Mars Reconnaissance Orbiter Extended Science Phase SPK, MRO NAV Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, Tue Feb 1 06:53:15 PST 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 71159 through 72339): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2021 OCT 01 00:01:10.000 2022 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_rec71361_71170_71361_r-v1.bsp spk_psp_rec71459_71359_71459_r-v1.bsp spk_psp_rec71552_71458_71552_r-v1.bsp spk_psp_rec71646_71550_71646_r-v1.bsp spk_psp_rec71729_71644_71729_r-v1.bsp spk_psp_rec71824_71727_71824_r-v1.bsp spk_psp_rec71907_71824_71907_r-v1.bsp spk_psp_rec72004_71898_72004_r-v1.bsp spk_psp_rec72094_72003_72094_r-v1.bsp spk_psp_rec72183_72094_72183_r-v1.bsp spk_psp_rec72266_72183_72266_r-v1.bsp spk_psp_rec72361_72266_72361_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_psp61.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 71164 2021-10-01T11:15:50.817 0.010 0.000 0.007 71170 2021-10-01T22:12:50.817 -0.001 -0.001 -0.001 71332 2021-10-14T12:54:50.817 -0.006 0.000 -0.001 71348 2021-10-15T18:35:50.817 0.015 0.000 -0.007 71359 2021-10-16T15:07:50.817 -0.008 0.000 0.005 71383 2021-10-18T12:44:50.817 0.005 -0.000 0.003 71401 2021-10-19T22:00:50.817 -0.002 -0.001 -0.000 71415 2021-10-20T23:57:50.817 -0.005 -0.000 0.001 71429 2021-10-22T02:20:50.817 -0.001 -0.000 -0.001 71442 2021-10-23T03:00:50.817 0.006 -0.000 0.005 71458 2021-10-24T07:51:50.817 -0.002 0.000 0.002 71472 2021-10-25T10:57:50.817 -0.002 -0.000 -0.001 71488 2021-10-26T17:04:50.817 0.002 0.000 0.002 71504 2021-10-27T22:59:50.817 0.000 -0.000 0.000 71519 2021-10-29T02:27:50.817 0.001 0.000 -0.000 71536 2021-10-30T10:49:50.817 -0.002 -0.000 -0.002 71550 2021-10-31T11:52:50.817 0.004 0.000 -0.004 71569 2021-11-01T23:57:50.817 0.006 0.000 -0.000 71583 2021-11-03T02:08:50.817 -0.001 0.000 -0.000 71600 2021-11-04T10:29:50.817 -0.004 0.000 -0.003 71619 2021-11-05T22:00:50.817 0.004 0.000 0.004 71633 2021-11-06T23:52:50.817 -0.002 -0.000 -0.002 71644 2021-11-07T20:12:50.817 0.002 0.000 0.000 71659 2021-11-08T23:57:50.817 0.002 -0.000 -0.002 71671 2021-11-09T22:57:50.817 -0.002 -0.000 -0.002 71682 2021-11-10T19:48:50.817 0.002 -0.000 0.001 71694 2021-11-11T17:43:50.817 -0.001 -0.000 -0.000 71710 2021-11-12T23:57:50.817 -0.001 0.000 -0.002 71727 2021-11-14T07:32:50.817 0.001 -0.000 0.001 71745 2021-11-15T17:35:50.817 0.001 -0.000 0.001 71765 2021-11-17T06:24:50.817 -0.012 0.001 0.002 71786 2021-11-18T22:16:50.817 0.008 0.000 0.009 71800 2021-11-19T23:57:50.817 -0.002 0.000 -0.000 71811 2021-11-20T21:01:50.817 0.001 0.000 0.001 71824 2021-11-21T20:13:50.817 0.001 -0.000 -0.001 71838 2021-11-22T22:44:50.817 0.000 -0.000 -0.000 71853 2021-11-24T03:18:50.817 -0.000 0.000 -0.000 71870 2021-11-25T11:19:50.817 0.002 0.000 0.002 71889 2021-11-26T22:48:50.817 -0.001 -0.000 -0.001 71898 2021-11-27T14:46:50.817 -0.001 0.000 0.001 71927 2021-11-29T21:03:50.816 -0.000 0.000 -0.000 71950 2021-12-01T16:59:50.816 0.001 -0.000 0.001 71965 2021-12-02T20:23:50.816 -0.000 0.000 0.000 71978 2021-12-03T21:22:50.816 0.000 0.000 0.000 71991 2021-12-04T21:40:50.816 0.001 -0.000 0.001 72003 2021-12-05T19:21:50.816 -0.002 0.000 0.001 72029 2021-12-07T20:44:50.816 0.001 -0.000 0.001 72049 2021-12-09T09:23:50.816 -0.001 -0.000 0.000 72066 2021-12-10T16:58:50.816 0.001 -0.000 -0.001 72082 2021-12-11T22:54:50.816 -0.002 -0.000 0.002 72094 2021-12-12T21:31:50.816 -0.001 0.000 0.001 72111 2021-12-14T06:06:50.816 0.000 -0.000 -0.000 72132 2021-12-15T21:09:50.816 -0.000 -0.000 -0.000 72145 2021-12-16T21:41:50.816 0.001 0.000 0.001 72157 2021-12-17T19:39:50.816 -0.002 0.000 -0.001 72171 2021-12-18T22:19:50.816 0.002 -0.000 0.002 72183 2021-12-19T19:39:50.816 0.001 0.000 -0.001 72198 2021-12-20T23:57:50.816 0.000 -0.000 -0.000 72210 2021-12-21T22:39:50.816 0.001 -0.000 -0.000 72221 2021-12-22T19:50:50.816 -0.001 -0.000 -0.002 72235 2021-12-23T21:34:50.816 0.001 -0.000 0.001 72249 2021-12-24T23:57:50.816 -0.001 -0.000 -0.001 72266 2021-12-26T07:20:50.816 -0.002 0.000 0.001 72284 2021-12-27T17:39:50.816 -0.000 0.000 -0.000 72305 2021-12-29T09:03:50.816 -0.001 -0.000 -0.001 72320 2021-12-30T12:59:50.816 -0.001 0.000 -0.002 72339 2021-12-31T23:57:50.816 0.001 -0.000 0.000