Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Fri Jul 30 03:36:49 PDT 2021 Objects in the Ephemeris -------------------------------------------------------- This SPK file contains ephemeris data for the Mars Reconnaissance Orbiter (MRO) spacecraft. The NAIF ID code for MRO is -74. Approximate Time Coverage -------------------------------------------------------- This file covers the following part of the Extended Science Phase of the MRO mission (orbits 68810 through 69978): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2021 APR 01 00:01:10.000 2021 JUL 01 01:01:09.184 Status -------------------------------------------------------- This file was created by merging regular reconstructed OD solution SPK files produced by the MRO NAV team during the Extended Science Phase of the mission. This file was created by NAIF for archiving in the Planetary Data System (PDS). Pedigree -------------------------------------------------------- The original SPK files used to create this file contained only reconstructed trajectory. They were officially delivered to the MRO project data base by the MRO NAV team. The list of the original files data from which has been merged into this file is provided in Appendix 1 of these comments. Segment Boundary Discontinuities -------------------------------------------------------- This SPK file contains a large number of SPK segments that came from original individual SPK files. Although, each segment provides continuous trajectory within the interval that it covers, in general a position and velocity discontinuity exists at the boundary of the segment and the segments whose coverages immediately precede or follow it. The times and magnitudes of these discontinuities are provided in Appendix 2 of these comments. Usage -------------------------------------------------------- This file should be used together with DE414 planetary ephemeris and MAR063 satellite ephemeris since the original SPK files contained subsets of these particular ephemeris in them. Contacts -------------------------------------------------------- If you have questions regarding this data contact Boris V. Semenov (818)-354-8136 Boris.Semenov@jpl.nasa.gov Appendix 1: Original SPK List -------------------------------------------------------- The original SPK files, the data from which has been included into this file, are: spk_psp_rec68860_68769_68860_r-v1.bsp spk_psp_rec68947_68855_68947_r-v1.bsp spk_psp_rec69040_68945_69040_r-v1.bsp spk_psp_rec69129_69037_69129_r-v1.bsp spk_psp_rec69220_69127_69220_r-v1.bsp spk_psp_rec69309_69218_69309_r-v1.bsp spk_psp_rec69399_69307_69399_r-v1.bsp spk_psp_rec69488_69397_69488_r-v1.bsp spk_psp_rec69580_69485_69580_r-v1.bsp spk_psp_rec69670_69577_69670_r-v1.bsp spk_psp_rec69758_69667_69758_r-v1.bsp spk_psp_rec69845_69755_69845_r-v1.bsp spk_psp_rec69937_69842_69937_r-v1.bsp spk_psp_rec70027_69934_70027_r-v1.bsp Appendix 2: Segment Boundary Discontinuity Summary -------------------------------------------------------- This SPK file contains a large number of SPK segments that came from original individual SPK files. Although, each segment provides continuous trajectory within the interval that it covers, in general a position and velocity discontinuity exists at the boundary of the segment and the segments whose coverage immediately precede and follow it. The times and magnitudes of these discontinuities are provided in the table included in this Appendix. The top portion of the table contains the name of this SPK file. All descriptive lines in the top portion of the file start with the ``#'' character to allow direct plotting of the data in the freeware ``gnuplot'' application. The table consists of 5 columns. The first column is the orbit number within which a segment boundary with discontinuity occurs. The next column contains the UTC time of that segment boundary. The last three columns (3..5) contain view coordinate frame components -- ``down track'' (this direction is parallel to the velocity vector), ``normal to plane'' (this direction is computed as cross product of position vector by velocity vector) and ``in plane'' (this direction is computed as a cross product of ``down track'' by ``normal to plane'') -- of the difference between the state vectors computed at that UTC time defining segment boundary at which a discontinuity exists. The pairs of segments and discontinuity times are determined using an algorithm that emulates the standard SPK loading priority -- ``last loaded segment takes precedence''. Therefore, the discontinuities summarized in the file are those which a user reading file would actually see. The difference components in the view coordinate frame were computed for each discontinuity using the following algorithm: -- A single state was computed from each pair of segment the J2000 frame at the time of discontinuity. -- For this pair of states, a position difference vector was computed by subtracting the state computed from the segment with higher priority from the state computed from segment with lower priority. Then, a frame transformation matrix rotating these difference vectors from J2000 to the view coordinate frame defined by the state obtained from the higher priority segment was computed, and the position difference vector was rotated to the view frame coordinates using this matrix. The segment boundary discontinuities for this file are: # # Summary of discontinuities at segment boundaries for # SPK file ./mro_psp59.