This document describes the Interplanetary Internet: a communication system to provide Internet-like services across interplanetary distances in support of deep space exploration. Our approach, which we refer to as bundling, builds a store-and-forward overlay network above the transport layers of underlying networks. Bundling uses many of the techniques of electronic mail, but is directed toward interprocess communication, and is designed to operate in environments that have very long speed-of-light delays. We partition the Interplanetary Internet into IPN Regions, and discuss the implications that this has on naming and routing. We discuss the way that bundling establishes dialogs across intermittently connected internets, and go on to discuss the types of bundle nodes that exist in the interplanetary internet, followed by a discussion of security in the IPN, a discussion of the IPN backbone network, and a discussion of remote deployed internets. Cerf, et al. Go thoughtfully in the knowledge that all interplanetary communication derives from the modulation of radiated energy, and sometimes a planet will be between the source and the destination. Therefore rely not on end-to-end connectivity at any time, for the universe does not work that way. Neither rely on ample bandwidth, for power is scarce out there and the bit error rates are high. Know too that signal strength drops off by the square of the distance, and there is a lot of distance. Consider the preciousness of interplanetary communication links, and restrict access to them with all your heart. Protect also the confidentiality of application data or risk losing your customers. Remember always that launch mass costs money. Think not, then, that you may require all the universe to adopt at once the newest technologies. Be backward compatible. Never confuse patience with inaction. By waiting for acknowledgement to one message before sending the next, you squander tracking pass time that will never come to you again in this life. Send as much as you can, as early as you can, and meanwhile confidently await responses for as long as they may take to find their way to you. Therefore be at peace with physics, and expect not to manage the network in closed control loops-neither in the limiting of congestion nor in the negotiation of connection parameters nor even in on-demand access to transmission bands. Each node must make its own operating choices in its own understanding, for all the others are too far away to ask. …