A key element of future space networks will be software-defined radios that measure aspects of link performance, support multiple wave form options, support advanced antenna features, and can interact with their networks to optimize network performance. These advanced software modems (ASMs) will incorporate system controls that manage ASM capabilities to support network communication and enhance mission success. Reactive Routing is an innovation in space networking by which unplanned changes in link performance are detected and analyzed, enabling automatic and immediate adjustments to the "contact plans" on which route computation in delay-tolerant networking (DTN) can be based. These changes in contact plans will result in route revisions that will reallocate traffic load per the revised transmission opportunities, improving network performance while reducing operations costs. Reactive Routing is only the first step toward the deployment of instrumented networks that monitor and examine their own operational experience and use the resulting insights to configure themselves for optimal performance. It is the beginning of our initiative to bring the power of ASMs to networks built on the DTN Bundle Protocol [1], and it is directed at the long haul link context where round trip signal time delays the reallocation of traffic. Other ASM expectations, such as dynamic onboard waveform libraries, steerable antennae, high speed encryption, and cognitive radio facilities are opportunities for further autonomous space network advances if we can harvest their potential at the network level.