Abstract: A coaxial rotor system includes a plurality of upper rotor blades and a plurality of lower rotor blades disposed at a mast assembly. The upper rotor blades rotate about an axis of rotation in a first direction and the lower rotor blades rotate about the axis of rotation in a second direction opposite the first direction. A control system disposed at the mast assembly between the upper and lower rotor blades includes an upper swashplate connected to the upper rotor blades and a lower swashplate connected to the lower rotor blades. The control system adjusts the upper swashplate and the lower swashplate relative to the mast assembly to adjust respective pitches of the upper and lower rotor blades relative to the axis of rotation. The control system is operable to adjust the upper swashplate and the lower swashplate relative to the mast assembly independently of one another.

Abstract: A coaxial rotor system includes a center mast non-rotatably disposed at and extending from a helicopter. A rotation axis extends along the center mast. An inner mast is disposed along the center mast and is rotatable about the rotation axis in a first direction. A portion of the inner mast extends above an end of the center mast. An outer mast circumscribes the center mast and is rotatable about the rotation axis in an opposite second direction. The center mast extends above an end of the outer mast. An upper rotor blade assembly is rotatable with the inner mast. A lower rotor blade assembly is rotatable with the outer mast. A control system disposed at the center mast between the upper and lower rotor blade assemblies is operable to adjust pitch of a plurality of upper rotor blades and to adjust pitch of a plurality of lower rotor blades.

Abstract: Perimeter truss reflector includes a perimeter truss assembly (PTA) comprised of a plurality of battens, each having an length which traverses a PTA thickness as defined along a direction aligned with a reflector central axis. A collapsible mesh reflector surface is secured to the PTA such that when the PTA is in a collapsed configuration, the reflector surface is collapsed for compact stowage and when the PTA is in the expanded configuration, the reflector surface is expanded to a shape that is configured to concentrate RF energy in a predetermined pattern. Each of the one or more longerons extend around at least a portion of a periphery of the PTA. These longerons each comprise a storable extendible member (SEM) which can be flattened and rolled around a spool, but exhibits beam-like structural characteristics when unspooled.