JUNO Nominal Orientation CK File ============================================================= Created on February 3, 3009 by Boris Semenov, NAIF/JPL. Summary ------------------------------------------------------------- This CK contains the nominal orientation of the JUNO spacecraft frame (JUNO_SPACECRAFT) based on the spin axis pointing and rotation time-lines from Juno_Prelim_CK_Info_MBJ_SKS_090202.xls (see Appendix 3) prepared by Stuart Stephens and Matthew Johnson, JPL and provided to NAIF on February 2, 2009. Implementation Notes ------------------------------------------------------------- The JUNO_SPACECRAFT orientation is provided in this file using a combination of two kinds of segments: - segments providing the orientation of the JUNO spin axis (+Z) encapsulated in the orientation of the JUNO_SPIN_AXIS frame (frame ID -61900) relative to the J2000 inertial frame. These segments were generated using SPICE utility program "prediCkt" based on the spin axis pointing profile from the source spreadsheet. See Appendix 1 below for more details about these segments ("prediCkt" inputs, fit accuracy, etc.) - segments providing the rotation of the spacecraft about the spin axis encapsulated in the orientation of the JUNO_SPACECRAFT frame (frame ID -61000) relative to the JUNO_SPIN_AXIS frame. These segments were generated using SPICE utility program "msopck" based on the rotation profile from the source spreadsheet. See Appendix 2 below for details about these segments ("msopck" setup parameters, input, etc.). The segments generated by "prediCkt" and "msopck" were merged together into a single file (this file) using SPICE utility "dafcat". After merging the file was augmented with these comments. Modeling Notes ------------------------------------------------------------- Users of this CK file should be aware that: - the time-lines in the source spreadsheet ignored Main Engine maneuvers, for which the pointing and spin rate will be different (see Appendix 3) - the time-lines in the source spreadsheet did not include Earth-repointing precessions and implemented very coarse Earth/Sun-pointing strategy (see Appendix 3) - the spin axis pointing (+Z of the JUNO_SPIN_AXIS frame) was modeled to be within 0.25 degrees of JUNO-Sun, JUNO-Earth, or JUNO-Anti Orbital Momentum Vector (depending of the attitude mode). The ZX plane of the JUNO_SPIN_AXIS frame was modeled to always contain Ecliptic North, with the +X axis to be as close to it as possible. - five minute windows were used for continuous transitions between the spin axis pointing modes. - the spin rate transitions (spin-ups and spin-downs) were not modeled (i.e. switches between 1 and 2 RPM happen instantaneously). Coverage ------------------------------------------------------------- This file provides the continuous coverage for the whole mission: Begin UTC End UTC ------------------------ ------------------------ 2011-AUG-07 17:06:20.000 2017-OCT-16 19:29:24.000 Related Kernels ------------------------------------------------------------- This was generated with and must be used together with the following kernels: Type Name ---- ------------------------------------------ LSK naif0009.tls SCLK JNO_SCLKSCET.00000.tsc FK juno_v00.tf (or later version) SPK 110807LD-120928-0930DSM-160803AD_to_pj34_r081118_v1.bsp Contact Information ------------------------------------------------------------- Contact Boris Semenov (Boris.Semenov@jpl.nasa.gov) if you have any questions regarding this file. Appendix 1: Information for Spin Axis Orientation