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 : Physical Sciences
Solar Simulator for a Portable Solar-Absorptance Instrument

A special-purpose solar simulator includes (1) a tungsten lamp that serves as a gray-body radiator with a temperature of 3,200 K and (2) a mosaic of filters such that the filtered lamp output has the same normalized spectral irradiance as that of sunlight outside the atmosphere of the...

Briefs : Physical Sciences
Portable Instrument Detects Very Dilute Airborne Organics

A small, lightweight, low-power instrument, denoted a proton-transferreaction/ ion-mobility spectrometer (PTR-IMS) has been developed for detecting airborne organic compounds at concentrations in the sub-parts-per-billion range. Instruments like this one could be used on distant planets...

Briefs : Physical Sciences
Quantum Mechanics of Harmonic Oscillator in External Fields

A report presents a theoretical study of a harmonic oscillator in homogeneous or nonhomogeneous externally applied electric and/or gravitational fields. The standard quantum-mechanical formalism for a simple harmonic oscillator, starting with the Hamiltonian and the associated creation...

Briefs : Mechanical & Fluid Systems
Algorithms for Collision Avoidant Formation Flying

A report discusses algorithms for realtime planning of translation paths of multiple spacecraft flying in formation. The algorithm takes account of requirements to avoid collisions while operating within resource constraints (e.g., not calling for an acceleration greater than maximum possible)...

Briefs : Mechanical & Fluid Systems
Integrated Colloid Thrusters for Microspacecraft

A report proposes the development of a microfabricated, integrated colloid thruster as a prototype of devices for propulsion and control of the attitudes of microspacecraft. (In a colloid thruster, a beam of positively charged, microscopic droplets is extracted electrohydrodynamically from a...

Briefs : Electronics & Computers
PCI Bridge to Instruments and Telecommunication Systems

A report describes a prototype system interface assembly (SIA) that performs the functions of a compact, radiation-hard application-specific integrated circuit (ASIC) to be built subsequently. The SIA ASIC would be installed in a spacecraft, where it would function as a peripheralcomponent...

Briefs : Physical Sciences
Effect of Gravitation on Noninteracting Trapped Fermions

A report presents a theoretical study of the thermodynamics of an ultralow-temperature gas of fermions that interact with a gravitational field and with an externally imposed trapping potential but not with each other. The gravitational field is taken to define the z axis and the trapping...

Briefs : Mechanical & Fluid Systems
Improvements in a Piezoelectrically Actuated Microvalve

A report discusses the continuing development of a normally closed, piezoelectrically actuated valve fabricated mostly by micromachining of silicon. The design and operation of the microvalve as described in the instant report are basically the same as those of the version described in...

Briefs : Mechanical & Fluid Systems
Low-Energy Transfer From Near-Earth to Near-Moon Orbit

A report presents a theoretical approach to designing a low-energy transfer of a spacecraft from an orbit around the Earth to ballistic capture into an orbit around the Moon. The approach is based partly on the one presented in “Low-Energy Interplanetary Transfers Using Lagrangian...

Briefs : Photonics/Optics
Testing Grazing-Incidence Mirrors at Nearly Normal Incidence

An optical system that utilizes visible light at nearly perpendicular incidence has been invented for use in testing the surface figures of nominally axisymmetric (paraboloidal, ellipsoidal, or conical) mirrors designed to function at grazing incidence. Such mirrors can be used as the...

Briefs : Photonics/Optics
Making Digital Composite Images for Technical Illustration

A method of generating three-dimensional composite digital images can serve multiple purposes in technical illustration. The method was devised to accelerate and facilitate the design of new electric lights and receptacles for large buildings, and can just as well be applied to the...

Briefs : Photonics/Optics
Phase-Retrieval Camera for Optical Testing

A portable instrument denoted a phase-retrieval camera (PRC) is designed to enable the testing of large, lightweight optics in the presence of vibrations and atmospheric turbulence. The development of the PRC was prompted by the fact that conventional optical-testing techniques are not sufficiently...

Briefs : Photonics/Optics
Liquid-Crystal Phase-Shifting Shearing Interferometer

The liquid-crystal phase-shifting shearing interferometer is a common-path interferometer based partly on a lateral-shear-plate interferometer. It bears a partial similarity to the liquid-crystal point-diffraction interferometer (LCPDI), which is also of the common-path type. The...

Briefs : Photonics/Optics
Fiber-Optic Phase-Locked Loop Sensitive to Local Strain Only

The figure schematically depicts an apparatus for measuring strain at only one designated location on a structure. The apparatus is a fiber-optic phase-locked loop, wherein strain in a multimode optical fiber gives rise to a change in the phase of modulation of a laser beam that...

Briefs : Photonics/Optics
Light Recycling and Color Scrolling for Brighter Displays

The efficiencies and thus the brightnesses of flat-panel projectors based on liquid-crystal devices (LCDs) and digital mirror devices (DMDs) would be increased by the combination of a color-scrolling technique and a light-recycling technique, according to a proposal. These techniques...

