MAVEN Reconstructed SPK, NAV Solution, 2023-04-01 to 2023-07-01, Version 1 =========================================================================== Created by Boris Semenov, NAIF/JPL, Wed Aug 2 15:28:28 PDT 2023 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 18506 through 19103): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2023 APR 01 00:01:09.185 2023 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_18480-18512_rec_v1.bsp trj_orb_18511-18572_rec_v1.bsp trj_orb_18571-18616_rec_v1.bsp trj_orb_18615-18649_rec_v1.bsp trj_orb_18648-18708_rec_v1.bsp trj_orb_18707-18756_rec_v1.bsp trj_orb_18755-18799_rec_v1.bsp trj_orb_18798-18841_rec_v1.bsp trj_orb_18840-18886_rec_v1.bsp trj_orb_18885-18938_rec_v1.bsp trj_orb_18937-18987_rec_v1.bsp trj_orb_18986-19031_rec_v1.bsp trj_orb_19030-19081_rec_v1.bsp trj_orb_19080-19130_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_230401_230701_v1.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 18511 2023-04-01T22:08:50.814 0.004 -0.001 -0.000 18517 2023-04-02T19:58:50.814 -0.016 0.004 0.003 18531 2023-04-04T23:13:50.814 -0.026 0.006 0.005 18543 2023-04-06T18:58:50.814 0.062 -0.016 -0.018 18551 2023-04-08T00:28:50.814 -0.071 0.010 0.015 18563 2023-04-09T19:15:50.814 0.030 -0.011 -0.017 18571 2023-04-11T00:26:50.814 0.014 -0.005 -0.008 18583 2023-04-12T20:06:50.814 -0.007 0.002 0.003 18595 2023-04-14T16:03:50.814 -0.008 0.003 0.005 18604 2023-04-16T00:58:50.814 0.006 -0.002 -0.004 18615 2023-04-17T19:03:50.814 0.002 0.001 -0.000 18621 2023-04-18T15:05:50.814 0.001 -0.000 -0.001 18628 2023-04-19T16:13:50.814 0.003 -0.000 0.001 18641 2023-04-21T16:40:50.814 -0.003 0.001 0.003 18648 2023-04-22T17:58:50.814 -0.015 0.006 0.015 18655 2023-04-23T19:28:50.814 0.007 -0.003 -0.008 18674 2023-04-26T17:43:50.814 0.004 -0.000 -0.004 18689 2023-04-28T23:36:50.814 0.003 -0.001 -0.004 18697 2023-04-30T05:27:50.814 -0.006 0.002 0.008 18707 2023-05-01T17:28:50.814 0.002 -0.001 -0.002 18715 2023-05-02T22:48:50.814 -0.006 0.002 0.009 18727 2023-05-04T20:08:50.814 0.001 0.000 -0.001 18739 2023-05-06T13:43:50.814 -0.006 0.001 -0.005 18747 2023-05-07T20:17:50.814 0.011 -0.002 -0.023 18755 2023-05-09T00:28:50.814 -0.004 0.001 0.003 18766 2023-05-10T16:28:50.814 0.003 -0.001 0.000 18773 2023-05-11T17:58:50.814 0.002 -0.000 0.001 18782 2023-05-13T04:43:50.814 -0.003 -0.000 0.008 18798 2023-05-15T14:28:50.814 0.006 -0.001 -0.021 18807 2023-05-16T22:58:50.814 -0.004 0.002 0.015 18819 2023-05-18T18:28:50.814 0.000 -0.000 -0.001 18835 2023-05-21T04:43:50.814 0.002 -0.001 -0.004 18840 2023-05-21T22:58:50.814 0.001 -0.000 -0.003 18847 2023-05-23T00:13:50.814 -0.000 0.000 -0.001 18858 2023-05-24T17:48:50.814 -0.000 0.000 0.001 18864 2023-05-25T14:28:50.814 0.001 -0.000 0.006 18876 2023-05-27T10:33:50.814 0.000 -0.000 0.001 18885 2023-05-28T20:13:50.815 0.002 -0.000 0.028 18891 2023-05-29T17:43:50.815 -0.003 0.001 -0.034 18903 2023-05-31T13:33:50.815 -0.000 0.000 -0.001 18922 2023-06-03T11:43:50.815 0.001 0.000 0.004 18929 2023-06-04T11:58:50.815 -0.002 0.001 0.001 18937 2023-06-05T17:58:50.815 -0.002 0.001 -0.007 18950 2023-06-07T16:58:50.815 0.002 -0.001 0.002 18963 2023-06-09T16:28:50.815 -0.003 0.001 -0.002 18976 2023-06-11T15:28:50.815 -0.001 0.000 0.001 18986 2023-06-13T04:18:50.815 -0.001 0.001 0.000 18999 2023-06-15T03:28:50.815 0.001 -0.000 -0.002 19012 2023-06-17T03:02:50.815 0.002 -0.001 -0.002 19020 2023-06-18T10:09:50.815 -0.001 -0.001 -0.002 19030 2023-06-19T21:40:50.815 0.008 -0.002 0.008 19048 2023-06-22T14:33:50.815 -0.002 0.001 0.001 19069 2023-06-25T20:08:50.815 0.008 -0.001 0.005 19080 2023-06-27T11:28:50.815 0.008 -0.003 -0.004 19088 2023-06-28T16:28:50.815 -0.004 0.001 0.003 19103 2023-06-30T23:18:50.815 0.004 -0.001 -0.003 End of comments.