HOSC DTN Work

HOSC Imp Direction Goal is to make HOSC a fully functioning DTN node Able to pass bundles Do custody transfers Prepare for support to payloads in concert with CGBA

ISS Pre-DTN Connectivity

ISS Pre-DTN State ISS is a traditional yet embellished system Supports manned space Ground transport over IP networks Space links using CCSDS (Silver) standard Onboard recording of downlink for replay Data loss (Hits) and Link loss (LOS) Hours of storage Distributed ground processing and access System has been upgraded on the ground since deployment (twice) System will soon be upgraded on-orbit (and ground again)

ISS CU-DTN

ISS CU-DTN CGBA is now a DTN node onboard the ISS CU-Boulder uplinks bundles to CGBA via user command modifiable command fields User acknowledgements are via a defined “DTN” command type HOSC routes command to a DTN command queue Allows participation by uplink managers Circumvents the normal command queue Allows for a different extra-operational flow The queue is a store and forward but not DTN and would equate to a priority queue CU-Boulder downlinks bundles asynchronously Downlink CCSDS packets may contain: Traditionally formatted science A bundle or fractional bundle Traditional formatted science and a bundle or fractional bundle

ISS CU-DTN CU-Boulder path is a single hop Uplink passes through the HOSC for management CU-Boulder has ION implementations on each end Can handle uplink in a traditional fashion and using bundles Can handle downlink in a single of mixed mode fashion No intermediate custody transfer is currently supported No downlink security mechanisms employed

ISS CU-DTN CU-Boulder sends a bundle encapsulated in a command to ERIS listenter on an ePVT server. ERIS forwards the command to the command server and the DTN command queue. After CSM requirements are met the command is forwarded to JSC and ultimately CGBA-5 on ISS. Acknowledgements are forwarded via Telemetry and Ku-Band Downlink science bundles are sent in CCSDS packets via Ku-Band to PDSS which forwards the data to CGBA-5. Acknowledgements to CGBA-5 are forwarded via S-band.

ISS w/HOSC-DTN The HOSC is in the process of developing an intermediate DTN node on the ISS downlink Based on DTN2 Will exist in the HOSC outbound science data path The HOSC must inspect the downlink CCSDS packets to extract the bundle data and route Help / support is needed to interpret the BioServe Channel Header Current the HOSC implementation is 32 bit RHEL5 We will be moving to 64 bit RHEL5 by the end of the year

ISS w/HOSC-DTN

ISS w/HOSC-DTN A Bundle Application (BA) on a DTN2 implementation will inspect CGBA-5 downlink APIDs and extract bundle data. For custody transfers The Ack will be sent to a CU listener on the CGBA5 ERIS-talker BA Ack would be routed to the ERIS uplink server at the HOSC and forwarded to CGBA-5 on the ISS DTN Router will forward acknowledged bundles to CU and await Ack

ISS w/HOSC-DTN Due to the separation of the HOSC data distribution and the command and control infrastructures, there is no direct feedback loop To fully outfit the HOSC as a DTN node, a route needs to be established to provide ACK/NAKs to the sending DTN node Route can be established over S-band Asymmetric (good) Supports testing of the custody transfer 1. Uses CU-Boulder as a node to transfer the acknowledgement to CGBA or 2. Updating the HOSC infrastructure to provide ack/nak via the DTN queue and provide acknowledgement directly to the uplink ISS w/HOSC-DTN

ISS w/HOSC-DTN A Bundle Application (BA) on a DTN2 implementation will inspect CGBA-5 downlink APIDs and extract bundle data. For custody transfers The Ack will be sent to a CU listener on the CGBA5 ERIS-talker BA Ack would be routed to the ERIS uplink server at the HOSC and forwarded to CGBA-5 on the ISS DTN Router will forward acknowledged bundles to CU and await Ack

ISS w/HOSC-DTN A Bundle Application (BA) on a DTN2 implementation will inspect CGBA-5 downlink APIDs and extract bundle data. For custody transfers The Ack will be sent to a ERIS listener on the DTN router (BA) platform The Ack is the CGBA-5 DTN command Ack will be issued no faster than n/sec (TBD) DTN Router will forward the bundle to CU and await Ack

JAXA-ISS DTN Participation On August 19, 2009 NASA conducted discussions at JAXA on ISS DTN participation Participation by Adrian Hooke (HQ), Kevin Gifford (UC-Boulder), Lee Pitts (MSFC-HOSC) Goal was to solicit a commitment from JAXA A preliminary Video-Conf was conducted prior to the Face-to-Face JAXA was eager to explore areas of cooperation ISS DTN experiment Support the use of DTN in exploration

JAXA-ISS DTN Participation Before completion of the Face-to-Face 3 (4) scenarios were discussed and modified to pursue Letter of agreement (LOA) to proceed was drafted JAXA program management discussed their commitment Three (3) scenarios where discussed Scenario 1 JAXA DTN Node uplinking bundles to CGBA-5 via TDRSS Data/Telemetry return via TDRSS/HOSC Scenario 2 JAXA DTN Node uplinking bundles to CGBA-5 via DTRS Data/Telemetry return via DRTS Scenario 3

JAXA-ISS DTN Participation Budgetary issues are a concern DTN Study budget ends in 2011 JAXA/NASA needs to show progress in calendar 2010 Areas of coordination still require more definition CGBA has tentatively agreed to support/HOST JAXA’s end node test activities Detail analysis and testing of onboard networks