Tech Briefs

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 : Test & Measurement
Instrumentation for Sensitive Gas Measurements

An improved instrument for optical absorption spectroscopy utilizes off-axis paths in an optical cavity in order to increase detection sensitivity while suppressing resonance effects. The instrument is well suited for use in either cavity ring-down spectroscopy (CRDS) [in which one pulses an...

Briefs : Physical Sciences
Gears Based on Carbon Nanotubes

Gears based on carbon nanotubes (see figure) have been proposed as components of an emerging generation of molecular-scale machines and sensors. In comparison with previously proposed nanogears based on diamondoid and fullerene molecules, the nanotube-based gears would have simpler structures and are more likely...

Briefs : Manufacturing & Prototyping
Fabrication of Spherical Reflectors in Outer Space

A process is proposed for fabrication of lightweight spherical reflectors in outer space for telescopes, radio antennas, and light collectors that would be operated there. The process would obviate the relatively massive substrates and frames needed to support such reflectors in normal Earth...

Briefs : Manufacturing & Prototyping
High-Temperature, High-Load-Capacity Radial Magnetic Bearing

A radial heteropolar magnetic bearing capable of operating at a temperature as high as 1,000°F (≈540°C) has been developed. This is a prototype of bearings for use in gas turbine engines operating at temperatures and speeds much higher than can be withstood by lubricated...

Briefs : Mechanical & Fluid Systems
Blended Buffet-Load-Alleviation System for Fighter Airplane

The capability of modern fighter airplanes to sustain flight at high angles of attack and/or moderate angles of sideslip often results in immersion of part of such an airplane in unsteady, separated, vortical flow emanating from its forebody or wings. The flows from these surfaces...

Briefs : Mechanical & Fluid Systems
Split-Resonator, Integrated-Post Vibratory Microgyroscope

An improved design for a capacitive sensing, rocking-mode vibratory microgyroscope is more amenable to mass production, relative to a prior design. Both the improved design and the prior design call for a central post that is part of a resonator that partly resembles a cloverleaf or a...

Briefs : Mechanical & Fluid Systems
Fast Laser Shutters With Low Vibratory Disturbances

The figure shows a prototype vacuum-compatible, fast-acting, long-life shutter unit that generates very little vibratory disturbance during switching. This is one of a number of shutters designed to satisfy requirements specific to an experiment, to be performed aboard a spacecraft in flight,...

Briefs : Software
Generating Animated Displays of Spacecraft Orbits
Tool for Interactive Plotting, Sonification, and 3D Orbit Display (TIPSOD) is a computer program for generating interactive, animated, four-dimensional (space and time) displays of spacecraft orbits.
Briefs : Software
Three-Dimensional Audio Client Library
The Three-Dimensional Audio Client Library (3DAudio library) is a group of software routines written to facilitate development of both stand-alone (audio only) and immersive virtual-reality application programs that utilize three-dimensional audio displays.
Briefs : Software
Single-Command Approach and Instrument Placement by a Robot on a Target
AUTOAPPROACH is a computer program that enables a mobile robot to approach a target autonomously, starting from a distance of as much as 10 m, in response to a single command. AUTOAPPROACH is used in conjunction with (1) software that analyzes images acquired by stereoscopic...
Briefs : Software
APGEN Version 5.0

Activity Plan Generator (APGEN), now at version 5.0, is a computer program that assists in generating an integrated plan of activities for a spacecraft mission that does not oversubscribe spacecraft and ground resources.

Briefs : Software
Training Software in Artificial-Intelligence Computing Techniques
The Artificial Intelligence (AI) Toolkit is a computer program for training scientists, engineers, and university students in three soft-computing techniques (fuzzy logic, neural networks, and genetic algorithms) used in artificial-intelligence applications. The program promotes an...
Briefs : Software
Diagnosis and Prognosis of Weapon Systems
The Prognostics Framework is a set of software tools with an open architecture that affords a capability to integrate various prognostic software mechanisms and to provide information for operational and battlefield decision-making and logistical planning pertaining to weapon systems. The Prognostics...
Briefs : Software
Predicting Noise From Aircraft Turbine-Engine Combustors
COMBUSTOR and CNOISE are computer codes that predict far-field noise that originates in the combustors of modern aircraft turbine engines — especially modern, low-gaseous-emission engines, the combustors of which sometimes generate several decibels more noise than do the combustors of...
Briefs : Software
Space Physics Data Facility Web Services
The Space Physics Data Facility (SPDF) Web services provides a distributed programming interface to a portion of the SPDF software. (A general description of Web services is available at and in many current software-engineering texts and articles focused on distributed programming.) The...
Briefs : Software
Parallel Adaptive Mesh Refinement Library
Parallel Adaptive Mesh Refinement Library (PARAMESH) is a package of Fortran 90 subroutines designed to provide a computer programmer with an easy route to extension of (1) a previously written serial code that uses a logically Cartesian structured mesh into (2) a parallel code with adaptive mesh refinement...
Briefs : Software
Estimating Effects of Multipath Propagation on GPS Signals
Multipath Simulator Taking into Account Reflection and Diffraction (MUSTARD) is a computer program that simulates effects of multipath propagation on received Global Positioning System (GPS) signals. MUSTARD is a very efficient means of estimating multipath-induced position and phase errors...
Briefs : Software
Central-Monitor Software Module

