Special Coverage

NASA Supercomputer Simulations Reveal 'Noisy' Aerodynamics
Robotic Gripper Cleans Up Space Debris
Soft Robot “Walks” on Any Terrain
Defense Advanced Research Projects Agency
Using Microwaves to Produce High-Quality Graphene
Transducer-Actuator Systems for On-Machine Measurements and Automatic Part Alignment
Wide-Area Surveillance Using HD LWIR Uncooled Sensors
Heavy Lift Wing in Ground (WIG) Cargo Flying Boat
Technique Provides Security for Multi-Robot Systems
Bringing New Vision to Laser Material Processing Systems
NASA Tests Lasers’ Ability to Transmit Data from Space

Direct Methanol Fuel Cells With Aerosol Feed

Direct methanol fuel cells that would function with aerosol feed (instead of all-gas or all-liquid feed) have been proposed. As explained below, aerosol feed would afford the advantages of liquid feed, while reducing or eliminating some of the disadvantageous effects of liquid feed.

Posted in: Briefs, TSP, Physical Sciences, Fuel cells, Methanol

Maximum-Likelihood Scheme for Tracking an Optical Source

A fine-pointing scheme that involves correlation of images and maximum-likelihood estimation has been proposed to enable tracking of optical sources. This scheme is intended for implementation in the pointing-control system of an imaging instrument (e.g., a telescope equipped with an image detector) to provide a capability for highly stable and accurate pointing to a specific area within a moving target, even under conditions that ordinarily give rise to pointing jitters. Such conditions include motion of the target relative to the instrument, instability of the platform that supports the instrument-aiming mechanism, and turbulence in the atmosphere or other optical medium. In the original intended application, the scheme would be implemented in a ground station for tracking a laser that would be part of an optical communication aboard a distant spacecraft. Other potential applications include stabilization of images for video cameras and precise pointing of lasers in military, industrial, and surgical settings. This scheme is expected to make it possible to achieve subpixel resolution in a high-disturbance environment.

Posted in: Briefs, TSP, Information Sciences, Calibration, Mathematical models, Optics, Optics, Vibration, Vibration, Reliability, Reliability

Quantum Superluminal Transmission of Random Messages

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 circumstances in which deception and secrecy are of more importance than are the specific contents of the messages.

Posted in: Briefs, TSP, Information Sciences, Communication protocols, Cryptography, Wireless communication systems, Communication protocols, Cryptography, Wireless communication systems

Goal-Based Fault Tolerance for Spacecraft Systems

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 fault tolerance, unlike in prior approaches to fault tolerance, it is not assumed that faults that necessitate deviations from prescribed sequences of commands will occur infrequently; instead, it is assumed that unpredictable conditions, including faults, can arise at any time, and fault tolerance is incorporated as an intrinsic feature of every aspect of system design in a unified approach to ensuring robust system behavior.

Posted in: Briefs, TSP, Information Sciences, Failure modes and effects analysis, Architecture, Computer software / hardware, Computer software and hardware, Architecture, Computer software / hardware, Computer software and hardware, Spacecraft

PWM and Synchronous Rectifier Controller ASICs

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 (PWM) controller for the circuitry on the primary side of a transformer in the module; the other ASIC is mainly a synchronous rectifier controller (SRC) for the circuitry on the secondary side of the transformer.

Posted in: Briefs, TSP, Electronics & Computers, Architecture, Integrated circuits, Architecture, Integrated circuits, Electric power, Spacecraft

DNS of a Supercritical H₂/O₂ Mixing Layer

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 conductivity), are complemented, at high pressure, by a thermal-diffusion factor.

Posted in: Briefs, TSP, Physical Sciences, Computational fluid dynamics, Mathematical models, Hydrogen fuel, Thermodynamics, Thermodynamics, Oxygen

Remote Agent as Applied to the Deep Space 1 Spacecraft

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 enable spacecraft to operate robustly with minimal human supervision, even in the face of hardware failures or unexpected events. It also is expected to offer similar benefits for communication networks, chemical plants, and other complex systems on Earth.

Posted in: Briefs, TSP, Information Sciences, Artificial intelligence, Computer software / hardware, Computer software and hardware, Artificial intelligence, Computer software / hardware, Computer software and hardware, Spacecraft

Pneumatic Accelerator for Launching a Spacecraft

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 precisely, a concrete tunnel lined with stainless-steel sheet) below the track. The connection between the sled and the piston would be made via a coupling plate that would slide along a slot on top of the tube. The slot would seal after passage of the coupling plate. As described thus far, the apparatus could be characterized as a modern, high-acceleration, high-speed version of pneumatic drives with slot connections to rail cars that were used in Europe during the 1840s.

Posted in: Briefs, TSP, Mechanical Components, Mechanics, Ground support, Pneumatic systems, Launch vehicles, Spacecraft, Vehicle acceleration

Hand-Held Optoelectronic Particulate Monitors

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, laboratory-bench-style particulate monitors, these instruments are based on diffraction of light by particles. However, these instruments are much smaller; exploiting recent advances in optics, electronics, and packaging, they are miniaturized into compact, hand-held units.

Posted in: ptb catchall, Tech Briefs, Briefs, TSP, Photonics, Physical Sciences, Downsizing, Measurements, Microscopy, Optics, Microscopy, Optics, Particulate matter (PM)

High-Performance Processor of Hyperspectral Images

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 terrain, and the purpose of collecting and analyzing the image data is to estimate the spatially varying abundances of materials of interest. Remote-sensing applications in which the RSHE could prove beneficial include assessment of crops, exploration for minerals, identification of military targets, urban-planning studies, environmental assessment, and large-area search-and- rescue operations.

Posted in: Tech Briefs, Briefs, Photonics, Computer software / hardware, Computer software and hardware, Imaging, Imaging and visualization, Remote sensing, Computer software / hardware, Computer software and hardware, Imaging, Imaging and visualization, Remote sensing, Data management

The U.S. Government does not endorse any commercial product, process, or activity identified on this web site.