UGM-96 Trident I first launch on 18 January 1977 at Cape Canaveral. The thin antenna-like structure mounted on the nose cone is the aerospike, which is composed of two parts. 1) The Extensible Boom is the long, slender, slightly tapered cylindrical structure; the wider "underside" is mounted to the nose cone. The narrow, top end of the Boom is for mounting:2) "flat, circular, metallic" plates (brownish/yellow color, above). The plates are mounted perpendicular to the Vertical Axis--much like an upturned Martini glass, the container representing the nosecone, with the stem and base representing the Boom and plate, respectively.
A drag-reducing aerospike is a device (see nose cone design) used to reduce the forebody pressure aerodynamic drag of blunt bodies at supersonic speeds. The aerospike creates a detached shock ahead of the body. Between the shock and the forebody a zone of recirculating flow occurs which acts like a more streamlined forebody profile, reducing the drag.
