Tech Briefs

Bulk Separation and Manipulation of Carbon Nanotubes by Type

Lyndon B. Johnson Space Center, Houston, Texas The utility of this invention is to extract metals (semi-metals) or semiconductors from bulk nanotube samples. The bulk material is a mixture of the two. These materials can then be used to clone a particular type of nanotube, place a particular type in a device, generate smart materials, or make sensing elements.

Posted in: Manufacturing & Prototyping, Briefs

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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.

Posted in: Materials, Briefs, TSP

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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: Materials, Briefs

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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.

Posted in: Materials, Briefs, TSP

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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: Materials, Briefs

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Cathode Discharge Catalytic Systems for Hydrogen Recovery from Methane

Methane previously vented into space is now used for hydrogen recovery. Marshall Space Flight Center, Alabama In the process of recovery and regeneration of cabin atmosphere to supply oxygen to facilitate extended-duration manned missions, including expeditions to Mars or a return to the Moon, one of the byproducts of this reaction is waste methane, which is vented into space. This innovation reclaims hydrogen from the methane using a low-power, non-thermal plasma discharge process based on distributed hollow-cathode and filamentary discharges. This hollow-cathode, non-thermal plasma (HCNTP) is characterized by electrons and heavy particles being in thermodynamic non-equilibrium with electrons heated to 10,000 K and above, while ions and neutral species remain at near ambient temperature. By using pulsed voltage waveforms for generating the plasma discharge, a majority of electric energy goes into heating electrons.

Posted in: Materials, Briefs

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Beneficiation of Planetary Regolith by Pneumatically Enhanced Tribocharging of Granular Material

This technique has applications in all types of material handling, mining, and processing. John F. Kennedy Space Center, Florida Liberation of oxygen from the mineral ilmenite (FeTiO3), which may be found on the Moon, Mars, or asteroids, is inefficient due to the abundance of other minerals in the excavated regolith that are present but not needed during the chemical processing. Energy for the reduction reaction is in short supply on the lunar, Martian, and asteroid surfaces. The ilmenite should be separated from other minerals to simplify and improve the process efficiency. Lunar and planetary basaltic lavas contain ilmenite, but they consist only of 12 to 20 percent by weight.

Posted in: Materials, Briefs

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