Lockheed Martin Corp., King of Prussia, Pennsylvania, has been awarded a $9,980,000 definitized modification (P00052) to previously awarded contract FA8219-20-C-0001 for Mark21A Reentry Vehicle (Mk21A) technology maturation and risk reduction research and development for reentry vehicles. The total cumulative face value of the contract is $268,095,741. Work will be performed in King of Prussia, Pennsylvania, and is expected to be completed Oct. 21, 2023. Fiscal 2022 and 2023 research, development, test, and evaluation funds in the amount of $9,750,000 are being obligated at the time of award. The Air Force Nuclear Weapons Center, Hill Air Force Base, Utah is the contracting activity.