I know what you're thinking right now, because I was thinking it too as soon as I saw the phrase "marsupial robot team:" you're thinking about robot koalas. Or robot kangaroos. Or maybe robot wombats. As awesome as that would be, today you're going to have to make do with something only slightly less awesome, which is this duo of a robotic boat and a hexacopter that cooperate to collect data on rivers and lakes.
The "marsupial" bit refers to the hexacopter, which uses the boat as (to stretch the metaphor slightly into the absurd) a pouch. With enough solar cells and good weather, the boat could power both itself and the hexacopter, extending its operating time significantly, or in the absolute best case, indefinitely. The whole thing runs ROS, and looks to be capable of very robust autonomous navigation, but the really cool part is how the boat and the hexacopter can team up and combine the data sets that they collect to create far more comprehensive and accurate maps than either could alone.
A particular aspect to be taken into account is the interaction of robots to take the best of the complementary visual perspectives they have of the environment. The goal is to use an aerial perspective to promote on-water safe navigation. In the application scenario, the robotic team, moving downriver, assesses a series of environmental variables. In case a pollution indicator is triggered the aerial platform is asked to perform a local survey. This information is passed on to a remote control centre, where a human operator is monitoring and configuring the mission.
The project is called RIVERWATCH, and it was part of ECHORD (the European Clearing House for Open Robotics Development) up until it actually started working, at which point it was transferred over to UNINOVA in Portugal. This is ongoing research, with several recent IEEE publications (w00t!), so we're certainly looking forward to some additional robotic marsupialness. Like maybe a submarine? Or a UGV? Or, a rocket?