniotic fluid sampler (amniocentesis tray) is a collection of devices used to aspirate amniotic fluid from...

  13. 21 CFR 872.6870 - Disposable fluoride tray.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Disposable fluoride tray. 872.6870 Section 872...) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6870 Disposable fluoride tray. (a) Identification. A disposable fluoride tray is a device made of styrofoam intended to apply fluoride topically to...

  14. 21 CFR 872.6870 - Disposable fluoride tray.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Disposable fluoride tray. 872.6870 Section 872...) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6870 Disposable fluoride tray. (a) Identification. A disposable fluoride tray is a device made of styrofoam intended to apply fluoride topically to...

  15. 21 CFR 872.6880 - Preformed impression tray.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Preformed impression tray. 872.6880 Section 872...) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6880 Preformed impression tray. (a) Identification. A preformed impression tray is a metal or plastic device intended to hold impression material...

  16. 21 CFR 872.6870 - Disposable fluoride tray.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Disposable fluoride tray. 872.6870 Section 872...) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6870 Disposable fluoride tray. (a) Identification. A disposable fluoride tray is a device made of styrofoam intended to apply fluoride topically to...

  17. 21 CFR 868.6100 - Anesthetic cabinet, table, or tray.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Anesthetic cabinet, table, or tray. 868.6100... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Miscellaneous § 868.6100 Anesthetic cabinet, table, or tray. (a) Identification. An anesthetic cabinet, table, or tray is a device intended to store...

  18. 21 CFR 868.6100 - Anesthetic cabinet, table, or tray.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Anesthetic cabinet, table, or tray. 868.6100... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Miscellaneous § 868.6100 Anesthetic cabinet, table, or tray. (a) Identification. An anesthetic cabinet, table, or tray is a device intended to store...

  19. 21 CFR 868.6100 - Anesthetic cabinet, table, or tray.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Anesthetic cabinet, table, or tray. 868.6100... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Miscellaneous § 868.6100 Anesthetic cabinet, table, or tray. (a) Identification. An anesthetic cabinet, table, or tray is a device intended to store...

  20. 21 CFR 868.6100 - Anesthetic cabinet, table, or tray.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Anesthetic cabinet, table, or tray. 868.6100... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Miscellaneous § 868.6100 Anesthetic cabinet, table, or tray. (a) Identification. An anesthetic cabinet, table, or tray is a device intended to store...

  1. 21 CFR 868.6100 - Anesthetic cabinet, table, or tray.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Anesthetic cabinet, table, or tray. 868.6100... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Miscellaneous § 868.6100 Anesthetic cabinet, table, or tray. (a) Identification. An anesthetic cabinet, table, or tray is a device intended to store...

  2. 21 CFR 872.6870 - Disposable flouride tray.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Disposable flouride tray. 872.6870 Section 872.6870 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... the teeth. To use the tray, the patient bites down on the tray which has been filled with a...

  3. 21 CFR 872.6870 - Disposable flouride tray.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Disposable flouride tray. 872.6870 Section 872.6870 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... the teeth. To use the tray, the patient bites down on the tray which has been filled with a...

  4. LDEF electronic systems: Successes, failures, and lessons

    NASA Technical Reports Server (NTRS)

    Miller, Emmett; Porter, Dave; Smith, Dave; Brooks, Larry; Levorsen, Joe; Mulkey, Owen

    1991-01-01

    Following the Long Duration Exposure Facility (LDEF) retrieval, the Systems Special Investigation Group (SIG) participated in an extensive series of tests of various electronic systems, including the NASA provided data and initiate systems, and some experiment systems. Overall, these were found to have performed remarkably well, even though most were designed and tested under limited budgets and used at least some nonspace qualified components. However, several anomalies were observed, including a few which resulted in some loss of data. The postflight test program objectives, observations, and lessons learned from these examinations are discussed. All analyses are not yet complete, but observations to date will be summarized, including the Boeing experiment component studies and failure analysis results related to the Interstellar Gas Experiment. Based upon these observations, suggestions for avoiding similar problems on future programs are presented.

  5. The Skills Minister's In-Tray

    ERIC Educational Resources Information Center

    Hancock's, Matthew

    2012-01-01

    In the "Adults Learning" autumn issue, the journal staff asked key players in the learning and skills sector what they thought should be at the top of new skills minister Matthew Hancock's in-tray. The new minister shares that his job in the further education and skills sector is to rise to the challenge and play his full part in giving…

  6. The Skills Minister's In-Tray

    ERIC Educational Resources Information Center

    Hancock's, Matthew

    2012-01-01

    In the "Adults Learning" autumn issue, the journal staff asked key players in the learning and skills sector what they thought should be at the top of new skills minister Matthew Hancock's in-tray. The new minister shares that his job in the further education and skills sector is to rise to the challenge and play his full part in giving…

  7. MISSE 1 and 2 Tray Temperature Measurements

    NASA Technical Reports Server (NTRS)

    Harvey, Gale A.; Kinard, William H.

    2006-01-01

    The Materials International Space Station Experiment (MISSE 1 & 2) was deployed August 10,2001 and retrieved July 30,2005. This experiment is a co-operative endeavor by NASA-LaRC. NASA-GRC, NASA-MSFC, NASA-JSC, the Materials Laboratory at the Air Force Research Laboratory, and the Boeing Phantom Works. The objective of the experiment is to evaluate performance, stability, and long term survivability of materials and components planned for use by NASA and DOD on future LEO, synchronous orbit, and interplanetary space missions. Temperature is an important parameter in the evaluation of space environmental effects on materials. The MISSE 1 & 2 had autonomous temperature data loggers to measure the temperature of each of the four experiment trays. The MISSE tray-temperature data loggers have one external thermistor data channel, and a 12 bit digital converter. The MISSE experiment trays were exposed to the ISS space environment for nearly four times the nominal design lifetime for this experiment. Nevertheless, all of the data loggers provided useful temperature measurements of MISSE. The temperature measurement system has been discussed in a previous paper. This paper presents temperature measurements of MISSE payload experiment carriers (PECs) 1 and 2 experiment trays.

  8. The bond strength of different tray adhesives on vinyl polysiloxane to two tray materials: an in vitro study.

    PubMed

    Ashwini, B L; Manjunath, S; Mathew, K Xavier

    2014-03-01

    There has been no established chemical bonding between custom tray resin and the elastomeric impression materials without the use of manufacturer's recommended specific tray adhesive. The present study was aimed to compare the bond strength of the manufacturer recommended tray adhesives with the universal tray adhesives using the medium body consistency vinyl polysiloxane (VPS) material and custom tray made of autopolymerising resin and visible light cure (VLC) resin. A total 90 cubicle specimens of autopolymerising resin and 90 specimens of VLC resin were tested for its tensile bond strength. Effectiveness of universal tray adhesive was compared with manufactured tray adhesive. Each of these specimens was then subjected to tensile load in hounsefield universal testing machine at a cross head speed of 5 mm/min and the results were compared and evaluated using one way analysis of variance and post hoc Tuckey's test. Analysis of bond strength revealed that the universal tray adhesive showed better strength and was statiscally significant when compared to the manufacture supplied tray adhesive. Comparison between both the groups, VLC resin showed better bond strength as compared to autopolymerizing resin. Universal tray adhesive had better tensile bond strength than the manufacturers recommended tray adhesive with the medium body viscosity VPS impression material for both autopolymerising and VLC tray resin.

  9. Results of the LDEF meteoroid and debris special investigation group

    NASA Astrophysics Data System (ADS)

    Zolensky, Michael E.; Kinard, William H.

    1993-08-01

    The Long Duration Exposure Facility was recovered in January, 1990, following 5.7 years of continuous exposure in low-Earth orbit. The gravity-stabilized nature of LDEF permits the resolution of the flux and trajectories of impacting meteoroids and spacecraft debris particulates. We have completed the collection of high-resolution, stereoscopic video imaging of all large impact features on the entire LDEF, and present here the preliminary results of our efforts to reduce these digitized images, and extract critical data. Contrary to our prior assumption, we find that impact craters in the T6 Al alloy are not paraboloid in cross section, but rather are better described by a 6th-order polynomial curve. We explore the implications of this discovery. We present results of detailed crater surveys of LDEF frame intercostal members, finding a unusual local variation in the impact frequency. In a discussion of impactor fluxes derived from LDEF results we explore apparent directionalities for impacting particulates which are not accounted for in current models. We briefly describe the special database designed and used by the M&D SIG. Finally, we present a list of recommendations for further LDEF analyses which will be necessary to ensure the safe design of spacecraft.

  10. Immediate or early cord clamping vs delayed clamping.

    PubMed

    Hutchon, D J R

    2012-11-01

    Over the past 40 years, there have been a number of review articles attempting to rationalise cord clamping practice. Early cord clamping was originally thought to be important in active management of the third stage of labour, but this was never evidence based. Without an evidence base to justify it, early cord clamping in clinical practice has remained very variable. There is good evidence that early cord clamping leads to hypovolaemia, anaemia and low iron stores in the neonate. We review all the evidence and discuss possible reasons why some obstetricians and midwives persevere with early clamping. We explain how a variable definition, defective education, deferred responsibility between obstetrician and paediatrician, variable guidelines and a lack of appreciation for the potential harm of the intervention, have all contributed. This study describes how the need for early cord clamping can be avoided in practically all clinical complications of birth.

  11. Natural and orbital debris particles on LDEF`s trailing and forward-facing surfaces

    SciTech Connect

    Hoerz, F.; See, T.H.; Bernhard, R.P.; Brownlee, D.E. |

    1995-02-01

    Approximately 1000 impact craters on the Chemistry of Meteoroid Experiment (CME) have been analyzed by means of Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Analysis (EDXA) to determine the compositional make-up of projectile residues. This report completes the authors systematic survey of gold and aluminum surfaces exposed at the trailing-edge (A03) and forward-facing (A11) LDEF sites, respectively. The major categories for the projectile residues were (1) natural, with diverse subgroups such as chondritic, monomineralic silicates, and sulfides, and (2) man made, that were classified into aluminum (metallic or oxide) and miscellaneous materials (such as stainless steel, paint flakes, etc). On CME gold collectors on LDEF`s trailing edge approximately 11 percent of all craters greater than 100 micron in diameter were due to man-made debris, the majority (8.6 percent) caused by pure aluminum, approximately 31.4 percent were due to cosmic dust, while the remaining 58 percent were indeterminate via the analytical techniques utilized in this study. The aluminum surfaces located at the A11 forward-facing site did not permit analysis of aluminum impactors, but approximately 9.4 percent of all craters were demonstratably caused by miscellaneous debris materials and approximately 39.2 percent were the result of natural particles, leaving approximately 50 percent which were indeterminate. Model considerations and calculations are presented that focus on the crater-production rates for features greater than 100 micron in diameter, and on assigning the intermediate crater population to man-made or natural particles. An enhancement factor of 6 in the crater-production rate of natural impactors for the `forward-facing` versus the `trailing-edge` CME collectors was found to best explain all observations (i.e., total crater number(s), as well as their computational characteristics). Enhancement factors of 10 and 4 are either too high or too low.

  12. Clinical accuracy outcomes of closed-tray and open-tray implant impression techniques for partially edentulous patients.

    PubMed

    Gallucci, German O; Papaspyridakos, Panos; Ashy, Linah M; Kim, Go Eun; Brady, Nicholas J; Weber, Hans-Peter

    2011-01-01

    The aim of this research was to compare the accuracy outcomes of open- and closed-tray implant impressions for partially edentulous patients. Eleven partially edentulous spaces in seven patients with two existing implants for fixed partial dentures were included. Group I (closed-tray) and group II (open-tray) were compared using microcomputed tomography scanning. No statistically significant differences were found between the closed- and open-tray techniques (P = .317). The subjective evaluation of patient comfort showed no differences with either impression technique. There were no differences seen between open- and closed-tray impression techniques in partially edentulous patients when implants had less than 10 degrees of angulation.

  13. Cantilever clamp fitting

    NASA Technical Reports Server (NTRS)

    Melton, Patrick B. (Inventor)

    1989-01-01

    A device is disclosed for sealing and clamping a cylindrical element which is to be attached to an object such as a wall, a pressurized vessel or another cylindrical element. The device includes a gland having an inner cylindrical wall, which is threaded at one end and is attached at a bendable end to a deformable portion, which in turn is attached to one end of a conical cantilever structure. The other end of the cantilever structure connects at a bendable area to one end of an outer cylindrical wall. The opposite end of cylindrical wall terminates in a thickened portion, the radially outer surface of which is adapted to accommodate a tool for rotating the gland. The terminal end of cylindrical wall also includes an abutment surface, which is adapted to engage a seal, which in turn engages a surface of a receiver. The receiver further includes a threaded portion for engagement with the threaded portion of gland whereby a tightening rotation of gland relative to receiver will cause relative movement between cylindrical walls and of gland. This movement causes a rotation of the conical structure and thus a bending action at bending area and at the bending end of the upper end of inner cylindrical wall. These rotational and bending actions result in a forcing of the deformable portion radially inwardly so as to contact and deform a pipe. This forcible contact creates a seal between gland and pipe, and simultaneously clamps the pipe in position.

  14. LDEF active optical system components experiment

    NASA Technical Reports Server (NTRS)

    Blue, M. D.

    1991-01-01

    A preliminary report on the Active Optical System Components Experiment is presented. This experiment contained 136 components in a six-inch deep tray including lasers, infrared detectors and arrays, ultraviolet light detectors, light-emitting diodes, a light modulator, flash lamps, optical filters, glasses, and samples of surface finishes. The experimental results for those component characteristics appear as much related to the passage of time as to the effects of the space environment, but organic materials and extreme-infrared reflectivity of black paints show unexpected changes.

  15. Analysis of surfaces from the LDEF A0114, phase 4

    NASA Technical Reports Server (NTRS)

    Gregory, John C.

    1991-01-01

    Progress made from 1 Mar. to 31 Aug. 1991 is presented. The work concentrated on profilometry measurements of eroded and corroded sample surfaces, optical transmission measurements, analysis of the pinhole camera, and x-ray photoelectron spectroscopic (XPS) analysis of some samples. The following papers are presented: (1) observation of Be-7 on the surface of the Long Duration Exposure Facility (LDEF) Spacecraft; (2) measurement of the passive attitude control performance of a recovered spacecraft; (3) effects on LDEF exposed copper flim and bulk; (4) measurements of erosion characteristics for metal and polymer surfaces using profilometry; (5) the interactions of atmospheric cosmogenic radionuclides with spacecraft surfaces; (6) pinhole cameras as sensors for atomic oxygen in orbit; and (7) interaction of atomic oxygen with solid surfaces in low earth orbit- results from LDEF experiment A0114.

  16. Automatic Surface Inoculation of Agar Trays1

    PubMed Central

    Wilkins, Judd R.; Mills, Stacey M.; Boykin, Elizabeth H.

    1972-01-01

    A machine is described which automatically inoculates a plastic tray containing agar media with a culture by use of either a conventional inoculating loop or a cotton swab. Isolated colonies were obtained with an inoculating loop when a heavy inoculum (109 cells/ml) was used or with a cotton swab when a light inoculum (ca. 104 cells/ml) was used. Trays containing combinations of differential or selective media were used to (i) separate mixtures of gram-positive and gram-negative bacteria, (ii) facilitate isolation of organisms from clinical specimens, and (iii) compare colony growth characteristics of pure cultures. The design of the machine is simple, it is easy to use, and it relieves the operator from the manual task of streaking cultures. Images PMID:16349943

  17. Interplanetary meteoroid debris in LDEF metal craters

    NASA Technical Reports Server (NTRS)

    Brownlee, D. E.; Horz, F.; Bradley, J.

    1992-01-01

    The extraterrestrial meteoroid residue found lining craters in the Long Duration Exposure Facility (LDEF) aluminum and gold targets is highly variable in both quantity and type. In typical craters only a minor amount of residue is found and for these craters it is evident that most of the impacting projectile was ejected during crater formation. Less than 10 percent of the craters greater than 100 microns contain abundant residue consistent with survival of a major fraction of the projectile. In these cases the residue can be seen optically as a dark liner and it can easily be analyzed by SEM-EDX techniques. Because they are rare, the craters with abundant residue must be a biased sampling of the meteoroids reaching the earth. Factors that favor residue retention are low impact velocity and material properties such as high melting point. In general, the SEM-EDX observations of crater residues are consistent with the properties of chondritic meteorites and interplanetary dust particles collected in the stratosphere. Except for impacts by particles dominated by single minerals such as FeS and olivine, most of the residue compositions are in broad agreement with the major element compositions of chondrites. In most cases the residue is a thin liner on the crater floor and these craters are difficult to quantitatively analyze by EDX techniques because the electron beam excites both residue and underlying metal substrate. In favorable cases, the liner is thick and composed of vesicular glass with imbedded FeNi, sulfide and silicate grains. In the best cases of meteoroid preservation, the crater is lined with large numbers of unmelted mineral grains. The projectiles fragmented into micron sized pieces but the fragments survived without melting. In one case, the grains contain linear defects that appear to be solar flare tracks. Solar flare tracks are common properties of small interplanetary particles and their preservation during impact implies that the fragments were

  18. CoFlo tray Design and Technology Report

    SciTech Connect

    William R. Trutna

    2005-04-04

    This report consists of two major segments. CoFlo Tray Design is the first section. The objectives of this section are: (1) Determine the design requirements for increased capacity by the substitution of CoFlo trays for sieve trays in a 15-tray 46-inch diameter column. The Design Basis was obtained from the Separations Research Program, which was solicited by an industrial customer on the use of CoFlo trays for their application. (2) Illustrate the design procedures so that they can be computerized to rapidly provide design and cost information for future customers. A summary of the research studies on which each design procedure is based is included. (3) Compare the costs of new sieve tray and CoFlo tray columns for this application to illustrate the savings inherent in the CoFlo process. Exhibits are the second section of this report and its objectives are to: (a) Report the extensive research studies on the CoFlo tray and related items; (b) Analyze present and potential future performance of the CoFlo tray; (c) Present comparative costs for sieve and CoFlo tray columns; and (d) List the applications for the CoFlo deentrainer.

  19. Automatic surface inoculation of agar trays.

    NASA Technical Reports Server (NTRS)

    Wilkins, J. R.; Mills, S. M.; Boykin, E. H.

    1972-01-01

    Description of a machine and technique for the automatic inoculation of a plastic tray containing agar media with a culture, using either a conventional inoculation loop or a cotton swab. The design of the machine is simple, it is easy to use, and it relieves the operator from the manual task of streaking cultures. The described technique makes possible the visualization of the overall qualitative and, to some extent, quantitative relationships of various bacterial types in a sample tested.

  20. Prototyped flexible grafting tray for reconstruction of mandibular defects.

    PubMed

    Zhou, Libin; Shang, Hongtao; Feng, Zhihong; Ding, Yuxiang; Liu, Wei; Li, Dichen; Zhao, Jinlong; Liu, Yanpu

    2012-07-01

    In our previous studies, prototyped individual bone-grafting trays have been used to restore discontinuous mandibular defects. However, the attempts have shown that the trays have shielded the graft from stress, which caused considerable resorption of bone. To eliminate the shielding, we designed a flexible tray. Finite element analysis was used to compare the distribution of strain on the bone grafts that were placed in flexible and conventional trays. The analogue computation suggested that most of the strain on the graft in the flexible tray resulted in a beneficial mechanical environment, while in the conventional tray more than half of graft was in the lowest class of strain (disuse - <50 μstrains). Animal experiments were conducted on hybrid dogs, and the prototype flexible tray was used to carry particles of autologous cancellous iliac bone to reconstruct a 40 mm defect in the mandibular body. Sequential radionuclide bone imaging was used to monitor the bone metabolism. Animals were killed at 4, 12 and 24 weeks, and specimens processed for quantitative histological examination. The data from the flexible trays were compared with those from the conventional trays, as in our previous study. The results showed that bone metabolism was more active in the flexible tray than in the conventional tray during the early stages. There was increased bony adaptation in the flexible tray. These results indicate that the flexible tray can efficiently eliminate the shielding from stress, and allow more occlusive force to be conducted on to the bone graft, which results in better remodelling of the graft. Copyright © 2011. Published by Elsevier Ltd.

  1. Biosensing with T-ray spectroscopy

    NASA Astrophysics Data System (ADS)

    Fischer, Bernd M.; Helm, Hanspeter; Abbott, Derek

    2007-07-01

    In the recent years, it has been shown that terahertz (or T-ray) spectroscopy is a versatile tool for biosensing and safety applications. This is due to the fact that the THz-spectra of many biomolecules show very characteristic, distinct spectroscopic features. Furthermore, most non-metallic packaging materials are nearly transparent in this frequency range (0.1 - 6 THz, 3 cm -1 - 200 cm -1), so that it is possible to non-invasively identify even sealed substances like pharmaceuticals, illicit drugs or explosives by their spectroscopic signatures. This opens a significant potential for a wide range of applications from quality control of pharmaceutical substances via safety applications through to biomedical applications. The individual spectroscopic features below approximately 5 THz that spurred the increased world wide interest in T-ray spectroscopy are mainly due to intermolecular rather than intramolecular vibrations in the polycrystalline samples. The spectra of more complex biomolecules, like proteins and nucleotides, typically show less or even no sharp features, due to the lack of long- range intermolecular order. Furthermore, due to the typically significantly smaller sample amount, the signal to noise ratio is strongly increased. Water shows a strong absorption in this frequency range, which all together makes real biomedical applications of T-ray spectroscopy rather difficult. Yet, by combining a careful sample preparation, novel experimental techniques and an advanced signal processing of the experimental data we can still clearly distinguish between even complex biomolecules and therefore demonstrate the potential the technique holds for biomedical applications.

  2. Inner Voltage Clamping

    PubMed Central

    Feldberg, Stephen W.; Delgado, Alicia B.

    1978-01-01

    Ketterer, et al. (1971) have suggested that a combination of electrostatic and chemical interactions may cause hydrophobic ions absorbed within a bilayer lipid membrane to reside in two potential wells, each close to a membrane surface. The resulting two planes of charges would define three regions of membrane dielectric: two identical outer regions each between a plane of absorbed charges and the plane of closest approach of ions in the aqueous phase; and the inner region between the two planes of adsorbed charges. The theory describing charge translocation across the inner region is based on a simple three-capacitor model. A significant theoretical conclusion is that the difference between the voltage across the inner region, Vi, and the voltage across the entire membrane, Vm, is directly proportional to the amount of charge that has flowed in a voltage clamp experiment. We demonstrate that we can construct an “inner voltage clamp” that can maintain, with positive feedback, a constant inner voltage, Vi. The manifestation of proper feedback is that the clamp current (after a voltage step) will exhibit pure (i.e., single time-constant) exponential decay, because the voltage dependent rate constants governing translocation will be independent of time. The “pureness” of the exponential is maximized when the standard deviation of the least-square fit of the appropriate exponential equation to the experimental data is minimized. The concomitant feedback is directly related to the capacitances of the inner and outer membrane regions, Ci and Co. Experimental results with tetraphenylborate ion adsorbed in bacterial phosphatidylethanolamine/n-decane bilayers indicate Ci ∼ 5 · 10-7F/cm2 and Co ≈ 5 · 10-5F/cm2. PMID:620078

  3. Results of the examination of LDEF polyurethane thermal control coatings

    NASA Technical Reports Server (NTRS)

    Golden, Johnny L.

