Materials & Coatings

Low-Weight, Durable, Low-Cost Metal Rubber Sensor System for Ultra-Long-Duration Scientific Balloons

Sensors integrated onto load-bearing seams measure axial loads in the most extreme environmental conditions. Goddard Space Flight Center, Greenbelt, Maryland Large axial load forces and extreme temperature ranges are typical for scientific balloon missions. Therefore, a durable, flexible, and thermally stable sensor material is needed. In this innovation, sensors have been designed to be integrated onto the load-bearing seams and/or outer balloon mesh polyethylene surface of the pressurized balloon system to measure accurately and continually axial loads under extreme environmental conditions for extended intervals (i.e. more than 100 days).

Posted in: Materials, Coatings & Adhesives, Metals, Sensors, Articles, Briefs, TSP

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Predictive Modeling of Corrosion Efficiencies and Toxicities

An analytical approach using a combination of descriptors successfully predicts the performance of a wide range of organic corrosion inhibitors. John F. Kennedy Space Center, Florida Atmospheric corrosion is significantly accelerated by the presence of heat, humidity, corrosive salts, and sunlight. At Kennedy Space Center (KSC), all of these accelerants are present, producing an extremely corrosive environment. Toxicity and environmental impacts of some inorganic corrosion inhibitors have severely limited the use of some of the most effective corrosion inhibitors. Unfortunately, robust, low-toxicity, high-performance organic corrosion inhibitors for coatings are not yet at a stage to replace the most effective inorganic inhibitors.

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Improving Foreign Object Damage Performance for 2D Woven Ceramic Matrix Composites

A model simulates high-speed impact response of ceramic matrix composites. John H. Glenn Research Center, Cleveland, Ohio As the power density of advanced engines increases, the need for new materials that are capable of high operating temperatures, such as ceramic matrix composites (CMCs), is critical for turbine hot-section static and rotating components. Such advanced materials can significantly increase engine operating temperatures relative to those with conventional superalloy metallic blades. They also show the potential to enable longer life, growth margin, reduced emissions, reduced weight, and increased performance when compared with superalloy blade materials.

Posted in: Materials, Composites, Articles, Briefs, TSP

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PICA-on-Edge

This material fills gaps between adjacent PICA blocks. Langley Research Center, Hampton, Virginia The current baseline ablator material for the Advanced Development Program (ADP) for the thermal protection system (TPS) of the Orion heat shield is phenolic impregnated carbon ablator (PICA). PICA is a low-density, low-strength material that must be isolated from mechanically and thermally induced deformations and strains of the underlying heat shield carrier structure. The current invention is being developed to provide a means of eliminating gaps between adjacent PICA blocks by filling the gaps with a compatible, relatively soft material that alleviates thermal and mechanical stresses that would occur in rigidly bonded PICA blocks. An ideal gap material should have comparable thermal and ablative performance to PICA, and have low enough porosity to prevent hot gas flow in the gap. It must be compliant enough that adjacent PICA blocks can move somewhat independently of each other and the underlying carrier structure to reduce thermal and mechanical stresses to acceptable levels.

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White, Electrically Dissipative Thermal Control Coating

Goddard Space Flight Center, Greenbelt, Maryland A highly reflective, white conductive coating system was developed using various layered coatings to maximize the structural, electrical, and optical reflectance properties for spacecraft radiators. The top layer of the system contains a highly reflective white pigment within a dissipative inorganic binder. This layer is above a highly conductive second layer containing a white conductive pigment within the same binder system.

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Hydrazine Absorbent/Detoxification Pad

This hydrazine-degrading pad has applications in hazardous-material emergency response situations. Lyndon B. Johnson Space Center, Houston, Texas A new chemistry was developed for existing hydrazine absorbent/detoxification pads. Enhancements include faster reaction rates, weight reduction, a color change that indicates spill occurrence, and another color change that indicates successful hydrazine degradation. The previous spill control pad, using copper oxide on the silica gel substrate as the reactant, affected only 50 percent degradation of hydrazine after 9 hours. The new prototypes have been found to degrade hydrazine from 95 to 99.9 percent in only 5 minutes, and to below detection limits within 90 minutes.

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Nanotechnology Approach to Lightweight, Multifunctional Polyethylene Composite Materials

Potential uses include personal armor, implantable prosthetics, and cut-resistant fabrics such as gloves worn by chefs and scuba divers. Langley Research Center, Hampton, Virginia Of several ideas being pursued by NASA for the reduction of radiation dosage to astronauts, the use of ultra-high-molecular-weight polyethylene (UHMWPE)-based composite materials for both radiation shielding and micrometeorite shielding appears to be particularly appealing. UHMWPE has long been understood to provide superior radiation shielding following encounters with energetic nucleons due to its high hydrogen content. Meanwhile, impacts of micrometeorites with UHMWPE tend to vaporize it, rather than causing spallation of the shield material, which then creates additional potentially damaging micrometeorites. Less widely appreciated is the high specific strength of UHMWPE and UHMWPE fibers, which provide structural integrity to the composite. Amongst thermoplastics, UHMWPE has the highest impact strength and is also highly resistant to abrasion. Despite this highly appealing combination of properties, UHMWPE’s key mechanical properties can be improved by forming composites with other nanostructured materials, leading to further performance increases and weight reductions. Such composites will increase the ability of UHMWPE structures to withstand micrometeorite impacts and maintain the structural integrity of a pressurized environment.

Posted in: Materials, Briefs, TSP

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