David Ray is senior vice president of space at SAIC, a federal contractor headquartered in Reston, Virginia. The United States needs resilient space-based sensing capabilities for global detection, tracking and custody of advanced ballistic and hypersonic missile threats. These capabilities must integrate into the missile defense kill chain with existing space-based and terrestrial sensing, command and control, and effectors to enable early and effective engagement of these threats. Blending existing investments with new elements presents a system of systems integration challenge. Smaller satellites from the Proliferated Warfighter Space Architecture (PWSA) and advanced effectors such as hypersonic missiles must rapidly integrate...