    1994-01-01

    This report summarizes the condition of polyurethane thermal control coatings subjected to 69 months of low earth orbit (LEO) exposure on the Long Duration Exposure Facility (LDEF) mission. Specimens representing all environmental aspects obtainable by LDEF were analyzed. Widely varying changes in the thermo-optical and mechanical properties of these materials were observed, depending on atomic oxygen and ultraviolet radiation fluences. High atomic oxygen fluences, regardless of ultraviolet radiation exposure levels, resulted in near original optical properties for these coatings but with a degradation in their mechanical condition. A trend in solar absorptance increase with ultraviolet radiation fluence was observed. Contamination, though observed, exhibited minimal effects.

  4. Atomic oxygen interactions with FEP Teflon and silicones on LDEF

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A.; Gebauer, Linda

    1991-01-01

    The Long Duration Exposure Facility (LDEF) spacecraft represents the first controlled unidirectional exposure of high-fluence atomic oxygen on fluorinated ethylene propylene (FEP Teflon) and silicones. The atomic oxygen erosion yield for FEP Teflon was found to be significantly in excess of previous low fluence orbital data and is an order of magnitude below that of polyimide Kapton. LDEF FEP Teflon erosion yield data as a function of angle of attack is presented. Atomic oxygen interaction with silicon polymers results in crazing of the silicones as well as deposition of dark contaminant oxidation products on adjoining surfaces. Documentation of results and possible mechanistic explanations are presented.

  5. Characterization of selected LDEF: Exposed polymer films and resins

    NASA Technical Reports Server (NTRS)

    Young, Philip R.; Slemp, Wayne S.

    1992-01-01

    The Long Duration Exposure Facility (LDEF) provided a unique environmental exposure of a wide variety of materials. The effects of 5 years and 10 months of Low-Earth Orbit (LEO) exposure of these materials to atomic oxygen, ultraviolet and particulate radiation, meteoroid and debris, vacuum, contamination, and thermal cycling is providing a data base unparalleled in the history of space environment research. Working though the Environmental Effects on Materials Special Investigation Group (MSIG), a number of polymeric materials in various processed forms have been assembled from LDEF investigators for analysis at the NASA Langley Research Center. This paper reports the status of on-going chemical characterization of these materials.

  6. The magnitude of impact damage on LDEF materials

    NASA Technical Reports Server (NTRS)

    Allbrooks, Martha; Atkinson, Dale

    1992-01-01

    The purpose of this report is to document the magnitude and types of impact damage to materials and systems on the LDEF. This report will provide insights which permit NASA and industry space-systems designers to more rapidly identify potential problems and hazards in placing a spacecraft in low-Earth orbit (LEO). This report is structured to provide (1) a background on LDEF, (2) an introduction to the LEO meteoroid and debris environments, and (3) descriptions of the types of damage caused by impacts into structural materials, and contamination caused by spallation and ejecta from impact events.

  7. Atomic oxygen interactions with FEP Teflon and silicones on LDEF

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A.; Gebauer, Linda

    1991-01-01

    The Long Duration Exposure Facility (LDEF) spacecraft represents the first controlled unidirectional exposure of high-fluence atomic oxygen on fluorinated ethylene propylene (FEP Teflon) and silicones. The atomic oxygen erosion yield for FEP Teflon was found to be significantly in excess of previous low fluence orbital data and is an order of magnitude below that of polyimide Kapton. LDEF FEP Teflon erosion yield data as a function of angle of attack is presented. Atomic oxygen interaction with silicon polymers results in crazing of the silicones as well as deposition of dark contaminant oxidation products on adjoining surfaces. Documentation of results and possible mechanistic explanations are presented.

  8. Passive stabilization of the Long Duration Exposure Facility (LDEF)

    NASA Technical Reports Server (NTRS)

    Das, A.

    1974-01-01

    The results of a study on the application of the magnetically anchored rate damper to gravity gradient stabilization of the Long Duration Exposure Facility (LDEF) are presented. The analyses and simulations required to investigate the use of an existing viscous magnetic rate damper for rate stabilizing the LDEF spacecraft were performed. The following tasks were included: linear performance estimates, capture and damper requirements, and performance prediction. Each of these tasks was performed for two gravity gradient stabilization configurations; an axisymmetric configuration for two-axis (pitch and roll) stability; and a non-axisymmetric configuration for three-axis stability. The results are presented by stabilization configuration.

  9. Drying time of tray adhesive for adequate tensile bond strength between polyvinylsiloxane impression and tray resin material.

    PubMed

    Yi, Myong-Hee; Shim, Joon-Sung; Lee, Keun-Woo; Chung, Moon-Kyu

    2009-07-01

    Use of custom tray and tray adhesive is clinically recommended for elastomeric impression material. However there is not clear mention of drying time of tray adhesive in achieving appropriate bonding strength of tray material and impression material. This study is to investigate an appropriate drying time of tray adhesives by evaluating tensile bonding strength between two types of polyvinylsiloxane impression materials and resin tray, according to various drying time intervals of tray adhesives, and with different manufacturing company combination of impression material and tray adhesive. Adhesives used in this study were Silfix (Dentsply Caulk, Milford, Del, USA) and VPS Tray Adhesive (3M ESPE, Seefeld, Germany) and impression materials were Aquasil Ultra (monophase regular set, Dentsply Caulk, Milford, Del, USA) and Imprint II Garant (regular body, 3M ESPE, Seefeld, Germany). They were used combinations from the same manufacture and exchanged combinations of the two. The drying time was designed to air dry, 5 minutes, 10 minutes, 15 minutes, 20 minutes, and 25 minutes. Total 240 of test specimens were prepared by auto-polymerizing tray material (Instant Tray Mix, Lang, Wheeling, Il, USA) with 10 specimens in each group. The specimens were placed in the Universal Testing machine (Instron, model 3366, Instron Corp, University avenue, Nowood, MA, USA) to perform the tensile test (cross head speed 5 mm/min). The statistically efficient drying time was evaluated through ANOVA and Scheffe test. All the tests were performed at 95% confidence level. The results revealed that at least 10 minutes is needed for Silfix-Aquasil, and 15 minutes for VPS Tray Adhesive-Imprint II, to attain an appropriate tensile bonding strength. VPS Tray Adhesive-Imprint II had a superior tensile bonding strength when compared to Silfix-Aquasil over 15 minutes. Silfix-Aquasil had a superior bonding strength to VPS Tray Adhesive-Aquasil, and VPS Tray Adhesive-Imprint II had a superior tensile

  10. Drying time of tray adhesive for adequate tensile bond strength between polyvinylsiloxane impression and tray resin material

    PubMed Central

    Yi, Myong-Hee; Shim, Joon-Sung; Lee, Keun-Woo

    2009-01-01

    STATEMENT OF PROBLEM Use of custom tray and tray adhesive is clinically recommended for elastomeric impression material. However there is not clear mention of drying time of tray adhesive in achieving appropriate bonding strength of tray material and impression material. PURPOSE This study is to investigate an appropriate drying time of tray adhesives by evaluating tensile bonding strength between two types of polyvinylsiloxane impression materials and resin tray, according to various drying time intervals of tray adhesives, and with different manufacturing company combination of impression material and tray adhesive. MATERIAL AND METHODS Adhesives used in this study were Silfix (Dentsply Caulk, Milford, Del, USA) and VPS Tray Adhesive (3M ESPE, Seefeld, Germany) and impression materials were Aquasil Ultra (monophase regular set, Dentsply Caulk, Milford, Del, USA) and Imprint II Garant (regular body, 3M ESPE, Seefeld, Germany). They were used combinations from the same manufacture and exchanged combinations of the two. The drying time was designed to air dry, 5 minutes, 10 minutes, 15 minutes, 20 minutes, and 25 minutes. Total 240 of test specimens were prepared by auto-polymerizing tray material (Instant Tray Mix, Lang, Wheeling, Il, USA) with 10 specimens in each group. The specimens were placed in the Universal Testing machine (Instron, model 3366, Instron Corp, University avenue, Nowood, MA, USA) to perform the tensile test (cross head speed 5 mm/min). The statistically efficient drying time was evaluated through ANOVA and Scheffe test. All the tests were performed at 95% confidence level. RESULTS The results revealed that at least 10 minutes is needed for Silfix-Aquasil, and 15 minutes for VPS Tray Adhesive-Imprint II, to attain an appropriate tensile bonding strength. VPS Tray Adhesive-Imprint II had a superior tensile bonding strength when compared to Silfix-Aquasil over 15 minutes. Silfix-Aquasil had a superior bonding strength to VPS Tray Adhesive

  11. LDEF - 69 Months in Space. First Post-Retrieval Symposium. Proceeding of a symposium held in Kissimmee, Florida, 2-8 June 1991.

    DTIC Science & Technology

    2007-11-02

    that hardware which was provided by the LDEF Project and functioned in support of the LDEF as an integrated vehicle. The LDEF Shared systems include...that hardware which was also provided by the LDEF project but which was distributed to individual experimenters and functioned independently in...the highest level of assembly and the broadest span of function of all of the systems on the LDEF mission. The LDEF Shared hardware is of particular

  12. Radiation exposure of LDEF: Initial results

    NASA Technical Reports Server (NTRS)

    Benton, E. V.; Frank, A. L.; Benton, E. R.; Csige, I.; Parnell, T. A.; Watts, J. W., Jr.

    1992-01-01

    Initial results from LDEF include radiation detector measurements from four experiments, P0006, P0004, M0004, and A0015. The detectors were located on both the leading and trailing edges of the orbiter and also on the Earthside end. This allowed the directional dependence of the incoming radiation to be measured. Total absorbed doses from thermoluminescent detectors (TLDs) verified the predicted spatial east-west dose ratio dependence of a factor approx. 2.5, due to trapped proton anisotropy in the South Atlantic Anomaly. On the trailing edge of the orbiter a range of doses from 6.64 to 2.91 Gy were measured under Al equivalent shielding of 0.42 to 1.11 g/sq cm. A second set of detectors near this location yielded doses of 6.48 to 2.66 Gy under Al equivalent shielding of 0.48 to 15.4 g/sq cm. On the leading edge, doses of 2.58 to 2.10 Gy were found under Al equivalent shielding of 1.37 to 2.90 g/sq cm. Initial charged particle LET (linear energy transfer) spectra, fluxes, doses and dose equivalents, for LET in H2O greater than or = 8 keV/micron, were measured with plastic nuclear track detectors (PNTDs) located in two experiments. Also preliminary data on low energy neutrons were obtained from detectors containing (6)LiF foils.

  13. Radiation exposure of LDEF: Initial results

    NASA Technical Reports Server (NTRS)

    Benton, E. V.; Frank, A. L.; Benton, E. R.; Csige, I.; Parnell, T. A.; Watts, John W., Jr.

    1991-01-01

    Initial results from Long Duration Exposure Facility (LDEF) include radiation detector measurements from four experiments; P0006, P0004, M0004, and A0015. The detectors were located on both the leading and trailing edges of the orbiter and also at the Earthside end. This allowed the directional dependence of the incoming radiation to be measured. Total absorbed doses from thermoluminescent detectors (TLDs) verified the predicted spatial east-west dose dependence of a factor of approx. 2.5, due to trapped proton anisotropy in the South Atlantic Anomaly (SAA). On the trailing edge of the orbiter, a range of doses from 664 to 291 rad were measured under nominal shielding of 0.42 to 8.45 g/sq cm. A second set of detectors near this locations results are also given. On the leading edge, doses of 258 to 210 rad were found under shielding of 1.25 to 2.48 g/sq cm. Initial charged particle LET (linear energy transfer) spectra, fluxes, doses, and dose equivalents, for LET in H2O greater than or = 5 keV/micron, were measured with plastic nuclear track detectors located in the four experiments. Also, preliminary data on low energy neutrons were obtained from detectors containing (6)LiF foils.

  14. Further analysis of LDEF FRECOPA micrometeoroid remnants

    NASA Astrophysics Data System (ADS)

    Borg, Janet; Bunch, Ted E.; Radicatidibrozolo, Filippo; Mandeville, Jean Claude

    1993-04-01

    In the Al collectors of experiment A0138-1 of the French Cooperative Payload (FRECOPA) payload, we identified a population of small craters (3-9 microns in diameter) induced by the impacts of micron-sized grains, mainly of extraterrestrial origin. Chemical analyses of the Interplanetary Dust Particle (IDP) remnants were made in the bottoms and on the rims of the craters, in addition to immediate off-rim areas. So far, the compositional investigation of the craters by Energy Dispersive Spectroscopy (EDS) has shown evidence of an extraterrestrial origin for the impacting grains. The systematic presence of C and O in the residues has been reported and may be compared with the existence of particles showing high proportions of biogenic light elements and detected in the close environment of P-Halley comet nucleus (called CHON particles). An analytical protocol has been established in order to extract molecular and possible isotopic information on these grains, a fraction of which could be of cometary origin. Although these very small craters may show crater features that are typical of the larger Long Duration Exposure Facility (LDEF) population (greater than 50 microns), some show unique morphologies that we have not previously observed. Our initial Laser Induced Mass Spectrometry (LIMS) analytical results show strong signals for nitrogen-bearing ions in craters characterized by high C and O contents; they also suggest that carbon contents in some craters could exceed that known for carbonaceous chondrites.

  15. Damage areas on selected LDEF aluminum surfaces

    NASA Technical Reports Server (NTRS)

    Coombs, Cassandra R.; Atkinson, Dale R.; Allbrooks, Martha K.; Watts, Alan J.; Hennessy, Corey J.; Wagner, John D.

    1993-01-01

    With the U.S. about to embark on a new space age, the effects of the space environment on a spacecraft during its mission lifetime become more relevant. Included among these potential effects are degradation and erosion due to micrometeoroid and debris impacts, atomic oxygen and ultraviolet light exposure as well as material alteration from thermal cycling, and electron and proton exposure. This paper focuses on the effects caused by micrometeoroid and debris impacts on several LDEF aluminum plates from four different bay locations: C-12, C-10, C-01, and E-09. Each plate was coated with either a white, black, or gray thermal paint. Since the plates were located at different orientations on the satellite, their responses to the hypervelocity impacts varied. Crater morphologies range from a series of craters, spall zones, domes, spaces, and rings to simple craters with little or no spall zones. In addition, each of these crater morphologies is associated with varying damage areas, which appear to be related to their respective bay locations and thus exposure angles. More than 5% of the exposed surface area examined was damaged by impact cratering and its coincident effects (i.e., spallation, delamination and blow-off). Thus, results from this analysis may be significant for mission and spacecraft planners and designers.

  16. Further analysis of LDEF FRECOPA micrometeoroid remnants

    NASA Technical Reports Server (NTRS)

    Borg, Janet; Bunch, Ted E.; Radicatidibrozolo, Filippo; Mandeville, Jean Claude

    1993-01-01

    In the Al collectors of experiment A0138-1 of the French Cooperative Payload (FRECOPA) payload, we identified a population of small craters (3-9 microns in diameter) induced by the impacts of micron-sized grains, mainly of extraterrestrial origin. Chemical analyses of the Interplanetary Dust Particle (IDP) remnants were made in the bottoms and on the rims of the craters, in addition to immediate off-rim areas. So far, the compositional investigation of the craters by Energy Dispersive Spectroscopy (EDS) has shown evidence of an extraterrestrial origin for the impacting grains. The systematic presence of C and O in the residues has been reported and may be compared with the existence of particles showing high proportions of biogenic light elements and detected in the close environment of P-Halley comet nucleus (called CHON particles). An analytical protocol has been established in order to extract molecular and possible isotopic information on these grains, a fraction of which could be of cometary origin. Although these very small craters may show crater features that are typical of the larger Long Duration Exposure Facility (LDEF) population (greater than 50 microns), some show unique morphologies that we have not previously observed. Our initial Laser Induced Mass Spectrometry (LIMS) analytical results show strong signals for nitrogen-bearing ions in craters characterized by high C and O contents; they also suggest that carbon contents in some craters could exceed that known for carbonaceous chondrites.

  17. Radioactivities induced in some LDEF samples

    NASA Technical Reports Server (NTRS)

    Reedy, Robert C.; Moss, Calvin E.

    1992-01-01

    Final activities are reported for gamma ray emitting isotopes measured in 35 samples from LDEF. In 26 steel trunnion samples, activities of Mn-54 and Co-57 were measured and limits set on other isotopes. In five Al end support retainer plates and two Al keel plate samples, Na-22 was measured. In two Ti clip samples, Na-22 was measured, limits for Sc-46 were obtained, and high activities for impurity Uranium and daughter isotopes were observed. Four sets of depth vs activity profiles were measured for the D sections of the trunnion. For all 4 profiles, the activities first decreased with increasing distance from the surface of the trunnion but were fairly flat near the center. These profiles are consistent with production by both the lower energy (approx. 100 MeV) trapped particles and high energy (approx. 10 GeV) galactic-cosmic ray particles. For the near surface samples, the earth quadrant had more Mn-54 than the space quadrant. For the D sections, there was less Mn-54 in the east trunnion than in the west trunnion. Comparisons are made among the samples and with activities measured by others. The limit for Sc-46 in the Ti clips is compared with the activities of Mn-54 produced in the steel pieces by similar reactions. Activities predicted by several models are compared with the measured activities.

  18. Radiation exposure of LDEF: Initial results

    NASA Technical Reports Server (NTRS)

    Benton, E. V.; Frank, A. L.; Benton, E. R.; Csige, I.; Parnell, T. A.; Watts, John W., Jr.

    1991-01-01

    Initial results from Long Duration Exposure Facility (LDEF) include radiation detector measurements from four experiments; P0006, P0004, M0004, and A0015. The detectors were located on both the leading and trailing edges of the orbiter and also at the Earthside end. This allowed the directional dependence of the incoming radiation to be measured. Total absorbed doses from thermoluminescent detectors (TLDs) verified the predicted spatial east-west dose dependence of a factor of approx. 2.5, due to trapped proton anisotropy in the South Atlantic Anomaly (SAA). On the trailing edge of the orbiter, a range of doses from 664 to 291 rad were measured under nominal shielding of 0.42 to 8.45 g/sq cm. A second set of detectors near this locations results are also given. On the leading edge, doses of 258 to 210 rad were found under shielding of 1.25 to 2.48 g/sq cm. Initial charged particle LET (linear energy transfer) spectra, fluxes, doses, and dose equivalents, for LET in H2O greater than or = 5 keV/micron, were measured with plastic nuclear track detectors located in the four experiments. Also, preliminary data on low energy neutrons were obtained from detectors containing (6)LiF foils.

  19. Comparison of Dimensional Accuracy between Open-Tray and Closed-Tray Implant Impression Technique in 15° Angled Implants.

    PubMed

    Balouch, F; Jalalian, E; Nikkheslat, M; Ghavamian, R; Toopchi, Sh; Jallalian, F; Jalalian, S

    2013-09-01

    Various impression techniques have different effects on the accuracy of final cast dimensions. Meanwhile; there are some controversies about the best technique. This study was performed to compare two kinds of implant impression methods (open tray and closed tray) on 15 degree angled implants. In this experimental study, a steel model with 8 cm in diameter and 3 cm in height were produced with 3 holes devised inside to stabilize 3 implants. The central implant was straight and the other two implants were 15° angled. The two angled implants had 5 cm distance from each other and 3.5 cm from the central implant. Dental stone, high strength (type IV) was used for the main casts. Impression trays were filled with poly ether, and then the two impression techniques (open tray and closed tray) were compared. To evaluate positions of the implants, each cast was analyzed by CMM device in 3 dimensions (x,y,z). Differences in the measurements obtained from final casts and laboratory model were analyzed using t-Test. The obtained results indicated that closed tray impression technique was significantly different in dimensional accuracy when compared with open tray method. Dimensional changes were 129 ± 37μ and 143.5 ± 43.67μ in closed tray and open tray, while coefficient of variation in closed- tray and open tray were reported to be 27.2% and 30.4%, respectively. Closed impression technique had less dimensional changes in comparison with open tray method, so this study suggests that closed tray impression technique is more accurate.

  20. Comparison of Dimensional Accuracy between Open-Tray and Closed-Tray Implant Impression Technique in 15° Angled Implants

    PubMed Central

    Balouch, F; Jalalian, E; Nikkheslat, M; Ghavamian, R; Toopchi, Sh; Jallalian, F; Jalalian, S

    2013-01-01

    Statement of Problem: Various impression techniques have different effects on the accuracy of final cast dimensions. Meanwhile; there are some controversies about the best technique. Purpose: This study was performed to compare two kinds of implant impression methods (open tray and closed tray) on 15 degree angled implants. Materials and Method: In this experimental study, a steel model with 8 cm in diameter and 3 cm in height were produced with 3 holes devised inside to stabilize 3 implants. The central implant was straight and the other two implants were 15° angled. The two angled implants had 5 cm distance from each other and 3.5 cm from the central implant. Dental stone, high strength (type IV) was used for the main casts. Impression trays were filled with poly ether, and then the two impression techniques (open tray and closed tray) were compared. To evaluate positions of the implants, each cast was analyzed by CMM device in 3 dimensions (x,y,z). Differences in the measurements obtained from final casts and laboratory model were analyzed using t-Test. Results: The obtained results indicated that closed tray impression technique was significantly different in dimensional accuracy when compared with open tray method. Dimensional changes were 129 ± 37μ and 143.5 ± 43.67μ in closed tray and open tray, while coefficient of variation in closed- tray and open tray were reported to be 27.2% and 30.4%, respectively. Conclusion: Closed impression technique had less dimensional changes in comparison with open tray method, so this study suggests that closed tray impression technique is more accurate. PMID:24724130

  1. Accuracy of impressions obtained with dual-arch trays.

    PubMed

    Wöstmann, Bernd; Rehmann, Peter; Balkenhol, Markus

    2009-01-01

    This study aimed to analyze the accuracy resulting from dual-arch impressions when compared to conventional impressions in complex preparations (ie, inlay and partial crown). One hundred eighty impressions were made using two different dual-arch trays; conventional trays served as the control. The accuracy of the dies obtained (Fuji-Rock EP, GC Europe) was assessed indirectly from the change of 59 transversal dimensions. Statistical analysis (t test, analysis of variance) revealed that less rigid dual-arch trays performed better than rigid ones. Though the inlay preparation was more difficult to reproduce with dual-arch trays, it can be concluded that the accuracy obtainable with nonrigid dual-arch trays is comparable to impressions taken from full-arch trays.

  2. [Progress in research and application of the edentulous custom trays].

    PubMed

    Sun, Y C; Jin, E L; Zhao, T; Wang, Y; Ye, H Q; Zhou, Y S

    2016-11-09

    Well designed and fabricated custom tray is the precondition to acquire qualified edentulous impression and key to successful complete denture. It has shown that primary impression without custom trays is hard to meet clinical requirements for successful restoration of complete denture. According to the fabrication techniques, edentulous custom tray can be classified into several types such as: compound trimming technique, handcrafted technique with polymerizing acrylic resin based on the study cast, and computer aided design and three dimensional printing(CAD & 3DP) technique based on the primary impression or study cast, etc. With regard to some special edentulous jaws, the custom tray and impression techniques such as open-window, frame cut, closed-mouth custom trays, and so on can be applied to acquire accurate impressions. All above technologies have their own characteristics and emphases. In clinic, appropriate custom trays should be selected according to residual ridge condition, oral status, and other clinical requirements of each edentulous patient.

  3. Saddle Clamp With Captive Components

    NASA Technical Reports Server (NTRS)

    Belrose, Charles R.

    1993-01-01

    Saddle clamp modified to prevent parts from falling off when installed or removed. Allows easy access for tightening or loosening bolts, and retains alignment with tube mounted in it when opened. All parts are held captive - bolts by retaining washers, floating nuts by pressing and swaging, and upper clamp band by tether. Upper and lower bolt flanges offset from each other to ensure access.

