Magazine

An algorithm computes the direction of arrival (both azimuth and elevation angles) of a lightning-induced electromagnetic signal from differences among the times of arrival of the signal at four antennas in a Y-shaped array on the ground. In the original intended application of the...

A pre-operational annealing process is under investigation as a potential means of preventing a sudden reduction of ionic conductivity in a β"—alumina solid electrolyte (BASE) during use. On the basis of tests described below, the sudden reduction of ionic conductivity, followed by a slow...

A reactive-ion etching (RIE) process has been developed to enable the formation of holes with steep sidewalls in a layer of silicon dioxide that covers a silicon substrate. The holes in question are through the thickness of the SiO2 and are used to define silicon substrate areas to be...

A computer program provides a high-level C-language interface to electronics circuitry that controls a SpaceWire interface in a system based on a space qualified version of the ADSP-21020 digital signal processor (DSP). SpaceWire is a spacecraft-oriented standard for packet-switching data-communication...

Three computer programs have been written to preprocess digitized outputs of sensors during rocket-engine tests at Stennis Space Center (SSC). The programs apply exclusively to the SSC "E" test-stand complex and utilize the SSC file format. The programs are the following:

Telescience Resource Kit (TReK) is a suite of application programs that enables geographically dispersed users to monitor scientific payloads aboard the International Space Station (ISS). TReK provides local ground support services that can simultaneously receive, process, record, playback,...

An improved data-labeling system provides for automatic association of data products of an exploratory robot (downlink information) with previously transmitted commands (uplink information) that caused the robot to gather the data. Such association is essential to correct and timely analysis of the...

A computer program solves the Navier- Stokes equations governing the flow of a viscous, compressible fluid in an axisymmetric or two-dimensional (2D) setting. To obtain solutions more accurate than those generated by prior such programs that utilize regular and/or fixed computational...

A combination of pulsed-source interferometry and acoustic diffraction has been proposed for use in imaging subsurface microscopic defects and other features in such diverse objects as integrated-circuit chips, specimens of materials, and mechanical parts. A specimen to be inspected by this technique...

A method of measuring the fraction of bacterial spores in a sample that remain viable exploits DPA-triggered luminescence of Tb3+ and is based partly on the same principles as those described in the immediately preceding article. Unlike prior methods for performing such live/dead...