The White Sands Missile Range Museum’s Missile Park

MK 42/45 Gun Mount for 5-Inch Ship-Launched Guided Projectile

The 5-inch guided projectile is a gun-launched, rocket sustained, fin stabilized, terminally guided projectile designed to be fired from suitably modified MK 42 Mod 9 & 10 and MK 45 Mod 0 naval gun mounts. The 5-inch guided projectile has a high degree of terminal accuracy. The semi-active laser guided projectile engages moving and stationary surface and shore targets and has the capability of both direct and indirect fire.

The projectile design is modular, consisting of the rocket motor, fuse, warhead, and guidance and control subsystems. The rocket motor provides 400 pounds of thrust with a 12 second duration. The fuse provides the capability to select either a point detonation or height of burst detonation. The warhead includes both blast/fragmentation and shaped charge mechanisms to provide lethality against a variety of targets. A gyro-stabilized semi-active laser seeker homes in on an illuminated target. The control section deflects the canards in response to guidance commands.

For a surface mission, the acquisition aim point of the projectile is designated either by a remote observer or by the fire control computer on the ship, using target range and velocity inputs available from the fire control radar or the electro-optical target tracking system. After launch, the projectile flies ballistically to the acquisition basket, where the preset timer initiates the guidance activation and target acquisition cycle for execution of the proper command and control. Communication procedures ensure that the laser is designating the target a few seconds prior to initiation of the guidance section’s target acquisition cycle. After acquisition, the canards are deployed and the seeker initiates tracking, which guides the projectile until target impact.