In this paper we discuss some of the challenges and approaches for providing safety assurance for modern weapon systems via software-based safety kernels. We argue that software-centric approaches for designing and verifying safety kernels are flawed. We claim that the design and verification of safety kernels for complex event-driven real-time systems is a matter of physics and dynamical system analysis of system design. We describe an approach for rapidly prototyping safety kernels (and plants and controllers) using an agent-based safety-kernel architecture. The approach utilizes multiagent modeling and hybrid automata.