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 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

5. GSAW 2006 5 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

6. GSAW 2006 6 XTCE Format Exchange between –working teams –missions –systems –agencies ►Reuse database ►Reduce costs Application field Planning Scheduling Command Management Real time Trending Analysis Simulators Spacecraft Manufacturers Instrument Manufacturers

7. GSAW 2006 7 XTCE Benefits Better interoperation between space agencies and contractors (or any other actor) Lets different philosophies collaborate in one data model –Accepts time division multiplexing, packet TM Separates “pure” telemetry and telecommand data from dedicated/proprietary processing data

8. GSAW 2006 8 XTCE in a nutshell (1/8) An XML Schema language describing 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) –…

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) That hierarchy allows integration of multiple databases into one overall database –ex: 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 TM and TC definitions are 80% similar

13. GSAW 2006 13 XTCE in a nutshell (4/8) Header for configuration data Default for generic settings Services for frames identification Telemetry and Telecommand … 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 SCOS-2000 ASCII files have been converted (other examples?) [ we may want to talk to Harris and Boeing about putting their work in here? –KR]

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

20. GSAW 2006 20 Conclusions XML is easy to work with due to the amount of libraries and tools available for it, and its broad industry acceptance XTCE powerful concepts are ideal for represent any legacy system TM & TC database [ that’s may little too strong… but something like that –kr] Non TM&TC data is not considered in XTCE; (dedicated software instructions, SW configuration variables) [ this actually may should be mentioned earlier in XTCE in a nutshell section…-kr]

21. GSAW 2006 21 Questions and Answers ?