Session
Advanced Technologies 1
Location
Salt Palace Convention Center, Salt Lake City, UT
Abstract
DTN (Delay/Disruption Tolerant Networking) is at foundation of NASA's LunaNet architecture, which will enable the robust communications, navigation, and networking capabilities needed to establish a long-term presence on the Moon. DTN is a network architecture composed of several different protocols that are designed to provide internetworking functionality and standardized multi-hop, end-to-end data delivery in highly stressed environments that are not optimal for traditional Internet Protocols. Bundle Protocol (BP) version 7, a store-and-forward protocol intended to run at the application layer on top of convergence layer protocols, provides the key delay tolerance functionality of DTN and is designed to handle intermittent connectivity, long delays, bit errors, and other common issues in a space-based network. The CCSDS (Consultative Committee for Space Data Systems) Custody Transfer specification provides the disruption tolerance by guaranteeing reliable delivery through bundle acknowledgements. NASA Goddard’s implementation of BP version 7 and the related specifications is provided by a generic C-language library (BPLib) that can be integrated within the standard core Flight System (cFS) architecture with a cFS application (BPNode), both of which are open source. Its design emphasizes customization at the build level, in-flight configurability through commands and tables, multi-threading, resource limitations, performance optimization, and various other considerations key to flight software. It leverages the open-source libraries QCBOR, to encode and decode bundles, and SQLite, to provide a storage database for bundles that cannot be immediately forwarded or delivered. Future work on Goddard’s BPNode includes support for additional convergence layer protocols, integration with the Bundle Protocol Security library to provide end-to-end data protection, and more. BPNode has been deployed on the CAPSTONE CubeSat (Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment) currently in orbit around the moon, and experimentation onboard the spacecraft has demonstrated the ability to scale BPNode down to link rates as low as 2 Kbps, while lab experimentation on more powerful machines has demonstrated its ability to scale up to data rates of almost 900 Mbps with large bundles. This paper will discuss the results of on-orbit DTN experimentation including uplink & downlink bundle flows, bundle transfers using the CCSDS Custody Transfer standard, and lessons learned from the cislunar experimentation in this challenging environment. As infrastructure in cislunar space continues to be built up in support of the ongoing Artemis missions, a cFS solution for DTN will allow for the deployment of increasingly complex networking architectures on flight software in and around the moon.
Document Type
Event
Delay/ Disruption Tolerant Networking in Cislunar Space
Salt Palace Convention Center, Salt Lake City, UT
DTN (Delay/Disruption Tolerant Networking) is at foundation of NASA's LunaNet architecture, which will enable the robust communications, navigation, and networking capabilities needed to establish a long-term presence on the Moon. DTN is a network architecture composed of several different protocols that are designed to provide internetworking functionality and standardized multi-hop, end-to-end data delivery in highly stressed environments that are not optimal for traditional Internet Protocols. Bundle Protocol (BP) version 7, a store-and-forward protocol intended to run at the application layer on top of convergence layer protocols, provides the key delay tolerance functionality of DTN and is designed to handle intermittent connectivity, long delays, bit errors, and other common issues in a space-based network. The CCSDS (Consultative Committee for Space Data Systems) Custody Transfer specification provides the disruption tolerance by guaranteeing reliable delivery through bundle acknowledgements. NASA Goddard’s implementation of BP version 7 and the related specifications is provided by a generic C-language library (BPLib) that can be integrated within the standard core Flight System (cFS) architecture with a cFS application (BPNode), both of which are open source. Its design emphasizes customization at the build level, in-flight configurability through commands and tables, multi-threading, resource limitations, performance optimization, and various other considerations key to flight software. It leverages the open-source libraries QCBOR, to encode and decode bundles, and SQLite, to provide a storage database for bundles that cannot be immediately forwarded or delivered. Future work on Goddard’s BPNode includes support for additional convergence layer protocols, integration with the Bundle Protocol Security library to provide end-to-end data protection, and more. BPNode has been deployed on the CAPSTONE CubeSat (Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment) currently in orbit around the moon, and experimentation onboard the spacecraft has demonstrated the ability to scale BPNode down to link rates as low as 2 Kbps, while lab experimentation on more powerful machines has demonstrated its ability to scale up to data rates of almost 900 Mbps with large bundles. This paper will discuss the results of on-orbit DTN experimentation including uplink & downlink bundle flows, bundle transfers using the CCSDS Custody Transfer standard, and lessons learned from the cislunar experimentation in this challenging environment. As infrastructure in cislunar space continues to be built up in support of the ongoing Artemis missions, a cFS solution for DTN will allow for the deployment of increasingly complex networking architectures on flight software in and around the moon.
