What do you do if you need a web that’s more than world-wide? You go with disruption tolerant networking:
Adrian Hooke, a veteran of the Apollo 11 mission launch team, manages the new space DTN project.“Typically spacecraft go off and do their thing, gather up data, and then on some schedule they connect to the ground and [we] pull down the results of what it has been doing and send up instructions for the next time period,” Hooke said.
Such manual operations are inefficient and expensive. But simply extending Earth’s Internet into space won’t work.
The Web uses Transmission-Control Protocol/Internet Protocol (TCP/IP), a type of communication language in which hosts and computers must be constantly connected.
This rarely happens in space, where intermittent connections are the norm because of the vast distances involved and the tendency of orbiting moons, rotating planets, and drifting satellites to temporarily disrupt wireless lines of communication.
Typical space delays, even those caused by solar storms, are handled in stride by DTN, Hooke said.
Each node in the network—whether it’s the International Space Station or a small orbiting robot—stores all the data it receives until a clear opportunity arises to pass its “bundle” along to the others in the network. DTN nodes do not discard data when a destination path can’t be identified.
(Hat tip to Nyrath.)