Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Wed Aug 2 17:24:48 PDT 2023 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 78180 through 79346): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2023 APR 01 00:01:10.000 2023 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_rec78204_78113_78204_r-v1.bsp spk_psp_rec78294_78203_78294_r-v1.bsp spk_psp_rec78372_78291_78372_r-v1.bsp spk_psp_rec78468_78371_78468_r-v1.bsp spk_psp_rec78560_78465_78560_r-v1.bsp spk_psp_rec78653_78557_78653_r-v1.bsp spk_psp_rec78742_78650_78742_r-v1.bsp spk_psp_rec78832_78739_78832_r-v1.bsp spk_psp_rec78920_78829_78920_r-v1.bsp spk_psp_rec79012_78918_79012_r-v1.bsp spk_psp_rec79100_79009_79100_r-v1.bsp spk_psp_rec79191_79098_79191_r-v1.bsp spk_psp_rec79281_79190_79281_r-v1.bsp spk_psp_rec79370_79281_79370_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_psp67.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 78189 2023-04-01T18:36:50.814 0.004 0.000 0.000 78203 2023-04-02T21:48:50.814 0.005 -0.000 -0.000 78217 2023-04-03T23:57:50.814 0.000 -0.000 -0.000 78228 2023-04-04T20:46:50.814 -0.000 0.000 -0.000 78240 2023-04-05T18:56:50.814 -0.012 0.001 0.001 78254 2023-04-06T20:11:50.814 0.006 -0.000 0.001 78266 2023-04-07T20:01:50.814 0.012 0.000 0.002 78278 2023-04-08T18:26:50.814 -0.010 0.000 -0.002 78291 2023-04-09T17:45:50.814 -0.003 -0.000 0.000 78307 2023-04-10T23:56:50.814 0.003 -0.000 -0.000 78318 2023-04-11T20:41:50.814 -0.001 -0.000 0.000 78332 2023-04-12T23:51:50.814 0.009 0.000 0.001 78343 2023-04-13T20:26:50.814 -0.013 -0.000 -0.002 78356 2023-04-14T20:21:50.814 0.010 -0.000 0.002 78371 2023-04-15T23:23:50.814 0.008 0.000 -0.001 78388 2023-04-17T06:53:50.814 0.009 -0.000 0.001 78409 2023-04-18T23:00:50.814 -0.003 0.000 0.000 78422 2023-04-19T23:40:50.814 0.002 0.000 0.000 78435 2023-04-20T23:25:50.814 -0.016 0.000 0.004 78448 2023-04-21T23:07:50.814 0.001 0.000 0.000 78465 2023-04-23T07:19:50.814 0.012 0.000 -0.002 78487 2023-04-24T23:57:50.814 -0.003 0.000 -0.001 78498 2023-04-25T20:38:50.814 0.013 0.000 0.001 78508 2023-04-26T15:21:50.814 -0.010 -0.000 -0.001 78524 2023-04-27T22:22:50.814 0.002 -0.000 0.000 78537 2023-04-28T23:09:50.814 -0.002 -0.000 -0.000 78549 2023-04-29T21:17:50.814 -0.004 0.000 -0.001 78557 2023-04-30T11:17:50.814 -0.007 0.000 0.001 78574 2023-05-01T19:54:50.814 0.008 -0.000 0.001 78585 2023-05-02T16:13:50.814 -0.013 0.000 0.002 78614 2023-05-04T23:09:50.814 -0.001 0.000 -0.000 78626 2023-05-05T20:54:50.814 0.014 -0.000 -0.002 78638 2023-05-06T18:29:50.814 -0.004 0.000 -0.001 78650 2023-05-07T17:14:50.814 -0.005 0.000 0.001 78666 2023-05-08T23:57:50.814 -0.013 0.000 -0.001 78684 2023-05-10T10:09:50.814 0.004 -0.000 0.001 78704 2023-05-11T21:55:50.814 0.006 0.000 0.001 78718 2023-05-12T23:57:50.814 -0.016 -0.000 -0.004 78729 2023-05-13T21:18:50.814 0.018 -0.000 -0.006 78739 2023-05-14T15:41:50.814 -0.009 -0.000 0.001 78752 2023-05-15T16:03:50.814 0.001 0.000 -0.000 78768 2023-05-16T22:03:50.814 0.004 0.000 -0.001 78781 2023-05-17T22:33:50.814 -0.001 0.000 0.000 78794 2023-05-18T22:38:50.814 -0.005 -0.000 0.001 78807 2023-05-19T23:57:50.814 0.002 -0.000 0.001 78818 2023-05-20T19:07:50.814 0.007 0.000 0.001 78829 2023-05-21T16:02:50.814 0.003 -0.000 -0.001 78845 2023-05-22T22:21:50.814 -0.009 0.000 0.003 78866 2023-05-24T14:18:50.814 -0.000 -0.000 0.000 78883 2023-05-25T21:48:50.814 0.005 -0.000 0.000 78896 2023-05-26T22:17:50.814 -0.015 0.000 -0.003 78910 2023-05-27T23:57:50.814 0.002 -0.000 -0.001 78918 2023-05-28T14:26:50.815 -0.008 -0.000 0.001 78936 2023-05-29T23:47:50.815 0.005 0.000 0.001 78957 2023-05-31T15:02:50.815 -0.015 -0.000 -0.003 78973 2023-06-01T21:42:50.815 0.010 -0.000 -0.004 78985 2023-06-02T19:27:50.815 0.002 0.000 0.000 78998 2023-06-03T19:42:50.815 -0.001 0.000 -0.000 79009 2023-06-04T16:39:50.815 -0.005 -0.000 0.001 79021 2023-06-05T15:55:50.815 -0.007 0.000 -0.001 79037 2023-06-06T22:02:50.815 -0.023 -0.000 -0.007 79058 2023-06-08T11:53:50.815 0.013 0.000 0.004 79076 2023-06-09T21:32:50.815 -0.012 -0.000 -0.004 79086 2023-06-10T16:11:50.815 0.018 0.000 0.007 79098 2023-06-11T15:07:50.815 0.008 -0.000 -0.002 79114 2023-06-12T20:36:50.815 0.014 0.000 0.004 79127 2023-06-13T21:41:50.815 -0.004 -0.000 0.001 79136 2023-06-14T14:11:50.815 0.019 -0.000 -0.005 79165 2023-06-16T21:36:50.815 -0.004 0.000 -0.002 79177 2023-06-17T19:36:50.815 0.006 -0.000 0.000 79190 2023-06-18T19:11:50.815 -0.016 0.000 0.005 79204 2023-06-19T20:53:50.815 -0.015 -0.000 -0.005 79226 2023-06-21T14:01:50.815 0.011 0.000 0.004 79243 2023-06-22T21:48:50.815 -0.007 -0.000 -0.003 79257 2023-06-23T23:57:50.815 -0.009 0.000 -0.004 79265 2023-06-24T16:06:50.815 -0.014 0.000 0.001 79281 2023-06-25T21:24:50.815 0.020 -0.001 -0.007 79294 2023-06-26T21:10:50.815 0.006 0.000 0.002 79306 2023-06-27T20:56:50.815 0.009 -0.000 0.002 79318 2023-06-28T19:46:50.815 -0.009 0.000 -0.005 79332 2023-06-29T21:07:50.815 -0.000 -0.000 -0.000 79345 2023-06-30T21:21:50.815 0.006 -0.000 -0.003