Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Fri Nov 5 06:03:40 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 69979 through 71158): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2021 JUL 01 00:01:10.000 2021 OCT 01 01:01:09.182 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_rec70027_69934_70027_r-v1.bsp spk_psp_rec70114_70024_70114_r-v1.bsp spk_psp_rec70208_70112_70208_r-v1.bsp spk_psp_rec70297_70206_70297_r-v1.bsp spk_psp_rec70387_70295_70387_r-v1.bsp spk_psp_rec70475_70385_70475_r-v1.bsp spk_psp_rec70560_70474_70560_r-v1.bsp spk_psp_rec70655_70558_70655_r-v1.bsp spk_psp_rec70741_70654_70741_r-v1.bsp spk_psp_rec70831_70739_70831_r-v1.bsp spk_psp_rec70921_70829_70921_r-v1.bsp spk_psp_rec71017_70919_71017_r-v1.bsp spk_psp_rec71094_71011_71094_r-v1.bsp spk_psp_rec71171_71092_71171_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_psp60.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 69990 2021-07-01T22:06:50.815 0.012 0.000 0.005 70002 2021-07-02T22:24:50.815 -0.015 -0.000 -0.006 70016 2021-07-03T22:43:50.815 -0.005 0.000 -0.002 70024 2021-07-04T14:56:50.815 0.002 0.000 0.000 70037 2021-07-05T15:51:50.816 -0.001 -0.000 -0.001 70052 2021-07-06T19:54:50.816 -0.007 -0.000 -0.003 70062 2021-07-07T14:36:50.816 0.011 0.000 0.005 70080 2021-07-09T00:15:50.816 0.008 0.000 0.004 70097 2021-07-10T08:03:50.816 0.001 -0.000 0.001 70112 2021-07-11T10:48:50.816 0.001 -0.000 -0.000 70129 2021-07-12T19:43:50.816 0.000 0.000 0.000 70144 2021-07-13T23:56:50.816 0.000 0.000 0.000 70161 2021-07-15T07:43:50.816 -0.001 -0.000 -0.000 70176 2021-07-16T11:43:50.816 0.003 0.000 0.002 70194 2021-07-17T21:26:50.816 0.016 0.000 0.008 70206 2021-07-18T18:36:50.816 -0.016 -0.000 0.007 70221 2021-07-19T23:55:50.816 -0.002 -0.000 -0.001 70237 2021-07-21T05:34:50.816 0.010 0.000 0.005 70253 2021-07-22T11:44:50.816 -0.002 0.000 -0.001 70266 2021-07-23T12:02:50.816 0.001 0.000 0.000 70285 2021-07-24T23:34:50.816 -0.003 -0.000 -0.002 70295 2021-07-25T17:03:50.816 0.001 0.000 -0.001 70318 2021-07-27T13:17:50.816 -0.002 -0.000 -0.001 70346 2021-07-29T15:52:50.816 -0.004 -0.000 -0.002 70362 2021-07-30T23:34:50.816 0.007 0.000 0.004 70372 2021-07-31T18:16:50.816 -0.007 -0.000 -0.004 70385 2021-08-01T17:23:50.816 0.002 -0.000 -0.001 70398 2021-08-02T18:54:50.816 -0.009 -0.000 -0.005 70411 2021-08-03T19:07:50.816 0.009 0.000 0.006 70423 2021-08-04T17:38:50.816 -0.003 -0.000 -0.002 70449 2021-08-06T18:16:50.816 0.007 -0.000 0.004 70464 2021-08-07T22:19:50.816 -0.008 -0.000 -0.005 70474 2021-08-08T16:12:50.816 -0.002 0.000 0.001 70505 2021-08-11T01:12:50.816 -0.002 -0.000 -0.001 70522 2021-08-12T10:46:50.817 -0.005 0.000 -0.004 70539 2021-08-13T17:47:50.817 0.005 0.000 -0.002 70550 2021-08-14T14:24:50.817 -0.012 0.000 0.004 70558 2021-08-15T04:54:50.817 0.012 0.000 -0.008 70571 2021-08-16T06:24:50.817 -0.008 -0.000 -0.006 70603 2021-08-18T18:14:50.817 0.011 0.000 0.007 70617 2021-08-19T20:25:50.817 -0.008 -0.000 -0.006 70625 2021-08-20T11:23:50.817 0.009 -0.000 0.006 70643 2021-08-21T21:02:50.817 0.003 -0.000 0.002 70654 2021-08-22T16:26:50.817 -0.002 -0.000 0.002 70666 2021-08-23T15:42:50.817 -0.007 -0.000 -0.004 70680 2021-08-24T18:13:50.817 0.004 -0.000 0.003 70699 2021-08-26T05:45:50.817 -0.002 0.000 -0.001 70721 2021-08-27T22:53:50.817 -0.005 0.000 -0.004 70739 2021-08-29T08:13:50.817 0.004 0.000 0.002 70758 2021-08-30T19:20:50.817 0.000 0.000 -0.000 70780 2021-09-01T13:13:50.817 0.001 -0.000 0.000 70793 2021-09-02T12:47:50.817 -0.004 0.000 0.002 70812 2021-09-04T01:06:50.817 -0.002 0.000 -0.002 70829 2021-09-05T08:07:50.817 0.003 0.000 -0.001 70843 2021-09-06T11:01:50.817 0.000 -0.000 0.000 70859 2021-09-07T16:56:50.817 -0.006 -0.000 -0.004 70876 2021-09-08T23:57:50.817 0.007 -0.000 -0.004 70895 2021-09-10T11:17:50.817 -0.001 0.000 0.000 70909 2021-09-11T13:45:50.817 -0.003 0.000 0.001 70919 2021-09-12T08:02:50.817 0.002 0.000 -0.002 70932 2021-09-13T09:26:50.817 -0.002 -0.000 -0.001 70952 2021-09-14T22:51:50.817 0.000 0.000 0.001 70965 2021-09-15T23:09:50.817 -0.001 -0.000 -0.001 70978 2021-09-16T22:27:50.817 0.001 0.000 -0.001 70990 2021-09-17T21:37:50.817 0.003 0.000 0.003 71000 2021-09-18T16:35:50.817 -0.003 0.000 -0.002 71011 2021-09-19T12:01:50.817 0.003 -0.000 -0.003 71024 2021-09-20T13:28:50.817 0.000 -0.000 0.000 71040 2021-09-21T18:55:50.817 0.006 -0.000 0.001 71052 2021-09-22T17:49:50.817 -0.004 -0.000 -0.004 71062 2021-09-23T12:31:50.817 0.001 0.000 0.001 71081 2021-09-25T00:03:50.817 0.003 0.000 0.002 71092 2021-09-25T19:29:50.817 0.001 0.000 -0.000 71108 2021-09-27T02:32:50.817 0.001 0.000 0.001 71125 2021-09-28T10:19:50.817 -0.000 -0.000 -0.000 71139 2021-09-29T11:50:50.817 0.006 0.000 -0.002