Briefs: Information Technology
Quantum Superluminal Transmission of Random Messages

In a proposed communication scheme, quantum entanglement and quantum nonlocality would be utilized to effect instantaneous transmission of randomly chosen messages to remote locations. Although the messages would not convey any information, they might nevertheless be of some value under...

Briefs: Information Technology
Goal-Based Fault Tolerance for Spacecraft Systems

A report discusses the concept of goal-based fault tolerance as implemented in NASA’s Mission Data System (MDS), which is a developmental architecture for unified flight, test, and ground software that is intended to be adaptable to a variety of next-generation deep-space missions. In...

Briefs: Electronics & Computers
PWM and Synchronous Rectifier Controller ASICs

A report describes two radiation-hard application-specific integrated circuits (ASICs) that constitute a mixed-signal chip set that performs all the control functions for a power-converter module (PCM) in a spacecraft power-supply system. One of these ASICs serves mainly as a pulse-width modulation...

Briefs: Physical Sciences
DNS of a Supercritical H₂/O₂ Mixing Layer

This report discusses direct numerical simulations (DNS) of a mixing layer between supercritical flows of oxygen and hydrogen. The governing conservation equations were those of fluctuation- dissipation (FD) theory, in which low-pressure typical transport properties (viscosity, diffusivity and...

Briefs: Information Technology
Remote Agent as Applied to the Deep Space 1 Spacecraft

A report presents updated information about the Remote Agent — a reusable artificial-intelligence software system that was described in “A Remote Agent Prototype for Spacecraft Autonomy” (NPO-19992), NASA Tech Briefs, Vol. 21, No. 3 (March 1997), page 106. This system was conceived to...

Briefs: Mechanical & Fluid Systems
Pneumatic Accelerator for Launching a Spacecraft

A report proposes the development of a ground-based launch-assist apparatus that would accelerate a spacecraft to a speed of about 270 m/s. The apparatus would include a track along which the spacecraft would ride on a sled coupled to a large piston driven by compressed air along a tube (more...

Briefs: Photonics/Optics

A portable instrumentation system that includes an airborne and a ground-based subsystem acquires multispectral image data over swaths of terrain ranging in width from about 1/2 to 1 km. The...

Briefs: Electronics & Computers

A lossless image-compression algorithm that can be executed entirely in electronic hardware has been developed. This algorithm yields about 15 percent more compression than does the...

Briefs: Physical Sciences

A highly sensitive, low-power, low-noise multifunctional active-excitation spectral analyzer (MAESA) that would span the wavelength range of 0.5 to 2.5 µm and would operate near room...

Briefs: Photonics/Optics

Software and electronic hardware are being developed to provide cockpit guidance and camera control for an air-to-air schlieren photography system that is to be used to take...

Briefs: Information Technology
Multirover Coordination Based on Contract Net Protocol

A computer program coordinates operations of multiple cooperating rovers (small exploratory robotic vehicles deployed from a lander spacecraft), each of which is equipped with computer hardware and software that schedule the tasks assigned to it. The program implements a contract net...

Briefs: Physical Sciences
Hand-Held Optoelectronic Particulate Monitors

Optoelectronic instruments are being developed for use in measuring the concentrations and sizes of microscopic particles suspended in air. The instruments could be used, for example, to detect smoke, explosive dust in grain elevators, or toxic dusts in industrial buildings. Like some older,...

Briefs: Photonics/Optics
High-Performance Processor of Hyperspectral Images

The Remote Sensing Hyperspectral Engine (RSHE) is a special-purpose, portable computer that performs high-performance processing of hyperspectral image data collected by a remote-sensing optoelectronic apparatus. Typically, the remote-sensing apparatus is airborne or spaceborne, the images are...

Briefs: Photonics/Optics

Arrays of HgCdTe infrared photodetectors have been developed to satisfy stringent performance requirements for use in NASA’s Tropospheric Emission Spectrometer. The design of these...