Segments ============================================================= These segments contain the orientation data for the JUNO_SPIN_AXIS frame (frame ID -61900) relative to the J2000 inertial frame based on the nominal orientation profile provided in Juno_Prelim_CK_Info_MBJ_SKS_090202.xls. These segments were generated using SPICE utility program "prediCkt" with the direction, orientation, and schedule specifications provided below. The orientation in these segments matches these specifications to 0.25000 degrees. Directions ------------------------------------------------------------- TOSUN is the geometric position of the Sun relative to JUNO. TOEARTH is the geometric position of the Earth relative to JUNO. JUNOPOS is the geometric position of JUNO relative to Jupiter. JUNOVEL is the geometric velocity of JUNO relative to Jupiter. JUNOORB is the JUNO orbital momentum vector computed as the cross product of the JUNO position and velocity relative to Jupiter. ECLIPN is the +Z axis (North pole) of the Ecliptic of J2000 inertial frame (ECLIPJ2000). \begindata DIRECTION_SPECS += ( 'TOSUN = POSITION OF SUN -' ) DIRECTION_SPECS += ( 'FROM JUNO -' ) DIRECTION_SPECS += ( 'CORRECTION NONE' ) DIRECTION_SPECS += ( 'TOEARTH = POSITION OF EARTH -' ) DIRECTION_SPECS += ( 'FROM JUNO -' ) DIRECTION_SPECS += ( 'CORRECTION NONE' ) DIRECTION_SPECS += ( 'JUNOPOS = POSITION OF JUNO -' ) DIRECTION_SPECS += ( 'FROM JUPITER -' ) DIRECTION_SPECS += ( 'CORRECTION NONE' ) DIRECTION_SPECS += ( 'JUNOVEL = VELOCITY OF JUNO -' ) DIRECTION_SPECS += ( 'FROM JUPITER -' ) DIRECTION_SPECS += ( 'CORRECTION NONE' ) DIRECTION_SPECS += ( 'JUNOORB = CROSS PRODUCT -' ) DIRECTION_SPECS += ( 'JUNOPOS JUNOVEL ' ) DIRECTION_SPECS += ( 'ECLIPN = FIXED ECLIPJ2000 -' ) DIRECTION_SPECS += ( 'XYZ 0 0 1' ) \begintext Orientations ------------------------------------------------------------- SUN_POINTED orientation has +Z along the direction from JUNO to the Sun and Ecliptic North pole defining the ZX plane. EARTH_POINTED orientation has +Z along the direction from JUNO to the Earth and Ecliptic North pole defining the ZX plane. MWR_ATTITUDE orientation has -Z along the JUNO orbital momentum vector (POS cross VEL) and Ecliptic North pole defining the ZX plane. \begindata ORIENTATION_NAME += 'SUN_POINTED' PRIMARY += '+Z = TOSUN' SECONDARY += '+X = ECLIPN' BASE_FRAME += 'J2000' ORIENTATION_NAME += 'EARTH_POINTED' PRIMARY += '+Z = TOEARTH' SECONDARY += '+X = ECLIPN' BASE_FRAME += 'J2000' ORIENTATION_NAME += 'MWR_ATTITUDE' PRIMARY += '-Z = JUNOORB' SECONDARY += '+X = ECLIPN' BASE_FRAME += 'J2000' \begintext Schedule ------------------------------------------------------------- Schedule is based on the following time-line from Juno_Prelim_CK_Info_MBJ_SKS_090202.xls: Pointing Direct Start End ------------------ ------- ------- Sun Launch L+76d Earth L+76d L+686d Sun L+686d L+829d Earth L+829d PJ3-14h MWR attitude (PJ3) PJ3-14h PJ3+3h Earth PJ3+3h PJ5-14h MWR attitude (PJ5) PJ5-14h PJ5+3h Earth PJ5+3h AJ5+10h MWR attitude (cal) AJ5+10h AJ5+20h Earth AJ5+20h PJ6-14h MWR attitude (PJ6) PJ6-14h PJ6+3h Earth PJ6+3h PJ7-14h MWR attitude (PJ7) PJ7-14h PJ7+3h Earth PJ7+3h PJ8-14h MWR attitude (PJ8) PJ8-14h PJ8+3h Earth PJ8+3h EOM where: Launch = 08/07/2011, 16:15 UTC PJ3 = 11/10/2016, 16:42:09.7 UTC PJ5 = 12/02/2016, 15:22:24.7 UTC AJ5 = 12/08/2016, 03:02:55.3 UTC PJ6 = 12/13/2016, 14:42:29.9 UTC PJ7 = 12/24/2016, 14:02:40.7 UTC PJ8 = 01/04/2017, 13:22:45.9 UTC EOM = 10/16/2017, 19:29:24.5 UTC (Impact into Jupiter) Five minute windows were inserted