White, Electrically Conductive, Radiation-Stable, Thermal Control Coating

Goddard Space Flight Center, Greenbelt, Maryland A highly reflective, white conductive coating system was developed using a layered approach with a combination of commercially available white conductive pigments within a conductive binder system. The top coating is a space-stable, radiation-resistant, highly reflective coating that has been tailored to provide optimum reflectance properties and meet vacuum thermal surface resistivities. The combined layer is a mixture of a highly reflective, electrically dissipative coating and a moderately reflective but highly conductive pigment in a conductive binder. A second, underlying layer of conductive white coating offers optimum adhesion to metal substrates and the topcoat. The system vacuum resistivity at room temperature is approximately 1 × 109 ohms/sq, and has a solar absorptance of less than 0.13 as measured on a Cary 5000 spectrophotometer.

Posted in: Briefs, TSP, Thermoelectrics, Coatings & Adhesives


Piezoelectric Actuated Inchworm Motor (PAIM)

This linear piezoelectric actuator can operate at temperatures of 77 K or below. NASA’s Jet Propulsion Laboratory, Pasadena, California Conventional piezoelectric materials, such as PZTs, have reasonably high electromechanical coupling over 70%, and excellent performance at room temperature. However, their coupling factor (converting electrical to mechanical energy and vice versa) drops substantially at cryogenic temperatures, as the extrinsic contributions (domain wall motions) are almost frozen out below 130 K.

Posted in: Briefs, TSP, Fluid Handling, Motors & Drives


Optical Fiber for Solar Cells

These materials enable new solar-powered devices that are small, lightweight, and can be used without connection to existing electrical grids. Ames Research Center, Moffett Field, California Polymeric and inorganic semiconductors offer relatively high quantum efficiencies, and are much less expensive and versatile to fabricate than non-amorphous silicon wafers. An optical fiber and cladding can be designed and fabricated to confine light for transport within ultraviolet and near-infrared media, using evanescent waves, and to transmit visible wavelength light for direct lighting.

Posted in: Briefs, Energy Storage, Solar Power, Fiber Optics


Pumped Subsea Energy Storage

This technique would be applicable to offshore oil platforms and energy storage for public utilities. NASA’s Jet Propulsion Laboratory, Pasadena, California A local energy source is desired for near-shore and offshore applications. Gas generators, diesel generators, and long-length submerged power cables tend to be expensive. A proposed solution is to use offshore wind with some type of energy storage mechanism for up to 1 GW-h. Energy storage in batteries is too expensive and massive, and subsea compressed air energy storage (CAES) has not been proven for very deep depths. Furthermore, CAES involves very great temperature changes that result in large inefficiencies.

Posted in: Briefs, TSP, Energy Efficiency, Energy Storage, Solar Power, Wind Power


Carbon Nanotube Tower-Based Supercapacitor

A new technology to create electrochemical double-layer supercapacitors is provided using carbon nanotubes as electrodes of the storage medium. This invention allows efficient transport between the capacitor electrodes through the porous nature of the nanotubes, and has a low interface resistance between the electrode material and the collector. Carbon nanotubes directly grown on a metal surface are used to improve the supercapacitor performance. The nanotubes offer a high surface area and usable porosity for a given volume and mass, both of which are highly desirable for supercapacitor operation.

Posted in: Briefs, Energy Storage


Design for Improving the Flatness of Solar Sails

An optically flat solar sail could be useful in optical communication and solar energy applications. NASA’s Jet Propulsion Laboratory, Pasadena, California This work describes a discontinuous or segmented mirror whose overall flatness is less dependent on the limited tension that can be supplied by the booms. A solar sail is a large, nominally flat sheet of extremely thin reflectorized film rigidly attached to a spacecraft, enabling propulsion via solar radiation pressure. Rip-stop fibers embedded in the backside of the film — with diameters ≈100× the thickness of the film — are commonly used to arrest tear propagation, which can easily occur in the handling and/or deployment of these gossamer-thin structures. Typically, the thin film or membrane that is the sail is systematically folded to enable both volumetrically compact transportation to space and mechanized deployment. It is the aggressive folding and creasing of the thin film that limits the ultimate flatness that can be achieved.

Posted in: Briefs, TSP, Solar Power


Negative Dielectric Constant Material Based on Ion-Conducting Materials

Langley Research Center, Hampton, Virginia Metamaterials, or artificial negative index materials (NIMs), have generated great attention due to their unique and exotic electromagnetic properties. A negative dielectric constant material, which is an essential key for creating the NIMs, was developed by doping ions into a polymer, a protonated poly(benzimidazole) (PBI).

Posted in: Briefs, TSP, Energy Storage, Sensors


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