The Navy gave Lockheed Martin Corp. [LMT] a $135 million contract modification for continued work on the Trident II D5 life extension program.

That award is in addition to the $654.9 million contract awarded to Lockheed earlier this year for production and deployed systems support for the Trident II D5 Fleet Ballistic Missile program in the current fiscal year 2007 ending Sept. 30.

The D5 life extension program will ensure a sufficient inventory of missiles to support the service life of Trident II Ohio-class submarines, which has been extended to 2042.

Lengthening the operational deployment of the Trident II D5 weapons system by an anticipated 14 years, the program will maintain a full force of operational missiles on the submarines and allow for disarmed missiles to be expended in routine test launches, providing continued assurance of safety, reliability, readiness and performance. Deliveries under the original D5 contract, which called for production of 425 missiles, began in 1989, and the final two missiles are scheduled for delivery this year. D5 life extension missile deliveries are scheduled to begin in 2011, with up to 108 additional missiles being delivered by 2017.