August 1999

Briefs: Electronics & Computers

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...

Briefs: Motion Control

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 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...

Briefs: Motion Control

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...

Briefs: Mechanical & Fluid Systems

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...

Briefs: Materials

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

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

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...

Briefs: Materials

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

Briefs: Robotics, Automation & Control

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....

Briefs: Information Technology

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

Briefs: Materials

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...

Briefs: Motion Control

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...

Briefs: Materials

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...

Briefs: Physical Sciences

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

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...

Briefs: Electronics & Computers

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...

Briefs: Materials

An improved magnetostrictive valve for remotely controlling a flow of liquid helium has been developed. Heretofore, flows of liquid helium have been controlled by use of valves with...

Videos