Magazine

A digital phase meter has been designed to satisfy stringent requirements for measuring differences between phases of radiofrequency (RF) subcarrier signals modulated onto laser beams involved in the operation of a planned space-borne gravitational- wave-detecting heterodyne laser...

Use of multiple-antenna radar systems aboard moving high-altitude platforms has been proposed for measuring rainfall. The platforms contemplated in the proposal would be primarily spacecraft, but, in principle, the proposal could also apply to aircraft. The problem of measuring rainfall...

A document discusses the physical and engineering principles affecting the design of the Smart Data Node in the Sky (SDNITS) — a proposed Earthorbiting satellite for relaying scientific data from other Earth-orbiting satellites to one or more ground station(s). The basic concept of the SDNITS is similar to that of...

A paper describes algorithms for guidance and control (G&C) of a spacecraft maneuvering near a planet, moon, asteroid, comet, or other small astronomical body. The algorithms were developed following a model- predictive-control approach along with a convexification of the governing...

A document presents further information on the subject matter of “Controlling Herds of Cooperative Robots” (NPO-40723), NASA Tech Briefs, Vol. 30, No. 4 (April 2006), page 81. To recapitulate: A methodology for controlling a herd of cooperative and autonomous mobile robots exploring the surface...

A report discusses the development of a computational model of a Mars Explorer Rover maneuvering across terrain under varying conditions. The model is used to increase understanding of the rover dynamics. Increased understanding is helpful in planning further tests and in extending the...

Surfer is an extensible framework for selecting and ranking grid resources. A resource is defined as anything that needs selecting such as compute resources, storage resources, and data resources. The user specifies the set of resource types desired, the constraints that must hold over all the resources, and the...

InvestigationOrganizer (IO) is a Webbased collaborative information system that integrates the generic functionality of a database, a document repository, a semantic hypermedia browser, and a rulebased inference system with specialized modeling and visualization functionality to support accident/mishap...

A recently invented method of detecting a selected messenger ribonucleic acid (mRNA) or deoxyribonucleic acid (DNA) sequence offers two important advantages over prior such methods: it is simpler and can be implemented by means of compact equipment. The simplification and miniaturization...

A process for manufacturing bulk diamond has been made practical by the invention of the High Pressure and Temperature Apparatus capable of applying the combination of very high temperature and high pressure needed to melt carbon in a sufficiently large volume. The rate of growth achievable in this...

A control architecture and algorithms to implement the architecture have been conceived to enable a robot to learn from its experiences and to combine knowledge gained from prior experiences in such a way as to be able to solve new problems. The architecture is an abstraction of an...

The Hypothetical Scenario Generator for Fault-tolerant Diagnostics (HSG) is an algorithm being developed in conjunction with other components of artificial- intelligence systems for automated diagnosis and prognosis of faults in spacecraft, aircraft, and other complex engineering systems....

A technology is sought that will enable delivery of active cleaning compositions triggered at a specific time/place by a large range of conditions. The solution must be environmentally safe, must function at a pH range between seven and 11 and temperatures between 5 and 80°C, be compatible for use...