  4. Image Processing Techniques for Assessment of Dental Trays

    DTIC Science & Technology

    2007-11-02

    brands of perforated metal trays with 170 lower arch cast models collected from patients having Angle Class 1 type occlusion with minor malocclusions ...appliance. The thickness of the space between the tray and the preparation is one of the important factors related with the dimensional stability of the...impression material. In the literature, the sufficient space for the impression material between the tray and the mucosa and teeth is recommended not

  5. Three-way trays: easy to use and abuse.

    PubMed

    Pesun, Igor J; Swain, Vanessa L

    2008-12-01

    The 3-way tray technique is popular as it provides master and opposing arch impressions and an interocclusal record at the same time. Excellent clinical results can be achieved with appropriate case selection, use of rigid tray and impression materials, attention to tray positioning and other details throughout the process, and clear understanding of the limitations of the technique by the operator and dental technician.

  6. The performance of the TOFr tray in STAR

    NASA Astrophysics Data System (ADS)

    Wu, Jian; Bonner, B.; Chen, H. F.; Dong, X.; Eppley, G.; Geurts, F.; Huang, S. L.; Li, C.; Llope, W. J.; Nussbaum, T.; Platner, E.; Roberts, J.; Ruan, L. J.; Shao, M.; Wang, X. L.; Xu, Z.; Xu, Z. Z.

    2005-02-01

    A tray of the STAR Time-Of-Flight detector (TOFr) based on the Multi-gap Resistive Plate Chamber technology was constructed and then operated in STAR during the RHIC 2003 spring physics run after beam-tested at AGS of BNL. The calibration procedure of the tray is introduced. The main properties of the chambers in the tray fulfill the requirements of the STAR experiment.

  7. Catheterization in the community: converting to the Foley catheter tray.

    PubMed

    Yates, Ann

    2011-11-01

    With the aim of minimizing clinical incidents and improving clinical practice, the Cardiff and Vale University Health Board carried out a trial of a Foley catheter tray to be carried by district nurses as emergency boot stock. As part of the trial all nurses had to undergo training on the Foley catheter tray prior to use. The district nurses using the tray reported improvement in confidence, efficiency, convenience and patient experience. Owing to the success of the initiative, use of the Foley catheter tray as emergency boot stock is now standard practice for District Nursing/Acute Response and out-of-hours care in the Cardiff and Vale area.

  8. An Economic Analysis of Alternative Tray Pack Sizes

    DTIC Science & Technology

    1990-08-01

    I"IC FILE COPY TECHNICAL REPORT AD NATICK/TR-90/048 AN ECONOMIC ANALYSIS OF ALTERNATIVE TRAY PACK SIZES BY NMARK M. DAVIS BENTLEY COLLEGE, WALTHAM...AUGUST 199 FINAL REPORT APR 89 TO SEP 89 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS AN ECONOMIC ANALYSIS OF ALTERNATIVE PE 62 786 TRAY PACK SIZES PR AH99...the current tray pack container to a 6/9 and to an 8/12 portion tray padr container. Force structures for field feeding were derived from data

  9. LDEF data correlation to existing NASA debris environment models

    NASA Technical Reports Server (NTRS)

    Atkinson, Dale R.; Allbrooks, Martha K.; Watts, Alan J.

    1992-01-01

    The Long Duration Exposure Facility (LDEF) was recovered in January 1990, following 5.75 years exposure of about 130 sq. m to low-Earth orbit. About 25 sq. m of this surface area was aluminum 6061 T-6 exposed in every direction. In addition, about 17 sq. m of Scheldahl G411500 silver-Teflon thermal control blankets were exposed in 9 of the 12 directions. Since the LDEF was gravity gradient stabilized and did not rotate, the directional dependence of the flux can be easily distinguished. During the disintegration of the LDEF, all impact features larger than 0.5 mm into aluminum were documented for diameters and locations. In addition, the diameters and locations of all impact features larger than 0.3 mm into Scheldahl G411500 thermal control blankets were also documented. This data, along with additional information collected from LDEF materials will be compared with current meteoroid and debris models. This comparison will provide a validation of the models and will identify discrepancies between the models and the data.

  10. The Long Duration Exposure Facility (LDEF). Mission 1 Experiments.

    ERIC Educational Resources Information Center

    Clark, Lenwood G., Ed.; And Others

    The Long Duration Exposure Facility (LDEF) has been designed to take advantage of the two-way transportation capability of the space shuttle by providing a large number of economical opportunities for science and technology experiments that require modest electrical power and data processing while in space and which benefit from postflight…

  11. Scoping estimates of the LDEF satellite induced radioactivity

    NASA Technical Reports Server (NTRS)

    Armstrong, Tony W.; Colborn, B. L.

    1990-01-01

    The Long Duration Exposure Facility (LDEF) satellite was recovered after almost six years in space. It was well-instrumented with ionizing radiation dosimeters, including thermoluminescent dosimeters, plastic nuclear track detectors, and a variety of metal foil samples for measuring nuclear activation products. The extensive LDEF radiation measurements provide the type of radiation environments and effects data needed to evaluate and help resolve uncertainties in present radiation models and calculational methods. A calculational program was established to aid in LDEF data interpretation and to utilize LDEF data for assessing the accuracy of current models. A summary of the calculational approach is presented. The purpose of the reported calculations is to obtain a general indication of: (1) the importance of different space radiation sources (trapped, galactic, and albedo protons, and albedo neutrons); (2) the importance of secondary particles; and (3) the spatial dependence of the radiation environments and effects expected within the spacecraft. The calculational method uses the High Energy Transport Code (HETC) to estimate the importance of different sources and secondary particles in terms of fluence, absorbed dose in tissue and silicon, and induced radioactivity as a function of depth in aluminum.

  12. Evaluation of seals, lubricants, and adhesives used on LDEF

    NASA Technical Reports Server (NTRS)

    Pippin, H. Gary; Keough, Bruce; Dursch, Harry

    1992-01-01

    A wide variety of seals, lubricants, and adhesives were used on LDEF. This paper will discuss the ongoing Materials Special Investigations Group investigation into the effect of the long term exposure of these various materials to the Low Earth Orbit (LEO) environment. This investigation includes the testing of hardware at Boeing, documenting and collating experimenter test results, and deriving 'lessons learned.'

  13. Materials And Processes Technical Information System (MAPTIS) LDEF materials data base

    NASA Technical Reports Server (NTRS)

    Funk, Joan G.; Strickland, John W.; Davis, John M.

    1993-01-01

    A preliminary Long Duration Exposure Facility (LDEF) Materials Data Base was developed by the LDEF Materials Special Investigation Group (MSIG). The LDEF Materials Data Base is envisioned to eventually contain the wide variety and vast quantity of materials data generated from LDEF. The data is searchable by optical, thermal, and mechanical properties, exposure parameters (such as atomic oxygen flux) and author(s) or principal investigator(s). Tne LDEF Materials Data Base was incorporated into the Materials and Processes Technical Information System (MAPTIS). MAPTIS is a collection of materials data which has been computerized and is available to engineers, designers, and researchers in the aerospace community involved in the design and development of spacecraft and related hardware. The LDEF Materials Data Base is described and step-by-step example searches using the data base are included. Information on how to become an authorized user of the system is included.

  14. Interplanetary meteoroid debris in LDEF metal craters

    NASA Technical Reports Server (NTRS)

    Brownlee, D. E.; Joswiak, D.; Bradley, J.; Hoerz, Friedrich

    1993-01-01

    We have examined craters in Al and Au LDEF surfaces to determine the nature of meteoroid residue in the rare cases where projectile material is abundantly preserved in the crater floor. Typical craters contain only small amounts of residue and we find that less than 10 percent of the craters in Al have retained abundant residue consistent with survival of a significant fraction (greater than 20 percent) of the projectile mass. The residue-rich craters can usually be distinguished optically because their interiors are darker than ones with little or no apparent projectile debris. The character of the meteoroid debris in these craters ranges from thin glass liners, to thick vesicular glass containing unmelted mineral fragments, to debris dominated by unmelted mineral fragments. In the best cases of meteoroid survival, unmelted mineral fragments preserve both information on projectile mineralogy as well as other properties such as nuclear tracks caused by solar flare irradiation. The wide range of the observed abundance and alteration state of projectile residue is most probably due to differences in impact velocity. The crater liners are being studied to determine the composition of meteoroids reaching the Earth. The compositional types most commonly seen in the craters are: (1) chondritic (Mg, Si, S, Fe in approximately solar proportions), (2) Mg silicate. amd (3) iron sulfide. These are also the most common compositional types of extraterrestrial particle types collected in the stratosphere. The correlation between these compositions indicates that vapor fractionation was not a major process influencing residue composition in these craters. Although the biases involved with finding analyzable meteoroid debris in metal craters differ from those for extraterrestrial particles collected in and below the atmosphere, there is a common bias favoring particles with low entry velocity. For craters this is very strong and probably all of the metal craters with abundant

  15. Timing of cord clamping revisited.

    PubMed

    Levy, Tali; Blickstein, Isaac

    2006-01-01

    Although cord cutting has been performed since the beginning of mankind, the timing and advantages of early versus delayed cord clamping are still controversial. Early cord clamping (within the first 30 s after birth) is usually justified for potential prevention of postpartum hemorrhage and for immediate treatment of the newborn, but at the same time, may increase Rh-sensitization. Delayed cord clamping is performed after a period of 30 s during which 'placental transfusion' of approximately 80 mL of blood occurs. This amount seems to protect the baby from childhood anemia without increasing hypervolemia-related risks. In preterm infants, delayed clamping appears to reduce the risk of intraventricular hemorrhage and the need for neonatal transfusion. Obtaining cord blood for future autologous transplantation of stem cells needs early clamping and seems to conflict with the infant's best interest. Although a tailored approach is required in the case of cord clamping, the balance of available data suggests that delayed cord clamping should be the method of choice.

  16. Revisiting impressions using dual-arch trays.

    PubMed

    Small, Bruce W

    2012-01-01

    Making routine perfect impressions is the goal of any restorative dentist. Using dual-arch trays is an easy, repeatable way to accomplish that goal, as long as each step is done before the next and each step is performed perfectly. This column reviewed several articles that support the metal dual-arch concept and provided some clinical tips that might help restorative dentists. The dual-arch technique does have its limits and is meant for one or two teeth in a quadrant when there are other teeth to occlude with. Also, if the case involves anterior guidance, a full-arch impression maybe advisable.

  17. Design of the Compartmented Meal Tray for Simultaneous Thermoprocessing of Foods

    DTIC Science & Technology

    1992-01-01

    molds . Prototype trays were tested and a one-tray design was finalized. Phase IH consisted of the fabrication of 200 <xnpartmented trays of the final...thermoforming molds would be made to fabricate the tray designs shown in Figures 11, 14, 15 and 16, These designs were selected because they best represented...demoristrafce the tray-design concepts, outlined in the Ifoase I report, by fabricating prototype molds and cxapartmented trays. iwo variables were used

  18. Toward Some Standards for the Library Card Catalog Tray

    ERIC Educational Resources Information Center

    Boudreau, Allan; Yucht, Donald J.

    1972-01-01

    Commercial card catalog trays are unrelated to actual in-use wear. Specifications for card catalog trays for the new Elemer Holmes Bobst Library at New York University, detailed in this article, are designed to meet the most demanding of actual needs. (1 reference) (Author)

  19. STS-5 crewmembers with meal tray assembly on middeck

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Commander Brand (in dark blue shirt), Pilot Overmyer (left), and Mission Specialist (MS) Lenoir (right) conduct microgravity experiments with food containers and meal tray assemblies in front of middeck port side wall and side hatch. Brand prepares to eat as meal tray assembly floats above his chest and Overmeyer and Lenoir look on. Sign on port side wall is labeled STS-5 Message Board.

  20. 21 CFR 872.3670 - Resin impression tray material.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Resin impression tray material. 872.3670 Section 872.3670 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...) Identification. Resin impression tray material is a device intended for use in a two-step dental mold...

  1. Sand Tray and Group Therapy: Helping Parents Cope

    ERIC Educational Resources Information Center

    James, Linda; Martin, Don

    2002-01-01

    Sand tray with group therapy can be an effective treatment approach for parents coping with adolescent substance abuse and/or dependency. Excerpts of parent sand trays are presented to demonstrate pretreatment tasks that decrease denial, reduce reactive anger, stop enabling behaviors, and build support systems. Parent-child relational issues,…

  2. Sand Tray and Group Therapy: Helping Parents Cope

    ERIC Educational Resources Information Center

    James, Linda; Martin, Don

    2002-01-01

    Sand tray with group therapy can be an effective treatment approach for parents coping with adolescent substance abuse and/or dependency. Excerpts of parent sand trays are presented to demonstrate pretreatment tasks that decrease denial, reduce reactive anger, stop enabling behaviors, and build support systems. Parent-child relational issues,…

  3. Gallium nitride T-ray transmission characteristics

    NASA Astrophysics Data System (ADS)

    Ferguson, Bradley; Mickan, Samuel P.; Hubbard, Seth; Pavlidis, Dimitris; Abbott, Derek

    2001-11-01

    T-ray imaging and spectroscopy both exploit the terahertz (THz) region of the spectrum. This gives rise to very promising industrial and biomedical applications, where non-invasive and sensitive identification of a substance is achievable, through a material's distinct absorption features in the THz band. Present T-ray systems are limited by low output power, and the race is now on to find more efficient THz emitters. We discuss the feasibility of a novel high-power gallium nitride emitter for terahertz generation. This paper details the advantages of such an emitter, primarily by virtue of its high-voltage capability, and evaluates the benefits of sapphire and silicon carbide substrates. The far-infrared transmission spectra for thin samples of GaN, sapphire and SiC are reported. A high-power THz emitter, that operates at room temperature and is potentially low-cost will open up a host of new possibilities and applications. The central result in this paper demonstrates that sapphire is the better choice over SiC, for the GaN supporting substrate, as we show that it has superior THz transmission characteristics.

  4. Internal V-Band Clamp

    DOEpatents

    Vaughn, Mark R.; Hafenrichter, Everett S.; Chapa, Agapito C.; Harris, Steven M.; Martinez, Marcus J.; Baty, Roy S.

    2006-02-28

    A system for clamping two tubular members together in an end-to-end relationship uses a split ring with a V-shaped outer rim that can engage a clamping surface on each member. The split ring has a relaxed closed state where the ends of the ring are adjacent and the outside diameter of the split ring is less than the minimum inside diameter of the members at their ends. The members are clamped when the split ring is spread into an elastically stretched position where the ring rim is pressed tightly against the interior surfaces of the members. Mechanisms are provided for removing the spreader so the split ring will return to the relaxed state, releasing the clamped members.

  5. Management of umbilical cord clamping.

    PubMed

    Webbon, Lucy

    2013-02-01

    The Royal College of Midwives (RCM) has updated its third stage of labour guidelines (RCM 2012) to be clearly supportive of a delay in umbilical cord clamping, although specific guidance on timing is yet to be announced. It is therefore imperative that both midwives and student midwives understand and are able to integrate delaying into their practice, as well as communicating to women the benefits; only in this way can we give women fully informed choices on this aspect of care. The main benefit of delayed cord clamping is the protection it can provide in reducing childhood anaemia, which is a major issue, especially in poorer countries. A review of the evidence found no risks linked to delayed clamping, and no evidence that it cannot be used in combination with the administration of uterotonic drugs. Delayed cord clamping can be especially beneficial for pre term and compromised babies.

  6. Assessing Tibial Tray Rotation in TKA: A Cadaveric Study.

    PubMed

    Hakki, Sam; El-Othmani, Mouhanad M; Gabriel, Christian; Mihalko, William M; Saleh, Khaled J

    2016-05-01

    Tibial anatomical landmarks for transverse plane rotation of the tibial tray have not been validated. The current authors propose aligning the tibial tray with both the anterior tibial center point of rotation (ATCPR) and the femoral trochlear groove (FTG) to establish the ideal tibial tray rotation in total knee arthroplasty (TKA). When the tibial tray centerline was aligned with ATCPR and FTG lines, the mean range of motion (ROM) was 144.3° (preoperatively 145°) and tibial rotation range was 22.8 mm (preoperatively, 24.9 mm). When the tibial component was rotated 5 mm medially to the ATCPR, the knee ROM decreased in flexion with patellar subluxation, while it decreased in extension when rotated 5 mm laterally. This method identifies the ideal tibial tray rotation in TKA, at which maximal range of tibial rotation and knee ROM are achieved without obvious overriding of components. [Orthopedics, 2016; 39(3):S67-S71.]. Copyright 2016, SLACK Incorporated.

  7. Reducing otolaryngology surgical inefficiency via assessment of tray redundancy.

    PubMed

    Chin, Christopher J; Sowerby, Leigh J; John-Baptiste, Ava; Rotenberg, Brian W

    2014-01-01

    Health care costs in Canada continue to rise. As a result of this relentless increase in healthcare spending, ways to increase efficiency and decrease cost are constantly being sought. Surgical treatment is the mainstay of therapy for many conditions in the field of Otolaryngology- Head and Neck Surgery. The evidence suggests that room exists to optimize tray efficiency as a novel means of improving operating room throughput. We conducted a review of instruments on surgical trays for 5 commonly performed procedures between July 5th, 2013 and September 20th, 2013 at St Joseph's Hospital. The Instrument Utilization Rate was calculated; we then designed new 'optimized' trays based on which instruments were used at least 20% of the time. We obtained tray building times from Central Processing Department, then calculated an overall mean time per instrument (to pack the freshly washed instruments). We then determined the time that could be saved by using our new optimized trays. In total, 226 instrument trays were observed (Table 1). The average Instrument Utilization Rate was 27.8% (+/- 13.1). Our optimized trays, on average, reduced tray size by 57%. The average time to pack one instrument was 17.7 seconds. By selectively reducing our trays, we plan to reduce tray content by an average of 57%. It is important to remember that this number looks at only 5 procedures in the Department of Otolaryngology- Head and Neck Surgery. If this was expanded city-wide to the rest of the departments, the improved efficiency could potentially be quite substantial.

  8. Further analysis of LDEF FRECOPA micrometeroid remnants

    NASA Astrophysics Data System (ADS)

    Borg, J.; Bunch, T. E.; Radicatidibrozolo, Filippo

    1992-06-01

    Experiments dedicated to the detection of interplanetary dust particles (IDP's) were exposed within the FRECOPA payload, installed on the face of the LDEF directly opposed to the velocity vector (west facing direction, location B3). We were mainly interested in the analysis of hypervelocity impact features of sizes less than or = 10 microns, found in thick Al targets devoted to the research of impact features. In the 15 craters found in the scanned area (approximately 4 sq. cm), the chemical analysis suggests an extraterrestrial origin for the impacting particles. The main elements we identified are usually refered to as chondrite elements: Na, Mg, Si, S, Ca, and Fe are found in various proportions, intrinsic Al being masked by the Al target; we notice a strong depletion in Ni, never observed in our samples. Furthermore, C and O are present in 90 percent of the cases; the C/O peak height ratio varies from 0.1 to 3. Impactor simulations by light gas gun hypervelocity impact experiments have shown that meaningful biogenic element and compound information maybe obtained from IDP residues below impacts of critical velocities, that are less than or = 4 km/sec for particles larger than 100 microns in diameter. Our results obtained for the smaller size fraction IDP's suggest that at such sizes, the critical velocity could be higher by a factor of 2 or 3, as chemical analysis of the remnants were possible in all the identified impact craters, performed on targets possibly hit at velocities greater than or = 7.5 km/s, which is the spacecraft velocity. These samples are now subjected to an imagery and analytical protocol that includes FESEM (field emission scanning electron microscopy) and LIMS (laser ionization mass spectrometry). The LIMS analyses were performed using the LIMA-ZA instrument. Results are presented, clearly indicating that such small events show crater features analogous to what is observed at larger sizes; our first analytical results, obtained for 2 events

  9. Influence of Custom Trays, Dual-Arch Passive, Flexed Trays and Viscosities of Elastomeric Impression Materials on Working Dies.

    PubMed

    Arora, Mansi; Kohli, Shivani; Kalsi, Rupali

    2016-05-01

    Dual arch impression technique signifies an essential improvement in fixed prosthodontics and has numerous benefits over conventional impression techniques. The accuracy of working dies fabricated from dual arch impression technique remains in question because there is little information available in the literature. This study was conducted to compare the accuracy of working dies fabricated from impressions made from two different viscosities of impression materials using metal, plastic dual arch trays and custom made acrylic trays. The study samples were grouped into two groups based on the viscosity of impression material used i.e. Group I (monophase), whereas Group II consisted of Dual Mix technique using a combination of light and heavy body material. These were further divided into three subgroups A, B and C depending on the type of impression tray used (metal dual arch tray, plastic dual arch tray and custom made tray). Measurements of the master cast were made using profile projector. Descriptive statistics like mean, Standard Deviation (SD) were calculated for all the groups. One way analysis of variance (ANOVA) was used for multiple group comparisons. A p-value of 0.05 or less was considered statistically significant. The gypsum dies obtained with the three types of impression trays using two groups of impression materials were smaller than the master models in dimensions. The plastic dual arch trays produced dies which were the least accurate of the three groups. There was no significant difference in the die dimensions obtained using the two viscosities of impression materials.

  10. LDEF's map experiment foil perforations yield hypervelocity impact penetration parameters

    NASA Technical Reports Server (NTRS)

    Mcdonnell, J. A. M.

    1992-01-01

    The space exposure of LDEF for 5.75 years, forming a host target in low earth orbit (LEO) orbit to a wide distribution of hypervelocity particulates of varying dimensions and different impact velocities, has yielded a multiplicity of impact features. Although the projectile parameters are generally unknown and, in fact not identical for any two impacts on a target, the great number of impacts provides statistically meaningful basis for the valid comparison of the response of different targets. Given sufficient impacts for example, a comparison of impact features (even without knowledge of the project parameters) is possible between: (1) differing material types (for the same incident projectile distribution); (2) differing target configurations (e.g., thick and thin targets for the same material projectiles; and (3) different velocities (using LDEF's different faces). A comparison between different materials is presented for infinite targets of aluminum, Teflon, and brass in the same pointing direction; the maximum finite-target penetration (ballistic limit) is also compared to that of the penetration of similar materials comprising of a semi-infinite target. For comparison of impacts on similar materials at different velocities, use is made of the pointing direction relative to LDEF's orbital motion. First, however, care must be exercised to separate the effect of spatial flux anisotropies from those resulting from the spacecraft velocity through a geocentrically referenced dust distribution. Data comprising thick and thin target impacts, impacts on different materials, and in different pointing directions is presented; hypervelocity impact parameters are derived. Results are also shown for flux modeling codes developed to decode the relative fluxes of Earth orbital and unbound interplanetary components intercepting LDEF. Modeling shows the west and space pointing faces are dominated by interplanetary particles and yields a mean velocity of 23.5 km/s at LDEF

  11. Induced radioactivity of LDEF materials and structural components

    NASA Technical Reports Server (NTRS)

    Harmon, B. A.; Laird, C. E.; Fishman, G. J.; Parnell, T. A.; Camp, D. C.; Frederick, C. E.; Hurley, D. L.; Lindstrom, D. J.; Moss, C. E.; Reedy, R. C.; hide

    1996-01-01

    We present an overview of the Long Duration Exposure Facility (LDEF) induced activation measurements. The LDEF, which was gravity-gradient stabilized, was exposed to the low Earth orbit (LEO) radiation environment over a 5.8 year period. Retrieved activation samples and structural components from the spacecraft were analyzed with low and ultra-low background HPGe gamma spectrometry at several national facilities. This allowed a very sensitive measurement of long-lived radionuclides produced by proton- and neutron-induced reactions in the time-dependent, non-isotropic LEO environment. A summary of major findings from this study is given that consists of directionally dependent activation, depth profiles, thermal neutron activation, and surface beryllium-7 deposition from the upper atmosphere. We also describe a database of these measurements that has been prepared for use in testing radiation environmental models and spacecraft design.

