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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 181 records · Page 10
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Experimental petrology and origin of rocks from the Descartes Highlands

Petrographic studies of Apollo 16 samples indicate that rocks 62295 and 68415 are crystallization products of highly aluminous melts. 60025 is a shocked, crushed and partially annealed plagioclase cumulate. 60315 is a recrystallized noritic breccia of disputed origin. 60335 is a feldspathic basalt filled with xenoliths and xenocrysts of anorthosite, breccia, and anorthite. The Fe/(Fe+Mg) of plagioclase appears to be a relative crystallization index. Low pressure melting experiments with controlled Po2 indicate that the igneous samples crystallized at oxygen fugacities well below the Fe/FeO buffer. Crystallization experiments at various pressures suggest that the 62295 and 68415 compositions were produced by partial or complete melting of lunar crustal materials, and not by partial melting of the deep lunar interior.

Walker, D.↗
NASA NTRS1974

Effects of diffusion on aluminum depletion and degradation of NiAl coatings

Experiments were performed to critically demonstrate the effects of diffusion on the aluminum depletion and degradation of NiAl coatings on superalloys. Pack aluminized IN 100 and Mar-M200 were diffusion annealed in 5 mtorr vacuum at 1100 C for 300 hr. Aluminum losses due to oxidation and vaporization were minimal. Metallographic and electron microprobe analyses showed considerable interdiffusion of the coating with the substrate, which caused a large decrease in the original aluminum level of the coating. Subsequent cyclic furnace oxidation tests were performed at 1100 C using 1 hr cycles on prediffused and as-coated specimens. The prediffusion treatment decreased the oxidation and as-coated specimens. The prediffusion treatment decreased the oxidation protection for both alloys, but more dramatically for IN 100. Identical oxidation tests of bulk NiAl, where such diffusion effects are precluded, showed no signs of degradation at twice the time needed to degrade the coated superalloys.

Smialek, J. L.↗
NASA NTRS1974

Method of protecting the surface of a substrate

The surface of a metallic base system is initially coated with a metallic alloy layer that is ductile and oxidation resistant. An aluminide coating is then applied to the metallic alloy layer. The chemistry of the metallic alloy layer is such that the oxidation resistance of the subsequently aluminized outermost layer is not seriously degraded.

Gedwill, M. A.↗
NASA NTRS1975

Chemical, mineralogical and textural systematics of non-mare melt rocks: Implications for lunar impact and volcanic processes

Based on a synthesis of chemical data for over 200 samples, the nonmare rocks with fine grained melt textures can be classified into 7 major groups: anorthositic basalts, troctolitic basalts, VHA basalts, Apollo 14-type KREEP basalts, Apollo 15-type KREEP basalts, Apollo 17-type KREEP basalts, and aluminous mare basalts. Review of chemical, mineralogical, textural and experimental evidence leads to preferred hypotheses for the origins of these rocks; those hypotheses are discussed in detail.

Irving, A. J.↗
NASA NTRS1975

High-resolution system for tropospheric wind and temperature profile measurements

This paper briefly describes the Jimsphere/Jimsonde system and presents some possible applications of the system. As space vehicles became larger and more sophisticated, an improved method for obtaining wind-profile data had to be found. To satisfy this need, the FPS-16 radar/Jimsphere system was developed. The Jimsphere is an aluminized mylar spherical balloon 2 m in diameter. The balloon is under superpressure and is tracked with a high-precision radar system. The development of this detailed wind-profile system was started in 1963, and the present design was established in 1964. To improve the system, a program was initiated in 1965 to obtain high-resolution temperature data simultaneously with the wind-profile data.

Camp, D. W.↗
NASA NTRS1976

Uniform solar cells

Solar cells used in radiation sensors can be efficiently matched by individual trimming. Strip of aluminized Mylar is used to adjust cell output to within required tolerances. Method is faster than individual selection of matched cells.

Source record↗
NASA NTRS1975

Solid rocket motor nozzles

The steps in the nozzle design process are examined. The nozzle designer's role in defining design requirements and constraints is included along with discussions of each of the three basic phases of the nozzle design process itself: (1) aerodynamic design, in which the gas-contacting surfaces are configured to produce the required performance within the envelope limits; (2) thermal design, in which termal liners and thermal insulators are selected and configured to maintain the surfaces as closely as practical against effects of erosion and to limit the structure temperature to acceptable levels; and (3) structural design, in which materials are selected and configured to support the thermal components and to sustain the predicted loads. Analytical techniques that are used to establish thermal and structural design integrity and to predict nozzle performance are discussed along with methods for nozzle quality assurance. Emphasis is placed on nozzle design and materials for modern high-temperature aluminized propellants. Recurring nozzle design problems of graphite cracking and ejection, differential erosion at material interfaces, lack of sufficient proven nondestructive testing (NDT) techniques, the uncertainty of adhesive bonding, and inadequate definition of material properties, particularly at high temperatures are considered.

