This paper addresses the need to analyze and validate the architectural requirements of complex systems-of-systems early in the development process. We present an iterative rapid prototyping process for studying the temporal behavior of the system-of-systems architecture via object-oriented architectural models expressed in UML-RT (UML for Real-Time extension) augmented with formal specification of timing requirements in terms of a time-series temporal logic. The UML-RT models are translated into coarse-grained simulation models that are exercised using the OMNeT++ simulation engine. We instrument the OMNeT++ simulation code with probes that send information to DBRover, a time-series temporal logic tool that simulates, builds, executes and monitors temporal assertions about a target application, for temporal property verification during prototype execution. We illustrate the proposed approach with a case study of the sensor-netting capability of a missile defense system.