Summary of Solar System Internet (SSI) Operations Concept

1. Summary of Solar System Internet (SSI) Operations Concept CCSDS DTN Working Group May 5, 2010

2. The Case for a Solar System Internet (SSI) • Future space missions will include features that cannot be accommodated by today’s link layer based communications • Multiple spacecraft • Intermittent connectivity and long light-time delays • Data flow across multiple hops and potential paths • Spacecraft that need to communicate without Earth in the loop (e.g., a lander and orbiter) • This complex topology will require a network layer in the space communications protocol stack to provide reliable routing and forwarding of data

3. IOAG Mandate to SISG • The IOAG’s Space Internetworking Strategy Group (SISG) should formalize a draft Solar System Internetwork (SSI) Operations Concept and candidate architectural definition in time for IOAG-13 and should prepare a mature architectural proposal for review and endorsement at the third Inter-Operability Plenary meeting (IOP-3). At that time, the IOAG is requested to present an enhanced service catalog for endorsement. The IOP Agencies should ensure representation from their programs and projects to work with SISG to identify potential missions which may benefit from adoption of the SSI-related standards, leading to a gradual build up of in-space and ground-based space internetworking To respond to this action, the SISG has developed an SSI Operations Concept document

4. SSI Purpose and Scope • The SSI will • Provide internetworked data communications services across the Solar System to support space mission users • Employ a confederated and interoperable infrastructure of nodes owned and operated by multiple space agencies • SSI participants will expose standard and agreed cross support services at the network layer of the ISO/OSI Reference Model • There will be no central management/ownership of the SSI; participating agencies will follow established, documented, interagency agreements for configuring cross support.

5. SSI Architecture SSI Node w/ forwarding capability (“Service Provider” or “Service User”) Landed Spacecraft SSI Node w/out forwarding capability (“Service User” only) Planetary WAN Planetary Station Spacecraft Planet Spacecraft MOCs Science Ops Center Relay Satellite Spacecraft Earth Station Terrestrial WAN Earth Station Control Center Planetary Station Control Center Earth

6. SSI Routing and Protocol • SSI provider nodes will offer a native network layer routing service based on: • the Internet protocol of the IP suite (low-delay and well connected environments), and/or • the Bundle Protocol (BP) of the DTN suite (delayed or disconnected environments) • Provider nodes will route data in the form of IP datagrams and/or BP bundles. • User applications will be exposed only at the SSI end nodes

7. SSI Coordination • Each agency will act as an SSI Service Provider for its user nodes, offering SSI services based on the capabilities of its provider nodes • Agencies participating as SSI providers will provide access to each other’s nodes via peering agreements • Long-term coordination: service agreements and scheduling rules • Short-term coordination: contact plan generation (may require iteration among User MOCs, provider nodes, and SSI Service Providers to accommodate time/event-specific requirements)

8. DTN Demonstrations • NASA’s DINET-3 (Deep Impact Network Experiment) • Deep Impact spacecraft using DTN to communicate in an operational environment • ESA’s METERON (Multipurpose End-To-End Robotic Operations Network) • Will use ISS to prototype potential Lunar and Mars communications scenarios • NASA planning to load and operate the DTN software suite on EO-1 spacecraft to demo the applicability of DTN to Earth science • NASA/U of CO’s Commercial Generic Bioprocessing Apparatus (CGBA) onboard ISS • In service 24x7, returning data via the Bundle Protocol (ION)