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Image via WikipediaOur solar system is big. Annoyingly so.
It’s so big that when it comes to communicating at these distances, even light speed doesn’t cut it. Transmitting data from the Earth to, say, a probe in orbit around Neptune takes about four hours. For a species that hopes to one day colonize our little space neighborhood and bring our information society
Sending a simple email between planets would be like playing a multimillion mile long game of croquet where all the hoops move at different speeds.
A loose coalition of smarty pantsinati have considered this problem for more than three decades. Chief among them has been Vint Cerf, often dubbed as one of “the fathers of the Internet” and current Google Chief Internet Evangelist. In 2009, Google unveiled a new interplanetary internet protocol developed by a team led by Cerf. The system compensated for these solar-system sized variables via a Delay- and Disruption-Tolerant Network (DTN). DTN is a networking architecture originally developed for the military that can function even when no clear end-to-end path is available.
DTNs stand in contrast to Transmission Control Protocol / Internet Protocol (TCP/IP), which is the standard the traditional internet is based on. Whereas TCP/IP assumes it will be able to transmit data over a period of milliseconds and will attempt to transmit said data repeatedly until delivery is confirmed, DTN is designed to compensate for massive lag and limited energy resources. An interplanetary DTN would work by sending bundles of data via a chain of relay nodes positioned around the solar system that would store the bundles and forward them along to the next celestial middleman when a clear path becomes available. Some models call for sending multiple replicas of the same data along several pathways to increase the chances of the information reaching its target in a timely manner.
You’re still sending data through the metaphorical croquet match, but in the DTN version, all the hoops are aware of where the ball has to go and where all the other moving hoops are and will forward the ball accordingly.
This interplanetary internet (IPN) isn’t just theoretical chalk talk either, it has already entered real world testing. DTN protocols are being utilized by the International Space Station as well as between various research labs around the world. And Google has even conducted a long range DTN test (80 light seconds, around 15 million miles) via a repurposing of NASA’s EPOXI spacecraft (formerly known as “Deep Impact”).
In an interview with NetworkWorld, Cerf describes the Google’s initiative to bring a standard internet architecture to the Final Frontier starting this year:
So during 2011, our initiative is to “space qualify” the interplanetary protocols in order to standardize them and make them available to all the space-faring countries. If they choose to adopt them, then potentially every spacecraft launched from that time on will be interwoven from a communications point of view. But perhaps more important, when the spacecraft have finished their primary missions, if they are still functionally operable — they have power, computer, communications — they can become nodes in an interplanetary backbone. So what can happen over time, is that we can literally grow an interplanetary network that can support both man and robotic exploration.
As the growing family of space nations fling more of their machines and flying laboratories farther into the cosmos, they will also—envisions Cerf—be adding hubs to the newly standardized space web. This new IPN will evolve space technology beyond the limitations of traditional point-to-point radio links allowing for more complex missions in need of a richer communication environment.
Additionally, as humans follow our machines into the farther reaches of the solar system, this will help cut down on the inevitable psychological detachment
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