Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Tue Feb 6 06:48:29 PST 2024 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 80528 through 81708): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2023 OCT 01 00:01:10.000 2024 JAN 01 01:01:09.183 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_rec80532_80447_80532_r-v1.bsp spk_psp_rec80625_80530_80625_r-v1.bsp spk_psp_rec80716_80623_80716_r-v1.bsp spk_psp_rec80809_80714_80809_r-v1.bsp spk_psp_rec80899_80808_80899_r-v1.bsp spk_psp_rec80984_80898_80984_r-v1.bsp spk_psp_rec81050_80982_81050_r-v1.bsp spk_psp_rec81343_81048_81343_r-v1.bsp spk_psp_rec81426_81341_81426_r-v1.bsp spk_psp_rec81522_81424_81522_r-v1.bsp spk_psp_rec81614_81520_81614_r-v1.bsp spk_psp_rec81702_81613_81702_r-v1.bsp spk_psp_rec81794_81700_81794_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_psp69.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 80530 2023-10-01T04:53:50.817 -0.004 -0.000 0.002 80547 2023-10-02T13:20:50.817 0.003 -0.000 0.000 80565 2023-10-03T23:32:50.817 0.003 0.001 0.002 80581 2023-10-05T03:43:50.817 -0.001 0.000 -0.001 80599 2023-10-06T15:07:50.817 -0.000 -0.000 -0.000 80612 2023-10-07T15:25:50.817 -0.002 -0.000 -0.001 80623 2023-10-08T10:48:50.817 -0.002 0.000 0.001 80642 2023-10-09T23:32:50.817 -0.012 -0.000 -0.008 80665 2023-10-11T17:58:50.817 0.005 -0.000 -0.000 80681 2023-10-13T00:00:50.817 -0.005 -0.000 -0.002 80694 2023-10-13T23:57:50.817 0.004 -0.000 -0.002 80706 2023-10-14T23:13:50.817 0.006 0.000 0.004 80714 2023-10-15T13:57:50.817 -0.001 0.000 -0.001 80726 2023-10-16T12:37:50.817 0.002 0.000 0.002 80744 2023-10-17T22:17:50.817 0.003 -0.000 0.002 80756 2023-10-18T19:53:50.817 -0.001 0.000 0.001 80771 2023-10-19T23:57:50.817 0.002 0.000 -0.001 80796 2023-10-21T23:31:50.817 0.001 0.000 0.001 80808 2023-10-22T21:02:50.817 -0.000 -0.000 0.001 80821 2023-10-23T22:08:50.817 -0.002 -0.000 -0.002 80843 2023-10-25T15:25:50.817 0.005 0.000 0.003 80879 2023-10-28T10:38:50.817 -0.003 0.000 -0.002 80898 2023-10-29T21:22:50.817 0.002 0.000 -0.001 80915 2023-10-31T06:04:50.817 0.003 0.000 0.002 80931 2023-11-01T11:40:50.817 -0.011 -0.000 -0.006 80945 2023-11-02T13:20:50.817 0.004 0.000 -0.003 80963 2023-11-03T23:25:50.817 0.001 -0.000 0.000 80974 2023-11-04T20:23:50.817 0.004 0.000 0.002 80982 2023-11-05T10:09:50.817 -0.003 0.000 0.003 81002 2023-11-07T00:45:50.817 -0.008 -0.000 -0.005 81021 2023-11-08T12:10:50.817 0.009 0.001 0.007 81040 2023-11-09T23:48:50.817 -0.008 0.000 -0.005 81048 2023-11-10T13:33:50.817 0.004 -0.001 -0.003 81244 2023-11-25T19:43:50.817 -0.001 0.000 -0.000 81253 2023-11-26T13:55:50.817 -0.004 -0.001 -0.003 81271 2023-11-27T23:28:50.817 0.006 -0.000 0.005 81283 2023-11-28T22:12:50.816 -0.005 -0.000 -0.004 81304 2023-11-30T12:58:50.816 -0.001 0.000 -0.000 81321 2023-12-01T21:14:50.816 -0.003 0.000 -0.000 81341 2023-12-03T09:27:50.816 0.003 0.000 -0.001 81356 2023-12-04T14:41:50.816 -0.001 -0.000 -0.001 81374 2023-12-05T23:57:50.816 0.005 -0.000 0.002 81386 2023-12-06T22:42:50.816 0.003 -0.000 0.002 81399 2023-12-07T22:23:50.816 -0.003 0.000 0.000 81414 2023-12-09T02:08:50.816 0.001 0.000 -0.000 81424 2023-12-09T20:46:50.816 -0.001 -0.000 0.000 81445 2023-12-11T12:34:50.816 -0.000 0.000 -0.000 81471 2023-12-13T13:43:50.816 0.002 -0.000 0.001 81483 2023-12-14T12:09:50.816 -0.006 -0.000 -0.005 81502 2023-12-15T23:38:50.816 0.002 -0.000 0.001 81520 2023-12-17T08:46:50.816 -0.002 -0.000 -0.000 81535 2023-12-18T13:22:50.816 -0.002 -0.000 -0.002 81554 2023-12-19T23:57:50.816 0.003 0.000 -0.003 81573 2023-12-21T12:25:50.816 0.002 0.000 0.001 81592 2023-12-22T23:57:50.816 -0.004 -0.000 -0.003 81613 2023-12-24T14:02:50.816 0.000 -0.000 -0.001 81630 2023-12-25T22:24:50.816 -0.001 0.000 0.000 81642 2023-12-26T21:28:50.816 0.003 0.000 0.002 81656 2023-12-27T23:33:50.816 -0.000 0.000 -0.000 81675 2023-12-29T11:08:50.816 -0.003 -0.000 -0.002 81692 2023-12-30T18:55:50.816 0.001 -0.000 0.001 81700 2023-12-31T09:06:50.816 -0.002 0.000 0.001