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
Delta-Doped CCDs as Detector Arrays in Mass Spectrometers

Delta-doped, back-illuminated charge-coupled devices (CCDs) are used as detector arrays in high-performance double- focusing miniature mass spectrometers of Mattauch-Herzog design (described below). The uses of delta-doped CCD detector arrays eliminates the need for microchannel plates...

Briefs : Physical Sciences
Arrays of Bundles of Carbon Nanotubes as Field Emitters

Experiments have shown that with suitable choices of critical dimensions, planar arrays of bundles of carbon nanotubes (see figure) can serve as high-current-density field emitter (cold-cathode) electron sources. Whereas some hot-cathode electron sources must be operated at supply...

Briefs : Mechanical & Fluid Systems
Staggering Inflation To Stabilize Attitude of a Solar Sail

A document presents computational simulation studies of a concept for stabilizing the attitude of a spacecraft during deployment of such structures as a solar sail or other structures supported by inflatable booms. Specifically, the solar sail considered in this paper is a square sail...

Briefs : Mechanical & Fluid Systems
Bare Conductive Tether for Decelerating a Spacecraft

A document describes a prototype of electrically conductive tethers to be used primarily to decelerate spacecraft and/or generate electric power for the spacecraft. Like prior such tethers, this tether is designed so that when it is deployed from a spacecraft in orbit, its motion across the...

Briefs : Physical Sciences
Flexible Skins Containing Integrated Sensors and Circuitry

Artificial sensor skins modeled partly in imitation of biological sensor skins are undergoing development. These sensor skins comprise flexible polymer substrates that contain and/or support dense one- and two-dimensional arrays of microscopic sensors and associated microelectronic...

Briefs : Manufacturing & Prototyping
Artificial Hair Cells for Sensing Flows

The purpose of this article is to present additional information about the flow-velocity sensors described briefly in the immediately preceding article. As noted therein, these sensors can be characterized as artificial hair cells that implement an approximation of the sensory principle of flow-sensing...

Briefs : Electronics & Computers
Optoelectronic Nose Senses Vapors Associated with Hazmat and Security Scenarios

Since 9/11, we are increasingly threatened by terrorist plots — the release of noxious substances into crowded public places or on airplanes, in crowded buildings, and in sports arenas. Anxieties about these rare events are mostly unrealized, but such events...

Briefs : Electronics & Computers
Video Guidance Sensor and Time-of-Flight Rangefinder

A proposed video guidance sensor (VGS) would be based mostly on the hardware and software of a prior Advanced VGS (AVGS), with some additions to enable it to function as a time-offlight rangefinder (in contradistinction to a triangulation or image-processing rangefinder). It would typically be...

Briefs : Physical Sciences
Optical Beam-Shear Sensors

A technique for measuring optical beam shear is based on collecting light from the four quadrants of the beam and comparing the optical power collected from each quadrant with that from the other three quadrants. As used here, "shear" signifies lateral displacement of a beam of light from a nominal optical axis.

Briefs : Software
The PICWidget

The Plug-in Image Component Widget (PICWidget) is a software component for building digital imaging applications. The component is part of a methodology described in “GIS Methodology for Planning Planetary-Rover Operations” (NPO-41812), which appears elsewhere in this issue of NASA Tech Briefs. Planetary rover missions return a...

Briefs : Software
Fusing Symbolic and Numerical Diagnostic Computations

"X-2000 Anomaly Detection Language" denotes a developmental computing language, and the software that establishes and utilizes the language, for fusing two diagnostic computer programs, one implementing a numerical analysis method, the other implementing a symbolic analysis method into a...

Briefs : Software
Probabilistic Reasoning for Robustness in Automated Planning

A general-purpose computer program for planning the actions of a spacecraft or other complex system has been augmented by incorporating a subprogram that reasons about uncertainties in such continuous variables as times taken to perform tasks and amounts of resources to be consumed....

Briefs : Software
Short-Term Forecasting of Radiation Belt and Ring Current

A computer program implements a mathematical model of the radiation-belt and ring-current plasmas resulting from interactions between the solar wind and the Earth's magnetic field, for the purpose of predicting fluxes of energetic electrons (10 keV to 5 MeV) and protons (10 keV to 1...

Briefs : Software
JMS Proxy and C/C++ Client SDK

JMS Proxy and C/C++ Client SDK ("JMS" signifies "Java messaging service" and "SDK" signifies "software development kit") is a software package for developing interfaces that enable legacy programs (here denoted "clients") written in the C and C++ languages to communicate with each other via a JMS broker. This...

Briefs : Software
XML Flight/Ground Data Dictionary Management

A computer program generates Extensible Markup Language (XML) files that effect coupling between the command- and telemetry-handling software running aboard a spacecraft and the corresponding software running in ground support systems. The XML files are produced by use of information from the flight...