Ellis, R. A.↗
NASA NTRS1976

Environmental charging of spacecraft-tests of thermal control materials for use on the global positioning system flight space vehicle. Part 2: Specimen 6 to 9

The NASA/USAF program on the Environmental Charging of Spacecraft Surfaces consists, in part, of experimental efforts directed toward evaluating the response of materials to the environmental charged particle flux. Samples of thermal blankets of the type to be used on the Global Positioning System Flight Space Vehicles were tested to determine their response to electron flux. The primary result observed was that no discharges were obtained with the quartz-fiber-fabric-covered multilayer insulation specimen. The taped aluminized polyester grounding system used on all specimens did not appear to grossly deteriorate with time; however, the specimens require specific external pressure to maintain constant grounding system resistance.

Stevens, N. J.↗
NASA NTRS1975

Dewar technology study

The development of a Dewar system for handling liquid helium under weightless conditions is described. Porous plug designs for the prevention of superfluid creep out of the dewar through the vent line were evaluated. For the purpose of designing a neck to provide a transition from the cold cavity to the outside, the loads carried by the neck and equipment supports were studied. Temperature, pressure, and mass flow instrumentation for monitoring Dewar performance were also evaluated. In addition, multilayer blankets consisting of aluminized Mylar separated by Dacron net sheets were designed to insulate the pressure vessel. The dewar system is suggested for use with the star tracking telescope aboard the relativity satellite.

Davis, W.↗
NASA NTRS1976

Purging of multilayer insulation by gas diffusion

An experimental investigation was conducted to determine the time required to purge a multilayer insulation (MLI) panel with gaseous helium by means of gas diffusion to obtain a condensable (nitrogen) gas concentration of less than 1 percent within the panel. Two flat, rectangular MLI panel configurations, one incorporating a butt joint, were tested. The insulation panels consisted of 15 double-aluminized Mylar radiation shields separated by double silk net spacers. The test results indicated that the rate which the condensable gas concentration at the edge or at the butt joint of an MLI panel was reduced was a significant factor in the total time required to reduce the condensable gas concentration within the panel to less than 1 percent. The experimental data agreed well with analytical predictions made by using a simple, one-dimensional gas diffusion model in which the boundary conditions at the edge of the MLI panel were time dependent.

Sumner, I. E.↗
NASA NTRS1976

Thermal performance of a customized multilayer insulation (MLI)

The thermal performance of a LH2 tank on a shroudless vehicle was investigated. The 1.52 m (60 in) tank was insulated with 2 MLI blankets consisting of 18 double aluminized Mylar radiation shields and 19 silk net spacers. The temperature of outer space was simulated by using a cryoshroud which was maintained at near liquid hydrogen temperature. The heating effects of a payload were simulated by utilizing a thermal payload simulator (TPS) viewing the tank. The test program consisted of three major test categories: (1) null testing, (2) thermal performance testing of the tank installed MLI system, and (3) thermal testing of a customized MLI configuration. TPS surface temperatures during the null test were maintained at near hydrogen temperature and during test categories 2 and 3 at 289 K (520R). The heat flow rate through the tank installed MLI at a tank/TPS spacing of 0.457 m was 1.204 watts with no MLI on the TPS and 0.059 watts through the customized MLI with three blankets on the TPS. Reducing the tank/TPS spacing from 0.457 m to 0.152 m the heat flow through the customized MLI increased by 10 percent.

Leonhard, K. E.↗
NASA NTRS1976

Degradation of a Multilayer Insulation Due to a Seam and a Penetration

The degradation of the thermal performance of a multilayer insulation due to the presence of a seam and a penetration was studied. The multilayer insulation had 30 aluminized Mylar radiation shields with silk net spacers. The seam, an offset butt joint, caused a heat input of 0.169 watt per meter in addition to the basic insulation thermal performance of 0.388 watt per square meter obtained before the installation of the butt joint. The penetration, a fiberglass tank support strut, provided a heat input (including the degradation of the insulation) of 0.543 watt in addition to the basic insulation thermal performance of 0.452 watt per square meter obtained before the penetration.

Sumner, I. E.↗
NASA NTRS1976

Amoeboid olivine aggregates in the Allende meteorite

Greyish-brown irregularly-shaped aggregates composed predominantly of olivine make up nearly 2% of the Allende meteorite by volume. Many of the aggregates are constructed of subspherical lumps of micron-sized crystals of olivine, pyroxene, nepheline and sodalite surrounded by coarser-grained olivine. Rarely, anorthite, spinel and perovskite are also present. The olivine ranges in composition from Fo64 to Fo99. Pyroxenes range from aluminous diopside to hedenbergite to very Al-rich and Ti-Al-rich varieties. The nepheline contains 1.6-2.4% K2O and 1.6-5.2% CaO but the sodalite is significantly poorer in these elements. The spinel contains 2.1-13.4% FeO. Textural information and oxygen isotopic data suggest that the aggregates are composed of primary, solid condensates from the solar nebula. The perovskite, spinel and Ti-Al-rich pyroxenes are the remains of high-temperature condensates, but the olivine compositions and the presence of feldspathoids indicate that some of the grains continued to react with the solar nebular vapor in the temperature range 500-900 K.

