The Internet as it stands today is the greatest revolution in the world of communications. It’s a technical marvel, enabling us to do many things that even up to a couple decades ago were firmly in the realms of science fiction. Indeed the incredible acceleration of technical innovation that we’ve experienced in recent history can be attributed to the wide reaching web that enables anyone to transmit information across the globe . So with the human race on the verge of a space revolution that could see a human presence reaching far out into our solar system a question burns away in the minds of those who’d venture forth.
How would we take the Internet with us?
As it stands currently the Internet is extremely unsuitable for inter-planetary communications, at least with our current level of technology. Primarily this is because the Internet is based off the back of the TCP/IP protocols which abstract away a lot of the messy parts of sending data across the globe. Unfortunately however due to the way these protocols are designed the transmission of data is somewhat unreliable as neither of the TCP/IP protocols make guarantees about when or how data will arrive at its destination. Here on Earth that’s not much of a problem since if there are any issues we can just simply request the data be sent again which can be done in fractions of a second. In space however the trade-offs that are made by the foundations of the Internet could cause immense problems, even at short distances like say from here to Mars.
Transmissions from Mars take approximately 3 minutes and 20 seconds to reach Earth since they travel at the speed of light. Such a delay is quite workable for scientific craft but for large data transfers it represents some very unique problems. For starters requesting that data be resent means that whatever system was relying on that data must wait a total of almost 7 minutes to continue what it was doing. This means unreliable protocols like the TCP/IP stack simply can not be used over distances like these when re-transmission of data is so costly and thus the Internet as it exists now can’t really reach any further than it already does. There is the possibility for something more radical, however.
For most space missions now the communication method of choice is usually a combination of proprietary protocols coupled with directed microwave communication. For most missions this works quite well, especially when you consider examples like Voyager which are 16 light hours from earth, however these systems don’t generalize very well since they’re usually designed with a specific mission in mind. Whilst an intrasolar internet would have to rely microwaves for its primary transmission method I believe that a network of satellites set up as anAldrin Cycler between the planets of our solar system could provide the needed infrastructure to make such a communications network possible.
In essence such satellites would be akin to the routers that power the Internet currently, with the main differences being that each satellite would verify the data in its entirety before forwarding it onto the next hop. Their primary function would also change depending on which part of the cycle they were in, with satellites close to a planet functioning as a downlink with the others functioning as relays. You could increase reliability by adding more satellites and they could easily be upgraded in orbit as part of missions that were heading to their destination planet, especially if they also housed a small space station. Such a network would also only have to operate between a planet and its two closest neighbors making it easy to expand to the outer reaches of the solar system.
The base stations on other planets and heavenly bodies would have to have massive caches that held a sizable portion of the Earth Internet to make it more usable. Whilst you couldn’t have real time updates like we’re used to here you could still get most of the utility of the Internet with nightly data uploads of the most updated content. You could even do bulk data uploads and downloads to the satellites when they were close to the other planets using higher bandwidth, shorter range communications that were then trickle fed over the link as the satellite made its way back to the other part of its cycle. This would be akin to bundling a whole bunch of tapes in a station wagon and sending it down the highway which could provide extremely high bandwidth, albeit at a huge latency.
Such a network would not do away with the transmission delay problems but it would provide a reliable, Internet like link between Earth and other planets. I’m not the first to toy with this kind of idea either, NASA tested their Disruption Tolerant Networking back in 2008 which was a protocol that was designed with the troubles of space in mind. Their focus was primarily on augmenting future, potentially data intensive missions but it could be easily be extended to cover more generalized forms of communication. The simple fact that agencies like NASA are already well on their way to testing this idea means we’re already on our way to extending the Internet beyond its earthly confines, and it’s only a matter of time before it becomes a reality.