eb-1 SMWG 15 July 2008 Erik Barkley 17 July 2008 DSN Event Sequence ReEngineering Overview eb-2 SMWG 15 July 2008 Outline Programmatic Background Ops Concept Summary Tour of revised sequencing structures Mission DSN DSN Mission Spacelink profile eb-3 SMWG 15 July 2008 Programmatic Background or What is a DSN SM SE to do? Do we ignore CCSDS? (knowing that we are trying to move towards CCSDS approach) Do we wait for CCSDS to finish its work? (that could take a while) Do we attempt to migrate towards the CCSDS approach? (we could at least get the conceptual underpinnings ready for the CCSDS approach) eb-4 SMWG 15 July 2008 Operations Concept Summary Time Long Range Planning Day-to-Day Operations eb-5 SMWG 15 July 2008 Space Link Session Profile Carrier Profile Id [ carrier profile data ] DSN 7-Day Schedule Sequence Reference [ schedule data ] Mission Sequence Sequence Identifier [ mission sequence data ] Carrier Profile Reference DSN Sequence Sequence Reference [ dsn sequence data ] Carrier Profile Reference Key Information Entity Relationships eb-6 SMWG 15 July 2008 Fundamental Approach One or more forward, return carrier profiles defined for usage scenarios on the HGA One or more forward, return carrier profiles defined for usage scenarios on the LGAs Approach is to orient carrier definition toward spacecraft, spacecraft usage, and direction to/from spacecraft (uplink/forward, downlink/return) Key parameters distinguishing carrier definitions for DSN Frequency EIRP (forward and return links) Polarization Modulation scheme Tune-in scheme (forward carrier) Coherence Model (return carrier) eb-7 SMWG 15 July 2008 Space Link Available State from Spacecraft perspective Approach is to orient carrier definition toward spacecraft, spacecraft usage, and direction to/from spacecraft (uplink/forward, downlink/return) If the approach is spacecraft oriented, then from a spacecraft perspective Return Space Link is still available (Forward Space Link is unavailable) If the approach is spacecraft oriented, then who/what deals with geometry if from S/C perspective RSL continues to be available, but TLM, etc service is not? DSN returns service interruption (geometric or other ground induced) information How is continuous radiation of return carrier to be stated for occultation type situations ? eb-8 SMWG 15 July 2008 Recap: Overall Approach Approach is to orient carrier definition toward spacecraft, spacecraft usage, and direction to/from spacecraft (uplink/forward, downlink/return) What about time? If the approach is spacecraft oriented, then, by definition, spacecraft events are at spacecraft ephemeris time From DSN perspective, events are at earth receive time Units = UTC (ie SCET UTC, ERT UTC) Mission spacecraft event sequence SCET UTC DSN e vent sequence Mission ERT UTC DSN echoes SCET UTC and return ERT UTC for mission verification purposes eb-9 SMWG 15 July 2008 Recap: Overall Approach Approach is to orient carrier definition toward spacecraft, spacecraft usage, and direction to/from spacecraft (uplink/forward, downlink/return) What about service events that do not relate directly to S/C carrier, like DOR antenna slews ? If the approach is spacecraft oriented, then, by definition, spacecraft events are about whether or not DOR Tones are on/off DSN returns service interruption (geometric or other ground induced) information eb-10 SMWG 15 July 2008 State Definition Evolution eb-11 SMWG 15 July 2008 Example Timing Relationships (applied against real Messenger Sequence) Diagram: P. Pechkam eb-12 SMWG 15 July 2008 Mission Sequence: Structure Overview eb-13 SMWG 15 July 2008 Mission Sequence: Return Sequence Overview eb-14 SMWG 15 July 2008 Mission Sequence: Return Space Link Change Event Details Spinrate EIRP_OFFSET eb-15 SMWG 15 July 2008 Mission Sequence: Return Transport States eb-16 SMWG 15 July 2008 Return Sequence: Mission Controlled Ground Events Polarization Conscan/Monopulse Fixed/Stop/Track eb-17 SMWG 15 July 2008 Mission Sequence: Forward Sequence Overview eb-18 SMWG 15 July 2008 Mission Sequencde Forward Space Link Change Events eb-19 SMWG 15 July 2008 Mission Sequence: Forward Data Transport States eb-20 SMWG 15 July 2008 Mission Sequence: Forward sequence mission controlled ground events eb-21 SMWG 15 July 2008 DSN Sequence Overview ( Mission) eb-22 SMWG 15 July 2008 DSN Sequence: Return Sequence Overview eb-23 SMWG 15 July 2008 DSN Sequence: Forward Sequenc Overview eb-24 SMWG 15 July 2008 Space Link Session Profile Overview eb-25 SMWG 15 July 2008 Forward Spaclink Parameters eb-26 SMWG 15 July 2008 Return Space Link Parameters