Trident

The ATK “rocket garden” near promontory, Utah, has a Trident C-4 sea launched ballistic missile on display. Projecting from the blunt nose of the missile is an “aerospike.” This is not an aerospike rocket engine (such as the X-33 was supposed to have), but instead a telescoping rod with a smallish flat plate. Stored within the nosecone, it would project forward shortly after launch. The plate – made of wood, of all things – would take the aerothermal heating load of hypersonic flight at relatively low altitude, and would set up a shockwave well ahead of the nosecone, reducing drag. The Trident has a blunt nose for packing purposes… a pointy nose simply wouldn’t fit within the limited missile tube length of a submarine. The aerospike lets it have more or less the aerodynamics of a pointy nose while being shorter.