chandra SPK file provided on 4/10/19 by Jon Giorgini of JPLs Solar System Dynamics Group. Giorgini writes: The new "chandra_merged.bsp" file includes the historical Chandra trajectory from launch through 2019-Apr-02 (CXO_10056_19245), with predicts to 2019-Sep-02. This is what is used currently in Horizons, with the trajectory data being supplied by CFA. BRIEF -- Version 4.0.0, September 8, 2010 -- Toolkit Version N0066 Summary for: chandra_merged.bsp Body: CHANDRA (-151) w.r.t. EARTH (399) Start of Interval (ET) End of Interval (ET) ------------------------ ------------------------ 1999 AUG 07 07:31:04.183 2019 SEP 02 12:01:09.182 Bodies: MERCURY BARYCENTER (1) w.r.t. SOLAR SYSTEM BARYCENTER (0) VENUS BARYCENTER (2) w.r.t. SOLAR SYSTEM BARYCENTER (0) EARTH BARYCENTER (3) w.r.t. SOLAR SYSTEM BARYCENTER (0) JUPITER BARYCENTER (5) w.r.t. SOLAR SYSTEM BARYCENTER (0) SATURN BARYCENTER (6) w.r.t. SOLAR SYSTEM BARYCENTER (0) URANUS BARYCENTER (7) w.r.t. SOLAR SYSTEM BARYCENTER (0) NEPTUNE BARYCENTER (8) w.r.t. SOLAR SYSTEM BARYCENTER (0) PLUTO BARYCENTER (9) w.r.t. SOLAR SYSTEM BARYCENTER (0) SUN (10) w.r.t. SOLAR SYSTEM BARYCENTER (0) MERCURY (199) w.r.t. MERCURY BARYCENTER (1) VENUS (299) w.r.t. VENUS BARYCENTER (2) MOON (301) w.r.t. EARTH BARYCENTER (3) EARTH (399) w.r.t. EARTH BARYCENTER (3) MARS (499) w.r.t. MARS BARYCENTER (4) Start of Interval (ET) End of Interval (ET) ------------------------ ------------------------ 1999 AUG 07 07:31:04.183 2019 SEP 02 12:01:09.182 ; chandra_merged.bsp LOG FILE ; Created 2019-04-02/13:02:18.19. ; ; BEGIN SPKMERGE COMMANDS LEAPSECONDS_KERNEL = /disk/data/leap-kernel SPK_KERNEL = chandra_merged.bsp LOG_FILE = chandra_merged.log SOURCE_SPK_KERNEL = ./cxo_99219_06045.bsp INCLUDE_COMMENTS = YES BODIES = -151 BEGIN_TIME = 1999 AUG 07 07:30:00.000 END_TIME = 2006 FEB 14 12:00:00.000 SOURCE_SPK_KERNEL = ./cxo_06002_10103.bsp INCLUDE_COMMENTS = YES BODIES = -151 BEGIN_TIME = 2006 FEB 14 12:00:00.000 END_TIME = 2010 FEB 25 12:00:01.000 SOURCE_SPK_KERNEL = ./CXO_10056_19245.bsp INCLUDE_COMMENTS = YES BODIES = -151 BEGIN_TIME = 2010 FEB 25 12:00:01.000 END_TIME = 2019 SEP 02 11:59:59.999 SOURCE_SPK_KERNEL = /disk/ftp/pub/eph/planets/bsp/de403.bsp INCLUDE_COMMENTS = NO BODIES = 1, 2, 3, 5, 6, 7, 8, 9, 10, 199, 299, 301, 399, 499 BEGIN_TIME = 1999 AUG 07 07:30:00.000 END_TIME = 2019 SEP 02 11:59:59.999 ; END SPKMERGE COMMANDS Chandra X-ray Observatory (CXO) formerly Advanced X-ray Astrophysics Facility (AXAF) JPL spacecraft ID -151 Launched