Briefs : Software
Cross-Compiler for Modeling Space-Flight Systems

Ripples is a computer program that makes it possible to specify arbitrarily complex space-flight systems in an easy-tolearn, high-level programming language and to have the specification automatically translated into LibSim, which is a textbased computing language in which such simulations are...

Briefs : Semiconductors & ICs
Microstrip Antenna Arrays on Multilayer LCP Substrates

A research and development effort now underway is directed toward satisfying requirements for a new type of relatively inexpensive, lightweight, microwave antenna array and associated circuitry packaged in a thin, flexible sheet that can readily be mounted on a curved or flat rigid or...

Briefs : Electronics & Computers
Multiple-Agent Air/Ground Autonomous Exploration Systems

Autonomous systems of multipleagent air/ground robotic units for exploration of the surfaces of remote planets are undergoing development. Modified versions of these systems could be used on Earth to perform tasks in environments dangerous or inaccessible to humans: examples of tasks could...

Briefs : Electronics & Computers
Multiloop Rapid-Rise/Rapid Fall High-Voltage Power Supply

A proposed multiloop power supply would generate a potential as high as 1.25 kV with rise and fall times <100 μs. This power supply would, moreover, be programmable to generate output potentials from 20 to 1,250 V and would be capable of supplying a current of at least 300 μA at...

Briefs : Electronics & Computers
Applications for Subvocal Speech

research and development effort now underway is directed toward the use of subvocal speech for communication in settings in which (1) acoustic noise could interfere excessively with ordinary vocal communication and/or (2) acoustic silence or secrecy of communication is required. By "subvocal speech" is meant...

Briefs : Electronics & Computers
A 640 x 512-Pixel Portable Long-Wavelength Infrared Camera

A portable long-wavelength infrared electronic camera having a cutoff wavelength of 9 μm has been built around an image sensor in the form of a 640 × 512- pixel array of AlxGa1–xAs/GaAs quantum well infrared photodetectors (QWIPs). This camera is an intermediate...

Briefs : Electronics & Computers
An Array of Optical Receivers for Deep-Space Communications

An array of small optical receivers is proposed as an alternative to a single large optical receiver for high-data-rate communications in NASA's Deep Space Network (DSN). Because the telescope for a single receiver capable of satisfying DSN requirements must be greater than 10 m in...

Briefs : Materials
Composite Elastic Skins for Shape-Changing Structures

Composite elastic skins having tailorable mechanical properties have been invented for covering shape-changing ("morphable") structures. These skins are intended especially for use on advanced aircraft that change shapes in order to assume different aerodynamic properties.

Briefs : Materials
Glass/Ceramic Composites for Sealing Solid Oxide Fuel Cells

A family of glass/ceramic composite materials has been investigated for use as sealants in planar solid oxide fuel cells. These materials are modified versions of a barium calcium aluminosilicate glass developed previously for the same purpose. The composition of the glass in mole...

Briefs : Manufacturing & Prototyping
Manufacturing Large Membrane Mirrors at Low Cost

Relatively inexpensive processes have been developed for manufacturing lightweight, wide-aperture mirrors that consist mainly of reflectively coated, edge-supported polyimide membranes. The polyimide and other materials in these mirrors can withstand the environment of outer space, and the mirrors...

Briefs : Manufacturing & Prototyping
Double-Vacuum-Bag Process for Making Resin-Matrix Composites

A double-vacuum-bag process has been devised as a superior alternative to a single-vacuum-bag process used heretofore in making laminated fiber-reinforced resin-matrix composite-material structural components. This process is applicable to broad classes of high-performance matrix...

Briefs : Medical
Surface Bacterial-Spore Assay Using Tb3+/DPA Luminescence

Equipment and a method for rapidly assaying solid surfaces for contamination by bacterial spores are undergoing development. The method would yield a total (nonviable plus viable) spore count of a surface within minutes and a viable-spore count in about one hour. In this method, spores...

Briefs : Medical
Simplified Microarray Technique for Identifying mRNA in Rare Samples

Two simplified methods of identifying messenger ribonucleic acid (mRNA), and compact, low-power apparatuses to implement the methods, are at the proof-of-concept stage of development. These methods are related to traditional methods based on hybridization of nucleic acid, but...

Briefs : Physical Sciences
High-Resolution, Wide-Field-of-View Scanning Telescope

A proposed telescope would afford high resolution over a narrow field of view (<0.10°) while scanning over a total field of view nominally 16° wide without need to slew the entire massive telescope structure. The telescope design enables resolution of a 1-m-wide object in a...

Briefs : Physical Sciences
Multispectral Imager With Improved Filter Wheel and Optics

Figure 1 schematically depicts an improved multispectral imaging system of the type that utilizes a filter wheel that contains multiple discrete narrow-band-pass filters and that is rotated at a constant high speed to acquire images in rapid succession in the corresponding spectral...

Question of the Week
Would You Own a Robot Pet?