  12. LDEF data correlation to existing NASA debris environment models

    NASA Technical Reports Server (NTRS)

    Atkinson, Dale R.; Allbrooks, Martha K.; Watts, Alan J.

    1991-01-01

    Since the Long Duration Exposure Facility was gravity gradient stabilized and did not rotate, the directional dependence of the flux can be easily distinguished. During the deintegration of LDEF, all impact features larger than 0.5 mm into aluminum were documented for diameters and locations. In addition, all diameters and locations of all impact features larger than 0.3 mm into Scheldahl G411500 thermal control blankets were also documented. This data, along with additional information collected from LDEF materials archived at NASA Johnson Space Center (JSC) on smaller features, will be compared with current meteoroid and debris models. This comparison will provide a validation of the models and will identify discrepancies between the models and the data.

  13. Radiation and temperature effects on LDEF fiber optic samples

    NASA Technical Reports Server (NTRS)

    Johnston, A. R.; Hartmayer, R.; Bergman, L. A.

    1993-01-01

    Results obtained from the JPL Fiber Optics Long Duration Exposure Facility (LDEF) Experiment since the June 1991 Experimenters' Workshop are addressed. Radiation darkening of laboratory control samples and the subsequent annealing was measured in the laboratory for the control samples. The long-time residual loss was compared to the LDEF flight samples and found to be in agreement. The results of laboratory temperature tests on the flight samples, extending over a period of about nine years, including the pre-flight and post-flight analysis periods, are described. The temperature response of the different cable samples varies widely, and appears in two samples to be affected by polymer aging. Conclusions to date are summarized.

  14. Induced radioactivity of LDEF materials and structural components

    NASA Technical Reports Server (NTRS)

    Harmon, B. A.; Laird, C. E.; Fishman, G. J.; Parnell, T. A.; Camp, D. C.; Frederick, C. E.; Hurley, D. L.; Lindstrom, D. J.; Moss, C. E.; Reedy, R. C.; Reeves, J. H.; Smith, A. R.; Winn, W. G.; Benton, E. V.

    1996-01-01

    We present an overview of the Long Duration Exposure Facility (LDEF) induced activation measurements. The LDEF, which was gravity-gradient stabilized, was exposed to the low Earth orbit (LEO) radiation environment over a 5.8 year period. Retrieved activation samples and structural components from the spacecraft were analyzed with low and ultra-low background HPGe gamma spectrometry at several national facilities. This allowed a very sensitive measurement of long-lived radionuclides produced by proton- and neutron-induced reactions in the time-dependent, non-isotropic LEO environment. A summary of major findings from this study is given that consists of directionally dependent activation, depth profiles, thermal neutron activation, and surface beryllium-7 deposition from the upper atmosphere. We also describe a database of these measurements that has been prepared for use in testing radiation environmental models and spacecraft design.

  15. VUV-induced degradation of FEP Teflon aboard LDEF

    NASA Technical Reports Server (NTRS)

    Brinza, David E.; Liang, Ranty H.; Stiegman, Albert E.

    1991-01-01

    Examination of fluorinated ethylene propylene (FEP) copolymer materials recovered from the Long Duration Exposure Facility (LDEF) reveals differing damage characteristics on leading edge (ram-facing) versus trailing edge (wake-facing surfaces). Silver/Teflon (Ag/FEP) thermal control materials on ram facing surfaces of the LDEF exhibited obvious degradation, with an apparent increase in diffuse light scattering, whereas identical materials on the wake facing surfaces showed little apparent damage with cursory inspection. Microscopic examination of both types of surfaces reveals the nature and extent of environment induced degradation of materials. The ram facing surfaces were clearly eroded by atomic oxygen impingement, while the wake facing material developed a thin, highly embrittled surface layer.

  16. The ionizing radiation environment of LDEF prerecovery predictions

    NASA Technical Reports Server (NTRS)

    Watts, John W., Jr.; Derrickson, James H.; Parnell, T. A.; Fishman, G. J.; Harmon, A.; Benton, E. V.; Frank, A. L.; Heinrich, Wolfgang

    1991-01-01

    The Long Duration Exposure Facility (LDEF) was exposed to several sources of ionizing radiation while in orbit. The principal ones were trapped belt protons and electrons, galactic cosmic rays, and albedo particles (protons and neutrons) from the atmosphere. Large solar flares in 1989 may have caused a small contribution. Prior to the recovery of the spacecraft, a number of calculations and estimates were made to predict the radiation exposure of the spacecraft and experiments. These were made to assess whether measurable radiation effects might exist, and to plan the analysis of the large number of radiation measurements available on the LDEF. Calculations and estimates of total dose, particle fluences, linear energy transfer spectra, and induced radioactivity were made. The principal sources of radiation is described, and the preflight predictions are summarized.

  17. Thermal expansion behavior of LDEF metal matrix composites

    NASA Technical Reports Server (NTRS)

    Le, Tuyen D.; Steckel, Gary L.

    1993-01-01

    The thermal expansion behavior of Long Duration Exposure Facility (LDEF) metal matrix composite materials was studied by (1) analyzing the flight data that was recorded on orbit to determine the effects of orbital time and heating/cooling rates on the performance of the composite materials, and (2) characterizing and comparing the thermal expansion behavior of post-flight LDEF and lab-control samples. The flight data revealed that structures in space are subjected to nonuniform temperature distributions, and thermal conductivity of a material is an important factor in establishing a uniform temperature distribution and avoiding thermal distortion. The flight and laboratory data showed that both Gr/Al and Gr/Mg composites were stabilized after prolonged thermal cycling on orbit. However, Gr/Al composites showed more stable thermal expansion behavior than Gr/Mg composites and offer advantages for space structures particularly where very tight thermal stability requirements in addition to high material performance must be met.

  18. The ionizing radiation environment of LDEF prerecovery predictions

    NASA Technical Reports Server (NTRS)

    Watts, John W., Jr.; Derrickson, James H.; Parnell, T. A.; Fishman, G. J.; Harmon, A.; Benton, E. V.; Frank, A. L.; Heinrich, Wolfgang

    1991-01-01

    The Long Duration Exposure Facility (LDEF) was exposed to several sources of ionizing radiation while in orbit. The principal ones were trapped belt protons and electrons, galactic cosmic rays, and albedo particles (protons and neutrons) from the atmosphere. Large solar flares in 1989 may have caused a small contribution. Prior to the recovery of the spacecraft, a number of calculations and estimates were made to predict the radiation exposure of the spacecraft and experiments. These were made to assess whether measurable radiation effects might exist, and to plan the analysis of the large number of radiation measurements available on the LDEF. Calculations and estimates of total dose, particle fluences, linear energy transfer spectra, and induced radioactivity were made. The principal sources of radiation is described, and the preflight predictions are summarized.

  19. Toward a homogeneous and efficient batch-tray dryer

    SciTech Connect

    Khattab, N.M.

    1996-06-01

    In batch-tray dryers, with equal loading of trays, a nonhomogeneous drying of the product may result. This will degrade the quality of the dried product, as some of it will be either overdried or underdried. To obtain homogeneous drying, the trays must be loaded in accordance with the condition of the inlet air to each tray, i.e., as the air gets cooler and more saturated with moisture when moving upward, the tray loading should be reduced. The aim of the present work is to develop an analytical method for obtaining the best loading pattern in batch-tray dryers, that guarantees a homogeneous and efficient drying of the product. A mathematical model that describes the mass and heat transfer inside the dryer is proposed. Homogeneous drying is achieved by solving the model under constraints imposed by some proposed control functions, giving as a result the loading of different trays. An algorithm of the calculation procedures is given, and an application to study drying of apricots is demonstrated. In addition, the performance of the dryer, loaded so as to achieve homogeneous drying of the product, was studied under a wide range of inlet air conditions to determine the one that gives maximum productivity of the dryer. The final result of those calculations is to obtain the necessary condition for a product of good quality dried in the most efficient way.

  20. Follow up on the crystal growth experiments of the LDEF

    NASA Technical Reports Server (NTRS)

    Nielsen, K. F.; Lind, M. D.

    1993-01-01

    The results of the 4 solution growth experiments on the LDEF have been published elsewhere. Both the crystals of CaCO3, which were large and well shaped, and the much smaller TTF-TCNQ crystals showed unusual morphological behavior. The follow up on these experiments was begun in 1981, when ESA initiated a 'Concept Definition Study' on a large, 150 kg, Solution Growth Facility (SGF) to be included in the payload of EURECA-1, the European Retrievable Carrier. This carrier was a continuation of the European Spacelab and at that time planned for launch in 1987. The long delay of the LDEF retrieval and of subsequent missions brought about reflections both on the concept of crystal growth in space and on the choice of crystallization materials that had been made for the LDEF. Already before the LDEF retrieval, research on TTF-TCNQ had been stopped, and a planned growth experiment with TTF-TCNQ on the SGF/EURECA had been cancelled. The target of the SGF investigation is now more fundamental in nature. None of the crystals to be grown here are, like TTF-TCNQ, in particular demand by science or industry, and the crystals only serve the purpose of model crystals. The real purpose of the investigation is to study the growth behavior. One of the experiments, the Soret Coefficient Measurement experiment is not growing crystals at all, but has it as its sole purpose to obtain accurate information on thermal diffusion, a process of importance in crystal growth from solution.

  1. Experimental impacts into Teflon targets and LDEF thermal blankets

    NASA Technical Reports Server (NTRS)

    Hoerz, F.; Cintala, M. J.; Zolensky, M. E.; Bernhard, R. P.; See, T. H.

    1994-01-01

    The Long Duration Exposure Facility (LDEF) exposed approximately 20 sq m of identical thermal protective blankets, predominantly on the Ultra-Heavy Cosmic Ray Experiment (UHCRE). Approximately 700 penetration holes greater than 300 micron in diameter were individually documented, while thousands of smaller penetrations and craters occurred in these blankets. As a result of their 5.7 year exposure and because they pointed into a variety of different directions relative to the orbital motion of the nonspinning LDEF platform, these blankets can reveal important dynamic aspects of the hypervelocity particle environment in near-earth orbit. The blankets were composed of an outer teflon layer (approximately 125 micron thick), followed by a vapor-deposited rear mirror of silver (less than 1000 A thick) that was backed with an organic binder and a thermal protective paint (approximately 50 to 75 micron thick), resulting in a cumulative thickness (T) of approximately 175 to 200 microns for the entire blanket. Many penetrations resulted in highly variable delaminations of the teflon/metal or metal/organic binder interfaces that manifest themselves as 'dark' halos or rings, because of subsequent oxidation of the exposed silver mirror. The variety of these dark albedo features is bewildering, ranging from totally absent, to broad halos, to sharp single or multiple rings. Over the past year experiments were conducted over a wide range of velocities (i.e., 1 to 7 km/s) to address velocity dependent aspects of cratering and penetrations of teflon targets. In addition, experiments were performed with real LDEF thermal blankets to duplicate the LDEF delaminations and to investigate a possible relationship of initial impact conditions on the wide variety of dark halo and ring features.

  2. Holographic data storage crystals for LDEF (A0044)

    NASA Technical Reports Server (NTRS)

    Callen, W. R.; Gaylord, T. K.

    1984-01-01

    Electro-optic holographic recording systems were developed. The spaceworthiness of electro-optic crystals for use in ultrahigh capacity space data storage and retrieval systems are examined. The crystals for this experiment are included with the various electro-optical components of LDEF experiment. The effects of long-duration exposure on active optical system components is investigated. The concept of data storage in an optical-phase holographic memory is illustrated.

  3. Preliminary results from the LDEF/UTIAS composite materials experiment

    NASA Technical Reports Server (NTRS)

    Tennyson, R. C.; Mabson, G. E.; Morison, W. D.; Kleiman, J.

    1992-01-01

    A total of 107 epoxy matrix composite samples containing carbon, boron, and aramid fiber reinforcements were flown on the Long Duration Exposure Facility (LDEF) satellite. For the first 371 days after deployment, strain and temperature data were recorded every 16 hours. Results were obtained on time to outgas, dimensional changes, coefficients of thermal expansion, atomic oxygen erosion, and damage due to micrometeoroid/debris impacts.

  4. Capabilities of the LDEF-2 heavy nuclei collection

    NASA Technical Reports Server (NTRS)

    Drach, J.; Price, P. B.; Salamon, M. H.; Tarle, G.; Ahlen, S. P.

    1985-01-01

    To take the next big step beyond High Energy Astronomy Observatory (HEAO-3) the Heavy Nuclei Collector (HNC), to be carried on an LDEF reflight, has the goals of greatly increased collecting power ( 30 actinides) and charge resolution sigma sub Z or = 0.25 E for Z up to approximately 100, which will provide abundances of all the charges 40 or Z or = 96 and permit sensitive searches for hypothetical particles such as monopoles, superheavy elements, and quark nuggets.

  5. Analysis of surfaces from the LDEF A0114, phase 2

    NASA Technical Reports Server (NTRS)

    Gregory, John C.

    1992-01-01

    Analysis of surfaces from the Long Duration Exposure Facility (LDEF) continued during the reporting period. Work has continued on profilometry measurements of eroded and corroded sample surfaces, optical transmission measurements, analysis of the pinhole camera, and x-ray photoelectron spectroscopy (XPS) analysis of some samples. Papers that have appeared or have been accepted for publications are listed. Several of these papers and an abstact are included.

  6. LDEF: 69 Months in Space. Part 4: Second Post-Retrieval Symposium

    NASA Technical Reports Server (NTRS)

    Levine, Arlene S. (Editor)

    1993-01-01

    A compilation of papers presented at the Second Long Duration Exposure Facility (LDEF) Post-Retrieval Symposium are presented. The papers represent the data analysis of the 57 experiments flown on the LDEF. The experiments include materials, coatings, thermal systems, power and propulsion, science (cosmic ray, interstellar gas, heavy ions, micrometeoroid, etc.), electronics, optics, and life sciences.

  7. LDEF: 69 Months in Space. Second Post-Retrieval Symposium, part 2

    NASA Technical Reports Server (NTRS)

    Levine, Arlene S. (Editor)

    1993-01-01

    This document is a compilation of papers presented at the Second Long Duration Exposure Facility (LDEF) Post-Retrieval Symposium. The papers represent the data analysis of the 57 experiments flown on the LDEF. The experiments include materials, coatings, thermal systems, power and propulsion, science (cosmic ray, interstellar gas, heavy ions, micrometeoroid, etc.), electronics, optics, and life science.

  8. LDEF: 69 Months in Space. First Post-Retrieval Symposium, part 3

    NASA Technical Reports Server (NTRS)

    Levine, Arlene S. (Editor)

    1992-01-01

    A compilation of papers presented at the First Long Duration Exposure Facility (LDEF) Post-Retrieval Symposium is presented. The papers represent the preliminary data analysis of the 57 experiments flown on the LDEF. The experiments include materials, coatings, thermal systems, power and propulsion, science (cosmic ray, interstellar gas, heavy ions, and micrometeoroid), electronics, optics, and life sciences.

  9. LDEF: 69 Months in Space. Part 3: Second Post-Retrieval Symposium

    NASA Technical Reports Server (NTRS)

    Levine, Arlene S. (Editor)

    1993-01-01

    Papers presented at the Second Long Duration Exposure Facility (LDEF) Post-Retrieval Symposium are included. The papers represent the data analysis of the 57 experiments flown on the LDEF. The experiments include materials, coatings, thermal systems, power and propulsion, science (cosmic ray, interstellar gas, heavy ions, micrometeoroid, etc.), electronics, optics, and life science.

  10. M and D SIG progress report: Laboratory simulations of LDEF impact features

    NASA Technical Reports Server (NTRS)

    Horz, Friedrich; Bernhard, R. P.; See, Thomas H.; Atkinson, Dale R.; Allbrooks, Martha K.

    1991-01-01

    Reported here are impact simulations into pure Teflon and aluminum targets. These experiments will allow first order interpretations of impact features on the Long Duration Exposure Facility (LDEF), and they will serve as guides for dedicated experiments that employ the real LDEF blankets, both unexposed and exposed, for a refined understanding of the Long Duration Exposure Facility's collisional environment.

  11. M and D SIG progress report: Laboratory simulations of LDEF impact features

    NASA Technical Reports Server (NTRS)

    Horz, Friedrich; Bernhard, R. P.; See, Thomas H.; Atkinson, Dale R.; Allbrooks, Martha K.

    1991-01-01

    Reported here are impact simulations into pure Teflon and aluminum targets. These experiments will allow first order interpretations of impact features on the Long Duration Exposure Facility (LDEF), and they will serve as guides for dedicated experiments that employ the real LDEF blankets, both unexposed and exposed, for a refined understanding of the Long Duration Exposure Facility's collisional environment.

  12. LDEF: 69 Months in Space. Part 1: Second Post-Retrieval Symposium

    NASA Technical Reports Server (NTRS)

    Levine, Arlene S. (Editor)

    1993-01-01

    A compilation of papers presented at the Second Long Duration Exposure Facility (LDEF) Post-Retrieval Symposium is included. The papers represent the data analysis of the 57 experiments flown on the LDEF. The experiments include materials, coatings, thermal systems, power and propulsion, science (cosmic ray, interstellar gas, heavy ions, micrometeoroid, etc.), electronics, optics, and life sciences.

  13. Follow up on the crystal growth experiments of the LDEF

    NASA Technical Reports Server (NTRS)

    Nielsen, K. F.; Lind, M. D.

    1992-01-01

    The 4 solution growth experiments on the LDEF were presented thoroughly elsewhere. The CaCO3-experiment, and to a certain extent also the TTF-TCNQ-experiments yielded useful results. In Jan. 1992, the next series of solution growth experiments were sent to ESA for shipment to KSC. As on the LDEF, the SGF (solution growth facility) of the EURECA-1 contains 4 large experiments. From the beginning, the planning and developments were introduced. Still, the basic concept was maintained, and the CaCO3-experiment, that showed the best results on the LDEF, will now be repeated with improved technology and in larger scale on the EURECA-1. The contents of the 4 SGF experiments are as follows: (1) growth of calcium-carbonate crystals; (2) formation and transformation of tri-calcium-phosphate; (3) growth of zeolite crystals; and (4) soret coefficient measurements (diffusion). The scientific background for the choice of experiments and the major improvements of the SGF are reviewed. Furthermore, some ideas on basic microgravity solution growth experimentation from ESA's newly established EWG (Expert Working Group) on solution growth are reported.

  14. LDEF contributions to cosmic ray and radiation environments research

    SciTech Connect

    Parnell, T.A.

    1995-02-01

    LDEF-1 carried three experiments which are producing significant advances in our knowledge of ultra heavy and anomalous cosmic rays, solar flare particles, and heavy nuclei in the trapped belts. Nine other experiments made measurements on the radiation environments or performed dosmetric monitoring. Data from those experiments, and from measurements of induced radioactivity in LDEF components have significantly improved our knowledge of LEO radiation environment. Measurements at various locations shielding depths of radiation absorbed dose, linear energy transfer spectra, proton, neutron and heavy ion fluences, and induced radioactivity have been made, and many of these results have been compared to models. This has allowed the assessment of accuracy, and the potential for improvement, of the models. Serendipitous results from the radiation measurements include the discovery of atmospheric Be-7 plated on the front surface of LDEF, which has motivated a series of new investigations. A sample of measurements and modeling results will be presented, as well as the status of archiving the measurements and models.

  15. Effects of orbital exposure on Halar during the LDEF mission

    NASA Technical Reports Server (NTRS)

    Brower, William E., Jr.; Holla, Harish; Bauer, Robert A.

    1992-01-01

    Thermomechanical Analysis (TMA), Differential Scanning Calorimetry (DSC), and Thermogravimetric Analysis (TGA) were performed on samples of Halar exposed on the LDEF Mission for 6 years in orbit and unexposed Halar control samples. Sections 10-100 microns thick were removed from the exposed surface down to a depth of 1,000 microns through the 3 mm thick samples. The TMA and DSC results, which arise from the entire slice and not just its surface, showed no differences between the LDEF and the control samples. TMA scans were run from ambient to 300 C; results were compared by a tabulation of the glass transition temperatures. DSC scans were run from ambient to 700 C; the enthalpy of melting was compared for the samples as a function of section depth with the sample. The TGA results, which arise from the surface of the sample initially, showed a sharp increase in the topmost 50 micron section (the exposed, discolored side) in the weight loss of 170 C in oxygen. This weight loss dropped to bulk values in the range of depth of 50-200 microns. The control sample showed only a slight increase in weight loss as the top surface was approached. The LDEF Halar sample appears to be mechanically undamaged, with a surface layer which oxidizes faster as a result of orbital exposure.

  16. Fullerenes in an impact crater on the LDEF spacecraft

    NASA Technical Reports Server (NTRS)

    Radicati di Brozolo, F.; Bunch, T. E.; Fleming, R. H.; Macklin, J.

    1994-01-01

    The fullerenes C60 and C70 have been found to occur naturally on Earth and have also been invoked to explain features in the absorption spectra of interstellar clouds. But no definitive spectroscopic evidence exists for fullerenes in space and attempts to find fullerenes in carbonaceous chondrites have been unsuccessful. Here we report the observation of fullerenes associated with carbonaceous impact residue in a crater on the Long Duration Exposure Facility (LDEF) spacecraft. Laser ionization mass spectrometry and Raman spectroscopy indicate the presence of fullerenes in the crater and in adjacent ejecta. Man-made fullerenes survive experimental hypervelocity (approximately 6.1 km s-1) impacts into aluminium targets, suggesting that space fullerenes contained in a carbonaceous micrometeorite could have survived the LDEF impact at velocities towards the lower end of the natural particle encounter range (<13 km s-1). We also demonstrate that the fullerenes were unlikely to have formed as instrumental artefacts, nor are they present as contaminants. Although we cannot specify the origin of the fullerenes with certainty, the most plausible source is the chondritic impactor. If, alternatively, the impact produced the fullerenes in situ on LDEF, then this suggests a viable mechanism for fullerene production in space.

  17. Fullerenes in an impact crater on the LDEF spacecraft.

    PubMed

    Radicati di Brozolo, F; Bunch, T E; Fleming, R H; Macklin, J

    1994-05-05

    The fullerenes C60 and C70 have been found to occur naturally on Earth and have also been invoked to explain features in the absorption spectra of interstellar clouds. But no definitive spectroscopic evidence exists for fullerenes in space and attempts to find fullerenes in carbonaceous chondrites have been unsuccessful. Here we report the observation of fullerenes associated with carbonaceous impact residue in a crater on the Long Duration Exposure Facility (LDEF) spacecraft. Laser ionization mass spectrometry and Raman spectroscopy indicate the presence of fullerenes in the crater and in adjacent ejecta. Man-made fullerenes survive experimental hypervelocity (approximately 6.1 km s-1) impacts into aluminium targets, suggesting that space fullerenes contained in a carbonaceous micrometeorite could have survived the LDEF impact at velocities towards the lower end of the natural particle encounter range (<13 km s-1). We also demonstrate that the fullerenes were unlikely to have formed as instrumental artefacts, nor are they present as contaminants. Although we cannot specify the origin of the fullerenes with certainty, the most plausible source is the chondritic impactor. If, alternatively, the impact produced the fullerenes in situ on LDEF, then this suggests a viable mechanism for fullerene production in space.

