MAVEN Reconstructed SPK, NAV Solution, 2021-04-01 to 2021-07-01, Version 1 =========================================================================== Created by Boris Semenov, NAIF/JPL, Fri Jul 30 04:05:03 PDT 2021 Objects in the Ephemeris -------------------------------------------------------- This SPK file contains ephemeris data for the Mars Atmosphere and Volatile Evolution Mission (MAVEN) spacecraft. The NAIF ID code for MAVEN is -202. Approximate Time Coverage -------------------------------------------------------- This file covers the following part of the orbital phase of the MAVEN mission (orbits 13669 through 14274): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2021 APR 01 00:01:09.185 2021 JUL 01 01:01:09.184 Status -------------------------------------------------------- This file was created by merging regular reconstructed OD solution SPK files produced by the MAVEN NAV team during the orbital 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 MAVEN project data base by the MAVEN 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 DE430 planetary ephemeris and MAR097 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: trj_orb_13660-13707_rec_v1.bsp trj_orb_13706-13753_rec_v1.bsp trj_orb_13752-13794_rec_v1.bsp trj_orb_13793-13847_rec_v1.bsp trj_orb_13846-13887_rec_v1.bsp trj_orb_13886-13940_rec_v1.bsp trj_orb_13939-13980_rec_v1.bsp trj_orb_13979-14026_rec_v1.bsp trj_orb_14025-14080_rec_v1.bsp trj_orb_14079-14127_rec_v1.bsp trj_orb_14126-14166_rec_v1.bsp trj_orb_14165-14212_rec_v1.bsp trj_orb_14211-14265_rec_v1.bsp trj_orb_14264-14306_rec_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 ./maven_orb_rec_210401_210701_v1.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 13672 2021-04-01T15:33:22.814 -0.000 -0.000 -0.003 13679 2021-04-02T15:38:50.814 -0.001 0.000 -0.002 13686 2021-04-03T16:58:50.814 -0.001 -0.000 -0.003 13695 2021-04-05T01:28:50.814 0.001 0.000 0.008 13706 2021-04-06T17:53:50.814 -0.001 -0.001 -0.026 13719 2021-04-08T16:03:50.814 -0.000 -0.000 0.021 13733 2021-04-10T18:37:50.814 -0.001 -0.000 0.008 13740 2021-04-11T19:50:50.814 0.001 -0.000 -0.007 13746 2021-04-12T17:30:50.814 -0.000 -0.000 0.002 13752 2021-04-13T15:13:50.814 -0.002 -0.000 0.008 13759 2021-04-14T17:03:50.814 0.001 0.000 -0.008 13766 2021-04-15T17:43:50.814 -0.001 -0.000 0.004 13773 2021-04-16T18:56:25.814 -0.001 -0.000 0.001 13779 2021-04-17T16:36:31.814 0.001 0.000 -0.003 13786 2021-04-18T18:24:26.814 0.000 0.000 -0.001 13793 2021-04-19T19:06:50.814 -0.000 -0.000 0.000 13809 2021-04-22T04:48:50.814 -0.002 -0.000 0.002 13819 2021-04-23T15:38:50.814 0.001 -0.000 0.002 13833 2021-04-25T19:19:50.814 -0.001 -0.000 0.000 13839 2021-04-26T16:48:50.814 -0.000 0.000 -0.000 13846 2021-04-27T16:38:50.814 0.001 -0.000 0.003 13853 2021-04-28T19:23:50.814 -0.002 -0.000 0.000 13866 2021-04-30T17:28:50.814 -0.001 0.000 -0.001 13873 2021-05-01T18:08:50.814 -0.003 0.001 -0.005 13880 2021-05-02T19:18:50.814 0.002 -0.001 0.004 13886 2021-05-03T17:13:50.814 -0.004 0.002 -0.005 13893 2021-05-04T18:23:50.814 0.007 -0.003 0.009 13899 2021-05-05T15:54:50.814 -0.002 0.001 -0.002 13912 2021-05-07T15:28:50.814 -0.001 -0.000 -0.000 13919 2021-05-08T16:28:50.814 0.004 -0.001 0.004 13926 2021-05-09T17:58:50.814 -0.001 0.000 -0.001 13939 2021-05-11T16:18:50.814 -0.001 0.000 -0.001 13953 2021-05-13T18:43:50.814 0.002 -0.001 0.001 13966 2021-05-15T17:33:50.814 -0.002 0.001 -0.001 13979 2021-05-17T16:25:50.814 0.001 -0.000 0.001 13987 2021-05-18T21:38:50.814 -0.005 0.002 -0.003 13994 2021-05-19T22:33:50.814 0.003 -0.001 0.002 14005 2021-05-21T15:08:50.814 -0.002 0.000 -0.001 14012 2021-05-22T15:58:50.814 0.001 -0.001 0.001 14018 2021-05-23T13:58:50.814 -0.001 0.000 -0.000 14025 2021-05-24T14:18:50.814 0.006 -0.002 0.002 14032 2021-05-25T17:13:50.814 -0.010 -0.002 -0.001 14040 2021-05-26T20:28:50.814 -0.000 -0.000 0.000 14045 2021-05-27T14:58:50.814 0.006 -0.002 0.002 14058 2021-05-29T13:28:50.815 0.007 -0.003 0.002 14067 2021-05-30T22:18:50.815 -0.006 0.002 -0.002 14079 2021-06-01T17:04:50.815 0.002 -0.001 0.000 14092 2021-06-03T15:43:50.815 0.001 -0.000 0.000 14104 2021-06-05T11:33:50.815 -0.008 0.003 -0.001 14112 2021-06-06T16:18:50.815 -0.006 0.003 -0.000 14118 2021-06-07T13:53:50.815 0.004 -0.002 0.000 14126 2021-06-08T20:04:50.815 0.008 0.001 0.000 14134 2021-06-09T23:21:50.815 -0.001 0.001 0.000 14139 2021-06-10T17:48:50.815 -0.003 -0.001 -0.000 14146 2021-06-11T19:03:50.815 0.005 -0.002 -0.000 14158 2021-06-13T13:58:50.815 -0.001 0.000 0.000 14165 2021-06-14T15:28:50.815 -0.008 0.003 0.001 14173 2021-06-15T19:58:50.815 0.009 -0.004 -0.001 14180 2021-06-16T22:13:50.815 -0.019 0.003 0.003 14198 2021-06-19T14:58:50.815 0.004 -0.001 -0.001 14204 2021-06-20T11:58:50.815 0.002 -0.000 -0.000 14211 2021-06-21T13:18:50.815 0.019 -0.007 -0.005 14220 2021-06-22T22:53:50.815 -0.007 -0.000 0.002 14227 2021-06-23T22:58:50.815 -0.008 0.003 0.002 14237 2021-06-25T10:58:50.815 0.012 -0.005 -0.003 14244 2021-06-26T11:58:50.815 0.004 -0.002 -0.000 14249 2021-06-27T08:13:50.815 0.042 0.015 -0.010 14252 2021-06-27T16:48:50.815 0.024 -0.007 0.000 14254 2021-06-28T00:03:50.815 -0.008 0.002 0.000 14264 2021-06-29T13:13:50.815 -0.004 0.001 0.002 End of comments.