A comprehensive library of technical briefs from engineering experts at NASA and major government, university, and commercial laboratories covering all aspects of innovations in electronics, software, photonics, imaging, motion control, automation, sensors, test, materials, manufacturing, mechanical, and mechatronics.

Briefs : Physical Sciences
Diffusion-Cooled Tantalum Hot-Electron Bolometer Mixers

A batch of experimental diffusion-cooled hot-electron bolometers (HEBs), suitable for use as mixers having input frequencies in the terahertz range and output frequencies up to about a gigahertz, exploit the superconducting/normal-conducting transition in a thin strip of tantalum. The...

Briefs : Physical Sciences
Improved Position Sensor for Feedback Control of Levitation

An improved optoelectronic apparatus has been developed to provide the position feedback needed for controlling the levitation subsystem of a containerless processing system. As explained below, the advantage of this apparatus over prior optoelectronic apparatuses that have served this...

Briefs : Physical Sciences
Relative-Motion Sensors and Actuators for Two Optical Tables

Optoelectronic sensors and magnetic actuators have been developed as parts of a system for controlling the relative position and attitude of two massive optical tables that float on separate standard air suspensions that attenuate ground vibrations. In the specific application for...

Briefs : Electronics & Computers
Compact Tactile Sensors for Robot Fingers

Compact transducer arrays that measure spatial distributions of force or pressure have been demonstrated as prototypes of tactile sensors to be mounted on fingers and palms of dexterous robot hands. The pressure-or force-distribution feedback provided by these sensors is essential for the further...

Briefs : Electronics & Computers
Improved Ion-Channel Biosensors

An effort is underway to develop improved biosensors of a type based on ion channels in biomimetic membranes. These sensors are microfabricated from silicon and other materials compatible with silicon. As described below, these sensors offer a number of advantages over prior sensors of this type.

Briefs : Electronics & Computers
Suspended-Patch Antenna With Inverted, EM-Coupled Feed

An improved suspended-patch antenna has been designed to operate at a frequency of about 23 GHz with linear polarization and to be one of four identical antennas in a rectangular array. The antenna (see Figure 1) includes a parasitic patch on top of a suspended dielectric superstrate, an...

Briefs : Electronics & Computers
System Would Predictively Preempt Traffic Lights for Emergency Vehicles

Two electronic communication-and- control systems have been proposed as means of modifying the switching of traffic lights to give priority to emergency vehicles. Both systems would utilize the inductive loops already installed in the streets of many municipalities to detect...

Briefs : Electronics & Computers
Hyperboloid Wire Basket Connector Technology Provides High-Performance Interconnect Solutions

As high-end electronics become more and more pervasive, reliability and the need to minimize failure are top priorities for many manufacturers. Traditionally, reliability has been a key issue for military, aerospace, and lifecritical systems. Today,...

Briefs : Electronics & Computers
CHEM-Based Self-Deploying Spacecraft Radar Antennas

A document proposes self-deploying spacecraft radar antennas based on cold hibernated elastic memory (CHEM) structures. Described in a number of prior NASA Tech Briefs articles, the CHEM concept is one of utilizing open-cell shape-memory-polymer (SMP) foams to make lightweight structures that...

Briefs : Electronics & Computers
Scalable Multiprocessor for High-Speed Computing in Space

A report discusses the continuing development of a scalable multiprocessor computing system for hard real-time applications aboard a spacecraft. "Hard real-time applications" signifies applications, like real-time radar signal processing, in which the data to be processed are generated at...

Briefs : Motion Control
Additional Drive Circuitry for Piezoelectric Screw Motors

Modules of additional drive circuitry have been developed to enhance the functionality of a family of commercially available positioning motors (Picomotor™ or equivalent) that provide linear motion controllable, in principle, to within increments ≤30 nm. A motor of this type includes...

Briefs : Electronics & Computers
Optical Position Encoders for High or Low Temperatures

Optoelectronic pattern-recognition systems (optical encoders)for measuring positions of objects of interest at temperatures well below or well above room temperature are undergoing development.At present,the development effort is concentrated on absolute linear, rotary, and Cartesian...

Briefs : Photonics/Optics
Tunable Optical True-Time Delay Devices Would Exploit EIT

Tunable optical true-time delay devices that would exploit electromagnetically induced transparency (EIT) have been proposed. Relative to prior true-time delay devices (for example, devices based on ferroelectric and ferromagnetic materials) and electronically controlled phase shifters,...

Briefs : Information Technology
An Architecture for Controlling Multiple Robots

The Control Architecture for Multirobot Outpost (CAMPOUT) is a distributed-control architecture for coordinating the activities of multiple robots. In the CAMPOUT, multiple-agent activities and sensor-based controls are derived as group compositions and involve coordination of more basic...

Briefs : Test & Measurement
Photodiode-Based, Passive Ultraviolet Dosimeters

Simple, passive instruments have been developed for measuring the exposure of material specimens to vacuum ultraviolet (VUV) radiation from the Sun. Each instrument contains a silicon photodiode and a coulometer. The photocharge generated in the photodiode is stored in the coulometer. The...

