Mechanical & Fluid Systems

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


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


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


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


Cooling Test Samples With a Combined Convective and Conductive System to Rapidly Reach 77 K

This innovation enables rapid cooling to 77 K of James Webb Space Telescope shields, which enables hypervelocity impact testing with micro-particle spheres. Lyndon B. Johnson Space Center, Houston, Texas In this innovation, a team successfully developed and implemented a combined convective and conductive cooling system that permits rapid cooling. Using a spray system, liquid nitrogen (LN2) was injected into a test article enclosure located in the target tank that was evacuated to a lower pressure than the surrounding ambient pressure of the White Sands Test Facility (WSTF). According to the saturation curve for nitrogen, temperatures lower than 77 K can be achieved by using the evaporative process as long as the pressure remains above the triple point where nitrogen ice is formed.

Posted in: Articles, Briefs, TSP


Titan Lake and Shore Sampler

The device is suitable for cryogenic dispensing of fluids, and for cryocoolers. NASA’s Jet Propulsion Laboratory, Pasadena, California A lake and shore sampling and sample distribution system was developed for a Titan lake environment (93.7 K, in liquid hydrocarbons). The Titan Lake and Shore Sampler (TLASS) would enable the chemical analysis of hydrocarbon lake samples via a Dual Rectilinear Ion and Orbitrap Mass Spectrometer and Nuclear Magnetic Resonance (NMR) Spectrometry.

Posted in: Briefs, TSP, Electronics & Computers, Data Acquisition


Hydraulic High-Pressure Valve Controller Using the In Situ Pressure Difference

This technology is applicable to any system or device requiring high-pressure-differential valves. NASA’s Jet Propulsion Laboratory, Pasadena, California Various applications exist where high-pressure valves are required, but the problem for control of such valves lies in that they have to move against a strong pressure differential that may require significant force, energy, and large actuators. The solution to this problem is to take advantage of the in situ pressure differential to operate valves by opening small valves to change the pressure on either chamber of a hydraulic cylinder that is connected to the valve’s moving element.

Posted in: Briefs, TSP


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