The Boeing Co., El Segundo, California, has been awarded a $22,772,840 modification (P00028) to contract FA8819-15-C-0007, to exercise Option Four for Space Based Space Surveillance Block 10 sustainment. This modification provides for the exercise of an option for the sustainment and required development necessary for Air Force operations and maintenance of the Space Based Space Surveillance system and Red Local Area Network. This effort includes systems engineering, operations, operations support, and contractor logistics support. Work will be performed in El Segundo, California; and Colorado Springs, Colorado, and is expected to be completed by June 20, 2022. This award is the result of a sole-source acquisition. Fiscal 2019 operations and maintenance funds in the amount of $14,943,930 are being obligated at the time of award. Space Superiority Systems Directorate, Space and Missile Systems Center, Los Angeles Air Force Base, California, is the contracting activity.