  18. Materials And Processes Technical Information System (MAPTIS) LDEF materials database

    NASA Technical Reports Server (NTRS)

    Davis, John M.; Strickland, John W.

    1992-01-01

    The Materials and Processes Technical Information System (MAPTIS) is a collection of materials data which was computerized and is available to engineers in the aerospace community involved in the design and development of spacecraft and related hardware. Consisting of various database segments, MAPTIS provides the user with information such as material properties, test data derived from tests specifically conducted for qualification of materials for use in space, verification and control, project management, material information, and various administrative requirements. A recent addition to the project management segment consists of materials data derived from the LDEF flight. This tremendous quantity of data consists of both pre-flight and post-flight data in such diverse areas as optical/thermal, mechanical and electrical properties, atomic concentration surface analysis data, as well as general data such as sample placement on the satellite, A-O flux, equivalent sun hours, etc. Each data point is referenced to the primary investigator(s) and the published paper from which the data was taken. The MAPTIS system is envisioned to become the central location for all LDEF materials data. This paper consists of multiple parts, comprising a general overview of the MAPTIS System and the types of data contained within, and the specific LDEF data element and the data contained in that segment.

  19. Fullerenes in an impact crater on the LDEF spacecraft

    NASA Technical Reports Server (NTRS)

    Radicati di Brozolo, F.; Bunch, T. E.; Fleming, R. H.; Macklin, J.

    1994-01-01

    The fullerenes C60 and C70 have been found to occur naturally on Earth and have also been invoked to explain features in the absorption spectra of interstellar clouds. But no definitive spectroscopic evidence exists for fullerenes in space and attempts to find fullerenes in carbonaceous chondrites have been unsuccessful. Here we report the observation of fullerenes associated with carbonaceous impact residue in a crater on the Long Duration Exposure Facility (LDEF) spacecraft. Laser ionization mass spectrometry and Raman spectroscopy indicate the presence of fullerenes in the crater and in adjacent ejecta. Man-made fullerenes survive experimental hypervelocity (approximately 6.1 km s-1) impacts into aluminium targets, suggesting that space fullerenes contained in a carbonaceous micrometeorite could have survived the LDEF impact at velocities towards the lower end of the natural particle encounter range (<13 km s-1). We also demonstrate that the fullerenes were unlikely to have formed as instrumental artefacts, nor are they present as contaminants. Although we cannot specify the origin of the fullerenes with certainty, the most plausible source is the chondritic impactor. If, alternatively, the impact produced the fullerenes in situ on LDEF, then this suggests a viable mechanism for fullerene production in space.

  20. Results from the testing and analysis of LDEF batteries

    NASA Technical Reports Server (NTRS)

    Spear, Steve; Dursch, Harry; Johnson, Chris

    1992-01-01

    Batteries were used on the Long Duration Exposure Facility (LDEF) to provide power to both the active experiments and the experiment support equipment such as the Experiment Initiative System, Experiment Power and Data System (data acquisition system), and the Environment Exposure Control Canisters. Three different types of batteries were used: lithium sulfur dioxide (LiSO2), lithium carbon monofluoride (LiCF), and nickel cadmium (NiCd). A total of 92 LiSO2, 10 LiCF, and 1 NiCd batteries were flown on the LDEF. In addition, approximately 20 LiSO2 batteries were kept in cold storage at NASA LaRC. The various investigations and post-flight analyses of the flight and control batteries are reviewed. The primary objectives of these studies was to identify degradation modes (if any) of the batteries and to provide information useful to future spacecraft missions. Systems SIG involvement in the post-flight evaluation of LDEF batteries was two-fold: (1) to fund SAFT (original manufacturer of the LiSO2 batteries) to perform characterization of 13 LiSO2 batteries (10 flight and 3 control batteries); and (2) to integrate investigator results.

  1. Split-tapered joint clamping device

    DOEpatents

    Olsen, Max J.; Schwartz, Jr., John F.

    1988-01-01

    This invention relates to a clamping device for removably attaching a tool element to a bracket element wherein a bracket element is disposed in a groove in the tool and a clamping member is disposed in said groove and in engagement with a clamping face of the bracket and a wall of the groove and with the clamping member having pivot means engaging the bracket and about which the clamping member rotates.

  2. Design and Production of Damage-Resistant Tray Pack Containers

    DTIC Science & Technology

    1985-07-01

    U) (01 ECHNICAL REPORT AD _____ 4ATICK/TR-86/008 < DESIGN AND PRODUCTION OF DAMAGE-RESISTANT TRAY PACK CONTAINE’.RS BY D I RICHARD D. CUMMINGS JULY...REPORT & PERIOO COVEREDDESIGN AND PRODUCTION OP DAMAGE-RESISTANT FINAL REPORT TRAY PACK CON’TAINERS 13 APRIL 1984 - 31 JULY 1985 G. PERFORMING ORG...Cont"nue on iee ,ide I ne.esar, od Identif, by bloPk nub.,) * TRAY PACK(S) LOADS CONTAINERS DAMAGE PACKAGING LOADING (HANDLING) SHIPPING TESTS 20

  3. Micromachined patch-clamp apparatus

    SciTech Connect

    Okandan, Murat

    2012-12-04

    A micromachined patch-clamp apparatus is disclosed for holding one or more cells and providing electrical, chemical, or mechanical stimulation to the cells during analysis with the patch-clamp technique for studying ion channels in cell membranes. The apparatus formed on a silicon substrate utilizes a lower chamber formed from silicon nitride using surface micromachining and an upper chamber formed from a molded polymer material. An opening in a common wall between the chambers is used to trap and hold a cell for analysis using the patch-clamp technique with sensing electrodes on each side of the cell. Some embodiments of the present invention utilize one or more electrostatic actuators formed on the substrate to provide mechanical stimulation to the cell being analyzed, or to provide information about mechanical movement of the cell in response to electrical or chemical stimulation.

  4. Determining the accuracy of stock and custom tray impression/casts.

    PubMed

    Millstein, P; Maya, A; Segura, C

    1998-08-01

    A study was conducted to evaluate the accuracy of casts made from stock tray and custom tray impressions using polysiloxane impression material. The results indicate that all casts distort but that impressions made from custom trays were more accurate and consistent in reproduction than were stock tray impressions.

  5. Long Duration Exposure Facility (LDEF) attitude measurements of the interplanetary dust experiment

    NASA Technical Reports Server (NTRS)

    Kassel, Philip C., Jr.; Singer, S. Fred; Mulholland, J. Derral; Oliver, John P.; Weinberg, Jerry L.; Cooke, William J.; Wortman, Jim J.; Motley, William R., III

    1992-01-01

    The Long Duration Exposure Facility (LDEF) Interplanetary Dust Experiment (IDE) was unique in providing a time history of impacts of micron-sized particles on six orthogonal faces of LDEF during the first year in orbit. The value of this time resolved data depended on and was enhanced by the proper operation of some basic LDEF systems. Thus, the value of the data is greatly enhanced when the location and orientation of LDEF is known for each time of impact. The location and velocity of LDEF as a function of time can be calculated from the 'two-line elements' published by GSFC during the first year of the LDEF mission. The attitude of LDEF was passively stabilized in a gravity-gradient mode and a magnetically anchored viscous damper was used to dissipate roll, pitch, and yaw motions. Finally, the IDE used a standard LDEF Experiment Power and Data System (EPDS) to collect and store data and also to provide a crystal derived clock pulse (1 count every 13.1072 seconds) for all IDE time measurements. All that remained for the IDE was to provide a system to calibrate the clock, eliminating accumulative errors, and also verify the attitude of LDEF. The IDE used solar cells on six orthogonal faces to observe the LDEF sunrise and provide data about the LDEF attitude. The data was recorded by the EPDS about 10 times per day for the first 345 days of the LDEF mission. This data consist of the number of IDE counts since the last LDEF sunrise and the status of the six solar cells (light or dark) at the time of the last IDE count. The EPDS determined the time that data was recorded and includes, with each record, the master EPDS clock counter (1 count every 1.6384 seconds) that provided the range and resolution for time measurements. The IDE solar cells provided data for an excellent clock calibration, meeting their primary purpose, and the time resolved LDEF attitude measurements that can be gleaned from this data are presented.

  6. Long Duration Exposure Facility (LDEF) attitude measurements of the interplanetary dust experiment

    NASA Technical Reports Server (NTRS)

    Kassel, Philip C., Jr.; Singer, S. Fred; Mulholland, J. Derral; Oliver, John P.; Weinberg, Jerry L.; Cooke, William J.; Wortman, Jim J.; Motley, William R., III

    1992-01-01

    The Long Duration Exposure Facility (LDEF) Interplanetary Dust Experiment (IDE) was unique in providing a time history of impacts of micron-sized particles on six orthogonal faces of LDEF during the first year in orbit. The value of this time resolved data depended on and was enhanced by the proper operation of some basic LDEF systems. Thus, the value of the data is greatly enhanced when the location and orientation of LDEF is known for each time of impact. The location and velocity of LDEF as a function of time can be calculated from the 'two-line elements' published by GSFC during the first year of the LDEF mission. The attitude of LDEF was passively stabilized in a gravity-gradient mode and a magnetically anchored viscous damper was used to dissipate roll, pitch, and yaw motions. Finally, the IDE used a standard LDEF Experiment Power and Data System (EPDS) to collect and store data and also to provide a crystal derived clock pulse (1 count every 13.1072 seconds) for all IDE time measurements. All that remained for the IDE was to provide a system to calibrate the clock, eliminating accumulative errors, and also verify the attitude of LDEF. The IDE used solar cells on six orthogonal faces to observe the LDEF sunrise and provide data about the LDEF attitude. The data was recorded by the EPDS about 10 times per day for the first 345 days of the LDEF mission. This data consist of the number of IDE counts since the last LDEF sunrise and the status of the six solar cells (light or dark) at the time of the last IDE count. The EPDS determined the time that data was recorded and includes, with each record, the master EPDS clock counter (1 count every 1.6384 seconds) that provided the range and resolution for time measurements. The IDE solar cells provided data for an excellent clock calibration, meeting their primary purpose, and the time resolved LDEF attitude measurements that can be gleaned from this data are presented.

  7. Analysis of systems hardware flown on LDEF: New findings and comparison to other retrieved spacecraft hardware

    NASA Astrophysics Data System (ADS)

    Dursch, Harry; Bohnhoff-Hlavacek, Gail; Blue, Donald; Hansen, Patricia

    1995-09-01

    The Long Duration Exposure Facility (LDEF) was retrieved in 1990 after spending 69 months in low-earth-orbit (LEO). A wide variety of mechanical, electrical, thermal, and optical systems, subsystems, and components were flown on LDEF. The Systems Special Investigation Group (Systems SIG) was formed by NASA to investigate the effects of the 69 month exposure on systems related hardware and to coordinate and collate all systems analysis of LDEF hardware. This report is the Systems SIG final report which updates earlier findings and compares LDEF systems findings to results from other retrieved spacecraft hardware such as Hubble Space Telescope. Also included are sections titled (1) Effects of Long Duration Space Exposure on Optical Scatter, (2) Contamination Survey of LDEF, and (3) Degradation of Optical Materials in Space.

  8. Monte Carlo modeling of atomic oxygen attack of polymers with protective coatings on LDEF

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A.; Degroh, Kim K.; Auer, Bruce M.; Gebauer, Linda; Edwards, Jonathan L.

    1993-01-01

    Characterization of the behavior of atomic oxygen interaction with materials on the Long Duration Exposure Facility (LDEF) assists in understanding of the mechanisms involved. Thus the reliability of predicting in-space durability of materials based on ground laboratory testing should be improved. A computational model which simulates atomic oxygen interaction with protected polymers was developed using Monte Carlo techniques. Through the use of an assumed mechanistic behavior of atomic oxygen interaction based on in-space atomic oxygen erosion of unprotected polymers and ground laboratory atomic oxygen interaction with protected polymers, prediction of atomic oxygen interaction with protected polymers on LDEF was accomplished. However, the results of these predictions are not consistent with the observed LDEF results at defect sites in protected polymers. Improved agreement between observed LDEF results and predicted Monte Carlo modeling can be achieved by modifying of the atomic oxygen interactive assumptions used in the model. LDEF atomic oxygen undercutting results, modeling assumptions, and implications are presented.

  9. Migration and generation of contaminants from launch through recovery: LDEF case history

    NASA Technical Reports Server (NTRS)

    Crutcher, E. R.; Nishimura, L. S.; Warner, K. J.; Wascher, W. W.

    1992-01-01

    It is possible to recreate the contamination history of the Long Duration Exposure Facility (LDEF) through an analysis of its contaminants and selective samples that were collected from surfaces with better documented exposure histories. This data was then used to compare estimates based on monitoring methods that were selected for the purpose of tracking LDEF's exposure to contaminants. The LDEF experienced much more contamination than would have been assumed based on the monitors. Work is still in progress but much of what was learned so far is already being used in the selection of materials and in the design of systems for space. Now experiments are being prepared for flight to resolve questions created by the discoveries on the LDEF. A summary of what was learned about LDEF contaminants over the first year since recovery and deintegration is presented. Over 35 specific conclusions in 5 contamination related categories are listed.

  10. Analysis of systems hardware flown on LDEF: New findings and comparison to other retrieved spacecraft hardware

    NASA Technical Reports Server (NTRS)

    Dursch, Harry; Bohnhoff-Hlavacek, Gail; Blue, Donald; Hansen, Patricia

    1995-01-01

    The Long Duration Exposure Facility (LDEF) was retrieved in 1990 after spending 69 months in low-earth-orbit (LEO). A wide variety of mechanical, electrical, thermal, and optical systems, subsystems, and components were flown on LDEF. The Systems Special Investigation Group (Systems SIG) was formed by NASA to investigate the effects of the 69 month exposure on systems related hardware and to coordinate and collate all systems analysis of LDEF hardware. This report is the Systems SIG final report which updates earlier findings and compares LDEF systems findings to results from other retrieved spacecraft hardware such as Hubble Space Telescope. Also included are sections titled (1) Effects of Long Duration Space Exposure on Optical Scatter, (2) Contamination Survey of LDEF, and (3) Degradation of Optical Materials in Space.

  11. A Comparison of Results from NASA's Meteoroid Engineering Model to the LDEF Cratering Record

    NASA Technical Reports Server (NTRS)

    Ehlert, S.; Moorhead, A; Cooke, W. J.

    2017-01-01

    NASA's Long Duration Exposure Facility (LDEF) has provided an extensive record of the meteoroid environment in low Earth orbit. LDEF's combination of fixed orientation, large collecting area, and long lifetime imposes constraints on the absolute flux of potentially hazardous meteoroids. The relative impact rate on each of LDEF's fourteen surfaces arises from the underlying velocity distribution and directionality of the meteoroid environment. For the first time, we model the meteoroid environment encountered by LDEF over its operational lifetime using NASA's Meteoroid Engineering Model Release 2 (MEMR2) and compare the model results with the observed craters of potentially hazardous meteoroids (i.e. crater diameters larger than approximately 0.75 mm). We discuss the extent to which the observations and model agree and how the impact rates across all of the LDEF surfaces may be utilized to help calibrate future versions of MEM.

  12. A Comparison of Results From NASA's Meteoroid Engineering Model to the LDEF Cratering Record

    NASA Technical Reports Server (NTRS)

    Ehlert, S.; Moorhead, A.; Cooke, W. J.

    2017-01-01

    NASA's Long Duration Exposure Facility (LDEF) has provided an extensive record of the meteoroid environment in Low Earth Orbit. LDEF's combination of fixed orientation, large collecting area, and long lifetime imposes constraints on the absolute flux of potentially hazardous meteoroids. The relative impact rate on each of LDEF's fourteen surfaces arises from the underlying velocity distribution and directionality of the meteoroid environment. For the first time, we model the meteoroid environment encountered by LDEF over its operational lifetime using NASA's Meteoroid Engineering Model Release 2 (MEMR2) and compare the model results with the observed craters of potentially hazardous meteoroids (i.e. crater diameters larger than approximately 0.6 mm). We discuss the extent to which the observations and model agree and how the impact rates across all of the LDEF surfaces may suggest improvements to the underlying assumptions that go into future versions of MEM.

  13. In-office technique to fabricate triple tray.

    PubMed

    Nanda, Aditi; Kaur, Harsimran; Koli, Dheeraj; Manak, Karan; Verma, Mahesh

    2015-01-01

    Dual arch impressions have been in use for many years. Five in-office techniques for fabrication of the tray have been suggested, in case the manufactured (stock) tray is not available to the clinician. The design consists of two parts of the tray (the plastic frame and lattice). Five types of materials for the lattice have been described. The indications, advantages, and disadvantages of the techniques together with an appraisal of the five different lattice materials have been described. Overall the techniques are simple and require materials that are easily available. It does not take much time and can be used to attain efficient results in case the stock tray is not available in the operatory.

  14. 103. CABLES ENTERING CABLE TRAY SHED AT EAST OF LSB; ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    103. CABLES ENTERING CABLE TRAY SHED AT EAST OF LSB; OXIDIZER APRON AND LAUNCH PAD IN BACKGROUND - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  15. Technique for adapting a spacer for a custom impression tray.

    PubMed

    Kaur, Harsimran; Nanda, Aditi; Verma, Mahesh; Koli, Dheeraj

    2016-12-01

    A method of adapting a spacer for the custom trays used to make a definite impression for complete dentures is presented. The technique can be used under a variety of conditions and offers several advantages.

  16. Limit analysis of pipe clamps

    SciTech Connect

    Flanders, H.E. Jr.

    1990-01-01

    The Service Level D (faulted) load capacity of a conventional three-bolt pipe-clamp based upon the limit analysis method is presented. The load distribution, plastic hinge locations, and collapse load are developed for the lower bound limit load method. The results of the limit analysis are compared with the manufacturer's rated loads. 3 refs.

  17. STS-5 crewmembers with meal tray assembly on middeck

    NASA Image and Video Library

    1982-11-16

    STS005-06-210 (16 Nov. 1982) --- Astronaut Vance D. Brand (in dark blue shirt), STS-5 commander; Robert F. Overmyer (left), pilot; and William B. Lenoir, mission specialist, conduct microgravity experiments with food containers and meal tray assemblies in front of middeck port side wall and side hatch. Brand prepares to eat as meal tray assembly floats above his chest and Overmeyer and Lenoir look on. Sign on port side wall is labeled STS-5 message board. Photo credit: NASA

  18. Tray Pack Improved Durability Packaging Rough Handling Test Results

    DTIC Science & Technology

    1985-03-01

    extra vacuum void volume space makes these underfilled Tray Packs much more susceptible to damage. It is the vacuum that causes the damage not the under...filled to 6 lb. 10 oz. The result of underfilling is that the vacuum level in the peas is much higher making it more susceptible to paneling damage...impact. (3) That the vacuum induced by underfilling and vacuum pack- ing Tray Packs filled with peas makes them highly suscep- tible to damage. (4) That

  19. Retort Racks for Polymeric Trays in 1400 Style Spray Retorts

    DTIC Science & Technology

    2003-05-01

    trays backup plate & support pillars to allow 35" shut height as required by most 3500 ton molding machines dedicated mounting rails for installation...hr. At this time, Stegner had modified all their pallet bottom plates to support the rack in all load bearing points and in addition, Wornick send two...COMBAT RATION NETWORK FOR TECHNOLOGY IMPLEMENTATION Retort Racks for Polymeric Trays in 1400 Style Spray Retorts Final Technical Report STP 2010

  20. Tensile bond strength between custom tray and elastomeric impression material.

    PubMed

    Maruo, Yukinori; Nishigawa, Goro; Oka, Morihiko; Minagi, Shogo; Irie, Masao; Suzuki, Kazuomi

    2007-05-01

    The aim of this study was to investigate how to achieve sufficient and stable adhesive strength between impression material and tray. Impression materials were molded between autopolymerizing resin columns, and tensile strength was measured as a function of these factors: tray storage time (1, 2, 4, 7, and 10 days), adhesive drying time (0, 1, 5, 10, and 15 minutes), and tray surface roughness (air abrasion, bur-produced roughness, and no treatment). Tensile bond strength was not affected by tray storage time throughout the entire evaluation period of 10 days. As for tray adhesive drying time, Reprosil and Exaimplant yielded extremely low values for drying times of 10 minutes or less (P<0.05), while Imprint II and Impregum were not influenced by drying time. Vinyl polysiloxane achieved the highest adhesive strength with bur-produced roughness, which was significantly higher than with air abrasion or no treatment (P<0.05), whereas polyether achieved the lowest value with bur-produced roughness (P<0.05). It was concluded that surface treatment of custom tray should be adapted to the type of impression material used to achieve optimum bond strength.

  1. Individualized menu slips improve the accuracy of patient food trays.

    PubMed

    Myers, E F; Knoz, S A; Gregoire, M B

    1991-11-01

    We evaluated the effect of five menu slip formats on worker preference and accuracy of food trays in a simulated hospital tray line. Menu slip formats were either individualized or preprinted, and various combinations of color coding, large type, and bold print were used to code the type of diet and the menu choices to be placed on the tray. Student volunteers who had not worked in hospital foodservice were used as tray line workers to reduce the possibility of prior preference for a menu slip format. Results indicate that menu slip format significantly affects both worker preference and the accuracy of assembled food trays. Errors were significantly lower with individualized formats that identified menu selections in bold print and type of diet in either large type or colored ink. The highest error rate was found with preprinted formats. An individualized menu slip that identified menu selections and diet orders with large type and bold print received the highest worker preference rating and resulted in the most accurate tray assembly.

  2. Prefabricated stock trays for impression of auricular region.

    PubMed

    Vibha, Shetty; Anandkrishna, G N; Anupam, Purwar; Namratha, N

    2010-06-01

    The conventional methods of impression making for maxillofacial defects are cumbersome and time consuming for both patient and operator. This study focuses upon standardizing and simplifying the impression making methodology for auricular prosthesis with the help of prefabricated stock trays for auricular region. The stock trays were designed on positive replicas of anatomical structures, broadly divided into long and narrow, short and broad and long and broad ear. For each stock tray, impressions of auricle, of patients of different morphology were made with plastic funnels of different shape and size ensuring at least 6 mm of space between the anatomical part and inner surface of funnel and master cast was obtained. Subsequent adaptation of wax was done and fabrications of stock stainless steel trays were done. A standardized stock tray for making of auricular impressions was developed. From this innovative technical procedure it is possible to get an accurate impression of auricular defects now by the use of prefabricated stock trays rather than the cumbersome conventional method.

  3. Influence of Custom Trays, Dual-Arch Passive, Flexed Trays and Viscosities of Elastomeric Impression Materials on Working Dies

    PubMed Central

    Kohli, Shivani; Kalsi, Rupali

    2016-01-01

    Introduction Dual arch impression technique signifies an essential improvement in fixed prosthodontics and has numerous benefits over conventional impression techniques. The accuracy of working dies fabricated from dual arch impression technique remains in question because there is little information available in the literature. Aim This study was conducted to compare the accuracy of working dies fabricated from impressions made from two different viscosities of impression materials using metal, plastic dual arch trays and custom made acrylic trays. Materials and Methods The study samples were grouped into two groups based on the viscosity of impression material used i.e. Group I (monophase), whereas Group II consisted of Dual Mix technique using a combination of light and heavy body material. These were further divided into three subgroups A, B and C depending on the type of impression tray used (metal dual arch tray, plastic dual arch tray and custom made tray). Measurements of the master cast were made using profile projector. Descriptive statistics like mean, Standard Deviation (SD) were calculated for all the groups. One way analysis of variance (ANOVA) was used for multiple group comparisons. A p-value of 0.05 or less was considered statistically significant. Results The gypsum dies obtained with the three types of impression trays using two groups of impression materials were smaller than the master models in dimensions. Conclusion The plastic dual arch trays produced dies which were the least accurate of the three groups. There was no significant difference in the die dimensions obtained using the two viscosities of impression materials. PMID:27437342

  4. Effects of orbital exposure on RTV during the LDEF mission

    NASA Technical Reports Server (NTRS)

    Brower, William E., Jr.; Golub, S. V.; Bauer, Robert A.