July 23, 1999 by STS-93 Operated for NASA/MSFC by Smithsonian Astrophysical Observatory Cambridge, MA http://chandra.harvard.edu SPICE SPK ephemeris file OUTPUT_SPK_TYPE = 9 POLYNOM_DEGREE = 7 CENTER_NAME = 'EARTH' REF_FRAME_NAME = 'J2000' Ephemeris Interval: 1999-219T07:30:00.000 to 2006-045T12:00:00.000 UTC ; ../merged_bsp/CXO_06002_10103.bsp LOG FILE ; Created 2010-04-01/18:31:52.00. ; ; BEGIN SPKMERGE COMMANDS LEAPSECONDS_KERNEL = naif0009.tls SPK_KERNEL = ../merged_bsp/CXO_06002_10103.bsp LOG_FILE = ../merged_bsp/CXO_06002_10103.log SOURCE_SPK_KERNEL = ../pe_bsp/pe10053.bsp INCLUDE_COMMENTS = NO BODIES = -151 BEGIN_TIME = 2010 FEB 22 12:00:00.000 END_TIME = 2010 APR 13 04:00:00.000 SOURCE_SPK_KERNEL = ../pe_bsp/pe10049.bsp INCLUDE_COMMENTS = NO BODIES = -151 BEGIN_TIME = 2010 FEB 18 12:00:00.000 END_TIME = 2010 FEB 22 12:00:00.000 SOURCE_SPK_KERNEL = ../pe_bsp/pe10046.bsp INCLUDE_COMMENTS = NO BODIES = -151 BEGIN_TIME = 2010 FEB 15 12:00:00.000 END_TIME = 2010 FEB 18 12:00:00.000 SOURCE_SPK_KERNEL = ../pe_bsp/pe10042.bsp INCLUDE_COMMENTS = NO BODIES = -151 BEGIN_TIME = 2010 FEB 11 12:00:00.000 END_TIME = 2010 FEB 15 12:00:00.000 SOURCE_SPK_KERNEL = ../pe_bsp/pe10040.bsp INCLUDE_COMMENTS = NO BODIES = -151 BEGIN_TIME = 2010 FEB 09 12:00:00.000 END_TIME = 2010 FEB 11 12:00:00.000 SOURCE_SPK_KERNEL = ../pe_bsp/pe10035.bsp INCLUDE_COMMENTS = NO BODIES = -151 BEGIN_TIME = 2010 FEB 04 12:00:00.000 END_TIME = 2010 FEB 09 12:00:00.000 SOURCE_SPK_KERNEL = ../pe_bsp/pe10032.bsp INCLUDE_COMMENTS = NO BODIES = -151 BEGIN_TIME = 2010 FEB 01 12:00:00.000 END_TIME = 2010 FEB 04 12:00:00.000 SOURCE_SPK_KERNEL = ../pe_bsp/pe10028.bsp INCLUDE_COMMENTS = NO BODIES = -151 BEGIN_TIME = 2010 JAN 28 12:00:00.000 END_TIME = 2010 FEB 01 12:00:00.000 SOURCE_SPK_KERNEL = ../pe_bsp/pe10025.bsp INCLUDE_COMMENTS = NO BODIES = -151 BEGIN_TIME = 2010 JAN 25 12:00:00.000 END_TIME = 2010 JAN 28 12:00:00.000 SOURCE_SPK_KERNEL = ../pe_bsp/pe10021.bsp INCLUDE_COMMENTS = NO BODIES = -151 BEGIN_TIME = 2010 JAN 21 12:00:00.000 END_TIME = 2010 JAN 25 12:00:00.000 SOURCE_SPK_KERNEL = ../pe_bsp/pe10018.bsp INCLUDE_COMMENTS = NO BODIES = -151 BEGIN_TIME = 2010 JAN 18 12:00:00.000 END_TIME = 2010 JAN 21 12:00:00.000 SOURCE_SPK_KERNEL = ../pe_bsp/pe10014.bsp INCLUDE_COMMENTS = NO BODIES = -151 BEGIN_TIME = 2010 JAN 14 12:00:00.000 END_TIME = 2010 JAN 18 12:00:00.000 SOURCE_SPK_KERNEL = ../pe_bsp/pe10012.bsp INCLUDE_COMMENTS = NO BODIES = -151 BEGIN_TIME = 2010 JAN 12 12:00:00.000 END_TIME = 2010 JAN 14 