Briefs : Test & Measurement
Measuring Radiation Patterns of Reconfigurable Patch Antennas on Wafers

An apparatus and technique have been devised for measuring the radiation pattern of a microwave patch antenna that is one of a number of identical units that have been fabricated in a planar array on a high-resistivity silicon wafer. The apparatus and technique are intended,...

Briefs : Test & Measurement
Hydraulic Apparatus for Mechanical Testing of Nuts

The figure depicts an apparatus for mechanical testing of nuts In the original application for which the apparatus was developed, the nuts are of a frangible type designed for use with pyrotechnic devices in spacecraft applications in which there are requirements for rapid, one-time separations...

Briefs : Medical
Solution Preserves Nucleic Acids in Body-Fluid Specimens

A solution has been formulated to preserve deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) in specimens of blood, saliva, and other bodily fluids. Specimens of this type are collected for diagnostic molecular pathology, which is becoming the method of choice for diagnosis of many...

Briefs : Medical
Oligodeoxynucleotide Probes for Detecting Intact Cells

A rapid, sensitive test using chemiluminescent oligodeoxynucleotide probes has been developed for detecting, identifying, and enumerating intact cells. The test is intended especially for use in detecting and enumerating bacteria and yeasts in potable water.

Briefs : Physical Sciences
Imaging of γ-Irradiated Regions of a Crystal

A holographic technique has been devised for generating a visible display of the effect of exposure of a photorefractive crystal to γ-rays. The technique exploits the space charge that results from trapping of electrons in defects induced by γ-rays.

Briefs : Physical Sciences
Digital Averaging Phasemeter for Heterodyne Interferometry

A digital averaging phasemeter has been built for measuring the difference between the phases of the unknown and reference heterodyne signals in a heterodyne laser interferometer. This phasemeter performs well enough to enable interferometric measurements of distance with accuracy of the...

Briefs : Physical Sciences
Part 2 of a Computational Study of a Drop-Laden Mixing Layer

This second of three reports on a computational study of a mixing layer laden with evaporating liquid drops presents the evaluation of Large Eddy Simulation (LES) models.

Briefs : Physical Sciences
Microwave-Spectral Signatures Would Reveal Concealed Objects

A proposed technique for locating concealed objects (especially small antipersonnel land mines) involves the acquisition and processing of spectral signatures over broad microwave frequency bands. This technique was conceived to overcome the weaknesses of older narrow-band...

Briefs : Mechanical & Fluid Systems
Demonstration of a Pyrotechnic Bolt-Retractor System

A paper describes a demonstration of the X-38 bolt-retractor system (BRS) on a spacecraft-simulating apparatus, called the Large Mobility Base, in NASA Flight Robotics Laboratory (FRL). The BRS design was proven safe by testing in NASA Pyrotechnic Shock Facility (PSF) before being demonstrated...

Briefs : Electronics & Computers
Low-Cutoff, High-Pass Digital Filtering of Neural Signals

The figure depicts the major functional blocks of a system, now undergoing development, for conditioning neural signals acquired by electrodes implanted in a brain. The overall functions to be performed by this system can be summarized as preamplification, multiplexing,digitization, and...

Briefs : Electronics & Computers
Iterative Demodulation and Decoding of Non-Square QAM

It has been shown that a non-square (NS)22n+1-ary (where n is a positive integer) quadrature amplitude modulation [(NS)2 22n+1-QAM] has inherent memory that can be exploited to obtain coding gains. Moreover, it should not be necessary to build new hardware to realize...

Briefs : Information Technology
Further Improvement in 3DGRAPE

"3DGRAPE/AL:V2" denotes version 2 of the Three - Dimensional Grids About Anything by Poisson's Equation with Upgrades from Ames and Langley computer program. The preceding version, 3DGRAPE/AL, was described in "Improved 3DGRAPE" (ARC-14069) NASA Tech Briefs ,Vol.21, No.5 (May 1997), page 66....

Briefs : Information Technology
Ground Support Software for Spaceborne Instrumentation

ION is a system of ground support software for the ion and neutral mass spectrometer (INMS) instrument aboard the Cassini spacecraft. By incorporating commercial off - the - shelf database, Web server, and Java application components, ION offers considerably more ground - support - service...

Briefs : Information Technology
MER SPICE Interface

MER SPICE Interface is a software module for use in conjunction with the Mars Exploration Rover (MER) mission and the SPICE software system of the Navigation and Ancillary Information Facility (NAIF) at NASA's Jet Propulsion Laboratory. (SPICE is used to acquire, record, and disseminate engineering, navigational, and other...

Briefs : Information Technology
Analyzing Contents of a Computer Cache

The Cache Contents Estimator (CCE) is a computer program that provides information on the contents of level-1 cache of a PowerPC computer. The CCE is configurable to enable simulation of any processor in the PowerPC family. The need for CCE arises because the contents of level-1 caches are not available to...

Question of the Week
Would You Cook with ‘Julia?’