    1993-01-01

    Thermomechanical analysis (TMA), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA) were performed on samples of RTV 511 exposed on the Long Duration Exposure Facility (LDEF) mission for 6 years in orbit and unexposed RTV 511 control samples. Slices 20- to 400-microns thick were removed from the exposed surface down to a depth of 1,500 microns through the 3-mm thick samples. The TMA and DSC results, which arise from the entire slice and not just its surface, showed no significant differences between the LDEF exposed and the control samples. TMA scans were run from ambient to 500 C; results were compared by a tabulation of the onset temperatures for flow. DSC scans were run from ambient to 600 C; no endotherms or exotherms occurred over the range observed. What appear to be glass transition temperatures were compared for the samples as a function of section depth within the sample and between the exposed and control samples. The TGA scans from 25 to 900 C, which arise from the surface of the sample initially, showed a slight increase in the top most 105-micron slice (the exposed, discolored side) in the weight loss at 600 C in oxygen. This weight loss dropped to bulk values at the next slice below the top section, a mean depth of 258 microns. The control sample also showed an increase in weight loss as the top surface was approached, but the 600 C weight losses were very inconsistent. The LDEF RTV sample appears to be mechanically undamaged, with a surface layer which oxidizes slightly faster as a result of orbital exposure.

  5. Status of LDEF ionizing radiation measurements and analysis

    NASA Technical Reports Server (NTRS)

    Parnell, Thomas A.

    1993-01-01

    At this symposium significant new data and analyses were reported in cosmic ray research, radiation dosimetry, induced radioactivity, and radiation environment modeling. Measurements of induced radioactivity and absorbed dose are nearly complete, but much analysis and modeling remains. Measurements and analyses of passive nuclear track detectors (PNTD), used to derive the cosmic ray composition and spectra, and linear energy transfer (LET) spectra, are only a few percent complete, but important results have already emerged. As one might expect at this stage of the research, some of the new information has produced questions rather than answers. Low-energy heavy nuclei detected by two experiments are not compatible with known solar or cosmic components. Various data sets on absorbed dose are not consistent, and a new trapped proton environment model does not match the absorbed dose data. A search for cosmogenic nuclei other than Be-7 on Long Duration Exposure Facility (LDEF) surfaces has produced an unexpected result, and some activation data relating to neutrons is not yet understood. Most of these issues will be resolved by the analysis of further experiment data, calibrations, or the application of the large LDEF data set that offers alternate data or analysis techniques bearing on the same problem. The scope of the papers at this symposium defy a compact technical summary. I have attempted to group the new information that I noted into the following groups: induced radioactivity; absorbed dose measurements; LET spectra and heavy ion dosimetry; environment modeling and three dimensional shielding effects; cosmogenic nuclei; and cosmic rays and other heavy ions. The papers generally are expository and have excellent illustrations, and I refer to their figures rather than reproduce them here. The general program and objectives of ionizing radiation measurements and analyses on LDEF has been described previously.

  6. Applications of T-ray spectroscopy in the petroleum field

    NASA Astrophysics Data System (ADS)

    Al-Douseri, Fatemah M.

    2005-11-01

    Because of heavy usage of petroleum products, which are the main source of energy in daily life and industry, a fast, reliable, and portable analysis system is needed to complement traditional techniques. Terahertz (THz) radiation, or T-rays, is electromagnetic radiation in the 0.1 to 10 THz frequency range. One unique attribute of T-rays is their ability to sensitively measure the induced molecular dipole moments in non-polar liquids such as aromatics, which make up the majority of the contents of many petroleum products. This information can lead to several applications in petroleum analysis. The application of T-rays to petroleum product analysis has the potential to make a significant impact in the petroleum field. In this dissertation, I show the first use of T-ray time-domain spectroscopy and Fourier transform infrared (FTIR) spectroscopy techniques for petroleum product analysis. I report on the feasibility of analyzing selected petroleum products, including gasoline, diesel, lubricating oil, and selected compounds of toluene, ethylbenzene, and xylene (BTEX). With the use of a T-ray time-domain spectrometer. I demonstrate that gasolines with different octane numbers and diesel all show specific absorption coefficients and refractive indexes in the spectral range from 0.5 to 2.0 THz. Furthermore, I report the qualitative and quantitative analysis of selected BTEX components in gasoline and diesel using FTIR spectroscopy in the 50 to 650 cm-1 region. I distinguish gasolines with different octane numbers from diesel and lubricating oil according to their different spectral features. I also determine the concentration of (o, m, p) xylene isomers in gasoline according to their specific absorption bands. The experimental results in this thesis, imply that linking between the knowledge of petroleum products and the development of T-ray spectrometer with the cooperation of industry might translate the T-ray spectroscopic system into a real world application in

  7. Long Duration Exposure Facility (LDEF) attitude measurements of the Interplanetary Dust Experiment

    NASA Technical Reports Server (NTRS)

    Kassel, Philip C., Jr.; Motley, William R., III; Singer, S. Fred; Mulholland, J. Derral; Oliver, John P.; Weinberg, Jerry L.; Cooke, William J.; Wortman, Jim J.

    1993-01-01

    Analysis of the data from the Long Duration Exposure Facility (LDEF) Interplanetary Dust Experiment (IDE) sun sensors has allowed a confirmation of the attitude of LDEF during its first year in orbit. Eight observations of the yaw angle at specific times were made and are tabulated in this paper. These values range from 4.3 to 12.4 deg with maximum uncertainty of plus or minus 2.0 deg and an average of 7.9 deg. No specific measurements of pitch or roll were made but the data indicates that LDEF had an average pitch down attitude of less than 0.7 deg.

  8. Atomic oxygen flux and fluence calculation for Long Duration Exposure Facility (LDEF)

    NASA Technical Reports Server (NTRS)

    Bourassa, Roger J.; Gillis, James R.

    1991-01-01

    The LDEF mission was to study the effects of the space environment on various materials over an extended period of time. One of the important factors for materials degradation in low earth orbit is the atomic oxygen fluxes and fluences experienced by the materials. These fluxes and fluences are a function of orbital parameters, solar and geomagnetic activity, and material surface orientation. Calculations of atomic oxygen fluences and fluxes for the LDEF mission are summarized. Included are descriptions of LDEF orbital parameters, solar and geomagnetic data, computer code FLUXAV, which was used to perform calculations of fluxes and fluences, along with a discussion of the calculated fluxes and fluences.

  9. Thermal control paints on LDEF: Results of sub-experiment 802-18

    NASA Technical Reports Server (NTRS)

    Jaggers, Christopher H.; Meshishnek, M. J.; Coggi, J. M.

    1992-01-01

    Several thermal control paints were flown on the LDEF, including the white paints Chemglaze A276, S13GLo, and YB-71, and the black paint D-111. The effects of low earth orbit, which includes UV radiation and atomic oxygen, varied significantly with each paint and its location on LDEF. This paper will examine the performance of these paints as determined by changes in their optical and physical properties, including solar absorptance, surface chemical changes, and changes in surface morphology. It will also provide a correlation of these optical and physical property changes to the physical phenomena that occurred in these materials during the LDEF mission.

  10. LDEF: Dosimetric measurement results (AO 138-7 experiment)

    NASA Technical Reports Server (NTRS)

    Bourrieau, J.

    1993-01-01

    One of the objectives of the AO 138-7 experiment on board the Long Duration Exposure Facility (LDEF) was a total dose measurement with Thermo Luminescent Detectors (TLD 100). Two identical packages, both of them including five TLD's inside various aluminum shields, are exposed to the space environment in order to obtain the absorbed dose profile. Radiation fluence received during the total mission length was computed, taking into account the trapped particles (AE8 and AP8 models during solar maximum and minimum periods) and the cosmic rays; due to the magnetospheric shielding the solar proton fluences are negligible on the LDEF orbit. The total dose induced by these radiations inside a semi infinite plane shield of aluminum are computed with the radiation transport codes available at DERTS. The dose profile obtained is in good agreement with the evaluation by E.V. Benton. TLD readings are performed after flight; due to the mission duration increase a post flight calibration was necessary in order to cover the range of the in flight induced dose. The results obtained, similar (plus or minus 30 percent) for both packages, are compared with the dose profile computation. For thick shields it seems that the measurements exceed the forecast (about 40 percent). That can be due to a cosmic ray and trapped proton contributions coming from the backside (assumed as perfectly shielded by the LDEF structure in the computation), or to an underestimate of the proton or cosmic ray fluences. A fine structural shielding analysis should be necessary in order to determine the origin of this slight discrepancy between forecast and in flight measurements. For the less shielded dosimeters, mainly exposed to the trapped electron flux, a slight overestimation of the dose (less than 40 percent) appears. Due to the dispersion of the TLD's response, this cannot be confirmed. In practice these results obtained on board LDEF, with less than a factor 1.4 between measurements and forecast

  11. Thermal control surfaces on the MSFC LDEF experiments

    NASA Technical Reports Server (NTRS)

    Wilkes, Donald R.; Whitaker, Ann F.; Zwiener, James M.; Linton, Roger C.; Shular, David; Peters, Palmer N.; Gregory, John C.

    1992-01-01

    There were five Marshall Space Flight Center (MSFC) experiments on the LDEF. Each of those experiments carried thermal control surfaces either as test samples or as operational surfaces. These materials experienced varying degrees of mechanical and optical damage. Some materials were virtually unchanged by the extended exposure while others suffered extensive degradation. The synergistic effects due to the constituents of the space environment are evident in the diversity of these material changes. The sample complement for the MSFC experiments is described along with results of the continuing analyses efforts.

  12. LDEF: Dosimetric measurement results (AO 138-7 experiment)

    NASA Astrophysics Data System (ADS)

    Bourrieau, J.

    1993-04-01

    One of the objectives of the AO 138-7 experiment on board the Long Duration Exposure Facility (LDEF) was a total dose measurement with Thermo Luminescent Detectors (TLD 100). Two identical packages, both of them including five TLD's inside various aluminum shields, are exposed to the space environment in order to obtain the absorbed dose profile. Radiation fluence received during the total mission length was computed, taking into account the trapped particles (AE8 and AP8 models during solar maximum and minimum periods) and the cosmic rays; due to the magnetospheric shielding the solar proton fluences are negligible on the LDEF orbit. The total dose induced by these radiations inside a semi infinite plane shield of aluminum are computed with the radiation transport codes available at DERTS. The dose profile obtained is in good agreement with the evaluation by E.V. Benton. TLD readings are performed after flight; due to the mission duration increase a post flight calibration was necessary in order to cover the range of the in flight induced dose. The results obtained, similar (plus or minus 30 percent) for both packages, are compared with the dose profile computation. For thick shields it seems that the measurements exceed the forecast (about 40 percent). That can be due to a cosmic ray and trapped proton contributions coming from the backside (assumed as perfectly shielded by the LDEF structure in the computation), or to an underestimate of the proton or cosmic ray fluences. A fine structural shielding analysis should be necessary in order to determine the origin of this slight discrepancy between forecast and in flight measurements. For the less shielded dosimeters, mainly exposed to the trapped electron flux, a slight overestimation of the dose (less than 40 percent) appears. Due to the dispersion of the TLD's response, this cannot be confirmed. In practice these results obtained on board LDEF, with less than a factor 1.4 between measurements and forecast

  13. Gamma ray spectrometry of LDEF samples at SRL

    NASA Technical Reports Server (NTRS)

    Winn, Willard G.

    1992-01-01

    A total of 31 samples from the Long Duration Exposure Facility (LDEF), including materials of aluminum, vanadium, and steel trunnions were analyzed by ultra-low-level gamma spectrometry. The study quantified particle induced activations of Na-22, Sc-46, Cr-51, Mn-54, Co-56, Co-57, Co-58, and Co-60. The samples of trunnion sections exhibited increasing activity toward the outer end of the trunnion and decreasing activity toward its radial center. The trunnion sections did not include end pieces, which were reported to collect noticeable Be-7 on their leading surfaces. No significant Be-7 was detected in the samples analyzed.

  14. LDEF Retrieval over the Namib Desert, Namibia, Africa

    NASA Image and Video Library

    1990-01-20

    STS032-85-029 (12 Jan. 1990) --- (ORIENT PHOTO WITH COLUMBIA'S CARGO BAY IN LOWER CENTER). This 70mm frame was taken during a battery of documentary photographs of the recently-recaptured Long Duration Exposure Facility (LEDF). The Atlantic Coast of Namibia serves as a backdrop for the colorful scene. After five-and-one half years orbiting Earth, LDEF was retrieved by STS-32 crewmembers and brought back home at the end of the eleven-day mission for scientific observation. The bus-sized spacecraft was held in the grasp of Columbia's remote manipulator system (RMS) end effector during the survey.

  15. Study of LDEF particulate contamination using atomic force microscopy

    NASA Astrophysics Data System (ADS)

    Anderson, Mark S.; Maag, Carl R.

    1992-02-01

    On the STS-32 Space Shuttle mission, a flight experiment provided an understanding of the effects of the environment on the long duration exposure facility (LDEF) from rendezvous with the shuttle until removal from the payload bay at the Orbiter Processing Facility (OPF) at NASA/KSC. The interim operational contamination monitor (IOCM) is an attached shuttle payload that has been used on two earlier flights (STS 51C and STS 28) to quantify the contamination deposited during the course of the missions. The IOCM can characterize by direct measurement the deposition of molecular and particulate contamination during any phase of flight, i.e., prelaunch, ascent, on-orbit operations, descent, and ferry flight of the shuttle. Measurements are made continually during these periods. Two types of particulate collection sensors are employed in order to avoid efficiency of collection uncertainties. In addition to these principal measurements, the IOCM actively measures the optical property changes of thermal control surfaces by calorimetry, the flux of the ambient atomic oxygen environment, the incident solar flux, and the absolute ambient pressure in the payload bay. The IOCM also provides a structure and sample holders for the exposure of passive material samples to the space environment, e.g., thermal cycling, atomic oxygen, and micrometeoroids and/or orbital debris, etc. One of the more salient results from the STS-32 flight suggests that the LDEF emitted a large source of contamination (mainly particulates) after berthing into the shuttle. The source emission rate of LDEF averaged 2.5 X 10-12 gr/cm2-sec for a period of eighty hours following berthing, falling off to a rate of 4.1 X 10-13 gr/cm2-sec just prior to re-entry. Post flight obscuration ratios on IOCM surfaces were measured at 2.4 percent. An atomic force microscope (AFM) was used to perform post-flight characterization of the IOCM sensors. The AFM is a new instrument capable of ultra high (atomic) resolution

  16. Syncom 4 deploy, LDEF retrieval highlight 10-day Columbia flight

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The objectives of Space Shuttle Mission STS-32 are described along with major flight activities, prelaunch and launch operations, trajectory sequence of events, and landing and post-landing operations. The primary objectives of STS-32 are the deployment of a Navy synchronous communications satellite (Syncom 4) and the retrieval of the Long Duration Exposure Facility (LDEF) launched from the Challenger in April 1984. Secondary STS-32 payloads include a protein crystal growth experiment, the Fluids Experiment Apparatus (FEA) for the investigation of microgravity materials processing, the Mesoscale Lighting Experiment, the Latitude-Longitude Locator Experiment, the Americal Flight Echocardiograph, and an experiment to investigate neurospora circadian rhythms in a microgravity environment.

  17. Is early cord clamping, delayed cord clamping or cord milking best?

    PubMed

    Vatansever, Binay; Demirel, Gamze; Ciler Eren, Elif; Erel, Ozcan; Neselioglu, Salim; Karavar, Hande Nur; Gundogdu, Semra; Ulfer, Gozde; Bahadir, Selcen; Tastekin, Ayhan

    2017-03-20

    To compare the antioxidant status of three cord clamping procedures (early clamping, delayed clamping and milking) by analyzing the thiol-disulfide balance. This randomized controlled study enrolled 189 term infants who were divided into three groups according to the cord clamping procedure: early clamping, delayed clamping and milking. Blood samples were collected from the umbilical arteries immediately after clamping, and the thiol/disulfide homeostasis was analyzed. The native and total thiol levels were significantly (p < .05) lower in the early cord clamping group compared with the other two groups. The disulfide/total thiol ratio was significantly (p = .026) lower in the delayed cord clamping and milking groups compared with the early clamping groups. Early cord clamping causes the production of more disulfide bonds and lower thiol levels, indicating that oxidation reactions are increased in the early cord clamping procedure compared with the delayed cord clamping and milking procedures. The oxidant capacity is greater with early cord clamping than with delayed clamping or cord milking. Delayed cord clamping or milking are beneficial in neonatal care, and we suggest that they be performed routinely in all deliveries.

  18. Delayed umbilical cord clamping in premature neonates.

    PubMed

    Kaempf, Joseph W; Tomlinson, Mark W; Kaempf, Andrew J; Wu, YingXing; Wang, Lian; Tipping, Nicole; Grunkemeier, Gary

    2012-08-01

    Delayed umbilical cord clamping is reported to increase neonatal blood volume. We estimated the clinical outcomes in premature neonates who had delayed umbilical cord clamping compared with a similar group who had early umbilical cord clamping. This was a before-after investigation comparing early umbilical cord clamping with delayed umbilical cord clamping (45 seconds) in two groups of singleton neonates, very low birth weight (VLBW) (401-1,500 g) and low birth weight (LBW) (greater than 1,500 g but less than 35 weeks gestation). Neonates were excluded from delayed umbilical cord clamping if they needed immediate major resuscitation. Primary outcomes were provision of delivery room resuscitation, hematocrit, red cell transfusions, and the principle Vermont Oxford Network outcomes. In VLBW neonates (77 delayed umbilical cord clamping, birth weight [mean±standard deviation] 1,099±266 g; 77 early umbilical cord clamping 1,058±289 g), delayed umbilical cord clamping was associated with less delivery room resuscitation, higher Apgar scores at 1 minute, and higher hematocrit. Delayed umbilical cord clamping was not associated with significant differences in the overall transfusion rate, peak bilirubin, any of the principle Vermont Oxford Network outcomes, or mortality. In LBW neonates (172 delayed umbilical cord clamping, birth weight [mean±standard deviation] 2,159±384 g; 172 early umbilical cord clamping 2,203±447 g), delayed umbilical cord clamping was associated with higher hematocrit and was not associated with a change in delivery room resuscitation or Apgar scores or with changes in the transfusion rate or peak bilirubin. Regression analysis showed increasing gestational age and birth weight and delayed umbilical cord clamping were the best predictors of higher hematocrit and less delivery room resuscitation. Delayed umbilical cord clamping can safely be performed in singleton premature neonates and is associated with a higher hematocrit, less delivery room

  19. An introduction to shuttle/LDEF retrieval operations: The R-bar approach option. [orbital mechanics and braking schedule

    NASA Technical Reports Server (NTRS)

    Hall, W. M.

    1978-01-01

    Simulated orbiter direct approaches during long duration exposure facility (LDEF) retrieval operations reveal that the resultant orbiter jet plume fields can significantly disturb LDEF. An alternate approach technique which utilizes orbital mechanics forces in lieu of jets to brake the final orbiter/LDEF relative motion during the final approach, is described. Topics discussed include: rendezvous operations from the terminal phase initiation burn through braking at some standoff distance from LDEF, pilot and copilot activities, the cockpit instrumentation employed, and a convenient coordinate frame for studying the relative motion between two orbiting bodies. The basic equations of motion for operating on the LDEF radius vector are introduced. Practical considerations of implementing an R-bar approach, namely, orbiter/LDEF relative state uncertainties and orbiter control system limitations are explored. A possible R-bar approach strategy is developed and demonstrated.

  20. The RFC clamp loader: structure and function.

    PubMed

    Yao, Nina Y; O'Donnell, Mike

    2012-01-01

    The eukaryotic RFC clamp loader couples the energy of ATP hydrolysis to open and close the circular PCNA sliding clamp onto primed sites for use by DNA polymerases and repair factors. Structural studies reveal clamp loaders to be heteropentamers. Each subunit contains a region of homology to AAA+ proteins that defines two domains. The AAA+ domains form a right-handed spiral upon binding ATP. This spiral arrangement generates a DNA binding site within the center of RFC. DNA enters the central chamber through a gap between the AAA+ domains of two subunits. Specificity for a primed template junction is achieved by a third domain that blocks DNA, forcing it to bend sharply. Thus only DNA with a flexible joint can bind the central chamber. DNA entry also requires a slot in the PCNA clamp, which is opened upon binding the AAA+ domains of the clamp loader. ATP hydrolysis enables clamp closing and ejection of RFC, completing the clamp loading reaction.

  1. The financial and environmental costs of reusable and single-use plastic anaesthetic drug trays.

    PubMed

    McGain, F; McAlister, S; McGavin, A; Story, D

    2010-05-01

    We modelled the financial and environmental costs of two commonly used anaesthetic plastic drug trays. We proposed that, compared with single-use trays, reusable trays are less expensive, consume less water and produce less carbon dioxide, and that routinely adding cotton and paper increases financial and environmental costs. We used life cycle assessment to model the financial and environmental costs of reusable and single-use trays. From our life cycle assessment modelling, the reusable tray cost (Australian dollars) $0.23 (95% confidence interval [CI] $0.21 to $0.25) while the single-use tray alone cost $0.47 (price range of $0.42 to $0.52) and the single-use tray with cotton and gauze added was $0.90 (no price range in Melbourne). Production of CO2 was 110 g CO2 (95% CI 98 to 122 g CO2) for the reusable tray, 126 g (95% CI 104 to 151 g) for single-use trays alone (mean difference of 16 g, 95% CI -8 to 40 g) and 204 g CO2 (95% CI 166 to 268 g CO2) for the single-use trays with cotton and paper Water use was 3.1 l (95% CI 2.5 to 3.7 l) for the reusable tray, 10.4 l (95% CI 8.2 to 12.7 l) for the single-use tray and 26.7 l (95% CI 20.5 to 35.4 l) for the single-use tray with cotton and paper Compared with reusable plastic trays, single-use trays alone cost twice as much, produced 15% more CO2 and consumed three times the amount of water Packaging cotton gauze and paper with single-use trays markedly increased the financial, energy and water costs. On both financial and environmental grounds it appears difficult to justify the use of single-use drug trays.

  2. Modelling hypervelocity impacts into aluminum structures based on LDEF data

    NASA Technical Reports Server (NTRS)

    Coombs, C. R.; Atkinson, D. R.; Watts, A. J.; Wagner, J. R.; Allbrooks, M. K.; Hennessy, C. J.

    1993-01-01

    Realizing and understanding the effects of the near-Earth space environment on a spacecraft during its mission lifetime is becoming more important with the regeneration of America's space program. Included among these potential effects are the following: erosion and surface degradation due to atomic oxygen impingement; ultraviolet exposure embrittlement; and delamination, pitting, cratering, and ring formation due to micrometeoroid and debris impacts. These effects may occur synergistically and may alter the spacecraft materials enough to modify the resultant crater, star crack, and/or perforation. This study concentrates on modelling the effects of micrometeoroid and debris hypervelocity impacts into aluminum materials (6061-T6). Space debris exists in all sizes, and has the possibility of growing into a potentially catastrophic problem, particularly since self-collisions between particles can rapidly escalate the number of small impactors. We have examined the morphologies of the Long Duration Exposure Facility (LDEF) impact craters and the relationship between the observed impact damage on LDEF versus the existing models for both the natural (micrometeoroid) and manmade (debris) environments in order to better define these environments.

