The surface interferometric skin-friction (SISF) measurement system is an instrument for determining the distribution of surface shear stress (skin friction) on a wind-tunnel model. The SISF system utilizes the established oil-film interference method, along with advanced image-data-processing...

A laboratory method has been conceived to enable the enumeration of: Cultivable bacteria and bacterial spores that are, variously, airborne by themselves or carried by, parts of, or otherwise associated with, other airborne particles; and Spore-forming bacteria among all of the...

A proposed approach to control of noise and chaos in dynamic systems would supplement conventional methods. The approach is based on fictitious forces composed of expectations governed by Fokker-Planck or Liouville equations that describe the evolution of the probability densities of the controlled...

A report proposes the development of a system to collect volatile elements and compounds from Lunar soil for use in supporting habitation and processing into rocket fuel. Prior exploratory missions revealed that H2, He, and N2 are present in Lunar soil and there are some indications that water ice may...

A report proposes to use electrostriction to manipulate the ullage in a tank containing a dielectric liquid in a microgravitational environment. In the original intended application, the liquid would be a spacecraft propellant and the goal would be to force the ullage (comprising bubbles...

A document presents equations for scoring rules in a diagnostic and/or prognostic artificial-intelligence software system of the rule-based inference- engine type. The equations define a set of metrics that characterize the evaluation of a rule when data required for the antecedence clause(s) of the...

A document describes the proposed addition of a radar function to the Autonomous Formation Flying Sensor, making possible coarse relative-position control to prevent collisions in the event of failure of one of the spacecraft. According to the proposal, in addition to tracking GPS-like...

The figure shows a compact, rugged, simple sensor head that is part of an instrumentation system for making measurements to characterize the severity of aircraft-icing conditions and/or to perform research on cloud physics. The quantities that are calculated from measurement data...

Electrolytes comprising, variously, LiPF6 or LiPF6 plus LiBF4 dissolved at various concentrations in mixtures of alkyl carbonates and alkyl esters have been found to afford improved low-temperature performance in rechargeable lithium-ion electrochemical cells. These and other...

A miniature electrostatic ion thruster is proposed that, with one exception, would be based on the same principles as those of the device described in the previous article, “Miniature Bipolar Electrostatic Ion Thruster” (NPO-21057). The exceptional feature of this thruster would be that, in...

A miniature electrostatic ion thruster is proposed for maneuvering small spacecraft. In a thruster based on this concept, one or more propellant gases would be introduced into an ionizer based on the same principles as those of the device described in the earlier article, “Miniature Bipolar...

The GigaTrack™ family of 2-GS/s track-and-hold amplifiers (THA) from Inphi® Corp. (Westlake Village, CA) delivers ultra-wide 18-GHz analog bandwidth. The bandwidth, sample rate, and linearity make direct conversion and software-defined receivers possible, and help advance highsample-...