February 2000

Figure 1 schematically depicts an experimental setup in which Rayleigh scattering from molecules of a flowing gas is used to measure the temperature and one component of the...

Briefs: Electronics & Computers
Integrated Optical Voltage-Measuring Apparatus

An integrated optical voltage-measuring apparatus based on a Mach-Zehnder interferometer has been designed and constructed. The main feature of this apparatus is that optical fibers link part of it to an optical sensor head placed at the source of the voltage to be measured, whether the source be a...

Briefs: Electronics & Computers
Integrated Test and Operations System

The Integrated Test and Operations System (ITOS) is a generic system of software for controlling spacecraft and components of spacecraft during development, testing, and operation in orbit. The ITOS...

The ULTRA SON computer program is designed for use in precise ultrasonic contact scan measurements for nondestructive characterization of materials. This program performs major functions...

Briefs: Electronics & Computers
Apparatus Records Acceleration and Temperature

An apparatus records triaxial acceleration and temperature as a function of time, operating unattended for as long as 3 weeks on power supplied by two D cells. The apparatus, which has dimensions of only 3.5 by 4.5 by 2.2 in. (8.9 by 11.4 by 5.6 cm) and weighs only 28.5 oz (0.81 kg) is designed...

Briefs: Electronics & Computers
DRAM Circuit Tolerates Single-Event Upsets

A dynamic random-access memory (DRAM) circuit that tolerates single-event upsets (SEUs) has been developed. A single-event upset is a bit flip caused by ionizing radiation. In a DRAM, the state of each bit (0 or 1) is stored as charge on a buried capacitor. The impingement of an energetic charged...

Researchers are following two approaches in an effort to improve the low-noise performances of InP-based high-electron-mobility transistors (HEMTs) that could be used as front-end...

An improved three-dimensional (3-D) scheme for modular packaging and interconnection of electronic circuits has been proposed to overcome deficiencies of an older scheme and to obtain...

Briefs: Software
Software for Monitoring Remote Systems and Executing Plans

The Knowledge Server Tools (KST) computer program comprises a distributed set of software tools for monitoring remote systems. Part of KST implements a knowledge server for monitoring the status of a remote system (e.g., a computer-controlled instrumentation system, a robot, or...

Briefs: Software
Monocoque Tank Analysis Spreadsheet System, Version 2.0

The Monocoque Tank Analysis Spreadsheet System (MONTASS) computer program is an integrated software system that incorporates Microsoft Excel worksheet software and Visual BASIC software. MONTASS was developed to enable rapid analysis and preliminary design of structural domes and...

Briefs: Software
Automated Planning and Scheduling for a Robotic Vehicle

A software system generates sequences of commands for the operation of a robotic vehicle. The system was adapted to control Rocky 7, a semiautonomous instrumented vehicle of the "rover" type used in scientific exploration of Mars. The software system was developed by integrating two...

Briefs: Materials
Protective Shells for Composite Overwrapped Pressure Vessels

White Sands Test Facility (WSTF) scientists have developed an energy-absorbing laminated shell that is a prototype of lightweight, inexpensive, and removable covers to shield and otherwise protect carbon-composite overwrapped pressure vessels (COPVs). Although COPVs are superior to...

Briefs: Materials
Nonevaporable Getters To Maintain Vacuum in Sealed MEMS

Nonevaporable getters have been proposed for use in maintaining vacuum inside hermetically sealed microelectromechanical systems (MEMS) that rely on vacuum for proper operation. A vibratory microgyroscope is an example of such a MEMS. The proposed getters could also be used in such vacuum...

Briefs: Mechanical & Fluid Systems
Spherical-Coordinates Encoder Module

The spherical-coordinates encoder module (SCEM) is a relatively simple and inexpensive electromechanical apparatus for quickly and easily measuring three-dimensional offsets between objects at distances...

Technological advances have driven the evolution of aircraft flight-control systems. In the dawn of 20th-century aviation, the Wright Brothers used cables and warping of wing surfaces to change...

