Using standard Internet Protocols and applications in space

Abstract

This paper discusses approaches for using standard Internet technologies to meet the communication needs of future space missions. It summarizes work done by the Operating Missions as Nodes on the Internet (OMNI) project at NASA/GSFC since 1997. That project arose from a small group of engineers who had been involved with building NASA communication systems for over 20 years. Since NASA needed communication systems for space long before the Internet evolved, NASA developed many custom protocols and communication techniques to meet its “space specific” communication needs. However, as the Internet evolved, it needed to address all of the same communication issues of errors, delays, and intermittent links. Those challenges may not have seemed space related, but the solutions developed can be used to address space communication issues. The key is to select the appropriate Internet Protocols that can support space communication while also providing direct interoperability with the terrestrial Internet. This paper uses a layered approach to discuss all aspects of using Internet technologies in space. It starts with the low-level physical, data link and data routing issues related to using Internet Protocols to support basic spacecraft communications. After identifying options for supporting basic datagram delivery in space, the paper describes issues for selecting transport protocols and applications to meet various mission data delivery needs. Information is provided throughout the paper to identify key implementation issues and provide information on the current status of products in each area. Finally, current implementation and usage of these protocols in both spacecraft and ground systems are discussed.