Lockheed Martin Corp. [LMT] gave Alliant Techsystems Inc. [ATK] a $90 million contract to provide solid rocket propulsion systems for the three stages of the Navy Trident II D-5 fleet ballistic missile, ATK announced.

Under terms of the annual contract, ATK will continue to supply Trident solid rocket propulsion systems to Lockheed through 2011.

Deployed in 1990, Trident II D-5 is the only U.S. submarine-launched strategic missile system in production today.