DTN was, or was supposed to be.

Contract-graph routing (a core part of dtn - where do you send packets when there are delays in your route graph) was spec'd to be used, and I believe they may have done an experiment. The balloons had schedules or predictable winds, and satellites come and go (at least back then), so forwarding packets to the right carrier (or two) to get the next hop home was a big part of it.