This issue of the Johns Hopkins APL Technical Digest is the first of two issues devoted to science and technologies that are being pursued by APL's Precision Engagement Business Area. From developing models and simulations to better understand the environmental effects on aerodynamic stability of small unmanned aircraft in complex environments, to conducting field demonstrations of autonomous operation of unmanned systems, the Business Area has devoted considerable resources to improving operational performance in the realms of command, control, intelligence, surveillance, and reconnaissance (C2ISR) and engagement.