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 68822 2021-04-01T22:44:50.814 0.019 0.000 -0.003 68834 2021-04-02T22:40:50.814 -0.010 -0.000 -0.000 68847 2021-04-03T22:44:50.814 0.006 -0.000 0.001 68855 2021-04-04T12:45:50.814 0.004 -0.000 -0.001 68873 2021-04-05T22:39:50.814 -0.011 0.000 0.000 68886 2021-04-06T22:38:50.814 0.012 0.000 -0.002 68897 2021-04-07T20:24:50.814 -0.012 0.000 -0.001 68912 2021-04-08T23:34:50.814 0.014 -0.000 0.000 68925 2021-04-09T23:57:50.814 -0.007 0.000 -0.000 68937 2021-04-10T22:38:50.814 -0.009 -0.000 -0.002 68945 2021-04-11T12:33:50.814 -0.001 0.000 0.000 68963 2021-04-12T22:38:50.814 -0.016 0.000 0.002 68976 2021-04-13T22:33:50.814 -0.001 -0.000 0.000 68988 2021-04-14T22:28:50.814 -0.002 -0.000 -0.000 69001 2021-04-15T22:28:50.814 0.005 0.000 0.001 69014 2021-04-16T22:28:50.814 0.022 0.000 0.003 69027 2021-04-17T22:28:50.814 -0.010 0.000 0.001 69037 2021-04-18T16:32:50.814 0.005 -0.000 -0.001 69053 2021-04-19T22:11:50.814 0.019 0.000 0.001 69065 2021-04-20T22:17:50.814 -0.011 -0.000 -0.002 69082 2021-04-22T05:42:50.814 -0.006 -0.000 -0.001 69104 2021-04-23T21:32:50.814 0.006 0.000 0.000 69117 2021-04-24T22:17:50.814 0.005 0.000 -0.001 69127 2021-04-25T17:57:50.814 0.000 0.000 0.000 69143 2021-04-26T23:57:50.814 0.007 0.000 0.002 69155 2021-04-27T22:17:50.814 -0.008 0.000 -0.002 69169 2021-04-28T23:57:50.814 -0.000 0.000 0.000 69181 2021-04-29T22:12:50.814 0.017 -0.000 -0.004 69194 2021-04-30T21:50:50.814 0.001 0.000 0.000 69208 2021-05-01T23:57:50.814 -0.004 0.000 -0.000 69218 2021-05-02T19:00:50.814 0.009 0.000 -0.001 69230 2021-05-03T18:07:50.814 0.003 -0.000 -0.000 69245 2021-05-04T22:07:50.814 0.004 -0.000 -0.000 69263 2021-05-06T06:50:50.814 0.000 -0.000 0.000 69277 2021-05-07T09:01:50.814 -0.011 -0.000 -0.001 69293 2021-05-08T16:11:50.814 0.014 -0.000 0.002 69307 2021-05-09T17:24:50.814 -0.009 -0.000 0.002 69322 2021-05-10T21:56:50.814 -0.004 -0.000 0.001 69336 2021-05-11T23:57:50.814 -0.001 -0.000 0.000 69349 2021-05-12T23:57:50.814 -0.012 -0.000 0.002 69360 2021-05-13T21:56:50.814 0.027 0.000 0.006 69374 2021-05-14T23:57:50.814 -0.003 0.000 -0.001 69386 2021-05-15T21:26:50.814 -0.002 -0.000 0.001 69397 2021-05-16T17:41:50.814 -0.006 0.000 0.001 69417 2021-05-18T06:46:50.814 -0.013 -0.000 -0.002 69437 2021-05-19T21:46:50.814 0.008 0.000 0.002 69450 2021-05-20T21:41:50.814 -0.009 0.000 -0.001 69464 2021-05-21T23:57:50.814 -0.005 0.000 -0.001 69473 2021-05-22T17:06:50.814 -0.001 0.000 -0.000 69485 2021-05-23T14:13:50.814 0.009 -0.000 -0.002 69497 2021-05-24T13:51:50.814 0.020 0.000 0.006 69514 2021-05-25T21:35:50.814 -0.020 -0.000 -0.006 69526 2021-05-26T19:21:50.814 0.005 -0.000 -0.001 69540 2021-05-27T21:10:50.815 0.013 -0.000 -0.003 69551 2021-05-28T17:15:50.815 -0.001 0.000 -0.000 69567 2021-05-29T23:57:50.815 -0.010 0.000 0.003 69577 2021-05-30T18:13:50.815 0.007 -0.000 -0.001 69593 2021-05-31T23:50:50.815 0.006 0.000 0.001 69604 2021-06-01T21:20:50.815 -0.003 0.000 0.000 69627 2021-06-03T15:24:50.815 0.005 0.000 0.001 69642 2021-06-04T20:40:50.815 -0.007 0.000 -0.001 69654 2021-06-05T18:40:50.815 -0.006 -0.000 0.002 69667 2021-06-06T18:29:50.815 0.004 -0.000 -0.001 69681 2021-06-07T20:55:50.815 0.009 -0.000 -0.003 69694 2021-06-08T21:10:50.815 0.016 0.001 -0.006 69707 2021-06-09T20:55:50.815 -0.019 0.000 -0.004 69720 2021-06-10T21:15:50.815 0.007 0.000 0.001 69731 2021-06-11T18:25:50.815 -0.006 -0.000 0.002 69746 2021-06-12T21:51:50.815 0.009 0.000 0.002 69755 2021-06-13T16:05:50.815 0.002 0.000 0.001 69771 2021-06-14T22:09:50.815 -0.010 -0.000 -0.004 69785 2021-06-15T23:57:50.815 0.008 -0.000 0.000 69796 2021-06-16T20:49:50.815 0.002 0.000 0.001 69806 2021-06-17T15:03:50.815 0.000 0.000 -0.000 69823 2021-06-18T23:34:50.815 -0.007 -0.000 -0.003 69834 2021-06-19T18:24:50.815 -0.002 -0.000 -0.001 69842 2021-06-20T09:50:50.815 -0.012 -0.000 0.004 69857 2021-06-21T14:14:50.815 -0.007 -0.000 0.003 69873 2021-06-22T20:44:50.815 -0.002 0.000 -0.001 69888 2021-06-24T00:53:50.815 0.002 0.000 0.001 69901 2021-06-24T23:40:50.815 0.003 0.000 0.001 69913 2021-06-25T22:07:50.815 -0.001 0.000 -0.000 69926 2021-06-26T23:57:50.815 0.001 0.000 0.000 69934 2021-06-27T13:52:50.815 -0.000 0.000 0.000 69951 2021-06-28T22:58:50.815 -0.000 -0.000 -0.000 69963 2021-06-29T20:24:50.815 -0.006 0.000 0.003 69975 2021-06-30T19:50:50.815 0.000 -0.000 0.000