An emerging generation of mission-critical systems employs distributed, dynamically reconfigurable open architectures. These sys- tems may include a variety of devices that sense and affect their envi- ronment and the configuration of the system itself. We call such systems Networked Cyber-Physical Systems (NCPS). NCPS can provide complex, situation-aware, and often critical services in applications such as dis- tributed sensing and surveillance, crisis response, self-assembling struc- tures or systems, networked satellite and unmanned vehicle missions, or distributed critical infrastructure monitoring and control. In this paper we lay out research directions centered around a new paradigm for the design of NCPS based on a notion of software frac- tionation that we are currently exploring which can serve as the basis for a new generation of runtime assurance techniques. The idea of software fractionation is inspired by and complementary to hardware fractiona- tion — the basis for the fractionated satellites of DARPA’s F6 program. Fractionated software has the potential of leading to software that is more robust, leveraging both diversity and redundancy. It raises the level of abstraction at which assurance techniques are applied. We specifically propose research in just-in-time verification and validation techniques, which are agile — adapting to changing situations and requirements, and efficient — focusing on properties of immediate concern in the context of locally reachable states, thus largely avoiding the state space explosion problem. We propose an underlying reflective architecture that main- tains models of itself, the environment, and the mission that is key for adaptation, verification, and validation.