As space travel technology has advanced, so too has the technology that allows astronauts on the International Space Station (ISS) to communicate with the rest of us here on Earth. To date, the ISS is about as far as we’ve needed our human-to-human communications tech to go. But with continued exploration and plans in the works to send people to Mars, communication networks will need to push more data at farther distances. That’s why, in June 2016, astronauts installed the first part of what will become a solar-system-wide internet.

Calm though it may look, space is a pretty hectic environment. Between cosmic debris, solar radiation, and other unseen forces, network disruption is a fact of life. To allow for this disruption, NASA scientists created a technology called Delay/Disruption Tolerant Networking, or DTN.

The DTN system works kind of like a railway in a coal mine. Like a railcar full of coal, a node full of data will stay put until network lines (or, in keeping with the simile, train tracks) are clear, at which point the node will proceed to pass the data to another node or on to its final destination. Partial data can be stored, meaning that one interruption of service won't disrupt the full transfer. This way, there’s less of a chance that a message from ground control to, say, astronauts halfway to Mars could get lost along the way. The DTN system is now part of the Telescience Resource Kit on the ISS, which is aimed at simplifying the software used on the space station to make it easier for researchers conducting experiments in space to transmit and receive data. 

For a visual representation of DTN at work, NASA produced the (not exactly self-explanatory) illustration below:

DTN’s inventors say the technology could be used for more than just super-cool cosmic phone calls. “Our experience with DTN on the space station leads to additional terrestrial applications especially for mobile communications in which connections may be erratic and discontinuous,” NASA visiting scientist Vinton G. Cerf said in a press statement.

In other words, DTN could be a great asset for ensuring consistent communication in disaster areas and other hard-to-network sites, and not just the far reaches of our solar system.