The Navy on Thursday evening awarded contracts to Lockheed Martin [LMT] and Austal for construction of the 25th and 26th Littoral Combat Ships (LCS).The awards modify the each shipbuilder's’ existing 10-ship block buy contract to add an 11th ship, including basic seaframe construction, selected ship systems integration and test, and selected ship systems equipment. Both vessels are not to exceed the $564 million congressional cost cap, according to the contracting notice, which does not specify how much money will be…