  3. A photon-phreak digs the LDEF happening

    NASA Astrophysics Data System (ADS)

    Smith, Alan R.; Hurley, Donna L.

    1992-06-01

    Radioactivities of the LDEF onboard experiments induced by gamma emitting rays in both intentional samples and spacecraft parts were examined. The long time greatly enhanced the ability to detect some of the longer lived nuclides, including: 2.6 yr Na-22 in Al and Fe; 5.3 yr Co-60 in Co, Ni, and In; 2.9 yr Rh-102 in In; and 38 yr Bi-207 in Pb. These radionuclides, along with such other as 33 yr Ar-42 in Ti, Fe, or Ni and 47 yr Ti-44 in the same elements, would be appropriate monitors of the high energy space radiation field on long round-trip voyages in the solar system. Additional candidate radionuclides are also discussed. Radiometric analysis of the LDEF samples was a substantial effort among a dedicated group of experts in low level counting, and highlights several important aspects of the procedures needed to achieve success in this kind of endeavor. Target elements should be chosen to differentiate between neutron and proton induced reactions, whenever this is feasible. Reactions should be chosen with a wide range of energy thresholds, to enable calculation of both intensity and energy spectra of the particle fluxes.

  4. LDEF polymeric materials: A summary of Langley characterization

    NASA Technical Reports Server (NTRS)

    Young, Philip R.; Slemp, Wayne S.; Whitley, Karen S.; Kalil, Carol R.; Siochi, Emilie J.; Shen, James Y.; Chang, A. C.

    1995-01-01

    The NASA Long Duration Exposure Facility (LDEF) enabled the exposure of a wide variety of materials to the low earth orbit (LEO) environment. This paper provides a summary of research conducted at the Langley Research Center into the response of selected LDEF polymers to this environment. Materials examined include graphite fiber reinforced epoxy, polysulfone, and additional polyimide matrix composites, films of FEP Teflon, Kapton, several experimental high performance polyimides, and films of more traditional polymers such as poly(vinyl toluene) and polystyrene. Exposure duration was either 10 months or 5.8 years. Flight and control specimens were characterized by a number of analytical techniques including ultraviolet-visible and infrared spectroscopy, thermal analysis, scanning electron and scanning tunneling microscopy, x-ray photoelectron spectroscopy, and, in some instances, selected solution property measurements. Characterized effects were found to be primarily surface phenomena. These effects included atomic oxygen-induced erosion of unprotected surfaces and ultraviolet-induced discoloration and changes in selected molecular level parameters. No gross changes in molecular structure or glass transition temperature were noted. The intent of this characterization is to increase our fundamental knowledge of space environmental effects as an aid in developing new and improved polymers for space application. A secondary objective is to develop benchmarks to enhance our methodology for the ground-based simulation of environmental effects so that polymer performance in space can be more reliably predicted.

  5. LDEF results for polymer matrix composite experiment AO 180

    NASA Technical Reports Server (NTRS)

    Tennyson, R. C.

    1992-01-01

    This report represents a summary of the results obtained to-date on a polymer matrix composite experiment (AO 180) located at station D-12, about 82 deg off the 'ram' direction. Different material systems comprised of graphite, boron, and aramid (Kevlar) fiber reinforcements were studied. Although previous results were presented on in-situ thermal-vacuum cycling effects, particularly dimensional changes associated with outgassing, additional comparative data will be shown from ground-based tests on control and flight samples. The system employed was fully automated for thermal-vacuum cycling using a laser interferometer for monitoring displacements. Erosion of all three classes of materials due to atomic oxygen (AO) will also be discussed, including angle of incidence effects. Data from this experiment will be compared to published results for similar materials in other LDEF experiments. Composite materials' erosion yields will be presented on an AO design nomogram useful for estimating total material loss for given exposure conditions in low Earth orbit (LEO). Optical properties of these materials will also be compared with control samples. A survey of the damage caused by micrometeoroids/debris impacts will be addressed as they relate to polymer matrix composites. Correlations between hole size and damage pattern will be given. Reference to a new nomogram for estimating the number distribution of micrometeoroid/debris impacts for a given space structure as a function of time in LEO will be addressed based on LDEF data.

  6. Resolving LDEF's flux distribution: Orbital (debris?) and natural meteoroid populations

    NASA Technical Reports Server (NTRS)

    Mcdonnell, J. A. M.

    1993-01-01

    A consistent methodology for the collation of data from both penetration and perforation experiments and from data in the Meteoroid and Debris Special Investigator Group (M-D SIG) data-base has led to the derivation of the average impact flux over LDEF's exposure history 1984-1990. Data are first presented for LDEF's N,S,E,W and Space faces ('offset' by 8 deg and 'tilted' by 1 deg respectively). A model fit is derived for ballistic limits of penetration from 1 micron to 1mm of aluminium target, corresponding to impactor masses from 10(exp -18) kg (for rho sub p = 2g/cu cm) to 10(exp -10) kg (for rho sub p = 1g/cu cm). A second order harmonic function is fitted to the N,S,E, and W fluxes to establish the angular distribution at regular size intervals; this fit is then used to provide 'corrected' data corresponding to fluxes applicable to true N,S,E,W and Space directions for a LEO 28.5 degree inclination orbit at a mean altitude of 465 km.

  7. LDEF results for polymer matrix composite experiment AO 180

    NASA Technical Reports Server (NTRS)

    Tennyson, R. C.

    1992-01-01

    This report represents a summary of the results obtained to-date on a polymer matrix composite experiment (AO 180) located at station D-12, about 82 deg off the 'ram' direction. Different material systems comprised of graphite, boron, and aramid (Kevlar) fiber reinforcements were studied. Although previous results were presented on in-situ thermal-vacuum cycling effects, particularly dimensional changes associated with outgassing, additional comparative data will be shown from ground-based tests on control and flight samples. The system employed was fully automated for thermal-vacuum cycling using a laser interferometer for monitoring displacements. Erosion of all three classes of materials due to atomic oxygen (AO) will also be discussed, including angle of incidence effects. Data from this experiment will be compared to published results for similar materials in other LDEF experiments. Composite materials' erosion yields will be presented on an AO design nomogram useful for estimating total material loss for given exposure conditions in low Earth orbit (LEO). Optical properties of these materials will also be compared with control samples. A survey of the damage caused by micrometeoroids/debris impacts will be addressed as they relate to polymer matrix composites. Correlations between hole size and damage pattern will be given. Reference to a new nomogram for estimating the number distribution of micrometeoroid/debris impacts for a given space structure as a function of time in LEO will be addressed based on LDEF data.

  8. Measured space environmental effects to LDEF during retrieval

    NASA Astrophysics Data System (ADS)

    Maag, Carl R.; Linder, W. Kelly; Borson, Eugene N.

    1993-06-01

    Data gathered by the Interim Operational Contamination Monitor (IOCM) with regard to the effect of the space environment on the STS-32 Shuttle mission and on the Long Duration Exposure Facility (LDEF) are reported. IOCM measures the deposition of molecular and particulate contamination during all flight phases. It also measures the thermophysical properties of thermal control surfaces by calorimetry, the flux of the ambient atomic oxygen environment, the incident solar flux, and the absolute ambient pressure in the payload bay. The IOCM also provides a structure and sample holders for the exposure of passive material samples to the space environment. One of the more salient results from the STS-32 flight suggests that the LDEF emitted a large number of particulates after berthing into the Shuttle. The mission atomic oxygen fluence was also calculated. Although the fluence was low by normal standards, the Kapton (trademark) passive samples exhibited the onset of erosion. Orbital debris and micrometeoroid impacts also occurred during the retrieval mission. The average perforation diameter was approximately 1.25 micrometers. The largest perforation diameter was measured at 65 micrometers.

  9. Measured space environmental effects to LDEF during retrieval

    NASA Technical Reports Server (NTRS)

    Maag, Carl R.; Linder, W. Kelly; Borson, Eugene N.

    1993-01-01

    Data gathered by the Interim Operational Contamination Monitor (IOCM) with regard to the effect of the space environment on the STS-32 Shuttle mission and on the Long Duration Exposure Facility (LDEF) are reported. IOCM measures the deposition of molecular and particulate contamination during all flight phases. It also measures the thermophysical properties of thermal control surfaces by calorimetry, the flux of the ambient atomic oxygen environment, the incident solar flux, and the absolute ambient pressure in the payload bay. The IOCM also provides a structure and sample holders for the exposure of passive material samples to the space environment. One of the more salient results from the STS-32 flight suggests that the LDEF emitted a large number of particulates after berthing into the Shuttle. The mission atomic oxygen fluence was also calculated. Although the fluence was low by normal standards, the Kapton (trademark) passive samples exhibited the onset of erosion. Orbital debris and micrometeoroid impacts also occurred during the retrieval mission. The average perforation diameter was approximately 1.25 micrometers. The largest perforation diameter was measured at 65 micrometers.

  10. Gamma-ray spectrometry of LDEF samples at SRL

    SciTech Connect

    Winn, W.G.

    1991-07-22

    A total of 31 samples from the Long Duration Exposure Facility (LDEF), including materials of aluminum, vanadium, and steel trunnions were analyzed by ultra-low-level gamma spectroscopy. The study quantified particle induced activations of {sup 22}Na, {sup 46}Sc, {sup 51}Cr, {sup 54}Mn, {sup 56}Co, {sup 57}Co, {sup 58}Co, and {sup 60}Co. The samples of trunnion sections exhibited increasing activity toward the outer end of the trunnion and decreasing activity toward its radial center. The trunnion sections did not include end pieces, which have been reported to collect noticeable {sup 7}Be on their leading surfaces. No significant {sup 7}Be was detected in the samples analyzed. The Underground Counting Facility at Savannah River Laboratory (SRL) was used in this work. The facility is 50 ft. underground, constructed with low-background shielding materials, and operated as a clean room. The most sensitive analyses were performed with a 90%-efficient HPGe gamma-ray detector, which is enclosed in a purged active/passive shield. Each sample was counted for one to six days in two orientations to yield more representative average activities for the sample. The non-standard geometries of the LDEF samples prompted the development of a novel calibration method, whereby the efficiency about the samples surfaces (measured with point sources) predicted the efficiency for the bulk sample.

  11. Characteristics of hypervelocity impact craters on LDEF experiment S1003 and implications of small particle impacts on reflective surfaces

    NASA Technical Reports Server (NTRS)

    Mirtich, Michael J.; Rutledge, Sharon K.; Banks, Bruce A.; Devries, Christopher; Merrow, James E.

    1993-01-01

    The Ion Beam textured and coated surfaces EXperiment (IBEX), designated S1003, was flown on LDEF at a location 98 deg in a north facing direction relative to the ram direction. Thirty-six diverse materials were exposed to the micrometeoroid (and some debris) environment for 5.8 years. Optical property measurements indicated no changes for almost all of the materials except S-13G, Kapton, and Kapton-coated surfaces, and these changes can be explained by other environmental effects. From the predicted micrometeoroid flux of NASA SP-8013, no significant changes in optical properties of the surfaces due to micrometeoroids were expected. There were hypervelocity impacts on the various diverse materials flown on IBEX, and the characteristics of these craters were documented using scanning electron microscopy (SEM). The S1003 alumigold-coated aluminum cover tray was sectioned into 2 cm x 2 cm pieces for crater documentation. The flux curve generated from this crater data fits well between the 1969 micrometeoroid model and the Kessler debris model for particles less than 10(exp -9) gm which were corrected for the S1003 positions (98 deg to ram). As the particle mass increases, the S1003 impact data is greater than that predicted by even the debris model. This, however, is consistent with data taken on intercostal F07 by the Micrometeoroid/Debris Special Investigating Group (M/D SIG). The mirrored surface micrometeoroid detector flown on IBEX showed no change in solar reflectance and corroborated the S1003 flux curve, as well as results of this surface flown on SERT 2 and OSO 3 for as long as 21 years.

  12. Characteristics of hypervelocity impact craters on LDEF experiment S1003 and implications of small particle impacts on reflective surfaces

    NASA Astrophysics Data System (ADS)

    Mirtich, Michael J.; Rutledge, Sharon K.; Banks, Bruce A.; Devries, Christopher; Merrow, James E.

    1993-04-01

    The Ion Beam textured and coated surfaces EXperiment (IBEX), designated S1003, was flown on LDEF at a location 98 deg in a north facing direction relative to the ram direction. Thirty-six diverse materials were exposed to the micrometeoroid (and some debris) environment for 5.8 years. Optical property measurements indicated no changes for almost all of the materials except S-13G, Kapton, and Kapton-coated surfaces, and these changes can be explained by other environmental effects. From the predicted micrometeoroid flux of NASA SP-8013, no significant changes in optical properties of the surfaces due to micrometeoroids were expected. There were hypervelocity impacts on the various diverse materials flown on IBEX, and the characteristics of these craters were documented using scanning electron microscopy (SEM). The S1003 alumigold-coated aluminum cover tray was sectioned into 2 cm x 2 cm pieces for crater documentation. The flux curve generated from this crater data fits well between the 1969 micrometeoroid model and the Kessler debris model for particles less than 10(exp -9) gm which were corrected for the S1003 positions (98 deg to ram). As the particle mass increases, the S1003 impact data is greater than that predicted by even the debris model. This, however, is consistent with data taken on intercostal F07 by the Micrometeoroid/Debris Special Investigating Group (M/D SIG). The mirrored surface micrometeoroid detector flown on IBEX showed no change in solar reflectance and corroborated the S1003 flux curve, as well as results of this surface flown on SERT 2 and OSO 3 for as long as 21 years.

  13. From overshoot to voltage clamp.

    PubMed

    Huxley, Andrew

    2002-11-01

    In 1939, A.L. Hodgkin and I found that the nerve action potential shows an "overshoot"--that is, the interior of the fibre becomes electrically positive during an action potential. In 1948, we did our first experiments with a voltage clamp to investigate the current-voltage relations of the nerve membrane. Between those dates, we spent much time speculating about the mechanism by which ions cross the membrane and how the action potential is generated. This article summarizes these speculations, none of which has been previously published.

  14. Summary of solar cell data from the Long Duration Exposure Facility (LDEF)

    NASA Technical Reports Server (NTRS)

    Hill, David C.; Rose, M. Frank

    1994-01-01

    The Long Duration Exposure Facility (LDEF) was composed of many separate experiments, some of which contained solar cells. These solar cells were distributed at various positions on the LDEF and, therefore, were exposed to the space environment with an orientational dependence. This report will address the space environmental effects on solar cells and solar cell assemblies (SCA's), including electrical interconnects and associated insulation blankets where flown in conjunction with solar cells.

  15. LDEF: 69 Months in Space. Third Post-Retrieval Symposium, part 1

    NASA Technical Reports Server (NTRS)

    Levine, Arlene S. (Editor)

    1995-01-01

    This volume (Part 1 of 3) is a compilation of papers presented at the Third Long Duration Exposure Facility (LDEF) Post-Retrieval Symposium. The papers represent the data analysis of the 57 experiments flown on the LDEF. The experiments include materials, coatings, thermal systems, power and propulsion, science (cosmic ray, interstellar gas, heavy ions, micrometeoroid, etc.), electronics, optics, and life science. In addition, papers on preliminary data analysis of EURECA, EOIM-3, and other spacecraft are included.

  16. LDEF: 69 Months in Space. Third Post-Retrieval Symposium, part 3

    NASA Technical Reports Server (NTRS)

    Levine, Arlene S. (Editor)

    1995-01-01

    This volume is a compilation of papers presented at the Third Long Duration Exposure Facility (LDEF) Post-Retrieval Symposium. The papers represent the data analysis of the 57 experiments flown on the LDEF. The experiments include materials, coatings, thermal systems, power and propulsion, science (cosmic ray, interstellar gas, heavy ions, micrometeoroid, etc.), electronics, optics, and life science. In addition, papers on preliminary data analysis of EURECA, EOIM-3, and other spacecraft are included.

  17. LDEF grappled by remote manipulator system (RMS) during STS-32 retrieval

    NASA Image and Video Library

    1990-01-20

    This view taken through overhead window W7 on Columbia's, Orbiter Vehicle (OV) 102's, aft flight deck shows the Long Duration Exposure Facility (LDEF) in the grasp of the remote manipulator system (RMS) during STS-32 retrieval activities. Other cameras at eye level were documenting the bus-sized spacecraft at various angles as the RMS manipulated LDEF for a lengthy photo survey. The glaring celestial body in the upper left is the sun with the Earth's surface visible below.

  18. Sixty-nine months in space: A history of the first LDEF (Long Duration Exposure Facility)

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The LDEF project is summarized from its conception, through its deployment, to the return of the experiments. A LDEF chronology and a fact sheet is included. The experiments carried more than 10,000 specimens to gather scientific data and to test the effects of long term space exposure on spacecraft materials, components, and systems. Results will be invaluable for the design of future spacecraft such as Space Station Freedom.

  19. Radiation and temperature effects on LDEF fiber optic cable samples. [long duration exposure facility

    NASA Technical Reports Server (NTRS)

    Johnston, Alan R.; Hartmayer, Ron; Bergman, Larry A.

    1992-01-01

    This paper will concentrate on results obtained from the Jet Propulsion Lab (JPL) Fiber Optics Long Duration Exposure Facility (LDEF) Experiment since the June 1991 Experimenters Workshop. Radiation darkening of the laboratory control samples will be compared with the LDEF flight samples. The results of laboratory temperature tests on the flight samples extending over a period of about nine years including the preflight and postflight analysis periods will be described.

  20. LDEF: 69 Months in Space. Third Post-Retrieval Symposium, part 2

    NASA Technical Reports Server (NTRS)

    Levine, Arlene S. (Editor)

    1995-01-01

    This volume is a compilation of papers presented at the Third Long Duration Exposure Facility (LDEF) Post-Retrieval Symposium. The papers represent the data analysis of the 57 experiments flown on the LDEF. The experiments include materials, coatings, thermal systems, power and propulsion, science (cosmic ray, interstellar gas, heavy ions, micrometeoroid, etc.), electronics, optics, and life science. In addition, papers on preliminary data analysis of EURECA, EOIM-3, and other spacecraft are included. This second of three parts covers spacecraft construction materials.

  1. Consignment trays and the hidden costs of sterilization.

    PubMed

    Ricupito, Gene

    2006-12-01

    Consignment implant trays are often an overlooked facet of the supply chain. If not handled properly, they can cost a hospital thousands of dollars in delivery charges as well as potentially decreasing the level of patient safety. It is critical that value analysis committees have input from central service and that time is taken to consider logistics before signing agreements, especially with regard to proper sterilization instructions and delivery method. If trays arrive too late, it is more likely that corners will be cut with the sterilization process.

  2. Geometry and mass model of ionizing radiation experiments on the LDEF satellite

    NASA Technical Reports Server (NTRS)

    Colborn, B. L.; Armstrong, T. W.

    1992-01-01

    Extensive measurements related to ionizing radiation environments and effects were made on the LDEF satellite during its mission lifetime of almost 6 years. These data, together with the opportunity they provide for evaluating predictive models and analysis methods, should allow more accurate assessments of the space radiation environment and related effects for future missions in low Earth orbit. The LDEF radiation dosimetry data is influenced to varying degrees by material shielding effects due to the dosimeter itself, nearby components and experiments, and the spacecraft structure. A geometry and mass model is generated of LDEF, incorporating sufficient detail that it can be applied in determining the influence of material shielding on ionizing radiation measurements and predictions. This model can be used as an aid in data interpretation by unfolding shielding effects from the LDEF radiation dosimeter responses. Use of the LDEF geometry/mass model, in conjunction with predictions and comparisons with LDEF dosimetry data currently underway, will also allow more definitive evaluations of current radiation models for future mission applications.

  3. High-speed pressure clamp.

    PubMed

    Besch, Stephen R; Suchyna, Thomas; Sachs, Frederick

    2002-10-01

    We built a high-speed, pneumatic pressure clamp to stimulate patch-clamped membranes mechanically. The key control element is a newly designed differential valve that uses a single, nickel-plated piezoelectric bending element to control both pressure and vacuum. To minimize response time, the valve body was designed with minimum dead volume. The result is improved response time and stability with a threefold decrease in actuation latency. Tight valve clearances minimize the steady-state air flow, permitting us to use small resonant-piston pumps to supply pressure and vacuum. To protect the valve from water contamination in the event of a broken pipette, an optical sensor detects water entering the valve and increases pressure rapidly to clear the system. The open-loop time constant for pressure is 2.5 ms for a 100-mmHg step, and the closed-loop settling time is 500-600 micros. Valve actuation latency is 120 micros. The system performance is illustrated for mechanically induced changes in patch capacitance.

  4. Use of Pindex system in fabrication of the sectional custom tray.

    PubMed

    Jabbari, Ehsan; Savabi, Omid; Nejatidanesh, Farahnaz

    2014-07-01

    This article describes a new, precise, and simple method for making an impression with an individual tray for a patient with microstomia. In this method, a Pindex system on the handle of the tray was used for attaching two parts of the sectional tray. © 2014 by the American College of Prosthodontists.

  5. LET spectra measurements on LDEF: variations with shielding and location.

    PubMed

    Benton, E V; Frank, A L; Csige, I; Frigo, L A; Benton, E R

    1996-11-01

    LET spectra measurements made with passive plastic nuclear track detectors (PNTDs) were found to depend on detector orientation, shielding and experiment location. LET spectra were measured at several locations on LDEF as part of the P0006 LETSME experiment (Benton and Parnell, 1984), the P0004 Seeds in Space experiment (Parks and Alston, 1984), the A00l5 Free Flyer Biostacks and the M0004 Fiber Optics Data Link experiment (Taylor, 1984). Locations included the east, west and Earth sides of the LDEF satellite. The LET spectra measured with PNTDs deviated significantly from calculations, especially for high LET particles (LET infinity H2O > or = 100 keV/micrometer). At high LETs, short-range inelastic secondary particles produced by trapped proton interactions with the nuclei of the detector were found to be the principal contributor to LET spectra. At lower LETs, the spectra appeared to be due to short-range, inelastic and stopping primary protons, with primary GCR particles making a smaller contribution. The dependence of LET spectra on detector orientation and shielding was studied using the four orthogonal stacks in the P0006 experiment. Both measurements of total track density and LET spectra showed a greater number of particles arriving from the direction of space than from Earth. Measurements of LET spectra in CR-39 PNTD on the east (leading) and west (trailing) sides of LDEF showed a higher rate of production at the west side. This was caused by a larger flux of trapped protons on the west side as predicted by the east/west trapped proton anisotropy in the South Atlantic Anomaly (SAA). Track density measured in CR-39 PNTDs increased as a function of shielding depth in the detector stack. A similar measurement made in a thick stack of CR-39 interspersed with layers of Al and exposed to 154 MeV protons at a ground-based accelerator showed a similar result, indicating that a significant fraction of the particle events counted were from secondaries and that the

  6. LET spectra measurements on LDEF: variations with shielding and location

    NASA Technical Reports Server (NTRS)

    Benton, E. V.; Frank, A. L.; Csige, I.; Frigo, L. A.; Benton, E. R.

