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

2. GSAW 2006 2 Outline Where does XTCE come from? Its goals and benefits How does it work? Usage so far Conclusions

3. GSAW 2006 3 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

4. GSAW 2006 4 CCSDS SM&C and XTCE ESA –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 XTCE Splinter Group 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.)

5. GSAW 2006 5 XTCE Goal XML-based non-proprietary standard format for exchanging TM/TC databases that will reduce human errors ambiguities, confusion, and lost time and money in difficult, sometimes lousy (painful) conversions between dissimilar systems

6. GSAW 2006 6 XTCE Format Exchange between –working teams –missions –systems –agencies ►Adapt only I/O ►Reuse legacy systems ►Reduce costs Application Field Planning Scheduling Command Management Real time Trending Analysis Simulators Spacecraft Manufacturers Instrument Manufacturers

7. GSAW 2006 7 XTCE Benefits Allows better interoperability –Across organisations (e.g. JWST) –Within a mission (e.g. S/C prime -> operations) Lets different philosophies collaborate in one data model Separates “pure” telemetry and telecommand data from dedicated/proprietary processing data Able to extend for data items not currently defined

8. GSAW 2006 8 XTCE in a nutshell (1/8) An XML Schema language describing data for: –Telemetry definitions –Data transmission and packaging –TM/TC parameter properties –Telecommand definitions Non TM&TC data is not considered part of XTCE (e.g. dedicated software instructions, SW configuration variables, page definitions, real- time scripts, etc.) TM and TC definitions are 80% similar between space systems

9. GSAW 2006 9 XTCE in a nutshell (2/8) XTCE describes a “SpaceSystem” - command & telemetry descriptions, in a hierarchical format The granularity of a space system’s description is left to the user, e.g. SpaceSystem may contain SpaceSystem(s) The hierarchy allows integration of multiple databases into one overall database –E.g.: multi-satellite missions, multi-instrument satellite

10. GSAW 2006 10 XTCE in a nutshell (2*/8) Space System Spacecraft level Instrument level Device level

11. GSAW 2006 11 XTCE in a nutshell (2**/8) Space System Constellation level Satellite level Instrument level

12. GSAW 2006 12 XTCE in a nutshell (3/8) A space system in XTCE is able to describe: –Telemetry parameters, their packaging and dedicated processing –Telecommand parameters, commands, its packaging and dedicated processing –Streams (up and down, with coding information) –Maintain minimal configuration information –Conversion information –Limits and pre/post command checks

13. GSAW 2006 13 XTCE in a nutshell (4/8) Header for configuration data Default for generic settings Telemetry for core data Telecommand for core data Services for frames identification Space System Header Defaults Telemetry Services Telecommand

14. GSAW 2006 14 XTCE in a nutshell (5/8) Telemetry data is distributed in several elements: –Parameter types –Parameters (instances of parameter types) –Containers (aka packets) –Messages –Streams –Algorithms

15. GSAW 2006 15 XTCE in a nutshell (6/8) Logical sequence of definitions: –Parameter types (alarms, calibrations) –Parameter instances –Containers (Packets) –Streams, messages and algorithms Example: CCSDS TM frames, packets and XTCE containers

16. GSAW 2006 16 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.ctrlErr.ctrl Packet headerPacket data field Ver #TypeP.hdr fAPIDGr. fSSCP.h.len Frame Packet Packet header

17. GSAW 2006 17 XTCE in a nutshell (8/8) Telecommand data is distributed in several elements: –Parameter types –Parameters –Containers –Messages –Streams –Algorithms

18. GSAW 2006 18 XTCE Applications so far James Webb Space Telescope XML Schema have been converted –Future work includes exchanging database with other archive systems and control center real-time systems SCOS-2000 ASCII files have been converted Hardware vendors deliver the database information in XTCE format to the spacecraft integrator on some US programs

19. GSAW 2006 19 CCSDS Documentation Draft CCSDS Green book release along with XTCE1.1 for internal CCSDS review CCSDS Magenta book (detailed user guide) is being written CCSDS Red Book released

20. GSAW 2006 20 Conclusions XML self-describing nature reduces learning curve and errors XML is easy to work with, due to the amount of libraries, tools, and broad industry acceptance XTCE powerful concepts are ideal for exchanging legacy, current and future TM & TC databases to planning systems, engineering analysis tools, and real-time command and control systems Easily translated between the project XML database format and XTCE, no longer just a concept but being used internationally XTCE covers about 80% of the TM/TC definitions reducing the errors between dissimilar systems

21. GSAW 2006 21 Questions and Answers ?