On March 25, 2019, John Hopkins University Applied Physics Laboratory, Laurel, Maryland, was awarded an indefinite-delivery/indefinite-quantity contract (HQ0034-19-D-0006) with a maximum amount of $873,000,000. To date, $678,040,449 has been awarded on seven exercised options. The purpose of the contract is to provide robust end-to-end systems engineering, operational analysis of component architectures across all aspects of the kill chain, technology concept exploration, and analysis and performance assessments in multiple warfare domains areas across regions and theaters of operation. The domains include air, land, sea, space and cyberspace. The warfare areas include air and missile defense; air-to-air combat (including manned and unmanned aircraft); countering unmanned vehicles (in all domains); time-critical target defeat; anti- surface warfare (including small-boats and gun-boats), anti-submarine warfare, and mining; offensive strike; electromagnetic maneuver warfare; electronic attack; negating counter-space capabilities, i.e. command and control (C2) systems, direct satellite attack, hardening, and replenishment; command, control, computers, communications (C4); intelligence, surveillance, and reconnaissance (C4ISR); counter-integrated air defense systems (IADS); offensive and defensive cyber capabilities; and nuclear systems to include nuclear command, control and communications (NC3) systems. These efforts provide assessments and alternative methods for countering contested environment capabilities. The seven exercised options provide a broad range of services which include engineering, research, development, test and evaluation, and analytic capabilities using operational knowledge of the national defense and security environments for the Office of the Secretary Defense (OSD). The contractor shall provide subject matter expertise, independent, objective system engineering and analysis to conduct studies, and assist OSD in resolving technical issues. The work will be performed in Alexandria, Virginia; and Laurel, Maryland. The work is expected to be completed on March 24, 2024. Washington Headquarters Services, Arlington, Virginia, is the contracting activity.