at the attitude mode boundaries to ensure smooth transitions. First and last times were reset to match the coverage boundaries on the SPK file 110807LD-120928-0930DSM-160803AD_to_pj34_r081118_v1.bsp. Times is the keywords below are ETs. \begindata CK-SCLK = 61 CK-SPK = -61 CK-FRAMES = -61900 CK-61900ORIENTATION += 'SUN_POINTED' CK-61900START += @2011-08-07/17:07:25.839 CK-61900STOP += @2011-10-22/16:13:36.185 CK-61900ORIENTATION += 'EARTH_POINTED' CK-61900START += @2011-10-22/16:18:36.185 CK-61900STOP += @2013-06-23/16:13:36.183 CK-61900ORIENTATION += 'SUN_POINTED' CK-61900START += @2013-06-23/16:18:36.183 CK-61900STOP += @2013-11-13/16:13:36.184 CK-61900ORIENTATION += 'EARTH_POINTED' CK-61900START += @2013-11-13/16:18:36.184 CK-61900STOP += @2016-11-10/02:40:45.884 CK-61900ORIENTATION += 'MWR_ATTITUDE' CK-61900START += @2016-11-10/02:45:45.884 CK-61900STOP += @2016-11-10/19:40:45.884 CK-61900ORIENTATION += 'EARTH_POINTED' CK-61900START += @2016-11-10/19:45:45.884 CK-61900STOP += @2016-12-02/01:21:00.884 CK-61900ORIENTATION += 'MWR_ATTITUDE' CK-61900START += @2016-12-02/01:26:00.884 CK-61900STOP += @2016-12-02/18:21:00.884 CK-61900ORIENTATION += 'EARTH_POINTED' CK-61900START += @2016-12-02/18:26:00.884 CK-61900STOP += @2016-12-08/13:01:31.484 CK-61900ORIENTATION += 'MWR_ATTITUDE' CK-61900START += @2016-12-08/13:06:31.484 CK-61900STOP += @2016-12-08/23:01:31.484 CK-61900ORIENTATION += 'EARTH_POINTED' CK-61900START += @2016-12-08/23:06:31.484 CK-61900STOP += @2016-12-13/00:41:06.084 CK-61900ORIENTATION += 'MWR_ATTITUDE' CK-61900START += @2016-12-13/00:46:06.084 CK-61900STOP += @2016-12-13/17:41:06.084 CK-61900ORIENTATION += 'EARTH_POINTED' CK-61900START += @2016-12-13/17:46:06.084 CK-61900STOP += @2016-12-24/00:01:16.884 CK-61900ORIENTATION += 'MWR_ATTITUDE' CK-61900START += @2016-12-24/00:06:16.884 CK-61900STOP += @2016-12-24/17:01:16.884 CK-61900ORIENTATION += 'EARTH_POINTED' CK-61900START += @2016-12-24/17:06:16.884 CK-61900STOP += @2017-01-03/23:21:22.084 CK-61900ORIENTATION += 'MWR_ATTITUDE' CK-61900START += @2017-01-03/23:26:22.084 CK-61900STOP += @2017-01-04/16:21:22.084 CK-61900ORIENTATION += 'EARTH_POINTED' CK-61900START += @2017-01-04/16:26:22.084 CK-61900STOP += @2017-10-16/19:30:30.675 \begintext Appendix 2: Information for Rotation About Spin Axis Segment ============================================================= This segment contains the orientation data representing rotation of the JUNO_SPACECRAFT frame (frame ID -61000) about the JUNO_SPIN_AXIS frame (frame ID -61900) according to the following profile provided in Juno_Prelim_CK_Info_MBJ_SKS_090202.xls: Spin Rate Start End Note --------- ------- ------- ---------------------------- 1 rpm L+1h L+447d 2 rpm L+447d L+455d Periodic Maintenance #1 1 rpm L+455d L+792d 2 rpm L+792d L+798d Earth Flyby 1 rpm L+798d L+982d 2 rpm L+982d L+990d Periodic Maintenance #2 1 rpm L+990d L+1345d 2 rpm L+1345d L+1353d Periodic Maintenance #3 1 rpm L+1353d L+1823d 2 rpm L+1823d EOM Orbital ops (following JOI) where L(Launch) = 08/07/2011, 16:15 UTC. The profile above was converted to the following input provided to "msopck" to make this segment (the columns are: start UTC, stop UTC, initial orientation for each period as three angles set to zero, and angular velocity representing 1 or 2 RPM CCW rotation about +Z): 2011-08-07T17:15:00 2012-10-27T16:15:00 0 0 0 0 0 0.10471975511966 2012-10-27T16:15:00 2012-11-04T16:15:00 0 0 0 0 0 0.20943951023932 2012-11-04T16:15:00 2013-10-07T16:15:00 0 0 0 0 0 0.10471975511966 2013-10-07T16:15:00 