Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Tue Apr 19 07:49:27 PDT 2022 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 72340 through 73494): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2022 JAN 01 00:01:10.000 2022 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_rec72361_72266_72361_r-v1.bsp spk_psp_rec72454_72361_72454_r-v1.bsp spk_psp_rec72544_72453_72544_r-v1.bsp spk_psp_rec72626_72542_72626_r-v1.bsp spk_psp_rec72723_72625_72723_r-v1.bsp spk_psp_rec72812_72723_72812_r-v1.bsp spk_psp_rec72897_72811_72897_r-v1.bsp spk_psp_rec72991_72895_72991_r-v1.bsp spk_psp_rec73075_72990_73075_r-v1.bsp spk_psp_rec73172_73074_73172_r-v1.bsp spk_psp_rec73260_73170_73260_r-v1.bsp spk_psp_rec73350_73258_73350_r-v1.bsp spk_psp_rec73438_73348_73438_r-v1.bsp spk_psp_rec73530_73436_73530_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_psp62.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 72349 2022-01-01T19:13:50.816 0.002 0.000 0.003 72361 2022-01-02T17:00:50.816 -0.000 -0.000 0.000 72383 2022-01-04T10:25:50.815 0.001 0.000 0.001 72403 2022-01-05T23:37:50.815 -0.001 0.000 0.000 72422 2022-01-07T11:30:50.815 0.001 0.000 0.001 72437 2022-01-08T15:47:50.815 -0.002 0.000 -0.002 72453 2022-01-09T20:37:50.815 -0.002 -0.000 0.002 72468 2022-01-11T01:45:50.815 -0.002 0.001 -0.002 72488 2022-01-12T15:10:50.815 -0.000 -0.000 -0.000 72499 2022-01-13T10:55:50.815 0.001 -0.000 -0.001 72514 2022-01-14T15:47:50.815 -0.000 0.000 -0.001 72531 2022-01-15T23:10:50.815 -0.001 0.000 -0.000 72542 2022-01-16T19:03:50.815 0.002 -0.000 -0.002 72557 2022-01-17T23:57:50.815 -0.001 0.000 -0.001 72568 2022-01-18T20:25:50.815 0.001 0.000 0.001 72579 2022-01-19T16:25:50.815 -0.000 -0.000 0.000 72594 2022-01-20T20:25:50.815 -0.001 0.000 0.002 72607 2022-01-21T21:25:50.815 -0.000 0.000 -0.000 72625 2022-01-23T07:04:50.815 0.000 0.000 0.000 72641 2022-01-24T13:00:50.815 -0.000 0.000 -0.000 72653 2022-01-25T11:44:50.815 0.002 -0.000 0.002 72665 2022-01-26T09:51:50.815 -0.003 0.000 -0.003 72685 2022-01-27T23:02:50.815 0.000 -0.000 0.000 72698 2022-01-28T23:16:50.815 -0.001 -0.000 0.000 72711 2022-01-29T23:57:50.815 0.000 -0.000 0.000 72723 2022-01-30T21:31:50.815 0.001 0.000 -0.002 72734 2022-01-31T19:12:50.815 0.001 -0.000 0.001 72747 2022-02-01T19:31:50.815 0.001 -0.000 0.001 72760 2022-02-02T19:50:50.815 -0.001 0.000 -0.001 72774 2022-02-03T22:01:50.815 0.001 0.000 0.002 72787 2022-02-04T22:19:50.815 0.000 -0.000 0.001 72801 2022-02-05T23:57:50.815 0.001 -0.000 -0.000 72811 2022-02-06T18:38:50.815 -0.000 0.000 -0.000 72820 2022-02-07T12:02:50.815 -0.000 0.000 -0.000 72835 2022-02-08T15:26:50.815 -0.001 0.000 0.000 72860 2022-02-10T14:50:50.814 0.000 0.000 0.000 72876 2022-02-11T20:45:50.814 0.003 -0.000 0.004 72884 2022-02-12T11:41:50.814 -0.004 0.000 -0.005 72895 2022-02-13T07:13:50.814 0.000 -0.000 -0.001 72910 2022-02-14T12:12:50.814 0.001 0.000 0.002 72929 2022-02-15T23:45:50.814 0.000 0.000 0.000 72947 2022-02-17T09:32:50.814 0.000 -0.000 0.000 72966 2022-02-18T21:03:50.814 -0.000 -0.000 -0.000 72979 2022-02-19T20:42:50.814 0.001 0.000 -0.001 72990 2022-02-20T17:42:50.814 -0.000 -0.000 0.000 73004 2022-02-21T20:07:50.814 -0.001 0.000 -0.001 73017 2022-02-22T20:26:50.814 0.000 -0.000 0.000 73030 2022-02-23T20:32:50.814 0.000 0.000 -0.000 73042 2022-02-24T19:11:50.814 -0.000 0.000 -0.000 73060 2022-02-26T04:55:50.814 -0.000 0.000 -0.001 73074 2022-02-27T06:27:50.814 -0.001 0.000 0.000 73093 2022-02-28T18:33:50.814 -0.000 0.000 -0.001 73107 2022-03-01T20:27:50.814 0.002 -0.000 0.002 73119 2022-03-02T19:10:50.814 -0.001 0.000 -0.002 73128 2022-03-03T11:55:50.814 0.001 -0.000 0.001 73143 2022-03-04T15:42:50.814 -0.000 0.000 -0.000 73153 2022-03-05T10:32:50.814 0.001 -0.000 0.002 73170 2022-03-06T17:52:50.814 -0.000 -0.000 0.000 73192 2022-03-08T11:41:50.814 -0.001 -0.000 -0.002 73205 2022-03-09T12:04:50.814 0.001 0.000 0.001 73220 2022-03-10T15:28:50.814 -0.001 0.000 0.000 73235 2022-03-11T20:05:50.814 0.000 -0.000 0.000 73250 2022-03-12T23:57:50.814 -0.001 -0.000 -0.002 73258 2022-03-13T14:02:50.814 0.001 0.000 -0.003 73271 2022-03-14T14:59:50.814 0.001 0.000 0.001 73286 2022-03-15T19:27:50.814 0.000 -0.000 0.001 73310 2022-03-17T16:23:50.814 0.001 -0.000 0.002 73326 2022-03-18T22:03:50.814 0.000 0.000 0.000 73336 2022-03-19T16:08:50.814 0.000 0.000 -0.001 73348 2022-03-20T14:20:50.814 -0.001 0.000 0.001 73372 2022-03-22T12:16:50.814 -0.001 0.000 -0.002 73391 2022-03-23T23:48:50.814 -0.001 0.000 -0.002 73409 2022-03-25T09:04:50.814 0.001 -0.000 0.001 73421 2022-03-26T07:44:50.814 -0.000 0.000 -0.001 73436 2022-03-27T10:53:50.814 -0.000 -0.000 0.000 73450 2022-03-28T14:07:50.814 -0.001 -0.000 -0.001 73463 2022-03-29T14:26:50.814 0.001 0.000 0.002 73476 2022-03-30T14:44:50.814 0.000 -0.000 0.000 73489 2022-03-31T15:02:50.814 -0.000 0.000 -0.000