1. NASA MSFC Engineering Directorate Huntsville, Alabama 10/29/2012 HOSC DTN Activities October 2013

2. Page 2 NASA MSFC Engineering Directorate Huntsville, Alabama Overview:  The purpose is to discuss highlights regarding HOSC DTN activities with CU-Boulder CGBA4  DTN Requirements - BP/TCP/ACS/ECOS  MSFC system requirements 1.MOP – IN36: 2.HOSC Operational software use: a.EHS 16.0.x b.EPC 11.0 c.PDSS 6.0 d.Web 16.0 e.DTN 2.0 (based on DTN2.8)  CU-Boulder system requirements 1.CGBA4-0 2.CGBA4-gse-0 - UCB telemetry - 3. ET2 – UCB command

3. Page 3 NASA MSFC Engineering Directorate Huntsville, Alabama HOSC G/W development  Conducted under the auspices of ECR HM-3410 √ Add Aggregate Custody Signal into the HOSC DTN2 node + Move the implementation to DTN2.8 + Implement ACS independently of ION + Feedback lessons learned and patches into the DTN2 community √ Transition the HOSC with build 15 to support upcoming payload activities √ Underwent testing with CU and GSFC to verify interoperability √ MSFC funded

4. Page 4 NASA MSFC Engineering Directorate Huntsville, Alabama

5. Page 5 NASA MSFC Engineering Directorate Huntsville, Alabama Outcome  Transition to DTN for CU science went painless after comprehensive testing  Transitioned in the time May 08 timeframe  Virtually unmanned activity since  Represents a 3 node path  DTN2 and ION interoperation was uneventful  Outages either intentional or accidental covered by DTN support  Downlink methodology is  bulk priority hourly  TTL of 24 hours  Operation was interrupted during an apparent Single Event Upset in September (mention oct 25 event)  When CGBA4 was reset after analysis, DTN operation resumed

6. Page 6 NASA MSFC Engineering Directorate Huntsville, Alabama Ongoing activities Pursue the implementation of DTN on ISS as an ISS capability enhancement via CR 13799. Joint activity between JSC and HOSC The implementation of DTN on ISS has the potential to reduce the cost of providing payloads with ground data handling services. Many requests have already been made to use DTN in order to gain experience in operating their payload the way that they believe will be the standard way to science and mission operations are conducted on future missions. Requests have come from NASA, Payload Developers and ISS International Partners. The following additions to the ISS C&T System are being pursued: DTN Gateway on the ISS PL LAN. DTN Node at the HOSC moving from S-band uplink to Ku uplink. DTN Gateway on the ISS Ops LAN. DTN Node at MCC-H. Payload access to the Ku Forward Link.