Briefs: Physical Sciences
Lithium-Based Primary Cells for Low-Temperature Operation

A report describes an experimental study of the low-temperature electrical characteristics of commercial Li/MnO2, Li/CFx, Li/SO2, Li/SOCl2, and Li/BCX primary electrochemical cells. These high-energy-density cells are under consideration for use...

A computational methodology for predicting the initiation and propagation of failures in laminated matrix/fiber composite-material structures has been developed. The methodology...

Briefs: Information Technology
Program for Designing a Mechanical System

Mechanical System Design/Analysis Tool (MSAT) is a user-friendly software system that facilitates and accelerates the processes of synthesizing and analyzing designs of mechanical systems. MSAT is...

Briefs: Mechanical & Fluid Systems
Experiments on Vibration and Noise in Fuselages

A paper summarizes a continuing program of vibro-acoustic testing of two aircraft fuselage structures: (1) a 12-ft (3.7-m)-long generic aluminum test-bed cylinder that contains stiffening rings and stringers and (2) the 40-ft (12.2-m)-long fuselage of a 10-passenger turboprop airplane, made of...

Briefs: Information Technology
Development of Flight Software for Small Explorer Spacecraft

A report describes a continuing program of development of flight software for the attitude-control system (ACS) and the command-and-data-handling (C&DH) system of a prototype standard spacecraft of the Small Explorer (SMEX)-Lite class. Both the C&DH and ACS parts of the...

Briefs: Materials
Program Predicts Uncertainties in Properties of CMCs

Probabilistic Ceramic Matrix Composite Analyzer (PCEMCAN) is a user-friendly computer program that predicts uncertainties in the mechanical and thermal properties of ceramic-matrix composite (CMC) materials. These materials are candidates for fabrication of structural components that will be...

Briefs: Electronics & Computers
Three-Phase Sine-Wave Generator

A variable-frequency, three-phase, sine-wave generator circuit has been designed for use as a source of polyphase excitation in studies of the propagation of traveling waves in plasmas. This circuit, combined...

An apparatus called a "pneumatic stinger" has been developed to enable a first spacecraft, operating under remote control, to grasp a second spacecraft that is in orbit or other...

Briefs: Mechanical & Fluid Systems
FoilSim: Software for Teaching About Airfoils

FoilSim is a computer program that calculates and graphically depicts information on flows of air around airfoils of various shapes. Although it is useful primarily as a teaching tool to enhance...

Servomotor drive manufacturers agree that the performance of today's digital drive is largely determined by the performance of its feedback device. Clearly, previous feedback solutions, such as...

Current proposed shapes for single-stage-to-orbit vehicles like the Lockheed-Martin X-33 and VentureStar reusable launch vehicle have extremely large base areas when compared with...

Briefs: Software
Program Estimates Loads in Launch Vehicles

Version 1.4 of the Launch Vehicle Loads Analysis for Preliminary Design (VLOADS 1.4) computer program calculates in-flight launch-vehicle structural loads (that is, spacecraft-launching rockets) for preliminary design. The program can also be used to calculate structural loads in upper stages and...

A magnetostrictive linear-translation mechanism has been designed to function as a micropositioning device at any temperature from ambient down to the temperature of liquid helium...

Briefs: Electronics & Computers
Managing Wire Harness Design Information

Wiring is a major deliverable in just about all electromechanical equipment. From airplanes to semiconductor capital equipment, the key component tying together all of the technological innovations...

Briefs: Motion Control
Finding a Solution for Bellows Coupling Failure

When a problem such as breaking bellows couplings threatens to halt a machinery production line, it is necessary to look beyond the obvious. In an application in which the coupling works on a Heidenhain encoder for an X-Y table that positions circuit boards, representatives of the user company and...

Briefs: Software
Software for Detecting Anomalies and Responding to Faults

The Automated Test Monitor computer program provides for continuous monitoring of the operations of a complex system (e.g., a spacecraft). This program implements a rigorous analytic (instead of an ad hoc) technique that prescribes exactly how to express requirements for the operation of...

Briefs: Information Technology
Program Generates Graphics To Help in Planning Space Flights

The Mission Planning Graphical Tool (MPGT) computer program provides a mouse-driven graphical representation of data on a spacecraft and its environment, for use in planning a space flight. MPGT is designed to be a generic software tool that can be configured to analyze any specified...

Briefs: Materials
Magnetostrictive Filter-Wheel Drive

The figure shows a prototype of a magnetostrictively actuated mechanism that would rotate an optical filter wheel for a high-performance infrared camera or telescope. Typically, a high-performance infrared instrument and its filter wheel are operated inside a cryogenic system. In conventional practice, the...

Briefs: Electronics & Computers
Supplementing Overvoltage Protection

Low-voltage high-current loads requiring precision voltage regulation are served by power systems that sense voltage remotely at the load. This creates the risk of an overvoltage (OV) condition at the...

A magnetostrictively actuated heat switch has been proposed for use in a variety of cryogenic equipment, including adiabatic-demagnetization refrigerators, calorimeters, and coolers for...

Small hybrid rocket engines of a proposed type would burn specially shaped hollow cylinders of solid fuel containing slanted oxygen-injection channels, as shown in the figure....

Parallel Visual 3 (pV3) is an interactive computer program that provides selected displays of data generated in numerical simulations - especially simulations that involve parallel...

A proposed "kinematic inchworm"-type linear actuator would move a mass as large as 2 kg along rails, with lengthwise position controllable in increments as small as 50 nm. The actuator could be...

Energy efficiency is a continuing focus of the power electronics industry. Motors consume the most electricity in commercial and industrial applications (followed at a distant second by...

Research has shown that with suitable processing, one can produce a polycrystalline version of a terbium/dysprosium alloy suitable for use in a magnetostrictive actuator for...

A technique that involves the use of crossed magnetic antennas in a natural waveguide has been proposed for tracking Martian dust storms from a single observing station; that is,...

Briefs: Robotics, Automation & Control
Miniature Turbomolecular Pump for High Vacuum

A proposed miniature turbomolecular pump would be a prototype of high-vacuum sources for a forthcoming generation of miniature, portable mass spectrometers and other scientific instruments. The...

Briefs: Materials
Extruding Tb/Dy for Magnetostrictive Actuators

A process that is undergoing development would be used to mass-produce textured polycrystalline rods of a terbium/dysprosium alloy for cryogenic magnetostrictive actuators. The rolling-and-heat-treatment process described in the preceding article yields a high degree of crystal orientation, but is...

A microwave-cavity applicator has been developed for coating multiple fibers by chemical vapor deposition (CVD). A prototype of the applicator was used to deposit silicon carbide...

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