Briefs : Photonics/Optics
Multi-Screen-Image- and Catalog-Viewing Program

A computer program enables the single- or multi-screen display of multispectral, multiresolution images — especially astronomical ones — stored as sets of data that range upward in size from hundreds of gigabytes. In cases of multi-screen displays, the software synchronizes the screens so that...

Briefs : Photonics/Optics
Software Automates Processing of SAR Image Data

The Automated SAR Image Processor (ASIP) computer program increases the efficiency of production of scientifically useful imagery from raw synthetic-aperture-radar (SAR) image data. In the absence of ASIP, the processing of SAR data is a labor-intensive task, often involving supporting personnel,...

Briefs : Photonics/Optics
Compact, Stiff, Lightweight, Quick-Release Clamp

The term "COSMOWRAP" denotes a compact, stiff, remotely actuatable, lightweight, quick-release clamp that could be substituted for the larger, heavier, and more-difficult-to-use toggle-action clamp now used in the space shuttle orbiter docking system (ODS) to perform contingency separations. In...

Briefs : Electronics & Computers
Ground-Traffic Information-Management System for an Airport

A computer-based system, and a method built around the use of the system, have been developed to automate the acquisition, integration, and management of data that have been generated at different rates by multiple, heterogeneous, incompatible sources. The system [hereafter denoted the...

Briefs : Electronics & Computers
Mixed-Signal Driver ASIC for IEEE 1394 and I²C Buses

The IEEE 1394 and I2C Mixed-Signal Driver is one of two application-specific integrated circuits (ASICs) designed to function together as an interface among the following three digital-signal buses:

A peripheral component interface (PCI) bus; A high-speed serial data bus that...
Briefs : Electronics & Computers
Unity-Power-Factor Interfaces for Data-Processing Equipment

Circuits for conditioning AC power supplied to computers are under development. A power conditioner of this type would be an interface between a conventional AC power line and a computer power supply (that is, an AC-to- DC converter) that contains one or more rectifier(s) and...

Briefs : Software
Program Injects Random Faults for Testing Computers

JIFI (Jet Propulsion Laboratory's Implementation of a Fault Injector) is a computer program for studying the ability of a computer to tolerate, detect, and/or recover from faults (that is, bit errors). JIFI affords the capability to inject faults into user-specified central- processing-unit...

Briefs : Electronics & Computers
InP HEMT MMIC Low-Noise Amplifier for 65 to 110 GHz

A monolithic microwave integrated circuit (MMIC) has been designed to function as a low-power-consumption, low-noise amplifier (LNA) at frequencies from about 65 to about 110 GHz. This MMIC incorporates TRW's state-of-the-art, InP-based, high-electron-mobility transistors (HEMTs) coupled with...

Briefs : Electronics & Computers
“Substrateless” Millimeter- and Submillimeter-Wave Circuits

Monolithic integrated circuits (in particular, Schottky-diode-based frequency multipliers) that operate at frequencies as high as a few terahertz are being developed in a program that utilizes the recent advances in methods of computer-aided design and micro-fabrication. In the...

Briefs : Electronics & Computers
Capacitors Containing Nanocrystalline BaTiO3 as Dielectric

Capacitors in which the main dielectric layers are made from sintered nanocrystalline BaTiO3 have been fabricated and tested in an initially successful and continuing effort to increase energy densities, breakdown potentials, and insulation resistances beyond those of prior...

Briefs : Electronics & Computers
Millimeter-Wave and Microwave Treatment of Atherosclerosis

Millimeter-wave/microwave ablation (essentially, heating by use of millimeter-wave and microwave electromagnetic radiation) has been proposed as a means of treating atherosclerotic lesions. Computational simulations have shown that by controlling and customizing temperature profiles in...

Briefs : Software
KPP — a Preprocessor for VHDL

KPP is a computer program that serves as a preprocessor for VHDL code. [“VHDL” signifies VHSIC Hardware Description Language, which is a language used by the United States Department of Defense for describing, designing, and simulating very-high-speed integrated circuits (VHSICs).] KPP is based on, and similar...

Briefs : Software
Software for Analyzing Valve-Actuator

A computer program assists engineers in analyzing data on the performances of actuators of fuel and oxidizer valves in the main engines of the space shuttle. The program could be adapted to similar use in other settings in which, as in the space shuttle, valve actuators are instrumented to provide data on...

Briefs : Software
Software for Network Processing of

The Electronic Portable Information Collection (EPIC) computer program is a computer system that processes work authorization documents (WADs). The EPIC System, which is also known as the Portable Data Collection System, comprises a central data server and portable data terminals. The central data server acts...

Briefs : Materials
Testing Soil for Electrokinetically Enhanced Bioremediation

The term “prefield test” denotes an in situ test of contaminated soil in preparation for in situ treatment of the soil by a method called “electrokinetically enhanced bioremediation” (EEB). A prefield test yields data that are helpful in designing and operating an efficient and...