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
Radiometer for Measuring Cirrus-Cloud Ice and Water Vapor

An airborne submillimeter-wavelength radiometer, expected to be built and tested in the near future, is designed primarily to yield measurement data that can be processed to quantify the ice contents and mean sizes (and, to some extent, the shapes) of ice crystals in cirrus clouds that...

Briefs : Physical Sciences
System For Measuring Osmotic Transport Properties of a Membrane

The membrane test cell (MTC) is an automated laboratory apparatus that applies a known osmotic potential across a membrane and measures the kinetics of the resulting transport of solvents across the membrane as a function of time. Data acquired by use of the MTC should prove...

Briefs : Physical Sciences
Vacuum Leak Detection Using Piezoelectric Film

A technique for detecting a small leak of gas into a vacuum involves the use of a diaphragm made of a thin film of poly (vinylidene fluoride) [PVDF]. To exploit the piezoelectricity of PVDF for this purpose, both sides of the film are coated with thin, electrically conductive layers that serve as...

Briefs : Information Technology
An Off-Line FQPSK-B Software Receiver

Software that performs the functions of an FQPSK-B receiver (and to some extent, an FQPSK-B transmitter) has been developed to reduce the risks and costs associated with the development of hardware FQPSK-B transmitters and receivers. (“FQPSK-B” signifies version B of Feher Quadrature-Phase-Shift Keying,...

Briefs : Information Technology
Update on Web Interactive Training

The Web Interactive Training (WIT) project at Kennedy Space Center has expanded its course offerings, enhanced its technical capabilities, and automated its administrative functions. Aspects of the WIT project at previous stages of development were reported in “Further Developments in Web Interactive...

Briefs : Physical Sciences
Quasi-Decoupling of Shvab-Zel’dovich Variables

A paper presents some novel conclusions concerning the Shvab-Zel’dovich (SZ) vari- ables, which are linear combinations of dep- endent variables in mathematical models of multicomponent, chemically reacting flows. The SZ variables represent scalar quantities that are conserved, that is, are not...

Briefs : Mechanical & Fluid Systems
Mechanism for Docking a Miniature Spacecraft

This report discusses a proposed docking mechanism to be located in a small hangar on the outside of the International Space Station (ISS). The mechanism would enable docking of a miniature robotic spacecraft (or free flyer) that would carry a video camera and would operate in the vicinity of the ISS....

Briefs : Mechanical & Fluid Systems
Emergency Tether-Deployment-and-Recoil-Mitigating Systems

A report describes an emergency tether-deployment (ETD) system designed to minimize the harm caused by two events that can occur during deployment of tethered payloads from a space shuttle in orbit. One such event is snagging of the tether during payout while the payload is near the...

Briefs : Materials
Analysis of Multilayer Thermal Insulation for Reentry

A paper presents a study of multilayer thermal insulations for protecting spacecraft against aerodynamic heating during reentry into a planetary atmosphere. A multilayer insulation considered in the study comprised (1) thin ceramic/composite foils coated with gold for high reflectance...

Briefs : Physical Sciences
Assessing Energetic-Ion Effects Using Energetic Protons Only

Two reports describe a method of assessing the susceptibility of digital electronic equipment to upsets (bit errors) caused by impingement of energetic ions (both protons and heavier ions) in outer space.

The method, which is applicable at the single-component, circuit-board,...

Briefs : Photonics/Optics
System Would Detect Aircraft to Turn Off Upward-Aimed Laser

An electronic system based on long-wavelength infrared (LWIR) sensors is being developed to detect aircraft flying near an upward-aimed, high-power laser beam. In the intended application, the system would alert a human laser operator and/or generate a signal to turn off the laser...

Briefs : Physical Sciences
Simplified Achromatic Nulling Beam Combiner

The figure schematically depicts a proposed achromatic nulling beam combiner. This instrument is intended for use in astronomy - principally, for attenuating light from stars or other bright sources in order to enable detection of fainter objects that lie near the bright sources. In comparison with a...

Briefs : Photonics/Optics
Low-Loss, High-Extinction-Ratio Polarizer

An improved optical polarizer has been proposed for use with a high-energy pulsed laser. This polarizer would separate the p- and s-polarized components (the components polarized parallel and perpendicular, respectively, to a designated plane or axis) of an incoming beam of light into two outgoing beams...

Briefs : Photonics/Optics
Rugged Laser-Diode Oxygen Sensor

A rugged laser-diode oxygen sensor is being developed for detecting leaks of oxygen from diverse systems, including rocket engines, cryogenic systems, and medical equipment. The sensor is required to have a range of 250 to 250,000 parts per million, to be accurate within 5 percent, to be capable of operating at...

