Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Wed Aug 5 12:00:37 PDT 2020 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 64124 through 65291): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2020 APR 01 00:01:10.000 2020 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_rec64186_64088_64186_r-v1.bsp spk_psp_rec64274_64184_64274_r-v1.bsp spk_psp_rec64361_64272_64361_r-v1.bsp spk_psp_rec64457_64360_64457_r-v1.bsp spk_psp_rec64546_64455_64546_r-v1.bsp spk_psp_rec64632_64544_64632_r-v1.bsp spk_psp_rec64723_64630_64723_r-v1.bsp spk_psp_rec64816_64721_64816_r-v1.bsp spk_psp_rec64905_64814_64905_r-v1.bsp spk_psp_rec64990_64903_64990_r-v1.bsp spk_psp_rec65082_64989_65082_r-v1.bsp spk_psp_rec65175_65080_65175_r-v1.bsp spk_psp_rec65265_65173_65265_r-v1.bsp spk_psp_rec65355_65263_65355_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_psp55.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 64133 2020-04-01T18:31:50.814 -0.000 -0.000 -0.000 64148 2020-04-02T22:41:50.814 0.000 -0.000 0.001 64161 2020-04-03T22:53:50.814 0.000 -0.000 0.000 64172 2020-04-04T19:27:50.814 -0.000 0.000 -0.001 64184 2020-04-05T16:51:50.814 0.000 -0.000 -0.001 64198 2020-04-06T20:04:50.814 -0.000 -0.000 -0.000 64205 2020-04-07T08:37:50.814 -0.000 0.000 0.000 64232 2020-04-09T11:39:50.814 0.000 0.000 0.001 64251 2020-04-10T23:11:50.814 -0.001 -0.000 -0.002 64264 2020-04-11T22:38:50.814 0.001 -0.000 -0.002 64272 2020-04-12T13:25:50.814 -0.001 -0.000 0.001 64291 2020-04-14T02:01:50.814 0.000 -0.000 -0.000 64302 2020-04-14T21:33:50.814 -0.000 0.000 0.000 64314 2020-04-15T21:00:50.814 -0.000 0.000 -0.001 64328 2020-04-16T23:10:50.814 0.001 0.000 0.002 64345 2020-04-18T06:59:50.814 0.001 0.000 0.003 64360 2020-04-19T09:59:50.814 0.000 -0.000 -0.000 64379 2020-04-20T22:29:50.814 0.000 -0.000 -0.000 64391 2020-04-21T21:00:50.814 0.001 -0.000 0.002 64402 2020-04-22T17:13:50.814 -0.001 -0.000 -0.002 64410 2020-04-23T08:32:50.814 0.001 -0.000 0.003 64431 2020-04-24T23:48:50.814 -0.000 -0.000 -0.000 64443 2020-04-25T21:53:50.814 -0.000 -0.000 -0.000 64455 2020-04-26T19:51:50.814 -0.000 0.000 0.000 64470 2020-04-27T23:57:50.814 -0.000 0.000 0.001 64490 2020-04-29T14:09:50.814 0.000 0.000 0.001 64503 2020-04-30T14:26:50.814 -0.001 0.000 -0.002 64520 2020-05-01T22:15:50.814 0.001 -0.000 0.002 64533 2020-05-02T22:33:50.814 -0.001 0.000 -0.003 64544 2020-05-03T18:10:50.814 -0.000 0.000 0.001 64559 2020-05-04T23:11:50.814 -0.000 -0.000 -0.001 64582 2020-05-06T18:18:50.814 0.000 -0.000 0.001 64593 2020-05-07T14:33:50.814 0.000 -0.000 0.000 64610 2020-05-08T22:33:50.814 -0.000 0.000 -0.001 64620 2020-05-09T17:15:50.814 0.000 0.000 0.000 64630 2020-05-10T10:59:50.814 -0.000 0.000 0.000 64649 2020-05-11T23:29:50.814 0.000 -0.000 0.001 64659 2020-05-12T18:11:50.814 0.000 0.000 0.001 64672 2020-05-13T18:29:50.814 0.000 0.000 0.001 64687 2020-05-14T22:28:50.814 -0.000 0.000 -0.002 64699 2020-05-15T20:59:50.814 0.000 -0.000 0.001 64711 2020-05-16T19:25:50.814 -0.000 0.000 -0.001 64721 2020-05-17T13:05:50.814 0.000 -0.000 -0.001 64734 2020-05-18T14:26:50.814 -0.000 0.000 -0.000 64747 2020-05-19T14:35:50.814 -0.000 -0.000 -0.001 64764 2020-05-20T22:32:50.814 -0.000 -0.000 -0.000 64778 2020-05-21T23:57:50.814 -0.000 0.000 0.000 64789 2020-05-22T21:17:50.814 0.000 0.000 0.002 64801 2020-05-23T19:43:50.814 -0.001 0.000 -0.003 64814 2020-05-24T19:39:50.814 0.000 0.000 0.001 64834 2020-05-26T09:26:50.814 0.000 -0.000 0.002 64851 2020-05-27T17:14:50.815 0.000 -0.000 0.000 64867 2020-05-28T23:09:50.815 0.000 0.000 0.002 64880 2020-05-29T23:27:50.815 -0.000 0.000 -0.002 64890 2020-05-30T18:09:50.815 0.000 -0.000 0.001 64903 2020-05-31T17:31:50.815 -0.000 -0.000 0.001 64919 2020-06-01T23:57:50.815 0.000 0.000 0.000 64931 2020-06-02T22:50:50.815 -0.000 0.000 -0.002 64944 2020-06-03T23:08:50.815 0.000 0.000 0.001 64957 2020-06-04T23:27:50.815 -0.000 0.000 -0.000 64970 2020-06-05T23:45:50.815 -0.000 0.000 -0.000 64981 2020-06-06T20:20:50.815 0.000 0.000 0.001 64989 2020-06-07T10:15:50.815 0.000 0.000 -0.000 65003 2020-06-08T13:28:50.815 0.000 0.000 0.001 65023 2020-06-10T02:54:50.815 -0.001 0.000 -0.003 65033 2020-06-10T21:11:50.815 0.001 -0.000 0.002 65051 2020-06-12T07:13:50.815 -0.001 0.000 -0.007 65070 2020-06-13T18:42:50.815 -0.001 0.000 -0.007 65080 2020-06-14T12:25:50.815 0.002 0.000 -0.015 65093 2020-06-15T13:46:50.815 -0.000 0.000 -0.001 65106 2020-06-16T14:04:50.815 0.000 -0.000 0.002 65119 2020-06-17T13:51:50.815 0.000 0.000 -0.000 65132 2020-06-18T14:28:50.815 -0.001 0.000 -0.003 65150 2020-06-19T23:57:50.815 0.000 0.000 0.000 65159 2020-06-20T17:07:50.815 -0.000 0.000 -0.001 65173 2020-06-21T18:20:50.815 -0.000 -0.000 0.001 65192 2020-06-23T06:17:50.815 -0.000 0.000 0.001 65209 2020-06-24T14:37:50.815 0.001 -0.000 0.005 65222 2020-06-25T14:59:50.815 -0.001 -0.000 -0.005 65239 2020-06-26T22:46:50.815 0.001 0.000 0.004 65251 2020-06-27T21:12:50.815 -0.001 0.000 -0.004 65263 2020-06-28T18:37:50.815 0.000 -0.000 -0.002 65280 2020-06-30T03:26:50.815 -0.000 -0.000 -0.001