Exchanging Databases with Dissimilar Systems Using CCSDS XTCE CCSDS Spacecraft Monitoring & Control WG And OMG Space Domain Task Force Presented by Mario Merri, ESA

Outline Where does XTCE come from? Its goals and benefits How does it work? Usage so far Conclusions GSAW 2006

XTCE History Object Management Group (OMG) standard originally developed by European Space Agency US Air force/Mission Operations (Lockheed Martin) Boeing Communications & Satellites NASA & JPL Being adopted by CCSDS via Agency Review under responsibility of SM&C WG GSAW 2006

CCSDS SM&C and XTCE ESA BNSC CNES CSA DLR INPE JAXA NASA/GSFC NASA/JPL M Merri (chairman), M Schmidt, A Ercolani, J Muller I Dankiewicz, S Cooper BNSC R Thompson (deputy chairman), B Harnett CNES B Béhal, E Poupart, R Soumagne CSA P Melanson DLR H Hofmann INPE PG Milani, AM Ambrosio JAXA T Yamada NASA/GSFC DC Lokerson, F Johnson, JK Marquart, JS Gal-Edd, C Fatig, R Jones , K Rice NASA/JPL A Oyake, P Shames, J Moholt ASI C Labonia OMG G Simon (Lockheed Martin), B Kizzort (Harris Corp.) XTCE Splinter Group GSAW 2006

XTCE Goals XML-based non-proprietary standard format for TM/TC databases Reduces human errors, ambiguities, confusion, and lost time in difficult, sometimes lossy (painful), conversions between systems GSAW 2006

Application field Exchange between Reuse database Reduce costs working teams missions systems agencies Reuse database Reduce costs Planning Scheduling XTCE Format Instrument Manufacturers Command Management Spacecraft Manufacturers Real time Simulators Trending Analysis GSAW 2006

XTCE Benefits Better interoperation between space agencies and contractors (or any other actor) Let different philosophies collaborate in one data model Accept time division multiplexing, packet TM Separate “pure” telemetry and telecommand data from dedicated/proprietary processing data GSAW 2006

XTCE in a nutshell (1/8) An XML schema file representing telemetry and telecommand data required for: Channel (de)coding and frame processing Data transmission and packaging Parameters calibrations, alarms, properties Telecommand definitions, transmissions (pre and post checks) … GSAW 2006

XTCE in a nutshell (2/8) XTCE separate information and describe a hierarchy of space systems The granularity of space systems is let to the user That hierarchy allows integration of multiple databases into one overall database ex: multi-satellite missions, multi-instrument satellite GSAW 2006

XTCE in a nutshell (2*/8) One satellite DB Space System Spacecraft level Space System Space System One satellite DB Instrument level Space System Space System Device level GSAW 2006

XTCE in a nutshell (2**/8) Space System Constellation level Space System Space System Multi-satellite DB Satellite level Space System Space System Instrument level GSAW 2006

XTCE in a nutshell (3/8) A space system in XTCE is able to describe: Telemetry parameters, packaging and dedicated processing Telecommand parameters, commands, packaging and dedicated processing Streams (up and down, with coding information) Maintain minimal configuration information TM and TC definitions are 80% similar GSAW 2006

XTCE in a nutshell (4/8) Header for configuration data Space System Header for configuration data Default for generic settings Services for frames identification Telemetry and Telecommand … Header Defaults Telemetry Telecommand Services GSAW 2006

XTCE in a nutshell (5/8) Telemetry data is distributed in several elements: Parameter types Parameters (instances of parameter types) Containers Messages Streams Algorithms GSAW 2006

XTCE in a nutshell (6/8) Logical definitions sequence: Parameter types (alarms, calibrations) Parameter instances Containers Streams, messages and algorithms Example: CCSDS TM frames, packets and XTCE containers GSAW 2006

XTCE in a nutshell (7/8) Parameters are put in sequence to form packets (containers) Packets are put together to form frames Streams are defined on top of generic frames Frame primary header Frame secondary header Frame data field Op.ctrl Err.ctrl Frame Packet Packet header Packet data field Ver # Type P.hdr f APID Gr. f SSC P.h.len Packet header GSAW 2006

XTCE in a nutshell (8/8) Telecommand data is distributed in several elements: Parameter types Parameters Containers Messages Streams Algorithms GSAW 2006

XTCE application so far James Webb Space Telescope XML schema have been converted SCOS-2000 ASCII files have been converted (other examples?) GSAW 2006

CCSDS Documentation Draft CCSDS Green book release along with XTCE1.1 for internal CCSDS review CCSDS Magenta book (detailed user guide) is being written GSAW 2006

Conclusions Working with XML is of easy access due to the amount of libraries and tools available to work with XML schemas The concepts implemented by XTCE are powerful and have the capabilities to represent any legacy system TM & TC database Non TM&TC data is not considered in XTCE; (dedicated software instructions, SW configuration variables) GSAW 2006

Questions and Answers ? GSAW 2006