Abstract: A Submarine Horizontal Launch TACTOM Capsule (SHLTC) provides the capability for launching a Tactical Tomahawk (TACTOM) cruise missile from a horizontal torpedo tube on a submarine. The SHLTC completely encapsulates the TACTOM missile in the torpedo tube and is ejected from the torpedo tube with the TACTOM missile during launch. The SHLTC contains the TACTOM missile in a closure assembly to protect the TACTOM missile from damage. Following safe exit from the submarine, thrust from the rocket motor allows the TACTOM missile to break through a forward tearing shell of the SHLTC. The TACTOM missile and SHLTC completely de-couple and the SHLTC safely sinks away from the submarine and missile. The TACTOM missile continues up to broach the surface and transition to cruise mode.