    1996-01-01

    LET spectra measurements made with passive plastic nuclear track detectors (PNTDs) were found to depend on detector orientation, shielding and experiment location. LET spectra were measured at several locations on LDEF as part of the P0006 LETSME experiment (Benton and Parnell, 1984), the P0004 Seeds in Space experiment (Parks and Alston, 1984), the A00l5 Free Flyer Biostacks and the M0004 Fiber Optics Data Link experiment (Taylor, 1984). Locations included the east, west and Earth sides of the LDEF satellite. The LET spectra measured with PNTDs deviated significantly from calculations, especially for high LET particles (LET infinity H2O > or = 100 keV/micrometer). At high LETs, short-range inelastic secondary particles produced by trapped proton interactions with the nuclei of the detector were found to be the principal contributor to LET spectra. At lower LETs, the spectra appeared to be due to short-range, inelastic and stopping primary protons, with primary GCR particles making a smaller contribution. The dependence of LET spectra on detector orientation and shielding was studied using the four orthogonal stacks in the P0006 experiment. Both measurements of total track density and LET spectra showed a greater number of particles arriving from the direction of space than from Earth. Measurements of LET spectra in CR-39 PNTD on the east (leading) and west (trailing) sides of LDEF showed a higher rate of production at the west side. This was caused by a larger flux of trapped protons on the west side as predicted by the east/west trapped proton anisotropy in the South Atlantic Anomaly (SAA). Track density measured in CR-39 PNTDs increased as a function of shielding depth in the detector stack. A similar measurement made in a thick stack of CR-39 interspersed with layers of Al and exposed to 154 MeV protons at a ground-based accelerator showed a similar result, indicating that a significant fraction of the particle events counted were from secondaries and that the

  7. LET spectra measurements on LDEF: variations with shielding and location

    NASA Technical Reports Server (NTRS)

    Benton, E. V.; Frank, A. L.; Csige, I.; Frigo, L. A.; Benton, E. R.

    1996-01-01

    LET spectra measurements made with passive plastic nuclear track detectors (PNTDs) were found to depend on detector orientation, shielding and experiment location. LET spectra were measured at several locations on LDEF as part of the P0006 LETSME experiment (Benton and Parnell, 1984), the P0004 Seeds in Space experiment (Parks and Alston, 1984), the A00l5 Free Flyer Biostacks and the M0004 Fiber Optics Data Link experiment (Taylor, 1984). Locations included the east, west and Earth sides of the LDEF satellite. The LET spectra measured with PNTDs deviated significantly from calculations, especially for high LET particles (LET infinity H2O > or = 100 keV/micrometer). At high LETs, short-range inelastic secondary particles produced by trapped proton interactions with the nuclei of the detector were found to be the principal contributor to LET spectra. At lower LETs, the spectra appeared to be due to short-range, inelastic and stopping primary protons, with primary GCR particles making a smaller contribution. The dependence of LET spectra on detector orientation and shielding was studied using the four orthogonal stacks in the P0006 experiment. Both measurements of total track density and LET spectra showed a greater number of particles arriving from the direction of space than from Earth. Measurements of LET spectra in CR-39 PNTD on the east (leading) and west (trailing) sides of LDEF showed a higher rate of production at the west side. This was caused by a larger flux of trapped protons on the west side as predicted by the east/west trapped proton anisotropy in the South Atlantic Anomaly (SAA). Track density measured in CR-39 PNTDs increased as a function of shielding depth in the detector stack. A similar measurement made in a thick stack of CR-39 interspersed with layers of Al and exposed to 154 MeV protons at a ground-based accelerator showed a similar result, indicating that a significant fraction of the particle events counted were from secondaries and that the

  8. [A clamp for suturing of duodenal stump].

    PubMed

    Komarov, I A

    1991-03-01

    An original clamp was used in suturing a duodenal stump after gastric resection in 77 patients. The complex relief of the blades of the clamp holds the duodenum reliably during application of the sutures and ensures their air-tightness. The trauma inflicted to the duodenum in this case is minimal. During resection of the stomach in 37 patients the author used the clamp in closure of the lesser curvature. Incompetence of the duodenal stump was not encountered.

  9. Design application and development of spacecraft in LEO utilizing LDEF results

    NASA Technical Reports Server (NTRS)

    Rauch, George B., Jr.; Sudduth, Richard D.

    1993-01-01

    In general, the results from the Long Duration Exposure Facility (LDEF) have provided much useful information on material sensitivity in the low-Earth orbit (LEO) environment. This is particularly true for selected materials such as thermal control coatings, composites, polymers, fasteners and solar cells. However, LDEF material sensitivity data for other materials like glasses, glass coatings, lubricants, adhesives and seal materials were limited. Some of this important LDEF material sensitivity data has not yet been addressed in detail at the LDEF meetings. The type of material information needed in the design and development of a new spacecraft in LEO depends to a large extent on program phase. In early program phases it is only necessary to have material sensitivity data to determine what materials may or may not work. Later program phases require details on the material strength, optical properties, and/or other long term survivability requirements for materials in LEO. Unfortunately, documentation of exposure results for many materials sensitivity experiments that flew on LDEF has not yet been summarized in a convenient form for use by multiple users. Documentation of this data in a form convenient for scientists, engineers as well as technicians remains a significant area of concern for the aerospace industry. Many of the material experiments that flew on LDEF were only designed to measure material sensitivity for one year in an LEO environment. However, some materials expected to survive one year simply did not survive the 5.8 years that LDEF eventually remained in orbit. Therefore the survivability of several materials in an LEO environment was determined by default. Most of the LDEF materials experiments were not designed to establish long term material survivability data. This long term material survivability data is particularly useful in later program phases of spacecraft development. The lack of more controlled materials experiments to determine long

  10. Astronaut Norman Thagard changes tray in RAHF for rodents

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Astronaut Norman Thagard changes a tray in the research animal holding facility (RAHF) for rodents at the Ames double rack facility aboard the Spacelab 3 science module in the cargo bay of the shuttle Challenger. Lending a hand is payload specialist Lodewijk van den Berg. Both men are wearing protective clothing and surgical masks for this procedure.

  11. 5. VIEW OF CABLE SHED AND CABLE TRAY EMANATING FROM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. VIEW OF CABLE SHED AND CABLE TRAY EMANATING FROM SOUTH FACE OF LAUNCH OPERATIONS BUILDING. MICROWAVE DISH IN FOREGROUND. METEOROLOGICAL TOWER IN BACKGROUND. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Operations Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  12. 40. Coffee bean drying trays that are stored in racks ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    40. Coffee bean drying trays that are stored in racks under building and pulled out to sun dry beans on terraces to the north and south of building. HAER PR, 6-MAGU, 1C-3 - Hacienda Buena Vista, PR Route 10 (Ponce to Arecibo), Magueyes, Ponce Municipio, PR

  13. Training to Increase Safe Tray Carrying among Cocktail Servers

    ERIC Educational Resources Information Center

    Scherrer, Megan D.; Wilder, David A.

    2008-01-01

    We evaluated the effects of training on proper carrying techniques among 3 cocktail servers to increase safe tray carrying on the job and reduce participants' risk of developing musculoskeletal disorders. As participants delivered drinks to their tables, their finger, arm, and neck positions were observed and recorded. Each participant received…

  14. 16 CFR Figure 7 to Subpart A of... - Specimen Tray

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 2 2013-01-01 2013-01-01 false Specimen Tray 7 Figure 7 to Subpart A of Part 1209 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS INTERIM SAFETY STANDARD FOR CELLULOSE INSULATION The Standard Pt. 1209, Subpt. A, Fig. 7 Figure...

  15. 16 CFR Figure 7 to Subpart A of... - Specimen Tray

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 2 2014-01-01 2014-01-01 false Specimen Tray 7 Figure 7 to Subpart A of Part 1209 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS INTERIM SAFETY STANDARD FOR CELLULOSE INSULATION The Standard Pt. 1209, Subpt. A, Fig. 7 Figure...

  16. 16 CFR Figure 7 to Subpart A of... - Specimen Tray

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Specimen Tray 7 Figure 7 to Subpart A of Part 1209 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS INTERIM SAFETY STANDARD FOR CELLULOSE INSULATION The Standard Pt. 1209, Subpt. A, Fig. 7 Figure...

  17. 16 CFR Figure 7 to Subpart A of... - Specimen Tray

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 2 2012-01-01 2012-01-01 false Specimen Tray 7 Figure 7 to Subpart A of Part 1209 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS INTERIM SAFETY STANDARD FOR CELLULOSE INSULATION The Standard Pt. 1209, Subpt. A, Fig. 7 Figure...

  18. 16 CFR Figure 7 to Subpart A of... - Specimen Tray

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 2 2011-01-01 2011-01-01 false Specimen Tray 7 Figure 7 to Subpart A of Part 1209 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS INTERIM SAFETY STANDARD FOR CELLULOSE INSULATION The Standard Pt. 1209, Subpt. A, Fig. 7 Figure...

  19. 4. VIEW OF CABLE SHED AND CABLE TRAY EMANATING FROM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. VIEW OF CABLE SHED AND CABLE TRAY EMANATING FROM NORTH FACE OF LAUNCH OPERATIONS BUILDING. TOPS OF BUNKER PERISCOPE AND FLAGPOLE ON ROOF OF LAUNCH OPERATIONS BUILDING IN BACKGROUND - Vandenberg Air Force Base, Space Launch Complex 3, Launch Operations Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  20. 21 CFR 884.1550 - Amniotic fluid sampler (amniocentesis tray).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Amniotic fluid sampler (amniocentesis tray). 884.1550 Section 884.1550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... inch 20 gauge needle with stylet and a 30 cc. syringe, as well as the various sample...

  1. 21 CFR 872.6880 - Preformed impression tray.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Preformed impression tray. 872.6880 Section 872.6880 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...) to reproduce the structure of a patient's teeth and gums. (b) Classification. Class I...

  2. Training to Increase Safe Tray Carrying among Cocktail Servers

    ERIC Educational Resources Information Center

    Scherrer, Megan D.; Wilder, David A.

    2008-01-01

    We evaluated the effects of training on proper carrying techniques among 3 cocktail servers to increase safe tray carrying on the job and reduce participants' risk of developing musculoskeletal disorders. As participants delivered drinks to their tables, their finger, arm, and neck positions were observed and recorded. Each participant received…

  3. 21 CFR 872.6880 - Preformed impression tray.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6880 Preformed impression tray. (a..., such as alginate, to make an impression of a patient's teeth or alveolar process (bony tooth sockets) to reproduce the structure of a patient's teeth and gums. (b) Classification. Class I...

  4. Astronaut Norman Thagard changes tray in RAHF for rodents

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Astronaut Norman Thagard changes a tray in the research animal holding facility (RAHF) for rodents at the Ames double rack facility aboard the Spacelab 3 science module in the cargo bay of the shuttle Challenger. Lending a hand is payload specialist Lodewijk van den Berg. Both men are wearing protective clothing and surgical masks for this procedure.

  5. 21 CFR 872.3670 - Resin impression tray material.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Resin impression tray material. 872.3670 Section 872.3670 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... fabrication of crowns, bridges, or full dentures. A preliminary plaster or stone model of the patient's...

  6. 21 CFR 872.3670 - Resin impression tray material.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Resin impression tray material. 872.3670 Section 872.3670 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... fabrication of crowns, bridges, or full dentures. A preliminary plaster or stone model of the patient's...

  7. Advanced motor driven clamped borehole seismic receiver

    DOEpatents

    Engler, Bruce P.; Sleefe, Gerard E.; Striker, Richard P.

    1993-01-01

    A borehole seismic tool including a borehole clamp which only moves perpendicular to the borehole. The clamp is driven by an electric motor, via a right angle drive. When used as a seismic receiver, the tool has a three part housing, two of which are hermetically sealed. Accelerometers or geophones are mounted in one hermetically sealed part, the electric meter in the other hermetically sealed part, and the clamp and right angle drive in the third part. Preferably the tool includes cable connectors at both ends. Optionally a shear plate can be added to the clamp to extend the range of the tool.

  8. Advanced motor driven clamped borehole seismic receiver

    DOEpatents

    Engler, B.P.; Sleefe, G.E.; Striker, R.P.

    1993-02-23

    A borehole seismic tool is described including a borehole clamp which only moves perpendicular to the borehole. The clamp is driven by an electric motor, via a right angle drive. When used as a seismic receiver, the tool has a three part housing, two of which are hermetically sealed. Accelerometers or geophones are mounted in one hermetically sealed part, the electric motor in the other hermetically sealed part, and the clamp and right angle drive in the third part. Preferably the tool includes cable connectors at both ends. Optionally a shear plate can be added to the clamp to extend the range of the tool.

  9. Atomic oxygen interactions with FEP Teflon and silicones on LDEF

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A.; Dever, Joyce A.; Gebauer, Linda; Hill, Carol M.

    1992-01-01

    The Long Duration Exposure Facility (LDEF) spacecraft has enabled the measurement of the effects of fixed orientation exposure of high fluence atomic oxygen on fluorinated ethylene propylene (FEP Teflon) and silicones. The atomic oxygen erosion yield for the FEP Teflon was found to be 3.64 x 10(exp -25) cm(exp 3)/atom. This erosion yield is significantly higher than that measured from previous low fluence orbital data. The FEP Teflon erosion yield was found to have the same dependence on oxygen arrival angle as Kapton and Mylar. Atomic oxygen interaction with silicon polymers results in the crazing of silicon. Released silicone contaminants were found to darken upon further atomic oxygen exposure.

  10. Particle directionality and trapped proton fluences on LDEF

    NASA Technical Reports Server (NTRS)

    Nefedov, N.; Csige, I.; Benton, E. V.; Frank, A. L.; Frigo, L. A.; Benton, E. R.

    1996-01-01

    Directionality of incident space radiation is a significant factor in spacecraft shielding and astronaut dosimetry in low Earth orbit (LEO). Particle directionality of GCR and trapped protons were measured on LDEF with plastic nuclear track detectors (PNTD) from the P0006 west-side experiment. This experiment consisted of a thick detector stack and is described more fully in a companion article (Benton et al., 1996). The anisotropy of the trapped protons produced maximum intensity for protons arriving from the west. The fluences of the eastward directed trapped protons have been measured by selection of the particles on the basis of range in the PNTDs. The measured fluences are compared with the model calculations of Armstrong and Colborn (1993).

  11. Gamma ray spectrometry of LDEF samples at SRS

    NASA Technical Reports Server (NTRS)

    Winn, Willard G.

    1991-01-01

    A total of 31 samples from Long Duration Exposure Facility (LDEF), including materials of Al, V, and steel trunnions were analyzed by ultralow level gamma spectrometry. The study quantified particle induced activations of Na-22, Sc-46, Cr-51, Mn-54, Co-56, Co-57, Co-58, and Co-60. The samples of trunnion sections exhibited increasing activity toward the outer end of the trunnion and decreasing activity toward its radial center. The trunnion sections did not include an end piece that collects noticeable Be-7 on its leading surface. No significant Be-7 was detected in the samples analyzed. The most sensitive analyses were performed with a 90 pct. efficient HPGe gamma ray detector, which is enclosed in a purged active/passive active shield.

  12. Thermal expansion behavior of LDEF metal matrix composites

    NASA Technical Reports Server (NTRS)

    Le, T. D.; Steckel, G. L.

    1992-01-01

    The effects of the space environment on the thermal expansion stability of metal matrix composites (graphite/Al and graphite/Mg) will be presented. A sample from each category of metal matrix composites mounted on the leading and trailing edge was chosen for analysis of the temperature-time-thermal strain histories. Typical thermal expansion curves over the same range of temperature were selected at the beginning, mid, and end of the recording duration. The thermal expansion of selected post-flight LDEF samples were measured over the same range of temperature in the laboratory using a Michelson laser interferometer. The thermal strains were monitored concurrently with a laser interferometer and a mounted strain gage.

  13. Degradation of electro-optic components aboard LDEF

    NASA Technical Reports Server (NTRS)

    Blue, M. D.

    1993-01-01

    Remeasurement of the properties of a set of electro-optic components exposed to the low-earth environment aboard the Long Duration Exposure Facility (LDEF) indicates that most components survived quite well. Typical components showed some effects related to the space environment unless well protected. The effects were often small but significant. Results for semiconductor infrared detectors, lasers, and LED's, as well as filters, mirrors, and black paints are described. Semiconductor detectors and emitters were scarred but reproduced their original characteristics. Spectral characteristics of multi-layer dielectric filters and mirrors were found to be altered and degraded. Increased absorption in black paints indicates an increase in absorption sites, giving rise to enhanced performance as coatings for baffles and sunscreens.

  14. LDEF fiber optic exposure experiment No. S-0109

    NASA Technical Reports Server (NTRS)

    Johnston, A. R.; Bergman, L. A.; Hartmayer, R.

    1992-01-01

    Ten fiber optic cable samples of different types were exposed in low-earth orbit for over 5.5 years on the Long-Duration Exposure Facility (LDEF). Four of the samples were mounted externally, and the remaining six were internal, under approximately 0.5 g cm(exp -2) of aluminum. The experiment was recovered in Jan. 1990, and laboratory evaluation of the effects of the exposure has continued since. An increase in fiber loss, presumed to be from radiation darkening, aging effects on polymer materials used in cabling, unique contamination effects on connector terminations, and micrometeoroid impacts were observed. In addition, the sample loss was measured for each sample as a function of temperature before and after the flight. All cable samples were functional, and the best exhibited no measurable change in performance, indicating that conventional fiber optic cables can perform satisfactorily in spacecraft. Experimental results obtained to date are presented and discussed.

  15. Atomic oxygen interactions with FEP Teflon and silicones on LDEF

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A.; Dever, Joyce A.; Gebauer, Linda; Hill, Carol M.

    1992-01-01

    The Long Duration Exposure Facility (LDEF) spacecraft has enabled the measurement of the effects of fixed orientation exposure of high fluence atomic oxygen on fluorinated ethylene propylene (FEP Teflon) and silicones. The atomic oxygen erosion yield for the FEP Teflon was found to be 3.64 x 10(exp -25) cm(exp 3)/atom. This erosion yield is significantly higher than that measured from previous low fluence orbital data. The FEP Teflon erosion yield was found to have the same dependence on oxygen arrival angle as Kapton and Mylar. Atomic oxygen interaction with silicon polymers results in the crazing of silicon. Released silicone contaminants were found to darken upon further atomic oxygen exposure.

  16. Measured space environmental effects to LDEF during retrieval

    NASA Technical Reports Server (NTRS)

    Maag, Carl R.; Linder, W. Kelly

    1992-01-01

    On the STS-32 shuttle mission, a space flight experiment provided an understanding of the effects of the space environment on the Long Duration Exposure Facility (LDEF) from rendezvous with the shuttle until removal from the payload bay at the Orbiter Processing Facility (OPF) at KSC. The Interim Operational Contamination Monitor (IOCM) is an attached shuttle payload that has been used on two earlier flights (STS 51C and STS 28) to quantify the contamination deposited during the course of the mission. The IOCM can characterize by direct measurement, the deposition of molecular and particulate contamination during any phase of flight. In addition to these principal measurements, the IOCM actively measures the thermophysical properties of thermal control surfaces by calorimetry, the flux of the ambient atomic oxygen environment, the incident solar flux, and the absolute ambient pressure in the payload bay. The IOCM also provides a structure and sample holders for the exposure of passive material samples to the space environment, e.g. thermal cycling, atomic oxygen, and micrometeoroids and/or orbital debris, etc. One of the more salient results from the STS-32 flight suggests that the LDEF emitted a large number of particulates after berthing into the shuttle. The mission atomic oxygen fluence was also calculated. Although the fluence was low by normal standards, the Kapton passive samples exhibited the onset of erosion. Orbital debris and micrometeoroid impacts also occurred during the retrieval mission. The average perforation diameter was approximately 12.5 microns. The largest perforation diameter was measured at 65 microns.

  17. Modified Technique for Making Auto-polymerized Polymethylmethacrylate Resin Custom Tray

    PubMed Central

    Reddy, Ramesh; Rajendran, Suresh; Balasubramaniam, Muthu Kumar

    2016-01-01

    Custom made tray for dental impression is designed to provide a uniform space for the impression material and thereby improve the accuracy of the resultant working cast. Auto-polymerized acrylic resins have been the most commonly used material for the fabrication of these trays. The custom tray produces more accurate and reliable results for inter-abutment distance at the occlusal and gingival level than stock trays. This article describes a modified technique for fabrication of auto-polymerized Polymethylmethacrylate (PMMA) resin trays. PMID:28050525

  18. Modified Technique for Making Auto-polymerized Polymethylmethacrylate Resin Custom Tray.

    PubMed

    Chidambaranathan, Ahila Singaravel; Reddy, Ramesh; Rajendran, Suresh; Balasubramaniam, Muthu Kumar

    2016-11-01

    Custom made tray for dental impression is designed to provide a uniform space for the impression material and thereby improve the accuracy of the resultant working cast. Auto-polymerized acrylic resins have been the most commonly used material for the fabrication of these trays. The custom tray produces more accurate and reliable results for inter-abutment distance at the occlusal and gingival level than stock trays. This article describes a modified technique for fabrication of auto-polymerized Polymethylmethacrylate (PMMA) resin trays.

  19. Is There A Difference in Bone Ingrowth in Modular Versus Monoblock Porous Tantalum Tibial Trays?

    PubMed Central

    Hanzlik, Josa A.; Day, Judd S.; Rimnac, Clare M.; Kurtz, Steven M.

    2015-01-01

    Contemporary total knee designs incorporating highly porous metallic surfaces have demonstrated promising clinical outcomes. However, stiffness differences between modular and monoblock porous tantalum tibial trays may affect bone ingrowth. This study investigated effect of implant design, spatial location and clinical factors on bone ingrowth in retrieved porous tantalum tibial trays. Three modular and twenty-one monoblock tibial trays were evaluated for bone ingrowth. Nonparametric statistical tests were used to investigate differences in bone ingrowth measurements by implant design, spatial location on the tray, substrate depth and clinical factors. Modular trays (5.3±3.2%) exhibited higher bone ingrowth than monoblock trays (1.6±1.9%, p=0.032). Bone ingrowth in both designs was highest in the initial 500 μm from the surface. Implantation time was positively correlated with bone ingrowth for monoblock trays. PMID:25743106

  20. Optimal heating conditions for forming a mouthguard using a circle tray: effect of different conditions on the thickness and fit of formed mouthguards.

    PubMed

    Takahashi, Mutsumi; Koide, Kaoru; Mizuhashi, Fumi

    2014-07-01

    The aim of this study was to determine the optimal heating conditions for sheet forming using a circle tray by comparing the thickness and fit of mouthguards formed under different conditions. Mouthguards were fabricated using ethylene vinyl acetate sheets (4.0mm thick) and a vacuum forming machine. The working model was trimmed to a height of 20mm at the incisor and 15 mm at the first molar. Two forming conditions were compared: square sheets were pinched by the clamping frame attached to the forming machine; and round sheets were pinched at the top and bottom and stabilized by a circle tray. Each condition was defined when the sheet sagged by 10-mm or 15-mm below the level of the clamp. The thickness of the sheet was determined for the incisal and molar portion. Additionally, the difference in fit according to the forming conditions was measured by examining the cross section. Differences in the thickness or the fit due to forming conditions were analyzed using two-way analysis of variance (ANOVA) followed by Bonferroni's multiple comparison tests. The thickness after formation was thicker at the 10-mm condition than that of 15-mm, and the fit at the 15-mm condition was better when that of 10-mm with square and round sheets. Within the limitation of this study, it was suggested that when forming a mouthguard using a 4.0-mm EVA sheet and a circle tray on a vacuum forming machine, the sheet should be formed at a sagging distance of 10-mm. Copyright © 2014 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.