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Multifunctional B/C Fiber Composites for Radiation Shielding

Marshall Space Flight Center, Alabama A versatile, novel, multifunctional hybrid structural composite of a high-hydrogen epoxy matrix (UN-10) coupled with boron and carbon fibers (IM-7) has been developed. Prototype laminates of 18×18 in. (≈46×46 cm), with the nominal areal density of 0.35 g/cm2, were fabricated in this effort. The hydrogen atoms in the epoxy will provide shielding strength against high-energy protons, electrons, and heavy ionic species, while the boron fibers that have a high neutron cross-section will help shield against neutrons and reduce the buildup of high-energy photons from secondary reactions. The carbon fibers will provide improved mechanical strength.

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Smart MMOD Thermal Blanket

A spacer is added to standard thermal blankets to improve MMOD shielding. Lyndon B. Johnson Space Center, Houston, Texas This innovation provides for significantly improved protection from micrometeoroid and orbital debris (MMOD) particles, and reliably determines the location, depth, and extent of MMOD impact damage.

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Using Black Polyimide/Kevlar as a Metering Structure Multi-Layer Insulation (MLI)

This is used as an inner cover for minimizing stray light and providing micrometeoroid protection. Goddard Space Flight Center, Greenbelt, Maryland Metering structures of remote sensing instruments often have large openings or access holes. Shear panels that are X-shaped, such as those proposed for the Neutron Star Interior Composition Explorer (NICER), generally consist of C-channels and L-brackets to minimize structural distortion. This type of metering structure has large openings on the sides. Structural panels that have large access holes, such as those studied for the Landsat Operational Land Imager (OLI), generally consist of aluminum honeycomb panels with composite facesheets. Both types of metering structure require multilayer insulation (MLI) blankets to shield the internal components such as optics from sunlight and Earth albedo, and to minimize heat loss to 3K space by radiation. The issues of conventional MLI blankets for these metering structures include MLI sagging, stray light, and risk of micrometeoroid damage to optics.

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Mechanical Carbon Materials for Aircraft Seal Applications

These materials are of interest to designers of high-speed rotating equipment such as rotary gas compressors and steam turbines. Metallized Carbon Corporation, Ossining, New York Modern mechanical carbon materials are being used in a wide variety of applications, including aircraft gear boxes, air turbine motor starters, and main shaft seals for both aircraft turbine engines and aircraft auxiliary power units (APUs). These self-lubricating materials are composed of fine-grained electrographite substances that are impregnated with proprietary inorganic chemicals to improve their lubricating qualities and oxidation resistance. These modern carbon-based materials are ideal for use in aircraft applications because of their low coefficient of friction, low wear rate at high sliding speed, high thermal conductivity, and resistance to oxidation in high-temperature air.

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Strong and Flexible Carbon Fiber Reinforced Phenolic Composites

Ames Research Center, Moffett Field, California A new class of phenolic and carbon-fiber-reinforced phenolic composites has been developed for thermal protection systems. The new materials have the advantage of being lightweight, strong, and tough, yet heat resistant and flexible. They retain excellent mechanical strength at high temperatures. This provides better thermal protection for reentry conditions with high heating rates.

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Hybrid Laminate Composite for Harsh Environments and High-Performance Applications

John F. Kennedy Space Center, Florida A multi-functional composite laminate material has been developed for structural and thermal applications for use in durable cryogenic fuel tanks for transportation vehicles and/or in the construction of habitats. The technology focuses on aerogel and fiber composites integrated into unique layups with thermal and mechanical energy absorption capabilities. The lightweight laminate composite system has multi-functionality for both high- and low-temperature applications. Combining structural and thermal attributes, the innovation is a lightweight aerogel-fiber laminate composite system with good compressive strength, tailorable for impact and acoustic energy absorption, reduced heat transfer, and/or fire barrier properties.

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Surface-Modified Nanoparticles Made From High-Molecular-Weight Carboxylic Acids

Starting materials include aluminum oxy hydroxides pretreated with low molecular-weight carboxylic acids. An improved class of alumoxanes and a method of synthesizing them have been invented. Alumoxanes are aluminum oxy hydroxide particles that have been modified with compounds containing carboxylic acid groups. For typical applications in which alumoxanes are required to be compatible with polymers, it is desirable that the modifying compounds be carboxylic acids that have high molecular weights (>500 Daltons) and/or are somewhat hydrophobic (characterized by solubility <5% in boiling water). Heretofore, the hydrophobicity of such compounds has made it difficult or impossible to synthesize alumoxanes in sufficiently high yields in acceptably short reaction times, and the alumoxane products have exhibited nonuniformities, both within and between batches. The present invention overcomes these shortcomings of prior approaches to synthesis of alumoxanes.

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