Interplanetary Internet (Artist's impression credit NASA JPL)
It’s not such a far-fetched idea. In fact, projects such as the Disruption Tolerant Networking program led by Dr. Kevin Gifford at the University of Colorado to test networking with the International Space Station (ISS), have shown that an interplanetary Internet will undoubtedly play an important role in future satellite missions, such as keeping in touch with the ISS and communicating with rovers in deep space.
In space, unlike on Earth, connections cannot be guaranteed due to very long distances and the risk of the Sun and planets blocking the signals. As a result, spacecraft often have intermittent communication with Earth. By using delay-tolerant networking
, an interplanetary Internet could change the way that we conduct space exploration, extending beyond our solar system and helping to contact spacecraft travelling light years away from Earth.
With delay-tolerant or “store-and-forward” networking, each connected device (node) in the system is capable of signal regeneration and stores data until the next node receives the data. In space, the wireless links between nodes would cause the sort of conventional networking that powers the Internet on Earth to “give up” sending data, but using delay tolerant networking ensures that data reach their destination reliably regardless of the current state of the transmission link.
Hosting an onboard router could transform the role of a satellite to become an active communications node capable of relaying signals in space. In 2003, Surrey flew CLEO (Cisco router in Low Earth Orbit) on its UK-DMC-1
satellite as an experimental hosted payload. The project—a collaboration between NASA Glenn Research Center, Cisco Systems, and Surrey—successfully validated the use of Internet in space coining the new term “orbital Internet” with Time Magazine
was switched on over 100 times for demonstration and its success has led to numerous follow-on projects including Cisco’s IRIS radiation-proof space router
that launched on Intelsat-14 in 2009. In 2007, the smallsat payload also introduced the fledgling IPv6 protocol to space
UK-DMC-1 demonstrated the first use of delay-tolerant networking in space
and served as a prototype for an interplanetary Internet that is now operating on the ISS.
In addition to hosting the pioneering CLEO payload, we at Surrey are actively evaluating these technologies and building them into our satellites: for example, delay tolerant networking could soon be used to reduce the time it takes to downlink satellite data to Earth. Instead of waiting for a scheduled satellite to pass over a ground station, the data could be sent from satellite to satellite via the inter-satellite link that provides the fastest route to wherever the data are needed. In surveillance and disaster monitoring applications, this timeliness could mean the difference between life and death.
The Internet has changed the way people and machines connect on Earth forever, using a common language to share information quickly between web servers, home computers, mobile phones and manufacturing lines. Interplanetary Internet will be the next revolution: connecting people, satellites, and planets together with reliable and highly flexible communications. Who knows where it will lead us next!