Grossman, L.↗
NASA NTRS1976

Refinement of Promising Coating Compositions for Directionally Cast Eutectics

The successful application of high creep strength, directionally solidified gamma/gamma prime-delta (Ni-19.7Cb-6Cr-2.5Al) eutectic superalloy turbine blades requires the development of suitable coatings for airfoil, root and internal blade surfaces. In order to improve coatings for the gamma/gamma prime-delta alloy, the current investigation had the goals of (1) refining promising coating compositions for directionally solidified eutectics, (2) evaluating the effects of coating/ substrate interactions on the mechanical properties of the alloy, and (3) evaluating diffusion aluminide coatings for internal surfaces. Burner rig cyclic oxidation, furnace cyclic hot corrosion, ductility, and thermal fatigue tests indicated that NiCrAlY+Pt(63 to 127 micron Ni-18Cr-12Al-0.3Y + 6 micron Pt) and NiCrAlY(63 to 127 micron Ni-18Cr-12Al-0.3Y) coatings are capable of protecting high temperature gas path surfaces of eutectic alloy airfoils. Burner rig (Mach 0.37) testing indicated that the useful coating life of the 127 micron thick coatings exceeded 1000 hours at 1366 K (2000 deg F). Isothermal fatigue and furnance hot corrosion tests indicated that 63 micron NiCrAlY, NiCrAlY + Pt and platinum modified diffusion aluminide (Pt + Al) coating systems are capable of protecting the relatively cooler surfaces of the blade root. Finally, a gas phase coating process was evaluated for diffusion aluminizing internal surfaces and cooling holes of air-cooled gamma/gamma prime-delta turbine blades.

Strangman, T. E.↗
NASA NTRS1976

Purging of a multilayer insulation with dacron tuft spacer by gas diffusion

The time and purge gas usage required to purge a multilayer insulation (MLI) panel with gaseous helium by means of gas diffusion to obtain a condensable gas (nitrogen) concentration of less than 1 percent within the panel are stipulated. Two different, flat, rectangular MLI panels, one incorporating a butt joint, were constructed of of 11 double-aluminized Mylar (DAM) radiation shields separated by Dacron tuft spacers. The DAM/Dacron tuft concept is known commercially as Superfloc. The nitrogen gas concentration as a function of time within the MLI panel could be adequately predicted by using a simple, one dimensional gas diffusion model in which the boundary conditions at the edge of the MLI panel were time dependent. The time and purge gas usage required to achieve 1 percent nitrogen gas concentration within the MLI panel varied from 208 to 86 minutes and 34.1 to 56.5 MLI panel purge volumes, respectively, for gaseous helium purge rates from 10 to 40 MLI panel volumes per hour.

Sumner, I. E.↗
NASA NTRS1977

Thermal performance of a modularized replaceable multilayer insulation system for a cryogenic stage

A rugged modularized MLI system for a 2.23-meter-diameter (87.6-in.-diam) liquid hydrogen tank was designed, fabricated, and tested under simulated near-earth and deep-space environments. The two blankets of the system were each composed of 17 double-aluminized Mylar radiation shields separated by silk net. The unit area weight of the installed system was 1.54 kg/sqm (0.32 lb/sq ft). The overall average heat transferred into the insulated tank was 22.7 and 0.98 watts (77.4 and 3.3 Btu/hr) during simulated near-earth and deep-space testing, respectively. The near-earth result was only 2.6 times that predicted for an undisturbed insulation system (i.e., no seams or penetrations). Tests indicate that this insulation concept could be useful for a cryogenic space tug or orbit transfer vehicle application.

Knoll, R. H.↗
NASA NTRS1977

Three-dimensional tracking solar energy concentrator and method for making same

A three dimensional tracking solar energy concentrator, consisting of a stretched aluminized polymeric membrane supported by a hoop, was presented. The system is sturdy enough to withstand expected windage forces and precipitation. It can provide the high temperature output needed by central station power plants for power production in the multi-megawatt range.

Miller, C. G.↗
NASA NTRS1977

Apollo 17 KREEPy basalt - A rock type intermediate between mare and KREEP basalts

The Apollo 17 KREEPy basalt is a unique lunar volcanic rock, observed only as clasts in the light friable breccia matrix (72275) of Boulder 1, Station 2 at Taurus-Littrow. Its status as a volcanic rock is confirmed by the absence of any meteoritic contamination, a lack of cognate inclusions or xenocrystal material, and low Ni contents in metal grains. The basalt was extruded 4.01 + or - 0.04 b.y. ago, approximately contemporaneously with the high-alumina mare basalts at Fra Mauro; shortly afterwards it was disrupted, probably by the Serenitatis impact, and its fragments emplaced in the South Massif. The basalt, which is quartz-normative and aluminous, is chemically and mineralogically intermediate between the Apollo 15 KREEP basalts and the high-alumina mare basalts in most respects. It consists mainly of plagioclase and pigeonitic pyroxene in approximately equal amounts, and 10-30% of mesostatis.

Ryder, G.↗