The structure of candidate next-generation integrated communication architectures for space communications and navigation address technologies, architectural attributes, mission services, and communications capabilities is improved by using software defined radios (SDRs). Evaluating lessons learned from development and operation of the early space SDRs on the NASA Space Communications and Navigation (SCaN) Testbed on the International Space Station (ISS) provide feedback for defining the communications architecture. An important attribute is leveraging SDR reconfigurability, which can be changes the way that operations are conducted.