One of the software modules of the emergency-vehicle traffic-light-preemption system of the two preceding articles performs numerous functions for the central monitoring subsystem. This module monitors the states of all units (vehicle transponders and intersection controllers): It provides real-time access to the...

Briefs : Software
Intersection-Controller Software Module
An important part of the emergencyvehicle traffic-light-preemption system summarized in the preceding article is a software module executed by a microcontroller in each intersection controller. This module monitors the broadcasts from all nearby participating emergency vehicles and intersections. It gathers...
Briefs : Software
Traffic-Light-Preemption Vehicle-Transponder Software Module

A prototype wireless data-communication and control system automatically modifies the switching of traffic lights to give priority to emergency vehicles. The system, which was reported in several NASA Tech Briefs articles at earlier stages of development, includes a transponder on each...

Briefs : Motion Control
Direct Steering Component for Recumbent Tricycles

When developing the steering component of the Catrike Speed recumbent tricycle, the manufacturer switched from metal bearings to igubal® plastic rod ends for lighter weight (80% less) and better dampening; they absorb more vibration from wheel to arms. This also enabled the...

Briefs : Electronics & Computers
Sensors for Pointing Moving Instruments Toward Each Other

Optoelectronic sensor systems are being developed for use in maintaining fixed relative orientations of two scientific- instrument platforms that are in relative motion. In the original intended application, the platforms would be two spacecraft flying in formation and separated by a long...

Briefs : Electronics & Computers
Improved Cathode Structure for a Direct Methanol Fuel Cell

An improved cathode structure on a membrane/electrode assembly has been developed for a direct methanol fuel cell, in a continuing effort to realize practical power systems containing such fuel cells. This cathode structure is intended particularly to afford better cell performance at a...

Briefs : Electronics & Computers
Improved Anode for a Direct Methanol Fuel Cell

A modified chemical composition has been devised to improve the performance of the anode of a direct methanol fuel cell. The main feature of the modified composition is the incorporation of hydrous ruthenium oxide into the anode structure. This modification can reduce the internal electrical...

Briefs : Electronics & Computers
X-Band, 17-Watt Solid-State Power Amplifier

An advanced solid-state power amplifier that can generate an output power of as much as 17 W at a design operating frequency of 8.4 GHz has been designed and constructed as a smaller, lighter, less expensive alternative to traveling-wave-tube X-band amplifiers and to prior solid-state X-band power...

Briefs : Electronics & Computers
Upgrading the Space Shuttle Caution and Warning System

A report describes the history and the continuing evolution of an avionic system aboard the space shuttle, denoted the caution and warning system, that generates visual and auditory displays to alert astronauts to malfunctions. The report focuses mainly on planned human-factors-oriented...

Briefs : Electronics & Computers
Fractal Reference Signals in Pulse-Width Modulation

A report proposes the use of waveforms having fractal shapes reminiscent of sawteeth (in contradistinction to conventional regular sawtooth waveforms) as reference signals for pulse-width modulation in control systems for thrusters of spacecraft flying in formation.

Briefs : Mechanical & Fluid Systems
Powder-Collection System for Ultrasonic/Sonic Drill/Corer

A system for collecting samples of powdered rock has been devised for use in conjunction with an ultrasonic/sonic drill/corer (USDC) — a lightweight, low-power apparatus designed to cut into, and acquire samples of, rock or other hard material for scientific analysis. The USDC was...

Briefs : Mechanical & Fluid Systems
Semiautomated, Reproducible Batch Processing of Soy

A computer-controlled apparatus processes batches of soybeans into one or more of a variety of food products, under conditions that can be chosen by the user and reproduced from batch to batch. Examples of products include soy milk, tofu, okara (an insoluble protein and fiber byproduct of soy...

Briefs : Information Technology
Simulation of Laser Cooling and Trapping in Engineering Applications

An advanced computer code is undergoing development for numerically simulating laser cooling and trapping of large numbers of atoms. The code is expected to be useful in practical engineering applications and to contribute to understanding of the roles that light, atomic...

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