Briefs : Photonics/Optics
Thermography Using YVO₄:Dy³⁺

A proposed thermographic technique would exploit the unique fluorescence characteristics of yttrium vanadate doped with dysprosium (YVO4:Dy3+). The particular aspect of the fluorescence characteristics that would be exploited in this technique is the relative intensity of emitted light as a...

Briefs : Photonics/Optics
Carbon-Composite Heat-Sinking Submounts for Laser Diodes

Carbon-composite submounts tipped with diamond are being developed as improved means of dissipating heat generated in high-power laser diodes. Copper is the traditional heat-sinking material for many applications other than laser diodes; it is not suitable for heat-sinking submounts for...

Briefs : Photonics/Optics
Estimating White-Light-lnterferometer Phases in Dim Light

A method has been developed to increase the accuracy of estimates of phase differences attributable to the optical-path-length difference between the arms of a long-baseline, white-light interferometer. The method is intended for use in the Space Interferometer Mission (SIM), in which...

Briefs : Photonics/Optics
Semiconductor Quantum Dots as Radiation-Hard Light Emitters

Light-emitting devices based on semiconductor quantum dots have been shown to be suitable for use in environments that include high levels of radiation that causes displacement damage in semiconductors - in particular, energetic protons. Conventional light-emitting diodes and other...

Briefs : Photonics/Optics
Optical-Based Method for Characterizing Protein Crystals

A method of characterization of growing of protein crystals involves the utilization of an optical imaging technique known as spatial phase imaging. The methods used heretofore have been, variously, invasive (e.g., adding a dye that is absorbed by the protein of interest), destructive...

Briefs : Software
Embeddable Fuzzy-Logic-Toolkit Software for Tcl/Tk

A computer program of the fuzzy-logictoolkit type has been devel- oped as a relatively simple, portable, highly compatible, means of providing fuzzy-logic reasoning capabilities for control and expert-system applications.

This program is designed to work with the high-level scripting language...

Briefs : Software
Program Analyzes Use of Registers by Another Program

Regprof is a computer program that analyzes the use of registers by another program that runs on a PowerPC

750 (or equivalent) computer. Regprof is useful for showing how well compilers make use of registers and for obtaining an indication of the susceptibility of application programs...

Briefs : Software
Real-Time Desktop Manager

Real-time Desktop Manager (RDM) is a computer program that manages displays and application programs. RDM was developed for use in connection with NASA’s remote manipulator system (RMS) group of flight controllers; it could also be used in chemical plants, laboratories, factories, hospitals, and other settings where...

Briefs : Electronics & Computers
FQPSK With an Outer Code for Greater Efficiency

A proposed method of FQPSK modulation and demodulation of a radio signal would incorporate any of a number of relatively simple (short-constraintlength) outer codes. By affording significant coding gains even when using a reduced-complexity (and thus suboptimal) FQPSK receiver, this method would...

Briefs : Electronics & Computers
Noncontact Scanning Surface Profilometers

A class of optoelectronic noncontact computer-controlled scanning surface profilometers is undergoing development for use in automated or semiautomated in- spection of nominally flat surfaces. When fully developed, these profilometers would generate three-dimensional maps of the scanned surfaces for...

Briefs : Electronics & Computers
Intuitive Control System for a Dexterous Robot

The Full Immersion Telepresence Testbed (FITT) is an experimental anthropomorphic-robot remote-control system that is so named because it gives a human control operator some of the sensations of the remote environment as though the operator were in that environment in place of the robot. In...

Briefs : Information Technology
Initialized Fractional Calculus

The fractional calculus (which admits of integrals and derivatives of non-integer order) dates back almost to the origin of the better-known ordinary (integer-order) calculus, but thus far has been treated more as a mathematical curiosity than as a scientific and engineering tool. Increasingly many physical...

Briefs : Electronics & Computers
Ultrasonic System Tracks Body Movements in Three Dimensions

A system based on ultrasonic sensors has been developed as a means of tracking moving objects with centimeter accuracy. The system is intended especially for tracking pertinent parts of the body of a human subject engaged in control of a remote anthropomorphic robot or immersed in a...

Briefs : Mechanical & Fluid Systems
Cylindrical Shape-Memory Rotary/Linear Actuator

A compact actuator generates rotary or linear motion with a large torque or force, respectively. The original version of this actuator is designed to pull a wedge that, until pulled, prevents retraction of the proposed extended nose landing gear of the space shuttle. The original version is also...