An instrument that noninvasively measures alternating current over a broad frequency band (typically from about 0.3 to about 110 MHz) has been invented. This instrument could be especially useful for assessing radio-frequency hazards by measuring currents in various parts of humans or personnel...

A photodetector circuit has been built for use in the receiver portion of a continuous-wave infrared Doppler lidar system for atmospheric research. As in nearly all Doppler lidar systems, the detection of the return signal in this system involves heterodyning, in a photodetector, with a...

"ACE" (for "advanced ceramic engineered") denotes a type of coating mate-rial that increases the ability of flexible thermal-insulation blankets to resist erosion. Developed for use on the insulating blankets on the space shuttle orbiters, these coating materials could also be used on similar...

A prototype dual-polarization microstrip patch rectenna dimensioned for an operating frequency of 8.51 GHz has been built to demonstrate a design concept for obtaining maximum output voltage from a rectenna of a given size. This rectenna contains nine square microstrip patch antenna elements in a...

A low-power, miniature Doppler lidar instrument is being developed for use in measuring opacity (from dust) and wind profiles in the Martian atmosphere. The instrument could also be used on Earth to measure turbulence in the atmospheric boundary layer, for assessments of urban and regional air...

Improved passive temperature-compensating attenuators have been developed for use in processing radio signals at frequencies up to about 18 GHz. In general, temperature-compensating circuits and devices are needed to minimize (preferably, to eliminate) undesired temperature dependences of the...

Lightweight, inflatable tubular structural components containing tape-spring reinforcements are undergoing development. The basic (without tape-spring reinforcement) tubular components are made, variously, of aluminum laminates or composite materials and are under consideration for use in...

A report describes direct numerical simulations of a droplet-laden mixing layer (e.g., evaporating droplets of a hydrocarbon fuel in air) undergoing a transition to mixing turbulence. The governing equations are those of Lagrangian transport of discrete droplets through a flowing gas, which...

Marshall Aerospace Vehicle Representation in C (MAVERIC) is a C-language computer program developed for use in performing high-fidelity simulations of flights and analyses of the guidance and control performances of the X-33 aerospace vehicle and the VentureStar reusable launch vehicle...

The Johnson Space Center (JSC) body-fluids monitor advances the state of the art of measuring hydration levels in humans during spaceflight. Neither bulky nor heavy, this noninvasive instrument is built around a commercial inductance-capacitance-resistance meter, which is used to obtain...

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 less...

A report describes wind-tunnel experiments on a rectangular supercritical wing and presents test cases that have been selected from the archived sets of experimental data for comparison with computational fluid dynamics (CFD) predictions. In the experiments, the wing was driven in...

Accelerations of one airplane encountering a vortex or pair of vortices in the wake of another airplane were computed in a parametric study. The approach taken in the study was to systematically investigate the effects of progressively more nearly complete descriptions of the interaction of...

Version 1.4 of the Launch Vehicle Loads Analysis for Preliminary Design (VLOADS 1.4) computer program calculates in-flight launch-vehicle structural loads (that is, spacecraft-launching rockets) for preliminary design. The program can also be used to calculate structural loads in upper stages and...