A report describes a study of nominal-performance (H2), robust-performance (μ-synthesis), and mixed H2/μ methods for designing fixed-order controllers applied to an active-tendon control system for suppressing seismic vibrations in a structure. The study involves an application of...

A proposed charge-coupled-device (CCD) camera would be mechanically shuttered by a planar array of micromachined, electromechanically actuated shutters. This proposal has arisen as part of the solution to the problem of designing a visible/near-infrared imaging spectrometer using a commercial...

Innovative designs of mufflers for engines of small airplanes have been investigated in an effort to satisfy conflicting demands to maximize the reduction of exhaust noise while minimizing back pressure, size, and weight. Automotive-type muffler designs are not suitable for this purpose because they entail...

A brief report presents drawings for the conceptual design of a spacecraft that would land on Mars or another remote planet. The spacecraft would have a tetrahedral shape, would include airbags to cushion impact, and would have a self-righting capability. The drawings show the general appearance of the spacecraft and show the outlines...

A proposed lightweight, off-axis reflector structure for a microwave communication antenna would be made of a carbon/carbon composite material. The structure was conceived for use aboard the Solar Probe spacecraft, where it would also serve as a shield to protect the spacecraft against solar radiation at...

Designing metal-matrix composites into actual components requires both experimental and analytical characterization of the behavior of these composites. This report describes mathematical modeling and experimental characterization of the elastoplastic behaviors of composite materials made...