2013-10-13T16:15:00 0 0 0 0 0 0.20943951023932 2013-10-13T16:15:00 2014-04-15T16:15:00 0 0 0 0 0 0.10471975511966 2014-04-15T16:15:00 2014-04-23T16:15:00 0 0 0 0 0 0.20943951023932 2014-04-23T16:15:00 2015-04-13T16:15:00 0 0 0 0 0 0.10471975511966 2015-04-13T16:15:00 2015-04-21T16:15:00 0 0 0 0 0 0.20943951023932 2015-04-21T16:15:00 2016-08-03T16:15:00 0 0 0 0 0 0.10471975511966 2016-08-03T16:15:00 2017-10-16T19:29:24 0 0 0 0 0 0.20943951023932 (Transitions between 1 and 2 rpm are instantaneous.) "msopck" Setup Parameters ------------------------------------------------------------- The following "msopck" setup parameters were used to generate this segment: \begindata LSK_FILE_NAME = 'naif0009.tls' SCLK_FILE_NAME = 'JNO_SCLKSCET.00000.tsc' FRAMES_FILE_NAME = 'juno_v00.tf' INTERNAL_FILE_NAME = 'JUNO NOMINAL ATTITUDE 090202' CK_TYPE = 2 CK_SEGMENT_ID = 'JUNO NOMINAL ROTATION 090202' INSTRUMENT_ID = -61000 REFERENCE_FRAME_NAME = 'JUNO_SPIN_AXIS' ANGULAR_RATE_PRESENT = 'YES' INPUT_TIME_TYPE = 'UTC' INPUT_DATA_TYPE = 'EULER ANGLES' EULER_ANGLE_UNITS = 'RADIANS' EULER_ROTATIONS_ORDER = ( 'X' 'Y' 'Z' ) ANGULAR_RATE_FRAME = 'INSTRUMENT' PRODUCER_ID = 'NAIF/JPL' \begintext "msopck" Run-Time Trace ------------------------------------------------------------- PRODUCT_CREATION_TIME = 2009-02-03T13:46:24 START_TIME = 2011-08-07T17:15:00.000 STOP_TIME = 2017-10-16T19:29:24.000 INTERPOLATION INTERVALS IN THE FILE SEGMENTS: SEG.SUMMARY: ID -61000, COVERG: 2011-08-07T17:15:00.000 2017-10-16T19:29:24.000 Appendix 3: Contents of Juno_Prelim_CK_Info_MBJ_SKS_090202.xls ============================================================= Below is the text dump of the Juno_Prelim_CK_Info_MBJ_SKS_090202.xls spreadsheet: ------------------------------------------------------------- Pointing Direct Start End Sun Launch L+76d Earth L+76d L+686d Sun L+686d L+829d Earth L+829d PJ3-14h MWR attitude (PJ3) PJ3-14h PJ3+3h Earth PJ3+3h PJ5-14h MWR attitude (PJ5) PJ5-14h PJ5+3h Earth PJ5+3h AJ5+10h MWR attitude (cal) AJ5+10h AJ5+20h Earth AJ5+20h PJ6-14h MWR attitude (PJ6) PJ6-14h PJ6+3h Earth PJ6+3h PJ7-14h MWR attitude (PJ7) PJ7-14h PJ7+3h Earth PJ7+3h PJ8-14h MWR attitude (PJ8) PJ8-14h PJ8+3h Earth PJ8+3h EOM Spin Rate Start End 1 rpm L+1h L+447d 2 rpm L+447d L+455d Periodic Maintenance #1 1 rpm L+455d L+792d 2 rpm L+792d L+798d Earth Flyby 1 rpm L+798d L+982d 2 rpm L+982d L+990d Periodic Maintenance #2 1 rpm L+990d L+1345d 2 rpm L+1345d L+1353d Periodic Maintenance #3 1 rpm L+1353d L+1823d 2 rpm L+1823d EOM Orbital ops (following JOI) Launch = 8/7/2011, 16:15 UTC (use 1-day resolution for everything except MWR attitude changes). MWR attitude = spin plane through center of Jupiter (via shortest possible turn from Earth-pointing), for 17-hour duration, starting 14 hours before perijove, and returning to Earth-pointing 3 hours after (plus a unique MWR apojove calibration, with TBD timing, but assumed to occur following AJ5). PJ3 = 11/10/2016, 16:42:09.7 UTC PJ5 = 12/02/2016, 15:22:24.7 UTC AJ5 = 12/08/2016, 03:02:55.3 UTC PJ6 = 12/13/2016, 14:42:29.9 UTC PJ7 = 12/24/2016, 14:02:40.7 UTC PJ8 = 01/04/2017, 13:22:45.9 UTC EOM = 10/16/2017, 19:29:24.5 UTC (Impact into Jupiter) Spin direction is positive (right-hand rule) around the spacecraft +Z axis (HGA is in +Z direction). This time-line ignores Main Engine maneuvers, for which the pointing and spin rate will be different. Other simplifying assumptions: No Earth-repointing precessions, very coarse Earth/Sun-pointing strategy. -------------------------------------------------------------