Trident II
ATK manufactures solid propulsion boost motor systems for all three stages of the Trident II (D5) missile under a contract from prime contractor Lockheed Martin Space Systems Company. ATK has a long history of producing solid propulsion systems for submarine-launched missiles, beginning with the Polaris missile in the 1950s.

The Trident II (D5) is a three-stage, solid propellant, inertial guided missile system that is the primary strategic weapons program in the U.S. Navy's Fleet Ballistic Missile system.

With a nominal range of 4,000 nautical miles, the D5 missile is launched under water from the Ohio class of nuclear-powered Trident submarines, each of which has 24 launch tubes. The Trident II D5 Missile was deployed in 1990 and is designed to be the primary U.S. strategic deterrent well into the 21st century.