Special Coverage

NASA Supercomputer Simulations Reveal 'Noisy' Aerodynamics
Robotic Gripper Cleans Up Space Debris
Soft Robot “Walks” on Any Terrain
Defense Advanced Research Projects Agency
Using Microwaves to Produce High-Quality Graphene
Transducer-Actuator Systems for On-Machine Measurements and Automatic Part Alignment
Wide-Area Surveillance Using HD LWIR Uncooled Sensors
Heavy Lift Wing in Ground (WIG) Cargo Flying Boat
Technique Provides Security for Multi-Robot Systems
Bringing New Vision to Laser Material Processing Systems
NASA Tests Lasers’ Ability to Transmit Data from Space

Submillimeter-Sized Bi2–xSbxTe3 Thermoelectric Devices

Submillimeter-sized thermoelectric devices based on thick films of Bi2–xSbxTe3 are undergoing development. As electronic circuits are designed with ever greater packaging densities and power densities, there is an increasing need for small thermoelectric devices to provide active spot cooling for power amplifiers and other heat-generating electronic components. Bi2–xSbxTe3 is the preferred thermoelectric material for the operational temperature range (2–xSbxTe3 thermoelectric devices could also be used as electric-power generators; moreover, because of the smallness of the thermoelectric legs in these devices, the numbers of legs can be of the order of 100 times those of conventional bulk thermoelectric devices, making it possible to generate higher potentials (of the order of 100 V), that are more compatible with other electronic components.

Posted in: Briefs, Electronics & Computers, Downsizing, Microelectricmechanical device, Microelectromechanical devices, Microelectricmechanical device, Microelectromechanical devices, Thermal management, Thermal management, Electro-thermal engines

High-Speed Complex-Amplitude Liquid-Crystal SLMs

High-speed complex-amplitude spatial light modulators (SLMs) containing liquid crystals with pixel electronic circuitry on single-crystal-silicon backplanes are undergoing development. The basic approach taken in this project is to use fast-switching liquid-crystal materials and modulation-enhancing device geometries that have not been used in prior display systems.

Posted in: Briefs, TSP, Electronics & Computers, Integrated circuits, Integrated circuits, Displays, Displays, Product development

Laser Heating for Testing Rocket-Engine Insulating Phenolic

A continuous-wave CO2 laser has been selected as a source of heat for testing the thermal response of carbon-cloth phenolic like that used as insulating material in a reusable solid-fuel rocket motor (RSRM). The particular thermal response of interest, observed during operation of an RSRM, is pocketing. By suitable adjustment of the size and power of the laser beam, the rate of heating can be made nearly identical to that in the RSRM nozzle during operation.

Posted in: Briefs, Test & Measurement, Lasers, Lasers, Solid propellants, Insulation, Rocket engines, Test equipment and instrumentation, Thermal testing

SIMON — School Internet Manager Over Networks

School Internet Manager Over Networks (SIMON) is a software tool, exclusively for use on Macintosh computers, that is designed to provide access to, and management of, Internet information for teachers and students in kindergarten through twelfth grade. By eliminating the requirement for advanced system services typically provided by proxy seravers (the computer tools of choice for access to the Internet), SIMON, which is available free on a NASA web site, has eliminated the related need for costly hardware servicing and system administration. Indeed, after installation, SIMON can maximize the overall utility of a user's local-area network (LAN), retrieve Internet information, and organize and present information to students. SIMON is not unique in the industry: several programs now commercially available perform a subset of functions that SIMON also performs. However, inasmuch as SIMON is uniquely tailored to the public-school milieu, it uses equipment commonly available to public schools, thereby reducing costs and serving as a more user-friendly product, relative to the other programs.

