Magazine

A software library has been developed that takes a highlevel description of a pattern to be satisfied and applies it to a target. If the two match, it returns success; otherwise, it indicates a failure. The target is semantically a tree that is constructed from elements of terminal and non-terminal...

This software addresses the problem of how to efficiently execute a knowledge base in the presence of missing data. Computationally, this is an exponentially expensive operation that without heuristics generates a search space of 1 + 2n possible scenarios, where n is the number of rules...

A computer program translates Unified Modeling Language (UML) representations of state charts into source code in the C, C++, and Python computing languages. ("State charts" signifies graphical descriptions of states and state transitions of a spacecraft or other complex system.) The UML representations constituting the input...

The Pointing History Engine (PHE) is a computer program that provides mathematical transformations needed to reconstruct, from downlinked telemetry data, the attitude of the Spitzer Space Telescope (formerly known as the Space Infrared Telescope Facility) as a function of time. The PHE also...

A universal-joint assembly has been devised for transferring axial tension or compression to a load cell. To maximize measurement accuracy, the assembly is required to minimize any moments and non-axial forces on the load cell and to exhibit little or no hysteresis. The requirement to...

Software has been developed for an improved method of correcting for the atmospheric optical effects (primarily, effects of aerosols and water vapor) in spectral images of the surface of the Earth acquired by airborne and spaceborne remote-sensing instruments. In this method, the variables...

A fixture has been devised for making the plumbing connections between a microfluidic device in a replaceable cartridge and an external fluidic system. The fixture includes a 0.25-in. (6.35-mm) thick steel plate, to which the cartridge is fastened by two 10-32 thumb screws. The plate holds one plumbing...

A mounting mechanism was designed and built to satisfy requirements specific to a developmental head-up display (HUD) to be used by pilots in a Boeing 757 airplane. This development was necessitated by the fact that although such mounting mechanisms were commercially available for other airplanes, there were none...

A description of the functions and data structures is defined that would be necessary to implement the Chapel concept of distributions, domains, allocation, access, and interfaces to the compiler for transformations from Chapel source to their run-time implementation for these concepts. A...

Researchers at JPL and Arizona State University conducted a comparative study of three candidate algorithms for estimating components of the Martian atmosphere, using raw (uncalibrated) data collected by the Thermal Emission Imaging System (THEMIS). THEMIS is an...

A paper [Chem. Phys. Lett. 345, 295 (2001)] describes theoretical studies of excited electronic states of nitrogen molecules, with a view toward utilizing those states in synthesizing tetrahedral N4, or Td N4 — a metastable substance under consideration as a high-energy-density rocket...

A document presents a summary of an onboard estimation algorithm now being used to calibrate the alignment of the Spitzer Space Telescope (formerly known as the Space Infrared Telescope Facility). The algorithm, denoted the S2P calibration filter, recursively generates estimates of the...

A document discusses concepts for the design of an antenna to be deployed from a spacecraft for measuring the ambient electric field associated with plasma waves at a location within 3 solar radii from the solar photosphere. The antenna must be long enough to extend beyond the...

A report describes an improved high-voltage isolator for preventing electrical discharge along the flow path of a propellant gas being fed from a supply at a spacecraft chassis electrical potential to an ion thruster at a potential as high as multiple kilovolts. The isolator must survive launch...

A paper discusses the continuing work of the Mobile Exploration System Project, which has been performing studies toward the design of hybrid communication networks for future exploratory missions to remote planets. A typical network could include stationary radio transceivers on a...

A way is sought to allow consumers to connect and disconnect two rubber-impregnated cloth surfaces in a consistent manner that is easy to assemble and disassemble. The cloth surfaces are in close proximity; the length of the connection will be about two meters. The connection must exhibit longterm...

A company is looking for environmentally inert methods to change the moisture management properties of conventional apparel textiles. The moisture management effect changes the way in which water vapor, moisture, and other liquids move through textiles, and can be activated via pH, temperature,...

The Board Design Test Vehicle is a method for objective evaluation and qualification of supplier capabilities for the fabrication of multilayer printed circuit boards. It is used to analyze and assess technical capability and reliability of products that are provided by a supplier, and provides a mechanism for supplier...

The clay film “Claist,” which comprises a natural or synthetic clay as a main component, exhibits uniform orientation of clay particle laminates. It is flexible, has a mechanical strength sufficient for use as a self-standing film, and has a structure in which laminates of clay particles are highly oriented. The...