12:00:00.000 SOURCE_SPK_KERNEL = ../pe_bsp/pe10007.bsp INCLUDE_COMMENTS = NO BODIES = -151 BEGIN_TIME = 2010 JAN 07 12:00:00.000 END_TIME = 2010 JAN 12 12:00:00.000 SOURCE_SPK_KERNEL = ../pe_bsp/pe10004.bsp INCLUDE_COMMENTS = NO BODIES = -151 BEGIN_TIME = 2010 JAN 04 12:00:00.000 END_TIME = 2010 JAN 07 12:00:00.000 SOURCE_SPK_KERNEL = ../pe_bsp/pe09365.bsp INCLUDE_COMMENTS = NO BODIES = -151 BEGIN_TIME = 2009 DEC 31 12:00:00.000 END_TIME = 2010 JAN 04 12:00:00.000 SOURCE_SPK_KERNEL = ../pe_bsp/pe09362.bsp INCLUDE_COMMENTS = NO BODIES = -151 BEGIN_TIME = 2009 DEC 28 12:00:00.000 END_TIME = 2009 DEC 31 12:00:00.000 SOURCE_SPK_KERNEL = ../merged_bsp/CXO_06002_10043.bsp INCLUDE_COMMENTS = NO BODIES = -151 BEGIN_TIME = 2006 JAN 02 12:00:00.000 END_TIME = 2009 DEC 28 12:00:00.000 ; END SPKMERGE COMMANDS Chandra X-ray Observatory (CXO) formerly Advanced X-ray Astrophysics Facility (AXAF) JPL spacecraft ID -151 Launched July 23, 1999 by STS-93 Operated for NASA/MSFC by Smithsonian Astrophysical Observatory Cambridge, MA http://chandra.harvard.edu SPICE SPK ephemeris file OUTPUT_SPK_TYPE = 9 POLYNOM_DEGREE = 7 CENTER_NAME = 'EARTH' REF_FRAME_NAME = 'J2000' Ephemeris Interval: 2006-002T12:00:00.000 to 2010-103T04:00:00.000 UTC ; /home/mission/FlightDynamics/HorizonsEphemeris/merged_sps/CXO_10056_19245.bsp ; Created 2019-04-02/13:56:54.00. ; ; BEGIN SPKMERGE COMMANDS LEAPSECONDS_KERNEL = /home/matlab_admin/matlab/SPICE/mice_Linux_32bit/data/naif0012.tls SPK_KERNEL = /home/mission/FlightDynamics/HorizonsEphemeris/merged_sps/CXO_10056_19245.bsp LOG_FILE = /home/mission/FlightDynamics/HorizonsEphemeris/merged_sps/CXO_10056_19245.log SOURCE_SPK_KERNEL = /home/mission/FlightDynamics/HorizonsEphemeris/stk_spk/chdr_19061_19245_stk.bsp INCLUDE_COMMENTS = NO BODIES = -151 BEGIN_TIME = 2019 MAR 02 12:00:00.000 END_TIME = 2019 SEP 02 12:00:00.000 SOURCE_SPK_KERNEL = /home/mission/FlightDynamics/HorizonsEphemeris/merged_sps/CXO_10056_19225.bsp INCLUDE_COMMENTS = NO BODIES = -151 BEGIN_TIME = 2010 FEB 25 12:00:00.000 END_TIME = 2019 MAR 02 12:00:00.000 ; END SPKMERGE COMMANDS Chandra X-ray Observatory (CXO) formerly Advanced X-ray Astrophysics Facility (AXAF) JPL spacecraft ID -151 Launched July 23, 1999 by STS-93 Operated for NASA/MSFC by Smithsonian Astrophysical Observatory Cambridge, MA http://chandra.harvard.edu SPICE SPK ephemeris file OUTPUT_SPK_TYPE = 9 POLYNOM_DEGREE = 7 CENTER_NAME = 'EARTH' REF_FRAME_NAME = 'J2000' Ephemeris Interval: 2010-056T12:00:00.000 to 2019-245T12:00:00.000 UTC