Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Wed May 3 07:17:26 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 77024 through 78179): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2023 JAN 01 00:01:10.000 2023 APR 01 01:01:09.185 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_rec77036_76944_77036_r-v1.bsp spk_psp_rec77126_77034_77126_r-v1.bsp spk_psp_rec77216_77124_77216_r-v1.bsp spk_psp_rec77306_77214_77306_r-v1.bsp spk_psp_rec77396_77304_77396_r-v1.bsp spk_psp_rec77486_77394_77486_r-v1.bsp spk_psp_rec77575_77483_77575_r-v1.bsp spk_psp_rec77665_77573_77665_r-v1.bsp spk_psp_rec77755_77663_77755_r-v1.bsp spk_psp_rec77830_77752_77830_r-v1.bsp spk_psp_rec77934_77827_77934_r-v1.bsp spk_psp_rec78024_77932_78024_r-v1.bsp spk_psp_rec78114_78021_78114_r-v1.bsp spk_psp_rec78204_78113_78204_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_psp66.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 77034 2023-01-01T19:03:50.816 -0.002 -0.000 0.001 77049 2023-01-02T23:57:50.816 -0.001 0.000 -0.001 77061 2023-01-03T22:44:50.816 0.005 -0.000 0.003 77074 2023-01-04T23:02:50.815 -0.002 -0.000 -0.001 77087 2023-01-05T23:20:50.815 0.002 -0.000 0.001 77100 2023-01-06T23:38:50.815 -0.000 0.000 -0.000 77113 2023-01-07T23:56:50.815 -0.000 -0.000 -0.000 77124 2023-01-08T19:16:50.815 -0.005 -0.000 0.003 77137 2023-01-09T20:30:50.815 -0.003 0.000 -0.001 77147 2023-01-10T14:43:50.815 -0.002 -0.000 0.001 77164 2023-01-11T23:17:50.815 -0.001 -0.000 -0.001 77175 2023-01-12T19:44:50.815 0.003 0.000 0.001 77188 2023-01-13T19:50:50.815 -0.005 0.000 -0.002 77202 2023-01-14T22:21:50.815 -0.001 0.000 -0.000 77214 2023-01-15T19:42:50.815 0.001 -0.000 -0.000 77230 2023-01-17T02:42:50.815 0.000 -0.000 0.000 77249 2023-01-18T14:08:50.815 0.001 -0.000 0.000 77267 2023-01-19T23:52:50.815 0.002 -0.000 0.001 77280 2023-01-20T23:57:50.815 0.001 0.000 0.000 77292 2023-01-21T22:37:50.815 0.005 -0.000 0.001 77304 2023-01-22T20:08:50.815 -0.004 -0.000 0.001 77318 2023-01-23T23:13:50.815 -0.005 -0.000 -0.002 77338 2023-01-25T11:37:50.815 -0.003 0.000 0.001 77351 2023-01-26T12:57:50.815 0.010 0.000 0.002 77370 2023-01-27T23:57:50.815 -0.002 0.000 -0.001 77379 2023-01-28T17:02:50.815 0.001 0.000 0.000 77394 2023-01-29T20:23:50.815 0.003 -0.000 -0.001 77411 2023-01-31T04:38:50.815 0.001 -0.000 0.000 77421 2023-01-31T23:06:50.815 -0.004 -0.000 -0.000 77436 2023-02-02T03:53:50.815 0.004 0.000 0.001 77453 2023-02-03T11:40:50.815 -0.005 0.000 -0.001 77471 2023-02-04T21:18:50.815 -0.003 0.000 -0.000 77483 2023-02-05T18:11:50.815 0.001 0.000 -0.000 77504 2023-02-07T10:06:50.815 0.000 0.000 -0.000 77522 2023-02-08T20:39:50.815 0.005 -0.000 0.001 77537 2023-02-09T23:57:50.815 -0.003 0.000 -0.000 77549 2023-02-10T22:27:50.814 -0.007 -0.000 -0.001 77559 2023-02-11T17:42:50.814 0.009 -0.000 0.002 77573 2023-02-12T18:31:50.814 0.004 -0.000 -0.001 77588 2023-02-13T23:57:50.814 0.013 -0.000 0.003 77601 2023-02-14T23:57:50.814 -0.006 -0.000 -0.001 77614 2023-02-15T23:57:50.814 -0.001 -0.000 -0.000 77631 2023-02-17T08:35:50.814 -0.006 -0.000 -0.001 77648 2023-02-18T16:23:50.814 -0.003 -0.000 -0.000 77663 2023-02-19T18:53:50.814 -0.003 -0.000 0.001 77678 2023-02-20T23:57:50.814 0.003 -0.000 0.001 77691 2023-02-21T23:57:50.814 -0.001 -0.000 0.000 77710 2023-02-23T12:18:50.814 -0.001 -0.000 -0.000 77727 2023-02-24T20:10:50.814 0.001 -0.000 0.000 77742 2023-02-25T23:57:50.814 -0.005 0.000 -0.001 77752 2023-02-26T17:23:50.814 0.001 -0.000 -0.000 77768 2023-02-27T23:57:50.814 0.005 -0.000 -0.000 77780 2023-02-28T23:15:50.814 -0.011 0.000 -0.001 77792 2023-03-01T21:41:50.814 0.009 -0.000 0.001 77806 2023-03-02T23:57:50.814 -0.011 0.000 -0.001 77817 2023-03-03T19:04:50.814 0.009 0.000 -0.002 77827 2023-03-04T13:41:50.814 -0.005 0.000 0.001 77848 2023-03-06T06:33:50.814 -0.004 -0.000 -0.000 77864 2023-03-07T11:49:50.814 0.002 -0.000 0.000 77875 2023-03-08T08:19:50.814 0.007 -0.000 0.001 77889 2023-03-09T10:04:50.814 0.003 -0.000 -0.001 77908 2023-03-10T22:48:50.814 0.001 -0.000 0.000 77922 2023-03-11T23:57:50.814 -0.006 0.000 0.001 77932 2023-03-12T18:10:50.814 -0.005 -0.000 0.001 77947 2023-03-13T23:46:50.814 -0.001 0.001 -0.000 77969 2023-03-15T16:55:50.814 -0.006 -0.000 -0.000 77981 2023-03-16T14:44:50.814 -0.012 -0.000 -0.002 77999 2023-03-17T23:57:50.814 0.010 -0.000 -0.001 78009 2023-03-18T18:30:50.814 -0.012 -0.000 0.002 78021 2023-03-19T17:42:50.814 0.004 0.000 0.001 78034 2023-03-20T18:00:50.814 0.005 -0.000 0.001 78050 2023-03-21T23:48:50.814 -0.015 -0.000 -0.002 78067 2023-03-23T06:23:50.814 0.006 0.000 0.000 78086 2023-03-24T19:02:50.814 -0.007 0.000 -0.000 78102 2023-03-25T23:52:50.814 -0.003 -0.000 -0.000 78113 2023-03-26T21:17:50.814 0.001 0.000 -0.000 78127 2023-03-27T23:57:50.814 -0.008 0.000 -0.001 78145 2023-03-29T10:07:50.814 0.001 0.000 0.000 78161 2023-03-30T14:15:50.814 0.006 0.000 0.000 78176 2023-03-31T19:17:50.814 -0.002 -0.000 0.000