MAVEN Reconstructed SPK, NAV Solution, 2021-07-01 to 2021-10-01, Version 1 =========================================================================== Created by Boris Semenov, NAIF/JPL, Fri Nov 5 05:48:11 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 14275 through 14886): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2021 JUL 01 00:01:09.184 2021 OCT 01 01:01:09.182 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_14264-14306_rec_v1.bsp trj_orb_14305-14352_rec_v1.bsp trj_orb_14351-14398_rec_v1.bsp trj_orb_14397-14450_rec_v1.bsp trj_orb_14449-14491_rec_v1.bsp trj_orb_14490-14538_rec_v1.bsp trj_orb_14537-14580_rec_v1.bsp trj_orb_14579-14631_rec_v1.bsp trj_orb_14630-14683_rec_v1.bsp trj_orb_14682-14720_rec_v1.bsp trj_orb_14719-14767_rec_v1.bsp trj_orb_14766-14818_rec_v1.bsp trj_orb_14817-14872_rec_v1.bsp trj_orb_14871-14999_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_210701_211001_v1.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 14278 2021-07-01T15:18:50.815 -0.005 0.001 0.002 14291 2021-07-03T14:18:50.815 0.007 -0.002 -0.005 14299 2021-07-04T18:28:50.815 -0.004 0.002 0.001 14305 2021-07-05T16:28:50.816 -0.006 0.002 0.003 14313 2021-07-06T22:07:20.816 0.013 -0.001 -0.010 14325 2021-07-08T16:07:50.816 -0.006 0.002 -0.001 14334 2021-07-10T01:18:50.816 0.001 0.000 -0.001 14346 2021-07-11T21:08:50.816 -0.011 0.001 0.011 14351 2021-07-12T15:23:50.816 -0.026 -0.002 0.028 14358 2021-07-13T16:18:50.816 0.005 -0.001 -0.006 14369 2021-07-15T08:48:50.816 -0.003 -0.001 0.003 14378 2021-07-16T15:58:50.816 0.004 -0.002 -0.004 14387 2021-07-18T00:43:50.816 0.002 -0.000 -0.003 14397 2021-07-19T12:48:50.816 0.002 -0.000 -0.003 14409 2021-07-21T09:18:50.816 -0.006 -0.002 0.009 14425 2021-07-23T17:18:50.816 0.004 -0.001 -0.003 14439 2021-07-25T20:53:50.816 0.002 0.000 -0.004 14449 2021-07-27T08:48:50.816 0.002 0.000 -0.005 14458 2021-07-28T18:18:50.816 -0.000 -0.000 0.001 14466 2021-07-29T21:58:50.816 -0.002 0.000 0.004 14476 2021-07-31T09:43:50.816 0.003 -0.000 -0.006 14486 2021-08-01T21:58:50.816 0.001 -0.000 -0.003 14490 2021-08-02T12:28:50.816 0.006 -0.000 -0.019 14503 2021-08-04T10:58:50.816 -0.005 0.001 0.011 14513 2021-08-06T00:04:50.816 -0.001 -0.000 0.006 14523 2021-08-07T11:13:50.816 0.002 -0.000 -0.007 14533 2021-08-08T23:19:50.816 -0.005 0.001 0.028 14537 2021-08-09T13:43:50.816 -0.004 0.001 0.027 14545 2021-08-10T18:38:50.816 0.004 -0.001 -0.038 14551 2021-08-11T17:13:50.816 -0.001 -0.000 0.033 14557 2021-08-12T13:58:50.817 -0.000 0.000 0.019 14563 2021-08-13T11:43:50.817 -0.001 0.000 -0.036 14572 2021-08-14T20:08:50.817 0.001 -0.000 0.005 14579 2021-08-15T22:28:50.817 -0.002 -0.001 -0.034 14604 2021-08-19T15:58:50.817 0.002 0.000 0.011 14612 2021-08-20T20:58:50.817 0.001 0.000 0.005 14623 2021-08-22T12:58:50.817 -0.005 -0.002 -0.021 14630 2021-08-23T13:33:50.817 0.007 0.001 0.014 14646 2021-08-25T23:18:50.817 -0.008 -0.001 -0.012 14660 2021-08-28T00:19:20.817 0.002 -0.001 -0.005 14670 2021-08-29T12:11:50.817 -0.000 0.000 0.001 14682 2021-08-31T09:08:50.817 0.010 0.001 0.007 14689 2021-09-01T10:18:50.817 -0.003 0.000 -0.001 14700 2021-09-03T00:43:50.817 -0.004 0.002 0.008 14710 2021-09-04T12:58:50.817 0.001 -0.000 -0.002 14719 2021-09-05T21:01:50.817 -0.004 0.001 0.007 14723 2021-09-06T12:28:50.817 0.040 -0.007 -0.026 14731 2021-09-07T16:58:50.817 -0.038 0.012 0.044 14743 2021-09-09T12:33:50.817 0.075 -0.015 -0.060 14755 2021-09-11T08:28:50.817 -0.046 -0.005 0.005 14766 2021-09-12T22:18:50.817 0.023 -0.005 -0.011 14777 2021-09-14T15:28:50.817 0.062 -0.004 -0.038 14785 2021-09-15T20:13:50.817 -0.104 0.012 0.077 14796 2021-09-17T11:03:50.817 0.008 -0.003 -0.008 14810 2021-09-19T15:33:50.817 0.044 0.017 0.014 14817 2021-09-20T15:30:50.817 0.022 -0.003 -0.020 14829 2021-09-22T10:14:50.817 0.011 -0.003 -0.012 14836 2021-09-23T12:13:50.817 0.009 -0.001 -0.008 14848 2021-09-25T07:58:50.817 -0.046 -0.006 0.027 14864 2021-09-27T16:58:50.817 0.011 -0.003 -0.011 14871 2021-09-28T18:48:50.817 0.004 0.000 -0.002 End of comments.