Magazine

The most accurate astronomical data is available from space-based observations that are not impeded by the Earth’s atmosphere. Such measurements may require spectral samples taken as long as decades apart, with the 1 cm/s velocity...

This software allows one to down-sample a measured surface map for model validation, not only without introducing any re-sampling errors, but also eliminating the existing measurement noise and measurement errors.

Thin, lightweight mirrors are needed for future x-ray space telescopes in order to increase x-ray collecting area while maintaining a reduced mass and volume capable of being launched on existing rockets. However, it is very difficult to determine the undistorted shape of such thin mirrors because the...

An interferometric Rayleigh scattering system was developed to enable the measurement of multiple, orthogonal velocity components at several points within very-high-speed or high-temperature flows. The velocity of a gaseous flow can be optically measured by sending laser...

The objective of this effort was to show that real-time aircraft control-surface hinge-moment information could be used to provide a robust and reliable prediction of vehicle performance and control authority degradation. For a given airfoil section with a control surface — be it a wing with an aileron,...

A generalized framework has been developed for systems validation that can be applied to both traditional and autonomous systems. The framework consists of an automated test case generation and execution system called Nemesis that rapidly and thoroughly identifies flaws or vulnerabilities within a system. By applying...

The frequency to voltage converter analog front end evaluation prototype (F2V AFE) is an evaluation board designed for comparison of different methods of accurately extracting the frequency of a sinusoidal input signal. A configurable input stage is routed to one or several of five separate,...

Faults in wiring systems are a serious concern for the aerospace and aeronautic (commercial, military, and civilian) industries. Circuit failures and vehicle accidents have occurred and have been attributed to faulty wiring created by open and/or short circuits. Often, such circuit failures...

Clock compensation for Gigabit Ethernet is necessary because the clock recovered from the 1.25 Gb/s serial data stream has the potential to be 200 ppm slower or faster than the system clock. The serial data is converted to 10-bit parallel data at a 125 MHz rate on a clock recovered from the...

Analog-to-digital converters (ADCs) are used in scientific and communications instruments on all spacecraft. As data rates get higher, and as the transition is made from parallel ADC designs to high-speed, serial, low-voltage differential signaling (LVDS) designs, the need...

A modified process yields lower levels of internal porosity for solder joints produced in reduced-gravity environments. The process incorporates both alternative materials and a modified procedure. The process provides the necessary cleaning action to enable effective...

A 3D networked, dense form of single-walled carbon nanotubes (SWNT) has been made through isotropic shrinking of a gel-like SWNT-water paste by very slow evaporation. Approximately 35 g of Raw HiPco nanotubes were cleaned by the method of soft baking (250 °C for 15 hours...

In response to the Columbia Accident Investigation Board report, a plug repair kit has been developed to enable astronauts to repair the space shuttle’s wing leading edge (WLE) during orbit. The plug repair kit consists of several 17.78-cm-diameter carbon/ silicon carbide (C/SiC) cover plates of...

The purpose of the invention is to covalently attach functionalized carbon nanotubes to silicon. This step allows for the introduction of carbon nanotubes onto all manner of silicon surfaces, and thereby introduction of carbon nanotubes covalently into...

Newly developed magnetic devices are used to create an interface between adjacent mirror segments so that once assembled, aligned, and phased, the multiple segments will behave functionally equivalent to a monolithic aperture mirror. One embodiment might be a kinematic interface that is reversible so...

Transpiration-cooled fasteners are proposed that operate like an open-loop heat pipe (self-tapping screws, bolts, and spikes) for use in on-orbit repair of thermal-insulation of a space shuttle or other spacecraft. By limiting the temperature rise of such a fastener and of the adjacent...

The aperture ion source was conceived to eliminate distortion in measurements of angular distributions of neutral atoms and molecules that require electronimpact ion sources. The approach simplifies the coupling between ion source and spectrometer while providing virtually distortion-free angular distributions and improved...

Generic, object-oriented fault models, built according to causal-directed graph theory, have been integrated into an overall software architecture dedicated to monitoring and predicting the health of mission- critical systems. Processing over the generic fault...