A communication controller circuit for a wind-tunnel model is undergoing development. The circuit is intended to serve as part of a highly miniaturized, distributed, modular electronic...

GENOA-PFA is a commercial version of the Composite Durability Structural Analysis (CODSTRAN) computer program, which simulates the progression of damage ultimately leading to...

Briefs: Materials
Molecular-Sieve Type 3Å

The term "Molecular-Sieve Type 3Å" denotes a clay-based, zeolite material that revolutionizes a fluid-purification process by removing trace water and iron from nitrogen tetroxide/nitric oxide (MON-3) mixtures used as oxidizer components of spacecraft propellants. Older processes of this type removed only water or iron...

Briefs: Materials
Composite Graphite Anodes Containing Cyclic Ether Additives

Scientists have developed a type of composite graphite anode that will benefit the U.S. space program and private industry by increasing the rechargeability of lithium-ion batteries. Rechargeable lithium-ion batteries, which are used on the space shuttle and Space Station, are also used...

Briefs: Materials
Polypyrrole and Polyaniline Doped With Lignosulfonic Acid

Experiments have shown that electrically conductive polymers with water-soluble fractions can be synthesized by polymerization of pyrrole or aniline in the presence of lignosulfonic acid, which is a polymeric acid that can be derived relatively easily from the spent sulfite liquor...

Briefs: Mechanical & Fluid Systems
Leak-Free Pressurizing Valve

A leak-free valve has been proposed as a more reliable, less expensive, adaptable alternative to a one-time-opening, pyrotechnically actuated valve (pyrovalve). In the original intended application, the pyrovalve...

Pneumatic cushions have been proposed for protecting the afterbodies of two-body instrumented soil-penetrator projectiles. These cushions would be, essentially, doughnut-shaped...

Briefs: Mechanical & Fluid Systems
Ultrasonic Measurement of Bending of Bolts

Work performed at Johnson Space Center has brought about a major improvement in the means for measuring the bending that occurs whenever stress is applied to a bolted joint. This major improvement...

Briefs: Manufacturing & Prototyping
Improvements in Rapid Prototyping

Several improvements have been proposed for the fabrication process known as "rapid prototyping." In this process, a model or prototype of a solid object is built up by controlled ejection of molten polymeric material through programmed orifices to form patterned layers. The second layer is deposited on top of...

An electron-beam ionizer has been designed to deliver ions to the entrance apertures of nine miniature quadrupole mass spectrometers in an array. A similar electron-beam ionizer could also...

A computer-controlled instrumentation system has been developed for use in measuring concentrations of various atomic species in the exhaust gases of a space-shuttle main engine on a...

The figure presents additional information on the optics of the atomic-absorption-spectroscopy (AAS) system described in the preceding article. The optics include (1) a periscopic...

A technique for ultrasonic characterization of plates has been extended to tubes and curved structures in general. In this technique, as explained in more detail below, one performs...

Briefs: Physical Sciences
Detecting Metal Ions by Voltammetry Using Diamond Electrodes

Experiments have demonstrated the feasibility of detecting multiple species of toxic metal ions and other ions of interest dissolved in water, by means of voltammetry with electrically conductive artificial diamond electrodes. Diamond is attractive as an electrode material because it...

A preconditioning technique has been developed for numerical solution of the Helmholtz equation as applied to the steady-state propagation of sound in a semi-infinite,...

A digital processing technique for separating two cochannel frequency-modulation (FM) signals involves a partial algebraic solution that gives the phases of the two signals to within...

Briefs: Materials
Tribological Characterization of Solid Surfaces

Reports labeled as chapters 2, 3, 4, 7, 8, 9, and 10 of a NASA technical memorandum that addresses topics in tribology have been compiled into a document that emphasizes those aspects of the subject matter that pertain to chemical-vapor-deposited (CVD) diamond and diamond-like films. The...

Briefs: Physical Sciences
Small Balloons for Local Aerial Exploration of Mars

A report proposes the use of lightweight balloon-borne instrumentation systems for exploration in the vicinity of a lander on the surface of Mars. Each system would comprise instrumentation with a mass of about 0.2 kg and a balloon with a mass of about 0.8 kg and volume of about 50...

Briefs: Mechanical & Fluid Systems
Using Electromagnetic Drag on Tethers To De-Orbit Spacecraft

Two papers propose the use of electrically conductive tethers to remove spent or dysfunctional spacecraft from orbit around the Earth in order to reduce the hazard of orbital debris. In comparison with onboard rockets, these tethers would be more cost-effective, more reliable, and...

An optoelectronic apparatus and a technique for its operation have been developed to facilitate and accelerate the measurement of distances of the order of tens of feet to within...

A portable, battery-powered camera unit contains a programmable digital camera that is implemented on a single chip utilizing active-pixel-sensor (APS) technology, plus circuitry for...

An improved method of accelerated testing reduces the time needed to analyze the abilities of zinc-rich primers to protect steel substrates against corrosion in a seacoast...

A developmental electro-optical system would enable remote real-time viewing of a scene through a multimode optical fiber, as though the fiber were a conventional image-transmitting optic...

Precise small apertures for a variety of optical applications can be formed in silicon-on-insulator (SOI) wafers by use of a photolithographic process developed specifically for the...

A method of processing phase measurements in an unequal-arm laser Michelson interferometer makes it possible to detect phase effects much smaller than the laser phase noise. In...

The figure depicts several aspects of a unique type of vertical-cavity surface-emitting lasers (VCSELs) that incorporate fiber Fabry-Perot (FFP) optical cavities. These lasers have been...

The size of a holographic data-storage system could be reduced by a proposed design modification that calls for replacement and repositioning of some optical components and the use of...

Monolithic semiconductor photodiodes that discriminate against infrared and visible light and that can be tailored to detect ultraviolet light in selected wavelength bands have been...

Pulse shepherding (defined below) can be exploited to impress synchronized amplitude-modulation pulses, with durations of the order of picoseconds, onto beams of light with...

Videos