DTN Demonstrations With ESA Ground Segment

In this paper we present the results of two Delay Tolerant Networking (DTN) demonstration activities carried out in the European Space Agency (ESA) Ground Segment. The first demonstration has been prepared with the OPS-SAT spacecraft, to demonstrate a full DTN protocol stack with CCSDS File Delivery Protocol (CFDP), Bundle Protocol (BP), Licklider Transmission Protocol (LTP), CCSDS Space Packet Protocol (SPP) and show the ESA Ground Segment BP implementation capabilities. In this first activity we demonstrated in-orbit file transfer on both uplink and downlink over a DTN network stack. The second demonstration has been performed in collaboration with Morehead State University (MSU), NASA JPL and D3TN, with the aim to show interoperability of DTN implementations across space agencies and external partners. Following a loss of communication with the spacecraft and failed lunar orbit insertion, the activity focused on an end-to-end data flow simulation with the spacecraft recorded data, involving the ESA Kourou ground station, the Lunar IceCube Engineering Model (EM), MSU ground segment and an operational DTN network of seven nodes. The demonstrations provide valuable lessons learned about interoperability testing, coordination, and planning in a multi-agency environment. The live operations performed during these activities provided insights on operational requirements that are relevant to future demonstrations and can help avoid some of the issues we encountered. The encouraging results obtained suggest that DTN technologies are getting ready for broader adoption.