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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

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Reactionless Drive Tube Sampling Device and Deployment Method

Springs and a counter-mass create a powerful and stable sampling device. NASA’s Jet Propulsion Laboratory, Pasadena, California A sampling device and a deployment method were developed that allow collection of a predefined sample volume from up to a predefined depth, precise sampling site selection, and low impact on the deploying spacecraft. This device is accelerated toward the sampled body, penetrates the surface, closes a door mechanism to retain the sample, and ejects a sampling tube with the sample inside. At the same time the drive tube is accelerated, a sacrificial reaction mass can be accelerated in the opposite direction and released in space to minimize the momentum impact on the spacecraft. The energy required to accelerate both objects is sourced locally, and can be a spring, cold gas, electric, or pyrotechnic. After the sample tube is ejected or extracted from the drive tube, it can be presented for analysis or placed in a sample return capsule.

Posted in: Briefs, TSP, Motors & Drives

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Nozzle Heat Flux Gauge

Marshall Space Flight Center, Alabama This innovation is a tungsten-rhenium gauge that can be placed into an aft exit cone of a rocket motor. It will measure heat flux with time for the full duration of the RSRM (reusable solid rocket motor) nozzle environment with equal response time.

Posted in: Briefs, Measuring Instruments

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Rotary-Hammer Core Sample Acquisition Tool

This tool can be used for drilling in construction, mining, or scientific research applications. NASA’s Jet Propulsion Laboratory, Pasadena, California NASA is developing technologies to enable in situ analysis and sample acquisition from planetary bodies. Missions to these diverse locations require autonomous, highly customizable, reliable tools. A tool capable of core generation, capture, and transfer, and customizable for different missions, would be very valuable.

Posted in: Briefs, TSP

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Photo-Chemical Machining (PCM) of metals…faster & more cost effective than you’d think!

Photo-Chemical Machining (PCM) or photo-etching of metals is a mature process used to create very accurate metal components. This process emerged in the 1960s as an offshoot of the printed circuit board industry. PCM can produce highly complex parts with very fine details, quickly, accurately and economically. Photo etching is a cost effective alternative to stamping, punching, laser cutting, water jet cutting, or electrical discharge machining (EDM) of thin gauge precision parts.

Posted in: Webinars, On-Demand Webinars, Metals

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Lubrication Considerations for Bearings

Bearings must be properly lubricated for optimized performance and long service lives, so choosing the correct lubrication is an integral consideration for engineers. AST Bearings’ tribological team has created this comprehensive whitepaper to best explain these lubrication considerations in rolling element bearings. The paper examines types of bearing lubricants (oil, grease and solid film), bearing lubrication methods, bearing lubrication shelf life, and a detailed table showing common bearing lubricants and properties.

Posted in: White Papers

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Robust Gimbal System for Small-Payload Manipulation

This is a low-mass, small-volume gimbal unit. NASA’s Jet Propulsion Laboratory, Pasadena, California Spaceborne gimbal systems are typically bulky with large footprints. Such a gimbal system may consist of a forked elevation stage rotating on top of the azimuth motor, and occupy a large volume. Mounting flexibility of such a system may be limited.

Posted in: Articles, Briefs, TSP, Motors & Drives

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