Posted in: Briefs, Software, Architecture, Computer software / hardware, Computer software and hardware, Internet, Architecture, Computer software / hardware, Computer software and hardware, Internet, Education, Education and training

RTM-Processable Resins Containing Thermosetting Plasticizers

A number of matrix resins that contain thermosetting plasticizers have been developed for use in the resin-transfer molding (RTM) of composite-material (fiber/matrix) parts. These resins and composites are candidates for use in manufacturing lightweight components of aircraft engines and other structures that must withstand temperatures up to and perhaps somewhat above 300 °C.

Posted in: Briefs, Materials, Molding, Composite materials, Heat resistant materials, Lightweight materials, Resins

Molded Plastic Simulated Landscapes

Simulated landscapes of Mars have been made of thermoplastic sheets molded to shapes derived from images of the Martian terrain. These simulated landscapes can be used to advantage in scientific experiments, simulations, educational displays, and other applications, in which unitary molded plastic sheets can be handled more easily and pose less risk of contamination than do simulated landscapes made of loose rocks. Fabrication begins with the selection of terrestrial rocks with a distribution of sizes and textures representative of the terrain of interest. The rocks are arranged on the vacuum table of a thermoforming apparatus. A sheet of thermoplastic material (e.g., polycarbonate 1.58 mm thick) is heated to drive off moisture, then is heated further to its softening temperature. When at the softening temperature, the sheet is placed over the rocks, then vacuum is applied via the table to pull the sheet down over the rocks. Once thus formed to the shape of the rocks, the sheet is allowed to cool, then is taken off the table. Any rocks inadvertently captured in the molded sheet are removed.

Posted in: Briefs, TSP, Mechanical Components, Mechanics

Burn-Resistant, Strong Nickel Alloys

Investigators at the Johnson Space Center White Sands Test Facility (WSTF) have developed specifications of the amounts of alloying elements needed to increase the specific strengths of nickel alloys while consistently maintaining their burn resistance. The issue of burn resistance versus strength arises because pure nickel resists burning in pure oxygen at pressures up to >104 psia (>69 MPa), but does not have enough specific strength to satisfy the requirements for use in engineered structures.

Posted in: Briefs, Materials, Fabrication, Materials properties, Nickel alloys

Aerogels With Gradients of Density

Aerogels with gradients in density have been produced in experiments, as part of an effort to develop materials that will be used in outer space to capture particles traveling at high speeds for the STARDUST mission.

Posted in: Briefs, TSP, Materials, Particulate matter (PM), Product development, Materials properties, Spacecraft

Ultracapacitors Store Energy in a Hybrid Electric Vehicle

A government/ industry/ academic cooperative has developed a hybrid electric transit bus (HETB). The goals of the development program, which continues, include doubling the fuel economy of city transit buses currently in service, and reducing emissions to one-tenth of the levels allowed by Environmental Protection Agency (EPA) standards. A unique aspect of the power system of the HETB is the use of capacitors in its the energy-storage subsystem. At a gross weight of more than 17,000 kg, this is the largest known vehicle to use capacitors to store energy.

Posted in: Briefs, TSP, Electronics & Computers, Energy storage systems, Ultracapacitors and supercapacitors, Energy storage systems, Ultracapacitors and supercapacitors, Buses, Hybrid electric vehicles

Interferometric System Images Small Vibrating Structures

A commercial scanning imaging white-light interferometer designed for measuring surface profiles of stationary objects has been modified into an interferometric instrument for imaging vibrating microelectromechanical structures. The modified instrument operates in a stroboscopic mode, generating a set of interferograms at a selected instant in the vibrational cycle. A number of sets of interferograms can be acquired at different instants of time corresponding to small increments of phase through the vibrational cycle so that the resulting collection of interferograms shows how the shape of the vibrating surface changes during the cycle; thus, the interferograms yield information on the shape and amplitude of the vibrational mode or modes.

Posted in: Briefs, TSP, Physical Sciences, Imaging, Imaging and visualization, Microelectricmechanical device, Microelectromechanical devices, Optics, Imaging, Imaging and visualization, Microelectricmechanical device, Microelectromechanical devices, Optics, Vibration, Vibration

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