Space Internetworking with IP and DTN
Keith Scott · SpaceOps 2008 Conference · 2008
There has been growing interest by the space community in moving from the current 'link-based' model of communicating with spacecraft to a network-based model.Successes with the Mars Exploration Rovers have demonstrated that relaying can dramatically increase the data rate over direct-to-Earth approaches, but the current system is manuallyintensive in that data movements are commanded from Earth.NASA is currently pursuing the use of networked approaches such as IP and Delay/Disruption Tolerant Networking for its Constellation program to reduce complexity and increase robustness.Unfortunately, using IP in environments where there may be one-way paths and/or network partitions still requires a high degree of human intervention and management.The DTN protocols being developed within the Internet Research Task Force can accommodate long delays and network disruptions as normal occurrences, with the hopes of reducing the human overhead involved in managing space mission operations.This paper describes protocols that can be used to support space networking, comparing and contrasting the approaches' strengths and weaknesses in environments with long latencies, changing topologies and link interruptions.It describes how each architecture can be implemented in the context of the current space communication infrastructure, and how graceful transition from current to network-based operations can be effected.We conclude with a discussion of the current state of standardization within the space community and the implications for international cross-support.