Briefs: Physical Sciences

The Propulsion group at Dryden Flight Research Center is performing analyses of the effectiveness of chemical-species sensors for detecting and assessing leakage. The group is also...

Briefs: Physical Sciences
Micromachined Emitter/Bolometer Structures for Infrared Gas Sensors

Infrared gas sensors that could be mass-produced at relatively low cost have been proposed for a variety of applications — for example, detecting carbon monoxide in air inside houses. A sensor of this type would include a housing into which ambient air could diffuse. The gas...

Briefs: Electronics & Computers

Complementary metal oxide semiconductor (CMOS) integrated-circuit image sensors that are highly tolerant of high-energy radiation ("radiation hard") are undergoing development. These devices are...

Briefs: Physical Sciences
Deployable Shell Structures With Shape-Control Actuators

Advanced control systems that include built-in smart-material elastic-deformation structural actuators have been proposed for deployable thin-shell structures that are required to be maintained in precise shapes once deployed. This approach to structural shape control was conceived to...

Briefs: Mechanical & Fluid Systems

An active-control surface modal (ACSM) device has been developed as an improved means of alleviating buffet of an aircraft. The ACSM device is a "smart" actuator system that includes an...

Briefs: Electronics & Computers

The figure depicts the basic geometric features of an antenna system designed to be part of a miniature atmosphere-sounding passive microwave radiometer to be flown at high...

Briefs: Electronics & Computers
Simple Phase Shifter for a Scanning-Beam Antenna

A simple, inexpensive device has been conceived for shifting the phase of a signal in a feed line of a scanning-beam microstrip antenna in order to change the direction of the beam. Heretofore, phase shifters used for this purpose have been relatively bulky and expensive.

Briefs: Electronics & Computers
High-Capacity Nickel-Hydrogen Cells

Nickel-hydrogen electrochemical cells with capacities of 350 ampere-hours have been developed. These cells are intended primarily for use in government and commercial satellites; they have been fully qualified to satisfy performance requirements for operation in geosynchronous satellites for as long as 15...

Briefs: Electronics & Computers

A compact Ka-band power amplifier has been built with GaAs field-effect transistors (FETs) and microstrip conductors on a quartz substrate. Prior to the development of this amplifier,...

Briefs: Electronics & Computers
Skutterudite Thermoelectric Unicouples for Generating Power

A report presents some results of continuing efforts to develop advanced thermoelectric devices and, more particularly, thermoelectric unicouples for generating electric power from diverse thermal sources, including automotive exhausts and other waste-heat sources. The basic principles...

Briefs: Electronics & Computers

Miniature proportional + integral + derivative (PID) temperature controllers that would be implemented as hybrid microcircuits have been proposed to satisfy special requirements to minimize size...

Briefs: Information Technology
External Data and Attribute Hyperlink Programs for Promis•e®

External Data and Attribute Hyperlink are computer programs that can be added to Promis•e®, which is a commercial software system that automates routine tasks in the design (including drawing schematic diagrams) of electrical control systems. The programs were...

Briefs: Software
Software for Parallel Computation of 3D Thermal Convection

A computer program solves the differential equations of three-dimensional (3D) thermal convection of an incompressible fluid by use of a parallel-processing, finite volume numerical scheme. The equations of conservation of momentum, and energy are integrated over macroscopic...

Briefs: Physical Sciences
Software for Simulating Two-Phase Systems

Møtran (signifying "multi-phase transient") is a package of software for simulating flows in two-phase (gas/liquid) fluid systems like networks of such components as pipes, T junctions, pumps, evaporators, and condensers. The software is based on a two-fluid formulation that can accommodate unequal...

Briefs: Software
Fourth-Generation Software for SEU Testing

RBK4 is a computer program for testing electronic components for susceptibility to single-event upsets (SEUs). RBK4 controls the computer on which it is executed to communicate with both the board holding the device under test (DUT), a power supply, and other laboratory instruments including...

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