Interplanetary Internet -- space-based IP Traffic would enable Mars-based Internet connection

Working with NASA and JPL, Vint Cerf has helped develop a new set of protocols that can stand up to the unique environment of space, where orbital mechanics and the speed of light make traditional networking extremely difficult. Though this space-based network is still in its early stages and has few nodes, he said that we are now at “the front end of what could be an evolving and expanding interplanetary backbone.”

The evolution of space data system standards has gone on in parallel with the evolution of the Internet, with conceptual cross-pollination where fruitful, but largely as a separate evolution. Since the late 1990s, familiar Internet protocols and CCSDS space link protocols have integrated and converged in several ways. While IP-like protocols are feasible for short hops -- from a ground station to orbiter, rover-to-lander, etc. -- delay-tolerant networking is needed to get information from one region of the solar system to another. It becomes apparent that the concept of a "region" is a natural architectural factoring of the InterPlanetary Internet.

Mr Cerf sums up the problem thusly, "...the speed of light is slow relative to distances in the solar system. A one-way radio signal from Earth to Mars takes between three and half and 20 minutes. So round trip time is of course double that. And then there’s the other problem: planetary rotation. If you’re communicating with something on the surface of the planet, it goes out of communication as the planet rotates. It breaks the available communications and you have to wait until the planet rotates back around again. So what we have is variable delay and disruption, and TCP does not do terribly well in those kinds of situations."

The Disruption Tolerant Networking (DTN) program establishes a long-term, readily accessible communications test-bed onboard the International Space Station (ISS). Two other components will serve as communications test computers that transmit messages between ISS and ground Mission Control Centers.

Read more at Wired and more info at NASA.