We had a very interesting presentation and discussion regarding the topic of interplanetary internet with my international colleagues, of which Vint Cerf—one of the “fathers of the internet”—is also a member. As a partner of the Interplanetary Networking Special Interest Group (IPNSIG), he took us on a journey that he has been involved with over the last 20 years regarding communication networks in space. A true mind-broadening experience.

Vint had invited Scott C Burleigh as his panelist. Scott recently retired as Principal Engineer with Jet Propulsion Laboratory, California Institute of Technology, Pasadena. Like Vint, Burleigh is a member of IPNSIG.

As humans extend their boundaries further into deep space, a robust Solar System Internet (SSI) architecture will become necessary and even inevitable. It is the vision of IPNSIG to extend networking to space, from the historical point-to-point and “bent pipe” communication architecture to a store-and-forward (packet-switched) design, interconnecting multiple nodes and networks within the coming century.

It was amazing to hear that decades-old technology is still the best way for interplanetary communication—modified, of course, for space communication.

Work began with a small group at the Jet Propulsion Laboratory and the MITRE Corporation in 1998. By 2004, the landing of the Spirit and Opportunity rovers on Mars led to the necessity to upgrade the supporting communication system to use a semi-automatic store-and-forward relay system, including the rovers and orbiting mapping satellites that were repurposed as relays.

By 2009, support from NASA and the U.S. Defense Advanced Research Projects Agency (DARPA) allowed further laboratory and terrestrial testing of a new suite of disruption-tolerant networking (DTN)-based protocols—the Bundle Protocol Suite. (Bundle protocol is an experimental DTN protocol designed for unstable communications networks. It groups data blocks into bundles and transmits them using a store-and-forward technique. Bundle protocols connect multiple subnets into a single network. They provide a custody-based retransmission service and store data for long periods. The signal retransmitter guarantees packet delivery. As such, they can easily cope with internet connectivity issues such as bandwidth delays and breakups.)

Subsequently, tests were undertaken with the EPOXI spacecraft, and the protocols were uploaded into the International Space Station (ISS) for crew support.

Collaborative activities with the European Space Agency (ESA), the Japan Aerospace Exploration Agency (JAXA) and the Korea Aerospace Research Institute (KARI) have been undertaken and are continuing. In one ESA experiment, METERON, a small robot vehicle in Germany, was controlled in real-time by an astronaut onboard the ISS. Other tests (such as NASA’s LLCD) demonstrated high-speed optical communication possibilities for future missions.

More recently, the Bundle Protocol Suite has been implemented on three major internet cloud provider platforms in support of further application, capacity and resiliency testing. As of this writing, most of the NASA laboratories and JAXA, ESA and KARI are engaged in further developing and testing the system.

In the discussion, we also talked about communication with possible aliens and the fact that they might communicate in totally different ways than us. This requires truly thinking outside the box. Quantum technologies were also discussed as potential breakthrough developments to overcome the current technology barriers we face.

It was a real privilege to have this discussion with those at the frontier of space communication.