In a proposed communication scheme, quantum entanglement and quantum nonlocality would be utilized to effect instantaneous transmission of randomly chosen messages to remote locations. Although the messages would not convey any information, they might nevertheless be of some value under...

A report discusses the concept of goal-based fault tolerance as implemented in NASA’s Mission Data System (MDS), which is a developmental architecture for unified flight, test, and ground software that is intended to be adaptable to a variety of next-generation deep-space missions. In goal-based...

A report describes two radiation-hard application-specific integrated circuits (ASICs) that constitute a mixed-signal chip set that performs all the control functions for a power-converter module (PCM) in a spacecraft power-supply system. One of these ASICs serves mainly as a pulse-width modulation...

This report discusses direct numerical simulations (DNS) of a mixing layer between supercritical flows of oxygen and hydrogen. The governing conservation equations were those of fluctuation- dissipation (FD) theory, in which low-pressure typical transport properties (viscosity, diffusivity and thermal...

A report presents updated information about the Remote Agent — a reusable artificial-intelligence software system that was described in “A Remote Agent Prototype for Spacecraft Autonomy” (NPO-19992), NASA Tech Briefs, Vol. 21, No. 3 (March 1997), page 106. This system was conceived to...

A computer program coordinates operations of multiple cooperating rovers (small exploratory robotic vehicles deployed from a lander spacecraft), each of which is equipped with computer hardware and software that schedule the tasks assigned to it. The program implements a contract net protocol...

A report proposes the development of a ground-based launch-assist apparatus that would accelerate a spacecraft to a speed of about 270 m/s. The apparatus would include a track along which the spacecraft would ride on a sled coupled to a large piston driven by compressed air along a tube (more...

Optoelectronic instruments are being developed for use in measuring the concentrations and sizes of microscopic particles suspended in air. The instruments could be used, for example, to detect smoke, explosive dust in grain elevators, or toxic dusts in industrial buildings. Like some older,...

The Remote Sensing Hyperspectral Engine (RSHE) is a special-purpose, portable computer that performs high-performance processing of hyperspectral image data collected by a remote-sensing optoelectronic apparatus. Typically, the remote-sensing apparatus is airborne or spaceborne, the images are of...

An assembly of lifting equipment has been devised to enable the safe removal of water filters used in electrical-discharge machining (EDM). As explained below, this equipment prevents injuries of a type formerly associated with changing the filters.

Infrared gas sensors that could be mass-produced at relatively low cost have been proposed for a variety of applications — for example, detecting carbon monoxide in air inside houses. A sensor of this type would include a housing into which ambient air could diffuse. The gas of...

A report describes a method of simultaneously measuring steady-state axial and tangential turbomachine-blade deflections by use of fiber-optic probes and probe actuators designed specifically for this purpose. Each fiber-optic probe illuminates a small spot and, by measuring a change in...

An apparatus has been devised to enable accurate, reproducible angular positioning of an ultrasonic probe used to diagnose the carotid artery. More specifically, the apparatus is intended for use in a clinical setting in which the intima-media thickness (IMT) of the carotid artery is measured by use of...

A report describes uniaxial-stress-versus-strain experiments that were performed on polycrystalline Tb76Dy24 alloy specimens. [Also see "Magnetoelastic Vibration Dampers" (NPO-20988) on page 56 of this issue.] The proposal is to use Tb-Dy alloys as vibration-damping materials at temperatures -100 K,...

Grid-Based Estimation of Surface Traversability Applied to Local Terrain (GESTALT) is a software library that helps a robotic wheeled vehicle choose a safe path across nearby terrain. The input to GESTALT consists mainly of three-dimensional range measurements of the nearby terrain taken by sensors...

Advanced control systems that include built-in smart-material elastic-deformation structural actuators have been proposed for deployable thin-shell structures that are required to be maintained in precise shapes once deployed. This approach to structural shape control was conceived to enable...