Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Thu Feb 2 13:33:52 PST 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 75844 through 77023): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2022 OCT 01 00:01:10.000 2023 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_rec75865_75776_75865_r-v1.bsp spk_psp_rec75957_75864_75957_r-v1.bsp spk_psp_rec76044_75956_76044_r-v1.bsp spk_psp_rec76130_76043_76130_r-v1.bsp spk_psp_rec76225_76129_76225_r-v1.bsp spk_psp_rec76311_76223_76311_r-v1.bsp spk_psp_rec76403_76309_76403_r-v1.bsp spk_psp_rec76497_76402_76497_r-v1.bsp spk_psp_rec76581_76495_76581_r-v1.bsp spk_psp_rec76667_76579_76667_r-v1.bsp spk_psp_rec76766_76665_76766_r-v1.bsp spk_psp_rec76856_76764_76856_r-v1.bsp spk_psp_rec76946_76854_76946_r-v1.bsp spk_psp_rec77036_76944_77036_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_psp65.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 75855 2022-10-01T23:55:50.817 0.000 -0.000 -0.008 75864 2022-10-02T15:40:50.817 0.000 -0.000 0.000 75878 2022-10-03T18:49:50.817 0.000 -0.000 -0.004 75899 2022-10-05T10:06:50.817 -0.000 -0.000 0.002 75919 2022-10-06T23:30:50.817 -0.000 -0.000 0.010 75927 2022-10-07T14:28:50.817 0.000 -0.000 -0.004 75944 2022-10-08T22:03:50.817 -0.000 -0.000 0.020 75956 2022-10-09T20:12:50.817 0.000 -0.000 0.012 75970 2022-10-10T22:53:50.817 0.000 0.000 0.010 75988 2022-10-12T08:33:50.817 -0.000 0.000 -0.033 76001 2022-10-13T08:51:50.817 0.000 0.000 0.030 76011 2022-10-14T03:33:50.817 0.000 -0.000 0.004 76028 2022-10-15T11:14:50.817 -0.001 0.000 -0.043 76043 2022-10-16T14:26:50.817 0.000 0.000 -0.002 76062 2022-10-18T02:56:50.817 0.000 -0.000 0.002 76078 2022-10-19T08:51:50.817 -0.000 -0.000 -0.003 76094 2022-10-20T14:35:50.817 0.000 -0.000 0.004 76108 2022-10-21T16:57:50.817 -0.000 -0.000 -0.004 76122 2022-10-22T18:53:50.817 0.000 0.000 0.001 76129 2022-10-23T07:08:50.817 -0.000 -0.000 0.002 76145 2022-10-24T14:08:50.817 -0.000 0.000 -0.002 76156 2022-10-25T10:43:50.817 0.000 -0.000 0.000 76172 2022-10-26T16:38:50.817 0.000 -0.000 0.001 76193 2022-10-28T07:54:50.817 0.000 0.000 0.001 76208 2022-10-29T11:57:50.817 -0.000 0.000 -0.002 76223 2022-10-30T14:58:50.817 0.000 -0.000 -0.002 76236 2022-10-31T16:18:50.817 0.000 0.000 0.002 76253 2022-11-01T23:57:50.817 -0.000 -0.000 -0.002 76261 2022-11-02T15:03:50.817 -0.000 -0.000 -0.005 76274 2022-11-03T15:21:50.817 -0.002 0.000 -0.010 76294 2022-11-05T04:45:50.817 0.001 0.000 0.003 76309 2022-11-06T07:46:50.817 -0.000 0.000 0.002 76329 2022-11-07T22:11:50.817 -0.001 0.000 -0.003 76347 2022-11-09T07:39:50.817 0.001 -0.000 0.002 76358 2022-11-10T04:25:50.817 0.000 -0.000 0.001 76375 2022-11-11T12:12:50.817 -0.000 0.000 -0.001 76391 2022-11-12T18:07:50.817 -0.000 0.000 -0.001 76402 2022-11-13T13:38:50.817 0.001 -0.000 -0.002 76420 2022-11-14T23:57:50.817 0.001 0.000 0.001 76433 2022-11-15T23:57:50.817 -0.001 0.000 0.002 76445 2022-11-16T23:05:50.817 0.000 -0.000 0.001 76458 2022-11-17T23:23:50.817 -0.001 -0.000 -0.002 76471 2022-11-18T23:41:50.817 0.000 -0.000 0.000 76485 2022-11-20T02:00:50.817 -0.000 -0.000 -0.001 76495 2022-11-20T19:31:50.817 0.000 -0.000 -0.001 76509 2022-11-21T22:44:50.817 0.000 0.000 0.001 76520 2022-11-22T18:39:50.817 0.000 0.000 -0.000 76539 2022-11-24T06:49:50.817 0.001 -0.000 0.002 76556 2022-11-25T14:36:50.817 0.001 -0.000 0.001 76571 2022-11-26T18:28:50.817 -0.001 -0.000 -0.003 76579 2022-11-27T08:33:50.817 0.002 -0.000 -0.004 76594 2022-11-28T13:39:50.816 -0.001 0.000 -0.002 76607 2022-11-29T13:57:50.816 0.000 -0.000 0.001 76620 2022-11-30T14:15:50.816 -0.000 0.000 -0.000 76636 2022-12-01T20:09:50.816 0.001 -0.000 0.002 76647 2022-12-02T16:44:50.816 -0.001 0.000 -0.002 76665 2022-12-04T01:19:50.816 -0.003 -0.000 0.005 76683 2022-12-05T12:02:50.816 -0.002 -0.000 -0.004 76692 2022-12-06T04:39:50.816 -0.002 0.000 -0.002 76710 2022-12-07T13:53:50.816 0.003 0.000 -0.001 76722 2022-12-08T12:54:50.816 0.001 -0.000 0.002 76739 2022-12-09T20:44:50.816 -0.001 -0.000 -0.002 76753 2022-12-10T22:55:50.816 0.002 0.000 0.002 76764 2022-12-11T18:23:50.816 -0.002 0.000 0.002 76786 2022-12-13T12:36:50.816 -0.003 0.000 -0.004 76803 2022-12-14T20:23:50.816 -0.001 -0.000 -0.001 76820 2022-12-16T04:10:50.816 -0.002 0.000 -0.002 76839 2022-12-17T15:41:50.816 -0.001 0.000 -0.001 76854 2022-12-18T18:37:50.816 -0.001 0.000 0.001 76869 2022-12-19T23:46:50.816 -0.002 -0.000 -0.002 76882 2022-12-20T23:57:50.816 0.001 -0.000 0.001 76894 2022-12-21T22:30:50.816 0.002 -0.000 0.002 76908 2022-12-22T23:57:50.816 0.000 0.000 -0.000 76920 2022-12-23T23:07:50.816 -0.001 -0.000 -0.001 76933 2022-12-24T23:25:50.816 0.001 -0.000 0.001 76944 2022-12-25T18:50:50.816 0.005 0.000 -0.003 76964 2022-12-27T09:23:50.816 0.005 -0.000 0.004 76978 2022-12-28T11:33:50.816 -0.000 0.000 -0.000 76993 2022-12-29T15:34:50.816 0.000 -0.000 0.000 77010 2022-12-30T23:23:50.816 -0.001 -0.000 -0.001 77023 2022-12-31T23:41:50.816 0.002 0.000 0.001