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Antenna for Measuring Electric Fields Within the Inner Heliosphere

A document discusses concepts for the design of an antenna to be deployed from a spacecraft for measuring the ambient electric field associated with plasma waves at a location within 3 solar radii from the solar photosphere. The antenna must be long enough to extend beyond the photoelectron and plasma sheaths of the spacecraft (expected to be of the order of meters thick) and to enable measurements at frequencies from 20 Hz to 10 MHz without contamination by spacecraft electric-field noise. The antenna must, therefore, extend beyond the thermal protection system (TPS) of the main body of the spacecraft and must withstand solar heating to a temperature as high as 2,000 °C while not conducting excessive heat to the interior of the spacecraft.

Posted in: Briefs, TSP

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Improved High-Voltage Gas Isolator for Ion Thruster

A report describes an improved highvoltage isolator for preventing electrical discharge along the flow path of a propellant gas being fed from a supply at a spacecraft chassis electrical potential to an ion thruster at a potential as high as multiple kilovolts. The isolator must survive launch vibration and must remain electrically nonconductive for thousands of hours under conditions that, in the absence of proper design, would cause formation of electrically conductive sputtered metal, carbon, and/or decomposed hydrocarbons on its surfaces.

Posted in: Briefs, TSP

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NASA Spinoff Keeps Drivers “Ice Free”

In the late 1990s, NASA Ames Research Center in California invented an anti-icing fluid that kept ice from building up on airplane wings. The fluid, when applied to a dry surface, prevented the ice from even forming a surface bond; if applied before ice formed, it served as a deicer. The formula contains propylene glycol, which has a very low freezing point, and a thickener that helps it adhere to the surface. Ice gathers on top of the surface, and can be wiped off with little effort.

Posted in: UpFront

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Recirculation of Laser Power in an Atomic Fountain

Optical and electronic subsystems of a frequency standard can be simplified. A new technique for laser-cooling atoms in a cesium atomic fountain frequency standard relies on recirculation of laser light through the atom-collection region of the fountain. The recirculation, accomplished by means of reflections from multiple fixed beam-splitter cubes, is such that each of two laser beams makes three passes. As described below, this recirculation scheme offers several advantages over prior designs, including simplification of the laser system, greater optical power throughput, fewer optical and electrical connections, and simplification of beam power balancing.

Posted in: Briefs, TSP

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Connection of Two Rubber-Impregnated Cloth Surfaces

A way is sought to allow consumers to connect and disconnect two rubber-impregnated cloth surfaces in a consistent manner that is easy to assemble and disassemble. The cloth surfaces are in close proximity; the length of the connection will be about two meters. The connection must exhibit longterm durability and be able to withstand in-use forces. The joining method should have similar ease-of-assembly as a zipper and be silent.

Posted in: NASA Tech Needs

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Technologies to Enhance Moisture, Vapor Transmission

A company is looking for environmentally inert methods to change the moisture management properties of conventional apparel textiles. The moisture management effect changes the way in which water vapor, moisture, and other liquids move through textiles, and can be activated via pH, temperature, or rising moisture levels. The solution would be applied in the presence of a surfactant. The effect does not have to be durable because the solution permits reapplication.

Posted in: NASA Tech Needs

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Thulium Puts Power Behind Eyesafe Fiber Lasers

One of the key advantages of fiber laser technology stems from the high conversion efficiency of the multimode pump radiation into high-brightness, single-mode laser light within the doped fiber lasing medium. Ytterbium-doped fiber lasers operating around 1μm often achieve around 80% pump- to-laser conversion efficiency and corresponding wall plug efficiencies over 25%, depending on the pump diodes used in the laser. As a result, high-power CW fiber lasers are more compact and require less cooling than a traditional solid-state laser of similar power.

Posted in: Articles, Features, ptb catchall, Photonics

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