The Applied Research Laboratory, The Pennsylvania State University (ARL/PSU), University Park, Pennsylvania, is awarded a $734,972,174 cost-plus-fixed-fee modification to previously awarded contract N00024-18-D-6401 to exercise an option for research, development, engineering, and test and evaluation in support of programs throughout the Department of Defense (DOD) within its core competency areas including: (1) Guidance, navigation and control of undersea systems; (2) Advanced thermal propulsion concepts and systems for undersea vehicles; (3) Advanced propulsors and other fluid machinery for marine systems; (4) Materials technology and manufacturing technology to meet the unique requirements of Naval systems and components; (5) Atmosphere and defense communications systems research that supports and complements maintained capabilities; and (6) Mission related and public service oriented research, technology developments, test evaluation and systems analysis required to provide a quick response to rapidly evolving DOD and other government agency requirements. Work will be performed in University Park, Pennsylvania and is expected to be completed by February 2028. Funds of multiple different appropriation types and years from program offices and agencies throughout the DOD may be obligated on individual task orders for efforts that fall within the core competency areas. The Naval Sea Systems Command, Washington Navy Yard, D.C., is the contracting activity.