Briefs : Mechanical & Fluid Systems
Spacecraft Solar-Wind Trim Panels for Pointing

A report proposes that spacecraft assigned to orbits distant from the Earth be equipped with trim panels that would intercept the solar wind to generate small torques to correct for disturbance torques and thereby help to maintain the spacecraft pointed in the required directions. Paired panels...

Briefs : Materials
Reaction-Forming Method for Joining SiC-Based Parts

Two reports present additional details about the method described in "Reaction-Forming Method for Joining SiC-Based Ceramic Parts" (LEW-16661), NASA Tech Briefs, Vol. 23, No. 3 (March 1999), page 50. To recapitulate: A carbonaceous mixture (typically a paste) is applied to a joint between...

Briefs : Information Technology
Subpixel Map Registration and Estimation of Uncertainty

A method of determining the location and the uncertainty in the location of a mobile robot to subpixel resolution on a map grid has been devised. The method is applicable to a robot equipped with stereoscopic vision equipment for mapping the local terrain and with sensors for determining...

Briefs : Mechanical & Fluid Systems
Control Methodology To Alter Automobile Rollover Tendencies

A methodology of active control has been developed in an effort to alter (preferably to reduce) the tendency of a four-wheel land vehicle to roll over during tight turns and similar maneuvers. At the time of reporting the information for this article, hardware and software to implement...

Briefs : Mechanical & Fluid Systems
Program for Computing Dynamics of Multiple Bodies

Symbolic Generator-Based Efficient Multibody Dynamics Algorithm (SOMBAT) is a program that enables speedy and accurate computations that solve equations of motion of multiple bodies. Originally intended for space-based applications (i.e., solving equations for the dynamics of a cluster of...

Briefs : Information Technology
A Method for Designing Low-Pass FIR Digital Filters

A class of finite-impulse-response (FIR) digital filters has been developed to perform certain frequency-limiting, decimation, and differentiation (with respect to time) functions on a time series of data samples. The method is implemented by use of design equations that contain parameters that...

Briefs : Materials
Computer Code Generates Two-Dimensional Unstructured Grids

TRiangular Unstructured Mesh generator by Point insEr Tion (TRUMPET) is a computer program that generates meshes that are composed of triangular cells and are bounded by complex shapes. The bounding shapes can be singly or multiply connected two-dimensional regions. The figure depicts...

Briefs : Materials
Designing Composite Repairs and Retrofits for Infrastructure

A method of analyzing and designing laminated composite-material wraps for columns, arches, domes, and other large reinforced-concrete structures involves an extension of composite-mechanics concepts and computational techniques developed previously for the analysis and design of the...

Briefs : Materials
Software for Predicting Life of Metal-Matrix Composites

LIPS (LIFE PREDICTION SOFTWARE) is a computer program for predicting the life of an object that is made of a unidirectional-fiber/metal-matrix composite (MMC) material and that is subjected to mechanical loading along the fiber direction. The program is derived from a theory formulated to...

Briefs : Electronics & Computers
Security System Based on Bragg Gratings in an Optical Fiber

The figure schematically illustrates an optoelectronic security system in which binary information on the identity of a person or object is encoded in Bragg gratings in an optical fiber. This is not the first optoelectronic security system based on fiber-optic Bragg gratings, but it is...

Briefs : Electronics & Computers
Higher-Resolution Optoelectronic Shaft-Angle Encoder

The apparatus shown schematically in the figure is an optoelectronic shaft-angle encoder that measures absolute angles with high resolution. This encoder is an improved version of the apparatus described in "High-Resolution Optoelectronic Shaft-Angle Encoder" (GSC-13543), Laser Tech Briefs,...

Briefs : Electronics & Computers
High-Power Laser Illuminator

A laser illuminator system has been developed for use in automated tracking of objects. In its original application, the system illuminates a 5° conical region expected to contain a small satellite at a distance up to 750 m from the space shuttle. If the satellite comes within this region, then a receiving...

Briefs : Electronics & Computers
Communication Controller Board for a Wind-Tunnel Model

A communication controller circuit for a wind-tunnel model is undergoing development. The circuit is intended to serve as part of a highly miniaturized, distributed, modular electronic analog/digital data-acquisition system that would be installed inside a wind-tunnel model (see Figure 1)....

Briefs : Software
Software for Simulating Progressive Fracture in Braided PMCs

GENOA-PFA is a commercial version of the Composite Durability Structural Analysis (CODSTRAN) computer program, which simulates the progression of damage ultimately leading to fracture in Polymer-Matrix Composite (PMC) material structures under various loading and environmental...

Briefs : Materials
Molecular-Sieve Type 3Å

The term "Molecular-Sieve Type 3Å" denotes a clay-based, zeolite material that revolutionizes a fluid-purification process by removing trace water and iron from nitrogen tetroxide/nitric oxide (MON-3) mixtures used as oxidizer components of spacecraft propellants. Older processes of this type removed only water or iron...

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