RIM-116 Rolling Airframe Missile

The RIM-116 Rolling Airframe Missile (RAM) is a small, lightweight, infrared homing surface-to-air missile in use by the German, Japanese, Greek, Turkish, South Korean, Saudi Arabian, Egyptian, Mexican, UAE, and United States navies. It was originally intended and used primarily as a point-defense weapon against anti-ship missiles. As its name indicates, the RAM rolls as it flies. The missile's radio-frequency tracking system uses a two-antenna interferometer that can measure phase interference of electromagnetic waves in one plane only; constant rolling allows the missile to scan in all directions. The rolling means only one pair of steering canards is required. As of 2005, it is the only U.S. Navy missile to operate in this manner.

The Rolling Airframe Missiles, together with the Mark 49 Guided Missile Launching System (GMLS) and support equipment, make up the RAM Mk 31 Guided Missile Weapon System (GMWS). The Mk-144 Guided Missile Launcher (GML) unit weighs 5,777 kilograms (12,736 lb) and stores 21 missiles. The original weapon cannot employ its own sensors prior to firing, so it must be integrated with a ship's combat system, which directs the launcher at targets. On U.S. ships, it is integrated with the AN/SWY-2 Ship Defense Surface Missile System (SDSMS) and Ship Self-Defense System (SSDS) Mk 1 or Mk 2-based combat systems.