Improved miniature biotelemetric units resembling large pills have been proposed for use in physiological monitoring of the gastrointestinal tract. The broad principles of design, operation,...

Briefs: Photonics/Optics
Lightweight Reflector Dishes Would Be Made by Spin Casting

Lightweight reflector dishes for radio antennas would be mass-produced cheaply by spin casting of polymers, according to a proposal. These reflector dishes were conceived for compact stowage followed by deployment and operation aboard spacecraft, but might also be useful on Earth in...

Briefs: Photonics/Optics
Retroreflective Communication Systems

A retroreflective communication system (RCS), is a state-of-the-art system that provides (1) two-way optical communication using only one transmitter and (2) multipath communication among remote locations. RCSs were conceived for use in communication among stations on the ground and aboard spacecraft in...

Briefs: Medical
Urine-Sample-Collection Device for Use on the Space Shuttle

The in-flight urine collection absorber (IUCA) is a Johnson Space Center (JSC) breakthrough. It features a lightweight, compact design and is easy to use for collection of urine samples by male and female space shuttle crewmembers. The IUCA is superior to currently available hardware...

Briefs: Robotics, Automation & Control
Adaptive Variable Bias Control for Magnetic Bearings

Adaptive variable bias control (AVBC) is an improved technique for controlling the currents supplied to the electromagnets in magnetic bearings. In AVBC, the bias currents are varied in...

The term "mechanical mirroring using controlled stiffness and actuators" ("MEMICA") denotes a developmental concept for reflecting contact forces, displacements, mechanical damping,...

A phased-array-fed cylindrical-reflector antenna with superquadric projected aperture has been designed to afford the ability to scan the beam over a wide angular range without...

Open-cell silicon carbide foam coated with a ferrite-filled absorbing resin has been found to be useful for black-body absorbers at millimeter and submillimeter wavelengths. The...

A commercial version of the NASA plasma-contactor hollow-cathode assembly (PC HCA) has been developed. The NASA PC HCA is a highly reliable hollow discharge cathode that is the most thoroughly...

Briefs: Photonics/Optics
Adaptive Filtering of SAR Interferograms

An algorithm for filtering synthetic-aperture-radar (SAR) interferograms has been developed which substantially improves the performance of subsequent phase-unwrapping. It accomplishes this task by filtering the interferogram strongly in areas where the scene contains little detail, and weakly where the...

Solar-blind photodetectors respond only to ultraviolet light at wavelengths shorter than those of the solar radiation that can penetrate atmosphere of the Earth. This wavelength range, traditionally...

Briefs: Physical Sciences
Parallel 3D EMPIC Algorithm Using Nonorthogonal Grids

Electromagnetic particle-in-cell (EMPIC) codes provide a capability for numerically simulating the motions of electrically charged particles in electromagnetic fields, and hence have become standard software tools in plasma physics research. Most existing EMPIC codes are based on the use of...

A recently developed method of parameterizing complex shapes that one seeks to optimize differs from prior such methods in two major respects: (1) instead of...

A versatile, ultrafast, low-power machine vision system in the form of a single integrated-circuit chip has been proposed for use in military targeting, industrial robotics, and other...

A special-purpose interface circuit for a computer hard-disk drive (HDD) enables rapid writing of image data from a scientific instrument to sequential sectors on the hard disk. The...

NASA has developed a system of hardware and software that can accommodate all necessary interfaces between (1) space-station flight computers and (2) a simulation host computer...

Briefs: Electronics & Computers
Forward-Link/Simulator PCI Card

The forward-link/simulator card (FLS) performs the fundamental satellite-telemetry data-transmission function for the forward (Earth-to-spacecraft) link in real time at rates up to 400 Mb/s. The FLS also simulates a Consultative Committee for Space Data Systems (CCSDS) telemetry data source that outputs data at...

Wearable sensor patches — miniature biotelemetric units — have been proposed for use in measuring temperature, heart rate, blood pressure, and possibly other physiological parameters....

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