The U.S. Department of Defense awarded 19 contracts on Wednesday, worth $3.3 billion in aggregate. The biggest of these awards went to American defense contracting giant Boeing, which will build a new flight of P-8A Poseidon sub-hunting aircraft for the Navy. But the second-biggest contract went to Britain's BAE Systems (BAES.Y -2.50%).

BAE won a $534.9 million fixed-price-level-of-effort, firm-fixed-price and cost-type-CLINs (contract line-item number) contract to provide system engineering/technical assistance support, training, and development support for the U.S. Air Force Nuclear Weapons Center's Minuteman III nuclear weapon system. BAE will work on this project through July 2021.

Built by Boeing, the LGM-30 Minuteman III is currently the only land-based intercontinental ballistic missile system in service in the United States. Supplementing submarine-launched missiles and strategic bombers, it constitutes one-third of the U.S. nuclear triad. Each Minuteman III is equipped with three independently targeting "MIRV" nuclear warheads, and with 450 Minutemen still operational, that's 1,350 warheads in total.