National Aerospace Solutions LLC, Arnold Air Force Base, Tennessee, has been awarded a $189,141,873 cost-plus-award-fee modification (P00174) to previously awarded contract FA9101-15-C-0500 for test operations and sustainment. This modification adds Option Year Six for test operations, technology development, equipment and facility sustainment, capital improvements and some support services for the Arnold Engineering Development Complex. Work will be performed at Arnold Air Force Base, Tennessee, and is expected to be completed by June 30, 2023. No funds are being obligated at the time of award. The total cumulative face value of the contract is $1,830,653,475.  The Air Force Test Center, Arnold Air Force Base, Tennessee, is the contracting activity.