Imagine a future in which human intelligence is scattered all over the solar system. That intelligence may take the form of incredibly capable robots that allow us to be "telepresent" in remote parts of the solar system without ever leaving Earth, or perhaps remote space outposts on the Moon or Mars where human beings are learning to live on other worlds. In some of these places there may be thousands or millions of intelligent systems that need to exchange information not only with other intelligence on Earth but also among themselves. How would such communication occur, and how would it differ from the information transfer across the terrestrial Internet that we know so well?

We are all familiar with the explosive growth of the Internet, and the way in which it has entered our daily lives. We log on and expect to instantly access information from...