Home

Selective Functionalization of Carbon Nanotubes

Lyndon B. Johnson Space Center, Houston, Texas This invention is a process by which carbon nanotubes can be chemically functionalized according to their precise electronic structure. The process involves an exploitation of charge transfer stability at the nanotube sidewall to direct selective reaction of certain electronic structures over others. This process forms the basis for manipulating and separating carbon nanotubes by their electronic structure by chemical means.

Posted in: Articles, Briefs

Read More >>

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.

Posted in: Articles, Briefs, TSP

Read More >>

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: Articles, Briefs, TSP, Composites

Read More >>

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.

Posted in: Briefs, TSP

Read More >>

Layered Composite Thermal Insulation System for Non-Vacuum Applications

The new blanket-type system is suitable for extreme outdoor environments. John F. Kennedy Space Center, Florida Ambient air insulation systems for low-temperature (sub-ambient) applications are difficult to achieve because of moisture ingress and environmental degradation, as well as thermal stress-cracking. Most currently accepted methods for externally applied outdoor environments are fraught with problems centered around moisture and sealing.

Posted in: Briefs

Read More >>

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.

Posted in: Briefs, TSP

Read More >>

Ultra-High-Temperature Ceramic Composites with SiC Reinforcements

Potential applications are at temperatures approaching 4,000 °F (≈2,200 °C). Ames Research Center, Moffett Field, California Future-generation materials for use on space transportation vehicles require substantial improvements in material properties, leading to increased reliability and safety, as well as intelligent design to allow for current materials to meet future needs. Ultra-high-temperature ceramics (UHTCs) composed primarily of metal diborides are candidate materials for sharp leading edges on hypersonic re-entry vehicles. The mechanical performance of ceramics in general would benefit from a high-aspect reinforcement phase.

Posted in: Briefs

Read More >>