Magazine

An advanced signal processor has been developed to enable high-resolution measurement of the frequency and phase shifts of noisy laser Doppler velocimeter (LDV) and phase Doppler particle analyzer (PDPA) signals. The purpose of the measurements is to exploit the phase Doppler principle to...

Epoxies and/or cyanate esters that incorporate polyhedral oligomeric silsesquioxane (POSS) compounds are undergoing development at Air Force Research Laboratory (AFRL). These formulations are expected to be useful as high-performance matrix resins for advanced, lightweight fiber/matrix composite...

David Spencer (MIT) developed semi-solid material processing through an accidental observation he made while dealing with the processing of metals in their mushy state. The semi-solid material process basically consists of two stages: pre-processing and processing. During pre-processing, the...

"Modular cryogenic insulation" denotes a chaff for installation in the partially evacuated annular spaces between the inner and outer walls of tanks used to store and transport liquid nitrogen and other cryogenic liquids. The insulating chaff was developed to replace low-density powders (e.g., perlite, silica aerogel,...

A computer program predicts the noise and ignition over pressure in the vicinity of a rocket during launch. The program has been developed to complement the vibroacoustic-prediction effort for rockets now in use and to provide the capability for prediction of vibroacoustic loads associated with...

A mechanical device has been developed for applying an adhesive patch, from the outside, to the wall of a spacecraft module that has lost pressure because of penetration by a meteoroid or a piece of orbital debris. This device will make it possible to seal and re-pressurize the affected module during space...

Real Time Schedule Publisher (RTSP) is a computer program that generates a report of the current schedules of as many as about 25 users within an organization. The report is refreshed every 5 minutes and displayed in a common area on a flat-panel computer monitor that serves as an...

A report proposes an apparatus that would extract water from the atmosphere of Mars and would consume little energy in doing so. The apparatus would include a set of copper plates surrounded by a thermal shield with slots through which atmospheric gas could circulate. At night, the slots...

A paper reviews theoretical and experimental research on the behaviors of supercritical fluids and, for comparison, subcritical fluids. Experiments with drops, isolated or in groups, streams, shear layers, mixing layers, jets, and sprays are tabulated and discussed as a precursor to...

A wastewater-recycling system contains biological and physicochemical water-treatment units. The system is suitable for use in environments in which clean water supplies are limited. Waste streams containing urine and washwater are purified into potable water with a recovery rate of 99 percent. The...

A report presents a computational study of a proposed plasma thruster for a spacecraft. The behavior of the plasma was computationally simulated by use of a mathematical model of magnetohydrodynamic flow implemented in the previously developed MACH2 computer program. To increase the...

A report proposes a liquid/vapor-hydrazine thruster for use in controlling the attitude of a small spacecraft. From the upstream to the downstream end, the thruster would include a tank containing liquid hydrazine, a fast liquid valve, a heated prevaporizing plenum, a fast gas...

A report proposes a small spacecraft attitude-control thruster in which the propellant material would be hydrazine that would be stored frozen until sublimed at the instant of use. From the upstream to the downstream end, the main components of the thruster would include a plug of solid...

Experiments have demonstrated the feasibility of making mirror structures that comprise a thin face plate of chemical-vapor-deposited (CVD) pyrolytic graphite (PG) integrated with a thicker backing plate of CVD PG open-cell foam. The backing plate serves as a stiff structural support for the face plate,...