General Dynamics awarded $51.7M for maintenance work on USS Mississippi General Dynamics Electric Boat has been awarded a $51.7M million contract modification by the U.S. Navy to plan and perform the post-shakedown availability, or PSA, on the nuclear submarine USS Mississippi; SSN-782. Electric Boat is a wholly owned subsidiary of General Dynamics. The PSA includes maintenance, repairs, alterations and testing. It will be performed at Electric Boat's Groton shipyard. Up to 400 employees will be engaged in the work, which is scheduled for completion by December. Initially awarded in April 2012, the contract has a total potential value of $67M.